钒氧化物薄膜材料的制备

【作者】 乔威；

【导师】 赵昆渝；

【作者基本信息】 昆明理工大学 ， 材料学， 2006， 硕士

【摘要】 本文分别以V₂O₅（AR）和工业产V₂O₄粉末为原料，采用无机溶胶—凝胶的方法，通过三种退火工艺分两步退火处理在玻璃衬底上成功的制备出了单相VO₂薄膜，并筛选出了最佳的单相薄膜制备工艺；同时探索了在单晶硅衬底上的VO₂薄膜制备方法，得到了在硅衬底上的VO₂单相薄膜；采用了无机掺杂法，得到了不同掺杂浓度的V_1-xMo_xO₂薄膜。通过X射线衍射仪、金相显微镜、紫外—可见分光光度计、R-T测试仪等对薄膜的物相成分、组织形貌、光学、温阻特性以及薄膜的厚度作了测试分析。XRD分析表明，在不同的退火工艺下制备出了具有不同取向生长的VO₂薄膜，这在XRD图谱上表现出很大的差异性。金相显微组织分析表明，真空退火得到的VO₂薄膜组织形貌不同程度的受退火前V₂O₅薄膜组织形貌的影响，当用有择优取向的V₂O₅薄膜来制备VO₂薄膜时，得到的VO₂薄膜也具有一定的取向；当用没有取向生长的V₂O₅薄膜时，得到了无取向生长的VO₂薄膜，其显微结构为致密的针状细晶组织。U-V光谱分析表明，不同退火工艺下的VO₂薄膜的吸收情况基本一致，均在波长400nm处出现一定吸收。R-T曲线表明，在580℃/1h退火的V₂O₅薄膜基础上，再经480℃/6h真空退火的VO₂薄膜在温度68℃电阻迅速降低，电阻突变2个数量级，计算得到该薄膜电阻温度系数TCR为-2.59％/K；对VO₂薄膜进行掺Mo实验，获得了不同掺杂浓度的V_1-xMo_xO₂薄膜。在本实验研究范围内，研究表明，退火温度和退火时间对VO₂相的转化和薄膜的生长有一定的影响。相同的工艺下，当膜厚从72.75μm减小到16.59μm，发现厚度的减小有利于单相VO₂薄膜的获得；在真空退火温度分别为450℃和480℃，退火时间从2h延长到6h有利于VO₂相的生成和结晶，在相同的真空退火时间下，升高退火温度有利于主相的结晶；综合对比时间和温度的影响，发现延长退火时间并降低退火温度和缩短退火时间并升高退火温度对VO₂薄膜的生成和结晶生长的影响是等效的。此外，本论文还以SOL—GEL法为重点对VO_x系列薄膜材料的制备方法、V₂O₅和VO₂薄膜材料的性质、应用及其研究动态进行了综述。更多还原

【Abstract】 The pure VO₂ thin films which undergone three techniques and two annealing process were fabricated on glass substrates by the method of inorganic SOL-GEL from V₂O₄ and V₂O₅ powder, and the best preparing process was chose; the preparing process on Si substrates was also researched, and we got the better method to prepare the VO₂ pure films; we got the Mo-doped V_1-xMo_xO₂ films in different solution by the method of inorganic doping. The phase-component, micro-structure, optical absorption, R-T properties and thickness of the thin films were characterized by XRD, microscope, UV-VIS and R-T equipments.The investigation from XRD reveals that different oriented VO₂ thin films were prepared from different annealing process. The research of microstructure reveal that VO₂ thin films’ structure was affected by V₂O₅ thin films’, when we annealed from the V₂O₅ thin films which have the oriented configuration we got the oriented VO₂ thin films too, this phenomenon disappeared when we use non- oriented V₂O₅ thin films, and the VO₂ thin films were of the compact structures like acerous structures. According to UV-VIS absorption analysis, we discovered that the absorption of different annealed samples in ultraviolet and vision region are similar, their maximum absorption appeared 400nm wavelength. From R-T curves we find that when the temperature is 68℃, the resistance of VO₂ thin films which undergone 480°C/6h vacuum annealing abruptly decrease with 2 magnitude, and TCR（=-2.59%/K） was calculated; we made the doping experiment and got V_1-xMo_xO₂ doping films in different solution; we also researched the effect of annealing temperature、 time and thickness on VO₂ thin films’ properties, and find that when the thickness decrease from 72.75um to 16.59um, thinner films are better to make pure VO₂ thin films ; at the vacuum temperature of 450℃ and 480℃, when the time was prolonged from 2h to 6h, longer annealing time make for VO₂’s creating in the same annealing temperature, higher temperature make for main phase’s crystal in the same annealing time; the process of higher temperature and longer annealing time are equivalent on effect of VO₂.In addition, this paper also introduced the preparation technology with SOL-GEL method as main, properties, application and the late development in worldwide of the V₂O₅ and VO₂ thin films.更多还原