CIRCULAR PHOTONIC CRYSTAL STRUCTURE, LIGHT EMITTING DIODE DEVICE AND PHOTOELECTRIC CONVERSION DEVICE

• US 20120251035A1
• Filed: 06/01/2011
• Published: 10/04/2012
• Est. Priority Date: 03/28/2011
• Status: Active Grant

• Current Assignee: Industrial Technology Research Institute
• Original Assignee: Industrial Technology Research Institute
• Inventors: Chang, Tien-Li, Lin, Hung-Yi, Chou, Ta-Hsin, Tsai, Jen-Hui, Hsu, Chia-Chen, Lin, Jian-Hung
• Granted Patent: US 8,755,645 B2
• Time in Patent Office: Days
• US Class Current: 385/14
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: G02B 1/005 made of photonic crystals or photonic band gap materials photonic band-gap structures or photonic lattices in integrated optics G02B6/1225; photonic band-gap structures or photonic lattices in optical fibres G02B6/02295
• CPC Class Codes: G02B 6/1225 comprising photonic band-gap structures or photonic lattices
• CPC Class Codes: H01L 31/0543 comprising light concentrating means of the refractive type, e.g. lenses
• CPC Class Codes: H10K 30/87 Light-trapping means
• CPC Class Codes: H10K 50/858 comprising refractive means, e.g. lenses
• CPC Class Codes: Y02E 10/52 PV systems with concentrators
• CPC Class Codes: Y02E 10/549 Organic PV cells

Abstract

A method applying a circular photonic crystal structure to improve optical properties of a photoelectric conversion device such as a light emitting diode device, an organic light emitting diode device or a solar cell is provided, wherein the circular photonic crystal structure is configured on a junction surface between two different mediums where passes a light emitted or received by the photoelectric conversion device. The circular photonic crystal structure provides isotropic photonic band gap which conduces high light extraction efficiency.

Claims

1. A photoelectric conversion device, comprising:

a photoelectric conversion part suitable for emitting or receiving a light;

a first medium located in a periphery of the photoelectric conversion part, wherein the light passes through the first medium and a second medium outside the first medium, and the first medium and the second medium have different refractive indices; and

a circular photonic crystal structure disposed at a junction surface between the first medium and the second medium, wherein the circular photonic crystal structure comprises a plurality of openings, one of the openings is located at a center of the circular photonic crystal structure and encircled by a plurality of concentric circles comprises the other openings.

2. The photoelectric conversion device as claimed in claim 1, wherein coordinates of centers of the openings on one of the concentric circles are determined by the following equations:

3. The photoelectric conversion device as claimed in claim 2, wherein b=N·

Δ

θ

_N.

4. The photoelectric conversion device as claimed in claim 2, wherein b is a random number.

5. The photoelectric conversion device as claimed in claim 2, wherein b is a constant.

6. The photoelectric conversion device as claimed in claim 2, wherein a is an integer, and 5≦

a≦

8.

7. The photoelectric conversion device as claimed in claim 1, wherein a distance between two adjacent concentric circles is between 300 nanometers and 2000 nanometers.

8. The photoelectric conversion device as claimed in claim 1, wherein a depth of each of the openings is between 50 nanometers and 300 nanometers.

9. The photoelectric conversion device as claimed in claim 1, wherein a filling rate of each of the openings is between 0.2 and 0.5.

10. The photoelectric conversion device as claimed in claim 1, wherein a profile of each of the openings comprises circular, elliptic or rectangular.

11. The photoelectric conversion device as claimed in claim 1, wherein the photoelectric conversion part comprises a light emitting diode, an organic electro-luminescent device or a photo-electro device.

12. The photoelectric conversion device as claimed in claim 1, wherein the first medium comprises semiconductor material or organic material.

13. A light emitting diode device, comprising:

a substrate;

a first-type doped semiconductor layer disposed on the substrate;

a second-type doped semiconductor layer disposed on the first-type doped semiconductor layer;

an active region located between the first-type doped semiconductor layer and the second-type doped semiconductor layer;

a first electrode disposed on the first-type doped semiconductor layer;

a second electrode disposed on the second-type doped semiconductor layer; and

a circular photonic crystal structure disposed on a top surface of the second-type doped semiconductor layer or between the first-type doped semiconductor layer and the substrate, wherein the circular photonic crystal structure comprises a plurality of openings, one of the openings is located at a center of the circular photonic crystal structure and encircled by a plurality of concentric circles comprises the other openings.

14. The light emitting diode as claimed in claim 13, wherein coordinates of a center of each of the openings is determined by the following equations:

15. The light emitting diode device as claimed in claim 14, wherein b=N·

Δ

θ

_N.

16. The light emitting diode device as claimed in claim 14, wherein b is a random number.

17. The light emitting diode device as claimed in claim 14, wherein b is a constant.

18. The light emitting diode device as claimed in claim 14, wherein a is an integer, and 5≦

a≦

8.

19. The light emitting diode device as claimed in claim 13, wherein a distance between two adjacent concentric circles is between 300 nanometers and 2000 nanometers.

20. The light emitting diode device as claimed in claim 13, wherein a depth of each of the openings is between 50 nanometers and 300 nanometers.

21. The light emitting diode device as claimed in claim 13, wherein a filling rate of each of the openings is between 0.2 and 0.5.

22. The light emitting diode device as claimed in claim 13, wherein a profile of each of the openings comprises circular, elliptic or rectangular.

23. A circular photonic crystal structure adapted to be configured on a junction surface between two different mediums where passes a light emitted or received by a photoelectric conversion device, the circular photonic crystal structure comprising:

a first opening located at a center of the circular photonic crystal structure; and

a plurality of second openings forming a plurality of concentric circles encircling the first opening.

24. The circular photonic crystal structure as claimed in claim 23, wherein coordinates of a center of the first opening or each of the second openings is determined by the following equations:

25. The circular photonic crystal structure as claimed in claim 24, wherein b=N·

Δ

θ

_N.

26. The circular photonic crystal structure as claimed in claim 24, wherein b is a random number.

27. The circular photonic crystal structure as claimed in claim 24, wherein b is a constant.

28. The circular photonic crystal structure as claimed in claim 24, wherein a is an integer, and 5≦

a≦

8.

29. The circular photonic crystal structure as claimed in claim 23, wherein a distance between two adjacent concentric circles is between 300 nanometers and 2000 nanometers.

30. The circular photonic crystal structure as claimed in claim 23, wherein a depth of each of the first or second openings is between 50 nanometers and 300 nanometers.

31. The circular photonic crystal structure as claimed in claim 23, wherein a filling rate of each of the first or second openings is between 0.2 nanometers and 0.5 nanometers.

32. The circular photonic crystal structure as claimed in claim 23, wherein a profile of each of the first or second openings comprises circular, elliptic or rectangular.