OLED device having improved lifetime and output

• US 20060244371A1
• Filed: 09/01/2005
• Published: 11/02/2006
• Est. Priority Date: 05/02/2005
• Status: Abandoned Application

• Current Assignee: Eastman Kodak Company
• Original Assignee: Eastman Kodak Company
• Inventors: Preuss, Donald R., Tyan, Yuan-Sheng, Tutt, Lee W., Shore, Joel D., Farruggia, Giuseppe, Cok, Ronald S.
• Application Number:
  US11/218,249
• Publication Number:
  US 20060244371A1
• Time in Patent Office: Days
• US Class Current: 313/506
• CPC Class Codes: H10K 50/19 Tandem OLEDs
• CPC Class Codes: H10K 50/852 comprising a resonant cavity structure, e.g. Bragg reflector pair
• CPC Class Codes: H10K 59/876 comprising a resonant cavity structure, e.g. Bragg reflector pair

Abstract

An organic light-emitting diode (OLED) device, comprising: a) a first OLED element; b) a second OLED element formed over the first OLED element; and c) a scattering layer optically coupled to the first and/or the second OLED elements; wherein the first and second OLED elements each include first and second spaced-apart conductors with one or more organic layers formed there-between, at least one organic layer of each of the first and second OLED elements being a light-emitting layer.

Claims

1. An organic light emitting diode (OLED) device, comprising:

a) a first OLED element;

b) a second OLED element formed over the first OLED element; and

c) a scattering layer optically coupled to the first and/or the second OLED elements;

wherein the first and second OLED elements each include first and second spaced-apart conductors with one or more organic layers formed there-between, at least one organic layer of each of the first and second OLED elements being a light-emitting layer.

2. The OLED device of claim 1, wherein the first and second OLED elements share a conductor.

3. The OLED device of claim 2 wherein the shared conductor is an electrode connected to an external power source.

4. The OLED device of claim 2 wherein the shared conductor is not connected to an external power source.

5. The OLED device of claim 4 wherein the shared conductor comprises an organic connective layer with or without doping materials.

6. The OLED device of claim 1 wherein at least one conductor of each OLED element is an electrode connected to an external power source.

7. The OLED device of claim 1 wherein at least one of the conductors comprises a metal, metal oxide, silver, aluminum, magnesium, alloys of silver, aluminum, or magnesium, or indium tin oxide or indium zinc oxide layer.

8. The OLED device of claim 1 wherein at least one of the conductors is patterned to form independently controllable light-emitting areas for at least one of the OLED elements.

9. The OLED device of claim 1 wherein the light-emitting organic layers of the first and second OLED elements emit the same color of light.

10. The OLED device of claim 1 wherein the light-emitting organic layers of the first and second OLED elements emit different colors of light.

11. The OLED device of claim 1 wherein the light-emitting organic layers of the first and/or second OLED elements emit substantially white light.

12. The OLED device of claim 1 wherein the first and second light-emitting organic layers emit complementary colors of light.

13. The OLED device of claim 1 wherein at least one of the conductors of the first or second OLED elements is at least partially reflective.

14. The OLED device of claim 1 wherein the scattering layer is in contact with a conductor, or forms a part of a conductor.

15. The OLED device of claim 1, further comprising a third OLED element formed over or under the first and second OLED elements.

16. The OLED device of claim 1, wherein the scattering layer is formed between the first and second OLED elements and is optically coupled to both the first and second OLED elements.

17. The OLED device of claim 1, wherein the scattering layer is formed as a part of a shared conductor of the first and second OLED elements and is optically coupled to both the first and second OLED elements.

18. The OLED device of claim 1, comprising one or more scattering layers optically coupled with each of the first and second OLED elements.

19. The OLED device of claim 1 wherein the OLED elements comprise materials having optical indices and layers thicknesses that in the absence of the scattering layer would form constructive optical interference that optimizes light output at a range of frequencies that does not correspond to the range of frequencies emitted by at least one of the OLED elements.

20. An organic light emitting diode (OLED) device, comprising:

a) substrate;

b) a first OLED element formed on the substrate;

c) a second OLED element formed over the first OLED element;

d) a cover provided over the first and second OLEDs; and

e) a scattering layer optically coupled with the first and/or the second OLED elements;

wherein the first and second OLED elements each include first and second spaced-apart conductors with one or more organic layers formed there-between, at least one organic layer of each of the first and second OLED elements being a light-emitting layer and wherein the first and second OLED elements have a first optical index range; and

wherein light emitted by the first and second OLED elements is emitted through either the cover or the substrate, the cover or substrate through which light is emitted having a second optical index; and

wherein a low-index element is formed between the scattering layer and the cover or substrate through which light is emitted, the low-index element having a third optical index lower than either of the first optical index range or the second optical index.