Nature of Charge Carriers in Disordered Molecular Solids: Are Polarons Compatible with Observations?

Polaronic theories for charge transport in disordered organic solids, particularly molecularly doped polymers, have been plagued by issues of internal consistency related to the magnitude of physical parameters. We present a natural resolution of the problem by showing that, in the presence of correlated disorder, polaronic carriers with binding energies $\Delta \sim 50–500\mathrm{meV}$ and transfer integrals $J\sim 1–20\mathrm{meV}$ are completely consistent with the magnitudes of field and temperature dependent mobilities observed.