Optical method for heterogeneity analysis in thin absorbing films.

Optical transmittance and reflectance are measured in situ at normal incidence during the deposition of thin Na(3)Sb films onto glass substrates. Complementary surface chemical analysis of these films is performed using Auger electron spectroscopy (AES). Both optical and AES measurements are used to develop a method for determining and analyzing the optical heterogeneity taking place within the thin film in the direction normal to the surface. The method allows deduction of the actual complex optical parameters of the films for optical homogeneity. Conversely, for optical heterogeneous behavior, the method gives information in terms of multilayer structures in our practical example on a thin intermediate layer at the substrate interface.