Electrophysical properties of epitaxial layers of solid solutions of lead and tin tellurides doped with cadmium

Abstract

Epitaxial layers of Pb_1−xSn_xTe (x≈0.2), undoped and doped with cadmium, are grown in a quasi-closed volume using the hot-wall method on BaF₂ fragments. The doping impurity is introduced directly into the material of the vapor source before synthesis in an equi-atom ratio with additional tellurium. The boundary of the limit of homogeneity from the side of the metallic components and in the region of the stoichiometric composition of the epitaxial layers doped with cadmium and the undoped epitaxial layers is established. The electrical conductivity and the Hall effect are investigated in the 77–450 K temperature range, and the temperature dependences of the intrinsic concentrations and of the ratio of the electron and hole mobilities are established. The temperature dependence of the Hall mobility is also investigated. The stability of the electrical parameters of the epitaxial layers are studied. It is shown that doping with cadmium enables highly stable n-type epitaxial layers to be obtained.