Organic electroluminescent light emitting material and device using same

• US 5,747,183 A
• Filed: 11/04/1996
• Issued: 05/05/1998
• Est. Priority Date: 11/04/1996
• Status: Expired due to Term

• Current Assignee: Universal Display Corporation
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: So, Franky, Shi, Song, Lee, H. C.
• Primary Examiner(s): Marquis, Melvyn I.
• Application Number:
  US08/743,257
• Time in Patent Office: 547 Days
• Field of Search: 428/690, 428/691, 313/503, 313/504, 313/505, 313/506
• US Class Current: 428/690
• CPC Class Codes: C09K 11/06 containing organic luminescent materials
• 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: H05B 33/18 characterised by the nature or concentration of the activator

Abstract

An organic electroluminescent display device (10) includes first and second electrode assemblies fabricated on a transparent substrates (12). Disposed between the electrode assemblies are one or more layers of organic electroluminescent light emitting materials (20). The organic electroluminescent light emitting material is preferably characterized by an emitted light having a wavelength of between 4000 Å and 6000 Å. This light emitting material may be comprised of a mixture of a first host emitting material and a second host emitting material, and may further include a dopant so as to improve the emission efficiency of the light emitting material as well as to adjust the emission characteristic to a desired specification.

Claims

1. An organic electroluminescent light emitting material characterized by an emitted light having a wavelength of between 4000 Å

and 6000 Å

, said light emitting material comprising a mixture of a first host emitting material adapted to emit light having a wavelength of between 4000 Å and

5000 Å

, and a second host emitting material adapted to emit light having a wavelength of between 5000 and 6000 Å

.

2. An organic electroluminescent light emitting material as in claim 1, wherein the first host emitting material comprises between 0.1 and 99% of said light emitting material.

3. An organic electroluminescent light emitting material as in claim 1, wherein the first host emitting material comprises between 25 and 75% of said light emitting material.

4. An organic electroluminescent light emitting material as in claim 1, further including at least one dopant material.

5. An organic electroluminescent light emitting material as in claim 4, wherein said dopant is a fluorescent dye dopant material having an emission wavelength of between 4000 to 6000 Å

.

6. An organic electroluminescent light emitting material as in claim 5, wherein said fluorescent dye dopant is present in said light emitting material in a concentration of between 0.1 and 10 mole percent.

7. An organic electroluminescent light emitting material as in claim 4, wherein said dopant is selected from the group of materials consisting of perylene, coumarin 6 (3-(2-benzothiazolyl)-7-(diethylamino)coumarin), coumarin 153 (2,3,6,7-tetrahydro-9-(trifluoromethyl-1H,5H,11H- 1!benzopyrano 6,7,8-ij!quinolizin-11-one), 1,4-bis(2,2-di-p-tolylvinyl)benzene, tetraphenylbutadiene, pentaphenylcyclopentadiene, bis(5-tert-butyl-2-benzoxazolyl thiophene, quinacridone, methylquinacridone, coronene, pentracene, and combinations thereof.

8. An organic electroluminescent light emitting material as in claim 1, wherein said first host emitting material is selected from the group of materials characterized by the formula (R--Q)2-Al--O--L wherein Q is a substituted 8-quinolinolate ligand, R is an 8-quinolinolate ring substituent, O--L is a plenolato ligand, wherein L is a hydrocarbon of from 6 to 24 carbons comprised of a phenyl moiety and Al is aluminum.

9. An organic electroluminescent light emitting material as in claim 1, wherein said first host emitting material is selected from the group of materials consisting of bis(2-methyl-8-quinolinolato phenolato)aluminum, bis(2-methyl-80-quinolinolato-2-cresolato)aluminum, bis(2-(2-hydroxylphenyl)benzoxazolate) zinc, bis(2-(2-hydroxylphenyl)-benzoxazolate) magnesium, and combinations thereof.

10. An organic electroluminescent light emitting material as in claim 1, wherein said second host emitting material is selected from the group consisting of tris(8-hydroxyl quinolinolate) aluminum, bis(10-hydroxybenzo(h)quinolinate)beryllium, bis(2-(2-hydroxyphenyl)benzothiazolate) zinc, and combinations thereof.

