CN112851687A - Organic compound, organic light emitting diode including the same, and device including the same - Google Patents

Abstract

The present disclosure relates to an organic compound, an organic light emitting diode and a device including the same, and more particularly, to an organic compound having a structure of the following chemical formula 1, and an Organic Light Emitting Diode (OLED) and an organic light emitting device including the same. The organic compound includes a triazine moiety for an electron acceptor and a fused heteroaromatic moiety for an electron donor separate from the triazine moiety. The organic compound includes electricity in a single moleculeA sub-acceptor moiety and an electron donor moiety, so that electrons can move within the molecule. In addition, since the organic compound includes a rigid fused heteroaromatic ring, three-dimensional deformation of the organic compound is limited, and thus the compound may have excellent luminous efficiency and color purity. [ chemical formula 1]

Description

Organic compound, organic light emitting diode including the same, and device including the same

Cross Reference to Related Applications

The present application claims priority from korean patent application No. 10-2019-0155568, filed in korea at 11/28/2019 and korean patent application No. 10-2020-0133836, filed in korea at 10/16/2020, the respective contents of which are hereby incorporated by reference in their entireties.

Technical Field

The present disclosure relates to an organic compound, and more particularly, to an organic compound having excellent light emitting properties, an organic light emitting diode and an organic light emitting device including the same.

Background

As display devices become larger, a flat display device having a lower space requirement is required. Among flat panel display devices that are currently widely used, Organic Light Emitting Diodes (OLEDs) are rapidly replacing liquid crystal display devices (LCDs).

The OLED can be formed to have a thickness less than

And can realize unidirectional or bidirectional image as electrode structureAnd (4) molding. In addition, the OLED may be formed on a flexible transparent substrate (e.g., a plastic substrate), so that the OLED may easily realize a flexible or foldable display. In addition, the OLED can be driven at a lower voltage of 10V or less. In addition, the OLED has relatively low driving power consumption compared to a plasma display panel and an inorganic electroluminescent device, and the color purity of the OLED is very high. In particular, the OLED can implement red, green, and blue colors, and thus it attracts much attention as a light emitting device.

In the OLED, when charges are injected into an emission material layer between an electron injection electrode (i.e., a cathode) and a hole injection electrode (i.e., an anode), the charges are recombined to form excitons, and then light is emitted as the recombined excitons are converted to a stable ground state. Conventional fluorescent materials have low luminous efficiency because only singlet excitons participate in the light emitting process. On the other hand, phosphorescent materials in which triplet excitons and singlet excitons participate in the light emission process exhibit higher luminous efficiency compared to fluorescent materials. However, the emission lifetime of the metal complex, which is a typical phosphorescent material, is too short to be used in commercial devices. In particular, a light-emitting material for realizing blue light emission shows deteriorated light-emitting properties and a short light-emitting lifetime.

Disclosure of Invention

Accordingly, embodiments of the present disclosure are directed to an organic compound that substantially obviates one or more problems due to limitations and disadvantages of the related art, and an OLED and an organic light-emitting device including the same.

An object of the present disclosure is to provide an organic compound having excellent luminous efficiency and color purity, and an OLED and an organic light-emitting device using the same.

Additional features and aspects will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the inventive concepts presented herein. Other features and aspects of the inventive concept may be realized and attained by the structure particularly pointed out or derived from the written description and claims hereof as well as the appended drawings.

To achieve these and other aspects of the inventive concept as embodied and broadly described, the present disclosure provides an organic compound having a structure of the following chemical formula 1:

[ chemical formula 1]

Wherein R is₁To R₁₂Each independently selected from hydrogen, halogen, cyano, unsubstituted or substituted C₁-C₂₀Alkyl, unsubstituted or substituted C₁-C₂₀Alkoxy, unsubstituted or substituted C₁-C₂₀Alkylamino radical, unsubstituted or substituted C₆-C₃₀Aryl and unsubstituted or substituted C₃-C₃₀Heteroaryl or R₁To R₁₂Two adjacent groups in (a) form an unsubstituted or substituted C₆-C₂₀Aromatic ring or unsubstituted or substituted C₃-C₃₀Heteroaromatic ring, wherein R₁To R₄Is cyano; r₁₃To R₁₅Each independently selected from hydrogen, unsubstituted or substituted C₁-C₂₀Alkyl, unsubstituted or substituted C₁-C₂₀Alkoxy, unsubstituted or substituted C₁-C₂₀Alkylamino radical, unsubstituted or substituted C₆-C₃₀Aryl and unsubstituted or substituted C₃-C₃₀Heteroaryl groups; and a is a fused heteroaromatic ring having the structure of the following chemical formula 2:

[ chemical formula 2]

Wherein R is₂₁To R₂₄Each independently selected from hydrogen, halogen, cyano, unsubstituted or substituted C₁-C₂₀Alkyl, unsubstituted or substituted C₁-C₂₀Alkoxy, unsubstituted or substituted C₁-C₂₀Alkylamino radical, unsubstituted or substituted C₆-C₃₀Aryl and unsubstituted or substituted C₃-C₃₀Heteroaryl or R₂₁To R₂₄Two adjacent groups in (a) form an unsubstituted or substituted C₆-C₂₀Aromatic ring or unsubstituted or substituted C₃-C₃₀A heteroaromatic ring; x is NR₂₅Oxygen (O) or sulfur (S), wherein R₂₅Selected from hydrogen, unsubstituted or substituted C₁-C₂₀Alkyl, unsubstituted or substituted C₁-C₂₀Alkoxy, unsubstituted or substituted C₁-C₂₀Alkylamino radical, unsubstituted or substituted C₆-C₃₀Aryl and unsubstituted or substituted C₃-C₃₀Heteroaryl groups.

In another aspect, the present disclosure provides an OLED comprising: a first electrode; a second electrode facing the first electrode; and an emission material layer disposed between the first electrode and the second electrode, wherein the first emission material layer includes the organic compound.

In another aspect, the present disclosure provides an organic light emitting device comprising a substrate and an OLED as described above disposed on the substrate.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the inventive concepts as claimed.

Drawings

The accompanying drawings, which are included to provide a further understanding of the disclosure and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the disclosure and together with the description serve to explain the principle of the disclosure.

Fig. 1 is a schematic diagram illustrating a light emitting mechanism of an organic compound of the present disclosure.

Fig. 2 is a schematic cross-sectional view of an organic light emitting display device illustrating one exemplary aspect of the present disclosure.

Fig. 3 is a schematic cross-sectional view illustrating an OLED according to one exemplary aspect of the present disclosure.

Fig. 4 is a schematic diagram illustrating a light emitting mechanism due to an energy level bandgap between light emitting materials according to an exemplary aspect of the present disclosure.

Fig. 5 is a schematic cross-sectional view illustrating an OLED according to another exemplary aspect of the present disclosure.

Fig. 6 is a schematic diagram illustrating a light emitting mechanism due to an energy level bandgap between light emitting materials according to another exemplary aspect of the present disclosure.

Fig. 7 is a schematic cross-sectional view illustrating an OLED diode according to another exemplary aspect of the present disclosure.

Fig. 8 is a schematic diagram illustrating a light emitting mechanism due to an energy level bandgap between light emitting materials according to another exemplary aspect of the present disclosure.

Fig. 9 is a schematic cross-sectional view illustrating an OLED according to another exemplary aspect of the present disclosure.

Fig. 10 is a schematic diagram illustrating a light emitting mechanism due to an energy level bandgap between light emitting materials according to another exemplary aspect of the present disclosure.

Fig. 11 is a schematic cross-sectional view illustrating an OLED according to still another exemplary aspect of the present disclosure.

Fig. 12 is a schematic cross-sectional view illustrating an organic light emitting display device according to still another exemplary aspect of the present disclosure.

Fig. 13 is a schematic cross-sectional view illustrating an OLED according to still another exemplary aspect of the present disclosure.

Fig. 14 is a schematic cross-sectional view illustrating an organic light emitting display device according to still another exemplary aspect of the present disclosure.

Fig. 15 is a schematic cross-sectional view illustrating an OLED according to still another exemplary aspect of the present disclosure.

Fig. 16 is a schematic cross-sectional view illustrating an OLED according to still another exemplary aspect of the present disclosure.

Detailed Description

Reference will now be made in detail to aspects of the present disclosure, examples of which are illustrated in the accompanying drawings.

