Light emitting diode comprising semiconductor nanocrystal complexes

• US 20070012941A1
• Filed: 07/13/2006
• Published: 01/18/2007
• Est. Priority Date: 07/13/2005
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Cheon, Kwang-Ohk
• Granted Patent: US 8,168,994 B2
• Time in Patent Office: Days
• US Class Current: 257/99
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: H01L 33/502 Wavelength conversion materials
• CPC Class Codes: H01L 33/56 Materials, e.g. epoxy or silicone resin
• CPC Class Codes: H01L 33/644 in intimate contact or integrated with parts of the device other than the semiconductor body

Abstract

A light emitting diode (LED) formed by depositing an LED chip and coupling a stability layer to the LED chip. Semiconductor nanocrystals are placed in a first matrix material to form a nanocrystal complex layer. The nanocrystal complex layer is deposited on top of the stability layer. A thickness of the stability layer is chosen to maximizes a power of a light output by the nanocrystal complex layer. The matrix material and the stability layer can be of the same type of material. Additional layers of matrix material can be deposited on top of the nanocrystal complex layer. These additional layers can comprise matrix material only or can comprise matrix material and semiconductor nanocrystals to form another nanocrystal complex layer.

Claims

1. A light emitting diode (LED) comprising:

an LED chip;

a stability layer; and

a nanocrystal complex layer comprising a semiconductor nanocrystal complex and a matrix material.

2. The LED of claim 1, wherein the stability layer is between the LED chip and the nanocrystal complex layer.

3. The LED of claim 1, further comprising at least one matrix material layer.

4. The LED of claim 3, wherein the at least one matrix material layer is over the nanocrystal complex layer.

5. The LED of claim 1, wherein the semiconductor nanocrystal complex comprises a a semiconductor nanocrystal core.

6. The LED of claim 5, wherein the semiconductor nanocrystal core comprises a binary semiconductor.

7. The LED of claim 5, wherein the semiconductor nanocrystal core comprises a ternary semiconductor.

8. The LED of claim 1, wherein the semiconductor nanocrystal complex absorbs energy at a first wavelength emitted by the LED chip and emits energy at a second wavelength.

9. The LED of claim 1, wherein the stability layer and the matrix material comprise the same type of material.

10. A method of forming a light emitting diode (LED) comprising:

depositing an LED chip;

coupling a stability layer to the LED chip;

forming a nanocrystal complex layer by placing semiconductor nanocrystals in a first matrix material; and

depositing the nanocrystal complex layer over the stability layer.

11. The method of claim 10, further comprising depositing an additional layer over the nanocrystal complex layer.

12. The method of claim 11, wherein the additional layer comprises a second matrix material.

13. The method of claim 12, wherein the additional layer comprises semiconductor nanocrystals.

14. The method of claim 10, wherein the stabiltiy layer comprises urethane/acrylate.

15. The method of claim 14, wherein the stability layer comprises 1.0 μ

l of urethane/acrylate.

16. The method of claim 10, wherein the first matrix material comprises 0.7 μ

l of urethane/acrylate.

17. A method of forming a light emitting diode (LED) comprising:

placing an LED chip at the bottom of an LED cup;

placing a plurality of layers of matrix material over the LED chip, wherein at least one of the plurality of layers comprises quantum dots.

18. The method of claim 17, further comprising placing at least one layer that does not comprise quantum dots between the LED chip and the at least one layer comprising quantum dots.

19. The method of claim 18, wherein a thickness of the at least one layer that does not comprise quantum dots substantially maximizes a power of a light output by the at least one layer comprising quantum dots.