Dissertations / Theses on the topic 'Thin film studies'
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McKinley, Iain Stewart. "Studies in thin film flows." Thesis, University of Strathclyde, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.366911.
Full textBoff, Arthur. "Electrochemical studies of thin-film diamond." Thesis, University of Oxford, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.496830.
Full textInameti, E. E. "Thermal studies of thin film fuses." Thesis, University of Nottingham, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.234026.
Full textUllah, Hanif. "Simulation studies of photovoltaic thin film devices." Doctoral thesis, Universitat Politècnica de València, 2015. http://hdl.handle.net/10251/48800.
Full textUllah, H. (2015). Simulation studies of photovoltaic thin film devices [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/48800
TESIS
Yoshiikawa, Osamu. "Studies on organic thin film solar cells." Kyoto University, 2009. http://hdl.handle.net/2433/123895.
Full text0048
新制・課程博士
博士(エネルギー科学)
甲第14742号
エネ博第195号
新制||エネ||44(附属図書館)
UT51-2009-D454
京都大学大学院エネルギー科学研究科エネルギー基礎科学専攻
(主査)教授 八尾 健, 教授 石原 慶一, 教授 辻井 敬亘
学位規則第4条第1項該当
Gu, Erdan. "Studies in thin film systems and X-ray multilayer film design." Thesis, University of Aberdeen, 1992. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU547604.
Full textNewson, Pamela Lynn. "Studies of diamond film formation." Diss., Georgia Institute of Technology, 1997. http://hdl.handle.net/1853/30529.
Full textBarnes, Jean-Paul L. P. Barnes. "TEM studies of thin film oxide/metal nanocomposites." Thesis, University of Oxford, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.398136.
Full textWhyte, Alex. "Thin film studies of planar transition metal complexes." Thesis, University of Edinburgh, 2013. http://hdl.handle.net/1842/7966.
Full textSethu, Murugesan. "Performance studies of thin film electroluminescent (TFEL) devices." Thesis, Nottingham Trent University, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.250453.
Full textSainju, Deepak. "Spectroscopic Ellipsometry Studies of Ag and ZnO Thin Films and Their Interfaces for Thin Film Photovoltaics." University of Toledo / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1430326934.
Full textSugimoto, Yoshiharu. "Studies of CdTe electrodeposition." Thesis, University of Southampton, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.241263.
Full textTetali, Bhaskar Reddy. "Stability studies of CdTe/CdS thin film solar cells." [Tampa, Fla.] : University of South Florida, 2005. http://purl.fcla.edu/fcla/etd/SFE0001135.
Full textPinitsoontorn, Supree. "3D atom probe studies of thin film magnetic materials." Thesis, University of Oxford, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.492054.
Full textLoh, Kian Ping. "Growth studies and surface modification of thin film diamonds." Thesis, University of Oxford, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.320658.
Full textMarcham, Max Ken. "Phase-resolved ferromagnetic resonance studies of thin film ferromagnets." Thesis, University of Exeter, 2012. http://hdl.handle.net/10036/3882.
Full textRose, John. "Nanomagnetic and nanostructural studies of thin film magnetic systems." Thesis, University of Glasgow, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.241740.
Full textChang, Shang-wen. "Cu₂S/ZnCdS thin film heterojunction solar cell studies." Diss., Virginia Polytechnic Institute and State University, 1985. http://hdl.handle.net/10919/54740.
Full textPh. D.
Giri, Dipak. "Single-molecule spectroscopic studies of thin-film chemical gradients." Diss., Kansas State University, 2016. http://hdl.handle.net/2097/35225.
