Fluorescence and delayed fluorescence-type organic light-emitting material and element

• US 8,993,129 B2
• Filed: 12/02/2010
• Issued: 03/31/2015
• Est. Priority Date: 12/07/2009
• Status: Active Grant

• Current Assignee: Kyushu University, NIPPON STEEL Chemical & Material Co., Ltd. (Nippon Steel Corporation)
• Original Assignee: Kyushu University, Nippon Steel & Sumikin Chemical Co., Ltd. (Nippon Steel Corporation)
• Inventors: Endo, Ayataka, Adachi, Chihaya, Yoshimura, Kazuaki, Kawada, Atsushi, Miyazaki, Hiroshi, Kai, Takahiro
• Primary Examiner(s): Bohaty, Andrew K
• Application Number:
  US13/514,248
• Publication Number:
  US 20120241732A1
• Time in Patent Office: 1,580 Days
• Field of Search: None
• US Class Current: 428/690
• CPC Class Codes: C07D 209/86 with only hydrogen atoms, hydrocarbon or substituted hydrocarbon radicals, directly attached to carbon atoms of the ring system
• CPC Class Codes: C07D 487/04 Ortho-condensed systems
• CPC Class Codes: C09B 57/00 Other synthetic dyes of known constitution
• 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 2211/1018 Heterocyclic compounds
• 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 2211/1059 containing three nitrogen atoms as heteroatoms
• CPC Class Codes: H05B 33/10 Apparatus or processes specially adapted to the manufacture of electroluminescent light sources
• CPC Class Codes: H10K 2101/20 Delayed fluorescence emission
• CPC Class Codes: H10K 50/11 characterised by the electroluminescent [EL] layers
• CPC Class Codes: H10K 85/6572 comprising only nitrogen in the heteroaromatic polycondensed ring system, e.g. phenanthroline or carbazole
• CPC Class Codes: Y10S 428/917 Electroluminescent

Abstract

Fluorescence-emitting material which improves luminous efficiency of an organic light-emitting element such as an organic EL element or an organic PL element and an organic light-emitting element using the fluorescence-emitting material. The fluorescence-emitting material includes a compound having an indolocarbazole skeleton represented by the following general formula (1), as defined in the specification.

The organic light-emitting element includes an organic EL element including: a substrate; an anode; a cathode; and a light-emitting layer, the anode and the cathode being laminated on the substrate and the light-emitting layer being sandwiched between the anode and the cathode, in which the light-emitting layer includes: the organic light-emitting material; and as a host material, an organic compound having excited triplet energy higher than that of the organic light-emitting material.

Claims

1. A fluorescence and delayed fluorescence type organic light-emitting element, comprising:

a substrate; and

at least one light-emitting layer comprising (i) an organic light-emitting material having no metal atom in the molecule, which light-emitting material emits fluorescence and delayed fluorescence and which has a difference between excited singlet energy (S1) and excited triplet energy (T1) of 0.2 eV or less, the light-emitting layer being provided on the substrate, and (ii) a host material having at least any one of excited singlet energy (S1) and excited triplet energy (T1) higher than those of the organic light-emitting material.

2. The fluorescence and delayed fluorescence-type organic light-emitting element according to claim 1, wherein the light-emitting material has a difference between excited singlet energy (S1) and excited triplet energy (T1) of 0.15 eV or less.

3. The fluorescence and delayed fluorescence-type organic light-emitting element according to claim 1, wherein the excited singlet energy (S1) of the host material is higher than the excited singlet energy (S1) of the organic light-emitting material by 0.1 eV or more, and/or the excited triplet energy (T1) of the host material is higher than the excited triplet energy (T1) of the organic light-emitting material by 0.1 eV or more.

4. The fluorescence and delayed fluorescence-type organic light-emitting element according to claim 1, wherein the excited singlet energy (S1) of the host material is higher than the excited singlet energy (S1) of the organic light-emitting material by 0.2 eV or more, and/or the excited triplet energy (T1) of the host material is higher than the excited triplet energy (T1) of the organic light-emitting material by 0.2 eV or more.

5. A fluorescence and delayed fluorescence organic light-emitting element, comprising:

a substrate;

an anode;

a hole-transporting layer;

at least one light-emitting layer comprising an organic light-emitting material having no metal atom in the molecule, which light-emitting material emits fluorescence and delayed fluorescence, the organic light-emitting material having a difference between excited singlet energy (S1) and excited triplet energy (T1) of 0.2 eV or less, the light-emitting layer being provided on the substrate, wherein light emission form the light-emitting layer consists substantially of fluorescence and delayed fluorescence which is generated substantially only by the organic light-emitting material; and

a cathode.

6. The fluorescence and delayed fluorescence-type organic light-emitting element according to claim 5, wherein the light-emitting material has a difference between excited singlet energy (S1) and excited triplet energy (T1) of 0.15 eV or less.

7. A fluorescence and delayed fluorescence-type organic light-emitting element, comprising:

a substrate; and

at least one light-emitting layer comprising an organic light-emitting material which has a difference between excited singlet energy (S1) and excited triplet energy (T1) of 0 to 0.2 eV, the organic light-emitting material having no metal atom in the molecule, the light-emitting layer being provided on the substrate, wherein the light emission of the element includes 36% or more of a delayed fluorescence component.

8. The fluorescence and delayed fluorescence-type organic light-emitting element according to claim 7, wherein the light-emitting material has a difference between excited singlet energy (S1) and excited triplet energy (T1) of 0.15 eV or less.

9. A fluorescence and delayed fluorescence-type organic light-emitting element, comprising:

a substrate; and

at least one light-emitting layer comprising an organic light-emitting material represented by the general formula (1);

10. A fluorescence and delayed fluorescence type organic light-emitting element, comprising:

a substrate; and

at least one light-emitting layer comprising an organic light-emitting material which emits fluorescence and delayed fluorescence and which has a difference between excited singlet energy (S1) and excited triplet energy (T1) of 0.2 eV or less, the light-emitting layer being provided on the substrate,

wherein the organic light-emitting material comprises a compound represented by the following general formula (1);

11. A fluorescence and delayed fluorescence type organic light-emitting element, comprising:

a substrate; and

at least one light-emitting layer comprising (i) an organic light-emitting material which emits fluorescence and delayed fluorescence and which has a difference between excited singlet energy (S1) and excited triplet energy (T1) of 0.2 eV or less, the light-emitting layer being provided on the substrate, and (ii) a host material having at least any one of excited singlet energy (S1) and excited triplet energy (T1) higher than those of the organic light-emitting material,

wherein the organic light-emitting material comprises a compound represented by the following general formula (1);

12. The fluorescence and delayed fluorescence-type organic light-emitting element according to claim 11, wherein n in the general formula (1) represents 1.

13. The fluorescence and delayed fluorescence-type organic light-emitting element according to claim 11, wherein at least one of Ar in the general formula (1) represents an aromatic heterocyclic group.

14. The fluorescence and delayed fluorescence-type organic light-emitting element according to claim 11, wherein at least one of Ar in the general formula (1) represents a group represented by the following general formula (2):

15. An organic light-emitting element according to claim 11, wherein the organic light-emitting element comprises an organic electroluminescence element comprising:

a substrate;

an anode;

a cathode; and

at least one light-emitting layer comprising the organic light-emitting material, the anode and the cathode being provided on the substrate and the light-emitting layer being sandwiched between the anode and the cathode.

16. The fluorescence and delayed fluorescence-type organic light-emitting element according to claim 11, wherein a light emission from a light-emitting layer comprises fluorescence and delayed fluorescence, and the light emission includes 36% or more of a delayed fluorescence component.