Label-free biosensor with multidimensional aspects of a molybdenum di-sulfide dual-gate Schottky tunnel field-effect transistor (D-G-STFET)

Abstract

In this research, we presented a simulation of a MoS₂-based dual-gate Schottky barrier tunnel field-effect transistor (D-G-STFET) with high-k dielectric (TiO₂), emerging as a promising device for detecting biomolecules. The source and drain regions consist of metals selected based on their work functions. Furthermore, the channel is made of MoS₂, with zirconium as the gate material, to enhance D-G-STFET biosensor performance. Using dual cavities etched beneath the dual gate electrode of the biosensor promotes biomolecule immobilization. Moreover, biomolecule immobilization, along with their charge density and dielectric constant (k), collectively alters the effective dielectric constant of the gate oxide. Which leads to changes in surface potential and drain current, ultimately determining the sensitivity of the biomolecules. We characterized the MoS₂ effect on the proposed biosensor device in terms of drain current, potential, electric field, conduction and valence band energy, and sensitivity of charged and neutral biomolecules. Additionally, we analyzed the influence of temperature on the proposed and conventional devices. Here, the proposed device shows superior performance than the silicon and GaN material of conventional devices. Proposed and conventional device simulations are calculated using SILVACO TCAD tool.