Engineering of Graphene-to-Semiconductor Contacts

The unique features of graphene when making contact with some common semiconductor materials such as silicon and IGZO are described in this paper. In addition to the image force induced barrier lowering observed in some metal-semiconductor contact, graphene contact is also affected by field induced graphene doping effect that leads to higher off current. Furthermore, the graphene-to-semiconductor interface plays a very important role on the turn-on characteristics leading which is the main factor that causes slow turn on. By isolating the interface states from the graphene electrode, the turn-on characteristics can be enhanced. Finally, we have demonstrated using graphene as an interface layer to turn a thermionic into a tunneling contact. We have used this technology to demonstrate the formation of an IGZO thin film transistor.