Compound and organic light-emitting device including same

A compound represented by Formula 1, and an organic light-emitting device including the compound: In Formula 1, when L1 and/or L2 is a phenyl group, a pyridyl group, a pyrimidyl group, and/or a 1,3,5-triazinyl group having binding sites that are ortho- or meta- to each other, and the compound of Formula 1 is included the second hole transport layer (HTL2), the efficiency and luminance half-life of a device may increase due to the HTL2 having a higher T1 (e.g., triplet) energy level compared to examples in the related art using a para-substituted phenyl linker.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Korean Patent Application No. 10-2015-0129089, filed on Sep. 11, 2015, in the Korean Intellectual Property Office, the entire content of which is incorporated herein by reference.

BACKGROUND

One or more aspects of example embodiments of the present disclosure are related to a compound and an organic light-emitting device including the compound.

2. Description of the Related Art

Organic light-emitting devices (OLEDs) are self-emission devices that have wide viewing angles, high contrast ratios, and short response times. In addition, OLEDs exhibit excellent luminance, driving voltage, and response speed characteristics, and produce full-color images.

An organic light-emitting device may include a first electrode on a substrate, and a hole transport region, an emission layer, an electron transport region, and a second electrode sequentially positioned on the first electrode. Holes provided from the first electrode may move to the emission layer through the hole transport region, and electrons provided from the second electrode may move to the emission layer through the electron transport region. The holes and the electrons may recombine in the emission layer to produce excitons. These excitons change (e.g., decay or transition) from an excited state to a ground state to thereby generate light.

SUMMARY

One or more aspects of example embodiments of the present disclosure are directed toward a material to be included in a hole transport region, and an organic light-emitting device with improved characteristics as the result of using the material.

One or more aspects of example embodiments of the present disclosure provide a compound represented by Formula 1:

In Formula 1,

R1to R8may each independently be selected from hydrogen, deuterium, a halogen, an amino group, a nitro group, a nitrile group, a substituted or unsubstituted C1-C60alkyl group, a substituted or unsubstituted C2-C60alkenyl group, a substituted or unsubstituted C2-C60alkynyl group, a substituted or unsubstituted C1-C60alkoxy group, a substituted or unsubstituted C3-C10cycloalkyl group, a substituted or unsubstituted C2-C10heterocycloalkyl group, a substituted or unsubstituted C3-C10cycloalkenyl group, a substituted or unsubstituted C2-C10heterocycloalkenyl group, a substituted or unsubstituted C6-C60aryl group, a substituted or unsubstituted C6-C60aryloxy group, a substituted or unsubstituted C6-C60arylthio group, a substituted or unsubstituted C1-C60heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, and a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group;

L1and L2may each independently be selected from a substituted or unsubstituted C6-C60arylene group, a substituted or unsubstituted C1-C60heteroarylene group, a substituted or unsubstituted divalent non-aromatic condensed polycyclic group, and a substituted or unsubstituted divalent non-aromatic condensed heteropolycyclic group;

one selected from L1and L2may be a phenyl group, a pyridyl group, a pyrimidyl group, or a 1,3,5-triazinyl group, having binding sites that are ortho- or meta- to each other;

n and m may each independently be an integer selected from 0 to 2 (excluding that both n and m are 0);

when n is 2, each L1may be independently selected from the above groups;

when m is 2, each L2may be independently selected from the above groups;

According to one or more example embodiments of the present disclosure, an organic light-emitting device includes a first electrode; a second electrode facing the first electrode; and an organic layer between the first electrode and the second electrode and including an emission layer, wherein the organic layer includes the compound.

According to one or more example embodiments of the present disclosure, a flat panel display device includes the organic light-emitting device, and a first electrode of the organic light-emitting device is electrically connected to a source electrode or a drain electrode of a thin film transistor.

DETAILED DESCRIPTION

In the drawing, the thicknesses of layers, films, panels, regions, etc., may be exaggerated for clarity. It will be understood that when an element such as a layer, film, region, or substrate is referred to as being “on” another element, it can be directly on the other element or intervening element(s) may also be present. In contrast, when an element is referred to as being “directly on” another element, no intervening elements are present.

A compound according to an example embodiment of the present disclosure may be represented by Formula 1:

In Formula 1,

R1to R8may each independently be selected from hydrogen, deuterium, a halogen, an amino group, a nitro group, a nitrile group, a substituted or unsubstituted C1-C60alkyl group, a substituted or unsubstituted C2-C60alkenyl group, a substituted or unsubstituted C2-C60alkynyl group, a substituted or unsubstituted C1-C60alkoxy group, a substituted or unsubstituted C3-C10cycloalkyl group, a substituted or unsubstituted C2-C10heterocycloalkyl group, a substituted or unsubstituted C3-C10cycloalkenyl group, a substituted or unsubstituted C2-C10heterocycloalkenyl group, a substituted or unsubstituted C6-C60aryl group, a substituted or unsubstituted C6-C60aryloxy group, a substituted or unsubstituted C6-C60arylthio group, a substituted or unsubstituted C1-C60heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, and a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group;

L1and L2may each independently be selected from a substituted or unsubstituted C6-C60arylene group, a substituted or unsubstituted C1-C60heteroarylene group, a substituted or unsubstituted divalent non-aromatic condensed polycyclic group, and a substituted or unsubstituted divalent non-aromatic condensed heteropolycyclic group;

one selected from L1and L2may be a phenyl group, a pyridyl group, a pyrimidyl group, and/or a 1,3,5-triazinyl group, having binding sites that are ortho- or meta- to each other;

n and m may each independently be an integer selected from 0 to 2 (excluding that both n and m are 0);

when n is 2, each L1may be independently selected from the above groups;

when m is 2, each L2may be independently selected from the above groups;

In recent years, a method of using a first hole transport layer and a second hole transport layer having a triplet energy level higher than that previously used in the available art has been used to increase the production efficiency of singlet excitons by triplet-triplet fusion (TTF), such that excitons produced in an emission layer may be effectively utilized and the efficiency of a light-emitting device may be improved. Accordingly, various compounds having a high triplet energy level have been tested for use as a material of the second hole transport layer.

