最近的研究发现，以金属有机钙钛矿三卤化物为敏化剂的太阳能电池制造工艺简单，光电转化效率高，引起了人们极大的关注。然而目前对此类电池的效率提高手段通常是通过优化制造工艺，原因是人们对电池的核心材料——金属有机钙钛矿的基本性质的解读还远远不够，也就使得从本质上提高器件效率较为困难。因此，本课题针对一系列金属有机钙钛矿，从晶体结构、电子性质等基础角度出发，找出赋予该化合物高光伏活性的原因。我们将依托上海光源，利用常压和高压X射线衍射，以及常规和原位X射线吸收精细结构探究钙钛矿化合物的晶体结构与电子性质，重点研究不同卤离子与金属间的关系，以及金属阳离子中的孤对电子的存在对结构的影响。同时通过模拟器件实际操作环境，研究该化合物在不同物理环境下（湿度、温度、气体环境等）的形成及降解的动力学过程。研究成果将对于材料的基础科学以及器件的应用方面都产生十分重要的影响。

Organometallic trihalide perovskites are currently attracting great interest for their potential to be simple yet efficient solid-state solar cells. Although the performance of organometallic trihalide perovskite photovoltaics has increased greatly over the last few years, there are several unanswered questions regarding the fundamental properties of the perovskite compounds. Based on Shanghai synchrotron radiation facility, we propose to study the electronic and crystal structure of a series of organometallic trihalide perovskites using synchrotron excited X-ray absorption fine structure and X-ray diffraction. We will be focusing on the bonding property between metal and mixed halide ions, as well as the role of lone-pair electrons in metals on the long-range and local crystal structures. Meanwhile, the kinetic information on how the structure responds to different physical environment (i.e. temperature, exposure to humidity or oxidizing agent) will be obtained by performing in situ synchrotron spectroscopy. Our result will provide insight in both the fundamental material science and the device design strategy.