Design and Sensitivity Investigation of Dielectric Modulated and Electrolyte-Based pH Sensing of Vertical TFET Biosensor

The potential for nanoscale devices to serve as a platform for the detection of biomolecules is immense. Several challenges have been faced in the device fabrication process. To address these issues, the uniformly doped concept was introduced. This study suggests the use of a vertical tunnel field-effect (VTFET) transistor with a pH base and a gate overlap dielectric modulation for label-free electrical recognition of biomolecules such as cells, deoxyribonucleic acids, proteins, enzymes, and others. In the present article, two simple approaches of sensitivity analysis are compared, the first one is the dielectric modulated analysis and the second one is the electrolytic-based pH sensing of vertical TFET biosensor. The proposed model incorporates the effects of pH and the dielectric constant to provide a generalised solution applicable to neutral biomolecules. To test the effectiveness of the proposed sensors, a thorough simulation is run using an ATLAS device simulator. The effects of pH changes on device characteristics like the device current (I
_DS
) and surface potential sensitivity are investigated. Additionally, pH sensors measure changes in hydrogen ion concentration in aqueous solutions and shifts in drain current caused by changes in the dielectric constant that have been used to analyse the sensitivity of dielectric modulated biosensors. The drain current sensitivity of the pH-hetero-VTFET biosensor is estimated as 8.8 × 10
⁵
which is higher than the sensitivity (9.1 × 10
⁴
) of DM-hetero-VTFET at the cavity length of 30 nm. Since it has been found that the proposed sensor exhibits significant variations in its surface potential and drain current (I
_ON
)
_,
so this device is preferable as an appropriate sensing transducer.