Yellow Emission from Low Coordination Site of Sr2SiO4:Eu2+, Ce3+: Influence of Lanthanide Dopants on the Electron Density and Crystallinity in Crystal Site Engineering Approach

Tutkimustuotos: Lehtiartikkelivertaisarvioitu

Tutkijat

Organisaatiot

  • State Key Laboratory of Crystal Materials
  • Shandong University
  • Bhabha Atomic Research Centre
  • University of Texas Rio Grande Valley
  • ShanghaiTech University

Kuvaus

Lanthanide doping through a crystal site engineering approach tunes the emission wavelength suitable for LED applications, but weak emission from low coordination sites remains a huge challenge. Herein the use of a sensitizer is reported to enhance the emission strength and unravel the crystallinity and phase, as this approach demands a large amount of dopants. Doping of Eu2+ ions at SrO10 and SrO9 sites of Sr2SiO4 (S2S), respectively, tunes the emission from green to yellow and controlled doping of a Ce3+ sensitizer quadruples the quantum efficiency of yellow emission. Remarkably, doping of Eu2+ at the SrO9 site produces polycrystals, whereas co-doping of Ce3+ and Eu2+ at the same site produces single crystals. DFT calculations further delineate the underlying changes wherein strong interaction of dopant with its neighbours determines the electron density, and thus the crystallinity and phase, rather than usual explanation of aliovalent conditions, which is further substantiated by TEM results. Irrespective of dopant valence, use of large amounts of dopants and their interaction with the host is responsible for the crystallinity and phase change (α′-S2S to β-S2S). The XPS valence band spectra experimentally evidences the changes in bonding nature of O 2p and O 2s orbitals of silicate and its electron density, due to doping at the two sites. In short, the outcomes resulting from this work could be extended for the development of other two-coordination site lanthanide-doped materials and crystallization of inorganic materials.

Yksityiskohdat

AlkuperäiskieliEnglanti
Sivut16149-16159
Sivumäärä11
JulkaisuChemistry - A European Journal
Vuosikerta24
Numero60
TilaJulkaistu - 26 lokakuuta 2018
OKM-julkaisutyyppiA1 Julkaistu artikkeli, soviteltu

ID: 37762323