Abstract
The unique features of the monolayer PbBiI originate from the gapped and gapless states protected by the time-reversal symmetry. These states appear with the angular momenta J = {1/2, 3/2}. The engineering of thermoelectric performance in monolayer PbBiI is highly desirable due to the forbidden backscattering mechanism of electrons. Herein, a known physical staggered exchange field is implemented to calculate the Onsager transport coefficients within the Kubo-Greenwood framework. This, in turn, enhances the power factor (PF) through highly dispersive and degenerate energy bands resulting from the staggered exchange field. We report exceptional 133%, 53%, and 22% enhancements of PF at temperatures 480 K, 460 K, and 440 K, respectively, when we turn on the exchange field to act on J = 3/2, J = 1/2, and both Js. The predicted PFs propose a new research line to achieve the highest thermoelectric efficiency in low-dimensional materials.
