Epitaxial Growth of Copper and Cobalt Phthalocyanines on KCl

• Published in: Japanese Journal of Applied Physics 2004-07, Vol.43 (7R), p.4344
• Main Authors: Hoshino, Akitaka, Takenaka, Yoshiko, Izukashi, Masahiro, Yoshida, Hidehito, Miyaji, Hideki
• Format: Article
• Language: English
• ISSN: 0021-4922; 1347-4065
• DOI: 10.1143/JJAP.43.4344

The crystal structures and epitaxial orientations of copper and cobalt phthalocyanines on a KCl (001) surface are investigated by transmission electron diffraction. Both the epitaxial crystals are found to have a parallel molecular arrangement with α(+)-type molecular stacking along their molecular columns and have essentially the same epitaxial orientations. On the basis of these structures, two kinds of epitaxial orientations are investigated. One, the primary orientation, is well explained by point-on-line coincidence at the interface. The other secondary orientation, which is slightly rotated from the primary orientation, does not show any exact coincidence at the interface. Adsorption energy calculations show that the most stable molecular orientation on the substrate nearly coincides with the molecular orientations observed in the epitaxial crystals. In addition to this, one of the two-dimensional axes of the epitaxial crystals at the interface nearly coincides with one of the substrate surface lattice vectors. On the basis of these findings, how the epitaxial orientations are determined during the crystal growth is discussed.