Fermiology-driven goniopolar transverse thermoelectricity in kagome metals.

The exotic geometry of the kagome lattice drives emergent quantum states and advances energy technologies; however, the anomalous Nernst effect (ANE)-based magnetic systems are fundamentally limited by low thermopowers (<6μ V K-1) and stray-field interference. Here we propose goniopolarity (axis-dependent carrier polarity) to achieve high zero-field transverse thermoelectric responses in kagome systems. By exploiting flat-band- and van Hove singularity-driven electronic states, we uncover exceptionally large goniopolar thermoelectric responses in LuCo6Ge6, including a transverse thermopower of 18.4 μV K-1 and a transverse Peltier conductivity of 105 A m-1 K-1 at room temperature and zero field. The synergy of flat bands with high electrical conductivity yields values an order of magnitude greater than those achieved in conventional ANE-based systems. Our findings establish goniopolar kagome metals as promising candidates for thermoelectrics.