OXONITRIDOBERYLLOSILICATE PHOSPHORS
A family of optionally substituted oxonitridoberyllosilicate photoluminescent compositions (i.e., phosphors) is characterized by the formula AE 1−x−y−u A y+u Be 1−y−z−v B y+z+v Si 1−z Al z O 1−v N 2+v : Eu x ,Ce u , where AE=Ba, Sr, Ca, Mg; A=Li, Na, K, Rb; 0 ≤x≤0.1; 0≤ u≤0.1; 0<(x+u); 0≤y≤1; 0≤z≤1; (y+z+v)≤1; and (x+y+u)≤1. These phosphors may be used in phosphor converted LEDs which may be advantageously employed in illumination and display applications, for example.
1 . A photoluminescent composition characterized by:
AE 1−x−y−u A y+u Be 1−y−z−v B y+z+v Si 1−z Al z O 1−v N 2+v : Eu x ,Ce u ;
AE=Ba, Sr, Ca, Mg;
A=Li, Na, K, Rb;
0
≤
x
≤
0.1
;
0
≤
u
≤
0.1
;
0
<
(
x
+
u
)
;
0
≤
y
≤
1
;
0
≤
z
≤
1
;
(
y
+
z
+
v
)
≤
1
;
and
(
x
+
y
+
u
)
≤
1.
2 . The photoluminescent composition of claim 1 , wherein (y+z+v)>0.
3 . The photoluminescent composition of claim 2 , wherein z>0.
4 . The photoluminescent composition of claim 1 wherein x>0 and u>0.
5 . The photoluminescent composition of claim 1 , wherein (y+u)>0.
6 . The photoluminescent composition of claim 1 characterized by Ba 0.9 Sr 0.05 K 0.015 Be 0.5 B 0.5 Si 0.5 Al 0.5 ON 2 : Eu 0.02 , Ce 0.015 .
7 . The photoluminescent composition of claim 1 characterized by Ba 0.48 Na 0.5 Be 0.5 B 0.5 SiON 2 : Eu 0.02 .
8 . The photoluminescent composition of claim 1 characterized by Ba 0.5 Sr 0.49 Be 0.5 B 0.5 SiO 0.5 N 2.5 : Eu 0.01 .
9 . The photoluminescent composition of claim 1 characterized by Sr 0.99 BSiN 3 : Eu 0.01 .
10 . The photoluminescent composition of claim 1 characterized by peak photoluminescent emission at 500 nm to 560 nm with a full width at half maximum of ≤55 nm.
11 . The photoluminescent composition of claim 1 characterized by:
Ba 1−x BeSiON 2 : Eu x ; and
0
<
x
≤
0.1
.
12 . The photoluminescent composition of claim 11 , wherein 0<x≤0.04.
13 . The photoluminescent composition of claim 11 , wherein 0.005≤x≤0.02.
14 . The photoluminescent composition of claim 11 , wherein x=0.01.
15 . The photoluminescent composition of claim 11 , wherein x=0.005.
16 . The photoluminescent composition of claim 11 , wherein x=0.0075.
17 . The photoluminescent composition of claim 11 characterized by peak photoluminescent emission at 520 nm to 530 nm with a full width at half maximum of ≤50 nm.
18 . The photoluminescent composition of claim 17 , wherein the full width at half maximum is ≤45 nm.
19 . A light emitting device comprising:
a light emitting diode that emits primary light; and
the luminescent composition of claim 1 arranged in an optical path of light output from the light emitting diode to absorb primary light and in response emit secondary light having a longer wavelength than the primary light.
20 . The light emitting device of claim 19 , wherein the primary light has a blue peak wavelength and the secondary light has a green peak wavelength and a full width at half maximum of ≤50 nm.