阅读说明：本技术 有机电致发光器件和用于其的稠合多环化合物 (Organic electroluminescent device and condensed polycyclic compound used therefor ) 是由 桑原博一 古江龙侑平 于 2021-02-07 设计创作，主要内容包括：提供了有机电致发光器件和用于有机电致发光器件的稠合多环化合物。有机电致发光器件包括彼此面对的第一电极和第二电极以及设置在第一电极与第二电极之间的多个有机层,其中,所述多个有机层中的至少一个有机层包括由式1表示的稠合多环化合物,并且该有机电致发光器件呈现出改善的发光效率。式1(Provided are an organic electroluminescent device and a condensed polycyclic compound for the organic electroluminescent device. The organic electroluminescent device includes first and second electrodes facing each other and a plurality of organic layers disposed between the first and second electrodes, wherein at least one of the plurality of organic layers includes a condensed polycyclic compound represented by formula 1, and exhibits improved luminous efficiency. Formula 1)

1. An organic electroluminescent device comprising:

a first electrode;

a second electrode facing the first electrode; and

a plurality of organic layers between the first electrode and the second electrode,

wherein the first electrode and the second electrode each independently include any one selected from Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF, Mo, Ti, In, Zn, Sn, and Yb, a compound of two or more thereof, a mixture of two or more thereof, or at least one oxide thereof, and

at least one organic layer among the plurality of organic layers includes a condensed polycyclic compound represented by formula 1:

formula 1

Wherein, in the formula 1,

R₁to R₁₂Each independently is a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted oxy group, a substituted or unsubstituted amine group, a substituted or unsubstituted alkyl group having 1 to 20 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 30 ring-forming carbon atoms, and optionally, R is₁To R₁₂Combine with an adjacent group to form a ring; and is

Two or more pairs of adjacent R₁To R₁₂Each of which is fused with a substituent represented by formula 2:

formula 2

Wherein, in the formula 2,

is R adjacent to the two or more pairs in formula 1₁To R₁₂A pair of fused positions in the group;

X₁and X₂Are all independently NAr₁O or S;

Ar₁is a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms, and optionally, Ar₁Combine with an adjacent group to form a ring;

R_aand R_bEach independently is a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted amino group, a substituted or unsubstituted alkyl group having 1 to 20 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 30 ring-forming carbon atoms, and optionally, R is_aAnd R_bCombine with an adjacent group to form a ring;

n₁is an integer from 0 to 4; and is

n₂Is an integer of 0 to 3.

2. The organic electroluminescent device of claim 1, wherein the plurality of organic layers comprises:

a hole transport region on the first electrode;

an emissive layer located on the hole transport region; and

an electron transport region on the emission layer and

wherein the emission layer includes the condensed polycyclic compound.

3. The organic electroluminescent device of claim 2, wherein the emissive layer emits delayed fluorescence.

4. The organic electroluminescent device according to claim 2, wherein the emission layer is a delayed fluorescence emission layer including a host and a dopant, and the dopant includes the condensed polycyclic compound represented by formula 1.

5. The organic electroluminescent device according to claim 1, wherein two or three substituents represented by formula 2 are fused with the fused polycyclic compound represented by formula 1, and the two or three fused substituents represented by formula 2 are identical to each other.

6. The organic electroluminescent device according to claim 1, wherein the substituent represented by formula 2 is represented by any one selected from formula 2-1 to formula 2-8:

formula 2-1

Formula 2-2

Formula 2-3

Formula 2-4

Formula 2-5

Formula 2-6

Formula 2-7

Formula 2-8

Wherein, in formulae 2-1 to 2-8,

Ar₁₁and Ar₁₂Each independently is a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms, and optionally, Ar₁₁And Ar₁₂Combine with adjacent groups to form a ring, an

R_aAnd R_bAnd n₁And n₂Are independently the same as defined in formula 2.

7. The organic electroluminescent device according to claim 1, wherein the substituent represented by formula 2 is represented by formula 2-a:

formula 2-a

Wherein, in the formula 2-a,

X₁and X₂And R_aAnd R_bAre independently the same as defined in formula 2.

8. The organic electroluminescent device according to claim 1, wherein the condensed polycyclic compound represented by formula 1 is represented by any one selected from formula 3-1 to formula 3-5:

formula 3-1

Formula 3-2

Formula 3-3

Formula 3-4

Formula 3-5

Wherein, in formulae 3-1 to 3-5,

A₁to A₈Each independently is a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted oxy group, a substituted or unsubstituted amine group, a substituted or unsubstituted alkyl group having 1 to 20 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 30 ring-forming carbon atoms, and optionally, A is₁To A₈Combine with an adjacent group to form a ring; and is

B₁And B₂、B₃And B₄And B₅And B₆Are all fused with the substituent represented by formula 2.

9. The organic electroluminescent device according to claim 8, wherein the condensed polycyclic compound represented by formula 1 is represented by any one selected from formula 4-1 to formula 4-8:

formula 4-1

Formula 4-2

Formula 4-3

Formula 4-4

Formula 4-5

Formula 4-6

Formula 4-7

Formula 4-8

Wherein, in formulae 4-1 to 4-8,

X₁₁、X₁₂、X₁₃、X₂₁、X₂₂and X₂₃Are all independently NAr₁O or S;

R_a1、R_a2、R_a3、R_b1、R_b2and R_b3Each independently is a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted amino group, a substituted or unsubstituted alkyl group having 1 to 20 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 30 ring-forming carbon atoms, and optionally, R is_a1、R_a2、R_a3、R_b1、R_b2And R_b3Combine with an adjacent group to form a ring;

n₁₁、n₁₂and n₁₃Each independently is an integer from 0 to 4;

n₂₁、n₂₂and n₂₃Each independently is an integer from 0 to 3; and is

Ar₁And A₁To A₈Are each independently the same as defined in formula 2 and formulae 3-1 to 3-5.

10. The organic electroluminescent device according to claim 1, wherein R_aAnd R_bEach independently is a hydrogen atom, a deuterium atom, a substituted or unsubstituted methyl group, a substituted or unsubstituted t-butyl group, a substituted or unsubstituted arylamine group, a substituted or unsubstituted phenyl group, or a substituted or unsubstituted carbazolyl group.

11. The organic electroluminescent device according to claim 1, wherein R₁To R₁₂Are each independently a hydrogen atom, a deuterium atom, or a position condensed with the substituent represented by formula 2.

12. The organic electroluminescent device according to claim 1, further comprising a cap layer on the second electrode and having a refractive index of 1.6 or more.

13. The organic electroluminescent device according to claim 1, wherein the condensed polycyclic compound represented by formula 1 is at least one selected from compounds represented by compound group 1:

compound group 1

14. A fused polycyclic compound represented by formula 1:

formula 1

Wherein, in the formula 1,

R₁to R₁₂Each independently is a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted oxy group, a substituted or unsubstituted amine group, a substituted or unsubstituted alkyl group having 1 to 20 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 30 ring-forming carbon atoms, and optionally, R is₁To R₁₂Combine with an adjacent group to form a ring; and is

Two or more pairs of adjacent R₁To R₁₂The groups are each fused with a substituent represented by formula 2,

formula 2

Wherein, in the formula 2,

is R adjacent to the two or more pairs in formula 1₁To R₁₂A pair of fused positions in the group;

X₁and X₂Are all independently NAr₁O or S;

Ar₁is a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms, and optionally, Ar₁Combine with an adjacent group to form a ring;

R_aand R_bEach independently is a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted amino group, a substituted or unsubstituted alkyl group having 1 to 20 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 30 ring-forming carbon atoms, and optionally, R is_aAnd R_bCombine with an adjacent group to form a ring;

n₁is an integer from 0 to 4; and is

n₂Is an integer of 0 to 3.

Technical Field

One or more aspects of embodiments of the present disclosure relate to an organic electroluminescent device and a fused polycyclic compound used for the organic electroluminescent device, for example, to a fused polycyclic compound used as a light emitting material and an organic electroluminescent device including the fused polycyclic compound.

Background

Organic electroluminescent displays are being developed as image display devices. Unlike a liquid crystal display device or the like, an organic electroluminescent display is a so-called self-luminous display device in which holes and electrons injected from a first electrode and a second electrode, respectively, are recombined in an emission layer, and a light-emitting organic compound in the emission layer emits light to realize display.

Display device applications require organic electroluminescent devices having low driving voltages, high luminous efficiencies, and/or long service lives (lifetimes), and new materials capable of stably obtaining these characteristics in organic electroluminescent devices are desired.

In recent years, in order to realize efficient organic electroluminescent devices, techniques for phosphorescent emission (using triplet energy) and/or delayed fluorescence emission (using singlet excitons generated by triplet exciton collision (triplet-triplet annihilation, TTA)) are being developed, and materials for Thermally Activated Delayed Fluorescence (TADF) are being developed.

Disclosure of Invention

One or more aspects of embodiments of the present disclosure relate to an organic electroluminescent device having improved luminous efficiency.

One or more aspects of embodiments of the present disclosure relate to a condensed polycyclic compound that may improve luminous efficiency of an organic electroluminescent device.

One or more example embodiments of the present disclosure provide an organic electroluminescent device including a first electrode, a second electrode facing the first electrode, and a plurality of organic layers between the first electrode and the second electrode. At least one organic layer among the plurality of organic layers includes a condensed polycyclic compound represented by formula 1:

formula 1

In formula 1, R₁To R₁₂May each independently be a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted oxy group, a substituted or unsubstituted amine group, a substituted or unsubstituted alkyl group having 1 to 20 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 30 ring-forming carbon atoms, and optionally (optinally, or "optionally"), R₁To R₁₂May be combined with an adjacent group to form a ring; and two or more pairs of adjacent R₁To R₁₂Each of which is fused with a substituent represented by formula 2:

formula 2

In formula 2, -₁To R₁₂A pair of fused positions in the group; x₁And X₂Can be NAr independently₁O or S; ar (Ar)₁May be a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms, and optionally, Ar₁May be combined with an adjacent group to form a ring; r_aAnd R_bMay each independently be a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted amino group, a substituted or unsubstituted alkyl group having 1 to 20 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 30 ring-forming carbon atoms, and optionally, R is_aAnd R_bMay be combined with an adjacent group to form a ring; n is₁May be an integer of 0 to 4; and n is₂May be an integer of 0 to 3. For example, twoOne or more substituents represented by formula 2 may be fused with formula 1.

