Essay about Graphene Science News

Submitted By SarahDohring
Words: 438
Pages: 2

Graphene’s two dimensions offer new physics, novel electronics
By Alexandra Witze

For seven years, researchers have been learning about the new physics provided by a super flat material called graphene. The substance looks very simple – nothing more than a sheet of honey-combed carbon atoms, which you can find within flakes from a pencil lead – but contains pretty bizarre physics. Scientists now understand how stacking one sheet of graphene on top of another in just the right way can change the way the electrons flow between the layers. Other researchers have also found that putting graphene on top of a slab of boron nitride lets them manipulate the electron flow far better than before. Unlike almost any other common material, graphene sometimes behaves according to the weird rules of quantum mechanics. When it comes to building new electronic devices, one of the drawbacks of single layer graphene is that it doesn’t have a “band gap,” or break in the energy levels that its electrons can occupy. Without a band gap, scientists can’t turn the flow of electrons on and off – a crucial part of any electronic gadget. But adding a second layer of graphene creates a band gap, making it so that the flow of electrons can be controlled instead of zooming around all over the place. Making bilayer graphene isn’t as easy as putting one layer on top of another. How the two layers are stacked relative to one another is important. If the carbon honeycombs of each layer are rotated less than five degrees relative to each other, then the two layers act as a true bilayer. But if the honeycombs are rotated 20 degrees or more, then the graphene layers continue to behave as two separate layers. Some researchers are pushing to make trilayer graphene, but as with bilayer, the