Splitting charge injection for ultrahigh on/off ratio in a floating-metal-gated planar organic ferroelectric memory

Abstract

Nonvolatile memories (NVMs) using ferroelectric materials have attracted tremendous attention as a prerequisite for a large variety of organic electronic devices. While the high on/off ratio should be taken into increasing consideration especially for high-density integrated circuits for high data accuracy that approves large computing dynamic range and improved energy efficiency. Here, we demonstrate a planar organic ferroelectric memory gated by a floating metal, on which ultrathin functional layers guarantee autonomous splitting of charge injection. One part of the injected charges goes directly into the bottom floating metal, intercoupling with the other in the semiconducting channel as modulated adaptively by switching the dipole polarization of the ferroelectric polymer. Therefore, typical electrical memory behaviors exhibiting an ultrahigh on/off ratio of 5.4 × 107 can be well achieved even in spite of the external bias direction. High-quality ultrathin semiconducting crystals allow for a high on-state current and a much-suppressed off-state current in a rather low range of 10−15 to 10−13 A. Our work thus presents a novel ferroelectric memory device, possessing highly adjustable conductances of the binary states like transistors and simple operations as two-terminal devices, yet yielding a record-high on/off ratio among organic ferroelectric memories.