Thèses : « Opto-electronic Devices »

1

Russell, Ben. « Modelling of novel opto-electronic devices ». Thesis, University of York, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.444759.

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Rajagopalan, Dharmashankar. « Opto-Electronic Processes in SrS:Cu ACTFEL Devices ». UKnowledge, 2006. http://uknowledge.uky.edu/gradschool_theses/273.

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The a. c. thin film electroluminescent (ACTFEL) devices are of scientific interest due to their applications in large area, flat panel displays. Of particular interest to the research community is the mechanism of electron transport and luminance in these devices. Toward this end, a physical model and a mathematical model for SrS:Cu ACTFEL Devices were developed and published earlier by our group. The purpose of this thesis is to obtain a qualitative and quantitative match between experiment and theory. A brief summary of the model can be found here [1]. Effects of variation in drive parameters in experimental steady state measurements, and analysis of VIL (Voltage-Current-Luminance) plots for different simulated device and drive parameters are performed. The effects of voltage amplitude, activator concentration, interface energy levels, and critical field for dipole collapse were studied. The plots matched qualitatively in that all major experimental features were produced in the simulated waveforms. The measured and the simulated peak currents are 72.5 mA/cm2 and 66.42 mA/cm2 for VA = 123 V. Experimental and theoretical charge transferred per pulse were 2.75 C/cm2 and 2.26 C/cm2. Peak experimental and simulated luminance values for VA = 123 V were 531 cd/m2 and 49150 cd/m2. Total experimental and simulated luminance values for VA = 123 V case were 6.2 cd/m2 and 561.2 cd/m2 respectively. The large difference is attributed to the loss factors such as optical losses (due to total internal reflection), scattering of electrons by impurities in the bulk phosphor layer, and concentration quenching; these have not been incorporated in the model yet.

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3

Ali, Nazar Thamer. « Opto-electronic characterization of multi-terminal polysilicon switching devices ». Thesis, University of Bradford, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.304120.

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4

Wang, Shouyin. « Characterisation of ZnSe and ZnCdSe/ZnSe opto-electronic devices ». Thesis, Heriot-Watt University, 1994. http://hdl.handle.net/10399/1394.

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Thorat, Ruhi P. « Opto-Electronic Properties of Self-Contacted MoS2 Monolayer Devices ». Ohio University / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1512731597427663.

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6

Toffanin, Stefano. « Multifunctional organic semiconductors as active materials for electronic and opto-electronic devices ». Doctoral thesis, Università degli studi di Padova, 2009. http://hdl.handle.net/11577/3426094.

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Since the first discovery of the photoelectric effect in anthracene, organic compounds have been studied as multi-functional materials because of their capability of showing a variety of properties such as charge transport, light absorption/emission, photoconductivity, electroluminescence and superconductivity. The work presented in this Ph.D. thesis aims at studying different classes of ?-conjugated organic materials that present functional properties suitable for the realization of opto-electronic devices. In particular we focus our attention on the two specific properties that are deeply correlated to the molecular arrangement in the realization of nano-scale multifunctional devices: charge transport and light emission. In the technologically appealing thin-films, the molecular arrangement is extremely sensitive to the deposition procedures and to the nature of the substrate. Thus, of great interest is the understanding at the micro- and nano-scale of the molecular architecture and morphological features which favour charge transport and/or energy transfer, in order to enhance performances of opto-electronic devices based on thin films. We show that in general linear ?-oligothiophenes can organize advantageously in thin-films in so as to guarantee the proper overlap between molecular orbitals which enables efficient field-effect charge transport. Introducing a new class of branched oligothiophenes (namely spider-like oligothiophenes) we aim at studying how complex 3D molecular architecture can affect optical emission, supermolecular organization and charge transport properties. Investigation on the enhancement of light emission efficiency of organic molecular systems is then carried out presenting a new host-guest lasing system obtained by co-evaporation of an oligo(9,9-diarylfluorene) derivative (T3, donor) with a well-known red-emitter dye (DCM, acceptor). In this binary blend, an efficient Förster energy transfer takes place from the T3 matrix to the dye molecules when the dye concentration is properly optimized. Moreover the mirrorless lasing measurements reveal that amplified spontaneous emission threshold of the 2% DCM:T3 sample is almost an order of magnitude lower than the 2% DCM:Alq3 model system measured in the same experimental conditions. The possibility of combining different functionalities in a single device is of great relevance for the further development of organic electronics in integrated components and circuitry. Organic light-emitting transistors (OLETs) have been demonstrated to be able to combine in a single device the electrical switching functionality of a field-effect transistor and the capability of light generation. When organic materials are implemented as active layers in device realization, interfaces formed by different materials are intrinsically important. The comprehension of the physics behind each interface is a crucial point to design new materials for device applications or to improve the performances of the existing ones Here we present a new approach for realizing ambipolar light-emitting transistor. In the heterostructure we propose the first layer and third layers are optimized for field-effect charge (electrons and holes) transport. The second layer is formed by a host-guest matrix with high optical performance and showing amplified spontaneous emission under optical pumping. The specificity of the presented tri-layer based OLET is the intrinsic separation of the charge transport region from the exciton formation region thus preventing completely the exciton-carrier quenching. The optimization of the charge transport and light emission properties allows the realization of a tri-layer heterojunction presenting balanced electron and hole mobility (~10-1-10-2 cm2/Vs), high charge carrier density in correspondence of the maximum electroluminescence emission (~ 1 KA/cm2) and intense light generation.
Fin dalla scoperta dell’effetto fotoelettrico nell’antracene, i composti organici sono stati studiati come materiali multifunzionali data la loro capacità di mostrare una varietà di proprietà differenti, come il trasporto di carica, emissione/assorbimento di luce, fotoconduttività, elettroluminescenza e superconduttività. Il lavoro presentato in questa tesi di dottorato si prefigge lo scopo di studiare differenti classi di materiali organici ? coniugati che presentino le proprietà funzionali adatte per la realizzazione di dispositivi optoelettronici. In particolare viene prestata particolare attenzione allo studio di due specifiche proprietà che sono profondamente connesse con l’organizzazione molecolare nei dispositivi multifunzionali con dimensioni nanometriche: il trasporto di carica e l’emissione di luce. Nei film sottili, univocamente considerati interessanti dal punto di vista tecnologico, l’organizzazione molecolare è fortemente dipendente dai processi di deposizione e dalla natura del substrato. Per aumentare le prestazioni dei dispositivi basati sui film sottili risulta fondamentale comprendere le strutture supermolecolari e le caratteristiche morfologiche su scala micro- e nanometrica che possono favorire il trasporto di carica e/o i processi di trasferimento di energia. Si dimostra che in generale gli oligotiofeni lineari depositati in film sottile possano organizzarsi vantaggiosamente in modo da garantire l’opportuna sovrapposizione tra gli orbitali molecolari che permette un efficiente trasporto di carica. Introducendo una nuova classe di oligotiofeni ramificati, denominati spider-like, ci proponiamo di studiare come una complessa architettura 3D possa modificare le proprietà di emissione, di organizzazione supermolecolare e di trasporto. Si procede quindi ad indagare la possibilità di aumentare l’efficienza di emissione di luce di sistemi organici molecolari mediante l’introduzione di un nuovo sistema host-guest con proprietà di lasing ottenuto sublimando un derivato diarilfluorenico (T3, donore) con una noto colorante emettitore nel rosso (DCM, accettare). In questa soluzione solida binaria, si verifica un efficiente trasferimento di energia alla Förster tra la matrice di T3 e le molecole di colorante quando la concentrazione di colorante viene opportunamente ottimizzata. Inoltre, la soglia di emissione spontanea amplificata del campione avente le molecole di DCM disperse al 2% in peso nel T3 risulta quasi un ordine di grandezza più bassa rispetto a quella del campione modello misurato nelle stesse condizioni sperimentali avente la stessa concentrazione in peso si molecole di DCM disperse in una matrice di Alq3. La possibilità di combinare diverse proprietà funzionali in un unico dispositivo risulta di notevole interesse per un ulteriore sviluppo dell’elettronica organica nei componenti integrati e nei circuiti. Si è dimostrato che i transistor organici ad emissione di luce sono capaci di combinare in un singolo dispositivo le proprietà di switch dei transistor ad effetto di campo con la capacità di generare luce. Quando i materiali organici vengono utilizzati come strati attivi nei dispositivi, le interfacce formate dai diversi materiali assumono un ruolo di primaria importanza. La comprensione dei processi fisici che avvengono ad ogni interfaccia è cruciale per disegnare nuovi materiali per dispositivi o per aumentare le prestazioni quelli già esistenti. In questo lavoro di tesi viene presentato un nuovo approccio per realizzare transistor ambipolari ad emissione di luce. Nell’eterogiunzione che viene proposta il primo e il terzo strato sono dedicati al trasporto di portatori di carica (elettroni e lacune) per effetto di campo mentre il secondo strato è formato da una soluzione solida host-guest che mostra efficiente emissione di luce ed emissione spontanea di luce se pompata otticamente. La specificità dell’approccio che presentiamo è che le regioni di trasporto di carica sono fisicamente separate da quella in cui avviene la formazione dell’eccitone. In questo modo viene ridotta completamente l’interazione tra l’eccitone e il portatore di carica. Dopo aver ottimizzato il trasporto di carica e le proprietà di emissione di luce, si è potuto realizzare un dispositivo basato sull’eterogiunzione a tre strati che presenta valori di mobilità per gli elettroni e le lacune bilanciati (~10-1-10-2 cm2/Vs), alta densità di portatori di carica in corrispondenza del massimo di elettroluminescenza (~ 1 KA/cm2) e intensa emissione di luce.

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Wallace, Chik-Ho Choy. « Modelling and electro-optic quantum-wells modulation devices ». Thesis, University of Surrey, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.267967.

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Billa, Muralidhar Reddy. « Liquid crystalline organic semiconductors for application in opto-electronic devices ». Thesis, University of Hull, 2015. http://hydra.hull.ac.uk/resources/hull:11267.

