Superior photo-carrier diffusion dynamics in organic-inorganic hybrid perovskites revealed by spatiotemporal conductivity imaging
Abstract
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 FAPbI3 thin 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.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Aug 18, 2021
- Source ID
- 10.1038/s41467-021-25311-1
Entities
People
- Fei Zhang
- Ji Hao
- Jiamin Quan
- Kai Zhu
- Keji Lai
- Xiaoming Wang
- Xiaoqin Li
- Xihan Chen
- Xuejian Ma
- Yanfa Yan
- Zhaodong Chu
- Zhiyuan Huang
Organizations
- National Science Foundation
- Robert A. Welch Foundation
- United States Army Corps of Engineers
- United States Department of Energy