Organic electroluminescence device emitting white light

• US 6,866,947 B1
• Filed: 04/01/2003
• Issued: 03/15/2005
• Est. Priority Date: 12/28/1999
• Status: Expired due to Term

• Current Assignee: Idemitsu Kosan Company Limited
• Original Assignee: Idemitsu Kosan Company Limited
• Inventors: Fukuoka, Kenichi, Tagami, Sanae, Hosokawa, Chishio
• Primary Examiner(s): GARRETT, DAWN L
• Application Number:
  US10/403,015
• Time in Patent Office: 714 Days
• Field of Search: 428/690, 428/917, 313/504, 313/506, 257/101
• US Class Current: 428/690
• CPC Class Codes: C09K 11/06 containing organic luminescent materials
• CPC Class Codes: C09K 2211/1003 Carbocyclic compounds
• 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: 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 50/11 characterised by the electroluminescent [EL] layers
• CPC Class Codes: H10K 50/125 specially adapted for multicolour light emission, e.g. for emitting white light
• CPC Class Codes: H10K 85/324 comprising aluminium, e.g. Alq3
• CPC Class Codes: H10K 85/60 Organic compounds having low molecular weight H10K85/10 - H10K85/50 take precedence
• CPC Class Codes: H10K 85/615 Polycyclic condensed aromatic hydrocarbons, e.g. anthracene
• CPC Class Codes: H10K 85/623 containing five rings, e.g. pentacene
• CPC Class Codes: H10K 85/624 containing six or more rings
• CPC Class Codes: H10K 85/626 containing more than one polycyclic condensed aromatic rings, e.g. bis-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 85/633 comprising polycyclic condensed aromatic hydrocarbons as substituents on the nitrogen 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 electroluminescence device emitting white light which emits white light and exhibits properties sufficient for practical applications, i.e., a high efficiency of light emission and a long life, is provided. The organic electroluminescence device emitting white light comprises a pair of electrodes and a layer of a light emitting medium disposed between the pair of electrodes, wherein the layer of a light emitting medium comprises a light emitting material emitting blue light and a fluorescent compound having at least one structure selected from a fluoranthene skeleton structure, a pentacene skeleton structure and a perylene skeleton structure.

Claims

1. An organic electroluminescence device which comprises a pair of electrodes and a layer of a light emitting medium disposed between the pair of electrodes, wherein the layer of a light emitting medium comprises a light emitting material emitting blue light and a fluorescent compound having at least one structure selected from (1) a fluoranthene skeleton structure and (2) a pentacene skeleton structure which is substituted with at least one group selected from a substituted or unsubstituted aryl group having 6 to 30 carbon atoms and a substituted or unsubstituted heterocyclic group having 5 to 30 carbon atoms, at the positions 6 and 13, respectively.

2. An organic electroluminescence device according to claim 1, wherein the layer of a light emitting medium comprises a light emitting layer A comprising the light emitting material emitting blue light and the fluorescent compound.

3. An organic electroluminescence device according to claim 2, wherein light emitting layer A further comprises a fluorescent dopant emitting blue light.

4. An organic electroluminescence device according to claim 3, wherein the fluorescent dopant emitting blue light is at least one compound selected from styrylamines, styryl compounds substituted with an amine and compounds having a condensed aromatic ring.

5. An organic electroluminescence device according to claim 1, wherein the layer of a light emitting medium comprises a light emitting layer emitting blue light and a light emitting layer A which comprises the light emitting material emitting blue light and the fluorescent compound.

6. An organic electroluminescence device according to claim 5, wherein light emitting layer A further comprises a fluorescent dopant emitting blue light.

7. An organic electroluminescence device according to claim 6, wherein the fluorescent dopant emitting blue light is at least one compound selected from styrylamines, styryl compounds substituted with an amine and compounds having a condensed aromatic ring.

8. An organic electroluminescence device according to claim 5, wherein the light emitting layer emitting blue light further comprises a fluorescent dopant emitting blue light.

9. An organic electroluminescence device according to claim 8, wherein the fluorescent dopant emitting blue light is at least one compound selected from styrylamines, styryl compounds substituted with an amine and compounds having a condensed aromatic ring.

10. An organic electroluminescence device according to claim 1, wherein the layer of a light emitting medium comprises a light emitting layer B comprising the light emitting material emitting blue light and a layer comprising the fluorescent compound.

