Operating mechanisms of organic bistable devices containing ZnO nanoparticles embedded in a poly-4-vinyl-phenol layer.

Scanning electron microscopy images showed that self-assembled ZnO nanoparticles were created inside a poly-4-vinyl-phenol (PVP) layer. Current-voltage (I-V) measurements on the Al/ZnO nanoparticles embedded in a PVP layer/indium tin oxide (ITO)/glass device fabricated by using a simple spin coating method at 300 K showed an electrical hysteresis behavior, indicative of an essential feature for a bistable device. The data fitting results of the I-V curves showed that the carrier transport mechanisms at low and high voltages were attributed to the space charge limited current and the Fowler-Nordheim tunneling processes, respectively. Possible operating mechanisms for the memory effects in the Al/ZnO nanoparticles embedded in a PVP layer/ITO devices are described on the basis of the I-V results.