Excellent Thermoelectric Performance of Monolayer ZrTe ₅ and Its Near‐Room Temperature Modulation by Uniaxial Strain

Abstract Monolayer , a topological insulating quantum material, exhibits exceptional near‐room temperature thermoelectric properties, as revealed by first‐principles calculations and Boltzmann transport theory. Pristine monolayer shows excellent ‐type thermoelectric performance, with a maximum figure of merit () reaching 2.41 (‐direction) and 4.74 (‐direction) at 500 K. Its maximum thermoelectric conversion efficiency exceeds 15% (the benchmark of commercial alloys) at a temperature difference () of 200 K and approaches 25% at = 350 K. Remarkably, it demonstrates dual‐type near‐room temperature thermoelectric behavior, with both ‐ and ‐type values surpassing 2 at 300 K (3.45 and 2.53, respectively, in the ‐direction). Tensile strain, while less affecting the direct topological gap and the indirect bandgap, significantly enhances the ‐type power factor at 4% and 6% strain levels due to increased valley degeneracy near the valence band maximum, boosting the Seebeck coefficient. This leads to a transition from ‐type to ‐type behavior, achieving peak values of 6.79 (4% strain) and 8.69 (6% strain) at 500 K and 400 K, respectively, in the ‐direction. These findings underscore monolayer ’s potential for near‐room temperature thermoelectric applications and highlight strain modulation as a promising strategy for performance enhancement.