Analysis of electronic, thermal, and thermoelectric properties of the half-Heusler CrTiSi material using density functional theory

In this study, we investigated the electronic structure, thermal, and thermoelectric properties of half-Heusler CrTiSi based on first-principles calculations. CrTiSi is an indirect band gap semiconductor with a band gap of 0.65 eV in the spin-up state. The presence of flat energy bands along the L and X directions indicates large effective masses for the charge carriers. CrTiSi has promising thermoelectric properties according to the high Seebeck coefficient, very larger power factor, and moderate thermal conductivity at room temperature with values of ∼128 μV K−1, 0.3 (1012 Wm−1 K−2 s−1), and 1.25 W mK−1, respectively. The effects of high pressure up to 35 GPa were determined on thermal properties comprising the crystal volume, thermal expansion coefficient, heat capacity, and Grüneisen parameter. Our results demonstrate that CrTiSi is a strong candidate for use in thermoelectric applications over an extensive temperature range.