Effect of In-substitution on luminescence properties of organic-inorganic lead bromide layered perovskite-type scintillators

(C6H5C2H4NH3)(2)PbBr4 single crystals substituted with various concentrations of In (5, 10, 25, and 50%) were grown by the solvent diffusion method, and the effect of In-substitution on photoluminescence (PL) and scintillation properties were investigated. PL and scintillation peaks due to excitons confined in inorganic layers were observed, and the decay times were consistent with those of the free excitonic luminescence. The photoluminescence quantum yields of the 5, 10, 25, and 50% In-substituted crystals were respectively 23.0, 24.7, 26.0, and 25.2%. The light yield of the 25% In-substituted crystal was estimated to be 14100 photons/MeV from the pulse height spectrum under Cs-137 gamma-rays irradiation.