Excellent thermoelectric performance of boron-doped n-type Mg3Sb2-based materials via the manipulation of grain boundary scattering and control of Mg content

Thermoelectric devices require thermoelectric materials with high figure-of-merit (ZT) values in the operating temperature range. In recent years, Zintl phase compound, n-Mg3Sb2, has received much attention owing to its rich chemistry and structural complexity. However, it hardly achieves ZT throughout medium Herein, by increasing sintering as possible, we successfully increased average grain size of compound 15 times, boundary scattering was manipulated obtain carrier mobility up 180 cm2 V?1 s?1. Simultaneously, optimized Mg content for ultralow lattice thermal conductivity. We first doped Mg3Sb2-based boron higher temperature, good stability, hardness. The synergistic optimization electrical transport resulted excellent (0.62 at 300 K, 1.81 773 K) an 1.4 (from K), which are than state-of-the-art n-type materials, demonstrating a potential device applications.