Nanostructure design for high performance thermoelectric materials based on anomalous Nernst effect using metal/semiconductor multilayer

Abstract

For developing high performance thermoelectric materials based on anomalous Nernst effect (ANE), we propose a ferromagnetic metal/semiconductor multilayer, where ferromagnetic metal/semiconductor interfaces prevent heat carrier transport (thermal conductivity reduction), and are expected to enhance the ANE coefficient additionally. The amorphous Co/Si multilayer displays an extremely-low thermal conductivity of ∼1.5 Wm−1 K−1 due to the interface phonon scattering and undoped Si amorphous layers with low thermal conductivity. Concurrently, the multilayers exhibit 2.4 times larger anomalous term of transverse Seebeck coefficient than Co films. This demonstrates that the nanostructure with the ferromagnetic metal/semiconductor interfaces is beneficial for developing thermoelectric generation based on ANE.