Memristor with Ag‐Cluster‐Doped TiO₂ Films as Artificial Synapse for Neuroinspired Computing

TLDR

Memristors, inspired by biological synapses, are considered essential for overcoming the von Neumann bottleneck, yet conventional devices struggle to continuously adjust conduction to faithfully emulate synaptic function. This study aims to enhance memristor performance by employing TiO₂ films with self‑assembled Ag nanoclusters introduced via a gradient Ag dopant. Fast learning and computing are achieved by applying pulse trains of hundreds of nanoseconds in width. The Ag‑cluster‑doped TiO₂ memristors exhibit gradual potentiation and depression under bipolar pulse trains, fully emulate excitation and inhibition, and support key synaptic plasticity phenomena such as short‑term to long‑term memory transitions, long‑term potentiation/depression, spike‑timing‑dependent plasticity, and paired‑pulse facilitation, with TEM revealing Ag filament formation that underpins this biosynaptic behavior.

Abstract

Abstract Memristor, based on the principle of biological synapse, is recognized as one of the key devices in confronting the bottleneck of classical von Neumann computers. However, conventional memristors are difficult to continuously adjust the conduction and dutifully mimic the biosynapse function. Here, TiO 2 films with self‐assembled Ag nanoclusters implemented by gradient Ag dopant are employed to achieve enhanced memristor performance. The memristors exhibit gradual both potentiating and depressing conduction under positive and negative pulse trains, which can fully emulate excitation and inhibition of biosynapse. Moreover, comprehensive biosynaptic functions and plasticity, including the transition from short‐term memory to long‐term memory, long‐term potentiation and depression, spike‐timing‐dependent plasticity, and paired‐pulse facilitation, are implemented with the fabricated memristors in this work. The applied pulses with a width of hundreds of nanoseconds timescale are beneficial to realize fast learning and computing. High‐resolution transmission electron microscopy observations clearly demonstrate that Ag clusters redistribute to form Ag conductive filaments between Ag and Pt electrode under electrical field at ON‐state device. The experimental data confirm that the oxides doped with Ag clusters have the potential for mimicking biosynaptic behavior, which is essential for the further creation of artificial neural systems.