OLED device with improved efficiency and robustness

• US 7,531,955 B2
• Filed: 07/12/2005
• Issued: 05/12/2009
• Est. Priority Date: 07/12/2005
• Status: Active Grant

• Current Assignee: Global OLED Technology LLC (LG Display Co., Ltd.)
• Original Assignee: Eastman Kodak Company
• Inventors: Tutt, Lee W., Cok, Ronald S.
• Primary Examiner(s): Roy; Sikha
• Assistant Examiner(s): Green; Tracie Y
• Application Number:
  US11/179,409
• Publication Number:
  US 20070013291A1
• Time in Patent Office: 1,400 Days
• Field of Search: 313501-512, 445 24- 25
• US Class Current: 313/501
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: H10K 2102/3026 Top emission
• CPC Class Codes: H10K 2102/331 Nanoparticles used in non-emissive layers, e.g. in packaging layer
• CPC Class Codes: H10K 50/8428 Vertical spacers, e.g. arranged between the sealing arrangement and the OLED
• CPC Class Codes: H10K 50/854 comprising scattering means
• CPC Class Codes: H10K 50/858 comprising refractive means, e.g. lenses

Abstract

An organic light-emitting diode (OLED) device including a substrate; an OLED formed on the substrate; a transparent cover provided over the OLED through which light from the OLED is emitted; separately formed spacer element particles having a first average size distributed above the OLED, providing spacing between the OLED and the cover, and forming a transparent gap between the OLED and the cover, and separately formed light-scattering element particles distributed over the OLED between the spacer element particles, having a second average size smaller than the first size and for scattering light emitted by the OLED.

Claims

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

a substrate;

an OLED formed on the substrate comprising a first electrode formed over the substrate, one or more layers of organic material, one of which emits light, formed over the first electrode, and a transparent second electrode formed over the one or more layers of organic material, the transparent second electrode and layer(s) of organic light-emitting material having a first refractive index range, wherein one of the first or second electrodes is patterned to form a plurality of separated light-emissive areas;

a transparent cover provided over the OLED through which light from the OLED is emitted, the cover having a second refractive index;

separately formed transparent spacer element particles having a first average size distributed above the transparent second electrode in one or more of the separated light-emissive areas, providing spacing between the transparent second electrode and the cover, and forming a transparent gap between the transparent second electrode and the cover, the transparent gap having a third refractive index lower than each of the first refractive index range and second refractive index; and

separately formed transparent light-scattering element particles distributed over, and in contact with, the transparent second electrode between the spacer element particles, having a second average size smaller than the first size and for scattering light emitted by the light-emitting layer.

2. The OLED device of claim 1, wherein the spacer element particles are deposited on the cover or the OLED.

3. The OLED device of claim 1, wherein the spacer element particles are in contact with the cover or the OLED or with both the cover and the OLED.

4. The OLED device of claim 1, wherein the spacer element particles are randomly located over the OLED, regularly distributed over the OLED, or are located between light-emitting portions of the OLED.

5. The OLED device of claim 1, wherein the spacer element particles comprise titanium dioxide, polymer, or barium oxide.

6. The OLED device of claim 1, wherein the spacer element particles are light-scattering particles.

7. The OLED device of claim 1, wherein the spacer element particles are affixed to the cover or OLED with an adhesive.

8. The OLED device of claim 7, wherein the adhesive is patterned.

9. The OLED device of claim 1, wherein the gap is filled with a low-index material.

10. The OLED device of claim 1, wherein the gap is filled with an inert gas, air, nitrogen, or argon.

11. The OLED device of claim 1, wherein the spacer element particles have an average particle size greater than 2 microns.

12. The OLED device of claim 1, wherein the light-scattering element particles have an average particle size less than 2 microns.

13. The OLED device of claim 1, wherein the light-scattering element particles have a refractive index greater than the refractive index of any component of the OLED.

14. The OLED device of claim 1, wherein the light-scattering element particles and the spacer element particles comprise the same material.

15. The OLED device of claim 1, wherein the light-scattering element particles and the spacer element particles comprise different materials.

16. The OLED device of claim 1, wherein the light-scattering element particles and the spacer element particles are deposited in a common step.

17. The OLED device of claim 1, wherein the light-scattering element particles are deposited within a matrix material.