Pristine GeTe shows inferior thermoelectric performance around unit due to the large carrier concentration induced by the presence of intrinsic high concentration of Ge vacancy. In this study, we report a thermoelectric figure of merit ZT of 1.56 at 700 K, realized in Sb-doped GeTe based thermoelectric (TE) materials via combined effect of suppression of intrinsic Ge vacancy and Sb doping. The non-equilibrium nature during melt spinning process plays very important role. For one thing, it promotes the homogeneity in Ge_1–xSb_xTe samples and refines the grain size of the product. Moreover the persistent Ge precipitated as impurity phase in the traditional synthesis process is found to be dissolved back into the GeTe sublattice, accompanying with a drastic suppression of Ge vacancies concentration which in combination with Sb electron doping significantly reduced the inherent carrier concentration in GeTe. Low carrier concentration, approaching the optimum carrier concentration ∼3.74 × 10⁻²⁰ cm⁻³ and a high power factor of 4.01 × 10⁻³ W m⁻¹ K⁻² at 750 K are achieved for Ge_0.98Sb_0.02Te sample. In addition, the enhanced grain boundary phonon scattering by refining the grain size through melt spinning (MS) process, coupled with the intensified alloying phonon scattering via Sb doping leads to low thermal conductivity of 1.53 W m⁻¹ K⁻¹ at 700 K for Ge_0.94Sb_0.06Te sample. All those contribute to a high ZT value, representing over 50% improvement in the ZT value compared to the Sb free samples, which provides an alternative way for ultrafast synthesis of high performance GeTe based thermoelectric material.

由于本征高浓度 Ge 空位的存在导致载流子浓度大，因此原始 GeTe 在单元周围显示出较差的热电性能。在这项研究中，我们报告了 700 K 时热电品质因数ZT为 1.56，这是通过抑制本征 Ge 空位和 Sb 掺杂的综合作用在 Sb 掺杂 GeTe 基热电 (TE) 材料中实现的。熔融纺丝过程中的非平衡性质起着非常重要的作用。一方面，它促进了 Ge _{1– x} Sb _{x中的同质性}Te 取样并细化产品的粒度。此外，在传统合成过程中作为杂质相沉淀的持久性 Ge 被发现溶解回 GeTe 亚晶格中，伴随着 Ge 空位浓度的急剧抑制，这与 Sb 电子掺杂相结合显着降低了 GeTe 中的固有载流子浓度。低载流子浓度，接近最佳载流子浓度~3.74 × 10 ^-20  cm ^-3和4.01 × 10 ^-3  W m ^-1  K ^-2的高功率因数在750 K Ge _0.98 Sb _0.02样品。此外，通过熔体纺丝 (MS) 工艺细化晶粒尺寸来增强晶界声子散射，再加上通过 Sb 掺杂增强合金化声子散射，导致700 K时 1.53 W m ⁻¹  K ⁻¹的低热导率Ge _0.94 Sb _0.06 Te 样品。所有这些都有助于提高ZT值，与无 Sb 样品相比， ZT值提高了 50% 以上，这为超快合成高性能 GeTe 基热电材料提供了一种替代方法。