High-temporal dynamic self-powered β-Ga₂O₃/GaN heterojunction ultraviolet photodetector

Abstract

Abstract In this report, we successfully fabricate a high-temporal-response β -Ga 2 O 3 /GaN heterojunction ultraviolet (UV) photodetector. A high-quality 2-inch single-crystalline β -Ga 2 O 3 film is grown on GaN template with a GaO x buffer layer using plasma-assisted molecule beam epitaxy. Based on the as-grown film, a self-powered heterojunction detector with a unilateral recessed interdigital electrode is constructed. The device exhibits a broad-spectrum UV selective response characteristics with a cut-off edge at 330 nm and achieves a responsivity of 0.7 A W −1 under zero bias. Under a bias of 5 V, the rapid photoresponse rise time and decay time are 30 μ s and 10.8 ms, respectively, and the photo-to-dark current ratio reaches 10 3 . Considering the heterojunction energy band structure of β -Ga 2 O 3 /GaN, the work function difference of 0.43 eV facilitates electron migration and enables the self-powered operation. These results demonstrate a promising and efficient approach for developing high-performance, self-powered UV photodetectors and offer a robust alternative to conventional high-energy-consuming UV detection systems.