A compound including benzocarbazole and an amine linked via an aromatic linking group at its para positions has been disclosed in the related art. However, the performance characteristics of the compound are not sufficiently positive for application in an actual device.

In order to resolve the lack of production efficiency of the above compound, the triplet energy level of the compound needs to be increased. According to one or more embodiments of the present disclosure, the substitution geometry of the linking group in a compound may be changed to increase the triplet energy level of a molecule, and when the compound is applied to a top-emission device, the efficiency of the device may be improved.

The substituents of the compound represented by Formula 1 will be described in more detail.

According to an example embodiment of the present disclosure, in Formula 1, R1to R8may each independently be selected from hydrogen, deuterium, and a phenyl group.

According to an example embodiment of the present disclosure, in Formula 1, R1, R4, R5, and R8may each independently be selected from hydrogen and deuterium; and R2, R3, R6, and R7may each independently be selected from hydrogen, deuterium, and a phenyl group. For example, R1, R3, R4, R5, R6, and R8may each independently be selected from hydrogen and deuterium and R2and R7may each be a phenyl group; or R1, R2, R4, R5, R7, and R8may each independently be selected from hydrogen and deuterium and R3and R6may each be a phenyl group.

In some embodiments, in Formula 1, L1and L2may each independently be one selected from Formulae 2a to 2e:

In Formulae 2a to 2e,

R11to R13may each independently be selected from hydrogen, deuterium, a halogen, a substituted or unsubstituted C1-C20alkyl group, a substituted or unsubstituted C6-C20aryl group, a substituted or unsubstituted C1-C20heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, and a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group; and

* may be a binding site.

In some embodiments, in Formula 1, Ar1and Ar2may each independently be one selected from Formulae 3a to 3d:

In Formulae 3a to 3d,

R11to R13and Z1may each independently be selected from hydrogen, deuterium, a halogen, a substituted or unsubstituted C1-C20alkyl group, a substituted or unsubstituted C6-C20aryl group, a substituted or unsubstituted C1-C20heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, and a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group;

p may be an integer selected from 1 to 9;

when p is 2 or more, each Z1moiety may be independently selected from the above groups; and

* denotes a binding site.

In some embodiments, the compound represented by Formula 1 may be further represented by one selected from Formula 2, 3, and 4:

In Formulae 2, 3, and 4, X1to X4may each independently be selected from CH and nitrogen (N), and

R1to R8, Ar1to Ar2, L1to L2, and n and m may each be the same as described herein in connection with Formula 1.

In some embodiments, the compound represented by Formula 1 may be one selected from Compounds 1 to 90:

As used herein, the term “organic layer” may refer to a single layer and/or a plurality of layers between the first electrode and the second electrode in an organic light-emitting device. The material included in the organic layer is not limited to being an organic material.

The drawing is a schematic view of an organic light-emitting device10according to an embodiment of the present disclosure. The organic light-emitting device10includes a first electrode110, an organic layer150, and a second electrode190coupled to a thin film transistor.

Hereinafter, a structure and a method of manufacturing the organic light-emitting device according to an embodiment of the present disclosure will be described with reference to the drawing.

Referring to the drawing, a substrate may be under the first electrode110or on the second electrode190. The substrate may be a glass substrate or a transparent plastic substrate, each with excellent mechanical strength, thermal stability, transparency, surface smoothness, ease of handling, and/or water resistance.

The first electrode110may be formed by depositing and/or sputtering a material for forming the first electrode on the substrate. When the first electrode110is an anode, the material for the first electrode may be selected from materials with a high work function to facilitate easy injection of holes. The first electrode110may be a reflective electrode, a semi-transmissive electrode, or a transmissive electrode. The material for the first electrode may be a transparent and/or highly conductive material, and non-limiting examples of such a material may include indium tin oxide (ITO), indium zinc oxide (IZO), tin oxide (SnO2), and zinc oxide (ZnO). When the first electrode110is a semi-transmissive electrode or a reflective electrode, at least one selected from magnesium (Mg), aluminum (Al), aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In), and magnesium-silver (Mg—Ag) may be used as a material for forming the first electrode.

The first electrode110may have a single-layer structure and/or a multi-layer structure including a plurality of layers. For example, the first electrode110may have a triple-layer structure of ITO/Ag/ITO, but embodiments of the present disclosure are not limited thereto.

The organic layer150may be on the first electrode110. The organic layer150may include an emission layer.

The hole transport region may include a hole transport layer (HTL) and at least one selected from a hole injection layer (HIL) and an electron blocking layer. The electron transport region may include at least one selected from a hole blocking layer (HBL), an electron transport layer (ETL), and an electron injection layer (EIL), but embodiments of the present disclosure are not limited thereto.

The hole transport region may have a single-layered structure formed of a single material, a single-layered structure formed of a plurality of different materials, and/or a multi-layered structure having a plurality of layers formed of a plurality of different materials.

The hole transport layer may include a first hole transport layer and a second hole transport layer.

For example, the hole transport region may have a single-layered structure formed of a plurality of different materials, a structure of hole injection layer/hole transport layer, a structure of hole injection layer/first hole transport layer/second hole transport layer, a structure of hole injection layer/first hole transport layer/second hole transport layer/electron blocking layer, and/or a structure of hole injection layer/hole transport layer/electron blocking layer, wherein layers of each structure are sequentially stacked on the first electrode110in this stated order, but embodiments of the present disclosure are not limited thereto.

