Theoretical Analysis for a Molecular Rectifier: Geometric and Electronic Structures
H, Mizuseki, K. Niimura, C. Majumder and Y. Kawazoe
Institute for Materials Research, Tohoku University, JP
Keywords: molecular rectifier, molecular electronics, molecular device, nanotechnology, simulation, donor - spacer - acceptor structure
Recently, the field of molecular electronics has attracted strong attention as a “post-silicon technology” to enable future nanoscale electronic devices. The realization of a molecular device with a unimolecular rectifying function is one of the most important requirements in nanotechnology. In the present study, the geometric and electronic structure of the alkyl derivative molecule C37H50N4O4 has been investigated theoretically using ab initio quantum mechanical calculations. This molecule has a donor - spacer - acceptor structure, and is a leading candidate for the creation of a molecular rectifying device . The electron transport in these molecules has been analyzed, based on spatial distribution of the frontier orbitals. It is seen that while the occupied orbitals are localized on the donor sub-unit, the unoccupied orbitals are localized on the acceptor sub-unit. The localization of the unoccupied orbital state on the acceptor moiety depends on both the excess electron and the acceptor group. Finally, we can examine the effect of a various acceptor and the length of s bridge.
 T. Mikayama, M. Ara, K. Uehara, A. Sugimoto, K. Mizuno and N. Inoue, Phys. Chem. Chem. Phys. 3 (2001) 3459.
NSTI Nanotech 2003 Conference Technical Program Abstract