ORGANIC LIGHT-EMITTING DEVICES

CROSS-REFERENCE TO RELATED APPLICATION

Korean Patent Application No. 10-2014-0007959, filed on Jan. 22, 2014, in the Korean Intellectual Property Office, and entitled: “Organic Light-Emitting Devices,” is incorporated by reference herein in its entirety.

BACKGROUND

1. Field

Embodiments relate to an organic light-emitting device.

2. Description of the Related Art

Organic light-emitting diodes (OLEDs), which are self-emitting diodes, may have advantages such as wide viewing angles, excellent contrast, quick response, high brightness, and excellent driving voltage characteristics, and may provide multicolored images.

An OLED may have a structure including a substrate, and an anode, a hole transport layer (HTL), an emission layer (EML), an electron transport layer (ETL), and a cathode which are sequentially stacked on the substrate. The HTL, the EML, and the ETL may be organic thin films formed of organic compounds.

An operating principle of an OLED having the above-described structure may be as follows:

When a voltage is applied between the anode and the cathode, holes injected from the anode may move to the EML via the HTL, and electrons injected from the cathode may move to the EML via the ETL. The holes and electrons (carriers) may recombine in the EML to generate excitons. When the excitons drop from an excited state to a ground state, light may be emitted.

SUMMARY

Embodiments are directed to an organic light-emitting device

According to one or more embodiments, an organic light-emitting device includes a first electrode; a second electrode disposed opposite to the first electrode; an emission layer (EML) disposed between the first electrode and the second electrode; and a hole transport region between the first electrode and the EML, wherein the EML includes at least one organometallic compounds represented by Formula 1 and the hole transport region includes at least one carbazole-based compounds represented by Formula 2:

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In Formulae 1 and 2,

R₁is selected from a deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid or a salt thereof, 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 C₃-C₁₀cycloalkenyl group, a substituted or unsubstituted C₃-C₁₀heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀heterocycloalkenyl group, a substituted or unsubstituted C₆-C₃₀aryl group, a substituted or unsubstituted C₆-C₃₀aryloxy group, a substituted or unsubstituted C₆-C₃₀arylthio group, a substituted or unsubstituted C₂-C₃₀heteroaryl group, —N(Q₁)(Q₂), —C(═O)(Q₃), and —Si(Q₄)(Q₅)(Q₆) (wherein, Q₁to Q₆are each independently a hydrogen, a substituted or unsubstituted C₁-C₆₀alkyl group, a substituted or unsubstituted C₆-C₃₀aryl group, or a substituted or unsubstituted C₂-C₃₀heteroaryl group);

R₂to R₆are each independently selected from a hydrogen, a deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid or a salt thereof, 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 C₃-C₁₀cycloalkenyl group, a substituted or unsubstituted C₃-C₁₀heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀heterocycloalkenyl group, a substituted or unsubstituted C₆-C₃₀aryl group, a substituted or unsubstituted C₆-C₃₀aryloxy group, a substituted or unsubstituted C₆-C₃₀arylthio group, a substituted or unsubstituted C₂-C₃₀heteroaryl group, —N(Q₁)(Q₂), —C(═O)(Q₃), and —Si(Q₄)(Q₅)(Q₆) (wherein, Q₁to Q₆are each independently selected from a hydrogen, a substituted or unsubstituted C₁-C₆₀alkyl group, a substituted or unsubstituted C₆-C₃₀aryl group, or a substituted or unsubstituted C₂-C₃₀heteroaryl group);

a is an integer selected from 1 to 3 and when a is 2 or greater, two or more R₄s may be the same or different;

b and c are each independently an integer selected from 1 to 6 and when b is 2 or greater, two or more R₅s may be the same or different, and when c is 2 or greater, two or more R₆s may be the same or different;

ring A is selected from or forms a pyrrole, an imidazole, a pyrazole, a triazole, a thiazole, an oxazole, an isothiazole, and isoxazole, a benzothiazole, a benzimidazole, a benzoxazole, a pyridine, a pyrazine, a pyrimidine, a pyridazine, an isoindole, an indole, an indazole, a purine, an isoquinoline, a phthalazine, a naphthyridine, a quinoxaline, a quinazoline, a cinnoline, a phenanthridine, an acridine, a phenanthroline, a phenazine, and a phenoxazine;

ring B is selected from or forms a benzene, a pentalene, an indene, a naphthalene, an azulene, a heptalene, an indacene, an acenaphthylene, a fluorene, a spiro-fluorene, a phenalene, a phenanthrene, an anthracene, a fluoranthene, a triphenylene, a pyrene, a chrysene, a pyrrole, an imidazole, a pyrazole, a triazole, an isothiazole, an isoxazole, a pyridine, a pyrazine, a pyrimidine, a pyridazine, an isoindole, an indole, an indazole, a purine, an isoquinoline, a quinoline, a phthalazine, a naphthyridine, a quinoxaline, a quinazoline, a cinnoline, a phenanthridine, an acridine, a phenanthroline, a phenazine, and a phenoxazine;

X₁and X₂are each independently N or C;

n is 1 or 2;

X is a boron atom (B), a nitrogen atom (N), or a phosphorus atom (P);

L₁to L₃are each independently selected from

i) a C₆-C₆₀arylene group; and

ii) a C₆-C₆₀group substituted with at least one of a deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid or a salt thereof, 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 C₃-C₁₀cycloalkenyl group, a substituted or unsubstituted C₃-C₁₀heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀aryl group, a substituted or unsubstituted C₆-C₆₀aryloxy group, a substituted or unsubstituted C₆-C₆₀arylthio group, and a substituted or unsubstituted C₂-C₆₀heteroaryl group;

n1 to n3 are each independently an integer selected from 0 to 5;

R₇₁to R₇₈and R₈₁to R₈₉are each independently selected from a hydrogen, a deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid or a salt thereof, 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 C₃-C₁₀cycloalkenyl group, a substituted or uusubstituted C₃-C₁₀heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀aryl group, a substituted or unsubstituted C₆-C₆₀aryloxy group, a substituted or unsubstituted C₆-C₆₀arylthio group, and a substituted or unsubstituted C₂-C₆₀heteroaryl group; and

Ar₁is selected from

i) a C₆-C₆₀aryl group and a C₂-C₆₀heteroaryl group; and

ii) a C₆-C₆₀aryl group and a C₂-C₆₀heteroaryl group, each substituted with at least one of a deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid or a salt thereof, 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 C₃-C₁₀cycloalkenyl group, a substituted or unsubstituted C_3-C₁₀heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀aryl group, a substituted or unsubstituted C₆-C₆₀aryloxy group, a substituted or unsubstituted C₆-C₆₀arylthio group and a substituted or unsubstituted C₂-C₆₀heteroaryl group.

In another embodiment, provided is an organic light-emitting device including a first electrode; a second electrode disposed opposite to the first electrode; an EML disposed between the first electrode and the second electrode; and a hole transport region between the first electrode and the EML, wherein the EML includes at least one organometallic compound represented by Formulae 1B and 1C and the hole transport region includes at least one carbazole-based compound represented by Formula 2A:

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In Formulae 1B, 1C, and 2A,

R₁is selected from a methyl group, an ethyl group, a propyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a text-butyl group, an n-pentyl group, an isopentyl group, a sec-pentyl group, a tert-pentyl group, an n-hexyl group, an isohexyl group, a sec-hexyl group, a tert-hexyl group, an n-heptyl group, an isoheptyl group, a sec-heptyl group, a tert-heptyl group, an n-octyl group, an isoctyl group, a sec-octyl group, a tert-octyl group, an n-nonenyl group, an isononenyl group, a sec-nonenyl group, a tert-nonenyl group, an n-decanyl, an isodecanyl, a sec-decanyl, a tert-decanyl, and —N(Q₁)(Q₂),

R₂is selected from a deuterium, —F, —Cl, a cyano group, a nitro group; a methyl group, an ethyl group, a propyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, a sec-pentyl group, a tert-pentyl group, an n-hexyl group, an isohexyl group, a sec-hexyl group, a tert-hexyl group, an n-heptyl group, an isoheptyl group, a sec-heptyl group, a tert-heptyl group, an n-octyl group, an isoctyl group, a sec-octyl group, a tert-octyl group, an n-nonenyl group, an isononenyl group, a sec-nonenyl group, a tert-nonenyl group, an n-decanyl, an isodecanyl, a sec-decanyl, and a tert-decanyl, each substituted with at least one F; a phenyl group, a naphthyl group, an anthryl group, a pyrenyl group, a phenanthrenyl group, a fluorenyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a triazinyl group, a quinolinyl group, an isoquinolinyl group, a quinoxalinyl group, a phenanthrolinyl group, and a carbazolyl group, each substituted with at least one F; and —C(═O)(Q₃),

wherein Q₁to Q₃are each independently a methyl group, an ethyl group, a propyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, a sec-pentyl group, a tert-pentyl group, an n-hexyl group, an isohexyl group, a sec-hexyl group, a tert-hexyl group, an n-heptyl group, an isoheptyl group, a sec-heptyl group, a tert-heptyl group, an n-octyl group, an isoctyl group, a sec-octyl group, a tert-octyl group, an n-nonenyl group, an isononenyl group, a sec-nonenyl group, a tert-nonenyl group, an n-decanyl, an isodecanyl, a sec-decanyl, and a tert-decanyl, each substituted with at least one F; a phenyl group, a naphthyl group, an anthryl group, a pyrenyl group, a phenanthrenyl group, a fluorenyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a triazinyl group, a quinolinyl group, an isoquinolinyl group, a quinoxalinyl group, a phenanthrolinyl group and a carbazolyl group, each substituted with F and at least one C₁-C₂₀alkyl group substituted with at least one —F,

R₄to R₆is a hydrogen,

a, b, and c are each independently an integer selected from 1 to 3 and when a is 2 or greater, two or more R₄S may be the same or different, when b is 2 or greater, two or more R₅s may be the same or different, and when c is 2 or greater, two or more R₆s may be the same or different,

n is 1 or 2;

X is a B atom, an N atom, or a P atom;

R₇₁, R₈₁, and R₈₂are each independently selected from a hydrogen, a deuterium, —F, a cyano group, a nitro group, a methyl group, an ethyl group, a tert-butyl group, a phenyl group, and a naphthyl group;

Ar₁is selected from i) a phenyl group, a naphthyl group, an anthryl group, a fluorenyl group, a pyridyl group, a pyrimidyl group, a pyrazinyl group, a triazinyl group, and a carbazole group; and

ii) a phenyl group, a naphthyl group, an anthryl group, a fluorenyl group, a pyridyl group, a pyrimidyl group, a pyrazinyl group, a triazinyl group, and a carbazole group, each substituted with at least one of a hydrogen, a deuterium, —F, a cyano group, a nitro group, a methyl group, an ethyl group, a tert-butyl group, a phenyl group, and a naphthyl group.

