【作者】 许旻；

【导师】 贺德衍；

【作者基本信息】 兰州大学 ， 凝聚态物理， 2006， 博士

【摘要】 二氧化钒（VO₂）是一种具有热致相变特性的金属氧化物,随着温度降低,大约在68℃附近,发生从金属到非金属（或半导体）的性质突变。由于相变温度接近室温,且相变前后光、电性能变化幅度较大,VO₂在很多领域具有重要的应用价值。 近年来,薄膜VO₂材料的研究有了飞速的发展,特别是在应用方面,已成功应用于太阳能控制的智能窗、激光防护的保护膜和制造红外成像的非制冷红外焦平面阵列等。 本论文研究了采用两种工艺方法制备VO₂薄膜:一种是在常温下利用脉冲磁控反应溅射沉积了高价态的氧化钒前驱薄膜,再通过真空热处理制备了VO₂薄膜;另一种是用射频磁控反应溅射沉积直接沉积VO₂薄膜。对氧化钒薄膜从物理化学性质、结构特征、热致相变特性、抗激光能力等方面进行了比较系统深入的研究。所开展的主要研究工作和所得到的研究结果有: （1）采用脉冲磁控溅射方法在常温下制备出V₂O₅薄膜,然后在真空中热处理还原制备出VO₂薄膜。实验研究和分析表明,要得到高质量的VO₂薄膜,溅射制备时的反应气体分压,真空退火处理时的退火温度与退火时间,以及退火的气氛种类等是影响VO₂薄膜结构和成分以及相变特性的关键工艺参数。 （2）用X射线衍射、X射线光电子能谱、原子力显微镜等手段对脉冲磁控溅射结合真空退火制备的氧化钒薄膜的组分、晶相、表面形貌进行了分析,测试了薄膜的相变特性、光学和电学特性及其变化规律。分析表明,薄膜中氧化钒的价态主要是混合价态,多种相共存。结构为多晶,没有明显的取向生长。通过优化制备过程中的工艺参数,在衬底温度为500℃左右,氧分压约为8%时,获得了能够满足使用要求的VO₂敏感薄膜。在红外波段波数为2000 cm^-1处,光透过率从低温态的到高温态变化了35%,电阻变化最大达到3个数量级。 （3）用射频磁控反应溅射方法沉积了VO₂红外敏感薄膜。研究了薄膜的沉积速率、电阻率变化、光学透过率变化和相结构变化规律。实验发现,在480℃的衬底温度下,当反应气体流量比O₂/Ar+O₂低于5%时,薄膜中的主要成分为金属钒;流量比处于6%～7.7%之间时主要为V₂O₃、V₂O₃+VO₂和低价氧化物;在7.8～8.5%时可以得到以VO₂为主要相的薄膜;处于9%～10%之间主要为混合相;大于10%主要为V₂O₅相。在反应气体流量比为更多还原

【Abstract】 Vanadium dioxide is a kind of metallic compound which undergoes a metal-semiconductor phase transition near 68℃. The phase transition is accompanied by significant changes in optical and electrical properties. For the characteristics that its phase transition temperature is near to room temperature and its optical and electrical performance have changed much during phase transition, VO₂ has a great number of potential applications.Many studies have been conducted extensively during the past decades, especially in the films application and preparation process. This material has been taken in use as smart window for controlling solar radiation, protection film for laser shield and infra-red sensitive material in uncooled infra-red focal plane array （UFPA）. Some preparation methods, such as organic sol-gel method, pulse laser deposition （PLD） and MOCVD have prepared high capability VO₂ films.The magnetron sputtering method was used in our research for preparation of VO₂ films. Research work has been done as follows in detail:（1） V₂O₅ films was deposited in room temperature substrate, then V₂O₅ films was changed into VO₂ films through heat-treatment. VO₂ films was received by accurate control of the vacuum pressure, heating-treatment temperature, time and gas.（2） How main process parameter of preparation partial pressure of reacting gas （oxygen）, substrate temperature and sputtering power influence the properties of the films. And then found the proper experimental condition.（3） Vanadium dioxide（VO₂） thin films were grown onto quartz glass and silicon substrates by two deposition technique. X-ray diffraction, X-ray photoelectron spectroscopy are used to analyze the composition, phase structure, crystalline and valence state of the film. Atomic force spectroscopy is used to identify the film surface morphology. The variation of transmission of films from low temperature to high temperature were also measured. These investigation revealed that films have high purity and good crystallite.（4） Vanadium dioxide（VO₂） thin films by reactive sputtering deposited were endured attacking from infra laser.更多还原