[ organic Compound ]

An organic compound applied to an Organic Light Emitting Diode (OLED) should have excellent charge affinity and maintain stable properties during driving of the OLED. In particular, the light emitting material is the most important factor determining the luminous efficiency of the OLED. The light emitting material should have high light emitting efficiency and high charge mobility, and should have an appropriate energy level with respect to other materials applied to the same emission layer and an adjacently disposed emission layer. The organic compound of the present disclosure has both an electron donor and an electron acceptor in one molecule, so that the organic compound may have a delayed fluorescence property. The organic compound of the present disclosure may have the structure of the following chemical formula 1:

[ chemical formula 1]

In chemical formula 1, R₁To R₁₂Each independently selected from hydrogen, halogen, cyano, unsubstituted or substituted C₁-C₂₀Alkyl, unsubstituted or substituted C₁-C₂₀Alkoxy, unsubstituted or substituted C₁-C₂₀Alkylamino radical, unsubstituted or substituted C₆-C₃₀Aryl and unsubstituted or substituted C₃-C₃₀Heteroaryl or R₁To R₁₂Two adjacent groups in (a) form an unsubstituted or substituted C₆-C₂₀Aromatic ring or unsubstituted or substituted C₃-C₃₀Heteroaromatic ring, wherein R₁To R₄Is cyano; r₁₃To R₁₅Each independently selected from hydrogen, unsubstituted or substituted C₁-C₂₀Alkyl, unsubstituted or substituted C₁-C₂₀Alkoxy, unsubstituted or substituted C₁-C₂₀Alkylamino radical, unsubstituted or substituted C₆-C₃₀Aryl and unsubstituted or substituted C₃-C₃₀Heteroaryl groups; and a is a fused heteroaromatic ring having the structure of the following chemical formula 2:

[ chemical formula 2]

In chemical formula 2, R₂₁To R₂₄Each independently selected from hydrogen, halogen, cyano, unsubstituted or substituted C₁-C₂₀Alkyl, unsubstituted or substituted C₁-C₂₀Alkoxy, unsubstituted or substituted C₁-C₂₀Alkylamino radical, unsubstituted or substituted C₆-C₃₀Aryl and unsubstituted or substituted C₃-C₃₀Heteroaryl or R₂₁To R₂₄Two adjacent groups in (a) form an unsubstituted or substituted C₆-C₂₀Aromatic ring or unsubstituted or substituted C₃-C₃₀A heteroaromatic ring; x is NR₂₅Oxygen (O) or sulfur (S), wherein R₂₅Selected from hydrogen, unsubstituted or substituted C₁-C₂₀Alkyl, unsubstituted or substituted C₁-C₂₀Alkoxy, unsubstituted or substituted C₁-C₂₀Alkylamino radical, unsubstituted or substituted C₆-C₃₀Aryl and unsubstituted or substituted C₃-C₃₀Heteroaryl groups.

As used herein, the term "without substituents" means that hydrogen is attached, in which case hydrogen includes protium, deuterium, and tritium.

As used herein, a substituent in the term "having a substituent" includes, but is not limited to, C having no substituent or halogen substitution₁-C₂₀Alkyl, unsubstituted or halogen-substituted C₁-C₂₀Alkoxy, halogen, cyano, -CF₃Hydroxyl, carboxyl, carbonyl, amino, C₁-C₁₀Alkylamino radical, C₆-C₃₀Arylamino, C₃-C₃₀Heteroarylamino group, C₆-C₃₀Aryl radical, C₃-C₃₀Heteroaryl, nitro, hydrazide, sulfonate, C₁-C₂₀Alkylsilyl group, C₆-C₃₀Arylsilyl and C₃-C₃₀A heteroaryl silyl group.

As used herein, the term "hetero", such as in "heteroaryl ring", "heteroarylene group", "heteroarylalkylene group", "heteroaryloxylene group", "heterocycloalkyl group", "heteroaryl group", "heteroarylalkyl group", "heteroaryloxy group", "heteroarylamino group", means that at least one carbon atom (e.g., 1 to 5 carbon atoms) constituting an aromatic or aliphatic ring is substituted with at least one heteroatom selected from the group consisting of N, O, S, P and combinations thereof.

In one exemplary aspect, R₁To R₁₅And R₂₁To R₂₄C in (1) respectively₆-C₃₀The aryl group may comprise C₆-C₃₀Aryl radical, C₇-C₃₀Aralkyl radical, C₆-C₃₀Aryloxy radical and C₆-C₃₀An arylamino group. In another exemplary aspect, R₁To R₁₅And R₂₁To R₂₄C in (1) respectively₃-C₃₀Heteroaryl may include C₃-C₃₀Heteroaryl group, C₄-C₃₀Heteroaralkyl radical, C₃-C₃₀Heteroaryloxy and C₃-C₃₀A heteroaromatic amino group.

As an example, R₁To R₁₅And R₂₁To R₂₄C in each case₆-C₃₀Aryl groups may independently include, but are not limited to, non-fused or fused aryl groups such as phenyl, biphenyl, terphenyl, naphthyl, anthracenyl, pentalenyl, indenyl, indenoindenyl, heptalenyl, phenylphenyl, indacenyl, phenalenyl, phenanthrenyl, benzophenanthrenyl, dibenzophenanthrenyl, azulenyl, pyrenyl, fluoranthenyl, triphenylenyl, triphenyl,

Aryl, tetra-biphenyl, butyl, heptadienyl, picene, pentabiphenyl, penta-phenyl, fluorenyl, indenofluorenyl, and spirofluorenyl.

In another exemplary aspect, R₁To R₁₅And R₂₁To R₂₄C in each case₃-C₃₀Heteroaryl groups may independently include, but are not limited to, non-fused or fused heteroaryl groups, such as pyrrolyl, pyridyl, pyrimidinyl, pyrazinyl, pyridazinyl, triazinyl, tetrazinyl, imidazolyl, pyrazolyl, indolyl, isoindolyl, indazolyl, indolizinyl, pyrrolizinyl, carbazolyl, benzocarbazolyl, dibenzocarbazolyl, indolocarbazolyl, indenocarbazolyl, benzofurocarbazolyl, benzothienocarbazolyl, carbolinyl, quinolyl, isoquinolyl, phthalazinyl, quinoxalinyl, cinnolinyl, quinazolinyl, purino, benzoquinolinyl, benzisoquinolinyl, benzoquinazolinyl, benzoquinoxalinyl, acridinyl, phenazinyl, phenoxazinyl, phenothiazinyl, phenanthrolinyl, perimidine, phenanthridinyl, pteridinyl, naphthyridinyl, furanyl, triazinyl, quinoxalinyl, cinnolinyl, quinoxalinyl, and phenanthridinyl groups, Pyranyl, oxazinyl, oxazolyl, oxadiazolyl, triazolyl, dioxinyl, benzofuranyl, dibenzofuranyl, thiopyranyl, xanthenyl, chromenyl, isochromenyl, thiazinyl, thienyl, benzothienyl, dibenzothienyl, difuranopyrazinyl, benzofurodibenzofuranyl, benzothiophenylthiothienyl, benzothiophenodibenzofuranyl, benzothiophenobenzophenylbenzofuranyl, benzothiophenylbenzofuranyl, benzofuranyl, dibenzofuranyl, and combinations thereofAnd dibenzofuranyl, xanthene-linked spiroacridinyl, substituted with at least one C₁-C₁₀An alkyl dihydroacridinyl group and an N-substituted spirofluorenyl group.

As an example, R₁To R₁₅And R₂₁To R₂₄Each is aryl or heteroaryl, R₁To R₁₅And R₂₁To R₂₄Each may independently be, but is not limited to, phenyl, biphenyl, pyrrolyl, triazinyl, furanyl, benzofuranyl, dibenzofuranyl, thienyl, benzothienyl, dibenzothienyl, or carbazolyl.

In another alternative aspect, R₁To R₁₂In or R₂₁To R₂₄Two adjacent groups in (A) may form C₆-C₂₀Aromatic ring or C₃-C₃₀(preferably C)₃-C₂₀) A heteroaromatic ring. As an example, when R₁To R₁₂In or R₂₁To R₂₄When two adjacent groups in (a) independently form a fused aromatic ring or fused heteroaromatic ring, the newly formed fused aromatic ring or heteroaromatic ring may include, but is not limited to, aromatic rings such as benzene and/or naphthalene rings; or heteroaromatic rings, such as pyridine, pyrimidine and/or carbazole rings.