In an embodiment, the plurality of organic layers may include a hole transport region on the first electrode, an emission layer on the hole transport region, and an electron transport region on the emission layer. The emission layer may include a condensed polycyclic compound.

In an embodiment, the emissive layer may emit delayed fluorescence.

In an embodiment, the emission layer may be a delayed fluorescence emission layer including a host and a dopant, and the dopant may be (or include) a fused polycyclic compound.

In embodiments, two or three substituents represented by formula 2 may be fused with the fused polycyclic compound represented by formula 1, and the two or three fused substituents represented by formula 2 may be identical to each other.

In an embodiment, the substituent represented by formula 2 may be represented by any one of formulae 2-1 to 2-8:

formula 2-1

Formula 2-2

Formula 2-3

Formula 2-4

Formula 2-5

Formula 2-6

Formula 2-7

Formula 2-8

In formulae 2-1 to 2-8, Ar₁₁And Ar₁₂May each independently be a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms, and optionally, Ar₁₁And Ar₁₂May be combined with an adjacent group to form a ring. R_aAnd R_bAnd n₁And n₂May each independently be the same as defined in formula 2.

In an embodiment, the substituent represented by formula 2 may be represented by formula 2-a:

formula 2-a

In the formula 2-a, X₁And X₂And R_aAnd R_bMay each independently be the same as defined in formula 2.

In embodiments, the fused polycyclic compound represented by formula 1 may be represented by any one of formulae 3-1 to 3-5:

formula 3-1

Formula 3-2

Formula 3-3

Formula 3-4

Formula 3-5

In formulae 3-1 to 3-5, A₁To A₈May each independently be a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted oxy group, a substituted or unsubstituted amine group, a substituted or unsubstituted alkyl group having 1 to 20 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 30 ring-forming carbon atoms, and optionally, a₁To A₈May be combined with an adjacent group to form a ring; b is₁And B₂、B₃And B₄And B₅And B₆May be each fused with a substituent represented by formula 2.

In embodiments, the fused polycyclic compound represented by formula 1 may be represented by any one of formulae 4-1 to 4-8:

formula 4-1

Formula 4-2

Formula 4-3

Formula 4-4

Formula 4-5

Formula 4-6

Formula 4-7

Formula 4-8

In formulae 4-1 to 4-8, X₁₁、X₁₂、X₁₃、X₂₁、X₂₂And X₂₃Can be NAr independently₁O or S; r_a1、R_a2、R_a3、R_b1、R_b2And R_b3May each independently be a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted amino group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstitutedA substituted aryl group having 6 to 30 ring-forming carbon atoms or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms, and optionally, R_a1、R_a2、R_a3、R_b1、R_b2And R_b3May be combined with an adjacent group to form a ring; n is₁₁、n₁₂And n₁₃May each independently be an integer of 0 to 4; n is₂₁、n₂₂And n₂₃May each independently be an integer of 0 to 3; ar (Ar)₁And A₁To A₈May be each independently the same as defined in formula 2 and formulae 3-1 to 3-5.

In the examples, R_aAnd R_b(and e.g. R)_a1、R_a2、R_a3、R_b1、R_b2And R_b3) May each independently be a hydrogen atom, a deuterium atom, a substituted or unsubstituted methyl group, a substituted or unsubstituted t-butyl group, a substituted or unsubstituted arylamine group, a substituted or unsubstituted phenyl group, or a substituted or unsubstituted carbazolyl group.

In the examples, R₁To R₁₂May each independently be a hydrogen atom, a deuterium atom, or a position condensed with the substituent represented by formula 2.

In some embodiments, the organic electroluminescent device may further include a capping layer on the second electrode and having a refractive index of 1.6 or more.

In the organic electroluminescent device according to an embodiment of the present disclosure, the first electrode and the second electrode may each independently include any one selected from silver (Ag), magnesium (Mg), copper (Cu), aluminum (Al), platinum (Pt), palladium (Pd), gold (Au), nickel (Ni), neodymium (Nd), iridium (Ir), chromium (Cr), lithium (Li), calcium (Ca), LiF, molybdenum (Mo), titanium (Ti), indium (In), zinc (Zn), tin (Sn), and ytterbium (Yb), a compound of two or more kinds thereof, a mixture of two or more kinds thereof, or at least one oxide thereof.

Fused polycyclic compounds according to embodiments of the present disclosure may be represented by formula 1.

Drawings

The accompanying drawings are included to provide a further understanding of the disclosure, and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the disclosure and, together with the description, serve to explain the principles of the disclosure. In the drawings:

fig. 1 is a cross-sectional view schematically showing an organic electroluminescent device according to an embodiment of the present disclosure;

fig. 2 is a cross-sectional view schematically showing an organic electroluminescent device according to an embodiment of the present disclosure;

fig. 3 is a cross-sectional view schematically showing an organic electroluminescent device according to an embodiment of the present disclosure; and

fig. 4 is a cross-sectional view schematically illustrating an organic electroluminescent device according to an embodiment of the present disclosure.

Detailed Description

The above objects, other objects, features and advantages of the present disclosure will be readily understood by the exemplary embodiments with reference to the accompanying drawings. This disclosure may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

When explaining each drawing, the same reference numerals are used to denote the same elements, and a repetitive description thereof may not be provided. In the drawings, the size and dimensions of elements may be exaggerated for clarity of illustration. It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could alternatively be termed a second element, and, similarly, a second element could alternatively be termed a first element, without departing from the scope of the present disclosure. The singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise.

In this specification, it will be understood that the terms "comprises," "comprising," and/or "having," and variations thereof, specify the presence of stated features, integers, steps, processes, elements, components, or groups thereof, but do not preclude the presence or addition of one or more other features, integers, steps, processes, elements, or groups thereof. It will also be understood that when a layer, film, region or panel is referred to as being "on" (under) "another layer, film, region or panel, the layer, film, region or panel can be directly on (under) the other layer, film, region or panel, or intervening layers, films, regions or panels may also be present. When an element is referred to as being "directly on," "directly connected to" or "directly coupled to" another element, there are no intervening elements present.

As used herein, when a statement such as "at least one of … …", "one of … …", and "selected from … … (or selected from … …)" follows (or precedes) a column of elements, the entire column of elements is modified, without modifying the individual elements in the column. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items. Furthermore, the use of "may" mean "one or more embodiments of the disclosure" when describing embodiments of the disclosure.

Hereinafter, an organic electroluminescent device and a fused polycyclic compound of an embodiment included therein according to an embodiment of the present disclosure will be described with reference to the accompanying drawings.

Fig. 1 to 4 are sectional views schematically illustrating an organic electroluminescent device according to an embodiment of the present disclosure. Referring to fig. 1 to 4, in each of the organic electroluminescent devices 10 according to the embodiments of the present disclosure, a first electrode EL1 and a second electrode EL2 are disposed to face each other, and a plurality of organic layers may be disposed between the first electrode EL1 and the second electrode EL 2. The plurality of organic layers may include a hole transport region HTR, an emission layer EML, and an electron transport region ETR. For example, each of the organic electroluminescent devices 10 according to the embodiment may include a first electrode EL1, a hole transport region HTR, an emission layer EML, an electron transport region ETR, and a second electrode EL2, which are sequentially stacked. In some embodiments, a cap layer CPL may be disposed on the second electrode EL 2.

The organic electroluminescent device 10 may include a condensed polycyclic compound according to an embodiment described below in at least one of the plurality of organic layers disposed between the first electrode EL1 and the second electrode EL 2. For example, the organic electroluminescent device 10 may include a condensed polycyclic compound in the emission layer EML disposed between the first electrode EL1 and the second electrode EL 2. However, the embodiment is not limited thereto, and the organic electroluminescent device 10 may include a condensed polycyclic compound in at least one of the hole transport region HTR and the electron transport region ETR among the plurality of organic layers disposed between the first electrode EL1 and the second electrode EL2 or in the capping layer CPL disposed on the second electrode EL 2.

Fig. 2 shows a cross-sectional view of the organic electroluminescent device 10 of the embodiment in which the hole transport region HTR includes the hole injection layer HIL and the hole transport layer HTL, and the electron transport region ETR includes the electron injection layer EIL and the electron transport layer ETL, compared to fig. 1. Fig. 3 shows a cross-sectional view of the organic electroluminescent device 10 of the embodiment in which the hole transport region HTR includes the hole injection layer HIL, the hole transport layer HTL, and the electron blocking layer EBL, and the electron transport region ETR includes the electron injection layer EIL, the electron transport layer ETL, and the hole blocking layer HBL, compared to fig. 1. Fig. 4 shows a cross-sectional view of the organic electroluminescent device 10 of an embodiment comprising a capping layer CPL arranged on the second electrode EL2, in comparison with fig. 2.

Hereinafter, it is described that the organic electroluminescent device 10 includes the fused polycyclic compound according to the embodiment in the emission layer EML, but the embodiment is not limited thereto, and in some embodiments, the fused polycyclic compound may be included in the hole transport region HTR, the electron transport region ETR, and/or the cap layer CPL.

