Performance Investigation of Pentacene Based Organic Double Gate Field Effect Transistor and its Application as an Ultrasensitive Biosensor

Document Type: Original Research Paper

Authors

1 Graduate Student, Department of Electronic, Faculty of Electrical Engineering, Yadegar- e- Imam Khomeini (RAH) Shahr-e-Rey Branch, Islamic Azad University, Tehran, Iran

2 Yadegar-e-Imam Khomeini (RAH) Shahre Rey Branch, Islamic Azad University, Tehran, Iran. E-mail: z.ahangari@iausr.ac.ir; z.ahangari@gmail.com

3 Assistant Professor, Department of Electronic, Faculty of Electrical Engineering, Yadegar- e- Imam Khomeini (RAH) Shahr-e-Rey Branch, Islamic Azad University, Tehran, Iran

10.22034/jna.2020.677394

Abstract

In this paper, the electrical performance of double gate organic field effect
transistor (DG-OFET) are thoroughly investigated and feasibility of the device
as an efficient biosensor is comprehensively assessed. The introduced device
provides better gate control over the channel, yielding better charge injection
properties from source to channel and providing higher on-state current in
comparison with single gate devices. The susceptibility of fundamental electrical
parameters with respect to the variation of design parameters is thoroughly
calculated. In particular, standard deviation and average value of main electrical
parameters signify that metal gate work function, channel thickness and gate
oxide thickness are fundamental design measures that may modify the device
efficiency. The insensitivity of off-state current to the change of channel length
and drain bias confirms feasibility of the device in the nanoscale regime. Next,
a nano cavity is embedded in the gate insulator region for accumulation of
biomolecules. The immobilization of molecules with different dielectric constants
in the gate insulator hollow alters the gate capacitance and results in the drain
current deviation with respect to the air- filled cavity condition. It is shown that
by the occupancy of the whole volume of the nanogap, a maximum range of onstate
current variation can be achieved.

Keywords