The organic compounds having the structures of chemical formulas 1 and 2 may be used as dopants in the emission layer and may have delayed fluorescence properties. The OLED includes a hole injection layer, a hole injection layer (anode), an electron injection layer (cathode), and an emission layer disposed between the anode and the cathode. In order to improve light emission efficiency, the emission layer may include a Hole Injection Layer (HIL), a Hole Transport Layer (HTL), an Emission Material Layer (EML), an Electron Transport Layer (ETL), and an Electron Injection Layer (EIL) respectively sequentially disposed on the hole injection layer. When holes injected from the anode and electrons injected from the cathode are recombined to form excitons in an excited state, the OLED emits light as unstable excitons are transferred to a stable ground state.

External quantum efficiency (EQE, η) of luminescent materials in EML_ext) Can be calculated by the following formula:

η_ext＝ηs/T×Γ×Φ×η_{output coupling}

Wherein eta_S/TIs the singlet/triplet ratio; Γ is the charge balance factor; Φ is the radiation efficiency; eta_{Output coupling}Is the output coupling efficiency.

η_S/TRepresents the exciton-to-light conversion rate, which is 0.25 in the conventional fluorescent material. When holes and electrons meet to form excitons, singlet excitons of paired spins and triplet excitons of unpaired spins are theoretically generated at a ratio of 1: 3. In the fluorescent material, only singlet excitons participate in light emission, and the remaining 75% of triplet excitons do not participate in light emission. The charge balance factor Γ represents the balance of holes and electrons forming an exciton, typically assuming a 1:1 match of 100% to have a value of "1". The radiation efficiency Φ is a value involved in the luminous efficiency of the actual luminescent material and depends on the photoluminescence of the dopants in the host-dopant system. The outcoupling efficiency is the ratio of light extracted outwards from the light emitted by the luminescent material. When a thin film is used by depositing an isotropic type light emitting material, individual light emitting molecules exist in a random state without any specific orientation. This randomly oriented outcoupling efficiency is generally assumed to be "0.2". Therefore, when all four factors defined in the above formula are considered, the maximum luminous efficiency of the OLED using the conventional fluorescent material is only about 5%.

On the other hand, phosphorescent materials have different light emission mechanisms that convert both singlet excitons and triplet excitons into light. Phosphorescent materials convert singlet excitons into triplet excitons through intersystem crossing (ISC). Therefore, when a phosphorescent material using both singlet excitons and triplet excitons is used, low luminous efficiency of the fluorescent material can be improved. However, when the conjugated structure or the condensed ring structure of the organic aromatic compound is increased, the excited triplet level of the compound is greatly decreased, and thus organic molecules that can be used as phosphorescent hosts are greatly limited. In addition, the phosphorescent host having a wide band gap causes a delay in charge injection and transport, and thus the OLED including the host exhibits an increased driving voltage and a deteriorated light emission life.

Delayed fluorescence materials have been developed which can solve the problems associated with the fluorescent and/or phosphorescent materials of the conventional art. RepresentsThe delayed fluorescence material is a Thermally Activated Delayed Fluorescence (TADF) material. The light emission mechanism of the delayed fluorescent material will be explained with reference to fig. 1, and fig. 1 is a schematic view showing the light emission mechanism of the organic compound of the present disclosure. As shown in FIG. 1, the singlet level S in the delayed fluorescent material DF₁ ^DFExciton and triplet energy level T₁ ^DFMay be transferred to an intermediate energy level state, i.e., ICT (intramolecular charge transfer) state, and then the intermediate state exciton may be transferred to a ground state (S)₀ ^DF；S₁ ^DF→ICT←T₁ ^DF)。

Since compounds that can be in the ICT state have little orbital overlap between the HOMO and LUMO states, there is little interaction between the HOMO and LUMO states. As a result, the change in the spin state of the electron has no influence on other electrons, and a new charge transfer band (CT band) that does not follow the selection rule is formed in the delayed fluorescent material. In the case of driving an OLED including a delayed fluorescent material, 25% of singlet excitons and 75% of triplet excitons are converted into an ICT state by heat or an electric field, and then the converted excitons transition to a ground state S₀And emits light. Therefore, the delayed fluorescent material can theoretically have an internal quantum efficiency of 100%.

Excited singlet level S of delayed fluorescence material DF₁ ^DFAnd excited triplet energy level T₁ ^DFEnergy band gap Δ E between_ST ^DFMust be equal to or less than about 0.3eV, for example, from about 0.05 to about 0.3 eV. Singlet energy level S₁ ^DFAnd triplet energy level T₁ ^DFEnergy band gap Δ E between_ST ^DFSmall materials may exhibit ordinary fluorescence (with singlet level S) using ground state crossing (ISC)₁ ^DFCan transition to the ground state) and delayed fluorescence using reverse intersystem crossing (RISC) (in which the triplet level T is₁ ^DFThe exciton can be transited upwards to the singlet state energy level S₁ ^DFThen from the triplet energy level T₁ ^DFSinglet energy level S of transition₁ ^DFThe exciton of (a) may transition to the ground state S₀ ^DF)。

As shown in chemical formulas 1 and 2, the organic compound includes a triazine moiety serving as an electron acceptor, a fused heteroaromatic moiety (e.g., an indolocarbazole moiety, a benzofurocarbazole moiety, and/or a benzothienocarbazole moiety) serving as an electron donor, and a phenylene moiety between the triazine moiety and the fused heteroaromatic moiety.

The conjugated structure between the fused heteroaromatic moiety of the electron donor and the triazine moiety of the electron acceptor is limited due to steric hindrance between these moieties. The molecule separates between a HOMO energy state and a LUMO energy state, thereby forming a dipole between the fused heteroaromatic moiety and the triazine moiety. The organic compound has enhanced luminous efficiency as the dipole moment in the molecule increases. The phenylene ring between the electron acceptor and the electron donor allows the distance between these moieties to be increased. Therefore, the overlap between HOMO and LUMO within a molecule is reduced, and the excited triplet level T can be lowered₁ ^DFAnd excited singlet energy level S₁ ^DFEnergy band gap Δ E between_ST ^DF。

In addition, the electron donor is composed of a rigid fused heteroaromatic ring, and thus the organic compound has a limited three-dimensional structure. When the organic compound emits light, there is no energy loss due to a change in three-dimensional configuration, and since the organic compound has a limited emission spectrum, the organic compound can achieve high color purity.

When an organic compound is used for an emission layer of the OLED (e.g., a dopant in the EML), the OLED may reduce its driving voltage and improve its light emitting efficiency. Since the OLED can be driven at a low voltage, the material in the OLED can be prevented from being deteriorated by heat generated by a high voltage. Since the current density of the OLED may be reduced due to the high light emitting efficiency of the organic compound, a load caused by driving the OLED is reduced, and the light emitting life of the OLED is enhanced.

In addition, the excited triplet level T of the organic compound having the structures of chemical formulas 1 and 2₁ ^DFMay be lower than the excited triplet level of a conventional phosphorescent material and may have a bandgap energy level narrower than that of the phosphorescent material. Unlike conventional phosphorescent materials, doIt is required to use an organic compound having a high triplet energy level and a wide band gap as a host. In addition, charge injection and transport delay problems due to the use of wide bandgap bodies can be prevented.

For example, the organic compounds of chemical formulas 1 and 2 may have, but are not limited to, an excited triplet level T of about 2.4eV to about 2.75eV₁ ^DFAnd a HOMO-LUMO level bandgap of from about 2.3eV to about 3.0eV, preferably from about 2.5eV to about 2.8 eV.

In one exemplary aspect, the 5-membered ring of the fused ring "a" in chemical formula 1 may be attached to the para position (i.e., the 3,4 or 5,6 position) of the carbazole moiety attached to the phenylene ring. As an example, such an organic compound may have the structure of the following chemical formula 3:

[ chemical formula 3]

In chemical formula 3, R₁To R₁₅Are respectively the same as defined in chemical formula 1, R₂₁And R₂₂Are respectively the same as defined in chemical formula 2; and B is a fused heteroaromatic ring having the structure of the following chemical formula 4:

[ chemical formula 4]

In chemical formula 4, R₂₃、R₂₄And X are respectively the same as defined in chemical formula 2.

In another exemplary aspect, the 5-membered ring of the fused ring "a" in chemical formula 1 may be attached to the meta position (i.e., 2,3 or 6,7 position) of the carbazole moiety attached to the phenylene ring. As an example, such an organic compound may have a structure of the following chemical formula 5:

[ chemical formula 5]

In chemical formula 5, R₁To R₁₅Are respectively the same as defined in chemical formula 1, R₂₁And R₂₂Are respectively the same as defined in chemical formula 2; and B is a fused heteroaromatic ring having the structure of the following chemical formula 6:

[ chemical formula 6]

In chemical formula 6, R₂₃、R₂₄And X are respectively the same as defined in chemical formula 2.

