Ion Irradiation of Halide Perovskites: Role of Defect Engineering for Enhanced Performance

ABSTRACT Halide perovskites are excellent materials for optoelectronic applications, exhibiting high radiation hardness that makes them ideal for space environments. This article reviews the ion beam modification of halide perovskites and highlights consistently beneficial material properties relevant to photovoltaic applications. Improvements such as prolonged photoluminescence lifetimes, enhanced open‐circuit voltage in solar cells, and strain relaxation are consistently observed across published experimental results. However, conventional ion beam interaction models fail to explain these phenomena as they ignore rapid defect recombination driven by the low ion migration activation energy of perovskites. The Hecking model provides a more realistic theoretical framework to describe defect formation in perovskites during ion irradiation. In this framework, the beneficial fluence regime likely correlates with a stable equilibrium of intrinsic point defects, whereas degradation is triggered by the formation of extended defects. These beneficial properties are predicted by the model and align with defect engineering strategies involving chemical modifications, such as mixed compositions, strain engineering, and the improved stability of 2D perovskites.