Heterocyclic compound and organic light-emitting device comprising same

An organic light-emitting device includes a heterocyclic compound represented by Formula 1 as a thermally activated delayed fluorescence dopant, where D1 is a group represented by Formula 2 and Rw is selected from: —F, a cyano group, and a C1-C20 alkyl group substituted with at least one —F:

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a National Phase Patent Application of International Patent Application Number PCT/KR2018/010175, filed on Aug. 31, 2018, which claims priority to Korean Patent Application No. 10-2018-0069059, filed Jun. 15, 2018. The entire contents of both are incorporated herein by reference.

FIELD

One or more embodiments of the present disclosure relate to a heterocyclic compound and an organic light-emitting device including the same.

BACKGROUND

Organic light-emitting devices are self-emission devices that produce full-color images, and also have wide viewing angles, high contrast ratios, short response times, and/or excellent characteristics in terms of brightness, driving voltage, and response speed, compared to devices in the art.

Description of Embodiments

Technical Problem

One or more embodiments of the present disclosure are directed toward a heterocyclic compound and an organic light-emitting device including the same.

Solution to Problem

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

In Formulae 1 and 2,

D1is a group represented by Formula 2,

n1 is an integer from 1 to 4,

L1is a single bond, a substituted or unsubstituted C5-C60carbocyclic group, or a substituted or unsubstituted C1-C60heterocyclic group,

a1 is an integer from 1 to 5,

R2and R6are each independently selected from 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 C1-C10heterocycloalkyl group, a substituted or unsubstituted C3-C10cycloalkenyl group, a substituted or unsubstituted C1-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 C1-C60heteroaryloxy group, a substituted or unsubstituted C1-C60heteroarylthio group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, —Si(Q1)(Q2)(Q3), —N(Q1)(Q2), —B(Q1)(Q2), —C(═O)(Q1), —S(═O)2(Q1), and —P(═O)(Q1)(Q2), wherein R2and R6are not substituted or unsubstituted carbazolyl groups,

b11 is an integer from 0 to 5,

Rwis selected from: —F, a cyano group, and a C1-C20alkyl group substituted with at least one —F;

a C6-C60aryl group substituted with at least one selected from —F, a cyano group, and a C1-C20alkyl group substituted with at least one —F;

a C1-C60heteroaryl group substituted with at least one selected from —F, a cyano group, and a C1-C20alkyl group substituted with at least one —F; and

a biphenyl group and a terphenyl group, each substituted with at least one selected from —F, a cyano group, and a C1-C20alkyl group substituted with at least one —F,

b12 is an integer from 1 to 5, and

One or more embodiments of the present disclosure provide an organic light-emitting device including: a first electrode; a second electrode facing the first electrode; and an organic layer located between the first electrode and the second electrode and including an emission layer, wherein the organic light-emitting device includes at least one heterocyclic compound represented by Formula 1.

One or more embodiments of the present disclosure provide an organic light-emitting device including: a first electrode; a second electrode facing the first electrode; and an organic layer located between the first electrode and the second electrode and including an emission layer, wherein the organic layer includes at least one heterocyclic compound represented by Formula 1.

Advantageous Effects of Disclosure

The organic light-emitting device including the heterocyclic compound may have low driving voltage, high efficiency, and/or a long lifespan.

DETAILED DESCRIPTION

One or more embodiments of the present disclosure provide a heterocyclic compound represented by Formula 1.

In Formula 1, A1may be a C5-C60carbocyclic group, a C1-C60heterocyclic group, a biphenyl group, or a terphenyl group.

The term “biphenyl group” as used herein refers to a divalent group including two directly linked benzene groups. The biphenyl group may be represented by the following formula:

In the above formula, * and *′ each indicates a binding site to a neighboring atom.

The term “terphenyl group” as used herein refers to a divalent group including three directly linked benzene groups. The terphenyl group may be represented by the following formula.

In the above formula, * and *′ each indicates a binding site to a neighboring atom.

In one embodiment, A1may be selected from a benzene group, a biphenyl group, and a terphenyl group.

In Formula 1, D1may be a group represented by Formula 2.

In Formula 1, n1 may be an integer from 1 to 4. n1 indicates the number of D1substituents, wherein when n1 is 2 or more, two or more D1(s) may be identical to or different from each other.

In one embodiment, n1 may be 2 or 3.

In one embodiment, n1 may be 2 or 3, and the n1 D1(s) may be identical to each other.

In Formula 2, Li may be a single bond, a substituted or unsubstituted C5-C60carbocyclic group, or a substituted or unsubstituted C1-C60heterocyclic group.

In one embodiment, Li may be selected from a single bond and groups represented by Formulae 3-1 to 3-46:

In Formulae 3-1 to 3-46,

d2 may be an integer from 1 to 2,

d3 may be an integer from 1 to 3,

d4 may be an integer from 1 to 4,

d5 may be an integer from 1 to 5,

d6 may be an integer from 1 to 6,

d8 may be an integer from 1 to 8, and

In Formulae 3-1 to 3-46, * and *′ each indicate a binding site to a neighboring atom.

In one or more embodiments, Li may be a single bond, but embodiments of the present disclosure are not limited thereto.

In Formula 2, a1 may be an integer from 1 to 5. a1 indicates the number of Li, wherein when a1 is 2 or more, two or more Li(s) may be identical to or different from each other.

In Formula 1, b11 may be an integer from 0 to 5. b11 indicates the number of R11, wherein when b11 is 2 or more, two or more R11(s) may be identical to or different from each other.

In one embodiment, R2and R6may each independently be selected from: a C1-C20alkyl group and a C1-C20alkoxy group;

a C1-C20alkyl group and a C1-C20alkoxy group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a cyano group, a phenyl group, and a biphenyl group;

In one embodiment, R2and R6may each independently be selected from: a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a tert-butyl group;

a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a tert-butyl group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, and a cyano group;

In one or more embodiments, R2and R6may each independently be selected from: a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a tert-butyl group;

a phenyl group, a biphenyl group, a terphenyl group, and a naphthyl group; and

a phenyl group and a naphthyl group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a cyano group, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a phenyl group, a naphthyl group, —Si(Q31)(Q32)(Q33), —N(Q31)(Q32), and —B(Q31)(Q32),

In Formula 1, Rwmay be selected from: —F, a cyano group, and a C1-C20alkyl group substituted with at least one —F;

a C6-C60aryl group substituted with at least one selected from —F, a cyano group, and a C1-C20alkyl group substituted with at least one —F;

a C1-C60heteroaryl group substituted with at least one selected from —F, a cyano group, and a C1-C20alkyl group substituted with at least one —F; and

a biphenyl group and a terphenyl group, each substituted with at least one selected from —F, a cyano group, and a C1-C20alkyl group substituted with at least one —F.