Full textDepartment of Chemistry
Daniel A. Higgins
This dissertation describes the application of single molecule spectroscopy and tracking to investigations of the nanoscale properties of thin-film chemical gradients and the transport dynamics of molecules dispersed within and upon these gradients. Chemical gradients are surface bound materials that incorporate gradually changing chemical and/or physical properties. A continuous and gradual change in the properties of gradients are expected and often required for their intended applications, which range from directed growth of cell colonies to combinatorial materials science. In reality, such conditions are almost never met due to spontaneous demixing and dewetting processes that can lead to properties variations on microscopic length scales. A better understanding on the properties of chemical gradients on microscopic length scales will aid in the production of better engineered materials. Single molecule spectroscopy (SMS) allows for gradient properties to be probed on nanometer-to-micrometer length scales. In this dissertation, quantitative measurements of gradient polarity (i.e., dielectric properties) are made along a sol-gel derived thin film that incorporates a macroscopic polarity gradient. These measurements report on the microscopic heterogeneity of the gradient film, and point to the occurrence of phase separation of the polar and nonpolar components along the gradient. Single molecule tracking (SMT) provides an important means to examine the dynamics of molecular mass transport in thin films and on surfaces. In this dissertation, SMT is employed to study mass transport in thin water films condensed over monolayer wettability gradients under ambient environments. The results show that the rate and the mechanism of molecular transport depend on the surface wettability, and on the ambient relative humidity. Finally, wettability gradients have been broadly used to drive the transport of liquid droplets. In this dissertation, these applications are extended to achieve spontaneous stretching of DNA by the propulsion of liquid droplets along the gradient. Single molecule fluorescence imaging of DNA stretched along these gradients demonstrates that hydrophobic surfaces play an important role in DNA stretching. The study also shows the surface tension force acting at the gradient-droplet contact line (interface) to be responsible for DNA elongation and alignment. Overall, single molecule methods have been shown to be highly useful for better understanding the properties of chemical gradients as described in this dissertation.
Morris, I. D. "Radiofrequency studies at low and intermediate temperatures." Thesis, University of Oxford, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.236305.
Full textHatton, Hilary J. "Magnetic and structural studies of nanoscale multilayer and granular alloy systems of Ag and FeCo." Thesis, University of Sheffield, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.286916.
Full textLi, Zuoli. "Studies of Thin Liquid Films Confined between Hydrophobic Surfaces." Diss., Virginia Tech, 2012. http://hdl.handle.net/10919/49557.
Full textIt is believed that the water molecules in the thin liquid films (TLFs) of water form clusters as a means to reduce their free energy when they cannot form H-bonds to neighboring hydrophobic surfaces. Dissolved gas molecules should enhance the stability of structured cluster due to the van der Waals force between the entrapped gas molecules and the surrounding water molecules1, which may enhance the strength of the hydrophobic force. Weaker long-range attractive forces detected in degassed water than in air-equilibrated water was found in the present work by means of AFM force measurements, supporting the effect of dissolved gas on the structuring of water. At last, temperature effects on hydrophobic interactions measured in ethanol and the thermodynamic analysis revealed similar results as those found in water, indicating that the hydrophobic force originates from H-bond propagated structuring in the mediums. •
Ph. D.
Kowarik, Stefan M. "Real-time studies of thin film growth of organic semiconductors." Thesis, University of Oxford, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.437357.
Full textCole, Alexander Alan. "Studies of spin dependent transport in magnetic thin film heterostructures." Thesis, University of Leeds, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.414159.
Full textRocha, Luciana Sarabando da. "Thin mercury film electrodes in dynamic speciation studies of metals." Doctoral thesis, Universidade de Aveiro, 2009. http://hdl.handle.net/10773/3083.
