Dissertations / Theses: 'Cu2O Films'

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Han, Sanggil. "Cu2O thin films for p-type metal oxide thin film transistors." Thesis, University of Cambridge, 2018. https://www.repository.cam.ac.uk/handle/1810/285099.

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The rapid progress of n-type metal oxide thin film transistors (TFTs) has motivated research on p-type metal oxide TFTs in order to realise metal oxide-based CMOS circuits which enable low power consumption large-area electronics. Cuprous oxide (Cu2O) has previously been proposed as a suitable active layer for p-type metal oxide TFTs. The two most significant challenges for achieving good quality Cu2O TFTs are to overcome the low field-effect mobility and an unacceptably high off-state current that are a feature of devices that have been reported to date. This dissertation focuses on improving the carrier mobility, and identifying the main origins of the low field-effect mobility and high off-state current in Cu2O TFTs. This work has three major findings. The first major outcome is a demonstration that vacuum annealing can be used to improve the carrier mobility in Cu2O without phase conversion, such as oxidation (CuO) or oxide reduction (Cu). In order to allow an in-depth discussion on the main origins of the very low carrier mobility in as-deposited films and the mobility enhancement by annealing, a quantitative analysis of the relative dominance of the main conduction mechanisms (i.e. trap-limited and grain-boundary-limited conduction) is performed. This shows that the low carrier mobility of as-deposited Cu2O is due to significant grain-boundary-limited conduction. In contrast, after annealing, grain-boundary-limited conduction becomes insignificant due to a considerable reduction in the energy barrier height at grain boundaries, and therefore trap-limited conduction dominates. A further mobility improvement by an increase in annealing temperature is explained by a reduction in the effect of trap-limited conduction resulting from a decrease in tail state density. The second major outcome of this work is the observation that grain orientation ([111] or [100] direction) of sputter-deposited Cu2O can be varied by control of the incident ion-to-Cu flux ratio. Using this technique, a systematic investigation on the effect of grain orientation on carrier mobility in Cu2O thin films is presented, which shows that the [100] Cu2O grain orientation is more favourable for realising a high carrier mobility. In the third and final outcome of this thesis, the temperature dependence of the drain current as a function of gate voltage along with the C-V characteristics reveals that minority carriers (electrons) cause the high off-state current in Cu2O TFTs. In addition, it is observed that an abrupt lowering of the activation energy and pinning of the Fermi energy occur in the off-state, which is attributed to subgap states at 0.38 eV below the conduction band minimum. These findings provide readers with the understanding of the main origins of the low carrier mobility and high off-state current in Cu2O TFTs, and the future research direction for resolving these problems.

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Besharat, Zahra. "Adsorption of molecular thin films on metal and metal oxide surfaces." Doctoral thesis, KTH, Materialfysik, MF, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-195613.

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Metal and metal oxides are widely used in industry, and to optimize their performance their surfaces are commonly functionalized by the formation of thin films. Self-assembled monolayers (SAMs) are deposited on metals or metal oxides either from solution or by gas deposition. Thiols with polar terminal groups are utilized for creating the responsive surfaces which can interact electrostatically with other adsorbates. Surface charge effects wetting and adhesion, and many other surface properties. Polar terminal groups in thiols could be used to modify these factors. Mixed SAMs can provide more flexible surfaces, and could change the resulting surface properties under the influence of factors such as pH, temperature, and photo-illumination. Therefore, in order to control these phenomena by mixed polar-terminated thiols, it is necessary to understand the composition and conformation of the mixed SAMs and their response to these factors. In this work, mixtures of thiols with carboxylic and amino terminal groups were studied. Carboxylic and amino terminal groups of thiol interact with each other via hydrogen bonding in solution and form a complex. Complexes adsorb to the surface in non-conventional orientations. Unmixed SAMs from each type, either carboxylic terminated thiols or amino terminated thiols are in standing up orientation while SAMs from complexes are in an axially in-plane orientation. Selenol is an alternative to replace thiols for particular applications such as contact with biological matter which has a better compatibility with selenol than sulfur. However, the Se-C bond is weaker than the S-C bond which limits the application of selenol. Understanding the selenol adsorption mechanism on gold surfaces could shed some light on Se-C cleavage and so is investigated in this work. Se-C cleavage happens in the low coverage areas on the step since atoms at steps have lower coordination making them more reactive than atoms on the terraces. Another area where the self-assembly of molecules is of importance is for dye sensitized solar cells, which are based on the adsorption of the dye onto metal oxides surfaces such as TiO2.The interface between the SAM of dye and the substrate is an important factor to consider when designing dyes and surfaces in dye sensitized solar cells (DSSCs). The quality of the self-assembled monolayers of the dye on the TiO2 surface has a critical influence on the efficiency of the DSSCs. Creation of just a monolayer of dye on the surface could lead to an efficient current of photo-excited electrons to the TiO2 and degeneration of the dye by redox. This work, T-PAC dye showed island growth with some ad-layer that is not in contact with the surface, whereas the MP13 dye adsorption is laminar growth. Cuprite (Cu2O) is the initial and most common corrosion product for copper under atmospheric conditions. Copper could be a good replacement for noble metal as catalysts for methanol dehydrogenation. Knowledge about the structure of Cu2O(100) and Cu2O(111) surfaces could be used to obtain a deeper understanding of methanol dehydrogenation mechanisms with respect to adsorption sites on the surfaces. In this work, a detailed study was done of Cu2O(100) surface which revealed the possible surface structures as the result of different preparation conditions. Studies of the structure of Cu2O(100) and Cu2O(111) surfaces show that Cu2O(100) has a comparatively stable surface and reduces surface reactivity. As a consequence, dehydrogenation of methanol is more efficient on the Cu2O(111) surface. The hydrogen produced from methanol dehydrogenation is stored in oxygen adatom sites on both surfaces.

QC 20161107

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Qian, Weizhong, and 钱伟忠. "Microbial electrodes and Cu2O-based photoelectrodes for innovative electricity generation and pollutant degradation." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2011. http://hub.hku.hk/bib/B47170281.

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Photoelectrochemical cells (PEC) and microbial fuel cells (MFC) are two promising environmental technologies with the purposes of energy production and pollutant degradation. In this study, p-type Cu2O thin film electrodes were synthesized by electrodeposition on the ITO glass. The influences of various electrodeposition conditions, including the deposition potential, temperature, electrolyte pH, substrates and deposition duration on the morphology and the photoelectrochemical properties of the Cu2O films were investigated. The so-called p-type micro-crystal Cu2O thin film photocathodes were synthesized at -0.4 V, 70 °C and pH 10. An innovative composite Cu2O/TiO2 photoelectrode was developed by dip-coating TiO2 on the surface of the Cu2O film. The outer TiO2 layer would help reduce the electron-hole recombination and hence improve the catalyst stability. The photocatalyst was shown to be capable of photocatalytic degradation of model pollutants. Under simulated solar irradiation, methylene blue, acridine orange, and bromocresso brilliant blue G were effectively degraded in the Cu2O-based PEC. The composite Cu2O/TiO2 photoelectrode could further enhance the photodegradation of the dyes. For the study on MFC with the saline wastewater-inoculated MFCs, an electricity output of 581 mW/m2 could be achieved at a NaCl concentration of 200 mM. Based on the characterization of the bioande using the electrochemical impedance spectroscopy (EIS) technique, the R(QR)(QR) model, instead of the conventional R(QR) model, was found to fit well with the EIS data of the carbon cloth bioanode. The results support the two-interface-based physical model for the description of the bioanode, including an interface on the flat electrode and the other for the porous biofilm matrix. The new model was employed to monitor the biofilm formation and development on the carbon clothe anode during the MFC start-up. In addition, photocatalytic MFC was developed by using the Cu2O film as the photocathode for the MFC. With the simulated solar light illumination, the PMFC open circuit voltage could be increased by 200 mV comparing to the MFC test. Moreover, the cathode material (Cu2O) is much less expensive than Pt used by common MFCs.
published_or_final_version
Civil Engineering
Master
Master of Philosophy

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Dhakal, Dileep, Thomas Waechtler, Schulz Stefan E, Robert Mothes, Stefan Moeckel, Heinrich Lang, and Thomas Gessner. "In-situ XPS Investigation of ALD Cu2O and Cu Thin Films after Successive Reduction." Universitätsbibliothek Chemnitz, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-147043.

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This talk was presented in the 14th International Conference on Atomic Layer Deposition (ALD 2014) in Kyoto, Japan on 18th June 2014. Abstract Atomic Layer Deposition (ALD) is emerging as a ubiquitous method for the deposition of conformal and homogeneous ultra-thin films on complex topographies and large substrates in microelectronics. Electrochemical deposition (ECD) is the first choice for the deposition of copper (Cu) into the trenches and vias of the interconnect system for ULSI circuits. The ECD of Cu necessitates an electrically conductive seed layer for filling the interconnect structures. ALD is now considered as a solution for conformal deposition of Cu seed layers on very high aspect ratio (AR) structures also for technology nodes below 20 nm, since physical vapor deposition is not applicable for structures with high AR. Cu seed layer deposition by the reduction of Cu2O, which has been deposited from the Cu(I) β-diketonate [(nBu3P)2Cu(acac)] (1) used as Cu precursor, has been successfully carried out on different substrates like Ta, TaN, SiO2, and Ru [1, 2]. It was found that the subsequent gas-phase reduction of the Cu2O films can be aided by introducing catalytic amounts of a Ru precursor into the Cu precursor, so that metallic copper films could potentially obtained also on non-catalytic substrates [3, 4]. In this work, in situ X-ray photoelectron spectroscopy (XPS) investigation of the surface chemistry during Cu2O ALD from the mixture of 99 mol % of 1 and 1 mol % of [Ru(η5 C5H4SiMe3)(η5-C7H11)] (2) as ruthenium precursor, and the reduction of Cu2O to metallic Cu by formic acid carried out on SiO2 substrate are demonstrated. Oxidation states of the Cu in the film are identified by comparing the Cu Auger parameter (α) [5] with literature data. α calculated after ALD equals 362.2 eV and after reduction equals 363.8 eV, comparable to the Cu2O and metallic Cu in thin-films [6] respectively. In addition, <10 % of Cu(I), Cu(II), and Cu(OH)2 species are identified from the Cu 2p3/2 and Cu L3VV Auger spectrum after reduction. Consequently, the ALD Cu2O is successfully reduced to metallic copper by in-situ thermal reduction using formic acid. [1] T. Waechtler et al., J. Electrochem. Soc., 156 (6), H453 (2009). [2] T. Waechtler et al., Microelectron. Eng., 88, 684 (2011). [3] S. Mueller et al., Conference Proceedings SCD 2011, Semiconductor Conference Dresden, pp. 1-4. [4] T. Waechtler et al., US Patent Application Publication, US 2013/0062768. [5] C. D. Wagner, Faraday Discuss. Chem. Soc., 60, 291 (1975). [6] J. P. Espinós et al., J. Phys. Chem. B, 106, 6921 (2002).

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Salek, Guillaume. "Élaboration et caractérisation de films minces absorbants de lumière à partir de dispersions colloïdales de nanoparticules d'oxydes Mn3-xCoxO4(0≤x≤3)et Cu2O." Toulouse 3, 2013. http://thesesups.ups-tlse.fr/2653/.

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Ce travail de thèse a porté sur l'élaboration de nanoparticules d'oxydes de compositions variables, par précipitation à basse température qui, après mise en suspension sans dispersant ou surfactant, permet l'obtention de films minces par dip-coating. Ces oxydes de métaux de transition semi-conducteurs absorbants de lumière présentent un intérêt pour des applications dans les domaines de la (photo)-catalyse et du photovoltaïque. Après une revue détaillée des résultats bibliographiques et une seconde partie dédiée aux techniques de caractérisation utilisées, une étude spécifique et minutieuse a été menée sur l'influence des paramètres de précipitation (température, pH, etc) pour la formation de nanoparticules de Mn3O4. A partir des résultats obtenus, la synthèse des nanoparticules a été étendue aux composés issus de la solution solide Mn3-xCoxO4 (0
This thesis work focused on the low temperature precipitation of oxide nanoparticles of various compositions, which were then used for preparing colloidal suspensions without surfactant or dispersing agent and thin films by the dip-coating method. These transition metal oxides, that are semiconductors and light absorbers, are interesting for (photo)-catalysis and photovoltaics. After a detailed literature review and a second part dedicated to the characterisation techniques used for this work, a specific and meticulous study was carried out to understand and control the main precipitation parameters (temperature, pH,. . . Etc) for the formation of Mn3O4 nanoparticles. From these results, the synthesis of oxide nanoparticles was extended to the Mn3-xCoxO4 (0

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Dhakal, Dileep. "Growth Monitoring of Ultrathin Copper and Copper Oxide Films Deposited by Atomic Layer Deposition." Doctoral thesis, Universitätsbibliothek Chemnitz, 2017. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-229808.

