Highly Efficient Photo‐Induced Recovery Conferred Using Charge‐Transfer Supramolecular Electrets in Bistable Photonic Transistor Memory

Abstract

Donor–acceptor type polymers and supramolecules are promising electrets in photonic field‐effect transistor (FET)‐type memory because of their diversified polymer‐structure design and favorable mechanical tolerance. Using intermolecular association, supramolecule electrets can surpass donor–acceptor type polymers with versatile facile combining processes. Currently, there has been no application of charge‐transfer (CT) supramolecules in electrets of photonic FET memory devices. Herein, a novel series of CT‐based supramolecular electrets comprising poly(1‐pyrenemethyl methacrylate) (PPyMA) and 7,7,8,8‐tetracyanoquinodimethane (TCNQ) is used to elucidate the effect of CT on photonic FET memory. Accordingly, memory devices based on the supramolecular electret with an equimolar content of pyrene and TCNQ exhibit superior bistable memory switchability using electrical/photoprograming with UV (365 nm) and green light (525 nm). This shows a broad memory window of 34 V and favorable memory ratio of over 106 after 104 s. The memory performance can be attributed to the favorable molecular association and dispersion between pyrene and TCNQ in the solid state. The results provide evidence that CT‐based supramolecular electrets warrant applications in optoelectronic applications.

A brief review on device operations and working mechanisms of organic transistor photomemories

“…In brief, in this section, we will discuss some photonic memories employing various photoresponsive charge storage materials such as inorganic perovskite/insulated polymer blending based floating gates, 7,24,40–42 strong intramolecular donor–acceptor (D–A) and aggregation-induced-emission (AIE) conjugated polymer electrets, 13,14,32 and supramolecular based polymer electrets. 43–45 In the case of other photoactive charge storage material developments (such as rod-coil or rod-like liquid crystals, hybrid metal/metal-oxide nanoparticles/thin-films, metal–organic frameworks, photochromic blends/monolayers, biomass-derived electrets, and small-molecules based), and other unique morphologies/topologies of charge trapping interfaces, as well as device structures that are not covered in this section, could be found in the recently published reports and reviews. 22,23,46–58 Below, the device structures and its memory characteristics to the device operations will be elaborated in detail.…”

“…74–76 However, just recently, the incorporation of photoactive supramolecular electret into the memory device has been reported and it showed superior bistable memory switchability with instantaneous photo-recovery capability under UV (365 nm) and green light (525 nm). 43 In this report, Yang et al have intensively investigated the photoactive supramolecular electret that constitutes of poly(1-pyrenemethyl methacrylate) (PPyMA) host polymer and 7,7,8,8-tetracyanoquinodimethane (TCNQ) guest molecule. Fig.…”

Improving the Photoresponse of Transistor Memory Using Self-Assembled Nanostructured Block Copolymers as a Photoactive Electret

“…We have previously proposed a novel series of charge transfer (CT)based supramolecular electrets comprising poly(1-pyrenemethyl methacrylate) (PPyMA) and 7,7,8,8-tetracyanoquinodimethane (TCNQ) on a high-performance phototransistor memory through a facile process. 35 For the devices based on a pure electret of PPyMA, the similar energy levels between arenes (pyrene and pentacene channel) induce the tendency of hole trapping, which exhibited a photorecovery behavior. In addition, the optimized CT interaction between pyrene and TCNQ endows the materials with favorable molecular association, photoelectrical properties, and charge ordering, conducing to the better retention capability and bistable switching phenomenon.…”

Enhancing the Memory-Stretchability Property of π-Conjugated Polymers Using Pendant Arene Side Chains in Nonvolatile Transistor Memory

“…In the past two decades, semiconducting polymers served as an active material in the optoelectronic devices have received extensive investigations for electronic applications such as field-effect transistors (FETs), − organic photovoltaic cells, − light-emitting diodes, − and memory devices − owing to their good flexibility, solution processability, and tunable electronic properties. To achieve wearable electronic devices, more efforts have been dedicated to improving the mechanical deformability of semiconducting polymers while maintaining their mobility to realize high-performance wearable electronics. − Among them, FET memory devices are currently regarded as potential candidates in the stretchable data-storage element because of their compatibility with integrated circuits and the increasing demand in high-density information-storage devices. − The device configuration of the conventional FET memory required an additional distinct charge-storage layer into FET devices, and different strategies have been approached such as ferroelectric materials, , polymer electrets, , and floating gate dielectrics. , However, these multilayer structures unavoidably complicate the fabrication process. Therefore, developing a single semiconductor layer with both characteristics of carrier transport and charge storage in FET memory devices is one of the most promising ways to reduce the process complexity and commercialize the organic memory device.…”

“…17−23 Among them, FET memory devices are currently regarded as potential candidates in the stretchable data-storage element because of their compatibility with integrated circuits and the increasing demand in high-density information-storage devices. 24−28 The device configuration of the conventional FET memory required an additional distinct charge-storage layer into FET devices, and different strategies have been approached such as ferroelectric materials, 29,30 polymer electrets, 31,32 and floating gate dielectrics. 33,34 However, these multilayer structures unavoidably complicate the fabrication process.…”