Utilized in everything from modern state-of-the-art monitors and solar cells to nanotubes, graphene is the new wonder material that, scientists claim,will shape future technologies. In its raw form, it’s a two-dimensional crystalline carbon allotrope, the basic structural element for charcoal, graphite, and fullerenes.
While there are different ways of producing usable end-products for graphene, the most effective is through chemical vapor deposition or CVD. To understand this process further, read on.
CVD is a method that uses gaseous reactants on a substrate to form solid deposits (e.g., CVD graphene on copper). Gas chemicals,typically carrier gases like helium and hydrogen,are fused on top of a solid substrate. This is done inside a thermal reaction chamber where high heat induces the creation of monolayers of graphene through this two-step process:
- Decomposition: Pyrolysis disassociates the chemicals in gases on top of a metal catalyst. This allows carbon atoms to be extracted while minimizing unwanted precipitation (soot formation).
- Synthesis: The disassociated atoms will then be put under 1,000 degrees Celsius. The heat and the catalyst fuse the disorganized carbon until pure deposits are produced.
The Substrate’s Importance
While CVDis effective, problems can still occur during this process. Carbon dissolving into the substrate and exfoliating the endproduct successfully are twoof the challengesgraphene manufacturers need to address. To prevent these, consider the surface where the chemical reaction occurs. Copper (CU), nickel (Ni), palladium (Pd), ruthenium (Ru), and iridium (Ir) are common metals that can be used; however,graphene production on copper and nickel hasbeen proven to be more successful.
Copper: Graphene on copper is widely used among manufacturers because of its high-level hydrostatic compression when coupling with carbon. This minimizes chances of reactants dissolving in the catalyst and ensures that the end product can be extracted efficiently.
Nickel: This has a faster carbon diffusion rate compared to other metals when hydrogen is used for pyrolysis. The result is graphene formation in a shorter time frame.
The End Product
CVDproduces high-grade, fine-grained, durable graphene monolayers en masse. The condensation and “crystallization” of carbon allows the material to gain the following features:
- Excellent conductivity for heat and electricity
- Pliability and transparency
- Being the thinnest and strongest material used for commercial purposes
- Nano-scale pores in the membrane
- Hydrogen storing
These are just glimpses of how producing CVD graphene on copper, nickel, and other substrates goes. Need this material for your business? Talk to a manufacturer today!