Cs(Pb,Sn)I3−xBrx全无机钙钛矿太阳能电池中缺陷产生、消除及钝化机制的研究

有机-无机杂化钙钛矿太阳能电池是一种新型薄膜光伏技术，其最高光电转化效率已达22.7%。然而该材料中有机阳离子在高温、光照、湿度、氧和高能辐照等条件下易发生分解，因此不稳定性制约了它的应用前景。将有机基团替代为无机离子所得到的Cs(Pb,Sn)I3−xBrx全无机钙钛矿太阳能电池的稳定性得到大幅提高，然而最高效率仅为13%左右。为了进一步提升无机钙钛矿太阳能电池的效率，深入研究电池中缺陷的产生、消除与钝化便显得尤为重要。因此本研究可以通过使用透射电子显微镜和电子阴极发光等电镜技术，深入研究无机钙钛矿的晶体结构、晶型转化和晶体缺陷，探究缺陷之间相互作用机理以及对太阳能电池性能的影响，探索消除和钝化缺陷的方法，从而进一步提高无机钙钛矿太阳能电池的各项性能。无机钙钛矿晶体结构和化学组成与有机-无机杂化钙钛矿材料高度相似，因此，这项研究势必对优化有机-无机杂化钙钛矿太阳能电池性能有重要指导意义。

Organic-inorganic hybrid perovskite solar cells form a new type of thin film photovoltaic technology, which has achieved a recorded power conversion efficiency of 22.7%. However, organic cations tend to be decomposed under elevated temperatures, light illumination, in the presence of moisture or under high-energy irradiation. By replacing organic cations with inorganic Cs+, the stability of Cs(Pb,Sn)I3−xBrx inorganic perovskite solar cell greatly improves while the recorded power conversion efficiency is only around 13%. To further improve the efficiency of the inorganic perovskite solar cells, it is critical to understand the formation, elimination and passivation of defects. Therefore, by utilizing advanced electron microscopy techniques, such as transmission electron microscope and cathodoluminescence, this research is aiming to throughout understand the crystal structure, phase transition and crystal defects; to unveil the relationship between interactions of different kinds of defects and solar cell performances; to explore a method to eliminate and passivate the defects and finally to further improve performances of Cs(Pb,Sn)I3−xBrx inorganic perovskite solar cells. Due to the close structure and composition similarities between inorganic perovskites and organic-inorganic hybrid perovskites, this research’s outcomes could have an important role to guide the improvement of the performance of organic-inorganic hybrid perovskite solar cells as well.