柔性无裂纹SnO2复合光阳极制备、微结构调控及其光电性能研究

Dye-sensitized solar cells based on indium tin oxide (ITO) coated plastic substrates are flexible, light and unbroken. But the organic substrates don’t endure high temperature annealing treatment, all the preparing process of photoanodes should be accomplished under the temperature about 150℃. The nanocrystal films prepared under low temperature shows many drawbacks, such as cracks, low firmness, low electron mobility, and so on. These problems have been the development bottleneck of flexible dye-sensitized solar cells (FDSCs). In this project, SnO2/metal oxide complex films will be deposited on ITO/PEN substrate by electrophoretic deposition method. The microstructure of SnO2 complex films will be designed and optimized in the following three aspects: morphology of nanocrystal particles, the metal oxide blocking layers and surface functional groups. So we can adjust the band edge structure of SnO2 complex films. And improve the surface modification uniformity and the connection of nanocrystals. It also can be expected to buffer the inner stress appeared during the drying process of the nanocrystal films. The electrodeposited films will be treated by mechanical compression and UV irradiation. As a result, we can prepare crack-free SnO2 complex films with fine electron migration performance under low temperature. The influential factors for the cracks in the nanocrystal films will be generally and essentially reveled. The efficient ways will also be explored to remove the cracks. The effect mechanism of the microstructure on the electron mobility and dark reaction process will also be thoroughly investigated. Based on the above experiments, the electron mobility of the nanocrystal photoanode films will be enhanced and the surface dark reaction will be effectively restrained. The results of this project will provide theoretical basis and reference data for the application of SnO2 complex films in flexible dye-sensitized solar cells.

采用镀氧化铟锡导电层的有机高分子薄膜作为柔性染料敏化太阳能电池电极衬底，具有可变形、重量轻和不易破碎等优点。但受基底耐热温度的限制，低温制备的纳米晶薄膜容易形成裂纹，牢固度差，电子迁移率低。针对上述问题，本项目拟在ITO/PEN柔性导电衬底上电泳沉积SnO2/金属氧化物复合薄膜，从纳米晶颗粒形貌、表面金属氧化物修饰层及表面吸附功能化基团等三个方面设计和优化SnO2复合薄膜的微结构，实现纳米晶颗粒间的紧密接触，缓冲薄膜干燥过程中内应力的变化，结合机械挤压、紫外光辐照等后处理工艺，在低温条件下制备具有良好电子传输性能的无裂纹SnO2复合薄膜。 探索影响纳米晶薄膜裂纹的因素及其作用规律，寻求避免裂纹的有效方法，探究薄膜微结构对SnO2复合薄膜电子迁移及复合过程的作用机制，提高电子迁移速率、减小表面副反应，为SnO2复合薄膜应用于柔性染料敏化太阳能电池提供实验数据和理论依据。

敏化太阳能电池由于其制备过程简单、价格低廉等特点受到了越来越多的关注。本课题围绕SnO2与金属氧化物复合及其微结构调控开展研究工作，采用机械压膜技术制备了具有良好颗粒连接性能和较小复合反应的无裂纹SnO2/ZnO复合薄膜光阳极，组装柔性敏化太阳能电池，优化后光电转换效率为3.95%。结合SnO2纳米片的高电子传输性能和TiO2纳晶颗粒的高比表面积优势，以ZnO纳米片作为模板制备了SnO2纳米片/TiO2纳晶颗粒复合薄膜光阳极，光电转化效率比纯TiO2纳晶颗粒光阳极组装的电池提高了约35%。随后，对ZnO纳米片模板进行改进，通过在ZnO纳米片表面引入TiO2层，控制ZnO种子层前驱体溶液中乙酸锌的浓度及水热工艺，制备了形貌可控的三维分级结构的ZnO纳米片-纳米棒复合薄膜。采用CdS/CdSe量子点共敏化所制备的ZnO纳米片-纳米棒复合薄膜，经优化后，获得6.0%的光电转换效率。分别以MnO2纳米棒和葡萄糖作为模板制备了纳米空心管状和空心微球状等空心结构SnO2微粒材料，研究SnO2微结构对电池光电性能的影响。该项目为SnO2光阳极的性能优化及其在柔性敏化太阳能电池中的应用提供一定的理论基础及参考数据。本课题已按照研究计划完成了相关研究内容，基本达到了预期目标，在基础研究和人才培养等方面取得了一定的进展。相关研究结果分别在学术期刊上发表科研论文10篇。申请发明专利3项，其中2项已获得授权。培养硕士研究生6名。