Electronic, optical and thermoelectric properties of Fe2ZrP compound determined: Via first-principles calculations

Abstract

In this study, based on the density functional theory and semi-classical Boltzmann transport theory, we investigated the structural, thermoelectric, optical and phononic properties of the Fe2ZrP compound. The results of the electronic band structure analysis indicate that Fe2ZrP is an indirect band gap semiconductor in the spin-down state with the band gap of 0.48 eV. Thermoelectric properties in the temperature range of 300-800 K were calculated. Fe2ZrP exhibits the high Seebeck coefficient of 512 μV K-1 at room temperature along with the huge power factor of 19.21 × 1011 W m-1 K-2 s-1 at 800 K, suggesting Fe2ZrP as a potential thermoelectric material. The Seebeck coefficient decreased with an increase in temperature, and the highest value was obtained for p-type doped Fe2ZrP when the optimum carrier concentration was 0.22 × 1023 cm-3; the n-type doped Fe2ZrP had high electrical conductivity than the p-type doped Fe2ZrP. Thermal conductivity increased with an increase in chemical potential. Optical calculations illustrated that there was a threshold in the imaginary dielectric function for the spin-down channel. Spin-dependent optical calculations showed that the intraband contributions affected only the spin-up optical spectra due to the free-electron effects. Generally, the results confirmed that the intraband contribution had the main role in the optical spectra in the low energy infra-red and visible ranges of light. We also presented the phononic properties and found that these materials were dynamically stable.