# Structure‐Function Integration in 2D Hybrid Perovskite for Fast Neutron and Gamma Ray Discrimination

## TL;DR

A new hybrid perovskite material is developed for efficient detection and discrimination of fast neutrons and gamma rays, with potential for advanced radiation detection and imaging.

## Contribution

A novel 2D hybrid perovskite material with superior neutron/gamma discrimination is introduced.

## Key findings

- Large (GABA)2PbBr4 single crystals were successfully grown with high quality and oriented structure.
- The material achieves a high figure-of-merit (FOM) of 1.74 for neutron/gamma discrimination.
- Flexible composite scintillation films show high-resolution X-ray imaging capabilities.

## Abstract

Efficient discrimination between fast neutrons and gamma rays is crucial yet challenging for radiation detection. Here, the successful growth of large‐size, high‐quality 2D organic–inorganic hybrid perovskite single crystals, (GABA)2PbBr4, via an in situ seed‐assisted cooling method is reported. This material integrates hydrogen‐rich GABA cations with heavy‐atom lead halide layers, offering strong excitonic emission, efficient γ‐ray absorption, and fast neutron sensitivity. X‐ray diffraction reveals highly oriented crystals along the (004) plane with a narrow full width at half maximum (FWHM) of 12.81″. Optical characterizations indicate a wide bandgap (≈3.0 eV), sharp excitonic emission, and prominent self‐trapped exciton behavior, supported by transient and temperature‐dependent photoluminescence. The crystals exhibit an energy resolution of 9.0% at 662 keV and a high light yield of 10 695 ph MeV−1. Notably, superior neutron/gamma pulse shape discrimination (PSD) is achieved with a maximum figure‐of‐merit (FOM) of 1.74, enabling clear signal separation. Additionally, flexible composite scintillation films based on (GABA)2PbBr4 demonstrate high‐resolution X‐ray imaging up to 10 LP mm−1. These results highlight the potential of (GABA)2PbBr4 as a multifunctional scintillator for advanced radiation detection and imaging applications.

Using an in situ seed‐assisted cooling method, large (28 × 7 × 3 mm3) (GABA)2PbBr4 single crystals are grown, featuring hydrogen‐rich organic layers and a dense PbBr4 framework. This architecture enables efficient γ‐ray absorption, fast‐neutron sensitivity, and clear n/γ pulse‐shape discrimination (FOM up to 1.74), highlighting its potential as a multifunctional scintillator.