Solving the graphene electronics conundrum: High mobility and high on-off ratio in graphene nanopatterned transistors

Tens of graphene transistors with nanoperforated channels and different channel lengths were fabricated at the wafer scale. The nanoholes have a central diameter of 20 nm and a period of 100 nm, the lengths of the channel being of 1, 2, 4 or 8 μm. We have found that the mobility in these 2 μm-wide transistors varies from about 10400 cm2/Vs for a channel length of 1 μm to about 550 cm2/Vs for a channel length of 8 μm. Irrespective of the mobility value, in all transistors the on-off ratio is at least 103 at drain and gate voltages less than 2 V. The channel length-dependent mobility and conductance values indicate the onset of strong localization of charge carriers, whereas the high on-off ratio is due to bandgap opening by nanoperforations.