Effects of Carrier Transport Layers on Performance Degradation in Perovskite Solar Cells under Proton Irradiation

Perovskite solar cells (PSCs) are potentially ideal for use in space satellites and spacecraft. While perovskites were found to be robust to space particle irradiations, it is important to investigate the influences of the carrier transport layers in PSCs on the irradiation-induced performance degradation. This study reports on the responses of different CsMAFAPbI3-based PSCs to 250 keV proton irradiation. Spiro-OMeTAD is used as a hole transport material in the cells, whereas SnO2, TiO2, and In2O3 are used as electron transport materials. After irradiation, the three different cells are not degraded up to 1 × 1013 p/cm2 and follow a similar degradation trend with further increasing the proton fluence until they are completely destroyed at 6 × 1014 p/cm2. By means of recycling, it is shown that SnO2, TiO2, and In2O3 have little influence on cell degradation, although the square resistances of SnO2, TiO2, and In2O3 on FTO/glass substrates are increased by 15–19% after irradiation of 6 × 1014 p/cm2; instead, the degradation of the spiro-OMeTAD material accounts for the reduced performance of the PSCs. The proton irradiation leads to a de-doping effect of spiro-OMeTAD, causing an efficiency decrease of the PSCs. A more radiation-resistant hole transport material to replace spiro-OMeTAD is therefore warranted to extend the lifetime of the PSCs in space environments.