Electrical and optical properties of one-dimensional metallophthalocyanine (M = Fe) thin films grown by thermal evaporation

Semiconducting molecular materials based on iron phthalocyanine and diamine ligands have been successfully used to prepare thin films by a thermal evaporation technique. The samples were deposited on corning glass substrates and crystalline silicon wafers and were characterized by FT-IR, UV-Vis, SEM and EDS. The optical parameters have been investigated using spectrophotometric transmission measurements in the 200-1,150 nm wavelength range. The UV-VIS spectra of the films show two well defined absorption bands, namely, the Soret and the Q-band. The values of the optical band gap E-g (direct transitions) calculated from the absorption spectra, ranged between 3.30 and 4.38 eV. The effect of temperature on the conductivity of the films was also evaluated and the electrical transport properties were studied by dc conductivity measurements. The electrical activation energies of the complexes, which were in the range of 0.04-0.64 eV, were calculated from Arrhenius plots.