When the hole transport region includes a hole injection layer, the hole injection layer may be formed on the first electrode110using one or more suitable methods, such as vacuum-deposition, spin coating, casting, Langmuir-Blodgett (LB) method, ink-jet printing, laser-printing, and/or laser-induced thermal imaging (LITI).

When the hole injection layer is formed by vacuum deposition, the deposition may be performed, e.g., at a deposition temperature of about 100° C. to about 500° C., at a vacuum degree of about 10−8torr to about 10−3torr, and a deposition rate of about 0.01 Å/sec to about 100 Å/sec, depending on the compound to be deposited in the hole injection layer and the structure of the hole injection layer to be formed.

When the hole injection layer is formed by spin coating, the coating may be performed, e.g., at a coating speed of about 2,000 rpm to about 5,000 rpm and at a temperature of about 80° C. to about 200° C., depending on the compound to be deposited in the hole injection layer and the structure of the hole injection layer to be formed.

When the hole transport region includes a hole transport layer, the hole transport layer may be formed on the first electrode110and/or on the hole injection layer using one or more suitable methods, such as vacuum-deposition, spin coating, casting, LB method, ink-jet printing, laser-printing, and/or LITI. When the hole transport layer is formed by vacuum-deposition and/or spin coating, the conditions for vacuum-deposition and coating may be similar to the above-described vacuum-deposition and coating conditions for forming the hole injection layer.

In some embodiments, the first hole transport layer may include a compound represented by Formula 201A:

In Formulae 201A,

L201to L203may each independently be selected from:

xa1 to xa3 may each independently be selected from 0 and 1;

R203and R211may each independently be selected from:

R213and R214may each independently be selected from:

a C1-C20alkyl group and a C1-C20alkoxy group;

R215and R216may each independently be selected from:

In some embodiments, R211in Formula 201A may be selected from a substituted or unsubstituted phenyl group and a substituted or unsubstituted pyridyl group.

In some embodiments, R213and R214in Formula 201A may each independently be selected from a methyl group and a phenyl group.

In some embodiments, the compound represented by Formula 201A may be selected from Compounds HT1 to HT33 below:

In some embodiments, the second hole transport layer may include the compound represented by Formula 1.

The thickness of the hole transport region may be about 100 Å to about 10,000 Å, and in some embodiments, about 100 Å to about 2,000 Å. When the hole transport region includes a hole injection layer and a hole transport layer, the thickness of the hole injection layer may be about 100 Å to about 10,000 Å, and in some embodiments, about 100 Å to about 1,000 Å. The thickness of the hole transport layer including both thicknesses of the first hole transport layer and the second hole transport layer may be about 50 Å to about 2,000 Å, and in some embodiments, about 100 Å to about 1,500 Å. When the thicknesses of the hole transport region, the hole injection layer, and the hole transport layer are each within these ranges, excellent hole transport characteristics may be obtained without a substantial increase in driving voltage.

The hole transport region may further include, in addition to the abovementioned materials, a charge-generating material to improve conduction. The charge-generating material may be homogeneously or non-homogeneously dispersed throughout the hole transport region.

The hole transport region may further include a buffer layer as well as the electron blocking layer, hole injection layer, and/or hole transport layer described above. Since the buffer layer may compensate for an optical resonance distance according to a wavelength of light emitted from the emission layer (e.g., be used to adjust the optical resonance distance to match the wavelength of light emitted from the emission layer), the light-emission efficiency of a formed organic light-emitting device may be improved. As a material included in the buffer layer, materials that are included in the hole transport region may be used. The electron blocking layer may prevent or reduce injection of electrons from the electron transport region.

An emission layer may be formed on the first electrode110and/or on the hole transport region using one or more suitable methods, such as vacuum-deposition, spin coating, casting, LB method, ink-jet printing, laser-printing, and/or LITI. When the emission layer is formed by vacuum-deposition and/or spin coating, the deposition and coating conditions for the emission layer may be similar to the deposition and coating conditions for the hole injection layer.

When the organic light-emitting device10is a full color organic light-emitting device, the emission layer may be patterned into a red emission layer, a green emission layer, and/or a blue emission layer, according to a sub pixel. Alternatively, the emission layer may have a stacked structure of a red emission layer, a green emission layer, and a blue emission layer, or may include a red-light emission material, a green-light emission material, and a blue-light emission material, which are mixed together in a single layer to thereby emit white light.

The emission layer may include a host and a dopant.

For example, the host may include at least one selected from TPBi, TBADN, ADN (also known as “DNA”), CBP, CDBP, and TCP:

Alternatively, the host may further include a compound represented by Formula 301:
Ar301-[(L301)xb1-R301]xb2.  Formula 301

In Formula 301,

a naphthalene, a heptalene, a fluorene, a spiro-fluorene, a benzofluorene, a dibenzofluorene, a phenalene, a phenanthrene, an anthracene, a fluoranthene, a triphenylene, a pyrene, a chrysene, naphthacene, a picene, a perylene, a pentaphene, and an indenoanthracene, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C1-C60alkyl group, a C2-C60alkenyl group, a C2-C60alkynyl group, a C1-C60alkoxy group, a C3-C10cycloalkyl group, a C2-C10heterocycloalkyl group, a C3-C10cycloalkenyl group, a C2-C10heterocycloalkenyl group, a C6-C60aryl group, a C6-C60aryloxy group, a C6-C60arylthio group, a C1-C60heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, and —Si(Q301)(Q302)(Q303) (wherein Q301to Q303may each independently be selected from hydrogen, a C1-C60alkyl group, a C2-C60alkenyl group, a C6-C60aryl group, and a C1-C60heteroaryl group);

a C1-C20alkyl group and a C1-C20alkoxy group;

xb1 may be selected from 0, 1, 2, and 3, and

xb2 may be selected from 1, 2, 3, and 4.

