High-performance and humidity robust multilevel lead-free all-inorganic Cs3Cu2Br5 perovskite-based memristors

Halide perovskites have attracted surge of interest in the memristor field due to their superior electrical property and corresponding remarkable device performances. However, the issues of toxicity and unstable properties still severely restrict their potential applications. Here, the lead-free all-inorganic perovskite Cs3Cu2Br5 films are adopted as the switching layer to fabricate memristors with Al/Cs3Cu2Br5/ITO structure. The prepared Al/Cs3Cu2Br5/ITO memristors exhibit typical reproducible bipolar resistive switching (RS) behavior with striking characteristics, including ultralow operating voltages (0.45, -0.39 V), moderate high resistance state/low resistance state ratio (asymptotic to 10(2)), and remarkable retention time (> 10(4) s). In addition, the multilevel storage capability can be achieved by controlling compliance current. The RS effect, stemming from the formation/rupture of both localized conductive Br vacancy/Al atom filaments, is proposed to illustrate the memristors. More importantly, the RS behavior of Al/Cs3Cu2Br5/ITO memristors maintains robustness in harsh environments with humidity up to 80%, enabling secure hardware applicable in extreme environments. This work demonstrates the opportunity for exploring the next-generation nonvolatile memories based on lead-free all-inorganic halide perovskites in future environmental-friendly and humidity robust electronics.

Automated summary

Halide perovskites have great potential for memristor applications due to their superior electrical property, but their toxicity and unstable properties limit their use. In this study, lead-free all-inorganic perovskite Cs3Cu2Br5 films were used to fabricate memristors with Al/Cs3Cu2Br5/ITO structure. These memristors exhibit reproducible bipolar resistive switching behavior with low operating voltages, moderate resistance state ratio, and long retention time. The resistive switching effect is attributed to the formation/rupture of conductive filaments. Furthermore, the memristors maintain robustness in harsh environments with high humidity. This work provides opportunities for developing next-generation nonvolatile memories based on lead-free all-inorganic halide perovskites.