Quantum dot composition, light emitting diode and display device including the light emitting diode

Patent metadata

Field	Value
Publication number	US-11737294-B2
Application number	US-202016892532-A
Country	US
Kind code	B2
Filing date	Jun 4, 2020
Priority date	Sep 25, 2019
Publication date	Aug 22, 2023
Grant date	Aug 22, 2023

Abstract

A quantum dot composition includes a quantum dot, and a ligand bonded to a surface of the quantum dot, wherein the ligand includes a body part including a charge transport moiety, and a head part bonded to the surface of the quantum dot. The quantum dot composition according may be applied to a light emitting diode and a display device to provide increased luminous efficiency and device life of the light emitting diode and the display device.

First claim

What is claimed is:

1. A quantum dot composition, comprising:
a quantum dot; and
a ligand bonded to a surface of the quantum dot,
wherein the ligand comprises:
a body part comprising a charge transport moiety; and
a head part combined with the surface of the quantum dot,
wherein the ligand further comprises a chain part connecting the body part and the head part, and
wherein the body part is represented by the following Formula 1-2:

in Formula 1-2,
R 3 to R 5 are each independently a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted alkyl group of 1 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 60 carbon atoms for forming a ring, or a substituted or unsubstituted heteroaryl group of 2 to 60 carbon atoms for forming a ring, and n 3 to n 5 are each independently an integer of 0 to 5.

2. The quantum dot composition of claim 1 , wherein the chain part is a substituted or unsubstituted alkyl group, a substituted or unsubstituted amine group, a substituted or unsubstituted oxy group, a substituted or unsubstituted thio group, a substituted or unsubstituted ester group, or a substituted or unsubstituted amide group.

3. The quantum dot composition of claim 1 , wherein the ligand is a monodentate ligand or a bidentate ligand.

4. The quantum dot composition of claim 1 , wherein the head part comprises at least one thiol group.

5. The quantum dot composition of claim 1 , wherein the quantum dot comprises a core and a shell at least partially surrounding the core.

6. The quantum dot composition of claim 1 , further comprising an organic solvent.

7. A light emitting diode, comprising:
a first electrode;
a hole transport region on the first electrode;
an emission layer on the hole transport region and comprising a quantum dot and a ligand bonded to a surface of the quantum dot;
an electron transport region on the emission layer; and
a second electrode on the electron transport region,
wherein the ligand comprises:
a body part comprising a charge transport moiety; and
a head part bonded to the surface of the quantum dot,

wherein the hole transport region comprises a first hole transport material, and
the first hole transport material and the body part each comprise a moiety having the same composition.

8. The light emitting diode of claim 7 , wherein the body part is represented by the following Formula 1-1 or Formula 1-2:

in Formula 1-1 and Formula 1-2,
R 1 to R 5 are each independently a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted alkyl group of 1 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 60 carbon atoms for forming a ring, or a substituted or unsubstituted heteroaryl group of 2 to 60 carbon atoms for forming a ring,
n 1 is an integer of 0 to 8, and
n 2 to n 5 are each independently an integer of 0 to 5.

9. The light emitting diode of claim 7 , wherein the quantum dot comprises a core and a shell at least partially surrounding the core, and the head part comprises at least one thiol group.

10. A light emitting diode, comprising:
a first electrode;
a hole transport region on the first electrode;
an emission layer on the hole transport region and comprising a quantum dot and a ligand bonded to a surface of the quantum dot;
an electron transport region on the emission layer; and
a second electrode on the electron transport region,
wherein the ligand comprises:
a body part comprising a charge transport moiety; and

a head part bonded to the surface of the quantum dot, and
wherein the electron transport region comprises a first electron transport material, and
the first electron transport material and the body part each comprise a moiety having the same composition.

11. A display device comprising a plurality of light emitting diodes, wherein each of the plurality of light emitting diodes comprises:
a first electrode;
a second electrode facing the first electrode; and
an emission layer between the first electrode and the second electrode and comprising a quantum dot and a ligand bonded to a surface of the quantum dot,
wherein the ligand comprises:
a body part having charge transport properties; and
a head part bonded to the surface of the quantum dot,
wherein the ligand further comprises a chain part connecting the body part and the head part, and
wherein the body part is represented by the following Formula 1-2:

in Formula 1-2,
R 3 to R 5 are each independently a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted alkyl group of 1 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 60 carbon atoms for forming a ring, or a substituted or unsubstituted heteroaryl group of 2 to 60 carbon atoms for forming a ring, and
n 3 to n 5 are each independently an integer of 0 to 5.

12. The display device of claim 11 , wherein the plurality of light emitting diodes comprise:
a first light emitting diode, and the quantum dot of the first light emitting diode is a first quantum dot to emit a first light;
a second light emitting diode, and the quantum dot of the second light emitting diode is a second quantum dot to emit a second light having a longer wavelength than the first light; and
a third light emitting diode, and the quantum dot of the third light emitting diode is a third quantum dot to emit a third light having a longer wavelength than the first light and the second light.

13. The display device of claim 12 , wherein:
the ligand of the first light emitting diode is a first ligand bonded to the first quantum dot,
the ligand of the second light emitting diode is a second ligand bonded to the second quantum dot, and
the ligand of the third light emitting diode is a third ligand bonded to the third quantum dot.

14. The display device of claim 12 , further comprising a color filter layer on the plurality of light emitting diodes,
wherein the color filter layer comprises:
a first filter to transmit the first light;
a second filter to transmit the second light; and
a third filter to transmit the third light.

Assignees

• Samsung Display Co Ltd

Inventors

• Jung Yunku
• Doh Hyunmi
• Park Jae Hong
• Shin Dongwoo
• Ha Jaekook
• Kim Sungwoon
• Nam Minki

Classifications

• H10K50/115 Primary

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

• C09K11/025 Primary

  non-luminescent particle coatings or suspension media · CPC title

• H10K71/00

  Manufacture or treatment specially adapted for the organic devices covered by this subclass · CPC title

• C09K11/08

  containing inorganic luminescent materials · CPC title

• H10K30/865

  Intermediate layers comprising a mixture of materials of the adjoining active layers · CPC title