Large anisotropy of electrical conductivity induced high thermoelectric performance of p-type CrSi2

• Transport properties of p-type CrSi2 may be better than that of n-type one.
• The high anisotropic electrical conductivity of p-type doping induces this behavior.
• Effective mass of holes along z direction is smaller than that along x direction.

A comparative study of thermoelectric performances about CrSi2 and β-FeSi2 were performed by using density functional theory and Boltzmann transport theory. It is found that the transport properties of p-type CrSi2 could be better than that of n-type. The high thermoelectric performance of p-type CrSi2 are possibly due to the high anisotropy of its electrical conductivity with p-type doping. For CrSi2, the effective mass of holes along the z direction is smaller than that along the x direction, and consequently the hole mobility along the z direction may be higher than that along the x direction. A high thermoelectric performance of CrSi2 could be achieved by hole doping with concentration range of 1–6 × 1021 cm−3. The transport properties of n-type β-FeSi2 may be better than p-type one.