Energy-band engineering and deep-ultraviolet photodetection of Ga2O3 alloys: a concise review

Gallium oxide (Ga2O3)-based solar-blind ultraviolet photodetectors gained much attention for their promising prospects in new-generation solid-state optoelectronics and electronics. Catering for the demands of broadband photodetection, tunable energy-band, adjusted carrier concentration and effective carrier transition, alloying engineering through doping is gradually launched as one of the research emphases. This review is proposed to understand the photodetection performances in view of energy-band engineering. Especially for the representative (InxGa1-x)2O3 and (AlyGa1-y)2O3 alloys, the conduction band edges upshift as the empty Al 3s and In 5s states are introduced with higher energy, hybridize with Ga 4s state. This leads to a result that low effective electron mass and high electron mobility could be achieved, contributing to high quality tunable performances of solar-blind UV photodetection. Thus, in this concise review article, the alloyed Ga2O3 for photodetection would be reviewed and discussed based on the current developments, from the viewpoint of energy-band theory.