KU Leuven-University of Leuven, Department of Chemistry, Division of Molecular Imaging and Photonics, Celestijnenlaan 200F, B-3001 Leuven, Belgium.
KU Leuven, Department of Metallurgy and Materials Engineering, Kasteelpark Arenberg 44, B-3001 Leuven, Belgium and imec, Kapeldreef 75, B-3001 Leuven, Belgium.
Nanoscale. 2016 Dec 8;8(48):20017-20026. doi: 10.1039/c6nr07912a.
One current key challenge in graphene research is to tune its charge carrier concentration, i.e., p- and n-type doping of graphene. An attractive approach in this respect is offered by controlled doping via well-ordered self-assembled networks physisorbed on the graphene surface. We report on tunable n-type doping of graphene using self-assembled networks of alkyl-amines that have varying chain lengths. The doping magnitude is modulated by controlling the density of the strong n-type doping amine groups on the surface. As revealed by scanning tunneling and atomic force microscopy, this density is governed by the length of the alkyl chain which acts as a spacer within the self-assembled network. The modulation of the doping magnitude depending on the chain length was demonstrated using Raman spectroscopy and electrical measurements on graphene field effect devices. This supramolecular functionalization approach offers new possibilities for controlling the properties of graphene and other two-dimensional materials at the nanoscale.
当前石墨烯研究的一个关键挑战是调节其载流子浓度，即石墨烯的 p 型和 n 型掺杂。在这方面，一种有吸引力的方法是通过在石墨烯表面物理吸附的有序自组装网络进行受控掺杂。我们报告了使用具有不同链长的烷基胺自组装网络实现可调谐的 n 型掺杂石墨烯。通过控制表面上强 n 型掺杂胺基团的密度来调节掺杂量。正如扫描隧道和原子力显微镜所揭示的那样，这种密度受烷基链长度的控制，烷基链在自组装网络中充当间隔物。通过在石墨烯场效应器件上进行拉曼光谱和电学测量，证明了掺杂量随链长的调制。这种超分子功能化方法为控制石墨烯和其他二维材料的纳米级性质提供了新的可能性。
