Scintillation in (C₆H₅CH₂NH₃)₂SnBr₄: green-emitting lead-free perovskite halide materials

We report the optical and scintillation properties of (C₆H₅CH₂NH₃)₂SnBr₄ with excellent absorption length at 20 keV of 0.016 cm, measured bandgap of 2.51 eV, and photoluminescence lifetime of 1.05 μs. The light yield obtained with the ²⁴¹Am source is 3600 ± 600 photons per MeV, which is much smaller than the maximum attainable light yield obtained from the bandgap. Temperature dependent radioluminescence measurements confirm the presence of thermal quenching at room temperature with the activation energy and the ratio between the attempt and the radiative transition rates of 61 meV and 129, respectively. Although thermal quenching affects light yield at room temperature, this green light-emitting perovskite opens an avenue for new lead-free scintillating materials.