KCl Treatment of CdS Electron-Transporting Layer for Improved Performance of Sb2(S,Se)3 Solar Cells

Aoxing Liu; Rongfeng Tang; Lei Huang; Peng Xiao; Yizhe Dong; Changfei Zhu; Hong Wang; Linhua Hu; Tao Chen

doi:10.1021/acsami.3c09500

KCl Treatment of CdS Electron-Transporting Layer for Improved Performance of Sb₂(S,Se)₃ Solar Cells

ACS Appl Mater Interfaces. 2023 Oct 18;15(41):48147-48153. doi: 10.1021/acsami.3c09500. Epub 2023 Oct 4.

Authors

Aoxing Liu¹, Rongfeng Tang¹, Lei Huang¹, Peng Xiao¹, Yizhe Dong¹, Changfei Zhu¹, Hong Wang², Linhua Hu³, Tao Chen¹

Affiliations

¹ Hefei National Research Center for Physical Sciences at the Microscale, CAS Key Laboratory of Materials for Energy Conversion, Department of Materials Science and Engineering, University of Science and Technology of China, No. 96 Jinzhai Road, Hefei, Anhui 230026, P. R. China.
² Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei 230026, P. R. China.
³ Key Laboratory of Photovoltaic and Energy Conservation Materials, CAS, Institute of Solid State Physics, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, Anhui 230031, China.

PMID: 37793191
DOI: 10.1021/acsami.3c09500

Abstract

Antimony sulfoselenide (Sb₂(S,Se)₃) is a promising light absorption material because of its high photoabsorption coefficient, appropriate band gap, superior stability, and abundant elemental storage. As an emerging solar material, hydrothermal deposition of Sb₂(S,Se)₃ solar cells has enabled a 10% efficiency threshold, where cadmium sulfide (CdS) is applied as an electron transport layer (ETL). The high-efficiency Sb₂(S,Se)₃ solar cells largely employ CdS as the ETL. In terms of efficiency improvement, there are two questions regarding the CdS substrate: (1) the high roughness of CdS grown on F-doped tin oxide glass which increases the roughness of the absorber layer and (2) the low conductivity of CdS films because of low purity of CdS film grown by chemical bath deposition. In this study, we demonstrate an effective potassium chloride (KCl) post-treatment to modify the CdS ETL for improving the Sb₂(S,Se)₃ solar cell efficiency. We found that KCl plays dual roles that reduce roughness and enhance conductivity of the CdS films, thus acquiring a maximum efficiency of 9.98%, which is 9.2% higher than the control device. This study provides a new method for the surface engineering of CdS layer to improve the morphological and electrical properties, which is significant for improving the performance of CdS-based thin-film solar cells.

Keywords: KCl; Sb2(S,Se)3; antimony selenosulfide; interface engineering; solar cell.