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

TL;DR

This study demonstrates wafer-scale fabrication of nanoperforated graphene transistors achieving high mobility and high on-off ratios, revealing charge localization effects and bandgap opening due to nanostructuring.

Contribution

It introduces a method to produce graphene transistors with nanoperforations that simultaneously exhibit high mobility and high on-off ratios, addressing a key challenge in graphene electronics.

Findings

Mobility ranges from 10400 to 550 cm²/Vs depending on channel length.

On-off ratio consistently between 10^3 and 10^4 at low voltages.

Charge localization and bandgap opening are key mechanisms.

Abstract

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 micrometers. We have found that the mobility in these 2 micrometer-wide transistors varies from about 10400 cm2/Vs for a channel length of 1 micrometer to about 550 cm2/Vs for a channel length of 8 micrometer. Irrespective of the mobility value, in all transistors the on-off ratio is in the range 10^3-10^4 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.