Defect Engineering in β-Ga₂O₃/4H-SiC Heterojunctions via Kr Ion Irradiation for Enhanced Solar-Blind Photodetector Performance

This study investigates the impact of 1302 MeV krypton ion irradiation on the structural, optical, and electrical properties of β-Ga₂O₃/4H-SiC heterostructures. Through a combination of X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), photoluminescence (PL), and current-voltage (I-V) measurements, we systematically analyzed irradiation-induced defect formation and its effects on device performance. The results reveal that irradiation introduces a significant density of gallium vacancies (<i>V</i>_Ga), oxygen vacancies (<i>V</i>_O), and Ga-O vacancy pairs (<i>V</i>_Ga-<i>V</i>_O), which considerably alter the material's optoelectronic properties. PL intensity at specific wavelengths was enhanced after irradiation, while changes in dark and photocurrent characteristics indicate increased carrier recombination and the formation of leakage current channels. Despite the rise in dark current, the irradiated sample exhibited a significantly enhanced responsivity of 288.20 A/W under a 10 V bias and 75 μW/cm² illumination (compared to 21.70 A/W in the control sample). These findings contribute to the understanding of radiation-induced defect dynamics in β-Ga₂O₃ heterojunctions in extreme environments and provide insights for designing radiation-tolerant optoelectronic devices for space applications, nuclear safety systems, and advanced communication technologies.