LAUSR

For decades, significant thermoelectric enhancements at high temperatures have been witnessed in many materials. However, efficient materials working well near room temperature are still restricted to Bi2Te3-based alloys in both conduction types, in which the scarcity of tellurium is a concern for large-scale applications. Recently, Mg3Sb2–Mg3Bi2 alloys, particularly in n-type conduction, have been revealed to show great potential for efficient thermoelectric applications. The corresponding challenges rely on the realization of sufficient charge carriers with a high mobility, which respectively depends on effective doping and the removal of scattering sources. In this work, both a high carrier concentration and an inherently high mobility are enabled in Sc-doped Mg3Sb2–Mg3Bi2 alloys with coarse grains, synthesized by a melting and hot-deforming technique. This eventually leads to an average figure of merit zT of 1.1 within 300–500 K in optimal compositions, which is superior to that of state-of-the-art n-...