The Degradation of Cu2ZnSn(S,Se)4 Kesterite Thin Film Solar Cells Induced by Proton Radiation

Abstract Aiming at the current bottleneck of Cu 2 ZnSn(S,Se) 4 (CZTSSe) thin film solar cells, an experimental analysis of the performance and loss mechanism of CZTSSe thin film solar cells upon proton radiation exposure is presented. In order to deduce the important cell parameters, the environment of the cells is simulated by subjecting the devices to 200 keV proton irradiation with fluences from 1 × 10 10 to 1 × 10 17 cm ‐2 . It is found that the damage constants are sensitive to the elemental diffusion at heterojunction and Na redistribution in device. The incidence of the proton can lead to bandgap, tails fluctuations, and Urbach energy changes in the cells those directly impact defects and structural disorder in CZTSSe material thereby the device performance. The time‐resolved photoluminescence results show that the carrier lifetime is also very sensitive to the distribution of interface elements, especially Na, Cd, and S. These findings may provide new ideas for solving the V OC deficit of CZTSSe solar cells. From this work, it can be also suggested that the CZTSSe thin film solar cells are robust to proton irradiation and have the potential for future space applications.