Department of Physics, University of Kashan, Kashan, 87317-53153, Iran.
Phys Chem Chem Phys. 2018 Jun 20;20(24):16853-16860. doi: 10.1039/c8cp02264j.
Spin-caloritronic effects in armchair graphene nanoribbons (AGNRs) with various ribbon widths and periodic structural defects in the form of triangular antidots were systematically studied. Our results showed that by engineering defects in AGNRs, one could not only reduce the phononic thermal conductance for enhancing the thermoelectric efficiency, but also induce a ferromagnetic ground state. Interestingly, AGNRs with triangular antidots exhibit spin-semiconducting behavior with a tunable spin gap and a narrow spin-polarized band around the Fermi level. Therefore, AGNRs with antidots exhibit spin-up and spin-down currents with opposite flow directions under a temperature gradient, and they also exhibit a giant spin Seebeck coefficient () and spin figure of merit () that are much larger than those of zigzag GNRs. Finally, these results pave the way towards the application of defective AGNRs in spin-caloritronic devices operating at room temperature with a giant spin thermoelectric efficiency.
我们系统地研究了具有不同宽度的扶手椅型石墨烯纳米带（AGNRs）以及以三角形反点形式存在的周期性结构缺陷的自旋-热电子学效应。研究结果表明，通过在 AGNRs 中引入缺陷，不仅可以降低声子热导以提高热电效率，还可以诱导出铁磁基态。有趣的是，具有三角形反点的 AGNRs 表现出可调谐的自旋能隙和在费米能级附近的窄自旋极化能带的自旋半导体行为。因此，在温度梯度下，具有反点的 AGNRs 表现出相反流动方向的自旋向上和自旋向下电流，并且它们还表现出比锯齿型 GNRs 大得多的巨大自旋塞贝克系数（）和自旋优值（）。最后，这些结果为在室温下具有巨大自旋热电效率的自旋-热电子学器件中应用有缺陷的 AGNRs 铺平了道路。
