Department of Chemistry, Institute for Functional Nanomaterials, University of Puerto Rico, Rio Piedras Campus, San Juan, Puerto Rico 00931.
J Am Chem Soc. 2012 Jul 11;134(27):11269-75. doi: 10.1021/ja3040416. Epub 2012 Jun 27.
Systematic density functional theory (DFT) computations revealed the existence of considerable C-H···F-C bonding between the experimentally realized graphane and fluorographene layers. The unique C-H···F-C bonds define the conformation of graphane/fluorographene (G/FG) bilayer and contribute to its stability. Interestingly, G/FG bilayer has an energy gap (0.5 eV) much lower than those of individual graphane and fluorographene. The binding strength of G/FG bilayer can be significantly enhanced by applying appropriate external electric field (E-field). Especially, changing the direction and strength of E-field can effectively modulate the energy gap of G/FG bilayer, and correspondingly causes a semiconductor-metal transition. These findings open new opportunities in fabricating new electronics and opto-electronics devices based on G/FG bilayer, and call for more efforts in using weak interactions for band structure engineering.
系统的密度泛函理论（DFT）计算揭示了实验中实现的石墨烷和氟石墨层之间存在相当大的 C-H···F-C 键合。独特的 C-H···F-C 键定义了石墨烷/氟石墨（G/FG）双层的构象并有助于其稳定性。有趣的是，G/FG 双层的能隙（0.5eV）远低于单个石墨烷和氟石墨的能隙。通过施加适当的外电场（E 场）可以显著增强 G/FG 双层的结合强度。特别是，改变 E 场的方向和强度可以有效地调节 G/FG 双层的能隙，并相应地导致半导体-金属转变。这些发现为基于 G/FG 双层制造新型电子和光电设备开辟了新的机会，并呼吁在能带结构工程中更多地利用弱相互作用。
