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

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.