近年来，基于钙钛矿材料（ABX3, A=Cs+, CH3NH3+(MA+), NH=CHNH3+(FA+); B=Pb2+, Sn2+; X= Cl-, Br-, I-）的新型太阳能电池取得了突飞猛进的进展。然而，电池的稳定性成为限制其进一步发展的瓶颈。本项目将围绕薄膜内离子迁移的形成机制和对电池稳定性的影响机制及解决方案展开，通过离子取代、溶剂辅助结晶等方法获得晶格能更高的钙钛矿材料，降低表面陷阱态诱导的电荷堆积，从而增强钙钛矿薄膜结构的稳定性。通过瞬态光电压和外电场诱导下正负离子自由基的迁移状况等微观动力学研究，明确电池迟滞效应的形成机制和离子迁移的诱发机制、迁移类型和迁移通道等，进一步阐明在一定光、热条件下，薄膜内的离子迁移对电池稳定性的影响机制，提出解决方案，最终制备稳定转换效率高达20%的钙钛矿太阳能电池。

Recently, the perovskite (ABX3, A=Cs+, CH3NH3+(MA+), NH=CHNH3+(FA+); B=Pb2+, Sn2+; X= Cl-, Br-, I-) solar cells have been made extremely rapid progress. However, the stability of the perovskite solar cells appears to be the bottleneck toward its commercialization. In the present project, we will focus on the formation mechanisms of ions migration and solutions to strengthen the stability of perovskite solar cells. The uniform ABX3 perovskite thin films with higher lattice energy can be obtained by means of ionic replacement and solution-assisted crystallization, which is able to alleviate the charge accumulation induced by the defects in film and thereby enhance the stability of solar cell. The mechanisms of hysteresis effects, the motivation, types and channels of ions migration are going to be explored in view of microscopic dynamics by the combination techniques of transient photovoltage decay and migration of positive/negative ions induced by the electric field. On the basis, we will study systematically the effect of ions migration on the stability of perovskite solar cells upon light soaking and/or with thermal treatment, and eventually long-term stable perovskite solar cell with efficiency above 20% is supposed to be obtained.