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

Patent metadata

Field	Value
Publication number	US-12514117-B2
Application number	US-202217723353-A
Country	US
Kind code	B2
Filing date	Apr 18, 2022
Priority date	Aug 9, 2021
Publication date	Dec 30, 2025
Grant date	Dec 30, 2025

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

What is claimed is:

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 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), 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).

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

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

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

5 . 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:
| E LUMO_ET-1 −E LUMO_H-1 |≤0.20 eV  (1).

6 . 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:
E LUMO_ET-2 −E LUMO_ET-3 |≥0.20 eV  (2).

7 . 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:
| E LUMO_ET-2 −E LUMO_ET-1 |≤0.20 eV  (3).

8 . 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).

9 . The light-emitting device of claim 8 , 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.

10 . The light-emitting device of claim 1 , wherein the first buffer layer further comprises at least one other electron transporting compound, and an absolute value of a LUMO energy level of the at least one other electron transporting compound is greater than or equal to an absolute value of a LUMO energy level of the first electron transporting compound (ET-1).

11 . The light-emitting device of claim 10 , wherein a mol % of the first electron transporting compound (ET-1) is in a range of about 90 mol % to about 30 mol %, based on the total compounds in the first buffer layer.

12 . The light-emitting device of claim 1 , wherein the second buffer layer further comprises at least one other electron transporting compound, and an absolute value of a LUMO energy level of the at least one other electron transporting compound is greater than or equal to an absolute value of a LUMO energy level of the second electron transporting compound (ET-2).

13 . The light-emitting device of claim 12 , wherein a mol % of the second electron transporting compound (ET-2) is in a range of about 90 mol % to about 30 mol %, based on the total compounds in the second buffer layer.

14 . The light-emitting device of claim 1 , wherein the dopant compound (D) is a phosphorescent dopant compound.

15 . The light-emitting device of claim 1 , wherein the first electron transporting compound (ET-1) is selected from following compounds:

16 . The light-emitting device of claim 1 , wherein the second electron transporting compound (ET-2) is selected from following compounds:

17 . The light-emitting device of claim 1 , wherein the dopant compound (D) is selected from Compounds G-1 to G-12:

18 . The light-emitting device of claim 1 , 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, and
any one unit of the emission units in the number of m comprises the emission layer, the first buffer layer, the second buffer layer, and the electron transport layer.

19 . An electronic apparatus comprising the light-emitting device of claim 1 .

20 . The electronic apparatus of claim 19 , wherein the emission units in the number of m comprise 1 to 7 blue emission units.

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