Master Degree / Yüksek Lisans Tezleri

Permanent URI for this collectionhttps://hdl.handle.net/11147/3008

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Subject: search.filters.subject.Sputtering (Physics)

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Now showing 1 - 5 of 5
  • Master Thesis
    The Effect of Bending Cycles on Optical and Electrical Properties of Multilayer Zto Ag Zto and Ito Transparent Conductive Oxide Thin Films Grown by Magnetron Sputtering
    (01. Izmir Institute of Technology, 2024) Çelikli, Cenkay; Özyüzer, Lütfi; Özdemir, Mehtap
    Bu tez, esnek yüzeylerde büyütülen Çinko Kalay Oksit (ZTO, Zn2SnO4)/Ag/ZTO (ZAZ) ve İndiyum Kalay Oksit (ITO, In2O3:SnO2) ince filmlerin yapısal, elektriksel ve optik özelliklerini incelemektedir. Karşılaştırma, İndiyum elementinin azalan bulunabilirliği ve yüksek maliyetleri nedeniyle yapılmıştır. Bu doğrultuda, gümüş ile tamamlanan ZTO tabanlı bir sandviç yapı geliştirilmiştir; bu yapı, yüksek iletkenlik ve şeffaflık gerektiren Şeffaf İletken Oksit (TCO) uygulamalarında ITO'ya benzer özellikler sunmaktadır. Deneysel çalışmalarda, magnetron sputtering tekniği kullanılarak ince film kaplama için optimum parametreler belirlenmiş ve polikarbonat yüzeyler üzerine örnekler büyütülmüştür. Yapısal karakterizasyon için yapışma testleri, profilometri ve Taramalı Elektron Mikroskobu (SEM) kullanılmış; elektriksel özellikler 2-probe ve 4-probe yöntemleriyle, optik özellikler ise spektrofotometre ile ölçülmüştür. Sonuçlar, ZAZ çok katmanlı yapısının ITO kaplamalarına kıyasla daha iyi performans sergilediğini göstermiştir. Bu çalışma, ZAZ ince filmlerinin ITO yerine kullanılabileceğini ve esnek giyilebilir teknolojilerdeki gelecekteki uygulamaları için bir rehber sunduğunu ortaya koymaktadır.
  • Master Thesis
    Growth and characterization of LiCoO2 thin films by magnetron sputtering for lithium ion batteries
    (01. Izmir Institute of Technology, 2024) Özcan, Polatkan; Özyüzer, Gülnur Aygün
    Bu tez, lityum iyon pillerde kullanılmak üzere mıknatıssal saçtırma yöntemiyle büyütülen ve karakterize edilen Lityum Kobalt Oksit (LiCoO₂) ince filmlerinin geliştirilmesi ve iyileştirilmesine odaklanmaktadır. Yüksek performanslı enerji depolama cihazlarına yönelik artan talep göz önünde bulundurularak, bu çalışmada LCO ince filmlerin elektrokimyasal özelliklerini iyileştirmek için kaplama parametrelerinin optimize edilmesine gayret edilmektedir. İleri karakterizasyon teknikleri, örneğin Taramalı Elektron Mikroskobu (SEM), Enerji Dağılımlı X-ışını Spektroskopisi (EDX), X-ışını Difraksiyonu (XRD), Raman Spektroskopisi, X-ışını Fotoelektron Spektroskopisi (XPS) ve Elektrokimyasal Döngüsel Voltametri filmlerin morfolojisini, bileşimini, kristal yapısını ve kimyasal durumlarını değerlendirmek için kullanılmaktadır. Ayrıca, bu araştırma tüm katı hal lityum iyon pillerde (ASSLIB'ler) elektrolit/katot ara yüzeyindeki zorluklara değinmekte olup, ara yüzey kararlılığını artırmayı ve direnci azaltmayı hedeflemektedir. Kaplama sürecinin iyileştirilmesi ve ara yüzey özelliklerinin kapsamlı bir şekilde anlaşılması ile çalışma, lityum iyon pillerin genel performansını ve güvenliğini önemli ölçüde artırmayı amaçlamaktadır. Bu araştırmadan elde edilen bulgular, pil teknolojisinin ilerlemesine katkıda bulunarak, daha verimli ve kararlı enerji depolama çözümlerinin geliştirilmesi için değerli içgörüler sunmaktadır. Bu çalışma, malzeme optimizasyonunun önemini vurgulamakta ve çeşitli uygulamalarda daha iyi performans, uzun ömür ve güvenlik sağlamak için pil teknolojisinde gelecekteki yenilikler için bir yol sunmaktadır.
  • Master Thesis
    Electrical Characterization of Vanadium Dioxide (vo₂) Thin Films Grown by Magnetron Sputtering Technique
    (01. Izmir Institute of Technology, 2024) Akyürek, Bora; Özyüzer, Gülnur Aygün
    The aim of this thesis is to determine the parameters required for the production of pure VO₂ thin films and to evaluate the usability of these films by calculating their MIT ratios. Vanadium dioxide (VO₂), a substance that exhibits a phase transition from the insulating state to the metallic state at approximately 68 °C, shows significant changes in its electrical conductivity and optical properties. To get pure VO2 thin films, and get optimum parameters for deposition, several parameters were varied during the manufacturing process,including temperature, oxygen-argon ratio, and coating time. Then, electrical characterization of the produced films was performed. Examining the temperature dependence of the resistance of thin films has been a critical aspect of electrical measurements to determine the MIT transition. With the help of the probe station, it was determined that the