The Novel Preparation Method of High-Performance Thermochromic Vanadium Dioxide Films by Thermal Oxidation of Vanadium-Stainless Steel Co-Sputtered Films and the Study of Its Long-Term Stability
| Autor: | Yang Yue-Lin, 楊岳霖 |
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| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 104 The preparation of high-performance thermochromic vanadium dioxide films and the assurance of its batch-to-batch uniformity were technically difficult since the oxidation number of vanadium ranged from +2 to +5 under various reducing or oxidizing atmospheres at elevated temperatures. In this work, the vanadium dioxide films were fabricated by thermal-oxidation of vanadium and stainless-steel (mainly containing Fe, Cr, Ni) co-sputtered thin films at elevated temperature under air atmosphere. The as-prepared vanadium oxide films were further characterized by four-point probe measurement, ellipsometry, grazing incidence X-ray diffraction (XRD) and X-ray photoelectron spectroscopic (XPS) analysis. Our experiments demonstrated that the use of SS target could efficiently deposit the magnetic atoms (iron and nickel) and nonmagnetic Cr elements into vanadium films in a stable plasma conditions. The shift of the main peak of XRD patterns to smaller angles showed the Fe, Cr, and Ni elements were successfully doped into vanadium oxide films. These dopants depressed the vanadium atoms from over-oxidization during the heat treatment. As a result, a noticeable amount of VO2(M) crystalline phase (higher V(+4)/V(+5) ratios) was obtained from the as-prepared films accompanied with the increment of the SS target voltage. The second part of this dissertation is to fabricate the barrier layer protection on the as-deposited VO2 films. The samples doped with stainless steel and covered with barrier layers show significant long-term stability in either wet or dry high temperature environment. With an equivalent barrier layers thickness, all samples can be ranked by its stability in both wet and dry test as follows: Wet condition (95% RH 80oC): ZnO/SiO2～TiO2/ZnO＞Parlyene N～VO2:SS＞TiO2/SiO2＞Plain VO2, and for dry condition(300oC): TiO2/ZnO＞ZnO/SiO2～TiO2/SiO2＞VO2:SS＞Plain VO2. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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