Molecular orbital analysis of frontier orbitals for molecular electronics: A case study of unimolecular rectifier and photovoltaic cell

Abstract

Recently, unimolecular devices have attracted significant attention as a 'post-silicon technology' to enable the fabrication of future nanoscale electronic devices. In this paper, we describe a candidate molecule for a rectifier function using porphyrin polymer and a photovoltaic cell using fullerene-based supramolecule. We have investigated the geometric and electronic structure of these organic molecules using an ab initio quantum mechanical calculation. These results for the porphyrin polymers show that the localization of the unoccupied orbital state on the acceptor moiety mostly depends on their structures. The calculated results for the electronic structure of a naphthalocyanine-fullerene supramolecule manifest that the HOMO's were localized on the donor sub-unit and the LUMO's were localized on the acceptor sub-unit. © 2003 Elsevier Ltd. All rights reserved.