CURRENT-INJECTING/TUNNELING LIGHT-EMITTING DEVICE AND METHOD

• US 20090212278A1
• Filed: 02/25/2009
• Published: 08/27/2009
• Est. Priority Date: 02/25/2008
• Status: Active Grant

• Current Assignee: Lightwave Photonics, Inc.
• Original Assignee: Lightwave Photonics, Inc.
• Inventors: King, David J., Jorgenson, Robbie J.
• Granted Patent: US 7,842,939 B2
• Time in Patent Office: Days
• US Class Current: 257/13
• CPC Class Codes: H01L 33/04 with a quantum effect structure or superlattice, e.g. tunnel junction
• CPC Class Codes: H01L 33/06 within the light emitting region, e.g. quantum confinement structure or tunnel barrier
• CPC Class Codes: H01L 33/105 with a resonant cavity structure
• CPC Class Codes: H01L 33/405 Reflective materials
• CPC Class Codes: Y10T 29/5313 Means to assemble electrical device

Abstract

An apparatus and method for making it. Some embodiments include a light-emitting device having a light-emitting active region; a tunneling-barrier (TB) structure facing adjacent the active region; a TB grown-epitaxial-metal-mirror (TB-GEMM) structure facing adjacent the TB structure, wherein the TB-GEMM structure includes at least one metal is substantially lattice matched to the active region; and a conductivity-type III-nitride crystal structure adjacent facing the active region opposite the TB structure. In some embodiments, the active region includes an MQW structure. In some embodiments, the TB-GEMM includes an alloy composition such that metal current injectors have a Fermi energy potential substantially equal to the sub-band minimum energy potential of the MQW. Some embodiments further include a second mirror (optionally a GEMM) to form an optical cavity between the second mirror and the TB-GEMM structure. In some embodiments, at least one of the GEMM is deposited on, and lattice matched to, a substrate.

Claims

1. An apparatus comprising:

a light-emitting device that includes;

a light-emitting active region;

a tunneling-barrier (TB) structure facing adjacent the active region;

a TB grown-epitaxial-metal-mirror (TB-GEMM) structure facing adjacent the TB structure, wherein the TB-GEMM structure includes at least one metal and is substantially lattice-matched to the active region;

a conductivity-type III-nitride crystal structure adjacent facing the active region opposite the TB structure; and

a current-conducting contact electrically connected to the conductivity-type III-nitride structure.

2. The apparatus of claim 1, wherein the active region includes a multiple-quantum-well (MQW) structure.

3. The apparatus of claim 1,

wherein the MQW structure of the active region includes quantum-well widths selected to provide a selected sub-band minimum energy potential, and

wherein the TB-GEMM structure includes an alloy composition such that metal current injectors have a Fermi energy potential that is substantially equal to the sub-band minimum energy potential of the MQW.

4. The apparatus of claim 1, wherein the light-emitting device further comprises:

a second mirror that is facing adjacent the conductivity-type III-nitride structure and facing the TB-GEMM structure to form an optical cavity between the second mirror and the TB-GEMM structure, wherein the active region is within the optical cavity.

5. The apparatus of claim 1, wherein the light-emitting device further comprises:

a second mirror comprising an optical-cavity grown-epitaxial-metal-mirror (OC-GEMM) structure that is facing adjacent the conductivity-type III-nitride structure and which forms an optical cavity between the OC-GEMM structure and the TB-GEMM structure, wherein the active region is within the optical cavity.

6. The apparatus of claim 4, wherein the active region is positioned a first distance away from a first face of the second mirror such that the active region is located at or substantially at an antinode of a first standing optical wave produced by interference of light emitted from the active region with light reflected by the second mirror to form at least one extraction mode.

7. The apparatus of claim 1, wherein the light-emitting device further comprises:

a substrate structure,

wherein the TB-GEMM structure is facing touching the substrate structure and is substantially lattice matched to a face of the substrate structure.

8. The apparatus of claim 5, wherein the light-emitting device further comprises:

a substrate structure,

wherein the OC-GEMM structure is facing touching the substrate structure and is substantially lattice matched to a face of the substrate structure.

