High Thermoelectric Performance of Large Size Bi2Te2.7Se0.3 Alloy Ingots

Bi2Te3-based alloys are currently the best room-temperature thermoelectric materials, and have been used widely in the field of thermoelectric refrigeration. Bi2Te3 ingots prepared by the zone-melting method provide convenience for large-scale commercial application. Currently, one trend is that the dimensionless thermoelectric figure-of-merit (ZT) value of the n-type Bi2Te2.7Se0.3 is slightly lower than that of the p-type Bi0.5Sb1.5Te3. In this paper, n-type Bi2Te2.7Se0.3 alloy ingots with large size were successfully prepared through the optimized zone-melting preparation process, and achieved a high ZT value of 1.16 at 360 K. This value is higher than all the n-type or p-type Bi2Te3-based ingots in current commercial applications.