Chemical Vapor Deposition Growth Of Two-Dimensional Materials On Copper

Two-dimensional materials have attracted significant attention and research interest due to their intriguing physical phenomena and extraordinary properties.The controlled synthesis of two-dimensional materials with high yield and high quality is the foundation of their study and applications.Chemical vapor deposition(CVD)is widely used to synthesize twodimensional materials due to its ability to produce high yield and crystallinity of products with controllable components and morphologies.This present thesis adopts Cu as the substrate to realize the controlled growth of graphene and h-BN(two typical two-dimensional materials)with well-defined layer number and sizes by designing new growth strategies and exploring the effect of growth conditions,and proposes the growth mechanism as well.The main results list as follows:1.Synthesis of large-size strictly monolayer graphene via cyclic atmospheric CVD.The uniformity and high quality of synthesized monolayer graphene sheet have been verified by Optical Microscope,Raman,TEM,and electronic measurement,respectively.At meantime,we explored the growth process and mechanism by isotope labelling and showed that the selective etching of few layers structures,the activation energy advantage of epitaxial growth and the evolution of copper surface are supposed to be responsible for the removal of few layers structures and formation of uniform and strictly monolayer graphene sheet.2.By systematically exploring the effect of growth conditions,such as the polishing way and oxidation of copper substrate,the dosage and heating temperature of the precursor,and the gases flow rate,on the density and morphologies of CVD synthesized h-BN,we controlled the sizes and morphologies of h-BN,reduced the density of h-BN efficiently,and prepared large size h-BN single crystal.