Magnetoresistance-enhanced electro-thermal conversion performance

Abstract Seeking novel and effective approaches to synergistically improve the electrical and thermal transport properties and electro-thermal conversion efficiency of Bi2Te3-based alloys is essential for commercial applications. Here, GdCo2/Bi0.37Sb1.63Te3 thermoelectric nanocomposites were designed and synthesized to achieve synergistic improvement of electrical and thermal properties. As confirmed by magnetoresistance measurement, the built-in magnetic field and magnetic scattering generated by magnetic nanoparticles decrease the carrier concentration and mobility, and increase the Seebeck coefficient. Meanwhile, GdCo2 nanoparticles lead to broad-frequency phonon scattering, which effectively reduces the lattice thermal conductivity of nanocomposites. Eventually, the average ZT of the nanocomposite is increased by 18% in the range of 300-500 K, and the cooling temperature difference is increased by 68% near room temperature. This work proves that the thermoelectromagnetic coupling effects generated by magnetic particles can effectively improve the electro-thermal conversion performance.