Abstract
We theoretically investigate the electronic charge transport in a
molecular system composed of a donor group (dinitrobenzene) coupled to
an acceptor group (dihydrophenazine) via a polyenic chain (unsaturated
carbon bridge). Ab initio calculations based on the Hartree-Fock
approximations are performed to investigate the distribution of electron
states over the molecule in the presence of an external electric field. For small bridge lengths (n=0-3) we find a homogeneous distribution of
the frontier molecular orbitals, while for n>3 a strong localization of
the lowest unoccupied molecular orbital is found. The localized orbitals
in between the donor and acceptor groups act as conduction channels when
an external electric field is applied. We also calculate the
rectification behavior of this system by evaluating the charge
accumulated in the donor and acceptor groups as a function of the
external electric field. Finally, we propose a phenomenological model
based on nonequilibrium Green's function to rationalize the ab initio
findings.
Users
Please
log in to take part in the discussion (add own reviews or comments).