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The synthesis and evaluation of novel photo-reactive liquid crystalline materials that exhibit light emitting, charge transporting and photovoltaic properties is described. Low-molar-mass liquid crystalline monomers, based on a series of substituted thiophenes, thieno[3,2-b]thiophenes, benzo[1,2-b:4,5-b']dithiophene, 4,7-dibromobenzo- 1,2,5-thiadiazole, fluorenes and carbazoles have been synthesised. Most of the materials synthesised incorporate two 9-octyl carbazole end groups at 3 positions. Some of the materials synthesised incorporate methacrylate end groups attached to the peripheries of the molecule at the end of flexible aliphatic chains. Polymerisation of these end groups allows the production of multilayer OLEDs with a very small pixel size due to the insoluble cross-linked network obtained after photo-polymerisation. The creation and analysis of novel multi-layer OLEDs with exceptionally small pixal size was possible by the incorporation of photo-polymerizable group into the liquid crystalline compounds. The molecular core incorporates either a 9-octyl carbazole end groups at the two ends of a fluorene moiety or an N-alkyl-substituted carbazole in the centre of the molecule. The presence of these two new types of liquid crystalline monomers for use as polymer networks in OLEDs should lead to higher electrochemical stability towards oxidation and thereby give rise to longer life-times in OLEDs containing them. Exceptinally, several of these novel OLED materials exhibit blue photoluminescence and electroluminescence, enabling their incorporation into multicolour OLEDs. This thesis details the synthesis of two different types of molecular central moieties, i.e., fluorene and carbazole with photopolymerisable end groups or 9-octyl carbazole end groups for implementation as initiators in multilayer organic devices. The photo reactive end groups are based on the acrylate moieties.

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Bao, Weixiao. « Liquid crystalline organic semiconductors for application in opto-electronic devices ». Thesis, University of Hull, 2014. http://hydra.hull.ac.uk/resources/hull:10866.

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This thesis collates and describes the research work carried out during my PhD programme. This work of research is mainly based on the synthesis and evaluations of novel liquid crystalline materials for use in plastic electronic applications, such as Organic Light Emitting Diode (OLED) and Organic Photovoltaic (OPV) devices. It also focuses on the study of the relationship between chemical structures and the mesomorphic behaviour, the liquid crystalline transition temperatures and energy levels of these new compounds. Optical Polarising Microscopy (OPM) and Differential Scanning Calorimetry (DSC) were used to identify the mesomophic behaviour and transition temperatures of all the new liquid crystals. A combination of UV-vis absorption and Cyclic Voltammetry (CV) was used to characterize the Highest Occupied Molecular Orbitals (HOMO), Lowest Occupied Molecular Orbitals (LUMO) energy levels and, therefore, the band gap (Eg) of the final compounds. Another primary focus of this work was the study and application of various aryl-aryl, cross-coupling reaction methods, including the Stille and the Suzuki reactions and a new direct arylation method. The reaction conditions were optimised during the research work for different compounds. The direct arylation method was found to be a successful and efficient way to synthesise new thiophene derivatives using aryl halides via C-H bond activation by palladium catalysts, but unfortunately not for all substrates. A series of fluorene- and carbazole-based materials have been developed for use as hole-transporting materials and electroluminescent materials in plastic electronic applications. Some of these materials exhibit nematic phases, which is beneficial due to the lower viscosity present in the nematic phase compared to that of the smectic phases. Some of them are found to form a glass above room temperature without any observable liquid crystal phases, despite significant supercooling below the melting point. The transition temperatures and mesomorphic behaviours of these novel materials were determined. The materials are expected to exhibit appropriate ionization potential (IP) and energy levels (HOMO, LUMO and Eg). A number of compounds incorporating a thiophene-based central core have been synthesized and evaluated as hole-transporting materials in OLEDs or/and as electron-donors in OPVs hopefully with the required appropriate energy levels. A compound with four 2,5-disubstituted thiophene rings in the molecular core shows promising properties for use as an electron-donor material with PCBM as an electron-acceptor in test OPV cells fabricated by members in the Organic Semiconductor Group in the Department of Physics at the University of Hull. Several liquid crystals based on thiazolo[5,4-d]thiazole central cores were synthesised by various aryl-aryl cross-coupling reaction pathways. The thiazolo-thiazole compounds based on five-membered rings only exhibit a nematic phase, while some thiazolo-thiazole compounds incorporating six-membered rings exhibit both a smectic phase and a nematic phase. However, this class of compounds exhibit relatively high melting points and liquid crystalline transition temperatures, as well as a very poor solubility, which indicates that they were not able to be used as organic semiconductors in plastic electronics applications. A class of oxadiazole homologues and a small number of isoxazole derivatives were successfully synthesized and purified. They were expected to possess relatively high electron affinity (EA) and strong fluorescence as potential materials for use as electron-transporting layers and/or emissive layers in OLEDs. The mesomorphic behaviour of these compounds is interesting and includes an unidentified SmX phase and a banana phase. The relationships between the chemical structures and mesomorphic behaviours of these materials were established.

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Mossanen-Shams, Iden. « Investigation of two opto-electronic sensing devices for determination of position ». Thesis, Brunel University, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.334351.

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Lauters, Michael E. « Organic Opto-Electronic Devices for Data Storage and Solid-State Lighting ». Diss., The University of Arizona, 2006. http://hdl.handle.net/10150/193770.

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Metal/organic/indium tin oxide (ITO) structures, including OLEDs, are demonstrated to contain multiple nonvolatile conductance states that can be programmed by the application of an external bias above a certain threshold voltage (Vth). These conductance states are stable and in turn can be probed by the use of a bias lower in value than Vth. The unbiased retention time of states is greater than several weeks, and more than 48,000 write-read-rewrite-read cycles have been performed with minimal degradation. It is found that the programming of a continuum of conductance states is possible, and techniques to do so are outlined. The electrical conductivity of the highest and lowest states can differ by six orders of magnitude. Switching speeds below 50 ns are shown, resulting in an energy requirement of about 100 pJ to switch from one conductance state to another. The memory phenomenon is shown to be influenced by the active layer thickness and anode/surface roughness while temperature dependence is limited. The electrical characteristics of these devices are consistent with metal diffusion or filament phenomena found in metal-insulator-metal structures, suggesting a possible mechanism by which the states are stored.Electroluminescent devices employing several new organic-inorganic lumophore-functionalized macromolecules are presented. In this study, macromolecules incorporating several lumophores covalently bonded to the vertices of a cubical core structure based on Polyhedral Oligomeric Silsesquioxane (POSS) in multiple configurations are implemented as light-emitting centers. The hole-transporting polymer poly(N-vinylcarbazole) (PVK) and electron-transporting additive 2-(4-biphenylyl)-5-(4-tert-butylphenyl)1,3,4-oxadiazole (PBD) are used as a two-part host to enhance the carrier transport in these simple solution-processed single-layer devices. A study of energy transfer in several systems is carried out to understand the requirements needed to create white-light emission from a single macromolecule. A single macromolecule incorporating twenty-one blue and one yellow lumophore is shown to exhibit field-independent stable white-light electroluminescence with Commission Internationale de l'Eclairage (CIE) coordinates of (0.31, 0.37). An external quantum efficiency of 0.55 percent and a maximum brightness of 1600 cd/m2 are attained with simple solution-processed single-layer devices. High solubility and ease of purification give these macromolecule white-light emitters advantages over their small molecule and polymeric type counterparts.

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Huang, Chih-Jung. « Opto-electronic class AB microwave power amplifier using photoconductive switch technology ». Diss., Columbia, Mo. : University of Missouri-Columbia, 2006. http://hdl.handle.net/10355/4458.

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Thesis (Ph.D.)--University of Missouri-Columbia, 2006.
The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (April 26, 2007) Vita. Includes bibliographical references.

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Landes, Christy. « The dependence of the opto-electronic properties of CdSe nanoparticles on surface properties ». Diss., Georgia Institute of Technology, 2003. http://hdl.handle.net/1853/30657.

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Jackson, A. « Synthesis and properties of materials for use in ferroelectric opto-electronic display devices ». Thesis, University of Hull, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.232908.

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Hu, Guang. « Liquid crystalline and polymer network organic semiconductors for application in opto-electronic devices ». Thesis, University of Hull, 2015. http://hydra.hull.ac.uk/resources/hull:13074.

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A series of novel liquid crystalline and photopolymerisable monomer organic semiconductors for plastic electronics applications, such as organic light-emitting diodes (OLEDs) and/or organic photovoltaics (OPVs) were synthesised and evaluated in this thesis. A number of synthetic reactions were carried out to obtain the desired compounds and intermediates under different reaction conditions. Different aryl-aryl cross-coupling reactions such as Suzuki reactions and direct arylations, palladium-catalysed systems [Pd(OAc)₂, Pd(OAc)₂+P(Ph)₃, and Pd(PPh₃)₄] for Suzuki aryl-aryl cross-couplings, and the choices of reaction solvents and base aqueous for N-alkyl substitutions were compared, optimised and analysed in this thesis. A variety of electron-withdrawing- or electron-donating moieties, including 2,7-disubstituted carbazole, 2,5-disubstituted thiophene rings, 1,4-disubstituted phenylene, 2,7-disubstituted fluorene, dibenzothiophene, benzothiadiazole and thieno[3,4-c]pyrrole-4,6-dione cores, were designed to incorporate in the molecular structure of various aromatic heterocyclic organic semiconductors. The relationship of liquid crystalline mesophases and molecular structures were analysed and established. Linear and co-axial aromatic backbones and short lateral chains contribute to the presence of liquid crystalline mesophases due to a large length-to-breadth ratio. Structural design of different aromatic cores promote the presence of different electroluminescent colours (i.e., organge for compound 53, green for compound 38, and blue for compound 41) and the tuning of device performance. Particularly, the nematic liquid crystalline 42 with a desired glass transition temperature above room temperature (32°C) and high clearing point (161°C) shows lower switch-on voltages (2.4 V) and higher OLED device brightness, current density and efficiency. Furthermore, There are excellent matches between the values of the ionization potential (IP = -5.53 eV) and the electron affinity (EA = -2.89 eV) of electroluminescent liquid crystalline 42 and the HOMO energy level of the hole-transport layer cross-linked OTPD (IP = -5.48 eV) and the LUMO energy level of electron-transporting layer of SPPO13 (EA = -2.91 eV), respectively. This advantageous combination of energy levels within the test OLED results in low charge-injection barriers for electrons and holes, respectively, leading to a high current density and a corresponding high density of excitons in the emissive layer where efficient recombination occurs efficiently with emission of light. In addition, novel photopolymerisable carbazole-functionalised triazatruxenes incorporating three or more cross-linkable endgroups including non-conjugated dienes and oxetanes at the end of aliphatic flexible spacers, were first reported and synthesised using simple one-step N-position substitution reactions. The cross-linking abilities of C=C double bonds, C≡C triple bonds, non-conjugated dienes and oxetanes attached to the triazatruxene core were compared and investigated. The result proved that non-conjugated dienes attached to more chemically and photochemically stable tertiary amides (90% @400 J/cm² UV for monomer 96) showed a greater tendency to photopolymerise than that attached to common ester bonds (72% @800 J/cm² UV for monomer K1). The photopolymerisable monomers also afford a cheap thin-film fabrication by solution spin-coating in organic optical-electrical devices. Hole test device of photopolymerisable triazatruxene 100 was fabricated by solution spin-coating. The effect of cross-linking and doping on hole-transporting capacity were studied in this work. It was found that cross-linking of photopolymerisable triazatruxenes 100 does not lead to a decrease of current density while photopolymerisable triaryamine monomer with similar star-shape does. Furthermore, the use of highly electronegative p-type dopant results in an increase of current density due to the formation of more free holes in a device by removing electrons from the host material.

