Enhanced Ultraviolet Emission from Poly(vinyl alcohol) ZnO Nanoparticles Using a SiO2-Au Core/Shell Structure

Enhanced near band gap edge (NBE) emissions of PVA-ZnO napoparticles were achieved by employing SiO2-Au core/shell nanostructures whereas the defect level emission (DLE) is greatly suppressed. A maximum enhancement of nearly 400% was observed using SiO2-Au for the emission with optical resonance at 554 nm. SiO2-Au core/shell nanostructures also show a superior tunability of resonance energy as compared to that of the pure metal nanoparticles. The enhancement of the NBE emission and suppressed DIE is ascribed to the transfer of the energetic electrons excited by surface plasmon from metal nanoparticles to the conduction band of ZnO nanoparticles.