Eco-friendly SnTe based thermoelectric materials are intensively studied recently as candidates to replace PbTe; yet the thermoelectric performance of SnTe is suppressed by its intrinsically high carrier concentration and high thermal conductivity. In this work, we confirm that the Ag and La co-doping can be applied to simultaneously enhance the power factor and reduce the thermal conductivity, contributing to a final promotion of figure of merit. On one hand, the carrier concentration and band offset between valence bands are concurrently reduced, promoting the power factor to a highest value of ∼2436 µW·m⁻¹·K⁻² at 873 K. On the other hand, lots of dislocations (∼3.16×10⁷ mm⁻²) associated with impurity precipitates are generated, resulting in the decline of thermal conductivity to a minimum value of 1.87 W·m⁻¹·K⁻¹ at 873 K. As a result, a substantial thermoelectric performance enhancement up to zT ≈ 1.0 at 873 K is obtained for the sample Sn_0.94Ag_0.09La_0.05Te, which is twice that of the pristine SnTe (zT ≈ 0.49 at 873 K). This strategy of synergistic manipulation of electronic band and microstructures via introducing rare earth elements could be applied to other systems to improve thermoelectric performance.

最近，人们对环保型SnTe基热电材料进行了深入研究，以替代PbTe。然而，SnTe固有的高载流子浓度和高导热性抑制了SnTe的热电性能。在这项工作中，我们确认可以同时使用Ag和La共掺杂来同时提高功率因数和降低热导率，从而最终提高品质因数。一方面，载流子浓度和价带之间的带偏移同时降低，从而将功率因数提高到873 K时的最高值〜2436 µW·m ^-1 ·K ^-2。另一方面，许多位错（ 〜3.16×10 ⁷毫米^-2）有杂质析出物生成，从而导致热导率的下降至1.87 W的最小值相关联·米^-1 ·K ^-1，在873 K.其结果是，大幅热电性能增强高达zT值≈1.0在873样品Sn _0.94 Ag _0.09 La _0.05 Te的K值是原始SnTe的两倍（在873 K时zT≈0.49）。通过引入稀土元素对电子带和微结构进行协同操纵的这种策略可以应用于其他系统，以改善热电性能。