Regulation of Zn/Sn ratio in kesterite absorbers to boost 10% efficiency of Cu2ZnSn(S, Se)4 solar cells |
(color online) (a) J–V curves and (b) EQE curves of best performance solar cells of R0–R4. (c) Efficiency, (d) open-circuit voltage, (e) short-circuit current density, (f) fill factor statistical box-charts for 18 solar cells of R0–R4. |