Dissertationen: „Oxide and sulphide thin films“

1

Ray, Sekhar chandra. „Preparation and study of some oxide and sulphide thin films deposited by dip and chemical vapour deposition Techniques“. Thesis, University of North Bengal, 1998. http://hdl.handle.net/123456789/633.

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2

Thongchai, Prem. „An investigation into the thin film deposition of binary oxide, ternary oxide and binary sulphide materials“. Thesis, University of Bath, 2019. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.767603.

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Metal oxide and metal sulphide materials dominate a wide range of attractive properties and also to provide potential performances to various applications. There is a challenge to prepare these materials as a thin film with great quality and properties. Aerosol-assisted chemical vapour deposition (AACVD) is a promising technique to offer a desired thin film. The objective of this work is the preparation of the metal oxide and metal sulphide thin films via AACVD technique with single source precursor. The properties of deposited films were characterised.

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3

Wallace, Anthony James. „Tin oxide thin films“. Thesis, Brunel University, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.294556.

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4

Hu, Xiao. „Ultra-thin oxide films“. Thesis, University of Oxford, 2016. https://ora.ox.ac.uk/objects/uuid:d7373376-84f1-459e-bffb-f16ce43f02b7.

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Oxide ultra-thin film surfaces have properties and structures that are significantly different from the terminations of the corresponding bulk crystals. For example, surface structures of epitaxial ultra-thin oxide films are highly influenced by the crystallinity and electronegativity of the metal substrates they grown on. Some enhanced properties of the novel reconstructions are related to catalysis, sensing and microelectronics, which has resulted in an increasing interest in this field. Ultra-thin TiO_x films were grown on Au(111) substrates in this work. Two well-ordered structures within monolayer coverage - honeycomb (HC) and pinwheel - were generated and investigated. Special attention has been paid to the uniform (2 x 2) Ti₂O₃ HC phase including its regular structure and imperfections such as domain boundaries (DBs) and point defects. Linear DBs with long-range repeating units have been observed; density functional theory (DFT) modelling has been used to simulate their atomic structures and calculate their formation energies. Rotational DBs/defects show up less frequently, however a six-fold symmetrical 'snowflake' DB loop stands out. Two types of point defects have been discovered and assigned to Ti vacancies and oxygen vacancies/hydroxyl groups. Their diffusion manners and pairing habits have been discussed within an experimental context. The results of growing NbO_x ultra-thin films on Au(111) are also presented in this thesis. An identical looking (2 x 2) HC structure to the Ti₂O₃ ultra-thin film has been formed; a stoichiometry of Nb2O3 is suggested. Another interesting reconstruction is a hollow triangle structure. Various sizes have been found, and sides of these equilateral triangles all show a double-line feature aligned along the { 1 ₁⁻ } directions of the Au(111) lattice. Chemical composition characterisations of NbO_x thin films are still required as is DFT modelling. Experimental techniques used in this thesis include scanning tunnelling microscopy (STM), low energy electron diffraction (LEED), and X-ray photoelectron spectroscopy (XPS). Ultra-thin oxide films were created by physical vapour deposition (PVD) in ultra-high vacuum (UHV) systems.

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5

Д`яченко, Олексій Вікторович, Алексей Викторович Дьяченко, Oleksii Viktorovych Diachenko, Анатолій Сергійович Опанасюк, Анатолий Сергеевич Опанасюк, Anatolii Serhiiovych Opanasiuk, D. Nam und H. Cheong. „Characterization Cupper Oxide thin films“. Thesis, Львівський національний університет ім. Івана Франка, 2015. http://essuir.sumdu.edu.ua/handle/123456789/48287.

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For obtaining of the CuO thin films have used spray pyrolysis method. Glass plates were cleaned in ultrasonic bath and washed with ethanol, used as a substrates. We used an aqueous solution of copper chloride (CuCl22H2O) with a concentration of 0.05 M as a precursor. The substrate temperature range from 570 to 720 K, with step Т=50 K. For atomization of precursor the air flow with a pressure of 0.25 MPa was used.

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6

Wu, Chen. „Elemental growth of oxide thin films“. Thesis, University of Oxford, 2010. http://ora.ox.ac.uk/objects/uuid:ac82a52f-bb62-41d0-a604-3cf7a95e5aaf.

