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

• Published in: Physica status solidi. PSS-RRL. Rapid research letters 2018-08, Vol.12 (8), p.n/a
• Main Authors: Kalita, Golap, Mahyavanshi, Rakesh D., Desai, Pradeep, Ranade, Ajinkya K., Kondo, Masaharu, Dewa, Takehisa, Tanemura, Masaki
• Format: Article
• Language: English
• Subjects: beta‐gallium oxide; Bias; Electric potential; Electronics; Gallium oxides; Graphene; Heterojunctions; Photodiodes; Photoelectric effect; Photoelectric emission; photovoltaic action; Power consumption; Response time; Silicon; Ultraviolet radiation; vertical Schottky diode
• ISSN: 1862-6254; 1862-6270
• DOI: 10.1002/pssr.201800198

We demonstrate the fabrication of a monolayer graphene/β‐Ga2O3 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/Ga2O3 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‐Ga2O3 heterostructure can be significant for self‐powered/low power consuming DUV detector applications. Kalita et al. demonstrate the fabrication of a graphene/β‐Ga2O3 heterostructure and its interesting prospect of producing a suitable Schottky barrier potential for deep‐ultraviolet responsive photovoltaic device. The authors reveal the bias dependent transient response behaviour for the fabricated graphene/β‐Ga2O3 Schottky junction. The transient response behaviour shows a faster response time for photovoltaic mode operation of the photodiode.