Controlled Synthesis Of Graphene By Atmospheric-Pressure Chemical Vapor Deposition

Graphene is one of the highly concerned materials and a kind of two-dimensional membrane with great potential.Because of its excellent electrical and mechanical properties,graphene has attracted many researchers,which has aroused the upsurge of academic circles and develop rapidly in recent years.Additionally,the synthesis of graphene is the basis of graphene application.Mechanical peeling,reduction of graphite oxide,synthesize graphene on SiC and chemical vapor deposition(CVD)is the main synthetic methods of graphene.Among them,chemical vapor deposition has attracted the attention of many graphene scientists because of its relatively low cost and simple operation.However,the industrialization of graphene by chemical vapor deposition still has a long way to go.In this paper,we synthesize graphene on the copper foil substrate by chemical vapor deposition.We synthesize uniform array of multi-point nucleation and then synthesize a large-area graphene.In addition,we research the graphene growth near the Cu grain boundaries.The grain boundary of polycrystalline graphene is the main reason that affects its electrical and mechanical properties.We heat the copper to oxidize it,and anneal the copper in high temperature.After that we get the lower energy Cu(111)crystal on the surface of copper foil.It is easy to get same-orientated graphene on Cu(111)grain crystal by APCVD.With the extension of growth time,we get the graphene with less grain boundaries and centimeter crystal domain size.In the experiment,we have found that graphene domains can grow across the copper grain boundary.The orientation of the graphene domains is determined by the nucleation stage,and the copper grain boundaries do not change graphene atomic arrangement.In addition,we explored the graphene growth results with different copper substrate,the degree of pre-oxidation and the growth temperature change.Due to the limitation of copper grain size,it is impossible to prepare a large single crystal graphene.We reduce the nucleation density by adjusting the growth parameters,and can prepare a large area of single-crystal graphene in a short time.