Calculation of the temperature behavior features of electrical conductivity in GeTe, SnTe and A(x–1) B(x) C semiconductors – solutions of Tc near-structural phase transition

Abstract

Temperature behavior calculation of the anomalous conductivity of the A4B6-type ferroelectric semiconductors (GeTe, SnTe and A(x–1) B(x)C) of Tc near-phase transitions is carried out in the paper. The proposed integrable (analytical) model is applicable both for describing the temperature behavior of the conductivity of GeTe multivalley semiconductors and SnTe-type systems. The influence of the structural phase transition on the systems’ conductivity is analyzed. The proposed analytical model of the conductivity behavior of ferroelectrics-semiconductors allows considering compounds with various spectra and compositions. The model is applicable both for the kinetic properties of multivalley semiconductors and for analyzing the effect of external influences on these properties: x composition and T temperature, as well as the presence of a structural phase transition in the system at Tc(x). It is shown that the graph can have the form of a break or the form of a smooth asymmetric maximum, depending on the value of the effective relaxation rate of carriers on soft phonons and the intervalley splitting of the anomalous conductivity near Tc in A4B6 systems. The calculation results are consistent with the experimental data. The dependence of the phase transition temperature Tc(x) on x composition is obtained.