Preparation And Characterization Of Graphene On Insulating Substrate

Graphene is the thinnest 2D material found up to now, which is formed by sp2-hybridized carbon. Since 2004, there has been an intense surge in interest in graphene of allcause of the special structure and outstanding physical and chemical properties. Since then, graphene has potential application value in areas of the traditional like the semiconductor industry and photovoltaic industry as well as new generation display, emerging areas such as lithium ion battery, solar cell, which is the promise of the best all-purpose material.This article adopts the method of chemical vapor deposition (CVD) with methane (CH4) as source of carbon, hydrogen(H2) as the reactant gas and argon(Ar) as carrier gas. In addition,the quality and layer of graphenesynthesized on the SiO2/ Si substrate and quartz substrate coated with 300 nm oxide layer have been stuied and characterized via Raman spectrum, transmission electron microscopy (TEM), energy spectrum and other essential technological means. The influence of the heating method, catalytic layer thickness, the growth time and cooling rate on its quality and layer number in the period of graphene growth process have been studied through the comparative experiment design in order to investigatethe best growth parameters of the preparation of large area high quality grapheneas well as to understand the growth mechanism.When Ni film thickness of 100,200,300 nm respectively, we obtained graphene on both sides of the Ni film.when Ni film thickness of 400 nm, Raman characterization showed that only on the top of the Ni film obtained the graphene, the insulating substrate and the interface of Ni membrane without any sign of graphene. Different growth time (5,10,20 min) affect the growth of the graphene can also, when growth time only 5 min, the insulating substrate and the interface of Ni membrane while obtained the signal of graphene, but after a four-point characterization, found that the graphene membrane without resistance, shows that when the growth time is too short, discontinuous graphene film.When the growth time extended to 20 min, can in the insulating substrate and the interface of Ni membrane for graphene membrane.In the end, high quality of single-layer graphene has been synthesized adopting hot CVD method with rapid heating process,besides with the optimizedratio of gas flow (H2/CH4=20/5sccm), growth temperature (950 ℃), growth time (20 min) and 300 nm Ni as catalytic film.