Full textNo presente trabalho, foi avaliado o desempenho e a aplicabilidade do eléctrodo de filme fino de mercúrio, em estudos de especiação dinâmica de metais vestigiais. Para tal, foram utilizadas duas técnicas electroanalíticas de redissolução: a clássica Voltametria de Redissolução Anódica (ASV) e a recentemente desenvolvida, Cronopotenciometria de Redissolução com varrimento do potencial de deposição (SSCP). As propriedades de troca-iónica e de transporte de massa de películas mistas preparadas a partir de dois polímeros com características distintas, o Nafion (NA) e o 4-Poliestireno sulfonato de sódio (PSS), foram avaliadas, antes da sua aplicação no âmbito da especiação de metais. Estas películas de NA-PSS demonstraram uma elevada sensibilidade, reprodutibilidade, estabilidade mecânica, bem como, propriedades de anti-bloqueio adequadas na modificação química do eléctrodo de filme fino de mercúrio (TMFE) e, na sua aplicação na determinação de catiões metálicos vestigiais em amostras complexas, por ASV. Para além disso, o desempenho de membranas do polielectrólito PSS em estudos de voltametria de troca-iónica (IEV) foi estudado. O objectivo desta investigação foi reunir as condições ideais na preparação de películas de PSS estáveis e com uma densidade de carga negativa elevada, de modo a aumentar a acumulação electrostática de catiões metálicos no filme polimérico e por conseguinte, conseguir incrementos no sinal voltamétrico. O desempenho e aplicabilidade do TMFE em estudos de especiação de metais vestigiais foram extendidos à SSCP como técnica analítica. Dada a elevada sensibilidade e resolução evidenciada pelo TMFE, este revelou ser uma alternativa adequada aos eléctrodos de mercúrio convencionais, podendo ser utilizado durante um dia de trabalho, sem degradação aparente do sinal analítico de SCP. As curvas de SSCP obtidas experimentalmente utilizando o TMFE estavam em concordância com aquelas previstas pela teoria. Para além disso, a constante de estabilidade (K) calculada a partir do desvio do potencial de meia-onda, para dois sistemas metal-complexo lábeis, aproxima-se não só do valor teórico, como também daquele obtido utilizando o eléctrodo de mercúrio de gota suspensa (HMDE). Adicionalmente, o critério experimental de labilidade inerente a esta técnica foi validado e o grau de labilidade para um dado sistema metal-complexo foi determinado, utilizando o filme fino de mercúrio depositado sob um eléctrodo rotativo (TMF-RDE). Este eléctrodo é muito útil na determinação de parâmetros cinéticos, como é o caso da constante de velocidade de associação (ka), uma vez que as condições hidrodinâmicas, durante a etapa de deposição, se encontram bem definidas.
In the present work the performance and applicability of the thin mercury film electrode (TMFE) in the dynamic speciation of trace metals was investigated. Two different electroanalytical stripping techniques were used: the classical anodic stripping voltammetry (ASV) and a recent developed technique, scanning stripping chronopotentiometry (SSCP). The ion-exchange and the mass transport features of novel mixed coatings of two sulfonated cation-exchange polymers with dissimilar characteristics, Nafion (NA) and poly(sodium 4-styrenesulfonate) (PSS) were evaluated, prior to its application in the field of trace metal analysis. Suitable NA-PSS polymer coatings could be used in the modification of TMFE, presenting a high sensitivity, reproducibility, mechanical stability and adequate antifouling properties in the ASV determination of trace metal cations in complex media. Also the features of the PSS polyelectrolyte layers for ion-exchange voltammetry (IEV) were evaluated. The goal was to search for the best conditions to obtain stable PSS coated electrodes, which could present high negative charge densities in order to enhance the electrostatic accumulation of cations within the film, thus enlarging the ASV signal. The applicability and performance of the TMFE in the trace metal speciation studies, by SSCP, were for the first time exploited. The optimized TMFE presented a high sensitivity and resolution, being an excellent complement to the conventional mercury electrodes and could be use for 1-day term with no significant variation in the SCP analytical signal and no apparent degradation. The calculated SSCP curves were in excellent agreement with experimental data at the TMFE and the stability constant (K), calculated from the shift in the SSCP half-wave potential, of two labile metal-complex systems were in good agreement with the ones obtained using the conventional Hanging mercury drop electrode (HMDE) and those predicted by theory . Additionally, the experimental lability diagnosis inherent to the SSCP technique was validated and a rigorous quantification of the lability degree was made. Due to the well defined hydrodynamic conditions at the thin mercury film rotating disk electrode (TMF-RDE), during the deposition step, this electrode is quite valuable in the determination of kinetic parameters, like the association rate constants (ka).
Hu, Yanhong. "Molecular dynamics studies of thin film nucleation and substrate modification." [Gainesville, Fla.] : University of Florida, 2003. http://purl.fcla.edu/fcla/etd/UFE0000955.
