Unraveling the role of hydrogen bromide in the growth of cesium lead bromide perovskite nanocrystals

Jingjing Cao; Qungui Wang; Wen Li; Cheng Yan; Xiankan Zeng; Yue Gao; Xiaotong Zheng; Jun Lu; Weiqing Yang

doi:10.1016/j.jcis.2022.06.170

Unraveling the role of hydrogen bromide in the growth of cesium lead bromide perovskite nanocrystals

J Colloid Interface Sci. 2022 Nov 15:626:591-598. doi: 10.1016/j.jcis.2022.06.170. Epub 2022 Jul 3.

Authors

Jingjing Cao¹, Qungui Wang¹, Wen Li¹, Cheng Yan¹, Xiankan Zeng¹, Yue Gao¹, Xiaotong Zheng¹, Jun Lu², Weiqing Yang³

Affiliations

¹ Key Laboratory of Advanced Technologies of Materials (Ministry of Education),School of Materials Science and Engineering, State Key Laboratory of Traction Power, Southwest Jiaotong University, Chengdu 610031, PR China.
² Key Laboratory of Advanced Technologies of Materials (Ministry of Education),School of Materials Science and Engineering, State Key Laboratory of Traction Power, Southwest Jiaotong University, Chengdu 610031, PR China. Electronic address: Junlyuprc@hotmail.com.
³ Key Laboratory of Advanced Technologies of Materials (Ministry of Education),School of Materials Science and Engineering, State Key Laboratory of Traction Power, Southwest Jiaotong University, Chengdu 610031, PR China. Electronic address: wqyang@swjtu.edu.cn.

PMID: 35809447
DOI: 10.1016/j.jcis.2022.06.170

Abstract

Hydrogen bromide (HBr) could substantially improve the quality of cesium lead bromide perovskite (CsPbBr₃) nanocrystals (NCs) and greatly enhance their optoelectronic performance. However, clarifying the role of HBr in the growth of CsPbBr₃ NCs has been a substantial challenge thus far. Herein, we design an in situ cryogenic photoluminescence system using liquid nitrogen to unravel the role played by HBr in the growth of CsPbBr₃ NCs. Compared with no HBr (∼40 s), HBr improves the nucleation rate of CsPbBr₃ NCs about two times (∼20 s), and its emission peak also exhibits a redshift of ∼30 nm. Thus, we conclude that HBr accelerates the nucleation rate of CsPbBr₃ NCs and extends their growth stage, affording the generation of large grains. Perovskite light-emitting diodes based on CsPbBr₃ NCs with added HBr also exhibit an outstanding performance. These outcomes provide new insights into the role of HBr in CsPbBr₃ NCs and help prepare high-quality CsPbBr₃ NCs for use in the fabrication of efficient CsPbBr₃ NC-based optoelectronic devices.

Keywords: Cesium lead bromide perovskite nanocrystals; Growth dynamics; Hydrogen bromide; Perovskite light-emitting diodes; in situ cryogenic PL spectra.