High responsivity self-powered DUV photodetectors based on β-Ga2O3/GaN heterogeneous PN junctions

Ultra-wideband gap (∼5.16 eV) β-Ga2O3 epitaxial thin films with a Ta-doping range of 0–0.9 at.% were grown on porous p-type GaN substrates via the MOCVD method. The crystalline quality of β-Ga2O3 epitaxial thin films can be improved by controlling the doping concentration, and the epitaxial film with a Ta-doping concentration of 0.23 at.% present the highest crystalline quality. Self-powered deep ultraviolet (DUV) detector based on the β-Ga2O3 epitaxial thin film with the highest crystal quality exhibits the best photoresponse under a 222 nm UV light. The device under the DUV light presents a high responsivity (1.88 A·W−1), a high photo-dark current ratio (2.3 × 103), a high detectability (2.7 × 1013 Jones) and a low rise/fall time (0.15/0.14 s), respectively. Our results provided a novel method for fabricating self-powered DUV photodetectors based on the Ga2O3 epitaxial films with high performance.