Design and Analysis of InP/GaN Surrounding Gate TFETs for High-Sensitivity Biosensing Applications

This study presents an advanced analytical model for the InP/GaN-graphene channel surrounding gate tunnel field-effect transistor (SGT-TFET) for next-generation biosensing applications. The proposed device leverages indium phosphide (InP) and gallium nitride (GaN) as the source and drain materials, respectively, while graphene serves as a highly conductive channel material. The surrounding gate structure ensures enhanced electrostatic control and increased sensitivity, crucial for detecting low-concentration biomolecules. The high carrier mobility of graphene minimizes short-channel effects and improves response times for real-time biosensing. Device simulations conducted using Silvaco TCAD reveal superior electrical performance, with an I ON /I OFF ratio of 10⁷ and low ambipolar current, making the device highly energy-efficient. The reduced tunneling barrier width contributes to an impressive ON current of 10 4 A/μm, enhancing signal detection for biomolecules in physiological samples. This work demonstrates the potential of InP/GaN-Graphene TFETs as highly sensitive biosensors for medical diagnostics and environmental monitoring applications.