Dynamics of Photogenerated Polaron-Excitons in Organic Semiconductors

In this work we performed numerical simulations of one π-conjugated polymer chain subjected to photogeneration. Within the SSH model modified to include the Brazoviskii-Kirova symmetry breaking term, we investigate the dynamics of photoexcitations to address the generation mechanism of polaron-excitons using the unrestricted Hartree-Fock approximation. It was obtained that after the photoexcitation the system relaxes spontaneously into a polaron-exciton in a transient state in a range of 200 fs. Our results also show that charged polarons are generated directly after this transient state.