Physical Model for the Current–Voltage Hysteresis and Impedance of Halide Perovskite Memristors

Abstract

An investigation of the kinetic behavior of MAPbI 3 memristors shows that the onset voltage to a high conducting state depends strongly on the voltage sweep rate, and the impedance spectra generate complex capacitive and inductive patterns. We develop a dynamic model to describe these features and obtain physical insight into the coupling of ionic and electronic properties that produce the resistive switching behavior. The model separates the memristive response into distinct diffusion and transitionstate-formation steps that describe well the experimental current− voltage curves at different scan rates and impedance spectra. The ac impedance analysis shows that the halide perovskite memristor response contains the composition of two inductive processes that provide a huge negative capacitance associated with inverted hysteresis. The results provide a new approach to understand some typical characteristics of halide perovskite devices, such as the inductive behavior and hysteresis effects, according to the time scales of internal processes.

Chemical Inductor

“…To illustrate the practical applicability of the concept of the chemical inductor, we show a specific model for a halide perovskite memristor that has been described recently. 58 It is formed by the dynamical equations The fast variable is the voltage u, and the slow variable is the current i c . The i c in equilibrium (d i c /d t = 0) rises from zero to a saturation value i c0 according to the occupation function θ(u) = [1 + e −(u−V T )/V m ] −1 that satisfies 0 ≤ θ ≤ 1, where V T is an onset voltage and V m is an ideality factor with a dimension of voltage, see the central gray line in Figure 9b.…”

“…An example is shown in Figure 9b by calculating the dynamical behavior of 22 and 23 under constraint 26. 58 The current measured at infinitely slow steps is the gray line, but fast sweeps lead to substantial differences in the forward and reverse scan currents. These hysteresis effects are very significant for the temporal behavior of electronic devices such as solar cells.…”

Inductive and Capacitive Hysteresis of Halide Perovskite Solar Cells and Memristors Under Illumination

“…The opposite is true if we apply a positive voltage at the gold contact, Figure 4B. The capacitive and inductive effects of these ions at the interfaces can be monitored by IS (Guerrero et al, 2021;Berruet et al, 2022;Taukeer Khan et al, 2022) as discussed in the latter sections.…”

“…MHP memristors emerge from solar cells, but their behavior in the current-voltage regime is very different. In solar cells, the inverted hysteresis is a property preferably minimized (Tress et al, 2016;Yang et al, 2017;Wu et al, 2018), while for memristors, it is amplified to permanent and reversible changes of the conductivity (Berruet et al, 2022). These characteristics have not been systematically studied yet, entailing significant attention.…”

Phase Separating Electrode Materials – Chemical Inductors?

“…They coined the term "chemical inductor" and provided a basic mathematical formulation, requiring interaction of fast and slow phenomena, representing a necessary condition for a system to be a chemical inductor. Two articles following, by these authors, linked previously measured possible chemical inductive behaviours to the mathematical formulation presented in [12] for halide perovskite memristors [13], FitzHugh-Nagumo neuron, the Koper-Sluyters electrocatalytic system, and potentiostatic oscillations of a semiconductor device [14].…”