High-pressure induces topology boosting thermoelectric performance of BiTe.

Decoupling conductivity(σ)and Seebeck coefficient(S)by electronic topological transitions (ETT) under high pressure (2-4 GPa) is a promising method for bismuth telluride (BiTe) to optimize thermoelectric (TE) performance. However, theScannot dramatically increase with increasingσwhen ETT occurs in BiTe, which impedes optimizing TE performance by utilizing ETT in BiTe. A new strategy of enhanced ETT by combining lattice distortions and high pressure is proposed in this work. The lattice distortions in BiTewere introduced by high pressure and high temperature (HPHT) treatment to generate surplus dislocations. Themeasurements ofσandSat HPHT in BiTewith lattice distortions show an enhanced ETT effect at 2 GPa, which causes decoupleσandSwith an anomalous increase in its|S|about 22%. The ETT effect causes the figure of merit (ZT) of BiTecan be improved to 0.275 at 1.50-2.62 GPa, 460 K, it is more than 62% compared with 0.79 GPa, at 450 K. The excellent TE performance of BiTearising from the lattice distortions can result in local non-hydrostatic pressure which enhances ETT under high pressure. This work provides a new strategy to enhance ETT to decoupleσandS, and search for better TE materials from the pressure dimension in the future.