Full textHudson, John Matthew. "Specular and diffuse X-ray scattering studies of surfaces and interfaces." Thesis, Durham University, 1994. http://etheses.dur.ac.uk/5516/.
Full textHarwood, N. M. "A neutron reflectivity study of thin films." Thesis, University of Reading, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.378329.
Full textGold, Jeffrey Stephen. "Characterization of a novel methyl radical source and related thin film growth studies." Morgantown, W. Va. : [West Virginia University Libraries], 2000. http://etd.wvu.edu/templates/showETD.cfm?recnum=1787.
Full textTitle from document title page. Document formatted into pages; contains xi, 108 p. : ill. (some col.) + appendix; 37 p. : ill. Includes abstract. Includes bibliographical references (p. 103-108; p. A-37).
Jarlöv, Asker. "Corrosion studies on multicomponent TiZrNbTa thin films." Thesis, Uppsala universitet, Strukturkemi, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-427555.
Full textNatsume, Yutaka. "Studies on Structures and Electronic Properties of Organic Thin Film Transistors." 京都大学 (Kyoto University), 2009. http://hdl.handle.net/2433/85402.
Full textSinha, Nipun. "Design, fabrication, packaging and testing of thin film thermocouples for boiling studies." [College Station, Tex. : Texas A&M University, 2006. http://hdl.handle.net/1969.1/ETD-TAMU-1824.
Full textMin, Byoung Koun. "Scanning tunneling microscopic studies of SiO2 thin film supported metal nano-clusters." Diss., Texas A&M University, 2004. http://hdl.handle.net/1969.1/2737.
Full textBanks, Daniel John. "Modelling studies on peripheral nerve neural signal transduction using thin-film microelectrodes." Thesis, University of Surrey, 1994. http://epubs.surrey.ac.uk/842690/.
Full textSimchi, Hamed. "Back surface studies of Cu(In,Ga)Se2 thin film solar cells." Thesis, University of Delaware, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=3642359.
Full textCu(In,Ga)Se2 thin film solar cells have attracted a lot of interest because they have shown the highest achieved efficiency (21%) among thin film photovoltaic materials, long-term stability, and straightforward optical bandgap engineering by changing relative amounts of present elements in the alloy. Still, there are several opportunities to further improve the performance of the Cu(In,Ga)Se2 devices. The interfaces between layers significantly affect the device performance, and knowledge of their chemical and electronic structures is essential in identifying performance limiting factors. The main goal of this research is to understand the characteristics of the Cu(In,Ga)Se2-back contact interface in order to design ohmic back contacts for Cu(In,Ga)Se2-based solar cells with a range of band gaps and device configurations. The focus is on developing either an opaque or transparent ohmic back contact via surface modification or introduction of buffer layers in the back surface.
In this project, candidate back contact materials have been identified based on modeling of band alignments and surface chemical properties of the absorber layer and back contact. For the first time, MoO3 and WO 3 transparent back contacts were successfully developed for Cu(In,Ga)Se 2 solar cells. The structural, optical, and surface properties of MoO 3 and WO3 were optimized by controlling the oxygen partial pressure during reactive sputtering and post-deposition annealing. Valence band edge energies were also obtained by analysis of the XPS spectra and used to characterize the interface band offsets.
As a result, it became possible to illuminate of the device from the back, resulting in a recently developed "backwall superstrate" device structure that outperforms conventional substrate Cu(In,Ga)Se2 devices in the absorber thickness range 0.1-0.5 µm. Further enhancements were achieved by introducing moderate amounts of Ag into the Cu(In,Ga)Se2 lattice during the co-evaporation method resulting in a 9.7% cell (with 0.3 µm thickness) which has the highest efficiency reported for ultrathin CIGS solar cells to date.
In addition, sulfized back contacts including ITO-S and MoS 2 are compared. Interface properties of different contact layers with (Ag,Cu)(In,Ga)Se2 absorber layers with various Ga/(Ga+In) and Ag/(Ag+Cu) ratios are discussed based on the XPS analysis and thermodynamics of reactions.
