Structural and Optical properties of CdO doped TiO2 thin films prepared by Pulsed Laser Deposition

Abstract

TiO2 thin films have been deposited at room temperature with different concentration of CdO of x= (0.0, 0.05, 0.1, 0.15and 0.2) wt. % onto glass substrates by pulsed laser deposition (PLD) technique using Nd-YAG laser with λ=1064nm, energy=800mJ and number of shots=500. The structural, morphological and optical characterizations of as- deposited films were carried out using X-ray diffraction (XRD), atomic force microscopy (AFM), and UV–vis transmittance spectroscopy. The Effect of CdO content on these properties was investigated. Characterizations by X-ray diffraction show a polycrystalline film, with tetragonal structure and formation of Rutile phase and many peaks (110), (101), (111) and (211) were appear. In addition, AFM investigation shows no cracks in the formed layer. The optical properties concerning the absorption and transmission spectra were studied for the prepared thin films using an ultraviolet–visible near-infrared spectrophotometer. The results show that the transmittance of the TiO2 film in the visible domain reaches 75%.Optical band gaps were calculated and found to be (3.62, 3.54, 3.45, 3.3 and 3.21) eV for the concentration of CdO x= (0.0, 0.05, 0.1, 0.15 and 0.2) wt. % respectively. At 350 nm the refractive index,extinction coefficient and dielectric constant were determined.