Dissertations / Theses on the topic 'Thin films'
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Han, Sanggil. "Cu2O thin films for p-type metal oxide thin film transistors." Thesis, University of Cambridge, 2018. https://www.repository.cam.ac.uk/handle/1810/285099.
Full textMackay, Ian. "Thin film electroluminescence /." Online version of thesis, 1989. http://hdl.handle.net/1850/10551.
Full textTam, Dickson Tai Shun. "An investigation on effect of Mn-doping on dielectric property of barium strontium stannate titanate." access abstract and table of contents access full-text, 2005. http://libweb.cityu.edu.hk/cgi-bin/ezdb/dissert.pl?msc-ap-b21175135a.pdf.
Full textAt head of title: City University of Hong Kong, Department of Physics and Materials Science, Master of Science in materials engineering & nanotechnology dissertation. Title from title screen (viewed on Sept. 4, 2006) Includes bibliographical references.
Yeung, Kwok Fai. "An investigation on effect of Mn-doping on dielectric property of barium strontium stannate titanate." access abstract and table of contents access full-text, 2005. http://libweb.cityu.edu.hk/cgi-bin/ezdb/dissert.pl?msc-ap-b21175317a.pdf.
Full textAt head of title: City University of Hong Kong, Department of Physics and Materials Science, Master of Science in materials engineering & nanotechnology dissertation. Title from title screen (viewed on Sept. 4, 2006) Includes bibliographical references.
Wallace, Anthony James. "Tin oxide thin films." Thesis, Brunel University, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.294556.
Full textPoulter, Mark W. "Pyroelectric organic thin films." Thesis, University of Oxford, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.303623.
Full textKamhawi, Khalid. "Transport in Thin Films." Thesis, Imperial College London, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.508624.
Full textBabkair, S. S. "Multilayer ferromagnetic thin films." Thesis, University of Salford, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.234564.
Full textHu, Xiao. "Ultra-thin oxide films." Thesis, University of Oxford, 2016. https://ora.ox.ac.uk/objects/uuid:d7373376-84f1-459e-bffb-f16ce43f02b7.
Full textCampbell-Rance, Debbie. "Electrodeposited Silica Thin Films." VCU Scholars Compass, 2010. http://scholarscompass.vcu.edu/etd/2123.
Full textMorris, Gareth David Morte. "Particle stabilised thin films." Thesis, Imperial College London, 2010. http://hdl.handle.net/10044/1/6206.
Full textCHIPMAN, RUSSELL ATWOOD. "POLARIZATION ABERRATIONS (THIN FILMS)." Diss., The University of Arizona, 1987. http://hdl.handle.net/10150/184051.
Full textRycroft, Ian M. "Electric, magnetic and optical properties of thin films, ultra thin films and multilayers." Thesis, University of Reading, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.318142.
Full textMorasch, Kevin R. "Nanoindentation induced thin film fracture." Online access for everyone, 2005. http://www.dissertations.wsu.edu/Thesis/Spring2005/k%5Fmorasch%5F042605.pdf.
Full textRen, Huilin. "Current Voltage Characteristics of a Semiconductor Metal Oxide Sensor." Fogler Library, University of Maine, 2001. http://www.library.umaine.edu/theses/pdf/RenH2001.pdf.
Full textMasson, Jean-Loup Didier. "Pattern formation and evolution in thin polymer films." Access restricted to users with UT Austin EID Full text (PDF) from UMI/Dissertation Abstracts International, 2001. http://wwwlib.umi.com/cr/utexas/fullcit?p3034981.
Full textTannenbaum, Jared Michael. "The development of a portable instrumented indentation system." Morgantown, W. Va. : [West Virginia University Libraries], 2008. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=5931.
Full textTitle from document title page. Document formatted into pages; contains xiv, 127 p. : ill. Includes abstract. Includes bibliographical references (p. 61-62).
Göktaş, Oktay Güneş Mehmet. "Subgap Absorption Spectroscopy In Microcrystalline Silicon Thin Films/." [s.l.]: [s.n.], 2004. http://library.iyte.edu.tr/tezler/master/fizik/T000461.pdf.
Full textNg, Hoi-pang. "Mechanical and electrical properties of nickel-aluminium thin films /." Hong Kong : University of Hong Kong, 2000. http://sunzi.lib.hku.hk/hkuto/record.jsp?B21852315.
