Operation of graphene transistors at giqahertz frequencies

Top-gated graphene transistors operating at high frequencies (gigahertz) have been fabricated and their characteristics analyzed. The measured intrinsic current gain shows an ideal 1/f-frequency dependence, indicating a FET-like behavior for graphene transistors. The cutoff frequency h is found to be proportional to the de transconductance gm of the device, consistent with the relation h = gJßπC¢). The peak h increases with a reduced gate length, and h as high as 26 GHz is measured for a graphene transί stor with a gate iength of 150 nm. The work represents a significant step toward the realization of graphene-based electronics for high-frequency applications.