Optoelectronic Modulation of Interfacial Defects in Lead‐Free Perovskite Films for Resistive Switching

Abstract Multifunctional nonvolatile photoelectronic memory devices with multilevel storage and logic operation are expected to perform logic‐in‐memory computing tasks and overcome the von Neumann bottleneck. Multifunctional resistive random‐access memory (RRAM) devices that are environmentally friendly, durable, and low power consuming are promising candidates for commercial applications. In this work, low‐dimensional, lead‐free perovskite Cs 3 Bi 2 Br 9 films with high weatherability are used to construct Ag/Cs 3 Bi 2 Br 9 /ITO RRAM devices with multilevel storage and logic operation functions. The devices demonstrate stable resistive switching (RS) up to 3200 cycles, an ultralow reset current (<0.4 mA), self‐compliance, and negative photoconductivity (NPC). Based on their NPC, the Cs 3 Bi 2 Br 9 RRAM devices are capable of photoelectronic multilevel storage and “OR” logic operations when programmed photoelectronic inputs are given. The interface effect based on the electron detrapping/retrapping processes of Ag/Cs 3 Bi 2 Br 9 /ITO structure is the mechanism proposed for the RS behavior. This work provides new insights regarding the RS behavior of lead‐free perovskite RRAM devices by photoelectronic modulation and highlights the potential of lead‐free perovskite RRAM devices for stable multilevel storage and logic‐in‐memory computing functions.