Abstract Lead sulfide (PbS) is a type of promising thermoelectric materials which is consist of elements with high natural abundance. However, the relatively low conversion efficiency limits its further application due to the high lattice thermal conductivity of PbS compared with that of PbTe. It has been widely accepted that nanostructuring and doping are effective ways to enhance the thermoelectric properties. Herein, nano/micro structure Bi doped PbS materials have beensynthesized by a facile method of hydrothermal synthesis. The nano/micro structure material systems exist abundant interface which could scatter mid- and low-frequency phonons effectively, combined with point defect such as Bi–Pb scattering high-frequency phonons, and thus the results show that the lattice thermal conductivity of PbS decreases with the increasing concentration of Bi3+ doping as expected. Moreover, the optimal power factor (PF) can be obtained by tuning the carrier concentration and mobility at the same time. The optimal thermoelectric figure of merit (ZT) can reach 0.89 for Pb0.96Bi0.04S at 773K and rises with the increase of the temperature without sign of saturation. Our work may shed light to further possible and environmentally friendly application of PbS-based thermoelectric materials.

中文翻译：

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热压Bi掺杂n型多晶PbS增强的热电性能

摘要 硫化铅（PbS）是一种由天然丰度高的元素组成的有前途的热电材料。然而，由于与 PbTe 相比，PbS 的晶格热导率较高，因此相对较低的转换效率限制了其进一步应用。纳米结构和掺杂是增强热电性能的有效方法已被广泛接受。在此，纳米/微米结构的Bi掺杂PbS材料已经通过简单的水热合成方法合成。纳米/微结构材料系统存在丰富的界面，可以有效地散射中低频声子，结合点缺陷如 Bi-Pb 散射高频声子，结果表明，正如预期的那样，随着 Bi3+ 掺杂浓度的增加，PbS 的晶格热导率降低。此外，可以通过同时调整载流子浓度和迁移率来获得最佳功率因数 (PF)。Pb0.96Bi0.04S 在 773K 时的最佳热电品质因数 (ZT) 可达到 0.89，并随温度升高而升高，无饱和迹象。我们的工作可能为进一步可能和环境友好地应用 PbS 基热电材料提供启示。04S 在 773K 且随温度升高而上升，无饱和迹象。我们的工作可能为进一步可能和环境友好地应用 PbS 基热电材料提供启示。04S 在 773K 且随温度升高而上升，无饱和迹象。我们的工作可能为进一步可能和环境友好地应用 PbS 基热电材料提供启示。