BRIEF DESCRIPTION OF THE DRAWING

Features will be apparent to those of skill in the art by describing in detail exemplary embodiments with reference to the attached drawings in which:

FIG. 1 illustrates a cross-sectional view schematically showing a structure of an organic light-emitting device according to an embodiment.

DETAILED DESCRIPTION

Example embodiments will now be described more fully hereinafter with reference to the accompanying drawing; however, they may 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 exemplary implementations to those skilled in the art.

In the drawing FIGURES, the dimensions of layers and regions may be exaggerated for clarity of illustration. Like reference numerals refer to like elements throughout.

As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. Expressions such as “at least one of,” when preceding a list of elements, modify the entire list of elements and do not modify the individual elements of the list.

As used herein, the expression “(organic layer) includes at least one organometallic compound” may be construed as “(organic layer) may include one organometallic compound belonging to a range of Formula 1 or two or more different organic compounds belonging to the range of Formula 1”.

For example, the organic layer may include an organometallic compound and may only include Compound 1. In this regard, Compound 1 may exist in an emission layer (EML) of an organic light-emitting device. In another embodiment, the organic layer is the organometallic compound and may include both Compound 1 and Compound 2. In this regard, Compound 1 and Compound 2 may exist in the same layer (for example, in the EML) or in different layers (for example, in a first EML and a second EML, respectively).

The organic layer may further include at least one layer selected from a hole injection layer (HTL), a hole transport layer (HTL), a functional layer having both hole injection and hole transport capabilities (hereinafter, an “H-functional layer”), a buffer layer, and an electron blocking layer (EBL) between a first electrode and the EML, and at least one layer selected from a hole blocking layer (HBL), an ETL, and an EIL between the EML and a second electrode.

As used herein, the expression, the “organic layer” is a term that refers to a single layer and/or a multi-layer disposed between the first electrode and the second electrode in the organic light-emitting device.

The organic layer includes the EML, wherein at least one organometallic compound is included in the EML.

The organometallic compound included in the EML may act as a phosphorescent dopant, and the EML may further include a host. The types of the host will be described below.

As described above, the organic light-emitting device including the organometallic compound may emit green light, for example, green phosphorescent light.

FIG. 1 illustrates a cross-sectional view schematically showing a structure of an organic light-emitting device 10 according to an embodiment. Hereinafter, a structure and a manufacturing method of an organic light-emitting device according to an embodiment will be described as follows:

The organic light-emitting device 10 may include a substrate 11, a first electrode 13, an organic layer 15, and a second electrode 17.

The substrate 11, which may be any substrate that is used in general organic light-emitting devices, may be a glass substrate or a apparent plastic substrate with excellent mechanical strength, thermal stability, transparency, surface smoothness, ease of handling, and water resistance.

The first electrode 13 may be formed by, e.g., depositing or sputtering a material for a first electrode on the substrate 11. When the first electrode 13 is an anode, the material for the first electrode 13 may be selected from materials with a high work function to enable ease of hole injection. The first electrode 13 may be a reflective electrode or a transmission electrode. The material for the first electrode 13 may be a transparent material with high conductivity, and examples of such a material may include indium tin oxide (ITO), indium zinc oxide (IZO), tin oxide (SnO₂), and zinc oxide (ZnO). When magnesium (Mg), aluminum (Al), aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In), magnesium-silver (Mg—Ag), or the like is used, the first electrode 13 may be used as a reflective electrode.

The first electrode 13 may have a single-layer structure or a multi-layer structure including at least two layers. For example, the first electrode 13 may have a three-layered structure of ITO/Ag/ITO, but is not limited thereto.

The organic layer 15 may be on the first electrode 13.

The organic layer 15 may include an EML between the first electrode 13 and the second electrode 17.

The organic layer 15 may further include a hole transport region between the first electrode 13 and the EML. The hole transport region may include at least one layer selected from an HIL, an HTL, an H-functional layer, a buffer layer, and an EBL.

The organic layer 15 may further include an electron transport region between the EML and the second electrode 17. The electron transport region may include at least one layer selected from at HBL, an ETL, and an EIL.

The HIL may be formed on the first electrode 13 by using various methods, such as vacuum deposition, spin coating, casting, and Langmuir-Blodgett (LB) deposition.

When the HIL is formed using vacuum deposition, vacuum deposition conditions may vary according to the compound that is used to form the HIL, and the desired structure and thermal properties of the HIL to be formed. For example, vacuum deposition may be performed at a temperature of about 100° C. to about 500° C., a pressure of about 10⁻⁸torr to about 10⁻³torr, and a deposition rate of about 0.01 to about 100 Å/sec. However, the deposition conditions are not limited thereto.

When the HIL is formed using spin coating, the coating conditions may vary according to the compound that is used to form the HIL, and the desired structure and thermal properties of the HIL to be formed. For example, the coating rate may be in the range of about 2000 rpm to about 5000 rpm, and a temperature at which heat treatment is performed to remove a solvent after coating may be in the range of about 80° C. to about 200° C. However, the coating conditions are not limited thereto.

A thickness of the HIL may be about 100 Å to about 10,000 Å, e.g., about 100 Å to about 1,000 Å. When the thickness of the HIL is within the range described above, the HIL may have satisfactory hole injection characteristics without a substantial increase in a driving voltage.

Then, the HTL may be formed on the HIL by using vacuum deposition, spin coating, casting, LB deposition, or the like. When the HTL is formed using vacuum deposition or spin coating, the deposition and coating conditions may be similar to those for the formation of the HIL, though the deposition and coating conditions may vary according to a compound that is used to form the HTL.

A thickness of the HTL may be in a range of about 50 Å to about 2,000 Å, e.g., about 100 Å to about 1,500 Å. When the thickness of the HTL is within the range described above, the HTL may have satisfactory hole transport characteristics without a substantial increase in a driving voltage.

A thickness of the H-functional layer may be in a range of about 500 Å to about 10,000 Å, e.g., about 100 Å to about 1,000 Å. When the thickness of the H-functional layer is within the range described above, the H-functional layer may have satisfactory hole injection and transport characteristics without a substantial increase in a driving voltage.

The hole transport region may include at least one carbazole-containing or carbazole-based compound represented by Formula 2:

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In Formula 2, X may be a boron atom, a nitrogen atom, or a phosphorus atom.

For example, in Formula 2, X may be an N atom, but the X is not limited thereto.

In Formula 2, L₁to L₃may be each independently selected from:

i) a C₆-C₆₀arylene group; and

ii) a C₆-C₆₀arylene group substituted with at least one of a deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid or a salt thereof, 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 C₃-C₁₀cycloalkenyl group, a substituted or unsubstituted C₃-C₁₀heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀aryl group, a substituted or unsubstituted C₆-C₆₀aryloxy group, a substituted or unsubstituted C₆-C₆₀arylthio group, and a substituted or unsubstituted C₂-C₆₀heteroaryl group.

For example, in Formula 2, L₁to L₃may be each independently selected from

i) a phenylene group, a naphthylenyl group, and an anthracenylene group; and

ii) a phenylene group, a naphthylenyl group, and an anthracenylene group, each substituted with at least one of a deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, and a substituted or unsubstituted C₁-C₆₀alkyl group.

In Formula 2, n1 represents the number of L₁s, which may be an integer of 0 to 5, and when n1 is an integer greater than 2, the n1 number of L₁s may be the same or different.

In Formula 2, n2 represents the number of L₂s and may be an integer of 0 to 5, and when n2 is greater than 2, the n2 number of L₂s may be the same or different.

In Formula 2, n3 represents the number of L₃s and may be an integer of 0 to 5, and when n3 is an integer greater than 2, the n3 number of L₃s may be the same or different.

For example, in Formula 2, n1 to n3 may be each independently an integer of 0 or 1, but n1 to n3 are not limited thereto.

In Formula 2, R₇₁to R₇₈and R₈₁to R₈₉may be each independently selected from a hydrogen, a deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid or a salt thereof, 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 C₃-C₁₀cycloalkenyl group, a substituted or unsubstituted C₃-C₁₀heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀aryl group, a substituted or unsubstituted C₆-C₆₀aryloxy group, a substituted or unsubstitutcd C₆-C₆₀arylthio group, and a substituted or unsubstituted C₂-C₆₀heteroaryl group.

For example, in Formula 2, R₇₁to R₇₈and R₈₁to R₈₉may be each independently selected from:

i) a hydrogen, a deuterium, a halogen atom, a cyano group, a nitro group, a C₁-C₆₀alkyl group, and a C₆-C₆₀aryl group;

ii) a C₁-C₆₀alkyl group substituted with at least one of a hydrogen, a deuterium, a halogen atom, a cyano group, and a nitro group; and

iii) a C₆-C₆₀aryl group substituted with at least one of a hydrogen, a deuterium, a halogen atom, a cyano group, a nitro group, and a C₁-C₆₀alkyl group, but they are not limited thereto.

For example, in Formula 2, R₇₁to R₇₈and R₈₁to R₈₉may be each independently selected from a hydrogen, a deuterium, —F, a cyano group, a nitro group, a methyl group, an ethyl group, a tert-butyl group, a phenyl group, and a naphthyl group, but they are not limited thereto.

