From Conductor to Insulator

February 01, 2012 at 11:14 AM

Graphene is one of those materials under vigorous study for use in future electronics. A single honeycomb layer of carbon atoms, it features high electron mobility but no bandgap, so, on its own, doesn’t work well as a semiconductor.

Add another layer, however, and, as we saw in our note on the next logic gate, interesting things may happen.

In particular, some UC Riverside researchers found that so-called bilayer graphene (BLG), which also has high mobility, can become an insulator once the number of electrons drops far enough. They did this by making a BLG sheet one plate of a capacitor, pulling away electrons. This isn’t a gradual process of conductivity changing linearly as electrons are depleted; at a certain point, there’s a fundamental shift in how the electrons organize themselves.

They go so far as to describe this shift as a form of “symmetry breaking,” which gives mass to particles – and they fancy this as the embodiment of a new quantum particle.

You can find more on what’s either a new particle or just another bit of useful knowledge about how to work with graphene in their unusually explanatory release.



Tags:
Category: Semiconductor

Please add a comment

You must be logged in to leave a reply. Login »

Login Required

In order to view this resource, you must log in to our site. Please sign in now.

If you don't already have an acount with us, registering is free and quick. Register now.

Sign In    Register