Wangxian Chen, Wentong Yang, Yixiong Ji, Yang Xu, Jiyuan Yu, Angela keyte, Qiang Zeng, Chao Ma, Pengjun Zhao, Aimin Chang, Fangyang Liu, Paul Mulvaney
A single-site co-doping strategy is proposed by using Na and Ag ions, which both target the same copper lattice site in CZTSSe. The synergistic effects of Na and Ag can help to achieve a V oc of 559 mV and a FF of 67.3% and an overall PCE of 13.2%.