Thermoelectric generators as self-oscillating heat engines

In a previous paper [ 1 ] a model of a solar cell was proposed in which the non-periodic source of energy—photon flux—drives the collective periodic motion of electrons in a form of plasma oscillation. Subsequently, plasma oscillations are rectified by the p–n junction diode into dc (work). This approach makes a solar cell similar to standard macroscopic heat motors or turbines which always contain two heat baths, the working medium and the periodically moving piston or rotor. Here, a very similar model is proposed in order to describe the operation principles of thermoelectric generators based either on bimetallic or semiconductor p–n junctions. Again plasma oscillation corresponds to a piston and sunlight is replaced by a hot bath. The mathematical formalism is based on the Markovian master equations which can be derived in a rigorous way from the underlying Hamiltonian models and are consistent with the laws of thermodynamics.