Effects of Intrachain Disorder on the Recombination Process of Polaron-pair in Conjugated Polymers

By using a nonadiabatic evolution method for the time-dependent Schrdinger equation and a Newtonian equation of motion for lattice, we investigate the disorder effects on the recombination process of oppositely charged polarons in a single polymer chain. The simulations are performed within the framework of an extended version of the Su-Schrieffer-Heeger model modified to include diagonal disorder and an external electric field. It is found that oppositely charged polarons can recombine into a neutral exciton in the presence of a weak electric field. But under the disordered system, the exciton can be produced under a wide range of applied electric field.