The application of thermoelectric technology is hindered by low efficiencies and high costs, demonstrating a strong demand for high-performance thermoelectric materials composed of low-cost and earth-abundant elements. PbS-based materials have attracted much attention for thermoelectric power generation due to their low-cost and earth-abundant features. However, the high lattice thermal conductivities and low electron mobilities of these materials limit their thermoelectric performance. Here, we show that we can largely reduce the lattice thermal conductivity of an n-type PbS-based material to 0.4 W m⁻¹ K⁻¹ through introducing zigzag nanoprecipitates with a uniform width of around 1 nm. The electron mobility was also successfully improved by reducing the effective mass through Se alloying. Finally, an extraordinary figure of merit of 1.7 at 900 K was realized in an n-type Pb_0.93Sb_0.05S_0.5Se_0.5 sample. A thermoelectric power generation module was fabricated with this n-type PbS material and our home-made high-performance p-type PbTe. It demonstrated a high conversion efficiency of 8.0% at a temperature difference of 565 K. Furthermore, a segmented module consisting of n-/p-Bi₂Te₃ and n-PbS/p-PbTe was fabricated, which exhibited a high conversion efficiency of 11.2% at a temperature difference of 585 K. This efficiency is the same as those of reported PbTe-based modules, and it was realized at a much lower cost. As a result, low-cost high-performance n-type PbS-based materials as a promising PbTe alternative will promote the extensive commercial application of thermoelectric power generation.

中文翻译：

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在低成本的基于PbS的热电材料中实现高效发电

低效率和高成本阻碍了热电技术的应用，这表明对由低成本且富含地球的元素组成的高性能热电材料的强烈需求。基于PbS的材料因其低成本和丰富的地球特性而引起了热电发电的广泛关注。但是，这些材料的高晶格热导率和低电子迁移率限制了它们的热电性能。在这里，我们表明可以将n型基于PbS的材料的晶格热导率大大降低至0.4 W m ^-1 K ^-1通过引入锯齿形纳米沉淀物，其均匀宽度约为1 nm。通过降低硒合金的有效质量，也成功地改善了电子迁移率。最终，在n型Pb _0.93 Sb _0.05 S _0.5 Se _0.5样品中获得了900 K时1.7的非凡品质因数。使用这种n型PbS材料和我们自制的高性能p型PbTe制造了一个热电发电模块。在565 K的温度差下，它显示出8.0％的高转换效率。此外，由n- / p-Bi ₂ Te ₃组成的分段模块制备了n-PbS / p-PbTe，在585 K的温差下显示出11.2％的高转换效率。该效率与报道的基于PbTe的模块相同，但实现效率却低得多成本。结果，低成本高性能的基于n型PbS的材料作为有希望的PbTe替代品将促进热电发电的广泛商业应用。