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This thesis reports on the elemental growth of oxide thin films including TiO_x, BaO_x and Ba_xTi_yO_z by Ti/Ba deposition and oxidation. The films were grown on two different substrates, Au(111) and SrTiO₃(001), and studied using a variety of surface characterisation techniques. On the reconstructed Au(111) surface, three different TiO_x structures were obtained with increasing Ti amounts deposited: a (2 × 2) Ti₂O₃ honeycomb structure, a pinwheel structure that is the result of a Moiré pattern, and a triangular island TiO_1.30 structure. The structures arise from raised Ti coverages and have increased Ti densities. Although Ba deposited on the reconstructed Au(111) has a weak interaction with the substrate, the BaO_x thin films can grow epitaxially and lift the Au(111) reconstruction. Two well-ordered phases, a (6 × 6) and a (2√3 × 2√3) BaO_x structure, were obtained which may have octopolar-based surface structures. For Ba & Ti deposition on Au(111), a locally ordered (5 × 5) BaxTiyOz structure was observed in the sub-monolayer regime. What is more interesting is the possible formation of a BaO-TiO surface alloy with short-range ordering achieved by Ba deposition on the (2 × 2) Ti₂O₃-templated Au(111) surface. This is the first time that surface-alloying has been observed for oxides. When Ti is deposited onto the SrTiO₃(001) surface, it is incorporated into the substrate by forming a variety of Ti-rich SrTiO₃ surface reconstructions, such as c(4 × 2), (6 × 2), (9 × 2) and (√5 ×√5)-R26.6°. Ti deposition provides a completely different route to obtaining these reconstructions at much lower anneal temperatures than the previously reported preparation procedures involving sputtering and annealing the SrTiO₃ sample. Anatase islands with (1 × 3) and (1 × 5) periodicities were also formed by increasing the Ti deposition amount and post-annealing. Reconstructed SrTiO₃ substrate surface has a lattice that differs from the bulk crystal and affects the epitaxial growth of BaO, however, a locally ordered BaO_x structure was observed on the sputtered substrate with a growth temperature of 300 °C. Depositing Ba & Ti on SrTiO₃(001) results in the formation of BaO_x clusters and the Ti incorporation into the substrate, forming the familiar Ti-rich SrTiO₃ surface reconstructions.

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7

Yang, Zheng. „Doping in zinc oxide thin films“. Diss., [Riverside, Calif.] : University of California, Riverside, 2009. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3359913.

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Thesis (Ph. D.)--University of California, Riverside, 2009.
Includes abstract. Available via ProQuest Digital Dissertations. Title from first page of PDF file (viewed March 12, 2010). Includes bibliographical references. Also issued in print.

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8

MARTINEZ, POZZONI UMBERTO LUIGI. „Oxide ultra-thin films on metals“. Doctoral thesis, Università degli Studi di Milano-Bicocca, 2009. http://hdl.handle.net/10281/7463.

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When the thickness of an oxide film is below a nm (few atomic layers) the interaction with the metal substrate, together with structural and morphology changes, can lead to completely different chemistry with espect to thicker films and can lead to new and unprecedented phenomena. This thesis focuses on the study of the structure and properties of different ultrathin oxide films epitaxially grown on metal subtrates and their interactions with adsorbed metal atoms and clusters.

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9

Barrioz, Vincent. „Laser-fibre system for in-situ stress monitoring of thin films“. Thesis, Bangor University, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.273632.

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10

Sands, D. „Growth and characterisation of thin films of zinc sulphide on silicon“. Thesis, University of Bradford, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.379798.

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11

Kiisk, Valter. „Optical investigation of metal-oxide thin films /“. Online version, 2006. http://dspace.utlib.ee/dspace/bitstream/10062/115/1/kiiskvalter.pdf.

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12

Holden, Anthony Peter. „Tunnelling studies of very thin oxide films“. Thesis, University of Cambridge, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.336960.

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13

Ponja, Sapna D. „Metal oxide thin films for optoelectronic applications“. Thesis, University College London (University of London), 2018. http://discovery.ucl.ac.uk/10045545/.

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This thesis details the use of aerosol assisted chemical vapour deposition to deposit transparent conducting oxide thin films. Transparent conducting oxides are a special class of materials that exhibit high optical transparency as well as good electrical conductivity, two properties usually in contradiction with each other. The combination of these properties in one material has established an essential role for transparent conducting oxides in a range of applications such as flat screen displays, photovoltaic cells, gas sensors, low-emissive coatings and light emitting diodes. Aerosol assisted chemical vapour deposition is increasingly becoming recognised as a simple, low-cost and reliable technique for depositing thin films. It involves generating an aerosol mist from a solution containing the precursors that is transported with the aid of an inert or reactive carrier gas into the reaction chamber where deposition takes place on a heated substrate. Two of the attractive features of this method are its versatility in allowing the use of precursors that are not suitable for conventional chemical vapour deposition methods as the method depends on solubility rather than volatility and the facility to use multiple precursors simultaneously within a single vessel. The focus of this work is on doping and co-doping of metal oxide thin films, namely ZnO and SnO2, to enhance their optoelectronic properties. The ZnO films were doped with group III elements aluminium or gallium, and the SnO2 films were doped with multivalent elements antimony or tungsten. All four systems were co-doped by introducing fluorine to replace the oxygen ion in the lattice. Fluorine was used as the co-dopant because of its established use in fluorine doped tin(IV) oxide transparent conducting oxides, a commercially available product. Co-doping has received less attention compared with single cation doping largely because of the limitations of other deposition methods. The rationale for co-doping is that it would allow greater tuning of the optoelectronic properties of the transparent conducting oxides to suit specific applications. All films synthesised in this investigation were characterised using a wide range of techniques including X-ray diffraction, energy and/or wavelength dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, UV-visible-near infrared spectroscopy and Hall effect measurements.

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14

Silverman, Lee Arnold 1959. „Sol-gel derived tantalum oxide thin films“. Thesis, Massachusetts Institute of Technology, 1987. http://hdl.handle.net/1721.1/14835.

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15

Owens, Jessica Margaret. „The sputter deposition of oxide thin films“. Thesis, University of Cambridge, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.627173.

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16

James, Amy Frances. „Tin-oxide thin films by thermal oxidation“. University of Western Cape, 2021. http://hdl.handle.net/11394/8239.

