Abstract
•The ZnS thin films were deposited with different Pb doping concentration (0.5, 1, 1.5, and 2 at.%).•The X-ray diffraction analysis indicates that the deposited films are polycrystalline related to cubic and hexagonal structure.•The films had a strong preferred orientation, it is (111) plane.•The films are good transparent (60% to 70%), and the shift of optical transmittance showing the decrease of optical band gap.•All the films of ZnS:Pb showed high resistivity.
In the present work, high quality Pb doped ZnS thin films were deposited on glass substrates at 450°C using spray ultrasonic technique. The dependence of the structural, morphological and optical properties of the films on the lead (Pb) doping amount was investigated by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), UV–vis–NIR spectrophotometry, and four-point method. The improvement of the obtained Pb:ZnS thin films properties were discussed as a function of Pb concentration (0.5 to 2 at.%). The average crystallite size of Pb:ZnS was found in the range of 25–37 nm. The scanning electron microscopy (SEM) reveals that the films are continuous, homogeneous and dense. The UV–vis–NIR spectroscopy characterizations demonstrated that all the films exhibit good transmittance (60–70%) in the visible region and their optical band gap energy (Eg) changes from 3.92 to 3.6 eV. The films electrical resistivity showed an apparent dependence on Pb content.