In Formula 2, Ar₁may be selected from:

i) a C₆-C₆₀aryl group and a C₂-C₆₀heteroaryl group; and

ii) a C₆-C₆₀aryl group and a C₂-C₆₀heteroaryl group, each substituted with at least one of a deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid or a salt thereof, 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 C₃-C₁₀cycloalkenyl group, a substituted or unsubstituted C₃-C₁₀heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀aryl group, a substituted or unsubstituted C₆-C₆₀aryloxy group, a substituted or unsubstituted C₆-C₆₀arylthio group, and a substituted or unsubstituted C₂-C₆₀heteroaryl group.

For example, in Formula 2, Ar₁may be selected from:

i) a C₆-C₆₀aryl group and a C₂-C₆₀heteroaryl group; and

ii) a C₆-C₆₀aryl group and a C₂-C₆₀heteroaryl group, each substituted with at least one of a deuterium, a halogen atom, a cyano group, a nitro group, a C₁-C₆₀alkyl group, and a C₆-C₆₀aryl group, but they are not limited thereto.

For example, in Formula 2, Ar₁may be selected from:

i) a phenyl group, a naphthyl group, an anthryl group, a fluorenyl group, a pyridyl group, a pyrimidyl group, a pyrazinyl group, a triazinyl group, and a carbazole group; and

In an implementation, the carbazole-based compound represented by Formula 2 may be represented by Formula 2A, but it is not limited thereto:

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In Formula 2A,

X may be a B atom, an N atom, or a P atom;

R₇₁, R₈₁, and R₈₂may be each independently selected from a hydrogen, a deuterium, —F, a cyano group, a nitro group, a methyl group, an ethyl group, a tert-butyl group, a phenyl group, and a naphthyl group;

Ar₁may be selected from:

i) a phenyl group, a naphthyl group, an anthryl group, a fluorenyl group, a pyridyl group, a pyrimidyl group, a pyrazinyl group, a triazinyl group, and a carbazole group; and

For example, the carbazole-based compound represented by Formula 2 may include one of Compounds 21 to 42, but it is not limited thereto:

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The carbazole-based compound represented by Formula 2 may be synthesized by a suitable organic synthesis method. A synthesis method of the carbazole-based compound may be easily understood by referring to the Examples described below.

The HIL may further include a hole injection material. Examples of the hole injection material include N,N′-diphenyl-N,N′-bis-[4-(phenyl-m-tolyl-amino)-phenyl]-biphenyl-4,4′-diamine (DNTPD), a phthalocyanine compound such as copper phthalocyanine, 4,4′,4″-tris(3-methylphenylphenylamino)triphenylamine (m-MTDATA), N,N′-di(1-naphthyl)-N,N′-diphenylbenzidine (NPB), TDATA, 2-TNATA, polyaniline/dodecylbenzenesulfonic acid (Pani/DBSA), poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate (PEDOT/PSS), polyaniline/camphor sulfonic acid (pani/CSA), or (polyaniline)/poly(4-styrenesulfonate) (PANI/PSS):

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At least one of the HIL, the HTL, and the H-functional layer may further include a carbazole derivative, such as N-phenylcarbazole or polyvinylcarbazole, N,N′-bis(3-methylphenyl)-N,N′-diphenyl-[1,1-biphenyl]-4,4′-diamine (TPD), 4,4′,4″-tris(N-carbazolyl)triphenylamine (TCTA), N,N′-di(1-naphthyl)-N,N′-diphenylbenzidine (NPB), or the like, but it is not limited thereto.

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At least one of the HIL, the HTL, and the H-functional layer may further include a charge-generating material in addition to the hole injection material, a hole transport material, and a material having hole injection and/or hole transport capabilities to improve conductivity of a film or the like.

The charge-generating material may be, for example, a p-dopant. The p-dopant may be one of quinone derivatives, metal oxides, and compounds with a cyano group, but the p-dopant is not limited thereto. For example, non-limiting examples of the p-dopant are quinone derivatives, such as tetracyanoquinodimethane (TCNQ), and 2,3,5,6-tetrafluoro-tetracyano-1,4-benzoquinodimethane (F4-TCNQ); metal oxides such as tungsten oxides and molybdenym oxides; and cyano group-containing compounds, such as Compound 200 below, but the p-dopant is not limited thereto.

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When the HIL, the HTL, or the H-functional layer further includes the charge-generating material, the charge-generating material may be homogeneously or non-homogeneously dispersed in the HIL, the HTL, or the H-functional layer.

A buffer layer may be between at least one of the HIL, the HTL, and the H-functional layer and the EML. The buffer layer may help compensate for an optical resonance distance of light according to a wavelength of the light emitted from the EML, and thus may increase efficiency. The buffer layer may include a suitable hole injecting material or hole transporting material. In an implementation, the buffer layer may include the same material as one of the materials included in the HIL, the HTL, and the H-functional layer that underlie the buffer layer.

Then, the EML may be formed on the hole transport region by vacuum deposition, spin coating, casting, LB deposition, or the like. When the EML is formed using vacuum deposition or spin coating, the deposition and coating conditions may be similar to those for the formation of the HIL, though the conditions for deposition and coating may vary according to the material that is used to form the EML.

As the host, Alq3, 4,4′-N,N′-dicarbazol-biphenyl (CBP), poly(n-vinylcarbazole) (PVK), 9,10-di(naphthalen-2-yl)anthracene (ADN), TCTA, 1,3,5-tris(N-phenylbenzimidazole2-yl)benzene (TPBI), 3-tert-butyl-9,10-di(naphth-2-yl)anthracene (TBADN), mCP, OXD-7, or the like may be used, but the host is not limited thereto.

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In an implementation, a carbazole-based compound represented by Formula 10, below, may be used as the host:

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In Formula 10, Ar₁may be selected from a substituted or unsubstituted C₁-C₆₀alkylene group, a substituted or unsubstituted C₂-C₆₀alkenylene group, —C(═O)—, —N(R₁₀₀)- (wherein, R₁₀₀is a substituted or unsubstituted C₆-C₆₀aryl group or a substituted or unsubstituted C₂-C₆₀heteroaryl group), a substituted or unsubstituted C₆-C₆₀arylene group, or a substituted or unsubstituted C₂-C₆₀heteroarylene group; p is an integer selected from 0 to 10; R₉₁to R₉₆may be each independently selected from a hydrogen, a deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid or a salt thereof, 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 C₃-C₁₀cycloalkenyl group, a substituted or unsubstituted C₃-C₁₀heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀aryl group, a substituted or unsubstituted C₆-C₆₀aryloxy group, a substituted or unsubstituted C₆-C₆₀arylthio group, or a substituted or unsubstituted C₂-C₆₀heteroaryl group, wherein two neighboring substituents of R₉₁to R₉₆bind to each other to selectively form a substituted or unsubstituted C_4-C₂₀alicyclic ring, a substituted or unsubstituted C₂-C₂₀heteroalicyclic ring, a substituted or unsubstituted C₆-C₂₀aromatic ring, or a substituted or unsubstituted C₂-C₂₀heteroaromatic ring; and q, r, s, t, u, and v may be each independently an integer selected from 1 to 4.

In Formula 10, Ar₁may be a C₁-C₅alkylene group, a C₂-C₅alkenylene group, —C(═O)—, or —N(R₁₀₀)-. In this regard, R₁₀₀may be any one selected from a phenyl group, a naphthyl group, an anthryl group, a fluorenyl group, a carbazolyl group, a pyridinyl group, a pyrimidinyl group, and a triazinyl group; a phenyl group, a naphthyl group, an anthryl group, a fluorenyl group, a carbazolyl group, a pyridinyl group, a pyrimidinyl group, and a triazinyl group, each substituted with at least one of a deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, a C₁-C₂₀alkyl group, a C₁-C₂₀alkoxy group, a phenyl group, a naphthyl group, an anthryl group, a fluorenyl group, a carbazolyl group, a pyridinyl group, a pyrimidinyl group, and a triazinyl group.

In Formula 10, R₉₁to R₉₆may be each independently any one of a hydrogen, a deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid or a salt thereof, a C₁-C₂₀alkyl group, and a C₁-C₂₀alkoxy group; and a C₁-C₂₀alkyl group and a C₁-C₂₀alkoxy group, each substituted with at least one of a deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, and an amino group.

The carbazole-based compound represented by Formula 10 may include one of the compounds below, but it is not limited thereto.

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The EML may include at least one of the compounds above. The organometallic compound included in the EML may act as a dopant (for example, a green phosphorescent dopant). In this regard, the EML may further include a host in addition to the organometallic compound.

The organometallic compound may be represented by Formula 1, below.

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In Formula 1, R₁may be selected from a deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid or a salt thereof, 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 C₃-C₁₀cycloalkenyl group, a substituted or unsubstituted C₃-C₁₀heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀heterocycloalkenyl group, a substituted or unsubstituted C₆-C₃₀aryl group, a substituted or unsubstituted C₆-C₃₀aryloxy group, a substituted or unsubstituted C₆-C₃₀arylthio group, a substituted or unsubstituted C₂-C₃₀heteroaryl group, —N(Q₁)(Q₂), —C(═O)(Q₃), and —Si(Q₄)(Q₅)(Q₆) (wherein, Q₁to Q₆may be each independently a hydrogen, a substituted or unsubstituted C₁-C₆₀alkyl group, a substituted or unsubstituted C₁-C₆₀alkoxy group, a substituted or unsubstituted C₆-C₃₀aryl group, or a substituted or unsubstituted C₂-C₃₀heteroaryl group); and

R₂to R₆may be each independently selected from a hydrogen, a deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid or a salt thereof, 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 C₃-C₁₀cycloalkenyl group, a substituted or unsubstituted C₃-C₁₀heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀heterocycloalkenyl group, a substituted or unsubstituted C₆-C₃₀aryl group, a substituted or unsubstituted C₆-C₃₀aryloxy group, a substituted or unsubstituted C₆-C₃₀arylthio group, a substituted or unsubstituted C₂-C₃₀heteroaryl group, —N(Q₁)(Q₂), —C(═O)(Q₃), and —Si(Q₄)(Q₅)(Q₆) (wherein, Q₁to Q₆are each independently a hydrogen, a substituted or unsubstituted C₁-C₆₀alkyl group, a substituted or unsubstituted C₁-C₆₀alkoxy group, a substituted or unsubstituted C₆-C₃₀aryl group, or a substituted or unsubstituted C₂-C₃₀heteroaryl group).

