Charge Plasma Doped Heterostructure TFET Biosensor for Diverse Biomolecular Sensing: Theoretical Insights

This manuscript investigates a heterostructure tunnel field effect transistor (TFET) biosensor employing an InGaAs_5.86GaAs_5.65 combination with charge plasma doping. The proposed device features a nanocavity designed for biosensing applications, enabling the detection of changes in the drain current (I_D) relative to the gate voltage (V_GS) and facilitating subsequent analysis. The study provides the device’s energy band diagram and evaluates various parameters. It also explores the impact of varying the biosensor’s cavity length on performance, highlighting the on-current (I_ON) variations with diverse biomolecule dielectric constants. The integration of the heterostructure and charge plasma doping in the proposed design significantly enhances performance, achieving an optimized drain current (I_D) of approximately 10⁵A/µm, ensuring superior sensitivity, selectivity, and biomolecular detection capabilities. A comparative analysis with existing designs demonstrates that the proposed design outperforms others across multiple parameters. In particular, the I_ON has increased and the subthreshold swing has fallen below 60 mV. All simulations are conducted using the Silvaco Atlas TCAD tool.