Organic bistable devices utilizing carbon nanotubes embedded in poly(methyl methacrylate)

The electrical and memory behavior of organic bistable memory devices in the form of metal-embedded insulator-metal (MIM) structure are described. The devices utilize layer-by-layer (LbL) deposited single walled carbon nanotubes (SWCNTs) as charge traps embedded between two polymethylmethacrylate (PMMA) insulating layers. The stack was sandwiched between two aluminium electrodes to form an Al/PMMA/SWCNTs/PMMA/Al structure. The current-voltage (I-V) characteristics of the devices exhibit electrical bistability and non-volatile memory characteristics in terms of switching between high conductive (ON) and low conductive (OFF) states. The different conductive states were programmed by application of a positive and negative voltage pulse for the ON and OFF states, respectively. A maximum ON/OFF ratio of 2 × 105 is achieved at low reading voltage of 1 V. Space-charge-limited-current (SCLC) conduction model was used to describe the carriers transport and the electrical bistability in the devices, which was attributed to the trapping and detrapping of electrons inside the SWCNTs.