Uniform color phosphor-coated light-emitting diode

• US 7,084,434 B2
• Filed: 11/26/2003
• Issued: 08/01/2006
• Est. Priority Date: 04/15/2003
• Status: Active Grant

• Current Assignee: Luminus Devices Incorporated (Sanan Optoelectronics Company Limited)
• Original Assignee: Luminus Devices Incorporated (Sanan Optoelectronics Company Limited)
• Inventors: Erchak, Alexei A., Brown, Michael Gregory, Meirav, Udi E.
• Primary Examiner(s): Nadav, Ori
• Application Number:
  US10/724,006
• Publication Number:
  US 20040207319A1
• Time in Patent Office: 979 Days
• Field of Search: 257/79, 257/98, 257/100, 257/103, 438 22- 27, 438/29
• US Class Current: 257/98
• CPC Class Codes: H01L 2933/0083 Periodic patterns for optical field-shaping in or on the semiconductor body or semiconductor body package, e.g. photonic bandgap structures
• CPC Class Codes: H01L 33/0093 Wafer bonding; Removal of the growth substrate
• CPC Class Codes: H01L 33/20 with a particular shape, e.g. curved or truncated substrate

Abstract

Light-emitting devices, and related components, systems and methods are disclosed.

Claims

1. A light-emitting device, comprising:

a multi-layer stack of materials including a light-generating region, a layer of p-doped semiconductor material, and a layer of n-doped semiconductor material supported by the light-generating region, a surface of the layer of n-doped semiconductor material being configured so that light generated by the light-generating region can emerge from the light-emitting device via the surface of the layer of n-doped semiconductor material, the surface of the layer of n-doped semiconductor material having a dielectric function that varies spatially according to a pattern;

a support that supports the multi-layer stack of materials;

a layer of reflective material that is capable of reflecting at least about 50% of light generated by the light-generating region that impinges on the layer of reflective material, the layer of reflective material being between the support and the multi-layer stack of materials such that a distance between the layer of p-doped semiconductor material and the layer of reflective material is less than a distance between the layer of n-doped semiconductor material and the layer of reflective material; and

a phosphor material disposed on the surface of the layer of n-doped semiconductor material,

wherein sidewalls of the light-emitting device are substantially devoid of the phosphor material.

2. The light-emitting device of claim 1, wherein the light emitting device is packaged.

3. The light-emitting device of claim 1, wherein the light-emitting device is in the form of a packaged die.

4. The light-emitting device of claim 1, wherein the light-emitting device is in the form of a packaged device that is free of an encapsulant.

5. The light-emitting device of claim 1, further comprising a layer comprising a material that is substantially transparent to light that emerges from the light-emitting device.

6. The light-emitting device of claim 5, wherein at least some of the phosphor material is disposed within the layer that comprises the material that is substantially transparent to light that emerges from the light-emitting device.

7. The light-emitting device of claim 1, wherein the reflective material is a heat sink material.

8. The light-emitting device of claim 7, wherein the heat sink material is configured so that the heat sink material has a vertical heat gradient during use of the light-emitting device.

9. The light-emitting device of claim 1, further comprising a heat sink material.

10. The light-emitting device of claim 9, wherein the heat sink material is configured so that the heat sink material has a vertical heat gradient during use of the light-emitting device.

11. The light-emitting device of claim 1, further including a current-spreading layer between the layer of n-doped semiconductor material and the light-generating region.

12. The light-emitting device of claim 1, further comprising electrical contacts configured to inject current into the light-emitting device.

13. The light-emitting device of claim 12, wherein the electrical contacts are configured to vertically inject electrical current into the light-emitting device.

14. The light-emitting device of claim 1, wherein the light-emitting device is selected from the group consisting of light-emitting diodes, lasers, optical amplifiers, and combinations thereof.

15. The light-emitting device of claim 1, wherein the light-emitting device comprises a light emitting diode.

16. The light-emitting device of claim 1, wherein the light-emitting device is selected from the group consisting of OLEDs, flat surface-emitting LEDs, HBLEDs, and combinations thereof.

17. The light-emitting device of claim 1, wherein the pattern has an ideal lattice constant and a detuning parameter with a value greater than zero.

18. The light-emitting device of claim 1, wherein the pattern does not extend into the light-generating region.

19. The light-emitting device of claim 1, wherein the pattern does not extend beyond the layer of n-doped semiconductor material.

20. The light-emitting device of claim 1,

wherein the light-generating region is between the layer of reflective material and the layer of n-doped semiconductor material.

21. The light-emitting device of claim 1, wherein the phosphor material is in the form of a layer, and a thickness of the layer of the phosphor material varies by less than about 20%.

22. The light-emitting device of claim 1, wherein the pattern is nonperiodic pattern or a complex periodic pattern.

23. The light-emitting device of claim 1, wherein the surface of the layer of n-doped semiconductor material has features with a size of less than about λ

/5, where λ

is a wavelength of light that can be generated by the light-generating region and that can emerge from the light-emitting device via the surface of the layer of n-doped semiconductor material.