23 November 2015

The solid solution Sr2−xLaxSiO4−xNx (0 ≥ x ≥ 1), obtained by concomitant substitution of Sr2+ by La3+ and O2− by N3− in Sr2SiO4, has been prepared by solid state reaction at 1500 °C in N2/H2 of mixtures of SrO, La2O3, SiO2 and Si3N4. Synchrotron radiation X-ray diffraction studies show a transition from the monoclinic P21/n symmetry of β-Sr2SiO4 to orthorhombic Pmnb α′,β-K2SO4type phase for x ≥ 0.2. The α′ phase is stabilized as a consequence of the increase in bond valence of the cations induced by nitriding. The activation with Eu2+ and Ce3+ of Sr2−xLaxSiO4−xNx produces luminescent materials with broad emission bands centered up to 650 nm under excitation at 405 nm. The emission wavelengths are tuned by La/N contents in a wide range with emission colours changing from yellow (x = 0.2) to orange-red (x = 1) for Eu2+phosphors and from blue-green (x = 0.2) to orange-yellow (x = 1) in Ce3+ samples.


Hits: 6179
Sustainable energy conversion & storage systems

Emission colour tuning through coupled N/La introduction in Sr_sub2sub_SiO_sub4sub_:Eu_sup2+sup_

Also at ICMAB

  • Accelerating organic solar cell material's discovery: high-throughput screening and big data

    11 June 2021 229 hit(s) Energy
    The discovery of novel high-performing materials such as non-fullerene acceptors and low band gap donor polymers underlines the steady increase of record efficiencies in organic solar cells witnessed during the past years. Nowadays, the resulting catalogue of organic photovoltaic materials is becoming unaffordably vast to be evaluated following classical experimentation methodologies: their requirements in terms of human workforce time and resources are prohibitively high, which slows momentum to the evolution of the organic photovoltaic technology.
  • Boost of Charge Storage Performance of Graphene Nanowall Electrodes by Laser-Induced Crystallization of Metal Oxide Nanostructures

    08 June 2021 218 hit(s) Energy
    Major research efforts are being carried out for the technological advancement to an energetically sustainable society. However, for the full commercial integration of electrochemical energy storage devices, not only materials with higher performance should be designed and manufactured but also more competitive production techniques need to be developed.
  • Unveiling Planar Defects in Hexagonal Group IV Materials

    01 June 2021 258 hit(s) Energy
    Recently synthesized hexagonal group IV materials are a promising platform to realize efficient light emission that is closely integrated with electronics. A high crystal quality is essential to assess the intrinsic electronic and optical properties of these materials unaffected by structural defects. Here, we identify a previously unknown partial planar defect in materials with a type I3 basal stacking fault and investigate its structural and electronic properties.
  • Battery Materials Design Essentials

    21 May 2021 378 hit(s) Energy
    The advanced materials industry is one of the leading technology sectors worldwide. The development of such materials is at the core of the technological innovations and has been possible in the last century thanks to the transition from “observational” science to “control” science.
  • Study of nanostructured ultra-refractory Tantalum-Hafnium-Carbide electrodes with wide electrochemical stability window

    04 May 2021 305 hit(s) Energy
    Transition metal carbides have gathered increasing attention in energy and electrochemistry applications, mainly due to their high structural and physicochemical properties. Their high refractory properties have made them an ideal candidate coating technology and more recently their electronic similarity to the platinum group has expanded their use to energy and catalysis. Here, we demonstrate that the nanostructuring and stoichiometry control of the highest melting point material to this date (Ta-Hf-C) results in outstanding electrochemical stability.

INSTITUT DE CIÈNCIA DE MATERIALS DE BARCELONA, Copyright © 2020 ICMAB-CSIC | Privacy Policy | This email address is being protected from spambots. You need JavaScript enabled to view it.