For example, in Formula 1, R₁may be selected from a deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid or a salt thereof, a C₁-C₂₀alkyl group, and a C₁-C₂₀alkoxy group;

a C₁-C₂₀alkyl group and a C₁-C₂₀alkoxy group, each substituted with at least one of a deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, and a phosphoric acid or a salt thereof;

a C₆-C₁₄aryl group and a C₂-C₁₄heteroaryl group;

a C₆-C₁₄aryl group and a C₂-C₁₄heteroaryl group, each substituted with at least one of a deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid or a salt thereof, a C₁-C₂₀alkyl group, a C₁-C₂₀alkoxy group, a C₆-C₁₄aryl group, and a C₂-C₁₄heteroaryl group;

—N(Q₁)(Q₂); and —C(═O)(Q₃);

a C₆-C₁₄aryl group and a C₂-C₁₄heteroaryl group;

—N(Q₁)(Q₂); and —C(═O)(Q₃), wherein Q₁to Q₃may be each independently selected from a hydrogen, a C₁-C₂₀alkyl group, and a C₁-C₂₀alkoxy group;

a C₆-C₁₄aryl group and a C₂-C₁₄heteroaryl group; and

a C₆-C₁₄aryl group and a C₂-C₁₄heteroaryl group, each substituted with at least one of a deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid or a salt thereof, and a C₁-C₂₀alkyl group, a C₁-C₂₀alkoxy group, a C₆-C₁₄aryl group, and a C₂-C₁₄heteroaryl group, each substituted with at least one F.

In an implementation, in Formula 1, R₁may be selected from

i) a deuterium, —F, —Cl, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid or a salt thereof, a methyl group, an ethyl group, a propyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, a sec-pentyl group, a tert-pentyl group, an n-hexyl group, an isohexyl group, a sec-hexyl group, a tert-hexyl group, an n-heptyl group, an isoheptyl group, a sec-heptyl group, a tert-heptyl group, an n-octyl group, an isoctyl group, a sec-octyl group, a tert-octyl group, an n-nonenyl group, an isononenyl group, a sec-nonenyl group, a tert-nonenyl group, an n-decanyl, an isodecanyl, a sec-decanyl, and a tert-decanyl;

ii) a methyl group, an ethyl group, a propyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, a sec-pentyl group, a tert-pentyl group, an n-hexyl group, an isohexyl group, a sec-hexyl group, a tert-hexyl group, an n-heptyl group, an isoheptyl group, a sec-heptyl group, a tert-heptyl group, an n-octyl group, an isoctyl group, a sec-octyl group, a tert-octyl group, an n-nonenyl group, an isononenyl group, a sec-nonenyl group, a tert-nonenyl group, an n-decanyl, an isodecanyl, a sec-decanyl, and a tert-decanyl, each substituted with at least one of a deuterium, —F, —Cl, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, and a phosphoric acid or a salt thereof;

iii) a phenyl group, a naphthyl group, an anthryl group, a pyrenyl group, a phenanthrenyl group, a fluorenyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a triazinyl group, a quinolinyl group, an isoquinolinyl group, a quinoxalinyl group, a phenanthrolinyl group, and a carbazolyl group;

iv) a phenyl group, a naphthyl group, an anthryl group, a pyrenyl group, a phenanthrenyl group, a fluorenyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a triazinyl group, a quinolinyl group, an isoquinolinyl group, a quinoxalinyl group, a phenanthrolinyl group, and a carbazolyl group, each substituted with at least one of a deuterium, —F, —Cl, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid or a salt thereof, a C₁-C₂₀alkyl group, a C₁-C₂₀alkoxy group, a phenyl group, a naphthyl group, an anthryl group, a pyrenyl group, a phenanthrenyl group, a fluorenyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a triazinyl group, a quinolinyl group, an isoquinolinyl group, a quinoxalinyl group, a phenanthrolinyl group, and a carbazolyl group;

v) —N(Q₁)(Q₂); and

vi) —C(═O)(Q₃).

R₂to R₆may be each independently selected from:

i) a hydrogen, a deuterium, —F, —Cl, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid or a salt thereof, a methyl group, an ethyl group, a propyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, a sec-pentyl group, a tert-pentyl group, an n-hexyl group, an isohexyl group, a sec-hexyl group, a tert-hexyl group, an n-heptyl group, an isoheptyl group, a sec-heptyl group, a tert-heptyl group, an n-octyl group, an isoctyl group, a sec-octyl group, a tert-octyl group, an n-nonenyl group, an isononenyl group, a sec-nonenyl group, a tert-nonenyl group, an n-decanyl, an isodecanyl, a sec-decanyl, and a tert-decanyl;

v) —N(Q₁)(Q₂); and

vi) —C(═O)(Q₃), wherein

Q₁to Q₃may be each independently selected from:

i) a methyl group, an ethyl group, a propyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, a sec-pentyl group, a tert-pentyl group, an n-hexyl group, an isohexyl group, a sec-hexyl group, a tert-hexyl group, an n-heptyl group, an isoheptyl group, a sec-heptyl group, a tert-heptyl group, an n-octyl group, an isoctyl group, a sec-octyl group, a tert-octyl group, an n-nonenyl group, an isononenyl group, a sec-nonenyl group, a tert-nonenyl group, an n-decanyl, an isodecanyl, a sec-decanyl, and a tert-decanyl;

iv) a phenyl group, a naphthyl group, an anthryl group, a pyrenyl group, a phenanthrenyl group, a fluorenyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a triazinyl group, a quinolinyl group, an isoquinolinyl group, a quinoxalinyl group, a phenanthrolinyl group, and a carbazolyl group, each substituted with at least one of a deuterium, —F, —Cl, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid or a salt thereof, and a C₁-C₂₀alkyl group (for example, —CF₃or the like) substituted with at least one —F, a C₁-C₂₀alkoxy group, a phenyl group, a naphthyl group, an anthryl group, a pyrenyl group, a phenanthrenyl group, a fluorenyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a triazinyl group, a quinolinyl group, an isoquinolinyl group, a quinoxalinyl group, a phenanthrolinyl group, and a carbazolyl group.

For example, in Formula 1, R₁may be selected from a methyl group, an ethyl group, a propyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, a sec-pentyl group, a tert-pentyl group, an n-hexyl group, an isohexyl group, a sec-hexyl group, a tert-hexyl group, an n-heptyl group, an isoheptyl group, a sec-heptyl group, a tert-heptyl group, an n-octyl group, an isoctyl group, a sec-octyl group, a tert-octyl group, an n-nonenyl group, an isononenyl group, a sec-nonenyl group, a tert-nonenyl group, an n-decanyl group, an isodecanyl group, a sec-decanyl group, a tert-decanyl group, and —N(Q₁)(Q₂), wherein Q₁and Q₂may be each independently selected from a methyl group, an ethyl group, a propyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, a sec-pentyl group, a tert-pentyl group, an n-hexyl group, an isohexyl group, a sec-hexyl group, a tert-hexyl group, an n-heptyl group, an isoheptyl group, a sec-heptyl group, a tert-heptyl group, an n-octyl group, an isoctyl group, a sec-octyl group, a tert-octyl group, an n-nonenyl group, an isononenyl group, a sec-nonenyl group, a tert-nonenyl group, an n-decanyl group, an isodecanyl group, a sec-decanyl group, and a tert-decanyl group;

a phenyl group, a naphthyl group, an anthryl group, a pyrenyl group, a phenanthrenyl group, and a fluorenyl group; and

a phenyl group, a naphthyl group, an anthryl group, a pyrenyl group, a phenanthrenyl group, and a fluorenyl group, each substituted with at least one of a deuterium, —F, —Cl, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid or a salt thereof, a C₁-C₂₀alkyl group, a C₁-C₂₀alkoxy group, a phenyl group, a naphthyl group, an anthryl group, a pyrenyl group, a phenanthrenyl group, a fluorenyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a triazinyl group, a quinolinyl group, an isoquinolinyl group, a quinoxalinyl group, a phenanthrolinyl group, and a carbazolyl group.

In an implementation, in Formula 1, R₂may be selected from a hydrogen, a halogen atom, a cyano group, and a nitro group; a C₁-C₆₀alkyl group substituted with at least one halogen atom; a C₆-C₃₀aryl group, and a C₂-C₃₀heteroaryl group, each substituted with at least one halogen atom; and —C(═O)(Q₃); wherein Q₃is a C₁-C₆₀alkyl group substituted with at least one halogen atom; and a C₆-C₃₀aryl group and a C₂-C₃₀heteroaryl group, each substituted with a halogen atom and a C₁-C₂₀alkyl group substituted with at least one halogen atom.

