US-12622167-B2 - Organic electroluminescent device

US12622167B2US 12622167 B2US12622167 B2US 12622167B2US-12622167-B2

Abstract

The present disclosure relates to an organic electroluminescent device. The organic electroluminescent device according to the present disclosure may exhibit low voltage, high efficiency, and/or long lifespan by including a light-emitting layer and an electron buffer layer comprising a specific organic electroluminescent material.

Inventors

Yoo-Jin Doh
Soo-yong Lee
Chi-Sik Kim
Seung-Hoon Yoo
Dong-Hyung Lee
Doo-Hyeon Moon
Soo-Jin Hwang

Assignees

ROHM AND HAAS ELECTRONIC MATERIALS KOREA LTD.

Dates

Publication Date: 20260505
Application Date: 20210903

Claims (9)

1 . An organic electroluminescent device comprising a first electrode; a second electrode facing the first electrode; a light-emitting layer between the first electrode and the second electrode; and an electron buffer layer and an electron transport zone between the light-emitting layer and the second electrode, wherein the electron buffer layer comprises a compound represented by the following formula 1-3: Wherein R 1 to R 6 each independently represent hydrogen or deuterium; L 1 represents a single bond, or a substituted or unsubstituted (C6-C30)arylene, L 2 represents a single bond, a substituted or unsubstituted (C6-C30)arylene, or a substituted or unsubstituted (3- to 30-membered)heteroarylene; Ar 1 represents a substituted or unsubstituted (C6-C30)aryl; Y represents O or S; Ring C represents a substituted or unsubstituted benzene ring, a substituted or unsubstituted naphthalene ring, or a substituted or unsubstituted phenanthrene ring; L 9 represents a single bond, a substituted or unsubstituted (C6-C30)arylene, or a substituted or unsubstituted (3- to 30-membered)heteroarylene; and R 9 represents a substituted or unsubstituted (C6-C30)aryl or a substituted or unsubstituted (3- to 30-membered)heteroaryl.
2 . An organic electroluminescent device comprising a first electrode; a second electrode facing the first electrode; a light-emitting layer between the first electrode and the second electrode; and an electron buffer layer and an electron transport zone between the light-emitting layer and the second electrode, wherein the electron buffer layer comprises a compound selected from the following compounds: wherein Dn means that n number of hydrogens is replaced with deuterium, wherein n represents an integer of 1 or more.
3 . An organic electroluminescent device comprising a first electrode; a second electrode facing the first electrode; a light-emitting layer between the first electrode and the second electrode; and an electron buffer layer and an electron transport zone between the light-emitting layer and the second electrode, wherein the electron buffer layer comprises a compound represented by the following formula 1-1: wherein L 1 represents a single bond; L 2 represents a single bond, a substituted or unsubstituted (C6-C30)arylene, or a substituted or unsubstituted (3- to 30-membered)heteroarylene; Ar 1 represents a substituted or unsubstituted (3- to 30-membered)heteroaryl; and R 1 to R 8 each independently represent hydrogen or deuterium; Ring A and Ring B each independently represent a substituted or unsubstituted benzene ring or a substituted or unsubstituted naphthalene ring; and R 21 and R 22 each independently represent hydrogen, deuterium, a substituted or unsubstituted (C1-C30)alkyl, a substituted or unsubstituted (C6-C30)aryl, a substituted or unsubstituted (3- to 30-membered)heteroaryl, or a substituted or unsubstituted (C3-C30)cycloalkyl; or may be linked to the adjacent substituent to form a ring(s); is selected from the following Group 1: [Group 1] wherein R 23 to R 26 each independently represent hydrogen, deuterium, halogen, cyano, a substituted or unsubstituted (C1-C30)alkyl, a substituted or unsubstituted (C6-C50)aryl, a substituted or unsubstituted (3- to 30-membered)heteroaryl, or a substituted or unsubstituted (C3-C30)cycloalkyl; or may be linked to the adjacent substituent to form a ring(s); a represents an integer of 1 to 3, b represents an integer of 1 to 4, c represents an integer of 1 to 5, and d represents an integer of 1 to 6; and when a to d are an integer of 2 or more, each of R 23 to R 26 may be the same or different; wherein the light-emitting layer comprises a compound selected from the following compounds: wherein Dn means that n number of hydrogens is replaced with deuterium, wherein n represents an integer of 1 or more.
4 . The organic electroluminescent device according to claim 3 , wherein the light-emitting layer further comprises a compound represented by the following formula 3: wherein Ring C, Ring D, and Ring E each independently represent a substituted or unsubstituted (C6-C30)aryl, or a substituted or unsubstituted (3- to 50-membered)heteroaryl; or Ring D and Ring E may be linked to each other to form a fused ring; Y 1 represents B; X 1 and X 2 each independently represent NR′, O, or S; R′ represents hydrogen, deuterium, halogen, cyano, a substituted or unsubstituted (C1-C30)alkyl, a substituted or unsubstituted (C6-C30)aryl, a substituted or unsubstituted (3- to 30-membered)heteroaryl, a substituted or unsubstituted (C3-C30)cycloalkyl, a substituted or unsubstituted (C1-C30)alkoxy, a substituted or unsubstituted tri(C1-C30)alkylsilyl, a substituted or unsubstituted di(C1-C30)alkyl(C6-C30)arylsilyl, a substituted or unsubstituted (C1-C30)alkyldi(C6-C30)arylsilyl, a substituted or unsubstituted tri(C6-C30)arylsilyl, a substituted or unsubstituted fused ring of (C3-C30) aliphatic ring and (C6-C30) aromatic ring, or -L 4 -N(Ar 13 )(Ar 14 ); or may be linked to at least one of Ring C, Ring D, and Ring E to form a ring; L 4 represents a single bond, a substituted or unsubstituted (C1-C30)alkylene, a substituted or unsubstituted (C6-C30)arylene, or a substituted or unsubstituted (3- to 30-membered)heteroarylene; and Ar 13 and Ar 14 each independently represent a substituted or unsubstituted (C1-C30)alkyl, a substituted or unsubstituted (C2-C30)alkenyl, a substituted or unsubstituted (C6-C30)aryl, or a substituted or unsubstituted (3- to 30-membered)heteroaryl.
5 . The organic electroluminescent device according to claim 4 , wherein the compound represented by formula 3 is selected from the following compounds: wherein D2 to D5 represent that two to five hydrogens each have been replaced with deuterium.
6 . The organic electroluminescent device according to claim 1 , wherein the compound represented by formula 1-3 is selected from the following compounds:
7 . The organic electroluminescent device according to claim 1 , further comprising a hole transport zone between the first electrode and the light-emitting layer, and wherein the hole transport zone includes a hole injection layer and a hole transport layer.
8 . The organic electroluminescent device according to claim 1 , wherein the electron transport zone includes an electron transport layer and an electron injection layer.
9 . The organic electroluminescent device according to claim 1 , wherein the light-emitting layer comprises a compound represented by the following formula 2: wherein L 11 and L 12 each independently represent a single bond, a substituted or unsubstituted (C6-C30)arylene, or a substituted or unsubstituted (3- to 30-membered)heteroarylene; Ar 11 and Ar 12 each independently represent a substituted or unsubstituted (C6-C30)aryl or a substituted or unsubstituted (3- to 30-membered)heteroaryl; and R 11 to R 18 each independently represent hydrogen or deuterium; provided that a compound represented by the following formula b is excluded from the formula 2

