Zinc oxide nanoparticles with different amounts of incorporated silver (ZnO:Ag; 0.6, 3, 6, and 9 at.% Ag) have been successfully synthesized by a simple sol gel method. The effect of Ag content on the properties of ZnO nanoparticles have been studied by various characterization techniques. The results from Xray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy (RS) suggest that elemental silver is present as a second phase. The UV-visible absorption and photoluminescence (PL) properties of the samples were also studied. PL data at room temperature reveals a strong blue emission. In addition, Raman spectroscopy results indicate a very strong A(1)(LO) mode resulting from oxygen vacancies and zinc interstitials. A new local vibrational mode (LVM) at 480 cm(-1) induced by silver can also be observed in the Raman spectra, suggesting silver incorporation into the ZnO lattice compensating the Zn vacancies, which is consistent with the XRD results. (C) 2015 Elsevier B.V. All rights reserved.