Air‐Stable, Eco‐Friendly <scp>RRAMs</scp> Based on Lead‐Free <scp>Cs₃Bi₂Br₉</scp> Perovskite Quantum Dots for High‐Performance Information Storage

Abstract

Development of lead‐free halide perovskites that are innocuous and stable has become an attractive trend in resistive random access memory (RRAM) fields. However, their inferior memory properties compared with the lead‐based analogs hinder their commercialization. Herein, the lead‐free Cs 3 Bi 2 Br 9 perovskite quantum dot (PQD)‐based RRAMs are reported with outstanding memory performance, where Cs 3 Bi 2 Br 9 quantum dots (QDs) are synthesized via a modified ligand‐assisted recrystallization process. This is the first report of applying Cs 3 Bi 2 Br 9 QDs as the switching layer for RRAM device. The Cs 3 Bi 2 Br 9 QD device demonstrates nonvolatile resistive switching (RS) effect with large ON/OFF ratio of 10 5 , low set voltage of −0.45 V, as well as good reliability, reproducibility, and flexibility. Concurrently, the device exhibits the notable tolerance toward moisture, heat and light illumination, and long‐term stability of 200 days. More impressively, the device shows the reliable light‐modulated RS behavior, and therefrom the logic gate operations including “AND” and “OR” are implemented, foreboding its prospect in logic circuits integrated with storage and computation. Such multifunctionality of device could be derived from the unique 2D layered crystal structure, small particle size, quantum confinement effect, and photoresponse of Cs 3 Bi 2 Br 9 QDs. This work provides the strategy toward the high‐performance RRAMs based on stable and eco‐friendly perovskites for future applications.