Liquid-assisted tip manipulation: fabrication of twisted bilayer graphene superlattices on HOPG
Liquid-assisted tip manipulation: fabrication of twisted bilayer graphene superlattices on HOPG
复制标题
液体辅助尖端操纵：在 HOPG 上制造扭曲双层石墨烯超晶格
DOI：
10.1039/c5nr03372a
复制
发表时间：
2015
期刊：
影响因子：
6.7
通讯作者：
Naugle Donald G.
中科院分区：
文献类型：
--
作者：
Yin Long Jing;Wang Wen Xiao;Feng Ke Ke;Nie Jia-Cai;Xiong Chang Min;Dou Rui-Fen;Naugle Donald G.
我们使用的扫描隧道显微镜（STM）的尖端操纵单一的弱结合的纳米级片的高度取向的热解石墨（HOPG）表面上，通过人工增加的尖端和样品的相互作用，通过使用液体硫醇分子的表面预处理。通过这种方式，可以将石墨片对着台阶撕开，并将该部分折叠到HOPG表面上，从而产生具有六边形对称性的石墨烯超晶格。定量讨论了针尖和样品表面的相互作用，包括货车德瓦尔斯力、静电力和由于形成高度弯曲的流体弯月面连接针尖和样品而产生的拉普拉斯压力引起的毛细吸引力，以理解STM针尖诱导石墨烯超晶格的形成机制。在潮湿条件下，毛细力在操纵石墨表面层中起着关键作用。我们的方法提供了一个简单可行的路线，以制备可控的超晶格和石墨烯纳米带，也更好地理解的过程中产生的石墨烯超晶格的表面上的HOPG与尖端。
We use the tip of a scanning tunneling microscope (STM) to manipulate single weakly bound nanometer-sized sheets on a highly oriented pyrolytic graphite (HOPG) surface through artificially increasing the tip and sample interaction by pretreatment of the surface using a liquid thiol molecule. By this means it is possible to tear apart a graphite sheet against a step and fold this part onto the HOPG surface and thus generate graphene superlattices with hexagonal symmetry. The tip and sample surface interactions, including the van der Waals force, electrostatic force and capillary attraction force originating from the Laplace pressure due to the formation of a highly curved fluid meniscus connecting the tip and sample, are discussed quantitatively to understand the formation mechanism of a graphene superlattice induced by the STM tip. The capillary force plays a key role in manipulating the graphite surface sheet under humid conditions. Our approach provides a simple and feasible route to prepare controllable superlattices and graphene nanoribbons and also to better understand the process of generation of a graphene superlattice on the surface of HOPG with the tip.