Self-powered solar-blind photodetectors based on AlN/a-Ga2O3 heterojunctions with a nanocolumnar structure on various substrates

Abstract

AlN/amorphous Ga₂O₃ heterojunction photodetectors were fabricated to achieve solar-blind UV detection. The responsivity and detectivity of the photodetector on a native substrate are 150% and 21.8% higher than those on a heterogeneous substrate at a 20 V bias, reaching 8.31 A W⁻¹ and 3.24 × 10¹⁴ Jones, respectively. The built-in electric field enables self-powered UV detection without an external power supply. The addition of a nanocolumnar AlN structure significantly improved the performance of the photodetector, achieving a photo-to-dark current ratio and responsivity up to 2.11 × 10⁷ and 9.17 mA W⁻¹ at 0 V bias. The fabricated photodetector has demonstrated self-powered and high-sensitivity UV detection.