Comparison of Structural and Optical Properties of CdS Thin Films Grown by CSVT, CBD and Sputtering Techniques

CdS thin films were deposited by three different processes; close spaced vapour transport (CSVT), chemical bath deposition (CBD), and sputtering technique on ITO coated glasses and their structural and optical properties were investigated through XRD, SEM, EDX and UV-Vis spectrometry, respectively....

Full description

Saved in:
Bibliographic Details
Published in:Energy procedia 2013, Vol.33, p.203-213
Main Authors: Islam, M.A., Hossain, M.S., Aliyu, M.M., Chelvanathan, P., Huda, Q., Karim, M.R., Sopian, K., Amin, N.
Format: Article
Language:English
Subjects:
CBD
CdS thin films
CSVT
sputtering
thermal annealing
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:CdS thin films were deposited by three different processes; close spaced vapour transport (CSVT), chemical bath deposition (CBD), and sputtering technique on ITO coated glasses and their structural and optical properties were investigated through XRD, SEM, EDX and UV-Vis spectrometry, respectively. The as-grown films are annealed at 400°C and 500°C for 30 min in air and the change in structural properties with the thermal stress were also investigated. The crystallite grain size, lattice constant, microstrain and dislocation densities of the films are quite different in these processes as observed from XRD analysis. The highest crystallinity is observed for sputtered CdS thin films. However, the crystalline property of CBD and sputtered CdS increases with the thermal annealing, while CSVT-CdS loses its crystalline form. No significant grain changes are observed for thermally annealed CdS thin films but some cracked lines are observed in CBD and CSVT CdS thin films from SEM images. The absorbance in the visible wavelength decreased for annealed CdS thin films, which might be due to fact that films are becoming denser followed by thermal annealing. Significant blue shifts observed for thermally annealed CdS thin films have been found from all processes. The band gap found for as-grown CSVT-CdS is 2.44 eV, for CBD-CdS is 2.38 eV and for sputtered-CdS is 2.42 eV. The disorder of phonon states in the films are observed from Urbach's tail. The absorption edges due to the exciton–phonon interaction or electron-phonon interaction are also observed from the values of steepness parameter.
ISSN:1876-6102
1876-6102
DOI:10.1016/j.egypro.2013.05.059