Defect proliferation in CsPbBr3 crystal induced by ion migration

• Published in: Applied physics letters Vol. 116; no. 6
• Main Authors: Zhang, Bin-Bin, Wang, Fangbao, Zhang, Hongjian, Xiao, Bao, Sun, Qihao, Guo, Jun, Hafsia, Ahmed Ben, Shao, Aihui, Xu, Yadong, Zhou, Jian
• Format: Journal Article
• Language: English
• Published: Melville American Institute of Physics 10-02-2020
• Subjects: Applied physics; Cesium ions; Crystal defects; Crystal growth; Ion migration; Perovskites; Photoelectric effect; Photoelectricity; Photovoltaic cells; Physical properties; Solar cells; Temperature dependence; Thermally stimulated current; Time dependence
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/1.5134108

Ion migration in halide perovskite materials usually brings an intractable problem in the working stability of solar cells and photoelectrical detectors. The mechanism of ion migration and its impact on physical properties are still open questions. In this work, the ion migration behavior in solution-grown CsPbBr3 crystals was observed by the hysteresis in current–voltage curves and the temperature dependent reversed current–time measurements. Defect proliferation phenomena (new defects of [VCs]− and [PbBr]2+) originating from ion migration were verified by thermally stimulated current spectroscopy. Our results also give evidence that Cs+ ions also participate in the process of ion migration except the widely considered Br− ions. Furthermore, the photoelectric properties of the CsPbBr3 device were found to be seriously deteriorated after the ion migration. Our work demonstrates the strong correlation between the ion migration and physical properties in halide perovskites.