A highly sensitive, large area, and self-powered UV photodetector based on coalesced gallium nitride nanorods/graphene/silicon (111) heterostructure

• Main Authors: Zulkifli, Nur 'Adnin Akmar, Park, Kwangwook, Min, Jung-Wook, Ooi, Boon S., Zakaria, Rozalina, Kim, Jongmin, Tan, Chee Leong
• Format: Article
• Published: AIP Publishing 2020
• Subjects: QC Physics; TK Electrical engineering. Electronics Nuclear engineering
• Online Access: http://eprints.um.edu.my/25686/; https://doi.org/10.1063/5.0018076

In this paper, we demonstrate an ultraviolet photodetector (UV-PD) that uses coalesced gallium nitride (GaN) nanorods (NRs) on a graphene/Si (111) substrate grown by plasma-assisted molecular beam epitaxy. We report a highly sensitive, self-powered, and hybrid GaN NR/graphene/Si (111) PD with a relatively large 100 mm2 active area, a high responsivity of 17.4 A/W, a high specific detectivity of 1.23 × 1013 Jones, and fast response speeds of 13.2/13.7 μs (20 kHz) under a UV light of 355 nm at zero bias voltage. The results show that the thin graphene acts as a perfect interface for GaN NRs, encouraging growth with minimum defects on the Si substrate. Our results suggest that the GaN NR/graphene/Si (111) heterojunction has a range of interesting properties that make it well-suited for a variety of photodetection applications. © 2020 Author(s).