Cl 掺杂提升N-PbS 热电性能的实验研究

铅基硫属化合物在中高温热电领域具有广泛的应用。相较于Te 和Se 元素, S 元素具有含量丰富, 价格低廉,且PbS 热稳定性高等优点, 近年来PbS 热电材料引起了研究人员的广泛兴趣。然而, PbS 热电材料本体固有高晶格热导率, 导致其较低的热电转化效率, 严重限制了其在热电领域的应用。为了降低其晶格热导率, 采用Cl 掺杂方法改善PbS 的热电性能。实验结果表明, 通过水热法制备了形貌可控的树枝状PbS 基纳米材料, 在烧结过程中形成了多孔结构PbS 基块体材料。通过测试结果可知, Cl 掺杂后的多孔PbS 材料的致密度和晶格热导率显著降低, 载流子浓度升高, 热电性能明显改善, 其中PbCl_0.02S_0.98 材料在773 K 时zT 值达到0.71, 较纯PbS 提升了约108.8%。

Experimental Study on the Improvement of Thermoelectric Performance ofN-PbS Through Cl Doping

Lead-based sulfur compounds have been widely used in middle- and high-temperature thermoelectric fields. Compared with Te and Se, S element has the advantages of abundant content, low price, and high thermal stability of PbS, and thus PbS thermoelectric materials have attracted extensive interest of researchers in recent years. However, the inherent high lattice thermal conductivity of PbSthermoelectric material leads to its low thermoelectric conversion efficiency, which severely limits its application in the field of thermoelectric.In order to reduce the lattice thermal conductivity, Cl doping method was used to improve the thermoelectric properties of PbS. The experimental results show that dendritic PbS-based nanomaterials with controllable morphology were prepared by hydrothermal method, and porous PbS-based bulk materials were formed during sintering. The results showed that the density and lattice thermalconductivity of porous PbS materials doped with Cl were significantly reduced, the carrier concentration was increased, and the thermoelectric properties were significantly improved. The zT value of PbCl_0.02S_0.98 material reached 0.71 at 773 K, which was about 108.8% higher than that of pure PbS.