[paper] Compact Modeling of Hysteresis in OTFTs

Compact modeling of hysteresis in organic thin-film transistors

A. Romero^a, J.A. Jiménez-Tejada^a, R. Picos^b, D. Lara^a, J.B. Roldán^a, M.J. Deen^c

Organic Electronics 129 (2024) 107048

DOI : 10.1016/j.orgel.2024.107048

a Departamento de Electrónica y Tecnología de Computadores, CITIC-UGR, Uni Granada, Spain
b Department of Industrial Engineering and Construction, Universitat de les Illes Balears, Spain
c Department of Electrical and Computer Engineering, McMaster University, Canada

Abstract: In this work, we propose a model that describes the temporal evolution of the threshold voltage and trapped charge density in Thin-Film Transistors (TFTs) under dynamic conditions, paving the way for the characterization and modeling of memory transistors. The model is expressed as a first-order differential equation for the trapped charge density, which is controlled by a time constant and an independent term proportional to the drain current. The time-dependent threshold voltage is introduced in a previously developed compact model for TFTs with special consideration to the contact effects. The combination of both models and the use of an evolutionary parameter extraction procedure allow for reproducing the experimental dynamic behavior of TFTs. The results of the model and the evolutionary procedure have been validated with published experimental data of pentacene-based transistors. The procedure is able to simultaneously reproduce three kinds of experiments with different initialization routines and constraints in each of them: output and transfer characteristics with hysteresis and current transients characteristics

FIG: a.) Modeling the contact regions and intrinsic channel of an OTFT structure (a bottom contact configuration); b.)  Comparison of experimental transfer characteristics

Acknowledgements : The authors acknowledge support from the project PID2022 139586NB-44 funded by MCIN/AEI/10.13039/501100011033 and FEDER, EU. Funding for open access charge: Universidad de Granada / CBUA.

Appendix: Supplementary material related to this article can be found online.

[paper] TFT Compact Model of AMOLEDs Image‐Retention

A Novel Charge Based TFT Compact Model Applicable 

to Image‐Retention Simulation of AMOLEDs

Genshiro Kawachi 

Tianma Japan Ltd., Kanagawa, Japan

SID Symposium Digest of Technical Papers, 51(1), 1390–1393. 

P‐193: Late‐News‐Poster; First published: 25 September 2020

DOI: 10.1002/sdtp.14145

Abstract: A novel TFT compact model based on surface potential and charge calculations has been developed. Two kinds of non‐quasi‐static (NQS) models are included to describe the transient effects of TFTs. Appling the new model, accurate simulation of image retention phenomena in AMOLEDs was realized.

Fig: Transient response of a 2T1C pixel circuit (a) after switching from black to gray level: (b) simulation assuming a distributed τ_NQS model and measured results are compared.