ABSTRACT Gallium nitride (GaN), a third‐generation wide‐bandgap semiconductor renowned for its superior radiation tolerance, holds promise for advanced β‐ray detection. Herein, a scalable liquid metal‐assisted in situ synthesis method is presented to fabricate Sn‐doped GaN homojunctions via gallium oxide printing followed by ammonolysis, enabling energy band engineering to suppress dark currents and enhance detection efficiency. X‐ray photoelectron spectroscopy verifies the complete conversion of Ga 2 O 3 to GaN, whereas Sn doping narrows the bandgap from 3.7 to 3.5 eV, yielding a rectification ratio of 8.3 and reducing dark current to the picoampere level by mitigating thermal carrier tunneling. The resulting ultrathin GaN homojunction β‐ray detector exhibits rapid response (∼3.9 s)/recovery time (∼0.2 s) with high stability at intensities of 5–20 mCi cm −2 under 20 keV, and its responsivity can reach 2.8 nA mCi −1 . This approach leverages two‐dimensional (2D) material properties to inspire β radiation detectors for nuclear medicine, environmental monitoring, and high‐energy physics applications.
Liu et al. (Mon,) studied this question.