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Atomic layer deposition (ALD) of copper films is getting enormous interest. Ultrathin Cu films are applied as the seed layer for electrochemical deposition (ECD) of copper in interconnect circuits and as the non-magnetic material for the realization of giant magnetoresistance (GMR) sensors. Particularly, Co/Cu multi-layered structures require sub 4.0 nm copper film thickness for obtaining strong GMR effects. The physical vapor deposition process for the deposition of the copper seed layers are prone to non-conformal coating and poor step coverage on side-walls and bottoms of trenches and vias, and presence of overhanging structures. This may cause failure of interconnections due to formation of voids after copper ECD. ALD is the most suitable technology for the deposition of conformal seed layers for the subsequent ECD in very high aspect ratio structures, also for the technology nodes below 20 nm. Surface chemistry during the ALD of oxides is quite well studied. However, surface chemistry during the ALD of pure metal is rather immature. This knowledge is necessary to optimize the process parameters, synthesize better precursors systems, and enhance the knowledge of existing metal ALD processes. The major goal of this work is to understand the surface chemistry of the used precursor and study the growth of ultrathin copper films using in-situ X-ray photoelectron spectroscopy (XPS). Copper films are deposited by ALD using the precursor mixture consisting of 99 mol% [(nBu3P)2Cu(acac)], as copper precursor and 1 mol% of Ru(η5 C7H11)(η5 C5H4SiMe3), as ruthenium precursor. The purpose in having catalytic amount of ruthenium precursor is to obtain the Ru doped Cu2O layers for subsequent reduction with formic acid at temperatures below 150 °C on arbitrary substrates. Two different approaches for the growth of ultrathin copper films have been studied in this dissertation. In the first approach, direct thermal ALD of copper has been studied by using H2 as co-reactant on Co as catalytic substrate. In the second approach, Ru-doped Cu2O is deposited by ALD using wet-O2 as co-reactant on SiO2 as non-catalytic substrate. The Ru-doped Cu2O is successfully reduced by using either formic acid or carbon-monoxide on SiO2
Atomlagenabscheidung (ALD) von Kupfer steht im Fokus der ALD Gemeinschaft. Ultradünne Kupferschichten können als Keimschicht für die elektrochemische Abscheidung (ECD) von Kupfer in der Verbindungstechnologie eingesetzt werden. Sie können ebenfalls für Sensoren, welche auf den Effekt des Riesenmagnetowiderstandes (GMR) basieren, als nicht-ferromagnetische Zwischenschicht verwendet werden. Insbesondere Multischichtstrukturen aus ferromagnetische Kobalt und Kupfer erfordern Schichtdicken von weniger als 4,0 nm, um einen starken GMR-Effekt zu gewährleisten. Das derzeit verwendete physikalische Dampfabscheidungsverfahren für ultradünne Kupferschichten, ist besonders anfällig für eine nicht-konforme Abscheidung an den Seitenwänden und Böden von Strukturen mit hohem Aspektverhältnis. Des Weiteren kann es zur Bildung von Löchern und überhängenden Strukturen kommen, welche bei der anschließenden Kupfer ECD zu Kontaktlücken (Voids) führen können. Für die Abscheidung einer Kupfer-Keimschicht ist die ALD besonders gut geeignet, da sie es ermöglicht, ultradünne konforme Schichten auf strukturierten Oberflächen mit hohem Aspektverhältnis abzuscheiden. Dies macht sie zu einer der Schlüsseltechnologien für Struckturgrößen unter 20 nm. Im Gegensatz zur Oberflächenchemie rein metallischer ALD sind die Oberflächenreaktionen für oxidische ALD Schichten sehr gut untersucht. Die Kenntnis der Oberflächenchemie während eines ALD Prozesses ist essenziel für die Bestimmung von wichtigen Prozessparametern als auch für die Verbesserung der Präkursorsynthese ansich. Diese Arbeit beschäftigt sich mit der Untersuchung der Oberflächenchemie und Charakterisierung des Wachstums von ultradünnen Metall-Cu-Schichten mittels In-situ XPS, welche eines indirekten (Oxid) bzw. direkten Metall-ALD Prozesses abgeschieden werden, wobei die Kupfer-Oxidschichten im Anschluss einem Reduktionsprozess unterworfen werden. Hierfür wird eine Präkursormischung bestehend aus 99 mol% [(nBu3P)2Cu(acac)] und 1 mol% [Ru(η5 C7H11)(η5-C5H4SiMe3)] verwendet. Die katalytische Menge an Ru, welche in der entstehenden Cu2O Schicht verbleibt, erhöht den Effekt der Reduktion der Cu2O Schicht auf beliebigen Substraten mit Ameinsäure bei Wafertemperaturen unter 150 °C. In einem ersten Schritt wird ein direkter thermisches Kupfer ALD-Prozess, unter Verwendung von molekularem Wasserstoff als Coreaktant, auf einem Kobalt-Substrat untersucht. In einem zweiten Schritt wird ein indirekter thermischer Cu2O-ALD-Prozess, unter gleichzeitiger Verwendung von Sauerstoff und Wasserdampf als Coreaktant, mit anschließender Reduktion durch Ameinsäure oder Kohlenstoffmonoxid zu Kupfer auf den gleichen Substraten betrachtet. Die vorliegende Arbeit beschreibt das Wachstum von ultradünnen und kontinuierlichen Kupfer-Schichten mittels thermischer ALD auf inerten- SiO2 und reaktiven Kobalt-Substraten

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Brandt, Iuri Stefani. "Eletrodeposição de filmes finos de Cu2O dopados com Co." reponame:Repositório Institucional da UFSC, 2012. http://repositorio.ufsc.br/xmlui/handle/123456789/93893.

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Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico, Programa de Pós-Graduação em Engenharia Elétrica, Florianópolis, 2010
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Com o objetivo de se obter filmes finos do óxido de cobre (Cu2O) com comportamento ferromagnético a temperatura ambiente, este trabalho se concentrou na investigação das propriedades de filmes finos de Cu2O dopados com Co. Os filmes foram obtidos através da técnica de eletrodeposição, com o emprego de um eletrólito contendo 0,4 M CuSO4 (sulfato de cobre), 3,0 M C3H6O3 (ácido lático) e 0,004-0,016 M CoSO4 (sulfato de cobalto). Hidróxido de sódio numa concentração de 5,0 M foi adicionado ao eletrólito para se obter um valor de pH igual a 10. O substrato utilizado foi silício do tipo n (100), e a deposição foi realizada a temperatura ambiente aplicando um potencial constante de -0,5 V vs. SCE. A caracterização foi conduzida através de difratometria de raios X, espectroscopia óptica, microscopia eletrônica de transmissão e medidas de magnetometria utilizando um magnetômetro de amostra vibrante (MAV), um SQUID (superconducting quantum interference devices) e uma balança de Faraday. Os resultados obtidos por difratometria de raios X mostraram que os filmes finos de Cu2O eletrodepositados apresentam uma orientação preferencial na direção (200), seguindo a do substrato, e somente picos referentes ao substrato e ao Cu2O foram encontrados. Além disso, o parâmetro de rede apresenta uma dependência sutil com a quantidade de íons Co2+ incorporados. Foi também verificado que esta incorporação leva a um aumento da energia de gap do Cu2O, alcançado o valor de 2,27 eV. A caracterização magnética revelou que estes filmes apresentam comportamento ferromagnético, com temperatura de Curie de aproximadamente 555 K. Análise realizada por microscopia eletrônica de transmissão indicou a não existência de partículas de segunda fase, que poderiam ser as responsáveis por este sinal. Através destes resultados comprovamos que os filmes finos de Cu2O obtidos neste trabalho apresentam uma dopagem com átomos de Co e se caracterizam como um semicondutor ferromagnético diluído com comportamento ferromagnético a temperatura ambiente, alcançando assim o objetivo central deste trabalho.

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Pelegrini, Silvia. "Efeito do dopante cloro nas propriedades estruturais e ópticas de filmes finos de Cu2O." reponame:Repositório Institucional da UFSC, 2014. https://repositorio.ufsc.br/xmlui/handle/123456789/128607.

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Tese (doutorado) - Universidade Federal de Santa Catarina, Centro de Ciências Físicas e Matemáticas, Programa de Pós-Graduação em Física, Florianópolis, 2014.
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Esta tese se concentra em eletrodepositar filmes finos de óxido cuproso (Cu2O) dopado com cloro e estudar as características estruturais e ópticas desses filmes. Os filmes foram eletrodepositados potenciostaticamente com duas concentrações de cloreto de cobre (CuCl2) na solução de deposição (0,01 e 0,1 M). Para a caracterização estrutural dos filmes utilizou-se a técnica de difração de Raios-X (DRX), obtendo-se os valores dos parâmetros de rede e informações sobre textura dos filmes produzidos. Utilizou-se também Microscopia Eletrônica de Varredura (FEG ? MEV) e Transmissão (TEM) para investigar a morfologia de crescimento e a estrutura dos filmes. Para determinar as fases presente nos filmes foi utilizada a Espectroscopia Raman. As propriedades ópticas foram investigadas através de espectros de reflectância, o que possibilitou determinar os índices de refração (n) e o gap (Eg) dos filmes estudados. A cristalinidade do material sofreu influência da quantidade de cloro adicionada ao eletrólito, o que é importante, pois pode influenciar nas propriedades elétricas e catalíticas deste material. Para obter informações sobre a composição química e a incorporação do cloro nos filmes de Cu2O, foram utilizadas as técnicas de Espectroscopia por Dispersão de Energia (EDS) e Espectroscopia de Emissão Óptica pela Descarga Luminescente (GDOES). Medidas de capacitância (CxV) e curvas de diodo Schottky (IxV) foram realizadas para caracterizar o tipo de semicondutor, demonstrando que os filmes de Cu2O são semicondutores tipo n.

Abstract : This thesis focuses on the electrodeposition of thin films of cuprous oxide (Cu2O) doped with chlorine and to study the structural and optical properties. The films were electrodeposited potentiostatically with two concentrations of copper (CuCl2) chloride in the deposition solution (0.01 and 0.1 M). For structural characterization of the films was used the X-Ray diffraction (XRD), obtaining the values of lattice parameters and information about texture of the films. Scanning Electron Microscopy (FEG - SEM) and Transmission Electron Microscopy (TEM) were used to investigate the growth morphology of the films. To determine the phases present in the films was used Raman Spectroscopy. The optical properties were investigated by Reflectance Spectra, which made possible to determine the refractive index (n) and gap (Eg) of the films. The crystallinity of the material was influenced by the amount of chlorine added to the electrolyte, which is important as it can influence the electrical and catalytic properties of this material. For information about the chemical composition and the incorporation of chlorine in the films of Cu2O, were used Energy Dispersive Spectroscopy (EDS) and Optical Emission Spectroscopy by Luminescent Discharge (GDOES) techniques. Capacitance measurements (CxV) curves and Schottky diode (IxV) measurements were performed to characterize the type of semiconductor, demonstrating that the Cu2O films are n - type semiconductors.

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Cretu, V., V. Postica, N. Ababii, F. Schütt, M. Hoppe, D. Smazna, V. Trofim, V. Sontea, R. Adelung, and O. Lupan. "Ethanol Sensing Performances of Zinc-doped Copper Oxide Nano-crystallite Layers." Thesis, Sumy State University, 2015. http://essuir.sumdu.edu.ua/handle/123456789/42506.

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The synthesis via chemical solutions (aqueous) (SCS) wet route is a low-temperature and cost-effective growth technique of high crystalline quality oxide semiconductors films. Here we report on morphology, chemical composition, structure and ethanol sensing performances of a device prototype based on zincdoped copper oxide nanocrystallite layer. By thermal annealing in electrical furnace for 30 min at temperatures higher than 550 ˚C, as-deposited zinc doped Cu2O samples are converted to tenorite, ZnxCu1-xOy, (x=1.3wt%) that demonstrate higher ethanol response than sensor structures based on samples treated at 450 ˚C. In case of the specimens after post-growth treatment at 650 ˚C was found an ethanol gas response of about 79 % and 91 % to concentrations of 100 ppm and 500 ppm, respectively, at operating temperature of 400 ˚C in air.

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Erickson, Matthew. "Reaction Velocities in Free Standing Aluminum and Cooper Oxide This Films." Master's thesis, University of Central Florida, 2009. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/4274.

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In this work we investigate the reaction propagation velocity of aluminum and copper oxide Metastable Intermolecular Composites (MIC's). All samples were deposited in a magnetron sputtering system using 2 aluminum targets and 2 copper targets. The copper is sputtered in an oxygen rich environment in order to obtain copper oxide rich films. Three different layer structures are used for various measurements that are composed of alternating 20 layer pairs, 30 layer pairs, and 40 layer pairs. All layer pairs maintain a constant total thickness of 3.2 microns. Each layer structure can be prepared independent of a substrate and is measured with the use of photodiodes or with direct device contact. Aluminum and copper oxide structures have potential use as propellants and additives to explosives, thus, accurate propagation velocity or burn rate measurements are important. The developed measurement system for burn rate measurements of Al/CuO MIC's can achieve and accuracy of 0.1 m/s. In order to determine the velocity limiting characteristics, MIC's on glass and silicon substrates were measured as well as free standing Al/CuO MIC's. Separate burn rate measurement devices were created in order to handle the variety of substrates. In addition, the ignition energy of the Al/CuO MIC was studied to further characterize the samples. This was done using both voltage and current probes of a reacting sample. Rutherford backscattering spectroscopy (RBS) was used for sample composition calibration. The pre- and post-reaction Al/CuO MIC's were also characterized by transmission electron microscopy (TEM).
M.S.E.E.
School of Electrical Engineering and Computer Science
Engineering and Computer Science
Electrical Engineering MSEE

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Araújo, Adriane Xavier. "Nucleação e evolução da rugosidade me filmes eletrodepositados de CuCo." Florianópolis, SC, 2005. http://repositorio.ufsc.br/handle/123456789/101882.

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Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Físicas e Matemáticas. Programa de Pós-Graduação em Física.
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O processo de eletrodeposição de filmes de cobre a partir de um eletrólito contendo sulfatos de cobre e cobalto, além de citrato de sódio como agente complexante, foi investigado quanto ao processo de nucleação e crescimento. A evolução da rugosidade foi acompanhada por microscopia de força atômica e as imagens foram analisadas sob a ótica da teoria de invariância por escala. Diversas funções estatísticas foram comparadas, a fim de determinar a relevância ou não desse método de análise. Dentre os vários métodos investigados, o método variacional demonstrou ser o mais exato e preciso na determinação do coeficiente de Hurst. Por outro lado, o uso da função largura de interface unidimensional se mostrou adequado na determinação dos coeficientes dinâmico, de crescimento e de rugosidade. O processo de nucleação dos filmes de cobre desse sistema é progressivo para baixos valores de sobrepotencial, passando a instantâneo à medida que o valor de sobrepotencial cresce. Da mesma forma, a evolução temporal da rugosidade apresenta invariância normal, passando para anômala, quando se aumenta o valor de sobrepotencial. O coeficiente de Hurst determinado pelo método variacional é menor em filmes de nucleação progressiva, evidenciando uma superfície mais irregular, como seria de se esperar.

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12

Kawwam, Mohammad. "Pulsed Laser Deposition and Structural Analysis of Crystalline CuO and GaN Thin Films." Thesis, Lyon 1, 2014. http://www.theses.fr/2014LYO10007.

