Facile Hydrothermal Synthesis and Resistive Switching Mechanism of the α-Fe2O3 Memristor

Among the transition metal oxides, hematite (α-Fe2O3) has been widely used in the preparation of memristors because of its excellent physical and chemical properties. In this paper, α-Fe2O3 nanowire arrays with a preferred orientation along the [110] direction were prepared by a facile hydrothermal method and annealing treatment on the FTO substrate, and then α-Fe2O3 nanowire array-based Au/α-Fe2O3/FTO memristors were obtained by plating the Au electrodes on the as-prepared α-Fe2O3 nanowire arrays. The as-prepared α-Fe2O3 nanowire array-based Au/α-Fe2O3/FTO memristors have demonstrated stable nonvolatile bipolar resistive switching behaviors with a high resistive switching ratio of about two orders of magnitude, good resistance retention (up to 103 s), and ultralow set voltage (Vset = +2.63 V) and reset voltage (Vreset = −2 V). In addition, the space charge-limited conduction (SCLC) mechanism has been proposed to be in the high resistance state, and the formation and destruction of the conductive channels modulated by oxygen vacancies have been suggested to be responsible for the nonvolatile resistive switching behaviors of the Au/α-Fe2O3/FTO memristors. Our results show the potential of the Au/α-Fe2O3/FTO memristors in nonvolatile memory applications.