A Model for Assessment of Nonlinear Phonon Drag Contribution to Thermopower in Metal/Semiconductor Nanocontacts

We propose a simple 1D model for estimating the "hidden" thermopower produced in nanocontacts, which is usually spent for inducing eddy currents. The developed equations describe non-equilibrium phonon population in semiconductor near the nanocontact as comprising two components: equilibrium and ballistic parts. The ballistic flow partially transfers its momentum to charge carriers (i.e. produces phonon drag), which results in electric polarization and eventually – in generation of the thermoelectric voltage. Numeric calculations showed that the effect is non-linear with respect to heat flux and contact size. The predicted phenomenon can possibly be used to develop thermoelectric converters with unique parameters.