WHITE LIGHT EMISSION ORGANIC ELECTROLUMINESCENT ELEMENT, ILLUMINATING DEVICE AND DISPLAY

• US 20110084601A1
• Filed: 06/26/2009
• Published: 04/14/2011
• Est. Priority Date: 07/01/2008
• Status: Abandoned Application

• Current Assignee: Konica Minolta Holdings Incorporated (Konica Minolta Inc.)
• Original Assignee: Konica Minolta Holdings Incorporated (Konica Minolta Inc.)
• Inventors: Nakayama, Yoriko, Iwasaki, Toshihiko, Hiyama, Kunimasa
• Application Number:
  US12/934,943
• Publication Number:
  US 20110084601A1
• Time in Patent Office: Days
• US Class Current: 313/504
• CPC Class Codes: C09K 11/06 containing organic luminescent materials
• CPC Class Codes: C09K 2211/1029 containing one nitrogen atom as the heteroatom
• CPC Class Codes: C09K 2211/1044 containing two nitrogen atoms as heteroatoms
• CPC Class Codes: C09K 2211/1088 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: 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 85/342 comprising iridium
• CPC Class Codes: H10K 85/657 Polycyclic condensed heteroaromatic hydrocarbons
• CPC Class Codes: Y02B 20/00 Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps

Abstract

Disclosed is a coating type organic EL element having excellent chromaticity stability to driving current, excellent chromaticity stability during continuous driving and excellent color rendering property.

Claims

1. A white light emission organic electroluminescent element comprising an anode side electrode, a cathode side electrode and at least one constituent layer provided between the anode side electrode and the cathode side electrode, the constituent layer comprising one or more light emission layers, in which at least one of the light emission layers contains a plurality of light emission materials having a different emission color, wherein the emission spectrum of the element has at least three emission maximums in a wavelength region of from 420 nm to 650 nm and an emission minimum in a wavelength region of from 480 nm to 510 nm, and has two adjacent emission maximum wavelengths, a wavelength difference between the two adjacent emission maximum wavelengths being from 30 nm to 70 nm.

2. The white light emission organic electroluminescent element of claim 1, wherein the emission spectrum has the emission maximum at least in each of a wavelength region of from 420 nm to 480 nm, a wavelength region of from 510 nm to 610 nm and a wavelength region of from 555 nm to 650 nm.

3. The white light emission organic electroluminescent element of claim 1, wherein the emission spectrum has four emission maximums in a wavelength region of from 420 nm to 650 nm.

4. The white light emission organic electroluminescent element of claim 1, wherein in the emission spectrum of two light emission materials having an emission maximum adjacent to each other among the plurality of light emission materials, the emission intensity is 30 or more at the wavelength where the emission spectrum of each of the two light emission materials overlaps, when the intensity of each emission maximum is set at 100.

5. The white light emission organic electroluminescent element of claim 1, wherein light emitted from the element has a color temperature of from 2500K to 7000K and a color difference Δ

uv falling within the range of ±

0.02.

6. The white light emission organic electroluminescent element of claim 1, wherein the emission spectrum of at least one of the plurality of light emission materials has an emission maximum in a wavelength region of from 420 nm to 480 nm, and has two emission maximums which are double peaks.

7. The white light emission organic electroluminescent element of claim 1, wherein all of the plurality of light emission materials are phosphorescence emission materials.

8. The white light emission organic electroluminescent element of claim 1, wherein the light emission materials include a compound having at least one of partial structures represented by the following formulae (A) to (C):

9. The white light emission organic electroluminescent element of claim 1, wherein the plurality of light emission materials comprise two or more kinds of light emission materials having an emission maximum in a wavelength region of from 555 nm to 650 nm.

10. The white light emission organic electroluminescent element of claim 1, wherein the emission spectrum satisfies the following formula:

λ

max(½

)−

λ

max≧

40 nm

wherein λ

max represents the longest emission maximum wavelength in the emission maximums spectrum; and

λ

max (½

) represents a wavelength which is on the wavelength side longer than the longest emission maximum wavelength and which exhibits ½

of the intensity of the emission maximum at the longest emission maximum wavelength.

11. The white light emission organic electroluminescent element of claim 1, wherein the total content of the light emission materials in the light emission layer is from 5 to 30% by mass.

12. The white light emission organic electroluminescent element of claim 1, the plurality of light emission materials comprising a first light emission material having an emission maximum in a wavelength region of from 420 nm to 480 nm and a second light emission material having an emission maximum in a wavelength region of from 555 nm to 650 nm, wherein when the content by mass of the first light emission material in the light emission layer is represented by α

and the content by mass of the second light emission material in the light emission layer is represented by β

, a ratio by mass β

/α

satisfies the following inequality;

β

/α

<

0.1

13. The white light emission organic electroluminescent element of claim 12, the plurality of light emission materials comprising a first light emission material having an emission maximum in a wavelength region of from 420 nm to 480 nm and a second light emission material having an emission maximum in a wavelength region of from 555 nm to 650 nm, wherein when the content by mass of the first light emission material in the light emission layer is represented by α

and the content by mass of the second light emission material in the light emission layer is represented by β

, a ratio by mass β

/α

satisfies the following inequality;

β

/α

<

0.05

14. The white light emission organic electroluminescent element of claim 1, wherein at least one of the light emission layers is formed by a wet process.

15. An illuminating device comprising the white light emission organic electroluminescent element of claim 1.

16. A display comprising the white light emission organic electroluminescent element of claim 1.