Abstract Compared with widely studied 18-electron half-Heusler (HH) thermoelectric (TE) materials, cation-deficient 19-electron HH compounds have also been recently demonstrated to possess excellent TE performance, exhibiting high potential for TE application. Here, a new defective 19-electron HH compound Ti1-xPtSb is developed with high density-of-state effective mass and low lattice thermal conductivity. The former results from the band degeneracy and high band effective mass, and the latter results from the enhanced phonon scattering by substantial intrinsic Ti vacancies. The optimized carrier concentration, combined with the low lattice thermal conductivity, contributes to a maximum zT of 0.7 in pure-phase Ti1-xPtSb (x = 0.14–0.18) samples, which is about 50% higher than that of the nominal TiPtSb sample, indicating that n-type Ti1-xPtSb HH compounds are promising TE materials.

中文翻译：

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一种具有重带和低晶格热导率的新型缺陷 19 电子 TiPtSb 半赫斯勒热电化合物

摘要 与广泛研究的 18 电子半赫斯勒 (HH) 热电 (TE) 材料相比，缺阳离子的 19 电子 HH 化合物最近也被证明具有优异的热电性能，在热电应用方面具有巨大潜力。在这里，开发了一种新的有缺陷的 19 电子 HH 化合物 Ti1-xPtSb，具有高态密度有效质量和低晶格热导率。前者是由能带简并和高能带有效质量引起的，而后者是由大量固有 Ti 空位增强的声子散射引起的。优化的载流子浓度与低晶格热导率相结合，使纯相 Ti1-xPtSb (x = 0.14-0.18) 样品中的最大 zT 为 0.7，比标称 TiPtSb 样品高约 50%，