Photovoltaic Action in Graphene–Ga₂O₃ Heterojunction with Deep‐Ultraviolet Irradiation

Abstract

We demonstrate the fabrication of a monolayer graphene/β‐Ga 2 O 3 heterostructure and its interesting prospect of producing a suitable Schottky barrier potential for deep‐ultraviolet (DUV) responsive photovoltaic device. The transient response behavior shows a faster response time for photovoltaic mode operation of the photodiode. The fast response at a zero bias is due to generation of photocurrent under an internal built‐in field in the graphene/Ga 2 O 3 interface without any contribution from the trapped carriers. The fabricated device also shows an excellent photoresponsivity of 6.1 A W −1 with a slower response time at a low reverse bias voltage (−1.5 V). The high photoresponsivity at a bias voltage can be related to carrier multiplication due to carriers trapping/release process. Our findings show that the graphene/β‐Ga 2 O 3 heterostructure can be significant for self‐powered/low power consuming DUV detector applications.