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∼58nm. The effect of sintering temperature on the thermoelectric property of the ball-mill sample was studied by sintering the material at 450°C and 550°C. The thermoelectric properties of the sintered pellets were measured in the temperature range of 30-350°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°C and 550°C, respectively. We achieved maximum figure-of-merit (ZT) of 0.8 at 350°C in case of sample sintered at 450°C which is attributed to the better power factor value in this sample.