Mechanism for an enhanced resistive switching effect of bilayer NiOx/TiO2 for resistive random access memory

Bilayer of NiOx/TiO2 thin film spin-coated and sputtering-deposited on the fluorine doped tin oxide (FTO) substrate is employed to develop a resistive random access memory device. An enhanced resistive switching (RS) behavior, which with appropriate resistance ratio of similar to 10(3), switching cycle endurance for 10(2) and long retention time for 10(4) s, is observed in the bilayer NiOx/TiO2 based device. Construction of contact-potential barrier, formation and rupture of a localized conduction filaments and migration of oxygen vacancy existed in the interface near electrodes co-contribute to the enhanced RS memory effects, but the migration of Ag+, Ni2x+ and diffusion of oxygen vacancies are the dominated ones. This work might give an insight into the mechanism of RS memory behaviors of an oxide-stacked structure device. (C) 2017 Published by Elsevier B.V.