Research On Controllable Preparation And Conductivity Property Of Graphene Film

Unique two-dimensional structure makes graphene films have large specific surface area, excellent electrical conductivity, high intensity and other features, especially outstanding light properties and unique Electronic Hall Effect. This makes it possible to have potential applications in the field of new electronic devices. Therefore, found by Manchester university researchers in2004, graphene was appreciated by many researchers. IBM has demonstrated a radio-frequency graphene transistor with the highest frequency so far:100GHz. Ruoff’s team in Northwestern University has synthesized a kind of graphene oxide paper. They suggest that among the known strategies for generating graphene-based materials, the modification of graphite oxide, is arguably the most versatile and easily scalable method, which opened up a road for graphene material researchers. However, the existence of oxygen functional groups on the graphene oxide film has destroyed the graphite structure, making GO film with high resistance, limiting its application in the field of electronics. This is a problem that should be firstly resolved.In this work, using modified Hummers method to prepare graphite oxide, graphene oxide (GO) film was assembled through ultrasonication, deposition and gravity sedimentary self-assembly processes. Then the film was reduced by heat treatment at different temperatures. Scanning electron microscope (SEM), Transmission electron microscopy (TEM) and Raman spectra were used to characterize the morphology and microstructure of films. Finally, RTS-9double electrical measurement four-point probe tester was employed to measure the electrical properties of films after heat treatment and the influence of heat treatment temperature on the conductivity performance of the sample was explored.The results showed that:1. Self-assembly is facile to prepare GO film with controllable thickness and size. Preferable micro layer structure and good light transmission of microscopically continuous film provide experimental basis for its application in electronics field.2. Effective reduction of graphene oxide film can be realized using high-temperature treatment. FT-IR and Raman results indicate that some oxygen functional groups were removed and the structure was rearranged through heat treatment. Conductivity was restored while morphology of the sample was maintained.3. Results of Four-point probe tester suggest:with increasing heat treatment temperature, the resistance of the film substantially decreases, while conductivity rises. A conductivity of536S/cm was obtained when heat treated at1100℃.