In one embodiment, Rwmay be selected from: —F, a cyano group, and a C1-C20alkyl group substituted with at least one —F; and

In one embodiment, Rwmay be selected from: —F, a cyano group, and —CF3; and

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a pyridinyl group, a pyrazinyl group, and a pyrimidinyl group, each substituted with at least one selected from —F, a cyano group, and —CF3.

In one or more embodiments, Rwmay be selected from: —F, a cyano group, and —CF3; and

a phenyl group substituted with at least one selected from —F, a cyano group, and —CF3.

In one or more embodiments, Rwmay be selected from —F, a cyano group, —CF3, and groups represented by Formulae 5-1 to 5-7:

In Formulae 5-1 to 5-7,

* indicates a binding site to a neighboring atom.

In Formula 1, b12 may be an integer from 1 to 5. b12 indicates the number of Rw, wherein when b12 is 2 or more, two or more Rw(s) may be identical to or different from each other.

In one embodiment, the heterocyclic compound may be represented by any one of Formulae 1A-1 to 1A-4 and 1B-1 to 1B-9:

In Formulae 1A-1 to 1A-4 and 1B-1 to 1B-9,

Rug and Rware the same as described in connection with Formula 1,

R12and R13are the same as described in connection with Ru in Formula 1,

Rwaand Rwbare the same as described in connection with Rwin Formula 1,

D1ato D1are the same as described in connection with D1in Formula 1,

b15 is 0, 1, 2, or 3, b16 is 1, 2, 3, or 4, and the sum of b15 and b16 is 4, and

b17 is 0, 1, or 2, b18 is 1, 2, or 3, and the sum of b17 and b18 is 3.

In one embodiment, in Formulae 1A-1 to 1A-4 and 1B-1 to 1B-9,

Rw, Rwa, and Rwbmay each independently be selected from: —F, a cyano group, and —CF3; and

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a pyridinyl group, a pyrazinyl group, and a pyrimidinyl group, each substituted with at least one selected from —F, a cyano group, and —CF3.

In one embodiment, the heterocyclic compound may be represented by any one of Formulae 1A-2-1 to 1A-2-6, 1A-4-1, 1B-1-1 to 1B-1-2, 1B-4-1 to 1B-4-3, and 1B-7-1 to 1B-7-3:

R11and Rware the same as described in connection with Formula 1,

R12and R13are the same as described in connection with Ru in Formula 1,

Rwato Rwdare the same as described in connection with Rwin Formula 1,

D1ato D1care the same as described in connection with D1in Formula 1,

In one embodiment, in Formulae 1A-2-1 to 1A-2-6, 1A-4-1, 1B-1-1 to 1B-1-2, 1B-4-1 to 1B-4-3, and 1B-7-1 to 1B-7-3,

Rwand Rwato Rwdmay each independently be selected from: —F, a cyano group, and —CF3; and

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a pyridinyl group, a pyrazinyl group, and a pyrimidinyl group, each substituted with at least one selected from —F, a cyano group, and —CF3.

In one or more embodiments, the heterocyclic compound may be represented by any one of Formulae HA-2-1 to HA-2-6, HA-4-1, HB-1-1 to HB-1-2, HB-4-1 to HB-4-3, and HB-7-1 to HB-7-3:

R11and Rware the same as described in connection with Formula 1,

Rwato Rwdare the same as described in connection with Rwin Formula 1, and

D1ato D1care the same as described in connection with D1in Formula 1.

In one embodiment, in Formulae HA-2-1 to HA-2-6, HA-4-1, HB-1-1 to HB-1-2, HB-4-1 to HB-4-3, and HB-7-1 to HB-7-3,

Rwand Rwato Rwdmay each independently be selected from: —F, a cyano group, and —CF3; and

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a pyridinyl group, a pyrazinyl group, and a pyrimidinyl group, each substituted with at least one selected from —F, a cyano group, and —CF3.

In one embodiment, the heterocyclic compound may have a symmetric structure (the heterocyclic compound may have at least one plane of symmetry).

In one embodiment, the heterocyclic compound may be selected from Compounds 1 to 126, but embodiments of the present disclosure are not limited thereto.

The heterocyclic compound includes a substituent having properties of an electron withdrawing group (EWG) as well as a substituent having properties of an electron donating group (EDG), and when these substituents are introduced in suitable positions, an energy difference between a singlet state and a triplet state of the compound may be appropriately or suitably adjusted. Accordingly, the heterocyclic compound may exhibit thermally activated delayed fluorescence (TADF).

The following Equation describes a suitable relationship between a singlet energy and a triplet energy of the heterocyclic compound: ΔEst=S1−T1<0.3 eV

The heterocyclic compound includes a structure represented by Formula 1. In particular, because the compound includes an EWG and an EDG, charge transfer within the molecule may be easily achieved. In addition, orbital overlap in the molecule may be efficiently or suitably blocked due to steric hindrance between the EWG and the EDG in the structure. Accordingly, ΔEstmay be extremely or suitably low while a singlet and a triplet state of the molecule do not overlap. Accordingly, reverse intersystem crossing from a triplet excited state to a singlet excited state may occur via thermal activation, even at room temperature, resulting in delayed fluorescence. Because excitons in the triplet state are used for emission, luminescence efficiency may be improved. Theoretically, ΔEstand oscillator strength generally have a trade-off relationship, such that the smaller the ΔEst, the lower the luminescence efficiency. However, in a case of a compound satisfying Formula 1, ΔEstmay be suppressed to a low value, and the structure may simultaneously have a high oscillator strength, such that the heterocyclic compound represented by Formula 1 may have relatively high photoluminescence quantum yield (PLQY).