The first electrode EL1 may have conductivity. The first electrode EL1 may be formed of a metal alloy and/or a conductive compound. The first electrode EL1 may be an anode. In some embodiments, the first electrode EL1 may be a pixel electrode. The first electrode EL1 may be a transmissive electrode, a transflective electrode, or a reflective electrode. When the first electrode EL1 is a transmissive electrode, the first electrode EL1 may include transparent metal oxide(s)Such as Indium Tin Oxide (ITO), Indium Zinc Oxide (IZO), zinc oxide (ZnO), and/or Indium Tin Zinc Oxide (ITZO). When the first electrode EL1 is a transflective electrode or a reflective electrode, the first electrode EL1 may include silver (Ag), magnesium (Mg), copper (Cu), aluminum (Al), platinum (Pt), palladium (Pd), gold (Au), nickel (Ni), neodymium (Nd), iridium (Ir), chromium (Cr), lithium (Li), calcium (Ca), LiF, molybdenum (Mo), titanium (Ti), a compound thereof, or a mixture thereof (e.g., a mixture of Ag and Mg). In some embodiments, the first electrode EL1 may have a multi-layer structure including a reflective layer or a transflective layer formed of the above-described materials and a transparent conductive layer formed of ITO, IZO, ZnO, ITZO, or the like. For example, the first electrode EL1 may have a three-layer structure of ITO/Ag/ITO, but is not limited thereto. The thickness of the first electrode EL1 may be aboutTo aboutFor example, aboutTo about

The hole transport region HTR is disposed on the first electrode EL 1. The hole transport region HTR may include at least one of a hole injection layer HIL, a hole transport layer HTL, a hole buffer layer, and an electron blocking layer EBL. The thickness of the hole transport region HTR may be, for example, aboutTo about

The hole transport region HTR may have a single layer formed of a single material, a single layer formed of a plurality of different materials, or a multilayer structure including a plurality of layers formed of a plurality of different materials.

For example, the hole transport region HTR may have a single-layer structure of the hole injection layer HIL or the hole transport layer HTL, or may have a single-layer structure formed of a hole injection material and a hole transport material. In some embodiments, the hole transport region HTR may have a single-layer structure formed of a plurality of different materials, or may have a structure in which a hole injection layer HIL/hole transport layer HTL, a hole injection layer HIL/hole transport layer HTL/hole buffer layer, a hole injection layer HIL/hole buffer layer, a hole transport layer HTL/hole buffer layer, or a hole injection layer HIL/hole transport layer HTL/electron blocking layer EBL are sequentially stacked from the first electrode EL1, but the embodiment is not limited thereto.

The hole transport region HTR may be formed using any suitable method, such as a vacuum deposition method, a spin coating method, a casting method, a langmuir-blodgett (LB) method, an inkjet printing method, a laser printing method, and/or a Laser Induced Thermal Imaging (LITI) method.

The hole injection layer HIL may include, for example, phthalocyanine compounds such as copper phthalocyanine, N '-diphenyl-N, N' -bis [4- (di-m-tolyl-amino) -phenyl ] -biphenyl-4, 4 '-diamine (DNTPD), 4',4 ″ -tris (3-methylphenylphenylamino) triphenylamine (m-MTDATA), 4',4 ″ -tris (N, N-diphenylamino) triphenylamine (TDATA), 4',4 ″ -tris { N- (2-naphthyl) -N-phenylamino } -triphenylamine (2-TNATA), poly (3, 4-ethylenedioxythiophene)/poly (4-styrenesulfonate) (PEDOT/PSS), polyaniline/dodecylbenzenesulfonic acid (PANI/DBSA), and the like, Polyaniline/camphorsulfonic acid (PANI/CSA), polyaniline/poly (4-styrenesulfonate) (PANI/PSS), N ' -di (naphthalene-1-yl) -N, N ' -diphenyl-benzidine (NPB), N ' -di (1-naphthyl) -N, N ' -diphenyl- (1,1' -biphenyl) -4,4' -diamine (NPD), triphenylamine-containing polyetherketone (TPAPEK), 4-isopropyl-4 ' -methyldiphenyliodonium tetrakis (pentafluorophenyl) borate, dipyrazino [2,3-f:2',3' -h ] quinoxaline-2, 3,6,7,10, 11-hexanenitrile (HAT-CN), and the like.

The hole transport layer HTL may include, for example, carbazole derivatives such as N-phenylcarbazole and/or polyvinylcarbazole, fluorene derivatives, N ' -bis (3-methylphenyl) -N, N ' -diphenyl- [1,1' -biphenyl ] -4,4' -diamine (TPD), triphenylamine derivatives such as 4,4',4 ″ -tris (N-carbazolyl) triphenylamine (TCTA), N ' -bis (naphthalen-1-yl) -N, N ' -diphenyl-benzidine (NPB), 4' -cyclohexylidenebis [ N, N-bis (4-methylphenyl) aniline ] (TAPC), 4' -bis [ N, N ' - (3-tolyl) amino ] -3,3' -dimethylbiphenyl (HMTPD), 1, 3-bis (N-carbazolyl) benzene (mCP), 9- (4-tert-butylphenyl) -3, 6-bis (triphenylsilyl) -9H-carbazole (CzSi), and the like.

The thickness of the hole transport region HTR may be aboutTo aboutFor example aboutTo aboutThe thickness of the hole injection layer HIL may be, for example, aboutTo aboutThe thickness of the hole transport layer HTL may be aboutTo aboutFor example, the electron blocking layer EBL may be about thickTo aboutWhen the thicknesses of the hole transport region HTR, the hole injection layer HIL, the hole transport layer HTL, and the electron blocking layer EBL satisfy the above-described ranges, satisfactory hole transport properties can be achieved,without significantly increasing the driving voltage.

In addition to the above materials, the hole transport region HTR may further include a charge generation material to improve conductivity. The charge generation material may be substantially uniformly or non-uniformly dispersed in the hole transport region HTR. The charge generating material may be, for example, a p-dopant. The p-dopant may be one of a quinone derivative, a metal oxide, and a cyano group-containing compound, but is not limited thereto. For example, non-limiting examples of the p-dopant may include quinone derivatives such as Tetracyanoquinodimethane (TCNQ) and/or 2,3,5, 6-tetrafluoro-7, 7,8, 8-tetracyanoquinodimethane (F4-TCNQ), metal oxides such as tungsten oxide and/or molybdenum oxide, and the like, but are not limited thereto.

As described above, the hole transport region HTR may include at least one of the hole buffer layer and the electron blocking layer EBL in addition to the hole injection layer HIL and the hole transport layer HTL. The hole buffer layer may compensate for a resonance distance of a wavelength of light emitted from the emission layer EML, and thus may improve light emitting efficiency. A material that may be included in the hole transport region HTR may also be included in the hole buffer layer. The electron blocking layer EBL may prevent or reduce injection of electrons from the electron transport region ETR to the hole transport region HTR.

The emission layer EML is disposed on the hole transport region HTR. The thickness of the emissive layer EML may be, for example, aboutTo aboutOr aboutTo aboutThe emission layer EML may have a single layer formed of a single material, a single layer formed of a plurality of different materials, or a multi-layer structure having a plurality of layers formed of a plurality of different materials.

The emission layer EML in the organic electroluminescent device 10 of the embodiment may include the condensed polycyclic compound of the embodiment.

In the specification, the term "substituted or unsubstituted" may represent an unsubstituted state or a state substituted with at least one substituent selected from the group consisting of a deuterium atom, a halogen atom, a cyano group, a nitro group, an amine group, a silyl group, an oxy group, a thio group, a sulfinyl group, a sulfonyl group, a carbonyl group, a boryl group, a phosphinoxide group, a phosphinyl sulfide group, an alkyl group, an alkenyl group, an alkoxy group, a hydrocarbon ring group, an aryl group, and a heterocyclic group. Each of these exemplary substituents may be further substituted or unsubstituted. For example, biphenyl can be interpreted as being an aryl group per se, or as a phenyl group substituted with a phenyl group.

In the specification, the phrase "combine with an adjacent group to form a ring" may denote a state of combining with an adjacent group to form a substituted or unsubstituted hydrocarbon ring or a substituted or unsubstituted heterocyclic ring. The hydrocarbon ring may be an aliphatic hydrocarbon ring or an aromatic hydrocarbon ring. The heterocyclic ring may be an aliphatic heterocyclic ring or an aromatic heterocyclic ring. The ring formed by bonding to the adjacent group may be monocyclic or polycyclic. In some embodiments, a ring formed by joining to each other may be connected to another ring to form a spiral structure.

In the specification, the term "adjacent groups" may denote a substituent on the same atom or point, a substituent on an atom directly connected to the base atom or point, or a substituent positioned spatially (e.g., within an intramolecular binding distance) with respect to the corresponding substituent. For example, two methyl groups in 1, 2-dimethylbenzene can be interpreted as "adjacent groups" to each other, and two ethyl groups in 1, 1-diethylcyclopentane can be interpreted as "adjacent groups" to each other.

In the specification, the term "direct bond" may represent a single bond.

In the specification, non-limiting examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.

In the specification, the alkyl group may be a straight-chain alkyl group, a branched-chain alkyl group or a cyclic alkyl group. The number of carbons in the alkyl group can be 1 to 50, 1 to 30, 1 to 20, 1 to 10, or 1 to 6. Examples of alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, isobutyl, 2-ethylbutyl, 3-dimethylbutyl, n-pentyl, isopentyl, neopentyl, tert-pentyl, cyclopentyl, 1-methylpentyl, 3-methylpentyl, 2-ethylpentyl, 4-methyl-2-pentyl, n-hexyl, 1-methylhexyl, 2-ethylhexyl, 2-butylhexyl, cyclohexyl, 4-methylcyclohexyl, 4-tert-butylcyclohexyl, n-heptyl, 1-methylheptyl, 2-dimethylheptyl, 2-ethylheptyl, 2-butylheptyl, n-octyl, tert-octyl, 2-ethyloctyl, 2-butyloctyl, 2-hexyloctyl, 2-ethylpentyl, 2-ethylbutyl, 3-dimethylbutyl, n-pentyl, cyclohexyl, 4-methylcyclohexyl, 4-butylcyclohexyl, 4-butylheptyl, 2-methylheptyl, 2-dimethylheptyl, 2-ethylheptyl, 2-octyll, 2-butyloctyl, 2-ethyloctyl, 2-butylhexyl, 2-pentyl, 2-butylhexyl, 2-pentyl, or a, 3, 7-dimethyloctyl, cyclooctyl, n-nonyl, n-decyl, adamantyl, 2-ethyldecyl, 2-butyldecyl, 2-hexyldecyl, 2-octyldecyl, n-undecyl, n-dodecyl, 2-ethyldodecyl, 2-butyldodecyl, 2-hexyldodecyl, 2-octyldodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, 2-ethylhexadecyl, 2-butylhexadecyl, 2-hexylhexadecyl, 2-octylhexadecyl, n-heptadecyl, n-octadecyl, n-nonadecyl, n-eicosyl, 2-ethyleicosyl, 2-butyleicosyl, 2-hexyleicosyl, 2-octyleicosyl, N-heneicosyl, n-docosyl, n-tricosyl, n-tetracosyl, n-pentacosyl, n-hexacosyl, n-heptacosyl, n-octacosyl, n-nonacosyl, n-triacontyl, and the like.

