Enhancing thermoelectric efficiency in twisted bilayer PdSe₂
Abstract
PdSe₂ is a promising two-dimensional (2D) material that has garnered significant attention for thermoelectric energy conversion applications due to its exceptional electronic and thermal properties. This study investigates the effect of twisting on the electron and phonon transport, as well as the thermoelectric properties of monolayer–twisted bilayer–monolayer PdSe₂ devices using full self-consistent ab initio nonequilibrium Green’s function methods combined with density functional theory. Our findings reveal that 90° twist angle significantly enhances the figure of merit (ZT), achieving values of 3.95 at 300 K and 6.25 at 600 K, an 81.19% increase at room temperature compared to nontwisted configurations. This enhancement is primarily due to the tunability of the band gap, weakened interlayer coupling, and boundary scattering at the interface. Additionally, our analysis suggests that adjusting the interlayer contact length could further optimize ZT. Achieving ZT values exceeding 3 in twisted bilayer PdSe₂ emphasizes the potential of exploiting twist modulations in 2D materials, representing significant progress toward developing highly efficient nanodevices capable of converting waste heat into electrical energy.
