Electrical properties of the 85% Bi2Te3 15% Bi2Se3 thermoelectric material doped with SbI3 AND CuBr

The temperature dependences of the Seebeck coefficient, resistivity, Hall coefficient, and carrier mobility of SbI3- and CuBr-doped 85% Bi2Te3-15% Bi2Se3 single crystals have been characterized at temperatures ranging from 77 to 600 K, and the degenerate temperature, scattering parameter, bandgap energy, and the effective masses of the electron and hole have been determined. The degenerate temperature of the 85% Bi2Te3-15% Bi2Se3 alloy is 103 K, and the scattering parameter is determined to be 0.1. The ratio of the electron to hole mobility b (= mu(e)/mu(h)) is 1.45, and the bandgap energy E-G at 0 K Of the 85% Bi2Te3-15% Bi2Se3 alloy is 0.245 eV which is higher than E-G Of the pure Bi2Te3. The effective mass of the electron and hole in the 85% Bi2Te3-15% Bi2Se3 alloy are m(e) = 0.056 m(o) and m(h) = 0.065 m(o), respectively. (C) 1998 Elsevier Science Ltd. All rights reserved.