Electroluminescent device capable of improving luminous efficiency by preventing a leakage current and improving electron transport properties and a display device including the same

Patent metadata

Field	Value
Publication number	US-10396306-B2
Application number	US-201815970252-A
Country	US
Kind code	B2
Filing date	May 3, 2018
Priority date	Dec 27, 2017
Publication date	Aug 27, 2019
Grant date	Aug 27, 2019

Abstract

An electroluminescent device, a method of manufacturing the same, and a display device including the same are disclosed. The electroluminescent device electroluminescent device includes a first electrode; a hole transport layer disposed on the first electrode; an emission layer disposed on the hole transport layer and including at least two light emitting particles; a first electron transport layer disposed on the emission layer and including at least two inorganic-organic composite particles; a second electron transport layer disposed on the first electron transport layer and including at least two inorganic oxide particles; and a second electrode disposed on the second electron transport layer, wherein the first electron transport layer has a lower work function than the second electron transport layer.

First claim

What is claimed is:

1. An electroluminescent device, comprising
a first electrode;
a hole transport layer disposed on the first electrode;
an emission layer disposed on the hole transport layer and comprising at least two light emitting particles;
a first electron transport layer disposed on the emission layer and comprising at least two inorganic-organic composite particles;
a second electron transport layer disposed on the first electron transport layer and comprising at least two inorganic oxide particles; and
a second electrode disposed on the second electron transport layer,
wherein the first electron transport layer has a lower work function than the second electron transport layer.

2. The electroluminescent device of claim 1 , wherein each of the inorganic-organic composite particles comprises an inorganic material core and at least two organic polymers bound to a surface of the inorganic material core.

3. The electroluminescent device of claim 2 , wherein the organic polymers is present in an amount in a range of about 3 weight percent to about 20 weight percent, based on a total amount of the first electron transport layer.

4. The electroluminescent device of claim 2 , wherein the organic polymers comprises at least one of an imine compound, an imine compound, an alcohol compound, an acrylic compound, a glycol compound, or a derivative thereof.

5. The electroluminescent device of claim 2 , wherein the inorganic material core comprises at least one of ZnO, TiO 2 , ZrO 2 , SnO 2 , WO 3 , Ta 2 O 3 , or a combination thereof.

6. The electroluminescent device of claim 2 , wherein an average particle diameter of the inorganic material cores is less than or equal to about 100 nanometers.

7. The electroluminescent device of claim 1 , wherein a difference between lowest unoccupied molecular orbital energy levels of the first electron transport layer and the second electron transport layer is greater than about 0 electronvolts and less than or equal to about 0.5 electronvolts.

8. The electroluminescent device of claim 1 , wherein the second electron transport layer is directly on the first electron transport layer.

9. The electroluminescent device of claim 1 , wherein the first electron transport layer has a thickness in a range of about 5 nanometers to about 25 nanometers.

10. The electroluminescent device of claim 1 , wherein the second electron transport layer has a thickness in a range of about 15 nanometers to about 35 nanometers.

11. The electroluminescent device of claim 1 , wherein the second electron transport layer consists of the at least two inorganic oxide particles.

12. The electroluminescent device of claim 1 , wherein the inorganic oxide particles comprise at least one of ZnO, TiO 2 , ZrO 2 , SnO 2 , WO 3 , Ta 2 O 3 , or a combination thereof.

13. The electroluminescent device of claim 1 , wherein at least one of the light emitting particles has a core-shell structure.

14. The electroluminescent device of claim 1 , wherein at least one of the light emitting particles comprises a Group II-VI compound that does not comprise Cd, a Group III-V compound, a Group IV-VI compound, a Group IV element or compound, a Group compound, a Group I-II-IV-VI compound that does not comprise Cd, or a combination thereof.

15. The electroluminescent device of claim 1 , wherein the first electron transport layer has a higher lowest unoccupied molecular orbital energy level than the second electron transport layer, and
the emission layer has a same lowest unoccupied molecular orbital energy level as the first electron transport layer or a higher lowest unoccupied molecular orbital energy level than the first electron transport layer.

16. A display device comprising the electroluminescent device of claim 1 .

Assignees

• Samsung Electronics Co Ltd

Inventors

• Kim Sung Woo
• Kim Tae Ho
• Park Kun Su
• Kim Chan Su
• Jang Eun Joo

Classifications

• G09G3/3208

  organic, e.g. using organic light-emitting diodes [OLED] · CPC title

• H05B33/20 Primary

  characterised by the chemical or physical composition or the arrangement of the material in which the electroluminescent material is embedded · CPC title

• H01L51/5072 Primary

  Electricity · mapped topic

• H01L51/5024

  Electricity · mapped topic

• H01L51/5203

  Electricity · mapped topic