A physics-based DC model for organic transistors incorporating contact effects

Abstract

In this article, we present a physics-based DC model for staggered organic thin film transistors (OTFTs) that incorporates the effects of physical mechanisms at both source and drain contacts. Bias-dependent carrier flows through metal–semiconductor junctions and across the overlapped region of these contacts result in effective contact voltages deviating from applied values. This phenomenon is addressed in terms of parasitic resistance and Schottky contact behavior, using a physics-based methodology to precisely calculate intrinsic drain and source contact voltages. The developed model is validated with experimental data from the literature and compared with existing models to ensure accuracy and reliability. I–V characteristics for OTFTs with various organic semiconductors demonstrate good agreement between our model and experimental measurements. Additionally, this model is utilized to estimate the transconductance and ON/OFF current ratio of each OTFT. The proposed model's ability to predict device performance with minimal fitting parameters highlights its practical utility and effectiveness in characterizing OTFT behavior across a range of organic semiconductors.