Functionalized spherical carbon nanostructure/poly(vinylphenol) composites for application in low power consumption write-once-read-many times memories.

We apply functionalized carbon nanoshell and carbon sphere based composites in poly(vinylphenol) matrix in write-once-read-many-times memory elements. The devices based on carbon nanoshells show an ON/OFF current ratio of 10(5) and long-term information retention. The functionalized carbon nanoshells and carbon spheres show improved dispersion in the poly(vinylphenol) matrix, allowing the preparation of homogeneous films even at the submicrometer scale. The low ON current allows low power operation, dissipating less than 10(-4) J per square meter device active area during the write operation, which is the most energy consuming one.

Enhanced absorption in a reverse saturable absorbing dye blended with carbon nanotubes.

Using nonlinear absorption at 532 nm in the nanosecond temporal regime, we have measured the low fluence nonlinear transmittance properties of the reverse saturable absorbing carbocyanine dye, 1,1',3,3,3',3'-hexamethylindotricarbocyanine iodide (HITCI), blended with well dispersed carbon nanotubes. The nonlinear optical properties of the blends are strongly dependent on the ratio of dye to nanotubes in solution. In the case where the nanotubes per dye molecule ratio is large, we see a distinctive enhancement in optical fluence limiting properties of the system, suggesting enhanced absorption of the excited states. However, when the nanotube to dye ratio decreases, the system's response is dominated by the behavior of the dye. We suggest that this can be understood as a two component system in which sensitized dye molecules associated with the nanotubes have an effectively different optical cross-section from the dye molecules far from the nanotubes. From classical antennae considerations, this is expected.

Meso-structure formation for enhanced organic photovoltaic cells.

[reaction: see text] Formation of a controlled fullerene mesophase within an organic host system has enabled us to create high-power conversion efficiency photovoltaics. This mesophase is formed using thermal gradients that provide a fluidic mobility of the fullerenes allowing for greater dispersion of nanocrystalline 1-(3-methoxycarbonyl)propyl-1-phenyl-(6,6)C61 (PCBM) within regioregular poly(3-hexylthiophene) (P3HT). From this reorganization of the component materials in the matrix the overall efficiency of the system jumps dramatically from the roughly 2.4% to 5.2%.