Nonadiabatic small‐polaron hopping electron transport in diphenoquinone‐doped polycarbonate

The dependences of electron mobility on the electric field F, temperature T, and hopping site distance R have been characterized in 3,5-dimethyl-3′,5′-di-tert-butyl-4,4′-diphenoquinone dispersed molecularly in a polycarbonate according to Schein’s analytical technique. The electron mobility can be described in the form a0R2 exp(−2R/R0) exp(−E0/kT) × exp[β(1/kT−1/kT0)F1/2], where a0, R0, β, and T0 are constants. Moreover, it is found that the zero-field activation energy E0 is independent of R. The invariable E0 and the exponential dependence of the Arrhenius prefactor on R strongly suggest that the electron transport therein is due to nonadiabatic small-polaron hopping. Based on the small-polaron theory, the transport properties are qualitatively discussed in terms of molecular properties.