Table of Contents
Indian Journal of Materials Science
Volume 2014, Article ID 367950, 5 pages
http://dx.doi.org/10.1155/2014/367950
Research Article

Variations of Optical and Structural Properties of Thin Films with Thermal Treatment

1Department of Physics and Astronomy, University of Nigeria, Nsukka 410001, Nigeria
2National Centre for Energy Research and Development, University of Nigeria, Nsukka 410001, Nigeria
3Department of Physics and Astronomy, University of Western Ontario, 1151 Richmond St., London, ON, Canada N6A 3K7

Received 4 December 2013; Accepted 27 January 2014; Published 12 March 2014

Academic Editors: A. Chatterji and P. B. Wagh

Copyright © 2014 A. B. C. Ekwealor et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

The effects of thermal treatment on the optical and structural properties of cobalt oxide thin films synthesized in the pores of PVP by chemical bath deposition technique were investigated. Films deposited were crystalline. The optical properties of the films were got from absorbance, transmittance reflectance, refractive index, absorption coefficient, and extinction coefficient measurements. The synthesized films turned out to be cobalt oxyhydroxide , CoO(OH), nanocrystals. The crystals obtained were of size 41.84 nm; however, as annealing temperature increased, the size decreased to 16.28 nm. The absorption coefficient, refractive index, and extinction coefficient were found to increase with increase in annealing temperature though not sequentially. For the same energy ranges of the incident photons, the absorption coefficient and refractive index ranged from 0.2 to 1.8 and from 1.4 to 2.3, respectively. The energy band-gap of the films ranged from 1.96 eV to 2.22 eV.