A two-step strategy improves the wide-temperature-range thermoelectric performance of Mg3+xBi1.29Sb0.7Te0.01

By adjusting the excess Mg content and refining the high-temperature sintering process, we optimized carrier concentration and mobility, in Mg 3 Bi 2 -based thermoelectric materials. Enhancing the power factor. The ZT value at 323 K increased from 0.05 to nearly 0.5, with a peak ZT of around 1 at 573 K.