Polychromatic LED's and related semiconductor devices

• US 7,745,814 B2
• Filed: 12/09/2004
• Issued: 06/29/2010
• Est. Priority Date: 12/09/2004
• Status: Expired due to Fees

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Haase, Michael A., Miller, Thomas J., Sun, Xiaoguang
• Primary Examiner(s): Parker; Kenneth A
• Assistant Examiner(s): NGUYEN, JOSEPH H
• Application Number:
  US11/009,241
• Publication Number:
  US 20060124918A1
• Time in Patent Office: 2,028 Days
• Field of Search: 257 12- 15, 257/21, 257/22, 257/79, 257/89, 257/97, 257/186, 257/189, 257/191, 257/200, 257/85, 257/90, 257/96
• US Class Current: 257/13
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: H01L 33/0008 having p-n or hi-lo junctions
• CPC Class Codes: H01L 33/06 within the light emitting region, e.g. quantum confinement structure or tunnel barrier
• CPC Class Codes: H01L 33/28 containing only elements of Group II and Group VI of the Periodic Table

Abstract

A semiconductor device is provided comprising a first potential well located within a pn junction and a second potential well not located within a pn junction. The potential wells may be quantum wells. The semiconductor device is typically an LED, and may be a white or near-white light LED. The semiconductor device may additionally comprise a third potential well not located within a pn junction. The semiconductor device may additionally comprise absorbing layers surrounding or closely or immediately adjacent to the second or third quantum wells. In addition, graphic display devices and illumination devices comprising the semiconductor device according to the present invention are provided.

Claims

1. A semiconductor device comprising a first potential well located within a pn junction that emits light at a first wavelength when the pn junction is biased, a second potential well that emits light at a second wavelength in response to an absorption of at least a portion of light at the first wavelength, and a first absorbing layer closely adjacent to the second potential well and having a band gap energy less than or equal to a first transition energy of the first potential well and greater than a second transition energy of the second potential well.

2. The semiconductor device according to claim 1, wherein the absorbing layer is immediately adjacent to said second potential well.

3. The semiconductor device according to claim 2 wherein said first potential well is a quantum well and wherein said second potential well is a quantum well.

4. The semiconductor device according to claim 3 which is an LED.

5. The semiconductor device according to claim 2 which is an LED.

6. The semiconductor device according to claim 1 additionally comprising a third potential well that emits light at a third wavelength in response to an absorption of at least a portion of light at the first wavelength.

7. The semiconductor device according to claim 6 additionally comprising a second absorbing layer immediately adjacent to said third potential well and having a band gap energy less than or equal to the first transition energy and greater than a third transition energy of the third potential well.

8. The semiconductor device according to claim 7 wherein said first potential well is a quantum well, wherein said second potential well is a quantum well, and wherein said third potential well is a quantum well.

9. The semiconductor device according to claim 8 which is an LED.

10. The semiconductor device according to claim 7 which is an LED.

11. The semiconductor device according to claim 7 wherein said first transition energy corresponds to green, blue or violet wavelength visible light, wherein said second transition energy corresponds to yellow, green or blue wavelength visible light, wherein said third transition energy corresponds to red, orange or yellow wavelength visible light.

12. A liquid crystal display comprising the semiconductor device according to claim 11, wherein said first, second and third transition energies are matched to the color filters of the liquid crystal display.

13. The semiconductor device according to claim 7 wherein said first transition energy corresponds to blue or violet wavelength visible light, wherein said second transition energy corresponds to yellow or green wavelength visible light, wherein said third transition energy corresponds to red or orange wavelength visible light.

14. The semiconductor device according to claim 6 wherein said first potential well is a quantum well, wherein said second potential well is a quantum well, and wherein said third potential well is a quantum well.

15. The semiconductor device according to claim 14 which is an LED.

16. The semiconductor device according to claim 6 which is an LED.

17. The semiconductor device according to claim 6, wherein said third potential well is not within the pn junction.

18. The semiconductor device according to claim 1 wherein said first potential well is a quantum well and wherein said second potential well is a quantum well.

19. The semiconductor device according to claim 18 which is an LED.

20. The semiconductor device according to claim 1 which is an LED.

21. The semiconductor device according to claim 1 wherein said first transition energy corresponds to ultraviolet wavelength light and wherein said second transition energy corresponds to visible wavelength light.

22. The semiconductor device according to claim 1 wherein said first transition energy corresponds to visible wavelength light and wherein said second transition energy corresponds to infrared wavelength light.

23. A graphic display device comprising the semiconductor device according to claim 1.

24. An illumination device comprising the semiconductor device according to claim 1.

25. The semiconductor device according to claim 1 which is a magenta-emitting LED.

26. The semiconductor device according to claim 1 which is a cyan-emitting LED.

27. A liquid crystal display comprising the semiconductor device according to claim 1.

28. The semiconductor device according to claim 1, wherein said second potential well is not within the pn junction.

29. The semiconductor device according to claim 1, wherein said first potential well comprises a III-V compound and said second potential well comprises a II-VI compound.

30. The semiconductor device according to claim 1, wherein said second potential well comprises a Cd(Mg)ZnSe alloy.