Dufton, Jesse T. R. "Computational studies of sulphide-based semiconductor materials for inorganic thin-film photovoltaics." Thesis, University of Bath, 2013. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.607142.
Full textBediako, Daniel Kwabena. "Structural and mechanistic studies of nickel-borate thin-film oxygen evolving electrocatalysts." Thesis, Massachusetts Institute of Technology, 2013. http://hdl.handle.net/1721.1/79266.
Full textCataloged from PDF version of thesis.
Includes bibliographical references.
Increases in global energy demand and rising levels of atmospheric carbon dioxide demand renewable alternatives to fossil fuels as the primary energy sources of the 21st century. Solar energy is by far the most abundant renewable energy resource, yet its widespread use has been hampered by a lack of suitable methods to store energy from sunlight in a cheap and efficient manner. Solar driven water splitting is a promising method of storing solar energy, but a critical bottleneck in developing efficient photoelectrochemical (PEC) water splitting systems lies in the kinetic sluggishness of the water splitting reactions, particularly the oxygen evolution reaction (OER). In this thesis the structural and mechanistic underpinnings for the activity of a promising nickel-based oxygen evolving catalyst (OEC) are discussed. The catalyst is particularly attractive as a result of the simplicity of its preparation as a thin film from aqueous borate-buffered solutions of Ni₂ . Electrochemical and in situ X-ray absorption near-edge structure (XANES) studies of this nickel-borate (Ni-Bi) catalyst indicate that upon initial electrodeposition, Ni centers in the film exist predominantly in the +3 oxidation state and the as-deposited material is largely inactive towards the OER. Catalytic activation is achieved by anodization of the as-deposited material in concentrated borate buffer, pH 9.2, a process which serves to oxidize the nickel centers to a mixed-valence Ni(II/IV) state. Extended X-ray absorption fine structure (EXAFS) spectroscopy studies indicate that Ni-Bi is comprised of nanometer-sized clusters of edge sharing NiO₆ octahedra. A structural transformation is observed during anodization that is akin to that observed in the [beta]-NiOOH-[gamma]-NiOOH transformation, challenging the long-held view that the phase that is the most catalytically active towards the OER is the all-Ni(III) [rho]-NiOOH. Electrokinetic studies indicate that the as-deposited Ni-Bi exhibits a Tafel slope close to 2.3 x 2RT/F, consistent with a turnover-limiting electron transfer (ET) from the geometrically distorted low-spin d⁷ Ni(III) state. Upon anodization to the mixed valence Ni(III/IV) state and elimination of geometric distortion, ET from the resting state becomes more facile resulting in a low Tafel slope of 2.3 x RT/2F, indicative of a rapid two-electron pre-equilibrium followed by a rate limiting chemical step, likely O₂ formation. Anodized Ni-Bi also exhibits an inverse third order dependence in proton activity and inverse first order dependence in borate anion. This kinetically-relevant two-electron, three-proton proton-coupled electron transfer (PCET) equilibrium prior to rate limiting O₂ formation forms the mechanistic basis for the pHdependent difference in activity between Ni-Bi and its cobalt-based analog, which contrarily mediates oxygen evolution via a kinetically-relevant one-electron, one-proton PCET transformation. The difference in catalytic O₂ evolution mechanism is a principal factor in the determination of the overall solar-to-fuels efficiency of PEC water splitting systems.
by Daniel Kwabena Bediako.
S.M.
Yang, Neng-Jye, and 楊能傑. "Studies on polymer thin film transistor." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/73628553819444921085.
Full textGokhale, Nikhil Suresh. "Studies On The Development Of Piezoelectric Thin Flm Based Impact Sensor." Thesis, 2008. http://hdl.handle.net/2005/770.
Full textLin, Jyu-Wun, and 林鉅文. "Studies of thin-film structural and electrical properties of F16CuPc-based thin-film transistors." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/17261671400125234664.
