Modelling the spectral reflectances of Sol-Gel tin doped indium oxide and aluminium doped zinc oxide coatings

N. Wolf, D. Gerstenlauer, J. Manara
Bavarian Center for Applied Energy Research, DE

Keywords: modelling, spectral reflectances, sol-gel, ITO, AZO


In this work it is shown that it is possible to model the spectral reflectances of tin doped indium oxide (ITO) and aluminium doped zinc oxide (AZO) Sol-Gel functional layers with different numbers of single coatings which form the functional layers and different doping concentrations by using only the Drude model. The Drude model is a classical model which is used to describe free electrons in any material. As the behavior of metals and semiconductors is essentially defined by free electrons, the dielectric behavior of such materials can be described by the Drude model quite well at wavelengths exceeding the plasma edge. The infrared-optical and electrical parameters from the modeling of the measured reflectances are discussed regarding the charge carrier density, the scattering time and the high frequency dielectric constant and how these parameters change with the processing of the different ITO respective AZO functional layers. It is also shown that the values of the charge carrier densities and the scattering times obtained by the fits are in good agreement with those found in the literature.