White light-emitting OLED device having a blue light-emitting layer doped with an electron-transporting or a hole-transporting material or both

• US 6,967,062 B2
• Filed: 06/26/2003
• Issued: 11/22/2005
• Est. Priority Date: 03/19/2003
• Status: Expired due to Term

• Current Assignee: Global OLED Technology LLC (LG Display Co., Ltd.)
• Original Assignee: Eastman Kodak Company
• Inventors: Spindler, Jeffrey P., Hatwar, Tukaram K., Ricks, Michele L., Winters, Dustin
• Primary Examiner(s): Garrett, Dawn L.
• Application Number:
  US10/606,446
• Publication Number:
  US 20040185300A1
• Time in Patent Office: 880 Days
• Field of Search: 428/690, 428/917, 313/504, 313/506, 313/112, 257/88, 257/98, 252/301.16
• 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 2211/1029 containing one nitrogen atom as the heteroatom
• CPC Class Codes: C09K 2211/107 with other heteroatoms
• CPC Class Codes: H10K 50/13 comprising stacked EL layers within one EL unit
• CPC Class Codes: H10K 50/156 comprising a multilayered structure
• CPC Class Codes: H10K 85/322 comprising boron
• CPC Class Codes: H10K 85/324 comprising aluminium, e.g. Alq3
• 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
• CPC Class Codes: Y02B 20/00 Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps
• CPC Class Codes: Y10S 428/917 Electroluminescent

Abstract

An organic light-emitting diode (OLED) device which produces substantially white light includes an anode; a hole-transporting layer disposed over the anode; and a blue light-emitting layer having a host doped with a blue light-emitting compound disposed directly on the hole-transporting layer and the blue light-emitting layer being doped with an electron-transporting or a hole-transporting material or both selected to improve efficiency and operational stability. The device also includes an electron-transporting layer disposed over the blue light-emitting layer; a cathode disposed over the electron-transporting layer; and the hole-transporting layer or electron-transporting layer, or both the hole-transporting layer and electron-transporting layer, being selectively doped with a compound which emits light in the yellow region of the spectrum which corresponds to an entire layer or a partial portion of a layer in contact with the blue light-emitting layer.

Claims

1. An organic light-emitting diode (OLED) device which produces white light, comprising:

a) an anode;

b) a hole-transporting layer disposed over the anode;

c) a blue light-emitting layer having a host doped with a blue light-emitting compound disposed directly on the hole-transporting layer and the blue light-emitting layer being doped with an electron-transporting or a hole-transporting material or both selected to improve efficiency and operational stability;

d) an electron-transporting layer disposed over the blue light-emitting layer;

e) a cathode disposed over the electron-transporting layer; and

f) the hole-transporting layer or electron-transporting layer, or both the hole-transporting layer and electron-transporting layer, being selectively doped with a compound which emits light in the yellow region of the spectrum which is included in an entire layer or a partial portion of a layer in contact with the blue light-emitting layer.

2. The OLED device of claim 1 wherein hole-transporting or the electron-transporting material in the blue light-emitting layer is selected to be in a range of from 0.5 to 10 percent by volume of the host material and when both are used, they are selected to be in a range of from 1 to 20 percent by volume of the host material.

3. The OLED device of claim 1 wherein the hole-transporting material in the blue light-emitting layer is:

1,1-Bis(4-di-p-tolylaminophenyl)cyclohexane;

1,1-Bis(4-di-p-tolylaminophenyl)-4-phenylcyclohexane;

4,4′

-Bis(diphenylamino)quadriphenyl;

Bis(4-dimethylamino-2-methylphenyl)-phenylmethane;

N,N,N-Tri(p-tolyl)amine;

4-(di-p-tolylamino)-4′

-[4(di-p-tolylamino)-styryl]stilbene;

N,N,N′

,N′

-Tetra-p-tolyl-4-4′

-diaminobiphenyl;

N,N,N′

,N′

-Tetraphenyl-4,4′

-diaminobiphenyl;

N,N,N′

,N′

-tetra-1-naphthyl-4,4′

-diaminobiphenyl;

N,N,N′

,N′

-tetra-2-naphthyl-4,4′

-diaminobiphenyl;

N-Phenylcarbazole;

