Konezny, S.J.Bussac, M.N.Zuppiroli, L.2010-01-192010-01-192010-01-19201010.1103/PhysRevB.81.045313https://infoscience.epfl.ch/handle/20.500.14299/45586WOS:000274002500075A charge carrier in the channel of an organic field-effect transistor (OFET) is coupled to the electric polarization of the gate in the form of a surface Fröhlich polaron [N. Kirova and M. N. Bussac, Phys. Rev. B 68, 235312 (2003)]. We study the effects of the dynamical field of polarization on both small-polaron hopping and trap-limited transport mechanisms. We present numerical calculations of polarization energies, band- narrowing effects due to polarization, hopping barriers, and interface trap depths in pentacene and rubrene transistors as functions of the dielectric constant of the gate insulator and demonstrate that a trap-and-release mechanism more appropriately describes transport in high-mobility OFETs. For mobilities on the order 0.1 cm^2/V s and below, all states are highly localized and hopping becomes the predominant mechanism.PACS numbers: 72.80.Le, 71.38.Fp, 72.20.Jvtext::journal::journal article::research article