Luminescent conjugated polymer nanowire y-junctions with on-branch molecular anisotropy

Luminescent conjugated polymer nanowire poly(9,9-dioctylfluorene) Y-junctions with on-branch molecular anisotropy was studied. An 80mL drop of a solution of PFO in tetrahydrofuran (THF) was deposited onto a glass slide and an alumina membrane was immediately brought in contact with the drop for preparation of PFO nanowire Y-junctions. A glass cover slip was pressed on top of the alumina template, thus facilitating penetration of the PFO solution into the template pores by capillary action. Pressure was applied to the cover slip overnight, in order to maximize pore wetting by the PFO solution. PFO nanowires were subsequently released from the template by dissolving the alumina in NaOH. The NaOH was removed, and the nanowire residue was washed with deionized water for 10 min. Near- and far-field optical-microscopy analysis revealed highly polarized photoluminescence from the branches and stems of individual Y-junctions, with, pronounced on-branch emission anisotropy due to emission from β-phase polymer chains.