Electronic structure and thermoelectric properties of orthorhombic SrLiAs

The electronic structure and the transport properties of orthorhombic SrLiAs were investigated using first-principles calculations and the semiclassical Boltzmann theory. It is found that the electrical conductivity along the y-direction is higher than those along other two directions, which is most likely originated from the covalent ladder-like structure formed by the Li and As atoms. Moreover, the transport properties of n-type SrLiAs are better than those of p-type one, due to the large band dispersion along the y-direction near the Fermi level. Further, the value of power factor with respect to relaxation time achieves 9.2 × 1011 W K−2 m−1 s−1 for n-type SrLiAs along the y-direction at 1000 K with an optimal carrier concentration of 6.5 × 1020 cm−3. The obtained minimum lattice thermal conductivity is comparable to those of other Zintl phase compounds.