Organic electroluminescent materials and devices

• US 10,074,806 B2
• Filed: 04/15/2014
• Issued: 09/11/2018
• Est. Priority Date: 08/20/2013
• Status: Active Grant

• Current Assignee: Universal Display Corporation
• Original Assignee: Universal Display Corporation
• Inventors: Adamovich, Vadim, Yamamoto, Hitoshi, Wang, Ting-Chih, Weaver, Michael S., Xia, Chuanjun, Alleyne, Bert, Boudreault, Pierre-Luc T., Dyatkin, Alexey Borisovich, Joseph, Scott
• Primary Examiner(s): Kosack, Joseph R
• Application Number:
  US14/253,505
• Publication Number:
  US 20150053939A1
• Time in Patent Office: 1,610 Days
• CPC Class Codes: C07D 213/06 containing only hydrogen and carbon atoms in addition to the ring nitrogen atom
• CPC Class Codes: C07D 213/22 containing two or more pyridine rings directly linked together, e.g. bipyridyl
• CPC Class Codes: C07D 213/26 Radicals substituted by halogen atoms or nitro radicals
• CPC Class Codes: C07D 215/06 having only hydrogen atoms, hydrocarbon or substituted hydrocarbon radicals, attached to the ring nitrogen atom
• CPC Class Codes: C07D 401/04 directly linked by a ring-member-to-ring-member bond
• CPC Class Codes: C07D 403/04 directly linked by a ring-member-to-ring-member bond
• CPC Class Codes: C07D 403/10 linked by a carbon chain containing aromatic rings
• CPC Class Codes: C07D 403/14 containing three or more hetero rings
• CPC Class Codes: C07D 471/04 Ortho-condensed systems
• CPC Class Codes: C07D 487/04 Ortho-condensed systems
• CPC Class Codes: C07D 491/048 the oxygen-containing ring being five-membered
• CPC Class Codes: C07D 495/04 Ortho-condensed systems
• CPC Class Codes: C07F 15/0033 Iridium compounds
• CPC Class Codes: H10K 2101/10 Triplet emission
• CPC Class Codes: H10K 50/11 characterised by the electroluminescent [EL] layers
• CPC Class Codes: H10K 71/00 Manufacture or treatment specially adapted for the organic devices covered by this subclass
• CPC Class Codes: H10K 85/342 comprising iridium
• 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 85/654 comprising only nitrogen as heteroatom H10K85/652 takes precedence
• CPC Class Codes: H10K 85/657 : Polycyclic condensed heteroaromatic hydrocarbons
• CPC Class Codes: H10K 85/6572 : comprising only nitrogen in the heteroaromatic polycondensed ring system, e.g. phenanthroline or carbazole
• CPC Class Codes: Y02E 10/549 : Organic PV cells

Abstract

A composition formed of a mixture of two compounds having similar thermal evaporation properties that are pre-mixed into an evaporation source that can be used to co-evaporate the two compounds into an emission layer in OLEDs via vacuum thermal evaporation process is disclosed.

Claims

1. A composition comprising:

a mixture of a first compound and a second compound;

wherein the first compound has a different chemical structure than the second compound;

wherein the first compound is capable of functioning as a phosphorescent emitter in an organic light emitting device at room temperature;

wherein the first compound has an evaporation temperature T1 of 150 to 350°

C.;

wherein the second compound has an evaporation temperature T2 of 150 to 350°

C., wherein the evaporation temperature of a compound is measured in a vacuum deposition tool at a constant pressure, between 1×

10<sup>−

7</sup> Torr to 1×

10<sup>−

8</sup> Torr, at a 2 Å

/sec deposition rate on a surface positioned at a set distance away from the evaporating compound;

wherein the absolute value of T1−

T2 is less than 20°

C.;

wherein the first compound has a concentration C1 in said mixture and a concentration C2 in a film formed by evaporating the mixture in a vacuum deposition tool at a constant pressure between 1×

10<sup>−

6</sup> Torr to 1×

10<sup>−

9</sup> Torr, at a 2Å

/sec deposition rate on a surface position at a predefined distance away from the mixture being evaporated; and

wherein the absolute value of (C1−

C2)/C1 is less than 5%;

wherein the first compound has a structure according to Formula I;

2. The composition of claim 1, wherein the first compound has a vapor pressure of P1 at T1 at 1 atm, the second compound has a vapor pressure of P2 at T2 at 1 atm;

and

wherein the ratio of P1/P2 is within the range of 0.90 to 1.10.

3. The composition of claim 1, wherein the first compound has a first mass loss rate and the second compound has a second mass loss rate, wherein the ratio between the first mass loss rate and the second mass loss rate is within the range of 0.90 to 1.10.

4. The composition of claim 1, wherein the phosphorescent emitter is capable of emitting light from a triplet excited state to a ground singlet state at room temperature.

5. The composition of claim 1, wherein the second compound is capable of functioning as a host in an organic light emitting device at room temperature.