11. An organic electroluminescent display device having an anode, a cathode, and a light emitting material disposed there between, said light emitting material having a wavelength of between 4000 Å

and 6000 Å

, said light emitting material comprising a mixture of a first host emitting material adapted to emit light having a wavelength of between 4000 Å and

5000 Å

, and a second host emitting material adapted to emit light having a wavelength of between 5000 and 6000 Å

.

12. An organic electroluminescent display device as in claim 11, wherein the first host emitting material comprises between 0.1 and 99% of said light emitting material.

13. An organic electroluminescent display device as in claim 11, wherein the first host emitting material comprises between 25 and 75% of said light emitting material.

14. An organic electroluminescent display device as in claim 11, further including at least one dopant material.

15. An organic electroluminescent display device as in claim 14, wherein said dopant is a fluorescent dye dopant material having an emission wavelength of between 4000 to 6000 Å

.

16. An organic electroluminescent display device as in claim 15, wherein said fluorescent dye dopant is present in said light emitting material in a concentration of between 0.1 and 10 mole percent.

17. An organic electroluminescent light emitting material as in claim 14, wherein said dopant is selected from the group of materials consisting of perylene, coumarin 6 (3-(2-benzothiazolyl)-7-(diethylamino)coumarin), coumarin 153 (2,3,6,7-tetrahydro-9-(trifluoromethyl-1H,5H,11H- 1!benzopyrano 6,7,8-ij!quinolizin-11-one), 1,4-bis(2,2-di-p-tolylvinyl)benzene, tetraphenylbutadiene, pentaphenylcyclopentadiene, bis(5-tert-butyl-2-benzoxazolyl thiophene, quinacridone, methylquinacridone, coronene, pentracene, and combinations thereof.

18. An organic electroluminescent display device as in claim 11, wherein said first host emitting material is selected from the group of materials characterized by the formula (R--Q)2-Al--O--L wherein Q is a substituted 8-quinolinolate ligand, R is an 8-quinolinolate ring substituent, O--L is a plenolato ligand, wherein L is a hydrocarbon of from 6 to 24 carbons comprised of a phenyl moiety and Al is aluminum.

19. An organic electroluminescent display device as in claim 11, wherein said first host emitting material is selected from the group of materials consisting of bis(2-methyl-8-quinolinolato phenolato)aluminum, bis(2-methyl-80-quinolinolato-2-cresolato)aluminum, bis(2-(2-hydroxylphenyl)benzoxazolate) zinc, bis(2-(2-hydroxylphenyl)benzoxazolate) magnesium, and combinations thereof.

20. An organic electroluminescent display device as in claim 11, wherein said second host emitting material is selected from the group consisting of tris(8-hydroxyl quinolinolate) aluminum, bis(10-hydroxybenzo(h)quinolinate)beryllium, bis(2-(2-hydroxyphenyl)benzothiazolate) zinc, and combinations thereof.

21. An organic electroluminescent light emitting device having an anode, a cathode, and a light emitting material disposed therebetween, said light emitting material being characterized by having two light emission maxima, a first maxima having a peak wavelength between 4000 and 5000 Å

, and a second maxima having a peak wavelength of between 5000 and 6000 Å

.

22. An organic electroluminescent light emitting device as in claim 21, wherein said light emitting material comprising a mixture of a first and second host emitting material.

23. An organic electroluminescent light emitting device as in claim 22, wherein the first host emitting material comprises between 0.1 and 99% of said light emitting material.

24. An organic electroluminescent light emitting device as in claim 22, wherein said first host emitting material is selected from the group of materials consisting of bis(2-methyl-8-quinolinolato phenolato)aluminum, bis(2-methyl-80-quinolinolato-2-cresolato)aluminum, bis(2-(2-hydroxylphenyl)benzoxazolate) zinc, bis(2-(2-hydroxylphenyl)benzoxazolate) magnesium, and combinations thereof.

25. An organic electroluminescent light emitting device as in claim 22, wherein said second host emitting material is selected from the group consisting of tris(8-hydroxyl quinolinolate) aluminum, bis(10-hydroxybenzo(h)quinolinate)beryllium, bis(2-(2-hydroxyphenyl)benzothiazolate) zinc, and combinations thereof.