掠射角溅射沉积纳米结构WO3薄膜及气致变色机理研究

WO3 thin films are a kind of ideal chromogentic material to regulate the transmittance of solar light. Gasochromic devices consisted with WO3 films as smart windows have many advantages such as simple structure, better stability and broader regulable transmittance range, which show a wider application prospect. Since the gasochromic reaction firstly occurs on the film surface, large specific surface area is good for the atoms/ions fast entering to the films. So fabrication of WO3 films with special nano-structure and novel morphology is significant to improve gasochromic properties. In this project, glancing angle sputter technology will be used to prepare WO3 films with large specific surface area and regular nano-structure. This approach offers not only a good adhesion between film and substrate but also precisely controlling of growth size and dimension. Dynamic process of films growth will be studied and nano-structured growth model will be found. The relationship between nano-structure and gasochromic properties will be investigated. The injection process of atoms/ions and intrinsic chemical reaction will be studied to further elucidate the gasochromatic mechanism of WO3 films. Improvement of the gasochromic properties will be realized through control of the film structure. The results obtained in this project will assist to rich the theoretic foundation for fabrication of good performance gasochromic devices.

WO3薄膜是一种理想的光控变色材料，由其组成的气致变色智能窗具有结构简单、调光可控范围宽、系统稳定性好等优点，因而应用前景广阔。由于气致变色反应首先在薄膜表面进行，大比表面积有利于原子/离子快速而充分地进入薄膜中。因此，制备特殊纳米结构和新颖表面形貌的WO3薄膜对提高气致变色性能具有重要意义。本项目采用掠射角溅射沉积法制备高结晶度、大比表面积、规则纳米结构的WO3薄膜，既保证薄膜与基底的良好结合力，又能精确控制薄膜的纳米尺度及生长方向。分析掠射角溅射沉积WO3薄膜的生长动力学，构建WO3薄膜纳米结构的生长模型，探明薄膜纳米结构与气致变色性能之间的关系。阐明反应原子/离子的注入过程以及与WO3发生化学反应的本质，进一步揭示和完善WO3薄膜气致变色机理，实现通过控制薄膜结构提高其气致变色性能的目的，为制备性能优异的气致变色器件提供坚实的理论基础。

三氧化钨（WO3）作为一种典型的宽带隙半导体金属氧化物，具有优良的致色特性，在智能窗和传感器等领域应用前景广阔。纳米结构WO3薄膜在气致变色方面主要具有以下两个优点：（1）由于气致变色反应首先在薄膜表面进行，大比表面积有利于原子/离子快速而充分地进入薄膜中，为气体在其内部扩散提供更多通道。（2）特殊的纳米结构形貌可提高表面原子活性，增加WO3薄膜对气体分子的敏感度。因此，本项目采用掠射角磁控溅射沉积法制备大比表面积、规则纳米结构的WO3薄膜，既保证薄膜与基底的良好结合力，又能精确控制薄膜的纳米尺度及生长方向。系统研究了溅射沉积参数对WO3薄膜晶体结构、组成、表面形貌的影响。重点考察了掠射角度、生长速率和基底旋转速率等参数对WO3薄膜生长动力学的影响，构建了生长模型。完成基于纳米结构WO3薄膜气致变色器件的制作并测试响应时间、致色深度。阐明反应原子/离子的注入过程以及与WO3发生化学反应的本质，揭示和完善纳米结构WO3薄膜的气致变色机理，为制备性能优异的气致变色器件提供坚实的理论基础。