基于同步辐射掠入射 X 射线衍射的钙钛矿太阳能电池退化机理研究

项目名称： 基于同步辐射掠入射 X 射线衍射的钙钛矿太阳能电池退化机理研究

项目编号： No.11505280

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 数理科学和化学

项目作者： 陈振华

作者单位： 中国科学院上海应用物理研究所

项目金额： 22万元

中文摘要： 近年来钙钛矿太阳能电池以其超高效率成了全世界的研究热点，但稳定性差成为其应用的瓶颈。本项目拟使用同步辐射掠入射 X 射线衍射(GIXRD)方法，通过设计原位固-气反应装置，实现对不同环境中钙钛矿薄膜表面和界面晶体结构的原位研究，阐明钙钛矿太阳能电池的退化机理。在前期合成甲胺铅碘钙钛矿(CH3NH3PbI3)的基础上，进一步以晶体结构表征为指导，在二氧化钛(TiO2)薄膜上制备高质量的CH3NH3PbI3薄膜。通过对钙钛矿在水氧气氛中的面外和面内GIXRD原位研究，获得其表面不同方向的晶格常数变化。进而改变X射线入射角来调控其分析深度，在温度变化的过程中原位研究钙钛矿在TiO2/CH3NH3PbI3界面的相变和晶格畸变，并结合第一性原理方法计算钙钛矿的态密度，探索钙钛矿薄膜表面和界面晶体结构变化对态密度和光伏性能的影响规律。本项目的开展，对于制备稳定和高效率的钙钛矿太阳能电池具有重要意义。

中文关键词： 钙钛矿；太阳能电池；同步辐射；原位研究；晶体结构

英文摘要： Perovskite solar cells attract much attention all over the world due to their ultra-high power conversion efficiency. However, the poor stability prevents their further application. The synchrotron based grazing incident X-ray diffraction (GIXRD) method will be employed in this project, to in-situ study of the surface and interfacial crystal structure of perovskite films in different conditions. The designed in-situ solid-gas reaction device will assist the in-situ GIXRD study, so that the degradation mechanism of perovskite solar cell can be explored. Based on our previous work on preparation of CH3NH3PbI3 nanocrystals, high quality CH3NH3PbI3 nanocrystals film will be fabricated on the mesoporous titanium dioxide (TiO2) layer, assisted by characterization of their crystal structures. Through in-situ GIXRD study of perovskite in the water and oxygen atmosphere with out-of-plane and in-plane mode, the change of surface lattice constants in different direction will be obtained. Furthermore, the depth dependent GIXRD analysis can be achieved by changing of X-ray incident angle, while the phase change and lattice distortion will be in-situ investigated at TiO2/CH3NH3PbI3 interface during the temperature changes. Combining with the density of state study by the first principle calculation, the rule among surface and interfacial crystal structure of perovskite, their density of state and photovoltaic performance will be constructed. The conducted project is significant to the development of stable and efficient perovskite solar cells.

英文关键词： Perovskite ;solar cell;synchrotron radiation;in-situ study;crystal structure