https://doi.org/10.1051/epjap:2007095
Structural and optical characteristics of CdS thin films deposited by infrared pulsed-laser technique
Physics Department, Faculty of Education, Ain Shams University, Heliopolis 11757, Cairo, Egypt
Corresponding author: Dr.A.Eldeeb@gmail.com
Received:
15
February
2007
Revised:
4
April
2007
Accepted:
27
April
2007
Published online:
13
June
2007
The influence of preparation conditions on the structure and optical properties of cadmium sulphide (CdS) thin films deposited on quartz substrates by means of the pulsed laser technique have been investigated. Oriented growth of hexagonal CdS nanoparticulate film with the C-axis perpendicular to the plane of the surface has been achieved up to a film thickness of 220 nm. The results indicate that the heat treatment played an important role on both crystal structure and optical properties. The grain size and the crystallinity of the films were increased, as well as the optical energy gap 
(allowed direct transitions) was increased from 2.45 to 2.50 eV upon annealing. The dispersion of the refractive index of virgin and annealed films were estimated and explained using the Wemple-Didomenico (WD) single-oscillator model. The dispersion parameters and
the free charge carrier concentrations were also estimated.
PACS: 61.10.Nz – X-ray diffraction / 78.20.Ci – Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity)
© EDP Sciences, 2007
