Polarized light emitting diode and method of forming the same

• US 8,004,000 B2
• Filed: 04/30/2007
• Issued: 08/23/2011
• Est. Priority Date: 08/30/2006
• Status: Expired due to Fees

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Min, Bok-ki, Sone, Cheol-soo
• Primary Examiner(s): Andújar; Leonardo
• Assistant Examiner(s): Klein; Jordan
• Application Number:
  US11/797,003
• Publication Number:
  US 20080054283A1
• Time in Patent Office: 1,576 Days
• Field of Search: 257/98, 257/99, 257/E33.055, 257/E33.067, 257E33071-E33074, 359/486
• US Class Current: 257/98
• CPC Class Codes: H01L 33/44 characterised by the coatings, e.g. passivation layer or anti-reflective coating

Abstract

Example embodiments are directed to a polarized light emitting diode and method of forming the same. The polarized light emitting diode may include a support layer, a semiconductor layer structure, and/or a polarization control layer. The semiconductor layer structure may be formed on the support layer and may include a light-emitting layer. The polarization control layer may be formed on the semiconductor layer structure and may include a plurality of metal nanowires. The polarized light emitting diode may be configured to control the polarization of emitted light. The method of forming a polarized light emitting diode may include forming on a substrate a semiconductor layer structure with a light emitting layer. A reflecting layer may be formed on the semiconductor layer structure with an attached support layer. The substrate may be removed from the semiconductor layer structure and a polarization control layer including metal nanowires may be formed on the semiconductor layer structure.

Claims

1. A light emitting diode, comprising:

a support layer;

a semiconductor layer structure on the support layer, the semiconductor layer structure including a light-emitting layer; and

a polarization control layer on the semiconductor layer structure, the polarization control layer including a plurality of metal nanowires and a transparent conducting layer, and being configured to control the polarization of emitted light, the plurality of metal nanowires enclosed within the transparent conducting layer so as to not contact a surface of the semiconductor layer structure, wherein an entire surface of the plurality of metal nanowires enclosed within the transparent conducting layer is directly in contact with the transparent conducting layer.

2. The light emitting diode of claim 1, wherein each of the plurality of metal nanowires has a polygonal or a circular cross-section.

3. The light emitting diode of claim 2, wherein the cross-section of each of the plurality of metal nanowires is rectangular.

4. The light emitting diode of claim 3, wherein each of the plurality of metal nanowires has a thickness between about 50 nm to about 1000 nm, inclusive.

5. The light emitting diode of claim 3, wherein each of the plurality of metal nanowires has a width smaller than half of the pitch of the plurality of metal nanowires.

6. The light emitting diode of claim 1, further comprising:

a reflecting layer between the support layer and the semiconductor layer structure.

7. The light emitting diode of claim 1, wherein each of the plurality of metal nanowires has a pitch smaller than half of a wavelength of light emitted from the light-emitting layer.

8. The light emitting diode of claim 1, wherein each of the plurality of metal nanowires are made of Al, Au, Ag, Pd, Pt, or an alloy thereof.

9. The light emitting diode of claim 1, wherein at least one of the metal nanowires of the plurality of metal nanowires is an electrode for applying a voltage to the semiconductor layer structure.

10. The light emitting diode of claim 1, further comprising:

a depolarizing layer configured to depolarize light reflected from the polarization control layer.

11. The light emitting diode of claim 10, wherein the depolarizing layer is made of an optical anisotropic material having a variable refractive index according to the polarization of incident light.

12. The light emitting diode of claim 10, wherein the depolarizing layer is a scattering layer.

13. The light emitting diode of claim 10, wherein the depolarizing layer is between the support layer and the semiconductor layer structure.

14. The light emitting diode of claim 10, wherein the depolarizing layer is between the polarization control layer and the semiconductor layer structure.

15. The light emitting diode of claim 10, wherein the depolarizing layer is in the semiconductor layer structure.

16. The light emitting diode of claim 10, further comprising:

a reflecting layer between the support layer and the semiconductor layer structure.

17. The light emitting diode of claim 16, wherein the depolarizing layer is between the reflecting layer and the semiconductor layer structure.

18. The light emitting diode of claim 10, further comprising:

a reflecting layer on each side surface of the support layer, the semiconductor layer structure, and the polarization control layer.

19. The light emitting diode of claim 1, further comprising:

a reflecting layer on each side surface of the support layer, the semiconductor layer structure, and the polarization control layer.

20. The light emitting diode of claim 1, wherein the transparent conducting layer is made of ITO or ZnO.

21. A method of forming a polarized light emitting diode, the method comprising:

forming a semiconductor layer structure on a substrate, the semiconductor layer structure including a first semiconductor layer, a light emitting layer, and a second semiconductor layer;

forming a reflecting layer on the second semiconductor layer;

forming a support layer and attaching it to the reflecting layer;

removing the substrate from the semiconductor layer structure; and

forming a polarization control layer on the first semiconductor layer, the polarization control layer including metal nanowires and a transparent conducting layer, the metal nanowires enclosed within the transparent conducting layer so as to not contact a surface of the semiconductor layer structure, wherein an entire surface of the metal nanowires enclosed within the transparent conducting layer is directly in contact with the transparent conducting layer.