Self‐reduction process and enhanced blue emission in SrAl 2 Si 2 O 8 : Eu, Tb via electron transfer from Tb 3+ to Eu 3

• Published in: Physica status solidi. A, Applications and materials science Vol. 214; no. 6
• Main Authors: Xu, Hongwei, Wang, Lili, Li, Minhong, Ran, Weiguang, Deng, Zhihan, Houzong, Ruizhi, Shi, Jinsheng
• Format: Journal Article
• Language: English
• Published: 01-06-2017
• ISSN: 1862-6300; 1862-6319
• DOI: 10.1002/pssa.201700013

Eu, Tb co‐doped SrAl
2
Si
2
O
8
luminescent materials were synthesized via a high‐temperature solid‐state reaction. Excitation spectra of SrAl
2
Si
2
O
8
: Eu
2+
gives two broad excitation bands maximizing at 270 and 330 nm, resulting from splitting Eu
2+
energy levels in octahedral crystal field. Eu single doped SrAl
2
Si
2
O
8
luminescent material exhibits two emission bands at about 406 and 616 nm. Intensity of the blue emission from Eu
2+
is always strong, compared with that of the red emission band of Eu
3+
. Reduction from Eu
3+
to Eu
2+
can be explained with the model of charge compensation. Blue emission in SrAl
2
Si
2
O
8
:
x
Eu was strengthened after incorporation of Tb, which can be explained by electron transfer from Tb
3+
to Eu
3+
. Under 230 nm excitation, intensity of Tb
3+
emission was nearly unchanged and that of Eu
2+
was increased, obviously due to the delivery of more electrons to Eu
3+
. The strongest emission of Eu
2+
in 0.09Eu/0.06Tb co‐doped SrAl
2
Si
2
O
8
and excited at 270 and 330 nm was remarkably enhanced by about four times compared to that of 0.15Eu Single doped SrAl
2
Si
2
O
8
. All of the results indicate that SrAl
2
Si
2
O
8
:
x
Eu,
y
Tb are potential blue emitting luminescent materials for UV‐LEDs. More importantly, this research may provide a new perspective in designing broad band blue luminescent materials.