Single crystalline graphene sheet and process of preparing the same

Abstract

A single-crystal graphene sheet includes a polycyclic aromatic molecule wherein a plurality of carbon atoms are covalently bound to each other, the single-crystal graphene sheet comprising between about 1 layer to about 300 layers; and wherein a peak ratio of a Raman D band intensity to a Raman G band intensity is equal to or less than 0.2. Also described is a method for preparing a single-crystal graphene sheet, the method includes forming a catalyst layer, which includes a single-crystal graphitizing metal catalyst sheet; disposing a carbonaceous material on the catalyst layer; and heat-treating the catalyst layer and the carbonaceous material in at least one of an inert atmosphere and a reducing atmosphere. Also described is a transparent electrode including a single-crystal graphene sheet.

Description

[0001]This application claims priority to Korean Patent Application No. 10-2007-0132682, filed on Dec. 17, 2007, and all the benefits accruing therefrom under 35 U.S.C. § 119, the contents of which in their entirety are herein incorporated by reference.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]This disclosure relates to a single-crystal graphene sheet and a process of preparing the same.[0004]2. Description of the Related Art[0005]Generally, graphite is a stack of two-dimensional graphene sheets formed from a planar array of carbon atoms bonded to form hexagonal structures. Recently, testing of graphene sheets revealed beneficial properties of single or multiple-layered graphene sheets. One beneficial property of graphene is that electrons flow in an entirely unhindered fashion in a graphene sheet, which is to say that the electrons flow at the velocity of light in a vacuum. In addition, graphene sheets exhibit an unusual half-integer quantum Hall effect for bo...

AI Technical Summary

Benefits of technology

The patent text describes a single-crystal graphene sheet and a process for preparing it. The sheet has several layers and a unique structure that makes it different from other graphene sheets. The sheet can be used as a transparent electrode and has unique properties that make it useful in various applications. The process involves forming a catalyst layer and disposing a carbonaceous material on it, which is then heat-treated to solid-solubilize the carbon in the catalyst layer and form the single-crystal graphene sheet. The technical effects of this patent text are the provision of a flexible and transparent electrode made of single-crystal graphene sheet with improved properties.

Problems solved by technology

However, carbon nanotubes are expensive due to low yields during synthesis and purification processes.

However, separating single wall carbon nanotubes can be problematic.

In this case, the separated graphene sheet does not include a uniform number of layers, and the ripped portions do not have a uniform shape.

Furthermore, a large-sized graphene sheet cannot be prepared using the micromechanical method.

However, the SiC single crystal material used as a starting material in SiC thermal decomposition is very expensive, and formation of a large-sized graphene sheet can be problematic.

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