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Pannu, Amandeep Singh. « Synthesis of 2D nanomaterial and their application in opto-electronic devices and sensing ». Thesis, Queensland University of Technology, 2021. https://eprints.qut.edu.au/211252/1/Amandeep%20Singh_Pannu_Thesis.pdf.

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This study demonstrates carbon dots synthesis from an inexpensive bio-waste precursor and their use in optoelectronic devices including flexible organic light emitting diodes (OLEDs) and optical sensors. This work is a pioneering demonstration of controlled and ordered growth of carbon nanomaterials into thin films and their flexible devices. It successfully demonstrates the use of two-dimensional carbon dots array as an active layer in flexible blue-cyan OLEDs. Furthermore, composite layer of carbon dots together with perovskites was used for green flexible OLEDs. Such human hair derived carbon dots have also been successfully used in sensors for chloroform detection at ppb level.

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Longo, Edoardo. « Peptide-based foldamers : new photo-controlled devices towards opto-electronic and mechanical applications ». Versailles-St Quentin en Yvelines, 2013. http://www.theses.fr/2013VERS0025.

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Afin de déterminer la longueur critique de formation d’hélices peptidiques dans l’eau, on a effectué des mesures de dichroïsme circulaire sur une série de peptides acétylés, composés de résidus alternés de L-Ala et Aib. Les longueurs critiques pour les transitions de structure random d’hélice 310 et de 310 à α sont l’hexapeptide et l’octapeptide. On a synthétisé une série complète de nanoparticules d’or utilisant les peptides de la série alternée Aib/L-Ala, après fonctionnalisation avec l’acide 3-mercaptan-propionique. L’étude a investigué la présence d’effets chiraux sur l’or causés par la présence des ligands peptidiques. Cet effet, déterminé par ECD, dépend de la structure secondaire du peptide et de l’aminoacide dans le ligand le plus proche de l’or. On a synthétisé deux nouveaux aminoacides avec des fonctionnalités azo-béniques sur la chaîne latérale pour des études de photo-isomérisation réversibles. Ces aminoacides ont été incorporés dans des nanoparticules métalliques. Une étude sur les propriétés magnétiques dépendant de l’isomérisation a été effectuée. On a synthétisé une série de peptides hélicoïdaux rigides avec des pyrènes ou ferrocènes à l’extrémité N-terminale. Ces peptides ont été préparés pour la formation des SAM sur des surfaces d’or pour applications en électrochimie, et contiennent un ou plusieurs résidus d’acide 4-amino-1,2-dithiolane-4-carboxylique (Adt), un résidu qui peut lier l’or par des liaisons disulfures. Pour un hexapeptide avec un ferrocene, on a fait des mésures électrochimiques pour tester les propriétés de oxydoréduction du ferrocene lié au peptide et de génération de photo-courant
An ECD investigation aimed at assessing the critical main-chain length for peptide helix formation in water was performed on a series of acetylated peptides composed of alternating Aib and Ala residues. The critical main-chain lengths for 310- and α-helices, although still formed to a partial extent, in aqueous solution are six and eight residues, respectively. A series of AuNps were synthesized from mercaptopropionic acid derivatives of alternating Aib/Ala peptides. Our studies established the occurrence of chiroptical properties in peptide-coated 2 nm diameter gold nanoparticles. Such behavior is strongly influenced by the secondary structure assumed by the coating peptides. Two new Cα-tetrasubstituted α-amino acids bearing azobenzene-derived side chains have been synthesized for photo-isomerization studies. These amino acids were incorporated into metal nanoparticles. The Au-derived nanoparticles exhibit magnetic susceptibility dependent on the light-driven isomerization. A series of ferrocene and pyrene labelled helical peptides containing one or more 4-amino-1,2-dithiolane-4-carboxylic acid (Adt) residues have been synthesized. These peptides were prepared for the formation of SAMs on gold surfaces for electrochemical applications. Preliminary experiments on the photo-current generation properties of a ferrocene labeled hexamer have been performed

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Longo, Edoardo. « Peptide-based foldamers : new photo-controlled devices towards opto-electronic and mechanical applications ». Doctoral thesis, Università degli studi di Padova, 2013. http://hdl.handle.net/11577/3422636.

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I An ECD investigation aiming at assessing the critical main-chain length for peptide helix formation in water solution is reported. To this goal, it was synthesized by a solution step-by-step protocol a complete series of N-terminally acetylated, C-terminally methoxylated oligopeptides, characterized only by alternating Aib and Ala residues, from the di- to the nonamer stage. All of these compounds were investigated by ECD in the far-UV region in water solution as a function of chemical structure, the presence/absence of the ester moiety at the C-terminus and temperature. The critical main-chain lengths for 310- and Î±-helices, although still formed to a partial extent, in aqueous solution are six and eight residues, respectively. II A whole series of AuNps was synthesized from mercaptopropionic derivatives of alternating Aib/Ala peptide series. Our studies established the occurrence of chiroptical properties in peptide-coated 2 nm diameter gold nanoparticles. The peptides induce a chiral effect onto the plasmon resonance band detectable via ECD. Such a behavior appears to be strongly influenced by the secondary structure assumed by the coating peptides. III The water solubility displayed by alternating Aib/Ala peptide series was investigated. The evidences of the formation of self-assembled structures in water, likewise responsible for the unexpected solubility properties, are presented. These peptide aggregates are spherical, with diameters up to 100 nm. They can also incorporate other molecular structures of relevant size, such as Au nanoparticles. Such systems may widen the number of applications currently accessible to self-assembled aggregates in the fields of biomedicine and materials science. IV Two new Ca-tetrasubstituted a-amino acids bearing two identical azobenzene-derived side chains have been synthesized. Photo-reversible isomerization process was detected. Intermediate chiral species are generated during the isomerization process driven by iii light. Diastereomers where generated when a chiral protein amino acid was inserted. The conjugation of one of the bis(azobenzene)-derived amino acids with different metal nanoparticles allowed the isomerization process to be detected even in solid state. Furthermore, the Au-derived nanoparticles exhibit a magnetic susceptibility dependence on the light-driven isomerization state that can be simply detected by 1H-NMR spectroscopy. Based on this behavior, these amino acids are of relevant potential for the development of a novel class of materials. V A series of Ferrocene and Pyrene labelled helical peptides containing one or more 4- amino-1,2-dithiolane-4-carboxylic acid (Adt) residues have been synthetized. Such peptides have been prepared to be employed in the formation of SAMs over gold surfaces (by means of linkage with the dithiolane Adt side chains) for electrochemical applications. In particular, the peptides have been designed for ensuring: (i) an highrigidity of the peptide scaffold and (ii) a parallel disposition of the peptide axle respect the metal surface. Conformational characterizations and CV tests on a Ferrocene binding 6-mer are presented. Preliminary experiment on the photo-current generation property has also been performed.
I Al fine di determinare la lunghezza critica per la formazione di eliche peptidiche in acqua è stata effettuata un’ indagine ECD su una serie completa di oligopeptidi acetilati composti da residui alternati di L-Ala ed Aib e terminante come estere metilico. Tali peptidi, pur non presentando funzionalità cariche o polari, risultano essere idrosolubili. L’ indagine È stata effettuata nell’ UV da 250 a 190 nm, ovvero nella regione dello spettro dicroico sensibile alla conformazione peptidica. Anche l’ assenza dell’ estere metilico (residuo C-terminale come carbossile o carbossilato) e la variazione della temperatura sono state studiate per osservare gli effetti sulla confomazione. Le lunghezze critiche per la transizione da struttura random ad elica 310 e da elica 310 ad elica risultano essere l’ esapeptide e l’ ottapeptide rispettivamente. II Una serie completa di nanoparticelle d’ Oro sono state sintetizzate dai peptidi della serie alternata Aib/L-Ala descritta, opportunamente funzionalizzati con acido 3-mercapto propionico. Lo studio ha stabilito la presenza di effetti chirali indotti sull’ oro dalla presenza dei leganti peptidici. Tale effetto È stato determinato via indagine ECD ed È dipendente dalla struttura secondaria del peptide e dall’ amminoacido più prossimo in catena nei leganti peptidici. III Le cause della solubilità in acqua evidenziata dai peptide della serie È stata indagata. Sono stati supposti dei meccanismi di auto aggregazione in acqua. Un’ indagine TEM ha confermato tale ipotesi. Nel caso dell’ undeca-peptide Z-Ala3-(AibAla)4OMe tali aggregati risultano sferici e di dimensioni dell’ ordine dei 100 nm. Ne È stata inoltre studiata la capacità di inglobare nanoaparticelle di Oro. Tali sistemi possono ampliare le applicazioni di sistemi auto assemblanti nei campi della biomedicina e dei materiali. IV Due nuovi ammino acidi CÎ± tetrasostituiti recanti due unità azobenzeniche identiche in catena laterale sono stati sintetizzati. Sono stati studiati processi di foto-isomerizzazione reversibili. E’ stata inoltre determinata la formazione di speci intermedie chirali durante tale processo. Tali amminoacidi sono stati accoppiati a residui chirali (L-Leu). In tal caso, durante il processo di isomerizzazione È stata riscontrata la formazione di speci diastereoisomeriche. Tali amminoacidi recanti due unità azobenzeniche sono stati quindi opportunamente derivatizzati per la formazione di nanoaparticelle metalliche. In particolare, il processo di foto-isomerizzazione È stato testato in fase solida su nanoparticelle di Oro con tali ammino acidi come leganti. E’ stato quindi svolto uno studio sulle proprietà magnetiche di tali nanoparticelle e la sua dipendenza dal processo di foto-isomerizzazione delle catene laterali dei leganti. V Sono stati sintetizzati una serie di peptidi elicoidali rigidi funzionalizzati con unità Pireneacetica o Ferrocenica all’ estremità N-terminale. La rigidità di tali eliche peptidiche È stata ottenuta utilizzando residui alternati di L-Ala ed Aib. Tali peptidi sono stati sintetizzati per formare SAM su superfici di Oro per applicazioni in elettrochimica. A tale scopo, i peptidi contengono anche uno o più residui di acido 4-ammino-1,2-ditiolano-4-carbossilico (Adt), un residuo in grado di legare l’ Oro grazie al legame disolfuro in catena laterale. Tale tipo di legame assicura inoltre una disposizione parallela delle catene peptidiche rispetto la superficie. Sono stati sintetizzati due decapeptidi recanti due Adt in posizione 1 e 8 (due giri esatti in un’ elica) ed una serie di esapeptidi recanti gli Adt in posizione 1 e 4 (un giro di elica 310). Tale geometria consente il legame più efficiente possibile alla superficie, in quanto i residui di Adt si trovano dallo stesso lato dell’ elica. I prodotti finali sono stati chimicamente caratterizzati. Sono state condotte approfondite indagini conformazionali su due esapeptidi. Su un esapeptide contenente Ferrocene sono stati inoltre condotti degli esperimenti di voltammetria ciclica e di generazione di foto-corrente.

