Journal ArticleSuperior photo-carrier diffusion dynamics in organic-inorganic hybrid perovskites revealed by spatiotemporal conductivity imagingMa, Xuejian; Zhang, Fei; Chu, Zhaodong; Hao, Ji; Chen, Xihan; Quan, Jiamin; Huang, Zhiyuan; Wang, Xiaoming; Li, Xiaoqin; Yan, Yanfa; Zhu, Kai; Lai, Keji<title>Abstract</title> <p>The outstanding performance of organic-inorganic metal trihalide solar cells benefits from the exceptional photo-physical properties of both electrons and holes in the material. Here, we directly probe the free-carrier dynamics in Cs-doped FAPbI₃thin films by spatiotemporal photoconductivity imaging. Using charge transport layers to selectively quench one type of carriers, we show that the two relaxation times on the order of 1 μs and 10 μs correspond to the lifetimes of electrons and holes in FACsPbI₃, respectively. Strikingly, the diffusion mapping indicates that the difference in electron/hole lifetimes is largely compensated by their disparate mobility. Consequently, the long diffusion lengths (3~5 μm) of both carriers are comparable to each other, a feature closely related to the unique charge trapping and de-trapping processes in hybrid trihalide perovskites. Our results unveil the origin of superior diffusion dynamics in this material, crucially important for solar-cell applications.</p>Nature2021-12-0110474713Nature Communications1212041-1723https://doi.org/10.1038/s41467-021-25311-11720595National Science Foundation