Blue light-emitting phosphor and light-emitting device using the same

• US 20070029565A1
• Filed: 08/01/2006
• Published: 02/08/2007
• Est. Priority Date: 08/02/2005
• Status: Abandoned Application

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Masuda, Masatsugu, Inoguchi, Tsukasa, Uemura, Toyonori
• Application Number:
  US11/497,663
• Publication Number:
  US 20070029565A1
• Time in Patent Office: Days
• US Class Current: 257/98
• CPC Class Codes: C09K 11/0883 Arsenides; Nitrides; Phosphides
• CPC Class Codes: C09K 11/7734 Aluminates
• CPC Class Codes: C09K 11/77342 Silicates
• CPC Class Codes: C09K 11/77348 Silicon Aluminium Nitrides or Silicon Aluminium Oxynitrides
• CPC Class Codes: H01L 2224/32245 the item being metallic
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00012 Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 33/502 Wavelength conversion materials
• CPC Class Codes: H05B 33/14 characterised by the chemical or physical composition or the arrangement of the electroluminescent material , or by the simultaneous addition of the electroluminescent material in or onto the light source

Abstract

A blue light-emitting phosphor emitting light with high efficiency by ultraviolet light of long wavelength as well as blue (to violet) light of short wavelength emitted from a semiconductor light-emitting element, particularly by the light having the wavelength in the range from 380 nm to 430 nm, is provided. A light-emitting device exhibiting high luminance and stable chromaticity is also provided by using the blue light-emitting phosphor. The blue light-emitting phosphor includes a divalent europium-activated or divalent europium- and manganese-activated aluminate phosphor, substantially represented by the general formula: a[(MI_1-c-dSr_cEu_d)(Mg_1-eM_e)]O.bAl₂O₃, where MI represents at least one kind of element selected from Ca and Ba, and a, b, c, d and e are numbers satisfying 0.1≦a/b≦1.0, 0.2≦c≦0.8, 0.01≦d≦0.5, and 0≦e≦0.05.

Claims

1. A blue light-emitting phosphor, comprising a divalent europium-activated or divalent europium- and manganese-activated aluminate phosphor, substantially represented by the following general formula (1):

a[(MI_1-c-dSr_cEu_d)(Mg_1-eMn_e)]O.bAl₂O₃  

 

(1)

(in the formula (1), MI represents at least one kind of element selected from Ca and Ba, and a, b, c, d and e are numbers satisfying 0.1≦

a/b≦

1.0, 0.2≦

c≦

0.8, 0.01≦

d≦

0.5, and 0≦

e≦

0.05).

2. The blue light-emitting phosphor according to claim 1, wherein MI is Ba.

3. The blue light-emitting phosphor according to claim 1, comprising the divalent europium-activated aluminate phosphor, with e being 0.

4. A light-emitting device, comprising:

a light-emitting element emitting primary light; and

a wavelength conversion unit absorbing at least part of said primary light and emitting secondary light having a wavelength equal to or longer than a wavelength of said primary light;

said wavelength conversion unit being made of at least one kind of phosphor, and said phosphor including the blue light-emitting phosphor as recited in claim 1.

5. The light-emitting device according to claim 4, wherein said light-emitting element is a gallium nitride (GaN)-based semiconductor, and said primary light emitted from said light-emitting element has a peak wavelength in a range from 380 nm to 430 nm.

6. The light-emitting device according to claim 4, wherein said wavelength conversion unit is made of the blue light-emitting phosphor, a green light-emitting phosphor and a red light-emitting phosphor, and in a light path of said wavelength conversion unit, said phosphors are stacked in order from the one emitting the secondary light of longer wavelength.

7. The light-emitting device according to claim 6, wherein said green light-emitting phosphor includes at least one kind of phosphor selected from:

a divalent europium- and manganese-activated aluminate phosphor substantially represented by the following general formula (2);

a(MII,Eu_f,Mn_g)O.bAl₂O₃  

 

(2)

(in the formula (2), MII represents at least one kind of element selected from Mg, Ca, Sr, Ba and Zn, and a, b, f and g are numbers satisfying a>

0, b>

0, 0.1≦

a/b≦

1.0, and 0.3≦

g/f≦

5.0);

a divalent europium-activated silicate phosphor substantially represented by the following general formula (3);

2(MIII_1-hEu_h)O.SiO₂  

 

(3)

(in the formula (3), MIII represents at least one kind of element selected from Mg, Ca, Sr and Ba, and h is a number satisfying 0.005≦

h≦

0.10); and

a divalent europium-activated strontium aluminate phosphor substantially represented by the following general formula (4);

(Sr_1-mEu_m)O.Al₂O₃  

 

(4)

(in the formula (4), m is a number satisfying 0.0001≦

m≦

0.3).

8. The light-emitting device according to claim 6, wherein said red light-emitting phosphor includes a divalent europium-activated nitride phosphor substantially represented by the following general formula (5):

(MIII_1-kEu_k)MIVSiN₃  

 

(5)

(in the formula (5), MIII represents at least one kind of element selected from Mg, Ca, Sr and Ba, MIV represents at least one kind of element selected from Al, Ga, In, Sc, Y, La, Gd and Lu, and k is a number satisfying 0.001≦

k≦

0.05).