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>Magister Scientiae - MSc
Tin dioxide (SnO2) thin films are a worthy candidate for an electron transport layer (ETL) in perovskite solar cells, due to its suitable energy level, high electron mobility of 240 cm2 v-1 s- 1, desirable band gap of 3.6 - 4.0 eV, and ultimately proves to be suited for a low temperature thermal oxidation technique for ETL production. A variety of methods are available to prepare SnO2 thin films such as spin and dip coating and chemical bath deposition. However, the customary solid-state method, which incorporates thermal decomposition and oxidation of a metallic Sn precursor compound in an oxygen abundant atmosphere prevails to be low in cost, is repeatable and allows for large-scale processing.

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17

Khokhlova, Mariya. „Interactions of cells with oxide thin films“. Thesis, Normandie, 2019. http://www.theses.fr/2019NORMC241.

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Dans le présent travail, nous montrons comment des couches minces d'oxydes peuvent être utilisées comme surfaces bioactives, un domaine de recherche encore peu exploré. À cet effet, des couches minces de TiO2, Al2O3, VOx et quelques autres oxydes ont été déposés sur des substrats de verre par la technique d'ablation laser pulsé (PLD), et l'adhésion, la prolifération et la différenciation de cellules souches mésenchymateuses humaines dérivées de moelle osseuse ont été évaluées. Le comportement des cellules a été analysé par rapport aux principaux paramètres de surface tels que la chimie, la mouillabilité, la morphologie et l'épaisseur des films. Nos résultats indiquent que les couches minces de TiO2 et Al2O3 peuvent non seulement favoriser l'adhésion et la croissance des cellules souches mésenchymateuses, mais peuvent également être utilisées pour influencer la différenciation ostéogénique et chondrogénique. En outre, l'effet de films minces d'oxydes sur l'adhésion et la croissance de lignées de cellules cancéreuses a été examiné. Nous avons montré que la culture de ces lignées cellulaires sur des films minces affecte leur croissance et, par conséquent, pourrait être une méthode utile pour effectuer des tests de dépistage des drogues.Cette étude fournira une meilleure compréhension de la corrélation entre la chimie de surface et la réponse cellulaire, qui a un role important dans le domaine de la fabrication de biomatériaux
In the present work we demonstrate how oxide thin films can be used as bioactive surfaces, a field of research which is still underexplored. For this purpose, thin films of TiO2, Al2O3, VOx and some others were deposited on glass substrates using the Pulsed Laser Deposition (PLD) technique, and adhesion, proliferation and differentiation of human bone marrow-derived mesenchymal stem cells were evaluated. Cell behavior was analyzed with respect to the various key surface parameters such as chemistry, wettability, morphology and the thickness of films.Our results indicate that thin films of TiO2 and Al2O3 can not only support mesenchymal stem cells adhesion and growth, but also can be used to influence osteogenic and chondrogenic differentiation path. Additionally, effect of oxide thin films on adhesion and growth of cancer cell lines was studied. We showed that culturing these cell lines on thin films affects their growth and, therefore, could be a valuable method to perform screening tests with drugs.This work will provide a better understanding of correlation between surface chemistry and cellular response, which has a high significance in the field of biomaterials fabrication

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18

Isukapati, Sundar Babu. „Gallium Oxide Thin Films for Optoelectronic Applications“. Youngstown State University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=ysu1527125539086742.

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19

Dulal, Prabin. „Optoelectronic Characteristics of Indium Oxide Thin Films“. Bowling Green State University / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1562680154150056.

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20

Wang, Hao. „Cathodic electrodeposition of thin ceramic oxide films“. Thesis, Imperial College London, 2008. http://hdl.handle.net/10044/1/11950.

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Cathodic electrodeposition (CELD) is achieved via hydrolysis of metal ions by electrogenerated base to form metal oxideihydroxide films on a cathodic substrate. Hydroxides and peroxides can then be converted to oxides by thermal treatment. In this study, Ti02 thin films (both rutile and anatase phases) and cobalt-doped anatase films were successfully produced through this method. These materials have presented applications in electronic and magnetic devices, such as piezo-ceramics as well as in catalysis. The CELD technology and the characterization of these thin films are described in detail in this thesis. The various parameters (deposition time, current density and annealing temperature etc.) that affect the characteristics ofTi02 films deposited on Pt and Ti substrates have been explored. Focus ion beam imaging (FIB) and scanning electron microscopy (SEM) analysis show that the thickness of the film increases as the deposition time increases. Applying current density greater than 30 mA'cm-2 results in the film having a porous structure, however, little difference between films was observed when the current density was 20 mA'cm-2 or less. XRD data gave an indication that the as-deposited films were amorphous; after annealing at elevated temperatures (400Ã‚Â°C ~ 1000Ã‚Â°C) anatase and rutile phases were formed successfully. Samples were thermally treated under three different atmospheres: air, argon and argon/hydrogen (10% hydrogen). Different characteristics were observed after annealing. SEM and atomic force microscopy (AFM) show that the particle size increased after annealing in argon and argon/hydrogen. Preferred orientation ofthe films annealed in different atmospheres was observed and further investigated using high temperature in-situ XRD. Ti1-xCOx02-o films were successfully prepared on Ti and Si substrates. When the annealing temperature was above 600Ã‚Â°C a CoTi03 phase was detected in the film, whilst maintaining the anneal temperature below 600Ã‚Â°C resulted in only anatase peaks ((101) and (200)) being observed. The films annealed at 400Ã‚Â°C show room-temperature ferromagnetism as determined by vibrating sample magnetometry, and the magnetization per unit volume was of the right order of magnitude (0.2-0.6JlB/CO) for dilute ferromagnetic oxide thin films. X-ray absorption spectroscopy studies showed that the cobalt was present as Co2+ and the XRD data were consistent with cobalt substituted anatase lattice as the lattice parameter increased from 9.0080(2) to 9.4780 (3)

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21

Jiang, Fang-Xing. „Tantalum oxide thin films for microelectronic applications /“. Online version of thesis, 1995. http://hdl.handle.net/1850/11925.

