Enhanced photoluminescence properties of bismuth sulfide nanocrystals with core-shell Ag@SiO2.

Abstract

A novel self-assembled hybrid nanocompound consisting of bismuth sulfide nanocrystals (Bi2S3 NCs) and Ag@SiO2 nanoparticles (NPs) is used to study the enhancement of photoluminescence by localized surface plasmon resonance (LSPR). Ag@SiO2 core-shell NPs were prepared by deposition of silica onto the surface of Ag NPs through the sol-gel method and followed by surface modification via 3-aminopropyltriethoxysilane for the coming conjugation with Bi2S3 NCs. We propose the photoluminescence enhancement by the LSPR effect through adjusting the thickness of silica shell and the Ag@SiO2 NP concentration. By modulating the thickness of the silica shell and the concentration of Ag NPs, the maximum enhancement of a 5.7 fold can be reached with the thickness of an SiO2 shell at 22.5 nm. A clear red shift of the emission peaks in the Bi2S3 NCs-Ag@SiO2 NPs hybrid structures is observed. Such a metal-enhanced Bi2S3 quantum dot (QD) fluorescence system may have promising applications in optoelectronic device.