ORGANIC ELECTROLUMINESCENT ELEMENT, DISPLAY DEVICE AND LIGHTING DEVICE

• US 20090091253A1
• Filed: 03/13/2007
• Published: 04/09/2009
• Est. Priority Date: 03/17/2006
• Status: Abandoned Application

• Current Assignee: Konica Minolta Holdings Incorporated (Konica Minolta Inc.)
• Original Assignee: Konica Minolta Holdings Incorporated (Konica Minolta Inc.)
• Inventors: Sugita, Shuichi, Yasukawa, Noriko, Kita, Hiroshi, Katoh, Eisaku, Suzuri, Yoshiyuki, Otsu, Shinya, Tsuji, Aki
• Application Number:
  US12/282,809
• Publication Number:
  US 20090091253A1
• Time in Patent Office: Days
• US Class Current: 313/504
• CPC Class Codes: C09K 11/06 containing organic luminescent materials
• CPC Class Codes: C09K 2211/1007 Non-condensed systems
• 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 2211/1033 with oxygen
• CPC Class Codes: C09K 2211/1037 with sulfur
• CPC Class Codes: C09K 2211/1044 containing two nitrogen atoms as heteroatoms
• CPC Class Codes: C09K 2211/1048 with oxygen
• CPC Class Codes: C09K 2211/1051 with sulfur
• CPC Class Codes: C09K 2211/1059 containing three nitrogen atoms as heteroatoms
• CPC Class Codes: C09K 2211/1074 containing more than three nitrogen atoms as heteroatoms
• CPC Class Codes: C09K 2211/1088 containing oxygen as the only heteroatom
• CPC Class Codes: C09K 2211/1092 containing sulfur as the only heteroatom
• 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: H05B 33/20 characterised by the chemical or physical composition or the arrangement of the material in which the electroluminescent material is embedded
• CPC Class Codes: H10K 2101/10 Triplet emission
• 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 85/1135 : Polyethylene dioxythiophene [PEDOT]; Derivatives thereof
• CPC Class Codes: H10K 85/322 : comprising boron
• CPC Class Codes: H10K 85/324 : comprising aluminium, e.g. Alq3
• CPC Class Codes: H10K 85/342 : comprising iridium
• CPC Class Codes: H10K 85/361 : Polynuclear complexes, i.e. complexes comprising two or more metal centers
• CPC Class Codes: H10K 85/40 : Organosilicon compounds, e.g. TIPS pentacene
• 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: H10K 85/657 : Polycyclic condensed heteroaromatic hydrocarbons
• CPC Class Codes: H10K 85/6572 : comprising only nitrogen in the heteroaromatic polycondensed ring system, e.g. phenanthroline or carbazole
• CPC Class Codes: H10K 85/6574 : comprising only oxygen in the heteroaromatic polycondensed ring system, e.g. cumarine dyes
• CPC Class Codes: H10K 85/658 : Organoboranes

Abstract

The first object of the present invention is to provide a blue phosphorescent light-emitting organic electroluminescent (EL) device driven at low voltage, and a display and illuminating device each using such an organic EL device. The second object of the present invention is to provide an organic EL device having long life, and an illuminating device and display each using such an organic EL device. Each organic EL device comprises an electrode and at least one organic layer on a substrate, and at least one of the organic layers is a light-emitting layer containing a host compound and a phosphorescent compound. In order to accomplish the first object, the host compound has an HOMO of from −7.20 to −5.42 eV and an LUMO of from −2.30 to −0.50 eV, and the phosphorescent compound is represented by the general formula (1). In order to accomplish the second object, the host compound is an electron-transporting host compound having an excited triplet energy T1 of not less than 2.7 eV, and the phosphorescent compound has an HOMO of from −5.15 to −3.50 eV and an LUMO of from −1.25 to +1.00 eV.

Claims

1. An organic electroluminescent element comprising a substrate having thereon electrodes and at least one organic layer,

wherein at least one organic layer is a light-emitting layer incorporating a host compound and a phosphorescent compound, the host compound has a HOMO level of −

7.20 to −

5.42 eV and a LUMO level of −

2.30 to −

0.50 eV, and the phosphorescent compound is represented by Formula (1),

2. The organic electroluminescent element of claim 1,

wherein the phosphorescent compound has the HOMO level of −

4.80 to −

3.50 eV, and the LUMO level of −

0.80 to 1.00 eV.

3. The organic electroluminescent element of claim 1,

wherein m2 is 0 in the phosphorescent compound represented by Formula (1).

4. The organic electroluminescent element of claim 1,

wherein a nitrogen-containing heterocycle formed by B₁ to B₄ is an imidazole ring in the phosphorescent compound represented by Formula (1).

13. The organic electroluminescent element of claim 1,

wherein Formula (1) is represented by Formula (II),

15. The organic electroluminescent element of claim 13,

wherein in Formula (II), the substituent represented by R₂ is represented by Formula (III),

17. The organic electroluminescent element of claim 15,

wherein Formula (III) is a mesityl group (a 2,4,6-trimethylphenyl group).

19. A display device having the organic electroluminescent element of claim 1.

20. A lighting device having the organic electroluminescent element of claim 1.

21. A display device having the lighting device of claim 20 and a liquid crystal element as a display means.

5. An organic electroluminescent element comprising a substrate having thereon an electrode and at least one organic layer,

wherein at least one organic layer is a light-emitting layer incorporating a phosphorescent compound and an electron-transporting host compound;

the phosphorescent compound has a HOMO level of −

5.15 to −

3.50 eV and a LUMO level of −

1.25 to 1.00 eV; and

the electron-transporting host compound has an excited triplet energy T1 of not less than 2.7 eV.

6. The organic electroluminescent element of claim 5,

wherein the phosphorescent compound has the HOMO level of −

4.80 to −

3.50 eV and the LUMO level of −

0.80 to 1.00 eV.

7. The organic electroluminescent element of claim 5,

wherein the phosphorescent compound is represented by Formula (1),

8. The organic electroluminescent element of claim 7,

wherein m2 is 0 in the phosphorescent compound represented by Formula (I).

9. The organic electroluminescent element of claim 7,

wherein a nitrogen-containing heterocycle formed by B₁ to B₅ is an imidazole ring in the phosphorescent compound represented by Formula (1).

10. The organic electroluminescent element of claim 5, comprising at least two positive hole transport layers between the light-emitting layer and an anode,

wherein an organic compound incorporated in a positive hole transport layer A which is in contact with the light-emitting layer has T1 of not less than 2.7 eV.

11. The organic electroluminescent element of claim 5, comprising at least two electron transport layers between the light-emitting layer and a cathode,

wherein an organic compound incorporated in an electron transport layer A which is in contact with the light-emitting layer has T1 of not less than 2.7 eV.

12. The organic electroluminescent element of claim 5, emitting a white light.

14. The organic electroluminescent element of claim 7,

wherein Formula (1) is represented by Formula (II),

16. The organic electroluminescent element of claim 14,

wherein, in Formula (II), the substituent represented by R₂ is represented by Formula (III),

18. The organic electroluminescent element of claim 16, wherein Formula (III) is a mesityl group (a 2,4,6-trimethylphenyl group).