Tailoring wide band gap PdS thin film doped with Cd ions using spin coating

Abstract

The bandgap value of the thin films of Pb1-xCdxS could be tailored between 3.7 and 2.59 eV by adjusting the value of doping parameter 0.0 ≤ x ≤ 1.0. Ultra-thin films of average thickness 115 nm were deposited on glass substrates using the spin coating method. The structure and microstructure properties of the obtained thin films were studied using Rietveld analysis of x-ray diffraction patterns with a grazing incidence setup. Scanning electron microscopy was used to investigate the film's surface morphology and thickness. Photoluminescence spectra were conducted to explore the various emitted colors correlated with defect states formed in the lattice of the obtained films. The effect of Cd content on the optical absorbance, reflectance, refractive index, extinction coefficient. Dielectric constant, loss functions, optical conductivity and nonlinear optical parameters of the films were investigated in detail. The film with Cd content x = 0.4 had superior properties among other films. All films displayed a normal and/or anomalous dispersions of n values depending on the wavelength range. Several linear and nonlinear optical and photonic applications have been proposed due to the films' improved nonlinear optical values.