A DC Compact Model of an Organic Electrochemical Transistor Based on a Semiconductor Physics and Thermodynamic Approach

Identifier:  imarina:9465589

Handle: https://hdl.handle.net/20.500.11797/imarina9465589

Authors:  Teka ET; Yoon Y; Teuerle L; Meier T; Kleemann H; Darbandy G; Iniguez B

Abstract:
Recent progress in printable electronics and biointerfaces has driven a growing interest in organic electronics for biosensor and neuromorphic applications, offering a valuable complement to traditional silicon technologies. Among organic electronics, organic electrochemical transistors (OECTs) have garnered significant attention for their high transconductance, biocompatibility, and dual ionic-electronic charge transport capabilities. While OECTs show strong promise, their variability due to fabrication and material inconsistencies, limited insight into charge transport, and absence of standard models hinder their integration. A robust, physics-based compact model can bridge these gaps and facilitate broader adoption of this device technology. This work presents a physics-based DC compact model for OECTs, integrating electrochemical interactions using the Nernst equation in the above threshold regime with drain bias-dependent diffusive charge transport in the subthreshold regime, unified by a hyperbolic tangent transition. It integrates the threshold voltage roll-off effect and the drain voltage-dependence of the hole mobility using the Poole-Frenkel mobility model. The model is validated against experimental data from four distinct geometries of p-type poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT: PSS) OECTs, which show excellent agreement with the measurements. The model reliably captures DC characteristics, making it suitable for incorporation into circuit simulation tools to support broader application development.