In another exemplary aspect, the 5-membered ring of the fused ring "a" in chemical formula 1 may be attached to the ortho position (i.e., position 1,2 or 7, 8) of the carbazole moiety attached to the phenylene ring. As an example, such an organic compound may have the structure of the following chemical formula 7:

[ chemical formula 7]

In chemical formula 7, R₁To R₁₅Are respectively the same as defined in chemical formula 1, R₂₁And R₂₂Are respectively the same as defined in chemical formula 2; and B is a fused heteroaromatic ring having the structure of the following chemical formula 8:

[ chemical formula 8]

In chemical formula 8, R₂₃、R₂₄And X are respectively the same as defined in chemical formula 2.

In another exemplary aspect, two groups substituted onto the triazine moiety can include the same aryl group. As an example, such an organic compound may include any organic compound having the structure of the following chemical formula 9:

[ chemical formula 9]

In another exemplary aspect, the two groups substituted onto the triazine moiety can include different aromatic rings. As an example, such an organic compound may include any organic compound having the structure of the following chemical formula 10:

[ chemical formula 10]

In another exemplary aspect, at least one of the two groups substituted to the triazine moiety can include a heteroaromatic ring. Such an organic compound may include any organic compound having the structure of the following chemical formula 11:

[ chemical formula 11]

[ organic light-emitting device and OLED ]

The organic compound having the structure of chemical formulas 1 to 11 may be applied to the EML of the OLED such that it can reduce a driving voltage, enhance light emitting efficiency, and improve the light emitting life of the OLED. The OLED of the present disclosure may be applied to an organic light emitting device, such as an organic light emitting display device or an organic light emitting lighting device. An organic light emitting display device including the OLED will be described. Fig. 2 is a schematic cross-sectional view of an organic light emitting display device according to an exemplary aspect of the present disclosure.

As shown in fig. 2, the organic light emitting display device 100 includes a substrate 110, a thin film transistor Tr on the substrate 110, and an Organic Light Emitting Diode (OLED) D connected to the thin film transistor Tr.

The substrate 110 may include, but is not limited to, glass, thin flexible materials, and/or polymer plastics. For example, the flexible material may be selected from the group consisting of Polyimide (PI), Polyethersulfone (PES), polyethylene naphthalate (PEN), polyethylene terephthalate (PET), Polycarbonate (PC), and combinations thereof, but is not limited thereto. The substrate 110 on which the thin film transistor Tr and the OLED D are disposed forms an array substrate.

The buffer layer 122 may be disposed on the substrate 110, and the thin film transistor Tr is disposed on the buffer layer 122. The buffer layer 122 may be omitted.

The semiconductor layer 120 is disposed on the buffer layer 122. In one exemplary aspect, the semiconductor layer 120 may include, but is not limited to, an oxide semiconductor material. In this case, a light blocking pattern may be provided under the semiconductor layer 120, and the light blocking pattern may prevent light from being incident toward the semiconductor layer 120, thereby preventing the semiconductor layer 120 from being deteriorated by the light. Alternatively, the semiconductor layer 120 may include, but is not limited to, polysilicon. In this case, opposite edges of the semiconductor layer 120 may be doped with impurities.

A gate insulating layer 124 formed of an insulating material is disposed on the semiconductor layer 120. The gate insulating layer 124 may include, but is not limited to, an inorganic insulating material, such as silicon oxide (SiO)_x) Or silicon nitride (SiN)_x)。

A gate electrode 130 made of a conductive material such as metal is disposed on the gate insulating layer 124 so as to correspond to the center of the semiconductor layer 120. Although the gate insulating layer 124 is disposed on the entire region of the substrate 110 in fig. 1, the gate insulating layer 124 may be patterned identically to the gate electrode 130.

An interlayer insulating layer 132 formed of an insulating material is disposed on the gate electrode 130, covering the entire surface of the substrate 110. The interlayer insulating layer 132 may include, but is not limited to, an inorganic insulating material (e.g., silicon oxide (SiO))_x) Or silicon nitride (SiN)_x) Or an organic insulating material (e.g., benzocyclobutene or photo-acrylic).

The interlayer insulating layer 132 has first and second semiconductor layer contact holes 134 and 136 exposing both sides of the semiconductor layer 120. The first and second semiconductor layer contact holes 134 and 136 are disposed on both sides of the gate electrode 130, spaced apart from the gate electrode 130. In fig. 1, a first semiconductor layer contact hole 134 and a second semiconductor layer contact hole 136 are formed in the gate insulating layer 124. Alternatively, when the gate insulating layer 124 is identically patterned with the gate electrode 130, the first and second semiconductor layer contact holes 134 and 136 are formed only within the interlayer insulating layer 132.

A source electrode 144 and a drain electrode 146 made of a conductive material such as metal are disposed on the interlayer insulating layer 132. The source electrode 144 and the drain electrode 146 are spaced apart from each other with respect to the gate electrode 130 and contact both sides of the semiconductor layer 120 through the first semiconductor layer contact hole 134 and the second semiconductor layer contact hole 136, respectively.

The semiconductor layer 120, the gate electrode 130, the source electrode 144, and the drain electrode 146 constitute a thin film transistor Tr, which functions as a driving element. The thin film transistor Tr in fig. 1 has a coplanar structure in which a gate electrode 130, a source electrode 144, and a drain electrode 146 are disposed on a semiconductor layer 120. Alternatively, the thin film transistor Tr may have a reverse-overlap structure in which a gate electrode is disposed under a semiconductor layer and source and drain electrodes are disposed on the semiconductor layer. In this case, the semiconductor layer may include amorphous silicon.

The gate and data lines intersect each other to define a pixel region, and a switching element connected to the gate and data lines may be further formed in the pixel region of fig. 1. The switching element is connected to a thin film transistor Tr as a driving element. Further, the power line is spaced in parallel with the gate line or the data line, and the thin film transistor Tr may further include a storage capacitor configured to constantly maintain a voltage of the gate electrode during one frame.

In addition, the organic light emitting display device 100 may include a color filter containing a dye or pigment for transmitting light of a specific wavelength emitted from the OLED D. For example, a color filter may transmit light of a particular wavelength, such as red (R), green (G), and/or blue (B), for example. Each of the red, green and blue color filters may be formed in each pixel region, respectively. In this case, the organic light emitting display device 100 may implement full color through a color filter.

For example, when the organic light emitting display apparatus 100 is a bottom emission type, a color filter may be disposed on the interlayer insulating layer 132 corresponding to the OLED D. Alternatively, when the organic light emitting display apparatus 100 is a top emission type, the color filter may be disposed on the OLED D (i.e., the second electrode 230).

In addition, the organic light emitting device 100 may include a color conversion layer (not shown) that converts light of a specific wavelength among the light emitted from the OLED D into light of a long wavelength range. The color conversion layer may comprise inorganic luminescent particles, such as quantum dots or quantum rods. For example, the color conversion layer may be disposed above or below the OLED D.

A passivation layer 150 is disposed on the source and drain electrodes 144 and 146 on the entire substrate 110. The passivation layer 150 has a flat top surface and a drain electrode contact hole 152 exposing the drain electrode 146 of the thin film transistor Tr. Although the drain electrode contact hole 152 is disposed on the second semiconductor layer contact hole 136, it may be spaced apart from the second semiconductor layer contact hole 136.

The OLED D includes a first electrode 210 disposed on the passivation layer 150 and connected to the drain electrode 146 of the thin film transistor Tr. The OLED D further includes an emission layer 220 and a second electrode 230 each sequentially disposed on the first electrode 210.

The first electrode 210 is disposed in each pixel region. The first electrode 210 may be an anode and include a conductive material having a relatively high work function value. For example, the first electrode 210 may include, but is not limited to, a transparent conductive material such as Indium Tin Oxide (ITO), Indium Zinc Oxide (IZO), Indium Tin Zinc Oxide (ITZO), tin oxide (SnO), zinc oxide (ZnO), Indium Cerium Oxide (ICO), and aluminum-doped zinc oxide (AZO), etc.

In one exemplary aspect, when the organic light emitting display apparatus 100 is a bottom emission type, the first electrode may have a single-layer structure of a transparent conductive oxide. Alternatively, when the organic light emitting display device 100 is a top emission type, a reflective electrode or a reflective layer may be disposed under the first electrode 210. For example, the reflective electrode or layer may include, but is not limited to, silver (Ag) or aluminum-palladium-copper (APC) alloy. In addition, a bank layer 160 is disposed on the passivation layer 150 to cover an edge of the first electrode 210. The bank layer 160 exposes the center of the first electrode 210. In the top emission type OLED D, the first electrode 210 may have a triple-layered structure of ITO/Ag/ITO or ITO/APC/ITO.

