Nonvolatile electrical bistability and operating mechanism of memory devices based on CdSe/ZnS nanoparticle/polymer hybrid composites

Current-voltage (I-V) measurements on Al/(core/shell-type CdSe/ZnS nanoparticles embedded in polymer/indium tin oxide)/glass devices showed a nonvolatile electrical bistability behavior. Capacitance-voltage (C-V) measurements on the devices showed a counterclockwise hysteresis with a flatband voltage shift due to the existence of the CdSe/ZnS nanoparticles. The on/off ratio of the electrical bistability for memory devices with a hybrid [poly-N-vinylcarbazole (PVK) and polystyrene (PS)] matrix layer was larger than those for memory devices with a PVK or a PS layer. Possible operating mechanisms for the devices are described on the basis of the I-V and the C-V results. (C) 2008 American Institute of Physics.