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Theng, Sharon Phooi San. « Feasibility of micro-mirror laterally-emitting thin-film electroluminescent devices for an opto-electronic integrated circuit ». Thesis, Nottingham Trent University, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.341286.

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20

Vettese, Carlo Ettore. « The effects of multi-quantum well inter-mixing on long-wavelength opto-electronic structures and devices ». Thesis, University of Nottingham, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.387226.

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21

Robinson, Benjamin. « A high resolution microscopy study of biological components for the incorporation in opto-electronic hybrid devices ». Thesis, University of Sheffield, 2013. http://etheses.whiterose.ac.uk/3977/.

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Optical microscopy and scanning probe microscopy techniques have been utilised to acquire high resolution topography and fluorescence images of several biological samples. Applying these techniques to patterned samples and single molecules allow the optical properties of a sample to be investigated near to and below the diffraction limit, allowing emission properties to be correlated with those of topography. Optically active biological samples outside of their cellular environment are prone to photo-degredation and in measuring them a challenge is to ensure that optical measurements can be made before the onset of damage to the fluorophore. In this study two forms of fluorescence microscope have been utilised with scanning probe techniques of AFM and SNOM. These techniques have been used alongside microcontact printed arrays of fluorescent proteins and photosynthetic light harvesting complexes to address the accuracy of the printing technique and it's applicablity to biological components for future bionanotechnological applications. Furthermore, the periodicity associated with the arrays has been applied to the techniques to address the relative resolutions of the microscopes as well as the samples being a drive behind implimenting biologically friendly components/techniques to the microscopes (such as liquid cells). Larger structures from photosynthetic bacteria have also been addressed in this study in the form of chlorosomes which are model structures for light harvesting in low light conditions. Studies on the spectral properties of populations of 3 species have been conducted in this work with fluorescence microscopy and it has been shown that populations show small local variations in fluorescence. Furthermore it has been shown that the developed scanning fluorescence technique can be applied to photo senstitive samples successfully with only a small number of cases where spectral properties were affected by the measurement technique. Using high resolution microscopy techniques this research shows the surface patterning techniques in conjunction with biological samples to have mixed success depending on the sample. It also shows spectral measurements on newly discovered chlorosomes with little photo degredation. It further shows the role that the microscopy techniques have in analysing biological systems in different configurations on substrates.

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Bryant, Daniel T. J. « The development of room temperature transparent conductive adhesive-laminate technology and its use in flexible opto-electronic devices ». Thesis, Swansea University, 2014. https://cronfa.swan.ac.uk/Record/cronfa42935.

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23

Fischer, Florian S. U. [Verfasser], et Sabine [Akademischer Betreuer] Ludwigs. « The impact of donor-acceptor polymer crystal structure and mesoscopic morphology on opto-electronic devices / Florian S. U. Fischer ; Betreuer : Sabine Ludwigs ». Stuttgart : Universitätsbibliothek der Universität Stuttgart, 2015. http://d-nb.info/1124841393/34.

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24

Simmonds, Adam. « INVESTIGATION OF ORGANIC OPTO-ELECTRONIC SEMICONDUCTING DEVICES : ANODE SURFACE ETCHING, APPLICATION INTO NOVEL INTEGRATED STRUCTURES, AND THE ANALYSIS OF PHOTOCURRENT PROPERTIES IN PHOTOVOLTAICS ». Diss., The University of Arizona, 2009. http://hdl.handle.net/10150/194757.

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Indium-tin oxide (ITO) is commonly used as the transparent electrode in organic photovoltaic (OPV) devices. ITO's transparent properties come at the expense of less than ideal electrode characteristics arising from insulating over-oxidized surface species. OPVs fabricated on the native ITO surface tend to exhibit poor performance with a high degree of variability from device to device. Aggressive acid etching of the ITO surface removes the majority of the insulating surface species leading to improvements in OPV efficiency with greater reproducibility and increased device to device consistency.Organic light emitting diodes (OLEDs) are planar electroluminescent light sources that naturally couple a portion of their emission into internally reflected modes within the device substrate. Although this coupling property is well known, few attempts have been made to integrate OLEDs as light sources for internal reflection elements. Furthermore, OPVs share the optical coupling properties of OLEDs and therefore can be used as integrated internal reflection detectors. Integrating both an OLED light source and an OPV detector onto the same substrate results in an internal reflection sensing platform that requires no free-space optics, has low power consumption requirements, and can be easily fabricated on substrates occupying an area less than one square inch. In this work we establish a functional prototype design, characterize the fundamental coupling properties, and demonstrate several surface sensing responses of this fully integrated optical sensing platform.The net solar power production from OPVs arises from the interactions between multiple currents through the device. The photocurrent is the only power producing current in the device and understanding the voltage dependent nature of this current is essential in OPV research. Analysis methods of conventional, inorganic photovoltaics do not adequately describe the photocurrent behavior commonly observed in OPVs. OPV analysis is therefore somewhat limited by the methods commonly employed. To improve upon the convention methods we develop a simplified method of OPV photocurrent analysis based on electrochemical methods that accurately describes the voltage dependence of the photocurrent and leads to greater insight into the key parameters involved in solar power production from OPVs.

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Basu, A. « Development of materials and methods for the next generation electronic, electrochemical and opto-electronic device systems ». Thesis(Ph.D.), CSIR-National Chemical Laboratory, Pune, 2016. http://dspace.ncl.res.in:8080/xmlui/handle/20.500.12252/5876.

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Scarpellini, M. « ADVANCED MATERIALS : PREPARATION, STUDY AND OPTIMIZATION OF THIN FILM FOR OPTO-ELECTRONIC DEVICE ». Doctoral thesis, Università degli Studi di Milano, 2010. http://hdl.handle.net/2434/150151.

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The term “optoelectronic devices” is by now used for devices in which both electrons and photons are essential for their operation, as a natural evolution from the definitions of electronic devices that involved only electrons and holes in their operation and of photonic devices that involved only photons in their operation. One of the new lighting technologies which emerged within the past two decades and has the potential of becoming more energy-efficient then the existing light sources, is the Solid State Lighting technology of Organic Light Emitting Diodes (OLEDs). In general, the basic OLED structure consists of a stack of fluorescent organic layers sandwiched between a transparent conducting anode and metallic cathode. When an appropriate current is applied to the device, holes are injected from the anode and electrons from the cathode; some of the recombination events between the holes and electrons result in electroluminescence (EL). The first part of this PhD Thesis surveyed different aspect in OLED technology that are currently under debate. In particular chapter 2 is devoted to the study, preparation and optimization of thin films between the organic hole transport layer and the anode surface while chapter 3 deals with the synthesis of trifluorene compound, with methoxy substituents, as possible UV-blue emitter. The second part of this PhD work is dedicated to the synthesis and study of new materials with interesting emissive and second order NLO properties. In particular pyrene based chromophores are investigated in chapter 4, while chapter 5 deals with the synthesis of organic-inorganic perylene-POSS hybrids with enhanced emissive properties.

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Hassan, Sa'ad. « Microfabrication of Plasmonic Device : PPBG BIosensor in Cytop, Reflection Itensity Modulator and Atomically Flat Nanohole Array ». Thesis, Université d'Ottawa / University of Ottawa, 2015. http://hdl.handle.net/10393/32324.

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This thesis details the fabrication of three different plasmon-polariton based devices: a plasmon-polariton Bragg grating (PPBG) biosensor, an intensity modulator incorporating grating couplers, and optically separated electrical contact, and finally an array of nanoholes in an ultrasmooth Au film. The biosensor involves a 35 nm Au stripe, lithographically stepped in width to produce a Bragg reflector. The waveguide is embedded in symmetric, Cytop claddings 8 µm thick. Channels are etched into the top cladding, exposing the waveguides and allowing for the integration of fluidics. The modulator involves a 20 nm Au pad, overlaid with 80 nm Au diffraction gratings, supported by an ultrathin (~3 nm) SiO2 insulator, on a p-doped Silicon wafer backed by an Al Ohmic contact. Electrical contact pads are separated from the waveguide by a thick dielectric (700 nm PMMA), and 2.5 µm vias in-filled with Au allow for electrical connection between the contact pads and waveguides. The nanohole array is machined by focused ion beam into an ultrasmooth Au film revealed by template stripping. The Au film is stacked on a thick film of Cytop between ~5 µm thick.

