Materials Science and Engineering Department, Rensselaer Polytechnic Institute, Troy, New York 12180, United States.
Nano Lett. 2012 Sep 12;12(9):4523-9. doi: 10.1021/nl301639t. Epub 2012 Aug 21.
Antimony telluride has a low thermoelectric figure of merit (ZT < ∼0.3) because of a low Seebeck coefficient α arising from high degenerate hole concentrations generated by antimony antisite defects. Here, we mitigate this key problem by suppressing antisite defect formation using subatomic percent sulfur doping. The resultant 10-25% higher α in bulk nanocrystalline antimony telluride leads to ZT ∼ 0.95 at 423 K, which is superior to the best non-nanostructured antimony telluride alloys. Density functional theory calculations indicate that sulfur increases the antisite formation activation energy and presage further improvements leading to ZT ∼ 2 through optimized doping. Our findings are promising for designing novel thermoelectric materials for refrigeration, waste heat recovery, and solar thermal applications.
碲化锑的热电器件性能系数（ZT<∼0.3）较低，这是由于由 Sb 反位缺陷产生的高简并空穴浓度导致 Seebeck 系数α较低。在这里，我们通过使用亚原子百分比的硫掺杂来抑制反位缺陷的形成，从而缓解了这一关键问题。在块状纳米晶碲化锑中，α增加了 10-25%，在 423 K 时 ZT 达到 0.95，优于最好的非纳米结构碲化锑合金。密度泛函理论计算表明，硫增加了反位形成的激活能，并预示着通过优化掺杂，ZT 有望进一步提高到 2。我们的发现为制冷、余热回收和太阳能热应用等新型热电材料的设计提供了有希望的思路。