In some embodiments, in Formula 301,

a C1-C20alkyl group and a C1-C20alkoxy group;

In some embodiments, the host may include a compound represented by Formula 301A:

In Formula 301 Å, L301, R301, xb1, and xb2 may each be the same as described herein in connection with Formula 301.

The compound represented by Formula 301 may include at least one compound selected from Compounds H1 to H42, but embodiments of the present disclosure are not limited thereto:

In some embodiments, the host may include at least one selected from Compounds H43 to H49, but embodiments of the present disclosure are not limited thereto:

The dopant may include at least one selected from a fluorescent dopant available in the related art and a phosphorescent dopant available in the related art.

In Formula 401,

X401to X404may each independently be selected from nitrogen and carbon;

rings A401and A402may each independently be selected from a substituted or unsubstituted benzene, a substituted or unsubstituted naphthalene, a substituted or unsubstituted fluorene, a substituted or unsubstituted spiro-fluorene, a substituted or unsubstituted indene, a substituted or unsubstituted pyrrole, a substituted or unsubstituted thiophene, a substituted or unsubstituted furan, a substituted or unsubstituted imidazole, a substituted or unsubstituted pyrazole, a substituted or unsubstituted thiazole, a substituted or unsubstituted isothiazole, a substituted or unsubstituted oxazole, a substituted or unsubstituted isoxazole, a substituted or unsubstituted pyridine, a substituted or unsubstituted pyrazine, a substituted or unsubstituted pyrimidine, a substituted or unsubstituted pyridazine, a substituted or unsubstituted quinoline, a substituted or unsubstituted isoquinoline, a substituted or unsubstituted benzoquinoline, a substituted or unsubstituted quinoxaline, a substituted or unsubstituted quinazoline, a substituted or unsubstituted carbazole, a substituted or unsubstituted benzimidazole, a substituted or unsubstituted benzofuran, a substituted or unsubstituted benzothiophene, a substituted or unsubstituted isobenzothiophene, a substituted or unsubstituted benzoxazole, a substituted or unsubstituted isobenzoxazole, a substituted or unsubstituted triazole, a substituted or unsubstituted oxadiazole, a substituted or unsubstituted triazine, a substituted or unsubstituted dibenzofuran, and a substituted or unsubstituted dibenzothiophene;

L401may be an organic ligand;

xc1 may be selected from 1, 2, and 3; and

xc2 may be selected from 0, 1, 2, and 3,

wherein Q401to Q407, Q411to Q417, and Q421to Q427may each be the same as described herein in connection with Q11.

L401may be a monovalent, a divalent, or a trivalent organic ligand. In some embodiments, L401may be selected from a halogen ligand (e.g., Cl or F), a diketone ligand (e.g., acetylacetonate, 1,3-diphenyl-1,3-propane dionate, 2,2,6,6-tetramethyl-3,5-heptanedionate, or hexafluoroacetonate), a carboxylic acid ligand (e.g., picolinate, dimethyl-3-a pyrazolecarboxylate, or benzoate), a carbon monoxide ligand, an isonitrile ligand, a cyano group ligand, and a phosphorus ligand (e.g., phosphine or phosphite), but embodiments are not limited thereto.

When A401in Formula 401 has a plurality of substituents, the plurality of substituents of A401may bind to each other to form a saturated or unsaturated ring.

When A402in Formula 401 has a plurality of substituents, the plurality of substituents of A402may bind to each other to form a saturated or unsaturated ring.

When xc1 in Formula 401 is two or more, a plurality of ligands

in Formula 401 may be identical to or different from each other. In Formula 401, when xc1 is 2 or more, A401and A402may each be directly connected (e.g., by a bond) or connected via a linking group (for example, a C1-C5alkylene group, —N(R′)— (here, R′ may be a C1-C10alkyl group or a C6-C20aryl group), and/or —C(═O)—) to A401and A402, respectively, of another adjacent ligand.

The phosphorescent dopant may include at least one selected from Compounds PD1 to PD74, but embodiments of the present disclosure are not limited thereto:

In some embodiments, the phosphorescent dopant may include PtOEP:

The fluorescent dopant may include at least one selected from DPVBi, DPAVBi, TBPe, DCM, DCJTB, Coumarin 6, and C545T.

Alternatively, the fluorescent dopant may include a compound represented by Formula 501:

In Formula 501,

a naphthalene, a heptalene, a fluorene, a spiro-fluorene, a benzofluorene, a dibenzofluorene, a phenalene, a phenanthrene, an anthracene, a fluoranthene, a triphenylene, a pyrene, a chrysene, a naphthacene, a picene, a perylene, a pentaphene, and an indenoanthracene, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C1-C60alkyl group, a C2-C60alkenyl group, a C2-C60alkynyl group, a C1-C60alkoxy group, a C3-C10cycloalkyl group, a C2-C10heterocycloalkyl group, a C3-C10cycloalkenyl group, a C2-C10heterocycloalkenyl group, a C6-C60aryl group, a C6-C60aryloxy group, a C6-C60arylthio group, a C1-C60heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, and —Si(Q501)(Q502)(Q503) (where, Q501to Q503are each independently selected from hydrogen, a C1-C60alkyl group, a C2-C60alkenyl group, a C6-C60aryl group, and a C1-C60heteroaryl group);

L501to L503may each be the same as described herein in connection with L301;

R501and R502may each independently be selected from:

xd1 to xd3 may each independently be selected from 0, 1, 2, and 3, and

xd4 may be selected from 1, 2, 3, and 4.

