The optical and electrical properties of two types of wet chemical processed tin doped indium oxide (ITO) films deposited by spin coating technique as well as of a commercial sputtered ITO film have been measured. The transmission and reflection spectra in the wavelength range 0.25 to 20 Am have been simulated using the Scout 2 software with different dielectric function models. The electrical parameters obtained from the modeling are compared with those obtained experimentally. The optical data of a low porosity (28%), low specific resistivity (q 6.3 Â 10 À 4 V cm) sol gel film deposited from an ethylene glycol solution of In and Sn salts and sintered at 550 -C, as well as those of an Asahi Glass sputtered film (q 1.9 Â 10 À 4 V cm) have been successfully fitted with the Drude model and the electrical parameters deduced from the fitting are in good agreement with the measured ones. On the other hand, the best fit of the optical data of a thick single coating prepared using dispersed crystalline nanoparticles was obtained using the Bruggemann effective medium theory coupled with the extended Drude model. The electrical and structural parameters deduced from the fitting are also in good agreement with those measured. The results are discussed in terms of the morphology of the coatings.

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In order to calculate the optical properties of evaporated Ge 30 Se 70 thin films and their relation to thickness, amorphous Ge 30 Se 70 thin films of different thicknesses were deposited by thermal evaporation at a base pressure of 7.5 × 10 −6 Torr at room temperature. The optical transmission and reflection spectra of all films were measured in the wavelength range of 0.2-2.5 m. Efficient parameterization of the spectral dependence of the optical constants of amorphous Ge-Se thin films was obtained by applying a suitable dielectric function model. The O'Leary, Johnson and Lim (OJL) model, based on joint density of states functions, was used to analyze the optical spectra. The best fit was obtained by configuring the film as two layers, the top layer consisting of bulk Ge 30 Se 70 material embedded in air medium containing different volumes of voids. Therefore, the OJL model coupled with the Bruggeman effective-medium approximation model were used to determine the optical constants of the Ge 30 Se 70 thin films. The photon energy dependence of the dielectric function, ε = ε r − iε i of the investigated films is presented. The film thickness, absorption coefficient α, refractive index n, extinction coefficient k, static refractive index n(0) and optical band gap Eg were deduced. We found that increasing the film thickness increased the direct optical energy gap and decreased the refractive index.

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