11. An organic electroluminescence device according to claim 10, wherein light emitting layer B further comprises a fluorescent dopant emitting blue light.

12. An organic electroluminescence device according to claim 11, wherein the fluorescent dopant emitting blue light is at least one compound selected from styrylamines, styryl compounds substituted with an amine and compounds having a condensed aromatic ring.

13. An organic electroluminescence device according to claim 1, wherein the layer of a light emitting medium comprises a hole transporting material or a hole injecting material.

14. An organic electroluminescence device according to claim 1, wherein the layer of a light emitting medium comprises a hole transporting layer or a hole injecting layer.

15. An organic electroluminescence device according to claim 1, wherein the layer of a light emitting medium comprises an electron transporting material or an electron injecting material.

16. An organic electroluminescence device according to claim 1, wherein the layer of a light emitting medium comprises an electron transporting layer or an electron injecting layer.

17. An organic electroluminescence device according to claim 1, wherein the layer of a light emitting medium contacts an anode and comprises an oxidizing agent.

18. An organic electroluminescence device according to claim 1, wherein the layer of a light emitting medium contacts a cathode and comprises a reducing agent.

19. An organic electroluminescence device according to claim 1, wherein a layer of an inorganic compound is disposed between at least one of the electrodes and the layer of a light emitting medium.

20. An organic electroluminescence device according to claim 1, wherein the light emitting material emitting blue light is a styryl derivative, an anthracene derivative or an aromatic amine.

21. An organic electroluminescence device according to claim 20, wherein the styryl derivative is at least one compound selected from distyryl derivatives, tristyryl derivatives, tetrastyryl derivatives and styrylamine derivatives.

22. An organic electroluminescence device according to claim 20, wherein the anthracene derivative is a compound having a phenylanthracene skeleton structure.

23. An organic electroluminescence device according to claim 20, wherein the aromatic amine is a compound having 2 to 4 nitrogen atoms which are substituted with an aromatic group.

24. An organic electroluminescence device according to claim 20, wherein the aromatic amine is a compound having 2 to 4 nitrogen atoms which are substituted with an aromatic group and having at least one alkenyl group.

25. An organic electroluminescence device according to claim 1, wherein the fluorescent compound has an electron-donating group.

26. An organic electroluminescence device according to claim 1, wherein the fluorescent compound has a peak wavelength of fluorescence at 540 to 650 nm.

27. The device according to claim 1, wherein said light emitting material emitting blue light is selected from the group consisting of species i-v below, and mixtures thereof:

in the above general formula [i], R^1′

to R^10′

each independently represent hydrogen atom, a halogen atom, cyano group, nitro group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 30 groups, a substituted or unsubstituted alkylthio group having 1 to 20 carbon atoms, a substituted or unsubstituted arylthio group having 6 to 30 carbon atoms, a substituted or unsubstituted arylalkyl group having 7 to 30 carbon atoms, an unsubstituted single ring group having 5 to 30 carbon atoms, a substituted or unsubstituted condensed multi-ring group having 10 to 30 carbon atoms or a substituted or unsubstituted heterocyclic group having 5 to 30 carbon atoms,

Ar¹ and Ar² each independently represent a substituted or unsubstituted aryl group having 6 to 30 carbon atoms or a substituted or unsubstituted alkenyl group where the substituent in the above groups is a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkoxy groups having 1 to 20 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 30 carbon atoms, a substituted or unsubstituted alkylthio group having 1 to 20 carbon atoms, a substituted or unsubstituted arylthio group having 6 to 30 carbon atoms, a substituted or unsubstituted arylalkyl group having 7 to 30 carbon atoms, an unsubstituted single ring group having 5 to 30 carbon atoms, a substituted or unsubstituted condensed multi-ring group having 10 to 30 carbon atoms or a substituted or unsubstituted heterocyclic group having 5 to 30 carbon atoms,

in the above general formula [ii], R^1′

to R^10′

each independently represent hydrogen atom, a halogen atom, cyano group, nitro group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 30 groups, a substituted or unsubstituted alkylthio group having 1 to 20 carbon atoms, a substituted or unsubstituted arylthio group having 6 to 30 carbon atoms, a substituted or unsubstituted arylalkyl group having 7 to 30 carbon atoms, an unsubstituted single ring group having 5 to 30 carbon atoms, a substituted or unsubstituted condensed multi-ring group having 10 to 30 carbon atoms or a substituted or unsubstituted heterocyclic group having 5 to 30 carbon atoms,