The fluorescent host may include at least one selected from compounds FD1 to FD8:

The amount of the dopant in the emission layer may be about 0.01 part to about 15 parts by weight based on 100 parts by weight of the host, but embodiments of the present disclosure are not limited thereto.

An electron transport region may be on the emission layer.

The electron transport region may include at least one selected from a hole blocking layer, an electron transport layer (ETL), and an electron injection layer, but embodiments of the present disclosure are not limited thereto.

When the electron transport region includes a hole blocking layer, the hole blocking layer may be formed on the emission layer using one or more suitable methods, such as vacuum-deposition, spin coating, casting, LB method, ink-jet printing, laser-printing, and/or LITI. When the hole blocking layer is formed by vacuum-deposition and/or spin coating, the deposition and coating conditions for the hole blocking layer may be similar to the deposition and coating conditions for the hole injection layer.

The hole blocking layer may include, for example, at least one selected from BCP and Bphen, but embodiments of the present disclosure are not limited thereto:

The thickness of the hole blocking layer may be about 20 Å to about 1,000 Å, and in some embodiments, about 30 Å to about 300 Å. When the thickness of the hole blocking layer is within this range, excellent hole blocking characteristics may be obtained without a substantial increase in driving voltage.

The electron transport region may have a structure of electron transport layer/electron injection layer or a structure of hole blocking layer/electron transport layer/electron injection layer, wherein layers of each structure are sequentially stacked on the emission layer in the stated order, but embodiments of the present disclosure are not limited thereto.

In some embodiments, the organic layer150of the organic light-emitting device includes an electron transport region between the emission layer and the second electrode190, wherein the electron transport region may include an electron transport layer. The electron transport layer may be a plurality of layers. In some embodiments, the electron transport region may include a first electron transport layer and a second electron transport layer.

The electron transport layer may include at least one selected from BCP, Bphen, Alq3, BAlq, TAZ, and NTAZ.

In some embodiments, the electron transport layer may include at least one compound selected from a compound represented by Formula 601 and a compound represented by Formula 602:
Ar601-[(L601)xe1-E601]xe2-  Formula 601

In Formula 601,

a naphthalene, a heptalene, a fluorene, a spiro-fluorene, a benzofluorene, a dibenzofluorene, a phenalene, a phenanthrene, an anthracene, a fluoranthene, a triphenylene, a pyrene, a chrysene, naphthacene, a picene, a perylene, a pentaphene, and an indenoanthracene, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C1-C60alkyl group, a C2-C60alkenyl group, a C2-C60alkynyl group, a C1-C60alkoxy group, a C3-C10cycloalkyl group, a C3-C10heterocycloalkyl group, a C3-C10cycloalkenyl group, a C3-C10heterocycloalkenyl group, a C6-C60aryl group, a C6-C60aryloxy group, a C6-C60arylthio group, a C1-C60heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, and —Si(Q301)(Q302)(Q303) (wherein Q301to Q303may each independently be selected from hydrogen, a C1-C60alkyl group, a C2-C60alkenyl group, a C6-C60aryl group, and a C1-C60heteroaryl group);

L601may be the same as described herein in connection with L301;

xe1 may be selected from 0, 1, 2, and 3; and

xe2 may be selected from 1, 2, 3, and 4.

In Formula 602,

X611may be selected from N and C-(L611)xe611-R611, X612may be selected from N and C-(L612)xe612-R612, X613may be selected from N and C-(L613)xe613-R613, and at least one selected from X611to X613may be N;

L611to L616may each be the same as described herein in connection with L301;

R611to R616may each independently be selected from:

xe611 to xe616 may each independently be selected from 0, 1, 2, and 3.

The compound represented by Formula 601 and the compound represented by Formula 602 may each be selected from Compounds ET1 to ET15:

The thickness of the electron transport layer may be about 100 Å to about 1,000 Å, and in some embodiments, about 150 Å to about 500 Å. When the thickness of the electron transport layer is within this range, excellent electron transport characteristics may be obtained without a substantial increase in driving voltage.

The electron transport layer may further include a metal-containing material in addition to the materials described above.

The metal-containing material may include a Li complex. The Li complex may include, for example, one selected from Compound ET-D1 (lithium quinolate, LiQ) and ET-D2.

The electron transport region may include an electron injection layer that facilitates electron injection from the second electrode190.

The electron injection layer may be formed on the electron transport layer using one or more suitable methods, such as vacuum-deposition, spin coating, casting, LB method, ink-jet printing, laser-printing, and/or LITI. When the electron injection layer is formed by vacuum-deposition and/or spin coating, the vacuum-deposition and coating conditions for the electron injection layer may be similar to the vacuum-deposition and coating conditions for the hole injection layer.

The electron injection layer may include at least one selected from, LiF, NaCl, CsF, Li2O, BaO, and LiQ.

The second electrode190is on the organic layer150. The second electrode190may be a cathode that is an electron injection electrode, and in this regard, a material for forming the second electrode190may be a material having a low work function. Non-limiting examples of such a material may include metal, alloy, an electrically conductive compound, and mixtures thereof. Non-limiting examples of the material for forming the second electrode190may include lithium (Li), magnesium (Mg), aluminum (Al), aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In), and magnesium-silver (Mg—Ag). In some embodiments, the material for forming the second electrode190may be ITO and/or IZO. The second electrode190may be a reflective electrode, a semi-transmissive electrode, or a transmissive electrode.

The organic layer of the organic light-emitting device according to an embodiment of the present disclosure may be formed by vacuum-depositing the compound according to an embodiment of the present disclosure and/or by using a wet method in which the compound is prepared in the form of solution, and the solution of the compound is used for coating.

