Transition metal oxide-based heterostructure memristors for nonvolatile ternary resistive switching realization

Abstract

Memristors are promising candidates for next-generation data storage due to their exceptional resistive switching (RS) capabilities, characterized by ultra-fast response times, low power consumption, and outstanding stability. However, current memristor technology achieves a storage capacity of only one bit per cell, which severely restricts the storage density of individual devices. Herein, we demonstrate Y2O3/TiO2 heterostructure-based memristors capable of binary and ternary data storage, with tunable functionality achieved by modulating electrical stress conditions. Under low-electrical stress conditions (−1.50 V/1.50 V), the Y2O3/TiO2 heterostructure memristor exhibits reliable binary RS behavior, featuring low cycle-to-cycle variability, narrow switching voltage distributions, and robust retention (>104 s). In contrast, ternary RS operation is activated under high-electrical stress conditions (+2.0 V/−2.5 V), achieving an enhanced resistance ratio (>102) with distinct intermediate and high-resistance states. Furthermore, the mechanisms and physical models for switching performance under different electrical stresses are thoroughly elucidated. This work introduces a heterostructure strategy to enhance memristor storage capacity, offering a competitive pathway for developing high-density logic hardware systems with advanced memory capabilities.