Fabrication of bistable switching memory devices utilizing polymer-zno nanocomposites

This work reports fabrication of bistable memory switching devices employing wet-chemically synthesized ZnO nanoparticles with polymethyl methacrylate and poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] polymers. ZnO nanoparticle-embedded polymer layers were coated on conducting indium tin oxide (ITO) glasses using the spin-coating technique. Synthesized ZnO nanoparticles were characterized by scanning electron microscopy, transmission electron microscopy, x-ray diffraction, energy-dispersive x-ray, and photoluminescence studies. These ZnO particles are 20 nm to 30 nm in size with hexagonal structure. Switching and memory effects of the devices fabricated employing the ZnO nanoparticle-polymer composite films were investigated using current-voltage (I-V) characteristics. The I-V measurements of both polymer devices showed electrical bistability. The ON to OFF current ratio of the bistable device was found to be ∼10³. The observed current-time response showed good memory retention behavior of the fabricated devices. The carrier transport mechanism of the devices has been described on the basis of I-V experimental results and electronic structure.