Numerical Modelling of Carrier Transport in Organic Field Effect Transistors

Abstract

Organic field effect transistors (OFETs), used in the fabrication of nano-sensors, are one of the most promising devices in the field of organic electronics, because of their light weight, flexible and low fabrication cost. However, the optimization of such OFETs is still in an early stage due to the very limited analytical as well as numerical models presented in the literature. This research presses to demonstrate a numerical carrier transport model based on finite element method (FEM), to investigate the I-V characteristic of OFETs. Two various organic semiconductor materials have been included in the study, polyaniline and pentacene, where a micro-scale as well as a nano-scale models have been presented. OFETs have been studied in terms of channel length, dielectric thickness, and doping level impact. We nominated the threshold voltage, the on/off current ratio, the sub threshold swing, and the field effect mobility’s as the main output evaluating parameters. The numerical model has shown the criticality of the doping effect on tuning the device flowing drain current, to exceed 300 μA saturation current, along with threshold voltage of -0.1 V under a channel length of 30 nm. Additionally, the study highlights the effectiveness of the polyaniline over pentacene as nano-channel length OFET, due to the boosted conductivity of polyaniline with respect to pentacene.

OFET Informatics: Observing the impact of organic transistor's design parameters on the device output performance using a machine learning algorithm

“…We attribute this to the capability of designing ultra‐low threshold voltage OFET, as previously reported in References 16–18. In addition, the previous investigation recorded a very acceptable and controllable on/off current ratio and subthreshold swing (SS) 19–22 . In such a context, selecting the primary active OSC material, the device dimension, and the doping level is the critical design parameters for the OFETs 23 .…”

“…In addition, the previous investigation recorded a very acceptable and controllable on/off current ratio and subthreshold swing (SS). [19][20][21][22] In such a context, selecting the primary active OSC material, the device dimension, and the doping level is the critical design parameters for the OFETs. 23 Moreover, the OFET architecture, based on the gate and the contact arrangement, can influence the overall device I-V transfer characteristics.…”

“…Also, it might vary from one architecture to another and shows dependence on the channel length scale 23 . Specifically, nano‐scale channel length reported different behavior when compared with micro‐scale devices 19 . Various attempts have been conducted in such a context to seek an optimum OFET design for specific design constraints 25,26 .…”

“…23 Specifically, nano-scale channel length reported different behavior when compared with micro-scale devices. 19 Various attempts have been conducted in such a context to seek an optimum OFET design for specific design constraints. 25,26 These constraints can be in threshold voltage, targeting ultra-low power consumption, or the on/off current ratio to eliminate the sub-threshold power dissipation.…”