Polarons in polysilanes: theoretical background and experimental detection

Charge carrier transport in disorder wide band-gap organics occurs by hopping. However, in many organic solids polaron effects arc important. The strong electron-phonon coupling causes carrier self-trapping and creates a quasiparticle, a polaron, which can move to on adjacent molecule only by carrying along the associated molecular deformation. On the example of polysilanes it is shown how the temperature and electric field dependences of charge carrier mobility can be utilized for the distinguishing between polaron and polaron-free transport. Another prove follows from thermally stimulated luminescence - the test is based on the assumption that the energy relaxation of polarons is much slower than that of charge carriers in a similarly disordered but rigid hopping system.