Agglomeration effects of thin metal catalyst on graphene film synthesized by chemical vapor deposition

The agglomeration effect of thin metal catalyst on graphene film grown via CVD was investigated. Among Ni and Co catalysts with 200 nm to 400 nm thickness, 200 nm-Ni exhibits the highest agglomeration and the worst non-uniformity of the synthesized graphene film. Agglomeration induces roughness of catalysts and in turn degrades thickness uniformity of graphene film due to non-uniform dissolution and precipitation of carbon across the catalyst film. Increasing catalyst thickness suppresses the agglomeration and improves uniformity of graphene film. Co shows higher resistant to agglomeration than Ni and improves uniformity of the synthesized graphene film.