POLYCHROMATIC LED AND METHOD FOR MANUFACTURING THE SAME

• US 20100090232A1
• Filed: 10/12/2009
• Published: 04/15/2010
• Est. Priority Date: 10/13/2008
• Status: Active Grant

• Current Assignee: Advanced Optoelectronic Technology, Inc.
• Original Assignee: Advanced Optoelectronic Technology, Inc.
• Inventors: TU, PO MIN, YEH, YING CHAO, LIN, WEN YU, WU, PENG YI, CHAN, SHIH HSIUNG, HUANG, SHIH CHENG
• Granted Patent: US 8,217,400 B2
• Time in Patent Office: Days
• US Class Current: 257/89
• CPC Class Codes: H01L 33/0093 Wafer bonding; Removal of the growth substrate
• 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

Abstract

A wavelength conversion layer is formed on a surface of a light emitting device for transforming a portion of light emitted from the light emitting device into light of a different wavelength. The transformed light is mixed with the untransformed light, and thus the light emitting device can emit light having preferred CIE coordinates.

Claims

1. A polychromatic light emitting diode device, comprising:

a substrate;

a multiple semiconductor layer formed on said substrate, wherein said multiple semiconductor layer comprises an n-type semiconductor layer, a p-type semiconductor layer and an active layer disposed between said n-type semiconductor layer and said p-type semiconductor layer, and said active layer emits light of a first wavelength; and

a first wavelength conversion layer formed on said multiple semiconductor layer, wherein said first wavelength conversion layer absorbs a portion of said first wavelength emitted from said active layer and emits a second wavelength, wherein said second wavelength is longer than said first wavelength.

2. The polychromatic light emitting diode device of claim 1, wherein the material of said first wavelength conversion layer is a Group III-V semiconductor material or a Group II-VI semiconductor material, wherein said Group III-V semiconductor material is Group III nitride, Group III phosphide or Group III arsenide.

3. The polychromatic light emitting diode device of claim 2, further comprising a second wavelength conversion layer formed on said first wavelength transformation layer, wherein said second wavelength conversion layer absorbs said first wavelength and said second wavelength from said first wavelength conversion layer and emits a third wavelength, and said third wavelength is longer than said second wavelength.

4. The polychromatic light emitting diode device of claim 3, wherein the material of said second wavelength conversion layer is Group III-nitride, Group III phosphide or Group III arsenide, wherein said Group II-VI semiconductor material is Group II oxide, Group II sulfide or Group II selenide.

5. The polychromatic light emitting diode device of claim 2, wherein said substrate is of sapphire, silicon carbide, lithium aluminate, lithium gallate, silicon, gallium nitride, zinc oxide, aluminum zinc oxide, gallium arsenide, gallium phosphide, gallium antimonide, indium phosphide, indium arsenide, zinc selenide or metal.

6. The polychromatic light emitting diode device of claim 5, further comprising a buffer layer between said substrate and said multiple semiconductor layer.

7. The polychromatic light emitting diode device of claim 6, further comprising a p-type electron blocking layer disposed between said active layer and said p-type semiconductor layer.

8. The polychromatic light emitting diode device of claim 7, further comprising a transparent conductive layer formed on said first wavelength transformation layer, and being in ohmic contact with said first wavelength transformation layer.

9. The polychromatic light emitting diode device of claim 8, further comprising a second wavelength conversion layer formed on said first wavelength conversion layer and a third wavelength conversion layer disposed on said second wavelength transformation layer.

10. The polychromatic light emitting diode device of claim 9, wherein said active layer emits ultraviolet light;

and said first wavelength transformation layer, said second wavelength transformation layer, and said third wavelength conversion layer separately emit blue light, green light and red light.

11. A method for manufacturing a polychromatic light emitting diode device, comprising steps of:

providing an epitaxial substrate;

forming a multiple semiconductor layer on said epitaxial substrate, wherein said multiple semiconductor layer comprises an n-type semiconductor layer, a p-type semiconductor layer and an active layer disposed between said n-type semiconductor layer and said p-type semiconductor layer, and said active layer emits a first wavelength;

forming a first wavelength conversion layer on said multiple semiconductor layer, wherein said first wavelength conversion layer absorbs a portion of said first wavelength emitted from said active layer and emits a second wavelength, wherein said second wavelength is longer than said first wavelength.

12. The method of claim 11, wherein the material of said first wavelength conversion layer is a Group III-V semiconductor material or a Group II-VI semiconductor material, wherein said Group III-V semiconductor material is Group III nitride, Group III phosphide or Group III arsenide semiconductor.

13. The method of claim 12, further comprising a step of forming a second wavelength conversion layer on said first wavelength transformation layer, wherein said second wavelength conversion layer absorbs said first wavelength and said second wavelength from said first wavelength conversion layer and emits a third wavelength, and said third wavelength is longer than said second wavelength.

14. The method of claim 13, wherein the material of said second wavelength conversion layer is a Group III nitride semiconductor, a Group III phosphide semiconductor or a Group III arsenide semiconductor.

15. The method of claim 11, further comprising a step of forming a buffer layer between said substrate and said multiple semiconductor layer and a p-type electron blocking layer between said active layer and said p-type semiconductor layer.

16. The method of claim 15, further comprising a step of forming a transparent conductive layer on said first wavelength transformation layer, wherein said transparent conductive layer is in ohmic contact with said first wavelength transformation layer.

17. The method of claim 16, further comprising a step of forming a metal substrate on said ohmic contact layer.

18. The method of claim 17, further comprising a step of removing said epitaxial substrate.

19. The method of claim 18, further comprising steps of:

forming a second wavelength conversion layer on said first wavelength transformation layer; and

forming a third wavelength conversion layer on said second wavelength transformation layer.

20. The method of claim 19, wherein said active layer emits ultraviolet light;

and said first wavelength transformation layer, said second wavelength transformation layer, and said third wavelength conversion layer separately emit blue light, green light and red light.