Plasmonic Au Nanoparticles Coated on ReS<sub>2</sub> Nanosheets for Visible-Near-Infrared Photodetectors
Venkatarao Selamneni, Abhishek Mukherjee, Harini Raghavan, P. Gomathi, Chandra Sekhar Reddy Kolli, Subhradeep Pal, Arnab Hazra, Parikshit Sahatiya
Abstract
Even though there are various reports on the fabrication of flexible photodetectors, still there is a need for the development of high-performance photodetectors. In recent years, the plasmonic photodetection technique has emerged as one of the prominent solutions to enhance photodetection performance. In this work, a flexible and high-performance broadband (visible-near-infrared (NIR)) plasmonic photodetector is demonstrated by integrating gold (Au) nanoparticles (NPs) on two-dimensional (2D) ReS2 nanosheets. Fabricated Au-NPs/ReS2 showed an approximately 15-fold enhancement in the photodetection performance compared to pristine ReS2. Photoresponsivity of the fabricated Au-NPs/ReS2 device in visible (Vis) and NIR regions is ∼2.1 and ∼1.3 A W–1, respectively. Significant enhancement in the photosensing performance of the device could be a combined effect of multiple factors, including localized surface plasmon resonance and effective charge transfer at the interface of Au-NPs and ReS2. The response speed of the fabricated device is approximately 200 ms. Furthermore, theoretical understanding of light interaction with Au-NPs is studied, and also electromagnetic simulations are performed using Lumerical Finite Difference Time Domain Multiphysics simulation to investigate the plasmon coupling effect of Au-NPs on 2D ReS2 nanosheets. To further understand the photodetection mechanism, the energy band diagram of the Au-NPs/ReS2 interface is drawn using ultraviolet photoelectron spectroscopy measurements.