Crystal structure, optical and dielectric properties of Ag:ZnO composite-like compounds

In recent years, non-magnetic elements-doped oxide materials have been projected as one of the promising materials for application in optoelectronics and spintronics. The primary goal of this research is to look into the influence of Ag on the structural, optical, and dielectric properties of ZnO compounds. The solid-state route method was used to prepare the Ag:ZnO compounds with 0, 3, 6, 9, and 12 at.% of Ag. The analysis of X-ray diffraction (XRD) pattern data reveals that the prepared compounds have been formed as composite-like compounds. The SEM microstructural study reveals the nano-sized grains in the range of 200–300 nm. The elemental color mapping using energy dispersive spectroscopy confirms that no undesirable external impurities were introduced into the final synthesized samples, and all elements are uniformly distributed in the prepared samples. The optical property, investigated through a UV–Vis spectrophotometer, indicates that the band gap has narrowed down upon the increase of Ag content. The transmittance value is found to increase drastically from 5% (for ZnO) to 55% (for 9% Ag:ZnO) compound. The frequency-dependent behavior of dielectric constant, dielectric loss, modulus spectroscopy, and ac conductivity of undoped as well as Ag:ZnO composite-like compounds has been analyzed and well explained with the help of the Maxwell-Weigner model. A further investigation was carried out using impedance spectroscopy to determine the charge transport mechanism that occurs within the grain and grain boundary regions.