Full text國立成功大學
光電科學與工程研究所
96
In this study, the structural and electrical transport properties of n-type copper hexadecafluorophthalocyanine (F16CuPc) thin-films as an active layer were investigated using organic thin films transistors (OTFTs). In part 1, we studied the influence of substrate temperature during thin-film growth of F16CuPc on the electrical characteristics and hysteresis effects in OTFTs using indium-tin-oxide (ITO) bottom contact and bottom gate device configuration. In part 2, we studied the effects of polymeric modification layers on the F16CuPc film growth and structural properties. In part 1, we have fabricated OTFTs using the F16CuPc films which were thermally evaporated on different temperature SiO2 surfaces ranging from 30 to 180 ℃. The device characteristics were analyzed using the standard charge-sheet MOSFET model equation. These F16CuPc films were characterized by X-ray diffraction (XRD), absorption spectroscopy, and Raman spectroscopy. When the substrate temperature was set to 120 ℃, the corresponding F16CuPc-based OTFTs exhibit the highest field-effect mobility, the largest modulated on/off current ratio, the lowest subthreshold swing, and the smaller hysteresis loops. XRD and absorption spectra results could not give a reasonable explanation of the devices’ performance of F16CuPc-based OTFTs. In contrast, Raman analysis results indicated F16CuPc grown on 120 ℃ substrate has a more homogeneous molecular structure and microstructure associated with lower reorganization, thus device performance. In part 2, the structural properties of F16CuPc films grown on various polymeric modification layers were investigated using contact angle meter, XRD, absorption spectroscopy, and Raman spectroscopy. Upon analyzing the surface free energy and interfacial adhesive force between F16CuPc and polymeric surfaces, we suggest that polymethylmethacrylate (PMMA) and polystyrene (PS) are the effective modification layers for the growth of F16CuPc film. The thin film structures of F16CuPc on polymeric modification layers, e.g. PMMA, PS, and poly(vinyl alcohol) are better than that on native SiO2 surfaces.
Yang, Chao-Shun, and 楊朝舜. "Studies of Indium Oxide Thin Film Transistors." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/03240568000849623861.
Full text國立臺灣大學
電子工程學研究所
96
Recently, oxide semiconductors have gained much attention in the academia and the industry. Oxide semiconductors usually are of transparency owing to their wide band-gap characteristics and can be used in transparent electronics. Applications concerned have been developed in the market gradually. In addition, oxidesemiconductor-based thin film transistors can be fabricated on flexible substrates. Its flexibility can be used in a lot of novel consumer electronics and displays like LC displays、OLED displays and e-Paper etc. Oxide semiconductors have special electronic configuration of (n-1)d10ns0 (n≧4).Because of the symmetric s orbital, oxide semiconductor can attain high mobility in both crystalline and amorphous structures. Actually, oxide semiconductor thin films can be grown with good quality on a wide variety of substrates at low temperatures. In this thesis, the oxide semiconductor material studied is indium oxide. Indium oxide is used as the active material of TFTs in this thesis. In general, indium oxide thin films are very conductive, and thus many laboratories over the world have much difficulty in making indium oxide TFTs with low enough off currents and proper on/off current ratios. In the thesis, unique method is introduced to reduce the off currents dramatically. By using the unique method, the on/off ratios of our indium oxide TFTs are over 1000 times higher than results of other groups.
Yeh, Barry B. L., and 葉柏良. "Studies of ZnO Transparent Thin Film Transistors." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/49118233620143268790.
Full text國立暨南國際大學
電機工程學系
95
In this thesis, the transparent thin-film-transistor with ZnO thin films was fabricated. To deposit ZnO film, RF-magnetron sputtering was used with the different Ar:O2 gas flow, power, and working pressure. Then, the sample was annealing with different temperature. The material and electrical characterizations were performed by four-point-probe measurement, Hall-effect measurement, XRD analysis, spectrophotometer, and HP4156 semiconductor parameter analysis. The ZnO thin film depositied with the O2(0.5%) flow ratio exhibits the optimum (0002) orientation. The resistivity of ZnO thin film is around ~10-3 Ω-cm and the Hall measurements indicates that the carrier concentration of ZnO film was between 1020~1021cm-3, and the corresponding electron mobility was about 1.0~1.5 cm2/Vs, respectively. The device shows an average transmission (λ=400~700nm) of 81.3%, the saturation mobility μsat=1.0~1.5cm2/Vs, on-off ratio ~106, and the leakage current around 10-10A. The transparent thin film transistors can be suitable for the future flat panel display applications.
