Magnetron-Sputtered Silver Nanoparticles for Surface Plasmons for Terahertz Sensors

Abstract

Silver (Ag) thin films of various thickness were prepared using DC magnetron sputtering for surface plasmonic resonance (SPR). SPR is the resonant oscillation of the electron in metal or semiconductors under the influence of light. Ag nanoparticles were formed by annealing Ag thin films at a high temperature. The effect of deposition time on the optical and structural properties of the Ag nanoparticles were investigated using UV–Vis spectrophotometer, x-ray diffraction, Raman spectroscopy, and field-emission scanning electron microscopy. In the UV–Vis transmission spectra, a blue shift in the absorption edge was observed with the decrease in the thickness of the films, which could be due to quantum confinement. Low deposition time and low dc power resulted in thinner (20–30 nm) film growth. Changes in the size of the nanoparticles resulted in the shift of the absorption edge and thus can be used to fabricate tunable optical sensors. These tunable Ag nanoparticles with variation in the deposition time will be used for surface plasmon resonance in two-dimensional (2D) material for terahertz photodetector applications. © 2023, The Minerals, Metals & Materials Society.