No abstract

Nanofibers of poly[(9,9-dioctylfluorenyl-2,7-diyl)-alt-co-(1,4-benzo-{2,1',3}-thiadiazole)] (F8BT) blended in polystyrene (PS) or polyethylene oxide (PEO) show different diameters and morphology according to the conjugated polymer concentration. Electroluminescence from ribbonlike F8BT nanofibers, obtained by an annealing process of the F8BT/PEO blend, is successfully obtained by applying 6 V bias. Electrical connection is achieved by incorporating the F8BT fibers of about 700 nm width and 110 nm height into a single layer organic light emitting device, whose architecture induces charge recombination on the conjugated polymer nanofibers. This simple method to electrically connect the conjugated polymer nanofibers offers a great potential for low-cost flexible nanodevice fabrication.

Nanosized zeolite L crystals containing about 550 strongly luminescent acceptor molecules have been modified by grafting a conjugated oligomer on their external surface. The 25 nm sized crystals have consequently been embedded in polymeric nanofibers obtained by electrospinning. The fluorescent molecule grafted on the external surface allows addressing the guests in the zeolite nanochannels through an efficient two-step energy transfer from the polymer nanofiber. The so obtained hybrid nanofibers exhibit intense emissions from the three fundamental colors using a single excitation wavelength. The molecule grafted on the external surface of the nanocrystal also induces a higher compatibility of the hybrid organic/inorganic nanomaterials in the conjugated polymer and therefore high concentrations of zeolites embedded in the nanofibers are obtained. Playing on this concentration, the emission of the nanofiber can be tuned and eventually be used for fabricating white-light emitting nanofibers. This hybrid nanomaterial opens new perspectives for low-cost nano organic light emitting diodes fabrication with considerable impact on the lighting and display technologies.