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Much effort over the past decades has been focused on improving carrier mobility in organic thin-film transistors by optimizing the organization of the material or the device architecture. Here we take a different path to solving this problem, by injecting carriers into states that are hybridized to the vacuum electromagnetic field. To test this idea, organic semiconductors were strongly coupled to plasmonic modes to form coherent states that can extend over as many as 105 molecules and should thereby favour conductivity. Experiments show that indeed the current does increase by an order of magnitude at resonance in the coupled state, reflecting mostly a change in field-effect mobility. A theoretical quantum model confirms the delocalization of the wavefunctions of the hybridized states and its effect on the conductivity. Our findings illustrate the potential of engineering the vacuum electromagnetic environment to modify and to improve properties of materials. [ABSTRACT FROM AUTHOR]

The propagation of surface plasmon polaritons guided along Au metal waveguides fabricated by electron-beam lithography is experimentally investigated using simultaneous near-field excitation and detection of plasmon-polariton modes localized at the air/Au interface. The directly measured propagation characteristics of surface plasmon-polaritons agree well with simulation results obtained using full-vector calculations and the analytic dispersion of asymmetric plasmonic waveguides for thin Au films. Our results demonstrate that near-field excitation/detection schemes are well suited for direct imaging and characterization of propagating surface plasmon-fields bound to thin-film metal layers, and can be used for fast and reliable characterization of plasmonic waveguide elements and nanodevices. [ABSTRACT FROM AUTHOR]

We demonstrate that ultrastiff bonding between nanoparticles can be engineered by ad hoc assemblies of ligands, reaching strengths comparable to that of strong covalent bonds. Our observation relies on femtosecond small-angle electron diffraction.

The article reports that "The Journal of Experimental Science" hosts a series of papers from presentations given at the Nano Science and Technology Institute (NSTI) Nanotech Conference and Trade Show held in Boston, Massachusetts. The authors of the papers were invited to contribute to the Journal.

The dynamics of the ring-closure reaction of poly-1,2-bis(2-methylthien-3-yl)perfluorocyclopentene in chloroform solution is investigated. Ultrafast transient absorption spectra are measured using 260 nm pump pulses. It is shown that the optical switching occurs on a sub-200 fs timescale. The presence of a transient band around 450 nm, which disappears in ∼200 ps, is ascribed to excited-state absorption of the dithiophene moiety. [Copyright &y& Elsevier]