Ag-TiO2和VO2/Ag-TiO2薄膜的制备及光致阻热性能研究

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	Ag-TiO2和VO2/Ag-TiO2薄膜的制备及光致阻热性能研究
其他题名	The preparation of Ag-TiO2 and VO2/Ag-TiO2 films and investigation of their photo-driven heat-preventing performance
	郑金玉
导师	李新军
	2007-06-08
学位授予单位	中国科学院广州能源研究所
学位授予地点	广州能源研究所
学位名称	硕士
关键词	智能窗半导体薄膜 Tio2 Vo2 光生载流子分离
摘要	节能智能窗是绿色节能建筑的一个主要组成部分，因为在夏天大部分的热量从窗户进入，增大了空调费用。常规的阻热薄膜存在着不能智能调节和可见光透过率低等缺点，从而促使人们探索开发新型节能智能窗。最近有关于VO2半导体薄膜热致“导体化”反射红外线的阻热智能窗的报道，虽然还存在技术不稳定的难题，但仍引起了人们的广泛关注。本论文基于光致半导体电荷分离，使半导体导体化反射红外线进而起到阻热作用的原理，探讨光致阻热薄膜的研究。本文采用溶胶-凝胶法通过分层控制工艺制备了Ag离子非均匀掺杂的TiO2薄膜，采用SEM、XRD对薄膜的结构进行表征，通过电化学方法、光催化活性评价实验分析了薄膜的电荷分离效率，通过紫外-可见分光光度计和傅立叶红外分光光度计检验电荷分离对薄膜光学性能的影响。利用无机溶胶-凝胶法制备了VO2薄膜，并将其与TiO2薄膜复合，利用自制加热平台和四探针电阻仪测试了紫外光照前后对VO2相变的影响。结果表明：（1）对Ag离子掺杂来说，采用分层控制非均匀掺杂方式（AT和TA）能有效提高TiO2薄膜的电荷分离效率，使薄膜红外区的透过率稍有降低。（2）掺杂浓度对TiO2薄膜的电荷分离效率影响很大，对于AT和TA掺杂来说，最佳掺杂浓度为0.5at%。（3）对于VO2/TiO2复合薄膜，与非均匀底部控制掺杂方式的TiO2薄膜复合的VO2薄膜，在紫外照射下，相变温度降低最明显。从Ag离子热处理转变为金属Ag与TiO2颗粒形成肖特基势垒，探讨了非均匀分布控制掺杂提高光生载流子分离效率的机理。探讨了紫外光作用下，非均匀底部控制掺杂方式的TiO2薄膜复合VO2薄膜影响VO2相变的机理。
其他摘要	Smart window is a very important part of the green energyefficient architecture. Because the most quantity of solar radiation passes though a window resulting in the enhanced room temperature in summer, which cause the higher expenses in air-condition. The defects of the traditional heat preventing films are inability to adjust smartly and low transmittance of the visible light. So, many researches have been done in order to find new energyefficient smart window. Recently, the application of VO2 films in temperature-driven smart window has been reported. Although, there are still some technical difficulties, it also gets abroad attentions. In this paper, we base on the separation of photo-generated carries to achieve the photo-driven semiconductor-metal transition of the semiconductor films in order to control the transmittance of these films. The silver-modified nano-structured TiO2 films were prepared by a layer-by-layer dip-coating sol-gel technique. The structure of the films was characterized by SEM and XRD. The separation efficiency of the photo-generated carriers was studied by the electrochemical workstation and photocatalytic degradation experiments. And the optical influence of the films by the separation of the carries was evaluated by UV-vis and FTIR spectrophotometer. VO2 films were prepared by aqueous sol-gel method and were composite with TiO2 films. Under the UV illumination, the phase transition of the composite VO2/TiO2 films was tested by four probe instrument. The results are as follows: (1) For the Ag-modifying films, the separation efficiency of the photo-generated carries can be evidently enhanced by the TA and AT modes. And furthermore, the enhanced separation of carries can reduce the transmittance of the infrared ray slightly. (2) The Ag loading content also has an important effect on the carries separation efficiency, and the optimal concentrations of TA and AT modes are both 0.5at%. (3) For the VO2/TiO2 films, under the UV illumination, the composite film of VO2 with bottom non-uniform doped TiO2 has the most evident reduction of the phase transition temperature. The mechanism for enhanced separate efficiency of photo-generated carries of Ag-modifying TiO2 films was based on the formation of the Schottky barriers and their non-uniform distribution. The mechanism for the effect of the phase transition of the composite VO2/TiO2 films by UV illumination was discussed.
页数	71
语种	中文
文献类型	学位论文
条目标识符	http://ir.giec.ac.cn/handle/344007/4023
专题	中国科学院广州能源研究所
推荐引用方式 GB/T 7714	郑金玉. Ag-TiO2和VO2/Ag-TiO2薄膜的制备及光致阻热性能研究[D]. 广州能源研究所. 中国科学院广州能源研究所,2007.

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