Full textGeddis, Demetris Lemarcus. "Single fiber bi-directional OE links using 3D stacked thin film emitters and detectors." Diss., Available online, Georgia Institute of Technology, 2004:, 2003. http://etd.gatech.edu/theses/available/etd-04082004-180141/unrestricted/geddis%5Fdemetris%5Fl%5F200312%5Fphd.pdf.
Full textDürr, Arndt Christian. "Growth and structure of DIP thin films and Au contacts on DIP thin films." [S.l. : s.n.], 2002. http://www.bsz-bw.de/cgi-bin/xvms.cgi?SWB10277647.
Full textPeterson, Sarah M. "Influence of scale, geometry, and microstructure on the electrical properties of chemically deposited thin silver films /." Connect to title online (ProQuest), 2007. http://proquest.umi.com/pqdweb?did=1453183211&sid=2&Fmt=2&clientId=11238&RQT=309&VName=PQD.
Full textTypescript. Includes vita and abstract. Includes bibliographical references (leaves 95-101). Also available online in ProQuest, free to University of Oregon users.
Serral, Serra Maria. "Modeling of thin polymer films." Doctoral thesis, Universitat Rovira i Virgili, 2015. http://hdl.handle.net/10803/306133.
Full textEste trabajo se centra en el estudio de dos sistemas diferentes de films poliméricos. En primer lugar, se analiza experimentalmente la respuesta viscoelástica de los films poliméricos multicapa (sándwiches) de polietileno lineal de baja densidad (LLDPE) y etilen-vinil-alcohol (EVOH). Partiendo de los datos experimentales se encuentra que la respuesta mecánica de los sándwiches se puede predecir mediante una regla aditiva utilizando los datos de los componentes puros, cuando éstos han sido procesados en las mismas condiciones. Por consiguiente, la respuesta no depende del grosor de las capas individuales, ni de los efectos interfaciales, sino que depende de la fracción volumétrica de EVOH y LLDPE en el sistema. Se propone adicionalmente un modelo más mesoscópico para la respuesta viscoelástica de los films de LLDPE y EVOH puros y los sándwiches. Éste se basa en el modelo de Maxwell Generalizado que corresponde a la analogía mecánica de la respuesta compleja del material. Mediante el ajuste del modelo a los datos experimentales podemos obtener información sobre el espectro de los tiempos de relajación, que nos dan conocimiento sobre la estructura microscópica del sistema. Finalmente, el segundo sistema que se investiga es completamente diferente al anterior. Este sistema consiste en filmes de “diblock-copolymers” que forman esferas y se someten a influencias externas. Para el estudio se utiliza una implementación numérica de la dinámica del sistema en una red conocida como “Cell Dynamics Simulation”. Por medio de las simulaciones demostramos que se pueden obtener formaciones de dominios esféricos altamente ordenados en films delgados sobre una superficie químicamente decorada con bandas paralelas. El orden de largo alcance depende de la conmensurabilidad de la estructura con la periodicidad de las bandas y del grosor del film, y su adecuada selección permite tener una disposición de esferas hexagonal o bien cuadrada, correspondiente a un empaquetamiento cúbico centrado (BCC).
This work is focused on the study of two different systems of thin polymeric films. In the first place, the viscoelastic response of multilayer polymeric films (sandwiches) of linear low-density polyethylene (LLDPE) and ethylene vinyl alcohol (EVOH) copolymer has been experimentally analyzed. From experimental data we find that the mechanical response of the studied sandwiches can be predicted through a mixing rule using the data of the pure constituents when they have been processed under the same conditions. Then, the response does not depend on the individual layer thickness, neither on the interfacial effects, but only on the volume fraction of the EVOH and LLDPE in the system. We additionally propose a more mesoscopic model for the viscoelastic response of the solid LLDPE and EVOH films and sandwiches. The model is formally a Generalized Maxwell (GM) model, which corresponds to a mechanical analog of the complex response of the material. Through the fitting of the model to the experimental data one can get information on the spectra of relaxation times, which bear information on the microscopic structure of the system. Finally, the second system investigated is completely different to the previous one. This system studied consists of films of sphere-forming diblock copolymers under external influences. For the study we use a numerical implementation of the dynamics of the system on a lattice that is referred to as Cell Dynamics Simulation. Using 3-Dimensional CDS we demonstrate that on patterned surfaces with chemically attractive parallel stripes, arrays of spherical domains with long-range order, required for nanoscopic applications, can be obtained. The long-range order depends on the commensurability of the structure with both the band periodicity and slit thickness, and their proper selection permits the system to switch from a hexagonal packing to a square packing corresponding to a body-centered orthohedron.
