Self assembled controlled luminescent transparent conductive photonic crystals for light emitting devices

• US 20080142810A1
• Filed: 10/10/2007
• Published: 06/19/2008
• Est. Priority Date: 10/10/2006
• Status: Abandoned Application

• Current Assignee: Structured Materials Industries Incorporated
• Original Assignee: Structured Materials Industries Incorporated
• Inventors: Sun, Shangzhu, Sbrockey, Nick M., Rice, Catherine E., Provost, Lloyd G., Tompa, Gary S.
• Application Number:
  US11/973,766
• Publication Number:
  US 20080142810A1
• Time in Patent Office: Days
• US Class Current: 257/76
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: C23C 16/407 of zinc, germanium, cadmium, indium, tin, thallium or bismuth
• CPC Class Codes: C23C 16/4481 by evaporation using carrier gas in contact with the source material C23C16/4486 takes precedence
• CPC Class Codes: C30B 25/18 characterised by the substrate
• CPC Class Codes: C30B 29/16 Oxides
• CPC Class Codes: C30B 29/406 Gallium nitride
• CPC Class Codes: G02B 6/1225 comprising photonic band-gap structures or photonic lattices
• CPC Class Codes: H01B 1/16 the conductive material comprising metals or alloys
• CPC Class Codes: H01L 33/32 containing nitrogen
• CPC Class Codes: H01L 33/42 Transparent materials

Abstract

A transparent conductive oxide contact layer to enhance the spectral output of a light emitting device and a methodology for its deposition. The transparent conductive oxide deposited on the light emitting device so as to have a columnar structure. The transparent conductive oxide contact layer may be preferably ZnO doped with a conductive element. Light emitting phosphors may also be deposited within the transparent conductive oxide contact layer.

Claims

1. A transparent conductive oxide contact layer to enhance spectral output of a light emitting device comprising a transparent conductive oxide deposited on the light emitting device so as to have a columnar structure.

2. The transparent conductive oxide contact layer as claimed in claim 1 wherein the oxide comprises at least one of ZnO, AlCuO and ITO.

3. The transparent conductive oxide contact layer as claimed in claim 1 wherein the oxide is doped with a conductive element selected from the group of:

Al, Ga, In, N, P and Sb.

4. The transparent conductive oxide contact layer as claimed in claim 1 wherein the oxide layer includes light emitting phosphors deposited therein.

5. The transparent conductive oxide contact layer as claimed in claim 1 wherein the layer is deposited by Chemical vapor deposition.

6. The transparent conductive oxide contact layer as claimed in claim 1 wherein the light emitting device comprises a gallium nitride (GaN) light emitting diode.

7. The transparent conductive oxide contact layer as claimed in claim 1 wherein the oxide layer includes bandgap modifying layers deposited therein.

8. In a light emitting device having multiple layers the improvement comprising a transparent conductive contact layer deposited directly on said light emitting device by chemical vapor deposition the transparent conductive contact layer have a columnar structure so as to direct the emitted light in a direction normal to the surface of the device.

9. The light emitting device as claimed in claim 8 wherein the transparent conductive contact layer comprises ZnO doped with a conductive element.

10. The light emitting device as claimed in claim 9 wherein the conductive element comprises at least one of:

Al, Ga, In, N, P, As, and Sb.

11. The light emitting device as claimed in claim 8 further including a light emitting phosphor deposited within the transparent conductive contact layer during the chemical vapor deposition process.

12. The light emitting device as claimed in claim 8 further including a passivation layer deposited on the transparent conductive contact layer during the chemical vapor deposition process.

13. The light emitting device as claimed in claim 8 wherein the light emitting device comprises a gallium nitride (GaN) light emitting diode.

14. A method for deposition of a transparent conductive oxide contact layer comprising the steps of:

a) providing a light emitting device;

b) placing said a light emitting device in a CVD reaction chamber;

c) depositing a transparent conductive oxide contact layer utilizing a carrier gas bubbled through liquid precursors of the components of the transparent conductive and an oxidizing gas; and

d) controlling the parameters of the deposition process so that the transparent conductive oxide is formed with at least a partially columnar structure.

15. The method for deposition as claimed in claim 14 wherein the transparent conductive oxide comprises ZnO doped with a conductive element.

16. The method for deposition as claimed in claim 15 wherein the conductive element is selected from the group of:

Al, Ga, In, N, P and Sb.

17. The method for deposition as claimed in claim 14 further including the step of depositing light emitting phosphors within the transparent conductive oxide contact layer.

18. The method for deposition as claimed in claim 14 wherein the oxide comprises at least one of ZnO, AlCuO and ITO.

19. The method for deposition as claimed in claim 14 further including the step of annealing the transparent conductive oxide to modify its properties.