Linear Electrical Conductivity of a Bipolar Semiconductor: Heating and Recombination

The linear electrical conductivity of a nondegenerate bipolar semiconductor, with metal contacts at both sides, is investigated for small values of the thermal conductivity in a general case, i.e., when both nonequilibrium charge carriers (electrons and holes) and nonequilibrium temperature are present. It must be emphasized that both concentration and energy nonequilibria arise automatically when an electric current flows, even in a linear approximation with respect to perturbation. The expression for the electrical conductivity is obtained. This expression depends on electrical conductivities of electrons and holes, the thermal conductivity, the bandgap, the lifetime of charge carriers, and the surface recombination rate at the contacts of a semiconductor with a metal.