The Effect of Annealing Temperature on The Structural and Optical Properties of Fe2O3Thin Films

Abstract

Chemical spray pyrolysis was used to deposit Fe2O3 thin films on preheatedglass substrates at (200)0C. The films were annealed at (300), (400)and (500)0C at ambient atmosphere. X ray diffraction (XRD) technique wasutilized to study the effect of annealing on the structure of Fe2O3 thin films.XRD technique was utilized to study the effect of annealing temperatureon structural properties of Fe2O3 thin films. It was found that the as depositthin film has amorphous structure but it became polycrystalline structure byannealing at (300) 0C with dominant orientation along [104] direction. withdominant orientation along [104] direction. Crystallinity of Fe2O3 thin filmswas improved with increasing annealing temperature (Ta). Crystallite sizeincreased with heat treatment from (23.3) to (29.3) nm for as deposit andannealed sample at (500) 0C respectively. Other structural parameters likemicro strain (η), dislocation density and number of crystallites per unit areawere calculated and correlated with the variation of Ta. UV-Visible spectrophotometerwas used to study the annealing effects on optical propertiesof Fe2O3 thin films. With increasing of Ta; optical energy gap (Eg) valuesincreased from (2.105) to (2.159) eV due to decreasing of localized statesinside the band gap from (0.396) to (0.162) eV.