Silent Synapse Activation by Plasma-Induced Oxygen Vacancies in TiO2 Nanowire-Based Memristor

Emulation of biological synapses by electronic devices will form a foundation for realizing brain-inspired computational systems. In addition to mimicking functional synapses, it is also important to demonstrate activation functionality of silent synapses in memristors, to emulate the evolutionary processes of human brain development. Here, a silent synapse without synaptic plasticity is achieved in a single-crystalline TiO(2)nanowire-based memristor. Importantly, the short-term plasticity transforms to long-term plasticity in plasma (O-2, Ar, and Ar-H-2) treated devices, representing activation of a silent synapse to a functional synapse. The memristive mechanism is attributed to the accumulation and diffusion of oxygen vacancies at the Pt/TiO(2)interface, which adjusts the Schottky barrier and conductance. The use of various plasma treatments also enables synaptic function modulation by changing the density of oxygen vacancies. The results provide a feasible method for activating silent synapses and modulating synaptic learning functions in a memristor-based artificial synapse.