Light-emitting device and electronic apparatus comprising light-emitting device

Patent metadata

Field	Value
Publication number	US-2026020495-A1
Application number	US-202519327498-A
Country	US
Kind code	A1
Filing date	Sep 12, 2025
Priority date	Aug 9, 2021
Publication date	Jan 15, 2026
Grant date	—

Abstract

A light emitting device in which: a) an absolute value of a lowest unoccupied molecular orbital (LUMO) energy level of a first electron transporting compound (ET-1) is smaller than an absolute value of a LUMO energy level of a host compound (H-1), b) an absolute value of a LUMO energy level of a second electron transporting compound (ET-2) is smaller than an absolute value of a LUMO energy level of a third electron transporting compound (ET-3), c) and an absolute value of a LUMO energy level of the second electron transporting compound (ET-2) is smaller than an absolute value of a LUMO energy level of the first electron transporting compound (ET-1).

First claim

1 . A light-emitting device comprising:
a first electrode;
a second electrode facing the first electrode; and
an interlayer located between the first electrode and the second electrode and comprising an emission layer,
wherein the interlayer comprises emission units in the number of m; and charge generating unit(s) in the number of (m−1), between the emission units that are adjacent to each other,
any one unit of the emission units in the number of m comprises an emission layer, a first buffer layer, a second buffer layer, and an electron transport layer,
the emission layer comprises a host compound (H-1) and a dopant compound (D),
the interlayer comprises a first buffer layer comprising a first electron transporting compound (ET-1), a second buffer layer comprising a second electron transporting compound (ET-2), and an electron transport layer comprising a third electron transporting compound (ET-3),
an absolute value of a lowest unoccupied molecular orbital (LUMO) energy level of the first electron transporting compound (ET-1) is smaller than an absolute value of a LUMO energy level of the host compound (H-1),
an absolute value of a LUMO energy level of the second electron transporting compound (ET-2) is smaller than an absolute value of a LUMO energy level of the third electron transporting compound (ET-3),
an absolute value of a LUMO energy level of the second electron transporting compound (ET-2) is smaller than an absolute value of a LUMO energy level of the first electron transporting compound (ET-1), and
at least one unit other than the any one unit of the emission units in the number of m comprises a delayed fluorescence dopant.

2 . The light-emitting device of claim 1 , wherein the emission units in the number of m comprise 1 to 7 blue emission units.

3 . The light-emitting device of claim 1 , wherein the first buffer layer is in contact with the emission layer.

4 . The light-emitting device of claim 1 , wherein the second buffer layer is in contact with the electron transport layer.

5 . The light-emitting device of claim 1 , wherein the first buffer layer is in contact with the second buffer layer.

6 . The light-emitting device of claim 1 , wherein the LUMO energy level of the first electron transporting compound (ET-1) and the LUMO energy level of the host compound (H-1) satisfy the following equation:

❘
"\[LeftBracketingBar]"

E

LUMO_ET
-
1

-

E

LUMO_H
-
1

❘
"\[RightBracketingBar]"

≤

0.2

eV
.

(
1
)

7 . The light-emitting device of claim 1 , wherein the LUMO energy level of the second electron transporting compound (ET-2) and the LUMO energy level of the third electron transporting compound (ET-3) satisfy the following equation:

❘
"\[LeftBracketingBar]"

E

LUMO_ET
-
2

-

E

LUMO_ET
-
3

❘
"\[RightBracketingBar]"

≥

0.2

eV
.

(
2
)

8 . The light-emitting device of claim 1 , wherein the LUMO energy level of the first electron transporting compound (ET-1) and the LUMO energy level of the second electron transporting compound (ET-2) satisfy the following equation:

❘
"\[LeftBracketingBar]"

E

LUMO_ET
-
2

-

E

LUMO_ET
-
1

❘
"\[RightBracketingBar]"

≤

0.2

eV
.

(
3
)

9 . The light-emitting device of claim 1 , wherein the emission layer further comprises at least one other host compound, and an absolute value of a LUMO energy level of the at least one other host compound is smaller than or equal to an absolute value of the LUMO energy level of the host compound (H-1).

10 . The light-emitting device of claim 9 , wherein a mol % of the host compound (H-1) is in a range of about 90 mol % to about 10 mol %, based on the total hosts in the emission layer.

11 . The light-emitting device of claim 1 , wherein the first buffer layer further comprises at least one other electron transporting compound, and an absolut

Assignees

• Samsung Display Co Ltd

Inventors

• Park Heungsu
• Kang Namsu
• Lee Songeun
• Lee Jongwon
• Lee Hyunshik
• Han Wonsuk

Classifications

• H10K85/626

  containing more than one polycyclic condensed aromatic rings, e.g. bis-anthracene · CPC title

• H10K85/615

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

• H10K50/19

  Tandem OLEDs · CPC title

• H10K85/6576

  comprising only sulfur in the heteroaromatic polycondensed ring system, e.g. benzothiophene · CPC title

• H10K50/11 Primary

  characterised by the electroluminescent [EL] layers · CPC title