FIRST-PRINCIPLES STUDY OF ZN-SB THERMOELECTRICS

We report local-density-approximation calculations of the electronic s tructure and thermoelectric properties of beta-Zn4Sb3. The material is a low carrier density metal with a complex Fermi-surface topology and a nontrivial dependence of the Hall concentration on the band filling . The band structure is rather covalent, consistent with experimental observations of good carrier mobility. At a band filling corresponding to the experimental Hall number, the calculated thermopower and tempe rature dependence are in good agreement with experiment. The high Seeb eck coefficient in a metallic material is remarkable, and arises in pa rt from the strong energy dependence of the Fermi surface topology nea r the experimental band filling. An improved thermoelectric performanc e is predicted for lower doping levels, i.e., higher Zn concentrations .