Library of Two-Dimensional Hybrid Lead Halide Perovskite Scintillator Crystals

Abstract

hybrid lead halide perovskites are potential candidates for high light yield scintillators as they have small band gaps between 3 and 4 eV and large excitonbinding energy. Here, we discuss the scintillation properties from a total of 11 organic/inorganic hybrid perovskite crystals with two already reported crystals, (PEA) 2 PbBr 4 and (EDBE)PbBr 4 . Their photoluminescence and X-ray luminescence (XL) spectra are dominated by narrow and broad band emissions, and they correspond to free exciton and self-trapped exciton, respectively. The lifetimes derived from time-resolved XL strongly vary from 0.6 to 17.0 ns. These values make this type of compound among the fastest scintillators. For the light yield derived from the XL, we found that only (PEA) 2 PbBr 4 , (EDBE)PbBr 4 , and (BA) 2 PbBr 4 crystals have light yields between 10,000 and 40,000 photons/ MeV. The mechanisms for thermal quenching and afterglow are discussed in order to optimize the light yields. With gamma-ray excitation, we reported the best energy resolution of 7.7% at 662 keV with excellent proportionality. Finally, this study paves the way toward the ultimate high light yield and fast scintillators for medical and homeland security applications.

Manipulating Color Emission in 2D Hybrid Perovskites by Fine Tuning Halide Segregation: A Transparent Green Emitter

“…[7] In addition, their unique optical properties, including quantum and dielectric confinement, Rashba splitting, and large exciton binding energy, make them attractive for different fields beyond light-emitting applications, such as spintronics, imaging, and scintillators. [8][9][10][11][12][13] The general formula of Ruddlesden-Popper perovskites is R 2 A n−1 B n X 3n+1 in which A is typically an organic cation (methylammonium, MA + ), B a divalent metal species such as Pb 2+ , X a halogen monovalent anion (I − , Br − , Cl − ), and R a large organic spacer cation. The R cation usually contains an alkyl chain capable to isolate the inorganic octahedra of the perovskite in n-dimensional sheets; the framework of these 2DP can be described as a quantum well system in which the organic cations is able to space the semiconductive sheets in a confined dimension (see cartoon of Figure 1a).…”

“…[ 7 ] In addition, their unique optical properties, including quantum and dielectric confinement, Rashba splitting, and large exciton binding energy, make them attractive for different fields beyond light‐emitting applications, such as spintronics, imaging, and scintillators. [ 8–13 ]…”

Structure‐Property Relationships and Idiosyncrasies of Bulk, 2D Hybrid Lead Bromide Perovskites

“…[258] An initial library of X-ray 2D perovskite scintillators was recently expanded where the effects of the spacer cation and halide anion on the scintillating an luminescence performance was investigated through PL and X-ray luminescence (XL)related characterizations. [259] In total, 11 different lead bromide and lead iodide crystals were synthesized, consisting of (BA) have light yields between 10,000 and 40,000 photons/ MeV. In terms of scintillating performances, (BA) 2 PbBr 4 performs the best, showcasing the highest and most stable light yield (~40,000 photons/MeV at RT), a fast XL decay time of 5.3 ns and negligible afterglow at low temperatures.…”

Scintillation in (C6H5CH2NH3)2SnBr4: green-emitting lead-free perovskite halide materials

“…Lead halide perovskite materials gain lots of interest as a new generation of scintillating materials. [1][2][3][4] The reported compounds are commonly hybrid organic-inorganic perovskite (HOIP) lead halide crystals [4][5][6][7] or all-inorganic perovskite (AIP) lead halide quantum dots 2,8 and nanosheets. 9 For HOIP lead halide crystals, the main application is low-energy radiation scintillators, e.g.…”

“…X-ray, nevertheless recently they were shown to be effective for gamma-ray and neutron spectroscopy with good energy resolution. 6,7 Although larger effective atomic number and mass density should favor AIP lead halide quantum dots and nanosheets for stopping high-energy radiation applications, their radiation absorption lengths are in fact much smaller than those in bulks. The short actual lengths are due to the presences of the ligands and/or adhesives making the packing fractions much lower than those in bulks.…”