Electrical Charge Coupling Dominates the Hysteresis Effect of Halide Perovskite Devices

Hysteresis effects in ionic-electronic devices are a valuable resource for the development of switching memory devices that can be used in information storage and brain-like computation. Halide perovskite devices show frequent hysteresis in current???voltage curves that can be harnessed to build effective memristors. These phenomena can be often described by a set of highly nonlinear differential equations that involve current, voltage, and internal state variables, in the style of the famous Hodgkin???Huxley model that accounts for the initiation and temporal response of action potentials in biological neurons. Here we extend the neuron-style models that lead to chemical inductors by introducing a capacitive coupling in the slow relaxation variable. The extended model is able to explain naturally previous observations concerning the transition from capacitor to inductor in impedance spectroscopy of MAPbBr solar cells and memristors in the dark. The model also generates new types of oscillating systems by the generation of a truly negative capacitance distinct from the usual inductive effect.

Automated summary

Hysteresis effects in ionic-electronic devices can be used to develop switching memory devices for information storage and brain-like computation. Halide perovskite devices exhibit frequent hysteresis in current-voltage curves, which can be utilized to build effective memristors. These phenomena can be described by nonlinear differential equations involving current, voltage, and internal state variables similar to the Hodgkin-Huxley model for action potentials in neurons. Furthermore, introducing a capacitive coupling in the slow relaxation variable extends the neuron-style models to explain observations in impedance spectroscopy of MAPbBr solar cells and memristors.