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22

Huang, Bin. „Mechanical characterization of thin films /“. View abstract or full-text, 2005. http://library.ust.hk/cgi/db/thesis.pl?MECH%202005%20HUANG.

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23

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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24

Yoon, Jongsik. „Nanostructured thin films for solid oxide fuel cells“. [College Station, Tex. : Texas A&M University, 2008. http://hdl.handle.net/1969.1/ETD-TAMU-3164.

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25

Backholm, Jonas. „Electrochromic Properties of Iridium Oxide Based Thin Films“. Doctoral thesis, Uppsala universitet, Fasta tillståndets fysik, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-8505.

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Electrochromic iridium oxide (IrOx) and iridium-tantalum oxide (IrTaOx) thin films were prepared by reactive magnetron sputtering. Composition, density, and structure were determined using Rutherford backscattering spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and electron energy loss spectroscopy. The electronic density of states (DOS) and the solid phase chemical diffusion coefficient (D) were determined for hydrogen in IrOx and IrTaOx by potentiostatic intermittent titration technique (PITT), and electrochemical impedance spectroscopy (EIS). The complex refractive indices were determined for colored and bleached IrOx and IrTaOx by inverting transmission and reflectance, measured using spectrophotometry in the 300-2500 nm wavelength range. A very porous structure, with a stoichiometry of IrO2.2, was found for IrOx. It contained ~4 nm sized grains. The IrTaOx had a denser structure built up by ~4 nm sized grains. The composition of IrTaOx was found to vary on a nanometer scale, with an average composition of IrTa1.4O5.6. It was found that DOS can be measured using PITT and EIS in the presence of spontaneous side reactions, even for systems influenced by non-negligible charge transfer kinetics and Ohmic drops. It was found that the measured DOS is 30-50% of the theoretically calculated DOS and that D is in the 10-10 – 10-11 cm2/s range for both materials. The hydrogen diffusion mechanism was described by an anomalous diffusion model, possibly indicating percolation or diffusion paths described by a fractal network. The refractive indices were found to be ~1.3 and ~2 for IrOx and IrTaOx, respectively, and independent of coloration state, whereas the extinction coefficients were found to modulate by ~30% for IrOx and ~50% for IrTaOx, making IrTaOx more favorable for electrochromic applications. A modulation peak was found at ~660 nm for both IrOx and IrTaOx associated with the removal of intraband transitions within the Ir t2g band.

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26

Garg, Ashish. „Growth and characterization of epitaxial oxide thin films“. Thesis, University of Cambridge, 2001. https://www.repository.cam.ac.uk/handle/1810/34609.

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Epitaxial oxide thin films are used in many technologically important device applications. This work deals with the deposition and characterization of epitaxial WO3 and SrBi2Ta2O9 (SBT) thin films on single crystal oxide substrates. WO3 thin films were chosen as a subject of study because of recent findings of superconductivity at surfaces and twin boundaries in the bulk form of this oxide. Highly epitaxial thin films would be desirable in order to be able to create a device within a film without patterning it, by locally creating superconducting regions (e.g. twins) within an otherwise defect free film by reducing or doping the film with Na. Films were deposited by reactive magnetron sputtering at various temperatures on single crystal SrTiO3 (100) and R-sapphire substrates. X-ray diffraction studies showed that the optimised films were highly (001) oriented, quality of epitaxy improving with decreasing deposition temperature. AFM studies revealed columnar growth of these films. Films were heat treated with Na vapour in order to reduce or dope them with Na. Low temperature measurements of the reduced films did not show existence of any superconductivity. SBT is a ferroelectric oxide and its thin films are attractive candidates for non-volatile ferroelectric random access memory (FRAM) applications. High structural anisotropy leads to a high degree of anisotropy in its ferroelectric properties which makes it essential to study epitaxial SBT films of different orientations. In this study, SBT films of different orientations were deposited on different single crystal substrates by pulsed laser ablation. Highly epitaxial c-axis oriented and smooth SBT films were deposited on SrTiO3 (100) substrates. AFM studies revealed the growth of these films by 3-D Stranski-Krastanov mode. However, these films did not exhibit any ferroelectric activity. Highly epitaxial (116)-oriented films were deposited on SrTiO3 (110) substrates. These films were also very smooth with root mean square (RMS) roughness of 15-20 Å. Films deposited on TiO2 (110) were partially a-/b-axis oriented and showed the formation of c-axis oriented SBT and many impurities. Completely a-/b-axis oriented SBT films were deposited on LaSrAlO4 (110) substrates. Films deposited at non-optimal growth temperatures showed the formation of many impurities. Attempts were also made towards depositing Sr2RuO4 films on LaSrAlO4 (110) substrates, which can act as a bottom electrode for ferroelectric SBT films.

