HCOO− Doping‐Induced Multiexciton Emissions in Cs3Cu2I5 Crystals for Efficient X‐Ray Scintillation

Self-trapped exciton (STE) luminescence, typically associated with structural deformation of excited states, has attracted significant attention in metal halide materials recently. However, the mechanism of multiexciton STE emissions in certain metal halide crystals remains largely unexplored. This study investigates dual luminescence emissions in HCOO