A Study of the Optical Conductivity, Extinction Coefficient and Dielectric Function of CdO by Sucessive Ionic Layer Adsorption and Reaction (SILAR) Techniques
Adrian Ohwofosirai *
Department of Physic and Astronomy, University of Nigeria, Nsukka
Matthew D. Femi
Department of Physic and Astronomy, University of Nigeria, Nsukka
Nwokike A. Ngozika
Department of Physic and Astronomy, University of Nigeria, Nsukka
Toluchi O. Joseph
Department of Chemistry, University of Nigeria, Nsukka, Nigeria
R. U. Osuji
Department of Physic and Astronomy, University of Nigeria, Nsukka
B. A. Ezekoye
Department of Physic and Astronomy, University of Nigeria, Nsukka
*Author to whom correspondence should be addressed.
Abstract
Aims: The research is to study the Optical Conductivity, Extinction Coefficient and Dielectric function using deposited CdO films
Place and Duration of Study: The research place is at the Material Science and Nanotechnology Unit, Department of Physics and Astronomy, University of Nigeria Nsukka, between of August 2012 to June 2013.
Methodology: The approach used in the deposition of CdO is the Solution Method, known as the Successive Ionic Layer Adsorption and Reaction techniques (SILAR) Technique and the UV-VIS-NIR spectroscopy was used for film characterization.
Results: The deposited CdO thin film has a low and high transmittance in the UV and visible region respectively. The band gap of the deposited CdO decreases with an increase in No. of cycles films and ranges from 1.45eV – 2.35eV, this was attributed to the increase in the thickness of films. Also studied is the variation of the film optical conductivity with the band gap, which was observed to decrease with an increase in band gap. Lastly, the relationship between the film band gap and the dielectric function of the materials was consider, the dielectric constant varies exponentially with the band gap and also increases with the number of cycles (film thickness).
Keywords: CdO, SILAR, extinction coefficients, bandgap