On the thermoelectric transport properties of graphyne by the first-principles method
On the thermoelectric transport properties of graphyne by the first-principles method
复制标题
第一性原理方法研究石墨烯的热电输运特性
DOI：
10.1063/1.4806069
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发表时间：
2013-05-28
影响因子：
4.4
通讯作者：
Lu, Shu-Shen
中科院分区：
文献类型：
--
作者：
Wang, Xiao-Ming;Mo, Dong-Chuan;Lu, Shu-Shen
石墨烯是另一种二维碳同素异形体，近年来受到越来越多的关注。利用第一性原理密度泛函计算方法，结合非平衡态格林函数理论，系统地、比较地研究了引力石的电子输运、热输运和热电输运性质。结果表明，在大部分温度范围内，石墨烯的声子导热系数比石墨烯的要小，但在低温下比石墨烯的声子热导大，这是由于石墨烯和石墨烯的键强度和声子谱不同所致。由于石墨烯的半导体性质，发现其温差电势比石墨烯大一个数量级。此外，石墨烯和石墨烯的TEP在化学势和温度等值线上显示出明显的峰值区域。最后，由于梯度石榴石具有较大的TEP和较低的热导率，因此其热电优值系数(ZT)远大于石墨烯的热电优值，这表明梯度石榴石具有较好的热电应用前景。(C)2013 AIP出版有限责任公司。
Graphyne, another two-dimensional carbon allotrope, has received increased attentions in recent years. By using the first-principles density functional calculations combined with the non-equilibrium Green's function formalism, we investigated the electronic, thermal, and thermoelectric transport properties of graphyne systematically and comparatively. It is found that the phonon thermal conductance of graphyne is greatly reduced compared to that of graphene in most temperature regions while larger than that of graphene at low temperatures, which is attributed to the different bond strengths and phonon spectra of graphyne and graphene. Due to the semiconductor property of graphyne, the thermoelectric power TEP) is found to be one magnitude larger than that of graphene. Besides, distinct peak value regions of TEP in the contour of chemical potential and temperature are displayed for graphyne and graphene. Finally, the thermoelectric figure of merit ZT) of graphyne is found to be much larger than that of graphene as a result of large TEP and greatly reduced thermal conductance in graphyne, which indicates preferred thermoelectric applications for graphyne. (C) 2013 AIP Publishing LLC.