Electrical and noise characteristics of graphene field-effect transistors

Low frequency noise in virgin (not aged) graphene transistors might be relatively low (comparable to average Si MOSFETs), at least for high quality devices with the bottom gate configuration. Graphene channels are the dominant sources of noise, even though the contact resistances have an important effect on the noise magnitude due to the voltage re-distribution between the contacts and the channel. Gate voltage dependences of noise in graphene transistors reveal that the noise mechanism cannot be described by a conventional McWhorter model and might be linked to graphene mobility fluctuations. Aging in ambience causes a substantial degradation of device characteristics and increase of noise level. The temperature dependences of the current-voltage characteristics of graphene revealed a new effect of a “memory step” near the charge neutrality voltage. Further studies of low frequency noise under such conditions might help in understanding of this novel phenomenon.