X-ray Scintillation in Lead Halide Perovskite Crystals

TL;DR

This study demonstrates that hybrid lead halide perovskite crystals, especially 2D types, are promising low-cost, efficient X-ray scintillators suitable for large-area applications, despite some thermal quenching at room temperature.

Contribution

The paper compares X-ray scintillation properties of 3D and 2D lead halide perovskite crystals, highlighting the potential of 2D perovskites for practical scintillator devices.

Findings

High X-ray luminescence yields (>120,000 photons/MeV) at low temperature.

2D (EDBE)PbCl4 exhibits reduced thermal quenching and moderate light yield at room temperature.

Perovskite crystals show minimal trap states and after-glow effects.

Abstract

Current technologies for X-ray detection rely on scintillation from expensive inorganic crystals grown at high-temperature, which so far has hindered the development of large-area scintillator arrays. Thanks to the presence of heavy atoms, solution-grown hybrid lead halide perovskite single crystals exhibit short X-ray absorption length and excellent detection efficiency. Here we compare X-ray scintillator characteristics of three-dimensional (3D) MAPbI3 and MAPbBr3 and two-dimensional (2D) (EDBE)PbCl4 hybrid perovskite crystals. X-ray excited thermoluminescence measurements indicate the absence of deep traps and a very small density of shallow trap states, which lessens after-glow effects. All perovskite single crystals exhibit high X-ray excited luminescence yields of >120,000 photons/MeV at low temperature. Although thermal quenching is significant at room temperature, the large exciton binding energy of 2D (EDBE)PbCl4 significantly reduces thermal effects compared to 3D perovskites, and moderate light yield of 9,000 photons/MeV can be achieved even at room temperature. This highlights the potential of 2D metal halide perovskites for large-area and low-cost scintillator devices for medical, security and scientific applications.