First-Principle Calculation of Bi2Te3-Based Thermoelectric Materials

Thermoelectric materials have received a lot of attention due to their unique ability to convert waste heat into electricity directly, and the thermoelectric figure of merit zT is the main criterion for characterizing the performance of thermoelectric materials. In this paper, Bi2Te3-based materials are investigated using the first-principle calculation software VASP, and the energy band structures of Bi2Te3, BiSbTe3, and Sb2Te3 have been calculated and analyzed under the consideration of SOC. The results show that the Bi2Te3-based materials are heavily affected by SOC, which provides further understanding of the high thermoelectric figure of merit of Bi2Te3-based materials. The defect formation energy of the p-type Sb2Te3 has been also calculated and the result is analyzed with Yb element doped to form a point defect, and the result of the study shows the possible occupancy of the dopant atom, which provides guidance for experiments.