On the Electrical Conductivity of Polar Semiconductors at High Frequencies



Stolz' expression for the complex electrical conductivity of polar semiconductors as a function of the applied frequency is numerically evaluated. The conductivity is represented in the usual form of the frequency spectrum, as well as in the form of an Argand diagram. The latter representation shows that this dispersion function of the complex conductivity of polar semiconductors is almost identical to the dispersion function of the dielectric permittivity given by Cole and Cole. From the approximate symmetry of the dispersion function in logarithmic relaxation time space, it is concluded that the relaxation time can be determined with reasonable accuracy from the peak of the imaginary part of the complex conductivity, or from the inflection point of the real part.