Transport and thermoelectric properties of the Pb1-xSnxTe topological crystalline insulator in the vicinity of the band inversion

Abstract

Semiconductor solid solutions Pb1-xSnxTe are well known as promising materials widely used in the IR electronics, thermoelectricity and other fields of science and technology. Recently, it has been found that these alloys in certain concentration ranges exhibit the properties characteristic of the new quantum objects of solid-state physics – topological crystalline insulators (TCIs), whose unique properties define new possibilities for practical use of these materials in spintronics, quantum computing and thermoelectricity. The fact that in Pb1-xSnxTe the band inversion near some composition xc, leads to the emergence of the TCI states stimulates a detailed study of the behavior of transport and thermoelectric properties near xc. In this work, for the Pb1-xSnxTe solid solutions in the composition range x = 0.59–0.68, we obtained the dependences of electrical conductivity, the Hall coefficient, charge carrier mobility, the Seebeck coefficient, and thermoelectric power factor on x at fixed temperatures in the interval (77–300) K. In the isotherms of all studied properties, we observed peaks at x ∼0.62 and attributed them to the band inversion and transition into the TCI state, which are accompanied by the self-organization processes in the crystal lattice.