The organic light-emitting device according to an embodiment of the present disclosure may be suitably included in one or more types or kinds of flat panel display apparatuses, for example, a passive matrix organic light-emitting display apparatus and an active matrix organic light-emitting display apparatus. For example, when the organic light-emitting device is included in an active matrix organic light-emitting display apparatus, a first electrode on a substrate may be a pixel electrode, and the first electrode may be electrically connected to a source electrode or drain electrode of a thin film transistor. In some embodiments, the organic light-emitting device may be included in a flat panel display apparatus that may display images on both sides.

Hereinbefore, the organic light-emitting device has been described with reference to the drawing, but embodiments of the present disclosure are not limited thereto.

Hereinafter, definitions of substituents used herein will be presented. The number of carbons used to restrict a substituent is not limited, and does not limit the properties of the substituent, and unless defined otherwise, the definition of the substituent is consistent with a general definition thereof.

The term “C2-C60alkenyl group” as used herein refers to a hydrocarbon group formed by substituting at least one carbon double bond in the middle or at the terminal of the C2-C60alkyl group, and non-limiting examples thereof may include an ethenyl group, a propenyl group, and a butenyl group. The term “C2-C60alkenylene group” as used herein refers to a divalent group having substantially the same structure as a C2-C60alkenyl group.

The term “C2-C60alkynyl group” as used herein refers to a hydrocarbon group formed by substituting at least one carbon triple bond in the middle or at the terminal of the C2-C60alkyl group, and non-limiting examples thereof may include an ethynyl group and a propynyl group. The term “C2-C60alkynylene group” as used herein refers to a divalent group having substantially the same structure as a C2-C60alkynyl group.

The term “C1-C10heterocycloalkyl group” as used herein refers to a monovalent monocyclic group including at least one heteroatom selected from N, O, P, and S as a ring-forming atom and 1 to 10 carbon atoms. Non-limiting examples thereof may include a tetrahydrofuranyl group and a tetrahydrothiophenyl group. The term “C2-C10heterocycloalkylene group” as used herein refers to a divalent group having substantially the same structure as a C2-C10heterocycloalkyl group.

The term “C6-C60aryloxy group” as used herein indicates —O-A102(wherein A102is the C6-C60aryl group), and a C6-C60arylthio group used herein indicates —S-A103(wherein A103is the C6-C60aryl group).

The term “monovalent non-aromatic condensed polycyclic group” as used herein refers to a monovalent group that has two or more rings condensed to each other, and has only carbon atoms as ring forming atoms (for example, the number of carbon atoms may be 8 to 60), wherein the molecular structure as a whole is non-aromatic in the entire molecular structure (e.g., the entire group is not aromatic). A non-limiting example of the monovalent non-aromatic condensed polycyclic group may include a fluorenyl group. The term “divalent non-aromatic condensed polycyclic group” as used herein refers to a divalent group having the same structure as the monovalent non-aromatic condensed polycyclic group.

The term “monovalent non-aromatic condensed heteropolycyclic group” as used herein refers to a monovalent group that has two or more rings condensed to each other, and has a heteroatom selected from N, O, P, and S, and 2 to 60 carbon atoms as ring-forming atoms, wherein the molecular structure as a whole is non-aromatic in the entire molecular structure (e.g., the entire group is not aromatic). The term “divalent non-aromatic condensed hetero-polycyclic group” as used herein refers to a divalent group having the same structure as the monovalent non-aromatic condensed hetero-polycyclic group.

As used herein, “Ph” refers to a phenyl group, “Me” refers to a methyl group, “Et” refers to an ethyl group, and “ter-Bu” or “But” refers to a tert-butyl group.

Hereinafter, an organic light-emitting device according to an embodiment of the present disclosure will be described in more detail with reference to Examples.

Synthesis Example

Intermediates I-1 to I-17 and I-18 to I-29, used as precursors for synthesizing the compound according to an example embodiment of the present disclosure, were synthesized as follows:

Synthesis of Intermediates I-1 to I-17

Synthesis of Intermediate I-1

19.1 g (100.0 mmol) of 4H-benzo[def]carbazole, 28.3 g (120.0 mmol) of 1-bromo-3-iodobenzene, 1.91 g (10.0 mmol) of CuI, 2.43 g (10.0 mmol) of 18-Crown-6, and 41.5 g (300.0 mmol) of K2CO3were dissolved in 300 mL of DMF, and the reaction solution was stirred at 140° C. for 12 hours. The reaction solution was then cooled to room temperature, 300 mL of water was added thereto, and an organic layer was collected by repeated extraction using 300 mL of diethyl ether three times. The organic layer thus collected was dried with magnesium sulfate, the magnesium sulfate was removed by filtration, and the residue obtained after evaporating a solvent therefrom was separated and purified using silica gel column chromatography to obtain 31.5 g of Intermediate I-1 (yield: 91%). The compound thus produced was identified by liquid chromatography-mass spectrometry (LC-MS).

Synthesis of Intermediate I-2

31.1 g (90.0 mmol) of Intermediate I-1, 19.9 g (99.0 mmol) of (4-bromophenyl)boronic acid, 5.20 g (4.5 mmol) of Pd(PPh3)4, and 37.3 g (270.0 mmol) of K2CO3were dissolved in 270 mL of a mixture of THF/H2O (1:1), and the reaction solution was stirred at 60° C. for 4 hours. The reaction solution was then cooled to room temperature, 270 mL of water was added thereto, and an organic layer was collected by repeated extraction using 250 mL of diethyl ether three times. The organic layer thus collected was dried with magnesium sulfate, the magnesium sulfate was removed by filtration, and the residue obtained after evaporating a solvent therefrom was separated and purified using silica gel column chromatography to obtain 25.0 g of Intermediate I-2 (yield: 79%). The compound thus produced was identified by LC-MS.