In the specification, the term "alkenyl group" means a hydrocarbon group including at least one carbon-carbon double bond in the middle or at the end of an alkyl group having 2 or more carbon atoms. The alkenyl group may be linear or branched. The number of carbon atoms is not particularly limited, and may be 2 to 30, 2 to 20, or 2 to 10. Examples of the alkenyl group include vinyl, 1-butenyl, 1-pentenyl, 1, 3-butadienylaryl, styryl, styrylvinyl, and the like, but are not limited thereto.

In the specification, the term "hydrocarbon ring" includes aliphatic hydrocarbon rings and aromatic hydrocarbon rings. The term "heterocycle" includes aliphatic heterocycles and aromatic heterocycles. The hydrocarbon ring and the heterocyclic ring may each independently be a monocyclic ring or a polycyclic ring.

In the specification, a hydrocarbon ring group may be any functional group or substituent derived from an aliphatic hydrocarbon ring or any functional group or substituent derived from an aromatic hydrocarbon ring. The number of carbons in the hydrocarbon ring group for forming a ring may be 5 to 60.

In the specification, the heterocyclic group may be a functional group or a substituent derived from a heterocyclic ring and including at least one hetero atom as an atom for forming a ring. The number of carbons in the heterocyclic group for forming a ring may be 5 to 60.

In the specification, the term "aryl" denotes any functional group or substituent derived from an aromatic hydrocarbon ring. The aryl group may be a monocyclic aryl group or a polycyclic aryl group. The number of ring-forming carbon atoms in the aryl group may be 6 to 30, 6 to 20, or 6 to 15. Examples of aryl groups include phenyl, naphthyl, fluorenyl, anthracenyl, phenanthryl, biphenyl, terphenyl, quaterphenyl, pentabiphenyl, hexabiphenyl, benzo [9,10]]Phenanthryl, pyrenyl, benzofluoranthenyl, phenanthrenyl, pyrenyl,and the like, but are not limited thereto.

In the specification, the fluorenyl group may be substituted, and two substituents thereof may be combined with each other to form a spiro structure. Examples of substituted fluorenyl groups are as follows, but embodiments of the disclosure are not limited thereto:

in the specification, the heteroaryl group may include at least one of boron (B), oxygen (O), nitrogen (N), phosphorus (P), silicon (Si), and sulfur (S) as a heteroatom. When the heteroaryl group contains two or more heteroatoms, the two or more heteroatoms may be the same as or different from each other. The heteroaryl group may be a monocyclic heterocyclic group or a polycyclic heterocyclic group. The number of ring-forming carbon atoms in the heteroaryl group can be 2 to 30, 2 to 20, or 2 to 10. Examples of heteroaryl groups include, but are not limited to, thienyl, furyl, pyrrolyl, imidazolyl, thiazolyl, oxazolyl, oxadiazolyl, triazolyl, pyridyl, bipyridyl, pyrimidinyl, triazinyl, acridinyl, pyridazinyl, pyrazinyl, quinolyl, quinazolinyl, quinoxalinyl, phenoxazinyl, phthalazinyl, pyridopyrimidinyl, pyridopyrazinyl, pyrazinopyrazinyl, isoquinolyl, indolyl, carbazolyl, N-arylcarbazolyl, N-heteroarylcarbazolyl, N-alkylcarbazolyl, benzoxazolyl, benzimidazolyl, benzothiazolyl, benzocarbazolyl, benzothienyl, dibenzothienyl, thienothienyl, benzofuryl, phenanthrolinyl, isoxazolyl, thiadiazolyl, phenothiazinyl, dibenzothienyl, dibenzofuranyl, and the like.

In the specification, the term "silyl group" includes alkylsilyl groups and arylsilyl groups. Examples of silyl groups include, but are not limited to, trimethylsilyl, triethylsilyl, t-butyldimethylsilyl, vinyldimethylsilyl, propyldimethylsilyl, triphenylsilyl, diphenylsilyl, phenylsilyl, and the like.

In the specification, the term "boron group" includes alkyl boron groups and aryl boron groups. Examples of boron groups include, but are not limited to, dimethyl boron group, diethyl boron group, tert-butyl methyl boron group, diphenyl boron group, phenyl boron group, and the like.

In the specification, the number of carbon atoms in the amine group (or referred to as "amino group") is not particularly limited, but may be 0 or 1 to 30. The term "amine group" may include alkylamino and arylamino groups. Examples of amine groups include, but are not limited to, methylamino, dimethylamino, phenylamino, diphenylamino, naphthylamino, 9-methyl-anthracenylamino, and the like.

In the specification, the term "hydrocarbon ring group" means any functional group or substituent derived from an aliphatic hydrocarbon ring. The hydrocarbon ring group may be a saturated hydrocarbon ring group having 5 to 20 ring-forming carbon atoms.

In the specification, the heterocyclic group may include at least one of B, O, N, P, Si and S as a heteroatom. When a heterocyclyl group contains two or more heteroatoms, the two or more heteroatoms may be the same as or different from each other. The heterocyclic group may be a monocyclic heterocyclic group or a polycyclic heterocyclic group, and includes a heteroaryl group. The number of ring-forming carbon atoms in the heterocyclic group may be 2 to 30, 2 to 20, or 2 to 10.

In the specification, -.

The fused polycyclic compounds of the embodiments include structures in which two or more polycyclic heterocycles are each fused to the central benzo [9,10] phenanthrene nucleus through two heteroatoms (including one boron atom). Thus, the polycyclic heterocycle may add four fused rings including one boron atom and two heteroatoms selected from the group consisting of nitrogen, oxygen, and sulfur. For example, in the fused polycyclic compounds of the embodiments, the polycyclic heterocycle may be fused to the benzo [9,10] phenanthrene nucleus using one boron atom and one heteroatom as a bidentate linker.

The fused polycyclic compounds of the embodiments may be represented by formula 1:

formula 1

In formula 1, R₁To R₁₂May each independently be a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted oxy group, a substituted or unsubstituted amine group, a substituted or unsubstituted alkyl group having 1 to 20 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 30 ring-forming carbon atoms. In some embodiments, R₁To R₁₂Any adjacent pair thereof may be combined with an adjacent group to form a ring. In some embodiments, R₁To R₁₂May each independently be a hydrogen atom or a deuterium atom.

Any pair of adjacent R₁To R₁₂The group may be fused with the substituent represented by formula 2. For example, two or more substituents represented by formula 2 may be fused to the core of formula 1. In formula 1, R₁To R₁₂At least two pairs of which may be condensed with the substituent represented by formula 2. For example, two or three substituents represented by formula 2 may be fused with the fused polycyclic compound represented by formula 1. A plurality of substituents represented by formula 2 may be the same (e.g., the same). However, the embodiments are not limited thereto, and in some embodiments, at least one of the plurality of substituents represented by formula 2 may have a structure different from other substituents.

Formula 2

In formula 2, -₁To R₁₂A pair of fused positions in the group. The substituent represented by formula 2 may be represented by a boron atom and X₁R adjacent to in formula 1₁To R₁₂Any pair of groups is fused.

X₁And X₂Can be NAr independently₁O or S. For example, X₁And X₂Can be NAr independently₁Or O. X₁And X₂May be the same as or different from each other. For example, X₁And X₂Both can be NAr₁Or O. In some embodiments, X₁And X₂One of which may be NAr₁And the other may be O.

Ar₁May be a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms. In some embodiments, Ar₁May be combined with an adjacent group to form a ring. For example, Ar₁And may be a substituted or unsubstituted phenyl group.

R_aAnd R_bMay each independently be a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted amino group, a substituted or unsubstituted alkyl group having 1 to 20 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 30 ring-forming carbon atoms. In some embodiments, R_aAnd R_bMay each independently combine with an adjacent group to form a ring. For example, R_aAnd R_bMay each independently be a hydrogen atom, a deuterium atom, a substituted or unsubstituted methyl group, a substituted or unsubstituted t-butyl group, a substituted or unsubstituted arylamine group, a substituted or unsubstituted phenyl group, or a substituted or unsubstituted carbazolyl group. R_aAnd R_bAt least one of which may be a substituted or unsubstituted methyl group, a substituted or unsubstituted t-butyl group, a substituted or unsubstituted arylamine group, a substituted or unsubstituted phenyl group, or a substituted or unsubstituted carbazolyl group.

n₁May be an integer of 0 to 4. n is₂May be an integer of 0 to 3. When n is₁And n₂When each of (1) is 0, a fused polycyclic compound according to the embodiment is represented by R_aAnd R_bAre not substituted (e.g., those positions are all hydrogen). When n is₁And/or n₂When it is an integer of 2 or more, R_aAnd/or R_bMay be the same, or a plurality of R_aAnd/or a plurality of R_bAt least one of which may be different.

The fused polycyclic compounds of the embodiments include structures in which two or more structures of formula 2 including one boron atom and two heteroatoms are fused with a central benzo [9,10] phenanthrene nucleus. Thus, the fused polycyclic compounds of the embodiments include two or more boron atoms, and two or more structures of formula 2 are connected at the central benzo [9,10] phenanthrene nucleus to form an extended conjugated structure, thereby stabilizing the structure of the polycyclic aromatic ring. The half-width and wavelength range of the resulting compound may be suitable for a blue light emitting material, and when the condensed polycyclic compound of the embodiment is applied to a light emitting device, the efficiency of the light emitting device may be improved.

The substituent represented by formula 2 may be represented by any one of formulae 2-1 to 2-8:

formula 2-1

Formula 2-2

Formula 2-3

Formula 2-4

Formula 2-5

Formula 2-6

Formula 2-7

Formula 2-8

Formula 2-1 to formula 2-8 are wherein X₁And X₂Is designated as O, S or NAr₁Example of equation 2.