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Cette thèse présente les résultats expérimentaux relatifs à l'étude des couches de GaN et de CuO déposées par la technique PLD (dépôt par laser à impulsions) sur des substrats de saphir, SrTiO3, quartz et MgO. Nous avons étudié les effets de plusieurs paramètres qui jouent sur la cristallisation et la morphologie des surfaces des films déposés, à savoir, la température du substrat, la pression au fond, la distance entre le substrat et la cible, la densité d'énergie du laser et la position du substrat. Les couches ont été caractérisées par XRD, microscopie à force atomique et Le microscope électronique à balayage, RHEED et RAMAN. Les résultats montrent que la rugosité et la qualité de la surface des films déposés par PLD dépendent de l'énergie cinétique de déposition des espèces chimiques. L'épaisseur du film, la cristallinité, l'homogénéité et la rugosité sont étroitement liés aux conditions de dépôt
The thesis presents experimental results related to the Pulsed Laser Deposition (PLD) of GaN and CuO thin films using sapphire, SrTiO3, quartz and MgO substrates. The evolution of crystallization and surface morphology of the as-deposited films were studied to investigate the influence of the process conditions such as: substrate heating, background pressure, target-substrate distance, laser energy density, and substrate location, which were systematically varied. The as-deposited films were characterized by X-ray diffraction, atomic force microscopy and scanning electron microscopy, X-ray photoelectron spectroscopy, RHEED and RAMAN techniques. The results convincingly demonstrate that the enhancement in film growth quality - the reduction in roughness and the delay of epitaxial breakdown - is related to the control of PLD species kinetics. The films thickness, crystallinity, homogeneity and surface roughness are strongly dependent on deposition conditions

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D'Angelo, Bandres Renato. "Preparation and characterization of Cu2-xZn1+ySnS4 for thin films solar cells." Doctoral thesis, Università degli studi di Trento, 2016. https://hdl.handle.net/11572/367797.

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CZTS non-stoichiometric thin films [Cu2-xZn1+xSnS4)] for solar cells applications have been successfully deposited on glass substrates using two different types of synthesis and two effective deposition methods: dip coating into a sol or drop-wise ink spin-coating. For dip-coating, a sol was prepared by mixing a solution of metal chlorides dissolved in methanol together with thiourea dissolved in ethylene glycol; tin chloride (either pentahydrate or anhydrous) was used as a tin source. The ink for spin-coating was prepared by hot-injection, starting from metal (copper, tin and zinc) chlorides like in the previous synthesis: the salts, dissolved in oleylamine, were heated at 130 Â°C, when a solution of pure sulfur in oleylamine was injected. The CZTS thin films samples from both methods have been recrystallized by two thermal treatments, respectively with and without an extra sulfur powder at 550 Â°C in Ar atmosphere. Treatment duration was shown to affect both structure and microstructure of CZTS coatings. Moreover, the optical properties of the final absorbing layers were also deeply affected by the type and length of thermal treatments. Spurious phases like SnO2, SnS and ZnS, were produced in some cases, and identified as a possible culprit for poor CZTS photovoltaic device efficiency. Based on the extensive evidence collected during this research work, the present Thesis provides a rationale for an effective preparation of kesterite thin films for photovoltaic applications.

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D'Angelo, Bandres Renato. "Preparation and characterization of Cu2-xZn1+ySnS4 for thin films solar cells." Doctoral thesis, University of Trento, 2016. http://eprints-phd.biblio.unitn.it/1614/1/PhD_Thesis_-_Renato_D'Angelo_Bandres.pdf.

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CZTS non-stoichiometric thin films [Cu2-xZn1+xSnS4)] for solar cells applications have been successfully deposited on glass substrates using two different types of synthesis and two effective deposition methods: dip coating into a sol or drop-wise ink spin-coating. For dip-coating, a sol was prepared by mixing a solution of metal chlorides dissolved in methanol together with thiourea dissolved in ethylene glycol; tin chloride (either pentahydrate or anhydrous) was used as a tin source. The ink for spin-coating was prepared by hot-injection, starting from metal (copper, tin and zinc) chlorides like in the previous synthesis: the salts, dissolved in oleylamine, were heated at 130 °C, when a solution of pure sulfur in oleylamine was injected. The CZTS thin films samples from both methods have been recrystallized by two thermal treatments, respectively with and without an extra sulfur powder at 550 °C in Ar atmosphere. Treatment duration was shown to affect both structure and microstructure of CZTS coatings. Moreover, the optical properties of the final absorbing layers were also deeply affected by the type and length of thermal treatments. Spurious phases like SnO2, SnS and ZnS, were produced in some cases, and identified as a possible culprit for poor CZTS photovoltaic device efficiency. Based on the extensive evidence collected during this research work, the present Thesis provides a rationale for an effective preparation of kesterite thin films for photovoltaic applications.

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Deuermeier, Jonas [Verfasser], Andreas [Akademischer Betreuer] Klein, and Lambert [Akademischer Betreuer] Alff. "Origins of limited electrical performance of polycrystalline Cu2O thin-film transistors / Jonas Deuermeier ; Andreas Klein, Lambert Alff." Darmstadt : Universitäts- und Landesbibliothek Darmstadt, 2017. http://d-nb.info/1127729209/34.

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Hariri, Abdul Kader. "Structural and electrical characteristics of CdS-Cu2S thin film solar cells." Thesis, University of Hull, 1985. http://hydra.hull.ac.uk/resources/hull:4707.

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A study has been made of a variety of factors influencing the efficiency and operational stability of front-wall CdS-Cu2S solar cells. In the course of this work -1 cm2 cells were fabricated with conversion efficiency of up to 8% without attempting to reduce reflection losses.The CdS films were produced by vacuum evaporation and the electrical and structural characteristics of these films were studied as a function of the rate and temperature of the deposition. Previously there had been some controversy concerning the nature of the CdS source material required for fabricating high performance CdS-based solar cells, but this work has shown that a variety of CdS sources can be employed successfully provided that the film deposition parameters are suitably chosen.A conventional chemical exchange technique was employed to convert the CdS film surface to Cu2SI with the thickness and stoichiometry of the resultant Cu2S layer being examined by means of electrochemical analysis.Changes in the electrical properties of the CdS-Cu2S cells due to post- fabrication anealing under a variety of different conditions were studied and correlated with structural changes monitored by means of Auger electron spectroscopy with the aid of argon ion etching. Depth profiles of the constituent element concentrations indicate that, for samples annealed in air, a deep penetration of copper into the CdS layer occurs together with a significant out-diffusion of cadmium from the CdS after only a few minutes at 1000C. In contrast, the copper penetration which results from vacuum or hydrogen annealing treatment is substantially less and no significant out-diffusion of cadmium is observed for annealing temperatures up to 4000C. Two different diffusion processes, one in the grain boundaries and one in the mid-grain regions, have been identified and their relative importance has been studied for annealing cycles performed under the same three different ambient atmospheres (air, vacuum or hydrogen). The normally rapid and undesirable grain boundary diffusion of copper was found to be significantly inhibited by the use of flowing hydrogen during annealing. A further technologically important observation concerns the effect of the deposition of a film of copper over the copper sulphide layer of a cell and subsequent annealing of it in air. The improved electrical stability which this treatment yields has been shown to be directly associated with reduced interdiffusion at the CdS-Cu2S interface. This interfacial diffusion has also been shown to be influenced by the CdS stoichiometry in the vicinity of the junction.Finally, a brief investigation was made into the use of the ion implantation technique as a means of doping the upper layer of the OdS film with copper without annealing the completed cell. The results have demonstrated the feasibility of this technique, with the best results being obtained using a copper ion fluence of 5.1014 ions cm-2 at 50 keV ion energy.

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Steele, Karl Christopher. "Evaluation of TiO2 and Ag-TiO2, CuO-TiO2 composite films for self-disinfection activity." Thesis, University of Salford, 2009. http://usir.salford.ac.uk/26923/.

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The removal or killing of microorganisms on surfaces is of concern in the health care setting, food preparation areas and general work environment. The use of TiO2 photosterilisation has been proposed as an alternative to chemical disinfection of surfaces as a means to reduce the need for increasingly concentrated and aggressive chemicals necessary to kill disinfectant-resistant organisms. The objective of this research was to evaluate the ability of photocatalytic oxidation to reduce bacterial and viral contaminants on surfaces coated with TiOa and Ag-TiC^, TiO2-Ag, Cu-TiC^, TiO2-Cu. There are no British Standards that cover evaluation of such surfaces. A method for evaluation of photocatalytic surfaces was therefore developed from BS EN 13697:2001 and used to evaluate the activities of a variety of catalytic surfaces coated with TiO2, Ag and Cu and multi-layers of Ag-TiO2,TiO2-Ag, Cu-TiO2,TiO2-Cu. The antimicrobial activities were found to be dependent on the nature of the coating. Highest killing activities were obtained with Ag and Cu alone but combinations of Ag or Cu with TiO2were more active than TiO2 alone and also retained some self- cleaning activity. The results showed that the developed method was adaptable for determination of the antimicrobial activity of coatings with a wide range of activities producing 100% killing of Escherichia coll in times from 3 min up to 4 h. The results showed that it was possible to produce self cleaning self disinfecting surfaces and that surfaces with TiO2 on top, although having reduced activity compared to Ag or Cu, were durable and may have applications in the prevention of transmission of infections on surfaces in a wide range of applications.

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Bergerot, Laurent. "Etude de l'élaboration d'oxyde transparent conducteur de type-p en couches minces pour des applications à l'électronique transparente ou au photovoltaïque." Thesis, Université Grenoble Alpes (ComUE), 2015. http://www.theses.fr/2015GRENI003/document.

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L'électronique transparente est actuellement limitée par la difficulté de construire une jonction p-n transparente, en raison du manque d'oxyde transparent conducteur (TCO) de type p réellement performant. L'oxyde cuivreux Cu2O est un TCO de type p prometteur, mais sa bande interdite relativement étroite pour un TCO (2,1 eV), limite sa transmittance dans le domaine visible. Dans le cadre de cette thèse, nous cherchons à augmenter cette valeur. Pour cela, nous explorons la méthode MOCVD comme technique de dépôt pour le dopage au strontium et au calcium de l’oxyde cuivreux. Ce dopage est supposé élargir la bande interdite du Cu2O d'après des calculs ab initio effectués à l'institut Tyndall, à Cork. Dans le chapitre I, nous présentons le contexte de cette thèse. Après avoir expliqué les conditions que doit remplir un matériau pour être un TCO de type p, nous présentons l'état de l'art concernant le Cu2O. Dans le chapitre II, nous présentons l'ensemble des techniques utilisées dans le cadre de cette thèse, de l'élaboration (MOCVD, recuits thermiques) à la caractérisation (MEB, MET, AFM, DRX, spectroscopie FTIR, spectroscopie Raman, XPS, spectroscopie UV-vis-NIR, mesures 4 pointes et mesures d'effet Hall). Au cours du chapitre III, l'influence des paramètres de la MOCVD sur la composition et la morphologie a été analysée pour l’élaboration de couches de Cu2O pures, non dopées en vue d'établir les conditions optimales de dépôt. Nous obtenons des couches continues sur substrat de Si/SiO2, alors qu'elles sont systématiquement hétérogènes avec des zones sans dépôt sur silicium. En outre, nous mettons en évidence le risque d'obtenir la phase cuivre métallique lorsque la concentration de précurseur est élevée, la pression partielle d'oxygène faible et/ou la température élevée. Partant de ces conditions optimales, nous étudions dans le chapitre IV l'influence du dopage au strontium sur les propriétés fonctionnelles des couches (résistivité, largeur de bande interdite et transmittance dans le visible). Une chute de la résistivité a été observée lors du dopage au strontium. Les couches non dopées ont des résistivités de l'ordre de 103 Ω.cm ou plus, contre 10 Ω.cm pour les couches contenant entre 6 et 15% de strontium. La conductivité est bien de type p avec une mobilité de l’ordre de 10 cm2.V-1.s-1 et une densité de porteur de quelques 1016 cm-3. L’écart très grand entre cette densité de porteur et la teneur globale en Sr est lié à la présence d’une contamination des couches par du carbonate et du fluorure de strontium mis en évidence par FTIR et XPS. L’influence réelle de ces impuretés n’a pu être déterminée. Enfin il n'a pas été constaté de variation significative des propriétés optiques, la bande interdite restant large d'environ 2,4 eV et la transmittance moyenne entre 500 et 1000 nm de l'ordre de 55%. Des tendances similaires sont observées dans le chapitre V qui aborde le dopage au calcium, avec comme particularité le fait pour un fort taux de dopage et sous assistance UV, d'aboutir à la présence d'espaces vides localisés à l'interface substrat/Cu2O qui pourrait être lié à la décomposition du carbonate de calcium. Finalement, nous procédons à des recuits thermiques des couches, dopées ou non, dans le chapitre VI. Pour les couches non dopées, cela permet de diminuer la résistivité jusqu’à des valeurs de 10-100 Ω.cm. Pour les couches dopées, cela permet aux couches ayant une résistivité initiale de 10 Ω.cm de descendre jusqu'à 1 Ω.cm. Au cours de cette thèse, nous avons établi les effets du dopage au Sr ou Ca qui conduisent à une forte chute de résistivité sans impact sur les propriétés optiques à la différence des résultats prévus par les calculs ab initio. Nous sommes ainsi parvenus à améliorer les propriétés des couches Cu2O transparentes de type p
Transparent electronic is currently limited by the lack of a really performant p-type transparent conducting oxide (TCO), which makes the elaboration of a transparent p-n junction challenging. Cuprous oxide Cu2O is a promising p-type TCO, but its optical transmittance in the visible spectrum is limited by its relatively low band gap (2.1 eV). In this thesis, we aim at increasing this value. To achieve that, we explore MOCVD as the growth method for strontium and calcium doping of cuprous oxide. According to ab-initio calculations performed at Tyndall Institute in Cork, doping with these elements is supposed to increase the band gap of Cu2O. In chapter I, we introduce the context of this thesis. After explaining the required conditions that a material must fulfil to be a p-type TCO, we present the state of the art of Cu2O. In chapter II, we present all the techniques used in this work, from the elaboration (MOCVD, thermal annealing) to characterization (SEM, TEM, AFM, XRD, FTIR, Raman spectroscopy, XPS, UV-vis-NIR spectroscopy, 4 point probe and Hall effect measurement). In chapter III, our objective is to synthesize pure, undoped Cu2O thin films. We explore the influence of the MOCVD parameters on the films composition and morphology. We get homogenous films on Si/SiO2 substrates, while we get heterogeneous films with un-deposited parts on silicon substrate. In addition, we show the risk to get the metallic copper phase when precursor concentration is high, oxygen partial pressure is low, and/or temperature is high. This enables us to determine the optimal deposition conditions. Starting from those optimal conditions, we study the influence of strontium doping on the functional properties of the films (resistivity, band gap and visible light transmittance) in chapter IV. A decrease of resistivity was observed with strontium doping. While undoped films show resistivity values of 103 Ω.cm or more, films doped from 6 to 15% strontium show resistivity values of about 10 Ω.cm. P-type conductivity was confirmed through Hall effect measurements, with a mobility close to 10 cm2.V-1.s-1 and a charge carrier density of about 1016 cm-3. The large difference between this carrier density and the Sr concentration can be linked with the presence of a strontium carbonate and fluoride contamination that was detected by FTIR and XPS. The exact influence of those impurities is not well known. In addition, no significant variation of optical properties was observed, the band gap remained close to 2.4 eV and average transmittance in the 500-1000 nm range was about 55%. Similar tendencies were observed for calcium doping, addressed in chapter V. Calcium doping showed the particularity of leading to the presence of cavities localized at the substrate/Cu2O interface, for a high dopant concentration and under UV assistance. Eventually, we performed thermal annealing on some samples, doped and undoped, in chapter VI. For undoped samples, it allowed to decrease resistivity in the 10-100 Ω.cm range. For doped samples, it allows samples showing initial resistivity of about 10 Ω.cm to decrease it to 1 Ω.cm. No impact of thermal annealing on sample morphology or composition was observed. In this thesis, we successfully established the effects of Sr or Ca doping, which lead to a significant decrease of the resistivity without impact on the optical properties, unlike what was predicted by the ab initio calculations. We were thus able to improve the p-type transparent Cu2O thin films properties

