Large Transverse Thermoelectric Power Factor in Topological Semimetal NbAs₂

Abstract

The distinctive properties of topological semimetals, including linear band dispersion and compensated electron‐hole carriers, have positioned these materials at the forefront of research in power generation and solid‐state cooling due to their remarkable magneto‐thermoelectric performance. In this work, the transverse thermoelectric characteristics of the topological semimetal NbAs2 are studied. Specifically, under a magnetic field of 9 T, the Nernst coefficient displays a linear and unsaturated trend, reaching a peak of 600 µV K−1 at 35 K. Consequently, this engenders a substantial transverse power factor (tPF) of 850 µW cm−1 K−2 under a 5 T magnetic field. The exceptional attributes of NbAs2 driven by its remarkably high carrier mobility and compensated electron‐hole concentration near the Fermi level are revealed by band structure analysis based on theoretical calculations and quantum oscillations. This work not only underscores the immense potential of topological semimetals as transverse thermoelectric materials for niche applications where magnetic fields exist but also provides valuable guidance for the discovery and optimization of topological materials for promising thermoelectric performance.