In the group represented by Formula 2, carbons 2 and 6 of a carbazole group may be substituted with a group (substituent) other than hydrogen. When a compound including a carbazole group substituted on carbons 3 and 6 is instead used in an emission layer of an organic light-emitting device, the compound may have a maximum emission wavelength on the higher end of 400 nm, for example, greater than 470 nm. Meanwhile, a compound including a carbazole group substituted on carbons 2 and 7 may have a shortened maximum emission wavelength of less than 450 nm. In contrast, because a group represented by Formula 2 includes a substituent on carbons 2 and 6 of carbazole, the heterocyclic compound represented by Formula 1 may be to emit deep-blue light having a maximum emission wavelength of 450 nm to 470 nm.

Furthermore, because the heterocyclic compound has relatively high charge (hole or electron) transport ability, an exciton formation ratio in an emission layer of an organic light-emitting device using the heterocyclic compound represented by Formula 1 may be improved. Accordingly, the organic light-emitting device may have low driving voltage, high efficiency, long lifespan, and/or high maximum quantum efficiency.

A synthesis method for the heterocyclic compound represented by Formula 1 would be understood by those of ordinary skill in the art by referring to the following examples.

At least one of the heterocyclic compound represented by Formula 1 may be used between a pair of electrodes of an organic light-emitting device. In one or more embodiments, the heterocyclic compound may be included in at least one of a hole transport region, an electron transport region, and an emission layer. In one or more embodiments, the heterocyclic compound represented by Formula 1 may be used as a material for a capping layer located outside a pair of electrodes of an organic light-emitting device.

Accordingly, provided is an organic light-emitting device including: a first electrode; a second electrode facing the first electrode; and an organic layer located between the first electrode and the second electrode and including an emission layer, wherein the organic light-emitting device includes at least one heterocyclic compound represented by Formula 1.

In one embodiment, provided is an organic light-emitting device including: a first electrode; a second electrode facing the first electrode; and an organic layer located between the first electrode and the second electrode and including an emission layer, wherein the organic layer includes at least one heterocyclic compound represented by Formula 1.

The expression “(an organic layer) includes at least one heterocyclic compound” as used herein may include a case in which “(an organic layer) includes identical heterocyclic compounds represented by Formula 1” (one same heterocyclic compound) and a case in which “(an organic layer) includes two or more different heterocyclic compounds represented by Formula 1”.

In one or more embodiments, the organic layer may include, as the heterocyclic compound, only Compound 1. In this regard, Compound 1 may exist (be included) only in the emission layer of the organic light-emitting device. In one or more embodiments, the organic layer may include, as the heterocyclic compound, Compound 1 and Compound 2. In this regard, Compound 1 and Compound 2 may exist in the same layer (for example, Compound 1 and Compound 2 may both (simultaneously) exist in an emission layer), or in different layers (for example, Compound 1 may exist in an emission layer and Compound 2 may exist in an electron transport layer).

In one embodiment, the first electrode is an anode, the second electrode is a cathode, and the organic layer further includes a hole transport region between the first electrode and the emission layer and an electron transport region between the emission layer and the second electrode; the hole transport region includes a hole injection layer, a hole transport layer, an emission auxiliary layer, an electron blocking layer, or any combination thereof; and the electron transport region includes a hole blocking layer, an electron transport layer, an electron injection layer, or any combination thereof.

In one embodiment, the hole transport region may include a hole transport layer,

the hole transport layer may include a first hole transport layer and a second hole transport layer, and

a material included in the first hole transport layer and a material included in the second hole transport layer may be identical to or different from each other.

In one embodiment, the emission layer of the organic light-emitting device may include the heterocyclic compound.

In one or more embodiments, the emission layer may consist of the heterocyclic compound, or in some embodiments, the emission layer may further include a host, and an amount of the heterocyclic compound may be 0.1 parts by weight to 50 parts by weight based on 100 parts by weight of the emission layer.

In one or more embodiments, the emission layer includes the heterocyclic compound and a host, and the heterocyclic compound may be or act as a dopant.

In one or more embodiments, the heterocyclic compound included in the emission layer is a thermally activated delayed fluorescence emitter (TADF emitter), and the emission layer may be to emit delayed fluorescence.

The host in the emission layer may include at least one of an anthracene-based compound, a pyrene-based compound, a spiro-bifluorene-based compound, a carbazole-based compound, a benzimidazole-based compound, a phosphine oxide-based compound, a dibenzofuran-based compound, a silicon-based compound, and a triazine-based compound, but embodiments of the present disclosure are not limited thereto.

In one embodiment, the emission layer includes the heterocyclic compound, and the emission layer may be to emit blue light having a maximum emission wavelength of 450 nm to 470 nm.

In one embodiment, the electron transport region of the organic light-emitting device may include at least one of a phosphine oxide-based compound and a benzimidazole-based compound, and

may further include an alkali metal, an alkaline earth metal, a rare earth metal, an alkali metal compound, an alkaline earth metal compound, a rare earth metal compound, an alkali metal complex, an alkaline earth metal complex, a rare earth metal complex, or any combination thereof.

The term “organic layer” as used herein refers to a single layer and/or all layers between the first electrode and the second electrode of the organic light-emitting device. A material included in “the organic layer” is not limited to an organic material. [Description ofFIG.1]

FIG.1is a schematic cross-sectional 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 electrode190.

Hereinafter, a structure of the organic light-emitting device10according to an embodiment of the present disclosure and a method of manufacturing the organic light-emitting device10according to an embodiment of the present disclosure will be described in connection withFIG.1.

InFIG.1, a substrate may be additionally disposed under the first electrode110or above the second electrode190. The substrate may be a glass substrate and/or a plastic substrate, each having 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 electrode110on the substrate. When the first electrode110is an anode, a material for forming the first electrode110may be selected from materials with a high work function to facilitate hole injection.

The first electrode110may have a single-layered structure or a multi-layered structure including two or more layers. In one or more embodiments, the first electrode110may have a three-layered structure of ITO/Ag/ITO, but embodiments of the present disclosure are not limited thereto.

The organic layer150is located on the first electrode110. The organic layer150includes an emission layer.

[Hole Transport Region in Organic Layer150]

The hole transport region may have i) a single-layered structure including (or consisting of) a single material, ii) a single-layered structure including (or consisting of) a plurality of different materials, or iii) a multi-layered structure having a plurality of layers including (or consisting of) a plurality of different materials.

