High thermoelectric properties of p-type pseudobinary (Cu_4Te_3)_x-(Bi_(0.5)Sb_(1.5)Te_3)_(1-x) alloys prepared by spark plasma sintering

摘要

Cu_4Te_3 substituted (Cu_4Te_3)_x-(Bi_(0.5)Sb_(1.5)Te_3)_(1-x) (x=0-0.2) alloys were prepared using spark plasma sintering technique and their thermoelectric properties were evaluated. Measurements show that the alloy with x=0.025 reveals very high electrical conductivity and low lattice thermal conductivity, the Seebeck coefficient that increases linearly with temperature is dependent on Cu_4Te_3 concentration. The maximum ZT value of 1.26 for the alloy with x=0.025 is achieved at 474 K, whereas that of the state-of-the-art thermoelectric material Bi_(0.5)Sb_(1.5)Te_3 is only 0.58 at 318 K, thus indicating that the currently prepared pseudobinary alloy is very encouraging.