Abstract
Novel phosphors of Na2Y2B2O 7:Ce3+ and Na2Y2B2O 7:Ce3+,Tb3+ were synthesized by a solid-state process and characterized with X-ray diffraction, photoluminescence (PL), PL excitation (PLE), and fluorescence decay time. The relationship between the observed Ce3+ emission properties and the crystal structure of Na2Y2B2O7 is built and the result shows that Ce3+ ions occupy two non-equivalent Y3+ sites in the host. The codoping of Tb3+ in Na2Y 2B2O7:Ce3+ can tune the emitting colour from blue to green and increase the luminescence quantum efficiency to 75.2% by the energy transfer of Ce3+→Tb3+. The energy transfer processes of Ce3+-Ce3+ and Ce 3+-Tb3+ are analysed and determined to be electric dipole-dipole and dipole-quadrupole, respectively. The broad PLE spectra of Na2Y2B2O7:Ce3+ and Na2Y2B2O7:Ce3+,Tb 3+ are well matched with the emission from near UV LED chips, which indicates that they are promising blue and green phosphors for phosphor-converted white LEDs.
Original language | English |
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Pages (from-to) | 65-71 |
Number of pages | 7 |
Journal | Journal of Solid State Chemistry |
Volume | 213 |
DOIs | |
Publication status | Published - 2014 May |
Externally published | Yes |
Keywords
- Energy transfer
- LED
- Luminescence
- Phosphors
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Condensed Matter Physics
- Physical and Theoretical Chemistry
- Inorganic Chemistry
- Materials Chemistry