Optical properties of Er3+–Ag co-doped ZnO nanocrystals prepared by combustions method

Abstract

The Er3+–Ag co-doped ZnO nanocrystals have been synthesized by citric acid-assisted combustions method. The effect of different concentration of silver nanoparticles (NPs) on Er3+ doped ZnO nanocrystals and the optical behaviors are explored. The nanocrystals were characterized by X-ray diffractions, scanning electron microscopy, UV–Vis–NIR absorption spectra, X-ray photoelectron spectroscopy, and photoluminescence, respectively. The luminous intensity of Er3+ doped ZnO nanocrystals was significantly influenced by the concentration of silver NPs. A large enhancement in up-conversion intensity has been observed when the concentration of silver NPs was 0.10 mol%. The effect of localized surface plasmon resonance of silver NPs and the energy transfer between the silver NPs and Er3+ ions (2H11/2 → 4I15/2, 4S3/2 → 4I15/2, and 4F9/2 → 4I15/2) are discussed as the sources of enhancement or quenching.