High-Performance Solar Blind Ultraviolet Photodetector Based on Single Crystal Orientation Mg-Alloyed Ga2O3 Film Grown by a Nonequilibrium MOCVD Scheme

Abstract

It is crucial to realize high photoresponsivity and a fast response speed to meet the application requirements of solar blind ultraviolet (SBUV) photodetectors (PDs) in wireless communication, fire warning, and other fields. Such high-performance PDs depend on high-quality films. In this paper, a nonequilibrium MOCVD growth scheme is reported to obtain Mg-alloyed Ga2O3 films with single crystal orientation. On the basis of this film, the fabricated PD exhibits a large on/off ratio of approximately 105 (I254\xa0nm\xa0light/Idark), ultrahigh external quantum efficiency of 4341%, and high photoresponsivity of 8.9 A/W under 3 V bias. The performance of this device is greatly enhanced compared to the performances of those PDs based on amorphous gallium oxide films previously reported, which is attributed to the fewer number of grain boundaries of the single crystal orientation Ga2O3 films. Furthermore, it is found that under the same growth conditions, Ga2O3 films doped with an appropriate amount of acceptor impurit...