Novel Sol–Gel Precursors for Thin Mesoporous Eu³⁺-Doped Silica Coatings as Efficient Luminescent Materials.

Abstract

Europium(III) ions containing mesoporous silica coatings have been prepared via a solvent evaporation-induced self-assembly (EISA) approach of different single-source precursors (SSPs) in the presence of Pluronic P123 as a structure-directing agent, using the spin-coating process. A deliberate tailoring of the chemical composition of the porous coatings with various Si:Eu ratios was achieved by processing mixtures of tetraethylorthosilicate (TEOS) and Eu3+-coordinated SSPs. Small-angle X-ray scattering (SAXS) and transmission electron microscopy (TEM) analyses demonstrate that the thin metal oxide-doped silica coatings consist of a porous network with a short-range order of the pore structure, even at high europium(III) loadings. Furthermore, luminescence properties were investigated at different temperatures and different degrees of Eu3+ contents. The photoluminescence spectra clearly show characteristic emission peaks corresponding to the 5D0 → 7FJ (J = 0–5) transitions resulting in a red luminescence visible by the eyes, although the films have a very low thickness (150–200 nm).

Surface-specific visible light luminescence from composite metal oxide nanocrystals

“…The quest for luminescent materials of sufficient availability, low price, and biocompatibility is at the heart of nanomaterials research and development with applications in areas such as sensing, lighting, medicine, nanoparticle transport, and the detection of electromagnetic fields [1][2][3][4][5][6]. Perhaps the most commercially important application of luminescent materials is in solid-state lighting (SSL) devices based on blue and near-UV light-emitting diodes (LEDs) [1,6].…”

“…Current commercial SSL downconverters use rareearth phosphors such as Ce 3? or Eu 2? embedded in oxide or nitride particles [3,4]. To reduce multiple scattering events and improve performance, there has been a drive to reduce particle size.…”

“…Another class of materials system is characterized by dopants (e.g., rare-earth ions) embedded in an inorganic particle which act as luminescence centers (Fig. 1) [3,4]. In some wide band gap semiconductors, significant luminescence can even be observed in undoped materials due to the presence of intrinsic defects [20][21][22][23].…”

Carboxylic acid-functionalized porous silica particles by a co-condensation approach

“…We already reported the possibility to use these organosilanes as ligands for the complexation of europium(III)ions and the preparation of thin europium(III)-doped silica coatings [30]. In this paper, we report the suitability of 5-(triethoxysilyl)-pentanoic acid as a precursor molecule in the synthesis of carboxylic acid group containing siliceous materials using a co-condensation approach.…”

Preparation and characterization of TAMP/TIMP-Ti and Zr compounds and their catalytic activity over propylene oxide and Ɛ-caprolactone

“…Schiff-bases, carboxylate anions, and their derivatives are useful ligands for the construction of new interesting metal catalysts [1][2][3][4][5][6][7]. Metal alcoholate compounds modified by carboxylates, β-diketonates, and Schiff-bases have attracted much attention as catalysts for ring opening polymerization of oxirane derivatives, lactides, and ε-caprolactone [8][9][10].…”