Aryloxyalkylcarboxylate solvent compositions for inkjet printing of organic layers

• US 9,252,363 B2
• Filed: 10/04/2012
• Issued: 02/02/2016
• Est. Priority Date: 10/04/2012
• Status: Active Grant

• Current Assignee: Universal Display Corporation
• Original Assignee: Universal Display Corporation
• Inventors: Cheon, Kwang-Ohk, Dong, Angang, Layek, Suman, Inbasekaran, Michael
• Primary Examiner(s): Bohaty, Andrew K
• Application Number:
  US13/644,480
• Publication Number:
  US 20140097406A1
• Time in Patent Office: 1,216 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: H10K 2101/10 Triplet emission
• CPC Class Codes: H10K 50/11 characterised by the electroluminescent [EL] layers
• CPC Class Codes: H10K 50/155 comprising dopants
• CPC Class Codes: H10K 71/135 using ink-jet printing
• CPC Class Codes: H10K 71/15 characterised by the solvent used
• CPC Class Codes: H10K 85/342 comprising iridium

Abstract

A liquid composition (e.g., inkjet fluid) for forming an organic layer of an organic electronic device (e.g., an OLED). The liquid composition comprises a small molecule organic semiconductor material mixed in a solvent in which the solvent compound has the following formula:

wherein R¹ is C_1-6 alkyl; R² is C_1-6 alkyl; and R³ is one or more optional substitutions independently selected from C_1-6 alkyl and lower aryl.

Claims

1. A liquid composition comprising:

a small molecule organic semiconductor material at a concentration in the range of 0.01-10 wt %; and

a solvent having a melting point of 25°

C. or lower, the solvent compound having the following formula;

2. The liquid composition of claim 1, wherein the solvent has a boiling point of 260°

C. or lower at 1 atm.

3. The liquid composition of claim 2, wherein the solvent has a boiling point in the range of 150-260°

C. at 1 atm.

4. The liquid composition of claim 1, wherein the solvent compound has a molecular weight in the range of 166-400.

5. The liquid composition of claim 1, wherein the small molecule organic semiconductor material is a phosphorescent emitting compound.

6. The liquid composition of claim 5, further comprising a small molecule host compound.

7. The liquid composition of claim 1, wherein the organic semiconductor material is a charge transporting material.

8. The liquid composition of claim 1, wherein the liquid composition has a viscosity in the range of 5-15 cPs at 23°

C.

9. The liquid composition of claim 1, wherein the solvent has a viscosity in the range of 5-15 cPs at 23°

C.

10. The liquid composition of claim 1, wherein the solvent is methyl phenoxyacetate or ethyl phenoxyacetate.

11. The liquid composition of claim 1, wherein the organic semiconductor material has a molecular weight of 3,000 or less.

12. The liquid composition of claim 1, further comprising another solvent to form a solvent blend.

13. The liquid composition of claim 12, wherein the another solvent is 3-phenoxytoluene.

14. The liquid composition of claim 1, wherein the solvent has a boiling point in the range of 150-260°

C. at 1 atm, a viscosity in the range of 5-15 cPs at 23°

C., and a molecular weight in the range of 166-400.

15. A method of forming an organic layer for an organic electronic device, comprising:

depositing the liquid composition of claim 1 on a surface; and

drying the liquid composition to form the organic layer on the surface.

16. The method of claim 15, wherein the organic electronic device is an organic light emitting device and the organic layer is an emissive layer.

17. The method of claim 16, wherein the surface is the surface of another organic layer or an electrode of the electronic device.