STRUCTURE AND SPECTROSCOPIC CHARACTERIZATION OF POLYCRYSTALLINE VANADYL PHTHALOCYANINE (VOPC) FILMS FABRICATED BY VACUUM DEPOSITION

The polycrystalline VOPc films in phases I, II, and a less-crystallize d alpha-form have been fabricated on an indium-tin-oxide-glass substra te. Room-temperature and low-temperature visible absorption spectrosco py, Fourier-transform infrared spectra, and X-ray diffraction patterns have been used to characterize and analyze the packing structures and interactions of VOPc molecules. Bethe splitting, broadening, and reds hift of the Q absorption band have been observed in the three packing structures. Thermochromism was found in phase II and the less-crystall ized cc-form, but not in phase I, from the temperature dependence of t he absorption spectra. The liquid nitrogen was found to be effective i n the crystallization of VOPc molecules.