Liang, Xin-Wei, and 梁信偉. "Studies of surface morphology and thin-film polymorphs in pentacene film." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/34460032672636841401.
Full text國立成功大學
光電科學與工程研究所
95
In this study, device characteristics of polycrystalline pentacene-based organic thin-film transistors (OTFTs) were investigated. In part 1, we studied the traps and fixed charges at the interface between gate dielectric and pentacene by using an external magnetic field during device operations. In the second part, we studied the correlation between surface morphology and molecular vibrational characterizations of polycrystalline pentacene thin-films. Part 1: External magnetic field effects in pentacene-based organic thin-film transistors (OTFTs) during device operations were studied. Herein, we showed that the output drain current (IDS), field-effect mobility, and threshold voltage (Vth) of pentacene devices were affected by the presence of a magnetic field. The upward magnetic force made the holes drift away from the pentacene/dielectric interface and/or detrapping from the immobile states, contributing to a larger IDS and a positive shift in Vth and thus, carrier mobility. The magnetic field-induced variations in electrical characteristics of pentacene-based OTFTs were different from that of gate-induced and light-induced bias-stress effects, suggesting that extra carriers from unintentional doping may play an important role in organic TFTs’ electrical characteristics. Part 2: We studied the molecular vibrational characterizations of pentacene molecules in polycrystalline films with grain morphology using atomic force microscopy and Raman mapping measurements. We applied the micro-Raman spectroscopy to identify the molecular microstructures within the polycrystalline pentacene films, including C-H in-plane bending and C-C aromatic stretching modes in the energy range of 1140-1200 and 1300-1400 cm-1, respectively. We observed that the grain had stronger Raman intensities for all bands in the grain boundaries. At the same time, the relative intensity of 1155 (v1) and 1158 (v0) cm-1 bands was higher in those associated with a larger v0-v1 splitting in the grains than those in the grain boundaries. For polycrystalline films, the microstructures were more ordered (crystalline) in the grain and more disordered (amorphous) in the grain boundary. Consequently, we deduced that the relative intensity of v1 band and the v0-v1 splitting was proportional to the fraction of the ordered area or density of the well-defined crystal unit cell.
陳宏裕. "Studies on the electrodeposition of CuInSe2 thin film." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/90071975872783476109.
Full text國立高雄師範大學
化學系
90
CuInSe2 is one of the emerging materials for solar cell applications,and has received considerable attention in recent years.CIS-based solar cells showing conversion efficiencies of the order of 15% had been reported.They exhibit lone term stability without any signs of degradation.Of the techniques that have been used to fabricated thin films of material including,for example,spray, prolysis, sputtering , vacumn evaporation, selenization of metallic films and electrodeposition. Electrodeposition is of particular interest in offering the greatest potential in terms of low costs and inexpensive deposition system. In our experiment,CIS films were analyzed from chloride electrolyte by cyclic voltammetry.We focus on different stoichiometry of one ion and two different ions in deposition process.In addition,we study pH value, triethanolamine addition and different deposition potentials related to reduction current and oxidation current.Cyclic Voltammograms have been obtained to understand the structure of CIS film. The stoichiometric composition of deposited material is characterized by energy dispersive spectrometer studies.
Yeh, G.-J., and 葉光兆. "Studies of the coercivity spin valve thin film." Thesis, 1998. http://ndltd.ncl.edu.tw/handle/12312531141982483705.
Full textHuang, Wung-Ui, and 黃文鈺. "Studies of Fabricating a-Si:H Thin-Film Transistors." Thesis, 1998. http://ndltd.ncl.edu.tw/handle/91171639480293114701.
