On the concept of an effective temperature Seebeck ratchet

Abstract

In disordered semiconductors, finite electric fields can heat up the charge carrier distribution to effective temperatures that can significantly exceed the lattice temperature. Here, we demonstrate that such effective temperatures can be utilized to drive a thermoelectric generator (TEG). We use this concept in a variant of the Seebeck ratchet, which was originally introduced by Büttiker, in which out-of-phase spatial modulations of the electrostatic potential and the (effective) temperature cause a DC current. In contrast to conventional TEGs, this design utilizes only a single doped semiconductor and works in a thin film geometry. We demonstrate the concept using kinetic Monte Carlo simulations and show that the proposed concept can outperform conventional TEGs of the same material. We provide an analytical model that semiquantitatively reproduces the numerical results. Finally, we propose how such a device might be realized.