Synaptic Behavior of Iodine-Enriched Copper-Based Perovskite Memristors Developed Through a Sustainable Solution Approach

Abstract

The advancement of digital technology has spurred the proliferation of data, creating a pressing need for efficient storage solutions. In this regard, memristors have emerged as promising contenders as next-generation non-volatile memory, offering superior electrical capabilities. Among memristor materials, lead halide perovskites have garnered significant interest due to their tuneable properties, facile synthesis methods, and remarkable resistive switching (RS) performance. However, concerns over environmental toxicity and stability remain. This issue has been addressed by switching to copper (Cu) based perovskites that exhibit wide bandgap semiconducting properties with zero toxicity and long-term stability. In this manuscript, a novel approach is investigated to achieve iodine-enriched Cs-Cu-I perovskite thin films for memristor applications. Through strategic functionalization of synthesis processes, superior optoelectronic properties are achieved in the thin films. This modified Cs-Cu-I based memristor (CCI device) exhibits excellent RS behavior at a low operating voltage of 0.7 V, with a long retention period of 4 x 103 s and very low power consumption of 2 x 10-9 W. The experimental realization of the synaptic behavior from the modified CCI device is demonstrated through its spike-rate-dependent plasticity (SRDP) behavior. The device response to short- and long-term pulses experimentally verifies the Atkinson and Shiffrin psychological model for training the human brain. This work not only highlights the potential of the modified CCI devices for RRAM but also paves the way for improved lead-free perovskite-based neuromorphic devices for biological applications. Memristors are promising for next-gen non-volatile memory, with lead halide perovskites leading the way. However, due to toxicity concerns, copper-based perovskites offer a safer alternative. A novel approach is adopted here to achieve iodine-rich Cs-Cu-I perovskite thin film that exhibits excellent resistive switching at low voltage and power, showing potential for lead-free, neuromorphic memory applications. image