Lattice Regularization by Manipulating Over-Stoichiometric Defects Yields High-Performance (Bi,Sb)Te Thermoelectrics.

BiTe-based alloys have historically dominated the commercial sector of near-ambient-temperature thermoelectric technology. However, the massive intrinsic defects form the "donor-like" effect and affect the transport properties of BiSbTe significantly. Here, it is demonstrated that the over-stoichiometric Sb fills Te vacancies and weakens the defect scattering, resulting in a desirable carrier mobility.