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NUNES, JOAO RICARDO CORTES. « INFRARED OPTO-ELECTRONIC DEVICE FOR DETECTION AND MEASURING VELOCITY OF BALLS USED AS CLEANING ARTIFACTS OF HEAT EXCHANGERS ». PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2018. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=35294@1.

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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO
Esta dissertação de Mestrado teve por objetivo a concepção, desenvolvimento e validação de um dispositivo opto-eletrônico, que opera na faixa do infravermelho, para detecção e medição da velocidade de esferas em meios turvos. A motivação para desenvolvimento deste tema resultou da necessidade de controlar a circulação de esferas para instrumentar um sistema alternativo de limpeza de trocadores de calor de hidrogeradores, que faz uso de artefatos abrasivos de geometria esférica. O método utilizado fundamenta-se no processamento do sinal eletrônico gerado por um circuito que produz pulsos proporcionais ao tempo de passagem da esfera no interior do contador, a cada interrupção do feixe luminoso. O tratamento do sinal, gerado por pares de sensores opto-eletrônicos perpendiculares entre si e montados transversalmente ao fluxo de água de resfriamento que transporta as esferas, é realizado por um controlador lógico programável, que atribui inteligência ao sistema. Dentre os resultados obtidos, constatou-se que o dispositivo consegue detectar esferas circulantes quando transportadas por fluxos de água com diferentes graus de turbidez (ensaios em laboratório) ou quando em operação no ambiente da usina hidrelétrica, cuja opacidade da água de resfriamento é dada pela incrustação removida durante o processo de limpeza. Como conclusão, pode-se afirmar que o dispositivo opto-eletrônico proposto atende às necessidades do projeto de construção de um sistema alternativo de limpeza por esferas abrasivas, conseguindo descartar falsos positivos na contagem das esferas, a exemplo de bolhas de ar ou partículas de incrustação cujas dimensões críticas diferem daquelas das esferas abrasivas.
This dissertation aimed at the design, development and validation of an optoelectronic device, operating in the infrared range, for counting and measuring the velocity of spheres in turbid media. The motivation to develop this theme resulted from the need to control the spheres circulation to implement an alternative system for cleaning heat exchangers used to cool hydrogenerators, which make use of spherical abrasive artefacts. The methodology used is based on the processing of the electronic signal generated by a circuit that produces pulses proportional to the time of passage of the sphere inside the meter, at each interruption of the light beam. The processing of the signal, which is generated by pairs of mutually perpendicular optoelectronic sensors and mounted transversely to the flow of cooling water carrying the spheres, is performed by a programmable logic controller, which provides intelligence to the system. Among the obtained results, it was verified that the device can detect circulating spheres both when transported by water flows with different degrees of turbidity (laboratory tests) and when in operation in the environment of the hydroelectric plant, whose opacity of the cooling water is given by the fouling removed during the cleaning process. As a conclusion, it can be stated that the proposed optoelectronic device meets the needs of the construction of the alternative system of cleaning by abrasive spheres and can eliminate false positives in the counting of the spheres, such as air bubbles or incrustation particles whose critical dimensions differ from those of the abrasive spheres.

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Testa, Rodolphe. « Mise au point d’un outil de mesure de la cinématique du genou en contexte clinique ». Thesis, Lyon 1, 2011. http://www.theses.fr/2011LYO10277/document.

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Ce travail rapporte le développement et la validation d’un système de mesure pour l’étude cinématique des rotations du genou en 3 dimensions. Pour cela, nous avons dans un premier temps étudié in‐vitro les avantages apportés par un système de mesure de référence par rapport à l’évaluation du clinicien. Dans un second temps, nous avons développé un outil de mesure optoélectronique utilisable dans un contexte clinique. Nous avons réalisé une étude de reproductibilité de ce système pour des mesures de rotation interne‐externe en charge sur une série de sujets sains. Enfin, nous avons utilisé le système en condition réelle lors d’une étude clinique de revue à 2 ans de recul. 16 sujets opérés d’une rupture partielle du LCA ont été revus lors d’une consultation. Des mesures de rotation interne‐externe du genou en charge ainsi que des mesures de proprioception ont été réalisées
The purpose of this work was to develop and to validate a new device for clinical 3D rotational kinematic evaluation of the knee. With this aim in view, we demonstrated in‐vitro the advantages of using a device for clinical evaluation of the knee. After, we developed a clinical opto‐electronic device. We validated it with a protocol for knee examination during an active weight bearing test of rotational laxity on healthy subjects. Last, the device was used in actual conditions for a clinical study. 16 patients were examined 2 years after an ACL partial reconstruction. Weight bearing tests of rotational laxity and proprioception evaluation were performed on the patients

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Chee, Kuan Way Augustus. « Novel investigations of contrast in the Scanning Electron Microscope towards a new generation of doping profiling techniques engineered for semiconductor (opto)electronic device technology ». Thesis, University of Cambridge, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.611845.

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31

Park, Juhong. « Fabrication of Large-Scale and Thickness-Modulated Two-Dimensional Transition Metal Dichalcogenides [2D TMDs] Nanolayers ». Thesis, University of North Texas, 2019. https://digital.library.unt.edu/ark:/67531/metadc1505271/.

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This thesis describes the fabrication and characterization of two-dimensional transition dichalcogenides (2D TMDs) nanolayers for various applications in electronic and opto-electronic devices applications. In Chapter 1, crystal and optical structure of TMDs materials are introduced. Many TMDs materials reveal three structure polytypes (1T, 2H, and 3R). The important electronic properties are determined by the crystal structure of TMDs; thus, the information of crystal structure is explained. In addition, the detailed information of photon vibration and optical band gap structure from single-layer to bulk TMDs materials are introduced in this chapter. In Chapter 2, detailed information of physical properties and synthesis techniques for molybdenum disulfide (MoS2), tungsten disulfide (WS2), and molybdenum ditelluride (MoTe2) nanolayers are explained. The three representative crystal structures are trigonal prismatic (hexagonal, H), octahedral (tetragonal, T), and distorted structure (Tʹ). At room temperature, the stable structure of MoS2 and WS2 is semiconducting 2H phase, and MoTe2 can reveal both 2H (semiconducting phase) and 1Tʹ (semi-metallic phase) phases determined by the existence of strains. In addition, the pros and cons of the synthesis techniques for nanolayers are discussed. In Chapter 3, the topic of synthesized large-scale MoS2, WS2, and MoTe2 films is considered. For MoS2 and WS2 films, the layer thickness is modulated from single-layer to multi-layers. The few-layer MoTe2 film is synthesized with two different phases (2H or 1Tʹ). The all TMDs films are fabricated using two-step chemical vapor deposition (CVD) method. The analyses of atomic force microscopy (AFM), high-resolution transmission electron microscopy (HRTEM), photoluminescence (PL), and Raman spectroscopy confirm that the synthesis of high crystalline MoS2, WS2, and MoTe2 films are successful. The electronic properties of both MoS2 and WS2 exhibit a p-type conduction with relatively high field effect mobility and current on/off ratio. In Chapter 4, vertically-stacked few-layer MoS2/WS2 heterostructures on SiO2/Si and flexible polyethylene terephthalate (PET) substrates is presented. Detailed structural characterizations by Raman spectroscopy and high-resolution/scanning transmission electron microscopy (HRTEM/STEM) show the structural integrity of two distinct 2D TMD layers with atomically sharp van der Waals (vdW) heterointerfaces. Electrical transport measurements of the MoS2/WS2 heterostructure reveal diode-like behavior with current on/off ratio of ~ 104. In Chapter 5, optically uniform and scalable single-layer Mo1-xWxS2 alloys are synthesized by a two-step CVD method followed by a laser thinning. Post laser treatment is presented for etching of few-layer Mo1-xWxS2 alloys down to single-layer alloys. The optical band gap is controlled from 1.871 to 1.971 eV with the variation in the tungsten (W) content, x = 0 to 1. PL and Raman mapping analyses confirm that the laser-thinning of the Mo1-xWxS2 alloys is a self-limiting process caused via heat dissipation to SiO2/Si substrate, resulting in fabrication of spatially uniform single-layer Mo1-xWxS2 alloy films.

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李重君. « Application studies on organic Opto-Electronic devices and materials ». Thesis, 2004. http://ndltd.ncl.edu.tw/handle/70861985384986358045.

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Tu, Ching-Yen, et 涂清彥. « Asymmetrical liquid crystal opto-electronic devices and their applications ». Thesis, 2019. http://ndltd.ncl.edu.tw/handle/aw32ka.

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碩士
國立中央大學
光電科學與工程學系
107
In this thesis, we report the asymmetrical optical properties of the three liquid crystal (LC) devices, including (i) cholesteric LC coupled with a quarter-wave plate and a linear polarizer, (ii) dichroic dye-doped 90° twisted nematic LC (DDd-90° TNLC), and (iii) dye-doped TNLC gratings. In the first part, the incident light passes through the linear polarizer and the quarter-wave plate to form a circularly polarized light which can be reflected by the planar textures of the cholesteric LC (CLC) plate, so the asymmetrical optical property can be achieved. Moreover, the reflection bandwidth and wavelength of the CLC plate is dependent on the angle of propagation direction of the incident light, so the 1D-DIMOS software was also adopted to simulate the limitation of visual angle of this LC device. In the second part, owing to the rubbing direction of the two glass substrates are perpendicular to each other and the dichroic dyes possess the polarization selective light absorption, the DDd-90° TNLC device has the asymmetrical light absorption property. By measuring the polarization rotation and the polarization selective light absorption, the asymmetrical optical properties of the DDd-90° TNLC are completely demonstrated and analyzed, and the experimental results do agree well with the theoretical analyses. Furthermore, in the final part, we extend such an interesting structure to the dye-doped TNLC grating fabricated through the photoalignment process. According to the experimental results and the theoretical simulation about the polarization rotation properties of the dye-doped TNLC gratings, we demonstrate that the same linearly polarized light (0˚ or 90˚) incident onto the illuminated and the unilluminated surfaces presents the asymmetric diffraction property. Moreover, the diffraction efficiency based on the dichroic dye absorption and phase difference between the two kinds of LC structures of the dye-doped TNLC grating can be tuned electrically.