Description

TECHNICAL FIELD The present disclosure relates to an organic electroluminescent device. BACKGROUND ART An organic electroluminescent device (OLED) changes electric energy into light by applying electricity to an organic electroluminescent material, and its basic structure was first reported by Eastman Kodak in 1987. The OLED commonly comprises an anode, a cathode, and an organic layer formed between the two electrodes. The organic layer of the OLED may comprise a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting layer (containing host and dopant materials), an electron buffer layer, a hole blocking layer, an electron transport layer, an electron injection layer, etc. The materials used in the organic layer can be classified into a hole injection material, a hole transport material, an electron blocking material, a light-emitting material, an electron buffer material, a hole blocking material, an electron transport material, an electron injection material, etc., depending on their functions. In such an OLED, holes from the anode and electrons from the cathode are injected into a light-emitting layer by the application of electric voltage, and excitons having high energy are produced by the recombination of the holes and electrons. The organic light-emitting compound moves into an excited state by the energy and emits light from energy when the organic light-emitting compound returns to the ground state from the excited state. In recent years, due to the potential of flat panel displays and general lighting devices, the development of new materials for this is continuously required. The development of excellent high-performance materials and more desirable device structures is required in order to improve the performance required in medium and large-sized OLED panels. Unlike red and green high-efficiency phosphorescent materials which have already been commercialized among the light-emitting materials of the OLED, it has been pointed out that a blue phosphorescent material is not suitable for long-term use such as several years or more, since the blue phosphorescent material has short lifespan and high driving voltage, and thus, a fluorescent material is used. As such, conventional materials have not been able to satisfy the light-emitting characteristics of the OLED, and thus development of an OLED including an organic electroluminescent material having excellent performance is required. KR 2015-0118269 and KR 2017-0053796 A disclose an OLED in that an anthracene-based compound substituted with a dibenzofuran derivative is comprised in a buffer layer. However, said references do not specifically disclose an OLED including a combination of organic electroluminescent materials specified herein. DISCLOSURE OF THE INVENTION Technical Problem The object of the present disclosure is to provide an organic electroluminescent material which is able to produce an organic electroluminescent device having low voltage, high efficiency, and long lifespan, and an organic electroluminescent device comprising the same. Solution to Problem As a result of intensive studies to solve the technical problem above, the present inventors found that the aforementioned objective can be achieved by an organic electroluminescent device comprising a first electrode; a second electrode facing the first electrode; a light-emitting layer between the first electrode and the second electrode; and an electron buffer layer and an electron transport zone between the light-emitting layer and the second electrode, wherein the electron buffer layer comprises a compound represented by the following formula 1, so that the present invention was completed. In formula 1, L1 and L2 each independently represent a single bond, a substituted or unsubstituted (C6-C30)arylene, or a substituted or unsubstituted (3- to 30-membered)heteroarylene;Ar1 and Ar2 each independently represent a substituted or unsubstituted (C6-C30)aryl or a substituted or unsubstituted (3- to 30-membered)heteroaryl; andR1 to R6 each independently represent hydrogen or deuterium;provided that Ar1, Ar2, L1, and L2 do not include a compound represented by the following formula a. Advantageous Effects of Invention By using an organic electroluminescent material according to the present disclosure, an organic electroluminescent device having low voltage, high efficiency and long lifespan can be provided. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows an example of an organic electroluminescent device according to one embodiment of the present disclosure. FIG. 2 shows an example of an organic electroluminescent device according to another embodiment of the present disclosure. MODE FOR THE INVENTION Hereinafter, the present disclosure will be described in detail. However, the following description is intended to explain the invention, and is not meant in any way to restrict the scope of the invention. The present disclosure relates to an organic electr