Characterization on proton irradiation-damaged interfaces of CIGS-related multilayered compound semiconductors for solar cells by electrochemical impedance spectroscopy

For multilayered thin film solar cells, the degradation mechanism of high energy particle damage is usually evaluated by photovoltaic parameters. However, for each interface of the complex system still lacks direct detection techniques to distinguish the radiation damage layer-by-layer. Herein, we propose to apply electrochemical impedance spectroscopy for diagnosing the degradation properties of the irradiated thin film solar cells. Our result shows that the irradiation-induced new capacitance with resistance from high energy proton is not only at the interface of n-CdS/p-CIGS pn-junction, but also the interfaces of n-ZnO/n-CdS and p-CIGS/Mo, which can be further distinguished by the impedance spectroscopy with bias flow.