Influence of doping by tin, tallium and copper on quantum mobility of holes in antimony telluride single crystals

Abstract

In this work we report the results of the extraction of quantum mobilty μq of holes from the Shubnikov – de Haas (SdH) effect at T = 4.2 K in single crystals Sb2–xSnxTe3 (x = 0.0; 0.005; 0.0075; 0.01); Sb2–xTlxTe3 (x = 0.0; 0.005; 0.015; 0.05) and Sb2–xCuxTe3(x = 0.0; 0.01; 0.03; 0.05; 0.07; 0.10), samples synthesized by the Bridgman method. Tl exhibits donor properties in Sb2Te3 while Sn and Cu show an acceptor behavior. Quantum mobility of holes, evaluated from SdH oscillations, decreases under doping in Sn doped samples about two times, in Tl doped samples about three times and in Cu doped samples less than two times at maximal Cu content x = 0.1. At the same time maximal Cu doping is 6 times (as compared with Sn) and 2 times (as compared with Tl) more. All measurements were made to Orient the magnetic field along the C3 axis. In this case, for the six-ellipsoid surface of Fermi light holes, all sections of ellipsoids coincide, and only one oscillation frequency is observed.