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Silva, Vinícius Teodoro da [UNESP]. "Influência da dopagem com Cu2+ no TiO2 em suas propriedades fotocatalíticas." Universidade Estadual Paulista (UNESP), 2017. http://hdl.handle.net/11449/150177.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Devido à crescente industrialização e aumento populacional nos últimos anos, processos alternativos e ambientalmente limpos são pesquisados para controle no descarte de resíduos no ambiente. Dentre estes processos, a fotocatálise heterogênea tem despertado interesse científico-tecnológico devido sua potencialidade para tal aplicação. Devido a isto, a motivação deste estudo é oriunda da necessidade do entendimento das propriedades fotocatalíticas dos materiais para posteriormente aplicá-los adequadamente na degradação de compostos orgânicos. O presente estudo tem por objetivo geral a investigação da influência da dopagem com Cu2+ no TiO2 nas propriedades estruturais, ópticas e fotocatalíticas. Para isto, os materiais foram sintetizados pelo método dos precursores poliméricos (Pechini) com posteriores tratamentos térmicos. Para entendimento de suas propriedades, estes foram caracterizados por difração de Raios X, espectroscopia de espalhamento Raman, espectroscopia óptica na região do ultravioleta e visível, microscopia eletrônica de varredura e espectroscopia de fotoluminescência. Experimentos fotocatalíticos para avaliação das atividades fotocatalíticas dos materiais foram feitos para descoloração do corante Rodamina B. Os resultados obtidos indicaram que o aumento da temperatura de tratamento, sendo estas, de 500, 600 e 700 ºC, provocou a transição de fase de anatase para rutilo nos materiais. Porém, a introdução do cobre nos materiais tratados à 500 e 600 ºC, promoveu a estabilização da fase anatase, enquanto que para a temperatura de 700 ºC, a introdução do dopante favoreceu a transição de fase de anatase para rutilo. Para todas as temperaturas de tratamento, a introdução do dopante provocou diminuições das energias de band gap, e também, distorções à ordem local, as quais levaram à formação de estados de energia. Estes defeitos promoveram um blueshift nas bandas de emissão fotoluminescentes dos materiais com o aumento da concentração de cobre. A amostra contendo 0,5% de cobre tratada termicamente à 500 ºC apresentou maior atividade fotocatalítica, permitindo aproximadamente 98,3% de descoloração da Rodamina B em 60 minutos de reação. Esta amostra foi depositada em substrato de alumínio pelo método de deposição eletroforética, obtendo-se aproximadamente 125 μm de espessura de material depositado. Este filme apresentou atividade fotocatalítica com aproximadamente 89,5% de descoloração do corante Rodamina B em 120 minutos de reação. O método Pechini foi eficiente para obtenção dos materiais a base de TiO2 dopados com Cu2+, os quais obtiveram atividade fotocatalítica para descoloração do corante Rodamina B. As técnicas de caracterização utilizadas permitiram o estudo da influência do dopante nas propriedades estruturais, ópticas e fotocatalíticas dos materiais. O método de deposição eletroforética do material em substrato de alumínio foi eficiente para obtenção do filme, o qual obteve atividade fotocatalítica na descoloração do corante.
Due to increasing industrialization and population growth in recent years, alternative and environmentally clean processes are search for control in the disposal of waste in the environment. Among these processes, the heterogeneous photocatalysis has aroused scientific and technological interest due to its potential for such application. Owing to this, the motivation of this study stems from the need of understanding the photocatalytic properties of the materials for later apply them suitably in the degradation of organic compounds. The present study has the general objective of investigating the influence of Cu2+ doping on TiO2 in the structural, optical and photocatalytic properties. For this, the materials were synthesize by the polymeric precursor method (Pechini) with subsequent heat treatment. For the understanding their properties, the materials were characterize by X Ray diffraction, Raman scattering spectroscopy, optical spectroscopy in the ultraviolet and visible region, scanning electron microscopy and photoluminescence spectroscopy. Photocatalytic experiments for evaluation of photocatalytic activity of materials were made to discoloration of Rhodamine B dye. The obtained results indicated that increasing treatment temperature, being these, 500, 600 and 700 ºC, led to anatase to rutile transformation in the materials. However, introduction of copper on materials treated at 500 and 600 ºC promoted anatase phase stabilization, while for 700 ºC, the introduction of dopant favored the anatase to rutile transition. For all treatment temperatures, introduction of dopant caused decreases in band gap energies, as well local order distortions, which led to the formation of energy states. These defects promoted a blueshift in the photoluminescent emission bands of materials with increasing copper concentration. The sample containing 0.5% of copper heat-treated at 500 ºC showed higher photocatalytic activity, allowing discoloration of approximately 98.3% of Rhodamine B in 60 minutes of reaction. This sample was deposited on aluminum substrate by electrophoretic deposition method, which obtained approximately 125 μm thickness of deposited material. This film had photocatalytic activity with approximately 89.5% of discoloration of Rhodamine B in 120 minutes of reaction. The Pechini method was efficient to obtain Cu2+ doped TiO2 based materials, which obtained photocatalytic activity for discoloration of the Rhodamine B dye. The characterization techniques allowed the study of the influence of the dopant on the structural, optical and photocatalytic properties of the materials. The method of electrophoretic deposition of the material on aluminum substrate was efficient to obtain the film, which obtained photocatalytic activity in the discoloration of the dye.

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Mueller, Steve, Thomas Waechtler, Lutz Hofmann, Andre Tuchscherer, Robert Mothes, Ovidiu Gordan, Daniel Lehmann, et al. "Thermal ALD of Cu via Reduction of CuxO films for the Advanced Metallization in Spintronic and ULSI Interconnect Systems." Universitätsbibliothek Chemnitz, 2012. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-84003.

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In this work, an approach for copper atomic layer deposition (ALD) via reduction of CuxO films was investigated regarding applications in ULSI interconnects, like Cu seed layers directly grown on diffusion barriers (e. g. TaN) or possible liner materials (e. g. Ru or Ni) as well as non-ferromagnetic spacer layers between ferromagnetic films in GMR sensor elements, like Ni or Co. The thermal CuxO ALD process is based on the Cu (I) β-diketonate precursor [(nBu3P)2Cu(acac)] and a mixture of water vapor and oxygen ("wet O2") as co-reactant at temperatures between 100 and 130 °C. Highly efficient conversions of the CuxO to metallic Cu films are realized by a vapor phase treatment with formic acid (HCOOH), especially on Ru substrates. Electrochemical deposition (ECD) experiments on Cu ALD seed / Ru liner stacks in typical interconnect patterns are showing nearly perfectly filling behavior. For improving the HCOOH reduction on arbitrary substrates, a catalytic amount of Ru was successful introduced into the CuxO films during the ALD with a precursor mixture of the Cu (I) β-diketonate and an organometallic Ru precursor. Furthermore, molecular and atomic hydrogen were studied as promising alternative reducing agents.

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Mueller, Steve, Thomas Waechtler, Lutz Hofmann, Andre Tuchscherer, Robert Mothes, Ovidiu Gordan, Daniel Lehmann, et al. "Thermal ALD of Cu via Reduction of CuxO films for the Advanced Metallization in Spintronic and ULSI Interconnect Systems." Technische Universität Chemnitz, 2011. https://monarch.qucosa.de/id/qucosa%3A19675.

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In this work, an approach for copper atomic layer deposition (ALD) via reduction of CuxO films was investigated regarding applications in ULSI interconnects, like Cu seed layers directly grown on diffusion barriers (e. g. TaN) or possible liner materials (e. g. Ru or Ni) as well as non-ferromagnetic spacer layers between ferromagnetic films in GMR sensor elements, like Ni or Co. The thermal CuxO ALD process is based on the Cu (I) β-diketonate precursor [(nBu3P)2Cu(acac)] and a mixture of water vapor and oxygen ("wet O2") as co-reactant at temperatures between 100 and 130 °C. Highly efficient conversions of the CuxO to metallic Cu films are realized by a vapor phase treatment with formic acid (HCOOH), especially on Ru substrates. Electrochemical deposition (ECD) experiments on Cu ALD seed / Ru liner stacks in typical interconnect patterns are showing nearly perfectly filling behavior. For improving the HCOOH reduction on arbitrary substrates, a catalytic amount of Ru was successful introduced into the CuxO films during the ALD with a precursor mixture of the Cu (I) β-diketonate and an organometallic Ru precursor. Furthermore, molecular and atomic hydrogen were studied as promising alternative reducing agents.

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Silva, Vinícius Teodoro da. "Influência da dopagem com Cu2+ no TiO2 em suas propriedades fotocatalíticas /." Araraquara, 2017. http://hdl.handle.net/11449/150177.

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Orientador: Leinig Antonio Perazolli
Banca: Maria Aparecida Zaghete Bertochi
Banca: Marcelo Henrique Armoa
Resumo: Devido à crescente industrialização e aumento populacional nos últimos anos, processos alternativos e ambientalmente limpos são pesquisados para controle no descarte de resíduos no ambiente. Dentre estes processos, a fotocatálise heterogênea tem despertado interesse científico-tecnológico devido sua potencialidade para tal aplicação. Devido a isto, a motivação deste estudo é oriunda da necessidade do entendimento das propriedades fotocatalíticas dos materiais para posteriormente aplicá-los adequadamente na degradação de compostos orgânicos. O presente estudo tem por objetivo geral a investigação da influência da dopagem com Cu2+ no TiO2 nas propriedades estruturais, ópticas e fotocatalíticas. Para isto, os materiais foram sintetizados pelo método dos precursores poliméricos (Pechini) com posteriores tratamentos térmicos. Para entendimento de suas propriedades, estes foram caracterizados por difração de Raios X, espectroscopia de espalhamento Raman, espectroscopia óptica na região do ultravioleta e visível, microscopia eletrônica de varredura e espectroscopia de fotoluminescência. Experimentos fotocatalíticos para avaliação das atividades fotocatalíticas dos materiais foram feitos para descoloração do corante Rodamina B. Os resultados obtidos indicaram que o aumento da temperatura de tratamento, sendo estas, de 500, 600 e 700 ºC, provocou a transição de fase de anatase para rutilo nos materiais. Porém, a introdução do cobre nos materiais tratados à 500 e 600 ºC, promoveu a est... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: Due to increasing industrialization and population growth in recent years, alternative and environmentally clean processes are search for control in the disposal of waste in the environment. Among these processes, the heterogeneous photocatalysis has aroused scientific and technological interest due to its potential for such application. Owing to this, the motivation of this study stems from the need of understanding the photocatalytic properties of the materials for later apply them suitably in the degradation of organic compounds. The present study has the general objective of investigating the influence of Cu2+ doping on TiO2 in the structural, optical and photocatalytic properties. For this, the materials were synthesize by the polymeric precursor method (Pechini) with subsequent heat treatment. For the understanding their properties, the materials were characterize by X Ray diffraction, Raman scattering spectroscopy, optical spectroscopy in the ultraviolet and visible region, scanning electron microscopy and photoluminescence spectroscopy. Photocatalytic experiments for evaluation of photocatalytic activity of materials were made to discoloration of Rhodamine B dye. The obtained results indicated that increasing treatment temperature, being these, 500, 600 and 700 ºC, led to anatase to rutile transformation in the materials. However, introduction of copper on materials treated at 500 and 600 ºC promoted anatase phase stabilization, while for 700 ºC, the introduction of dopant favored the anatase to rutile transition. For all treatment temperatures, introduction of dopant caused decreases in band gap energies, as well local order distortions, which led to the formation of energy states. These defects promoted a blueshift in the photoluminescent emission bands of materials with increasing copper concentration. The sample containing 0.5% of copper heat-treated at 500 ºC show...
Mestre

