Simple preparation method of millimeter level monocrystalline graphene

Abstract

The invention belongs to the technical field of advanced carbon materials and semiconductor technologies, and especially relates to a simple and stable preparation method of large-area monocrystalline graphene. The method is suitable for preparing millimeter level monocrystalline graphene. The method is characterized in that the monocrystalline graphene is prepared through a low pressure chemical vapor deposition technology at 1000DEG C by using methane (CH4) as a carbon source and hydrogen as a reducing gas. Acetone or ethanol ultrasonic treatment of copper foil is not needed, polishing and other pretreatment processes of the copper foil by adopting a complex electrochemical process are not needed, a several-hours and high-hydrogen flow annealing process is not needed, and only complete extraction of air in a reactor and guaranteeing of no introduction of gases in the heating process are needed, so the simple treatment method greatly reduces the nucleating density of graphene on the copper foil, and realizes growth of the monocrystalline graphene with the opposite side distance reaching 1mm in 2-3h. Results of scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Raman spectrum analysis of a sample prove that the sample is the monocrystalline graphene and has few defects.

Description

Technical field [0001] The invention belongs to the technical field of advanced carbon materials and semiconductor technology, and particularly relates to a simple and stable preparation method for large-area single crystal graphene. Background technique [0002] Graphene is a new and advanced two-dimensional planar nanomaterial formed by bonding and connecting single-layer carbon atoms in sp2 hybrid mode. It is precisely because of the special bonding and connection method of graphene and the perfect two-dimensional The characteristics make graphene have excellent properties in electricity, optics, heat, and mechanics. For example: the mechanical strength of graphene is up to 130Gpa, and its carrier migration rate is up to 15000cm·m -1 ·K -1 , More than 10 times that of ordinary silicon wafers, and its thermal conductivity is as high as 5000W·m -1 ·K -1 Obviously, the excellent performance of graphene has greater advantages than other materials of the same type. Therefore, grap...

AI Technical Summary

Problems solved by technology

However, the existence of a large number of grain boundaries in polycrystalline graphene reduces the advantages of graphene in electrical, optical, and thermal aspects such as electronic conductivity and thermal conductivity, while single-crystal graphene reduces the impact of grain boundaries on graphene. Therefore, it is very important to grow large-area single-crystal graphene

However, most of the currently known methods for growing single-crystal graphene require very complex pretreatments (such as chemical polishing, electrochemical polishing, etc.), long-term annealing processes with high hydrogen flow rates, and complex gas changes during the growth process. Even the copper sheet is modified by designing some components, and some growth methods need to grow for several hours or even tens of hours, and the process is cumbersome and complicated.

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