Radiation Tolerance and Degradation Pathways in Mixed-Cation Metal-Halide Perovskites

Metal-halide perovskites (MHPs) exhibit notable radiation resilience and are considered a strong candidate for future solar power applications. However, their radiation tolerance is counterintuitive to their intrinsic structural softness. In this talk, I will present our latest insights into what exactly happens when space radiation - protons and electrons - interacts with these soft lattice systems. While the radiation-induced atomic displacement damage likely occurs at a much higher rate than previously thought, a combination of lattice softness, strong electron-phonon coupling, and low thermal conductivities synergistically heals the damage. I will argue that despite lattice softness being a virtue, it makes MHPs highly vulnerable to electronic ionization which drives thermal effects. Backed by fresh experimental findings, I will show that electrons induce significant structural damage in mixed-cation MHPs causing amorphization. Protons primarily lead to atomic displacements and are tolerated fairly well. Radiation effects in MHPs are therefore not entirely dictated by displacement damage, in stark contrast to the behavior of Si and III-V semiconductors.