Scalable Layer‐Controlled Oxidation of Bi ₂ O ₂ Se 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 Bi ₂ O ₂ Se single‐crystalline film and achieves layer‐controlled oxidation by developing large‐scale UV‐assisted intercalative oxidation, resulting β‐Bi ₂ SeO ₅ /Bi ₂ O ₂ Se heterostructures. The resulting β‐Bi ₂ SeO ₅ /Bi ₂ O ₂ Se memristor demonstrates remarkable self‐rectifying resistive switching performance (over 10 ⁵ 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‐Bi ₂ SeO ₅ /Bi ₂ O ₂ Se 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‐Bi ₂ SeO ₅ thickness modulation and theoretical ab initio calculations.