The emission layer 220 is disposed on the first electrode 210. In one exemplary aspect, the emission layer 220 may have a single-layer structure of an Emission Material Layer (EML). Alternatively, the emission layer 220 may have a multi-layer structure of a Hole Injection Layer (HIL), a Hole Transport Layer (HTL), an Electron Blocking Layer (EBL), an EML, a Hole Blocking Layer (HBL), an Electron Transport Layer (ETL), and/or an Electron Injection Layer (EIL) (see fig. 3,5, 7, 9, and 11). In one aspect, the emissive layer 220 may have one emissive portion. Alternatively, the emission layer 220 may have a plurality of emission parts to form a serial structure.

The emission layer 220 includes any one of the structures having chemical formulas 1 to 11. As an example, the organic compound having the structure of chemical formulas 1 to 11 may be applied to a dopant in the EML, in which case the EML may further include a host and optionally other light emitting materials.

The second electrode 230 is disposed on the substrate 110 provided with the emission layer 220. The second electrode 230 may be disposed on the entire display area and may include a conductive material having a relatively low work function value compared to the first electrode 210. The second electrode 230 may be a cathode. For example, the second electrode 230 may include, but is not limited to, aluminum (Al), magnesium (Mg), calcium (Ca), silver (Ag), an alloy thereof, or a combination thereof, such as an aluminum-magnesium alloy (Al-Mg). When the organic light emitting display apparatus 100 is a top emission type, the second electrode 230 is thin to have a light transmitting (semi-transmitting) characteristic.

In addition, an encapsulation film 170 may be disposed on the second electrode 230 to prevent external moisture from penetrating into the OLED D. The encapsulation film 170 may have, but is not limited to, a stacked structure of a first inorganic insulating film 172, an organic insulating film 174, and a second inorganic insulating film 176.

In addition, the organic light emitting display device 100 may further include a polarizer to reduce external light reflection. For example, the polarizer may be a circular polarizer. When the organic light emitting display apparatus 100 is a bottom emission type, a polarizer may be disposed under the substrate 100. Alternatively, when the organic light emitting display device 100 is a top emission type, the polarizer may be disposed over the encapsulation film 170. In addition, in the top emission type organic light emitting display device 100, a cover window may be attached to the encapsulation film 170 or the polarizer. In this case, the substrate 110 and the cover window may have flexibility, and thus the organic light emitting display device 100 may be a flexible display device.

As described above, the emission layer 220 of the OLED includes any organic compound having the structure of chemical formulas 1 to 11. The organic compound has excellent light emitting properties, and thus by applying the organic compound, the OLED D can improve its light emitting efficiency, reduce its driving voltage and power consumption, and achieve a long light emitting life.

We will now describe the OLED in more detail. Fig. 3 is a schematic cross-sectional view illustrating an OLED according to one exemplary aspect of the present disclosure. As shown in fig. 3, the OLED D1 includes a first electrode 210 and a second electrode 230 facing each other, and an emission layer 220 having a single emission part is disposed between the first electrode 210 and the second electrode 230. The organic light emitting display device 100 (fig. 2) may include a red pixel region, a green pixel region, and a blue pixel region, and the OLED D1 may be disposed in the green pixel region.

In an exemplary aspect, the emissive layer 220 includes an EML240 disposed between the first electrode 210 and the second electrode 230. In addition, the emission layer 220 may include at least one of an HTL 260 disposed between the first electrode 210 and the EML240 and an ETL270 disposed between the second electrode 230 and the EML 240. In addition, the emission layer 220 may further include at least one of an HIL 250 disposed between the first electrode 210 and the HTL 260 and an EIL 280 disposed between the second electrode 230 and the ETL 270. Alternatively, the emission layer 220 may further include a first exciton blocking layer (i.e., EBL 265 disposed between the HTL 260 and the EML 240) and/or a second exciton blocking layer (i.e., HBL 275 disposed between the EML240 and the ETL 270).

The first electrode 210 may be an anode that supplies holes to the EML 240. The first electrode 210 may include, but is not limited to, a conductive material having a relatively high work function value, for example, a Transparent Conductive Oxide (TCO). In one exemplary aspect, the first electrode 210 may include, but is not limited to, ITO, IZO, ITZO, SnO, ZnO, ICO, AZO, and the like.

The second electrode 230 may be a cathode that supplies electrons to the EML 240. The second electrode 230 may include, but is not limited to, a conductive material having a relatively low work function value, i.e., a highly reflective material, such as Al, Mg, Ca, Ag, alloys thereof, combinations thereof, and the like.

The EML240 may include a first compound H and a second compound DF. The first compound H may be a host and the second compound DF may be a delayed fluorescence material (dopant). For example, organic compounds having the structures of chemical formulas 1 to 11 may be used as the second compound in the EML 240. As an example, the EML240 may emit green light. We will describe the first compound and the energy level relationship between the first and second compounds later.

The HIL 250 and the HTL 260 may be sequentially disposed between the first electrode 210 and the EML 240. The HIL 250 is disposed between the first electrode 210 and the HTL 260, and improves interfacial properties between the inorganic first electrode 210 and the organic HTL 260. In one exemplary aspect, HIL 250 can include, but is not limited to, 4',4 ″ -tris (3-methylphenylamino) triphenylamine (MTDATA), 4',4 ″ -tris (N, N-biphenyl-amino) triphenylamine (NATA), 4',4 ″ -tris (N- (naphthalen-1-yl) -N-phenyl-amino) triphenylamine (1T-NATA), 4',4 ″ -tris (N- (naphthalen-2-yl) -N-phenyl-amino) triphenylamine (2T-NATA), copper phthalocyanine (CuPc), tris (4-carbazol-9-yl-phenyl) amine (TCTA), N ' -biphenyl-N, N ' -bis (1-naphthyl) -1,1' -biphenyl-4, 4' -diamine (NPB; NPD), 1,4,5,8,9, 11-hexaazatriphenylolhexacyanecarbonitrile (bipyrazine [2,3-f:2'3' -H ] quinoxaline-2, 3,6,7,10, 11-hexacyanecarbonitrile; HAT-CN), 1,3, 5-tris [4- (biphenylamino) phenyl ] benzene (TDAPB), poly (3, 4-ethylenedioxythiophene) polystyrenesulfonic acid (PEDOT/PSS) and/or N- (biphenyl-4-yl) -9, 9-dimethyl-N- (4- (9-phenyl-9H-carbazol-3-yl) phenyl) -9H-fluoren-2-amine. The HIL 250 may be omitted according to the structure of the OLED D1.

The HTL 260 is disposed adjacent to the EML240 between the first electrode 210 and the EML 240. In one exemplary aspect, the HTL 260 may include, but is not limited to, N ' -biphenyl-N, N ' -bis (3-methylphenyl) -1,1' -biphenyl-4, 4' -diamine (TPD), NPB, 4' -bis (N-carbazolyl) -1,1' -biphenyl (CBP), poly [ N, N ' -bis (4-butylphenyl) -N, N ' -bis (phenyl) -benzidine ] (poly-TPD), poly [ (9, 9-dioctylfluorenyl-2, 7-diyl) -co- (4,4' - (N- (4-sec-butylphenyl) diphenylamine)) ] (TFB), bis [4- (N, N-di-p-tolyl-amino) -phenyl ] cyclohexane (TAPC) ] (TFB), 3, 5-bis (9H-carbazol-9-yl) -N, N-diphenylamine (DCDPA), N- (biphenyl-4-yl) -9, 9-dimethyl-N- (4- (9-phenyl-9H-carbazol-3-yl) phenyl) -9H-fluoren-2-amine and/or N- (biphenyl-4-yl) -N- (4- (9-phenyl-9H-carbazol-3-yl) phenyl) biphenyl-4-amine.

The ETL270 and the EIL 280 may be sequentially disposed between the EML240 and the second electrode 230. The ETL270 includes a material having high electron mobility to stably supply electrons to the EML240 through fast electron transport. In one exemplary aspect, the ETL270 may include, but is not limited to, any of oxadiazole-based compounds, triazole-based compounds, phenanthroline-based compounds, benzoxazole-based compounds, benzothiazole-based compounds, benzimidazole-based compounds, triazine-based compounds, and the like.

