Inhibition of Phase Segregation in Cesium Lead Mixed-Halide Perovskites by B-Site Doping

Daocheng Hong; Peiyang Zhao; Yu Du; Cheng Zhao; Yuren Xia; Zhihong Wei; Zhong Jin; Yuxi Tian

doi:10.1016/j.isci.2020.101415

Inhibition of Phase Segregation in Cesium Lead Mixed-Halide Perovskites by B-Site Doping

iScience. 2020 Aug 21;23(8):101415. doi: 10.1016/j.isci.2020.101415. Epub 2020 Jul 29.

Authors

Daocheng Hong¹, Peiyang Zhao², Yu Du², Cheng Zhao², Yuren Xia², Zhihong Wei², Zhong Jin³, Yuxi Tian⁴

Affiliations

¹ Key Laboratory of Mesoscopic Chemistry of MOE, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu 210023, China; Key Laboratory for Advanced Technology in Environmental Protection of Jiangsu Province, Yancheng Institute of Technology, Yancheng 224051, China.
² Key Laboratory of Mesoscopic Chemistry of MOE, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu 210023, China.
³ Key Laboratory of Mesoscopic Chemistry of MOE, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu 210023, China. Electronic address: jinzhong@nju.edu.cn.
⁴ Key Laboratory of Mesoscopic Chemistry of MOE, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu 210023, China. Electronic address: tyx@nju.edu.cn.

Abstract

The emergence of all-inorganic halide perovskites has shown great potential in photovoltaic and optoelectronic devices. However, the photo-induced phase segregation in lead mixed-halide perovskites has severely limited their application. Herein, by real-time monitoring the photoluminescence (PL) spectra of metal mixed-halide perovskites under light irradiation, we found that the photo-induced phase transition can be significantly inhibited by B-site doping. For pristine mixed-halide perovskites, an intermediate phase of CsPbBr_xI_3-x can only be stabilized under low excitation power. After introducing Sn²⁺ ions, such intermediate phase can be stabilized in nitrogen atmosphere under high excitation power and phase segregation can be started after the exposure in oxygen due to oxidization of Sn²⁺. Replacing Sn²⁺ by Mn²⁺ can further improve the intermediate phase's tolerance to oxygen proving that B-site doping in perovskites structure by Sn²⁺ or Mn²⁺ could effectively minimize the light-induced phase segregation and promote them to serve as promising candidates in photovoltaic and light-emitting devices.

Keywords: Devices; Electrical Property; Optical Property.