Solid-State Neutron Detection Based on Methylammonium Lead Bromide Perovskite Single Crystals

Perovskite-based semiconductors, such as methylammonium and cesium lead halides (MPbX₃: M = CH₃NH₃⁺ or Cs⁺; X = I^-, Br^-, or Cl^-), have attracted immense attention for several applications, including radiation detection, due to their excellent electronic and optical properties.^1,2,3,4,5,6 In addition, the combination of perovskites with other materials enables unique device structures. For example, robust and reliable diodes result when combined with metal oxide semiconductors. This device can be used for detection of nonionizing and ionizing radiation. In this paper, we report a unique perovskite single-crystal-based neutron detector using a heterojunction diode based on single-crystal MAPbBr₃ and gallium oxide (Ga₂O₃) thin film. The MAPbBr₃/Ga₂O₃ diodes demonstrate a leakage current of ∼7 × 10^-10 A/mm², an on/off ratio of ∼10², an ideality factor of 1.41, and minimal hysteresis that enables alpha particle, gamma-ray, and neutron detection at a bias as low as (-5 V). Gamma discrimination is further improved by 85% by optimizing the thickness of the perovskite single crystal. The MAPbBr₃/Ga₂O₃ diodes also demonstrate a neutron detection efficiency of ∼3.92% when combined with a ¹⁰B neutron conversion layer.