Solvent-Dependent Electrical Characteristics and Mechanical Stability of Flexible Organic Ferroelectric Field-Effect Transistors.

Do-Kyung Kim,Hyeonju Lee,Jin-Hyuk Bae,Jaehoon Park,Xue Zhang

doi:10.3390/mi10110727

Abstract

Flexible organic ferroelectric field-effect transistors (Fe-FETs) have attracted attention for next-generation memory applications. A fundamental understanding of the electrical properties and mechanical stability of transistors is a prerequisite to realizing practical flexible electronics. Here, we demonstrate the solvent-dependent electrical characteristics and mechanical stability of flexible Fe-FETs. Poly(vinylidene fluoride-trifluoro-ethylene) (P(VDF-TrFE)) based Fe-FETs were fabricated by using dimethylformamide (DMF) and methyl ethyl ketone (MEK) solvents on a polyimide substrate. P(VDF-TrFE) from DMF formed a smoother surface than a surface from MEK; the surface property greatly affected the electrical properties and mechanical stability of the devices. Larger hysteresis and higher mobility were obtained from Fe-FET using DMF compared to those characteristics from using MEK. Furthermore, Fe-FET using DMF showed lower degradation of on-current and mobility under repetitive mechanical stress than an MEK-based Fe-FET, due to its excellent semiconductor-insulator interface. These results will guide appropriate solvent selection and contribute to the improvement of flexible Fe-FET electrical properties and mechanical stability in the next generation of memory devices.

Highlights

Nonvolatile memory functions that can be programmed, read out, and erased electrically are required in almost all electronic devices [1]
Organic field-effect transistors (Fe-FETs) fabricated on a flexible substrate still incur critical problems in electrical performance, even though useful performance from these Fe-FETs has been achieved when fabricated on a rigid substrate like glass or silicon
A deep understanding of the electrical characteristics and mechanical stability of flexible Fe-FETs are required for their utilization in flexible electronic applications

Summary

Introduction

Nonvolatile memory functions that can be programmed, read out, and erased electrically are required in almost all electronic devices [1]. It is still required to clarify how the boiling point of solvents for ferroelectric insulators affects the performance of Fe-FETs. This is important because boiling point and chemical properties of solvents inevitably dictate the morphological properties, such as grain size and surface roughness, of solution-processed ferroelectric films [17,18,19,20,21].

Results

Conclusion