Performance Degradation of Ga₂O₃-Based X-Ray Detector Under Gamma-Ray Irradiation

X-ray response performances of a p-NiO/β-Ga₂O₃ hetero-junction diode (HJD) X-ray detector were studied before and after γ-ray irradiation at −200 V, with a total dose of 13.5 kGy(Si). The response performances of the HJD X-ray detector were influenced by the trap-assistant conductive process of the HJD under reverse bias, which exhibited an increasing net (response) current, nonlinearity, and a long response time. After irradiation, the Poole–Frenkel emission (PFE) dominated the leakage current of HJDs due to the higher electric field caused by the increased net carrier concentration of β-Ga₂O₃. This conductive process weakened the performance of the HJD X-ray detector in terms of sensitivity, output linearity, and response speed. This study provided valuable insights into the radiation damage and performance degradation mechanisms of Ga₂O₃-based radiation detectors and offered guidance on improving the reliability and stability of these radiation detectors.