6. The composition of claim 1, wherein the composition is in liquid form at a temperature less than T1 and T2.

7. The composition of claim 1, wherein R¹ is selected from the group consisting of phenyl, biphenyl, terphenyl, tetraphenyl, pentaphenyl, pyridine, phenyl pyridine and pyridyl phenyl.

8. The composition of claim 1, wherein L is selected from the group consisting of phenyl, pyridyl, biphenyl, terphenyl and a direct bond.

9. The composition of claim 1, wherein R⁴ and R⁵ are each independently selected from the group consisting of phenyl, pyridyl, biphenyl, and terphenyl.

10. The composition of claim 1, wherein the second compound has a structure according to Formula III:

11. The composition of claim 10, wherein R² and R³ are each independently selected from the group consisting of hydrogen, deuterium, non-fused aryl, non-fused heteroaryl and combinations thereof.

12. The composition of claim 10, wherein the second compound has a structure selected from the group consisting of:

13. The composition of claim 1, wherein n is 1.

14. The composition of claim 1, wherein R^A, R^B, R^C, R^D, and R^E are each independently selected from the group consisting of hydrogen, deuterium, alkyl, cycloalkyl, and combinations thereof.

15. The composition of claim 1, wherein at least one of R^C and R^E contains a branched alkyl moiety with branching at a position further than the α

position to the carbonyl group.

16. The composition of claim 1, wherein R^D is hydrogen.

17. The composition of claim 1, wherein at least one of R^C and R^E has the following structure:

18. The composition of claim 1, wherein the first compound has a structure according to Formula IV:

19. The composition of claim 18, wherein R^H and R^J are each independently selected from the group consisting of hydrogen, deuterium, alkyl, cycloalkyl, and combinations thereof.

20. The composition of claim 18, wherein R^H and R^J are methyl.

21. The composition of claim 1, wherein the second compound is selected from the group consisting of:

22. The composition of claim 1, wherein the first compound is selected from the group consisting of:

23. The composition of claim 1, wherein the mixture of the first compound and the second compound is selected from the group consisting of:

(Compound E5

24. The composition of claim 1, wherein the mixture of the first compound and the second compound is

25. A first device comprising a first organic light emitting device, the first organic light emitting device comprising:

an anode;

a cathode; and

an organic layer, disposed between the anode and the cathode, comprising a first composition comprising a mixture of a first compound and a second compound, wherein the first compound has different chemical structure than the second compound;

wherein the first compound is capable of functioning as a phosphorescent emitter in an organic light emitting device at room temperature;

wherein the first compound has evaporation temperature of T1 150 to 350°

C.;

wherein the second compound has evaporation temperature of T2 150 to 350°

C., wherein the evaporation temperature of a compound is measured in a vacuum deposition tool at a constant pressure, between 1×

10<sup>−

7</sup> Torr to 1×

10<sup>−

8</sup> Torr, at a 2 Å

/sec deposition rate on a surface positioned at a set distance away from the evaporating compound;

wherein the absolute value of T1−

T2 is less than 20°

C.;

wherein the first compound has a concentration C1 in said mixture, and a concentration C2 in a film formed by evaporating the mixture in a vacuum deposition tool at a constant pressure between 1×

10<sup>−

6</sup> Torr to 1×

10<sup>−

9</sup> Torr, at a 2 Å

/sec deposition rate on a surface positioned at a predefined distance away from the mixture being evaporated; and

wherein absolute value of (C1−

C2)/C1 is less than 5%;

wherein the first compound has a structure according to Formula I;

26. A method for fabricating an organic light emitting device comprising a first electrode, a second electrode, and a first organic layer disposed between the first electrode and the second electrode, wherein the first organic layer comprises a first composition comprising a mixture of a first compound and a second compound, the method comprising:

providing a substrate having the first electrode disposed thereon;

depositing the first composition over the first electrode; and

depositing the second electrode over the first organic layer, wherein the first compound has different chemical structure than the second compound;

wherein the first compound is capable of functioning as a phosphorescent emitter in an organic light emitting device at room temperature;

wherein the first compound has an evaporation temperature T1 of 150 to 350°

C.;

wherein the second compound has an evaporation temperature T2 of 150 to 350°

C., wherein the evaporation temperature of a compound is measured in a vacuum deposition tool at a constant pressure, between 1×

10<sup>−

7</sup> Torr to 1×

10<sup>−

8</sup> Torr, at a 2 Å

/sec deposition rate on a surface positioned at a set distance away from the evaporating compound;

wherein absolute value of T1−

T2 is less than 20°

C.;

wherein the first compound has a concentration C1 in said mixture, and a concentration C2 in a film formed by evaporating the mixture in a vacuum deposition tool at a constant pressure between 1×

10<sup>−

6</sup> Torr to 1×

10<sup>−

9</sup> Torr, at a 2 Å

/sec deposition rate on a surface positioned at a predefined distance away from the material; and

wherein absolute value of (C1−

C2)/C1 is less than 5%;

wherein the first compound has a structure according to Formula I;