Nanoporous materials possess low thermal conductivities derived from effective phonon scatterings at grain boundaries and interfaces. Thus nanoporous thermoelectric materials have full potential to improve their thermoelectric performance. Here we report a high ZT of 1.7 ± 0.2 at 823 K in p-type nanoporous polycrystalline SnSe fabricated via a facile solvothermal route. We successfully induce indium selenides (InSe_y) nanoprecipitates in the as-synthesized SnSe matrix of single-crystal microplates, and the nanopores are achieved via the decompositions of these nanoprecipitates during the sintering process. Through detailed structural and chemical characterizations, it is found that the extralow thermal conductivity of 0.24 W m^–1 K^–1 caused by the effective phonon blocking and scattering at induced nanopores, interfaces, and grain boundaries and the high power factor of 5.06 μW cm^–1 K^–2 are derived from a well-tuned hole carrier concentration of 1.34 × 10¹⁹ cm^–3via inducing high Sn vacancies by self-doping, contributing to high ZTs. This study fills the gap of achieving nanoporous SnSe and provides an avenue in achieving high-performance thermoelectric properties of materials.

中文翻译：

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通过纳米孔设计具有非凡热电特性的多晶锡硒

纳米多孔材料的热导率低，这是由于晶界和界面处的有效声子散射引起的。因此，纳米多孔热电材料具有充分的潜力来改善其热电性能。在这里，我们报道了通过简便的溶剂热途径制备的p型纳米多孔多晶SnSe在823 K时的高ZT为1.7±0.2 。我们成功地在单晶微板的合成SnSe基质中诱导了硒化铟（InSe _y）纳米沉淀，并且通过在烧结过程中这些纳米沉淀的分解获得了纳米孔。通过详细的结构和化学表征，发现0.24 W m的极低导热率^–1 K ^–1是由声子在诱导的纳米孔，界面和晶界处的有效声子阻挡和散射以及5.06μWcm的高功率因数引起的^–1 K ^–2源自于1.34×10的微调的空穴载流子浓度¹⁹ cm ^–3通过自掺杂诱导高锡空位，从而导致高ZT s。这项研究填补了实现纳米多孔SnSe的空白，并为实现材料的高性能热电性能提供了一条途径。