Light-emitting device

Patent metadata

Field	Value
Publication number	US-2025248208-A1
Application number	US-202519017963-A
Country	US
Kind code	A1
Filing date	Jan 13, 2025
Priority date	Jan 31, 2024
Publication date	Jul 31, 2025
Grant date	—

Abstract

A highly reliable light-emitting device is provided. The light-emitting device includes a first insulating layer, a first electrode, a second electrode, and an organic compound layer. The first electrode is formed over the first insulating layer. The organic compound layer is positioned between the first electrode and the second electrode. The contour of the second electrode is substantially aligned with the contour of the organic compound layer. The organic compound layer includes a light-emitting layer and an electron-injection layer. The electron-injection layer contains a metal or a metal oxide, a first organic compound, and a second organic compound. The first organic compound includes a first π-electron deficient heteroaromatic ring with an electron-donating group. The second organic compound includes a second π-electron deficient heteroaromatic ring. The LUMO level of the second organic compound is lower than or equal to that of the first organic compound by 0.20 eV or more.

First claim

What is claimed is:

1 . A light-emitting device comprising:
a first electrode; a second electrode; and an organic compound layer, wherein the first electrode, the second electrode, and the organic compound layer are over a first insulating layer, wherein the first electrode is in contact with the first insulating layer, wherein the organic compound layer is between the first electrode and the second electrode, wherein the second electrode and the organic compound layer are separated from at least one of a plurality of other light-emitting devices adjacent to the light-emitting device, wherein a contour of the second electrode and a contour of the organic compound layer are aligned or substantially aligned with each other when seen from a direction perpendicular to a surface of the first insulating layer, wherein the organic compound layer comprises a light-emitting layer and an electron-injection layer, wherein the electron-injection layer is a mixed layer comprising a metal or an oxide of the metal, a first organic compound, and a second organic compound, wherein the first organic compound comprises a first π-electron deficient heteroaromatic ring with an electron-donating group, wherein the second organic compound comprises a second π-electron deficient heteroaromatic ring, and wherein a LUMO level of the second organic compound is lower than a LUMO level of the first organic compound by 0.20 eV or more.

2 . The light-emitting device according to claim 1 ,
wherein the organic compound layer comprises a p-type layer between the electron-injection layer and the second electrode, and wherein the p-type layer comprises a fifth organic compound having a hole-transport property and a second metal oxide or a sixth organic compound comprising at least one of a halogen group and a cyano group.

3 . A light-emitting device that is one light-emitting device among a plurality of light-emitting devices included in a light-emitting device group, the light-emitting device group comprising:
a first electrode group over one insulating surface; a second electrode group facing the first electrode group; and a first layer group between the first electrode group and the second electrode group, wherein the light-emitting device comprises a first electrode, a second electrode, and a first layer, wherein the first electrode is one electrode included in the first electrode group, wherein the first electrodes of the plurality of light-emitting devices are independent of each other, wherein the first layer is one layer included in the first layer group, wherein the first layers of the plurality of light-emitting devices are independent of each other, wherein the second electrode is one electrode included in the second electrode group, wherein the second electrodes of the plurality of light-emitting devices are independent of each other, wherein the second electrode and the first layer overlap with the first electrode, wherein the first layer comprises a light-emitting layer and an electron-injection layer, wherein the electron-injection layer is a mixed layer comprising a metal or an oxide of the metal, a first organic compound, and a second organic compound, wherein the first organic compound comprises a first π-electron deficient heteroaromatic ring with an electron-donating group, wherein the second organic compound comprises a second π-electron deficient heteroaromatic ring, wherein a LUMO level of the second organic compound is lower than a LUMO level of the first organic compound by 0.20 eV or more, and wherein a distance between the first layer included in the light-emitting device and the first layer included in another light-emitting device adjacent to the light-emitting device is greater than or equal to 0.5 μm and less than or equal to 5 μm.

4 . The light-emitting device according to claim 3 ,
wherein the first layer comprises a p-type layer between the electron-injection layer and the second electrode, and wherein the p-type layer comprises a fifth organic compound having a hole-transport property and a second metal oxide or a sixth organic compound comprising at least one of a halogen group and a cyano group.

5 . The light-emitting device according to claim 3 , wherein a contour of the second electrode and a contour of the first layer are aligned or substantially aligned with each other when seen from a direction perpendicular to the insulating surface.

6 . The light-emitting device according to claim 3 , wherein an end portion of the second electrode in a cross-section and an end portion of the first layer in a cross-section are aligned with each other in a direction perpendicular or substantially perpendicular to the insulating surface.

7 . The light-emitting device according to claim 1 , wherein a relation LUMO1−0.80≤LUMO2≤LUMO1−0.20 is satisfied where the LUMO level of the first organic compound is LUMO1 (eV) and the LUMO level of the second organic compound is LUMO2 (eV).

8 . The light-emitting device according to claim 1 , wherein the first π-electron deficient heteroaromatic ring is a heteroaromatic ring comprising two or more pyridine rings.

9 . The light-emitting device according to claim 1 , wherein the first organic compound has an acid dissociation constant pK a greater than or equal to 8.

10 . The light-emitting device according to claim 1 , wherein the first π-electron deficient heteroaromatic ring is different from the second π-electron deficient heteroaromatic ring.

11 . The light-emitting device according to claim 1 , wherein the second organic compound comprises at least one of an imidazole ring, a pyrazole ring, an oxazole ring, a thiazole ring, a triazole ring, a pyrazine ring, a pyrimidine ring, a pyridazine ring, and a triazine ring.

12 . The light-emitting device according to claim 1 , wherein the second organic compound has an acid dissociation constant pK a less than 4.

13 . The light-emitting device according to claim 1 ,
wherein the light-emitting layer comprises a third organic compound, wherein the third organic compound comprises a third it-electron deficient heteroaromatic ring, and wherein the third it-electron deficient heteroaromatic ring is the same as the second it-electron deficient heteroaromatic ring.

14 . The light-emitting device according to claim 1 ,
wherein the light-emitting layer comprises a third organic compound, and wherein the third organic compound is the same as the second organic compound.

15 . The light-emitting device according to claim 13 ,
wherein the organic compound layer comprises an electron-transport layer between the light-emitting layer and the electron-injection layer, wherein the electron-transport layer comprises a fourth organic compound, and wherein the fourth organic compound is different from the third organic compound.

16 . The light-emitting device according to claim 1 , wherein the metal belongs to any of Group 3, Group 11, and Group 13 in the periodic table.

17 . The light-emitting device according to claim 1 , wherein the electron-donating group is any one or more of an alkyl group, an alkoxy group, an aryloxy group, an alkylamino group, an arylamino group, and a heterocyclic amino group.

18 . The light-emitting device according to claim 1 , wherein in the case where a threshold value of electron density distribution in atomic units is 0.0004 e/a 0 3 , a minimum value of an electrostatic potential of the first organic compound is smaller than or equal to −0.085 E h .

Assignees

• Semiconductor Energy Lab

Inventors

• Sasaki Toshiki
• Ohsawa Nobuharu
• Seo Hiromi
• Fukuzaki Shinya

Classifications

• H10K2101/30

  Highest occupied molecular orbital [HOMO], lowest unoccupied molecular orbital [LUMO] or Fermi energy values · CPC title

• H10K85/657

  Polycyclic condensed heteroaromatic hydrocarbons · CPC title

• H10K85/649

  Aromatic compounds comprising a hetero atom · CPC title

• H10K50/171 Primary

  Electron injection layers · CPC title

• H10K50/11 Primary

  characterised by the electroluminescent [EL] layers · CPC title