Synthesis of Intermediate I-3

Intermediate I-3 (yield: 78%) was synthesized in substantially the same manner as Intermediate I-2 using Intermediate I-1 and (3-bromophenyl)boronic acid. The compound thus produced was identified by LC-MS.

Synthesis of Intermediate I-4

Intermediate I-4 (yield: 73%) was synthesized in substantially the same manner as Intermediate I-2 using Intermediate I-1 and (6-bromopyridin-2-yl)boronic acid. The compound thus produced was identified by LC-MS.

Synthesis of Intermediate I-5

Intermediate I-5 (yield: 81%) was synthesized in substantially the same manner as Intermediate I-2 using Intermediate I-1 and (8-bromodibenzo[b,d]furan-2-yl)boronic acid. The compound thus produced was identified by LC-MS.

Synthesis of Intermediate I-6

Intermediate I-6 (yield: 78%) was synthesized in substantially the same manner as Intermediate I-2 using Intermediate I-1 and (6-bromo-9-phenyl-9H-carbazol-3-yl)boronic acid. The compound thus produced was identified by LC-MS.

Synthesis of Intermediate I-7

Intermediate I-7 (yield: 79%) was synthesized in substantially the same manner as Intermediate I-2 using Intermediate I-1 and (3′-bromo-[1,1′-biphenyl]-3-yl)boronic acid. The compound thus produced was identified by LC-MS.

Synthesis of Intermediate I-8

Intermediate I-8 (yield: 92%) was synthesized in substantially the same manner as Intermediate I-1 using 4H-benzo[def]carbazole and 1-bromo-3-iodobenzene. The compound thus produced was identified by LC-MS.

Synthesis of Intermediate I-9

Intermediate I-9 (yield: 79%) was synthesized in substantially the same manner as Intermediate I-2 using Intermediate I-8 and (3-bromophenyl)boronic acid. The compound thus produced was identified by LC-MS.

Synthesis of Intermediate I-10

Intermediate I-10 (yield: 92%) was synthesized in substantially the same manner as Intermediate I-1 using 4H-benzo[def]carbazole and 1-bromo-4-iodobenzene. The compound thus produced was identified by LC-MS.

Synthesis of Intermediate I-11

Intermediate I-11 (yield: 80%) was synthesized in substantially the same manner as Intermediate I-2 using Intermediate I-10 and (3-bromophenyl)boronic acid. The compound thus produced was identified by LC-MS.

Synthesis of Intermediate I-12

Intermediate I-12 (yield: 81%) was synthesized in substantially the same manner as Intermediate I-1 using 4H-benzo[def]carbazole and 1,4-dibromonaphthalene. The compound thus produced was identified by LC-MS.

Synthesis of Intermediate I-13

Intermediate I-13 (yield: 77%) was synthesized in substantially the same manner as Intermediate I-2 using Intermediate I-12 and (4-bromophenyl)boronic acid. The compound thus produced was identified by LC-MS.

Synthesis of Intermediate I-14

Intermediate I-14 (yield: 76%) was synthesized in substantially the same manner as Intermediate I-1 using 4H-benzo[def]carbazole and 2,8-dibromodibenzo[b,d]furan. The compound thus produced was identified by LC-MS.

Synthesis of Intermediate I-15

Intermediate I-15 (yield: 75%) was synthesized in substantially the same manner as Intermediate I-2 using Intermediate I-14 and (3-bromophenyl)boronic acid. The compound thus produced was identified by LC-MS.

Synthesis of Intermediates I-16 and I-17

Synthesis of Intermediate I-30

7.82 g (44.0 mmol) of N-bromosuccinimide was added to a solution prepared by completely dissolving 3.82 g (20.0 mmol) of 6H-benzo[def]carbazole in 100 mL of carbon tetrachloride (CCl4), and the mixture was stirred at a temperature of 80° C. for 30 minutes. The reaction solution was cooled to room temperature and stirred for 30 minutes to precipitate crystals. The crystals were collected using reduced-pressure filtration and washed with methanol, and thus 3.82 g of Intermediate I-3 (yield: 55%) was obtained as white crystals. The compound thus produced was identified by LC-MS.

Synthesis of Intermediate I-31

3.49 g (10.0 mmol) of Intermediate I-3, 2.68 g (22.0 mmol) of phenylboronic acid, 1.15 g (1.0 mmol) of Pd(PPh3)4, and 4.14 g (30.0 mmol) of K2CO3were dissolved in 40 mL of a mixture of THF/H2O (2:1), and the reaction solution was stirred at 80° C. for 5 hours. The reaction solution was cooled to room temperature, 40 mL of water was added thereto, and an organic layer was collected by repeated extraction using 50 mL of diethyl ether three times. The organic layer thus collected was dried with magnesium sulfate, the magnesium sulfate was removed by filtration, and the residue obtained after evaporating a solvent therefrom was separated and purified using silica gel column chromatography to obtain 2.61 g of Intermediate I-4 (yield: 76%). The compound thus produced was identified by LC-MS.

Synthesis of Intermediate I-16

Intermediate I-16 (yield: 89%) was synthesized in the same manner as Intermediate I-1 using Intermediate I-31 and 1-bromo-3-iodobenzene. The compound thus produced was identified by LC-MS.

Synthesis of Intermediate I-17

Intermediate I-17 (yield: 73%) was synthesized in the same manner as Intermediate I-2 using Intermediate I-16 and (4-bromophenyl)boronic acid. The compound thus produced was identified by LC-MS.

