Light emitting element and display device including the same

Patent metadata

Field	Value
Publication number	US-2025056966-A1
Application number	US-202418675348-A
Country	US
Kind code	A1
Filing date	May 28, 2024
Priority date	Aug 2, 2023
Publication date	Feb 13, 2025
Grant date	—

Abstract

Embodiments provide a light emitting element that includes a first electrode, a first light emitting unit disposed on the first electrode, a charge generation unit disposed on the first light emitting unit, a second light emitting unit disposed on the charge generation unit, and a second electrode disposed on the second light emitting unit. The first light emitting unit includes a first hole transport region disposed on the first electrode, a first emission layer disposed on the first hole transport region, and a first electron transport region disposed on the first emission layer. The charge generation unit includes an n-type charge generation layer disposed on the first light emitting unit, and a p-type charge generation layer disposed on the n-type charge generation layer. At least one of the p-type charge generation layer and the first hole transport region each independently includes a tertiary amine compound including a cycloalkyl moiety.

First claim

1 . A light emitting element comprising:
a first electrode; a first light emitting unit disposed on the first electrode; a charge generation unit disposed on the first light emitting unit; a second light emitting unit disposed on the charge generation unit; and a second electrode disposed on the second light emitting unit, wherein the first light emitting unit comprises:
a first hole transport region disposed on the first electrode;
a first emission layer disposed on the first hole transport region; and
a first electron transport region disposed on the first emission layer,
the charge generation unit comprises:
an n-type charge generation layer disposed on the first light emitting unit; and
a p-type charge generation layer disposed on the n-type charge generation layer,
at least one of the p-type charge generation layer and the first hole transport region each independently comprises a tertiary amine compound comprising a cycloalkyl moiety, and a first refractive index of the p-type charge generation layer with respect to a visible light is greater than a second refractive index of the first hole transport region with respect to the visible light.

2 . The light emitting element of claim 1 , wherein
the first refractive index is in a range of about 1.78 to about 2.0, and the second refractive index is in a range of about 1.50 to about 1.78.

3 . The light emitting element of claim 1 , wherein a relation between the first refractive index and the second refractive index is represented by Mathematical Equation 1:

0.001
≤

n
⁢
1

-

n
⁢
2

≤
0.2

[

Mathematical
⁢

Equation
⁢

1

]

wherein in Mathematical Equation 1,
n1 is the first refractive index, and
n2 is the second refractive index.

4 . The light emitting element of claim 1 , wherein a first extinction coefficient of the p-type charge generation layer is greater than a second extinction coefficient of the first hole transport region.

5 . The light emitting element of claim 4 , wherein the relation between the first extinction coefficient and the second extinction coefficient is represented by the following Mathematical Equation 2:

0.0001
≤

k
⁢
1

-

k
⁢
2

≤
0.1

[

Mathematical
⁢

Equation
⁢

2

]

wherein in Mathematical Equation 2,
k1 is the first extinction coefficient, and
k2 is the second extinction coefficient.

6 . The light emitting element of claim 1 , wherein the tertiary amine compound is represented by Formula 1:

wherein in Formula 1,
L 1 , L 2 , and L 3 are each independently a direct linkage, a substituted or unsubstituted arylene group of 6 to 30 ring-forming carbon atoms, a substituted or unsubstituted heteroarylene group of 2 to 30 ring-forming carbon atoms, or a substituted or unsubstituted cycloalkylene group of 5 to 30 ring-forming carbon atoms,
R 1 is a substituted or unsubstituted cycloalkyl group of 5 to 30 carbon atoms,
R 2 is a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a hydroxyl group, a silyl group, a substituted or unsubstituted alkyl group of 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group of 5 to 30 ring-forming carbon atoms, a substituted or unsubstituted aryl group of 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 30 ring-forming carbon atoms, and
R 3 is a group represented by Formula 2:

wherein in Formula 2,
X is C(R y1 )(R y2 ), N(R y3 ), O, or S,
R x1 to R x8 and R y1 to R y3 are each independently a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a hydroxyl group, a substituted or unsubstituted alkyl group of 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group of 5 to 30 ring-forming carbon atoms, a substituted or unsubstituted aryl group of 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 30 ring-forming carbon atoms, or combined with an adjacent group to form a ring,
except that one of R x1 to R x8 is a position connected with Formula 1.

7 . The light emitting element of claim 6 , wherein R 1 is a group represented by one of Formula 3-1 to Formula 3-5:

wherein in Formula 3-1 to Formula 3-5,

is a position connected to L 1 in Formula 1, and
at least one hydrogen atom is optionally substituted with a deuterium atom.

8 . The light emitting element of claim 6 , wherein the first hole transport region comprises the compound represented by Formula 1.

9 . The light emitting element of claim 1 , wherein the first hole transport region comprises at least one compound selected from Compound Group 1:

10 . The light emitting element of cla

Assignees

• Samsung Display Co Ltd

Inventors

• Im Yirang
• Kim Seulong
• Kim Yongmin
• Kim Yunjeong
• Park Jihee
• Jeong Geunhyuk

Classifications

• H10K85/631

  Amine compounds having at least two aryl rest on at least one amine-nitrogen atom, e.g. triphenylamine · CPC title

• H10K59/12

  Active-matrix OLED [AMOLED] displays · CPC title

• H10K50/15

  Hole transporting layers · CPC title

• H10K50/125

  specially adapted for multicolour light emission, e.g. for emitting white light · CPC title

• H10K50/19 Primary

  Tandem OLEDs · CPC title