Advances in thermoelectrics are motivated by the innovation of thermoelectric theories. The Rashba effect, spin-dependent band splitting, paves a new path to enhance thermoelectric performance. Herein, we investigate the Rashba effect in GeTe, in which the rhombohedral distortion provides a unique handle to examine the mechanism of the Rashba effect for tuning thermoelectric properties. Fundamentally, we discover that the Rashba effect originates from the specific atomic site displacement. Experimentally, Sn-doped GeTe has a strong Rashba effect and yields an ultra-high power factor, meanwhile additional Sb alloying effectively tunes the carrier concentration. Moreover, microstructure characterizations reveal that the co-existence of grain boundaries, nanoprecipitates, and stacking faults significantly reinforces phonon scatterings and leads to an ultra-low lattice thermal conductivity. Finally, a high figure of merit is achieved in Ge_1−x−ySn_xSb_yTe. The demonstrated benchmark figure of merit originated from the Rashba effect can provide a promising arena for enhancing thermoelectric performance in wide materials.

热电理论的创新推动了热电学的发展。自旋相关的能带分裂的拉什巴效应为增强热电性能开辟了一条新途径。在本文中，我们研究了GeTe中的Rashba效应，其中菱形体畸变提供了独特的方法来检查Rashba效应调节热电性能的机理。从根本上讲，我们发现Rashba效应源自特定的原子位点位移。实验上，掺Sn的GeTe具有很强的Rashba效应，并能产生超高功率因数，同时额外的Sb合金有效地调节了载流子浓度。此外，微观结构表征表明，晶界，纳米沉淀，堆垛层错明显增强了声子的散射，并导致了超低的晶格热导率。最后，在Ge中获得了很高的功绩_1-x-y Sn _x Sb _y Te。源自拉什巴效应的已证明基准品质因数可为增强广泛材料中的热电性能提供有前途的舞台。