Sun Minglei, Chou Jyh-Pin, Zhao Yiming, Yu Jin, Tang Wencheng
School of Mechanical Engineering, Southeast University, Nanjing, Jiangsu 211189, China.
Phys Chem Chem Phys. 2017 Oct 25;19(41):28127-28132. doi: 10.1039/c7cp04535b.
Using density functional theory computations with van der Waals (vdW) corrections, we reveal that C-HF-C hydrogen bonding exists in graphane/fluorographene and fluorographane/fluorographane bilayers. The significant C-HF-C hydrogen bonding is strong enough to combine two separate monolayers to form the bilayer. Interestingly, both the graphane/fluorographene and fluorographane/fluorographane bilayers are metallic in the most stable stacking configuration. Applying a perpendicular electric field can effectively open a bandgap for both bilayers, and we found that the field-induced gap opening for both graphane/fluorographene and fluorographane/fluorographane bilayers can be enhanced by biaxial tensile strain. These results are expected to aid in the design of novel electronic and optoelectronic devices based on graphene materials, and they highlight the use of weak interactions for modulating band structures in two-dimensional materials.
通过使用带有范德华（vdW）校正的密度泛函理论计算，我们揭示了在石墨烷/氟化石墨烯和氟化石墨烷/氟化石墨烷双层中存在C-HF-C氢键。显著的C-HF-C氢键足够强，能够将两个单独的单层结合形成双层。有趣的是，在最稳定的堆叠构型中，石墨烷/氟化石墨烯和氟化石墨烷/氟化石墨烷双层都是金属性的。施加垂直电场可以有效地为这两种双层打开带隙，并且我们发现，双轴拉伸应变可以增强石墨烷/氟化石墨烯和氟化石墨烷/氟化石墨烷双层的场致带隙打开。这些结果有望有助于基于石墨烯材料的新型电子和光电器件的设计，并且突出了利用弱相互作用来调制二维材料中的能带结构。