Full text國立中央大學
電機工程學系
86
In this study, the matrix of a-Si:H (thin-film transistors) were fabricatedon a 5 cm x 5 cm Corning 7059 glass substrate. The TFT matrix had 120 x 60 pixels and was made by using four levels of mask. To study the fabrication processes of TFTs, three topics were focused :(1) the light-penetrable TFT, (2)the light-reflective TFT, and (3) the Al-alloy gate materials in TFT. Since thedesigned mask defined source and drain pattern of TFT at the same level, so, the source and drain electrodes had the same conductive material. The light-penetrable TFT﹁ould have a transparent electrode material on source and drain regions. The transparent conductive ITO (indium-tin-oxide) waschosen as the electrode material. But, it had a poor ohmic contact to n+-a:Si:Hsource and drain layer. A thin Mo metal film added between the ITO and n+-aSi:H layers was emplyed to improve the ohmic contact, and hence the electrical characteristics of a TFT. The light-reflective TFT had light-reflective source and drain metal electrodes and the Al metal film was adopted in this work. Since, in the employed 4-masks TFT fabrication processes, an over-etching or under-etching ofn+-a-Si:H layer. The performances of this employed TFT were compared with thoseof a conventional TFT. Finally, several Al-alloies, such as Al-1 Nd, Al-2Nd, Al-Mo-B, Al-Cu-Ti-B, were used as the gate electrodes of TFTs and the characteristics of the obtained TFTs were compared with that of a TFT having Al gate electrode.
Chen, Bor Yir, and 陳伯宜. "STUDIES ON HYDROGENATED AMORPHOUS SILICON THIN-FILM TRANSISTORS." Thesis, 1995. http://ndltd.ncl.edu.tw/handle/37871854788960845465.
Full text呂俊億. "Optical studies of n-type InN thin film." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/m98582.
Full textChen, He-Sheng, and 陳和聲. "Property Studies of TiO2-CuxOy Thin Film Diodes." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/30917657470777404203.
Full text明志科技大學
材料工程研究所
99
Titanium dioxide in high-power process has a wide process window and better structural properties. The low-power process will not be able to get titanium dioxide structured. If the structural propertied of titanium dioxide was not good, then in this case will have a greater leakage current with this devise. The bandgap of Cu2O and Cu4O3 is about 2.25 eV and 1.7 eV in this experiment. Copper oxide and titanium dioxide will be produced diodes in a variety of conditions, the results show high-power process of titanium dioxide with Cu4O3 have best rectifying characteristics and photovoltaic effect. High-power process titanium dioxide film with Cu4O3 diode for the different test, the test results of photovoltaic efficiency show this result is about 0.15%, the conversion efficiency loss is because the low parallel resistance, and also because the relationship between the parallel resistance is too low lead sin-wave testing can’t be negative half-wave-type filter for full-wave rectifier test. At ESD test, the devise can live at 8kV electrostatic bombardment, but cause leak current lead the trigger voltage and clamping voltage properties not well.
Kuo, Dong-Lin, and 郭東霖. "Studies of ZnO-Based Transparent Thin-Film Transistor." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/42233240051946527537.
Full text國立成功大學
電機工程學系碩博士班
97
Abstract In this thesis, we demonstrate an all sputtering, all lithography technology process to fabricate low voltage operational, enhancement mode N-Type ZnO-TFT by using high-k material (Y2O3) as the gate oxide. The effects of different processing parameters of ZnO layer and device geometric structures to the electrical performance of device will be discussed in Chapter 4. We also did some applications of saving device area、driving OLED and fabricating TTFT array on glass substrate. Finally by improve the series resistance of TFT device, we fabricated devices had characters as field effect mobility (μFE) 6.5(cm2/V.s), ION/OFF~105, and Vth<5V. There are two parts in this thesis. In the first part, we discuss the ZnO-TFT characters when we use different sputtering parameters and structures. The thin film and devices were analyzed by XRD、AFM、SEM/EDS、C-V and I-V measurements. In the second part, by reducing the series resistance we can fabricate good performance TFT devices; finally, we fabricate a TTFT array of ZnO-TFT on glass substrate.