4,4′

-Bis[N-(1-naphthyl)-N-phenylamino]biphenyl (NPB);

4,4′

-Bis[N-(1-naphthyl)-N-(2-naphthyl)amino]biphenyl (TNB);

4,4″

-Bis[N-(1-naphthyl)-N-phenylamino]p-terphenyl;

4,4′

-Bis[N-(2-naphthyl)-N-phenylamino]biphenyl;

4,4′

-Bis[N-(3-acenaphthenyl)-N-phenylamino]biphenyl;

1,5-Bis[N-(1-naphthyl)-N-phenylamino]naphthalene;

4,4′

-Bis[N-(9-anthryl)-N-phenylamino]biphenyl;

4,4″

-Bis[N-(1-anthryl)-N-phenylamino]-p-terphenyl;

4,4′

-Bis[N-(2-phenanthryl)-N-phenylamino]biphenyl;

4,4′

-Bis[N-(8-fluoranthenyl)-N-phenylamino]biphenyl;

4,4′

-Bis[N-(2-pyrenyl)-N-phenylamino]biphenyl;

4,4′

-Bis[N-(2-naphthacenyl)-N-phenylamino]biphenyl;

4,4′

-Bis[N-(2-perylenyl)-N-phenylamino]biphenyl;

4,4′

-Bis[N-(1-coronenyl)-N-phenylamino]biphenyl;

2,6-Bis(di-p-tolylamino)naphthalene;

2,6-Bis[di-(1-naphthyl)amino]naphthalene;

2,6-Bis[N-(1-naphthyl)-N-(2-naphthyl)amino]naphthalene;

N,N,N′

,N′

-Tetra(2-naphthyl)-4,4″

-diamino-p-terphenyl;

4,4′

-Bis{N-phenyl-N-[4-(1-naphthyl)-phenyl]amino}biphenyl;

4,4′

-Bis[N-phenyl-N-(2-pyrenyl)amino]biphenyl;

2,6-Bis[N,N-di(2-naphthyl)amine]fluorene;

1,5-Bis[N-(1-naphthyl)-N-phenylamino]naphthalene;

4,4′

,4″

-tris[(3-methylphenyl)phenylamino]triphenylamine (MTDATA);

or

4,4′

-Bis[N-(3-methylphenyl)-N-phenylamino]biphenyl (TPD).

4. The OLED device of claim 1 wherein the electron-transporting materials in the blue light-emitting layer is:

BAlq;

Aluminum trisoxine [alias, tris(8-quinolinolato)aluminum(III)];

Magnesium bisoxine [alias, bis(8-quinolinolato)magnesium(II)];

Bis[benzo{f}-8-quinolinolato]zinc (II);

Bis(2-methyl-8-quinolinolato)aluminum(III)-μ

-oxo-bis(2-methyl-8-quinolinolato) aluminum(III);

Indium trisoxine [alias, tris(8-quinolinolato)indium];

Aluminum tris(5-methyloxine) [alias, tris(5-methyl-8-quinolinolato) aluminum(III)];

Lithium oxine [alias, (8-quinolinolato)lithium(I)];

Gallium oxine [alias, tris(8-quinolinolato)gallium(III)];

or

Zirconium oxine [alias, tetra(8-quinolinolato)zirconium(IV)].

5. The OLED device of claim 1 wherein the hole-transporting material is NPB and the electron-transporting material is Alq.

6. The OLED device of claim 1 wherein the hole-transporting material is NPB and the electron-transporting material is BAlq.

7. The OLED device of claim 1 wherein the yellow light-emitting compound is:

wherein R₁, R₂, R₃, R₄, R₅, R₆ represent one or more substituents on each ring where each substituent is individually selected from the following groups;

Group 1;

hydrogen, or alkyl of from 1 to 24 carbon atoms;

Group 2;

aryl or substituted aryl of from 5 to 20 carbon atoms;

Group 3;

carbon atoms from 4 to 24 necessary to complete a fused aromatic ring of phenyl, naphthyl, anthracenyl, phenanthryl, pyrenyl, or perylenyl;

Group 4;

heteroaryl or substituted heteroaryl of from 5 to 24 carbon atoms such as thiazolyl, furyl, thienyl, pyridyl, quinolinyl or other heterocyclic systems, which may be bonded via a single bond, or may complete a fused heteroaromatic ring system;

Group 5;

alkoxylamino, alkylamino, or arylamino of from 1 to 24 carbon atoms;

or

Group 6;

fluorine, chlorine, bromine or cyano.