In formulae 2-1 to 2-8, Ar₁₁And Ar₁₂Each independently is a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms. In some embodiments, Ar₁₁And Ar₁₂May each independently combine with an adjacent group to form a ring. Ar (Ar)₁₁And Ar₁₂May each independently bind Ar in formula 2₁The same is described.

R_aAnd R_bAnd n₁And n₂May each independently be the same as described in connection with formula 2.

In some embodiments, the substituent represented by formula 2 may be represented by formula 2-a:

formula 2-a

Formula 2-a is wherein R is specified_aAnd R_bExamples of formula 2 for the substitution position of (a). As represented by formula 2-a, R_aAnd R_bEach substituted para to the boron atom.

In the formula 2-a, X₁And X₂And R_aAnd R_bMay each independently be the same as described in connection with formula 2.

The fused polycyclic compound represented by formula 1 may be represented by any one of formulae 3-1 to 3-5:

formula 3-1

Formula 3-2

Formula 3-3

Formula 3-4

Formula 3-5

Formulas 3-1 to 3-5 are examples of formula 1 in which the number of substituents and the fusion position in formula 1 are specified.

In formulae 3-1 to 3-5, A₁To A₈May each independently be a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted oxy group, a substituted or unsubstituted amine group, a substituted or unsubstituted alkyl group having 1 to 20 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 30 ring-forming carbon atoms. In some embodiments, A₁To A₈May be combined with an adjacent group to form a ring.

B₁And B₂、B₃And B₄And B₅And B₆May be all positions condensed with the substituent represented by formula 2. In formula 3-1 and formula 3-2, two substituents represented by formula 2 are linked (fused), and one substituent of the two substituents represented by formula 2 is at B₁And B₂Condensed in position and the other in B₃And B₄Fused at position. In formulae 3-3 to 3-5, three substituents represented by formula 2 are linked (fused), and one of the three substituents represented by formula 2 is in B₁And B₂Condensed in position, the other being in B₃And B₄Condensed in position, one more in B₅And B₆Fused at position.

The fused polycyclic compound represented by formula 1 may be represented by any one of formulae 4-1 to 4-8:

formula 4-1

Formula 4-2

Formula 4-3

Formula 4-4

Formula 4-5

Formula 4-6

Formula 4-7

Formula 4-8

Formulas 4-1 to 4-8 are examples of formula 1 in which the substituents represented by formula 2 are fused at specific positions and have specific stereochemistry (e.g., positions of boron atom and heteroatom).

In formulae 4-1 to 4-8, X₁₁、X₁₂、X₁₃、X₂₁、X₂₂And X₂₃Can be NAr independently₁O or S. X₁₁、X₁₂、X₁₃、X₂₁、X₂₂And X₂₃May all independently combine with X in formula 2₁And X₂The same is described.

R_a1、R_a2、R_a3、R_b1、R_b2And R_b3May each independently be a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted amino group, a substituted or unsubstituted alkyl group having 1 to 20 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 30 ring-forming carbon atoms. In some embodiments, R_a1、R_a2、R_a3、R_b1、R_b2And R_b3May be combined with an adjacent group to form a ring. R_a1、R_a2、R_a3、R_b1、R_b2And R_b3May each independently bind R in formula 2_aAnd R_bThe same is described.

n₁₁、n₁₂And n₁₃May each independently be an integer of 0 to 4. n is₂₁、n₂₂And n₂₃May each independently be an integer of 0 to 3. n is₁₁、n₁₂、n₁₃、n₂₁、n₂₂And n₂₃May each independently relate to n in formula 2₁And n₂The same is described.

Ar₁And A₁To A₈May be each independently the same as described in formula 2 and formulae 3-1 to 3-5.

The fused polycyclic compound of the embodiment may be any one of the compounds represented by compound group 1. The organic electroluminescent device 10 of the embodiment may include at least one condensed polycyclic compound among the compounds represented by the compound group 1 in the emission layer EML:

compound group 1

The emission spectrum of the fused polycyclic compound represented by formula 1 may have a half-width of about 10nm to about 50nm, for example, may have a half-width of about 20nm to about 40 nm. When the condensed polycyclic compound has the above-described half-width of the emission spectrum, the luminous efficiency of the organic electroluminescent device 10 including the condensed polycyclic compound can be improved. In addition, when the condensed polycyclic compound of the embodiment is used as a blue light emitting device material of the organic electroluminescent device 10, the lifespan of the organic electroluminescent device 10 may be improved.

The fused polycyclic compound represented by formula 1 of the embodiment may be a Thermally Activated Delayed Fluorescence (TADF) emitting material. In addition, the fused polycyclic compound represented by formula 1 of the embodiment may be a compound having a singlet-triplet energy level difference (Δ E) between the lowest triplet excitation level (T1 level) and the lowest singlet excitation level (S1 level) of about 0.6eV or less_ST) Is thermally activated delayed fluorescence dopant.

The condensed polycyclic compound represented by formula 1 of the embodiment may be a light-emitting (luminescent) material having a luminescence center wavelength of about 430nm to about 490 nm. For example, the fused polycyclic compound represented by formula 1 of the embodiment may be a blue Thermally Activated Delayed Fluorescence (TADF) dopant. However, the embodiment is not limited thereto, and when the fused polycyclic compound of the embodiment is used as a light emitting material, the fused polycyclic compound may be used as a dopant material to emit light having any suitable wavelength, for example, may be a red emitting dopant or a green emitting dopant.

The emission layer EML in the organic electroluminescent device 10 of the embodiment may emit delayed fluorescence. For example, the emission layer EML may emit Thermally Activated Delayed Fluorescence (TADF).

In some embodiments, the emission layer EML of the organic electroluminescent device 10 may emit blue light. For example, the emission layer EML of the organic electroluminescent device 10 of the embodiment may emit blue light in a range of about 490nm or more. However, the embodiment is not limited thereto, and the emission layer EML may emit green or red light.

In some embodiments, the organic electroluminescent device 10 of an embodiment may include a plurality of emission layers. A plurality of emission layers may be sequentially stacked, for example, the organic electroluminescent device 10 including a plurality of emission layers may emit white light. The organic electroluminescent device 10 including a plurality of emission layers may be an organic electroluminescent device having a serial structure. When the organic electroluminescent device 10 includes a plurality of emission layers, at least one emission layer may include the condensed polycyclic compound of the embodiment as described above.

In an embodiment, the emission layer EML includes a host and a dopant, and may include the above-described condensed polycyclic compound as a dopant. For example, the emission layer EML in the organic electroluminescent device 10 of the embodiment may include a host for emitting delayed fluorescence and a dopant for emitting delayed fluorescence, and may include the above-described condensed polycyclic compound as a dopant for emitting delayed fluorescence. The emission layer EML may include at least one of the condensed polycyclic compounds represented by the compound group 1 as a thermally activated delayed fluorescence dopant.

Any suitable material can be used as host material for the emissive layer EML, for example fluoranthene derivatives, pyrene derivatives, arylacetylene derivatives, anthracene derivatives, fluorene derivatives, perylene derivatives,Derivatives, and the like, without particular limitation. In some embodiments, the host material may include a pyrene derivative, a perylene derivative, and/or an anthracene derivative. In some embodiments, an anthracene derivative represented by formula 5 may be used as a host material of the emission layer EML:

formula 5

In formula 5, R₃₁To R₄₀May each independently be a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted silyl group, a substituted or unsubstituted alkyl group having 1 to 10 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 30 ring-forming carbon atoms, and optionally, R₃₁To R₄₀May be combined with an adjacent group to form a ring. In some embodiments, R₃₁To R₄₀May be combined with an adjacent group to form a ring.

In formula 5, c and d may each independently be an integer of 0 to 5.

The anthracene derivative represented by the formula 5 may be represented by any one of the compound 5-1 to the compound 5-16:

in an embodiment, the emission layer EML may include tris (8-hydroxyquinoline)Aluminum (Alq)₃) 4,4' -bis (N-carbazolyl) -1,1' -biphenyl (CBP), poly (N-vinylcarbazole) (PVK), 9, 10-bis (naphthalen-2-yl) Anthracene (ADN), 4' -tris (carbazol-9-yl) -triphenylamine (TCTA), 1,3, 5-tris (1-phenyl-1H-benzo [ d]Imidazol-2-yl) benzene (TPBi), 2-tert-butyl-9, 10-bis (naphthalen-2-yl) anthracene (TBADN), Distyrylarylene (DSA), 4 '-bis (9-carbazolyl) -2,2' -dimethyl-biphenyl (CDBP), 2-methyl-9, 10-bis (naphthalen-2-yl) anthracene (MADN), bis [2- (diphenylphosphino) phenyl ] bis]Ether oxide (DPEPO), hexaphenylcyclotriphosphazene (CP1), 1, 4-bis (triphenylsilyl) benzene (UGH)₂) Hexaphenylcyclotrisiloxane (DPSiO)₃) Octaphenylcyclotetrasiloxane (DPSiO)₄) 2, 8-bis (diphenylphosphoryl) dibenzofuran (PPF), 3 '-bis (N-carbazolyl) -1,1' -biphenyl (mCBP), 1, 3-bis (N-carbazolyl) benzene (mCP), and the like as host materials. However, embodiments are not so limited and may include any suitable delayed fluorescence emission host material other than the listed host materials.

In some embodiments, the emission layer EML in the organic electroluminescent device 10 of an embodiment may also include any other suitable dopant material. In an embodiment, the emission layer EML may further comprise styryl derivatives (e.g. 1, 4-bis [2- (3-N-ethylcarbazolyl) vinyl ] benzene (BCzVB), 4- (di-p-tolylamino) -4' - [ (di-p-tolylamino) styryl ] stilbene (DPAVB) and N- (4- ((E) -2- (6- ((E) -4- (diphenylamino) styryl) naphthalen-2-yl) vinyl) phenyl) -N-phenylaniline (N-BDAVBi)), perylene and derivatives thereof (e.g. 2,5,8, 11-tetra-tert-butylperylene (TBP)), pyrene and its derivatives (e.g., 1,1' -bipyrene, 1, 4-bipyrenylbenzene), and the like as the dopant material.

