Dimensionality‐Dependent Resistive Switching in 0D and 2D Cs3Sb2I9: Energy‐Efficient Synaptic Functions with the Layered‐Phase

Abstract The authors introduce two polymorphs of Cs 3 Sb 2 I 9 for resistive switching behavior under the application of an external bias. The devices based on the dimer phase contain self‐formed metallic bridges and thereby an initial low‐resistive state, which switches to a high‐resistive one upon application of a suitable voltage. The devices based on the layered phase, in contrast, are initially in a high‐state and thereby require a voltage to switch to a low‐resistive one. Since the layered‐phase of the perovskite is environmentally stable, a closed loop pulsed switching (CLPS) measurement protocol is employed to devices with the layered‐phase to further control the make‐and‐break of the conducting bridges. Interface‐modified devices (prohibiting a contact between the two electrodes due to ion migrations) have exhibited multiple functionalities of the human brains, such as excitatory/inhibitory postsynaptic currents and spike voltage/duration/timing dependent plasticity, transition from a short term memory to a long term memory, and potentiation/depression behavior with extremely low energy consumption per synaptic event. The device characteristics have also followed the Ebbinghaus curve of forgetting and the Atkinson–Shiffrin model of memory applicable in the human brains. This study hence concludes that the layered‐phase of Cs 3 Sb 2 I 9 exhibits energy‐efficient artificial synaptic functions for next‐generation memory applications.