Dielectric modulated organic thin film transistor trench biosensor for label-free detection: Modeling and simulation analysis

In the present paper, a biosensor is proposed with a split gate dielectric modulated bottom gate top contact organic thin-film transistor. A cavity is marked below gate metal for enhancing sensitivity in biomedical applications. The organic thin-film transistors-based biosensors have shown applications over advanced biosensing platforms due to their intrinsic ability to transfer and amplify received biological signals into respective electrical signals. Immobilizing the biomolecules inside the cavity generates changes in surface potential. The analysis is carried out via different performance metrics that directly affect device electrical characteristics such as a change in spacer length applied voltages (V-gs and V-ds) as well as channel material. After modeling, the device output characteristics are compared corresponding to simulated outcomes that validated our results. The proposed model structure is categorized by dividing it into different sections. Each categorized section's surface potential is further evaluated via 1- and 2-dimensional Poisson's equation. The simulations to recreate biomolecules in terms of dielectric constant and charge density are done in the Silvaco ATLAS tool. The maximum value of sensitivity of proposed biosensor is around 300 in the case of charged biomolecule detection.