LAUSR

The optical properties of CdS0.9Mn0.1 thin film with different thicknesses (d = 300, 450, 600, 750, 900 and 1000 nm) were explored. The Swanepoel method was employed to calculate the thickness of the studied films. Analyses of the absorption spectra indicated the existence of allowed indirect and direct transition mechanism in the CdS0.9Mn0.1 thin films. Both the absorption coefficient and optical band gap decreased while Urbach energy increased as the film thickness increased. The Wimple–DiDomenico single oscillator model was used to describe the dispersion of the refractive index. The film thickness dependence of the dispersion parameters was studied. The optical dielectric constants, optical conductivity, electrical susceptibility, and non-liner optical parameters such as the refractive index, first-order susceptibility (χ(1)\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ \chi^{(1)} $$\end{document}) and third-order susceptibility (χ(3)\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ \chi^{(3)} $$\end{document}) were determined. The present results show that the film thickness is an important factor which affected the optical parameters.