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Rabelo, Adriano César. "Filmes finos de compostos semicondutores: preparação de CdS e da junção Cu2-XSe/MEH-PPV." Universidade Federal de Uberlândia, 2008. https://repositorio.ufu.br/handle/123456789/17297.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
In this work thin films of semiconductor compounds were prepared. Focus was on a recipe for preparation of cadmium sulphide onto copper selenide substrate. Copper selenide thin films dissolve when in contact with the chemical bath for deposition cadmium sulphide. This drawback triggered an investigation for using milder chelating agents. A new bath composition was determined from chemical equilibrium analysis of about ten species supposedly present in the bath, mass balance and charge balance. From the results, a thin film of. cadmium sulphide has been prepared on glass substrate by chemical bath deposition using sodium acetate, sodium hydroxide and thiourea. Absorption spectra of the film in the visible range was registered and compared with the spectra from others authors. The band gap of the film was estimated from the spectra. The junction copper selenide and poly-2-methoxy-5- (2 -ethylhexyloxy)-phenylenevinilene was prepared and characterized. Copper selenide was prepared on copper by chemical bath deposition using sodium selenosulphate. The polymeric film was prepared by casting technique, in which the polymer is dissolved in tetrahidrofurane, dropped onto the substrate and let to dry. Ohmic contact was prepared using graphite conductive glue. This glue was developed for this purpose and is made up from graphite powder, epoxy and polimercaptan dissolved in tetrahidrofurano. The electrical properties of the junction were determined from current-potential curves. By using the Fowler-Nordheim model, the energy barrier height was calculated. The results were compared with the literature results obtained with a similar devices, namely ITO/MEH-PPV. The energy barrier height of copper selenide/MEH-PPV is about thirty times smaller than the energy barrier height of ITO/MEH-PPV. The conclusion is that copper selenide is a promising material for use in photoluminescent diodes.
No presente trabalho prepararam-se compostos semicondutores na forma de filmes finos. Ênfase foi dada ao sulfeto de cádmio visando seu uso sobre seleneto de cobre. Filmes finos de seleneto de cobre se dissolvem quando mergulhados na solução de preparação de filmes finos de sulfeto de cádmio. Este inconveniente foi contornado mediante o uso de agentes complexantes mais suaves. Foi possível preparar sulfeto de cádmio em meio de acetato de sódio, tiouréia e hidróxido de sódio. A composição foi determinada numericamente a partir das constantes de equilíbrio das espécies presentes no meio reacional (cerca de dez espécies), pelo balanço de massa e pelo balanço de carga. Foi preparado um filme de sulfeto de cádmio nas condições experimentais encontrada sobre vidro. O espectro de absorção do filme foi medido na região do visível e comparado com o espectro obtido por outros autores. O band gap do filme foi estimado a partir dos espectros de absorção. Preparou-se e caracterizou-se a junção entre seleneto de cobre e poli- 2-metóxi-5-(2 -etilhexiloxi)-fenilenovinileno como semicondutor. O seleneto de cobre foi preparado sobre cobre por reação com selenossulfato de sódio. O filme do material polimérico foi preparado sobre o seleneto de cobre por evaporação de uma solução do polímero em tetrahidrofurano. Os contato elétrico foi estabelecido no substrato de cobre e no filme polimérico com cola de grafite. A cola de grafite foi desenvolvida para esta finalidade e constitui-se na dissolução de resina comercial epóxi e polimercaptana em tetrahidrofurano misturados com grafite em pó. As características elétricas da junção entre os dois semicondutores foram determinadas a partir de curvas corrente potencial. Com uso do modelo de Fowler- Nordheim , calculou-se o valor da barreira de energia entre banda de valência do seleneto de cobre e a banda de condução do polímero. O valor obtido foi comparado com o obtido por outros autores em dispositivos similares (ITO/MEHPPV) e foi cerca de trinta vezes menor. Concluiu-se que o seleneto de cobre é um material com características.
Mestre em Química

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Д`яченко, Олексій Вікторович, Алексей Викторович Дьяченко, Oleksii Viktorovych Diachenko, Артем Михайлович Мєшков, Артем Михайлович Мешков, Artem Mykhailovych Mieshkov, Анатолій Сергійович Опанасюк, Анатолий Сергеевич Опанасюк, Anatolii Serhiiovych Opanasiuk, and Є. О. Левченко. "Структурні особливості плівок CuO нанесених методом спрей-піролізу." Thesis, Сумський державний університет, 2015. http://essuir.sumdu.edu.ua/handle/123456789/41118.

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Оксид міді – один з небагатьох широкозонних матеріалів, який може бути отриманий p-типу провідності. Це екологічно безпечний напівпровідник із значенням ширини забороненої зони, що змінюється в діапазоні від 1,3 до 2,1 еВ. Такі властивості роблять цю сполуку незамінною при створенні ряду електронних приладів (сонячних елементів, фотодетекторів, газових детекторів та ін.) на основі гетеропереходів.

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Pesetski, Aaron A. "Experimental study of the inductance of pinned vortices in YBa?Cu?O?-? and La?.??Sr?.??CuO? superconducting thin films /." The Ohio State University, 2000. http://rave.ohiolink.edu/etdc/view?acc_num=osu1488202678772565.

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Poinot, Delphine. "Etude de couches minces de CuO pour électrode positive à forte capacité surfacique : Application aux microbatteries au lithium." Phd thesis, Université Sciences et Technologies - Bordeaux I, 2011. http://tel.archives-ouvertes.fr/tel-00834384.

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La miniaturisation des appareils électroniques et la multiplication de leur fonctionnalités explique l'intérêt croissant porté aux microsources d'énergie telles que les microbatteries au lithium. Ces dernières sont principalement conçues pour une utilisation rechargeable, mais des systèmes non rechargeables peuvent également êtes envisagés pour certaines applications. Actuellement, la principale limitation de ces systèmes est leur capacité surfacique, n'excédant pas 200 µAh.cm-2. Afin d'obtenir une forte capacité surfacique, nous nous sommes intéressés à CuO, un matériau réagissant avec le lithium suivant un mécanisme de conversion, et présentant une capacité volumique théorique élevée (425 µAh .cm-2.µm-1). Des couches minces de CuO ont ainsi été préparées par pulvérisation radiofréquence à cathode magnétron sous atmosphère réactive (Ar + O2). L'influence des paramètres de dépôts (concentration d'oxygène, pression totale, température des substrats, distance cible-substrat, configuration de la cible) sur leurs propriétés chimiques, morphologiques et structurales a été étudiée. Ces dernières ont également été corrélées à leurs performances électrochimiques, obtenues avec un électrolyte liquide ou un électrolyte solide.

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Choi, Taeyoung. "STM studies of charge transfer and transport through metal-molecule complexes on ultrathin insulating films." The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1299525515.

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Д`яченко, Олексій Вікторович, Алексей Викторович Дьяченко, Oleksii Viktorovych Diachenko, Анатолій Сергійович Опанасюк, Анатолий Сергеевич Опанасюк, Anatolii Serhiiovych Opanasiuk, Денис Ігорович Курбатов, et al. "The performance optimization of thin-film solar converters based on n-ZnMgO / p-CuO heterojunctions." Thesis, Jadavpur University, 2017. http://essuir.sumdu.edu.ua/handle/123456789/65510.

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In this paper, we present the results of the calculations of optical losses in the solar cells layers based on heterojunction n-ZnMgO / p-CuO with ZnO and ITO frontal contacts. The calculations were carried out taking into account a light absorption in the auxiliary layers of the device. As a result, the spectral dependencies of transmittance Т() in the absorber layer of solar cell were defined. It is made possible to optimize the design of the solar cells based on such heterojunctions.

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Д`яченко, Олексій Вікторович, Алексей Викторович Дьяченко, Oleksii Viktorovych Diachenko, Надія Миколаївна Опанасюк, Надежда Николаевна Опанасюк, Nadiia Mykolaivna Opanasiuk, Денис Ігорович Курбатов, Денис Игоревич Курбатов, Denys Ihorovych Kurbatov, and H. Cheong. "Наноструктуровані плівки CuО, синтезовані методом пульсуючого спрей-піролізу." Thesis, Астропринт, 2016. http://essuir.sumdu.edu.ua/handle/123456789/46070.

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Всі відомі оксиди в нелегованому стані мають електронний тип провідності, що утруднює створення гетеропереходів на їх основі, які є обов'язковою складовою більшості приладів електроніки. Саме тому важливим є отримання та вивчення властивостей плівок оксидних матеріалів, що мають р-тип провідності, до яких зокрема відноситься оксид міді. У порівнянні з іншими методами отримання плівок оксиду міді, спрей-піроліз не вимагає дорогого вакуумного обладнання, високоякісних підкладок, забезпечує великі швидкості нанесення шарів на підкладках великої площі з різних прекурсорів. Тому, метою роботи стало вивчення властивостей плівок оксиду міді, нанесених методом пульсуючого спрей-піроліза.

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Brandt, Iuri Stefani. "Propriedades relacionadas às vacâncias de Cu em filmes eletrodepositados de Cu20 e emissão de pares pósitron-elétron correlacionados de superfícies." reponame:Repositório Institucional da UFSC, 2013. https://repositorio.ufsc.br/xmlui/handle/123456789/123035.

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Tese (doutorado) - Universidade Federal de Santa Catarina, Centro de Ciências Físicas e Matemáticas, Programa de Pós-Graduação em Física, Florianópolis, 2013
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Esta tese de doutorado é dividida em dois capítulos. O primeiro tem por objetivo estudar a relação entre propriedades ópticas, elétricas e magnéticas de filmes de óxido de cobre do tipo I (Cu2O) em função da densidade de vacâncias de Cu deste material. O crescimento de camadas de Cu2O foi obtido por meio da técnica de eletrodeposição. Propriedades como parâmetro de rede, direção de crescimento, gap de energia, índice de refração, resistividade elétrica e magnetização de saturação foram estudas em função do pH do eletrólito de eletrodeposição, da espessura dos filmes e dos substratos utilizados. Os resultados demonstram que o aumento de vacâncias de Cu eleva o índice de refração e diminui a resistividade do Cu2O. Também se observou que vacâncias de Cu podem levar filmes de Cu2O não dopados a apresentarem resposta ferromagnética a campos magnéticos externos aplicados e quando dopados com íons Co2+ o sinal de magnetização é fortalecido devido a formação de vacâncias pela dopagem. Este resultado é de grande importância para compreensão das propriedades magnéticas em semicondutores de óxidos de transição. No capítulo II serão apresentados resultados inéditos para espectroscopia de coincidência de pares pósitron-elétron correlacionados, esta é a primeira vez em que este tipo de experimento é de maneira consistente realizado. Os resultados obtidos indicam que a divisão de energia entre pósitrons e elétrons V emitidos é assimétrica, concordando com resultado teórico existente na literatura. Experimentos para detecção de pares elétron-elétron correlacionados excitados por pósitrons apresentaram de forma inesperada emissão de pares com energia superior a do feixe de pósitrons incidente. O mecanismo que proporciona esta energia adicional permanece não esclarecido

This thesis is divided in two chapters. The first aims to study the relation between optical, electrical, and magnetic properties of cuprous oxide (Cu2O) films with the density of Cu vacancies in this material. Cu2O layers growth was carried out by electrodeposition technique. Properties as lattice parameter, growth direction, energy gap, refraction index, electrical resistivity, and saturation magnetization were studied as function of electrolyte pH, film thickness, and substrate. Results revealed that the enhancement of Cu vacancies increases the Cu2O refraction index and decreases its electrical resistivity. Was also observed that Cu vacancies can lead undoped Cu2O films to present ferromagnetic response to external applied magnetic fields and when doped with Co2+ ions the magnetization signal is stronger due to the formation of additional vacancies. This last result is of great importance to understanding of magnetic properties in transition metal oxide semiconductors. In chapter II will be presented unprecedented results for positron-electron pair coincidence spectroscopy, this is the first time that this kind of experiment is performed in a consistent manner. The obtained results show that the energy shared between emitted positrons and electrons is not symmetric, in accordance with theoretical result in literature. Experiments for detection of electron-electron correlated pairs excited by positrons presented an unexpected emission of pairs with VII energy higher than the incident positron beam, and the mechanism of this emission process remains unclear.

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Barros, Dominique de. "Les films supraconducteurs de type Hg(1-x)RexBa2Ca(n-1)CunO(2n+2+delta) : synthèse par spray pyrolyse, mécanismes de cristallisation et propriétés." Grenoble INPG, 2004. http://www.theses.fr/2004INPG0030.

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Cette étude porte sur la synthèse de films de cuprates supraconducteurs à base de mercure, préparés à partir d'oxydes précurseurs déposés par spray pyrolyse de nitrates. Les conditions thermodynamiques établies pour l'obtention de massifs supraconducteurs ont été transposées à la synthèse de films de type Hg,Re-12(n-1)n sur magnésie et aluminate de lanthane. Différentes croissances de phases apparaissent en fonction de la nature du substrat, concluant que les conditions thermodynamiques ne sont pas les seuls paramètres régissant la formation des phases supraconductrices. Les films ainsi obtenus présentent de fortes textures bi-axiales. Ceci s'accompagne de valeurs de densités de courant critique élevées (7. 105 A/cm2, 77K), les températures critiques étant supérieures à 110K. Parallèlement, des films destinés à la réalisation de dispositifs micro-électroniques, ont été synthétisés sur saphir, en utilisant une couche d'adaptation d'oxyde de cérium.

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Leite, Marco Antonio Barreto. "Estrategias para obtenção de precursores unicos para a deposição de Nb2O5 ZrO2 e CuO por deposição quimica de vapor por metalorganicos." [s.n.], 2003. http://repositorio.unicamp.br/jspui/handle/REPOSIP/249805.

