Organic light emitting diode

Patent metadata

Field	Value
Publication number	US-11839145-B2
Application number	US-202016923047-A
Country	US
Kind code	B2
Filing date	Jul 7, 2020
Priority date	Nov 25, 2019
Publication date	Dec 5, 2023
Grant date	Dec 5, 2023

Abstract

An organic light emitting diode includes a first electrode, a hole transport region disposed on the first electrode, an emission layer disposed on the hole transport region, an electron transport region disposed on the emission layer, and a second electrode disposed on the electron transport region. The hole transport region includes a first hole transport layer which is directly disposed on the lower portion of the emission layer and has a first refractive index, and a second hole transport layer which is disposed on the lower portion of the first hole transport layer and has a second refractive index, thereby exhibiting an improved luminous efficiency characteristic.

First claim

What is claimed is:

1. An organic light emitting diode comprising:
a first electrode;
a hole transport region disposed on the first electrode;
an emission layer disposed on the hole transport region;
an electron transport region disposed on the emission layer; and
a second electrode disposed on the electron transport region,
wherein the hole transport region comprises:
a first hole transport layer having a first refractive index; and
a second hole transport layer having a second refractive index greater than the first refractive index and being disposed under the first hole transport layer,
wherein the first hole transport layer comprises a fluorene compound represented by Formula 1 below:

wherein, in Formula 1 above,
R 1 and R 2 are each independently a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms,
n is an integer of 1 to 3, and
Ar 1 to Ar 4 are each independently a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a substituted or unsubstituted amino group, a substituted or unsubstituted aryl group having 6 to 60 carbon atoms, a substituted or unsubstituted heterocyclic group having 2 to 60 carbon atoms, or are bonded to an adjacent group to form a ring, and
wherein R 1 and R 2 are each independently an unsubstituted n-butyl group or a n-pentyl group substituted with CF 3 , when n is 1.

2. The organic light emitting diode of claim 1 , wherein the first hole transport layer is directly disposed under the emission layer.

3. The organic light emitting diode of claim 1 , wherein a ratio of a thickness T 1 of the first hole transport layer and a thickness T 2 of the second hole transport layer satisfies a relationship of Expression 1 below:
1≤ T 2 /T 1 ≤3.  [Expression 1]

4. The organic light emitting diode of claim 1 , wherein a difference between the first refractive index and the second refractive index is at least 0.2.

5. The organic light emitting diode of claim 4 , wherein the first refractive index is from 1.2 to 1.7, and the second refractive index is from 1.7 to 1.9.

6. The organic light emitting diode of claim 1 , wherein the fluorene compound is any one among the compounds represented by Compound Group 1 below:

7. The organic light emitting diode of claim 1 ,
wherein the second hole transport layer comprises a compound represented by Formula 2 below:

wherein, in Formula 2 above,
Ar 1 and Ar 2 are a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or bonded to an adjacent group to form a ring,
a to c are each independently an integer of 0 to 5,
L 1 and L 2 are each independently a substituted or unsubstituted cycloalkylene group having 3 to 10 ring-forming carbon atoms, a substituted or unsubstituted heterocycloalkylene group having 2 to 10 ring-forming carbon atoms, a substituted or unsubstituted cycloalkenylene group having 3 to 10 ring-forming carbon atoms, a substituted or unsubstituted arylene group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroarylene group having 2 to 60 ring-forming carbon atoms,

L 3 is a substituted or unsubstituted cycloalkyl group having 3 to 10 ring-forming carbon atoms, a substituted or unsubstituted heterocycloalkyl group having 2 to 10 ring-forming carbon atoms, a substituted or unsubstituted cycloalkenyl group having 3 to 10 ring-forming carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 60 ring-forming carbon atoms,
p and s are each independently an integer of 0 to 3,
q and r are each independently an integer of 0 to 4, and
R 3 to R 7 are each independently a hydrogen atom, a deuterium atom, a halogen atom, a hydroxy group, a cyano group, a nitro group, an amino group, a substituted or unsubstituted silyl group, a substituted or unsubstituted oxy group, a substituted or unsubstituted alkyl group having 1 to 60 carbon atoms, a substituted or unsubstituted heterocycloalkyl group having 3 to 60 ring-forming carbon atoms, a substituted or unsubstituted aryl group having 6 to 60 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 60 ring-forming carbon atoms.

8. The organic light emitting diode of claim 7 , wherein the compound represented by Formula 2 above is any one among the compounds represented by Compound Group 2 below:

9. The organic light emitting diode of claim 1 , wherein the hole transport region further comprises a third hole transport layer disposed under the second hole transport layer, and the third hole transport layer comprises a p-dopant.

10. The organic light emitting diode of claim 1 , wherein a difference of a refractive index between the emission layer and the first hole transport layer is at least 0.2.

11. An organic light emitting diode comprising:
a first electrode;
a hole transport region disposed on the first electrode;
an emission layer disposed on the hole transport region;
an electron transport region disposed on the emission layer; and
a second electrode disposed on the electron transport region,
wherein the hole transport region comprises a plurality of hole transport layers having different refractive indexes, and
a layer, among the plurality of the hole transport layers, which is adjacent to the emission layer comprises a fluorene compound represented by Formula 1 below:

wherein, in Formula 1 above,
R 1 and R 2 are each independently a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms,
n is an integer of 1 to 3, and
Ar 1 to Ar 4 are each independently a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a substituted or unsubstituted amino group, a substituted or unsubstituted aryl group having 6 to 60 carbon atoms, a substituted or unsubstituted heterocyclic group having 2 to 60 carbon atoms, or are bonded to an adjacent group to form a ring, and
wherein R 1 and R 2 are each independently an unsubstituted n-butyl group or a n-pentyl group substituted with CF 3 , when n is 1.

12. The organic light emitting diode of claim 11 , wherein the hole transport region comprises:
a first hole transport layer having a first refractive index; and
a second hole transport layer which has a second refractive index greater than the first refractive index and is disposed under the first hole transport laye

Assignees

• Samsung Display Co Ltd

Inventors

• Ye Jimyoung
• Ko Hyomin

Classifications

• H10K85/655

  comprising only sulfur as heteroatom · CPC title

• H10K85/654

  comprising only nitrogen as heteroatom (H10K85/652 takes precedence) · CPC title

• H10K85/636

  comprising heteroaromatic hydrocarbons as substituents on the nitrogen atom · CPC title

• H10K85/615 Primary

  Polycyclic condensed aromatic hydrocarbons, e.g. anthracene · CPC title

• H10K85/633

  comprising polycyclic condensed aromatic hydrocarbons as substituents on the nitrogen atom · CPC title