Hänni-Ciunel, Katarzyna. "Interactions in thin aqueous films." [S.l.] : [s.n.], 2006. http://opus.kobv.de/tuberlin/volltexte/2006/1432.
Full textHuang, Bin. "Mechanical characterization of thin films /." View abstract or full-text, 2005. http://library.ust.hk/cgi/db/thesis.pl?MECH%202005%20HUANG.
Full textSong, Gang. "Hydrogen in thin niobium films." [S.l. : s.n.], 2000. http://deposit.ddb.de/cgi-bin/dokserv?idn=961906529.
Full textKedsongpanya, Sit. "Nanolaminated Thin Films for Thermoelectrics." Thesis, Linköping University, Linköping University, Department of Physics, Chemistry and Biology, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-56699.
Full textEnergy harvesting is an interesting topic for today since we face running out of energy source, a serious problem in the world. Thermoelectric devices are a good candidate. They can convert heat (i.e. temperature gradient) to electricity. This result leads us to use them to harvest waste heat from engines or in power plants to generate electricity. Moreover, thermoelectric devices also perform cooling by applied voltage to device. This process is clean, which means that no greenhouse gases are emitted during the process. However, the converting efficiency of thermoelectrics are very low compare to a home refrigerator. The thermoelectric figure of merit (ZTm) is a number which defines the converting efficiency of thermoelectric materials and devices. ZTm is defined by Seebeck coefficient, electrical conductivity and thermal conductivity. To improve the converting efficiency, nanolaminated materials are good candidate.
This thesis studies TiN/ScN artificial nanolaminates, or superlattices were grown by reactive dc magnetron sputtering from Ti and Sc targets. For TiN/ScN superlattice, X-ray diffraction (XRD) and reciprocal space map (RSM) show that we can obtain single crystal TiN/ScN superlattice. X-ray reflectivity (XRR) shows the superlattice films have a rough surface, supported by transmission electron microscopy (TEM). Also, TiN/ScN superlattices grew by TiN as starting layer has better crystalline quality than ScN as starting layer. The electrical measurement shows that our superlattice films are conductive films.
Ca-Co-O system for inherently nanolaminated materials were grown by reactive rf magnetron sputtering from Ca/Co alloy target. The XRD shows we maybe get the [Ca2CoO3]xCoO2 phase, so far. The energy dispersive X-ray spectroscopy (EDX) reported that our films have Al conmination. We also discovered unexpected behavior when the film grown at high temperature showed larger thickness instead of thinner, which would have been expected due to possible Ca evaporation. The Ca-Co-O system requires further studies.
Kobler, Johannes. "Thin Films from Porous Nanoparticles." Diss., lmu, 2008. http://nbn-resolving.de/urn:nbn:de:bvb:19-98694.
Full textRoss, Caroline Anne. "Electromigration in thin metal films." Thesis, University of Cambridge, 1989. https://www.repository.cam.ac.uk/handle/1810/250938.
Full textMa, Fuyuan. "Electrochemically active organic thin films." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape10/PQDD_0020/NQ44501.pdf.
Full textPradhan, Sailesh. "Tensile testing of thin films /." Available to subscribers only, 2006. http://proquest.umi.com/pqdweb?did=1203573161&sid=10&Fmt=2&clientId=1509&RQT=309&VName=PQD.
Full text"Department of Mechanical Engineering and Energy Processes." Includes bibliographical references (leaves 73-84). Also available online.
Music, Denis. "Boron suboxide based thin films /." Linköping : Univ, 2003. http://www.bibl.liu.se/liupubl/disp/disp2003/tek835s.pdf.
Full textYim, Sanggyu. "Structure of phthalocyanine thin films." Thesis, Imperial College London, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.405780.
Full textMohd, Yatim Yazariah. "Unsteady flows of thin films." Thesis, University of Strathclyde, 2010. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=14374.
Full textBunce, Christopher Edward. "Magnetisation dynamics in thin films." Thesis, University of York, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.495860.
Full textLin, Keng-Yu. "Thin films for thermoeletric applications." Thesis, Linköpings universitet, Tunnfilmsfysik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-109106.
Full textKarl, Werner Josef. "Piezomagnetic thin-films and devices." Thesis, University of Sheffield, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.425487.
