Correlation between Structural Evolution and Device Performance of CH3NH3PbI3 Solar Cells under Proton Irradiation

Abstract

Organic–inorganic hybrid perovskite has gained enormous attention due to its potential applications in next-generation space solar cells. Although the influence of particle irradiation on perovskite materials and devices has been studied, the correlation between the structural evolution of materials and device performance under irradiation deserves to be further clarified. Herein, the relationship between the structural damage and performance degradation of CH3NH3PbI3 (MAPbI3) solar cells under 50 keV proton irradiation up to 1 × 1015 p cm–2 has been revealed by means of comprehensive experimental characterization and defect simulation. MAPbI3 films and solar cells exhibited excellent tolerance to proton irradiation up to 1 × 1014 p cm–2. In contrast, due to the partial amorphization caused by the degradation of organic groups at a higher proton fluence of 1 × 1015 p cm–2, the photoluminescence spectrum of MAPbI3 films quenched, the carrier lifetime shortened from 57.8 to 17.6 ns, and the density of trap states increased from 8.32 × 1015 to 1.69 × 1016 cm–3. Coupled with the deactivation of the hole transport layer, MAPbI3-based solar cells become inoperative under high irradiation greater than 1 × 1014 p cm–2. In addition, the photovoltaic performance of solar cells showed a noticeable recovery phenomenon when the fluence was no more than 1 × 1014 p cm–2, which was attributed to the imbalance between irradiation-induced defect generation at a high incident rate and defect recombination at different locations. Our results predict that, compared to accelerated simulation experiments on the ground, perovskite materials served in actual space environments at the same fluence have better resistance to proton irradiation due to a low injection rate, thus proving their application prospect in space solar cells.