Light emitting element and method for producing light emitting element

Patent metadata

Field	Value
Publication number	US-2021126216-A1
Application number	US-201817041430-A
Country	US
Kind code	A1
Filing date	Mar 28, 2018
Priority date	Mar 28, 2018
Publication date	Apr 29, 2021
Grant date	—

Abstract

Alight-emitting element includes an anode electrode, a cathode electrode, a light-emitting layer, a positive hole transport layer, and an electron transport layer. The light-emitting layer, the positive hole transport layer, and the electron transport layer are provided between the anode electrode and the cathode electrode. The light-emitting layer includes QD phosphor particles, a positive hole transport substance configured to transport positive holes transported thereto by the positive hole transport layer, an electron transport substance configured to transport electrons transported thereto by the electron transport layer, and a photosensitive host material.

First claim

1 . A light-emitting element comprising:
an anode electrode; a cathode electrode; a light-emitting layer; a positive hole transport layer configured to transport positive holes supplied from the anode electrode to the light-emitting layer; and an electron transport layer configured to transport electrons supplied from the cathode electrode to the light-emitting layer, wherein, the light-emitting layer, the positive hole transport layer, and the electron transport layer are provided between the anode electrode and the cathode electrode and the light-emitting layer includes a photosensitive host material, quantum dot phosphor particles configured to emit light in association with a bonding of the positive holes and the electrons, and at least one of a positive hole transport substance configured to transport the positive holes transported thereto by the positive hole transport layer, and an electron transport substance configured to transport the electrons transported thereto by the electron transport layer.

2 . The light-emitting element according to claim 1 ,
wherein the light-emitting layer includes both the positive hole transport substance and the electron transport substance.

3 . The light-emitting element according to claim 1 ,
wherein the light-emitting layer includes the positive hole transport substance and a substance having positive hole transport properties and included in the positive hole transport layer and the positive hole transport substance are the same substance.

4 . The light-emitting element according to claim 3 ,
wherein a highest occupied molecular orbital (HOMO) level of the light-emitting layer and a HOMO level of the positive hole transport layer are the same level.

5 . The light-emitting element according to claim 1 ,
wherein the light-emitting layer includes the electron transport substance and a substance having electron transport properties and included in the electron transport layer and the electron transport substance are the same substance.

6 . The light-emitting element according to claim 5 ,
wherein a lowest unoccupied molecular orbital (LUMO) level of the light-emitting layer and a LUMO level of the electron transport layer are the same level.

7 . The light-emitting element according to claim 1 , further comprising:
an electron blocking layer constituted by only the photosensitive host material, between the positive hole transport layer and the light-emitting layer.

8 . The light-emitting element according to claim 1 , further comprising:
an electron blocking layer constituted by the photosensitive host material and the positive hole transport substance, between the positive hole transport layer and the light-emitting layer.

9 . The light-emitting element according to claim 1 , further comprising:
a positive hole blocking layer constituted by only the photosensitive host material, between the electron transport layer and the light-emitting layer.

10 . The light-emitting element according to claim 1 , further comprising:
a positive hole blocking layer constituted by the photosensitive host material and the electron transport substance, between the electron transport layer and the light-emitting layer.

11 . The light-emitting element according to claim 1 ,
wherein the photosensitive host material is negative-working.

12 . The light-emitting element according to claim 1 , further comprising:
an edge cover, between the anode electrode and the light-emitting layer, configured to cover a peripheral edge of the anode electrode and including an opening exposing a portion of the anode electrode, wherein the light-emitting layer is configured to cover the opening of the edge cover, a side surface of the opening, and a portion of an upper edge of the edge cover and the positive hole transport layer has a width greater than a width of the light-emitting layer.

13 . The light-emitting element according to claim 1 , further comprising:
an edge cover, between the anode electrode and the light-emitting layer, configured to cover a peripheral edge of the anode electrode and including an opening exposing a portion of the anode electrode, wherein the light-emitting layer is configured to cover the opening of the edge cover, a side surface of the opening, and a portion of an upper edge of the edge cover and the positive hole transport layer is configured to cover the opening of the edge cover and a portion of the side surface of the opening.

14 . A method for manufacturing a light-emitting element including
an anode electrode, a cathode electrode, a light-emitting layer, a positive hole transport layer configured to transport positive holes supplied from the anode electrode to the light-emitting layer, and an electron transport layer configured to transport electrons supplied from the cathode electrode to the light-emitting layer, the light-emitting layer, the positive hole transport layer, and the electron transport layer being provided between the anode electrode and the cathode electrode, the method comprising: a light-emitting layer formation step of forming the light-emitting layer, wherein the light-emitting layer formation step includes an application step of applying, on a base material, a liquid including a photosensitive host material, quantum dot phosphor particles configured to emit light in association with a bonding of the positive holes and the electrons, and at least one of a positive hole transport substance configured to transport the positive holes transported thereto by the positive hole transport layer and an electron transport substance configured to transport the electrons transported thereto by the electron transport layer, an exposure step of exposing the photosensitive host material, and a development step of developing the photosensitive host material, and the photosensitive host material is developed and the light-emitting layer is patterned.

15 . The method for manufacturing a light-emitting element according to claim 14 ,
wherein, in the application step, a liquid including both the positive hole transport substance and the electron transport substance is applied.

Assignees

• Sharp Kk

Inventors

• Umeda Tokiyoshi
• Tsukamoto Yuto
• Kanehiro Masayuki
• Nakanishi Youhei

Classifications

• H10K50/15

  Hole transporting layers · CPC title

• H10K50/115 Primary

  comprising active inorganic nanostructures, e.g. luminescent quantum dots · CPC title

• H10K2101/40

  Interrelation of parameters between multiple constituent active layers or sublayers, e.g. HOMO values in adjacent layers · CPC title

• H05B33/10

  Apparatus or processes specially adapted to the manufacture of electroluminescent light sources · CPC title

• H05B33/14

  characterised by the chemical or physical composition or the arrangement of the electroluminescent material {, or by the simultaneous addition of the electroluminescent material in or onto the light source} · CPC title