Nonvolatile Flexible Memory Based on a Planar Zigzag‐Type Nitrogen‐Doped Picene

Abstract

Recently, flexible electronics have attracted considerable interests and emerged as an important topic due to their unique superiorities. [1-3] With the advantages of lightweight, softness, foldability, and shape diversity, flexible devices hold great promise for next-generation wearable artificial intelligent electronics, such as biosensors, e-skin, and robotics. [4-12] Among these promising fields, flexible resistive memory, which utilizes bistable resistance states to encode and storebinary digital data, is considered as one of the most powerful contenders for the next-generation intelligent information storage technology. [13-26] Flexible resistive memory devices possess a simple twoterminal metal/insulator/metal (MIM) structure, which is conducive to repetitive conformal deformation. More intriguingly, they can succeed to mimic biological synaptic functions, [24-27] which satisfy the critical requirements for future neuromorphic computing systems. To date, a versatile range of functional materials have been demonstrated for flexible resistive memory applications, including inorganic materials, [28-30] organic materials, [31-33] and inorganic-organic hybrid materials. [34-36] Compared to inorganic counterparts, organic active materials appear to be more suitable for flexible functionality, given their low cost, high scalability, and inherent compatibility with flexible substrates. [1,2,25] Their optoelectronic properties can be feasibly modulated by molecular design-cumsynthesis strategy, which endows them with superior stretchable and adaptable abilities. [16,33] However, despite these charming merits, the application of soft organic materials sometimes suffers from insufficient repeatability of behaviors, [2,37] which is closely correlated with the nonuniform morphology across the resistive switching film. Therefore, from a material perspective, seeking for organic components that are inert to processing technique and hold orderly film morphologies still deserves particular research endeavors. Among the developed organic functional materials, nitrogendoped acenes have emerged as an important platform for highperformance organic electronics. [38-43] Their properties can be feasibly modulated by the number/valence/position of nitrogen atoms, which afford possibilities of achieving exceptional solidstate microstructures and optoelectronic properties. [39,43] To date, nitrogen-doped acenes have demonstrated to be promising candidates for various fields such as organic solar cells (OSCs), [42,44] organic field-effect transistors (OFETs), [43,45] and organic lightemitting diodes (OLEDs). [46,47] Nevertheless, their applications in flexible memory devices remain rarely explored. In this article, we designed a planar zigzag-structured nitrogen-doped picene (PBDN, Figure 1a,b) and explored its potential for flexible resistive memory.

Organic Memory and Memristors: From Mechanisms, Materials to Devices

“…Organic small molecules have a clear structure, easy purification, low cost, and lightweight, which have caused a widespread research boom in the field of resistive switch memory. [87,114,[154][155][156] Yang and co-workers proposed that the basic structure of the device is a five-layer structure of Al/small molecules/metal nanoclusters/thermally processed small molecules/Al. [157] The resistance switching mechanism of the device can be considered that it is difficult to inject carriers from the electrode into the small molecule layer at first, thus showing the OFF state; when the applied bias voltage is large enough, the metal nanocluster will be polarized, and the opposite charge will be in the metal nanocluster.…”

Molecular-Shape-Controlled Binary to Ternary Resistive Random-Access Memory Switching of N-Containing Heteroaromatic Semiconductors

“…A variety of organic materials including polymers, ,, small molecules, − and organic–inorganic hybrid compounds − have been used as electroactive elements in ReRAM devices. Especially, the resistances of some metal/organic/metal structured memory devices can be effectively adjustable through molecular engineering, leading to multilevel data storage. ,,− However, the probable instability of organic active compounds under high voltages often causes device degradation and/or failure during long-term operation. , Another challenge faced by organic-based ReRAM is the non-ideal resistive switching because of the inferior intrinsic conductivity of organic molecules .…”

Nonvolatile Ternary Resistive Memory Performance of a Benzothiadiazole-Based Donor–Acceptor Material on ITO-Coated Glass

“…Organic materials have attracted a great deal of attention for a wide range of applications in microelectronics, optoelectronic devices, and intelligent systems [1][2][3][4][5][6][7][8][9][10]. Intriguingly, nowadays organic materials have also found their foothold in the information storage field, which relies on their resistance switching behaviors under external stimuli (e.g., optical, electrical, and magnetic inputs) [8,[11][12][13][14][15][16][17][18][19][20]. Light weight, high flexibility and low-cost fabrication techniques with solution processing endow organic materials with outstanding merits for advanced memory electronics.…”