For example, in Formula 1, R₂may be selected from a hydrogen, —F, —Cl, a cyano group, and a nitro group;

a methyl group, an ethyl group, a propyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, a sec-pentyl group, a tert-pentyl group, an n-hexyl group, an isohexyl group, a sec-hexyl group, a tert-hexyl group, an n-heptyl group, an isoheptyl group, a sec-heptyl group, a tert-heptyl group, an n-octyl group, an isoctyl group, a sec-octyl group, a tert-octyl group, an n-nonenyl group, an isononenyl group, a sec-nonenyl group, a tert-nonenyl group, an n-decanyl group, an isodecanyl group, a sec-decanyl group, and a tert-decanyl group, each substituted with at least one F;

a phenyl group, a naphthyl group, an anthryl group, a pyrenyl group, a phenanthrenyl group, a fluorenyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a triazinyl group, a quinolinyl group, an isoquinolinyl group, a quinoxalinyl group, a phenanthrolinyl group, and a carbazolyl group, each substituted with at least one F; and —(═O)(Q₃);

wherein Q₁to Q₃are each independently a methyl group, an ethyl group, a propyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, a sec-pentyl group, a tert-pentyl group, an n-hexyl group, an isohexyl group, a sec-hexyl group, a tert-hexyl group, an n-heptyl group, an isoheptyl group, a sec-heptyl group, a tert-heptyl group, an n-octyl group, an isoctyl group, a sec-octyl group, a tert-octyl group, an n-nonenyl group, an isononenyl group, a sec-nonenyl group, a tert-nonenyl group, an n-decanyl, an isodecanyl, a sec-decanyl, and a tert-decanyl, each substituted with at least one F; a phenyl group, a naphthyl group, an anthryl group, a pyrenyl group, a phenanthrenyl group, a fluorenyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a triazinyl group, a quinolinyl group, an isoquinolinyl group, a quinoxalinyl group, a phenanthrolinyl group, and a carbazolyl group, each substituted with F and a C₁-C₂₀alkyl group substituted with at least one F.

In Formula 1, R₃may be a hydrogen.

In Formula 1, a represents the number of R₄s, wherein a is an integer selected from 1 to 3 and when a is 2 or greater, two or more R₄s may be the same or different.

In Formula 1, b and c may be each independently an integer selected from 1 to 6 and when b is 2 or greater, two or more R₅s may be the same or different and when c is 2 or greater, two or more R₆s may be the same or different. b represents the number of R₅s, and R₅is a substituent of ring A in Formula 1. When R₅is a hydrogen, ring A in Formula 1 may be an unsubstituted ring. c represents the number of R₆s, wherein R₆is a substituent of ring B in Formula 1. When R₆is a hydrogen, ring B in Formula 1 may be an unsubstituted ring.

In Formula 1, A may form a ring structure selected from a pyrrole, an imidazole, a pyrazole, a triazole, a thiazole, an oxazole, an isothiazole, an isoxazole, a benzothiazole, a benzimidazole, a benzoxazole, a pyridine, a pyrazine, a pyrimidine, a pyridazine, an isoindole, an indole, an indazole, a purine, an isoquinoline, a quinoline, a phthalazine, a naphthyridine, a quinoxaline, a quinazoline, a cinnoline, a phenanthridine, an acridine, a phenanthroline, a phenazine, and a phenoxazine. For example, N and X₁in Formula 1 may be included in the ring structure of A.

In Formula 1, B may form a ring structure selected from a benzene, a pentalene, an indene, a naphtalene, an azulene, a heptalene, an indacene, an acenaphthylene, a fluorene, a spiro-fluorene, a phenalene, a phenanthrene, an anthracene, a fluoranthene, a triphenylene, a pyrene, a chrysene, a pyrrole, an imidazole, a pyrazole, a triazole, an isothiazole, an isoxazole, a pyridine, a pyrazine, a pyrimidine, a pyridazine, an isoindole, an indole, an indazole, a purine, an isoquinoline, a quinoline, a phthalazine, a naphthyridine, a quinoxaline, a quinazoline, a cinnoline, a phenanthridine, an acridine, a phenanthroline, a phenazine, and a phenoxazine. For example, C and X₂in Formula 1 may be included in the ring structure of B.

For example, in Formula 1, A may form a pyridine, a pyrimidine, a pyrazine, or a pyrazole, but it is not limited thereto. In an implementation, in Formula 1, A may form a pyridine or a pyrazole.

In Formula 1, B may form a benzene or a naphthalene, but it is not limited thereto. In an implementation, B may form a benzene, but it is not limited thereto.

In Formula 1, X₁and X₂may be each independently N or C. According to an embodiment, X₁may be each independently N or C, and X₂may be C.

In an implementation, the organometallic compound represented by Formula 1 may be represented by Formula 1A, below:

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In Formula 1A, descriptions of R₁R₂, R₄to R₆, a, b, c, A, B, X₁, X₂and n are the same as described herein.

In an implementation, the organometallic compound represented by Formula 1 may be represented by Formula 1B or 1C, but it is not limited thereto:

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In Formulae 1B and 1C, descriptions of R₁, R₂, R₄to R₆, a, b, c, and n are the same as described herein.

For example, in Formulae 1B and 1C, R₁may be a deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid or a salt thereof, a C₁-C₂₀alkyl group, and a C₁-C₂₀alkoxy group;

a C₁-C₂₀alkyl group and a C₁-C₂₀group, each substituted with at least one of a deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, and a phosphoric acid or a salt thereof;

a C₆-C₁₄aryl group and a C₂-C₁₄heteroaryl group;

—C(═O)(Q₃);

R₂and R₄to R₆may be each independently selected from a hydrogen, a deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid or a salt thereof, a C₁-C₂₀alkyl group, and a C₁-C₂₀alkoxy group;

a C₆-C₁₄aryl group and a C₂-C₁₄heteroaryl group;

—N(Q₁)(Q₂); and —C(═O)(Q₃),

wherein Q₁to Q₃may be each independently selected from:

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

a C₆-C₁₄aryl group and a C₂-C₁₄heteroaryl group; and

a C₆-C₁₄aryl group and a C₂-C₁₄heteroaryl group, each substituted with at least one of a deuterium, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid or a salt thereof, and a C₁-C₂₀alkyl group, a C₁-C₂₀alkyl group, a C₁-C₂₀alkoxy group, a C₆-C₁₄aryl group, and a C₂-C₁₄heteroaryl group, each substituted with at least one F;

a, b and c may be each independently an integer of 1 to 3 and when a is 2 or greater, two or more R₄s may be the same or different, when b is 2 or greater, two or more R₅s may be the same or different, and when c is 2 or greater, two or more R₆s may be the same or different, and n may be 1 or 2.

In an implementation, in Formulae 1B and 1C, R₁may be selected from a methyl group, an ethyl group, a propyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, a sec-pentyl group, a tert-pentyl group, an n-hexyl group, an isohexyl group, a sec-hexyl group, a tert-hexyl group, an n-heptyl group, an isoheptyl group, a sec-heptyl group, a tert-heptyl group, an n-octyl group, an isoctyl group, a sec-octyl group, a tert-octyl group, an n-nonenyl group, an isononenyl group, a sec-nonenyl group, a tert-nonenyl group, an n-decanyl, an isodecanyl, a sec-decanyl, a tert-decanyl, and —N(Q₁)(Q₂),

R₂may be selected from a hydrogen, —F, —Cl, a cyano group, and a nitro group;

a methyl group, an ethyl group, a propyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, a sec-pentyl group, a tert-pentyl group, an n-hexyl group, an isohexyl group, a sec-hexyl group, a tert-hexyl group, an n-heptyl group, an isoheptyl group, a sec-heptyl group, a tert-heptyl group, an n-octyl group, an isoctyl group, a sec-octyl group, a tert-octyl group, an n-nonenyl group, an isononenyl group, a sec-nonenyl group, a tert-nonenyl group, an n-decanyl, an isodecanyl, a sec-decanyl and a tert-decanyl, each substituted with at least one F;

The organometallic compound represented by Formula 1 may include one of Compounds 1 to 16, but it is not limited thereto.

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The organometallic compound represented by Formula 1 may be synthesized by a suitable organic synthesis method. A synthesis method of the organometallic compound may be easily understood by referring to the Examples described below.

When the EML includes a host and a dopant (the organometallic compound represented by Formula 1), an amount of the dopant may be selected from a range of about 0.01 wt % to about 15 wt %, based on 100 wt % of the EML, but the amount is not limited thereto.

A thickness of the EML may be about 200 Å to about 700 Å. When the thickness of the EML is in the range described above, the EML may have excellent light emitting ability without a substantial increase in driving voltage.

Meanwhile, when the organic light-emitting device is a full color organic light-emitting device, the EML may be patterned into a red EML, a green EML, and a blue EML, according to a red subpixel, a green subpixel, and a blue subpixel, respectively. In this regard, the blue EML may include the organometallic compound represented by Formula 1 as a dopant.

Meanwhile, the EML may have a multi-layered structure in which the red EML, the green EML, and the blue EML are layered to emit white light or a single-layered structure simultaneously including a red emission material, a green emission material, and a blue emission material. The organic light-emitting device including the EML further includes a red color filter, a green color filter, and a blue color filter to emit full colors.

Then, the ETL is formed an the EML by various methods such as vacuum deposition, spin coating, or casting. When the ETL is formed by vacuum deposition or spin coating, the deposition and coating conditions may be similar to those for forming the HIL, though the deposition and coating conditions may vary according to a compound that is used to form the ETL.

An electron-transporting material may be any suitable electron-transporting material that may stably transport electrons injected from an electron injection electrode (cathode). Non-limiting examples of the electron-transporting material are quinoline derivatives, such as tris(8-quinolinorate)aluminum (Alq3), TAZ, BAlq, beryllium bis(benzoquinolin-10-olate) (Bebq2), 9,10-di(naphthalene-2-yl)anthracene (ADN), Compound 101, Compound 102, and Bphen, but they are not limited thereto.

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A thickness of the ETL may be from about 100 Å to about 1,000 Å, and in some embodiments, may be from about 150 Å to about 500 Å. When the thickness of the ETL is within these ranges, the ETL may have a satisfactory electron transporting ability without a substantial increase in driving voltage.

In an implementation, the ETL may further include a metal-containing material in addition to any suitable electron-transporting organic compound.

The metal-containing material may include a Li complex. Non-limiting examples of the Li complex are lithium quinolate (LiQ) and Compound 203 below:

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Then, the EIL, which facilitates the injection of electrons from the cathode, may be formed on the ETL. Any suitable electron-injecting material may be used to form the EIL.

Non-limiting examples of the materials for forming the EIL are an EIL material such as LiF, NaCl, CsF, Li₂O, and BaO. The deposition conditions for forming the EIL may be similar to those for the formation of the HIL, though the deposition conditions may vary according to the compound that is used to form the EIL.

