Carbon-based Electronics: Graphene and GNRs

In the past 40 years, Si CMOS technology is the ruler of electronic society. The scaling down process, which is precisely predicted by Moore's Law, is always being the driving force of the aggressive innovation cycles in the technology. However, with the device scaling down, today's Si CMOS devices are facing the increasing challenges including short-channel effects, gate leakage, gate control and so on. It is estimated that the scaling down process will be invalid during a limit of time, no more than 10 ~15 years. Therefore, finding new materials and technologies to replace silicon-based devices is an urgent issue now.

Graphene, a carbon-based 2D single atomic layer, is considered to be the potential material for the next generation electronic devices. With the zero bandgap and linear E-k dispersion relation, graphene's mobility is extremely high (106 cm2/V-s). The 2D structure of the graphene makes it a suitable 2DEG material for high speed field-effect devices, which can be used in RF or analog circuits.

Graphene nano ribbon (GNR) is a ribbon-like graphene structure, with the width of only a few-atom length. Due to the quantum confinement along the ribbon width, GNRs should be considered as a 1D electron system. The electron confinement along the width direction opens a band gap for GNRs. GNRs' electronic and optical properties are size and crystallographic-related and much different from the graphene's. This geometry-related properties of GNRs provide many interesting research topics. In this project, we focus on the theoretical calculation of the electric and optical properties of graphene and GNRs.