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Orientador: Maria Domingues Vargas
Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Quimica
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Resumo: Este trabalho teve como objetivo estudar precursores únicos para a deposição de filmes finos dos óxidos metálicos de nióbio, zircônio e cobre. Foram sintetizados e caracterizados os compostos [Nb(OPr)5]2 (2.1), [Nb(OPr)5(HOPr)] (2.2), [{Zr(HOBu)2(HFTB)2}(HOBu)] (3.1), [Cu(hfacac)2L] onde L=THF (4.1), O(Et)2 (4.2), O(Pr)2 (4.3), cis-trans DMOTHF (4.4) e cis-trans DMTHF (4.5) (HFTB = hexafluorotercbutóxido, hfacac = 1,1,1,5,5,5,-hexafluoro-2,4-pentanodiona, DMOTHF = 1,4-dimetoxotetrahdrofurano e DMTHF = 1,4-dimetiltetrahidrofurano). Os compostos foram analisados e caracterizados por espectroscopia no infravermelho, Raman, RMN ou RPE e difratometria de raios-X de monocristal (composto 3.1). Os dados cristalográficos do composto (2.1) são a= 9,632(2) Å, b= 9,799(4) Å, c= 22,108(6) Å, a = 84,30(5)°, b = 82,07(7)°, g = 76,05(9)°, Z= 2 grupo espacial P(-1). O alcóxido heteroléptico de zircônio 3.1 foi exaustivamente analisado por RMN de H a -90°C e foi proposta uma estrutura em solução para este composto. O composto 4.3 foi analisado por RPE-ESEEM e as distâncias entre os átomos de hidrogênio e o átomo de cobre foram medidas. Foram feitos estudos térmicos de DQV dos compostos 2.1, 2.2, 3.1 e 4.1. Os filmes dos óxidos metálicos obtidos por DQV foram caracterizados por XPS, UV-Vis de reflectância e EDX que indicavam ser filmes de Nb2O5 e Cu2O. Os produtos voláteis eliminados na DQV foram identificados por RMN em solução e, a partir da identificação dos produtos voláteis, foram propostos mecanismos das reações de decomposição do precursor 2.1 e 3.1.
Abstract: The aims of this work were to propose and study precursors for low pressure chemical vapor deposition of metal oxides thin films of niobium, zirconium and copper to be used in the electronic industry. This work describes the synthesis and characterization of four new precursors for MOCVD: [Nb(OPr)5]2 (2.1), [Nb(OPr)5(HOPr)] (2.2), [{Zr(HOBu)2(HFTB)2}(HOBu)] (3.1), [Cu(hfacac)2L] where L=THF (4.1), O(Et)2 (4.2), O(Pr)2 (4.3), cis-trans DMOTHF (4.4) and cis-trans DMTHF (4.5). The compounds were analyzed and characterized by FTIR, Raman, RMN and EPR spectroscopy and in one case (compound 2.1) by a X-ray diffraction study. Crystallographic data for compound (2.1) are a= 9,632(2) Å, b= 9,799(4) Å, c= 22,108(6) Å, a = 84,30(5)°, b = 82,07(7)°, g = 76,05(9)°, Z= 2 and it is in space group P(-1). The heteroleptic zirconium alkoxide, compound 3.1 was exhaustively characterized by H-RMN at -90°C and a structure in solution was proposed. In order to obtain the internuclear distance between hydrogen and copper atoms, the copper compound 4.3 was studied by EPR-ESEEM. CVD experiments were carried out for all proposed precursors but only compounds 2.1, 2.2, 3.1 and 4.1 resulted in successful thin film deposits. These thin films were characterized by XPS, UV-Vis reflectance and also EDS as thin films of Nb2O5 and Cu2O, respectively. The volatile part produced in the CVD reactor was characterized by H and F-RMN spectroscopies. These results led to the proposition of a mechanism for the deposition reactions of the precursors 2.1 and 3.1.
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Kaidi, Zainhia. "Réactivité électrochimique de phases cristallines [alpha], [beta] et HTMo6SE8-xSx et de films minces : étude de l'intercalation de Zn2+, Cu2+, Ni2+ et Cd2+." Metz, 2000. http://docnum.univ-lorraine.fr/public/UPV-M/Theses/2000/Kaidi.Zainhia.SMZ0047.pdf.

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Des réactions topotactiques d'intercalation ont été menées par électrochimie dans des matrices à clusters de Molybdène plus connues sous le nom de phases de Chevrel. Dans une première partie, l'intercalation électrochimique de Zinc, Cadmium, Cuivre et Nickel a été réalisée dans trois séries de binaires Mo6Se8-xSx : les phases [alpha] issues de la désintercalation des ternaires NiyMo6Se8-xSx, les phases [beta] issues d'un traitement thermique (470 – 700°C des phases [alpha], et les phases HT obtenues par synthèse directe. Les variations des paramètres de maille et mesures du taux d'intercalat ont été déterminées pour chaque matrice et chaque cation. Les phases [alpha] témoignent de capacité d'accueil supérieure aux autres structures hôtes en liaison avec l'existence de sites d'accueil totalement vacants. Les binaires [beta] de formule générale Moy[Mo6Se8-xSx] présentent une réactivité électrochimique et des taux d'intercalation voisins de ceux des phases HT, pour un cation donne et un taux de Soufre fixé. La présence de Molybdène dans les cavités 2 altèrent la diffusion des cations dans les canaux. Les 1. 18 atomes de Molybdène présents dans la cavité 1 de la phase [beta]Mo6S8 rendent rédhibitoire l'insertion de cations. Dans une seconde partie, le comportement électrochimique de couches minces ternaires CuxMo6S8 préparées par ablation laser a été étudié. Des traitements de désinsertion suivis d'insertion peuvent être effectués par voltamperométrie. L'integrité du réseau hôte est globalement maintenue malgré les faibles épaisseurs (de 300 à 1200 A). Les caractéristiques des films (épaisseur et stœchiométries) varient logiquement avec l'opération pratiquée. La basse dimensionnalité des films entraîne une réactivité supérieure à celle des cristallites (intercalation de Plomb à température ambiante). La mise en œuvre de la spectrométrie d'impédance électrochimique a permis d'accéder à la détermination de coefficient de diffusion du Cuivre dans le réseau hôte Mo6S8 et au contrôle de l'épaisseur des films

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Christofoli, Eduardo Pires. "Transforma??es tecnol?gicas no cinema contempor?neo: um estudo sobre a primeira d?cada do s?culo XXI." Pontif?cia Universidade Cat?lica do Rio Grande do Sul, 2011. http://tede2.pucrs.br/tede2/handle/tede/4461.

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O presente estudo tem como objetivo identificar os principais marcos tecnol?gicos do cinema e suas implica??es nos processos cinematogr?ficos contempor?neos. O trabalho aborda as atividades de produ??o, distribui??o e exibi??o de filmes, para entender como a substitui??o da tecnologia vem transformando cada setor, estes em fase de adapta??es para o chamado cinema digital. O projeto busca analisar o que ocorre com as principais atividades cinematogr?ficas, verificando como o cinema contempor?neo vem sofrendo a a??o direta ou indireta desses processos de transforma??o. O cinema vive um processo de transi??o, e este estudo pretende analisar como as tecnologias digitais est?o alterando o paradigma do suporte f?lmico, transformando o cinema em um hibridismo de tecnologias anal?gicas e digitais

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Silva, Dilleys Ferreira da. "Estudo dos efeitos fotoinduzidos por Raio-X em filmes vítreos do sistema [Sb(PO3)3]n-Sb2O3 dopados com CuO." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/88/88131/tde-29032010-150508/.

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A fotosensibilidade à radiação dos vidros fosfatos é uma propriedade que tem despertado grande interesse nas últimas décadas12. No presente trabalho, foi realizado um estudo sistemático e comparativo dos fenômenos fotoinduzidos por meio da caracterização de filmes do sistema (Sb(PO3)3)n - Sb2O3 quando dopados com óxido de cobre (CuO). Neste estudo, foram observadas as mudanças fotoestruturais e os efeitos causados por ação dos Raios-X. Os danos causados pela radiação sobre as amostras foram investigados através de medidas de perfilometria, Difração de Raio-X, EPR (Electron Paramagnetic Resonance) e SFG (Sum Frequency Generation) para a análise morfológica dos filmes, usadas para a compreensão das mudanças estruturais ocorridas. Além disso, foram realizadas medidas de absorção UV-Vis para a determinação de suas propriedades ópticas. Estudos recentes mostraram que o sistema vítreo (Sb(PO3)3)n - Sb2O3 sofre efeito de fotoclareamento e fotocontração, devido a irradiação com laser UV16. Nossos resultados mostraram que filmes do mesmo sistema vítreo dopados com 3%CuO, quando irradiados com Raio-X, apresentam efeito de fotoescurecimento, que foi observado visivelmente, e fotoexpansão, que foi confirmado por medidas de perfilometria. Ambos os efeitos, fotoescurecimento e fotoexpansão, ocorrem simultaneamente nos filmes irradiados e tem uma evidente dependência com a variação de parâmetros como espessura do filme e tempo de exposição à radiação
The photosensibility to radiation of phosphate glasses is a property that has attracted great interest in the last decades12. In this work, we realized a systematic and comparative study of the photoinduced phenomena through characterization of the doped copper oxide (CuO) (Sb(PO3)3)n-Sb2O3 system films. In this study, we observed the photostructural changes and the effects caused by X-ray. The radiation damage on the samples was investigated by measurements of profilometry, X-ray diffraction, EPR (Electron Paramagnetic Resonance) and SFG (Sum Frequency Generation) for morphological analysis, used for the understanding of the structural changes occurred. Besides that, we realized UV-Vis absorption measurements for the determination of its optical properties. Recents studies have shown the (Sb(PO3)3)n-Sb2O3 glassy system has photobleaching and photocontraction effects, when irradiated with UV laser16. Our results have shown that films of the same glassy system doped with 3%CuO, when irradiated with X-ray, show the photodarkening effect, which was visually observed, and photoexpansion, which was confirmed by profilometry measurements. Both effects, photodarkening and photoexpansion, occur simultaneously in the irradiated films and have a evident dependence with the parameters changes, as film thickness and radiation exposure time.

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El, Younsi Imane. "Elaboration et caractérisation de nouvelles couches sensibles pour la réalisation de capteurs de CO2." Thesis, Toulouse 3, 2015. http://www.theses.fr/2015TOU30344/document.

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La mesure du taux de CO2 est un besoin relativement récent. Les travaux sur l'utilisation de nouveaux matériaux pour la réalisation de capteurs de gaz, efficaces et peu chers, suscitent des intérêts scientifique et technologique croissants. L'objectif de ces travaux de thèse est l'élaboration et la caractérisation de nouvelles couches sensibles obtenues par pulvérisation cathodique radiofréquence pour la réalisation de capteurs de CO2. Les films minces ont été déposés à partir d'une cible céramique de CuO, dans diverses conditions de dépôt, en variant la pression d'argon dans l'enceinte et la puissance RF appliquée. Dans un premier temps, nous avons caractérisé la structure et la microstructure des films bruts et recuits sous air par DRX, MEB, AFM et spectroscopie Raman. Nous avons également étudié les propriétés physiques des films minces ainsi que leur surface accessible par adsorption de gaz krypton (méthode de Brunauer, Emmett et Teller). Le traitement thermique à 450°C n'affecte pas la structure cristalline des couches, en revanche il tend à faire chuter fortement la surface accessible entre les colonnes. Après l'optimisation des paramètres de fonctionnement de la cellule de mesure, nous avons caractérisé les performances des films de CuO pour la détection du CO2. La meilleure réponse (?R/R=51 %) a été obtenue pour une couche élaborée à 2 Pa avec une puissance RF de 30W. De plus, la température optimale de mesure est relativement basse (T= 250°C). Le contrôle de la microstructure et plus particulièrement de la taille des grains s'est avéré être le paramètre principal qui impacte la réponse sous CO2. Les meilleurs résultats ont été obtenus avec des tailles de grains proches d'une vingtaine de nanomètres de diamètre. Une bonne modélisation de la réponse électrique en fonction de la taille des grains a pu être réalisée en prenant en compte un circuit électrique équivalent comportant une zone enrichie en porteur de type trous à la surface des grains et dont l'épaisseur est de l'ordre de la longueur de Debye
The measure of the rate of CO2 is a recent need. The works on the use of new materials for the conception of gas sensors based semiconductor oxides, effective and not expensive; arouse a huge interest in our society. The objective of this thesis is the elaboration and the characterization of new sensitive layers obtained by RF sputtering for the realization of the sensors of CO2. Thin films were deposited using two targets: CuFeO2 and CuO, under three conditions by varying argon pressure and RF power. First of all, the structure and the microstructure were studied for the as-deposited samples. Surface investigations carried out by Atomic Force Microscopy (AFM), X-ray Diffraction (XRD), Raman spectroscopy, BET measurements and MEB-FEG images have shown a strong influence of deposition technique parameters on film surface topography and morphology. In a second step, the thin films were annealed in air in order to oxidize the phase. For the composite CuO/CuFe2O4, Glow discharge optical emission spectrometry technique showed a structure in two layers stacked on top of each other for the thinner films. For the cupric films, no changes on both structure and microstructure have been revealed. Our films have then been evaluated for CO2 detection. The sensitive layers with different thicknesses were sensitive to 5000 ppm of CO2. The deposition parameters are optimized to obtain microstructure features which can enhance the sensitivity of the thin films as gas sensors. Best response was obtained for a cupric sample deposited in P2 30W conditions and was close to 50% at T = 250°C. We have demonstrates that cupric oxide alone can detect the CO2 gas and that the growth conditions determine the film surface characteristics. The gas sensing characteristics of these films are strongly influenced by both surface morphology and microstructure

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Chapelle, Audrey. "Élaboration et caractérisation de films minces nanocomposites obtenus par pulvérisation cathodique radiofréquence en vue de leur application dans le domaine des capteurs de CO2." Toulouse 3, 2012. http://thesesups.ups-tlse.fr/1858/.

