A Mobility Model Considering Temperature and Contact Resistance in Organic Thin-Film Transistors

Na Li,Junkai Huang,Wanling Deng,Weijing Wu,Zhi Luo

doi:10.1109/jeds.2020.2974031

Abstract

Based on the device physics, a mobility model for organic thin-film transistors (OTFTs) is presented considering temperature and contact resistance. As a function of the surface potential, the mobility model including hopping mechanism is able to explain the dependence of temperature and gate bias. The contact resistance is also considered in order to extract the correct mobility. Furthermore, with the assumption that the trapped carrier concentration dominates Poisson’s equation, and combining the mobility model, a DC compact model accounting for contact resistance and temperature is proposed suitable for the temperature scaling from 83 to 295K. Through the extensive comparisons between the model results and the numerical iteration or experimental data, the validity of the mobility and current models is strongly supported.

Highlights

Organic thin-film transistors (OTFTs) have received a great intention due to their applications in largearea devices, large-scale complementary integrated circuits, driving circuits for flat panel displays, memory components for transaction cards, smart cards, identification cards and various gas sensors [1]–[3]
Kim et al [11] reported a high mobility organic thin-film transistors (OTFTs), and they found that the carrier transport mechanism varied from variable range hopping (VRH) or Gaussian disorder-based model (GDM) to multiple trap and release (MTR), depending on the operating temperature
We present a compact mobility model as a function of temperature for OTFTs

Summary

INTRODUCTION

Organic thin-film transistors (OTFTs) have received a great intention due to their applications in largearea devices, large-scale complementary integrated circuits, driving circuits for flat panel displays, memory components for transaction cards, smart cards, identification cards and various gas sensors [1]–[3]. It is of crucial importance to understand the carrier transport properties in these organic materials for designing and synthesizing better materials and devices Over these years, several mobility models have been reported to describe the characteristics of OTFTs [5]–[12]. Maiti et al [8]–[10] summarized several carrier transport mechanisms and developed a physical-based compact mobility model as a function of surface potential. Combining the mobility and drain current models, a DC compact model considering contact resistance and temperature is proposed with temperature scaling from 83 to 295K. The calculated drain current is verified by available experimental data at different temperatures

THE HOPPING MOBILITY MODEL

SECOND STEP

THE COMPACT DC MODEL

RESULTS AND DISCUSSIONS

CONCLUSION