Inductive and Capacitive Hysteresis of Current-Voltage Curves: Unified Structural Dynamics in Solar Energy Devices, Memristors, Ionic Transistors, and Bioelectronics

Abstract

Hysteresis observed in the current-voltage curves of both electronic and ionic devices is a phenomenon where the curve's shape is altered on the basis of the measurement speed. This effect is driven by internal processes that introduce a time delay in the response to an external stimulus, leading to measurements being dependent on the history of the past disturbances. This hysteresis effect has posed challenges, particularly in solution-processed photovoltaic devices such as halide perovskite solar cells, where it significantly complicates the evaluation of performance quality. In other devices, such as memristors and organic electrochemical transistors for neuromorphic applications, hysteresis is an inherent aspect of their functionality, facilitating transitions between different conductivity states. Natural and artificial ionically conducting channels also exhibit pronounced hysteresis, a crucial component for generating action potentials in neurons. In this study, we aim to categorize various forms of hysteresis by identifying shared elements among diverse physical, chemical, and biological conducting systems. Our method involves examining hysteresis from multiple angles, using simplified models that capture essential response types. We analyze system behavior using techniques such as linear sweep voltammetry and impedance spectroscopy and transient currents resulting from small voltage steps. Our investigation reveals two primary hysteresis types based on how current responds to rapid sweep rates: capacitive hysteresis and inductive hysteresis. These terms correspond to the dominant component in the equivalent circuit, determining the transient time response. Remarkably, these concepts provide insights into vastly different systems, spanning solar cells, capacitors, transistors, electrofluidic nanopores, and protein ion channels. The consistency in electrical responses across the different cases enables the identification of the primary cause of hysteresis. We also elucidate the frequency dependence of hysteresis and the stepwise responses of solar cells, illustrating how fundamental relaxations contribute to the overall surplus or deficit of current during extensive voltage sweeps that define the current-voltage curve. Published by the American Physical Society 2024

Hysteresis in memristors produces conduction inductance and conduction capacitance effects

“…In the set side, the impedance shows an inductor feature, and as it has been explained in many publications, it is associated with the inverted (inductive) hysteresis. 22,35 In the negative side, the impedance spectra are purely capacitive, as also observed in the experimental data of Fig. 1.…”

“…This is the famous “negative capacitance” of solar cells, 47–50 which has been connected to inverted hysteresis 36,37,51 that here we also term inductive hysteresis. 35 In Fig. 3, the conductance and susceptance of a TiN/Ti/HfO 2 /W resistive RAM memory device are shown.…”

“…It has been possible to classify the types of hysteresis displayed by memristors. 35 In a set cycle, where the conductance changes to a high value, the I – V curve makes a counter clockwise loop. The hysteresis is inductive (or inverted), see Fig.…”

“…Furthermore, it has been shown that the small signal ac impedance characteristics reveal the type of hysteresis inherent to the dynamical properties of the model. 35 The inductive characteristic, represented by the arc in the fourth quadrant of the complex impedance plane related to the counter clockwise cycle of the current–voltage in the positive voltages, is reported in Fig. 1d .…”

Accelerating the Assessment of Hysteresis in Perovskite Solar Cells

“…As nonlinearity and memory effects play a dominant role in “hysteretical” current–voltage characteristics, we aim to determine a minimum delay time, in terms of scan rate, to carry out current–voltage measurements under steady-state conditions. Recently, hysteresis effects have been classified into two major types, capacitive and inductive, according to the dominant response of impedance spectroscopy . We use circuit theory as inspiration that describes the extraordinarily complex physical processes that turn out to be ubiquitous in halide perovskites, requiring eventual transformations of electrical elements along the voltage changes.…”