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Transparent conductive nanofibrous membranes have been successfully fabricated by sputter-coating a metal (Au, Pd, Pt, Ni, Ag, or Au/Pd alloy) onto a water-soluble-polymer nanofibrous template, followed by the dissolution of the template in a water bath. The size of the conductive nanofibers can be facilely controlled by adjusting the diameter of the polymer nanofibers as well as the sputter-coating time. The as-prepared samples were characterized by SEM, TEM, FTIR, and TGA, and the results reveal that the as-prepared conductive nanofibers consist of many metal nanoparticles held together after the dissolution of the polymer template, which is likely due to the coalescence of the metal nanoparticles as well as the bridging effect of the polymer chains between the adjoining metal nanoparticles. The transmittance of the film decreases but the conductivity of the film increases with the time of sputter-coating. The as-prepared transparent nanofibrous membrane also shows good mechanical and metallic propertie...

We combine CdSe semiconductor nanocrystals (or quantum dots) and single-crystal ZnO nanowires to demonstrate a new type of quantum-dot-sensitized solar cell. An array of ZnO nanowires was grown vertically from a fluorine-doped tin oxide conducting substrate. CdSe quantum dots, capped with mercaptopropionic acid, were attached to the surface of the nanowires. When illuminated with visible light, the excited CdSe quantum dots injected electrons across the quantum dot-nanowire interface. The morphology of the nanowires then provided the photoinjected electrons with a direct electrical pathway to the photoanode. With a liquid electrolyte as the hole transport medium, quantum-dot-sensitized nanowire solar cells exhibited short-circuit currents ranging from 1 to 2 mA/cm2 and open-circuit voltages of 0.5-0.6 V when illuminated with 100 mW/cm2 simulated AM1.5 spectrum. Internal quantum efficiencies as high as 50-60% were also obtained.