《Microcavity effects and optically pumped in single conjugated polymer》.pdf

LETTERS Microcavity effects and optically pumped lasing in single conjugated polymer nanowires 1 2 1 DEIRDRE O’CARROLL , INGO LIEBERWIRTH AND GARETH REDMOND * 1Tyndall National Institute, Lee Maltings, Prospect Row, Cork, Ireland 2 Max Planck Institute for Polymer Research, Ackermannweg 10, D-55128 Mainz, Germany *e-mail: gareth.redmond@tyndall.ie Published online: 25 February 2007; doi:10.1038/nnano.2007.35 Conjugated polymers have chemically tuneable opto-electronic heated above its glass transition temperature or melting point. properties and are easily processed, making them attractive Due to the high surface energy of the template, a thin surface materials for photonics applications1,2. Conjugated polymer film covers the pore walls during initial wetting, forming lasers, in a variety of resonator geometries such as nanotubes with well-defined wall thickness. Nanowire formation 3 4 5 microcavity , micro-ring , distributed feedback and photonic occurs on longer time scales because the cohesive forces for pore bandgap6 structures, have been fabricated using a range of filling are considerably weaker than the adhesive forces for wall coating and imprinting techniques. Currently, one-dimensional wetting17. A scanning electron microscope (SEM) image of a wire nanowires are emerging as promising candidates for integrated, array (Fig. 1a), acquired following dissolution of the alumina subwavelength active and passive photonic devices7–10. We template (with aqueous NaOH), confirms that aligned forests of report the first observation of optically pumped