Effect of silver doping on the structural, morphological, optical and electrical properties of sol–gel deposited nanostructured ZnO thin films

Abstract

In this paper, we report the study of physical and optical properties of undoped and silver-doped zinc oxide (SZO) thin films prepared by sol–gel dip-coating process onto glass substrates. The structural, morphological, optical and electrical properties of the thin films as a function of silver concentration have been investigated using X-Ray Diffraction (XRD), Scanning Electronic Microscopy (SEM), Atomic Force Microscopy (AFM), UV–visible spectrophotometry and four points probe technique. XRD spectra have shown that undoped thin film exhibit (101) orientation while doped ones display a strong c-axis orientation. SEM micrographs and AFM images have revealed that grain sizes and surface roughness decrease with increasing silver concentration. The UV–visible transmittance results show that Ag-doped ZnO thin films exhibit better transparency than undoped ones. A change in the optical bandgap of ZnO thin films is also revealed. The electrical measurements have shown that the resistivity of the thin films decrease with increasing Ag doping. The present results show that ZnO thin films doped with 4at.% Ag have more suitable properties of high transmittance and low resistivity for optoelectronic device applications.