Research on the Fabrication and X‐Ray Detection Performance of MAPbBr₃‐Based 3D/2D Heterojunctions

Perovskite materials, renowned for their high mean atomic number, charge carrier mobility–lifetime product, and X‐ray absorption coefficient, have emerged as exceptional candidates for the fabrication of high‐sensitivity X‐ray detectors. Herein, a BA 2 PbBr 4 /MAPbBr 3 heterojunction is epitaxially grown, with ion migration effectively suppressed through the passivation of surface defects of the 3D heterojunction. Additionally, the presence of an internal electric field within the heterojunction facilitated the extraction and accumulation of photoinduced charge carriers, further enhancing device sensitivity (5964.05 μC Gy −1 cm −2 ). The fabricated 2D/3D perovskite heterojunction devices show outstanding self‐driven X‐ray detection performance at 0 V mm −1 bias (1195.5 μC Gy −1 cm −2 ), surpassing that of α‐Se detectors (20 μC Gy −1 cm −2 ). The proposed method for the fabrication of self‐driven detectors is relatively simple and is therefore expected to contribute to the commercialization of perovskite‐based X‐ray detectors.