Thermoelectric properties of n-type (Pb1-xGex)Te fabricated by hot pressing method

Abstract

To investigate the effects of solid solution alloying on the thermoelectric properties of PbTe-based thermoelectric materials, 0.3 wt% Bi-doped (Pb1-xGex)Te alloy powders (0 less than or equal to x less than or equal to 0.15) were fabricated by "melting/grinding" process, and hot-pressed at 650 degrees C and 750 degrees C for 1 hour in vacuum. At the temperatures ranging from 25 degrees C to 450 degrees C, the (Pb1-xGex)Te alloys exhibited more negative Seebeck coefficient, higher electrical resistivity and lower thermal conductivity with increasing. the GeTe content. The temperature, where the figure-of-merit of (Pb1-xGex)Te reached a maximum, was lowered with increasing the GeTe content x. When hot-pressed at 650 degrees C, 0.3 wt% Bi-doped PbTe and (Pb0.9Ge0.1)Te exhibited a maximum figure-of-merit of 1.07x10(-3)/K at 400 degrees C and 1.25 x 10(-3)/K at 300 degrees C, respectively.