Physics of Supramolecular Systems and Surfaces, University of Bielefeld, 33615 Bielefeld, Germany.
ACS Nano. 2011 May 24;5(5):3896-904. doi: 10.1021/nn200297n. Epub 2011 Apr 25.
Graphene-based materials have been suggested for applications ranging from nanoelectronics to nanobiotechnology. However, the realization of graphene-based technologies will require large quantities of free-standing two-dimensional (2D) carbon materials with tunable physical and chemical properties. Bottom-up approaches via molecular self-assembly have great potential to fulfill this demand. Here, we report on the fabrication and characterization of graphene made by electron-radiation induced cross-linking of aromatic self-assembled monolayers (SAMs) and their subsequent annealing. In this process, the SAM is converted into a nanocrystalline graphene sheet with well-defined thickness and arbitrary dimensions. Electric transport data demonstrate that this transformation is accompanied by an insulator to metal transition that can be utilized to control electrical properties such as conductivity, electron mobility, and ambipolar electric field effect of the fabricated graphene sheets. The suggested route opens broad prospects toward the engineering of free-standing 2D carbon materials with tunable properties on various solid substrates and on holey substrates as suspended membranes.
基于石墨烯的材料已被提议应用于从纳米电子学到纳米生物技术等领域。然而，要实现基于石墨烯的技术，需要大量具有可调物理和化学性质的独立二维（2D）碳材料。通过分子自组装的自下而上方法具有满足这一需求的巨大潜力。在这里，我们报告了通过电子辐照诱导芳香族自组装单层（SAM）的交联及其随后的退火来制造和表征石墨烯。在这个过程中，SAM 被转化为具有明确定义厚度和任意尺寸的纳米晶石墨烯片。输运数据表明，这种转变伴随着从绝缘体到金属的转变，可以用来控制所制造的石墨烯片的电特性，如电导率、电子迁移率和双极性电场效应。所提出的途径为在各种固体基底和作为悬膜的有孔基底上工程化具有可调性质的独立二维碳材料开辟了广阔的前景。
