Title: Fabrication of ultraviolet photodetector using Au nanoparticles decorated ZnO NRs/GaN

Authors: Shireen Mohammed Abed; Sabah M. Mohammad; Zainuriah Hassan; A. Muhammad; M.A. Ahmad; Mohd Syamsul

Addresses: Institute of Nano Optoelectronics Research and Technology (INOR), Universiti Sains Malaysia (USM), 11800, Penang, Malaysia; Department of Physics, College of Education for Pure Science, University of Anbar, 55431, Anbar, Iraq ' Institute of Nano Optoelectronics Research and Technology (INOR), Universiti Sains Malaysia (USM), 11800, Penang, Malaysia ' Institute of Nano Optoelectronics Research and Technology (INOR), Universiti Sains Malaysia (USM), 11800, Penang, Malaysia ' Department of Physics, Sule Lamido University, Kafin-Hausa, 048, Jigawa State, Nigeria ' Institute of Nano Optoelectronics Research and Technology (INOR), Universiti Sains Malaysia (USM), 11800, Penang, Malaysia ' Institute of Nano Optoelectronics Research and Technology (INOR), Universiti Sains Malaysia (USM), 11800, Penang, Malaysia; Faculty of Science and Engineering and Institute of Nano Science and Nano Engineering, Waseda University, Shinjuku, Tokyo, 169-8555, Japan

Abstract: This work focuses on improving the performance of ultraviolet (UV) photodetectors (PDs) based on n-ZnO nanorods (NRs) on Mg-doped-gallium nitride (GaN) through the utilisation of surface plasmon resonance (SPR) induced by gold (Au) nanoparticles (NPs). ZnO NRs were grown on a seeded p-GaN substrate, enabling the growth of high-density ZnO nanorods in various orientations. Au NPs were then deposited on the surface of ZnO NRs using a photo-deposition method with pre-prepared Au NPs liquid obtained via laser ablation. ZnO and GaN materials, with their inherent broad bandgap characteristics and unique electrical, optical, and structural features, are commonly employed for creating UV PDs. The defect emission levels in ZnO NRs promote SPR in Au NPs, enhancing the electromagnetic field and facilitating the transfer of electrons across the barrier height at the Au NP/ZnO interface. This results in improved optical and electrical properties on the surface of ZnO NRs. The incorporation of Au NPs enhances the responsivity and sensitivity of ZnO NRs UV photodetectors. The fabricated UV detector, utilising ZnO NRs array decorated with Au nanoparticles, exhibits highly sensitive and repeatable characteristics, including a high responsivity (R), the highest gain current, and a high external quantum efficiency (EQE) of 43.03 A/W, 7264, and 14621.52%, respectively, under UV light illumination at 365 nm. By employing SPR through Au NPs, this study demonstrates significant enhancements in the performance of UV photodetectors based on ZnO NRs/GaN, contributing to the advancement of visible-blind UV PDs.

Keywords: Au nanoparticles; ZnO nanorods; Mg doped-GaN; SPR; surface plasmon resonance; UV photodetectors; photo-deposition method.

DOI: 10.1504/IJNT.2024.141756

International Journal of Nanotechnology, 2024 Vol.21 No.4/5, pp.236 - 250

Published online: 01 Oct 2024 *

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