White light emitting device

• US 20070228931A1
• Filed: 03/30/2007
• Published: 10/04/2007
• Est. Priority Date: 03/31/2006
• Status: Abandoned Application

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electro-Mechanics Co., Ltd. (Samsung Group)
• Inventors: Kim, Bum Joon, Shin, Hyun Gyu
• Application Number:
  US11/730,246
• Publication Number:
  US 20070228931A1
• Time in Patent Office: Days
• US Class Current: 313/501
• CPC Class Codes: C09K 11/77342 Silicates
• CPC Class Codes: C09K 11/7774 Aluminates
• 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 33/508 having a non-uniform spatial arrangement or non-uniform concentration, e.g. patterned wavelength conversion layer, wavelength conversion layer with a concentration gradient of the wavelength conversion material
• CPC Class Codes: Y02B 20/00 Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps

Abstract

A high quality white light emitting device capable of adjusting color balance easily. A substrate is provided. A light emitting structure includes an n-type semiconductor layer, an active layer and a p-type semiconductor layer sequentially formed on the substrate. Here, the light emitting structure emits primary radiation. Wavelength conversion film elements absorb a portion of the primary radiation and convert the absorbed portion of the primary radiation into secondary radiation of a different wavelength. The wavelength conversion film elements define an open region for selectively transmitting the primary radiation therethrough.

Claims

1. A white light emitting device comprising:

a substrate;

a light emitting structure including an n-type semiconductor layer, an active layer and a p-type semiconductor layer sequentially formed on the substrate, the light emitting structure emitting primary radiation; and

wavelength conversion film elements for absorbing a portion of the primary radiation and converting the absorbed portion of the primary radiation into secondary radiation of a different wavelength,

wherein the wavelength conversion film elements define an open region for selectively transmitting the primary radiation therethrough.

2. The white light emitting device according to claim 1, wherein the wavelength conversion film elements are formed on the p-type semiconductor layer.

3. The white light emitting device according to claim 1, wherein the wavelength conversion film elements are formed underneath the substrate.

4. The white light emitting device according to claim 1, wherein the wavelength conversion film elements are interposed between the light emitting structure and the substrate.

5. The white light emitting device according to claim 1, wherein the primary radiation is combined with the secondary radiation to produce white light.

6. The white light emitting device according to claim 1, wherein the p-type semiconductor, the active layer and the n-type semiconductor comprise a nitride semiconductor.

7. The white light emitting device according to claim 1, wherein the wavelength conversion film elements absorb at least 90% of the primary radiation incident thereon.

8. The white light emitting device according to claim 1, wherein the wavelength conversion film elements are made of a homogeneous material.

9. The white light emitting device according to claim 1, wherein the wavelength conversion film elements comprise a wavelength convertible, material selected from a group consisting of phosphor, metal silicate, oxide and semiconductor.

10. The white light emitting device according to claim 9, wherein the semiconductor comprises AlGaInP or ZnSe.

11. The white light emitting device according to claim 9, wherein the metal silicate comprises europium-silicate.

12. The white light emitting device according to claim 11, wherein the europium-silicate has a composition expressed by Eu_xSi_yO_z, where 0<

x<

30, 0<

y<

30, and 0<

z<

30.

13. The white light emitting device according to claim 1, wherein the primary radiation comprises blue light, and the secondary radiation comprises light in a range from green to red wavelengths, or yellow light.

14. The white light emitting device according to claim 1, wherein the primary radiation comprises light in a range from blue to red wavelengths, and the secondary radiation comprises red light.

15. The white light emitting device according to claim 1, wherein white light is emitted through a top surface of the light emitting structure which opposes the substrate.

16. The white light emitting device according to claim 1, wherein white light is emitted through an underside surface of the substrate which opposes the light emitting structure.