Luminescence nanostructured materials

Electron Transfer Reactions Coherent Control OF Chemical Reactions Lasers, Ultrafast Pulse ItecHNOLOGY Luminescence Molecular Beam Epitaxy, Semiconductors Nanostructured Materials, Chemistry of Noni.inf.ar Optical Processes... 

Nanostructured materials. 2. Luminescence. 3. Rare earth metals-Optical properties. 4. Coordination compounds. I. Bettencourt-Dias, Ana de, editor. 

It is possible to alter the intrinsic properties of materials by chemical nanocoating, which cannot be achieved by conventional methods. Generally the core-shell nanostructures are divided into two categories (1) lanthanides doped in the core (2) lanthanides doped in the shell. The former are synthesized in order to improve the quantum efficiency of lanthanide ions or design bio-labels, while the latter are meant for the study of surface modifications on the lanthanide luminescence or the synthesis of lanthanide-doped hollow nanospheres. 

Rare earth silicates exhibit potential applications as stable luminescent materials for phosphors, scintillators, and detectors. Silica and silicon substrates are frequently used for thin films fabrication, and their nanostructures including monodisperse sphere, NWs are also reliable templates and substrates. However, the composition, structure, and phase of rare earth silicates are rather complex, for example, there are many phases like silicate R2SiOs, disilicate R2Si207 (A-type, tetragonal), hexagonal Rx(Si04)602 oxyapatite, etc. The controlled synthesis of single-phase rare earth silicate nanomateriais can only be reached with precisely controlled experimental conditions. A number of heat treatment based routes, such as solid state reaction of rare earth oxides with silica/silicon substrate, sol-gel methods, and combustion method, as well as physical routes like pulsed laser ablation, have been applied to prepare various rare earth silicate powders and films. The optical properties of rare earth silicate nanocrystalline films and powders have been studied. 

Plasmonic nanostructures that are materials consisting of noble metal nanoparticles with sizes of 1-100 nm are known as specific substrates for surface enhanced Raman scattering and luminescence enhancement [1-4]. These effects are stimulated by the localized surface plasmon absorption (LSPA) and may be controlled by the change of metal nanoparticle sizes, their concentration and a substrate choice [5]. New opportunities for surface-enhanced effect realization and optimization are now discussed in connection with bimetallic nanostructures [6]. At the technological aspect one of the simplest types of a binary nanostructure is a stratified system made of two different monolayers, each is consisted of definite metal nanoparticles. The LSPA properties of these binary close-packed planar nanostructures are the subject of the paper. 

Another interesting phenomenon is producing luminescence from electrochemical reactions. This can be achieved by doping crystalline metal oxides and related materials or anodic metal oxide layers (Meulenkamo et al., 1993) or depositing organic molecules onto nanostructured porous materials such silicon (Martin et al., 2006). 

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