A thickness of the EIL may be from about 1 Å to about 100 Å, and in some embodiments, may be from about 3 Å to about 90 Å. When, the thickness of the EIL is within these ranges, the EIL may have a satisfactory electron injection ability without a substantial increase in driving voltage.

The second electrode 17 may be on the organic layer 15. The second electrode 17 may be a cathode that is an electron injection electrode, wherein a material for forming the second electrode 17 may include a metal, an alloy, and an electro-conductive compound, which have a low work function, or a mixture thereof. In this regard, the second electrode 17 may be formed of lithium (Li), magnesium (Mg), aluminum (Al), aluminum lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In), magnesium-silver (Mg—Ag), or the like, which may be formed as a thin film type transmission electrode. In some embodiments, to manufacture a top-emission light-emitting device, the transmission electrode may be formed of ITO or IZO.

Although the organic light-emitting device 10 of FIG. 1 is described above, the embodiments are not limited thereto.

When a phosphorescent dopant is used in the EML, the HBL may be formed between the ETL and the EML by using vacuum deposition, spin coating, casting, LB deposition, or the like, in order to prevent diffusion of triplet excitons or holes into the ETL. When the HBL is formed by using vacuum deposition or spin coating, the conditions for deposition and coating may be similar to those for the formation of the HIL, although the conditions for deposition and coating may vary according to the compound that is used to form the HBL. A suitable hole-blocking material may be used, and non-limiting examples of the hole-blocking material include oxadiazole derivatives, triazole derivatives, phenanthroline derivatives, or the like. In some embodiments, BCP shown below may be used as a hole-blocking material.

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A thickness of the HBL may be from about 20 Å to about 1,000 Å, and in some embodiments, may be from about 30 Å to about 300 Å. When the thickness of the HBL is within these ranges, the HBL may have an improved hole blocking ability without a substantial increase in driving voltage.

The organometallic compound represented by Formula 1 may include a first fluorine and a second fluorine (as may be seen in Formula 1′, below), and thus, an electron density of a benzene ring (that is combined with or bound to the first fluorine and the second fluorine) may become low. As a result, light emitted by the organometallic compound may have a short wavelength shift, e.g., the light may be blue shifted light. Also, ligands of the organometallic compound may easily trap electrons and thus, a great amount of excitons may be formed with holes that are injected into the EML. As a result, the organic light-emitting device including the organometallic compound may have high emission efficiency.

A pyridine ring (among the ligands) may include an R₁substituent, which may include an alkyl group or the like, such that the electron density of the pyridine ring may be adjusted, and thus, emission color may be easily moved to a short wavelength or a long wavelength and an amount of electrons or holes trapped may be adjusted, such that the organic light-emitting device including the organometallic compound may have high emission efficiency.

In an implementation, when R₂in Formula 1′ is an electron withdrawing group, the electron density of the benzene ring bound to R₂may be further lowered. As a result, light emitted from the organometallic compound may have a short wavelength shift, e.g., blue shifted light. Also, the ligands of the organometallic compound may easily trap electrons and thus, a great amount of excitons may be formed along with holes injected into the EML. As a result, the organic light-emitting device including the organometallic compound may have high emission efficiency.

Accordingly, the organometallic compound represented by Formula 1 may emit light of variously tuned colors and may simultaneously provide high emission efficiency.

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The carbazole-based compound represented by Formula 2 may stably inject and transport holes to lower a driving voltage of the organic light-emitting device 10.

The organometallic compound represented by Formula 1 and the carbazole-based compound represented by Formula 2 may have each of the HOMO and LUMO energy levels adjusted to facilitate the movement of charges from the hole transport region to the EML. Accordingly, more charges may move from the hole transport region to the EML in the organic light-emitting device 10. Accordingly, as more excitons are formed due to a combination of the holes and the electrons in the EML, the efficiency and brightness of the organic light-emitting device 10 may increase.

The unsubstituted C₁-C₆₀alkyl group (or a C₁-C₆₀alkyl group) used herein may be a linear or branched C₁-C₆₀alkyl group, such as methyl, ethyl, propyl, isobutyl sec-butyl, pentyl, iso-amyl, or hexyl, wherein the substituted C₁-C₆₀alkyl group refers to the unsubstituted C₁-C₆₀alkyl group in which at least one hydrogen atom is substituted with a deuterium; —F; —Cl; —Br; —I; —CN; a hydroxyl group; —NO₂; an amino group; an amidino group; a hydrazine group; a hydrazone group; a carboxyl group or a salt thereof; a sulfonic acid group or a salt thereof; a phosphoric acid or a salt thereof; tri(C₆-C₆₀aryl)silyl;

a C₁-C₆₀alkyl group, a C₁-C₆₀alkoxy group, a C₂-C₆₀alkenyl group, and a C₂-C₆₀alkynyl group;

a C₁-C₆₀alkyl group, a C₁-C₆₀alkoxy group, a C₂-C₆₀alkenyl group, and a C₂-C₆₀alkynyl group, each substituted with at least one of a deuterium, —F, —Cl, —Br, —I, —CN, a hydroxyl group, —NO₂, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, and a phosphoric acid or a salt thereof;

a C₃-C₆₀cycloalkyl group, a C₃-C₆₀cycloalkenyl group, a C₆-C₆₀aryl group, a C₂-C₆₀heteroaryl group, a C₆-C₆₀aralkyl group, a C₆-C₆₀aryloxy group, and a C₆-C₆₀arylthio group, each substituted with a deuterium, —F, —Cl, —Br, —I, —CN, a hydroxyl group, —NO₂, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid or a salt thereof, C₁-C₆₀alkyl group, and a C₁-C₆₀alkyl group, a C₁-C₆₀alkoxy group, a C₂-C₆₀alkenyl group, a C₂-C₆₀alkynyl group, a C₆-C₆₀aryl group, and a C₂-C₆₀heteroaryl group, each substituted with at least one F.

The unsubstituted C₁-C₆₀alkoxy group (or C₁-C₆₀alkoxy group) used herein has a formula of —OA (where A is the unsubstituted C₁-C₆₀alkyl group described above), and detailed examples thereof are methoxy, ethoxy, and isopropyloxy, and at least one hydrogen atom of these alkoxy groups may be substituted with the same substituent as described above in connection with the substituted C₁-C₆₀alkyl group.

The unsubstituted C₂-C₆₀alkenyl group (or C₂-C₆₀alkenyl group) used herein refers to an unsubstituted C₂-C₆₀alkyl group having one or more carbon-carbon double bonds at a center or end thereof. Examples of the unsubstituted C₂-C₆₀alkenyl group are ethenyl, propenyl, and butenyl. At least one hydrogen atom of these unsubstituted C₂-C₆₀alkenyl groups may be substituted with the same substituent as described above in connection with the substituted C₁-C₆₀alkyl group.

The unsubstituted C₂-C₆₀alkynyl group (or C₂-C₆₀alkynyl group) used herein refers to an unsubstituted C₂-C₆₀alkyl group having one or more carbon-carbon triple bonds at a center or end thereof. Examples of the unsubstituted C₂-C₆₀alkynyl group are ethynyl, propynyl, and the like. At least one hydrogen atom of these alkynyl groups may be substituted with the same substituent as described above in connection with the substituted C₁-C₆₀alkyl group.

The unsubstituted C₃-C₆₀cycloaryl group is a monovalent saturated cyclic hydrocarbon group having 3 to 60 carbon atoms, and detailed examples thereof include a cyclopropyl, a cyclobutyl, a cyclopentyl, a cyclohexyl, a cyclooctyl, or the like. At least one hydrogen atom of the unsubstituted C₃-C₆₀cycloaryl group may be substituted with the same substituent as described above in connection with the substituted C₁-C₆₀alkyl group.

The unsubstituted C₃-C₆₀cycloalkenyl group refers to a ring-type unsaturated hydrocarbon group that has at least one carbon-carbon double bond, but that is not an aromatic ring, wherein examples thereof include a cyclopropenyl, a cyclobutenyl, a cyclopentenyl, a cyclohexenyl, a cycloheptenyl, a 1,3-cyclohexadienyl group, a 1,4-cyclohexadienyl group, a 2,4-cycloheptadienyl group, and a 1,5-cyclooctadienyl group. At least one hydrogen atom of the cycloalkenyl group may be substituted with the same substituent as described above in connection with the substituted C₁-C₆₀alkyl group.

The unsubstituted C₆-C₆₀aryl group is a monovalent group having a carbocyclic aromatic system having 6 to 60 carbon atoms including at least one aromatic ring. The unsubstituted C₆-C₆₀arylene group is a divalent group having a carbocyclic aromatic system having 6 to 60 carbon atoms including at least one aromatic ring. When the aryl group and the arylene group include two or more rings, the rings may be fused to each other. At least one hydrogen atom of these aryl groups and arylene groups may be substituted with the same substituent as described above in connection with the substituted C₁-C₆₀alkyl group.

Examples of the substituted or unsubstituted C₆-C₆₀aryl group are a phenyl group, a C₁-C₁₀alkylphenyl group (for example, ethylphenyl group), a C₁-C₁₀alkylbiphenyl group (for example, ethylbiphenyl group), a halophenyl group (for example, an o-, m- or p-fluorophenyl group, a dichlorophenyl group), a dicyanophenyl group, a trifluoromethoxyphenyl group, o-, m-, and p-tolyl groups, o-, m- and p-cumenyl groups, a mesityl group, a phenoxyphenyl group, a (α,α-dimethylbenzene)phenyl group, a (N,N′-dimethyl)aminophenyl group, a (N,N′-diphenyl)aminophenyl group, a pentalenyl group, an indenyl group, a naphthyl group, a halonaphthyl group (for example, a fluoronaphthyl group), a C₁-C₁₀alkylnaphthyl group (for example, a methylnaphthyl group), a C₁-C₁₀alkoxynaphthyl group (for example, a methoxynaphthyl group), an anthracenyl group, a azulenyl group, a heptalenyl group, an acenaphthylenyl group, a phenalenyl group, a fluorenyl group, an anthraquinolinyl group, a methylanthryl group, a phenanthryl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, an ethyl-chrysenyl group, a picenyl group, a perylenyl group, a chloroperylenyl group, a pentaphenyl group, a pentasenyl group, a tetraphenylenyl group, a hexaphenyl group, a hexacenyl group, a rubicenyl group, a coroneryl group, a trinaphthylenyl group, a heptaphenyl group, a heptacenyl group, a pyranthrenyl group, and an ovalenyl group, and examples of the substituted C₆-C₆₀aryl group may be easily understood by referring to the examples of the unsubstituted C₆-C₆₀aryl group and the substituents of the substituted C₁-C₆₀alkyl group. Examples of the substituted or unsubstituted C₆-C₆₀arylene group may be easily understood by referring to examples of the substituted or unsubstituted C₆-C₆₀aryl group.

