Using Pseudo-ZTs for Thermoelectric Materials Search

Abstract

Thermoelectrics is attracting intensive research interests. The band structure information of new compounds is growing rapidly with the power of first principle calculations. However, not every thermoelectric materials candidate can be experimentally investigated due to limited resources. Therefore, we need to develop an efficient approach of screening and selecting the most promising ones from the various band structure databases of new compounds. Here we propose the concept of pseudo-ZT s: zt and zt , where zt only measures the electronic e L e influence and zt only scales the lattice contribution. Using zt and zt helps avoid playing the "seesaw balancing game" between the Seebeck L e L coefficient and the conductivities. It also helps reveal deeper physics on how dimensionality, carrier concentration and band structure will affect ZT quantitatively. A range of thermoelectric materials are tested, and ~400 new compounds are calculated for predictions. The pseudo-ZT s can serve as a good guidance for thermoelectric materials search, in addition to the semi-empirical “ β ” indicator. SE