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Huang, Li-Chen, et 黃麗真. « Liquid Crystals and Polymers in Application of Opto-Electronic Devices ». Thesis, 2012. http://ndltd.ncl.edu.tw/handle/09335018955268470858.

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博士
國立臺灣大學
物理研究所
100
Novel materials, liquid crystals, photopolymers and conducting polymers, have many significant applications in micro optics, organic photovoltaic (OPV) cells and liquid crystal displays (LCD) manufacturing. In this dissertation, we successfully fabricate polymer microlens arrays and polymer solar cell devices by using these materials and investigate the electric, optical and physical properties to characterize their several advantages and vantages in the future position for optoelectronic devices. At first, a low-temperature self-assembly method using phase separation is demonstrated for the first time to fabricate polymer microlens arrays. In this study, we present a simple method of producing microlens arrays based on liquid crystal/photopolymer blends phase separation. The morphology of the microlens arrays has been measured by SEM, AFM and scanning white light interferometer. Our results show that the microlens arrays obtained from our experiments have a comparable light-gathering capability and can be applied in optical systems. In the latter, there are two topics concerning polymer solar cells. The first one is “Self-Assembled Multilayers Modified ITO in Polymer Solar Cells by Soft-Imprinting”. In this work, surface modification of indium tin oxide (ITO)-coated substrates through the use of self-assembled multilayers by the soft-imprinting method has been applied to adjust the anode work function and device performance in polymer solar cells based on a P3HT:PCBM heterojunction. The efficiency and morphology of the solar device with CF3-terminal group materials as a buffer layer have been measured and investigated. These results demonstrate that the soft-imprinting method is an effective and rapid procedure that enhances the quality of polymer solar cells and indicates potential implications for other organic devices containing an interface between a blended organic active layer and an electrode layer. In the second topic, we represent a fascinating approach – the rubbing method – to produce periodic grooves of PEDOT:PSS layer and apply it in polymer solar cells based on a P3HT:PCBM heterojunction. The 500 nm wide and 10 nm deep grating-like features have a profound effect on carrier mobility, light trapping and hole collection efficiency, leading to an increase in the short circuit density, filling factor and power conversion efficiency. These results indicate the feasibility of the rubbing method which is applicable to high-efficiency OPV cells.

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Chen, Yen Chung, et 陳彥仲. « Preparation of Functional Composite Microspheres Used on Opto-Electronic Devices ». Thesis, 2011. http://ndltd.ncl.edu.tw/handle/08510642353397056973.

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博士
國防大學理工學院
國防科學研究所
100
Anisotropic conductive film (ACF) is generally used as an interconnection material for flip chip technology has a wide application in a variety of electronics modules packaging technologies. ACFs are adhesive films that become conductive due to consisting mainly of epoxy resins, curing agents, conductive particles and other additives agents. Conductive particles are core-polymer microspheres and shell- Au/NiP. General manufacture includes sensitization, activation and metalization of polymer microspheres. To improve the shortcomings of traditional sensitization and activation, two brand new microwave irradiation-sensitization/activation and microwave irradiation-ethanol activation are applied in this research for comparisons with traditional sensitization/activation. Palladium adsorption on PMMA microsphere surfaces increases with the microwave irradiation power in microwave irradiation-sensitization/activation. At 150~200W of the microwave irradiation power, the palladium adsorption amount is 2~3 times the traditional sensitization/activation and the retention ratio of palladium adsorption also increases. More hydrophilic oxygen-containing functional groups are formed in microwave radiation-ethanol reduction to build possibly coordinate covalent bonds with palladium atoms or ions and increase the palladium catalyst adsorption. Palladium nano-particles of 4 to 6nm in size with better catalytic activities are formed on microsphere surfaces without dispersants in the above two microwave irradiation activation approaches. Smoother and more uniform coatings with higher adhesion are formed after electroless plating when compared with the traditional sensitization/activation.

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Panzi, Mukhokosi Emma. « Electrical and Opto-Electronic Devices Based on SnSe2 Thin Films ». Thesis, 2018. https://etd.iisc.ac.in/handle/2005/4729.

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SnSe2 is a semiconductor with unique and interesting properties such as band gap with layer thickness dependence. Theoretically, it has been predicted that the band gap can be varied between 1.2 and 2.04 eV. This range of band gap enables it to absorb a wide range of electromagnetic radiations suitable for various opto-electronic and other sensing device applications. Single or few layers of this material have been developed by various techniques such as mechanical exfoliation using scotch tape method for applications in photodetectors, gas sensors and phototransistors. In the first part of this work, we have grown SnSe2 thin films of varying thicknesses on a soda lime glass substrate by DC magnetron sputtering of Sn metal target followed by selenisation and have provided experimental demonstration of the band gap engineering of layered SnSe2 thin films. We have shown that for films < 50 nm thick, the band gap is ~ 2.04 eV, whereas the band gap is approximately ~ 1.2 eV, similar to that of bulk, for a 1200 nm thick film. The observed variation is consistent with the theoretically predicted layer thickness-dependent band gap of SnSe2. We fabricated photoconductors on the thin films and found that 400-1200 nm thick samples are responsive to IR radiation of wavelength 1064 nm, while thinner films of less than 140 nm thick were irresponsive to IR but responsive to white light. We estimated the average response and recovery time constants as ~7.76 and ~2.5 s at biases of 5 and 10V, respectively. In an attempt to improve the time constants, we fabricated a hetero-structure based on n-SnSe2 thin film and commercially available p-PEDOT:PSS. Interestingly, the device powers itself without any external bias. Due to strong built-in potential at the interface, the response and recovery time constants improved to ~1.33 and 1.22 s. The time constants were improved further by increasing the mobility at the interface and reducing the depletion width by fabricating a p-Si/n-SnSe2 hetero-structure. The observed response and recovery time constants were ~ 57/34 μs with the device operating even under zero-bias condition. Finally, we studied the temperature-dependent (100-350K) electrical transport properties of SnSe2 thin film of band gap of ~ 1.2 eV prepared on soda lime glass substrate. After extracting material parameters, we demonstrated the implication of this study in temperature sensing.

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Lin, Zhong-Han, et 林宗翰. « Production of Polyaniline/Graphene Composite Film and Application in Opto-electronic Devices ». Thesis, 2012. http://ndltd.ncl.edu.tw/handle/mwz64t.

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碩士
國立臺北科技大學
化學工程研究所
100
Since the discovery of conducting polymers in 1977, there’s lots of scientists keep doing the research in it. In different kind of conducting polymers, Polyaniline (PANI) got the special properties of electrochemistry and the stability of environment, which produces a wild potential of business application, so the composite material of main kind of PANI is attracting a lot of concern, and it’s because of there is only a few mass of aniline ,which can make the polymer mixture conduct, with cheep price of PANI. Graphene is one of the most famous carbon nano-materials these years, it has very good performance of physical properties. To bring it to mass production and lower the cost, there is lots of people get involved with the production research of graphene. This study is going to use the conduting properties with the properties of almost transparent, to maintain the optical properties of PANI, and enhance its conducting ability, extend the field of applications. After we produced PANI/(Functionalized-)Graphene, the SEM, FT-IR, UV-Vis, Four-Poing-Probe, Cyclic Voltammetry, and White Light Interferometers were used to analyze the chemical properties and physical properties, then, we used these composite films as an electrode of Dye-sensitized solar cells. Finally, I imitate the system of the sun optic to test its efficiency. After the production of PANI/(Func.-)Graphene Composite Film, we were sure that the addition of graphene could enhance the ability of conducting and performed well in electrochemistry test. And the best condition of opto-electronic conversion efficiency is 0.3%PANI/Graphene and 0.5%PANI/Func.-graphene, both kind of composite film could promote the efficiency much higher than pure PANI.

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38

Wang, Wen Chyuan, et 王文銓. « The Study of ZnSe/GaAs Heterojunction Opto-Electronic Devices by Using CVD ». Thesis, 2001. http://ndltd.ncl.edu.tw/handle/95629600646793916332.

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碩士
國立海洋大學
電機工程學系
89
In this thesis, the ZnSe epilayers were grown on an oriented-(100) GaAs substrate using low cost furnace CVD system. The ZnSe epilayer were analyzed by using SEM, SIMS, XRD, and PL measurements. Because there is approximately 0.27% lattice mismatch only between ZnSe and GaAs substrate, the surface morphology of the ZnSe epilayer is smooth, the distribution of the main elements is uniformity and the ZnSe epilayer is to a single crystal. From the PL measurement at 10K for the ZnSe epilayer, it indicates the NBE excitation emission is at 443nm(2.78eV). With the increasing of the temperature, the intensities of the NBE peak decrease and the FWHM becomes broader. Then it shifts toward longer wavelengths region. For the In-doped ZnSe epilayer, the D1 peak at 456nm(2.73eV) can be observed due to the In atoms replace the Zn sites that induce the transition between a shallow donor and the valence band level. We utilized the n-ZnSe epilayer to fabricate the ZnSe/GaAs HBT. The current gain of ZnSe/GaAs HBT is 5.8. In addition, we also utilized the n-ZnSe epilayer to fabricate Au-ZnSe/GaAs planar metal-semiconductor-metal photodetectors for optoelectronic integration of short-wavelength components. The Au-ZnSe/GaAs MSM-PD without any passivation and antireflection coating exhibits the photo-responsivity is 3.41A/W at 470nm light wavelength, and bias at 10V. In order to improve the sensitivity of Au-ZnSe/GaAs MSM-PD, we integrated Au-ZnSe/GaAs MSM-PD and ZnSe/GaAS HBT in one chip. The signal of Au-ZnSe/GaAs MSM-PD can be amplified by ZnSe/GaAS HBT to raise the photo-responsivity. It demonstrated the studying of integrated photodetectors and amplifiers based on ZnSe grown on GaAs substrate are useful to develop low cost blue light opto-electronic devices and have a great potential for the applications of the short wavelength OEIC.

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Chien, Mao-Hsiung, et 簡茂雄. « Investigation of ZnSe on GaAs Substrate for Heterojunction Opto-Electronic Devices Using Chemical Vapor Deposition ». Thesis, 2000. http://ndltd.ncl.edu.tw/handle/08853004122068253591.