The unsubstituted C₂-C₆₀heteroaryl group used herein refers to a monovalent group having a system composed of one or more aromatic rings having at least one heteroatom selected from nitrogen (N), oxygen (O), phosphorous (P), and sulfur (S) and carbon atoms as the remaining ring atoms. The unsubstituted C₂-C₆₀heteroarylene group used herein refers to a divalent group having a system composed of one or more aromatic rings having at least one heteroatom selected from nitrogen (N), oxygen (O), phosphorous (P), and sulfur (S) and carbon atoms as the remaining ring atoms. In this regard, when the unsubstituted C₂-C₆₀heteroaryl group and the unsubstituted C₂-C₆₀heteroarylene group each include two or more rings, the rings may be fused to each other. At least one hydrogen atom of the unsubstituted C₂-C₆₀heteroaryl group and the unsubstituted C₂-C₆₀heteroarylene group may be substituted with the same substituent described in connection with the C₁-C₆₀alkyl group.

Examples of the unsubstituted C₂-C₆₀heteroaryl group are a pyrazolyl group, an imidazolyl group, an oxazolyl group, a thiazolyl group, a triazolyl group, a tetrazolyl, an oxadiazolyl group, a pyridinyl group, a pyridazinyl group, a pyrimidinyl group, a triazinyl group, a carbazolyl group, an iodolyl group, a quinolinyl group, an isoquinolinyl group, a benzimidazolyl group, an imidazopyridinyl group, and an imidazopyrimidinyl group. Examples of the unsubstituted C₂-C₆₀heteroarylene group may be easily understood by referring to the examples of the substituted or unsubstituted C₂-C₆₀arylene group.

The substituted or unsubstituted C₆-C₆₀aryloxy group indicates —OA₂(where A₂is the substituted or unsubstituted C₆-C₆₀aryl group), and the substituted or unsubstituted C₆-C₆₀arylthio group indicates —SA₃(where A₃is the substituted or unsubstituted C₆-C₆₀aryl group).

The following Examples and Comparative Examples are provided in order to highlight characteristics of one or more embodiments, but it will be understood that the Examples and Comparative Examples are not to be construed as limiting the scope of the embodiments, nor are the Comparative Examples to be construed as being outside the scope of the embodiments. Further, it will be understood that the embodiments are not limited to the particular details described in the Examples and Comparative Examples.

EXAMPLE
Synthesis Example 1
Synthesis of Compound 1

Synthesis of Intermediate 1(1)

Intermediate 1(1) was synthesized according to Reaction Scheme 1(1) below:

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3.6 g (17.3 mmol) of 2-(2,4-difluorophenyl)-4-methylpyridine was dissolved in 45 mL of 2-ethoxy ethanol and then 2.4 g (7.6 mmol) of iridium chloride hydrate and 15 mL of distilled water were added thereto, which was then stirred at a temperature of 130° C., for 20 hours to prepare a reaction solution. After the completion of the reaction, the reaction solution was cooled to room or ambient temperature and a precipitate was filtered therefrom, which was washed with methanol and then dried in a vacuum atmosphere to obtain Intermediate 1(1) (4.3 g, 60% yield).

Synthesis of Compound 1

Compound 1 was synthesized according to Reaction Scheme 1(2) below:

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1.0 g (1.03 mmol) of Intermediate 1(1), 0.38 g (2.44 mmol) of phenyl pyridine, and 0.34 g (2.46 mmol) of K₂CO₃were added to 30 mL of 2-ethoxy ethanol and then stirred at a temperature of 130° C. for 12 hours to prepare a reaction solution. After the completion of the reaction, the reaction solution was cooled to ambient temperature and a precipitate was filtered therefrom, which was then washed with methanol. The precipitate obtained therefrom was dissolved by using dichloromethane, a product obtained therefrom was filtered by using a silica short pad, a dichloromethane solution, filtered therefrom was boiled again, and methanol was gradually added thereto to precipitate and obtain Compound 1 (0.60 g, 53% yield).

¹H NMR: 8.56 (3H), 8.30 (1H), 7.97 (3H), 7.53 (4H), 7.00 (7H), 2.36 (6H). APCI-MS (m/z): 755 [M+]

Synthesis Example 2
Synthesis of Compound 2

Synthesis of Intermediate 2(1)

Intermediate 2(1) was synthesized according to Reaction Scheme 2(1):

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2.7 g (17.3 mmol) 2-phenylpyridine was dissolved in 45 mL of 2-ethoxy ethanol, 2.4 g (7.6 mmol) of iridium chloride hydrate and 15 mL of distilled water were added thereto and then stirred at a temperature of 130° C. for 20 hours to prepare a reaction solution. After the completion of the reaction, the reaction solution was cooled to ambient temperature, a precipitate was filtered therefrom, which was then washed with methanol to wash and dry the same in a vacuum atmosphere to obtain Intermediate 2(1) (4.0 g, 60% yield).

Synthesis of Compound 2

Compound 2 was synthesized according to Reaction Scheme 2(2):

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0.84 g. (1.03 mmol) of Intermediate 2(1), 0.5 g 2.44 mmol) of 2-(2,4-difluorophenyl)-4-methylpyridine(2-(2,4-difluorophenyl)-4-methylpyridine), and 0.34 g (2.46 mmol) of K₂CO₃were added to 30 mL of 2-ethoxy ethanol and then stirred at a temperature of 130° C. for 12 hours to prepare a reaction solution. After the completion of the reaction, the reaction solution was cooled to ambient temperature, and a precipitate was filtered therefrom and then washed with methanol. The precipitate obtained therefrom was dissolved by using dichloromethane, a product obtained therefrom was filtered by using a silica short pad, a dichloromethane solution filtered therefrom was boiled again, and methanol was gradually added thereto to precipitate and obtain Compound 2 (0.57 g, 50% yield).

¹H-NMR: 8.57 (3H), 8.29 (3H), 7.80 (3H), 7.54 (8H), 6.98 (5H), 2.36 (6H). APCI-MS (m/z): 705 [M+]

Synthesis Example 3
Synthesis of Compound 32

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Synthesis of Intermediate A

3.344 g (20 mmol) of carbazole was added to 40 mL of DMPU, and 0.761 g (4 mmol) of CuI, 11.057 g (80 mmol) of K₂CO₃, and 0.1 g (4 mmol) of 18-crown-6 were added thereto to prepare a mixture. The mixture was stirred at a temperature of 170° C. for 20 hours, cooled to ambient temperature, and then a solvent was removed through vacuum distillation to obtain a product. 100 mL of dichloromethane was added to the product obtained therefrom to dissolve the same and then washed several times with water to obtain a washed dichloromethane layer. The washed dichloromethane layer was dried with magnesium sulfate and then dried by reduced pressure to obtain a crude product. The erode product was separated and purified by using a silica gel column chromatography and then recrystallized with hexane to obtain 3.28 g (yield 67%) of a solid form Intermediate A.

Synthesis of Intermediate B

2.433 g (10 mmol) of Intermediate A was added to 100 mL of 80% acetic acid, 1.357 g (5.35 mmol) of iodine (I₂) and 0.333 g (1.46 mmol) of ortho-periodic acid (H₅IO₆) were added thereto and then stirred in nitrogen atmosphere at a temperature of 80° C. for 2 hours to obtain a reaction solution. After the completion of the reaction, the reaction solution was extracted three times with 50 mL of ethyl ether to collect organic layers, and the collected organic layers were dried with magnesium sulfate and then reduced pressure filtered to obtain a crude product. The crude product was separated and purified by using a silica gel column chromatography to obtain 3.23 g (yield 87%) of Intermediate B.

text missing or illegible when filed

Synthesis of Intermediate C

13 g (53 mmol) of 2-bromofluorene was dissolved in 60 mL of acetic acid and 60 g (200 mmol) of sodium dichromate was added slowly thereto at a temperature of 0° C. to obtain a mixture. After stirring the mixture for 12 hours, 200 mL of distilled water was added thereto and then sufficiently stirred to obtain a yellow solid. The yellow solid obtained therefrom was filtered and then dried to obtain 10 g (yield 78%) of Intermediate C.

Synthesis of Intermediate D

8 g (31.6 mmol) of Intermediate C was dissolved in 60 mL of THF, 38 mL (38 mmol) of 1M phenyl magnesium bromide was slowly added thereto at a temperature of −78° C. and then stirred for next two hours to obtain a mixture. The mixture was stirred again at ambient temperature for 5 hours. 50 mL of ammonium chloride aqueous solution was added to the mixture and then extracted three times with 40 mL of ethyl acetate to collect organic layers. The collected organic layers were dried with magnesium sulfate and a solvent was evaporated therefore to obtain a crude product, which was separated and purified by using a silica gel column chromatography to obtain 10 g (yield 95%) of Intermediate D. A structure of Intermediate D was identified through ¹H-NMR.

