Performance Optimization of Germanium-Graphene Heterojunction Tunnel Field Effect Transistor using Dual Metal Strip

This work presents and investigates a Dual Metal Gate Graphene Nanoribbon (DMHGNR) with a Germanium heterojunction-based Tunnel Field-Effect Transistor (DMHGNRTFET). The impact of a dual metal strip combined with a hetero-dielectric on the heterojunction TFET architecture is analyzed. Optimization of the ON/OFF current and their ratio is achieved by the use of design engineering, bandgap engineering, and work function engineering. Simulations are carried out to evaluate the proposed DMHGNRTFET together with GNRGeTFET and GNRSiTFET by examining surface potential, energy band diagrams, carrier concentration, electric field distribution, Id-Vgs characteristics, and transconductance. The DMHGNRTFET exhibits an Ion/Ioff ratio of approximately ̴10¹², alongside a minimal subthreshold swing (SS) of 33.9 mV/decade. It features the lowest threshold voltage observed at 0.41 V and achieves a maximum Ion of 2.44 × 10⁻4 A/μm. The findings of SILVACO TCAD simulations suggest the potential for enhanced performance in low power applications of the DMHGNRTFET.