Effects of Excitation Density on the Scintillation Properties of Organic–Inorganic Layered Perovskite-type Compounds

Abstract

The scintillation properties of organic-inorganic layered perovskite-type compounds were analyzed using pulsed beams having different linear energy transfers (LETs). Initially the decay was slower and then became faster at higher LETs. A possible cause of the slower decay at higher LETs is the competition between the radiative process and trapping at nonradiative sites, resulting in some excitons not being trapped at nonradiative sites at which other excitons have already been trapped at higher LETs. The faster decay at higher LETs is attributed to the interaction of excited states, such as biexciton formation or a nonradiative Auger process. In addition, the LET dependence was most pronounced for (C 6 H 5 C 2 H 4 NH 3 ) 2 PbBr 4 , whose radiative rate and luminescence quantum efficiency were the highest among the investigated compounds. This result is because the radiative process in this compound, as a major decay process, is more significantly influenced by excited state interactions at higher LETs.

Scintillation Properties of an Organic–Inorganic Lead Iodide Perovskite Single Crystal Having Quantum Well Structures

“…Excitons confined in the inorganic layers have a high binding energy, and thus fast and highly efficient luminescence can be expected. (18,19) As further advantages, the perovskite crystals can be grown at a low cost owing to a low-temperature process in comparison with most inorganic scintillators synthesized by melt-growth methods (e.g., Czochralski, Bridgeman, and Floating Zone methods). (6,(20)(21)(22) According to a previous study, (C 6 H 5 C 2 H 4 NH 3 ) 2 PbBr 4 has shown high LY (14000 ph/MeV) and fast scintillation decay time (11 ns).…”

Photoluminescence and Scintillation Properties of Ce-, Pr-, and Tb-doped (Gd,Lu)2Hf2O7 Crystals

“…(3) In general, an X-or γ-ray scintillator requires a high scintillation light yield (LY), short decay time, high energy resolution, high density, large effective atomic number, and low afterglow. Therefore, there has been continuous R&D to develop more desirable materials in single crystal, (4)(5)(6)(7)(8)(9)(10)(11)(12) ceramic, (13)(14)(15) glass, (16)(17)(18)(19) and liquid forms. (20)(21)(22) A high density and a large effective atomic number are important for obtaining large cross sections against X-and γ-rays; (23) thus, pyrochlore rare-earth hafnates (RE 2 Hf 2 O 7 , RE: rare earth) are potential scintillators with high density (9.0 and 9.7 g/cm 3 for Gd 2 Hf 2 O 7 and Lu 2 Hf 2 O 7 , respectively (24) ) and large effective atomic numbers (66-69).…”

Comparative Study of Optical and Scintillation Properties of Tm-doped La2Si2O7 and Lu2Si2O7 Single Crystals

“…For several decades until now, solid-state scintillators in various forms of materials, including plastics, (5) glasses, (6)(7)(8)(9)(10) single crystals, (11)(12)(13)(14)(15)(16) transparent ceramics, (17)(18)(19)(20) and composite materials, have been developed. (21,22) Among all the possible materials, single crystals are one of the promising choices because the single-crystal scintillator has many advantages, including high chemical stability, transparency, and high scintillation light yield. An obvious disadvantage is the typically higher cost to produce single crystals.…”