Controlled Growth of Graphene on Metal Substrates and STM Characterizations for Microscopic Morphologies

Abstract

Recently,chemical vapor deposition (CVD) has been widely applied to the large-scale synthesis of graphene on various metal substrates.As a powerful and direct imaging method,scanning tunneling microscopy (STM) has been used to study the microscopic morphologies of graphene on metal substrates,for the purpose of further optimizing the growth parameters.This review presents the recent progress in the controlled growth of graphene on Cu foils,Pt foils,and Ni substrates,as well as the research of the microscopic morphologies,defect states,and stacking orders of graphene.Monolayer growth of graphene on Cu and Pt foils follows a surface catalyzed growth mechanism,while bilayer graphene growth follows an epitaxial growth mechanism.After the formation of a bilayer,the corrugated substrate breaks the planar conjugated π bonds of graphene,inducing a binding configuration change from sp2 to sp3.Then,pristine wrinkles are introduced by the thermal expansion mismatch between graphene and the metal substrates.Finally,the roughness of graphene on the Pt foils is considerably less than that of graphene on Cu foils,and the multifaceted interweaving Pt substrate has almost no effect on the in-plane continuity of graphene.