Optical band-gap and dielectric behavior in Ho – doped ZnO nanoparticles

Abstract

The optical band-gap and dielectric properties of Zn Ho 1−x xOδ nanoparticulate powders with x¼0.0, 0.005, 0.0075, 0.01, and 0.015 prepared by combustion reaction (CR) method were investigated at room temperature. Both optical band-gap, Eg, and dielectric constant, ε′, values increased with increasing Ho doping concentration; being ∼3.234 and ∼3.268 eV, and ∼37 and ∼50 for x¼0 and 0.015, respectively at room temperature. The dielectric behavior was described by the Cole–Cole model (Cole and Cole, 1941) [22] and the results were discussed in terms of defects such as oxygen vacancies VO or/and interstitial oxygen O present in Ho – doped ZnO nanoparticles, introduced during the sample preparation.