On thermopower calculations with temperature-dependent electron energies

Abstract

It is argued that the thermoelectric transport coefficients in a coupled electron-phonon system depend on the interaction of phonons with a heat bath. When the phonon mean free path is short, temperature-dependent energy levels may be introduced in the Boltzmann equation which yields the usual formulae for the thermopower with temperature-dependent energies inserted. For weak phonon-heat-bath interaction and strong electron-phonon interaction, a transport equation for new quasi-particles is obtained and the energy current includes transport of the electron-phonon interaction and phonon energies carried along by a quasi-particle.