Effects of a second valence band and resonant states on transport in undoped Pb1−xSnxTe

Abstract

The temperature dependence of the Hall coefficient of n‐ and p‐type Pb1−xSnxTe samples (x = 0.2) is analysed taking into account the temperature dependent effective masses and nonparabolicity. It is shown that the energetic separation between the edges of conduction and second valence band, respectively, is Δ2 = 0.34 eV as in PbTe. From the analysis of p‐type samples the existence of resonant states, which are degenerated with the upper valence band, is deduced. The concentration of these states is of the same order as the hole concentration.