Organic ferroelectric field-effect transistor with P(VDF-TrFE)/PMMA blend thin films for non-volatile memory applications

Abstract

Among the many ferroelectrics polymers, poly(vinylidene fluoride-co-trifluoroethylene) [P(VDF-TrFE)] has drawn a great attention with its promising memory properties such as large remanent polarization, good fatigue and retention properties. Since the ferroelectric layer plays a critical role in the operation of memory device, it is important to control the structure of ferroelectric thin film. In order to improve the performance of a ferroelectric device, in this contribution we employed P(VDF-TrFE) layers blended with various compositions of an amorphous poly(methyl methacrylate) (PMMA) from 0 wt.% to 20 wt.%. In metal/ferroelectric/metal capacitor structure, we observed the decrease of remanent polarization from 9.13 μC/cm 2 to 4.7 μC/cm 2 and increase of coercive voltage from 9.5 V to 15.2 V with PMMA. Polarization switching time of the ferroelectric blend films estimated from the switched polarization vs. time curves increases with the amount of PMMA. Furthermore, ferroelectric field-effect transistors (FeFETs) based on ferroelectric P(VDF-TrFE) and PMMA blend films with single-crystalline tri-isopropylsilylethynyl pentacene (TIPS-PEN) channels show that both ON and OFF currents of the transistors are maintained with the PMMA contents despite the reduction of remanent polarization of P(VDF-TrFE)/PMMA films.