Full textAdamjee, Admil. "Ormosil thin films for waveguides." Thesis, University of Sheffield, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.301907.
Full textLogan, Randy. "Optical metrology of thin films." Thesis, Massachusetts Institute of Technology, 1997. http://hdl.handle.net/1721.1/46094.
Full textSong, Ohsung. "Magnetoelastic coupling in thin films." Thesis, Massachusetts Institute of Technology, 1994. http://hdl.handle.net/1721.1/28083.
Full textAessopos, Angelica. "Surfactant instabilities on thin films." Thesis, Massachusetts Institute of Technology, 2005. http://hdl.handle.net/1721.1/88902.
Full text"June 2005."
Includes bibliographical references (pages 89-92).
The deposition of a surfactant drop over a thin liquid film may be accompanied by a fingering instability. In this work, we present experimental results which identify the critical parameters that govern the shape and extend of the fingering phenomena. It was found that the normalized wavelength, [lambda]/t, scales with Marangoni number, Ma=[Delta][gamma]t/[mu]D, to the -1 exponent for any Marangoni higher than 4.3 · 10⁷. On the other end, for Marangoni < 4.3 · 10⁷ the normalized wavelength scales with Ma to the -0.4 but becomes in addition a funcion of the Prandtl number, Pr=[upsilon]/D, which demonstrates the critical significance of bulk diffusion on the spreding behavior. Finally, we present a numerical implementation of a mathematical model which is capable of reproducing the experimentally observed trends.
by Angelica Aessopos.
S.M.
Marshall, J. M. "Thin lead zirconate titanate films." Thesis, Cranfield University, 2006. http://dspace.lib.cranfield.ac.uk/handle/1826/10743.
Full textД`яченко, Олексій Вікторович, Алексей Викторович Дьяченко, Oleksii Viktorovych Diachenko, Анатолій Сергійович Опанасюк, Анатолий Сергеевич Опанасюк, Anatolii Serhiiovych Opanasiuk, D. Nam, and H. Cheong. "Characterization Cupper Oxide thin films." Thesis, Львівський національний університет ім. Івана Франка, 2015. http://essuir.sumdu.edu.ua/handle/123456789/48287.
Full textShu, Rui. "Nonstoichiometric Multicomponent Nitride Thin Films." Licentiate thesis, Linköpings universitet, Tunnfilmsfysik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-170529.
Full textJOTHIMUTHU, PREETHA. "Photodefinable Polydimethylsiloxane (PDMS) Thin Films." University of Cincinnati / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1212181335.
Full textQureshi, Uzma. "Host thin films incorporating nanoparticles." Thesis, University College London (University of London), 2007. http://discovery.ucl.ac.uk/1446050/.
Full textMorales, Morales Oswaldo [UNESP]. "Construção e caracterização de células solares de filmes finos de CdS e CdTe." Universidade Estadual Paulista (UNESP), 2012. http://hdl.handle.net/11449/91965.
Full textCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Neste trabalho, o objeto de estudo foi células Solares CdS/CdTe. Estas células usam o filme de sulfeto de cádmio (CdS) como semicondutor do tipo n e o filme de telureto de cádmio (CdTe) como semicondutor do tipo p. O recorde mundial, alcançado no laboratório, para estas células é 16,5% de eficiência. Nos Laboratórios do Departamento de Física e Química de Unesp - Ilha Solteira, este trabalho é pioneiro na fabricação de Células Solares de CdS/CdTe. Para realizar este trabalho foi necessário melhorar o sistema de deposição por spray de SnO2:F já existente, acondicionar o sistema de banho químico para deposição do filme de CdS e implementar o sistema de sublimação para depositar a camada de CdTe. Todos estes sistemas de deposição de filmes finos foram implementados no laboratório do Grupo de Desenvolvimento e Aplicação de Materiais (GDAM). A fabricação da Célula Solar CdS/CdTe consistiu na deposição sequencial sobre vidro de a) Eletrodo condutor transparente utilizando óxido de estanho dopado com Flúor (SnO2:F) pelo método de spray, com controle automático de jato; b) deposição de sulfeto de Cádmio (CdS) pelo método de banho Químico (CBD); c) deposição de Telureto de Cádmio (CdTe) pela técnica de sublimação no espaço fechado (CSS) e d) deposição do contato metálico traseiro de prata por colocação de camada liquida e posteriormente a melhora deste contato com grafite-prata. A estrutura final destas células foi: Vidro/SnO2:F/CdS/CdTe/contato. A caracterização estrutural e óptica das camadas destas células foi realizada pelas técnicas de DRX e UV-vis; os parâmetros elétricos das células foram determinados pela construção da curva I-V. A camada CdTe da célula solar foi tratada termicamente com dicloreto de cádmio (CdCl2) para comparar a sua eficiência com outra célula que não foi tratada...
