Influence of Cr incorporation on structural, dielectric and optical properties of ZnO nanoparticles

This study demonstrated the effect of Cr doping on structural, dielectric and optical behavior of ZnO nanoparticles synthesized through sol-gel method. Characteristic investigations have been carried out by X-ray diffraction, Field emission scanning electron microscope, Energy dispersive X-ray spectrometry, and Transmission electron microscope. The results confirmed the formation of nanoparticles in polycrystalline single phase with hexagonal wurtzite structure. The crystallite size has been found to vary around 20 nm. Dielectric studies were carried out by Impedance spectroscopy. The decrease effect of dielectric parameters with increase in dopant has been explained on the basis of Maxwell-Wagner model and Koops phenomenological theory. The impedance analysis suggested that the contribution of grain boundaries is dominating over grain contribution. A red shift in UV-vis spectra signified that band gap can be tuned by Cr doping from 3.32 to 3.22 eV because of the s-d and p-d exchange interactions. (C) 2014 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.