ORGANIC ELECTROLUMINESCENCE DEVICE

• US 20120126205A1
• Filed: 01/31/2011
• Published: 05/24/2012
• Est. Priority Date: 11/22/2010
• Status: Abandoned Application

• Current Assignee: Idemitsu Kosan Company Limited
• Original Assignee: Idemitsu Kosan Company Limited
• Inventors: Kawamura, Yuichiro, Saito, Hiroyuki, Kuma, Hitoshi, Kawamura, Masahiro, Jinde, Yukitoshi, Ito, Hirokatsu
• Application Number:
  US13/017,978
• Publication Number:
  US 20120126205A1
• Time in Patent Office: Days
• US Class Current: 257/40
• CPC Class Codes: H10K 2101/40 Interrelation of parameters between multiple constituent active layers or sublayers, e.g. HOMO values in adjacent layers
• CPC Class Codes: H10K 50/11 characterised by the electroluminescent [EL] layers
• CPC Class Codes: H10K 50/13 comprising stacked EL layers within one EL unit
• CPC Class Codes: H10K 50/165 comprising dopants
• CPC Class Codes: H10K 50/18 Carrier blocking layers
• CPC Class Codes: H10K 85/623 containing five rings, e.g. pentacene
• CPC Class Codes: H10K 85/626 containing more than one polycyclic condensed aromatic rings, e.g. bis-anthracene
• CPC Class Codes: H10K 85/6572 comprising only nitrogen in the heteroaromatic polycondensed ring system, e.g. phenanthroline or carbazole

Abstract

An organic electroluminescence device includes an anode, an emitting layer, a blocking layer, an electron injecting layer, and a cathode in sequential order. The emitting layer includes a host and dopant. The blocking layer includes an aromatic heterocyclic derivative. A triplet energy E^T_b (eV) of the blocking layer is larger than a triplet energy E^T_h (eV) of the host. An affinity A_b (eV) of the blocking layer and an affinity A_b (eV) of the electron injecting layer satisfy a relationship of A_e−A_b<0.2.

Claims

1. An organic electroluminescence device comprising an anode, an emitting layer, a blocking layer, an electron injecting layer, and a cathode in sequential order, wherein

the emitting layer comprises a host and a dopant,

the blocking layer comprises an aromatic heterocyclic derivative,

a triplet energy E^T_b (eV) of the aromatic heterocyclic derivative is larger than a triplet energy E^T_h (eV) of the host, and

an affinity A_b (eV) of the blocking layer and an affinity A, (eV) of the electron injecting layer satisfy a relationship of A_e−

A_b<

0.2.

2. The organic electroluminescence device according to claim 1, wherein

the triplet energy E^T_b (eV) of the aromatic heterocyclic derivative and the triplet energy E^T_h (eV) of the host satisfy a relationship of E^T_h+0.2<

E^T_b

3. The organic electroluminescence device according to claim 1, wherein

the triplet energy E^T_b (eV) of the aromatic heterocyclic derivative and the triplet energy E^T_h (eV) of the host satisfy a relationship of E^T_h+0.3<

E^T_b

4. The organic electroluminescence device according to claim 1, wherein

the triplet energy E^T_b (eV) of the aromatic heterocyclic derivative and the triplet energy E^T_h (eV) of the host satisfy a relationship of E^T_h+0.4<

E^T_b

5. The organic electroluminescence device according to claim 1, wherein

the aromatic heterocyclic derivative included in the blocking layer has six or more cyclic structures, and

the triplet energy E^T_b (eV) of the aromatic heterocyclic derivative having the six or more cyclic structures is larger than the triplet energy E^T_h (eV) of the host.

6. The organic electroluminescence device according to claim 1, wherein

the triplet energy E^T_b (eV) of the aromatic heterocyclic derivative and a triplet energy E^T_Alq (eV) of tris(8-quinolinolato)aluminum complex satisfy a relationship of E^T_b>

E^T_Alq.

7. The organic electroluminescence device according to claim 1, wherein

an electron mobility of the aromatic heterocyclic derivative is 10⁻

6 cm²/Vs or more in an electric field intensity of 0.04 MV/cm to 0.5 MV/cm.

8. The organic electroluminescence device according to claim 1, wherein

an electron mobility of a material for forming the electron injecting layer is 10⁻

6 cm²/Vs or more in an electric field intensity of 0.04 MV/cm to 0.5 MV/cm.

9. The organic electroluminescence device according to claim 1, wherein

the dopant exhibits a fluorescent emission of a main peak wavelength of 550 nm or less, and

a triplet energy E^T_d (eV) of the dopant is larger than the triplet energy E^T_h (eV) of the host.

