Memory effect of nonvolatile bistable devices based on CdSe/ZnS nanoparticles sandwiched between C60 layers

Current-voltage and conductance-voltage (G-V) measurements on three-layer Al/C-60/CdSe nanoparticles/C-60/indium tin oxide (ITO) structures fabricated by using a spin-coating method showed a nonvolatile electrical bistable behavior. Capacitance-voltage (C-V) measurements on Al/C-60/CdSe nanoparticles/C-60/ITO structures showed a clockwise hysteresis with a flatband voltage shift due to the existence of the CdSe nanoparticles, indicative of memory effects in the devices. Current-time measurements showed that the devices exhibited excellent memory retention ability at ambient conditions. Possible operating mechanisms for the memory effects in the Al/C-60/CdSe nanoparticles/C-60/ITO devices are described on the basis of the G-V and the C-V results. (C) 2007 American Institute of Physics.