Organic light emitting devices with wide gap host materials

• US 20040209116A1
• Filed: 10/06/2003
• Published: 10/21/2004
• Est. Priority Date: 04/21/2003
• Status: Abandoned Application

• Current Assignee: The Trustees of Princeton University (Princeton University), University of Southern California
• Original Assignee: University of Southern California
• Inventors: Holmes, Russell, Forrest, Stephen, Thompson, Mark E., Ren, Xiaofan
• Application Number:
  US10/680,066
• Publication Number:
  US 20040209116A1
• Time in Patent Office: Days
• US Class Current: 428/690
• CPC Class Codes: C09K 11/06 containing organic luminescent materials
• 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 2211/1044 containing two nitrogen atoms as heteroatoms
• CPC Class Codes: C09K 2211/1096 containing other heteroatoms
• CPC Class Codes: C09K 2211/185 of the platinum group, i.e. Os, Ir, Pt, Ru, Rh or Pd
• CPC Class Codes: H05B 33/14 characterised by the chemical or physical composition or the arrangement of the electroluminescent material , or by the simultaneous addition of the electroluminescent material in or onto the light source
• CPC Class Codes: H10K 2101/10 Triplet emission
• CPC Class Codes: H10K 50/11 characterised by the electroluminescent [EL] layers
• CPC Class Codes: H10K 85/324 comprising aluminium, e.g. Alq3
• CPC Class Codes: H10K 85/342 comprising iridium
• CPC Class Codes: H10K 85/40 Organosilicon compounds, e.g. TIPS pentacene
• CPC Class Codes: H10K 85/615 Polycyclic condensed aromatic hydrocarbons, e.g. anthracene
• CPC Class Codes: H10K 85/631 Amine compounds having at least two aryl rest on at least one amine-nitrogen atom, e.g. triphenylamine
• CPC Class Codes: H10K 85/649 Aromatic compounds comprising a hetero atom

Abstract

The present invention relates to organic light emitting devices (OLEDs), and more specifically to efficient OLEDs having an emissive layer having host material with a wide energy gap. The present invention also relates to materials for use as a wide gap host material.

Claims

1. An organic light emitting device comprising an emissive layer disposed between and electrically connected to an anode and a cathode, wherein the emissive layer comprises a host material and a phosphorescent emissive material, and wherein

the host material comprises a compound of the formula VI

Y—

[X(Ar¹)(Ar²)(Ar³)]_n  

 

(VI)

wherein;

each X is independently selected from Si, Ge, Sn, Pb, Se, Ti, Zr, and Hf;

Y is selected from phenyl, alkyl, cycloalkyl, and a group of the formula

Ar′

-A-Ar″

wherein each Ar′ and

Ar″

are independently selected from an aromatic group, and

A is alkyl, cycloalkyl, —

O—

, or Si(R′

)(R″

)

wherein R′ and

R″

are independently selected from phenyl or alkyl;

each Ar¹, Ar², and Ar³ are independently selected from alkyl or an aromatic group; and

each Ar¹, Ar², and Ar³ may be independently substituted with one or more of alkyl, alkenyl, alkoxy, phenyl, aralkyl, halogen, NH₂, NHR, NR₂, SiR₃ and CN, and additionally or alternatively, one or more of adjacent Ar¹, Ar², Ar³ may be linked together by a linking group selected from a covalent bond, —

O—

, —

CH₂—

, —

CHR—

, —

CR₂—

, —

NH— and

—

NR—

;

each R is selected from alkyl, alkenyl, aryl, and aralkyl;

n is an integer between 2 up to the maximum number of sites on Y that can accept a substituent;

wherein the host material has an energy gap of at least 3.2 eV and a triplet energy of at least about 3.0 eV.

2. The organic light emitting device of claim 1, wherein X¹ and X² are both Si.

3. The organic light emitting device of claim 1, wherein each Ar¹, Ar², and Ar³are independently selected from phenyl or substituted phenyl.

4. The organic light emitting device of claim 1, wherein the phosphorescent emissive material emits in the blue region of the visible spectrum.

5. The organic light emitting device of claim 1, wherein the host material has an energy gap of at least 3.5 eV.

6. An organic light emitting device of claim 1, wherein the host material comprises a compound of the formula VII:

7. The organic light emitting device of claim 6, wherein X¹ and X² are both Si.

8. The organic light emitting device of claim 7, wherein each Ar¹, Ar², Ar³, Ar⁴, Ar⁵, and Ar⁶ are independently selected from an aromatic group.

9. The organic light emitting device of claim 7, wherein each Ar¹, Ar², Ar³, Ar⁴, Ar⁵, and Ar⁶ are independently selected from a phenyl or substituted phenyl.

18. The organic light emitting device of claim 1, wherein the host material is a compound having the formula XI or a compound of the formula XII:

19. The organic light emitting device of claim 18, wherein X¹ and X² are both Si.

20. The organic light emitting device of claim 18, wherein the host material is a compound having the formula

21. The organic light emitting device of claim 18, wherein the host material is a compound having the formula

10. An organic light emitting device comprising an emissive layer disposed between and electrically connected to an anode and a cathode, wherein the emissive layer comprises a host material and a phosphorescent emissive material, and wherein

the host material comprises a compound of the formula VIII

wherein

X¹ and X² are independently selected from Si, Ge, Sn, Pb, Se, Ti, Zr, and Hf;

Ar is phenyl;

Ar¹, Ar², Ar³, Ar⁴, Ar⁵, and Ar⁶ are independently selected from an aromatic group and an alkyl group;

each of Ar, Ar¹, Ar², Ar³, Ar⁴, Ar⁵, and Ar⁶ may be independently substituted with one or more of alkyl, alkenyl, alkoxy, phenyl, aralkyl, halogen, NH₂, NHR, NR₂, SiR₃ and CN;

and additionally or alternatively, one or more of adjacent Ar, Ar¹, Ar², Ar³, Ar⁴, Ar⁵, and Ar⁶ may be linked together by a linking group selected from a covalent bond, —

O—

, —

CH₂—

, —

CHR—

, —

CR₂—

, —

NH— and

—

NR—

; and

each R is selected from alkyl, alkenyl, aryl, and aralkyl.

