Thin films (1−200 nm) of the title compounds were prepared by vapor deposition on glass at a controlled temperature. Film growth was studied in situ by optical absorption spectroscopy and measurement of the electrical conductivity. Independent of substrate temperature, a layered growth was found for ultrathin films of F16PcZn. During further deposition, this was followed by island formation (Stranski−Krastanov). Island growth from the beginning of deposition (Volmer−Weber) was found for MePTCDI. Both growth modes were confirmed by atomic force microscopy (AFM). Substrate temperature had a clear influence on the crystal structure of F16PcZn. A structure consisting of parallel stacks of molecules is formed first under all conditions. At lower temperature, this growth continues including, however, an increasing portion of amorphous material, whereas a square lattice of molecules is formed at higher temperature. This was found to be the stable modification of F16PcZn since films deposited at lower temperature could be irreversibly transformed into this structure by annealing of the films. A reversible dependence of optical absorption spectra on temperature was found for the stable modification of both materials in the range from 78 to 450 K. Bands were found to narrow considerably at lower temperature, and shifts were observed that were characteristic for stronger intermolecular interaction which was very well- defined at lower temperature. A considerable mobility of molecules on the lattice site as well as between sites is indicated by the results of this study. The optical data are discussed in terms of an established model of transition dipole coupling.

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By changing the chemical composition of phthalocyanine molecules, the electrical properties of the ensemble in the solid state can be influenced directly. This is shown for phthalocyaninatomanganese (PcMn) as compared with purely divalent central metals and for complexes in which the ligand system has been modified by either electron‐withdrawing heteroatoms such as N instead of CH leading to tetrapyridotetraazaporphyrinatozinc (TPyTAPZn) or substituents such as F instead of H leading to hexadecafluorophthalocyaninatozinc (F16PcZn). The accessibility of additional oxidation states of Mn or the stabilisation of frontier orbital states by the ligand leads to a lower ionisation potential and interactions with impurities or dopant molecules are changed. A change in the observed majority carrier (n‐type behaviour) is seen even under UHV conditions. Measurements of the thermoelectric power and electrical conductivity are presented of the pure films and after exposure to oxidising ambient. During film growth either island growth or a growth following the Stranski‐Krastanov mechanism was observed. The comparison of the temperature dependence of thermopower and electrical conductivity leads to a discussion of the type of majority carriers, their generation as well as their transportation. For the materials investigated in this study the band model fails to explain the observed properties and a localised transport mechanism has to be considered. A transport in localised states close to the Fermi edge is discussed for TPyTAPZn and F16PcZn.

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