Effect of a blocking layer on the decrease in the leakage current in organic bistable devices.

The electrical bistabilities and the memory stabilities of organic bistable devices (OBDs) based on multi-core-shell CdSe/CdS/ZnS nanoparticles embedded in a polystyrene (PS) layer fabricated by using a spin-coating method were investigated. The current density-voltage (J-V) curves for the Al/multi-core-shell CdSe/CdS/ZnS nanoparticles embedded in PS layer/WO3/indium-tin-oxide (ITO) devices showed current bistability with a maximum ON/OFF ratio of 1 x 10(3), which was much larger than that of a device without a WO3 layer. The leakage current of the OBDs was decreased by insertion of the WO3 layer between the PS layer containing nanoparticles and the ITO electrode, resulting in a decrease in the current deviation between the experimental and the simulated currents in the low-voltage region. The effects of the WO3 blocking layer on the electrical characteristics of the OBDs were investigated, and the carrier transport mechanisms for the OBDs were described on the basis of the J-V experimental data and theoretical results.