Polyoxometalate Accelerated Cationic Migration for Reservoir Computing

Abstract

Memristor‐based reservoir computing systems represent an attractive approach in processing the time‐series information with a low training cost, in a range of fields from finance to engineering. Previous investigations have identified the charming potential of organic devices for next‐generation memory devices. However, the structural inhomogeneity and wide energy bandgap of most organic polymers usually lead to low‐yield and high operation power microelectronic devices, that permit their further application in neuromorphic computing. Herein, an organic‐inorganic hybrid memristor that can be conveniently processed into crossbar devices with tolerable yield via spin‐coating is shown. The doped inorganic polyoxometalate (POM) clusters via supramolecular assembly strategy not only act as the charge trapping modules but also assist the formation of conductive filaments due to their delocalized electrostatic adsorption property. With the dynamic short‐term memory property, the designed memristor devices can be used as a reservoir framework to process temporal information directly. A smaller reservoir with 100 memristors can be used for the recognition of emotion patterns efficiently. This strategy demonstrates the unique role of POM in developing low‐power and repeated memristors, which provides a new material platform to design advanced function memristors for neuromorphic computing.

The Old Polyoxometalates in New Application as Molecular Resistive Switching Memristors

“…[49,50] S. T. Han et al adopted the supramolecular doping strategy to prepare a POM/polymer hybrid, which has been spin-coated into a two-terminal memristor with structure of Ag/ P3HT@TDA-PW/Ag (Figure 10a). [51] This memristor exhibited bipolar resistance switching behavior with high ON/OFF ratio of 10 6 and good endurance (Figure 10b). The resistance switching mechanism was assigned to metal conductive filament (ECM), in which the electrostatic interaction between POMs anions and Ag + was key to the rapid migration of Ag + (Figure 10c).…”

Functional Materials for Memristor‐Based Reservoir Computing: Dynamics and Applications

“…Reproduced with permission. [242] Copyright 2022, Wiley-VCH. f) Schematic representation of the phase-separated morphology-controlled memory behaviors of PS m -b-PCzMA n copolymer films.…”

“…The TS type devices exhibit fast switching and self-relaxation might be more suitable for the construction of RC system. [242] An earlier case was proposed by Midya and co-workers, they explored the physical memristor implemented RC system using a diffusive memristor (Ag doped SiO x as the switching layer) as the reservoir, and a 1T1R structure as the readout layer. [51] Waveforms were used to test the short-term dynamic features of the diffusive memristor.…”

Experimental observation of the role of countercations in modulating the electrical conductance of Preyssler-type polyoxometalate nanodevices

“…12,13 Polyoxometalates (POMs) are candidates of choice owing to their remarkable reversible multi-redox states 14,15 and photo-stimulable redox properties, 16,17 and they have attracted growing interest with several recent demonstrations of proof-of-principles such as silicon-integrated POM-based memory devices 18 and unconventional (in-memory and neuromorphic) computing devices. 19–21…”

“…12,13 Polyoxometalates (POMs) are candidates of choice owing to their remarkable reversible multi-redox states 14,15 and photo-stimulable redox properties, 16,17 and they have attracted growing interest with several recent demonstrations of proof-of-principles such as silicon-integrated POM-based memory devices 18 and unconventional (in-memory and neuromorphic) computing devices. [19][20][21] In solution, it is well known that the nature of counterions has a strong impact on the redox potentials for the POMs, and hence on the electron transfer rates. 22 In the specific case of POM-based molecular junctions, the interactions with un-avoidable counterions also control many properties of POMbased materials and devices.…”