White color light emitting device

• US 20030218180A1
• Filed: 05/06/2003
• Published: 11/27/2003
• Est. Priority Date: 05/15/2002
• Status: Active Grant

• Current Assignee: Sumitomo Electric Industries Limited (Sumitomo Corporation)
• Original Assignee: Sumitomo Electric Industries Limited (Sumitomo Corporation)
• Inventors: Fujiwara, Shinsuke
• Granted Patent: US 6,858,869 B2
• Time in Patent Office: Days
• US Class Current: 257/100
• CPC Class Codes: H01L 2224/16245 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 2224/48257 connecting the wire to a die pad of the item
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 2224/8592 Applying permanent coating, e.g. protective coating
• 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 2924/181 Encapsulation
• CPC Class Codes: H01L 33/08 with a plurality of light emitting regions, e.g. laterally discontinuous light emitting layer or photoluminescent region integrated within the semiconductor body H01L27/15 takes precedence
• CPC Class Codes: H01L 33/285 characterised by the doping materials
• CPC Class Codes: H01L 33/502 Wavelength conversion materials
• CPC Class Codes: H01L 33/504 Elements with two or more wavelength conversion materials
• CPC Class Codes: H01L 33/505 characterised by the shape, e.g. plate or foil

Abstract

An ultraviolet type white color light emitting device (Q) including a 340 nm-400 nm ultraviolet InGaN-LED, a first fluorescence plate of ZnS doped with more than 1×10¹⁷ cm⁻³ Al, In, Ga, Cl, Br or I for absorbing ultraviolet rays and producing blue light (fluorescence), a second fluorescence plate of ZnSSe or ZnSe doped with more than 1×10¹⁷ cm⁻³ Al, In, Ga, Cl, Br or I for absorbing the blue light, producing yellow light (fluorescence) and synthesizing white color light by mixing the yellow light with the blue light.

A blue light type white color light emitting device (R) including a 410 nm-470 nm blue light InGaN-LED, a fluorescence plate of ZnS_xSe_1-x (untreated 0.2≦x≦0.6; heat-treated 0.3≦x≦0.67) doped with more than 1×10¹⁷ cm⁻³ Al, In, Ga, Cl, Br or I for absorbing the blue light, producing 568 nm-580 nm yellow light (fluorescence) and synthesizing white color light by mixing the yellow light with the blue LED light.

Claims

1. A white color light emitting device comprising:

an InGaN-type LED emitting 340 nm-400 nm ultraviolet rays;

a first fluorescence plate of ZnS doped with more than 1×

10¹⁷ cm<sup>−

3</sup> Al, In, Ga, Cl, Br or I for converting the ultraviolet rays into blue light; and

a second fluorescence plate of ZnS Se 1-x or ZnSe doped with more than 1×

10¹⁷ cm<sup>−

3</sup> Al, In, Ga, Cl, Br or I for converting the blue light into yellow light and synthesizing white color light by mixing the blue light emitted from the first fluorescence plate with the yellow light emitted from the second fluorescence plate.

2. The white color light emitting device according to claim 1, wherein the ZnS of the first fluorescence plate is a polycrystal with an average grain size larger than a thickness of the first fluorescence plate.

3. The white color light emitting device according to claim 1, wherein the ZnS of the first fluorescence plate is a single crystal.

4. The white color light emitting device according to claim 1, wherein the ZnSSe or ZnSe of the second fluorescence plate is a polycrystal with an average grain size larger than a thickness of the second fluorescence plate.

5. The white color light emitting device according to claim 1, wherein the ZnSSe or ZnSe of the second fluorescence plate is a single crystal.

6. The white color light emitting device according to claim 1, wherein the first fluorescence plate is composed of a ZnS crystal heat-treated in a Zn atmosphere.

7. The white color light emitting device according to claim 1, wherein the second fluorescence plate is composed of a ZnSSe or ZnSe crystal heat-treated in a Zn atmosphere.

8. A white color light emitting device comprising:

a light emitting diode (LED) emitting blue light; and

a fluorescence plate of ZnS_xSe_1-x doped with more than 1×

10¹⁷ cm<sup>−

3</sup> Al, In, Ga, Cl, Br or I for converting the blue light into yellow light and synthesizing white color light by mixing the blue light with the yellow light.

9. A white color light emitting device comprising:

a light emitting diode (LED) emitting blue light between 410 nm and 470 nm; and

a fluorescence plate of ZnS_xSe_1-x doped with more than 1×

10¹⁷ cm<sup>−

3</sup> Al, In, Ga, Cl, Br or I for converting the blue light into yellow light between 568 nm and 580 nm and synthesizing white color light by mixing the 410 nm-470 nm blue light with the 568 nm-580 nm yellow light.

10. The white color light emitting device according to claim 9, wherein the ZnS_xSe_1-x of the fluorescence plate is heat-treated in a Zn atmosphere and the ZnS ratio x of the ZnS_xSe_1-x satisfies an inequality 0.3≦

x≦

0.67.

11. The white color light emitting device according to claim 9, wherein the ZnS_xSe_1-x of the fluorescence plate is not heat-treated and the ZnS ratio x of the ZnS_xSe_1-x satisfies an inequality 0.2≦

x≦

0.6.

12. The white color light emitting device according to claim 9, wherein the ZnS_xSe_1-x of the fluorescence plate is a polycrystal with an average grain size larger than a thickness of the fluorescence plate.

13. The white color light emitting device according to claim 9, wherein the ZnS_xSe_1-x of the fluorescence plate is a single crystal.

14. The white color light emitting device according to claim 9, wherein a wavelength λ

_LED of the blue light emitted by the LED satisfies an inequality of λ

_LED(nm)≧

1239/(2.65+1.63x-0.63×

2), where x is a ZnS mixture rate of the ZnS_xSe_1-x of the fluorescence plate.

15. The white color light emitting device according to claim 9, wherein the blue light LED is an InGaN-LED having an InGaN active layer.