Phase-Separated, Printed Organic Thin-Film Transistor-Based Nonvolatile Memory with Enhanced Data Retention

Abstract

A nonvolatile memory thin film transistor (TFT) is an essential building block in all electronic applications for calculation and identification. In particular, organic memory TFTs using bilayered polymer electrets have attracted significant attention due to excellent mechanical flexibility and fast operating speed. However, the data retention characteristics over an extended period of time remains a major reliability issue for nonvolatile memory devices. Here, the enhancement of data retention in flexible and printed organic memory TFTs by introducing a phase-separated tunneling layer is demonstrated. The tunneling layer is formed during an active layer printing process with a blend ink of small-molecule organic semiconductor and polystyrene insulator. The effect of the dielectric tunneling layer on data retention characteristics is systematically investigated. The printed nonvolatile memory devices with the phase-separated tunneling layer exhibit significantly improved data retention time of over 10 years, validating the feasibility of applying flexible memory into wearable electronics and smart Internet-of-Things devices.