Mechanistic and Kinetic Analysis of Perovskite Memristors with Buffer Layers: The Case of a Two-Step Set Process

With
the increasing demand for artificially intelligent
hardware
systems for brain-inspired in-memory and neuromorphic computing, understanding
the underlying mechanisms in the resistive switching of memristor
devices is of paramount importance. Here, we demonstrate a two-step
resistive switching set process involving a complex interplay among
mobile halide ions/vacancies (I–/VI+) and silver ions (Ag+) in perovskite-based memristors
with thin undoped buffer layers. The resistive switching involves
an initial gradual increase in current associated with a drift-related
halide migration within the perovskite bulk layer followed by an abrupt
resistive switching associated with diffusion of mobile Ag+ conductive filamentary formation. Furthermore, we develop a dynamical
model that explains the characteristic I–V curve that helps to untangle and quantify the switching
regimes consistent with the experimental memristive response. This
further insight into the two-step set process provides another degree
of freedom in device design for versatile applications with varying
levels of complexity.