¹H-NMR (CDCl3, 400 MHz) δ (ppm) 7.64 (d, 1H), 7.54-7.47 (m, 2H), 7.44 (d, 1H), 7.39-7.33 (m, 3H), 7.30-7.23 (m, 5H), 2.46 (s, 1H)

Synthesis of Intermediate E

10 g (30 mmol) of Intermediate D was dissolved in 60 mL of benzene and 2.4 mL (45 mmol) of concentrated sulfuric acid was diluted in a small amount of benzene and then added to prepare a mixture. The mixture was stirred at a temperature of 80° C. for 5 hours, benzene was evaporated therefrom and 1 N sodium hydroxide aqueous solution was added to a residual solution to adjust pH to 7, and then extracted three times with 40 mL ethyl acetate to collect organic layers. The collected organic layers were dried with magnesium sulfate and a solvent was evaporated therefrom to obtain a crude product, which was separated and filtered by using a silica gel column chromatography to obtain 6 g (yield 50%) of Intermediate E.

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Synthesis of Intermediate K

340 mg (8.56 mmol) of Intermediate E and 142 mg (1.2 mmol) of 4-aminobenzonitrile were dissolved in 5 mL of toluene, 0.144 g (1.5 mmol) of t-BuONa, 0.018 g (0.02 mmol) of Pd(dba)₂, and 0.004˜0.006 g (0.02˜0.03 mmol) of (t-Bu)₃P were added thereto and then stirred at a temperature of 80° C. for 5 hours to obtain a reaction solution. The reaction solution was extracted three times with 20 mL of ethyl ether to collect organic layers. The collected organic layers were dried with magnesium sulfate and a solvent was evaporated therefrom to obtain a residue, which was separated and purified by using a silica gel column chromatography to obtain 0.27 g (yield 73%) of Intermediate K.

Synthesis of Compound 32

267 mg (0.614 mmol) of Intermediate K and 0.332 g (0.9 mmol) of Intermediate B were dissolved in 10 mL of toluene, and then 0.144 g (1.5 mmol) of t-BuONa, 0.018 g (0.02 mmol) of Pd(dba)₂, and 0.004˜0.006 g (0.02˜0.03 mmol) of (t-Bu)₃P were added thereto and then stirred at a temperature of 90° C. for 6 hours to obtain a reaction mixture. The reaction mixture was extracted three times with 30 mL of ethyl ether to collect organic layers. The collected organic layers were dried with magnesium sulfate and a solvent was evaporated therefrom to obtain a residue, which was separated and purified by using a silica gel column chromatography to obtain 0.236 g (yield 57%) of Compound 32. A structure of Compound 32 was confirmed through ₁H-NMR.

₁H-NMR (CDCl₃, 400 MHz) δ (ppm) 7.94 (d, 1H), 7.87 (d, 1H), 7.69 (d, 1H), 7.63 (d, 1H), 7.57 (d, 2H), 7.52 (dd, 2H), 7.48 (m, 1H), 7.42 (d, 2H), 7.35 (m, 6H), 7.24 (m, 3H), 7.13 (m, 9H), 7.08 (dd, 1H), 6.92 (d, 2H)

Synthesis Example 4
Synthesis of Compound 31

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Synthesis of Intermediate L

The same synthesis method for Intermediate K was used to obtain 0.30 g (yield 79%) of Intermediate L, except that 142 mg (1.2 mmol) of phenylamine was used instead of 4-aminobenzonitrile.

Synthesis of Compound 31

The same synthesis method for Compound 32 was used to obtain 0.236 g (yield 57%) of Compound 31, except that 267 mg (0.614 mmol) of Intermediate L was used instead of Intermediate K. A structure of Compound 31 was identified through ₁H-NMR.

1H-NMR (CDCl₃, 400 MHz) δ (ppm) 7.97 (d, 1H), 7.90 (d, 1H), 7.69 (d, 1H), 7.65 (d, 1H), 7.60 (d, 2H), 7.56 (dd, 2H), 7.48 (m, 1H), 7.40 (d, 2H), 7.35 (m, 6H), 7.24 (m, 3H), 7.16 (m, 10H), 7.11 (dd, 1H), 6.93 (d, 2H)

Synthesis Example 5
Synthesis of Compound 33

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Synthesis of Intermediate M

The same synthesis method for Intermediate K was used to obtain 0.32 g (yield 82%) of Intermediate M, except that 142 mg (1.2 mmol) of pyridine-2-yl amine was used instead of 4-aminobenzonitrile.

Synthesis of Compound 33

The same synthesis method for Compound 32 was used to obtain 0.236 g (yield 57%) of Compound 33, except that 267 mg (0.614 mmol) of Intermediate M was used instead of Intermediate K. A structure of Compound 33 was identified through ₁H-NMR.

¹-NMR (CDCl₃, 400 MHz) δ (ppm) 7.91 (d, 1H), 7.83 (d, 1H), 7.69 (d, 1H), 7.62 (d, 1H), 7.60 (d, 2H), 7.53 (dd, 2H), 7.49 (m, 1H), 7.40 (d, 2H), 7.35 (m, 6H), 7.21 (m, 2H), 7.17 (m, 10H), 7.13 (dd, 1H), 6.90 (d, 2H)

Example 1

An anode was prepared by cutting a Corning 15 Ωcm²(1,200 Å) ITO glass substrate to a size of 50 mm×50 mm×0.7 mm, ultrasonically cleaning the glass substrate by using isopropyl alcohol and pure water for 5 minutes each, and then irradiating UV light for 30 minutes and exposing to ozone to clean. Then, the anode was loaded into a vacuum deposition apparatus.

2-TNATA was deposited on the ITO glass substrate to form an HIL having a thickness of 600 Å, and then, Compound 31 was deposited on the HIL to form an HTL having a thickness of 300 Å. Subsequently, CBP as a host and Compound 1 as a blue phosphorescent dopant were vacuum-deposited on the HTL at a weight ratio of 95:5 to form an EML having a thickness of 200 Å. Compound 201 was deposited on the EML to form an EIL having a thickness of 300 Å and LiF was deposited on the ETL to form an EIL having a thickness of 10 Å, and Al was deposited on the EIL to form a second electrode (cathode) having a thickness of 3,000 Å to manufacture an organic light-emitting device.

Example 2

An organic light-emitting device was manufactured in the same manner as in Example 1, except that Compound 32 was used instead of Compound 31 when forming an HTL.

Example 3

An organic light-emitting device was manufactured in the same manner as in Example 1, except that Compound 33 was used instead of Compound 31 when forming an HTL.

Example 4

An organic light-emitting device was manufactured in the same manner as in Example 1, except that Compound 2 was used instead of Compound 1 when forming as EML.

Example 5

An organic light-emitting device was manufactured in the same manner as in Example 1, except that Compound 32 was used instead of Compound 31 when forming an HTL and Compound 2 was used instead of Compound 1 when forming an EML.

Example 6

An organic light-emitting device was manufactured in the same manner as in Example 1, except that Compound 33 was used instead of Compound 31 when forming an HTL and Compound 2 was used instead of Compound 1 when forming an EML.

Comparative Example 1

An organic light-emitting device was manufactured in the same manner as in Example 1, except that TPD was used instead of Compound 31 when forming an HTL.

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Comparative Example 2

An organic light-emitting device was manufactured in the same manner as in Example 1, except that NPB was used instead of Compound 31 when forming an HTL.

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Comparative Example 3

An organic light-emitting device was manufactured in the same manner as in Example 1, except that F₂Irpic used instead of Compound 1 when forming an EML.

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Comparative Example 4

An organic light-emitting device was manufactured in the same manner as in Example 1, except that Compound A was used instead of Compound 31 when forming an HTL and DPVBi was used instead of Compound 1 when forming an EML.

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Comparative Example 5

An organic light-emitting device was manufactured in the same manner as in Example 1, except that Compound B was used instead of Compound 31 when forming an HTL and DPVBi was used instead of Compound 1 when forming an EML.

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Comparative Example 6

An organic light-emitting device was manufactured in the same manner as in Example 1, except that NPB was used instead of Compound 31 when forming an HTL and Compound C was used instead of Compound 1 when forming an EML.

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Evaluation Example

Driving voltages, brightness, and efficiencies (at a current density of 10 mA/cm²) of the organic light-emitting devices of Examples 1 to 6 and Comparative Examples 1 to 6 were evaluated by using a PR650 Spectroscan source measurement unit (a product of PhotoResearch). The results obtained therefrom are as shown in Table 1.

TABLE 1

Driving
Bright-
Effi-

voltage
ness
ciency

HTL
Dopant
(V)
(cd/m²)
(cd/A)

Example 1
Compound 31
Compound 1
5.2
4850
49.2

Example 2
Compound 32
Compound 1
5.3
4920
50.3

Example 3
Compound 33
Compound 1
5.4
4790
51.2

Example 4
Compound 31
Compound 2
5.1
4700
48.6

Example 5
Compound 32
Compound 2
5.3
4870
48.0

Example 6
Compound 33
Compound 2
5.2
4690
48.7

Comparative
TPD
Compound 1
5.9
3980
41.0

Example 1

Comparative
NPB
Compound 1
6.0
3970
40.7

Example 2

Comparative
Compound 31
F₂Irpic
6.2
3840
41.2

Example 3

Comparative
Compound A
DPVBi
5.6
4180
42.9

Example 4

Comparative
Compound B
DPVBi
5.9
4330
38.9

Example 5

Comparative
NPB
Compound C
5.7
4060
41.5

Example 6

Referring to Table 1, the organic light-emitting devices of Examples 1 to 6 exhibited lower driving voltages than the organic light-emitting devices of Comparative Examples 1 to 6, and the organic light-emitting devices of Examples 1 to 6 showed excellent I-V-L characteristics with improved efficiencies.

As described above, the embodiments may provide an organic light-emitting device having high efficiency and high color purity.

The embodiments may provide a high definition organic light-emitting device.

Example embodiments have been disclosed herein, and although specific terms are employed, they are used and are to be interpreted in a generic and descriptive sense only and not for purpose of limitation. In some instances, as would be apparent to one of ordinary skill in the art as of the filing of the present application, features, characteristics, and/or elements described in connection with a particular embodiment may be used singly or in combination with features, characteristics, and/or elements described in connection with other embodiments unless otherwise specifically indicated. Accordingly, it will be understood by those of skill in the art that various changes in form and details may be made without departing from the spirit and scope of the present invention as set forth in the following claims.

ORGANIC LIGHT-EMITTING DEVICES

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