Electroluminescent devices for lighting applications

• US 8,288,187 B2
• Filed: 10/27/2010
• Issued: 10/16/2012
• Est. Priority Date: 01/20/2010
• Status: Active Grant

• Current Assignee: Universal Display Corporation
• Original Assignee: Universal Display Corporation
• Inventors: Cheon, Kwang Ohk, Inbasekaran, Mike, Brown, Julie J.
• Primary Examiner(s): Maldonado, Julio J
• Assistant Examiner(s): PATHAK, SHANTANU
• Application Number:
  US12/913,443
• Publication Number:
  US 20110177641A1
• Time in Patent Office: 720 Days
• Field of Search: None
• US Class Current: 438/46
• CPC Class Codes: H10K 2101/10 Triplet emission
• CPC Class Codes: H10K 50/11 characterised by the electroluminescent [EL] layers
• CPC Class Codes: H10K 50/125 specially adapted for multicolour light emission, e.g. for emitting white light
• CPC Class Codes: H10K 50/13 comprising stacked EL layers within one EL unit
• CPC Class Codes: H10K 71/00 Manufacture or treatment specially adapted for the organic devices covered by this subclass
• CPC Class Codes: H10K 71/12 using liquid deposition, e.g. spin coating
• CPC Class Codes: H10K 71/16 using physical vapour deposition [PVD], e.g. vacuum deposition or sputtering
• CPC Class Codes: H10K 71/40 Thermal treatment, e.g. annealing in the presence of a solvent vapour

Abstract

A method of fabricating an organic light emitting device is provided. A first electrode is provided, over which the rest of the device will be fabricated. A first organic layer is deposited over the first electrode via solution processing. The first organic layer includes:

• • i. an organic host material of the first organic layer;
  • ii. a first organic emitting material of the first organic layer;
  • iii. a second organic emitting material of the first organic layer;

A second organic layer is deposited over and in direct contact with the first organic layer. The second organic layer includes an organic emitting material of the second organic layer. A second electrode is then deposited over the second organic layer. The device may include other layers.

Claims

1. A method, comprising:

a. providing a first electrode;

b. providing a first solution having;

an organic host material of a first organic layer;

a first organic emitting material of the first organic layer; and

a second organic emitting material of the first organic layer,

wherein the first organic emitting material of the first organic layer is present in a concentration of 0.01-5wt %; and

wherein the amount of the first organic emitting material of the first organic layer is measured to a variance of less than 5%;

c. depositing the first organic layer over the first electrode via solution processing using the first solution, the first organic layer further comprising;

i. the organic host material of the first organic layer;

ii. the first organic emitting material of the first organic layer;

iii. the second organic emitting material of the first organic layer;

wherein the first and second organic emitting materials are co-doped in the organic host material;

d. depositing a second organic layer over and in direct contact with the first organic layer, the second organic layer further comprising an organic emitting material of the second organic layer; and

e. depositing a second electrode over the second organic layer.

2. The method of claim 1, wherein:

a. the first organic emitting material of the first organic layer has a peak emissive wavelength in the visible spectrum of 590-700 nm.

b. The second organic emitting material of the first organic layer has a peak emissive wavelength in the visible spectrum at 500-590 nm.

c. The organic emitting material of the second organic layer has a peak emissive wavelength in the visible spectrum of 400-500 nm.

3. The method of claim 2, wherein:

the second organic emitting material of the first organic layer is present in the first organic layer in a concentration that is 1.1 to 500 times the concentration of the concentration of the first organic emitting material, and not more than 40 wt %.

4. The method of claim 2, wherein:

the first organic emitting material of the first organic layer is present in the first organic layer in a concentration of 0.2-4 wt %;

the second organic emitting material of the first organic layer is present in the first organic layer in a concentration that is 2 to 200 times the concentration of the concentration of the first organic emitting material.

5. The method of claim 1, wherein the first organic emitting material of the first organic layer, the second organic emitting material of the first organic layer, and the organic emitting material of the second organic layer are all small molecule materials.

6. The method of claim 1, wherein the second organic layer comprises an organic host and the organic emitting material of the second organic layer, and wherein the second organic layer is deposited by vapor deposition, wherein the organic host of the second organic layer and the organic emitting material of the second organic layer are co-deposited.

7. The method of claim 1, further comprising, prior to depositing the first organic layer:

a. depositing a third organic layer comprising an organic material of the third organic layer over the first electrode via solution processing;

b. depositing a fourth organic layer comprising an organic material of the fourth organic layer over the third organic layer via solution processing

wherein the third organic layer does not dissolve when the fourth organic layer is deposited, and the fourth organic layer does not dissolve when the first organic layer is deposited.

8. The method of claim 1, wherein the organic light emitting device emits light having a CIE coordinate of x coordinate in the range of 0.15-0.65, and y coordinate in the range of 0.1-0.7.

9. The method of claim 8, wherein the organic light emitting device emits light having a CIE coordinate of x coordinate in the range of 0.25-0.5, and y coordinate in the range of 0.2-0.5.

10. The method of claim 1, wherein the first organic layer further comprises a third organic emitting material of the first organic layer.

11. The method of claim 1, wherein the amount of the first organic emitting material of the first organic layer is measured to a variance of less than 1%.

12. The method of claim 1, wherein:

a. the first organic emitting material of the first organic layer has a peak emissive wavelength in the visible spectrum of 590-700 nm;

b. the second organic emitting material of the first organic layer has a peak emissive wavelength in the visible spectrum at 570-590 nm; and

c. a third organic emitting material of the first organic layer has a peak emissive wavelength in the visible spectrum of 500-570 nm.