Thermal and electric transport in semiconductors under a thermal field: emergence of nonequilibrium charge carriers
Oleg Yu Titov, Andrey Meriuts, Gabino Espejo, Igor N Volovichev, Yuri G Gurevich, Oleg I Lyubimov
A new point of view on thermoelectric phenomena as a transport process of non-equilibrium charge carriers is presented. It is shown that Fermi quasilevels which characterise transport in systems far from equilibrium can be nonmonotonic functions of position. The role of recombination in forming thermoelectric phenomena is discussed for the first time. It is shown that in the presence of thermal fields a new term in the expression for recombination appears which depends on the inhomogeneity of the temperature field. If electron and hole temperatures are different, which is typical of semiconductors, then one more new term appears in the expression for recombination proportional to the difference of electron and hole temperatures. A new method for the characterisation of semiconductor materials connected with the measurement of thermopower is proposed. It is shown that nonstationary thermal fields are best suited for this purpose.