Improved Carrier Lifetimes of CdSe Thin Film via Te Doping for Photovoltaic Application

Jiayou Xue; Xuke Yang; Xiaoqing Bao; Liuchong Fu; Sen Li; Menglin Huang; Jun Wang; Haisheng Song; Shiyou Chen; Chao Chen; Kanghua Li; Jiang Tang

doi:10.1021/acsami.3c00461

Improved Carrier Lifetimes of CdSe Thin Film via Te Doping for Photovoltaic Application

ACS Appl Mater Interfaces. 2023 Apr 12;15(14):17858-17866. doi: 10.1021/acsami.3c00461. Epub 2023 Mar 31.

Authors

Jiayou Xue^{1

2}, Xuke Yang¹, Xiaoqing Bao¹, Liuchong Fu¹, Sen Li¹, Menglin Huang³, Jun Wang⁴, Haisheng Song^{1

5}, Shiyou Chen³, Chao Chen^{1

2

5}, Kanghua Li^{1

6}, Jiang Tang^{1

2

5}

Affiliations

¹ Wuhan National Laboratory for Optoelectronics (WNLO) and School of Optical and Electronic Information (SOEI), Huazhong University of Science and Technology, Wuhan 430074, Hubei, China.
² China-EU Institute for Clean and Renewable Energy, Huazhong University of Science and Technology, Wuhan 430074, Hubei, China.
³ Key Laboratory of Computational Physical Sciences (MOE), and State Key Laboratory of ASIC and System, School of Microelectronics, Fudan University, Shanghai 200433, China.
⁴ School of Physics and Optoelectronic Engineering, Shandong University of Technology, Zibo 255000, China.
⁵ Optics Valley Laboratory, Wuhan 430074, Hubei, China.
⁶ School of Integrated Circuit, Huazhong University of Science and Technology, Wuhan 430074, Hubei, China.

PMID: 37000018
DOI: 10.1021/acsami.3c00461

Abstract

Cadmium selenide (CdSe) solar cells have proven to be a remarkable potential top cell for a silicon-based tandem application. However, the defects and short carrier lifetimes of CdSe thin films greatly limit the solar cell performance. In this work, a Te-doped strategy is proposed to passivate the Se vacancy defects and increase the carrier lifetime of the CdSe thin film. The theoretical calculation helps to reveal the mechanism of nonradiative recombination of the CdSe thin film in depth. After Te-doping, the calculated capture coefficient of CdSe can be reduced from 4.61 × 10^-8 cm³ s^-1 to 2.32 × 10^-9 cm³ s^-1. Meanwhile, the carrier lifetime of CdSe thin film is increased nearly 3-fold from 0.53 to 1.43 ns. Finally, the efficiency of the Cd(Se,Te) solar cell is improved to 4.11%, about a relative 36.5% improvement compared to the pure CdSe solar cell. Both theoretical calculations and experiments prove that Te can effectively passivate bulk defects and improve the carrier lifetime of CdSe thin films, deserving further exploration to improve solar cell performance.

Keywords: DFT; cadmium selenide; carrier lifetime; defect passivation; solar cells.