Ultrahigh seebeck coefficient and thermoelectric power factor in semimetal WTe2

Weyl semimetals are renowned for their intriguing physical properties and ultrahigh transverse thermoelectric power factor, but commonly exhibit exceedingly low Seebeck coefficient, and conventional strategies for the optimization of thermoelectric performance are unable to rectify this issue. In light of the distinct compensatory electronic structure inherent to semimetal materials, we propose an easy mechanism with the potential to achieve exceedingly high Seebeck power factors, by synergistic adjustment of the semimetal Fermi surface feature and temperature-dependent density of states. By diminishing the symmetrical distribution of electrons and holes in proximity to the Fermi surface, alongside the competitive Seebeck effect, we find a considerable surge in the Seebeck coefficient from ∼4/33 to 530/520 μV/K in the armchair/zigzag direction, respectively. Based on the ultrahigh power factor ∼14.6 W/mK2 achieved at 50 K, we highlight the potential of semimetallic materials as candidates for the next generation of flexible, high-performance thermoelectric devices.