Optical and scintillation characteristics of organic–inorganic layered compounds with a linear alkyl diamine

We prepared organic–inorganic layered perovskite-type compounds having a linear alkyl diamine (NH 3 C n H 2n NH 3 )PbCl 4 ( n = 6: (1, 6-DHX)PbCl 4 , n = 7: (1,7-DHP)PbCl 4 , n = 8: (1,8-DIO)PbCl 4 , n = 9: (1,9-DIN)PbCl 4 , n = 10: (1,10-DID)PbCl 4 , n = 11: (1,11-DIU)PbCl 4 ) and investigated their photoluminescence and scintillation characteristics. A broad band peak that should be attributed to self-trapped excitons (STEs) were observed at 555 nm ((1,6-DHX)PbCl 4 ), 520 nm ((1,7-DHP)PbCl 4 ), 525 nm ((1,8-DIO)PbCl 4 ), 525 nm ((1,9-DIN)PbCl 4 ), 550 nm ((1,10-DID)PbCl 4 ), and 530 nm ((1,11-DIU)PbCl 4 ) in scintillation. Also, they showed a scintillation decay time of 2.2 ns ((1,6-DHX)PbCl 4 ), 3.0 ns ((1,7-DHP)PbCl 4 ), 2.8 ns ((1,8-DIO)PbCl 4 ), 5.6 ns ((1,9-DIN)PbCl 4 ), 3.5 ns ((1,10-DID)PbCl 4 ), and 4.7 ns ((1,11-DIU)PbCl 4 ) due to the STE recombination. Further, the scintillation light yield of the (1,9-DIN)PbCl 4 crystal was the highest (1,200 photons/5.5 MeV- α ), and its value was higher than that of an undoped zinc oxide crystal.