The effect of thickness on the optical properties of Cu2S thin films

Abstract

In this work, the optical properties of Cu2S with different thickness (1400, 2400, 4400) Ǻ have been prepared by chemical spray pyrolys is method onto clean glass substrate heated at 283 oC ±2. The effect of thickness on the optical properties of Cu2S has been studied. It was found that the optical properties of the electronic transitions on fundamental absorption edge were direct allowed and the value of the optical energy gap of Cu2S (Eg) for direct transition decreased from (2.4-2.1) eV with increasing of the thickness from (1400 - 4400)Ǻ respectively. Also it was found that the absorption coefficient is increased with increasing of thicknesses. The optical constants such as extinction coefficient, refractive index and the imaginary part of the dielectric constant have similar termed of variation for the absorption coefficient.

Keywords

• Cu2S thin films, optical properties, chemical spray pyrolys method.