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27

Molapo, David Theko. „Infrared studies of oxide catalysts and thin films“. Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp02/NQ32452.pdf.

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28

Vonk, Vedran. „Growth and structure of complex oxide thin films“. Enschede : University of Twente [Host], 2006. http://doc.utwente.nl/57134.

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29

Unsworth, Larry David Brash J. L. „Protein adsorption to chemisorbed polyethylene oxide thin films“. *McMaster only, 2005.

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30

Depaz, Michael. „Processing and characterization of zinc oxide thin films“. [Tampa, Fla.] : University of South Florida, 2007. http://purl.fcla.edu/usf/dc/et/SFE0002235.

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31

Murphy, Thomas Patrick. „Electrochromic properties of tin-nickel oxide thin films“. Thesis, Oxford Brookes University, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.284756.

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32

Hilou, H. W. „Electrical properties of R.F. sputtered thin oxide films“. Thesis, University of Nottingham, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.355425.

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33

Elfallal, Ibrahim Abdel-Wahab. „A study of indium tin oxide thin films“. Thesis, University of Salford, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.261449.

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34

Rauf, Ijaz Ahmad. „Structure and properties of indium oxide thin films“. Thesis, University of Cambridge, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.358371.

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35

Hou, Ya-Ching. „Surface far-infrared emission from oxide thin films“. Thesis, University of Cambridge, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.616237.

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36

Hong, Yuanjia. „Magnetic and Transport Properties of Oxide Thin Films“. ScholarWorks@UNO, 2007. http://scholarworks.uno.edu/td/615.

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My dissertation research focuses on the investigation of the transport and magnetic properties of transition metal and rare earth doped oxides, particularly SnO2 and HfO2 thin films. Cr- and Fe-doped SnO2 films were deposited on Al2O3 substrates by pulsed-laser deposition. Xray- diffraction patterns (XRD) show that the films have rutile structure and grow epitaxially along the (101) plane. The diffraction peaks of Cr-doped samples exhibit a systematic shift toward higher angles with increasing Cr concentration. This indicates that Cr dissolves in SnO2. On the other hand, there is no obvious shift of the diffraction peaks of the Fe-doped samples. The magnetization curves indicate that the Cr-doped SnO2 films are paramagnetic at 300 and 5 K. The Fe-doped SnO2 samples exhibit ferromagnetic behaviour at 300 and 5 K. Zero-field-cooled and field-cooled curves indicate super paramagnetic behavior above the blocking temperature of 100 K, suggesting that it is possible that there are ferromagnetic particles in the Fe-doped films. It was found that a Sn0.98Cr0.02O2 film became ferromagnetic at room temperature after annealing in H2. We have calculated the activation energy and found it decreasing with the annealing, which is explained by the increased oxygen vacancies/defects due to the H2 treatment of the films. The ferromagnetism may be associated with the presence of oxygen vacancies although AMR was not observed in the samples. Pure HfO2 and Gd-doped HfO2 thin films have been grown on different single crystal substrates by pulsed laser deposition. XRD patterns show that the pure HfO2 thin films are of single monoclinic phase. Gd-doped HfO2 films have the same XRD patterns except that their diffraction peaks have a shift toward lower angles, which indicates that Gd dissolves in HfO2. Transmission electron microscopy images show a columnar growth of the films. Very weak ferromagnetism is observed in pure and Gd-doped HfO2 films on different substrates at 300 and 5 K, which is attributed to either impure target materials or signals from the substrates. The magnetic properties do not change significantly with post deposition annealing of the HfO2 films.

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37

Lopez, Mark Gerard. „Aspects of electroforming in silicon oxide thin films“. Thesis, Keele University, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.385191.

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38

Dyachenko, A. V. „Spray pyrolysis deposition of magnesium oxide thin films“. Thesis, Сумський державний університет, 2014. http://essuir.sumdu.edu.ua/handle/123456789/34844.

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Magnesium oxide seems to be a good candidate regarding its bulk properties: large band gap (7.8 eV), high thermal conductivity and stability and an alternative dielectric to silicon dioxide (SiO2) to reduce the electric field in capacitive networks. MgO, widely used as a substrate for high-temperature superconductor films deposition, has attracted much attention due to its low dielectric constant, low dielectric loss, and less mismatch with YBCO films. With a low dielectric loss, MgO shows a wide application in microwave devices. Due to its low refractive index, MgO is especially a suitable buffer for epitaxial optical waveguide films. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/34844

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Vemuri, Venkata Rama Sesha Ravi Kumar. „Fabrication and characterization of zirconium oxide thin films“. To access this resource online via ProQuest Dissertations and Theses @ UTEP, 2009. http://0-proquest.umi.com.lib.utep.edu/login?COPT=REJTPTU0YmImSU5UPTAmVkVSPTI=&clientId=2515.

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40

Liu, Yandi. „Block Copolymer Lithographyfor Nano-porous Oxide Thin Films“. Thesis, KTH, Skolan för elektroteknik och datavetenskap (EECS), 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-254331.

