Nonvolatile memory devices with Cu2S and Cu-Pc bilayered films

An organic bistable device with a structure Cu∕Cu2S/copperphthalocyanine (Cu-Pc)∕Pt was fabricated. Compared to the single layer organic device composed of Cu∕Cu-Pc∕Pt, the bilayer devices were observed to show distinct bistability with the resistance ratio of the off/on states up to 107 and low switch voltage (0.75–0.85V). At least 105 switching cycles were achieved in the “write-read-erase-read” cycle voltage. The filament mechanism for the device is supported by the “metallic” behavior in their temperature dependence of the resistance in the on state. Such a memory device provides a promising structure for the nonvolatile memory.