DYNAMICS OF CHARGE-TRANSFER IN MOLECULAR SWITCHES II - EFFECTIVE POTENTIALS AND COULOMB INTERACTION

The charge transport on a single conducting polymer chain, with impuri ty molecules working as switches, is investigated. The dynamics of sol itons through the sites that work like a switch is numerically studied using the Su-Schrieffer-Heeger model extended to include short-range Coulomb interactions. The time-dependent unrestricted Hartree-Fock app roximation is used. The considered molecular switches are single and p airs of donor-acceptor molecules bonded to the chain. The influence of the parameters of the molecules on the charge transport and the role of the length of separation between the sites where the donor and acce ptor molecules bond are determined. The effects of the inclusion of sh ort-ranged Coulomb interactions are analyzed. We write effective poten tials determining the soliton behavior for each case, where the switch ing sites allow the soliton to pass, be reflected or trapped. (C) 1998 Elsevier Science S.A. All rights reserved.