Carrier transport mechanisms of organic bistable devices fabricated utilizing colloidal ZnO quantum dot-polymethylmethacrylate polymer nanocomposites

Organic bistable devices (OBDs) fabricated utilizing ZnO quantum dots (QDs) embedded in a poly(methyl methacrylate) (PMMA) layer were fabricated by using a spin-coating technique. Transmission electron microscopy images revealed that 5-nm-diameter ZnO QDs were formed inside the PMMA polymer layer. Current-voltage (I-V) measurements on Al/ZnO QDs embedded in PMMA layer/indium-tin-oxide devices at 300 K showed electrical bistability. The maximum ON/OFF ratio of the current bistability for the OBDs was as large as 4×104. Carrier transport mechanisms for the OBDs are described by using several models to fit the experimental I-V data.