Small LED source with high brightness and high efficiency

• US 9,419,189 B1
• Filed: 10/30/2014
• Issued: 08/16/2016
• Est. Priority Date: 11/04/2013
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Soraa, Inc.
• Inventors: Huang, Kevin, David, Aurelien J. F., Aldaz, Rafael, Krames, Michael Ragan, Steranka, Frank M., Trottier, Troy
• Primary Examiner(s): Kusumakar, Karen
• Assistant Examiner(s): Bowen, Adam S
• Application Number:
  US14/528,818
• Time in Patent Office: 656 Days
• Field of Search: 257/98
• US Class Current: 1/1
• CPC Class Codes: H01L 33/32 containing nitrogen
• CPC Class Codes: H01L 33/46 Reflective coating, e.g. dielectric Bragg reflector
• 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

Abstract

Small LED sources with high brightness and high efficiency apparatus including the small LED sources and methods of using the small LED sources are disclosed.

Claims

1. A lighting system comprising:

a submount;

at least one pump light emitting diode (LED) disposed on said submount, and comprising a light-emitting active region having a base area;

a color-converting material overlying the at least one pump LED and defining at least one light emitting surface for emitting substantially white light and having an emitting area less than 250 μ

m×

250 μ

m;

wherein the at least one pump LED and the color-converting material are configured such that the light emitting surface has a surface brightness of at least about 800 mW/mm² and the lighting system has a white wall-plug efficiency of at least 25%.

2. The lighting system of claim 1, wherein the LED is formed on a substrate comprising a bulk III-nitride-containing compound.

3. The lighting system of claim 1, wherein the at least one pump LED is configured to emit violet light.

4. The lighting system of claim 1, wherein the at least one pump LED is configured to emit blue light.

5. The lighting system -of claim 1, wherein the at least one light emitting surface emits light characterized by a CCT in a range from about 2000K to about 10000K.

6. The lighting system of claim 1, wherein the at least one pump LED is configured to be driven at a current density in a range of about 100 A/cm2 to about 1000 A/cm2.

7. The lighting system of claim 1, wherein light emitted by the lighting system exhibits a gamut of at least 70% of NTSC gamut.

8. The lighting system claim 1, wherein the at least one pump LED comprises a flip-chip configuration.

9. The lighting system of claim 1, wherein the base area is characterized by a base shape that is substantially rectilinear.

10. The lighting system of claim 1, wherein the submount is characterized by a reflectivity higher than 80% within at least a wavelength in a range of 400 nm to 700 nm.

11. The lighting system of claim 1, further comprising at least one reflective material in proximity to at least one of the at least one pump LED and in proximity to the color conversion material.

12. The lighting system of claim 11, wherein the reflective material is characterized by a reflectivity higher than 90% within at least a wavelength in a range of 400 nm to 700 nm.

13. The lighting system of claim 11, comprising an air gap between the reflective material and at least one of the at least one LED and the color conversion material.

14. The lighting system of claim 13, wherein at least one of the reflective material or the submount forms a diffuse reflector.

15. The lighting system of claim 14, wherein at least one of the reflective material or the submount comprises a metal material.

16. The lighting system of claim 14, wherein at least one of the reflective material or the submount comprises a dielectric stack.

17. The lighting system of claim 1, wherein a combined thickness of the submount, the at least one pump LED, and the light-converting material is less than 1 mm.

18. The lighting system of claim 1, further comprising:

a display component wherein the at least one pump light-emitting diode is coupled to the display component.

19. The lighting system of claim 18, wherein the display component comprises a flat panel display.

20. A lighting system comprising:

at least one light emitting diode (LED), wherein the LED comprises at least a base area, wherein at least 80% of the base area is used for light generation; and

a color-converting material overlying the at least one LED and defining at least one light emitting surface for emitting substantially white light and having an emitting area less than 250 μ

m×

250 μ

m;

wherein the at least one pump LED and the color-converting material are configured such that the light emitting surface has a surface brightness of at least about 800 mW/mm².