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Les travaux sur l'utilisation de nouveaux matériaux pour la conception de systèmes de mesure de la qualité de l'air, efficaces et peu chers, suscitent un intérêt croissant dans notre société. L'objectif de ces travaux de thèse est l'élaboration et la caractérisation de couches minces nanocomposites obtenues par pulvérisation cathodique RF à partir d'une cible de CuFeO2, en vue de leur utilisation comme couche sensible pour la détection du CO2. Les films minces ont été déposés dans quatre conditions différentes en variant la pression d'argon dans l'enceinte et la distance cible-substrat. Dans un premier temps, nous avons caractérisé la structure et la microstructure des films bruts de dépôt par DRX, MEB et MET, EPMA, XPS, AFM et spectroscopie Raman. Ces analyses ont permis de révéler la présence de cuivre métallique dans les dépôts, dont les teneurs sont dépendantes des conditions d'élaboration, mais également de déterminer la nature de la matrice oxyde. Cette dernière est constituée d'une phase spinelle CuxFe3-xO4 (avec x proche de zéro) et de cuprite Cu2O. Elles ont ainsi pu mettre en évidence le caractère réducteur de la technique de pulvérisation. L'étude des couches minces traitées thermiquement sous air a ensuite montré une nanostructuration en deux couches superposées. La composition, l'épaisseur et la porosité de chacune des couches ont été déterminées par analyses couplées XPS, EPMA, MEB. La couche de surface s'avère être du CuO et la couche de cœur du CuFe2O4. La couche de CuO présente des épaisseurs et des porosités différentes suivant les conditions de dépôt utilisées pour les échantillons bruts : les plus grandes épaisseurs et porosités sont obtenues pour les films bruts possédant la plus grande teneur en cuivre métallique. Enfin, après la mise en œuvre et l'optimisation d'une cellule de mesure, nos matériaux originaux associant, avec différentes microstructures, des oxydes de type p (CuO) et n (CuFe2O4) ont été testés en vue de la détection du CO2. La meilleure réponse a été obtenue pour une couche élaborée dans les conditions les plus réductrices et est proche de 50%. Les temps de réponse et de recouvrement sont de 65 et 8 min, respectivement. Les réponses de ces matériaux ont également été testées avec succès pour d'autres gaz tels que NO2, H2 et C2H5OH
This work involves the deposition and the characterization of nanocomposites thin films by rf-sputtering method from a delafossite (CuFeO2) target for use as sensing materials for CO2 gas sensors. Thin films were deposited using four conditions by varying argon pressure and target-to-substrate distance. First of all, the structure and the microstructure were studied for the as-deposited samples. The presence of metallic copper showed the reducing feature of the technique. Spherical copper particles were found to be within the layer, as well as rod-shape particles were localized at the interface with the substrate. Metallic copper content was dependant of the deposition conditions. Indeed, incident particles are very energetic at low pressure and small target-to-substrate distance, leading to a partial reduction of the growing layer. In this case, metallic copper content is important. In a second step, the thin films were annealed in air in order to oxidize the phases and to obtain the composite CuO/CuFe2O4. Scanning electron microscopy images showed a structure in two layers stacked on top of each other. Analysis by photoelectron spectroscopy revealed that the surface layer is composed by CuO and the heart layer by CuFe2O4. Finally, the original material associating a p-type oxide (CuO) and a n-type oxide (CuFe2O4) showed a p-type semiconductor behavior to CO2 gas. Best response was obtained for a sample deposited in the most reducing conditions and was close to 50%. Response and recovery time were 65 and 8 min, respectively

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Rocha, Cristiane Lima. "Luz, c?mera e a??o: homofobia, heteronormatividade e resist?ncia no curr?culo dos filmes "Billy Elliot", "Carol", "C.R.A.Z.Y. - Loucos de Amor" e "Madame Sat?"." UFVJM, 2017. http://acervo.ufvjm.edu.br/jspui/handle/1/1468.

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Linha de pesquisa: Curr?culos, avalia??o, pr?ticas pedag?gicas e forma??o de professores.
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A presente disserta??o analisa como os discursos homof?bicos que circulam nos curr?culos dos filmes "Billy Elliot (Inglaterra, 2000)", "Carol (Reino Unido/Estados Unidos, 2015)", "C.R.A.Z.Y. - Loucos de Amor (Canad?, 2005)" e "Madame Sat?" (Brasil, 2002), demandam corpos normalizados em um padr?o heteronormativo e que efeitos t?m sobre as personagens. Tomo como metodologia a an?lise do discurso, de inspira??o foucaultiana. As an?lises ser?o realizadas por meio das falas, as cenas, dos sons, das imagens, nas coisas expl?citas e silenciadas. Bem como, os conceitos de curr?culo, g?nero, homofobia, heteronormatividade, norma, discurso, rela??es de saber-poder e processos de subjetiva??o e posi??es de sujeito foram eleitos como ferramentas te?rico-conceituais para essa pesquisa. Em termos te?ricos, esta disserta??o se inscreveu no campo dos Estudos Culturais, na vers?o dos estudos p?s-cr?ticos de curr?culo. Assim, o conceito central da investiga??o ? curr?culo, compreendendo-se que ele ensina modos de ser, pensar e agir ?s pessoas, bem como produz determinados tipos de sujeitos e corpos. Igualmente, o conceito de discurso tem espa?o importante, sendo entendido como "pr?ticas que formam sistematicamente os objetos de que falam" (FOUCAULT, 1986, p. 56). Destaco que o discurso da homofobia circula nos mais diversos espa?os produzindo efeitos sobre os corpos, demandando posi??es de sujeito, seja nos filmes, nas novelas, na escola, na fam?lia, na religi?o, na roda de amig@s. O problema central desta investiga??o ?: como os discursos sobre g?nero, por meio de discursos homof?bicos, t?m demandado corpos normalizados em um padr?o heteronormativo nos filmes em an?lise? Para isso, trago como objetivos espec?ficos: verificar os processos de constru??o de pr?ticas ditas femininas e masculinas nos filmes investigados; registrar quais marcas s?o nomeadas e classificadas como "normais" ?s posi??es de g?nero; identificar quais posi??es de sujeito generificados s?o demandadas e produzidas em atividades cotidianas nos filmes em quest?o; investigar como se expressam as desigualdades de g?nero nos longa-metragens pesquisados; analisar quais mecanismos, t?cnicas e estrat?gias de poder s?o utilizadas no refor?o ? homofobia nessas obras cinematogr?ficas; identificar e analisar poss?veis tentativas de apagamento de marcas homossexuais ou escapes nas personagens dos filmes. O argumento central ? de que h? uma reitera??o do padr?o heteronormativo no curr?culo dos filmes investigados mesmo quando se percebe uma suposta tentativa de romper com padr?es tidos como ideais e normais. Desse modo, soma-se ao discurso homof?bico e heteronormativo, por exemplo, discursos biologicistas, religiosos, psicol?gicos e moralistas, demandando posi??es de sujeito heterossexuais.
Disserta??o (Mestrado Profissional) ? Programa de P?s-Gradua??o em Educa??o, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2017.
The present dissertation analyzes how the homophobic discourses circulating in the curricula of the films "Billy Elliot (England, 2000)", "Carol (United Kingdom / United States, 2015)", "C.R.A.Z.Y. - Madras de Amor (Canada, 2005)" and "Madame Sat? (Brazil, 2002)", demand normalized bodies in a heteronormative pattern and what effects they have on the characters. I take as a methodology the analysis of the discourse, inspired by Foucauld. The analyzes will be carried out through the speeches, the scenes, the sounds, the images, the explicit and silenced things. As well as some concepts ? curriculum, gender, homophobia, heteronormativity, norm, discourse, knowledge-power relations and subjectivation processes and subject positions ? were chosen as theoretical-conceptual tools for this research. In theoretical terms, this dissertation was inscribed in the field of Cultural Studies, in the version of post-critical curriculum studies. Thus, the central concept of research is curriculum, it is understood that it teaches ways of being, thinking and acting to people, as well as producing certain types of subjects and bodies. Likewise, the concept of discourse has important space, being understood as "practices that systematically form the objects of which they speak" (Foucault 1986: 56). I emphasize that the discourse of homophobia circulates in the most diverse spaces producing effects on the bodies, demanding positions of subject, be it in the movies, novels, school, family, religion, the wheel of friends. The central problem of this research is: how have gender discourses, through homophobic discourses, demanded normalized bodies in a heteronormative pattern in the films under analysis? For that, I have as specific objectives: to verify the processes of construction of so-called feminine and masculine practices in the investigated films; Register which brands are named and classified as "normal" to gender positions; Identify which generalized subject positions are demanded and produced in daily activities in the films in question; To investigate how gender inequalities are expressed in the studied films; To analyze which mechanisms, techniques and strategies of power are used to reinforce homophobia in these cinematographic works; Identify and analyze possible attempts to erase homosexual marks or escapes in the characters of the films. The central argument is that there is a reiteration of the heteronormative pattern in the curriculum of the investigated films even when one perceives an alleged attempt to break with patterns considered as ideal and normal. In this way, it adds up to the homophobic and heteronormative discourse, for example, biological, religious, psychological and moral discourses, demanding heterosexual subject positions.

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Tseng, Chien-Chih, and 曾建誌. "Deposition and characterization of Cu2O and Cu2O-Ag2O films." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/58573222275204341231.

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博士
國立中興大學
材料科學與工程學系所
101
Cu2O is a P-type semiconductor with a direct band gap and it has a high optical transparency at wavelength above 500 nm and with a high absorption coefficient at the wavelength below. The oxide semiconductor is a non-toxic material, and having a low production cost. The theoretical photo-electrical conversion efficiency of 20% makes it possible to be used as an absorber layer in thin film solar cells. According to a recent report, Cu2O-based oxide heterojunction solar cells with higher than 6% conversion efficiency have been fabricated. This opens up a new interest in further optimizing the opto-electronic properties of Cu2O films. This study aims at a new approach to enhance optical absorption of Cu2O films in visible light range, and increase their photon-to-current efficiency. In the present attempt, the opto-electronic properties are expected to be improved by mixing cubic-Ag2O with Cu2O. The increase of photon-to-current efficiency can be achieved by band gap engineering. The band gaps of Cu2O and Cubic-Ag2O are 2.3 eV and 1.6 eV, respectively. When the heterojunction of Cu2O-Ag2O is formed, the optical absorption of visible light as well as the photon-to-current efficiency can be enhanced. This is because that the conduction band (CB) electrons can be injected from Cu2O to Ag2O. Oppositely, the valence band (VB) holes can be injected from Ag2O to Cu2O. In the experiment, Cu2O and Cu2O-Ag2O thin films were prepared by DC-reactive magnetron sputtering and a plasma oxidation process on glass substrates (or ITO glass). After deposition, the microstructure of the films was examined using X-ray diffractometry, transmission electron microscopy (TEM) and Field-Emission Scanning Electron Microscopy (FE-SEM). A UV-VIS-NIR photometer and a Photoluminescence measurement system were used to characterize the optical and electrical properties of these films. An incident photon-to-current efficiency (IPCE) system and a photoelectrochemistry measurement system (PEC) were used to characterize the opto-electrical properties of these films. The microstructure study using TEM revealed that Ag2O films were to decompose during a thermal treatment at temperatures higher than 250 oC. The Ag2O films hence have to be deposited at low temperature. The Cu2O-Ag2O-Ag nanocomposite consisted of Cu2O, Ag2O, and small amount of Ag phases. The results of Photoluminescence (PL) measurement confirmed that the Cu2O-Ag2O-Ag(4 at.%) sample might produce more electron-hole pairs than other samples, which caused the increase of photo-current. The coupling of Ag2O phase with Cu2O could enhance light absorption and created more electron-hole pairs due to the small band gap of Ag2O. The effects of Cu2O-Ag2O interface is verified on the enhanced photocurrent and quantum efficiency (IPCE). The Cu2O-Ag2O nanocomposite films can therefore be used as the active absorption layer in Cu2O-based solar cells. Finally, the results revealed that plasma oxidation could be used to prepare Cu2O films with fewer defects than those produced by reactive magnetron sputtering. In this part of study, it was also proved that Cu2O-Ag2O thin films with fewer defects can be prepared through plasma oxidation. By using GZO/Cu2O-Ag2O thin films as an oxide p-n heterojunction, the ratio increase of current of the GZO/Cu2O-Ag2O thin films under illumination was higher than that of the GZO/Cu2O thin films. This result implies that the Cu2O-Ag2O thin films could be used to increase photovoltaic effect on oxide solar cells.

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Ding, Jhan-Yang, and 丁展揚. "Preparation and Properties of Cu2O Powders and N-doped Cu2O Thin Films." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/41994313188819219584.

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碩士
義守大學
材料科學與工程學系
101
In this study, using high-temperature oxidation, the copper powder and nano copper, changing the atmosphere and the reaction temperature to prepare cuprous oxide powder, and observe the particle size and purity. By reactive RF magnetron sputtering on glass, sapphire substrate (0001) and MgO (100) cuprous oxide thin films deposited on the effects of different parameters on the crystal structure of cuprous oxide thin films, surface morphology, optical properties, and electrical properties of experimental parameters to change the target, changing the atmosphere, changing the substrate temperature. The experimental results show that the nano copper powders reaction temperature of 600℃ and the atmosphere of oxygen, the particle size of Cu2O powder is 300nm. Use copper target sputtered Cu2O thin film, the substrate is at the room temperature, about 50% of visible light transmittance and energy gap of about 2.2eV, resistivity is 5(Ω-cm), and the substrate temperature was 500℃, the visible light transmittance of about 80%, which energy gap of about 2.4eV, resistivity 32(Ω-cm). Use CuO target sputtered Cu2O thin film, the substrate is at room temperature the visible light transmittance of approximately 60% and the energy gap of about 2.35eV. The substrate temperature was 500, the visible light transmittance of 85%, the energy gap of about 2.65eV.

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Chiu, Wei-Ming, and 邱偉銘. "Pulsed Laser Deposition of Cu2O Thin Films." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/425c55.

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碩士
國立臺北科技大學
光電工程系研究所
97
In this study, thin films of cuprous oxide were deposited on Al2O3 substrates by pulsed laser deposition technique. An Nd:YAG Q-switched laser operating at a wavelength of 266nm, a pulsed duration less than 10ns, and a repetition rate of 10Hz, was used to ablate a Cu2O target. The Target for the deposition was obtained by sintering high-purity CuO powder(99.999%) at 1000℃ for 5 hours. The effects of the growth parameters on the film morphology, roughness, crystallinity, and optical properties were systematically investigated. In addition, the effects of the target for PLD on the film qualities were also investigated in details. The X-ray diffraction results show that the structure of the films changes from Cu2O and CuO phase with the different parameters. In particular conditions, we proposed that the Cu2O thin films was the single crystal by X-ray diffraction. Finally, we also find the Cu2O thin films grown on a MgO films exhibits different structure.

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Tsai, Yi-Ting, and 蔡議霆. "Structure and photoelectrochemical properties of electrodeposited p-Cu2O films." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/95477266205519086432.

