Improving the performance of kesterite solar cells by solution germanium alloying

Cation substitution is an effective strategy to regulate the defects/electronic property of kesterite Cu 2 ZnSn(S,Se) 4 (CZTSSe) absorbers and improve device photovoltaic performance. Here we report Ge alloying kesterite Cu 2 Zn(Sn,Ge)(S,Se) 4 (CZTGSSe) via...