Optical properties of mixed coordination of polytypes of TaS2 in the photon energy range 0.5-6.0 eV

It is shown that the transmission and reflectivity spectra obtained by averaging the dielectric function of trigonal prismatic coordination 2H-TaS2 and octahedral coordination 1T-TaS2 are very similar to the measured spectra of 4Hb and 6R-TaS2, two of the mixed coordination polytypes of TaS2. This indicates that the individual layers of TaS2 macro-molecules contribute additively to the physical properties of this layer material. The main difference between the calculated and measured spectra indicates charge transfer of up to 0.2 of an electron per TaS2 formula unit from the octahedral to the trigonal prismatic layers in both 4Hb and 6R-TaS2. (author)