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碩士
明志科技大學
材料工程研究所
98
Hydrogen (H2) has the potential in the future alternative energy because of its abundance on earth. Therefore, many researchers are attracted to develop hydrogen production with more efficient methods. The application of the photoelectrochemical (PEC) effect of some oxides is one of the most promising measures. Copper(I) oxide (Cu2O) is an attractive oxide of p-Type semiconductor in this regard. It has several advantages, such as: (1) band gap energy of 2.0–2.2 eV, (2) high absorption coefficient over the wavelength range in the solar spectrum, (3) non-toxic and (4) highly abundant. In this study, p-type Cu2O films were electrodeposited in a bath composed of an aqueous solution of Cu2SO4 stabilized with lactic acid as chelating agent. The pH value of the electrolyte was adjusted by adding a NaOH aqueous solution. The photoelectrochemical response of films with (111) preferred orientation was measured on a potentiostat electrochemical analyzer. A halogen lamp of 150 W was used as the light source. XRD, XPS and FE-SEM were used for structural investigations. Experimental results show that Cu2O films have strong photoelectrochemical response. In the XPS investigation, surface layer of the deposited Cu2O was further oxidized to CuO during drying and handling of samples in the ambient atmosphere. After cyclic voltammetry (CV) test, Cu(OH)2 layer was deposited on the surface, according to the XPS experimental results. The fact reveals that Cu2O was reduced to pure copper in the cathodic reaction and further oxidized to Cu(OH)2 in the anodic reaction. The reduction was confirmed by the ICP experiment of the electrolyte after the cathodic reaction.

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Hu, Min-An, and 胡敏安. "Characterization of Al doped CuO/Cu2O thin films prepared by reactive ion beam sputter deposition." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/13140111319922810255.

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碩士
國立臺灣科技大學
電子工程系
104
Aluminum doped copper oxide thin films have been deposited by reactive ion beam sputter deposition at 300C with an Ar:O2 ratio at 3:2, 2:1 and 6:1. With Ar:O2 ratio at 3:2, regardless of Al concentration, single phase CuO thin films were obtained. The introduction of Al results in CuO (111) diffraction peak shifting to larger angles, indicating the incorporation of Al in CuO. The introduction of Al results in change from indirect bandgap to direct bandgap and the bandgap of CuO increases from 2.45 eV to 2.89 eV as Al concentration reaches 10 at.%. With Ar:O2 ratio at 2:1, the thin films are mixed CuO and Cu2O phases or polycrystalline CuO. The introduction of Al results in increase of transmittance to 60%, while the bandgap remains the same. With Ar:O2 ratio at 6:1, polycrystalline Cu2O thin films were obtained regardless of Al concentration. The introduction of Al results in increase of transmittance to 70%, while the bandgap remains approximately the same. Doping of Al results in drop of the resistance from 500 Ω·cm to 200 Ω·cm for both CuO and Cu2O.

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44

Hsu, Ging-Ying, and 許靜瑩. "Preparation and Properties of and N-doped Cu2O Thin Films." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/pmn7h4.

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碩士
義守大學
材料科學與工程學系
103
The experiment by RF magnetron sputtering system to experiment copper target, and purged with argon, oxygen and nitrogen mixed atmosphere, a nitrogen atmosphere to change the doping concentration of the substrate is also changed, and a thin film X-ray diffraction structural analysis, SEM observed surface patterns, UV-visible transmittance measurements, Hall measuring instrument measuring resistive coating, to explore the microstructure and properties of copper oxide thin film changes. Experimental results show that at a temperature of 500 ℃, sputtering power of 100W, at a pressure 5mTorr experimental growth conditions, all the grown films are preferred direction, and the preferred direction will increase as a mixed atmosphere of nitrogen concentration, the (200) direction will be preferably converted to (111) preferred orientation, and then converted by the (111) preferred orientation of (200) preferred orientation. Surface Microstructures cuprous oxide film with increasing nitrogen atmosphere, the grain becomes small; the average transmittance in the visible region, along with the nitrogen increases, more and more low penetration from 66.73% down to 54.03% up again to 68.95%; by the Hall measurement results show cuprous oxide film resistivity with doping amount of nitrogen from the 4Ω-cm to 18Ω-cm.

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45

Chiang, Zong-Yi, and 江宗益. "The study on the doping and properties of Cu2O films." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/m7xkc2.

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碩士
義守大學
材料科學與工程學系
104
In this experiment, the uprous oxide (Cu2O) films were deposited on corning glass 1737 substrates by RF magnetron sputtering. The doping effects on the properties of Cu2O thin films by various N2 flow ratios (20%~80%), co-doping level of La or Sr ranging from 0 to 9at% were investigated. It is found that nitrogen doping can suppress the formation of CuO phase in the Cu2O films and improve the optoelectronic properties of Cu2O:N films.The optimal Cu2O:N film has band gap energy of 2.54 eV, transparency of 43% and resistivity of 112 Ω-cm at N2 ratio of 20%. The La doped Cu2O films are highly (111) textured. The degree of prefer orientation along (111) is up to 90%. La doping dramatically improve the optical properties of Cu2O films with band gap energy of 3.01 eV and transparency of up to 62%. The Cu2O film has optimal resistivity of 316 Ω-cm, carrier mobility of 13.5 cm2/Vs and carrier concentration of 6.14x1015cm-3 at N2 flow ratio of 20% and La-doping of 3at%. Sr-doping can effectinely enhance the electrical properties of Cu2O films.The Cu2O film has resistivity of 3.63Ω-cm, carrier mobility of 2.75 cm2/Vs and carrier concentration of 1.09x1018 cm-3 at N2 ratio of 20% and Sr-doping of 9at%. The band gap energy of the Sr doped Cu2O film is determined to be 2.71 eV for the films deposited at N2 ratio of 40% and Sr-doping of 6at%.

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46

Ko, Yi-Chun, and 柯怡君. "Study on variation of surface microstructure of electrodeposited Cu2O thin films." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/35794657869216497976.

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碩士
大同大學
材料工程學系(所)
98
Cuprous oxide is an inexpensive and non-toxic semiconductor material itself has a 2.1eV band gap of the p -type semiconductor , and absorption in the visible region the advantages of large , highly potential for solar energy conversion , it can be used in solar cells and photocatalyst on. In the study, cuprous oxide were fabricated on stainless steel substrate by electrochemical deposition, with ionic surfactant,Cetyl trimethylammonium bromide (CTAB) and Sodium lauryl sulfate (SDS) as shape controlled agent. The influence of additives on crystal morphology of Cu2O was observed in potential and doping ionic surfactants’ concentration. The Cetyl trimethylammonium bromide (CTAB) and Sodium lauryl sulfate (SDS) influenced crystal planes in (111) and (110).The SEM investigated that the morphology changes are pyramid shape、 s p he r e – l ik e、flower-leaves、columnar shape and cube.

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47

Huang, Teng-Hung, and 黃騰弘. "Characteristics of Mg-doped Cu2O films prepared by chemical bath deposition." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/04667764979674436668.

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碩士
中原大學
電子工程研究所
103
In this study, Magnesium doped Cu2O(Cu2O:Mg) films was prepared by Chemical bath deposition. The Magnesium doped cuprous oxide (Cu2O: Mg) films are prepared by using copper sulfate (CuSO4) solution with the addition of magnesium nitrate (Mg(NO3)2) as the source of magnesium. The films are annealed in nitrogen at different temperature. X-ray diffraction patterns show that the Cu2O:Mg films have a sphalerite structure with a dominant plane orientation of Cu2O(111). SEM measurement results show that grain size of Cu2O:Mg films becomes larger and uniform, after annealing. The Cu2O:Mg films surface is relatively smooth. In Electrical characteristics, we plate gold (Au) about 1500Å on Cu2O:Mg films as electrode to form Au/Cu2O:Mg/Cu Schottky diode elements. The Au/ Cu2O:Mg/Cu Schottky diode is characterized by I-V and C-V measurement. The C-V measurement results show that carrier concentration of Cu2O:Mg films with different annealing temperature about 2.65×1017~1.54×1016. PL and hot probe measurement results are displayed Mg-doped copper oxide films after 500℃ annealing, which conductive have a tendency into P-type.

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48

You-JyunChen and 陳宥駿. "Cu/Cu2O composite films for novel perovskite solar cells and photodetectors." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/g45r6j.

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博士
國立成功大學
光電科學與工程學系
107
In recent year, the energy issues have been arguing endlessly. From the stop nuclear power generation to the vote through on nuclear energy by referendum. People are gradually realizing the importance of energy and never want to use “ love ” to generate electricity. According to the announcement of the Taiwan Power Company, the power generation structure of Taiwan in 107 year is mainly based on thermal power generation with fuel, gas, and coal burning of more than 80%. Nuclear energy is 11.4%, and other renewable, pumping, and steam energy sources are still less than 9%. This shows that the form of overall power generation still has a negative impact on the environment. As people's awareness of environmental protection rises, thermal power generation will cause air pollution problems and the setting storage sites of nuclear wastes have become a topic of debate between public opinion and policy. Countries around the world are actively developing and using clean renewable energy. We hope to reduce and solve the pollution problems caused by traditional power generation in the most positive way, and replace thermal and nuclear power with green energy. Green energy power generation is commonly found in solar, wind, hydro, and biomass energy generation. While perovskite-based solar cells has grown very rapidly in just a few years, which power conversion efficiency (PCE) has increased from the initial 3.8% to more than 24.2%, it is considered to have great potential and can compete with crystal Si-based solar cells. However, due to the inherent defects of the perovskite, it is susceptible to the external environment and the chemical reaction of the metal electrode makes the poor stability. How to improve stability? The first way is to optimize the composition of the perovskite. Although this method is very useful, it is also very laborious. On the other hand, incorporating proper carrier transport layers and electrodes into perovskite-based solar cells is also considered as effective ways to maintain device stability as well as the efficiency of perovskite-based solar cells. Therefore, this study researches the effect of inorganic hole transport material Cu/Cu2O on perovskite solar cells to expect stability improved as well as the PCE increased. The first part uses the ion beam sputtering system to deposit the Cu/Cu2O composite films by adjusting the ratio of argon and oxygen. To keep the organic hole transport material Spiro-OMeTAD on the perovskite, the organic material acts as a buffer layer so that the deposition of Cu/Cu2O does not damage the light absorbing layer perovskite. The mobilities of Cu/Cu2O are at least three orders of magnitude higher than the organic hole transport layers of Spiro-OMeTAD. In addition to helping the hole transport, it also isolates the organic material from direct contact with the external atmosphere and the metal electrode, effectively improving device efficiency and long-term stability. The second part controlled the composition and thickness, the transmission and conductivity of the Cu/Cu2O composite electrode have been optimized for efficient perovskite solar cells. PCEs of 14.10% and 9.37% have been achieved for the bifacial-illuminated perovskite-based solar cell when the one sun AM1.5G illumination is incident from the fluorine-doped tin oxide (FTO) side and Cu/Cu2O side, respectively. This result opens up the possibility for a bifacial-illuminated devices in combination with a power-generating window in the building-integrated photovoltaics. The third part of the photodetector is to use a Cu/Cu2O as the carrier transfer electrode to directly replace the organic hole transport material and the metal electrode. This work reveals that the perovskite/(Cu/Cu2O) heterojunction photodetector a promising candidate for applications in bifacial-illuminated and flexible/wearable optoelectronic technologies.

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49

Chen, Liang-Yu, and 陳亮宇. "Fabrication and Characterization of Cr-doped SnO2 Films and Cu2O/SnO2 Heterojunctions." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/08316463359926321338.

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碩士
明志科技大學
化工與材料工程研究所
96
Undoped and Cr-doped SnO2 thin films were deposited on Corning 1737 glasses by using the reactive DC magnetron co-sputtering technique. The Cr concentration of Cr-doped SnO2 films was modulated by controlling the sputtering power of the Cr target during deposition and determined by energy dispersive x-ray analysis. The influences of Cr concentration on the crystal structure, morphology and topography, optical transmittance, magnetic characteristics and electrical properties of SnO2 films were studied. The results show that the electrical conductivity and optical transmittance decrease with increasing the Cr concentration. Paramagnetic characteristics due to the Cr doping were also observed in the Cr-doped SnO2 films. The enhancement of electrical conductivity and carrier concentration due to surface treatment on SnO2 films by acid aques solution was observed and ascribed to the reduction reaction of H+ ions with oxygen atoms of SnO2 films which increases oxygen vacancies and then enhances the electrical conductivity of films. Oxide heterojunctions were fabricated by electrodepositing cuprous oxide (Cu2O) films on F-doped SnO2 (FTO) and Sn-doped SnO2 (ATO) conductive glasses. Nonlinear and rectifying behaviors were observed in current-voltage measurements on Cu2O/ATO and Cu2O/FTO heterojunctions. However, the large turn-on voltage, 4~6 V, which may be correlated to the electron affinity of SnO2 implies the existence of conduction barriers at the interface between Cu2O and FTO/ATO layers. This can be attributed to the poor adhesion of Cu2O layers with FTO and ATO substrates.

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50

Liang, Ru-Meng, and 梁茹夢. "Effect of Annealing on the Electrodeposited Cu2O Films for Photoelectrochemical Hydrogen Generation." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/57177308910755149510.

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碩士
國立交通大學
材料科學與工程系所
97
The Cu2O films were electrodeposited in two different pH values of plating bath. We controlled the deposition times and overpotentials to study the growth of Cu2O films. The film deposited in pH 9 bath demonstrated a preferred orientation in (200) plane, and in pH 11 bath revealed a preferred orientation of (111). The film deposited in pH 9 bath under -0.3 V for 100 min and the film deposited in pH 11 bath under -0.3 V for 60 min were used to study the annealing effect. The annealing temperatures were 150, 200, 250, 300, and 350 ℃, and the annealing times were 10, 30, and 60 min. The grain sizes for these two films were both decreased after annealing. However, their resistivity exhibited an opposite direction. The pH 9 films after annealing revealed a reduced resistivity as the temperature and annealing time were increased. On the other hand, the pH 11 films after annealing showed increased as the temperature and annealing time were increased. The pH 9 film after annealing at 350 ℃ for 30 min demonstrated a stable resistivity reduction decreased from 1.602 to 3.96E-4 Ω㎝. We studied the photoelectrochemical properties of Cu2O film for H2 generation before and after annealing process. The photocurrents were collected to explore the effect of annealing. The results indicated that both films had best performance at 350 ℃ annealing for 60 min. The photocurrent of pH 9 film annealed at 350 ℃ for 60 min was -141 μA㎝-2, and the pH 11 film annealed at 350 ℃ for 60 min was -119 μA㎝-2. The photocurrents revealed the resistivity transition of Cu2O films which was affected by the annealing process. The results exhibited that the annealing process could improve the crystallinity and was greatly enhanced conductivity of Cu2O film. As a result, enhanced the photoelectrochemical performance.

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