Graphene-buckyball hybrid has a decent bandgap

Thanks to graphene’s high electrical conductivity, the carbon allotrope is considered to be an excellent successor to silicon. However, the application of graphene in electronics has been hindered by the fact that it hasn’t got a bandgap on its own – it needs to be induced, for example by bonding it to another 2D material. With this in mind, researchers of the Chinese Academy of Sciences set out to create a carbon material that naturally has a useful bandgap – not too small and not too large.

Jian Zheng and co-workers linked together units of another once-promising carbon-based material, soccer-ball-shaped C₆₀ molecules nicknamed buckyballs, creating a sheet of them. This forms a new type of 2D material, taking the thickness from a few atoms at most to that of a medium-sized molecule. In a way, this polymerized C₆₀ is like a mash-up of graphene and buckyballs.

This is reflected in the electronic properties of the buckyball networks. Their electrical conductivity was found to be in between that of graphene and free buckyballs. More importantly, measurements revealed a useful 1.6 eV bandgap.