Thermoelectric properties of p-type Bi2Te3-Sb2Te3-Sb2Se3 pseudo- ternary alloys fabricated by hot pressing method

摘要

P-type 20% Bi2Te3-(80-x)% Sb2Te3-x% Sb2Se3 (0≤x≤7) alloy powders, fabricated by mechanical alloying andmelting/grinding processes, were hot pressed and theirthermoelectric properties were characterized with the Sb2Se3content and the powder processing method. The Seebeckcoefficient and electrical resistivity of the hot-pressed 20%Bi2Te3-(80-x)% Sb2Te3-x% Sb2Se3 alloys increased with increasingthe Sb2Se3 content due to the reduction of the hole concentration.Although the total thermal conductivity of the hot-pressed 20%Bi2Te3-(80-x)% Sb2Te3-x% Sb2Se3 alloys decreased withincreasing the Sb2Se3 content due to the reduction of Kel, thelattice thermal conductivity Kph was not lowered. The figure-of-merit of the hot-pressed 20% Bi2Te3-(80-x)% Sb2Te3-x% Sb2Se3alloys decreased with increasing the Sb2Se3 content, because theincrement of the electrical resistivity was much larger than thedecrement of the thermal conductivity and the increment of theSeebeck coefficient.