Wenli Xu, Yingzhao Zhang, Rui Wang, Chenyang Liu, Jialin Liu, Xiangyu Huo, Xinying Liu, He Zhang, Jianxu Ding*

Cite this article: Chin. J. Struct. Chem., 2025, 44(1), 100454. DOI: 10.1016/j.cjsc.2024.100454

Publication date: January 1, 2025

Keywords: Perovskite; Single crystal films; Space confined method; Surface passivation; Photodetectors

ABSTRACT

Ultra-thin single crystal film (SCF) without grain boundary, inherits low charge recombination probability as bulk single crystals. However, its low depth brings a high surface defects ratio and hinders carrier transport and extraction, which affects the performance and stability of optoelectronic devices such as photodetectors, and thus surface defect passivation is of great practical significance. In this paper, we used the space confined method to grow MAPbBr3 SCF and selected BA2PbI4 for surface defect passivation. The results reveal that BA cation passivates MA vacancy surface defects, reduces carrier recombination, and enhances carrier lifetime. The carrier mobility is as high as 33.6 cm2V-1s-1, and the surface defect density is reduced to 3.4 × 1012 cm-3. Thus, the self-driven vertical MAPbBr3 SCF photodetector after surface passivation exhibits more excellent optoelectronic performance.