Solid State Solar-Thermal Energy Conversion Center (S3TEC Center)

Thermoelectrics made from earth abundant materials and with high figure of merit zT greater than 1 are required for waste heat recovery with global impact. While recent breakthroughs made by Snyder and his thermoelectric group have finally achieved this goal in PbTe alloys, the toxicity of Pb and the expense of Te make this material not practical for wide scale applications. Luckily, however, the Band Structure Engineering approach, first described by Dresslehaus, is not limited to IV-VI thermoelectric semiconductors such as PbTe but can be extended to other semiconductors such as Half-Heuslers, skutterudites and Mg2Si. This has already shown in Mg2Si-Mg2Sn which can achieve zT > 1. More importantly, we have demonstrated that these high values are achieved by favorable material parameters which can be manipulated with Band Structure and Phonon Engineering.