By way of example, the ETL270 may include, but is not limited to: tris- (8-hydroxyquinolinylaluminum) (Alq)₃) 2-biphenyl-4-yl-5- (4-tert-butylphenyl) -1,3, 4-oxadiazole (PBD), spiro-PBD, lithium quinolate (Liq), 1,3, 5-tris (N-phenylbenzimidazol-2-yl) benzene (TPBi), bis (2-methyl-8-hydroxyquinoline-N1, O8) - (1,1' -biphenyl-4-hydroxy) aluminum (BALq), 4, 7-biphenyl-1, 10-phenanthroline (Bphen), 2, 9-bis (naphthalen-2-yl) -4, 7-biphenyl-1, 10-phenanthroline (NBphen), 2, 9-dimethyl-4, 7-biphenyl-1, 10-phenanthroline (BCP), 3- (4-biphenylyl) -4-phenyl-5-tert-butylphenyl-1, 2, 4-Triazole (TAZ), 4- (naphthalen-1-yl) -3, 5-biphenyl-4H-1, 2, 4-triazole (NTAZ), 1,3, 5-tris (p-pyridin-3-yl-phenyl) benzene (TpPyPB), 2,4, 6-tris (3'- (pyridin-3-yl) biphenyl-3-yl) 1,3, 5-triazine (TmPPPyTz), poly [9, 9-bis (3' - ((N, N-dimethyl) -N-ethylammonium) -propyl) -2, 7-fluorene]-Cross-2, 7- (9, 9-dioctylfluorene)](PFNBr), tris (phenylquinoxaline) (TPQ) and/or biphenyl-4-triphenylsilyl-phenylphosphine oxide (TSPO 1).

The EIL 280 is disposed between the second electrode 230 and the ETL270, and may improve physical properties of the second electrode 230, and thus may improve the lifetime of the OLED D1. In an exemplary aspect, EIL 280 can include, but is not limited to, alkali and/or alkaline earth halides (e.g., LiF, CsF, NaF, and BaF)₂Etc.), and/or organometallic compounds (e.g., lithium quinolinate, lithium benzoate, sodium stearate, etc.).

When holes are transferred to the second electrode 230 via the EML240 and/or electrons are transferred to the first electrode 210 via the EML240, the OLED D1 may have a short lifetime and a reduced light emitting efficiency. To prevent these phenomena, the OLED D1 according to this aspect of the invention may have at least one exciton blocking layer adjacent to the EML 240.

For example, OLED D1 of the exemplary aspect includes EBL 265 between HTL 260 and EML240 to control and prevent electron transfer. In one exemplary aspect, EBL 265 may include, but is not limited to, TCTA, tris [4- (diethylamino) phenyl ] amine, N- (biphenyl-4-yl) -9, 9-dimethyl-N- (4- (9-phenyl-9H-carbazol-3-yl) phenyl) -9H-fluoren-2-amine, TAPC, MTDATA, 1, 3-bis (carbazol-9-yl) benzene (mCP), 3 '-bis (N-carbazolyl) -1,1' -biphenyl (mCBP), CuPc, N '-bis [4- (bis (3-methylphenyl) amino) phenyl ] -N, N' -diphenyl- [1,1 '-biphenyl ] -4,4' -diamine (tpdnd), TDAPB, DCDPA and/or 2, 8-bis (9-phenyl-9H-carbazol-3-yl) dibenzo [ b, d ] thiophene.

In addition, OLED D1 may also include HBL 275 as a second exciton blocking layer between EML240 and ETL270, such that holes cannot be transferred from EML240 to ETL 270. In one exemplary aspect, HBL 275 may include, but is not limited to, any of oxadiazoles, triazoles, phenanthrolines, benzoxazoles, benzothiazoles, benzimidazoles, and triazines, all of which may be used in ETL 270.

For example, HBL 275 may include compounds that have relatively low HOMO levels compared to the light emitting material in EML 240. HBL 275 may include, but is not limited to BCP, BALq, Alq₃PBD, spiro-PBD, Liq, bis-4, 5- (3, 5-bis-3-pyridylphenyl) -2-methylpyrimidine (B3PYMPM), bis [2- (diphenylphosphino) phenyl]Ether oxides (DPEPO), 9- (6- (9H-carbazol-9-yl) pyridin-3-yl) -9H-3, 9' -bicarbazole, and combinations thereof.

As described above, the EML240 includes the first compound H and the second compound DF of any organic compound having the structures of chemical formulas 1 to 11, which have delayed fluorescence properties. Both the electron acceptor moiety and the electron donor moiety coexist in the organic compound, and therefore the dipole moment between these moieties increases and the HOMO state is easily separated from the LUMO state. Since the organic compound has a structure that increases dipole moment, it has a delayed fluorescence property. In addition, the organic compound has a limited three-dimensional conformation due to the rigid fused heteroaromatic moiety, and there is little energy loss in emission, so the organic compound can realize light emission with improved luminous efficiency and color purity.

In addition, the host for realizing delayed fluorescence induces triplet excitons generated at the dopant to participate in luminescence without quenching as non-radiative recombination. For this purpose, the energy level between the host and the delayed fluorescent material should be adjusted. Fig. 4 is a schematic diagram illustrating a light emitting mechanism due to an energy level bandgap between light emitting materials according to an exemplary aspect of the present disclosure.

As shown in FIG. 4, the excited singlet level S of the first compound H of the host in EML240₁ ^HAnd excited triplet energy level T₁ ^HThe excited singlet level S of the second compound DF which should each be higher than the delayed fluorescent material₁ ^DFAnd excited triplet energy level T₁ ^DF. As an example, the excited triplet level T of the first compound₁ ^H1Can be higher than the excited triplet energy level T of the second compound DF₁ ^DFAt least about 0.5eV, such as at least about 0.2 eV.

When excited singlet level S of the first compound₁ ^HAnd excited triplet energy level T₁ ^HNot sufficiently higher than the singlet level S of the second compound DF₁ ^DFAnd excited triplet energy level T₁ ^DFExcited triplet level T of the second compound DF₁ ^DFThe exciton at (b) can be transferred to the excited triplet level T of the first compound H in the reverse direction₁ ^H. In this case, the triplet excitons of the first compound H, which are inversely transferred to the triplet excitons and cannot emit, are quenched to be non-emitted, and thus the triplet exciton energy of the second compound DF having the delayed fluorescence property cannot contribute to light emission. As an example, the excited singlet level S of the second compound DF₁ ^DFAnd excited triplet energy level T₁ ^DFEnergy band gap Δ E between_ST ^DFDelayed fluorescence can be achieved with an energy equal to or less than about 0.3eV, such as from about 0.05eV to about 0.3 eV.

In addition, the LUMO level and HOMO level of the first compound H and the second compound DF need to be adjusted in order to rapidly inject holes and electrons into the EML240 to efficiently recombine excitons. For example, it is preferable that the HOMO energy level (HOMO) of the first compound H^H) HOMO energy level (HOMO) with second compound DF^DF) Energy level band gap (| HOMO)^H-HOMO^DFI) or the LUMO energy Level (LUMO) of the first compound H^H) With the LUMO energy Level (LUMO) of the second compound DF^DF) Bandgap of energy level (| LUMO)^H-LUMO^DF|) may be equal to or less than about 0.5eV, for example from about 0.1eV to about 0.5 eV.

When the EML240 includes both the first compound H of the host and the second compound DF of the organic compound having the structure of chemical formulas 1 to 11, exciton energy may be transferred to the second compound DF without energy loss during light emission. In particular, the first compound H as a host included in the EML240 together with the organic compound having the structure of chemical formulas 1 to 11 does not need to have a high triplet energy level T₁ ^HAnd a wide HOMO-LUMO energy level bandgap. Therefore, problems (i.e., delays in charge injection and transport) caused by the use of a host having a wide energy band gap can be minimized.

In one exemplary aspect, the first compound H as a host in EML240 may include, but is not limited to, 9- (3- (9H-carbazol-9-yl) phenyl) -9H-carbazol-3-carbonitrile (mCP-CN), CBP, mCBP, DPEPO, 2T-NATA, TCTA, 1,3, 5-tris [ (3-pyridyl) -benzene-3-yl ] benzene (TmPyPB), 2, 6-bis (9H-carbazol-9-yl) pyridine (PYD-2Cz), 3', 5 ' -bis (carbazol-9-yl) - [1, 1' -biphenyl ] -3, 5-dicarbonitrile (DCzTPA), 4' - (9H-carbazol-9-yl) biphenyl-3, 5-dicarbonitrile (4 ' - (9H-carbazol-9-yl) biphenyl- 3, 5-dicyan-dehyde (pCzB-2CN), 3' - (9H-carbazol-9-yl) biphenyl-3, 5-dicyan-itrile (mCzB-2CN), 4- (3- (triphenylen-2-yl) phenyl) dibenzo [ b, d ] thiophene, 9- (4- (9H-carbazol-9-yl) phenyl) -9H-3,9 ' -bicarbazole and/or 9- (3- (9H-carbazol-9-yl) phenyl) -9H-3,9 ' -bicarbazole.

