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

Abstract

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 shows 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.