The object of this work was the study solar Cells CdS/CdTe. These cells use a cadmium sulfide film as an n-type semiconductor and a cadmium telluride film as a p- type semiconductor The world record for maximum efficiency achieved in laboratory for these cells is 16.5%. In laboratories of Departament of Physics and Chemistry of Unesp-Ilha Solteira, this work is a pioneer in the manufacture of CdS/CdTe Solar Cell. To carry out this work it was necessary to improve the existing system of Spray deposition of SnO2: F, conditioning of the system for chemical bath deposition of CdS film and manufacture the sublimation system to deposit the CdTe layer. All of these systems for the deposition of thin films were developed in the laboratory. The manufacture of CdS/CdTe solar cell consisted of sequential deposition on glass of a) transparent conductive tin oxide doped with fluorine (SnO 2:F) using automatic control system of the spray; b) deposition of cadmium sulfide (CdS) for method (CBD); c) deposition of cadmium telluride for technique in closed space sublimation (CSS) and d) the rear metallic contact of silver was deposited by placing the liquid layer and subsequent improvement of contact with graphite-silver. The final structure of cell used in this work was: glass/SnO2:F/CdS/CdTe/contact. The CdTe solar cell layer was heat treated with cadmium dichloride (CdCl2) to compare its efficiency with another cell that was not treated with cadmium dichloride. Then we investigated the performance of only putting back metal contact layer of silver of silver and silver-graphite layer, the latter was giving better results, achieving an efficiency is a well more than 5%
Gonçalves, Thaís Matiello [UNESP]. "Caracterização de filmes finos obtidos por deposição de vapor químico assistido a plasma (PECVD) e deposição e implantação iônica por imersão em plasma (PIIID)." Universidade Estadual Paulista (UNESP), 2012. http://hdl.handle.net/11449/99671.
Full textCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Filmes finos de carbono amorfo hidrogenado contendo silício e dopados com flúor foram produzudos pelos métodos de Deposição de Vapor Químico Assistido e Plasma (PECVD) e Deposição e Implantação Iônica por Imersão em Plasma (PIIID). Para PECVD foi utilizada uma pressão total de gases/vapor de 100 mTorr e inicialmente, 100W de potência de excitação. A proporção dos gases foi estudada, mantendo a concentração do hexametildisiloxano (HMDSO) em 75% e variando a proporção do argônio (Ar) e do hexafluoreto de enxofre (SF6). As porcentagens de flúor utilizadas na alimentação do plasma variaram em 0,6,9 e 12,5%. Visando maior concentração atômica de flúor na estrutura dos filmes, determinou-se a proporção de gases/vapor mais apropriada (75% HMDSO, 19% Ar e 6% SF6), e posteriormente, foi realizado um novo estudo da potência de excitação. Variando a potência entre 40 e 70 W, 50 W foi considerada como sendo a melhor condição de excitação para a descarga luminosa, considerando os efeitos causados pela corrosão relacionada ao flúor e a incorporação do elemento. Um estudo sobre as mesmas proporções foi realizada pela técnica de PIIID, com uma pressão total de 50 mTorr, potência de 50 W e pulsos negativos com magnitude de 800 V. Para este método o filme produzido com 12,5% de SF6 foi escolhido como sendo a melhor opção, tendo em vista que apresentou a maior quantidade atômica de flúor em sua estrutura. Posteriormente, a intensidade dos pulsos aplicados foi variada entre 544 e 14801 V, onde verificou-se que o aumento da intensidade dos pulsos resulta na diminuição da incorporação de flúor
Hydrogenated amorphous carbon films containing silicon and doped with fluorine were produced by two methods: Plasma Enhanced Chemical Vapor Deposition (PECVD) and Deposition (PIIID). For PECVD a total pressure of 100 mTorr was used at a excitation power of 100 W. The gas/vapor proportion was studied, keeping 75% hexamethyldisiloxane and varying the argon (Ar) and sulfur hexafluoride (SF6) ratio. The following proportions of SF6) ratio. The following proportions of SF6 were examined: 0, 6, 9 and 12.5%. Aiming for the highest atomic concentration of fluorine in film structure the best condition (75% HMDSO, 19% Ar and 6% SF6) was determined and a new study of the influence of the radiofrequency power. Considering the corrosion effects gernerated by fluorine in the plasma, variation of the applied power between 40 and 70 W, allowed the selection of 50 W as the best conditions. A study employing the same proportior PIIID was performed using 50 mTorr of total pressure, an applied power of 50 W and a pulse bias of 800 V. Considering the results of the chemical characterizations, films were produced with 12.5% of SF6 in the plasma feed. Subsequently, bias voltage was varied between 544 and 1480 V, where it was observed that the increasing the pulse bias decreased the fluorine concentration in film structure
Silva, Vitor Diego Lima da [UNESP]. "Investigação de contatos elétricos e propriedades de filmes finos de SnO2 dopados com os íons terras raras Eu3+ e Ce3+." Universidade Estadual Paulista (UNESP), 2012. http://hdl.handle.net/11449/99676.
