Tailoring of Thermoelectric Properties in Bi2Te3 by Varying the Sintering Temperature

Bismuth Telluride (Bi2Te3) nanocrystalline material was synthesized using high energy planetary ball-mill at 600 RPM. The Reitveld refined X-ray diffraction pattern of the powder samples confirms the formation of pure Bi2Te3 phase with the particle size of similar to 58nm. The effect of sintering temperature on the thermoelectric property of the ball-mill sample was studied by sintering the material at 450 degrees C and 550 degrees C. The thermoelectric properties of the sintered pellets were measured in the temperature range of 30-350 degrees C using various characterization techniques. The samples exhibit maximum power factor value of 3mW/m-K and 2.4mW/m-K for the sintering temperature of 450 degrees C and 550 degrees C, respectively. We achieved maximum figure-of-merit (ZT) of 0.8 at 350 degrees C in case of sample sintered at 450 degrees C which is attributed to the better power factor value in this sample.