Intertwined electronic–phononic one-dimensionality as the origin of extraordinary thermoelectric transport in bulk Rb2PtC2

Thermoelectric materials, which convert heat directly into electricity, are promising for sustainable energy applications. Using first-principles calculations, we predict that rubidium platinum carbide (Rb2PtC2) exhibits nearly ideal one-dimensional electronic and phononic characteristics, resulting in transport similar to densely aligned nanowires. This enables exceptional performance, with a power factor an order of magnitude higher than that of several well-known high-performance thermoelectric materials. As a consequence, the material has the potential to reach an unprecedented figure of merit. Moreover, defect calculations show that the conduction type can be tuned between p-type and n-type by adjusting growth conditions. These findings identify Rb2PtC2 as a rare bulk material intrinsically exhibiting nanowire-like transport, offering a new paradigm for designing next-generation thermoelectric compounds.