Highly efficient n-(Bi, Sb)2Te3 thermoelectric materials for temperatures below 200 K

The possibility of using an n-type Bi_2?x Sb_xTe₃ solid solution in thermoelectric refrigerators at T<200 K is considered. It is shown that, if the material under consideration is optimized for the above temperature region, the temperature dependence of the Seebeck coefficient α becomes less pronounced, and the crystal-lattice thermal conductivity κ_L decreases as compared to what is observed in a conventional n-Bi₂Te_3?y Se_y solid solution. These factors and a high mobility of charge carriers μ₀ bring about an increase in the parameter β ～ ZT, where Z is the thermoelectric efficiency.