A Physically based compact I-V model for monolayer TMDC channel MOSFET and DMFET biosensor

TL;DR

This paper presents a physically based compact model for monolayer TMDC MOSFETs and DMFET biosensors, accurately capturing electrostatics and transport, validated against experiments and simulations, and applied to performance analysis and biosensing.

Contribution

The work introduces a novel compact model that incorporates first-principles density of states and solves Poisson's and drift-diffusion equations for monolayer TMDC devices, including biosensors.

Findings

Model accurately predicts device characteristics.

Monolayer WSe2 FET shows excellent ON/OFF performance.

Biosensor model effectively detects biomolecules.

Abstract

In this work, a compact transport model has been developed for monolayer transition metal dichalcogenide (TMDC) channel MOSFET. The analytical model solves the Poisson's equation for the inversion charge density to get the electrostatic potential in the channel. Current is then calculated by solving the drift-diffusion equation. The model makes gradual channel approximation to simplify the solution procedure. The appropriate density of states obtained from the first principle density functional theory simulation has been considered to keep the model physically accurate for monolayer TMDC channel FET. The outcome of the model has been benchmarked against both experimental and numerical quantum simulation results with the help of a few fitting parameters. Using the compact model, detailed output and transfer characteristics of monolayer $WSe_2$ FET have been studied, and various performance parameters have been determined. The study confirms excellent ON and OFF state performances of monolayer $WSe_2$ FET which could be viable for the next generation high-speed, low power applications. Also, the proposed model has been extended to study the operation of a biosensor. A monolayer $MoS_2$ channel based dielectric modulated FET is investigated using the compact model for detection of a biomolecule in a dry environment.