Modeling of optical and electrical properties of In2O3 : Sn coatings made by various techniques

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 mu m 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 (rho = 6.3 x 10(-4) Omega cm) sol-gel film deposited from an ethylene glycol solution of In and Sri salts and sintered at 550 degrees C, as well as those of all Asahi Glass sputtered film (rho = 1.9 x 10(-4) Omega 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. (c) 2005 Elsevier B.V. All rights reserved.