Study On Electrically Bistable Characteristics Based On Polymer/Inorganic Nanocrystal Composite Films

Organic electrically bistable memory devices are promising branch in organic electronics due to its advantages such as simple technology, flexible, low-cost, large capacity data storage and so on. It’s possible to be the one of the new memory device which will replace the inorganic semiconductor memory. In recent years, the electrically bistable memory devices based on the polymer/inorganic nanoparticles composite film have attracted the interests of international researchers with the rapid develop of inorganic nanotechnology. In this thesis, two different kinds of inorganic nanoparticles were prepared by chemical method. Electrically bistable devices have been fabricated using single or bilayer structure by a simple spin-coating method. We studied the electrically bistable performance and the principles of the devices. The main contents are listed as follows:(1) The ZnS nanoparticles capped by dodecanethiol were prepared using a one-pot reaction method, in which deodecanethiol was used as sulfide sources and capping ligands. X-ray diffraction and transmission electron microscopy measurements have been used to characterize the crystal structure and morphology of the as-obtained samples. Electrically bistable devices with a structure of ITO/PEDOT:PSS/PVK:ZnS/Al were fabricated based on blends of ZnS nanoparticles and a semiconducting polymer poly (N-vinylcarbazole)(PVK) by using a simple spin-coating method. Current-voltage characteristics were employed to study the electrical bistability properties of the device by varying the mass ratios of Cu2S nanoparticles to polymer. The current-voltage characteristics of the pure PVK devices and the devices which were treated by UV03were tested to study the function of the n-dodecanethiol layer. And the electrical transition from a low conducting state to a high conducting state was discussed.(2) The ZnO nanoparticles were synthesized by a one-pot water bath heating reaction. X-ray diffraction have been used to characterize the crystal structure of the as-obtained samples. We fabricated devices with a structure of ITO/ZnO:PEO/PMMA/Al. Current-voltage measurement were performed to study the electrical properties of the devices by varying the mass ratios of ZnO to PEO. We also tested the atomic force microscope images of the ZnO:PEO film to study the impact of PKO. We compared the devices of ITO/ZnO:PEO/Al, ITO/PMMA/Al and ITO/ZnO:PEO/PMMA/Al to study the working principles of the devices. At last, we tested the stability of the devices under different voltage level.