Robust Zn:Ga2O3 DUV Photodetectors With Ultra-High Responsivity and Selectivity

Deep ultraviolet (DUV) photodetectors based on Ga₂O₃ have shown promise, yet face challenges in achieving high responsivity and spectral selectivity simultaneously. Here, we demonstrate a breakthrough in Zn:Ga₂O₃ photodetectors through innovative defect engineering, via a one-step approach combining low-temperature film growth and in-situ high-temperature annealing. Zn doping introduces deep-level acceptors to enhance the photoconductive gain, while passivating donor defects to suppress sub-bandgap absorption. The optimized device exhibits an ultrahigh responsivity (1543 A/W) and impressively high UV-visible rejection ratio (3.47 × 10⁵), surpassing most reported Ga²O³ photodetectors. Notably, the device with moderate Zn doping preserves operational stability at high temperature up to 300 °C. Such defect engineering offers a promising strategy to mitigate the typical responsivity-selectivity trade-off, paving the way for extreme-environment DUV photodetection applications.