Imaging technique observes growth of graphene

This discovery by a team at Surrey University could be a significant step closer to mass commercialisation and production of graphene for electronic devices. Their findings are detailed in ACS Applied Nano Materials.

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Using video imagining, the team from Surrey’s Advanced Technology Institute (ATI) have shown graphene growing over an iron catalyst, using a silicon nitride membrane produced within a silicon chip. The membrane is only a few tens of nanometres thin, and heating and cooling can be rapidly controlled by means of modulating an electrical signal that is sent to the iron layer. This acts as a catalyst and as an electrical resistor to supply the heat.

The imaging is said to use Fermi-level contrast to visualise doping levels of graphene. This contrast mechanism can be used to identify the point of electrical contact between neighbouring graphene flakes. This imaging reveals also that physical contact alone between flakes is not sufficient to form electronic contact, which suggests additional bonding is required before electrons are able to jump from flake to flake.