Light-emitting element with multiple light-emitting stacked layers

• US 8,927,958 B2
• Filed: 11/21/2012
• Issued: 01/06/2015
• Est. Priority Date: 07/12/2011
• Status: Active Grant

• Current Assignee: Epistar Corporation
• Original Assignee: Epistar Corporation
• Inventors: Hsieh, Min-Hsun, Lin, Yi-Chieh, Lee, Rong-Ren
• Primary Examiner(s): Tran, Long K
• Assistant Examiner(s): Tran, Dzung
• Application Number:
  US13/683,476
• Publication Number:
  US 20130075696A1
• Time in Patent Office: 776 Days
• Field of Search: 257/13, 257/81, 257/103, 257/14, 257/99, 257/79
• US Class Current: 257/13
• CPC Class Codes: H01L 33/06 within the light emitting region, e.g. quantum confinement structure or tunnel barrier
• 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-emitting device includes a carrier; a first light-emitting element formed on a first portion of the carrier, including: a first MQW structure configured to emit a first light with a first dominant wavelength; a second MQW structure configured to emit a second light with a second dominant wavelength on the first MQW structure; wherein the first MQW structure and the second MQW structure both comprise InxGa1-xP or InxGa1-xAs, wherein 0<x<1; and a second light-emitting element, formed on a second portion on of the carrier, including a light-emitting stacked layer configured to emit a third light with a third dominant wavelength, wherein the third light is blue, wherein a difference between the first dominant wavelength and the second dominant wavelength is 5 nm to 30 nm.

Claims

1. A light-emitting device, comprising:

a carrier;

a first light-emitting element, formed on a first portion of the carrier, comprising;

a first MQW structure configured to emit a first light with a first dominant wavelength;

a second MQW structure configured to emit a second light with a second dominant wavelength on the first MQW structure;

wherein the first MQW structure and the second MQW structure both comprise In_xGa_1-xP or In_xGa_1-xAs, wherein 0<

x<

1; and

a second light-emitting element, formed on a second portion of the carrier, comprising a light-emitting stacked layer configured to emit a third light with a third dominant wavelength, wherein the third light is blue,

wherein a difference between the first dominant wavelength and the second dominant wavelength is 5 nm to 30 nm.

2. The light-emitting device of claim 1, wherein the first light, the second light, and the third light are mixed to generate a mixed light, and CRI of the mixed light is at least 90.

3. The light-emitting device of claim 2, wherein R9 of the mixed light is at least 50.

4. The light-emitting device of claim 1, wherein the second dominant wavelength is larger than the third dominant wavelength.

5. The light-emitting device of claim 1, further comprising a wavelength conversion layer on the second light-emitting element.

6. The light-emitting device of claim 1, wherein the first light and the second light are substantially red light.

7. The light-emitting device of claim 1, further comprising a bonding layer between the carrier and the first MQW structure.

8. The light-emitting device of claim 5, wherein the second light-emitting element emits cool white light;

the first light, the second and cool white light are mixed to generate a mixed light which is warm white light.

9. The light-emitting device of claim 1, wherein the difference between first dominant wavelength and the second dominant wavelength is between 10 nm and 25 nm.

10. The light-emitting device of claim 1, wherein the first MQW structure comprising a first well layer with a first indium proportion, the second MQW structure comprising a second well layer with a second indium proportion, and a difference between the first indium proportion and the second indium proportion is between 1% to 6%.

11. The light-emitting device of claim 10, wherein the first MQW structure is between the second MQW structure and the carrier, and the first indium proportion is larger than the second indium proportion.

12. The light-emitting device of claim 1, wherein the first MQW structure is between the second MQW structure and the carrier, and the first dominant wavelength is larger than the second dominant wavelength.

13. The light-emitting device of claim 1, wherein the first MQW structure comprises a first number of MQW pairs, the second MWQ structure comprises a second number of MQW pairs, and the first number is different from the second number.

14. The light-emitting device of claim 13, wherein the first MQW structure is between the second MQW structure and the carrier, and the first number is larger than the second number.

15. The light-emitting device of claim 13, further comprising a third MQW structure having a third number of MQW pairs on the second MQW structure.

16. The light-emitting device of claim 15, wherein the first number is larger than the second number and the third number is smaller than the second number.

17. The light-emitting device of claim 15, further comprising a first tunneling layer between the first MQW structure and the second MQW structure and a second tunneling layer between the third MQW structure and the second MQW structure.

18. The light-emitting device of claim 15, wherein the third MQW structure emits a fourth light with a fourth dominant wavelength, and the first dominant wavelength, the second dominant wavelength, and the fourth dominant wavelength are different from each other.

19. The light-emitting device of claim 18, wherein the first dominant wavelength is larger than the second dominant wavelength and the second dominant wavelength is larger than the fourth dominant wavelength.