Enhanced thermoelectric performance of nanostructured manganese telluride via antimony doping

Abstract

Abstract Manganese telluride is a good thermoelectric material for medium temperature applications. Pristine MnTe is a p-type semiconductor with an average hole concentration of 10 19 c m − 3 . Many dopants like Sodium, Copper and Sulphur were incorporated in the MnTe and their thermoelectric properties were studied. Antimony is an ideal dopant to alter the thermoelectric properties. Compounds belonging to the series M n 1 − x S b x T e with (x = 0, 0.005, 0.01, 0.015, 0.02) were prepared using a combination of High Energy Ball Milling (HEBM), melt quenching and hot press techniques. Structural, electrical and thermo-electric properties of these compounds were determined. Carrier concentration and mobility were measured by Hall measurement techniques. Charge carrier concentration increases with Sb doping while mobility and effective mass decreases. Seebeck coefficient and electrical conductivity were measured in the temperature range 100 K–730 K, and thermal conductivity was evaluated in the temperature range 100 K–300 K. The power factor and figure of merit (ZT) were also estimated. The highest power factor achieved is at 730 K and is 1768 μ W m − 1 K − 2 for M n 0.98 S b 0.02 T e . The highlight of the present study is the rise in electrical conductivity and reduction in the thermal conductivity with Sb doping.