Thermoelectric Properties of Bi2Te2.7Se0.3 Solid Solution with Various Grain Sizes

Resumo

The electrical conductivity (σ) and the coefficients of thermal e.m.f. (α), Holl (R_H), and thermal conductivity (χ) of extruded n-Вi₂Te_2.7Se_0.3 samples with various grain sizes are studied in the temperature range 77–300 K after extrusion and upon subsequent annealing. It is shown that annealing substantially increases σ and χ and has a little effect on α at 77 K. This indicates that at 77 K, the structural imperfections of grains play the main role in the electron and phonon scattering. There is a correlation between the degree of texture and thermoelectric properties.