Tuning of electrical conductivity and hysteresis effect in poly(methyl methacrylate)–carbon nanotube composite films

Reproducible current vs. voltage hysteresis has been observed in single-walled carbon nanotubes (SWCNTs) embedded in poly (methyl methacrylate) (PMMA) measured under various experimental conditions. We have observed a stable hysteresis loop along anticlockwise direction in positive bias region and the width of the hysteresis was reduced/quenched when the film was exposed to monochromatic light. By varying the SWCNTs content in PMMA composite thin films, the electrical conductance behavior of the Al/PMMA-SWCNTs/ITO sandwich structure can be tuned in a controlled manner. The conductivity increases with SWCNTs concentration. The hysteresis effects of the composite films have been attributed to the injection of electrons from the electrode to the trap site located in the PMMA and SWCNTs layer. Such nanocomposites are expected to be useful for various nanotechnology-based devices.