Cation Engineering of Cu-Doped CsPbI₃: Lead Substitution and Dimensional Reduction for Improved Scintillation Performance

To date, inorganic halide perovskite nanocrystals show promising contributions in emerging luminescent materials due to their high tolerance to defects. In particular, the development of cesium lead iodide (CsPbI3) has shown its efficiency for light-harvesting properties. However, further implementation is hindered due to the toxicity of the lead content. Therefore, in this study, we introduced Cu atoms to partially substitute Pb atoms (5% Cu) in the CsPbI3 lattice as a solution to reduce the Pb toxicity. Partial substitution of Pb with Cu atoms in CsPbI3 host lattice increases the Stokes shift (∼67 nm) compared to pristine CsPbI3, thereby preventing the undesired self-absorption. An outcome is focused on the champion of a fast component (τ1) decay time of ∼0.6 ns. Temperature-dependent radioluminescence outlines an incremental change in the emission intensity marginally centered at 713 ± 16 nm, which indicates that Cu-doped CsPbI3 is not greatly affected by temperature. In addition, we report that the light yield pristine CsPbI3 after doping is increased to 3.0 ± 0.8 photons/keV. Our work provides physical insights into a tunable scintillation property using transition metal doping toward lead-free-based scintillating perovskites.