The hole transport region may include at least one layer selected from a hole injection layer, a hole transport layer, an emission auxiliary layer, and an electron blocking layer.

In one or more embodiments, the hole transport region may have a single-layered structure including (or consisting of) a plurality of different materials, or a multi-layered structure having a hole injection layer/hole transport layer, a hole injection layer/hole transport layer/emission auxiliary layer, a hole injection layer/emission auxiliary layer structure, a hole transport layer/emission auxiliary layer, or a hole injection layer/hole transport layer/electron blocking layer, wherein the constituting layers of each structure are sequentially stacked from the first electrode110in this stated order, but embodiments of the present disclosure are not limited thereto.

In Formulae 201 and 202,

xa5 may be an integer from 1 to 10, and

In one or more embodiments, in Formula 202, R201and R202may optionally be linked to each other via a single bond, a dimethyl-methylene group, or a diphenyl-methylene group, and R203and R204may optionally be linked to each other via a single bond, a dimethyl-methylene group, or a diphenyl-methylene group.

In one embodiment, in Formulae 201 and 202,

L201to L205may each independently be selected from:

In one or more embodiments, xa5 may be 1, 2, 3, or 4.

wherein Q31to Q33are the same as described above.

In one or more embodiments, at least one of R201to R203in Formula 201 may each independently be selected from:

In one or more embodiments, in Formula 202, i) R201and R202may be linked to each other via a single bond, and/or ii) R203and R204may be linked to each other via a single bond.

In one or more embodiments, R201to R204in Formula 202 may be selected from:

a carbazolyl group; and

In one or more embodiments, the compound represented by Formula 201 may be represented by Formula 201A(1), but embodiments of the present disclosure are not limited thereto:

In one or more embodiments, the compound represented by Formula 201 may be represented by Formula 201A-1, but embodiments of the present disclosure are not limited thereto:

In one or more embodiments, the compound represented by Formula 202 may be represented by Formula 202A:

In one or more embodiments, the compound represented by Formula 202 may be represented by Formula 202A-1:

R211and R212are the same as described in connection with R203, and

The hole transport region may include at least one compound selected from Compounds HT1 to HT39, but compounds to be included in the hole transport region are not limited thereto:

The emission auxiliary layer may increase the light-emission efficiency of the device by compensating for an optical resonance distance of the wavelength of light emitted by an emission layer, and the electron blocking layer may block or reduce the flow of electrons from an electron transport region. The emission auxiliary layer and the electron blocking layer may include the materials as described above.

In one embodiment, a lowest unoccupied molecular orbital (LUMO) energy level of the p-dopant may be −3.5 eV or less.

The p-dopant may include at least one selected from a quinone derivative, a metal oxide, and a cyano group-containing compound, but embodiments of the present disclosure are not limited thereto.

In one or more embodiments, the p-dopant may include at least one selected from:

a metal oxide (such as tungsten oxide and/or molybdenum oxide);

a compound represented by Formula 221,

In Formula 221,

[Emission Layer in Organic Layer150]

The emission layer may include a host and a dopant. The dopant may include at least one of a phosphorescent dopant and a fluorescent dopant.

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

The host may include a compound represented by Formula 301:
[Ar301]xb11-[(L301)xb1-R301]xb21.  <Formula 301>

In Formula 301,

xb1 may be an integer from 0 to 5,

xb21 may be an integer from 1 to 5,

In one embodiment, Ar301in Formula 301 may be selected from:

When xb11 in Formula 301 is 2 or more, two or more Ar301(s) may be linked to each other via a single bond.

In one embodiment, the compound represented by Formula 301 may be represented by Formula 301-1 or Formula 301-2:

In Formulae 301-1 and 301-2,

xb22 and xb23 may each independently be 0, 1, or 2,

L302to L304are each independently the same as described in connection with L301,

xb2 to xb4 may each independently be the same as described in connection with xb17and

R302to R304are each independently the same as described in connection with R301.

In one or more embodiments, L301to L304in Formulae 301, 301-1, and 301-2 may each independently be selected from:

wherein Q31to Q33are the same as described above.

In one or more embodiments, R301to R304in Formulae 301, 301-1, and 301-2 may each independently be selected from:

wherein Q31to Q33are the same as described above.

In one or more embodiments, the host may include an alkaline earth metal complex. In one or more embodiments, the host may be selected from a Be complex (for example, Compound H55) and an Mg complex. In some embodiments, the host may be a Zn complex.

[Phosphorescent Dopant Included in Emission Layer in Organic Layer150]

The phosphorescent dopant may include an organometallic complex represented by Formula 401:
M(L401)xc1(L402)xc2<Formula 401>

In Formulae 401 and 402,

L401may be selected from ligands represented by Formula 402, and xc1 may be 1, 2, or 3, wherein when xc1 is 2 or more, two or more of L401(s) may be identical to or different from each other,

L402may be an organic ligand, and xc2 may be an integer from 0 to 4, wherein when xc2 is 2 or more, two or more of L402(s) may be identical to or different from each other,

X401to X404may each independently be nitrogen or carbon,

X401and X403may be linked via a single bond or a double bond, and X402and X404may be linked via a single bond or a double bond,

A401and A402may each independently be a C5-C60carbocyclic group or a C1-C60heterocyclic group,

X406may be a single bond, O, or S,

R401and R402may each independently be selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a substituted or unsubstituted C1-C20alkyl group, a substituted or unsubstituted C1-C20alkoxy group, a substituted or unsubstituted C3-C10cycloalkyl group, a substituted or unsubstituted C1-C10heterocycloalkyl group, a substituted or unsubstituted C3-C10cycloalkenyl group, a substituted or unsubstituted heterocycloalkenyl 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, —Si(Q401)(Q402)(Q403), —N(Q401)(Q402), —B(Q401)(Q402), —C(═O)(Q401), —S(═O)2(Q401), and —P(═O)(Q401)(Q402), and Q401to Q403may each independently be selected from a C1-C10alkyl group, a C1-C10alkoxy group, a C6-C20aryl group, and a C1-C20heteroaryl group,

In one or more embodiments, in Formula 402, i) X401may be nitrogen and X402may be carbon, or ii) both X401and X402may be nitrogen (simultaneously).

