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

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-timingdependent 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.

A New Memristor with 2D Ti3C2Tx MXene Flakes as an Artificial Bio‐Synapse

“…These relatively stable resistance values and set and reset voltages satisfy data storage requirements. As shown in Figure S2f in the Supporting Information, under the action of low current compliance, the device displays a slow continuous change when it is turned on, so there is potential for this device to be used in bio‐synaptic applications …”

“…The memristor, which is a nonlinear resistor with a memory function, has been studied to implement artificial synapses . Memristors have remarkable data processing capabilities that are superior to those of current digital architectures, so memristors can be better simulated and calculated on a biological scale …”

Recommended Methods to Study Resistive Switching Devices

“…Some works have applied triangular or sinusoidal signals (no relaxation time) to switch RS devices, [118,119] but to the best of our knowledge this method has been only used for proof of concept switching, not for endurance tests. Normally the larger the relaxation time, the higher the endurance measured.…”

Memristors with organic‐inorganic halide perovskites

“…The modulation of the synaptic weight by stimulus can be quantitatively simulated by the RS of a memristor. Many representative synaptic characteristics have been realized with memristors, including spike‐timing‐dependent plasticity (STDP), spike‐rate‐dependent plasticity (SRDP), paired pulse facilitation (PPF), excitatory postsynaptic current (EPSC), short‐term plasticity (STP), long‐term potentiation (LTP), and long‐term depression (LTD) . The gradual tuning of resistance states of the memristor bear striking resemblances to the synaptic plasticity.…”