11. The organic light emitting device of claim 10, wherein X¹ and X² are both Si.

12. The organic light emitting device of claim 10, wherein Ar, Ar¹, Ar², Ar³, Ar⁴, Ar⁵, and Ar⁶ are independently selected from an aromatic group.

13. The organic light emitting device of claim 12, wherein Ar, Ar¹, Ar², Ar³, Ar⁴, Ar⁵, and Ar⁶ are phenyl or substituted phenyl.

14. The organic light emitting device of claim 10, wherein the host material is a compound having the formula IX or X:

15. The organic light emitting device of claim 14, wherein X¹ and X² are both Si.

16. The organic light emitting device of claim 14, wherein Ar¹, Ar², Ar³, Ar⁴, Ar⁵, and Ar⁶ are an aromatic group.

17. The organic light emitting device of claim 16, wherein Ar¹, Ar², Ar³, Ar⁴, Ar⁵, and Ar⁶ are phenyl or substituted phenyl.

22. An organic light emitting device comprising an emissive layer disposed between and electrically connected to an anode and a cathode, wherein the emissive layer comprises a host material and a phosphorescent emissive material, and wherein

the host material comprises a compound of the formula VI_a

Y—

[X(Ar¹)(Ar²)(Ar³)]_n  

 

(VI_a)

wherein;

each X is independently selected from Si, Ge, Sn, Pb, Se, Ti, Zr, and Hf;

Y is selected from phenyl, alkyl, cycloalkyl, or a group of the formula

Ar′

-A-Ar″

wherein each Ar′ and

Ar″

are phenyl, and

A is alkyl, cycloalkyl, —

O—

, or Si(R′

)(R″

)

wherein R′ and

R″

are independently selected from phenyl or alkyl;

each Ar¹, Ar², and Ar³ are independently selected from alkyl or a phenyl; and

each Ar¹, Ar², and Ar³ may be independently substituted with one or more of alkyl, alkenyl, alkoxy, phenyl, alkylphenyl, halogen, NH₂, NHR, NR₂, SiR₃ and CN, and additionally or alternatively, one or more of adjacent Ar¹, Ar², Ar³ may be linked together by a linking group selected from a covalent bond, —

O—

, —

CH₂—

, —

CHR—

, —

CR₂—

, —

NH— and

—

NR—

;

each R is selected from alkyl, alkenyl, phenyl, and alkylphenyl;

n is an integer between 2 up to the maximum number of sites on Y that can accept as a substituent.

23. The organic light emitting device of claim 22, wherein X¹ and X² are both Si.

24. The organic light emitting device of claim 22, wherein the phosphorescent emissive material emits in the blue region of the visible spectrum.

25. The organic light emitting device of claim 22, wherein the host material has an energy gap of at least 3.2 eV.

26. The organic light emitting device of claim 22, wherein the host material has an energy gap of at least 3.5 eV.

28. The organic light emitting device of claim 22, wherein the first organic layer is disposed between the hole transport layer and the second organic layer.

29. The organic light emitting device of claim 22, wherein the host material has an energy gap of at least 3.5 eV.

30. The organic light emitting device of claim 22, wherein the first organic layer is an electron blocking layer.

31. The organic light emitting device of claim 22, wherein the first organic layer comprises mCP.

32. The organic light emitting device of claim 22, wherein the phosphorescent emissive material emits in the blue region of the visible spectrum.

27. An organic light emitting device comprising

an anode;

a first organic layer which is a charge balancing layer;

a second organic layer which is an emissive layer comprising a host material and a phosphorescent emissive material; and

a cathode

wherein the first organic layer is in physical contact with the second organic layer and is disposed between the anode and the second organic layer or is disposed between the cathode and the second organic layer;

and wherein the host material has an energy gap of at least 3.2 eV.

33. An organic light emitting device comprising

an anode;

a hole transporting layer;

a charge balancing layer;

an emissive layer comprising a host material and a phosphorescent emissive material; and

a cathode

wherein

the charge balancing layer is in physical contact with the emissive layer and is disposed between the and the emissive layer and the hole transporting layer; and

the hole mobility of the HTL is at least about three time that of the charge balancing layer.

34. The organic light emitting device of claim 33, wherein the hole mobility of the hole transporting layer is at least about one order of magnitude higher that the charge balancing layer.

35. The organic light emitting device of claim 33,wherein the charge balancing layer is an electron blocking layer.

36. The organic light emitting device of claim 33, wherein the phosphorescent emissive material emits in the blue region of the visible spectrum.

37. The organic light emitting device of claim 33, wherein the host material has an energy gap of at least 3.2 eV.

38. The organic light emitting device of claim 37, wherein the host material has an energy gap of at least 3.5 eV.