Flexible ultra-short channel organic ferroelectric non-volatile memory transistors

Abstract

Ferroelectric non-volatile memory devices are the most promising type of memory for future use in commercial applications. However, conventional planar organic ferroelectric memory transistors usually show poor performance in current density, operating speed and mechanical stability. There are three main factors which restrict the performance of organic ferroelectric memory transistors: the intrinsic low charge mobility of the organic semiconductor material; the large surface roughness of the ferroelectric layer; and the relative long channel length. In this research, a novel device architecture with an ultra-short channel length was invented. Benefiting from the short channel length, the memory device devised in this research exhibits a large current density of up to 6.32 mA cm⁻² and a fast operating speed. Furthermore, the current flows across the semiconductor layer from the bottom mesh source electrode to the top drain electrode, which reduced the influence of the poor interface quality caused by the use of poly(vinylidene fluoride-co-trifluoroethylene) [P(VDF–TrFe)] and enhances the performance of mechanical stability under bending. In addition, the main memory properties are comparable or superior to previously reported organic ferroelectric memories and inorganic ferroelectric memory with a vertical structure. Therefore, benefiting from the ultra-short channel length and special device structure, the ferroelectric memory in this research exhibited a large driving force, excellent bending characteristics and outstanding storage performance, which has great potential for wearable and flexible electric devices.