High-performance self-powered p-GaN/Ga 2 O 3 solar-blind photodetector via in situ GaON interface engineering

Abstract Semiconductor interface engineering is critical for optimizing heterojunction optoelectronic devices. In this paper, we report on a high-performance self-powered p-GaN/ Ga 2 O 3 heterojunction solar-blind photodetector enhanced via an in situ –generated GaON interlayer. Using oxygen plasma treatment and high-temperature annealing, the GaON layer acts as a modulation spacer that physically separates the heterojunction interface. The artificially designed interlayer can effectively extend the depletion region and suppresses band-to-band tunneling, leading to a dramatic reduction in dark current. The treated detector exhibits a dark current reduction of 4 orders of magnitude (down to 10 pA at −10 V), enabling highly specific detectivity of 2.7 × 10 13 (1.6 × 10 13 ) Jones at 250 nm (350 nm) and achieves a remarkable responsivity of 1.4 (0.75) A W −1 at 250 nm (350 nm). In addition, the optimized device structure enables a fast separation of electron-hole pairs, yielding rapid rise/decay times of 21 μ s/49 μ s. Our findings demonstrate the remarkable role of GaON interlayers in suppressing the leakage current and modulating carrier dynamics, offering an effective route for fabricating high-sensitivity, self-powered semiconductor UV photon detectors.