Effect of bromine substitution in a linear alkyl monoamine on the luminescent properties of organic–inorganic layered perovskite-type compounds

2-dimensional organic–inorganic perovskite-type compounds (C n H 2n+1 NH 3 ) 2 PbBr 4 (n = 3 (C 3 ) 2 PbBr 4 , n = 4 (C 4 ) 2 PbBr 4 ), (BrC n H 2n NH 3 ) 2 PbBr 4 (n = 2 (C 2 Br) 2 PbBr 4 , n = 3 (C 3 Br) 2 PbBr 4 ) were fabricated to investigate the effect of bromine substitution in a linear alkyl monoamine on the luminescent properties. A photoluminescence peak derived from free excitons appeared in all the crystals when excited by 340 nm light. These quantum yields were 2.5 % ((C 3 ) 2 PbBr 4 ), 9.5 % ((C 4 ) 2 PbBr 4 ), 0.9 % ((C 2 Br) 2 PbBr 4 ), and 6.1 % ((C 3 Br) 2 PbBr 4 ). Further, an emission peak was also observed from all the crystals under X-ray, and the scintillation light yields were 2100 ((C 3 ) 2 PbBr 4 ), 4400 ((C 4 ) 2 PbBr 4 ), and 2200 ((C 3 Br) 2 PbBr 4 ) photons/MeV. In addition, short photoluminescence and scintillation lifetimes originating from free excitons on the order of nanoseconds were observed. • The effect of bromine substitution on the luminescent properties of the hybrid compounds was investigated. • The compounds showed a short scintillation decay time due to free excitons. • The positive correlation between a quantum yield and a scintillation light yield was observed.