Transport properties of CdS nanowire embedded poly(3-hexyl thiophene) nanocomposite

Enhancement of interfacial polymer crystallinity using chromism in single inorganic nanowire-polymer nanohybrids for photovoltaic applications

Interfaces play an important role in bulk heterojunction organic/inorganic hybrid photovoltaic devices, but directly probing the interface in order to improve device characteristics is exceedingly difficult. We report on a method to form core-shell inorganic nanowire-polymer hybrids of a conducting polymer, poly(3-hexlthiophene-2,5-diyl) (P3HT), and a semiconducting nanowire, cadmium sulfide (CdS), using solution processing to create the polymer shell around the nanowire in order to study the polymer-nanowire interface directly without interference from bulk effects. We have used the rod-coil transition (chromism) in P3HT to seed and enhance the crystallinity at the polymer-nanowire interface. We have shown that creating more order within the P3HT main chain, by controlling the temperature and the solvent quality, can increase the extent of polymer crystallinity present at the polymer-nanowire interface. We believe using the rod-coil transition to create more order in P3HT and the resulting polymer-nanowire interface will provide a facile pathway for designing future organic-inorganic photovoltaic devices.

Materialization of single multicomposite nanowire: entrapment of ZnO nanoparticles in polyaniline nanowire

We present materialization of single multicomposite nanowire (SMNW)-entrapped ZnO nanoparticles (NPs) via an electrochemical growth method, which is a newly developed fabrication method to grow a single nanowire between a pair of pre-patterned electrodes. Entrapment of ZnO NPs was controlled via different conditions of SMNW fabrication such as an applied potential and mixture ratio of NPs and aniline solution. The controlled concentration of ZnO NP results in changes in the physical properties of the SMNWs, as shown in transmission electron microscopy images. Furthermore, the electrical conductivity and elasticity of SMNWs show improvement over those of pure polyaniline nanowire. The new nano-multicomposite material showed synergistic effects on mechanical and electrical properties, with logarithmical change and saturation increasing ZnO NP concentration.

Heterointerfaces in semiconductor nanowires

Semiconductor nanowires have attracted considerable recent interest due to their unique properties, including their highly anisotropic geometry, large surface-to-volume ratio, and carrier and photon confinement. Currently, tremendous efforts are devoted to the rational synthesis of advanced nanowire heterostructures. Yet, if functional devices are to be made from these materials, precise control over their composition, structure, morphology, and dopant concentration must be achieved. Their fundamental properties must also be carefully investigated since the presence of a large surface and interfacial area in nanowires can profoundly alter their performance. In this article, the progress, promise, and challenges in the area of nanowire heterostructured materials are reviewed, with particular emphasis on the effect of different types of heterointerfaces on device properties.