Scalable Layer‐Controlled Oxidation of Bi₂O₂Se for Self‐Rectifying Memristor Arrays With sub‐pA Sneak Currents

Abstract

Smart memristors with innovative properties are crucial for the advancement of next‐generation information storage and bioinspired neuromorphic computing. However, the presence of significant sneak currents in large‐scale memristor arrays results in operational errors and heat accumulation, hindering their practical utility. This study successfully synthesizes a quasi‐free‐standing Bi2O2Se single‐crystalline film and achieves layer‐controlled oxidation by developing large‐scale UV‐assisted intercalative oxidation, resulting β‐Bi2SeO5/Bi2O2Se heterostructures. The resulting β‐Bi2SeO5/Bi2O2Se memristor demonstrates remarkable self‐rectifying resistive switching performance (over 105 for ON/OFF and rectification ratios, as well as nonlinearity) in both nanoscale (through conductive atomic force microscopy) and microscale (through memristor array) regimes. Furthermore, the potential for scalable production of self‐rectifying β‐Bi2SeO5/Bi2O2Se memristor, achieving sub‐pA sneak currents to minimize cross‐talk effects in high‐density memristor arrays is demonstrated. The memristors also exhibit ultrafast resistive switching (sub‐100 ns) and low power consumption (1.2 pJ) as characterized by pulse‐mode testing. The findings suggest a synergetic effect of interfacial Schottky barriers and oxygen vacancy migration as the self‐rectifying switching mechanism, elucidated through controllable β‐Bi2SeO5 thickness modulation and theoretical ab initio calculations.