Silver Nanoparticles Dispersed on Silica Glass for Applications as Photothermal Selective Material

AbstractSilver nanoparticles dispersed into a resin are deposited on silica glasses by the spin coating method and heated around 100°C. UV-VIS measurements show high stability of the optical spectra after heat treatment, suggesting that the morphology of the silver nanoparticles are stable. The transmission electronic microscopy images exhibit huge spherical aggregates and prolate silver nanoparticles. In order to evaluate the roughness and solar optical properties, reflectance spectra, atomic force microscopy and perfilometric measurements are performed. The chemical composition and morphology of the films are analyzed by energy-dispersive X-ray spectroscopy, EDX. The optical properties of the films show high absortance and low emissivity in the visible and near infrared range, respectively, suggesting their potential use as photothermal selective materials with good thermal stabilization. This feature is an important prerequisite of coatings for the solar collector manufacturing. The optical properties, the thin film thickness and roughness are correlated among them to understand the selective response of the coatings