TITLE:
Photoluminescence Studies of ZnO, ZnO:Eu and ZnO:Eu Nanoparticles Covered with Y2O3 Matrix
AUTHORS:
Laishram Robindro Singh
KEYWORDS:
Nanoparticles, Phase Segregation, Dispersion, Luminescence, Core-Shell
JOURNAL NAME:
Materials Sciences and Applications,
Vol.6 No.4,
March
27,
2015
ABSTRACT: Development of advanced display and lighting technology such as field emission displays and
plasma display panels requires phosphor which has a high efficiency and low degradation. Particle
sizes and the locations of dopants in the hosts take an important role in the luminescence emissions
of phosphors. ZnO nanoparticles are widely employed in plasma field emission display devices
and well investigated; however, lanthanide (Ln3+) doped ZnO needs more investigations. In
ZnO:Eu the lanthanide ions (Eu3+) may occupy either Zn2+ lattice site or on surface of ZnO crystal.
The emissions of Eu3+ ion on the surface are the characteristic of Eu2 O3 , which leads to weak luminescence
emission. To observe such phenomena, nanoparticles of ZnO, 2 at.% Eu3+ doped ZnO
(ZnO:Eu) and ZnO:Eu covered with yattria matrix were prepared by wet chemical method at low
temperature. The prepared nanoparticles were characterized by XRD and TEM. XRD data reveal
the significant phase segregation of the annealed nanoparticles compared with lower heated samples.
This phase segregation of Eu3+ ion establishes responsible for the decrease luminescence intensity
of annealed ZnO:Eu nanoparticles compared with the as-prepared ZnO:Eu nanoparticles.
Improvement on luminescence emissions could be achieved only for the as-prepared ZnO:Eu nanoparticles
while covered with yattria matrix.