  This work evaluates the performance of carbon nanotube field effect
transistors (CNTFET) using few layer graphene as the contact electrode
material. We present the experimental results obtained on the barrier height at
CNT graphene junction using temperature dependent IV measurements. The
estimated barrier height in our devices for both holes and electrons is close
to zero or slightly negative indicating the Ohmic contact of graphene with the
valence and conduction bands of CNTs. In addition, we also report that there is
no correlation between the barrier height and thickness of graphene.
