Electrical transport properties of gate tunable graphene lateral tunnel diodes

A detailed study of the electrical transport properties of gate tunable graphene lateral tunnel diodes is presented. The graphene-Al2O3-graphene lateral tunnel diodes are fabricated on Si/SiO2 substrates, and the fabricated devices show rectifying characteristics at the low voltage below 1 V. The rectifying behavior can be controlled by applying back gate voltages. As a result, the devices show high asymmetry and strong nonlinearity current-voltage (I-V) characteristics, which are desirable properties for applications such as optical rectennas and infrared detectors. The electrical transport mechanism of the graphene lateral diodes is analyzed by extracting parameters from the measured I-V characteristics. We find that trap- assisted tunneling from the defect levels in the Al2O3 layer is the most likely mechanism of the forward current of the fabricated graphene lateral diodes. (c) 2020 The Japan Society of Applied Physics