Complex borides based on AlLiB14 as high-temperature thermoelectric compounds

Abstract

AlLiB₁₄ is examined as a potential high-temperature thermoelectric material. First-principles methods are used to investigate the thermoelectric behavior and it is found to have a band gap of 2.13 eV, and an electronic dispersion with characteristic indicative of having a high Seebeck coefficient. Semiclassical Boltzmann transport theory predicts that AlLiB₁₄ will have a Seebeck coefficient greater than 200 μV K⁻¹, at temperatures near 1000 K and carrier concentrations around 1 × 10²⁰ cm⁻³. Using a elasticity based expression for the thermal conductivity, the thermoelectric figure of merit is approximated to be 0.45 × 10⁻³ T at moderate doping levels.