Ionic Behaviors of Perovskite Devices and Their Neuromorphic Applications

Abstract The ionic properties of perovskite materials have long been regarded as an origin of instability, with conventional perspectives asserting that such intrinsic characteristics are inevitable and severely hinder practical applications. However, recent studies reveal that ion migration is controllable and reversible, and can even be actively harnessed to enhance device performance. These observations underscore the dual nature of ion migration as a double‐edged sword: while it triggers hysteresis and phase segregation, it also serves as the physical basis for novel functionalities such as neuromorphic computing and bio‐inspired vision systems. This review systematically examines the origin of ionic defects, migration mechanisms, and their impacts on perovskite device performance, emphasizing a fundamental transition in research philosophy from passive suppression to active control of the ion migration phenomenon. Building on this framework, the design principles of novel perovskite optoelectronic devices leveraging ionic properties, along with their groundbreaking applications in image recognition, artificial retinas, and low‐power brain‐inspired memoristive and computational devices, are critically analyzed. Finally, future directions for perovskite ionic devices are proposed, offering a forward‐looking perspective to expand the research frontiers of perovskite devices, unlock their full potential, and inspire futuristic device applications.