CsPbBr 3 Perovskite Planar Detectors Surpass CdZnTe in High‐Energy Gamma‐Ray Spectroscopy

Abstract The detection of high‐energy gamma radiation (>1 MeV) at room temperature requires large‐volume semiconductor crystals with high absorption efficiency, charge transport properties, and stability. The CsPbBr 3 perovskite is a promising candidate due to its congruent melting growth, high defect tolerance, and cost‐effective fabrication. In this study, the performance of CsPbBr 3 is evaluated as a gamma‐ray detector across a wide energy range and up to 1332 keV and compare its efficacy to commercial CdZnTe (CZT) detectors of similar crystal thickness. The CsPbBr 3 detectors demonstrate high energy resolution, superior spectral fidelity for high‐energy gamma peaks (>1 MeV), and long‐term operational stability over 225 days without performance loss. Notably, CsPbBr 3 resolves closely spaced gamma lines with an excellent signal‐to‐noise ratio, including weak emissions from depleted uranium sources. Its more balanced charge transport compared to CZT minimizes signal distortion, even in thick detectors, and enables precise spectral peak definition without complex correction algorithms. Comparative measurements on planar detectors demonstrate that CsPbBr 3 achieves comparable energy resolution to CZT at energies <0.5 MeV and outperforms at high energies, making it a strong alternative for next‐generation radiation detection applications.