Notable Performance Enhancement of CsPbI2Br Solar Cells by a Dual-Function Strategy with CsPbBr3 Nanocrystals

Yanzhou Wang; Yali Li; Zhe Gao; Qiulu Chen; Weining Liu; Yujun Fu; Qiming Liu; Deyan He; Junshuai Li

doi:10.1021/acsami.3c13868

Notable Performance Enhancement of CsPbI₂Br Solar Cells by a Dual-Function Strategy with CsPbBr₃ Nanocrystals

ACS Appl Mater Interfaces. 2023 Nov 22;15(46):53558-53567. doi: 10.1021/acsami.3c13868. Epub 2023 Nov 8.

Authors

Yanzhou Wang¹, Yali Li¹, Zhe Gao¹, Qiulu Chen¹, Weining Liu¹, Yujun Fu¹, Qiming Liu¹, Deyan He¹, Junshuai Li¹

Affiliation

¹ LONGi Institute of Future Technology, and School of Materials & Energy, Lanzhou University, 222 South Tianshui Road, Lanzhou 730000, China.

PMID: 37939372
DOI: 10.1021/acsami.3c13868

Abstract

Herein, a dual-function strategy, in which CsPbI₂Br is treated by CsPbBr₃ nanocrystals (NCs) via addition and surface modification to construct the "electron bridge" and gradient heterojunction, respectively, to notably improve the performance of the CsPbI₂Br solar cells, is proposed. The "electron bridge" formed by the CsPbBr₃ NCs provides an extra transport channel for the photogenerated electrons in the CsPbI₂Br layer, thus facilitating electron transport. Meanwhile, surface modification of CsPbI₂Br by the CsPbBr₃ NCs forms a gradient heterojunction between the CsPbI₂Br layer and the P3HT layer, enhancing hole extraction accordingly. In addition, the CsPbBr₃ NC treatment passivates the defects at the bulk and surface of the CsPbI₂Br layers, thus suppressing carrier recombination. Thanks to these positive effects of the CsPbBr₃ NCs, the demonstration device with a simple configuration of ITO/SnO₂/CsPbI₂Br/P3HT/Ag achieves a notable power conversion efficiency of 17.03%, which is among the highest efficiencies reported for CsPbI₂Br-based solar cells.

Keywords: CsPbBr3 nanocrystals; CsPbI2Br solar cells; dual-function strategy; electron bridge; gradient heterojunction.