The enhancement of thermoelectric (TE) performance is essentially associated with optimizing the scattering effect of electron and phonon. Here, we demonstrate a stacking faults modulation strategy in GeTe materials to simultaneously realize high carrier mobility and low lattice thermal conductivity. Excess Cu doping in GeTe can significantly decrease the concentration of Ge vacancy layer and form a “vacancy/Cu-Cu/vacancy” sandwich-like stacking faults structure. As a result, the hole mobility is remarkably improved to nearly ∼100 cm² V^-1 s^-1 at room temperature due to the weakened carrier scattering from vacancy layer, which ensures superior electrical transport properties. Meanwhile, the sandwich-like stacking faults brings much stronger scattering effect on phonons, thus leading to extremely low lattice thermal conductivity of 0.38 W m^-1 K^-1. With synergistically optimized scattering effect on carriers and phonons, a peak thermoelectric figure of merit over 2.0 is achieved in Ge_0.89Cu_0.06Sb_0.08Te at 750 K. This work provides an effective strategy to realize selective scattering of phonons and carriers through 2D defect modulation, and makes up the important piece of multi-scale microstructure tailoring for TE materials.

热电（TE）性能的提高基本上与优化电子和声子的散射效果有关。在这里，我们演示了GeTe材料中的堆垛层错调制策略，以同时实现高载流子迁移率和低晶格导热率。GeTe中过量的Cu掺杂会显着降低Ge空位层的浓度，并形成“空位/ Cu-Cu /空位”夹心状的堆叠断层结构。结果，空穴迁移率显着提高到约100 cm ² V ^-1 s ^-1由于弱化了空位层中的载流子散射，因此在室温下可确保优异的电传输性能。同时，类似三明治的堆垛层错给声子带来更强的散射效应，从而导致极低的晶格热导率0.38 W m ^-1 K ^-1。通过协同优化载流子和声子的散射效应，在750 K的Ge _0.89 Cu _0.06 Sb _0.08 Te中获得了超过2.0的峰值热电品质因数。这项工作为通过2D缺陷调制实现声子和载流子的选择性散射提供了有效的策略。 ，并构成了TE材料的多尺度微结构定制的重要部分。