Optical characteristics of self-assembled ultrathin films of tetra-copperphthalocyanine by attenuated total reflection

Multilayer thin films consisting of alternate layer-pairs of cationic macrocycles (tetra-copperphthalocyanine) and anionic macromolecules (polyethylenimine) were fabricated on thin silver film using alternate electrostatic self-assembly technique. The optical properties of the film were characterized by uv-vis absorption spectra and attenuated total reflection measurements. From the data analysis based on the multilayer reflection theory, it was shown that the ultra thin films were successfully fabricated by self-assembly technique with the mean layer-pairs thickness of 25 Å. Moreover, especially for tetracopperphthalocyanine layer, we obtained the anisotropy in dielectric constants with respect to the surface normal, indicating anisotropic orientation of the tetra-copperphthalocyanine molecules on the polyethylenimine layer.