γ‑ray Radiation on Flexible Perovskite Solar Cells

Flexible solar cells are promising for space applications due to their unique properties including lightweight and flexibility. In particular, flexible perovskite solar cells (f-PSCs) with high efficiencies have a much stronger competitiveness, but study about the radiation tolerance of f-PSCs is still absent. Herein, the radiation tolerance of methylammonium (MA)/formamidinium (FA)/cesium (Cs)-based triple cation f-PSCs under γ-ray was investigated systematically, with a planar heterojunction structure of PEN/ITO/SnO₂/perovskite/spiro-OMeTAD/Ag. The results show that the photovoltaic performance of the cells experienced an obvious deterioration after γ-ray irradiation, especially the short-circuit current density. It is mainly attributed to the decreased transparency of the flexible substrate, namely, poly­(ethylene naphthalate) (PEN), and the decomposition of perovskite films under γ-ray irradiation. In spite of the performance degradation, the radiation tolerance of f-PSCs was still much better than that of rigid counterparts. It suggests that f-PSCs are more suitable for space application, showing better prospects.