Modeling of Organic Metal-Insulator-Semiconductor Capacitor

TL;DR

This paper presents a physics-based model for an organic MIS capacitor that demonstrates capacitance variation with gate voltage, validated through simulation and experimental results, despite low charge concentration in the organic semiconductor.

Contribution

The paper introduces a novel physics-based model for organic MIS capacitors, validated with simulations and experiments, highlighting their capacitance behavior despite low charge levels.

Findings

Capacitance varies with gate voltage similar to traditional MIS capacitors.

Model accurately predicts charge concentration and surface potential.

Experimental results confirm the model's validity.

Abstract

In this paper, we demonstrate the principle of operation of a metal-insulator-semiconductor (MIS) capacitor based on undoped organic semiconductor. In spite of low charge concentration within the semiconductor, this device exhibits a capacitance variation with respect to applied gate voltage $V_g$, resembling the capacitance-voltage $C$-$V$ characteristics of a traditional doped semiconductor based MIS capacitor. A physics based model is developed to derive charge concentration, surface potential $\psi_s$ and the capacitance of organic MIS capacitor. The model is validated with TCAD simulation results and is further verified with experimental results obtained from fabricated organic MIS capacitor consisting of poly(4-vinylphenol) and poly(3-hexylthiophene-2,5-diyl) as insulator and semiconductor, respectively.