To Be or Not to Be – Review of Electrical Bistability Mechanisms in Polymer Memory Devices

Abstract

Organic memory devices are a rapidly evolving field with much improvement in device performance, fabrication, and application. But the reports have been disparate in terms of the material behavior and the switching mechanisms in the devices. And, despite the advantages, the lack of agreement in regards to the switching behavior of the memory devices is the biggest challenge that the field must overcome to mature as a commercial competitor. This lack of consensus has been the motivation of this work wherein various works are compiled together to understand influencing factors in the memory devices. Different works are compared together to discover some clues about the nature of the switching occurring in the devices, along with some missing links that would require further investigation. The charge storage mechanism is critically analyzed alongside the various resistive switching mechanisms such as filamentary conduction, redox‐based switching, metal oxide switching, and other proposed mechanisms. The factors that affect the switching process are also analyzed including the effect of nanoparticles, the effect of the choice of polymer, or even the effect of electrodes on the switching behavior and the performance parameters of the memory device.

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

“…With the increasing demand on ultrahigh-density data-storage (UHDDS) systems in advanced information processors and flexible electronics, the prospect of adopting organic materials as memory medium in UHDDS semiconductors has aroused more attention. − Organic materials afford attractive merits of low cost, easy processing, excellent miniaturization potential, and few environmental footprints as compared to inorganic electronics. − In addition, organic memory materials hold promise to realize UHDDS since their structures can be tuned at the molecular level to induce multiple resistive switching characteristics. Attributed to their structural adjustability and scalability, not surprisingly, organic molecules have been demonstrated as promising materials for high-performance semiconductors such as organic photovoltaics, , organic field-effect transistors, , organic light-emitting diodes, , and organic batteries. , Their application in organic resistive random-access memory (ReRAM) is currently also under progress.…”

“…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 .…”

High On/Off Ratio Organic Resistive Switching Memory Based on Carbazolyl Dicyanobenzene and a Polymer Composite

“…In particular, organic resistive switching memory (ORSM) based on organic materials possesses unique merits, such as compatibility with large-area solution processing, mechanical flexibility, possibility of multilevel storage, and easy modulation by molecular design and synthesis strategy. − It has been reported that single-component organic molecule, , multicomponent organic molecules, , and organic–inorganic hybrid materials , present resistive switching effect through charge transfer, trapping, conformation change, redox reaction, and filamentary conduction. Particularly, the multicomponent organic molecules consisting of small molecule and polymer has been used as the active layer of high-performance ORSM, whose crystallization and phase separation can be restrain .…”

Improved Performance of NbOx Resistive Switching Memory by In-Situ N Doping

“…Resistive random access memory (RRAM) is highly popular, owing to its high write and erase speeds, high storage density, and multi-level storage; additionally, it is considered the most potential candidate for next-generation memory [ 1 , 2 , 3 , 4 , 5 , 6 , 7 ]. Several studies have reported the excellent performance of RRAM, such as MoS 2 filament transistors with high on/off ratio (2.6 × 10 9 ), power-efficient h-BN memories, and cellulose memories with a significant on/off ratio (10 6 ) and low SET/RESET voltages (<0.5 V) [ 8 , 9 , 10 ].…”