When the EML240 includes the first compound H of the host and the second compound DF of the delayed fluorescent material, the content of the second compound DF in the EML240 may be about 10% by weight to about 70% by weight, preferably about 10% by weight to about 50% by weight, more preferably about 20% by weight to about 40% by weight, but is not limited thereto.

Fig. 5 is a schematic cross-sectional view illustrating an OLED according to another exemplary aspect of the present disclosure. As shown in fig. 5, the OLED D2 includes a first electrode 210, a second electrode 230 facing the first electrode 210, and an emission layer 220A disposed between the first electrode 210 and the second electrode 230. The organic light emitting display device 100 (fig. 2) may include a red pixel region, a green pixel region, and a blue pixel region, and the OLED D1 may be disposed in the green pixel region.

The emission layer 220A having a single emission part includes an EML 240A. In addition, the emission layer 220A may include at least one of an HTL 260 disposed between the first electrode 210 and the EML 240A and an ETL270 disposed between the second electrode 230 and the EML 240A. In addition, the emission layer 220 may further include at least one of an HIL 250 disposed between the first electrode 210 and the HTL 260 and an EIL 280 disposed between the second electrode 230 and the ETL 270. Alternatively, emissive layer 220A also includes EBL 265 disposed between HTL 260 and EML 240A, and/or HBL 275 disposed between EML 240A and ETL 270. The first and second electrodes 210 and 230 and other layers of the emissive layer 220A except the EML 240A may be substantially identical in construction to the corresponding electrodes and layers in the OLED D1.

In this aspect, EML 240A includes a first compound H, a second compound DF, and a third compound FD. The first compound H may be a host, the second compound DF may be a delayed fluorescent material (first dopant), and the third compound FD may be a fluorescent material (second dopant). The first compound H may be the same as the first compound H in the above aspect. The second compound DF may include any organic compound having a structure of chemical formulas 1 to 11. When the EML 240A further includes the fluorescent material FD and the delayed fluorescent material DF, the OLED D2 having significantly enhanced luminous efficiency can be realized by adjusting the energy level between the host and the dopant.

The EML240 (see fig. 3) contains only the host first compound H and the second compound DF having a delayed fluorescence property, which theoretically exhibits an internal quantum efficiency of at most 100%, which is equivalent to a conventional phosphorescent material such as a metal complex. However, an additional charge transfer transition (CT transition) within the delayed fluorescent material is caused due to the bond between the electron acceptor and the electron donor generating and conformational distortion within the delayed fluorescent material, and the delayed fluorescent material has various geometric configurations. As a result, the delayed fluorescent material exhibits a very wide spectrum with FWHM (full width at half maximum) during light emission, which results in poor color purity. In addition, the delayed fluorescent material utilizes triplet exciton energy as well as singlet exciton energy during light emission while rotating each part in its molecular structure, thereby causing Twisted Internal Charge Transfer (TICT). As a result, the light emitting lifetime of the OLED including only the delayed fluorescent material may be reduced due to the weakening of the molecular bonding force between the delayed fluorescent materials.

The EML 240A of this aspect further includes a third compound FD of a fluorescent or phosphorescent material in order to prevent the color purity and the light emitting life of the OLED D1 from being deteriorated when the EML includes only a delayed fluorescent material as a dopant. Referring to fig. 6, the triplet exciton energy of the second compound DF having the delayed fluorescence property is upwardly converted into its own singlet exciton energy, and then the converted singlet exciton energy of the second compound DF may be transferred to the third compound FD in the same EML240 through FRET (Forster resonance energy transfer) mechanism, thereby realizing super fluorescence.

When the EML 240A includes the first compound H of the host, the second compound DF having a delayed fluorescence property, and the third compound FD of a fluorescent or phosphorescent material, it is necessary to adjust the energy level properties between these light emitting materials. Fig. 6 is a schematic diagram illustrating a light emitting mechanism due to an energy level bandgap between light emitting materials according to another exemplary aspect of the present disclosure.

As shown in FIG. 6, the excited singlet level S of the second compound DF₁ ^DFAnd excited triplet energy level T₁ ^DFEnergy band gap Δ E between_ST ^DFMay be equal to or less than about 0.3eV in order to achieve delayed fluorescence. Excited singlet level S of first compound H of host in EML 240A₁ ^HAnd excited triplet energy level T₁ ^HRespectively higher than the excited singlet level S of the second compound₁ ^DFAnd excited triplet energy level T₁ ^DF. As an example, the excited triplet level T of the first compound H1₁ ^H1Can be higher than the excited triplet energy level T of the second compound DF₁ ^DFAt least about 0.2eV, preferably at least about 0.3eV, and more preferably at least about 0.5 eV.

In addition, the EML 240A requires a third compound FD that achieves high luminous efficiency and color purity, as well as efficient transfer of exciton energy from the second compound DF (which is converted into an ICT complex state at the EML 240A by a RISC mechanism) to a fluorescent or phosphorescent material in the EML 240A. For this purpose, the excited triplet level T of the second compound DF₁ ^DFExcited triplet level T higher than third Compound FD₁ ^FD. Optionally, excited singlet level S of the second compound DF₁ ^DFExcited singlet level S that may be higher than third compound FD₁ ^FD. The first compound H and the second compound DF may be compounds described in the above aspects, respectively.

In addition, the exciton energy should be efficiently transferred from the second compound DF of the delayed fluorescent material to the third compound FD of the fluorescent or phosphorescent material to realize super fluorescence. As an example, a fluorescent or phosphorescent material having a large overlapping region of an absorption (Abs.) spectrum and a Photoluminescence (PL) spectrum of the second compound DF having a delayed fluorescence property may be used as the third compound FD.

The third compound FD may emit green light. The third compound FD of the green light-emitting fluorescent material may include, but is not limited to, BODIPY nuclei and/or quinoacridine nuclei. By way of example, the third compound may include, but is not limited to, 5, 12-dimethylquinolino [2,3-b ] acridine-7, 14(5H,12H) dione, 5, 12-diethylquinolino [2,3-b ] acridine-7, 14(5H,12H) dione, 5, 12-dibutyl-3, 10-difluoroquinolino [2,3-b ] acridine-7, 14(5H,12H) dione, 5, 12-dibutyl-3, 10-bis (trifluoromethyl) quinolino [2,3-b ] acridine-7, 14(5H,12H) dione, 5, 12-dibutyl-2, 3,9, 10-tetrafluoroquinolino [2,3-b ] acridine-7, 14(5H,12H) dione, and 1,7, 7-tetramethyl-2, 3,6, 7-tetrahydro-1H, 5H-benzo [ i, j ] quinazolin-9-yl) ethenyl ] -4H-pyran-4-enylidene } malononitrile (DCJTB). Alternatively, the third compound FD may include any metal complex emitting green light as a phosphorescent material.

In one exemplary aspect, the content of the first compound H in the EML 240A may be greater than the content of the second compound DF, and the content of the second compound DF may be greater than the content of the third compound FD. In this case, exciton energy can be efficiently transferred from the second compound DF to the third compound FD. For example, EML 240A may include, but is not limited to, about 60% to about 75% by weight of first compound H, about 20% to about 40% by weight of second compound DF, and about 0.1% to about 5% by weight of third compound FD.

The OLED according to the preceding aspect has a single layer EML. Alternatively, the OLED of the present disclosure may include multiple layers of EMLs. Fig. 7 is a schematic cross-sectional view illustrating an OLED diode according to another exemplary aspect of the present disclosure. Fig. 8 is a schematic diagram illustrating a light emitting mechanism due to an energy level bandgap between light emitting materials according to another exemplary aspect of the present disclosure.

As shown in fig. 7, the OLED D3 of this aspect includes a first electrode 310 and a second electrode 330 facing each other, and an emission layer 320 having a single emission part disposed between the first electrode 310 and the second electrode 330. The organic light emitting display device 100 (fig. 2) may include a red pixel region, a green pixel region, and a blue pixel region, and the OLED D1 may be disposed in the green pixel region.

