Biaxial strain-induced enhancement in the thermoelectric performance of monolayer WSe2

The effects of biaxial strain on the electronic structure and thermoelectric properties of monolayer WSe2 have been investigated by using first-principles calculations and the semi-classical Boltzmann transport theory. The electronic band gap decreases under strain, and the band structure near the Fermi level of monolayer WSe2 is modified by the applied biaxial strain. Furthermore, the doping dependence of the thermoelectric properties of n- and p-doped monolayer WSe2 under biaxial strain is estimated. The obtained results show that the power factor of n-doped monolayer WSe2 can be increased by compressive strain while that of p-doping can be increased with tensile strain. Strain engineering thus provides a direct method to control the electronic and thermoelectric properties in these two-dimensional transition metal dichalcogenides materials.