In some embodiments, the emission layer EML may include two dopant materials, each having a different lowest triplet excited level (T1 level). The emission layer EML of the organic electroluminescent device 10 of the embodiment may include a host having a first lowest triplet excitation level, a first dopant having a second lowest triplet excitation level lower than the first lowest triplet excitation level, and a second dopant having a third lowest triplet excitation level lower than the second lowest triplet excitation level. In an embodiment, the emission layer EML may include the fused polycyclic compound of the above-described embodiment as the first dopant.

In the organic electroluminescent device 10 of the embodiment including the host, the first dopant, and the second dopant in the emission layer EML, the first dopant may be a delayed fluorescence dopant, and the second dopant may be a fluorescence dopant. In some embodiments, the condensed polycyclic compound represented by formula 1 may be used as an auxiliary dopant in the organic electroluminescent device 10 of the embodiment.

For example, when the emission layer EML of the organic electroluminescent device 10 of the embodiment includes a plurality of dopants, the emission layer EML may include the polycyclic compound of the above embodiment as the first dopant and one of the above suitable dopant materials as the second dopant. For example, when the emission layer EML emits blue light, the emission layer EML may further include any one selected from the group consisting of spiro-DPVBi, spiro-6P, styrylbenzene (DSB), styrylarylide (DSA), Polyfluorene (PFO) -based polymer, and poly (P-phenylene vinylene) (PPV) -based polymer as the second dopant. Organometallic complexes or metal complexes (such as (4, 6-F) may also be used₂ppy)₂Irpic) and/or perylene and derivatives thereof and the like as the second dopant.

In some embodiments, in the organic electroluminescent device 10 of the embodiment including the condensed polycyclic compound as the first dopant of the emission layer EML, the emission layer EML may emit green or red light, and the second dopant material may be the above-mentioned suitable dopant, green fluorescent dopant, or red fluorescent dopant.

The emission layer EML in the organic electroluminescent device 10 of the embodiment may be a phosphorescent (phosphorescent) emission layer. For example, the condensed polycyclic compound according to the embodiment may be included in the emission layer EML as a phosphorescent host material.

In the organic electroluminescent device 10 of the embodiment shown in fig. 1 to 4, the electron transport region ETR is disposed on the emission layer EML. The electron transport region ETR may include at least one of a hole blocking layer HBL, an electron transport layer ETL, and an electron injection layer EIL, but the embodiment is not limited thereto.

The electron transport region ETR may have a single layer formed of a single material, a single layer formed of a plurality of different materials, or a multi-layer structure including a plurality of layers formed of a plurality of different materials.

For example, the electron transport region ETR may have a single-layer structure of the electron injection layer EIL or the electron transport layer ETL, or may have a single-layer structure formed of an electron injection material and an electron transport material. In some embodiments, the electron transport region ETR may have a single-layer structure formed of a plurality of different materials, or may have a structure in which an electron transport layer ETL/an electron injection layer EIL or a hole blocking layer HBL/an electron transport layer ETL/an electron injection layer EIL are sequentially stacked from the emission layer EML, but is not limited thereto. The thickness of the electron transport region ETR may be, for example, aboutTo about

The electron transport region ETR may be formed using any suitable method, such as a vacuum deposition method, a spin coating method, a casting method, a langmuir-blodgett (LB) method, an inkjet printing method, a Laser Induced Thermal Imaging (LITI) method, or the like.

When the electron transport region ETR includes the electron transport layer ETL, the electron transport layer ETL may include an anthracene compound. However, the embodiment is not limited thereto, and the electron transport layer ETL may include, for example, tris (8-hydroxyquinoline) aluminum (Alq)₃) 1,3, 5-tris [ (3-pyridyl) -phen-3-yl]Benzene, 2,4, 6-tris (3' - (pyridin-3-yl) biphenyl-3-yl) -1,3, 5-triazine, 2- (4- (N-phenylbenzimidazol-1-yl) phenyl) -9, 10-dinaphthylanthracene, 1,3, 5-tris (1-phenyl-1H-benzo [ d ] b]Imidazol-2-yl) benzene (TPBi), 2, 9-dimethyl-4, 7-diphenyl-1, 10-phenanthroline (BCP), 4, 7-diphenyl-1, 10-phenanthroline (Bphen), 3- (4-biphenyl) -4-phenyl-5-tert-butylphenyl-1, 2, 4-Triazole (TAZ), 4- (naphthalen-1-yl) -3, 5-diphenyl-4H-1, 2, 4-triazole (NTAZ), 2- (4-biphenyl) -5- (4-tert-butylphenyl) -1,3, 4-oxadiazole (tBu-PBD)Bis (2-methyl-8-hydroxyquinoline-N1, O8) - (1,1' -biphenyl-4-hydroxy) aluminum (BALq), bis (benzoquinoline-10-hydroxy) beryllium (Bebq)₂) 9, 10-bis (naphthalen-2-yl) Anthracene (ADN), diphenyl (4- (triphenylsilyl) phenyl) phosphine oxide (TSPO1), or mixtures thereof. The thickness of the electron transport layer ETL may be aboutTo aboutFor example aboutTo aboutWhen the thickness of the electron transport layer ETL satisfies the above range, satisfactory electron transport characteristics can be obtained without significantly increasing the driving voltage.

When the electron transport region ETR includes the electron injection layer EIL, the electron injection layer EIL may use a metal halide (such as LiF, NaCl, CsF, RbCl, RbI, and/or CuI), a lanthanide metal (such as Yb), a metal oxide (such as Li, or Yb)₂O and/or BaO), lithium quinolinolate (LiQ), and the like, but the embodiment is not limited thereto. The electron injection layer EIL may also be formed of a mixture of an electron injection material and an insulating organic metal salt. The organometallic salt may be a material having an energy bandgap of about 4eV or more. The organometallic salts may include, for example, metal acetates, metal benzoates, metal acetoacetates, metal acetylacetonates, and/or metal stearates. The thickness of the electron injection layer EIL may be aboutTo aboutFor example aboutTo aboutWhen the thickness of the electron injection layer EIL satisfies the above range, satisfactory electron injection performance can be obtained without significantly increasing the driving voltage.

The electron transport region ETR may comprise a hole blocking layer HBL as described above. The hole blocking layer HBL may include, for example, at least one of 2, 9-dimethyl-4, 7-diphenyl-1, 10-phenanthroline (BCP) and 4, 7-diphenyl-1, 10-phenanthroline (Bphen), but is not limited thereto.

The second electrode EL2 is disposed on the electron transport region ETR. The second electrode EL2 may be a common electrode or a cathode. The second electrode EL2 may be a transmissive electrode, a transflective electrode, or a reflective electrode. When the second electrode EL2 is a transmissive electrode, the second electrode EL2 may be formed of a transparent metal oxide such as ITO, IZO, ZnO, ITZO, or the like.

When the second electrode EL2 is a transflective or reflective electrode, the second electrode EL2 may include Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF, Mo, Ti, a compound thereof, or a mixture thereof (e.g., a mixture of Ag and Mg). In some embodiments, the second electrode EL2 may have a multi-layer structure including a reflective layer or a transflective layer formed of the above-described materials and a transparent conductive layer formed of ITO, IZO, ZnO, ITZO, or the like.

In some embodiments, the second electrode EL2 may be connected to an auxiliary electrode. When the second electrode EL2 is connected to the auxiliary electrode, the resistance of the second electrode EL2 may be reduced.

In some embodiments, the organic electroluminescent device 10 of the embodiment may include a buffer layer between the emission layer EML and the electron transport region ETR. The buffer layer may control or influence the concentration of excitons generated in the emission layer EML. In some embodiments, the buffer layer may include at least some of the emitter layer material. For example, the buffer layer may include a host material of the emission layer material (e.g., the same host material as included in the emission layer EML). Depending on the combination of the host material and the dopant material included in the emission layer EML, the lowest triplet excited level of the buffer layer material may be controlled or selected to be higher than or substantially equal to the lowest triplet excited level of the second dopant or lower than or substantially equal to the lowest triplet excited level of the first dopant.

In some embodiments, a cap layer CPL may be further provided on the second electrode EL2 of the organic electroluminescent device 10 according to the embodiment. The cap layer CPL may include an organic layer and/or an inorganic layer. The cap layer CPL may be, for example, a single layer of an organic layer or an inorganic layer, or a layer in which an organic layer and an inorganic layer are sequentially stacked. The cap layer CPL may have a refractive index of about 1.6 or greater in the wavelength range of about 560nm to about 600 nm. The cap layer CPL may include the amine compound CPL1 and/or the amine compound CPL 2:

in some embodiments, cap layer CPL may include α -NPD, NPB, TPD, m-MTDATA, Alq₃CuPc, N4, N4, N4', N4' -tetrakis (biphenyl-4-yl) biphenyl-4, 4 '-diamine (TPD15), 4',4 ″ -tris (carbazol-9-yl) triphenylamine (TCTA), and the like. In some embodiments, the capping layer CPL may include silicon nitride, aluminum nitride, zirconium nitride, titanium nitride, hafnium nitride, tantalum nitride, silicon oxide, aluminum oxide, titanium oxide, tin oxide, cerium oxide, silicon oxynitride, or the like.

The fused polycyclic compound of the embodiment as described above includes a structure in which two or more structures of formula 2, each of which includes one boron atom and two hetero atoms, are fused with the central benzo [9,10] phenanthrene nucleus. The condensed polycyclic compound represented by formula 1 according to the embodiment has an extended conjugated structure, and thus when the condensed polycyclic compound of the embodiment is used as a light emitting material of an organic electroluminescent device, high efficiency of the organic electroluminescent device may be achieved.

Hereinafter, the fused polycyclic compound according to the embodiments of the present disclosure will be described in more detail with reference to examples and comparative examples. The embodiments are provided as illustrations to facilitate understanding of the present disclosure, and the scope of the present disclosure is not limited thereto.

