Gate tunable non-linear currents in bilayer graphene diodes

TL;DR

This study demonstrates how gate voltages can control non-linear current flow and rectification in bilayer graphene diodes, enabling tunable electronic properties through local Fermi level adjustments.

Contribution

It introduces a method to control and characterize non-linear currents and rectification in bilayer graphene diodes via gate voltages, revealing tunable bandgap properties.

Findings

Gate voltage controls rectification direction.

Bandgap tunable from 0 to 130 meV.

Non-linear current behavior observed.

Abstract

Electric transport of double gated bilayer graphene devices is studied as a function of charge density and bandgap. A top gate electrode can be used to control locally the Fermi level to create a pn junction between the double-gated and single-gated region. These bilayer graphene pn diodes are characterized by non-linear currents and directional current rectification, and we show the rectified direction of the source-drain voltage can be controlled by using gate voltages. A systematic study of the pn junction characteristics allows to extract a gate-dependent bandgap value which ranges from 0 meV to 130 meV.