title: Color control in coaxial two-luminophore nanowires.
abstract: We report a general and simple approach to take control of the color of light-emitting two-luminophore hybrid nanowires (NWs). Our strategy is based on the spatial control at the nanoscale (coaxial geometry) and the spectral selection of the two kinds of luminophores in order to restrict complex charge and energy transfers. Thus, it is possible to control the color of the photoluminescence (PL) as an interpolation of the CIE (Commission Internationale de l'Eclairage) coordinates of each luminophore. For this purpose, we selected a green-emitting semiconducting polymer and a red-emitting hexanuclear metal cluster compound, (n-Bu4N)2Mo6Br8F6, dispersed in a poly(methyl-methacrylate) (PMMA) matrix. The great potential and the versatility of this strategy have been demonstrated for two configurations. First, a yellow PL with a continuous change along the nanowire has been evidenced when the proportion of the PPV shell versus the nanocomposite core, that is, the green/red volumic ratio, progressively shifts from 1:2 to 1:5. Second, an extremely abrupt change in the PL color with red-green-yellow segments has been achieved. A simple model corroborates the effectiveness of this strategy. PL excitation and time-resolved experiments also confirm that no significant charge and energy transfers are involved. The two-luminophore hybrid nanowires may find widespread nanophotonic applications in multicolor emitting sources, lasers and chemical and biological sensors.
authors.affiliation: Institut des Matériaux Jean Rouxel, Université de Nantes, CNRS, France. alexandre.garreau@cnrs-imn.fr
authors.forename: Alexandre
authors.initials: A
authors.lastname: Garreau
authors.forename: Florian
authors.initials: F
authors.lastname: Massuyeau
authors.forename: Stéphane
authors.initials: S
authors.lastname: Cordier
authors.forename: Yann
authors.initials: Y
authors.lastname: Molard
authors.forename: Eric
authors.initials: E
authors.lastname: Gautron
authors.forename: Patricia
authors.initials: P
authors.lastname: Bertoncini
authors.forename: Eric
authors.initials: E
authors.lastname: Faulques
authors.forename: Jany
authors.initials: J
authors.lastname: Wery
authors.forename: Bernard
authors.initials: B
authors.lastname: Humbert
authors.forename: Alain
authors.initials: A
authors.lastname: Bulou
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Duvail
mesh_terms: D003116:Color; D003198:Computer Simulation; D008027:Light; D008163:Luminescent Measurements / Q000379:methods*; D008422:Materials Testing; D008956:Models, Chemical; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D010316:Particle Size; D012542:Scattering, Radiation