10. The organic electroluminescence device according to claim 1, wherein

a hole transporting zone is provided between the anode and the emitting layer,

a hole transporting layer is adjacent to the emitting layer in the hole transporting zone, and

a triplet energy E^T_ho (eV) of the hole transporting layer is larger than the triplet energy E^T_h (eV) of the host.

11. The organic electroluminescence device according to claim 1, wherein

a material for forming the electron injecting layer is the same as a material for forming the blocking layer.

12. The organic electroluminescence device according to claim 1, wherein

a material for forming the electron injecting layer is the same as a material for forming the blocking layer, and

the electron injecting layer is doped with a donor.

13. The organic electroluminescence device according to claim 1, wherein

the dopant is at least one compound selected from the group consisting of a pyrene derivative, aminoanthracene derivative, aminochrysene derivative, aminopyrene derivative, fluoranthene derivative and boron complex.

14. The organic electroluminescence device according to claim 1, wherein

the host is a compound that contains a double bond only in a cyclic structure.

15. The organic electroluminescence device according to claim 1, wherein

the dopant is a compound that contains a double bond only in a cyclic structure.

16. An organic electroluminescence device comprising an anode, an emitting layer, a blocking layer, an electron injecting layer, and a cathode in sequential order, wherein

the emitting layer comprises a host and a dopant,

the blocking layer comprises an aromatic heterocyclic derivative,

a triplet energy E^T_b (eV) of the aromatic heterocyclic derivative is larger than a triplet energy E^T_h (eV) of the host, and

the aromatic heterocyclic derivative has an azine ring.

17. The organic electroluminescence device according to claim 16, wherein

the aromatic heterocyclic derivative is represented by a formula (1) below,

18. The organic electroluminescence device according to claim 16, wherein

an electron mobility of the aromatic heterocyclic derivative is 10⁻

6 cm²/Vs or more in an electric field intensity of 0.04 MV/cm to 0.5 MV/cm.

19. The organic electroluminescence device according to claim 16, wherein

the triplet energy E^T_b (eV) of the aromatic heterocyclic derivative and the triplet energy E^T_h (eV) of the host satisfy a relationship of E^T_h+0.2<

E^T_b.

20. The organic electroluminescence device according to claim 16, wherein

the triplet energy E^T_b (eV) of the aromatic heterocyclic derivative and the triplet energy E^T_h (eV) of the host satisfy a relationship of E^T_h+0.3<

E^T_b

21. The organic electroluminescence device according to claim 16, wherein

the triplet energy E^T_b (eV) of the aromatic heterocyclic derivative and the triplet energy E^T_h (eV) of the host satisfy a relationship of E^T_h+0.4<

E^T_b

22. The organic electroluminescence device according to claim 16, wherein

the aromatic heterocyclic derivative included in the blocking layer has six or more cyclic structures, and

the triplet energy E^T_b (eV) of the aromatic heterocyclic derivative having the six or more cyclic structures is larger than a triplet energy E^T_h (eV) of the host.

23. The organic electroluminescence device according to claim 16, wherein

an electron mobility of a material for forming the electron injecting layer is 1×

10<sup>−

6</sup> cm²/Vs or more in an electric field intensity of 0.04 MV/cm to 0.5 MV/cm.

24. The organic electroluminescence device according to claim 16, wherein

the dopant exhibits a fluorescent emission of a main peak wavelength of 550 nm or less, and

a triplet energy E^T_d (eV) of the dopant is larger than the triplet energy E^T_h (eV) of the host.

25. The organic electroluminescence device according to claim 16, wherein

a hole transporting zone is provided between the anode and the emitting layer,

a hole transporting layer is adjacent to the emitting layer in the hole transporting zone, and

a triplet energy E^T_ho (eV) of the hole transporting layer is larger than the triplet energy E^T_h (eV) of the host.

26. The organic electroluminescence device according to claim 16, wherein

a material for forming the electron injecting layer is the same as a material for forming the blocking layer.

27. The organic electroluminescence device according to claim 16, wherein

a material for forming the electron injecting layer is the same as a material for forming the blocking layer, and

the electron injecting layer is doped with a donor.

28. The organic electroluminescence device according to claim 16, wherein

the dopant is at least one compound selected from the group consisting of a pyrene derivative, aminoanthracene derivative, aminochrysene derivative, aminopyrene derivative, fluoranthene derivative and boron complex.

29. The organic electroluminescence device according to claim 16, wherein

the host is a compound that contains a double bond only in a cyclic structure.

30. The organic electroluminescence device according to claim 16, wherein

the dopant is a compound that contains a double bond only in a cyclic structure.