Silver Iodide Induced Resistive Switching in CsPbI₃ Perovskite‐Based Memory Device

Abstract

Lead halide perovskites‐based memory devices have attracted considerable interest due to their unique current–voltage (I–V) hysteresis. Herein, all‐inorganic CsPbI3 perovskite film surviving 30 d of air storage is prepared by using a poly‐vinylpyrrolidone‐assisted passivation method under fully open‐air condition. Afterwards, a memory device with a sandwich structure of Ag/CsPbI3/indium tin oxide is manufactured. From I–V characteristics of pristine device, a spontaneous reaction between the active Ag electrode and I− ions under air exposure is suggested. Furthermore, complete degradation of Ag electrode and formation of AgIx are verified, which also accompanies with generation of more iodine vacancies (VI) in perovskite film. The memory device with AgIx layer shows a bipolar resistive switching behavior, ultrahigh ON/OFF ratio (above 106), nonvolatile, reliable, and reproducible switching performance. Cell area and temperature dependent characteristics propose that the resistive switching is dominated by VI filament in low‐resistance state and thermally assisted hopping in high‐resistance state. This study provides a new insight to understand switching behavior from the way of electrode degradation and metal iodide formation in lead iodide perovskites‐based memory devices and also suggests a potential application for AgIx‐induced resistive switching in CsPbI3‐based memory device.

Memristor networks for real-time neural activity analysis

“…This result is consistent with the findings obtained in other perovskite-based memristors, including Ag/CH 3 NH 3 PbI 3 /Ag devices that exhibited increase/decrease in V I concentration that correspond to the increase/decrease in the device conductivity 23 , and Ag/CsPbBr 3 / Ag devices that showed increased V Br concentration after SET processes 28 . Moreover, redox reaction peaks observed during cyclic-voltammetry measurements suggest possible electrochemical reactions between the silver electrodes and the iodine ions removed from the CsPbI 3 film 23,29 ( Supplementary Fig. 2), further supporting the hypothesis that the formation of V I s leads to the memristive effect.…”

Ion Migration: A “Double‐Edged Sword” for Halide‐Perovskite‐Based Electronic Devices

“…Besides optoelectronic devices such as solar cells and LED devices, HOIP materials also show their great potential in memory devices on next‐generation computing systems. Reliable, fast response HOIP‐based memory devices have been demonstrated by different researchers . Yoo et al prepared HOIP‐based memory devices (Au/ HOIP/FTO) with small on–off voltage and remarkable RS behaviors .…”

Forming‐Free, Nonvolatile, and Flexible Resistive Random‐Access Memory Using Bismuth Iodide/van der Waals Materials Heterostructures

“…The adjustable resistance of the insulator is achieved by forming metallic or defect filaments with low resistance either by electrochemical metal dissolution or by changing the valence charge of the insulator. [ 15,16 ] Generally, the insulator used is either a transition metal oxide or perovskite oxide such as Sr 2 TiO 4 and Cr‐doped SrZrO 3 . [ 16,17 ] However, the synthesis of these materials often requires high temperatures and highly complex fabrication processes that are incompatible with flexible applications.…”

“…It functions analogously to the human synapse and offers flexible applications with a high on/off ratio, multistate‐storage capability, and low set/reset voltage. [ 13–15,20–27 ] For example, Choi et al. fabricated an organo‐lead halide perovskite RRAM with an on/off ratio of 10 6 , low set/reset voltage of 0.13 V, and four states of information storage.…”