Full textCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
O objetivo principal deste trabalho é elucidar quais são os mecanismos de transporte de portadores de carga presentes na interface entre SnO2 e o contato metálico, pois tal conhecimento é fundamental para a aplicação na eletrônica. Além disso, é objetivo aqui também, estudar características de transporte em SnO2 dopado com alguns íons terras-raras. As amostras de SnO2 dopadas em Eu3+ e Ce3+ utilizadas nesta pesquisa foram sintetizadas a partir do método sol-gel e os filmes finos depositados pela técnica dip-coating. Os contatos estudados foram feitos a partir dos metais In, Sn e Al, depositados via evaporação resistiva. Medidas de resistência em função da temperatura nas amostras dopadas com Eu indicaram uma variação significativa da resistividade, de até 10 vezes, quando alterado o metal do contato. Isto se deve a diferença entre a função de trabalho de cada metal, que consequentemente acarreta em variação da barreira de potencial na junção metal-semicondutor. Pela característica das curvas de corrente medida em função da tensão aplicada, observou-se que os dois mecanismos de condução elétrica dominantes na interface são a emisssão termiônica, quando em baixas temperaturas e tensões de menor intensidade, e o tunelamento através da barreira, quando em temperaturas mais altas e tensões de maior intensidade. Com base nesses resultados e na aplicação do método proposto por Rhoderick estimou-se os valores da altura da barreira de potencial na junção metal-semicondutor, em 132 meV, 162 meV e 187 meV para os metais In, Al, Sn, respectivamente. Além disso, o tratamento térmico realizado nas amostras promoveu, de modo geral, a diminuição da resistividade do dispositivo devido, provavelmente, ao estreitamento da barreira de potencial e consequente aumento da...
The main goal of this work is the verification of electrical transport mechanisms of charge carriers at the interface between SnO2 and the metallic contact, because this knowledge is fundamental for electronic applications. Besides, another goal here is to investigate transport characteristics of rare-earth doped SnO2 samples doped with Eu3+ and Ce3+ used in this research were made from the sol-gel method and the thin films were deposited via dip-coating technique. The analyzed contacts were deposited from metals In, Sn and Al, via resistive evaporation technique. Resistance as function of temperature measurements applied to Eu-doped samples indicates a significant resistivity, up to 10 times, when the contact metal is varied. This is due to the differences in the work function of each metal, leading to variation in the potential barrier at interface of the metal-semiconductor junction. The characteristics of the current-voltage curves yield two dominant electrical mechanisms at the interface: thermo-ionic emission, for low temperatures and higher applied bias, and quantum tunneling through the barrier, when the temperature is higher and so is the applied bias magnitude. Based on these results and the application of the method proposed by Rhoderick, the potential barrier height of metal-semiconductor junction values were evaluated, yielding 132 meV, 162 meV and 187 meV for the metals In, Al and Sn, respectively. Besides, generally speaking, thermal annealing promotes the resistivity decrease, probably due to the potential barrier narrowing, increasing the tunneling probability. The variation of Ce3+ concentration, from 0,1% also leads to variation in the device resistivity, but this is not related to the potential at the junction interface, instead it is related with other bulk factors, as the charge... (Complete abstract click electronic access below)
Moffat, Steven H. "Transport and infrared properties of ion irradiated YBa2Cu3O7-8 thin films /." *McMaster only, 1997.
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