Ar³ and Ar⁴ each independently represent a substituted or unsubstituted aryl group having 6 to 30 carbon atoms or a substituted or unsubstituted alkenyl group, where the substituent in the above groups is a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkoxy groups having 1 to 20 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 30 carbon atoms, a substituted or unsubstituted alkylthio group having 1 to 20 carbon atoms, a substituted or unsubstituted arylthio group having 6 to 30 carbon atoms, a substituted or unsubstituted arylalkyl group having 7 to 30 carbon atoms, an unsubstituted single ring group having 5 to 30 carbon atoms, a substituted or unsubstituted condensed multi-ring group having 10 to 30 carbon atoms, a substituted or unsubstituted heterocyclic group having 5 to 30 carbon atoms or a substituted or unsubstituted alkenyl group having 4 to 40 carbon atoms,

n represents a number of 1 to 3, m represents a number of 1 to 3 and n+m≧

2,

in the above general formula [iii], R^1′

to R^8′

each independently represent hydrogen atom, a halogen atom, cyano group, nitro group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 30 groups, a substituted or unsubstituted alkylthio group having 1 to 20 carbon atoms, a substituted or unsubstituted arylthio group having 6 to 30 carbon atoms, a substituted or unsubstituted arylalkyl group having 7 to 30 carbon atoms, an unsubstituted single ring group having 5 to 30 carbon atoms, a substituted or unsubstituted condensed multi-ring group having 10 to 30 carbon atoms or a substituted or unsubstituted heterocyclic group having 5 to 30 carbon atoms,

Ar³ and Ar⁴ each independently represent a substituted or unsubstituted aryl group having 6 to 30 carbon atoms or a substituted or unsubstituted alkenyl group, where the substituent in the above groups is a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkoxy groups having 1 to 20 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 30 carbon atoms, a substituted or unsubstituted alkylthio group having 1 to 20 carbon atoms, a substituted or unsubstituted arylthio group having 6 to 30 carbon atoms, a substituted or unsubstituted arylalkyl group having 6 to 30 carbon atoms, an unsubstituted single ring group having 5 to 30 carbon atoms, a substituted or unsubstituted condensed multi-ring group having 10 to 30 carbon atoms, a substituted or unsubstituted heterocyclic group having 5 to 30 carbon atoms or a substituted or unsubstituted alkenyl group having 4 to 40 carbon atoms,

in the above general formula [iv], R^1″

to R^10″

each independently represent hydrogen atom, an alkenyl group, an alkyl group, a cycloalkyl group, an aryl group which may be substituted, an alkoxy group, an aryloxy group, an alkylamino group, an aryl amino group or a heterocyclic group which may be substituted;

a and b each represent an integer of 1 to 5 and, when any of a and b represents an integer of 2 or greater, a plurality of R^1″

or R^2″

may represent the same or different groups, a plurality of groups represented by R^1″

or R^2″

may be bonded to each other to form a ring, and a pair of groups represented by R^3″

and R^4″

, R^5″

and R^6″

, R^7″

and R^8″

or R^9″

and R^10″

may form a ring via the bonding within the pair;

L¹ represents a single bond, —

O—

, —

S—

, —

N(R)—

, R representing an alkyl group or an aryl group which may be substituted, or an arylene group,

in the above general formula [v], R^11″

to R^20″

each independently represent hydrogen atom, an alkenyl group, an alkyl group, a cycloalkyl group, an aryl group, an alkoxy group, an aryloxy group, an alkylamino group, an arylamino group or a heterocyclic group which may be substituted;

c, d, e and f each represent an integer of 1 to 5 and, when any of c, d, e and f represents an integer of 2 or greater, a plurality of R^11″

, R^12″

, R^16″

or R^17″

may represent the same or different groups, a plurality of groups represented by R^11″

, R^12″

, R^16″

or R^17″

may be bonded to each other to form a ring and a pair of groups represented by R^13″

and R^14″

or R^18″

and R^19″

may form a ring via the bonding within the pair;

L² represents a single bond, —

O—

, —

S—

, —

N(R)—

, R representing an alkyl group or an aryl group which may be substituted, or an arylene group.

