CNU Center for Innovative Engineering Education, Chungnam National University, Daejeon 305-764, Korea.
Nanotechnology. 2012 Oct 5;23(39):395704. doi: 10.1088/0957-4484/23/39/395704. Epub 2012 Sep 12.
The electronic properties of graphene depend critically on its lattice orientation and edge type. However, it is very difficult to identify them, and they are accessible only using sophisticated tools. In this paper, we show an easy and reliable way to reveal the lattice orientation and edge type of graphene and graphite flakes, i.e. multi-layered graphene. Nematic liquid crystals have the potential to align themselves into three symmetric and equivalent orientations on crystalline graphite. The director of macroscopic texture due to the elasticity indicates the lattice orientation of the top graphite layer. By analyzing the director orientation using a polarizing optical microscope, we were able to show the lattice orientation, chiral angle and edge type of graphene and graphite flakes on the macroscopic scale. As liquid crystals are soft and easily removable, our technique has little chance of influencing the following processes for graphene manipulation.
石墨烯的电子性质与其晶格取向和边缘类型密切相关。然而，要识别它们非常困难，只能使用复杂的工具。在本文中，我们展示了一种简单可靠的方法，可以揭示石墨烯和石墨薄片（即多层石墨烯）的晶格取向和边缘类型。向列液晶有可能在结晶石墨上自行排列成三个对称且等效的取向。由于弹性，宏观纹理的指向表明顶层石墨层的晶格取向。通过使用偏光显微镜分析指向矢的方向，我们能够在宏观尺度上显示石墨烯和石墨薄片的晶格取向、手性角和边缘类型。由于液晶柔软且易于去除，我们的技术几乎不会影响后续的石墨烯处理过程。
