Charges on semiconducting nanotubes in polar media: Polarons and excitons

Charge carriers on semiconducting nanotubes immersed in the polar medium such as polar solvents undergo self-trapping into polarons. In the effectively 1d regime polarons are found to have binding energies of approximately 30–35% of the binding energy of excitons. As the thermal dissociation of excitons would occur into polaron pairs, the thermal ionization energy of excitons is substantially reduced, which is expected to lead to enhanced separation of charges.