Intrinsic polarity extend β-Ga2O3/Janus-XP (X=P, As) heterostructures potential in UV/IR dual-band photodetector: A theoretical study

Abstract

Although β-Ga2O3/black phosphorus (α-BP) has been employed to realize ultraviolet and infrared (UV/IR) dual-band photodetector, how to employ intrinsic polarity to improve the optoelectronic properties of β-Ga2O3/α-BP heterostructure further has not been demonstrated yet. Here, by investigating the interfacial electronic and optical properties of β-Ga2O3/Janus-XP (X=P, As) heterostructures with intrinsic polarity, we found that all β-Ga2O3/Janus-XP heterostructures exhibit type-II band alignment, regardless of the direction of intrinsic polarity. Moreover, β-Ga2O3/Janus-AsP heterostructures with intrinsic polarity possess stronger stability, more effective charge transfer with a lower tunneling barrier, and better UV/IR dual-band optical detection, which could be further improved when the direction of intrinsic polarity points away from the interface. The underlying mechanism is the extra carriers driving force introduced by intrinsic polarity. Our findings provide a deep understanding of β-Ga2O3/Janus-XP heterostructures and suggest an effective way to design high-performance β-Ga2O3 UV/IR dual-band photodetectors.