Abstract
The optical properties of SrSi2AlO2N3 doped with Eu2+ and Yb2+ are investigated towards their applicability in LEDs. The Eu2+-doped material shows emission in the green, peaking around 500 nm. The emission is ascribed to the 4f65d1–4f7 transition on Eu2+. In view of the too low quantum efficiency and the considerable thermal quenching of the emission at the operation temperature of high power LED (>1W/mm2) this phosphor is only suitable for application in low power LEDs. The Yb2+ emission shows an anomalously red-shifted emission compared to Eu2+, which is characterized by a larger FWHM, a larger Stokes shift and lower thermal quenching temperature. The emission is ascribed to self-trapped exciton emission. The Yb2+ activated phosphor is found to be unsuitable for the use in any phosphor-converted LEDs.
| Original language | Undefined/Unknown |
|---|---|
| Pages (from-to) | 1341-1346 |
| Number of pages | 6 |
| Journal | Journal of Luminescence |
| Volume | 129 |
| Issue number | 11 |
| Publication status | Published - 2009 |