Linear and Non-linear Optical Parameters of Diluted Magnetic Semiconductor CdS0.9Mn0.1 Thin Film: Influence of the Film Thickness

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 (vð1Þ) and
third-order susceptibility (vð3Þ) were determined. The present results show
that the film thickness is an important factor which affected the optical
parameters.