Digital and analog resistive switching in NiO-based memristor by electrode engineering

Abstract

An electroforming-free bipolar resistive switching (RS) is demonstrated in NiO-based memristors with different RS types, digital and analog. Au/NiO/Pt devices show the digital RS with low operating voltages (0.6/−0.7 V), large ON/OFF ratio (102), longer retention (103 s), and hence, are suitable for low power memory applications. On the other hand, Au/NiO/ITO devices exhibit analog RS with a lower operating current (∼μA), longer endurance (>102 cycles), and retention (103 s). Notably, one of the synaptic features, conductance modulation, is demonstrated in Au/NiO/ITO devices. The crystalline phases, microstructure, and defect density of sputtered NiO films depend on the nature of the bottom electrode, and thereby, the switching behavior can be tuned by electrode engineering. Unequivocally, the fabricated NiO-based memristors with multifunctional capability are found to be promising and pave the way for a new paradigm of fusion between information technology and bio-inspired computing.