Assessment of graphene nanomesh and nanoroad transistors by chemical modification

Chemical modification of graphene plays an important role on opening a bandgap for potential digital electronic device applications. We propose and examine the performance limits of graphene nanoroad and graphene nanomesh transistors created by selective hydrogenation and fluorination of graphene. First principle ab intio simulations with a ballistic transistor model are applied to model two-dimensional transistor channels made of hydrogenated or fluorinated graphene nanoroads and nanomeshes. It is shown that array of graphene nanoroads defined by hydrogenation or fluorination of atomically narrow dimmer lines in a 2D graphene are most ideal for transistor channel material in terms of delivering a large on-current, which significantly outperforms Si MOSFETs. In addition, comparable performance to silicon can be achieved by careful designed graphene nanomesh through patterned hydrogenation or fluorination. Fluorination is shown to be energetically more preferred and easier to achieve than hydrogenation.