OLED WITH MULTI-EMISSIVE MATERIAL LAYER

• US 20170301871A1
• Filed: 04/14/2017
• Published: 10/19/2017
• Est. Priority Date: 04/15/2016
• Status: Active Grant

• Current Assignee: Arizona Board of Regents (University of Arizona)
• Original Assignee: Arizona Board of Regents (University of Arizona)
• Inventors: Li, Jian
• Granted Patent: US 11,335,865 B2
• Time in Patent Office: Days
• CPC Class Codes: C09K 11/025 non-luminescent particle coatings or suspension media
• CPC Class Codes: C09K 11/06 containing organic luminescent materials
• CPC Class Codes: C09K 2211/1007 Non-condensed systems
• CPC Class Codes: C09K 2211/1011 Condensed systems
• CPC Class Codes: C09K 2211/1014 bridged by heteroatoms, e.g. N, P, Si or B
• CPC Class Codes: C09K 2211/1029 containing one nitrogen atom as the heteroatom
• CPC Class Codes: C09K 2211/185 of the platinum group, i.e. Os, Ir, Pt, Ru, Rh or Pd
• CPC Class Codes: H10K 30/865 Intermediate layers comprising a mixture of materials of the adjoining active layers
• CPC Class Codes: H10K 50/13 comprising stacked EL layers within one EL unit
• CPC Class Codes: H10K 50/18 Carrier blocking layers
• CPC Class Codes: H10K 50/181 Electron blocking layers
• CPC Class Codes: H10K 85/341 Transition metal complexes, e.g. Ru(II)polypyridine complexes H10K85/331 takes precedence
• CPC Class Codes: H10K 85/346 comprising platinum
• CPC Class Codes: H10K 85/615 Polycyclic condensed aromatic hydrocarbons, e.g. anthracene
• CPC Class Codes: H10K 85/622 containing four rings, e.g. pyrene
• CPC Class Codes: H10K 85/623 containing five rings, e.g. pentacene
• CPC Class Codes: H10K 85/624 containing six or more rings
• CPC Class Codes: H10K 85/625 containing at least one aromatic ring having 7 or more carbon atoms, e.g. azulene
• CPC Class Codes: H10K 85/626 containing more than one polycyclic condensed aromatic rings, e.g. bis-anthracene
• CPC Class Codes: H10K 85/6572 comprising only nitrogen in the heteroaromatic polycondensed ring system, e.g. phenanthroline or carbazole

Abstract

The present invention relates to organic light emitting devices with a multi-emissive material layer (EML), where a multi-EML generally refers to an emissive layer having at least two layers of emissive material, each layer having a different emitter concentration (e.g. a first EML in direct contact with a second EML, and the emitter concentration of the first EML (hole favorable) exceeds that of the second EML (electron favorable)).

Claims

1. An organic light emitting device comprising:

an anode;

a cathode;

an emissive layer between the anode and the cathode, the emissive layer comprising a first emissive layer in direct contact with a second emissive layer, the first emissive layer comprising a first emitter and the second emissive layer comprising a second emitter, and the concentration of the first emitter in the first emissive layer exceeds the concentration of the second emitter in the second emissive layer.

2. The organic light emitting device of claim 1, wherein the emissive layer comprises a third emissive layer comprising a third emitter, wherein the third emissive layer is in direct contact with the second emissive layer, and the concentration of the second emitter in the second emissive layer exceeds the concentration of the third emitter in the third emissive layer.

3. The organic light emitting device of claim 2, wherein the emissive layer comprises a fourth emissive layer comprising a fourth emitter, wherein the fourth emissive layer is in direct contact with the third emissive layer, and the concentration of the third emitter in the third emissive layer exceeds the concentration of the fourth emitter in the fourth emissive layer.

4. The organic light emitting device of claim 1, wherein the first emitter and the second emitter are the same.

5. The organic light emitting device of claim 1, wherein the first and second emissive layers comprise a host material.

6. The organic light emitting device of claim 1, wherein at least one of the first and second emitters emits red or blue light.

7. The organic light emitting device of claim 1, wherein each of the first emitter and the second emitter comprises an organometallic complex represented by Formula I:

8. The organic light emitting device of claim 1, wherein each of the first emitter and the second emitter comprises an organometallic complex, wherein the metal in each of the organometallic complex is Pt(II), Pd(II), or Ir(III).

9. The organic light emitting device of claim 7, wherein M is Pt(II) or Pd(II).

10. The organic light emitting device of claim 7, wherein the organometallic complex is represented by Formula II:

11. The organic light emitting device of claim 7, wherein the organometallic complex is represented by Formula III:

12. The organic light emitting device of claim 11, wherein:

M is Pt or Pd;

R¹, R², R³, and R⁴ each independently represents hydrogen, halogen, hydroxy, amino, nitro, thiol, substituted or unsubstituted C₁-C₄ alkyl, substituted or unsubstituted alkoxy, or substituted or unsubstituted aryl;

Y^1a represents N, P, SiR^5a, or CR^5a;

Y^1b represents N, P, SiR^5a, or CR^5a;

Y^2c, Y^2d, and Y^2f each independently represents C or N;

R^5a each independently represents substituted or unsubstituted C₁-C₄ alkyl or substituted or unsubstituted aryl;

Y^3a, Y^3b, Y^3d, and Y^3e each independently represents C or N;

Y^4a, Y^4b, Y^4d, and Y^4e each independently represents C or N; and

n is 0, 1, or 2.

13. The organic light emitting device of claim 7, wherein the organometallic complex is represented by Formula IV:

14. The organic light emitting device of claim 7, wherein the organometallic complex has one of the following structures:

15. The organic light emitting device of claim 1, comprising an electron blocking layer between the anode and the emissive layer.

16. The organic light emitting device of claim 15, wherein the electron blocking layer comprises a host material and a dopant.

17. The organic light emitting device of claim 16, wherein host material comprises a carbazole-based material.

18. The organic light emitting device of claim 17, wherein the carbazole-based material comprises one of the following structures:

19. The organic light emitting device of claim 16, wherein the dopant is a fluorescent material.

20. The organic light emitting device of claim 19, wherein the fluorescent material comprises one of the following structures:

1. Aromatic Hydrocarbons and Their Derivatives