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Volume 6
Research & Reviews: Journal of Material Sciences
ISSN: 2321-6212
Advanced Materials 2018
September 04-06, 2018
September 04-06, 2018 | Zürich, Switzerland
21
st
International Conference on
Advanced Materials & Nanotechnology
Eu
2+
/Eu
3+
-activated nitride based red phosphors with narrow emission band for white light emitting
diodes
Jianyan Ding, Xufeng Zhou
and
Yuhua Wang
Lanzhou University, China
T
he rare earth Eu
2+
/Eu
3+
ions have been widely used to act as activator for phosphors, especially red phosphors. Compared
with oxide, Eu
2+
activated nitride based phosphors commonly present broad excitation band and red emission light
due to the larger crystal field splitting and higher nephelauxetic resulting from N
3-
ions. The compact host lattices produced
by the edge or face shared (Al, Si) N
4
tetrahedrons present excellent thermal stability and high bright red emission light.
However, its broad emission band resulted from 4f-5d transitions of Eu
2+
ions leads to low color purity. Different from Eu
2+
ions, Eu
3+
activated phosphors can emit a sharp red emission light due to its f-f transitions, but sharp excitation band limits
their application. For solving this problem, the charge transfer band of Eu
3+
-N
3-
in α-M
3
B
2
N
4
(M=Ca, Sr) and Li
2
SiN
2
has been
investigated in our work. Meanwhile, Eu
2+
activated Ca
5
Si
2
Al
2
N
8
has also been displayed for comparison. The results show that
Eu
2+
or Eu
3+
activated phosphors have its own advantages and disadvantages, which also indicates their different application in
WLEDs and FEWs.
Figure:
Eu
3+
activated nitride red phosphors of α-M3B2N4 (M = Ca, Sr) with broad excitation band of Eu
3+
-N
-
.
Recent Publications
1. Ding J, Li Y, Wu Q et al. (2015) Novel red and green emitting Li 2 SiN 2: Eu
3+
/Tb
3+
phosphors with a broad charge
transfer band. Journal of Materials Chemistry C 3(33):8542-8549.
2. Ding J, Wu Q, Li Y, et al. (2016) Eu
2+
-activated Ca
5
Si
2
Al
2
N
8
– A novel nitridoalumosilicate red phosphor containing the
special polyhedron of separated corner-shared [Al
2
N
6
] and [Si
2
N
6
]. Chemical Engineering Journal 302: 466-474.
3. Ding J, YouH, Wang Y, et al. (2018) Site occupation and energy transfer of Ce
3+
-activated lithiumnitridosilicate Li
2
SrSi
2
N
4
with broad-yellow-light-emitting property and excellent thermal stability. Journal of Materials Chemistry C 6(13):3435-
3444.
4. Ding J, Wu Q, Li Y, et al. (2017) α-M
3
B
2
N
4
(M= Ca, Sr): Eu
3+
: a nitride-based red phosphor with a sharp emission line and
broad excitation band used for WLED. The Journal of Physical Chemistry C 121(18): 10102-10111.
5. Ding J, Wu Q, Li Y, et al. (2016) Self-Activated Yellow Light Emitting Phosphors of α, β-Ca
3
B
2
N
4
with Long Afterglow
Properties. Inorganic Chemistry 55(21):10990-10998.
Biography
Jianyan Ding has expertise in Physics and Materials Science. At present, his main research interest is focused on nitride based red phosphors used for white
light emitting diodes (WLEDs). In order to realize the red phosphors, several nitride based phosphors activated by Eu
3+
/Eu
2+
have been reported by him. The red
phosphors with narrow emission band and broad excitation band have been realized. However, there are still some problems need to be resolved, such as: thermal
stability, quantum efficiency and preparation condition. In the future work, Eu
3+
/Eu
2+
activated nitride based red phosphors would be improved through investigating
the relationship between luminescence properties and crystal or electron structure.
dingjy16@lzu.edu.cnJianyan Ding et al., Res. Rev. J Mat. Sci. 2018, Volume 6
DOI: 10.4172/2321-6212-C3-021