28. The device according to claim 27, wherein said light emitting material emitting blue light is a species of formula i.

29. The device according to claim 27, wherein said light emitting material emitting blue light is a species of formula ii.

30. The device according to claim 27, wherein said light emitting material emitting blue light is a species of formula iii.

31. The device according to claim 27, wherein said light emitting material emitting blue light is a species of formula iv.

32. The device according to claim 27, wherein said light emitting material emitting blue light is a species of formula v.

33. An organic electroluminescence device according to claim 1, wherein the fluorescent compound is selected from the group consisting of the following compounds (1), (2), (3), (4), (5), (6), (7), (8), (9), (10), (11), (14), (15), (16), (17), (18), (20), (1′

), (2′

) and mixtures thereof;

wherein in the above formulae (1) to (11) and (14) to (16), X¹ to X²⁰ each independently represent hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, a linear, branched or cyclic alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 30 carbon atoms, a substituted or unsubstituted arylamino group having 6 to 30 carbon atoms, a substituted or unsubstituted alkylamino group having 1 to 30 carbon atoms, a substituted or unsubstituted arylalkylamino group having 7 to 30 carbon atoms or a substituted or unsubstituted alkenyl group having 8 to 30 carbon atoms, adjacent substituents and adjacent groups represented by X¹ to X²⁰ may be bonded to each other to form a cyclic structure, and, when the adjacent substituents represented by X¹ to X²⁰ are aromatic groups, the substituents may the same group;

wherein in the above formulae (17) and (18), R¹ to R⁴ each independently represent an alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, any of a pair of groups represented by R¹ and R² and a pair of groups represented by R³ and R⁴ may be bonded to each other through a carbon—

carbon bond, —

O—

or —

S—

, R⁵ to R¹⁶ each independently represent hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, a linear, branched or cyclic alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 30 carbon atoms, a substituted or unsubstituted arylamino group having 6 to 30 carbon atoms, a substituted or unsubstituted alkylamino group having 1 to 30 carbon atoms, a substituted or unsubstituted arylalkylamino group having 7 to 30 carbon atoms or a substituted or unsubstituted alkenyl group having 8 to 30 carbon atoms, and adjacent substituents and adjacent groups represented by R⁵ to R¹⁶ may be bonded to each other to form a cyclic structure;

wherein in the above formula (20), R¹⁵ to R²⁶ each independently represent hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an aryloxy group having 6 to 20 carbon atoms, an arylalkyl group having 6 to 20 carbon atoms, an aryl group having 6 to 30 carbon atoms, an arylamino group having 6 to 30 carbon atoms, an alkylamino group having 2 to 20 carbon atoms or an arylalkylamino group having 6 to 30 carbon atoms, the groups represented by R¹⁵ to R²⁶ may be substituted, at least one pair of groups represented by R¹⁵ to R²⁶ which are adjacent to each other are not hydrogen atom and form a cyclic structure, and Ar¹ and Ar² each represent a substituted or unsubstituted aryl group having 6 to 30 carbon atoms or a substituted or unsubstituted heterocyclic group having 5 to 30 carbon atoms;

X═

Z═

Y 

 

(1′

)

X═

W 

 

(2′

)

wherein in the above formulae (1′

) and (2′

), Z represents a tetravalent group represented by any of the following general formulae (1) to (6);

wherein in the above formulae (1′

) and (2′

), X and Y each independently represent a divalent group represented by any of the following formulae (7) to (10);

and in the above formulae (1′

) and (2′

), W represents a divalent group represented by any of the following formulae (11) to (13);

wherein in the above formulae (1) to (13) for X, Y and Z under formulae (1′

) and (2′

), R⁰ to R⁹⁹ each independently represent hydrogen atom, a halogen atom, cyano group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 6 to 10 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted amino group having 1 to 30 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 20 carbon atoms, a substituted or unsubstituted alkoxycarbonyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aralkyl group having 6 to 30 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms or a substituted or unsubstituted heterocyclic group having 5 to 30 carbon atoms, and adjacent groups represented by R⁰ to R⁹⁹ may be bonded to each other to form a cyclic structure.