M Akbari Eshkalak - Departmentof Electrical Engineering, Islamic Azad University of Qazvin, Qazvin, Iran
R Faez - Department of Electrical Engineering, Sharif University Of Technology, Tehran, Iran
P Ataei - Departmentof Electrical Engineering, Islamic Azad University of Qazvin, Qazvin, Iran

The Graphene Nano-Ribbon Field Effect Transistor (GNRFET) is an emerging technology that received muchattention in recent years. Selection of a suitable gate dielectric constant is important in determining device performance. In this paper, different gate dielectric materials for GNRFET are examined. The Non- Equilibrium Green’s Function (NEGF) method in mode space representation is used to solve the Schrödinger equation self- consistently with two dimensional (2D) poisson equation. We assume a tight-binding Hamiltonian in our study. The results show that the GNRFET with high dielectric constant has higher transconductance, lower Off- state current, higher On-state current and higher ratio of Ion/Ioff in comparison with low dielectric GNRFET. Furthermore, the GNRFET with low dielectric constant has smaller capacitances in gate, drain and source. The GNRFET with high dielectric constant has lower Sub-threshold Swing.

Graphene Nanoribbon FET; Schrödinger- Poisson formalism; Non Equilibrium Green’s function (NEGF); Gate Insulator