Optical characterisation of thin film cadmium oxide prepared by a modified reactive thermal evaporation process

Abstract

The optical transmission spectra of transparent conducting cadmium oxide (CdO) thin films deposited by a modified reactive evaporation process onto glass substrates have been measured. The interference fringes were used to calculate the refractive index, thickness variation, average thickness and absorption coefficient of the films. The influence of the partial pressure of oxygen (PO2), during film deposition on the transmittance, optical constants and bandgap of the films is studied. The observation of an optimum value of PO2­ (= 0.040 Pa) at which the transmission is maximum is considered to be a particularly significant result. So, too, is the result that the width of the bandtail has a minimum at the optimum PO2 value.


Key words: CdO Films, Optical Transmittance, Evaporation


(Global Journal of Pure and Applied Sciences: 2003 9(4): 567-574)