In-Situ Loading Bridgman Growth of Mg3Bi1.49Sb0.5Te0.01 Bulk Crystals for Thermoelectric Applications

The single crystal growth of Mg 3 Bi 2 -based thermoelectric materials is of great significance for their applications near room temperature. So far, it is still a big challenge to grow such bulk single crystals and attempts are primarily focused on the metal flux methods. For the first time, bulk single crystals of n-type Mg 3 Bi 1.49 Sb 0.5 Te 0.01 are directly grown by applying an In-situ Loading Bridgman method. The as-grown single crystal features an excellent carrier mobility of 220 cm 2 V −1 s −1 , which is among the best compared to other Mg 3 Bi 2 -based bulk materials. Besides, this method is successfully developed to fast grow uniform polycrystalline materials with high thermoelectric and mechanic performance. As demonstrated by the single-leg device, a large temperature difference of 10.5 K is achieved at the supplied electric current of 0.6 A, much superior to other room temperature state-of-the-art thermoelectric materials. With the single crystalline and polycrystalline materials prepared reliably and conveniently, in-depth investigations on the Mg 3 Bi 2 thermoelectric system can be greatly benefited, which should as well significantly facilitate their practical applications at room temperature.