Color converting element and light emitting device including the same

Patent metadata

Field	Value
Publication number	US-9490403-B2
Application number	US-201514666178-A
Country	US
Kind code	B2
Filing date	Mar 23, 2015
Priority date	Sep 21, 2012
Publication date	Nov 8, 2016
Grant date	Nov 8, 2016

Abstract

Disclosed are a color converting element and a method for manufacturing the color converting element. The disclosed color converting element includes: first wavelength conversion cells spaced apart from one another; and second wavelength conversion cells arranged among the first wavelength conversion cells. The first and second wavelength conversion cells are made of a material containing glass. The color converting element of the disclosed technology is configured in that color converting cells having different color converting characteristics are periodically arranged, when the color converting element is applied to a color converting glass material which may improve thermal and chemical durability of white LEDs, thus minimizing the degradation of efficiency or luminance caused by an interaction between color converting phosphors or active ions and allowing for ease of adjustment of color rendering index.

First claim

What is claimed is:

1. A light emitting device comprising:
a substrate;
a light emitting diode disposed over the substrate and including a light emitting structure, the light emitting structure including a first conductive type semiconductor layer, a second conductive type semiconductor layer and an active layer disposed between the first conductive type semiconductor layer and the second conductive type semiconductor layer; and
a color converting element disposed over the light emitting diode,
wherein the light emitting structure includes an elongated shape extending in a first direction and includes a mesa including the second conductive type semiconductor layer and the active layer,
wherein the color converting element includes:
a plurality of first wavelength conversion cells separated from one another; and
a plurality of second wavelength conversion cells each disposed between the first wavelength conversion cells, and

wherein at least one of interfaces between the first wavelength conversion cells and the second wavelength conversion cells has an elongated shape extending in a second direction, and the first direction is not parallel to the second direction.

2. The light emitting device of claim 1 , wherein the first and second wavelength conversion cells are arranged in a stripe pattern.

3. The light emitting device of claim 2 , wherein the first direction is substantially perpendicular to the second direction.

4. The light emitting device of claim 1 , wherein the first and second wavelength conversion cells are arranged in a lattice pattern.

5. The light emitting device of claim 1 , wherein the color converting element has a greater horizontal cross-sectional area than an upper surface of the light emitting diode.

6. The light emitting device of claim 5 , wherein the upper surface of the light emitting diode is covered by the color converting element.

7. The light emitting device of claim 1 , wherein the first and second wavelength conversion cells includes a glass containing material.

8. The light emitting device of claim 7 , wherein the glass containing material includes a ceramic phosphor-containing glass or crystallized glass material.

9. The light emitting device of claim 7 , wherein the glass containing material includes an active ion for color conversion, quantum dot or nanocrystal-containing glass or crystallized glass material.

10. The light emitting device of claim 1 , wherein the color converting element further includes a plurality of third wavelength conversion cells separated from one another, and each of the third wavelength conversion cells is disposed between the first wavelength conversion cells and the second wavelength conversion cells.

11. The light emitting device of claim 1 , wherein the light emitting diode includes:
a first contact electrode and a second contact electrode disposed over the light emitting structure and forming ohmic contact with the first and second conductive type semiconductor layers, respectively;
an insulation layer insulating the first contact electrode and the second contact electrode while partially covering the first and second contact electrodes; and
first and second pad electrodes disposed over the insulation layer and electrically connected to the first and second contact electrodes, respectively.

12. The light emitting device of claim 11 , wherein the second contact electrode is disposed over the mesa.

13. The light emitting device of claim 12 , wherein the first contact electrode forms ohmic contact with the first conductive type semiconductor layer around the mesa, and an ohmic contact area between the first contact electrode and the first conductive type semiconductor layer has an elongated shape extending in the first direction.

14. The light emitting device of claim 1 , wherein the first and second wavelength conversion cells have the same or different widths less than or equal to 300 μm.

15. The light emitting device of claim 1 , further including:
a distributed Bragg reflector disposed between the color converting element and the light emitting diode.

16. The light emitting device of claim 15 , wherein the distributed Bragg reflector transmits light emitted from the light emitting diode and reflects light emitted from the color converting element and is subjected to wavelength conversion in the color converting element.

17. The light emitting device of claim 15 , wherein the distributed Bragg reflector includes a first distributed Bragg reflector and a second distributed Bragg reflector disposed over the first distributed Bragg reflector, and the first distributed Bragg reflector reflects light having a shorter wavelength than the second distributed Bragg reflector.

Assignees

• Postech Academy—Industry Found
• Seoul Viosys Co Ltd
• Posco Led Co Ltd

Inventors

• Chung Woon Jin
• Han Ka Ram
• Lee Yi Kwon

Classifications

• H10H20/0361

  of wavelength conversion means · CPC title

• H10H20/8514

  characterised by their shape, e.g. plate or foil · CPC title

• H10H20/8513

  having two or more wavelength conversion materials · CPC title

• H10H20/841

  Reflective coatings, e.g. dielectric Bragg reflectors · CPC title

• H10H20/821

  of the light-emitting regions, e.g. non-planar junctions · CPC title