Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA.
J Phys Condens Matter. 2012 Aug 8;24(31):314213. doi: 10.1088/0953-8984/24/31/314213. Epub 2012 Jul 20.
In this paper, we show that a graphene quantum disk (GQD) can be generated on monolayer graphene via structural modification using the electron beam. The electronic structure and local optical responses of the GQD, supported on monolayer graphene, were probed with electron energy-loss spectrum imaging on an aberration-corrected scanning transmission electron microscope. We observe that for small GQD, ~1.3 nm in diameter, the electronic structure and optical response are governed by the dominating edge states, and are distinctly different from either monolayer graphene or double-layer graphene. Highly localized plasmon modes are generated at the GQD due to the confinement from the edge of the GQD in all directions. The highly localized optical response from GQDs could find use in designing nanoscale optoelectronic and plasmonic devices based on monolayer graphene.
在本文中，我们通过使用电子束对单层石墨烯进行结构修饰，展示了可以在其上生成石墨烯量子盘（GQD）。我们利用校正像差的扫描透射电子显微镜中的电子能量损失谱成像技术，探测了支撑在单层石墨烯上的 GQD 的电子结构和局域光学响应。我们观察到，对于直径约 1.3nm 的小 GQD，其电子结构和光学响应由主导的边缘态决定，与单层石墨烯或双层石墨烯明显不同。由于 GQD 边缘在各个方向上的限制，在 GQD 中产生了高度局域的等离激元模式。来自 GQD 的高度局域光学响应可能有助于设计基于单层石墨烯的纳米尺度光电和等离激元器件。
