Abstract
Non-radiative energy transfers (ET) from Ce3 to Pr3+ in Y3Al5O12:Ce3, Pr3+ and from Sm3 to Eu3 in CaMoO4:Sm3, Eu3 are studied based on photoluminescence spectroscopy and fluorescence decay patterns. The result indicates an electric dipoledipole interaction that governs ET in the LED phosphors. For Ce3 concentration of 0.01 in YAG:Ce3, Pr3+, the rate constant and critical distance are evaluated to be 4.5×10-36 cm 6 s-1 and 0.81 nm, respectively. An increase in the red emission line of Pr3+ relative to the yellow emission band of Ce 3, on increasing Ce3 concentration is observed. This behavior is attributed to the increase of spectral overlap integrals between Ce3 emission and Pr3+ excitation due to the fact that the yellow band shifts to the red spectral side with increasing Ce3 concentration. In CaMoO4:Sm3, Eu3, Sm 3Eu3 transfer occurs from 4G5/2 of Sm3 to 5D0 of Eu3. The rate constant of 8.5×10-40 cm6 s-1 and the critical transfer distance of 0.89 nm are evaluated.
Original language | English |
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Pages (from-to) | 429-432 |
Number of pages | 4 |
Journal | Journal of Luminescence |
Volume | 131 |
Issue number | 3 |
DOIs | |
State | Published - Mar 2011 |
Keywords
- Energy transfer
- LED phosphors
- YAG:Ce,Pr