8. The OLED device of claim 6 wherein the yellow-emitting dopants includes 5,6,11,12-tetraphenylnaphthacene (rubrene);

6,11-diphenyl-5,12-bis(4-(6-methyl-benzothiazol-2-yl)phenyl)naphthacene (DBzR) or 5,6,11,12-tetra(2-naphthyl)naphthacene (NR), the formulas of which are shown below;

9. The OLED device of claim 1 wherein the blue light emitting compound includes distyrylamine derivatives as shown by the formula

10. The OLED device of claim 1 wherein the blue emitting compound dopant further includes perylene and its derivatives.

11. The OLED device of claim 10 wherein the perylene derivative is 2,5,8,11-tetra-tert-butyl perylene (TBP).

12. The OLED device of claim 1 wherein the blue light emitting compound is represented by the following formulas:

13. The OLED device of claim 1 wherein the concentration of blue emitting dopants, is in the range of greater than 0 and less than 10% percent by volume of the host material.

14. The OLED device of claim 1 wherein thickness of the hole-transporting layer is between 5 nm-300 nm.

15. The OLED device of claim 1 wherein the hole-transporting layer includes two or more sublayers, the sublayer closest to the blue light-emitting layer being doped with yellow-emitting dopants.

16. The OLED device of claim 15 wherein the dopant in the hole transport material is 5,6,11,12-tetraphenylnaphthacene (rubrene);

6,11-diphenyl-5, 12-bis(4-(6-methyl-benzothiazol-2-yl)phenyl)naphthacene (DBzR);

or 5,6,11,12-tetra(2-naphthyl)naphthacene (NR), and the thickness of the layer containing yellow dopant is in a range between 1 nm-300 nm.

17. The OLED device of claim 1 wherein thickness of the blue light-emitting layer is in a range between 5 nm-100 nm.

18. The OLED device of claim 1 wherein a hole-injecting layer is provided between the anode and the hole-transporting layer.

19. The OLED device of claim 18 wherein the hole-injecting layer comprises CFx, CuPC, or m-MTDATA.

20. The OLED device of claim 18 wherein the thickness of hole injecting layer is 0.1 nm-100 nm.

21. The OLED device of claim 1 wherein thickness of the electron-transporting layer is in a range between 5 nm-150 nm.

22. The OLED device of claim 1 wherein the cathode is selected from the group consisting of LiF/Al, Mg:

Ag alloy, Al—

Li alloy, and Mg—

Al alloy.

23. The OLED device of claim 1 wherein the cathode is transparent.

24. The OLED device of claim 1 wherein the electron-transporting layer is transparent.

25. The organic light-emitting diode (OLED) device of claim 1 wherein the electron-transporting layer is doped with a green light-emitting dopant or a combination of green and yellow light-emitting dopants.

26. The OLED device of claim 25 wherein of the green dopant in the electron-transporting layer includes a coumarin compound.

27. The OLED device of claim 26 wherein the coumarin compound includes C545T or C545TB.

28. The OLED device of claim 25 wherein the green light-emitting dopant is selected from the group consisting of:

29. The OLED device of claim 25 wherein green dopant concentration is between 0.1-5% percent by volume of the electron transport material in the electron transporting layer.

30. The OLED device of claim 1 further including a buffer layer disposed on the cathode layer.

31. The OLED device of claim 30 wherein thickness of the buffer layer is in a range between 1 nm-1000 nm.

32. The OLED device of claim 1 further including a color filter array.

33. The OLED device of claim 1 wherein the hole-transporting layer includes an aromatic tertiary amine.

34. The OLED device of claim 1 wherein the electron-transporting layer includes copper phthalocyanine compound.

35. The OLED device of claim 1 wherein the blue light-emitting layer includes host material selected from the group consisting of:

and wherein the blue light-emitting dopant includes

or derivatives thereof.

36. The OLED device of claim 3 wherein the blue light-emitting layer includes host material selected from the group consisting of:

and wherein the blue light-emitting dopant includes

or derivatives thereof.