In one or more embodiments, when xc1 in Formula 401 is 2 or more, two A401(s) in two or more L401(s) may optionally be linked to each other via X407, which is a linking group, two A402(s) may optionally be linked to each other via X408, which is a linking group (see Compounds PD1 to PD4 and PD7). X407and X408may each independently be a single bond, *—S—*′, *—C(═O)—*′, *—N(Q413)-*′, *—C(Q413)(Q414)-*′, or *—C(Q413)═C(Q414)-*′ (wherein Q413and Q414may each independently be hydrogen, deuterium, a C1-C20alkyl group, a C1-C20alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, or a naphthyl group), but embodiments of the present disclosure are not limited thereto.

L402in Formula 401 may be a monovalent, divalent, or trivalent organic ligand. In one or more embodiments, L402may be selected from halogen, diketone (for example, acetylacetonate), carboxylic acid (for example, picolinate), —C(═O), isonitrile, —CN, and phosphorus (for example, phosphine and/or phosphite), but embodiments of the present disclosure are not limited thereto.

In one or more embodiments, the phosphorescent dopant may be selected from, for example, Compounds PD1 to PD25, but embodiments of the present disclosure are not limited thereto:

The fluorescent dopant may include the heterocyclic compound represented by Formula 1.

In addition, the fluorescent dopant may include an arylamine compound or a styrylamine compound.

The fluorescent dopant may include a compound represented by Formula 501.

In Formula 501,

xd1 to xd3 may each independently be an integer from 0 to 3,

xd4 may be an integer from 1 to 6.

In one embodiment, Ar501in Formula 501 may be selected from:

In one embodiment, L501to L503in Formula 501 may each independently be selected from:

In one or more embodiments, R501and R502in Formula 501 may each independently be selected from:

In one or more embodiments, xd4 in Formula 501 may be 2, but embodiments of the present disclosure are not limited thereto.

In one or more embodiments, the fluorescent dopant may be selected from Compounds FD1 to FD22:

In one or more embodiments, the fluorescent dopant may be selected from the following compounds, but embodiments of the present disclosure are not limited thereto.

[Electron Transport Region in Organic Layer150]

The electron transport region may have i) a single-layered structure including (or consisting of) a single material, ii) a single-layered structure including (or consisting of) a plurality of different materials, or iii) a multi-layered structure having a plurality of layers consisting of a plurality of different materials.

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

In one or more embodiments, the electron transport region may have an electron transport layer/electron injection layer structure, a hole blocking layer/electron transport layer/electron injection layer structure, an electron control layer/electron transport layer/electron injection layer structure, or a buffer layer/electron transport layer/electron injection layer structure, wherein the constituting layers of each structure, are sequentially stacked from an emission layer. However, embodiments of the structure of the electron transport region are not limited thereto.

The electron transport region (for example, a buffer layer, a hole blocking layer, an electron control layer, and/or an electron transport layer in the electron transport region) may include a metal-free compound containing at least one Tr-electron-deficient nitrogen-containing ring.

The term “7-electron-deficient nitrogen-containing ring” indicates a C1-C60heterocyclic group having at least one *—N=*′ moiety as a ring-forming moiety.

In one or more embodiments, the electron transport region may include a compound represented by Formula 601:
[Ar601]xe11-[(L601)xe1-R601])xe21<Formula 601>

In Formula 601,

xe1 may be an integer from 0 to 5, and

xe21 may be an integer from 1 to 5.

In one embodiment, at least one of the xe11 Ar601(s) and the xe21 R601(s) may include the π-electron-deficient nitrogen-containing ring.

In one embodiment, ring Ar601in Formula 601 may be selected from:

When xe11 in Formula 601 is 2 or more, two or more of Ar601(s) may be linked to each other via a single bond.

In one embodiment, Ar601in Formula 601 may be an anthracene group.

In one or more embodiments, the compound represented by Formula 601 may be represented by Formula 601-1:

In Formula 601-1,

X614may be N or C(R614), X615may be N or C(R615), X616may be N or C(R616), and at least one of X614to X616may be N,

L611to L613may each independently be the same as described in connection with L601,

xe611 to xe613 may each independently be the same as described in connection with xe1,

R611to R613may each independently be the same as described in connection with R601, and

In one embodiment, L601and L611to L613in Formulae 601 and 601-1 may each independently be selected from:

In one or more embodiments, R601and R611to R613in Formulae 601 and 601-1 may each independently be selected from:

wherein Q601and Q602are the same as described above.

The electron transport region may include at least one compound selected from Compounds ET1 to ET36, but embodiments of the present disclosure are not limited thereto:

The thicknesses of the buffer layer, the hole blocking layer, and the electron control layer may each independently be 20 Å to about 1,000 Å, for example, about 30 Å to about 300 Å. When the thicknesses of the buffer layer, the hole blocking layer, and the electron control layer are within these ranges, excellent hole blocking characteristics and/or excellent electron control characteristics may be obtained without a substantial increase in driving voltage.

A thickness of the electron transport layer may be about 100 Å to about 1,000 Å, for example, about 150 Å to about 500 Å. When the thickness of the electron transport layer is within the range described above, satisfactory electron transport characteristics may be obtained without a substantial increase in driving voltage.

The metal-containing material may include at least one selected from an alkali metal complex and an alkaline earth-metal complex. A metal ion of the alkali metal complex may be selected from a lithium (Li) ion, a sodium (Na) ion, a potassium (K) ion, a rubidium (Rb) ion, and a cesium (Cs) ion, and a metal ion of the alkaline earth-metal complex may be selected from a beryllium (Be) ion, a magnesium (Mg) ion, a calcium (Ca) ion, a strontium (Sr) ion, and a barium (Ba) ion. A ligand coordinated with the metal ion of the alkali metal complex or the alkaline earth-metal complex may be selected from a hydroxy quinoline, a hydroxy isoquinoline, a hydroxy benzoquinoline, a hydroxy acridine, a hydroxy phenanthridine, a hydroxy phenyloxazole, a hydroxy phenylthiazole, a hydroxy diphenyloxadiazole, a hydroxy diphenylthiadiazole, a hydroxy phenylpyridine, a hydroxy phenylbenzimidazole, a hydroxy phenylbenzothiazole, a bipyridine, a phenanthroline, and a cyclopentadiene, but embodiments of the present disclosure are not limited thereto.

