Abstract
Copyright © 2015 John Wiley & Sons, Ltd. Yttrium aluminate (Y3A5O12) was doped with different rare earth ions (i.e. Gd3+, Ce3+, Eu3+ and/or Tb3+) in order to obtain phosphors (YAG:RE) with general formula,Y3-x-aGdxREaAl5O12 (x = 0; 1.485; 2.97 and a = 0.03). The synthesis of the phosphor samples was done using the simultaneous addition of reagents technique. This study reveals new aspects regarding the influence of different activator ions on the morpho-structural and luminescent characteristics of garnet type phosphor. All YAG:RE phosphors are well crystallized powders containing a cubic-Y3Al5O12 phase as major component along with monoclinic-Y4Al2O9 and orthorhombic-YAlO3 phases as the impurity. The crystallites dimensions of YAG:RE phosphors vary between 38 nm and 88 nm, while the unit cell slowly increase as the ionic radius of the activator increases. Under UV excitation, YAG:Ce exhibits yellow emission due to electron transition in Ce3+ from the 5d level to the ground state levels (2F5/2, 2F7/2). The emission intensity of Ce3+ is enhanced in the presence of the Tb3+ ions and is decreased in the presence of Eu3+ ions due to some radiative or non-radiative processes that take place between activator ions. By varying the rare earth ions, the emission colour can be modulated from green to white and red.
Original language | English |
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Pages (from-to) | 929-936 |
Journal | Luminescence |
Volume | 31 |
Issue number | 4 |
DOIs | |
Publication status | Published - 1 Jun 2016 |
Keywords
- luminescence
- phosphors
- rare earth
- wet chemical synthesis
- yttrium aluminium garnet