High performance flexible memristors based on a lead free AgBiI4 perovskite with an ultralow operating voltage

Abstract

Organic–inorganic halide perovskite materials exhibit excellent memristive properties, such as high ON/OFF ratio and low switching voltage. However, the toxicity of lead and poor stability strictly limit their further commercial applications. Herein, a high-quality nontoxic and stable AgBiI₄ perovskite film is successfully synthesized via a low-temperature dynamic hot casting method, and resistive switching (RS) memory devices based on AgBiI₄ are reported for the first time. The RS memory devices with the ITO substrate exhibit typical bipolar nonvolatile memory behaviors with an ultralow operating voltage (≈0.16 V), high ON/OFF ratio (≈10⁴), reversible RS by pulse voltage operation (>700) and long data retention (>10⁴ s), superior to those of most of the other perovskite-based memory devices. Furthermore, a high performance flexible nonvolatile resistive switching (RS) memory device based on a AgBiI₄ perovskite with a PEN substrate is fabricated. The flexible device also displays good stability under repeated bending tests (>1000 cycles). By analyzing the current–voltage responses, and the transmission electron microscopy, energy dispersive spectroscopy and X-ray photoelectron spectroscopy results, we propose a mechanism involving conducting filaments formed by Ag cations to describe the RS behavior of the Ag/PMMA/AgBiI₄/ITO device. Our work demonstrates that AgBiI₄ is promising for nonvolatile memory devices and paves the way for realizing low-power consumption flexible nonvolatile memory devices.