(Phys.org)—Electrons can dash through graphene with almost no resistance,a property that gives graphene distinguished potential for replacing silicon in next-generation, highly efficient electronic devices. But currently it's very difficult to control the electrons moving through graphene because graphene has no band gap, or which means the electrons don't need to cross any energy barrier in order to conduct electricity. As a result,the electrons are always conducting, all the time, and which means that this form of graphene can't be used to build transistors because it has no "off" state. In order to control the electron movement in graphene and enable "off" states in future graphene transistors,graphene needs a non-zero band gap—an energy barrier that can prevent electrons from conducting electricity when desired, making graphene a semiconductor instead of a full conductor.
Source: phys.org