Realizing <i>p</i>-type NbCoSn half-Heusler compounds with enhanced thermoelectric performance via Sc substitution

Abstract

<i>N</i>-type half-Heusler NbCoSn is a promising thermoelectric material due to favourable electronic properties. It has attracted much attention for thermoelectric applications while the desired <i>p</i>-type NbCoSn counterpart shows poor thermoelectric performance. In this work, <i>p</i>-type NbCoSn has been obtained using Sc substitution at the Nb site, and their thermoelectric properties were investigated. Of all samples, Nb_0.95Sc_0.05CoSn compound shows a maximum power factor of 0.54 mW/mK² which is the highest among the previously reported values of <i>p</i>-type NbCoSn. With the suppression of thermal conductivity, <i>p</i>-type Nb_0.95Sc_0.05CoSn compound shows the highest measured figure of merit <i>ZT</i> = 0.13 at 879 K.