Temperature-modulated switching behaviors of diffusive memristor for biorealistic emulation of synaptic plasticity

Abstract

Temperature is known as an important factor in biological synaptic transmission. In this study, temperature-modulated switching behaviors are reported in an amorphous carbon (a-C) diffusive memristor device to emulate biorealistic synaptic plasticity. The devices exhibit memory switching and threshold switching behaviors depending on the compliance current and ambient temperature. As confirmed by conducting atomic force microscopy, the thermal effect can promote the electrochemical formation of a stable metallic conductive filament. A series of timing-controlled pulse experiments are carried out to study the temperature effect on the switching characteristics, and the device shows second-order memristive behaviors. Frequency-dependent synaptic plasticity and timing-controlled spike-time-dependent plasticity are demonstrated in the device, which are analogous to the synaptic strength in a biological synapse at elevated temperatures. As a proof of concept, the forgetting behavior of numerical images learned at different temperatures and different pulse durations is conceptually emulated with synaptic device arrays. It is expected the present device with second order memristive behaviors provides alternatives for biorealistic synaptic applications.