Examples of the invention

1. Synthesis of fused polycyclic Compounds

An exemplary synthetic method of the fused polycyclic compound according to the present embodiment will be described for compound 9, compound 25, compound 27, compound 53, compound 58, compound 59, compound 76, and compound 81. Synthetic methods of the fused polycyclic compound are provided as examples and are not limited thereto.

(1) Synthesis of Compound 9

Synthesis of intermediate Compound A

2, 11-dibromobenzo [9,10]]Phenanthrene (20.0g, 51.8mmol), 3-phenoxyphenol (20.3g, 109mmol), CuI (0.49g, 2.59mmol), K₂CO₃(28.6g, 207mmol) and iron (III) tris (2, 4-pentanedione) (Fe (III) (acac)₃1.67g, 5.2mmol) was added to 1-methyl-2-pyrrolidone (NMP, 117mL) and heated and stirred at 180 ℃ for 24 hours. The mixture was cooled, filtered through Celite (Celite), and separated by adding toluene and water to obtain an organic layer. The organic layer was concentrated, purified by column chromatography (silica gel), concentrated, and washed with additional hexane to obtain intermediate compound a (25.3g, yield: 82%). The molecular weight of intermediate compound a was determined to be 597 by FAB-MS.

Synthesis of Compound 9

Intermediate compound a (23g, 38.5mmol) was added to tert-butyl benzene (96mL) under argon (Ar) and cooled to-30 ℃ and tert-butyllithium (1.6M/L pentane, 96mL, 154mmol) was added slowly thereto. The mixture was allowed to approach room temperature for about 1 hour, then the mixture was heated and stirred at about 60 ℃ for 3 hours. The reaction solution was cooled to-30 c,and BBr was slowly added thereto₃(38.6g, 154mmol) and heated and stirred at an internal temperature of 30 ℃ for 1 hour. The reaction solution was ice-cooled, and N, N-diisopropylethylamine (20.0g, 154mmol) was added thereto and heated and stirred at 100 ℃ for 2 hours. After cooling and addition of water, the resulting mixture was filtered through celite and the organic layer was concentrated. The concentrated organic layer was purified by silica gel column chromatography to obtain compound 9(7.79g, yield: 33%). The molecular weight of compound 9 was determined by FAB-MS measurement to be 612. The compound 9 obtained was purified by sublimation again (300 ℃, 8.7X 10)^-3Pa) and used as a sample for evaluation.

(2) Synthesis of Compound 25

Synthesis of intermediate Compound B

The reaction was carried out using substantially the same conditions as those for synthesizing intermediate compound A, except that 3- (diphenylamino) phenol (18.9g) was used instead of 3-phenoxyphenol. As a result, intermediate compound B (15.6g, yield: 72%) was obtained.

Synthesis of Compound 25

The reaction was carried out using substantially the same conditions as those for the synthesis of compound 9, except that the obtained intermediate compound B (15.0g) was used instead of intermediate compound a. As a result, compound 25(4.44g, yield: 29%) was obtained. The molecular weight of compound 25 was 762 by FAB-MS. The obtained compound 25 was purified by sublimation (300 ℃, 8.7X 10)^-3Pa) for evaluation.

(3) Synthesis of Compound 27

Synthesis of intermediate Compound C and intermediate Compound D

Under Ar atmosphere, 1, 3-dibromo-5-methoxybenzene (25.0g, 94.0mmol), diphenylamine (33.4g, 197mmol), Pd (dba)₂(1.62g，2.82mmol)、P(^tBu)₃HBF₄(0.68g, 3.76mmol) and^tBuONa (27.1g, 282mmol) was added to 470mL of toluene and heated and stirred at 80 ℃ for 2 h. After addition of water, the resulting mixture was filtered through celite, and the organic layer was separated and concentrated. The concentrated organic layer was purified by silica gel column chromatography to obtain intermediate compound C (41.6g, yield: 80%). Thereafter, intermediate compound C was dissolved in 500mL of CH₂Cl₂In and BBr is added thereto₃(46.4g, 185mmol) and stirred at 0 ℃ for 24 h. After addition of water, the resulting mixture was filtered through celite, and the organic layer was concentrated and purified by silica gel column chromatography to obtain intermediate compound D (29.8g, yield: 75%). The molecular weight of intermediate compound D was determined by FAB-MS to be 429.

Synthesis of intermediate Compound E

The reaction was carried out using substantially the same conditions as those for synthesizing intermediate compound A, except that the obtained intermediate compound D (28.3g) was used in place of 3-phenoxyphenol. As a result, intermediate compound E (20.0g, yield: 70%) was obtained. The molecular weight of intermediate compound E was 1080 as determined by FAB-MS.

Synthesis of Compound 27

Intermediate Compound E (18.0g, 16.7mmol) was dissolved in 180mL of ODCB, and BBr was added thereto₃(13.4g, 53.6mmol) and stirred at 180 ℃ for 10 h. Subjecting the reaction solution toN, N-diisopropylethylamine (20.0g, 154mmol) was added thereto under ice-cooling, and the resulting mixture was filtered through celite, and the organic layer was concentrated. The concentrated organic layer was purified by silica gel column chromatography to obtain compound 27(12.8g, yield: 70%). Compound 27 has a molecular weight of 1097 as determined by FAB-MS. The obtained compound 27 was purified by sublimation (300 ℃, 8.7X 10)^-3Pa) for evaluation.

(4) Synthesis of Compound 53

Synthesis of intermediate Compound F

1, 3-dibromo-5-chlorobenzene (35.0g, 129mmol), diphenylamine (43.8g, 259mmol) and Pd₂(dba)₃(2.49g, 2.72mmol), Sphos (2.23g, 5.44mmol) and^tBuONa (37.9g, 394mmol) was added to 500mL of toluene and heated and stirred at 80 ℃ for 5 hours. The mixture was cooled, filtered through celite, and separated by adding toluene and water to obtain an organic layer. The organic layer was concentrated, purified by column chromatography (silica gel), concentrated, and washed with additional hexane to obtain intermediate compound F (45.0g, yield: 78%). Intermediate compound F has a molecular weight of 447 as determined by FAB-MS.

Synthesis of intermediate Compound G

Intermediate compound F (35.0g, 78.3mmol), aniline (7.29g, 78.3mmol), Pd (dba)₂(1.80g，3.13mmol)、P(^tBu)₃HBF₄(1.82g, 6.26mmol) and^tBuONa (11.29g, 117mmol) was added to 200mL of toluene, followed by heating and stirring at 80 ℃ for 5 hours. The mixture was cooled, filtered through celite, and separated by adding toluene and water to obtain an organic layer. The organic layer was concentrated, purified by column chromatography (silica gel), concentrated, and combined with additional hexaneAlkane washing was conducted to obtain intermediate compound G (28.0G, yield: 71%). The molecular weight of intermediate compound G was determined by FAB-MS to be 504.

Synthesis of intermediate Compound H

Using substantially the same conditions as those for synthesizing intermediate compound C, a reaction was conducted to obtain intermediate compound H (25.0G, yield: 78%) from 2, 11-dibromobenzo [9,10] phenanthrene (10.0G, 25.9mmol) and intermediate compound G (26.1G, 51.8 mmol). The molecular weight of intermediate compound H was determined by FAB-MS to be 1232.

Synthesis of Compound 53

Intermediate Compound H (15.0g, 12.2mmol) was added to 162mL of ODCB, and BBr was added thereto₃(18.3g, 73mmol) and then heated and stirred at 180 ℃ for 6 hours. The mixture was cooled, N-diisopropylethylamine (47.0g, 365mmol) was added thereto, and the mixture was filtered after adding 1L of acetonitrile. The obtained product was purified by silica gel column chromatography to obtain compound 53(8.0g, yield: 53%). The molecular weight of compound 53 was 1247 as determined by FAB-MS. The compound 53 thus obtained was purified by sublimation (430 ℃, 8.2X 10)^-3Pa) for evaluation.

(5) Synthesis of Compound 58

Synthesis of intermediate Compound I

1-bromo-3-fluorobenzene (16.0g, 91.4mmol), 3- (diphenylamino) phenol (35.8g, 137mmol) and K₃PO₄(58.2g, 274mmol) was added to 160mL of NMP, followed by heating and stirring at 180 ℃ for 8 hours. Will be provided withThe mixture was cooled, filtered through celite, and separated by adding toluene and water to obtain an organic layer. The organic layer was concentrated, purified by column chromatography (silica gel), concentrated, and washed with additional hexane to obtain intermediate compound I (30.0g, yield: 79%). The molecular weight of intermediate compound I was 416 as determined by FAB-MS.

Synthesis of intermediate Compound J

Using intermediate compound I (28.0G, 67.3mmol) and aniline (6.26G, 67.3mmol), a reaction was carried out using substantially the same conditions as those for the synthesis of intermediate compound G to obtain intermediate compound J (22.0G, yield: 76%). The molecular weight of intermediate compound J was determined by FAB-MS to be 429.

Synthesis of intermediate Compound K

Using substantially the same conditions as those for synthesizing intermediate compound C, a reaction was conducted to obtain intermediate compound K (21.0g, yield: 75%) from 2, 11-dibromobenzo [9,10] phenanthrene (10.0g, 25.9mmol) and intermediate compound J (22.2g, 51.8 mmol). The molecular weight of intermediate compound K was found to be 1081 by FAB-MS.

Synthesis of Compound 58

Using substantially the same conditions as those for synthesizing compound 53, a reaction was conducted to obtain compound 58(3.0g, yield: 14%) from intermediate compound K (21.0g, 19.4 mmol). Compound 58 had a molecular weight of 1097 by FAB-MS. The compound 58 thus obtained was purified by sublimation (415 ℃, 8.7X 10)^-3Pa) for evaluation.

(6) Synthesis of Compound 59

Synthesis of intermediate Compound L

A reaction was carried out using substantially the same conditions as those for synthesizing intermediate compound I to obtain intermediate compound L (14.0g, yield: 72%) from 1, 3-dibromo-5-fluorobenzene (15.0g, 59.1mmol) and phenol (8.34g, 88.6 mmol). The molecular weight of intermediate compound L was determined by FAB-MS to be 328.

