Electronic structure and fast neutron direct-conversion detection in organic–inorganic hybrid perovskites

Abstract

Traditional semiconductor neutron detectors improve neutron detection efficiency by covering organic materials as the neutron conversion layer. However, the injection efficiency of the recoil proton into the semiconductor detector is also affected by the scattering of the conversion layer itself. Here, we report the hybrid perovskite MAPbBr3 (MA = CH3NH3+) material, which merges the converter and semiconductor together at the atomic-scale, as a fast neutron direct-conversion detector to achieve efficient recoil proton injection. This hybrid material has a hydrogen concentration of 2.87 × 1022 n cm−3 and a μτ product of 4.49 × 10−3 cm2 V−1, combining the advantages of organic and inorganic materials. For two-dimensional perovskite materials, (PEA)2PbBr4 (PEA = C6H5CH2CH2NH3+) has a higher hydrogen concentration. However, the carrier transport in the Z direction is hindered by its double quantum well structure. The MAPbBr3 detectors achieved direct fast neutron detection and exhibited a good response with a deuterium–tritium (D–T) mixed beam neutron generator. Further calculations show that MAPbBr3 exhibits a self-repairing effect, and the existence of H-vacancy defects neither creates deep-level defects nor significantly affects the interlayer band alignment. This work opens up a new strategy for high-efficiency fast neutron detectors from the perspective of organic and inorganic hybrid materials.