Memristive devices based on Cu-doped NbO films with large self-rectifying ratio

To address the problem of sneak currents in large-scale crossbar arrays without extra access devices like transistors or selectors, memristive devices with self-rectifying characteristics are highly desired. Herein, memristive devices of Pt/Cu-NbOx/TiN with a large rectification ratio (~1.43 × 105 at ±2 V) are realized in Cu-doped NbOx thin films. The large rectification ratio is due to the large Schottky barrier height at the Pt/Cu-doped NbOx interface, which is closely related to the changes of the band structure through Cu doping. More importantly, the devices can facilitate the fabrication of memristive crossbar arrays whose scale can reach maximal 486 × 486 (~230 kbits) with 10% read margin. This work clearly proves the feasibility of the self-rectifying memristive devices for bio-inspired computing.