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

The electron injection layer may have i) a single-layered structure including (or consisting of) a single material, ii) a single-layered structure including (or consisting of) a plurality of different materials, or iii) a multi-layered structure having a plurality of layers consisting of a plurality of different materials.

The electron injection layer may include an alkali metal, an alkaline earth metal, a rare earth metal, an alkali metal compound, an alkaline earth-metal compound, a rare earth metal compound, an alkali metal complex, an alkaline earth-metal complex, a rare earth metal complex, or any combination thereof.

The alkali metal may be selected from Li, Na, K, Rb, and Cs. In one embodiment, the alkali metal may be Li, Na, or Cs. In one embodiment, the alkali metal may be Li or Cs, but embodiments of the present disclosure are not limited thereto.

The rare earth metal may be selected from scandium (Sc), yttrium (Y), cerium (Ce), terbium (Tb), ytterbium (Yb), and gadolinium (Gd).

The alkali metal compound, the alkaline earth-metal compound, and the rare earth metal compound may be selected from oxides and halides (for example, fluorides, chlorides, bromides, and/or iodides) of the alkali metal, the alkaline earth metal, and the rare earth metal.

The alkali metal compound may be selected from alkali metal oxides (such as Li2O, Cs2O, and/or K2O), and alkali metal halides (such as LiF, NaF, CsF, KF, Lil, NaI, CsI, and/or KI). In one embodiment, the alkali metal compound may be selected from LiF, Li2O, NaF, Lil, NaI, CsI, and KI, but embodiments of the present disclosure are not limited thereto.

The alkaline earth-metal compound may be selected from alkaline earth-metal oxides (such as BaO, SrO, CaO, BaxSr1-xO (0<x<1), and/or BaxCa1-xO (0<x<1)). In one embodiment, the alkaline earth-metal compound may be selected from BaO, SrO, and CaO, but embodiments of the present disclosure are not limited thereto.

The rare earth metal compound may be selected from YbF3, ScF3, Sc2O3, Y2O3, Ce2O3, GdF3, and TbF3. In one embodiment, the rare earth metal compound may be selected from YbF3, ScF3, TbF3, YbI3, ScI3, and TbI3, but embodiments of the present disclosure are not limited thereto.

The alkali metal complex, the alkaline earth-metal complex, and the rare earth metal complex may include ions of alkali metal, alkaline earth-metal, and rare earth metal as described above, and a ligand coordinated with a metal ion of the alkali metal complex, the alkaline earth-metal complex, or the rare earth metal complex may be selected from hydroxy quinoline, hydroxy isoquinoline, hydroxy benzoquinoline, hydroxy acridine, hydroxy phenanthridine, hydroxy phenyloxazole, hydroxy phenylthiazole, hydroxy diphenyloxadiazole, hydroxy diphenylthiadiazole, hydroxy phenylpyridine, hydroxy phenylbenzimidazole, hydroxy phenylbenzothiazole, bipyridine, phenanthroline, and cyclopentadiene, but embodiments of the present disclosure are not limited thereto.

The electron injection layer may include (or consist of) an alkali metal, an alkaline earth metal, a rare earth metal, an alkali metal compound, an alkaline earth-metal compound, a rare earth metal compound, an alkali metal complex, an alkaline earth-metal complex, a rare earth metal complex, or any combination thereof, as described above. In one or more embodiments, the electron injection layer may further include an organic material. When the electron injection layer further includes an organic material, the alkali metal, alkaline earth metal, rare earth metal, alkali metal compound, alkaline earth-metal compound, rare earth metal compound, alkali metal complex, alkaline earth-metal complex, rare earth metal complex, or combination thereof may be homogeneously or non-homogeneously dispersed in a matrix including (or consisting of) the organic material.

The second electrode190is located on the organic layer150having the structure described above. The second electrode190may be a cathode, which is an electron injection electrode, and in this regard, a material for forming the second electrode190may be selected from a metal, an alloy, an electrically conductive compound, and any combination thereof, each having a relatively low work function.

The second electrode190may include at least one selected from lithium (Li), silver (Ag), magnesium (Mg), aluminum (Al), aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In), magnesium-silver (Mg—Ag), ITO, and IZO, but embodiments of the present disclosure are not limited thereto. The second electrode190may be a transmissive electrode, a semi-transmissive electrode, or a reflective electrode.

An organic light-emitting device20according toFIG.2includes a first capping layer210, a first electrode110, an organic layer150, and a second electrode190sequentially stacked in this stated order; an organic light-emitting device30according toFIG.3includes a first electrode110, an organic layer150, a second electrode190, and a second capping layer220sequentially stacked in this stated order; and an organic light-emitting device40according toFIG.4includes a first capping layer210, a first electrode110, an organic layer150, a second electrode190, and a second capping layer220.

RegardingFIGS.2to4, the first electrode110, the organic layer150, and the second electrode190may be understood by referring to the description presented in connection withFIG.1.

In each of the organic light-emitting devices20and40, light generated in an emission layer of the organic layer150may pass through the first electrode110(which is a semi-transmissive electrode or a transmissive electrode), and the first capping layer210toward the outside, and in the organic layer150of each of the organic light-emitting devices30and40, light generated in an emission layer may pass through the second electrode190(which is a semi-transmissive electrode or a transmissive electrode) and the second capping layer220toward the outside.

The first capping layer210and the second capping layer220may increase the external luminescent efficiency of the device according to the principle of constructive interference.

The first capping layer210and the second capping layer220may each independently be an organic capping layer consisting of an organic material, an inorganic capping layer consisting of an inorganic material, or a composite capping layer including an organic material and an inorganic material.

At least one of the first capping layer210and the second capping layer220may each independently include at least one material selected from carbocyclic compounds, heterocyclic compounds, amine-based compounds, porphyrin derivatives, phthalocyanine derivatives, naphthalocyanine derivatives, alkali metal complexes, and alkaline earth-metal complexes. The carbocyclic compound, the heterocyclic compound, and the amine-based compound may be optionally substituted with a substituent containing at least one element selected from oxygen (O), nitrogen (N), sulfur (S), selenium (Se), silicon (Si), fluorine (F), chlorine (CI), bromine (Br), and iodine (I). In one embodiment, at least one of the first capping layer210and the second capping layer220may each independently include an amine-based compound.

