Graphene Production by Chemical Vapor Deposition
The production of graphene has become instrumentally important due to its unique combination of electrical, optical, and mechanical properties. This article will discuss the production of graphene through chemical vapor deposition(CVD). CVD is a favored method for producing graphene, as it produces a high quality and large amount of material, allowing for more applicability and a reduction in cost.
CVD is a method that uses condensed gases to create a reaction in which new materials are deposited on various surfaces. This process is often used in the production of semiconductors, metals, and other materials. Chemical vapor deposition has proven to be a highly effective method for producing graphene.
One of the main benefits of CVD is that it can produce extremely large areas of graphene. CVD is able to do this through a number of processes such as thermal heat up, plasma-activated heating and catalytic chemical vapor deposition.
The thermal heat up is the most simple CVD method. It works by using a heated surface, usually a silica or ceramic substrate, to vaporize the source material, usually a hydrocarbon gas. The vaporized hydrocarbon is then able to react with the heated surface, forming small graphene sheets on the surface. This method can be used to produce single layer up to multilayered graphene.
Plasma-activated heating CVD uses a plasma discharge to heat the substrate. This often results in multi-layer graphene formation. The plasma is activated by either a high-frequency AC power source or a pulsed DC source. This method typically results in a higher quality material, with less defects.
The catalytic chemical vapor deposition method relies on the presence of a catalyst, usually nickel, cobalt, iron or gold, to drive the deposition of graphene. The catalyst is heated to a high temperature in a tube furnace and a hydrocarbon gas, usually methane, is introduced. The methane reacts with the catalyst, forming small graphene sheets on the surface. The resultant graphene material often contains fewer defects compared to other CVD methods.
CVD is a preferred method for producing graphene due to the large areas of graphene that can be produced with a high quality product. It has also been proven to be a cost-effective production method, reducing the overall cost of the graphene. The CVD process also offers good scalability, leading to an easier transition from laboratory to production.
The ability to produce large areas of graphene with a high quality product and a cost effective process makes CVD a favored production method. Graphene has shown promise in many applications, and CVD will continue to be an important part of the graphene production process.
