A magneto-thermoelectric with a high figure of merit in topological insulator Bi₈₈Sb₁₂

High thermoelectric performance is generally achieved by synergistically optimizing two or even three of the contradictorily coupled thermoelectric parameters. Here we demonstrate magneto-thermoelectric correlation as a strategy to achieve simultaneous gain in an enhanced Seebeck coefficient and reduced thermal conductivity in topological materials. We report a large magneto-Seebeck effect and high magneto-thermoelectric figure of merit of 1.7 ± 0.2 at 180 K and 0.7 T in a single-crystalline Bi₈₈Sb₁₂ topological insulator. This result fills a gap of a high performance below 300 K and is promising for low-temperature thermoelectric applications. The large magneto-Seebeck response is attributed to the ultrahigh mobility and the Dirac band dispersion. The application of a low magnetic field to achieve a high thermoelectric performance can be extended to topological materials with similar features that are rapidly emerging because it synergistically optimizes the thermoelectric parameters.