title: Visible tunable lighting system based on polymer composites embedding ZnO and metallic clusters: from colloids to thin films.
abstract: The development of phosphor devices free of heavy metal or rare earth elements is an important issue for environmental reasons and energy efficiency. Different mixtures of ZnO nanocrystals with Cs2Mo6I8(OOC2F5)6cluster compound (CMIF) dispersed into polyvinylpyrrolidone matrix have been prepared by very simple and low cost solution chemistry. The resulting solutions have been used to fabricate highly transparent and luminescent films by dip coating free of heavy metal or rare earth elements. The luminescence properties of solution and dip-coated films were investigated. The luminescence of such a system is strongly dependent on the ratios between ZnO and CMIF amounts, the excitation wavelength and the nature of the system. By varying these two parameters (ratio and wavelength), a large variety of colors, from blue to red as well as white, can be achieved. In addition, differences in the luminescence properties have been observed between solutions and thin films as well as changes of CMIF emission band maximum wavelength. This may suggest some possible interactions between the different luminophore centers, such as energy transfer or ligands exchange on the Mo6clusters.
authors.affiliation: Institut des Sciences Chimiques de Rennes (ISCR), UMR 6226, CNRS-University of Rennes 1, Rennes, France; Laboratory for Innovative Key Materials and Structures (LINK), UMI 3629 CNRS-Saint Gobain-NIMS, National Institute for Materials Science (NIMS), Tsukuba, Japan; Optical and Electronic Materials Unit, NIMS, Tsukuba, Japan.
authors.forename: Thai Giang
authors.initials: TG
authors.lastname: Truong
authors.affiliation: Laboratory for Innovative Key Materials and Structures (LINK), UMI 3629 CNRS-Saint Gobain-NIMS, National Institute for Materials Science (NIMS), Tsukuba, Japan; NIMS-Saint-Gobain Center of Excellence for Advanced Materials, NIMS, Tsukuba, Japan.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Dierre
authors.affiliation: Laboratory for Innovative Key Materials and Structures (LINK), UMI 3629 CNRS-Saint Gobain-NIMS, National Institute for Materials Science (NIMS), Tsukuba, Japan; Optical and Electronic Materials Unit, NIMS, Tsukuba, Japan; NIMS-Saint-Gobain Center of Excellence for Advanced Materials, NIMS, Tsukuba, Japan.
authors.forename: Fabien
authors.initials: F
authors.lastname: Grasset
authors.affiliation: Optical and Electronic Materials Unit, NIMS , Tsukuba , Japan.
authors.forename: Noriko
authors.initials: N
authors.lastname: Saito
authors.affiliation: Optical and Electronic Materials Unit, NIMS, Tsukuba, Japan; Department of Metallurgy and Ceramics Science, Tokyo Institute of Technology, Tokyo, Japan.
authors.forename: Norio
authors.initials: N
authors.lastname: Saito
authors.affiliation: Fine Particles Engineering Group, NIMS , Tsukuba , Japan.
authors.forename: Thi Kim Ngan
authors.initials: TK
authors.lastname: Nguyen
authors.affiliation: Sialon Unit, NIMS , Tsukuba , Japan.
authors.forename: Kohsei
authors.initials: K
authors.lastname: Takahashi
authors.affiliation: Laboratory for Innovative Key Materials and Structures (LINK), UMI 3629 CNRS-Saint Gobain-NIMS, National Institute for Materials Science (NIMS), Tsukuba, Japan; Fine Particles Engineering Group, NIMS, Tsukuba, Japan.
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Uchikoshi
authors.affiliation: Institut des Sciences Chimiques de Rennes (ISCR), UMR 6226, CNRS-University of Rennes 1 , Rennes , France.
authors.forename: Marian
authors.initials: M
authors.lastname: Amela-Cortes
authors.affiliation: Institut des Sciences Chimiques de Rennes (ISCR), UMR 6226, CNRS-University of Rennes 1 , Rennes , France.
authors.forename: Yann
authors.initials: Y
authors.lastname: Molard
authors.affiliation: Institut des Sciences Chimiques de Rennes (ISCR), UMR 6226, CNRS-University of Rennes 1 , Rennes , France.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Cordier
authors.affiliation: Laboratory for Innovative Key Materials and Structures (LINK), UMI 3629 CNRS-Saint Gobain-NIMS, National Institute for Materials Science (NIMS), Tsukuba, Japan; Optical and Electronic Materials Unit, NIMS, Tsukuba, Japan; NIMS-Saint-Gobain Center of Excellence for Advanced Materials, NIMS, Tsukuba, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Ohashi
keywords: 102 Porous / Nanoporous / Nanostructured materials; 103 Composites; 105 Low-Dimension (1D/2D) materials; 20 Organic and soft materials (colloids, liquid crystals, gel, polymers); 204 Optics / Optical applications; 301 Chemical syntheses / processing; 505 Optical / Molecular spectroscopy; ZnO; colloidal solution; luminescence; metal clusters; thin films