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碩士
國立海洋大學
光電科學研究所
88
In this thesis, the ZnSe epilayers were grown on an oriented-(100) GaAs substrate using low cost furnace CVD system. The ZnSe epilayer were analyzed by using SEM, SIMS, XRD, and PL measurements. Because there is approximately 0.27% lattice mismatch only between ZnSe and GaAs substrate, the surface morphology of the ZnSe epilayer is smooth, the distribution of the main elements is uniformity and the ZnSe epilayer is to a single crystal. From the PL measurement at 13K for the ZnSe epilayer, it indicates the NBE excitation emission is at 446nm(2.78eV). With the increasing of the temperature, the intensities of the NBE peak decrease and the FWHM becomes broader. Then it shifts toward longer wavelengths region. For the In-doped ZnSe epilayer, the D1 peak at 454nm(2.73Ev) can be observed due to the In atoms replace the Zn sites that induce the transition between a shallow donor and the valence band level. ZnSe/GaAs planar metal-semiconductor-metal photodetectors are promising candidates for optoelectronic integration of short-wavelength components. The Au-ZnSe/GaAs MSM-PD and ITO-ZnSe/GaAs MSM-PD photodetector without any passivation and antireflection coating exhibits the photo-responsivity are 4.89A/W and 5.75A/W respectively at 470nm light wavelength , 10V bias. The fabricated photodetector has the strongest photo-responsivity in the wavelength of 470nm. The results demonstrate the studying ZnSe/GaAs MSM photodetector will be suitable for the applications of the short wavelength photo-detectors. We can measurement yielded an FWHM of 16ns and 15ns for a bias voltage of 10V. In addition, the novel structure of self-aligned ZnSe/GaAs heterojunction photo-transistor also reveals the strong photo-responsivity in 470nm. It demonstrated the studying of photodetectors based on ZnSe grown on GaAs substrate are useful to develop low cost short wavelength blue light opto-electronic devices and have a great potential for the applications of the short wavelength OEIC.

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Wu, Kun-Tai, et 吳坤泰. « Investigation of ZnSe/Si Heterojunction Opto-Electronic Devices By Using IR Furnace Chemical Vapor Deposition ». Thesis, 1998. http://ndltd.ncl.edu.tw/handle/10040727614414982668.

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碩士
國立海洋大學
電機工程學系
86
In this thesis, the ZnSe epilayers were grown on an oriented-(111) Si substrate by using IR furnace CVD system and two-step growth process to overcome the approximately 4.1% lattice mismatch between ZnSe and Si substrate. The ZnSe epilayer were analyzed by using SEM, SIMS, XRD, and PL measurements. The surface morphology of the ZnSe epilayer is smooth, the distribution of the main elements are uniformity and the ZnSe epilayer approaches to a single crystal. From the PL measurement at 10K for the ZnSe epilayer, it indicates the NBE excitation emission is at 444nm(2.793eV). With the increasing of the temperature, the intensities of the NBE peak decrease and the FWHM becomes broader. Then it shifts toward longer wavelengths region. For the In-doped ZnSe epilayer, we observe the D1 peak is at 452nm due to the In replace the Zn site induce the transition between a shallow donor and the valence band level. The optimum ZnSe epilayers can be achieved successfully to fabricate the devices of the Schottky barrier diodes and heterojunction bipolar transistor. The carrier concentration of the ZnSe epilayer and the barrier heights of the ZnSe/Si Schottky barrier diodes with various Schottky metals were estimated by the I-V and C-V measurement. In addition, the Au-ZnSe/Si Schottky photodiode exhibits strong responsivity in 450nm. The common-emitter current gain for the novel structure of self- aligned ZnSe/Si HBT is high about 28. And the ZnSe/Si heterojunction photo-transistor also reveals the strong photo-responsivity in 470nm. It demonstrated the studying of photodetectors based on ZnSe grown on Si substrate are useful to develop low cost short wavelength blue light opto- electronic devices and have a great potential for the applications of the short wavelength OEIC.

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Sriram, Pavithra, et 沛維翠. « Hybridizing Rigid and Flexible Plasmonic Devices with 2D- Transition Metal Dichalcogenides for Energy and Opto-Electronic Applications ». Thesis, 2018. http://ndltd.ncl.edu.tw/handle/kjsggb.

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42

Liao, Chung-Chi, et 廖崇吉. « Properties of coupled surface plasmon polaritons in metal-dielectric-metal structures and their potential application in opto-electronic devices ». Thesis, 2014. http://ndltd.ncl.edu.tw/handle/44547676271748911915.

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博士
國立臺灣科技大學
電子工程系
102
In this thesis, the properties of surface plasmon-polaritons (SPPs) in symmetrical metal-dielectric-metal (MDM) structures were investigated and their applications in opto-electronic devices were realized. The numerically obtained dispersion relations are found to be highly tunable by varying the dielectric thickness and to cross the left of air light line, which indicates the SPPs are radiative in specific condition. The emission properties of an organic layer embedded in a metal-organic-metal (MOM) structure were investigated. Because of the competition by the radiative SPW in MOM structure, the population of excitons that recombine to form non-radiative SPW should be reduced. This may account for why the MOM sample photoluminescence peak intensity is about four times that of the single-metal sample. In addition, due to simultaneous excitation of the organic fluorescence emission and the radiative SPPs in MOM sample and the latter emission wavelength is tunable by varying the middle organic layer thickness, the color-tunable mixed photoluminescence form MOM sample were hence achieved. A surface plasmon resonance (SPR) scheme with prism/metal/dielectric/metal/analyte structure was developed. The surface plasma wave (SPW) dispersion curves within the MDM structure can be controlled by tuning the dielectric layer thickness. Therefore, the properties of the SPWs on the sensing surface of the SPR sensor can be tuned by coupling between them. The proposed tuning procedure was based on the tendency for anticrossing formation to occur between two non-parallel dispersion curves, and the reduction in the angular dip widths of the SPR sensors using the proposed procedure was demonstrated both numerically and experimentally. In addition, two surface plasma resonant modes are simultaneously excited in the SPR sensor. One of them is highly sensitive to the change in the optical constant of analyte, while the other is barely influenced by that change and then can be a reference signal to remove any drift caused by mechanical and physical disturbance. Thus, we may obtain a stable, real signal from the differential output between them.

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Washington, Andrew L. « Surfactant assisted electrospinning of conjugated poly-p-phenylenevinylene derivatives for opto-electronic devices ; electrospinning water-soluble polymers for paper applications / ». 2006. http://proquest.umi.com/pqdweb?did=1273119321&sid=1&Fmt=2&clientId=10361&RQT=309&VName=PQD.

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44

Lee, Kuo-Chung, et 李國忠. « Temperature Compensation Techniques for High Temperature Rapid Thermal Processor and Fabrication of Si Opto-Electronic Devices Utilizing Room Temperature Processes ». Thesis, 1998. http://ndltd.ncl.edu.tw/handle/58915986913867458572.

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博士
國立臺灣大學
電機工程學系
86
The main topic of this thesis is to discuss the Si dioxide related technologies. The thesis consists of two main parts. The first part is high temperature rapid thermal related oxide. The second part is the fabrication of Si opto-electronic devices utilizing room temperature process. For the first part, we discuss the temperature compensation techniques for high temperature rapid thermal processor in chapter 2. We put monitor wafers on different susceptors, such as quartz susceptor, Si susceptor or Si rings on Si susceptor. The monitor wafers'' oxide thickness distribution behave different for different susceptors. The role of Si rings is different for different susceptors. In a transparent susceptor with poor thermal conductivity such as planar quartz, Si rings work as radiation barrier to prevent heat radiation loss through quartz susceptor. In a susceptor with good thermal conductivity such as Si, Si rings work as heat conductive media to transfer heat from monitor wafer to susceptor. In chapter 2, we also do numerical simulations to analyze the monitor wafers'' temperature distributions with different designed patterned susceptors. When using Si rings as patterned susceptor, although the monitor wafers'' front surface temperature distributions can be improved, their back surface temperature distributions show very large temperature gradients. In order to improve the monitor wafers'' back surface temperature distribution, we designed back patterned Si susceptor as temperature compensator. We found that when using back patterned Si susceptor as temperature compensator, except the monitor wafers'' front surface temperature distributions can be improved, their back surfaces sustain much smaller temperature gradients. In chapter 3, we use irradiation-then-nitridation (ITN) method to improve the radiation hardness of MOS gate dielectrics. The ITN process will introduce more nitrogen at the SiO2/Si interface. Since the existence of strong Si-N bonds at the SiO2/Si interface, oxynitrides exhibit better performance and are more reliable than conventional oxides. It appears that more nitrogen atoms can be incorporated into oxides by ITN method. The ITN treated samples are more radiation hard than those nitrided in N2O directly. For the second part, we fabricate Si opto-electronic devices utilizing room temperature process. We use saturated H2SiF6 to deposit SiO2 (liquid phase deposited SiO2) to fabricate opto-electronic devices, or adding HCl into the non-saturated H2SiF6 to etch the Si into porous structure to fabricate opto-electronic devices. In chapter 4, we study the electrical properties of the liquid phase deposited (LPD) SiO2. The electrical properties of LPD SiO2 grown on native or on bare Si are much different. The larger tunneling current for LPD SiO2 grown on bare Si may be due to the surface roughness and the boundaries between oxide seeds'' domains. The existed negative charges will also affect the MOS diodes'' reverse biased dark current. In chapter 5, we use the LPD SiO2 to fabricate the MOS solar cells. First, we fabricate the edge-illuminated LPD MOS solar cells. With a series combination of 120 pieces edge-illuminated LPD MOS solar cells, high open circuit voltages of 25~33 V can be obtained in a small area. Second, we fabricate the planar LPD MOS solar cells. For the LPD SiO2 grown on native oxide, the MOS solar cells perform worse. For the LPD SiO2 grown on bare Si, the MOS solar cells perform well. For the best performed LPD MOS solar cells, the LPD SiO2 thickness ranges from 4.5 nm to 5.0 nm. With additional thin transparent Al film on the exposure area, the solar cells'' parameters are all improved. The optimal thin transparent Al thickness is about in the range between 4.0 nm to 5.0 nm. Trap-assisted tunneling and photoconductivity properties of LPD SiO2 are found. The thicker oxide thickness makes the LPD SiO2 MOS solar cells to be more reliable than conventional MIS ones. In chapter 6, we add HCl into the non-saturated H2SiF6 to etch the Si into porous structure. This kind of porous Si called stain etched porous Si. Photo-luminescence and electro-luminescence properties of this stain etched porous Si can be found. We also oxidize the stain etched porous Si in the rapid thermal processor or in the furnace. For the rapid thermal oxidized porous oxide, the thicker the initial porous Si is, the smaller the porous oxide dielectric breakdown field behaves. However for the furnace oxidized porous oxide, the dielectric breakdown field is much larger than the conventional oxide. This is due to the electron traps exist in the furnace oxidized porous oxide. In addition, the trapped electrons in the furnace oxidized porous oxide can be "erase out" or "re-write" into the oxide by the biased voltage. This property of furnace oxidized porous oxide has the potential to be used as the material of gate dielectrics for nonvolatile memory''s applications.

