Size dependent plasmonic properties of Ga@Ag & Cs@Ag liquid–metal nanospheres

Abstract

The water-flow like behavior of liquid metals at room temperature has always been fascinating with enabling novel applications towards portable and flexible devices. Many liquid metal alloys based studies have been done but fundamental liquid metals are not much studied due to their tendency towards toxicity/oxidation during applications. In the present study, Mie theory based theoretical model simulated Gallium (Ga) and Cesium (Cs) liquid metals with their core–shell nanospheres coated with Silver (Ag) of different size spectra are used to investigate their localized surface plasmon resonance (LSPR) wavelength and sensitivity of the peak position to the particle size and shell thickness. We assess that the optical properties (absorption and scattering efficiencies) of liquid metal nanoparticles (NPs) (Ga and Cs) coated with noble metal (Ag) can be effectively tuned with controlled size of core and shell layers. The resonance peaks are found in UV–Visible–NIR region for bare NPs and UV–Visible region for core–shell NPs. It is observed that the absorption efficiency increases with increasing the core size as well as shell thickness. These results can be used in the application of UV plasmonics for biosensor devices, solar cells, reformable plasmonic devices, therapeutic agents and certain light absorption/scattering based applications.