Ag, Ti dual-cation substitution in Cu 2 ZnSn(S,Se) 4 induced growth promotion and defect suppression for high-efficiency solar cells

• Published in: Journal of materials chemistry. A, Materials for energy and sustainability Vol. 10; no. 42; pp. 22791 - 22802
• Main Authors: Chen, Xing-Ye, Ishaq, Muhammad, Ahmad, Nafees, Tang, Rong, Zheng, Zhuang-Hao, Hu, Ju-Guang, Su, Zheng-Hua, Fan, Ping, Liang, Guang-Xing, Chen, Shuo
• Format: Journal Article
• Language: English
• Published: 01.11.2022
• ISSN: 2050-7488; 2050-7496
• DOI: 10.1039/D2TA05909F

The existence of various detrimental defects inside the absorber layer is a major obstacle limiting the performance of kesterite Cu 2 ZnSn(S,Se) 4 (CZTSSe) thin-film solar cells. Cationic substitution is a viable strategy for overcoming this challenge and has drawn tremendous research attention. In this work, a dual-cation substituted CZTSSe involving Ag and Ti to separately occupy partial Cu and Sn lattice sites is proposed. Under 6% Ag and 1% Ti dual-cation substitution, the champion CZTSSe device delivers a highly interesting efficiency of 12.73%, accompanied by an outstanding V OC of 530 mV. Further investigation demonstrates that Ag introduction can improve the density and crystallinity of CZTSSe thin films while decreasing the concentration of Cu Zn acceptor defects. Further Ti substitution can effectively eliminate fine grains and reduce the defect density of Cu Sn and [2Cu Zn + Sn Zn ] defects, as well as the core level defects. This work explores the synergistic effect of Ag, Ti dual-cation substitution in CZTSSe solar cells for the first time, and the clarified device performance improvement mechanism opens up promising possibilities for the bright development of CZTSSe thin-film photovoltaic technology.