In one embodiment, at least one of the first capping layer210and the second capping layer220may each independently include the compound represented by Formula 201 or the compound represented by Formula 202.

In one or more embodiments, at least one of the first capping layer210and the second capping layer220may each independently include a compound selected from Compounds HT28 to HT33 and Compounds CP1 to CP5, but embodiments of the present disclosure are not limited thereto:

The organic light-emitting device according to an embodiment has been described in connection withFIGS.1to4. However, embodiments of the present disclosure are not limited thereto.

The layers constituting the hole transport region, the emission layer, the layers constituting the electron transport region may be formed in a set or predetermined region using one or more suitable methods selected from vacuum deposition, spin coating, casting, Langmuir-Blodgett (LB) deposition, ink-jet printing, laser-printing, and laser-induced thermal imaging (LITI).

When the layers constituting the hole transport region, the emission layer, and the layers constituting the electron transport region are formed by spin coating, the spin coating may be performed at a coating speed of about 2,000 rpm to about 5,000 rpm and at a heat treatment temperature of about 80° C. to 200° C., depending on the material to be included and the structure of the layer to be formed.

[General Definition of Substituents]

The term “C6-C60aryloxy group” as used herein refers to —OA102(wherein A102is a C6-C60aryl group), and a C6-C60arylthio group used herein refers to —SA103(wherein A103is a C6-C60aryl group).

The term “C1-C60heteroaryloxy group” as used herein refers to —OA104(wherein A104is a C1-C60heteroaryl group), and the term “C1-C60heteroarylthio group” as used herein refers to —SA105(wherein A105is a C1-C60heteroaryl group).

The term “monovalent non-aromatic condensed heteropolycyclic group” as used herein refers to a monovalent group including two or more rings condensed to each other, at least one heteroatom selected from N, O, Si, P, and S, in addition to carbon atoms (for example, 1 to 60 carbon atoms) as a ring-forming atom, and non-aromaticity in its entire molecular structure. Examples of the monovalent non-aromatic condensed heteropolycyclic group include a carbazolyl group. The term “divalent non-aromatic condensed heteropolycyclic group” as used herein refers to a divalent group having substantially the same structure as the monovalent non-aromatic condensed heteropolycyclic group.

The term “C5-C60carbocyclic group” as used herein refers to a monocyclic or polycyclic group that includes only carbon as a ring-forming atom and consists of 5 to 60 carbon atoms. The C5-C60carbocyclic group may be an aromatic carbocyclic group or a non-aromatic carbocyclic group. The C5-C60carbocyclic group may be a ring, such as benzene, a monovalent group, such as a phenyl group, or a divalent group, such as a phenylene group. In one or more embodiments, depending on the number of substituents connected to the C5-C60carbocyclic group, the C5-C60carbocyclic group may be a trivalent group or a quadrivalent group.

The term “C1-C60heterocyclic group” as used herein refers to a group having substantially the same structure as the C5-C60carbocyclic group, except that as a ring-forming atom, at least one heteroatom selected from N, O, Si, P, and S is used in addition to carbon (the number of carbon atoms may be in a range of 1 to 60).

The term “biphenyl group” as used herein refers to “a phenyl group substituted with a phenyl group”. In other words, the “biphenyl group” is “a substituted phenyl group” having “a C6-C60aryl group” as a substituent.

The term “terphenyl group” as used herein refers to “a phenyl group substituted with a biphenyl group”. The “terphenyl group” is “a substituted phenyl group” having “a C6-C60aryl group substituted with a C6-C60aryl group” as a substituent.

Hereinafter, a compound according to embodiments and an organic light-emitting device according to embodiments will be described in more detail with reference to Synthesis Examples and Examples. The wording “B was used instead of A” used in describing Synthesis Examples indicates that an identical molar equivalent of B was used in place of A.

Synthesis Example

Synthesis Example 1: Synthesis of Compound 1

2,6-diphenyl-9H-carbazole (1 eq), 2,6-difluorobenzonitrile (0.45 eq), and K3PO4(2 eq) were dissolved in DMF and then stirred at 160° C. for 12 hours. After cooling the mixture, the mixture was poured into a NaCl aqueous solution to terminate the reaction, and further stirred for 30 minutes. The resulting precipitate was filtered, extracted with distilled water and DCM, dried over MgSO4, and then dried under reduced pressure. An obtained organic layer (liquid) was purified by column chromatography (MC/Hex) to thereby obtain Compound 1. (Yield: 65%)

Synthesis Example 2: Synthesis of Compound 60

(1) Synthesis of Intermediate 60-1

Intermediate 60-1 was synthesized in substantially the same manner as used to synthesize Compound 1, except that 4-bromo-3,5-difluorobenzonitrile was used instead of 2,6-difluorobenzonitrile. (Yield: 45%)

(2) Synthesis of Compound 60

Intermediate 60-1 (1 eq), (3,5-difluorophenyl)boronic acid (1 eq), Pd(PPh3)4(5 mol %), and 4.15 g of K2CO3(3 eq) were dissolved in a THF/H2O (2:1) mixed solution, and then stirred at 80° C. for 16 hours. The reaction solution was cooled to room temperature, and then extracted three times with water and diethyl ether. An organic layer obtained therefrom was dried over magnesium sulfate, and a residue obtained by evaporation of a solvent was separated and purified by silica gel column chromatography to thereby obtain Compound 60. (Yield: 33%)

Synthesis Example 3: Synthesis of Compound 61

(1) Synthesis of Intermediate 61-1

Intermediate 61-1 was synthesized in the substantially same manner as used to synthesize Compound 1, except that 4-bromo-2,6-difluorobenzonitrile was used instead of 2,6-difluorobenzonitrile. (Yield: 30%)

(2) Synthesis of Compound 61

Compound 61 was synthesized in substantially the same manner as used to synthesize Compound 60, except that Intermediate 61-1 was used instead of Intermediate 60-1. (Yield: 50%)

Synthesis Example 4: Synthesis of Compound 62

(1) Synthesis of Intermediate 62-1

Intermediate 62-1 was synthesized in substantially the same manner as used to synthesize Compound 1, except that 4-bromo-2,6-difluorobenzonitrile was used instead of 2,6-difluorobenzonitrile. (Yield: 50%)

