Abstract
A spectroscopic investigation of sodium germanate glasses activated with Ce3+, Tb3+ and Ce3+/Tb3+ is carried out by analyzing their photoluminescence spectra and decay times. Non-radiative energy transfer from Ce3+ to Tb3+ is observed upon near-UV excitation at 310 nm (peak emission wavelength of AlGaN-based LEDs). The non-radiative nature of this energy transfer is inferred from the increase in the decay rate of the Ce3+ emission when the glass is co-doped with Tb3+. From an analysis of the Ce3+ emission decay time curve it is inferred that an electric dipole-quadrupole interaction might to be the dominant mechanism for the Tb3+ emission sensitized by Ce3+. Energy transfer from Ce3+ to Tb3+ leads to a simultaneous emission of these ions in the blue, green, yellow and red, resulting in white light with CIE1931 chromaticity coordinates, x = 0.30 and y = 0.32, which correspond to cold white light with a colour temperature of 7320 K and very small deviation from the Planckian black-body radiator locus (0.005).
Original language | English |
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Pages (from-to) | 451-456 |
Number of pages | 6 |
Journal | Optical Materials |
Volume | 37 |
Issue number | C |
DOIs | |
State | Published - 2014 |
Bibliographical note
Publisher Copyright:© 2014 Elsevier B.V. All rights reserved.
Keywords
- Ce
- Germanate glass
- Non-radiative energy transfer
- Photoluminescence
- Tb
- White light