Linear theory of thermoelectric cooling

A new approach is suggested to explain the Peltier effect. It assumes the refusal of Peltier's effect as an isothermal effect. This approach is based on the representation of occurrence of induced thermal fluxes in a structure of two conducting media through which a d.c. electric current drives. These induced thermal diffusion fluxes arise to compensate the change of the thermal fluxes carried out by an electric current (the drift thermal fluxes) during their driving through the junction in accordance with the general Le Chatelier-Brawn principle. The occurrence of these thermal diffusion fluxes leads to the temperature heterogeneity in the structure and, as a result, to cooling or to heating of the junction. Within the framework of this conception the thermoelectric cooling is analyzed. It is shown that in the general case the Peltier effect always occurs together with another thermoelectric effect. This thermoelectric effect is predicted for the first time, and we have called it the barrierless thermoelectric effect. Both these effects essentially depend on the junction surface thermal resistance. The Peltier effect disappears in the limiting case of a very large surface thermal resistance while the barrierless effect disappears in the limiting case of a very small surface thermal resistance.