Display device and method for manufacturing the same

Patent metadata

Field	Value
Publication number	US-11765954-B2
Application number	US-202117354210-A
Country	US
Kind code	B2
Filing date	Jun 22, 2021
Priority date	Oct 15, 2020
Publication date	Sep 19, 2023
Grant date	Sep 19, 2023

Abstract

A display device including a first light emitting element including a first emission layer and a first charge transport layer adjacent to the first emission layer, the first emission layer including a first quantum dot to emit first light, and a second light emitting element including a second emission layer and a second charge transport layer adjacent to the second emission layer, the second emission layer including a second quantum dot to emit second light that is longer in wavelength than the first light. The first charge transport layer includes a first metal oxide. The second charge transport layer includes a second metal oxide different from the first metal oxide.

First claim

What is claimed is:

1. A display device comprising:
a first light emitting element comprising a first emission layer and a first charge transport layer adjacent to the first emission layer, the first emission layer comprising a first quantum dot to emit first light; and
a second light emitting element comprising a second emission layer and a second charge transport layer adjacent to the second emission layer, the second emission layer comprising a second quantum dot to emit second light that is longer in wavelength than the first light,
wherein the first charge transport layer comprises a first metal oxide,
wherein the second charge transport layer comprises a second metal oxide different from the first metal oxide,
wherein the first charge transport layer comprises a first hole transport layer and a first electron transport layer spaced from the first hole transport layer with the first emission layer therebetween,
wherein the second charge transport layer comprises a second hole transport layer and a second electron transport layer spaced from the second hole transport layer with the second emission layer therebetween,
wherein the first hole transport layer comprises the first metal oxide, and
wherein the second hole transport layer comprises the second metal oxide.

2. The display device of claim 1 , wherein the first charge transport layer has a first energy level, and
wherein the second charge transport layer has a second energy level different from the first energy level.

3. The display device of claim 1 , wherein the first electron transport layer has a first conduction band minimum, and
wherein the second electron transport layer has a second conduction band minimum, the second conduction band minimum being greater in absolute value than the first conduction band minimum.

4. The display device of claim 1 , wherein the first electron transport layer comprises the first metal oxide, and
wherein the second electron transport layer comprises the second metal oxide.

5. The display device of claim 1 , further comprising a pixel defining film defining a plurality of openings in which the first light emitting element and the second light emitting element are arranged,
wherein the first charge transport layer and the second charge transport layer are in the plurality of openings.

6. The display device of claim 1 , wherein the first metal oxide is an oxide of a first metal, and
wherein the second metal oxide is an oxide of a second metal, the first metal and the second metal being different from each other.

7. The display device of claim 1 , wherein the first metal oxide and the second metal oxide each are an oxide of a material in which a main metal is doped with a doping metal, and
wherein a first doping ratio of the doping metal in the first metal oxide is different from a second doping ratio of the doping metal in the second metal oxide.

8. The display device of claim 1 , wherein the first metal oxide is an oxide of a material in which a first main metal is doped with a first doping metal,
wherein the second metal oxide is an oxide of a material in which a second main metal is doped with a second doping metal, and
wherein the first doping metal and the second doping metal are different from each other.

9. The display device of claim 1 , wherein one of the first metal oxide or the second metal oxide comprises a metal oxide particle and a shell surrounding the metal oxide particle, the metal oxide particle and the shell having different energy levels from each other.

10. The display device of claim 1 , wherein a first oxidation of the first metal oxide is different from a second oxidation of the second metal oxide.

11. The display device of claim 1 , wherein the first charge transport layer is smaller in thickness than the second charge transport layer.

12. A method for manufacturing the display device of claim 1 , the method comprising:
manufacturing the first light emitting element comprising the first emission layer and the first charge transport layer adjacent to the first emission layer, the first emission layer comprising the first quantum dot to emit the first light; and
manufacturing the second light emitting element comprising the second emission layer and the second charge transport layer adjacent to the second emission layer, the second emission layer comprising the second quantum dot to emit the second light that is longer in wavelength than the first light,
wherein the first charge transport layer is formed by providing the first metal oxide through a printing process,
wherein the second charge transport layer is formed by providing the second metal oxide different from the first metal oxide through a printing process,
wherein the first charge transport layer comprises the first hole transport layer and the first electron transport layer spaced from the first hole transport layer with the first emission layer therebetween,
wherein the second charge transport layer comprises the second hole transport layer and the second electron transport layer spaced from the second hole transport layer with the second emission layer therebetween,
wherein the first hole transport layer comprises the first metal oxide, and
wherein the second hole transport layer comprises the second metal oxide.

13. The method of claim 12 , further comprising forming a pixel defining film defining a plurality of openings in which the first light emitting element and the second light emitting element are arranged,
wherein the first charge transport layer is formed by applying the first metal oxide to a first opening from among the plurality of openings, and
wherein the second charge transport layer is formed by applying the second metal oxide to a second opening from among the plurality of openings.

14. The method of claim 12 ,
wherein the first hole transport layer has a first valance band maximum, and the second hole transport layer has a second valance band maximum, and
wherein the second valance band maximum is smaller in absolute value than the first valance band maximum.

15. The method of claim 12 ,
wherein the first electron transport layer has a first conduction band minimum, and the second electron transport layer has a second conduction band minimum, and
wherein the second conduction band minimum is greater in absolute value than the first conduction band minimum.

16. A display device comprising:
a first light emitting element comprising a first emission layer and a first charge transport layer adjacent to the first emission layer, the first emission layer comprising a first quantum dot to emit first light; and
a second light emitting element comprising a second emission layer and a second charge transport layer adjacent to the second emission layer, the second emission layer comprising a second quantum dot to emit second light that is longer in wavelength than the first light,
wherein the first charge transport layer comprises a first metal oxide,
wherein the second charge transport layer comprises a second metal oxide different from the first metal oxide,
wherein the first charge transport layer comprises a first hole transport layer and a first electron transport layer spaced from the first hole transport layer with the first emission layer therebetween,
wherein the second charge transport layer comprises a second hole transport layer and a second electron transport layer spaced from the second hole transport layer with the second emission layer therebetween,
wherein the first hole transport layer has a first valance band maximum, and
wherein the seco

Assignees

• Samsung Display Co Ltd

Inventors

• Kang Jingoo
• Kim Sungwoon
• Lee Changhee

Classifications

• H10K50/14 Primary

  Carrier transporting layers · CPC title

• H10K59/35 Primary

  comprising red-green-blue [RGB] subpixels · CPC title

• H10K50/115 Primary

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

• H10K59/38

  comprising colour filters or colour changing media [CCM] · CPC title

• H10K50/15

  Hole transporting layers · CPC title