Metal Filament Growth in Electrically Conductive Polymers for Nonvolatile Memory Application

Abstract

Solution processable polymers that can reproducibly form metal filament by applying voltage are investigated for nonvolatile memory application. Up to present, the understanding of materials enabling to make the metal filament has not been well-documented and the vacuum deposition methods were dominantly used in device fabrication. After screening various polymers, we found that only the polymers having two functionalities, the presence of strongly coordinating heteroatom (S or N) with metal ions and the electrical conductivity, showed the reproducible filament formation behavior. Among the polymers screened, the regiorandom poly(3-hexylthiophene) showed the best switching endurance over 30,000 write-read-erase-read cycles without any switching failure.

Switching and memory characteristics of thin films of an ambipolar organic compound: effects of device processing and electrode materials

“…The data reveal the important influences of both metallic electrodes on the operation of metal/organic thin film/metal structures. First, in all the devices studied, when switching and NDR effects are seen, these phenomena are observed together; this contrasts to some reports in the literature where switching (from a low conductivity state to a state of higher conductivity) is observed without NDR [26][27][28].…”

Electrical memory devices based on inorganic/organic nanocomposites

“…As in copper-ion memories, [73][74][75] mobile metallic ions from the electrodes or the nanoparticles can migrate to form a conductive filament between the two electrodes when a high enough voltage is applied to the device. It has been observed using a current-sensing atomic force microscope [76][77][78][79] and an infrared microscope 80 that only the switching occurred in localized areas of the devices.…”

Reproducible resistive switching in nonvolatile organic memories

“…9,10 We note that the yield of working devices is often low and that the forming and switching bias voltages are irreproducible. 11 To improve the reliability, we have deliberately added an Al 2 O 3 layer with controlled thickness. We show that reproducible memories can then be obtained not only for nominal electron only ͑e-only͒, but also for nominal hole only ͑h-only͒, and nominal bipolar diodes.…”