Surface characterization of thin films of tetrathiofulvalene 7,7,8,8-tetracyano-p-quinodimethane evaporated on NaCl(001)

Thin films of tetrathiofulvalene 7,7,8,8-tetracyano-p-quinodimethane, a quasi-one-dimensional charge transfer organic metal, have been grown on cleaved NaCl substrates by evaporation in high vacuum. The films are polycrystalline and textured, and are comprised of rectangular c*-oriented microcrystals with their a and b axis parallel to both the [110] and [-110] substrate directions. The growth is basically determined by an oriented nucleation and the one dimensionality of the compound induced by the pi bonding along the stack. An x-ray photoelectron spectroscopy analysis of the films reveals that the films are stoichiometric and suggests that the charge transfer is not homogeneously distributed and that it should be negligible at the surface. (C) 1998 American Vacuum Society. [S0734-2101(98)01204-4].