The high temperature thermoelectric properties of Te-doped TiCoSb Half-Heusler compounds

Half-Heusler compounds of Te-doped TiCoSb were prepared by solid-state reaction. XRD analysis confirmed that all the sample were crystallized in the single-phase. Their thermoelectric properties were measured in the temperature rang of 300-850 K. The un-doped TiCoSb compound shows n-type conduction and possesses high Seebeck coefficient at high temperatures. Te doping on Sb site results in a significant reduction of the electrical resistivity and Seebeck coefficient. The thermal conductivity also decreases little with increasing Te content. The maximum value of ZT is nearly 5 times larger than the un-doped TiCoSb compounds.