SOME COMMENTS ON THE ELECTRONIC-PROPERTIES OF THE SURFACE SPACE-CHARGE LAYER OF COPPER PHTHALOCYANINE THIN-FILMS

A simple analysis, using a theory of the surface space charge layer of semiconductors, of the published values of the work function phi and surface ionization energy PHI(s) of copper phthalocyanine (CuPc) thin films was performed. Using a well known position of the Fermi level E( F) within the band gap E(g) the values of its absolute band bending e V(2) and surface electron affinity X(s) were determined. A small negat ive value of the absolute band bending e V(s) = - 0. 17 -/+ 0. 15 eV h as been interpreted by the existence of the filled electronic surface states localized in the band gap below the Fermi level E(F). Such stat es were predicted theoretically for thin films and the crystalline sur face of CuPc, and attributed to surface lattice defects of a high conc entration.