Synthesis of Intermediates I-18 to I-29

Synthesis of Intermediate I-18

14.3 g (100.0 mmol) of 1-aminonaphthalene, 23.3 g (100.0 mmol) of 4-bromobiphenyl, 4.6 g (5.0 mmol) of Pd2(dba)3, 1.0 g (5.0 mmol) of P(tBu)3, and 14.4 g (150.0 mol) of NaOtBu were dissolved in 300 mL of toluene, and the reaction solution was stirred at 80° C. for 5 hours. The reaction solution was cooled to room temperature, 300 mL of water was added thereto, and an organic layer was extracted using 300 mL of diethyl ether three times. The organic layer thus collected was dried with magnesium sulfate, the magnesium sulfate was removed by filtration, and the residue obtained after evaporating a solvent therefrom was separated and purified using silica gel column chromatography to obtain 26.0 g of Intermediate I-18 (yield: 88%). The compound thus produced was identified by LC-MS.

Intermediates I-19 to I-29 were synthesized in substantially the same manner as Intermediate I-18 using appropriate or suitable amine and halide intermediates in an amination method using a Pd catalyst.

Representative Synthesis Example

Synthesis of Compound 3

4.2 g (10.0 mmol) of Intermediate I-2, 2.9 g (10.0 mmol) of Intermediate I-18, 0.46 g (0.5 mmol) of Pd2(dba)3, 0.1 g (0.5 mmol) of P(tBu)3, and 1.44 g (15.0 mol) of NaOtBu were dissolved in 30 mL of toluene, and the reaction solution was stirred at 80° C. for 5 hours. The reaction solution was cooled to room temperature, 30 mL of water was added thereto, and an organic layer was collected by repeated extraction using 30 mL of diethyl ether three times. The organic layer thus collected was dried with magnesium sulfate, the magnesium sulfate was removed by filtration, and the residue obtained after evaporating a solvent therefrom was separated and purified using silica gel column chromatography to obtain 5.5 g of Compound 3 (yield: 86%). The compound thus produced was identified by LC-MS and1H NMR.

Compounds 4 to 87 were synthesized by reacting appropriate or suitable Intermediate precursors (selected from Intermediates I-1 to I-17 and Intermediates I-18 to I-29) for each of Compounds 4 to 87 in the same manner as used in the synthesis of Compound 3. The compounds thus produced were confirmed by LC-MS and1H NMR. The results are shown in Table 1.

EXAMPLE

A glass substrate of ITO/Ag/ITO of 70/1000/70 Å was cut to a size of 50 mm×50 mm×0.5 mm, sonicated in isopropyl alcohol and pure water for 5 minutes, and then cleaned with UV and ozone for 30 minutes to prepare an anode. The glass substrate was then mounted on a vacuum depositor.

N-([1,1′-biphenyl]-4-yl)-9,9-dimethyl-N-(4-(9-phenyl-9H-carbazol-3-yl)phenyl)-9H-fluoren-2-amine (HT1) and F4-TCNQ were vacuum co-deposited on the ITO substrate at a weight ratio of 98:2 to form a hole injection layer having a thickness of 100 Å. Compound HT1 was vacuum deposited on the hole injection layer to form a first hole transport layer having a thickness of 1,200 Å, and Compound 3 was vacuum deposited on the first hole transport layer to form a second hole transport layer having a thickness of 100 Å.

9,10-di-naphthalene-2-yl-anthracene (ADN) as a blue host and N,N,N′,N′-tetraphenyl-pyrene-1,6-diamine (TPD) as a blue dopant were co-deposited on the second hole transport layer at a weight ratio of 98:2 to form an emission layer having a thickness of 300 Å. Then, 2-(4-(9,10-di(naphthalen-2-yl)anthracen-2-yl)phenyl)-1-phenyl-1H-benzo[d]imidazole (L201) was deposited on the emission layer to form an electron transport layer having a thickness of 300 Å. LiF, which is a halogenated alkali metal, was deposited on the electron transport layer to form an electron injection layer having a thickness of 10 Å, and MgAg was vacuum deposited at a weight ratio of 90:10 to form a cathode electrode having a thickness of 120 Å, thereby completing the manufacture of an organic light-emitting device.

Examples 2 to 21

Additional organic light-emitting devices were manufactured as examples in substantially the same manner as in Example 1, except that each of Compounds 4 to 87 was used instead of Compound 3 in the formation of the second hole transport layer.

Comparative Examples 1 and 2

Additional organic light-emitting devices were manufactured as comparative examples in substantially the same manner as in Example 1, except that each of Compounds A and B was used instead of Compound 3 in the formation of the second hole transport layer.

Device performance characteristics (driving voltage, luminance, efficiency, and color coordinate) during device operation at a current density of 10 mA/cm2, as well as the time elapsed for luminance to reduce to half of the initial luminance at a current density of 50 mA/cm2are shown in Table 2 for each of the manufactured organic light-emitting devices.

As shown in Table 2, when the compound having a phenyl group, a pyridyl group, a pyrimidyl group, and/or a 1,3,5-triazinyl group linker having binding sites that are ortho- or meta- to each other is included in the second hole transport layer, the efficiency and luminance half-life of a device may increase due to having a T1(e.g., triplet) energy level higher than in the Comparative Examples including Compounds A and B, which have a para-substituted phenyl linker.

As described above, according to the above embodiments of the present disclosure, an organic light-emitting device including the compound represented by Formula 1 may have an increased T1energy level, and thus the characteristics of the organic light-emitting device may be improved.

It should be understood that the example embodiments described herein should be considered in a descriptive sense only and not for purposes of limitation. Descriptions of features or aspects within each example embodiment should typically be considered as being available for other similar features or aspects in other example embodiments.

As used herein, the terms “use”, “using”, and “used” may be considered synonymous with the terms “utilize”, “utilizing”, and “utilized”, respectively. Further, the use of “may” when describing embodiments of the present disclosure refers to “one or more embodiments of the present disclosure”.