Memristor in a Reservoir System—Experimental Evidence for High-Level Computing and Neuromorphic Behavior of PbI₂

Abstract

Lead halides in an asymmetric layered structure form memristive devices which are controlled by the electronic structure of the PbX2|metal interface. In this paper, we explain the mechanism that stands behind the I–V pinched hysteresis loop of the device and shortly present its synaptic-like plasticity (spike-timing-dependent plasticity and spike-rate-dependent plasticity) and nonvolatile memory effects. This memristive element was incorporated into a reservoir system, in particular, the echo-state network with delayed feedback, which exhibits brain-like recurrent behavior and demonstrates metaplasticity as one of the available learning mechanisms. It can serve as a classification system that classifies input signals according to their amplitude.

Light‐Induced Synaptic Effects Controlled by Incorporation of Charge‐Trapping Layer into Hybrid Perovskite Memristor

“…This indicates that the device is the n‐type semiconductor Schottky‐junction type memristor. [ 10b,26 ] Interestingly, the resistive switching performance of the Au/HOIP/ITO and Au/HOIP/CN‐NPs/ITO observed under potentiodynamic conditions are the same and do not depend on illumination (Figure 2c). This indicates, that the resistive switching (observed here as an I / V hysteresis loop) does not engage the HOIP/ITO interface but should be attributed to the switching via modulation of the Schottly barrier at the Au/HOIP interface.…”

“…This conclusion is fully consistent with our previous observations in related systems. [ 10a,26 ] The device structures are presented in Figure 2d. Figure 2e,f contain spike‐timing dependent plasticity (STDP) represented with an antisymmetric Hebbian learning rule.…”

Nonlinearity in Memristors for Neuromorphic Dynamic Systems

“…[78,79] A memfractive system is mathematically modeled by fractional derivatives and fractional integrals. Such a theoretical model has recently been adopted to explain the highly asymmetric hysteresis I-V relationship in ITO/semiconductor/Cu structures including material systems such as lead iodide, [80] methylammonium iodobismuthates, [81] and tin mixed ligand complex [SnI 4 {(C 6 H 5 ) 2 SO} 2 ]. [82,83]…”

In-materioneuromimetic devices: dynamics, information processing and pattern recognition

“…Moreover, the accuracy in controlling the memristance value in analog memristors is still considered to be a big concern, however, recent studies on pulse and signal classification define the safe limits of their applicability. 89,97,101 On the contrary, most memristors are known that they are based on the filamentary-switching mechanism. In filamentary switching, memristors can have either a high resistance state (HRS) or a low resistance state (LRS) and therefore the systems based on these devices are considered error-tolerant.…”

“…Such behavior is not a unique feature in classical analog electronics: any bandpass filter (active or passive) can perform similarly. The expected advantage of reservoir memristive devices in comparison to analog filters is a very high slope of their frequency characteristics, especially if they are embedded in a single node echo state machine 89,97 as shown in Figure 10. In such systems, low-frequency signals should be amplified, whereas the signals of frequencies higher than the characteristic cut-off frequency should be slowly attenuated.…”