Influence of Ar gas on optical and morphology properties of films (CdS) prepared by pulse laser deposition (PLD) technique

Abstract

Cadmium sulfide thin films, formed by pulse laser deposition method, resulted in CdS thin films deposited on glass substrate with different Ar gas (5, 10 and 15) torr. Structural (X-ray) diffraction, morphological (atomic force microscope) and optical (transmittance and absorption) spectra of CdS films have been investigated. The high value of transmittance determined from optical transmittance spectra was 72%. Direct band gap energy of prepared films are (2.54, 2.16 and 2.72) eV with different pressure of Ar gas. X-ray diffraction synthesis proved CdS films in crystalline with hexagonal structure. By using Scherrerś equation, average grain size about 80nm was determined. AFM image shown the morphology of formation films and the effect of gas pressure on nanostructure.