Performance study of double-gate graphene nanoribbon TFET for low power applications

Tunnel field-effect transistors (TFETs) are considered suitable for low-power applications because of their steep subthreshold swing and reduced leakage current. However, conventional silicon TFETs suffer from low ON current, which limits their performance. In this work, a double-gate graphene nanoribbon-based PNPN TFET is proposed, which enhances tunnelling efficiency and switching behaviour. Armchair graphene nanoribbons (AGNRs) are preferred for TFET applications because they exhibit a suitable bandgap, improved electrostatic control, and reduced leakage current. The graphene channel improves carrier mobility, while PNPN doping increases the electric field at the tunnelling junction. The proposed device is designed and simulated using the Silvaco ATLAS TCAD tool, and key parameters, including transfer characteristics, electric field, surface potential, transconductance, transconductance efficiency, and cut-off frequency, are analysed. The simulation results show an increased ON current (10⁻²), an average subthreshold swing of 26.6 mV/dec, a cut-off frequency of 20.6 THz, and enhanced performance, indicating suitability for low-power and high-frequency applications.