Light Mixing LED

• US 20060006375A1
• Filed: 09/14/2005
• Published: 01/12/2006
• Est. Priority Date: 04/14/2003
• Status: Abandoned Application

• Current Assignee: Epistar Corporation
• Original Assignee: Epistar Corporation
• Inventors: Hsu, Chen-Ke, Ou, Chen
• Application Number:
  US11/162,562
• Publication Number:
  US 20060006375A1
• Time in Patent Office: Days
• US Class Current: 257/14
• 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 light mixing LED includes a first active layer containing In laminated adjacent to an n-type nitride-based semiconductor stack layer, a second active layer containing In laminated adjacent to a p-type nitride-based semiconductor stack layer, and a tunnelable barrier layer formed between the first active layer and the second active layer.

Claims

1. A light mixing LED comprising:

an n-type nitride-based semiconductor stack layer;

a p-type nitride-based semiconductor stack layer; and

multiple active layers of quantum well structure, sandwiched between the n-type nitride-based semiconductor stack layer and the p-type nitride-based semiconductor stack layer, wherein the multiple active layers comprising;

a first active layer containing In laminated adjacent to the n-type nitride-based semiconductor stack layer;

a second active layer containing In laminated adjacent to the p-type nitride-based semiconductor stack layer, wherein a first principal peak wavelength of light emitted from the first active layer is longer than a second principal peak wavelength of light emitted from the second active layer; and

a tunnelable barrier layer formed between the first active layer and the second active layer,

wherein a color rendering coordinate of a mixed light in a chromaticity diagram is set at a predetermined value in a range between that of the first principal peak wavelength and that of the second principal peak wavelength substantially in proportion to a thickness of the tunnelable barrier layer.

2. The light mixing LED of claim 1, wherein the thickness of the tunnelable barrier is between 2.5 nm and 10 nm.

3. The light mixing LED of claim 1, wherein the first principal peak wavelength is in a range between 440 nm and 500 nm, and the second principal peak wavelength is in a range between 520 nm and 650 nm.

4. The light mixing LED of claim 1, wherein the first active layer comprises a quantum well structure with r1 quantum wells, wherein r1 is greater than 0.

5. The light mixing LED of claim 1, wherein the second active layer comprises a quantum well structure with r2 quantum wells, wherein r2 is greater than 0.

6. The light mixing LED of claim 1, wherein the tunnelable barrier layer comprises an undoped layer.

7. The light mixing LED of claim 1, further comprising a third active layer formed between the first active layer and the n-type semiconductor stack layer, and a second tunnelable barrier layer formed between the first active layer and the third active layer, wherein a third principal peak wavelength of the third active layer is longer than that of the first principal peak wavelength.