Non equilibrium carriers of charge in theory of thermoelectric phenomena

Y. Gurevich, G. Logvinov, O. Titov, I. Volovichev

Departamento de Física, CINVESTAV del I.P.N., Apartado Postal 14-740, 07000, D.F., México, México

SEPI-ESIME Culhuacán, Instituto Politécnico Nacional, Av. Santa Ana 1000, Col. San Francisco, Culhuacán, C.P. 04430, D.F., México, México

O. Usikov Institute for Radiophysics and Electronics, National Academy of Science of Ukraine, 12 Acad.Proskury St., C.P. 61085, Kharkov, Ukraine.

We suggest a new approach for describing the thermoelectric phenomena in semiconductor structures. This approach takes into account that carriers of both signs (electrons and holes) contribute in these phenomena in the real circuits. It is shown that for the correct description of the thermoelectric phenomena in bipolar systems it is necessary to consider the nonequilibrium carriers even in the linear approximation by an electric field. For that, it was accounted for the first time the inhomogeneous thermal generation and recombination in the presence of the temperature field.

In the offered report there is stated the theory of thermoelectric phenomena in semiconductor structures with accounting the generation and recombination processes in multi-temperature approximation. The basis of this theory is following:

- Basis equations for generation and recombination processes are obtained in semiconductors in the presence of the different electron and phonon temperatures.
- The Poisson equation is obtained in the multi-temperature approximation. This equation is necessary for the correct calculation of the bulk charge layers in semiconductor structures under the presence of the thermoelectric current.
- The boundary conditions for the partial electric currents and the heat fluxes are formulated. These boundary conditions take into account the surface recombination, surface electric conductivity, surface thermal conductivity, and the temperature difference at the contacts of the closed thermoelectric circuit.
- The effective values of thermo-e.m.f., and the Peltier coefficient are calculated. Within the frame of the given approach they are depended on the rates of the surface and bulk recombination and the surface electric and thermal conductivity, besides the traditional parameters.