MePTCDI

In this subsection, we apply the relations obtained above for calculations of the energies of edge excitons in MePTCDI and PTCDA crystals. As we already mentioned, these crystals are quasi-one-dimensional. The distance between the molecules within the one-dimensional stacks is 0.34 nm for MePTCDI (45) and 0.337 nm for PTCDA (46)-(48). 

To compare the energies of edge and lowest energy bulk states in MePTCDI and PTCDA, we use for these crystals the fitting parameters obtained in (41) to explain the frequency dependence of the polarization ratio in absorption spectra of MePTCDI crystals. These fitting parameters are collected in Table 12.1. 

Using these data (without any new fitting parameter) we obtain the parameters a, / , A and M, which we need for the calculation of energies of edge and lowest energy bulk states in PTCDA and MePTCDI crystals. 

Table 12.2 Comparison of the energies of the lowest bulk and surface states. In MePTCDI the lowest surface state is red-shifted in comparison with the bulk in PTCDA the surface state is blue-shifted.

Energies of the lowest bulk and surface states in MePTCDI and PTCDA... 

In studies of electrochemical photocurrents obtained at molecular semiconductor thin films (PcZn, (CN)sPcZn, TPyTAPZn, MePTCDI) and their dependence on the concentration of the reactant in the electrolyte (O2, ethylthiolate (RS ), hydroquinone/benzoquinone (HQ/BQ), Fe(CN)g, a sat-... 

Schlettwein, D., H. Graaf, J.-P. Meyer, T. Oekermann, and N.I. Jaeger (1999). Molecular interactions in thin films of hexadecafluorophthalocyaninatozinc (F16PcZn) as compared to islands of iV,iV -dimethylperylene-3,4,9,10-bicarboxunide (MePTCDI). J. Phys. Chem. B 103, 3078-3086. 

Hoffmann M et al (2000) The lowest energy Frenkel and charge-transfer excitons in quasi-one-dimensional stmctures application to MePTCDI and PTCDA crystals. Chem Phys 258 73-96... 

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