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This thesis focuses on employing a new patterning technique called block copolymer lithography to transfer the nano-porous pattern from the polymer template to the underlying oxide thin film. Nano-porous block copolymer films are produced by spin-coating polymer solution on wafers followed by annealing, UV exposure and development processes. Reactive-ion etching is then used to etch the oxide films based on the pattern of polymer template and the polymer is then removed. The obtained oxide microstructure is characterized by SEM, showing a nanomesh of microdomains with the same hole size and density as the initial block copolymer layer. The advantages of block copolymer lithography include uniform nanopatterning, cost efficiency and simple processing. The nano-porous oxide thin films could be used as hard mask for nanopatterning in microelectronics and for energy storage applications.
Denna avhandling fokuserar på användningen av en ny mönstringsteknik som kallas block-sampolymerlitografi som används för att överföra nano-porösa mönster från polymermaller till en underliggande oxidtunnfilm. Nano-porösa blocksampolymerfilmer framställs genom spinbeläggningspolymerlösning på skivor följt av glödgning, UV-exponering och utvecklingsprocesser. Reaktionjon etsning används sedan för att etsa oxidfilmerna baserat på mönstret av polymermaller och därefter blir polymeren avlägsnad. Den erhållna oxidmikrostrukturen karakteriseras av SEM, som visar en nanomesh av mikrodomäner med samma hålstorlek och densitet som det ursprungliga blocksampolymerskiktet. Fördelarna med block-sampolymerlitografi innefattar likformig nanomönstring, kostnadseffektivitet och enkel bearbetning. De nanoporösa oxidtunnfilmerna kan användas som en hard mask för nanomönstring i mikroelektronik och för energilagringsapplikationer.

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Sánchez, Rodríguez Daniel. „Obtaining advanced oxide thin films at low temperatures by chemical methods. Thermal analysis of thin films“. Doctoral thesis, Universitat de Girona, 2015. http://hdl.handle.net/10803/328723.

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L'objectiu d'aquest treball és analitzar mètodes químics de baix cost com a ruta per a sintetitzar òxids avançats a baixa temperatura. En particular, hem explorat l'SHS per a la síntesi d'un òxid catalitzador fent servir pólvores de ciano complexes heteronuclears. També hem explorat el transport de calor per a sintetitzar capes via VCS concloent que les capes primes rarament experimentaran una combustió. Per això hem analitzat la condició necessària per que tingui lloc una combustió volumètrica en una mostra sòlida que reacciona sense intercanvi de gasos amb el seu entorn. Per fer-ho, hem ampliat el criteri de Frank-Kaminetskii per a sistemes d'escalfament continu i per a reactors cilíndrics. Per la part experimental em fet servir tècniques l'anàlisi tèrmica (TA). Hem desenvolupat un mètode per a mesurar la conductivitat tèrmica en pólvores per DSC. Finalment, hem desenvolupat dos criteris per a comprovar la fiabilitat en la mesura de la temperatura als experiments de TA.
The aim of this work is to analyse chemical methods as a route to synthesise advanced oxides at low cost and low temperatures. In particular, we have explored the combustion synthesis of a catalytic perovskite-type oxide from heteronuclear cyano complex powders. We have also explored heat transfer to synthesise films via VCS and concluded that thin films will hardly experience combustion. In particular, we have analysed the conditions needed for a thermal explosion to occur in a solid sample reacting without any gas exchange with its surroundings. For that purpose, we have extended the Frank-Kamenetskii relationship to continuous heating systems and to cylindrical reactors. The experimental component of this work is based on thermal analysis methods (TA). We have developed a new method to measure thermal conductivity of powders by DSC. Finally, we have developed two analytical relationships to check the reliability of the sample temperature in TA experiments.

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Snyder, Mark Q. „Modification of Semi-metal Oxide and Metal Oxide Powders by Atomic Layer Deposition of Thin Films“. Fogler Library, University of Maine, 2007. http://www.library.umaine.edu/theses/pdf/SnyderMQ2007.pdf.

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43

Lee, King Hung. „Ellipsometric studies of the nucleation of zinc sulphide films in ultra-high vacuum“. Thesis, Queen's University Belfast, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.335519.

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44

Rooth, Mårten. „Metal Oxide Thin Films and Nanostructures Made by ALD“. Doctoral thesis, Uppsala University, Department of Materials Chemistry, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-8898.

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Thin films of cobalt oxide, iron oxide and niobium oxide, and nanostructured thin films of iron oxide, titanium oxide and multilayered iron oxide/titanium oxide have been deposited by Atomic Layer Deposition (ALD). The metal oxides were grown using the precursor combinations CoI2/O2, Fe(Cp)2/O2, NbI5/O2 and TiI4/H2O. The samples were analysed primarily with respect to phase content, morphology and growth characteristics.

Thin films deposited on Si (100) were found to be amorphous or polycrystalline, depending on deposition temperature and the oxide deposited; cobalt oxide was also deposited on MgO (100), where it was found to grow epitaxially with orientation (001)[100]Co3O4||(001)[100]MgO. As expected, the polycrystalline films were rougher than the amorphous or the epitaxial films. The deposition processes showed properties characteristic of self-limiting ALD growth; all processes were found to have a deposition temperature independent growth region. The deposited films contained zero or only small amounts of precursor residues.

The nanostructured films were grown using anodic aluminium oxide (AAO) or carbon nanosheets as templates. Nanotubes could be manufactured by depositing a thin film which covers the pore walls of the AAO template uniformly; free-standing nanotubes retaining the structure of the template could be fabricated by removing the template. Multilayered nanotubes could be obtained by depositing multiple layers of titanium dioxide and iron oxide in the pores of the AAO template. Carbon nanosheets were used to make titanium dioxide nanosheets with a conducting graphite backbone. The nucleation of the deposited titanium dioxide could be controlled by acid treatment of the carbon nanosheets.

