Organic electroluminescent element

• US 20060134464A1
• Filed: 12/20/2005
• Published: 06/22/2006
• Est. Priority Date: 12/22/2004
• Status: Abandoned Application

• Current Assignee: UDC Ireland Limited (Universal Display Corporation)
• Original Assignee: Fuji Photo Film Co Limited (Fujifilm Holdings Corporation)
• Inventors: Nariyuki, Fumito
• Application Number:
  US11/311,130
• Publication Number:
  US 20060134464A1
• Time in Patent Office: Days
• US Class Current: 428/690
• 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 2211/1044 containing two nitrogen atoms as heteroatoms
• CPC Class Codes: C09K 2211/1059 containing three nitrogen atoms as heteroatoms
• 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 33/20 characterised by the chemical or physical composition or the arrangement of the material in which the electroluminescent material is embedded
• CPC Class Codes: H10K 50/11 characterised by the electroluminescent [EL] layers
• CPC Class Codes: H10K 85/324 comprising aluminium, e.g. Alq3
• CPC Class Codes: H10K 85/342 comprising iridium
• 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 85/654 comprising only nitrogen as heteroatom H10K85/652 takes precedence
• 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

Abstract

An organic electroluminescent element having at least one organic compound layer between a pair of electrodes. The at least one organic compound layer includes at least one luminescent layer, and the luminescent layer comprises at least one luminescent dopant and plural host compounds. The main peak in the emission spectrum of a single-layer film comprising only the plural host compounds prepared under the same film-forming conditions under which the luminescent layer is prepared has a wavelength that is at least 15 nm longer than the main peak wavelength of the emission spectrum of each of the plural host compounds.

Claims

1. An organic electroluminescent element comprising at least one organic compound layer between a pair of electrodes, wherein the at least one organic compound layer includes at least one luminescent layer, the luminescent layer comprises at least one luminescent dopant and plural host compounds, and the main peak in an emission spectrum of a single-layer film comprising only the plural host compounds prepared under the same film-forming conditions under which the luminescent layer is prepared has a wavelength that is at least 15 nm longer than the main peak wavelength of an emission spectrum of each of the plural host compounds.

2. The organic electroluminescent element according to claim 1, wherein at least one of the plural host compounds contained in the luminescent layer is a compound having an electron affinity Ea of 2.8 eV or more.

3. The organic electroluminescent element according to claim 1, wherein at least one of the plural host compounds contained in the luminescent layer is a compound having an ionization potential Ip of 5.4 eV or less.

4. The organic electroluminescent element according to claim 3, wherein at least one of the plural host compounds contained in the luminescent layer is a compound having an electron affinity Ea of 2.8 eV or more.

5. The organic electroluminescent element according to claim 1, wherein the main peak in an emission spectrum of a single-layer film comprising only the plural host compounds prepared under the same film-forming conditions under which the luminescent layer is prepared has a wavelength that is 20 to 120 nm longer than the main peak wavelength of an emission spectrum of each of the plural host compounds.

6. The organic electroluminescent element according to claim 1, wherein the main peak in an emission spectrum of a single-layer film comprising only the plural host compounds prepared under the same film-forming conditions under which the luminescent layer is prepared has a wavelength that is 30 to 100 nm longer than the main peak wavelength of an emission spectrum of each of the plural host compounds.

7. The organic electroluminescent element according to claim 1, wherein at least one of the plural host compounds contained in the luminescent layer is a compound represented by formula (A-1):

8. The organic electroluminescent element according to claim 1, wherein at least one of the plural host compounds contained in the luminescent layer is a compound represented by formula (B-1):

9. The organic electroluminescent element according to claim 1, wherein at least one of the plural host compounds contained in the luminescent layer is a compound represented by formula (C-1):

10. The organic electroluminescent element according to claim 1, wherein at least one of the plural host compounds contained in the luminescent layer is a compound represented by formula (D-1):

11. The organic electroluminescent element according to claim 1, wherein at least one of the plural host compounds contained in the luminescent layer is a compound represented by formula (E-1):

12. The organic electroluminescent element according to claim 1, wherein the light emitted from the luminescent dopant contained in the luminescent layer is phosphorescent light.

13. The organic electroluminescent element according to claim 1, in which the relationships of Δ

Ip>

0 eV and Δ

Ea>

0 eV are satisfied, wherein Ip(D) represents an ionization potential of the luminescent dopant;

Ip(H)min represents the minimum ionization potential among those of the plural host compounds;

Δ

Ip represents Ip(D)−

Ip(H)min;

Ea(D) represents an electron affinity of the luminescent dopant;

Ea(H)max represents the maximum electron affinity among those of the plural host compounds; and

Δ

Ea represents Ea(H)max−

Ea(D).

14. The organic electroluminescent element according to claim 1, wherein the luminescent layer is formed by a vapor deposition method in which a mixture of the plural host compounds is used as a deposition source.

15. A method of producing an organic electroluminescent element, the method comprising forming at least one luminescent layer between a pair of electrodes by a vapor deposition method in which at least one luminescent dopant and a mixture of plural host compounds are used as deposition sources, wherein the main peak in an emission spectrum of a single-layer film comprising only the plural host compounds prepared under the same film-forming conditions under which the luminescent layer is prepared has a wavelength that is at least 15 nm longer than the main peak wavelength of an emission spectrum of each of the plural host compounds.