Synthesis of intermediate Compound M

Mixing the intermediate compound L (13.9g, 42.6mmol), diphenylamine (6.0g, 35.5mmol) and Pd₂(dba)₃(0.81g, 0.89mmol), XantPhos (0.86mmol) and^tBuONa (4.1g, 42.6mmol) was added to 79mL of toluene and stirred at 80 ℃ for 5 hours and/or at 100 ℃ for 3 hours. The mixture was cooled, filtered through celite, and separated by adding toluene and water to obtain an organic layer. The organic layer was concentrated, purified by column chromatography (silica gel), concentrated, and washed with additional hexane to obtain intermediate compound M (12.0g, yield: 81%). The molecular weight of intermediate compound M was determined to be 416 by FAB-MS.

Synthesis of intermediate Compound N

Using intermediate compound M (28.0G, 67.3mmol) and aniline (6.26G, 67.3mmol), a reaction was carried out using substantially the same conditions as those for the synthesis of intermediate compound G to obtain intermediate compound N (22.0G, yield: 76%). The molecular weight of intermediate compound N was determined by FAB-MS to be 429.

Synthesis of intermediate compound O

Using substantially the same conditions as those for synthesizing intermediate compound C, a reaction was conducted to obtain intermediate compound O (20.0g, yield: 71%) from 2, 11-dibromobenzo [9,10] phenanthrene (10.0g, 25.9mmol) and intermediate compound N (22.2g, 51.8 mmol). The molecular weight of intermediate compound O was 1081 as determined by FAB-MS.

Synthesis of Compound 59

Using substantially the same conditions as those for synthesizing compound 53, a reaction was conducted to obtain compound 59(1.2g, yield: 6%) from intermediate compound O (19.0g, 17.6 mmol). Compound 59 had a molecular weight of 1097 by FAB-MS. The obtained compound 59 was purified by sublimation (405 ℃, 8.2X 10)^-3Pa) for evaluation.

(7) Synthesis of Compound 76

Synthesis of intermediate Compound P

The reaction was carried out using substantially the same conditions as those for synthesizing intermediate compound A to obtain intermediate compound P (12.6g, yield: 75%) from 2,6, 10-tribromobenzo [9,10] phenanthrene (10.0g, 21.5mmol) and 3-phenoxyphenol (13.2g, 71.0 mmol). The molecular weight of intermediate compound P was 781 as determined by FAB-MS.

Synthesis of Compound 76

Except using obtainedThe reaction was carried out under substantially the same conditions as those for the synthesis of Compound 9, except that intermediate Compound P (23.0g, 29.5mmol) was used. As a result, Compound 76(5.50g, yield: 23%) was obtained. The molecular weight of compound 76 was 804 as determined by FAB-MS. The compound 76 obtained was purified by sublimation (320 ℃, 8.3X 10)^-3Pa) for evaluation.

(8) Synthesis of Compound 81

Synthesis of intermediate Compound Q

The reaction was carried out using substantially the same conditions as those for synthesizing intermediate compound A to obtain intermediate compound Q (12.1g, yield: 70%) from 2,6, 10-tribromobenzo [9,10] phenanthrene (8.0g, 17.2mmol) and 3- (diphenylamino) phenol (14.8 mmol). The molecular weight of intermediate compound Q was 1006 as determined by FAB-MS.

Synthesis of Compound 81

Using substantially the same conditions as those for synthesizing compound 53, a reaction was conducted to obtain compound 81(2.2g, yield: 22%) from intermediate compound Q (10.0g, 9.94 mmol). The molecular weight of compound 81 was 1029 as determined by FAB-MS. The obtained compound 81 was purified by sublimation (390 ℃, 8.4X 10)^-3Pa) for evaluation.

2. Fabrication and evaluation of organic electroluminescent devices comprising fused polycyclic Compounds

Fabrication of organic electroluminescent devices

In the manufacture of the organic electroluminescent devices of examples 1 to 8, compound 9, compound 25, compound 27, compound 53, compound 58, compound 59, compound 76, and compound 81 were used as the emission layer dopant materials, respectively.

Illustrative Compounds

The organic electroluminescent devices of comparative examples were fabricated using the compounds X-1 of comparative example to the compounds X-5 of comparative example:

comparative example Compounds

An organic electroluminescent device including the condensed polycyclic compound of the example in an emission layer was manufactured as follows. Examples 1 to 8 correspond to organic electroluminescent devices manufactured using the corresponding compound 9, compound 25, compound 27, compound 53, compound 58, compound 59, compound 76, and compound 81 as light-emitting materials. Comparative examples 1 to 5 correspond to organic electroluminescent devices manufactured using the respective comparative example compounds X-1 to X-5 as light emitting materials.

Forming a first electrode with a thickness of 150nm using ITO, forming a hole injection layer with a thickness of 10nm from 1,4,5,8,9, 12-hexaazabenzo [9,10] phenanthrene hexacyanonitrile (HAT-CN), a first hole transport layer with a thickness of 80nm from N, N '-bis (1-naphthyl) -N, N' -diphenyl- (1,1 '-biphenyl) -4,4' -diamine (alpha-NPD), a second hole transport layer with a thickness of 5nm from 1, 3-bis (N-carbazolyl) benzene (mCP), an emission layer with a thickness of 20nm from 3,3 '-bis (N-carbazolyl) -1,1' -biphenyl (mCBP) by doping 1% of the corresponding exemplary compound or comparative exemplary compound, an electron transport layer with a thickness of 30nm from 1,3, 5-tris (N-phenylbenzimidazol-2-yl) benzene (TPBi), an electron injection layer 0.5nm thick was formed from LiF and a second electrode 100nm thick was formed from Al. A 70nm thick cap layer was formed on the second electrode from N4, N4 '-diphenyl-N4, N4' -bis (9-phenyl-9H-carbazol-3-yl) - [1,1 '-biphenyl ] -4,4' -diamine (CPL 1). Each layer is formed by a deposition method under a vacuum atmosphere.

Disclosed are compounds for manufacturing the organic electroluminescent devices of examples and comparative examples.

Experimental examples

The efficiencies of organic electroluminescent devices fabricated using experimental example compound 9, experimental example compound 25, experimental example compound 27, experimental example compound 53, experimental example compound 58, experimental example compound 59, experimental example compound 76, and experimental example compound 81, and comparative example compound X-1 to comparative example compound X-5 were evaluated. The evaluation results are shown in table 1. Maximum emission wavelength in the emission spectrum is λ_maxIndicating that the maximum value of the external quantum efficiency is EQE_maxExpressed at 1000cd/m²Lower external quantum efficiency value by EQE_1000nitAnd (4) showing.

TABLE 1

Referring to the results of table 1, it can be seen that examples of the organic electroluminescent device using the fused polycyclic compound according to the embodiments of the present disclosure as a light emitting material each exhibited improved luminous efficiency while maintaining the emission wavelength of blue light, compared to comparative examples.

Exemplary compounds have a structure in which two or more tetracyclic fused polycyclic heterocycles (each including a boron atom and a heteroatom as a bidentate linker) are fused with a central benzo [9,10] phenanthrene nucleus having a high T1 level, thereby having a half-width and a wavelength range suitable for a blue light emitting material and an extended conjugated system, and thus, stability of a compound molecule can be improved. Accordingly, the example organic electroluminescent device may exhibit improved luminous efficiency compared to the comparative example organic electroluminescent device. Exemplary organic electroluminescent devices include a fused polycyclic compound as a Thermally Activated Delayed Fluorescence (TADF) dopant, and thus can achieve high device efficiency in a blue wavelength region (e.g., deep blue wavelength region).

Neither comparative example compound X-1 (included in comparative example 1) nor comparative example compound X-2 (included in comparative example 2) has a benzo [9,10] phenanthrene moiety, and the stability of these compounds is reduced compared to the example compounds. Therefore, the organic electroluminescent devices of comparative examples 1 and 2 exhibited reduced device efficiency compared to the examples.

The comparative example compounds X-3 to X-5 included in the comparative examples 3 to 5 each have a benzo [9,10] phenanthrene moiety, but have a structure in which only one tetracyclic fused polycyclic heterocycle including a boron atom and a heteroatom is fused to a benzo [9,10] phenanthrene nucleus. The polycyclic compound structures of comparative example compound X-3 to comparative example compound X-5, which contain one boron atom, each have a too short wavelength of about 440nm or less, and the stability of these compounds is reduced compared to the example compounds, and therefore, the organic electroluminescent devices of comparative examples 3 to 5 each have reduced device efficiency compared to the examples.

The organic electroluminescent device of the embodiment may exhibit improved high-efficiency device characteristics.

The condensed polycyclic compound of the embodiment may be included in an emission layer of the organic electroluminescent device to contribute to high efficiency of the organic electroluminescent device.

As used herein, the terms "substantially," "about," and the like are used as approximate terms and not terms of degree, and are intended to explain the inherent deviation of a measured or calculated value that one of ordinary skill in the art would recognize.

Any numerical range recited herein is intended to include all sub-ranges subsumed within the recited range with the same numerical precision. For example, a range of "1.0 to 10.0" is intended to include all sub-ranges between (and including) the recited minimum value of 1.0 and the recited maximum value of 10.0 (and including the recited minimum value of 1.0 and the recited maximum value of 10.0), i.e., having a minimum value equal to or greater than 1.0 and a maximum value of equal to or less than 10.0, such as, for example, 2.4 to 7.6. Any maximum numerical limitation recited herein is intended to include all lower numerical limitations subsumed therein, and any minimum numerical limitation recited in this specification is intended to include all higher numerical limitations subsumed therein. Accordingly, applicants reserve the right to modify the specification (including the claims) to expressly state any sub-ranges encompassed within the ranges expressly stated herein.

While the present disclosure has been described with reference to the exemplary embodiments thereof, it is to be understood that the present disclosure is not limited to these embodiments, but various changes and modifications may be made by one skilled in the art without departing from the spirit and scope of the present disclosure.

Therefore, the technical scope of the present disclosure is not intended to be limited to the contents set forth in the detailed description of the specification, but is intended to be defined by the appended claims and equivalents thereof.