TCAD Device Modeling and Simulation Study of Organic Field Effect Transistor-Based pH Sensor with Tunable Sensitivity for Surpassing Nernst Limit

A dual-gate organic field effect transistor (DG-OFET)-based pH sensor is proposed that will be able to detect the variations in the aqueous (electrolyte) medium. In this structure, a source-sided underlap technique with a dual-gate sensing approach has been used. The change in ON-current (ION) was o...

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Bibliographic Details
Published in:Electronics (Basel) 2023-01, Vol.12 (3), p.536
Main Authors: Majeed, Lubna, Amin, Syed Intekhab, Rasool, Zuber, Bashir, Ishrat, Kumar, Naveen, Anand, Sunny
Format: Article
Language:English
Subjects:
Biocompatibility
Circuit design
Computer-aided design
Design and construction
Dielectrics
Electric fields
Electrodes
Electrolytes
Field effect transistors
Glass substrates
Mathematical models
Methods
Semiconductor devices
Semiconductor doping
Sensitivity analysis
Sensors
Silicon dioxide
Simulation
Tantalum
Tantalum oxides
Transistors
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Summary:A dual-gate organic field effect transistor (DG-OFET)-based pH sensor is proposed that will be able to detect the variations in the aqueous (electrolyte) medium. In this structure, a source-sided underlap technique with a dual-gate sensing approach has been used. The change in ON-current (ION) was observed due to parallel examination of electrolytes in two gates underlapping the region of the structure. For the evaluation of the sensitivity of DG-OFET, the change in the drain current was exploited for different pH and corresponding charge densities utilizing 2D physics-based numerical simulation. The simulation results were extracted with the help of the software package Silvaco TCAD-ATLAS. The simulated results display that the proposed DG-OFET shows significantly higher sensitivity for high-k dielectrics. The voltage sensitivity achieved by DG-OFET with SiO2 as a dielectric in our work is 217.53 mV/pH which surpasses the Nernst Limit nearly four times. However, using a high-k dielectric (Ta2O5) increases it further to 555.284 mV/pH which is more than nine times the Nernst Limit. The DG-OFET pH sensor has a lot of potential in the future for various flexible sensing applications due to its flexibility, being highly sensitive, biocompatible and low-cost.
ISSN:2079-9292
2079-9292
DOI:10.3390/electronics12030536