Thermoelectric properties of gamma-graphyne nanoribbon incorporating diamond-like quantum dots
Thermoelectric properties of gamma-graphyne nanoribbon incorporating diamond-like quantum dots
复制标题
结合类金刚石量子点的伽马石墨烯纳米带的热电特性
DOI：
10.1088/0022-3727/49/13/135303
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发表时间：
2016
影响因子：
3.4
通讯作者：
Zhong Jianxin
中科院分区：
文献类型：
--
作者：
Wang Caihua;Ouyang Tao;Chen Yuanping;Zhou Benhu;Zhong Jianxin
利用非平衡格林函数理论研究了含有类金刚石量子点的γ-石墨烯纳米带的弹道热电性能。计算表明，引入类金刚石量子点后，可以显著提高热电转换效率。这种增强主要源于声子和电子热导的显著抑制以及保留的高塞贝克系数。同时，量子点几何尺寸的变化会导致热电性能出现明显的振荡行为，这是由于类金刚石量子点中准束缚态引起的共振电子电导。当纳米带中嵌入多量子点时，我们发现热电效率可以进一步提高（即使在室温下，稳定的品质系数也可以达到1.55）。研究结果表明，加入类金刚石量子点是优化γ-石墨烯热电性能的可行方法，并可为纳米级热电器件的设计和制造提供有益的指导。
The ballistic thermoelectric properties of γ-graphyne nanoribbons incorporating diamond-like quantum dots are theoretically investigated by means of a nonequilibrium Green's function. The calculation shows that as the diamond-like quantum dot is introduced, the thermoelectric conversion efficiency can be enhanced dramatically. Such enhancement mainly stems from the significant suppression of phononic and electronic thermal conductance and the reserved high Seebeck coefficient. Meanwhile, variation of the geometric size of the quantum dot will result in an obvious oscillatory behavior of thermoelectric performance, which is attributed to the resonant electronic conductance caused by the quasi-bound state in diamond-like quantum dots. When the nanoribbon is embedded with multi-quantum dots, we find that the thermoelectric efficiency can be improved further (the stable figure of merit can achieve 1.55 even at room temperature). These findings demonstrate the incorporation of diamond-like quantum dots is a viable approach to optimize the thermoelectric performance of γ-graphyne, and could provide helpful guidance for designing and fabricating nanoscale thermoelectric devices.