An accurate analytical modeling of dielectric modulated 2-D material FET-based biosensors using Green’s function approach

Abstract Field-Effect Transistor (FET)-based biosensors offer a significant advancement in the detection of biomolecules due to their ability to convert biological events into measurable electrical signals without the need for labeling. The sensor architecture is defined by a dual-gate FET with dual-sided cavities filled with biomolecules to amplify the electrostatic modulation. According to the author’s knowledge, there has been no reports on the analytical modeling of biosensors for accurately modeling 2-D potential distribution inside the channel utilizing Green’s function approach.By dividing the device into multiple dielectric regions, the 2-D Poisson’s equation is solved accurately using a multi-zone Green’s function approach under mixed boundary conditions. This analytical framework enables precise evaluation of 2-D potential distribution and I-V characteristics in the subthreshold regime, which are critical for quantifying biomolecular interactions. The proposed analytical model is validated against Silvaco TCAD for both the surface potential and I-V characteristics in the subthreshold regime for different channel materials and lengths and strong correlation is achieved between the analytical and TCAD data. The analytical model is utilized for evaluating the interaction of FET-based biosensors to different biomolecules and higher drain current sensitivity is achieved with increasing dielectric constant of biomolecules.