Solution-Processed Polymer Thin-Film Memristors with an Electrochromic Feature and Frequency-Dependent Synaptic Plasticity

Emerging organic synaptic devices are promising in exploring soft and biocompatible neuromorphic computing systems. By means of a simple and low-cost solution process, the polymer thin-film memristors are designed and characterized. The polymer memristors have a bilayer structure composed of an ion-rich semiconducting layer and an ion-collecting conducting layer, where the ion redistribution depending on device operation history has an impact on carrier concentration and results in the memristive characteristics. A visible electrochromic feature is observed during the electrical measurements, supporting the proposed Li + ion drift/diffusion mechanism. The polymer memristors show the continuous and reversible conductivity tuning with a temporary memory effect, which enables the successful emulation of the frequency-dependent synaptic plasticity. The polymer thin-film memristors may offer a strategy for developing building blocks of organic neuromorphic circuits.