Cesium Lead Bromide (CsPbBr₃) Thin‐Film‐Based Solid‐State Neutron Detector Developed by a Solution‐Free Sublimation Process

Abstract The majority of solid‐state radiation sensors are predominantly single crystals. However, for low‐cost and large‐area device applications, thin films are a better option. The first evidence of neutron detection using a Gallium Oxide/Cesium Lead Bromide (Ga₂O₃/CsPbBr₃) solid‐state diode enabled by an innovative close space sublimation (CSS) method that allows deposition of thick CsPbBr₃ films is demonstrated. Furthermore, indirect neutron sensing is achieved using a ¹⁰B layer for diodes biased at voltages as low as –5 V, showing the potential for low‐power operation. The neutron response is enabled by the low leakage current (≈10⁻⁸ A mm^–2), rectification of ≈10⁴, capacitance as low as 15 pF, and fast response of the Ga₂O₃/CsPbBr₃ diode. The superior performance of the CsPbBr₃ is due to the phase purity, stoichiometry control, and large single‐grain columnar growth of the films obtained by the CSS method.