Conductivity of two-dimensional metal-organic hybrid films

We calculate the conductivity of two-dimensional hybrid multilayer films formed by the self-assembly of an ordered Liquid crystalline array of molecular columns on an ultra-thin MBE grown metal layer. Electrons in the metal interact with the molecular overlayer, forming new energy bands which have novel transport properties. Because of the short mean free path encountered in these structures due to strong Coulomb and surface roughness scattering, conductivity changes occur where the molecular columns bond strongly to the metal surface. The local conductivities are calculated using Kubo-Greenwood formula for the hybrid system, and the global conductivity is obtained via a many-body diffusion model. The model includes both the general effects of a dielectric overlayer on electron scattering in the metal, and the specific effect of real and virtual electron capture by the molecular columns. The frequency-dependent conductivity is calculated for a range of columnar lengths and external gate fields. (C) 2000 Elsevier Science B.V. All rights reserved.