title: Impurity effects on polaron-exciton formation in conjugated polymers.
abstract: Combining the one-dimensional tight-binding Su-Schrieffer-Heeger model and the extended Hubbard model, the collision of two oppositely charged polarons is investigated under the influence of impurity effects using a non-adiabatic evolution method. Results show that electron-electron interactions have direct influence on the charge distribution coupled to the polaron-exciton lattice defect. Additionally, the presence of an impurity in the collisional process reduces the critical electric field for the polaron-exciton formation. In the small electric field regime, the impurity effects open three channels and are of fundamental importance to favor the polaron-exciton creation. The results indicate that the scattering between polarons in the presence of impurities can throw a new light on the description of electroluminescence in conjugated polymer systems.
authors.affiliation: Institute of Physics, University of Brasilia, 70.919-970 Brasilia, Brazil.
authors.forename: Luiz Antonio
authors.initials: LA
authors.lastname: Ribeiro
authors.forename: Wiliam Ferreira
authors.initials: WF
authors.lastname: da Cunha
authors.forename: Pedro Henrique
authors.initials: PH
authors.lastname: de Oliveira Neto
authors.forename: Ricardo
authors.initials: R
authors.lastname: Gargano
authors.forename: Geraldo
authors.initials: G
authors.lastname: Magela e Silva