Microwave irradiation is found to be effective to provide highly crystalline nanostructured materials. In this work, this technique has been used to produce highly improved thermoelectric (TE) material based on aluminum (Al) doped zinc oxide (ZnO) nanostructures (NSs). The effect of Al dopant at the concentration range 0.5–3 mol % on the structural and TE properties has been investigated in more details. The optimum concentration of Al for better TE performance is found to be 2 mol %, which could significantly increase the electrical conductivity and reduce the thermal conductivity of ZnO NSs and thus enhance the TE performance. This concentration showed almost metallic conductivity behavior for ZnO NSs at low temperatures, e.g., below 500 K. The electrical conductivity reached 400 S/m at room temperature, which is around 200 times greater than the value recorded for the pure ZnO NSs. Remarkably, the measured room temperature thermal conductivity of the microwave synthesized ZnO NSs was very low, which is around 4 W/m·K. This value was further reduced to 0.5 W/m·K by increasing the Al doping to 3 mol %. The figure of merit recorded 0.028 at 675 K, which is 15 times higher than that of the pure ZnO NSs. The output power of a single leg module made of 2 mol % Al doped ZnO NSs was 3.7 µW at 485 K, which is higher by 8 times than that of the pure sample. These results demonstrated the advantage of the microwave irradiation rout as a superior synthetic technique for producing and doping promising TE nanomaterials like ZnO NSs.

中文翻译：

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基于铝掺杂ZnO纳米结构的微波辐射制备高性能热电材料

发现微波辐射可有效提供高度结晶的纳米结构材料。在这项工作中，该技术已用于生产基于铝（Al）掺杂的氧化锌（ZnO）纳米结构（NSs）的高度改进的热电（TE）材料。已经详细研究了浓度范围为0.5–3 mol％的Al掺杂剂对结构和TE性能的影响。发现具有更好的TE性能的Al的最佳浓度为2mol％，这可以显着提高ZnO NSs的电导率并降低ZnO NSs的热导率，从而增强TE性能。此浓度显示了在低温（例如低于500 K）下ZnO NSs几乎具有金属导电性的行为。室温下电导率达到400 S / m，这是纯ZnO NSs记录值的200倍左右。值得注意的是，微波合成的ZnO NSs的室温室温热导率非常低，约为4 W / m·K。通过将Al掺杂增加到3mol％，该值进一步降低到0.5W / m·K。品质因数在675 K时记录为0.028，比纯ZnO NSs高15倍。由2 mol％的Al掺杂的ZnO NSs制成的单腿模块的输出功率在485 K下为3.7 µW，比纯样品高出8倍。这些结果证明了微波辐照溃败作为生产和掺杂有前景的TE纳米材料（如ZnO NSs）的优良合成技术的优势。微波合成的ZnO NSs的室温热导率非常低，约为4 W / m·K。通过将Al掺杂增加到3mol％，该值进一步降低到0.5W / m·K。品质因数在675 K时记录为0.028，比纯ZnO NSs高15倍。由2 mol％的Al掺杂的ZnO NSs制成的单腿模块的输出功率在485 K下为3.7 µW，比纯样品高出8倍。这些结果证明了微波辐照溃败作为生产和掺杂有前景的TE纳米材料（如ZnO NSs）的优良合成技术的优势。微波合成的ZnO NSs的室温热导率非常低，约为4 W / m·K。通过将Al掺杂增加到3mol％，该值进一步降低到0.5W / m·K。品质因数在675 K时记录为0.028，比纯ZnO NSs高15倍。由2 mol％的Al掺杂的ZnO NSs制成的单腿模块的输出功率在485 K下为3.7 µW，比纯样品高出8倍。这些结果证明了微波辐照溃败作为生产和掺杂有前景的TE纳米材料（如ZnO NSs）的优良合成技术的优势。是纯ZnO NS的15倍。由2 mol％的Al掺杂的ZnO NSs制成的单腿模块的输出功率在485 K下为3.7 µW，比纯样品高出8倍。这些结果证明了微波辐照溃败作为生产和掺杂有前景的TE纳米材料（如ZnO NSs）的优良合成技术的优势。是纯ZnO NS的15倍。由2 mol％的Al掺杂的ZnO NSs制成的单腿模块的输出功率在485 K下为3.7 µW，比纯样品高出8倍。这些结果证明了微波辐照溃败作为生产和掺杂有前景的TE纳米材料（如ZnO NSs）的优良合成技术的优势。