Two-terminal flexible memristors based on polymer-quamtum dots nanocomposites

Abstract

Memory module is an integral part of all electronic systems. The capability to store information stably and for a long time is directly related to the performance of the electronic systems. Polymer materials will become the matrix materials of the next generation of flexible wearable electronic devices. Different from the traditional inorganic semiconductor materials led by silicon, polymers are difficult to be integrated with high complexity due to the characteristics of materials. Therefore, the memory modules of such flexible devices need to have the characteristics of simple structure, easy large-scale production and high stability. Two-terminal memristors are expected to be used as memory cells of flexible devices due to their simple structure, simple fabrication process and easy 3D integration. Because particles will diffuse from high concentration to low concentration at room temperature, the stability of double ended memristors that operated by forming conductive filaments (or ion migration) is often not so good. The two-terminal memristor with carrier trap as its operating mechanism makes up for these defects. In this article, the electrical properties of a series of two-terminal memristors based on polymer two-dimensional material quantum dot nanocomposites are explored. The device stores information by trapping carriers. First, by exploring the two-terminal organic memristors based on polyvinylpyrrolidone- tungsten disulfide quantum dots nanocomposite, we found that the storage function of the device is completely due to the existence of tungsten disulfide quantum dots. Tungsten disulfide quantum dots capture and release the carriers to achieve the "write" and "erase" behavior of devices. Then, in order to explore the thermal stability of two-terminal organic memristors, the electrical characteristics of devices based on polyimide-molybdenum disulfide quantum dot nanocomposite were investigated. The results show that the memristor has high temperature resistance when the polymer and two-dimensional materials that compose the active layer have high temperature resistance characteristics. The stretching of the flexible device will inevitably lead to the destruction of the two-terminal organic memristors. It is very important that the active layers of the memristors can be completely repaired after damage and still work normally after repair. Based on this, the electrical characteristics of devices based on poly vinyl alcohol-imidazole modified graphene nanocomposites are also investigated. The results showed that the active layer was successfully healed by hydrogen bonds, and all electrical properties were recovered after self-healing.