Organic bistable memory based on Au nanoparticle/ZnO nanorods composite embedded in poly (vinylpyrrolidone) layer

Organic non-volatile memory devices were fabricated by embedding Au nanoparticle (NP)/ZnO nanorods (NRs) composite in an insulating poly (vinylpyrrolidone) as the active layer. The complete active materials were synthesized with an entire aqua solution process. Transmission electron microscopy images revealed that the Au NP/ZnO NRs composite exhibits an aster-like structure where Au NP is at the center while ZnO NRs are surrounding. Current-voltage (I-V) measurements of such device demonstrated electrical bistability with excellent on/off ratio of 4 × 103 under 1 V reading voltage. We attributed the high on/off ratio of the memory device to the large surface area of the Au NP/ZnO NRs composite where large amount of charges can be stored. In addition, the surrounding ZnO NRs act as spacers, which can effectively prevent the center gold nanoparticles from aggregation. Consequently, a low current leakage can be expected. Our study paved a way of employing a nanocomposite as a material for high performance organic memory devices.