Effects of Cu doping on thermoelectric properties of Al-Si-Ru semiconducting quasicrystalline approximant
Effects of Cu doping on thermoelectric properties of Al-Si-Ru semiconducting quasicrystalline approximant
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Cu掺杂对Al-Si-Ru半导体准晶近似体热电性能的影响
DOI：
10.1103/physrevmaterials.5.125401
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发表时间：
2021
影响因子：
3.4
通讯作者：
Kaoru Kimura
中科院分区：
文献类型：
--
作者：
Yutaka Iwasaki;Koichi Kitahara;Kaoru Kimura
我们试图通过优化载流子浓度来改善Al-Si-Ru半导体近似物的热电性能。研究了Cu掺杂对Al-Si-Ru半导体准晶（标称组成为Al69−0.75xSi7.5CuxRu23.5−0.25x(x=0,2,4,6,8)）热电性能的影响。在近似室温的情况下，温度的增加会导致塞贝克系数的降低和电导率的增加。利用密度泛函理论和玻尔兹曼输运理论计算了空穴浓度和带隙的变化。温度的依赖关系可以定量地描述为空穴浓度的增加和带隙的缩小。Cu的掺入增加了空穴浓度，缩小了带隙。最大无因次优值从400k时的0.03增加到500k时的0.2。这些结果表明，半导体准晶近似物可以作为低品位废热回收的热电材料。
We have attempted to improve the thermoelectric performance of an Al–Si–Ru semiconducting approximant through optimizing the carrier concentration. The effects of Cu doping on the thermoelectric properties of an Al–Si–Ru semiconducting quasicrystalline approximant with the nominal composition of Al69−0.75xSi7.5CuxRu23.5−0.25x(x=0,2,4,6,8) are investigated. At approximately room temperature, an increase ofleads to a decrease of the Seebeck coefficientand an increase of the electrical conductivity. Density functional theory and the Boltzmann transport theory are used to calculateas the hole concentration and the band gap are varied. The temperature dependence ofis quantitatively described by an increase of the hole concentration and narrowing of the band gap with increasing. Cu doping is shown to increase the hole concentration and narrow the band gap. The maximum dimensionless figure of merit increases from 0.03 at 400 K forto 0.2 at 500 K for. These results indicate that the semiconducting quasicrystalline approximant could be a suitable candidate as a thermoelectric material for low grade waste heat recovery.