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45

鄧順達. « Opto-electronic Device and their application in plane Display ». Thesis, 2003. http://ndltd.ncl.edu.tw/handle/58337175341051254866.

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碩士
長庚大學
半導體科技研究所
91
Abstract Most of the liquid crystal display market is covered by AM-LCD using amorphous silicon TFT (a-Si TFT) as a switch device for each pixel in recent years. The mobility of a-Si TFT, which is 0.5 ~ 1.0 cm2/Vs, drives each pixel sufficiently. The poly-Si TFT with its mobility as high as 30 ~ 500 cm2/Vs and high driving ability enable to integrate various circuit for many applications. Recently, poly silicon TFTs directly fabricated on plastic substrates has been investigated. Plastic substrates have the advantages of low cost, light- weighted, thin-shaped, and rugged characteristics. Although plastic substrates have several advantages, but the use of plastic substrates involves a lot of technological challenges. Examples include low working temperature and weakly bonded films. The highest working temperature for plastic substrates are around 250℃, which limits the maximum processing temperature. Therefore, we must employ a low temperature process and strong bonded films to fabricate poly-silicon thin films on plastic substrates Low temperature polycrystalline silicon has been prepared by XeCl excimer laser annealing (ELA) of amorphous silicon film on silicon, glass and plastic substrate. It analyze the size of polysilicon varied with laser energy density, number of laser shots, and moving velocity. Abstract The groups III-nitride semiconductors, especially Gallium nitride (GaN), have been successfully employed to realize blue-green light-emitting diodes, blue laser diodes and UV light source. The growth and characteristics of the III-V nitrides semiconductor that consist of undoped GaN, n-type GaN, p-type GaN, AlGaN and InGaN/GaN MQW had been systematically studied. Using MOCVD techniques, the InGaN/GaN MQW green and blue LEDs were successfully fabricated. From the results of the photoluminescence (PL) measured at 325nm He-Cd laser, the X-Ray diffraction (XRD) measurement, hall measurement and optics microscope (OM) views to realize the characteristic. On the other hand, the InGaN/GaN MQW blue LED were also discussed in this chapter. The output power were 8mW. The peak wavelength range were 445~480nm.

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Pádua, Ana Carolina Correia da Silva. « Design and assembly of an opto-electronic device for artificial olfaction ». Doctoral thesis, 2020. http://hdl.handle.net/10362/108950.

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47

In, Ho Chi, et 何梓賢. « Self-aligned coupling between optical fiber and opto-electronic device on Si-submount ». Thesis, 1995. http://ndltd.ncl.edu.tw/handle/87766526852803675627.

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碩士
國立交通大學
電子物理學系
83
A simple and useful Si-Submount was constructed and used to finished the coupling between an opto-electronic device and an optical fiber. Submount is made of Si(100)-wafer, in according to the mature silicon fabrication technique. One of its significant function, self-alignment, was to reduce the time consuming during active alignment which was required in case light coupling into an fiber-core. Testing on the accuracy of self-alignment was performed with the submount we made and LED devices. Finally, we conduct the whole self-aligned packaging among SEL device, submount and optical fiber, and obtained an coupling efficiency up to 90％.

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48

Sung, Duen-Ren, et 宋敦仁. « Using a three-dimensional opto-electronic device to evaluate low-temperature thermoplastic cervical orthoses ». Thesis, 1994. http://ndltd.ncl.edu.tw/handle/77278141186524353477.

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碩士
國立成功大學
醫學工程學系
82
Cervical spine immobilization devices are widely used to stabilize the cervical spine and prevent neurological deficits associated with unstable fracture. A large variety of cervical orthoses is available and may be divided into four basic groups. In this study, we used a low temperature thermoplastic material like Aquaplast to make a newly modified custom- molded cervical collar. The aim of this study is to quantify their efficiency, using a opto-electronic device. Eight healthful male volunteers were instructed to actively move their necks as much as possible in the directions of flexion, extension, lateral bending and axial rotation while upright sitting. We used a four-camera opto-electronic device (Selspot) to evaluaate the collar.The mean percentage of normal motion of head to thorax allowed are 12.5% flexion, 41.6% extension, 31.5% bending, and 7.5% rotation.

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Parashar, Piyush Kumar. « Plasmonic silicon solar cells : influence of metal and hybrid nanostructured layers on opto-electronic properties on the device ». Thesis, 2018. http://localhost:8080/xmlui/handle/12345678/7571.

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Yang, Chu-Shou, et 楊祝壽. « Growth, physical properties and fabrication of the opto-electronic device of II-VI compound semiconductor self-assembled quantum dots ». Thesis, 2003. http://ndltd.ncl.edu.tw/handle/h84efe.

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博士
中原大學
應用物理研究所
91
Epilayers, quantum dots, and light emitting diode structures, which were made of the binary and ternary II-VI compound semiconductors, were grown by the molecular beam epitaxy. The reflectivity, photoluminescence, high pressure Raman scattering, ambient and high-pressure x-ray diffraction measurement, and atomic force microscopy were used to investigate the interesting physical properties. Five topics were studied. Firstly, the lattice vibration of the ZnSe1-xTex epilayers was investigated. The dependence of the longitudinal optical (LO) and transverse optical (TO) phonon frequency on the Te concentration was found to follow previous theoretical predictions. However, an additional vibration mode was observed at the energy between that of the LO and TO phonons. The microscopic force constants FZnTe and FZnSe were evaluated to be 6.46×106 amu•(cm-2) and 2.91×106 amu•(cm-2), respectively. In addition, the Raman spectra were recorded at high pressure up to 20 GPa. The pressure at which the semiconductor to metal transition occurred was characterized by the disappearance of the LO phonon and was found to decrease with the Te concentration. Current results imply the decreasing crystal stability with the Te concentration. Secondly, from the high pressure x-ray measurement, it was found that the zinc blende (ZB) to rock salt (RS) phase transition pressures of the Zn0.93Mn0.07Se and Zn0.76Mn0.24Se bulk crystals are around 11.8±1.5 GPa and 9.9±0.5 GPa, respectively. Their respective bulk moduli are 61.8±0.8 GPa and 62.4±0.8 GPa. The pressure-induced ZB to RS structure phase transition is proposed as a signature of the semiconductor to metal transition for Zn1-xMnxSe. The above proposal is further corroborated by the observation of the disappearance of the longitudinal optical (LO) phonon at the pressure where the ZB to RS structure transition occurs. Thirdly, the effect of substrate misorientation angle (SMA) on the band gap energies of the II-VI compound semiconductor epilayers, Zn1-xMgxSe, Zn1-xMnxSe, ZnSe1-xTex, Zn1-xCdxSe and ZnSe1-xSx, was studied by the optical spectroscopy. The band gap energies were found to increase with the substrate misorientation (tilting) angle for the Zn1-xMgxSe, ZnSe1-xTex, Zn1-xCdxSe, and ZnSe1-xSx epilayers. For the Zn1-xMnxSe epilayers, however, the band gap energies decrease with SMA. Both the decrease (for the Zn1-xMnxSe epilayers) and increase (for the other epilayers) in band gap energy were attributed to the increasing incorporation of smaller ion as the SMA was increased. The dependence of energy gap on SMA is almost linear for the ZnSe1-xTex and Zn1-xMnxSe epilayers. While, for the Zn1-xMgxSe and Zn1-xCdxSe epilayers, the energy gap increases abruptly at small tilt angle, then becomes insensitive to the SMA at the tilting angle larger than 10 degrees. In the case of ZnSe1-xSx epilayers, the situation is opposite. At small angle, the band gap energy is almost not influenced by the SMA. At SMA larger than 10 degrees, the band gap energy increases suddenly. The sudden increase with the SMA at large tilting angle results from the abrupt increase in kink density which is a function of the square of tilt angle. The energy difference between the energy gap of the epilayer grown on (001) substrate and the energy gap of the epilayer grown on (001) substrate with 15 degrees tilt toward [010] is largest (18 meV) for the Zn1-xMgxSe epilayers. While, for the Zn1-xMnxSe, ZnSe1-xSx and ZnSe1-xTex epilayers, the energy differences are about 5 meV. Fourthly, the morphology and the size dependent PL spectra of the type II ZnTe QD grown in the ZnSe matrix were obtained. The coverage of ZnTe was varied from 2.5 to 4.0 mono-layers (MLs). The PL peak energy is found to decrease with the dot size. For the 2.5 and 3.0 MLs samples, the PL peak energy decreases monotonically with the increasing temperature. However, for the 3.5 MLs sample, as the temperature is increased, the PL peak energy exhibits blue shift first then red shift as the temperature is increased above 40K. Carrier thermalization and carrier transfer between QDs are used to explain the experimental data. Temperature dependent line width broadening model is employed to fit the high temperature data. The activation energy, which was found by the simple PL intensity quenching model, of the 2.5, 3.0, and 3.5 MLs are 6.35, 9.40, and 18.87 meV, respectively. Finally, the orange light emitting diodes (LEDs) have been successfully fabricated by using the type II ZnTe QDs. The LEDs structure, which coupled with the ZnCdSe quantum well in the active layer, has a higher luminescence efficiency than that one without ZnCdSe quantum well. The room temperature electroluminescence of the LEDs emits wavelengths at 582.1 and 629.3 nm. The turn on voltage decreases with the thickness of active layer.

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