STUDY OF BILAYER GRAPHENE BASED 2D FET

Abstract

In recent years there has been a shift in industry from bulk devices to 2D devices. Major reasons for that is 2D devices are more energy efficient and have a greater mobility of carriers and low contact resistance. In continuation of the same in this thesis an attempt has been made to come up with a 2D FET made up of bilayer graphene. A bilayer graphene structure is generated in Quantum Atomistic Toolkit (QATK) and its band gap has been deduced. Electrodes are added in source and drain region to vary the voltage across the device. Two gate electrodes are also added on top and bottom of the structure with voltage Vtg and Vbg. We have used Landauer Buttiker Equation to find the device current. Current Vs Drain voltage graph is calculated to see the variation with respect to different del_Vgs. Finally, a comparison for device current has been made among the different del_Vgs values.

Bilayer graphene does not naturally have a bandgap, as its band structure typically shows a small overlap between the valence and conduction bands, making it behave more like a semimetal. However, it is possible to induce a bandgap in bilayer graphene by applying an external electric field perpendicular to the graphene plane. This process, known as electric field-induced bandgap engineering, allows for the modification of bilayer graphene's electronic properties, potentially transforming it into a semiconductor. By adjusting the strength of the applied electric field, the magnitude of the bandgap can be controlled.