悬空石墨烯对其表面金纳米膜形貌的影响

Morphological evolution and liquid-like behavior of gold nanofilm on the suspended graphene

石墨烯与金属间的相互作用是石墨烯器件研究中的关键问题之一,其涉及石墨烯器件的电学接触、锂离子电池石墨烯电极、石墨烯金属光学等方面.本文重点研究了不同层数的悬空石墨烯表面金纳米膜退火前后的形貌演化过程,观测到两个重要的现象:1)排除基底影响后的悬空石墨烯层数可以通过金纳米膜的形貌特征进行确认,但其随层数的变化趋势与有基底支撑的石墨烯正好相反;2)退火处理后的悬空石墨烯上的金纳米膜形貌演化过程具有类似水滴在荷叶上的行为.对悬空石墨烯表面金属纳米膜在退火前后的形貌变化规律及其现象背后的物理机理进行了详细的讨论和理论解释.

The morphological evolutions of gold nanofilm on the suspended graphene is investigated before and after an annealing process, and two important phenomena are observed. First, the layer number of suspended graphene can be determined by the morphological change of gold nanofilm, and it is noteworthy that as-observed results without the substrate supporting effect are completely contrary to previously reported results of the graphene supported by the substrate. Second, after a rapid and careful annealing process, the gold nanofilm on the suspended graphene show＇s a liquid-like behavior as if the water is on the lotus leave surface. The mechanisms behind these phenomena are discussed in detail. These results provide very useful information for many applications such as metal intercalation in graphene, electronic contact between metal and graphene, fabrication of patterned suspended graphene device, etc.