Electronic structure as a guide in screening for potential thermoelectrics: Demonstration for half-Heusler compounds
In this study, we adopt a high-throughput search strategy that begins with electronic structure features to screen a set of half-Heusler compounds for thermoelectric performance. This is motivated by the contradictory electrical transport requirements, specifically high electrical conductivity σ and high thermopower S for obtaining high figure of merit ZT. We use an electronic fitness function that measures the extent to which a specific band structure decouples σ and S for this purpose. We then perform detailed, more costly, calculations of thermal conductivity and electrical properties for those compounds that have a high electronic fitness. This provides an efficient method for identifying promising compounds from a set of candidates. Lastly, we apply this to a set of 75 previously studied half-Heusler compounds. The approach identifies several compounds as having potential as thermoelectric materials. Importantly, these include not only some previously identified candidates, but also some other compounds that had not been identified previously using other screening methods.