9. The apparatus of claim 1, wherein the TB-GEMM structure comprises:

a compound that includes (Hf_xZr_yTi_z)R where x+y+z=1 and where x is between 0 and 1, inclusive, and where y is between 0 and 1, inclusive, and where z is between 0 and 1, inclusive, and wherein R is N or B₂.

10. The apparatus of claim 1, further comprising an insulating interfacial layer located between the TB-GEMM structure and the TB structure.

11. A method for making a light-emitting device, the method comprising:

forming a light-emitting active region;

forming a tunneling-barrier (TB) structure such that in the light-emitting device the TB structure is facing adjacent the active region;

forming a TB grown-epitaxial-metal-mirror (TB-GEMM) structure such that in the light-emitting device the TB-GEMM structure is facing adjacent the TB structure, wherein the TB-GEMM structure includes at least one metal and wherein the TB-GEMM structure is substantially lattice matched to the active region;

forming a conductivity type III-nitride crystal structure such that in the light-emitting device the conductivity type III-nitride crystal structure is facing adjacent the active region opposite the TB structure; and

forming a current-conducting contact such that in the light-emitting device the current-conducting contact is electrically connected to the conductivity type III-nitride.

12. The method of claim 11, wherein the forming of the active region includes forming a multiple-quantum-well (MQW) structure.

13. The method of claim 11,

wherein the forming of the MQW structure of the active region includes forming quantum-well widths selected to provide a selected sub-band minimum energy potential, and

wherein the TB-GEMM structure includes an alloy composition such that metal current injectors have a Fermi energy potential that is substantially equal to the sub-band minimum energy potential of the MQW.

14. The method of claim 11, further comprising forming a second mirror such that in the light-emitting device the second mirror is facing adjacent the conductivity-type III-nitride structure and facing the TB-GEMM structure to form an optical cavity between the second mirror and the TB-GEMM structure, wherein the active region is within the optical cavity.

15. The method of claim 11, further comprising forming a second mirror comprising an optical-cavity grown-epitaxial-metal-mirror (OC-GEMM) structure, such that in the light-emitting device the OC-GEMM structure is facing adjacent the conductivity-type III-nitride structure and forms an optical cavity between the OC-GEMM structure and the TB-GEMM structure, wherein the active region is within the optical cavity.

16. The method of claim 14, wherein the light-emitting device is formed such that in the light-emitting device the active region is located a first distance away from a first face of the second mirror such that the active region is located at or substantially at an antinode of a first standing optical wave produced by interference of light emitted from the active region with light reflected by the second mirror to form at least one extraction mode.

17. The method of claim 11, wherein the method further comprises:

providing a substrate structure; and

forming the TB-GEMM structure on, and facing touching, the substrate structure and is substantially lattice matched to a face of the substrate structure.

18. The method of claim 15, wherein the method further comprises:

providing a substrate structure; and

forming the OC-GEMM structure on, and facing touching, the substrate structure and is substantially lattice matched to a face of the substrate structure.

19. The method of claim 11, wherein the TB-GEMM structure comprises:

a compound that includes (Hf_xZr_yTi_z)R where x+y+z=1 and where x is between 0 and 1, inclusive, and where y is between 0 and 1, inclusive, and where z is between 0 and 1, inclusive, and wherein R is N or B₂.

20. The method of claim 11, further comprising forming an insulating interfacial layer such that in the light-emitting device the interfacial layer is located between the TB-GEMM structure and the TB structure.

21. An apparatus for making a light-emitting device, the apparatus comprising:

means for forming a light-emitting active region;

means for forming a tunneling-barrier (TB) structure such that in the light-emitting device the TB structure is facing adjacent the active region;

means for forming a TB grown-epitaxial-metal-mirror (TB-GEMM) structure such that in the light-emitting device the TB-GEMM structure is facing adjacent the TB structure, wherein the TB-GEMM structure includes at least one metal and wherein the TB-GEMM structure is substantially lattice matched to the active region;

means for forming a conductivity type III-nitride crystal structure such that in the light-emitting device the conductivity type III-nitride crystal structure is facing adjacent the active region opposite the TB structure; and

means for forming a current-conducting contact such that in the light-emitting device the current-conducting contact is electrically connected to the conductivity type III-nitride.