Deviations from Wiedemann-Franz law in quasi-one-dimensional organic crystals

Abstract

The physical reasons that lead to deviations from the Wiedemann-Franz law in low-dimensional organic crystals with electronic type conduction are investigated. The kinetic coefficients were modeled as functions of Fermi energy. It is shown that the Lorentz number becomes dependent on crystal purity and unlike the case of ordinary materials has a maximum in the domain of intermediary electronic concentrations. At higher concentrations the Lorentz number may be diminished in the purest crystals by an order of magnitude and even more. This diminution gives important contribution to the increase of the thermoelectric figure of merit. It is favorable for thermoelectric applications of such materials.