论文标题
通过功能化来调整曲折Zag石墨烯纳米纤维的柔性电信和电子特性
Tuning flexoelectricty and electronic properties of zig-zag graphene nanoribbons by functionalization
论文作者
论文摘要
使用最先进的第一原理计算，在机械弯曲下探索了锯齿石墨烯纳米纤维的挠性和电子性能。发现了从平面极化对所施加应变梯度上诱导的弯曲的线性依赖性。石墨烯纳米纤维的下柔韧性特性可以通过氢和氟官能化（CH和CF纳米骨）的两个以上的数量级改进。预计CF纳米骨会预测平面柔性效应很大。这种增强的起源在于碳和氟原子之间的电性差异，即使对于较小的应变梯度，也打破了平面电荷对称性。通过与氢和氟（CHF Janus型纳米苯）共同功能化，可以进一步改善柔韧性效应，在该碳中，即使在平坦的纳米骨中也形成了从平面偶极矩中出现的自发性。我们还发现弯曲可以控制价带最大值的电荷定位，因此可以调整孔有效质量和带隙。这些结果为理解氢和氟官能化石墨烯纳米纤维的柔韧性和电子性质提供了重要的进步，这可能对柔性电子应用具有重要意义。
The flexoelectric and electronic properties of zig-zag graphene nanoribbons are explored under mechanical bending using state of the art first principles calculations. A linear dependence of the bending induced out of plane polarization on the applied strain gradient is found. The inferior flexoelectric properties of graphene nanoribbons can be improved by more than two orders of magnitude by hydrogen and fluorine functionalization (CH and CF nanoribbons). A large out of plane flexoelectric effect is predicted for CF nanoribbons. The origin of this enhancement lies in the electro-negativity difference between carbon and fluorine atoms, which breaks the out of plane charge symmetry even for a small strain gradient. The flexoelectric effect can be further improved by co-functionalization with hydrogen and fluorine (CHF Janus-type nanoribbon), where a spontaneous out of plane dipole moment is formed even for flat nanoribbons. We also find that bending can control the charge localization of valence band maxima and therefore enables the tuning of the hole effective masses and band gaps. These results present an important advance towards the understanding of flexoelectric and electronic properties of hydrogen and fluorine functionalized graphene nanoribbons, which can have important implications for flexible electronic applications.
