OPTICAL AND STRUCTURAL CHARACTERIZATION OF RF-SPUTTERED CEO2 THIN-FILMS

The optical and structural properties of r.f. sputtered CeO2 thin film s deposited on Pyrex substrates have been studied as a function of sub strate temperature during deposition. The refractive index, n, extinct ion coefficient, k, and bandgap of the films were calculated from refl ectance, R, and transmittance, T, spectra in the wavelength range 340- 900 nm. The refractive index of CeO2 films at 550 nm comprises values from about 2.25-2.4 depending on the substrate temperature during depo sition. The extinction coefficient was negligible for wavelength value s higher than 400 nm. The value obtained for the bandgap was 3.1 eV. T he X-ray diffraction patterns showed the same (fcc) cubic structure wi th preferential orientation depending on substrate temperature during deposition. The scanning force microscope measurements showed that the roughness and grain size of the CeO2 films increase with increasing s ubstrate temperature.