Eu3+-Doped Wide Band Gap Zn2SnO4 Semiconductor Nanoparticles: Structure and Luminescence
Nanocrystalline Zn2SnO4 powders doped with Eu3+ ions were synthesized via a mechanochemical solid-state reaction method followed by postannealing in air at 1200 °C. X-ray diffraction (XRD), energy-dispersive X-ray (EDX), and Raman and photoluminescence (PL) spectroscopies provide convincing evidence...
Saved in:
Published in | Journal of physical chemistry. C Vol. 120; no. 33; pp. 18887 - 18894 |
---|---|
Main Authors | , , , , , , , |
Format | Journal Article |
Language | English |
Published |
United States
American Chemical Society
25.08.2016
|
Subjects | |
Online Access | Get full text |
Cover
Loading…
Summary: | Nanocrystalline Zn2SnO4 powders doped with Eu3+ ions were synthesized via a mechanochemical solid-state reaction method followed by postannealing in air at 1200 °C. X-ray diffraction (XRD), energy-dispersive X-ray (EDX), and Raman and photoluminescence (PL) spectroscopies provide convincing evidence for the incorporation of Eu3+ ions into the host matrix on noncentrosymmetric sites of the cubic inverse spinel lattice. Microstructural analysis shows that the crystalline grain size decreases with the addition of Eu3+. Formation of a nanocrystalline Eu2Sn2O7 secondary phase is also observed. Luminescence spectra of Eu3+-doped samples show several emissions, including narrow-band magnetic dipole emission at 595 nm and electric dipole emission at 615 nm of the Eu3+ ions. Excitation spectra and lifetime measurements suggest that Eu3+ ions are incorporated at only one symmetry site. According to the crystal field theory, it is assumed that Eu3+ ions participate at octahedral sites of Zn2+ or Sn4+ under a weak crystal field, rather than at the tetrahedral sites of Zn2+, because of the high octahedral stabilization energy for Eu3+. Activation of symmetry forbidden (IR-active and silent) modes is observed in the Raman scattering spectra of both pure and doped samples, indicating a disorder of the cation sublattice of Zn2SnO4 nanocrystallites. These results were further supported by the first principle lattice dynamics calculations. The spinel-type Zn2SnO4 shows effectiveness in hosting Eu3+ ions, which could be used as a prospective green/red emitter. This work also illustrates how sustainable and simple preparation methods could be used for effective engineering of material properties. |
---|---|
Bibliography: | USDOE Office of Energy Efficiency and Renewable Energy (EERE), Transportation Office. Fuel Cell Technologies Office AC36-08GO28308 NREL/JA-5900-67318 |
ISSN: | 1932-7447 1932-7455 |
DOI: | 10.1021/acs.jpcc.6b05335 |