Dual-conductivity mechanism investigation of 2D α-MoO3-based multi-level memristor

Emerging two-dimensional (2D) transition-metal oxides provide significant opportunities for the development of memristors with high density and low power consumption. 2D α-MoO3 is one of the most promising candidates used in memristors as a functional layer. However, previous studies have not sufficiently investigated the conducting mechanism of memristors based on α-MoO3. In this work, we fabricated a cross-point structured memristor based on α-MoO3 with different electrodes, optimized its performance, and investigated its conducting mechanism in detail. By the introduction of a hybrid electrode structure with an Ag/Ti stack, multi-level non-volatile storage properties were realized. Based on the results of current-voltage curve fitting and temperature characterization combined with high-resolution transmission electron microscopy microscopic characterization, a dual-conductivity mechanism was proposed. During the resistive switching process, the migration of both cations and anions contributed to conductivity modulation, and two types of conducting filaments composed of Ag and oxygen vacancies were simultaneously formed. The device exhibited good electrical characteristics, including >103 endurance, high Off-state resistance to ON-state resistance ratio (104), multi-level memristive modes, and fast response (10 µs). The present work validates the application potential of 2D α-MoO3 nanosheets in high-density storage.