Surface plasmon resonance enhanced band-edge emission of CdS–SiO₂core–shell nanowires with gold nanoparticles attached

Abstract

Inspired by the good match between the surface-plasmon energy of Au nanoparticles and the emitted photon energy of CdS nanowires, CdS–SiO2 core–shell nanowires with Au nanoparticles attached (CdS–SiO2–Au) were prepared to investigate the interaction between the semiconductor and the metal. Photoluminescent and lifetime measurement reveal that the band-edge emission of CdS nanowires in this hybrid structure has a fivefold enhancement compared with pure CdS nanowires due to the surface plasmon resonance. In addition, the existence of an optimized thickness of the SiO2 layer for the emission enhancement indicates that the interactions between the metal and the semiconductor occur constructively only at appropriate distances. These CdS–SiO2–Au nanowires with tailored morphologies and enhanced band-edge emission have potential applications in solar cells, photodetectors and bio-nanotechnology.