From Tracks to Hotspots: Particle-Dependent Radiation Energy Deposition in MAPbI₃ Perovskite

Geant4 (version 11.3.2) simulations were used to study particle-dependent radiation interaction in MAPbI₃ under electron, photon, and neutron irradiation. The analysis focused on spatial distributions of interaction events, released energy, secondary-particle generation, and process-specific contributions. A 1 mm single-layer MAPbI₃ target was used to identify the intrinsic material response, while multilayer MAPbI₃ containing detector geometries were considered to assess device-like effects. Electrons produced extended charged particle tracks governed by direct energy loss and secondary-electron cascades. Photons showed weak direct energy deposition, with the response mainly controlled by secondary electrons generated in discrete electromagnetic interactions. Neutrons produced sparse but locally intense energy-release patterns dominated by recoil particles and nuclear-reaction products. The results show that total released energy alone is insufficient to describe radiation response in MAPbI₃; spatial morphology and the balance between primary and secondary contributions are essential for interpreting both detector operation and possible radiation-induced degradation.