Carrier Transport Mechanisms of Organic Bistable Devices Fabricated Utilizing Hybrid C60/Poly(methyl methacrylate) Nanocomposites

Organic bistable devices (OBDs) based on nanocomposites consisting of C 60 embedded in the poly(methyl methacrylate) (PMMA) layer were fabricated by using a spin coating method. The current density--voltage ($J$--$V$) curves of the Al/C 60 embedded in PMMA layer/indium--tin-oxide devices exhibited an electrical bistability with a low-conductivity state, a transition state, and a high-conductivity state. The $J$--$V$ curves for OBDs containing hybrid C 60 and PMMA except a low voltage range were reasonably fitted by using the space-charge-limited current conduction model. The trapped electron densities of the OBDs were attributed to the space charge relative to the internal electric field.