Organic light emitting devices with wide gap host materials

• US 20040209115A1
• Filed: 04/21/2003
• 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 J., Forrest, Stephen R., Thompson, Mark E., Djurovich, Peter, Ren, Xiaofan
• Application Number:
  US10/420,430
• Publication Number:
  US 20040209115A1
• 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 emissive material is the primary carrier of holes and electrons;

the host material has and energy gap of at least 3.2 eV; and

the device has a external quantum efficiency of at least about 3%.

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

3. The organic light emitting device of claim 1, wherein the external quantum efficiency is at least about 5%.

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

5. The organic light emitting device of claim 1, wherein the host is selected from high molecular weight alkanes, polyalkanes, arylsilanes, siloxanes, silsequioxanes, nonconjugated polyarylelnes and carboranes, wherein the host material has a melting point above about 90°

C. and a glass transition temperature above about 85°

C.

6. 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 emissive material is the primary carrier of holes;

the host material is the primary carrier of electrons, and the host material has an energy gap of at least 3.2 eV; and

the device has a external quantum efficiency of at least about 3%.

7. The organic light emitting device of claim 6, wherein the emissive material emits light in the blue region of the visible spectrum.

8. The organic light emitting device of claim 6, wherein the external quantum efficiency is at least about 5%.

9. The organic light emitting device of claim 6, wherein the host has an energy gap of at least 3.5 eV.

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 emissive material is the primary carrier of electrons;

the host material is the primary carrier of holes, and the host material has an energy gap of at least 3.2 eV; and

the device has a external quantum efficiency of at least about 3%.

11. The organic light emitting device of claim 10, wherein the emissive material emits light in the blue region of the visible spectrum.

12. The organic light emitting device of claim 10, wherein the external quantum efficiency is at least about 5%

13. The organic light emitting device of claim 10, wherein the host has an energy gap of at least 3.5 eV.

14. 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, wherein the host material comprises a compound of the formula I

15. The organic light emitting device of claim 14, wherein the host material comprises a compound of the formula I wherein X is Si.

16. The organic light emitting device of claim 14, wherein the host material comprises a compound of the formula IV

17. The organic light emitting device of claim 16, wherein the host material comprises a compound of the formula IV wherein

each R¹ is independently selected from alkyl, alkenyl, aralkyl and halogen;

each R² is independently selected from alkyl, alkenyl, aralkyl and halogen;

each R³ is independently selected from alkyl, alkenyl, aralkyl and halogen;

each R⁴ is independently selected from alkyl, alkenyl, aralkyl and halogen;

each of n, m, and p are independently selected from the values 0, 1, 2, 3 and 4; and

q is selected from the values 1, 2, 3 and 4.

18. The organic light emitting device of claim 17, wherein the host material comprises a compound of the formula

19. The organic light emitting device of claim 14, wherein the emissive material emits light in the blue region of the visible spectrum.

20. 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 an host material and an emissive material, wherein the host material comprises a compound of the formula II

21. The organic light emitting device of claim 20, wherein the host material comprises a compound of the formula II, wherein X is Si.

22. The organic light emitting device of claim 21, wherein the host material comprises a compound of the formula II, wherein L is each L is independently selected from —

O—

, —

CH₂—

, —

CHR—

, —

CR₂— and

—

NR—

;

23. The organic light emitting device of claim 22, wherein the host material comprises a compound of the formula II, wherein L is —

CH₂—

.

24. The organic light emitting device of claim 23, wherein the host material comprises a compound of the formula

25. The organic light emitting device of claim 20, wherein the emissive material emits light in the blue region of the visible spectrum.

26. 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 an host material and an emissive material, wherein the host material comprises a compound of the formula V

27. The organic light emitting device of claim 26, wherein the host material comprises a compound of the formula V, wherein R⁵ is phenyl, which may be unsubstituted or optionally substituted with one or more halogen, alkyl, alkenyl, alkoxy, aryl, aralkyl, NH₂, NHR, NR₂ and CN.

28. The organic light emitting device of claim 26, wherein the host material comprises a compound of the formula V, wherein R⁵ is phenyl.

29. The organic light emitting device of claim 26, wherein the emissive material emits light in the blue region of the visible spectrum.