Organic light-emitting element with regulation insulating layer and two-component electron transport layer and method of making

Patent metadata

Field	Value
Publication number	US-9490444-B2
Application number	US-201214235895-A
Country	US
Kind code	B2
Filing date	Apr 11, 2012
Priority date	Aug 3, 2011
Publication date	Nov 8, 2016
Grant date	Nov 8, 2016

Abstract

The present invention provides an organic light-emitting element with improved chemical stability at the interface between the light-emitting layer and the electron transport layer, which maintains excellent, stable luminous efficiency for a long period. For this purpose, one aspect of the present invention is an organic EL element having a substrate, and a hole injection layer, a buffer layer, a light-emitting layer, a regulation layer, an electron transport layer and a cathode which are sequentially layered on one side of the substrate. The regulation layer is made of NaF, which is not chemically reactive with the light-emitting layer or the electron transport layer, and the electron transport layer is made of a CT complex using a host material and an n-type dopant, which are both organic materials.

First claim

The invention claimed is:

1. An organic light-emitting element comprising:
an anode;
a cathode disposed opposite the anode;
an organic light-emitting layer disposed between the anode and the cathode, and containing an organic light-emitting material;
an electron transport layer disposed between the organic light-emitting layer and the cathode, and transporting electrons injected from the cathode to the organic light-emitting layer; and
a regulation layer disposed between and in contact with the organic light-emitting layer and the electron transport layer, and regulating transfer of constituent molecules of the organic light-emitting layer and of the electron transport layer while allowing transfer of electrons therebetween, wherein
the electron transport layer is made of an organic substance,
the regulation layer is not chemically reactive with the electron transport layer or the organic light-emitting layer,
the electron transport layer contains: a first organic substance having an electron transport property; and a second organic substance that is of n-type and is different from the first organic substance, and
a difference in energy level between a highest occupied molecular orbital of the first organic substance and a lowest unoccupied molecular orbital of the second organic substance is no more than 1.6 eV.

2. The organic light-emitting element of claim 1 , wherein
the regulation layer is made of a chemical compound including: a first material; and a second material that is different from the first material, and
lattice energy of the chemical compound is greater than binding energy between any atoms of the constituent molecules of the organic light-emitting layer and of the electron transport layer.

3. The organic light-emitting element of claim 1 , wherein
the regulation layer is an insulative layer.

4. The organic light-emitting element of claim 1 , wherein
the regulation layer has a thickness no less than 1 nm and no more than 10 nm.

5. The organic light-emitting element of claim 1 , wherein
the regulation layer is made of either one or both of an alkali metal fluoride and an alkaline-earth metal fluoride.

6. The organic light-emitting element of claim 5 , wherein
the alkali metal fluoride is NaF.

7. The organic light-emitting element of claim 5 , wherein
the alkaline-earth metal fluoride is MgF 2 .

8. The organic light-emitting element of claim 1 , wherein
the electron transport layer contains:
BPhen, Alq 3 or BCP, as the first organic substance; and
Ru(terpy) 2 , Cr(bpy) 3 , Cr(TMB) 3 , PyB or CoCp 2 , as the second organic substance.

9. An organic light-emitting element comprising:
an anode;
a cathode disposed opposite the anode;
an organic layer disposed between the anode and the cathode, and containing an organic substance;
a chemical compound layer disposed between the organic layer and the cathode; and
a regulation layer disposed between and in contact with the organic layer and the chemical compound layer, and regulating transfer of constituent molecules of the organic layer and of the chemical compound layer while allowing transfer of electrons therebetween, wherein
the chemical compound layer is made of an organic substance,
the regulation layer is not chemically reactive with the organic layer or the chemical compound layer,
the chemical compound layer contains: a first organic substance; and a second organic substance that is different from the first organic substance, and
a difference in energy level between a highest occupied molecular orbital of the first organic substance and a lowest unoccupied molecular orbital of the second organic substance is no more than 1.6 eV.

10. The organic light-emitting element of claim 9 , wherein
the regulation layer is made of a chemical compound including: a first material; and a second material that is different from the first material, and
lattice energy of the chemical compound is greater than binding energy between any atoms of the constituent molecules of the organic layer and of the chemical compound layer.

11. The organic light-emitting element of claim 9 , wherein
the regulation layer is an insulative layer.

12. The organic light-emitting element of claim 9 , wherein
the regulation layer has a thickness no less than 1 nm and no more than 10 nm.

13. The organic light-emitting element of claim 9 , wherein
the regulation layer is made of either one or both of an alkali metal fluoride and an alkaline-earth metal fluoride.

14. The organic light-emitting element of claim 13 , wherein
the alkali metal fluoride is NaF.

15. The organic light-emitting element of claim 13 , wherein
the alkaline-earth metal fluoride is MgF 2 .

16. The organic light-emitting element of claim 9 , wherein
the chemical compound layer contains:
BPhen, Alq 3 or BCP, as the first organic substance; and
Ru(terpy) 2 , Cr(bpy) 3 , Cr(TMB) 3 , PyB or CoCp 2 , as the second organic substance.

17. An organic light-emitting element, comprising:
an anode;
a cathode disposed opposite the anode;
an organic light-emitting layer disposed between the anode and the cathode, and containing an organic substance;
an insulative layer disposed in contact with the organic light-emitting layer; and
an electron transport layer disposed in contact with the insulative layer and containing: a first organic substance; and a second organic substance that is different from the first organic substance, wherein
a difference in energy level between a highest occupied molecular orbital of the first organic substance and a lowest unoccupied molecular orbital of the second organic substance is no more than 1.6 eV,
the insulative layer contains a chemical compound including: a first material; and a second material that is different from the first material, and
lattice energy of the chemical compound is greater than binding energy between any constituent atoms of the organic substance contained in the organic light-emitting layer, and is greater than binding energy between any constituent atoms of the first organic substance and the second organic substance contained in the electron transport layer.

18. An organic light-emitting element, comprising:
an anode;
a cathode disposed opposite the anode;
an organic layer disposed between the anode and the cathode and containing an organic substance;
an insulative layer disposed in contact with the organic layer; and
a chemical compound layer disposed in contact with the insulative layer and containing: a first organic substance; and a second organic substance that is different from the first organic substance, wherein
a difference in energy level between a highest occupied molecular orbital of the first organic substance and a lowest unoccupied molecular orbital of the second organic substance is no more than 1.6 eV,
the insulative layer contains a chemical compound including: a first material; and a second material that is different from the first material, and
lattice energy of the chemical compound is greater than binding energy between any constituent atoms of the organic substance contained in the organic layer, and is greater than binding energy between any constituent atoms of the first organic substance and the second organic substance contained in the chemical compound layer.

19. An organic light-emitting device including the organic light-emitting element according to claim 1 .

20. An organic light-emitting element comprising:
an anode;
a cathode disposed opposite the ano

Assignees

• Aonuma Masaki
• Katagiri Hiroshi
• Joled Inc

Inventors

• Aonuma Masaki
• Katagiri Hiroshi

Classifications

• C09K11/06

  containing organic luminescent materials · CPC title

• H10K50/16 Primary

  Electron transporting layers · CPC title

• H10K50/165 Primary

  comprising dopants · CPC title

• H01L51/56

  Electricity · mapped topic

• H01L51/5072 Primary

  Electricity · mapped topic