(2) Synthesis of Compound 62

Compound 62 was synthesized in substantially the same manner as used to synthesize Compound 60, except that Intermediate 62-1 was used instead of Intermediate 60-1, and (2,6-difluorophenyl)boronic acid was used instead of (3,5-difluorophenyl)boronic acid. (Yield: 35%)

Synthesis Example 5: Synthesis of Compound 80

(1) Synthesis of Intermediate 80-1

Intermediate 80-1 was synthesized in substantially the same manner as used to synthesize Compound 1, except that 2,6-dimesityl-9H-carbazole was used instead of 2,6-diphenyl-9H-carbazole, and 1-bromo-3,5-difluorobenzene was used instead of 2,6-difluorobenzonitrile. (Yield: 40%)

(2) Synthesis of Compound 80

Compound 80 was synthesized in substantially the same manner as used to synthesize Compound 60, except that Intermediate 80-1 was used instead of Intermediate 60-1, and (4-cyano-2,6-difluorophenyl)boronic acid was used instead of (3,5-difluorophenyl)boronic acid. (Yield: 35%)

Synthesis Example 6: Synthesis of Compound 94

(1) Synthesis of Intermediate 94-1

Intermediate 94-1 was synthesized in substantially the same manner as used to synthesize Compound 1, except that 2,6-di-tert-butyl-9H-carbazole was used instead of 2,6-diphenyl-9H-carbazole, and 4-bromo-2,6-difluorobenzonitrile was used instead of 2,6-difluorobenzonitrile. (Yield: 43%)

(2) Synthesis of Compound 94

Compound 94 was synthesized in substantially the same manner as used to synthesize Compound 62, except that Intermediate 94-1 was used instead of Intermediate 62-1. (Yield: 25%)

Synthesis Example 7: Synthesis of Compound 109

(1) Synthesis of Intermediate 109-1

Intermediate 109-1 was synthesized in substantially the same manner as used to synthesize Intermediate 94-1, except that 6-(tert-butyl)-2-phenyl-9H-carbazole was used instead of 2,6-di-tert-butyl-9H-carbazole. (Yield: 40%)

(2) Synthesis of Compound 109

Compound 109 was synthesized in substantially the same manner as used to synthesize Compound 60, except that Intermediate 109-1 was used instead of Intermediate 60-1. (Yield: 36%)

Synthesis Example 8: Synthesis of Compound 113

Compound 113 was synthesized in substantially the same manner as used to synthesize Compound 1, except that 6,6′-difluoro-[1,1′-biphenyl]-3,3′-dicarbonitrile was used instead of 2,6-difluorobenzonitrile. (Yield: 20%)

1H NMR and MS/FAB of the compounds synthesized according to Synthesis Examples 1 to 9 are shown in Table 1 below.

Additional compounds other than the compounds shown in Table 1 may be easily recognized by those skilled in the art by referring to the above synthesis routes and source materials.

The compounds listed in Table 1 were respectively mixed in poly(methyl methacrylate) (PMMA) at a mass ratio of 9:1, and then dissolved in dichloromethane to obtain a solution which was then spin-coated on quartz and then measured.

HOMO energy levels were measured by cyclic voltammetry (CV). LUMO energy levels were measured by calculating a difference of optical band gap at HOMO energy level. Triplet (T1) energy levels were measured from 77K photoluminescence (PL) spectra. Absolute photo-luminescence quantum yields (AbPLQY) were measured using a film doped with each compound at a concentration of 10 wt % in PMMA. The measured results are shown in Table 2.

As an anode, a 15 Ωcm2(1,200 Å) ITO glass substrate available from Corning Inc. was cut to a size of 50 mm×50 mm×0.7 mm, sonicated using isopropyl alcohol and pure water for 5 minutes each, and then cleaned by irradiation of ultraviolet rays and ozone exposure for 30 minutes. Then, the resultant glass substrate was loaded onto a vacuum deposition apparatus. NPD was vacuum-deposited on the substrate to form a hole injection layer having a thickness of 300 Å, and then TCTA as a hole transport compound was vacuum-deposited thereon to form a first hole transport layer having a thickness of 200 Å. CzSi as a hole transport compound was vacuum-deposited on the first hole transport layer to form a second hole transport layer having a thickness of 100 Å. DPEPO and Compound 1 were co-deposited at a weight ratio of 90:10 on the second hole transport layer to form an emission layer having a thickness of 200 Å. Subsequently, DPEPO was deposited on the emission layer to form a first electron transport layer having a thickness of 200 Å, and then, TPBI was deposited on the first electron transport layer to form a second electron transport layer having a thickness of 300 Å.

LiF, which is a halogenated alkaline metal, was deposited on the second electron transport layer having a thickness of 10 Å, and then Al was vacuum deposited to form a LiF/AI electrode (cathode electrode) having a thickness of 3,000 Å, thereby completing manufacture of an organic light-emitting device.

Examples 2 to 8 and Comparative Examples 1 to 3

Additional organic light-emitting devices were manufactured in substantially the same manner as in Example 1, except that the respective Compounds described in Table 3 were used instead of Compound 1 in forming an emission layer.

The organic light-emitting devices manufactured in Examples 1 to 8 and Comparative Examples 1 to 3, were driven at a current density of 50 mA/cm2and their performances were measured, and the results are shown in Table 1.

As shown in Table 3, when a compound according to an embodiment of the present disclosure is used as a dopant in an emission layer, all Examples using the compound of the present disclosure showed excellent I-V-L characteristics including improved driving voltage and higher efficiency, compared to the organic light-emitting device of Comparative Example 1 using DPS from the related art. In addition, it can be confirmed that compared to Comparative Examples 2 and 3, driving voltage is improved and luminescence efficiency is excellent.

In other words, when the compound of the present disclosure is used as a material for an emission layer, the compound exhibits excellent effects in terms of driving voltage, luminance, and efficiency.

Although the present disclosure has been described with reference to the Synthesis Examples and Examples, these examples are provided for illustrative purpose only, and one of ordinary skill in the art may understand that these examples may have various modifications and other examples equivalent thereto. Accordingly, the scope of the present disclosure should be determined by the technical concept of the claims.