Low temperature atomic layer deposition of GaOxNy thin film on III-GaN:Mg for UV photodetector

Abstract

In this work, a UV photodetector was fabricated by constructing a heterojunction between β phase GaOxNy prepared by atomic layer deposition and p-GaN prepared by metal organic chemical vapor deposition. The p-GaN layer shows an extremely sharp absorption characteristic with a cutoff edge of ∼365 nm, while β-GaOxNy shows a broad absorption behavior in the UV region due to its low crystal quality grown at low temperature (200 °C). The β-GaOxNy/GaN photodetector exhibits an obvious rectifying characteristic due to the formation of the type-II heterojunction and shows a high responsivity of 1.46 A/W at a bias voltage of −5 V and a rapid response speed (a rise time of 3.3 ms and a decay time of 6.8 ms). The investigation of the β-GaOxNy/GaN photodetector suggests a simple and effective strategy for next-generation high-performance optoelectronic devices.