Impact of Scan Rate and Mobile Ion Concentration on the Anomalous J-V Curves of Metal Halide Perovskite-Based Memristors

Bias voltage scan rate and mobile ion concentration have a strong influence in J-V curves of metal halide perovskite-based memristors. In addition to hysteresis, in some cases J-V curves also show an anomalous drop in current known as negative differential resistance. This feature is usually related to electrochemical reactions between the reactive metal and <inline-formula> <tex-math notation="LaTeX">$\text{I}^{-}$ </tex-math></inline-formula> ions, and to air exposure. However, in devices with low-reactive electrodes, its origin is still under debate. In this work, we propose a theoretical model based on ionic-electronic drift-diffusion. This model sheds light into the ionic-electronic processes that shape hysteresis, and it helps to explain the appearance and evolution of a negative resistance in memristors with low-reactive contacts and capacitive hysteresis. Finally, experimental J-V curves are presented to validate the proposed model.