Electronic Structure of Thermoelectric Material ZnSb from First-Principles

ZnSb has been studied intensively in recent years and has shown promising features for thermoelectric applications. The figure of merit has been reported to be above one. Even though many researchers have investigated ZnSb, there are still features and behaviors of this thermoelectric material that are not well-understood. In this work, we utilized a first-principle full potential and an all electron method to calculate the electronic structure of ZnSb, which has an orthorhombic P/bca structure with Zn and Sb both in 8(c) positions. We used a density functional theory potential and the linear combination of atomic orbitals (LCAO) formalism. The calculated indirect band gap of ZnSb is about 0.56 eV; it is located at non high symmetry points and agrees with the experimental finding of 0.53 eV. The smallest direct gap, at the X point, is 0.89 eV. The calculated electron and hole effective masses in ZnSb are also consistent with the reported data from experimental works. This work was funded in part by DOE (Award # DE-NA0003679), NSF (Award # HRD 1736136) and ARO (Award # W911NF-15-1-0483).