Temperature Dependence of Cu2ZnSnS4 Photovoltaic Cell Properties

We studied the temperature dependence of current--voltage characteristics of Cu 2 ZnSnS 4 (CZTS) photovoltaic cells to determine their fundamental properties. The open circuit voltage ($V_{\text{oc}}$) in CZTS cells increased from 0.61 to 0.85 V and showed a linear relationship with decreasing temperature in the range from 150 to 350 K. The $V_{\text{oc}}$ at 0 K was extrapolated to about 1.2 V, which is lower than the bandgap energy of CZTS. These results suggest that the reason for the lower $V_{\text{oc}}$ in CZTS cells is recombination at the interface between the CZTS and buffer layers.