Localized surface plasmon resonance tunability and growth mechanism in Au/VO2thermochromic structure

It is well known that gold nanoparticles (Au NPs) have significant localized surface plasmon resonance (LSPR) effects in the visible region, making them play a key role in the color regulation of VO₂ films. In this study, Au NPs were prepared by ion beam sputtering and post annealing treatment, and then VO₂ films were deposited on Au NPs by pulsed laser deposition to obtain Au-VO₂ composite films. The influence of Au deposition time on the LSPR peak position, peak intensity, and full width at half maximum of composite films was studied. As the size of Au NPs increases, the LSPR peak of Au NPs undergoes a redshift from 525 to 601 nm. Simultaneously, Au-VO₂ composite films also exhibit adjustable LSPR characteristics with the absorption peak shifting towards longer wavelengths, ranging from 626 to 670 nm. Au-VO₂ composite films shows a color transition from blue-green to yellow-green, accompanied by a near-infrared solar modulation efficiency of 10.8% and a phase transition temperature at approximately 50 ℃. Furthermore, this study conducted an in-depth exploration of the intricate growth mechanism of VO₂ films forming on the surface of Au NPs. The findings presented in this work provide valuable experimental evidence and design principles for utilizing the LSPR effect of metal NPs to control the color and thermochromic properties of VO₂ films.