Description
Researchers are getting better at making graphene by the chemical vapour deposition (CVD) method. This is a high temperature process, around 1000°C, growing graphene as a single crystal monolayer on copper foils. A team in China has reported growing high-quality graphene at millimetre scale using oxidised copper foil where the oxygen promotes the graphene domain formation. Another team in the USA reports growing high quality graphene again at millimetre scale, this time the secret is excluding oxygen.
So, we have two papers, both report growing high quality graphene one says the secret is the presence of oxygen and the other team says the secret is the absence of oxygen. They both can’t be right, can they? Well, yes, they can. The team growing graphene in the presence of oxygen results in fewer domains that grow to large sizes forming the graphene sheet. The team growing without oxygen grew many small domains and these rapidly covered the surface of the copper foil and as these collide, they seamlessly join up forming the high-quality single crystal sheet
Interpreting the research can sometimes be confusing. In this case we have two routes to make graphene with different growth strategies. However, the important thing to focus on is that they each achieve a similar end.
High quality monolayer large-scale graphene is being used by many other teams around the world. Another team has developed an astonishingly precise microscope magnetometer that can map the flow of electrons in graphene. They found that under certain conditions the electrons flow in whirlpool-like vortexes. This was predicted by theory and is the first time it has been observed in practise. We mark this work in the cover artwork of this month’s issue.
On the industrial and commercial side, we are seeing continuing investment in graphene companies. US battery manufacturer, Lyten, announced it is sending evaluation battery pouch cells to major automotive manufacturers including the giant company Stellantis. In the announcement the company let slip that they have received a total of $410 million dollars of investment to date. This is higher than the £300 million that we counted through previous public disclosures.
Of course, as usual there is so much more to explore in this fascinating issue,
please do read on…
Adrian Nixon
1st June 2024
