Photoluminescence and micro-Raman scattering in ZnO nanoparticles: The influence of acetate adsorption

Ultraviolet (UV) emitting ZnO nanoparticles have been prepared by direct solvent evaporation of an alcohol solution containing KOH and zinc acetate. The particle size of ZnO becomes stable at an average diameter of 4-5 nm. Upon drying, the ZnO nanoparticle powder shows strong UV emission, suggesting that the surface states of ZnO have been eliminated with acetate molecules adsorption. Raman spectra show the presence of Zno E-2((2)) optical phonon mode, which is red-shifted when compared to bulk ZnO. The CO stretching mode in the Raman spectra is red-shifted to 1401 cm(-1), indicating strong binding of acetate on the ZnO surfaces. (c) 2005 Elsevier B.V. All rights reserved.