Introduction
Graphene is a two-dimensional material with honeycomb structure, which has attached world-wide attention and research interest, due to its unique physical, mechanical, and electrical properties. There are different ways to created or isolated graphene monolayers, but by far the most popular way is an approach called chemical vapour deposition (CVD) which can produce relatively high quality graphene. The CVD “bottom-up” synthesis has evolved to a scalable and reliable production method of large-area graphene.
Fig 1 Structure of Graphene
CVD is a way of depositing gaseous reactants onto a substrate, which is reasonably straightforward, although some specialist equipment is necessary. In typical CVD, gas molecules are combined in a reaction chamber which is typically set at ambient temperature. When the combined gases come into contact with the substrate within the reaction chamber, a reaction occurs that create a material film on the substrate surface. Frequently, volatile by-products are also produced, which are removed by gas flow through the reaction chamber.
Fig 2 Schematic diagram of CVD process
Applications
Photovoltaic Cells: Graphene films are transparent, conductive, and highly flexible, which are considered to be great candidates for transparent conductive electrodes in photovoltaic cells.
Optical Electronics: Graphene is an almost completely transparent material which is able to optically transmit up to 97.7% of light. In addition, with highly conductive, it works well in optoelectronic applications such as LCD touchscreens for smartphones, desktop computers and televisions.
Composite Materials: Graphene is strong, stiff and very light, so it can be utilized (probably integrated into plastics such as epoxy) to create a material that can replace steel in the structure of aircraft, improving fuel efficiency and reducing weight.
Ultrafiltration: Graphene could be used as an ultrafiltration medium to act as a barrier between two substances. The benefit of using graphene is that it is only one single atom thick and can also be developed as a barrier that electronically measures strain and pressures between the two substances.