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Söderlind, Fredrik. „Colloidal synthesis of metal oxide nanocrystals and thin films“. Doctoral thesis, Linköpings universitet, Institutionen för fysik, kemi och biologi, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-11831.

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A main driving force behind the recent years’ immense interest in nanoscience and nanotechnology is the possibility of achieving new material properties and functionalities within, e.g., material physics, biomedicine, sensor technology, chemical catalysis, energy storing systems, and so on. New (theoretical) possibilities represent, in turn, a challenging task for chemists and physicists. An important feature of the present nanoscience surge is its strongly interdisciplinary character, which is reflected in the present work. In this thesis, nanocrystals and thin films of magnetic and ferroelectric metal oxides, e.g. RE2O3 (RE = Y, Gd, Dy), GdFeO3, Gd3Fe5O12, Na0.5K0.5NbO3, have been prepared by colloidal and sol-gel methods. The sizes of the nanocrystals were in the range 3-15 nm and different carboxylic acids, e.g. oleic or citric acid, were chemisorbed onto the surface of the nanoparticles. From FT-IR measurements it is concluded that the bonding to the surface takes place via the carboxylate group in a bidentate or bridging fashion, with some preference for the latter coordination mode. The magnetic properties of nanocrystalline Gd2O3 and GdFeO3 were measured, both with respect to magnetic resonance relaxivity and magnetic susceptibility. Both types of materials exhibit promising relaxivity properties, and may have the potential for use as positive contrast enhancing agents in magnetic resonance imaging (MRI). The nanocrystalline samples were also characterised by transmission electron microscopy (TEM), x-ray photoelectron spectroscopy (XPS), and quantum chemical calculations. Thin films of Na0.5K0.5NbO3, GdFeO3 and Gd3Fe5O12 were prepared by sol-gel methods and characterized by x-ray powder diffraction (XRPD) and scanning electron microscopy (SEM). Under appropriate synthesis conditions, rather pure phase materials could be obtained with grain sizes ranging from 50 to 300 nm. Magnetic measurements in the temperature range 2-350 K indicated that the magnetization of the perovskite phase GdFeO3 can be described as the sum of two contributing terms. One term (mainly) due to the spontaneous magnetic ordering of the iron containing sublattice, and the other a susceptibility term, attributable to the paramagnetic gadolinium sublattice. The two terms yield the relationship M(T)=M0(T)+χ(T)*H for the magnetization. The garnet phase Gd3Fe5O12 is ferrimagnetic and showed a compensation temperature Tcomp ≈ 295 K.

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Glavic, Artur [Verfasser]. „Multiferroicity in oxide thin films and heterostructures / Artur Glavic“. Aachen : Hochschulbibliothek der Rheinisch-Westfälischen Technischen Hochschule Aachen, 2012. http://d-nb.info/1025883497/34.

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47

Yang, Hung-Pao 1980. „A study of P-type zinc oxide thin films /“. Thesis, McGill University, 2006. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=99550.

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In the past decade, p-type ZnO material has been investigated extensively. Its properties offer the potential for broad applications including the development of ultraviolet light emitting devices. Although n-type ZnO material is well known and studied for decades, the fabrication method and properties of p-type ZnO material are still to date not clearly understood.
In this report, reproducible p-type ZnO thin films sputtered on glass substrates are reported. On the same substrate, p-type ZnO film is local and surrounded by n-type ZnO regions. The thickness of the films is typically three microns after several hours of deposition by radio-frequency magnetron sputtering technique. Both p-type ZnO and n-type thin films are characterized by optical and electrical measurements at room temperature.
The crystal structure of p-type ZnO is examined by X-ray diffraction patterns. The X-ray diffraction patterns show that the material is polycrystalline and has (100) and (101) preferred orientation. Photoluminescence spectra of ZnO help to identify the energy levels in the material and spectra analysis reveals the presence of defects and dopants in the material. For p-type ZnO, the resistivity, the hole concentration and hole mobility are found to be 148.8 O-cm, 4.34 x 1018/cm3 and 1.72 x 10-2 cm2/V-sec respectively.

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Yagoubi, Benabdella. „A study of some thin transition metal oxide films“. Thesis, Brunel University, 1989. http://bura.brunel.ac.uk/handle/2438/5348.

