Organic light emitting devices with electron blocking layers

• US 6,951,694 B2
• Filed: 03/28/2003
• Issued: 10/04/2005
• Est. Priority Date: 03/29/2002
• Status: Expired due to Term

• Current Assignee: University of Southern California
• Original Assignee: University of Southern California
• Inventors: Thompson, Mark E., Adamovich, Vadim, Ren, Xiaofan, Tamayo, Arnold, Djurovich, Peter I.
• Primary Examiner(s): YAMNITZKY, MARIE ROSE
• Application Number:
  US10/402,684
• Publication Number:
  US 20040048101A1
• Time in Patent Office: 921 Days
• Field of Search: 428/690, 428/917, 313/504, 313/506, 548/103
• US Class Current: 428/690
• CPC Class Codes: C09K 11/06 containing organic luminescent materials
• CPC Class Codes: C09K 2211/1044 containing two nitrogen atoms as 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 2102/103 comprising indium oxides, e.g. ITO
• CPC Class Codes: H10K 50/18 Carrier blocking layers
• CPC Class Codes: H10K 50/181 Electron blocking layers
• CPC Class Codes: H10K 85/30 Coordination compounds
• CPC Class Codes: H10K 85/324 comprising aluminium, e.g. Alq3
• CPC Class Codes: H10K 85/342 comprising iridium
• CPC Class Codes: H10K 85/346 comprising platinum
• 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
• CPC Class Codes: Y10S 428/917 Electroluminescent

Abstract

The present invention relates to organic light emitting devices (OLEDs), and more specifically to efficient OLEDs having electron blocking layers. The devices of the present invention comprise at least one electron blocking layer which functions to confine electrons to specific regions of the light emitting devices. The present invention also relates to materials for use as electron blockers that show increased stability when incorporated into an organic light emitting device.

Claims

1. An organic light emitting device, comprising an electron blocking layer disposed adjacent to an emissive layer, wherein the electron blocking layer comprises a compound of the formula I

wherein M is a metal;

each A¹ and A² is, independently, a monodentate ligand;

or A¹ and A² are covalently joined together to form a bidentate ligand;

each of R¹, R², R³, R⁴, R⁵, R⁶, and R⁷ is, independently, H, alkyl, alkenyl, alkynyl, alkylaryl, CN, CF₃, C_xF_2x+1, trifluorovinyl, CO₂R, C(O)R, NR₂, NO₂, OR, halo, aryl, heteroaryl, substituted aryl, substituted heteroaryl or a heterocyclic group, and additionally, or alternatively, any one or more of R¹ and R², or R² and R³, or R³ and R⁴, or R⁴ and R⁵, or R⁵ and R⁶, or R⁶ and R⁷ together form, independently, a fused 5- to 6-member cyclic group, wherein said cyclic group is cycloalkyl, cycloheteroalkyl, aryl, or heteroaryl, and wherein the fused 5- to 6-member cyclic group may be optionally substituted with one or more of alkyl, alkenyl, alkynyl, alkylaryl, CN, CF₃, C_xF_2x+1, trifluorovinyl, CO₂R, C(O)R, NR₂, NO₂, OR, halo;

each R is independently H, alkyl, alkenyl, alkynyl, alkylaryl, and aryl;

m is 1, 2, or 3; and

n is 0, 1, or 2,

wherein m+n equals 3.

2. The organic light emitting device of claim 1, wherein the electron blocking layer comprises a compound of the formula I, wherein R² and R³ are H.

3. The organic light emitting device of claim 2, wherein the electron blocking layer comprises a compound of the formula I, wherein R¹ is alkyl or aralkyl.

4. The organic light emitting device of claim 2, wherein the electron blocking layer comprises a compound of the formula I, wherein R¹ is methyl.

5. The organic light emitting device of claim 2, wherein the electron blocking layer comprises a compound of the formula I, wherein m is 2 and n is 1.

6. The organic light emitting device of claim 5, wherein the electron blocking layer comprises a compound of the formula I, wherein M is Ir.

7. The organic light emitting device of claim 1, wherein the electron blocking layer comprises a compound of the formula

8. An organic light emitting device, comprising an electron blocking layer disposed adjacent to an emissive layer, wherein the electron blocking layer comprises a compound of the formula III

wherein M is a metal;

each of R¹, R², R³, R⁴, R⁵, R⁶, and R⁷ is, independently, H, alkyl, alkenyl, alkynyl, alkylaryl, CN, CF₃, C_xF_2x+1, trifluorovinyl, CO₂R, C(O)R, NR₂, NO₂, OR, halo, aryl, heteroaryl, substituted aryl, substituted heteroaryl or a heterocyclic group, and additionally, or alternatively, any one or more of R¹ and R², or R² and R³, or R³ and R⁴, or R⁴ and R⁵, or R⁵ and R⁶, or R⁶ and R⁷ together form, independently, a fused 5- to 6-member cyclic group, wherein said cyclic group is cycloalkyl, cycloheteroalkyl, aryl, or heteroaryl, and wherein the fused 5- to 6-member cyclic group may be optionally substituted with one or more of alkyl, alkenyl, alkynyl, alkylaryl, CN, CF₃, C_xF_2x+1, trifluorovinyl, CO₂R, C(O)R, NR₂, NO₂, OR, halo; and

each R is independently H, alkyl, alkenyl, alkynyl, alkylaryl, and aryl.

