Half-Heusler phases as prospective p-type thermoelectric materials

摘要

It is well known that most of the half-Heuslers with potential thermoelectric properties are n-type due to electron domination in the transport. However, p-type half-Heusler alloys can be prepared by appropriate combination of elements. These alloys are multi-component and exhibit resistivity values 1000-3000 /spl mu//spl Omega/ cm and thermopower values hundreds of /spl mu/V/K. Such values are typical for state-of-the-art thermoelectric materials and the power factor S/sup 2//spl sigma/ can be in the range of 10-15 /spl mu/W cm/sup -1/ K/sup -2/ at room temperature. In addition to the high power factors, low thermal conductivities are expected due to the presence of heavy elements. We have studied a series of such alloys and the details are presented in this paper.