MIT transition occurred at approximately 68 °C. The results obtained using structural characterization techniques revealed that characteristic vibration modes were observed in the analyses performed with Raman spectroscopy, while XRD analyses revealed that the crystal structure was preserved. Additionally, XPS analyses did not detect any surface contamination other than carbon. SEM and EDX analyses evaluated the surface morphology and elemental stoichiometry and showed that the internal structure of the films was intact. These results support the usability of VO₂ thin films in advanced electronic and optical applications and contribute to the determination of optimum production parameters. This thesis demonstrates the potential of VO₂ in various technological applications by efficiently utilizing MIT properties.
  • Master Thesis
    Production and Characterization of Hfo2 High-K Dielectric Layers by Sputtering Technique
    (Izmir Institute of Technology, 2010) Cantaş, Ayten; Aygün Özyüzer, Gülnur
    HfO2 thin films have been deposited on Si by in-situ spectroscopic ellipsometric sputtering technique. The grown films have been examined by various diagnostic and analysis techniques (Spectroscopic Ellipsometer (SE), FTIR, XRD, XPS). The optimization of in-situ SE sputtering system has been processed according to the measurement results of the grown HfO2 films. From the measurements simultaneously taken by using SE, film thickness, refractive index and real part of dielectric function have been examined as a function of deposition time. It was found that the thickness changes linearly with deposition time. The formation of undesired SiO2 interfacial layer has been tried to be prevented and searched by using FTIR. MOS capacitors from the oxides having best qualities have been produced to obtain electrical properties of grown oxides. The process of production-characterization and development of oxidation conditions have been achieved and the following results have been obtained: (a) Low O2/Ar gas ratio and 30-40 watt power have been considered as the most convenient oxidation parameters. (b) The formation of SiO2 interface has not been prevented but formation of HfxSiOy has been obtained. (c) The refractive index value (n.2.1) of bulk HfO2 at 632 nm has been obtained.
  • Master Thesis
    Antistatic Applications: Metal Coated Fibers by Magnetron Sputtering
    (Izmir Institute of Technology, 2011) Meriç, Zeynep; Özyüzer, Lütfi
    The utilization of textile materials with nanotechnology is increasing in many industries especially for automobile, medical and health care. These materials have recently been of increasing interest to both the academic and the industrial sectors. Today, a wide range of nanoparticles, nanofilms and nanocomposites with various structures can be applied to the fibers, bringing new properties to the final textile product. For all these technical applications, it is desirable to produce such textile materials with especially designed surface features to meet various needs. Various techniques have been developed to functionalize textile materials. Physical vapor deposition (PVD) has been applied to modify textile materials various functions and solvent-free process. In this study, for this aim we designed a new magnetron sputtering system which is called inverted magnetron sputtering. The surfaces of synthetic fibers, such as PP and PA, whose diameters are in the range between 60-125 μm, coated with electrical conductors. In this study silver is usedbecause of silver has the highest electical conductivity in metals and additionally it has antibacterial properties. Textile fibers were coated in nanometer thickness and electrical conductivity is aimed to increase. These fibers weaved into fabrics in order to investigate antistatic and antibacterial properties. For characterization optical microscope and SEM images were taken. Besides, XRD, electrical results, mechanical strength tests were done. In order to determine optimum film thickness, by using three different methods coating thicknesses were investigated and results compared. Resistances of Ag on fibers were found and film thickness calculated from bulk Ag resistivity. The thickness was also calculated from deposited mass of silver. The both results were compared with independent thickness measurement on a glass substrate with a surface profilometer. The analysis of data commented surface scattering effect. When these fibers were weaved to become fabric due to these properties, fabrics will take place of technical textiles. Besides, the obtained fabrics have potentials to be used for electromagnetic shielding, radar absorbing materials and infrared camouflage.