9. The organic light emitting device of claim 8, wherein the electron blocking layer comprises a compound of the formula III, wherein R² and R³ are H.

10. The organic light emitting device of claim 9, wherein the electron blocking layer comprises a compound of the formula III, wherein R¹ is alkyl or aralkyl.

11. The organic light emitting device of claim 9, wherein the electron blocking layer comprises a compound of the formula III, wherein R¹ is methyl.

12. The organic light emitting device of claim 11, wherein the electron blocking layer comprises a compound of the formula III, wherein M is Ir.

13. The organic light emitting device of claim 8, wherein the electron blocking layer comprises a compound of the formula

14. An organic light emitting device comprising

an anode;

a hole transporting layer;

an electron blocking layer comprising an electron blocking material;

an emissive layer disposed adjacent to the electron blocking layer;

an electron transporting layer; and

a cathode;

wherein the electron blocking material comprises a compound of the formula I

wherein M is a metal;

each A¹ and A² is, independently, a monodentate ligand;

or A¹ and A² are covalently joined together to form a bidentate ligand;

each of R¹, R², R³, R⁴, R⁵, R⁶, and R⁷ is, independently, H, alkyl, alkenyl, alkynyl, alkylaryl, CN, CF₃, C_xF_2x+1, trifluorovinyl, CO₂R, C(O)R, NR₂, NO₂, OR, halo, aryl, heteroaryl, substituted aryl, substituted heteroaryl or a heterocyclic group, and additionally, or alternatively, any one or more of R¹ and R², or R² and R³, or R³ and R⁴, or R⁴ and R⁵, or R⁵ and R⁶, or R⁶ and R⁷ together form, independently, a fused 5- to 6-member cyclic group, wherein said cyclic group is cycloalkyl, cycloheteroalkyl, aryl, or heteroaryl, and wherein the fused 5- to 6-member cyclic group may be optionally substituted with one or more of alkyl, alkenyl, alkynyl, alkylaryl, CN, CF₃, C_xF_2x+1, trifluorovinyl, CO₂R, C(O)R, NR₂, NO₂, OR, halo;

each R is independently H, alkyl, alkenyl, alkynyl, alkylaryl, and aryl;

m is 1, 2, or 3; and

n is 0, 1, or 2,

wherein m+n equals 3.

15. The organic light emitting device of claim 14, wherein the electron blocking layer comprises a compound of the formula I, wherein R² and R³ are H.

16. The organic light emitting device of claim 15, wherein the electron blocking layer comprises a compound of the formula I, wherein R¹ is alkyl or aralkyl.

17. The organic light emitting device of claim 15, wherein the electron blocking layer comprises a compound of the formula I, wherein R¹ is methyl.

18. The organic light emitting device of claim 14, wherein the electron blocking layer comprises a compound of the formula I, wherein m is 2 and n is 1.

19. The organic light emitting device of claim 18, wherein the electron blocking layer comprises a compound of the formula I, wherein M is Ir.

20. The organic light emitting device of claim 14, wherein the electron blocking layer comprises a compound of the formula

21. The organic light emitting device of claim 14, wherein the electron blocking layer comprises a compound of the formula

wherein M is a metal;

each of R¹, R², R³, R⁴, R⁵, R⁶, and R⁷ is, independently, H, alkyl, alkenyl, alkynyl, alkylaryl, CN, CF₃, C_xF_2x+1, trifluorovinyl, CO₂R, C(O)R, NR₂, NO₂, OR, halo, aryl, heteroaryl, substituted aryl, substituted heteroaryl or a heterocyclic group, and additionally, or alternatively, any one or more of R¹ and R², or R² and R³, or R³ and R⁴, or R⁴ and R⁵, or R⁵ and R⁶, or R⁶ and R⁷ together form, independently, a fused 5- to 6-member cyclic group, wherein said cyclic group is cycloalkyl, cycloheteroalkyl, aryl, or heteroaryl, and wherein the fused 5- to 6-member cyclic group may be optionally substituted with one or more of alkyl, alkenyl, alkynyl, alkylaryl, CN, CF₃, C_xF_2x+1, trifluorovinyl CO₂R, C(O)R, NR₂, NO₂, OR, halo; and

each R is independently H, alkyl, alkenyl, alkynyl, alkylaryl, and aryl.

22. The organic light emitting device of claim 21, wherein the electron blocking layer comprises a compound of the formula III, wherein R² and R³ are H.

23. The organic light emitting device of claim 22, wherein the electron blocking layer comprises a compound of the formula III, wherein R¹ is alkyl or aralkyl.

24. The organic light emitting device of claim 23, wherein the electron blocking layer comprises a compound of the formula III, wherein R¹ is methyl.

25. The organic light emitting device of claim 24, wherein the electron blocking layer comprises a compound of the formula III, wherein M is Ir.

26. The organic light emitting device of claim 14, wherein the electron blocking layer comprises a compound of the formula