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This thesis analyses the effect of varying the compositions of co-evaporated V205/TeO2, W03/CeO2, SiO/TeO2 and W03/TeO2 amorphous thin films on their electrical and optical properties. Some information about the electronic properties of these oxides may be obtained by comparison of the results. In the oxide systems containing transition metal ions the expression for hopping energy at low temperatures contains a term due to the hopping energy of polarons in addition to that due to the disorder. In the dielectric SiO/TeO2 thin films the distortion of 'the molecule is thought to be quite weak and thus the carriers do not form polarons. They would move by hopping at the band edge at low temperatures and by excitation to a mobility edge at high temperatures. The electrical conductivity of V205/TeO2 amorphous thin films is discussed in the light of the Mott(1968) theory. The optical absorption edge was found to obey the direct forbidden transitions equation cc ico=B(fiw-EOP)3'2. The frequency-squared dependence of the conductivity of W03/CeO2 thin films (high content of CeO2) in the frequency region where the capacitance is constant is associated with the lead resistance according to Street et al (1971). The optical energy gap of the films varies with the composition in same way as in doped crystalline semiconductors. The value of the, optical W03/Ce02 was calculated using the Davis and Mott (1970) formula for non-direct optical transitions. The capacitance of SiO/TeO2 thin films is found to be almost independent of frequency as well as of temperature. This is due to a strong ionic bonding which characterises a good insulator. The optical absorption edge of SiO/TeO2 is found to be sharper than that of W03/ CeO2 and very similar to that found in most crystalline solids. The value of the optical energy gap is calculated using the same formula as in W03/CeO2. The systematic change of the optical gap with composition is observed only in a limited range of compositions. The a. c electrical properties of W03/Te02 amorphous thin films are described using the Springett(1974) and Elliott(1977) models. The optical absorption edge of WO3/TeO2 is found to lead to new arguments about the origin of the Urbach edges.The a. c electrical conductivity shows a frequency dependence of the form as ca wS in all samples studied in the present work. The mechanism of conduction at low temperatures with the index varying from 0.5 to I is thought to be due to hopping of electrons between localized states in the gap. At high fields the d. c current shows a non-linear dependence on the applied electric field. This is thought to be due to either space charge or Schottky effects in the oxides containing transition metal ions. In SiO/TeO2 dielectric films, the non-linear dependence of current on the electric field is thought to be due to either the Poole-Frenkel effect or at slightly lower fields it could be due to impurities.

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49

Potter, D. „Zinc-based thin films for transparent conducting oxide applications“. Thesis, University College London (University of London), 2018. http://discovery.ucl.ac.uk/10041886/.

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This thesis describes the synthesis of zinc-based transparent conducting oxide (TCO) thin films, as sustainable alternatives to commercial TCOs. There are two main aims to this work. The first is the discovery of suitable TCO materials, which involves finding the optimum optoelectronic properties for applications in photovoltaic devices. The second aim is investigating the scale up of aerosol assisted chemical vapour deposition (AACVD), which is the technique used to deposit the majority of the films in this work. The films deposited in this work were characterised by X-ray diffraction (XRD) to find the crystal structures, X-ray photoelectron spectroscopy (XPS) to find the elemental compositions, scanning electron microscopy (SEM) to analyse the surface morphologies, UV/vis spectroscopy to find the optical properties, and by Hall effect measurements to find the electrical properties. Aluminium, gallium, indium, silicon, and fluorine have been examined as dopants for ZnO, in various combinations, and at different concentrations. The films were generally found to have high transparency, and electrical properties that approached those of industrial TCO materials. The merits of the films are particularly promising, when considering the relative ease through which the films were synthesised. Additionally, the effect of varying the solvent used to make up the precursor solution is investigated. The deposition of ZnSb2O6 thin films via spin coating is also discussed. This thesis also details an investigation into the scale-up of AACVD. An aerosol transport study was performed, whereby the aerosol was transported prior to deposition. It was found that a considerable amount of aerosol was condensing within the tubing, prior to reaching the reactor. Additionally, increasing the film growth rates was investigated by depositing FTO films using high concentrations in the precursor solution. Growth rates of approximately 2 μm min-1 were achieved, making the use of AACVD for commercial applications significantly more feasible.

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50

Min, Yongki 1965. „Properties and sensor performance of zinc oxide thin films“. Thesis, Massachusetts Institute of Technology, 2003. http://hdl.handle.net/1721.1/17032.

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Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2003.
Includes bibliographical references (p. 144-152).
This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Reactively sputtered ZnO thin film gas sensors were fabricated onto Si wafers. The atmosphere dependent electrical response of the ZnO micro arrays was examined. The effects of processing conditions on the properties and sensor performance of ZnO films were investigated. Using AFM, SEM, XRD and WDS, the 02/Ar ratios during sputtering and Al dopant were found to control the property of ZnO films. Subsequent annealing at 700 C improved the sensor response of the films considerably although it had only minor effects on the microstructure. DC resistance, I-V curves and AC impedance were utilized to investigate the gas response of ZnO sensors. ZnO films prepared with high O2/Ar ratios showed better sensitivity to various gases, a feature believed to be related to their lower carrier density. Al doped ZnO showed measurable sensitivity even with lower resistance attributable to their porous microstructure. AC impedance identified two major components of the total resistance including Schottky barriers at the Pt-ZnO interfaces and a DC bias induced constriction resistance within the ZnO films. Time dependent drift in resistance of ZnO films has been observed. Without applied bias, the ZnO films showed a fast and a slow resistance change response when exposed to gases with varying oxygen partial pressure with both response components dependent on operating temperature. Even at the relatively low operating temperatures of these thin film sensors, bulk diffusion cannot be discounted. The oxygen partial pressure dependence of the sensor resistance and its corresponding activation energy were related to defect process controlling the reduction/oxidation behavior of the ZnO.
(cont.) In this study, time dependent DC bias effects on resistance drift were first discovered and characterized. The DC bias creates particularly high electric fields in these micro devices given that the spacing of the interdigited electrodes falls in the range of microns. The high electric field is believed to initiate ion migration and/or modulate grain boundary barrier heights, inducing resistance drift with time. Such DC bias resistance induced drift is expected to contribute to the instability of thin film micro array sensors designed for practical applications. Suggestions for stabilizing sensor response are provided.
by Yongki Min.
Ph.D.

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