Tailored Phase Transformation of CsPbI2Br Films by Copper(II) Bromide for High-Performance All-Inorganic Perovskite Solar Cells

Kai-Li Wang; Rui Wang; Zhao-Kui Wang; Meng Li; Yue Zhang; Heng Ma; Liang-Sheng Liao; Yang Yang

doi:10.1021/acs.nanolett.9b01553

Tailored Phase Transformation of CsPbI₂Br Films by Copper(II) Bromide for High-Performance All-Inorganic Perovskite Solar Cells

Nano Lett. 2019 Aug 14;19(8):5176-5184. doi: 10.1021/acs.nanolett.9b01553. Epub 2019 Jul 18.

Authors

Kai-Li Wang^{1

2}, Rui Wang³, Zhao-Kui Wang^{1

3}, Meng Li¹, Yue Zhang¹, Heng Ma², Liang-Sheng Liao¹, Yang Yang³

Affiliations

¹ Institute of Functional Nano and Soft Materials (FUNSOM) , Soochow University, Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices , Suzhou , Jiangsu 215123 , China.
² College of Physics and Electronic Engineering , Henan Normal University , Xinxiang 453007 , P.R. China.
³ Department of Materials Science and Engineering , University of California , Los Angeles , California 90095 , United States.

PMID: 31310720
DOI: 10.1021/acs.nanolett.9b01553

Abstract

All-inorganic-based perovskites achieved by replacing the organic component with cesium (Cs) have drawn more attention because of their intrinsic inorganic stability. However, the cell efficiency in all-inorganic perovskite solar cells is still far below that in organic-inorganic hybrid perovskite-based devices. Here, we develop a new strategy to mediate the CsPbI₂Br crystallization by directly doping copper(II) bromide (CuBr₂) into a perovskite precursor. The incorporation of CuBr₂ played a role in retarding the crystallization dynamics process of CsPbI₂Br film, resulting in a high-quality all-inorganic perovskite film with enlarged grain size, improved carrier mobilities, and reduced trap states. The fabricated perovskite solar cells delivered a champion power conversion efficiency of 16.15%, which is the highest efficiency in CsPbI₂Br based all-inorganic perovskite solar cells and largely higher than 13.24% for pristine CsPbI₂Br based device. The developed doping method paves a new route to fabricate high-performance all-inorganic perovskite solar cells.

Keywords: CsPbIBr; Inorganic perovskites; copper(II) bromide; crystallization; phase transformation.