In one exemplary aspect, emissive layer 320 includes an EML 340. The emission layer 320 may include at least one of an HTL 360 disposed between the first electrode 310 and the EML 340 and an ETL 370 disposed between the second electrode 330 and the EML 340. In addition, the emission layer 320 may further include at least one of an HIL 350 disposed between the first electrode 310 and the HTL 360 and an EIL 380 disposed between the second electrode 330 and the ETL 370. Alternatively, the emissive layer 320 may further include an EBL 365 disposed between the HTL 360 and the EML 340, and/or an HBL 375 disposed between the EML 340 and the ETL 370. The configurations of the first and second electrodes 310 and 330 and other layers of the emission layer 320 except for the EML 340 may be substantially the same as the corresponding electrodes and layers of the OLEDs D1 and D2.

The EML 340 includes a first EML (EML1, lower EML, first layer) 342 and a second EML (EML2, upper EML, second layer) 344. EML1342 is disposed between EBL 365 and HBL 375 and EML 2344 is disposed between EML1342 and HBL 375. One of the EML1342 and EML 2344 contains a second compound DF (first dopant) of a delayed fluorescent material, and the other of the EML1342 and EML 2344 contains a fifth compound FD (second dopant) of a fluorescent or phosphorescent material. Hereinafter, it will be explained that EML1342 contains the second compound DF and EML 2344 contains EML 340 of the fifth compound FD.

EML1342 comprises a first compound H1 of the first body and a second compound DF of the delayed fluorescence material. EML 2344 comprises a fourth compound H2 of a second host and a fifth compound FD of a fluorescent or phosphorescent material.

The second compound DF in EML1342 includes any organic compound having chemical formulas 1 to 11, and has delayed fluorescence. Therefore, the triplet exciton energy of the second compound DF in EML1342 can be transited up to its own singlet exciton energy by RISC mechanism. Although the second compound DF has a high internal quantum efficiency, it has poor color purity due to its FWHM width. In contrast, the fifth compound FD of a fluorescent or phosphorescent material in EML 2344 has an advantage in color purity due to its narrow FWHM, but its internal quantum efficiency is low because its triplet excitons cannot participate in the light emitting process.

However, in this exemplary aspect, singlet exciton energy and triplet exciton energy of the second compound DF having delayed fluorescence characteristics in the EML1342 may be transferred to the fifth compound FD in the EML 2344 disposed adjacent to the EML1342 through a FRET mechanism, and final light emission occurs in the fifth compound FD within the EML 2344. In other words, the triplet exciton energy of the second compound DF is converted upwards in the EML1342 by the RISC mechanism into its own singlet exciton energy. Then, the converted singlet exciton energy of the second compound DF is transferred to the singlet exciton energy of the fifth compound FD in EML 2344.

The fifth compound FD in EML 2344 can emit light using triplet exciton energy as well as singlet exciton energy. The OLED D3 can achieve super-fluorescence since the singlet exciton energy generated at the second compound DF of the delayed fluorescent material in the EML1342 is efficiently transferred to the fifth compound FD of the fluorescent or phosphorescent material in the EML 2344. In this case, although the second compound DF compound having a delayed fluorescence property is used only to transfer exciton energy to the fifth compound FD, a large amount of light emission occurs in the EML 2344 of the fifth compound FD containing a fluorescent or phosphorescent material. Thus, the OLED D3 can improve quantum efficiency and color purity with a narrow FWHM. The fifth compound FD may be a fluorescent or phosphorescent material emitting red or green light. For example, the fifth compound FD may be the same as the third compound in the second aspect.

EML1342 and EML 2344 each comprise a first compound H1 of the first body and a fourth compound H2 of the second body, respectively. The exciton energy generated at the first compound H1 and the fourth compound H2 is mainly transferred to the second compound DF of the delayed fluorescent material. For this reason, excited singlet level S of the first compound H1 and the fourth compound H2₁ ^H1And S₁ ^H2And excited triplet energy level T₁ ^H1And T₁ ^H2Respectively higher than the excited singlet level S of a second compound DF having delayed fluorescence properties₁ ^DFAnd excited triplet energy level T₁ ^DF. As an example, the excited triplet level T of the first compound H1 and the fourth compound H2₁ ^H1And T₁ ^H2Can be higher than the excited triplet energy level T of the second compound DF₁ ^DFAt least about 0.2eV, such as at least about 0.3eV, and preferably at least about 0.5 eV.

In addition, the excited singlet level S of the fourth compound H2 in EML 2344₁ ^H2Excited singlet level S higher than FD of the fifth compound₁ ^FD. Alternatively, the excited triplet level T of the fourth compound H2₁ ^H2Excited triplet level T that may be higher than FD of the fifth compound₁ ^FD. In this case, the singlet exciton energy generated at the fourth compound H2 may be transferred to the singlet energy of the fifth compound FD.

Furthermore, the exciton energy should be efficiently transferred in EML 2344 from the second compound DF (which is converted to the ICT complex by RISC in EML 1342) to the fifth compound FD of fluorescent or phosphorescent material. For this purpose, the excited singlet level S of the second compound DF in EML1342₁ ^DFHigher than fifth in EML 2344Excited singlet level S of Compound FD₁ ^FD. Alternatively, the excited triplet level T of the second compound DF in EML1342₁ ^DFHigher than excited triplet level T of the fifth compound FD in EML 2344₁ ^FD。

In addition, the HOMO level (HOMO) of the first compound H1 and/or the fourth compound H2^H) HOMO energy level (HOMO) with second compound DF^DF) Energy level band gap (| HOMO)^H-HOMO^DFI) or the LUMO energy Level (LUMO) of the first compound H1 and/or the fourth compound H2^H) With the LUMO energy Level (LUMO) of the second compound DF^DF) Bandgap of energy level (| LUMO)^H-LUMO^DF|) may be equal to or less than about 0.5 eV. When the light emitting material does not satisfy the above relationship, non-radiative recombination may occur at the second compound DF to quench, or exciton energy may not be transferred from the host to the dopant, and thus the light emitting efficiency in the OLED D3 is reduced.

The first compound H1 and the fourth compound H2 may be the same as or different from each other. In one exemplary aspect, the first compound H1 and the fourth compound H2 may be the same as the first compound H in the above aspect. The second compound DF of the delayed fluorescent material may be any organic compound having a structure of chemical formulas 1 to 11. The fifth compound FD may have a narrow FWHM and a broad abs spectrum with an overlapping region with the PL spectrum of the second compound DF. As an example, the fifth compound FD may be a fluorescent or phosphorescent material emitting green or red light. For example, the fifth compound FD may be the same as the third compound described in the second aspect.

In one exemplary aspect, the content of each of the first compound H1 and the fourth compound H2 in EML1342 and EML 2344 may be greater than or equal to the content of each of the second compound DF and the fifth compound FD in the same layer, respectively. In addition, the content of the second compound DF in EML1342 may be greater than the content of the fifth compound FD in EML 2344. In this case, the exciton energy can be efficiently transferred from the second compound DF to the fifth compound FD by a FRET mechanism. As an example, the content of the second compound DF in the EML1342 may be about 1% to about 70% by weight, preferably about 10% to about 50% by weight, more preferably about 20% to about 50% by weight, but is not limited thereto. In contrast, EML 2344 may include about 90% to about 99%, preferably about 95% to about 99%, by weight of fourth compound H2, and about 1% to about 10%, preferably about 1% to about 5%, by weight of fifth compound FD.

In another exemplary aspect, when EML 2344 is disposed adjacent to HBL 375, fourth compound H2 included in EML 2344 together with fifth compound FD may be the same material as HBL 375. In this case, the EML 1344 may have a hole blocking function as well as an emission function. In other words, EML 2344 may function as a buffer layer that blocks holes. In one aspect, HBL 375 may be omitted where EML 2344 may be a hole blocking layer as well as an emissive material layer.

On the other hand, when EML 2344 is disposed adjacent to EBL 365, fourth compound H2 in EML 2344 may be the same as EBL 365. In this case, the EML 2344 may have an electron blocking function as well as a transmitting function. In other words, EML 2344 may function as a buffer layer that blocks electrons. In one aspect, EBL 365 may be omitted where EML 2344 may be an electron blocking layer as well as an emissive material layer.

An OLED with three layers of EMLs will be explained. Fig. 9 is a schematic cross-sectional view illustrating an OLED according to another exemplary aspect of the present disclosure. Fig. 10 is a schematic diagram illustrating a light emitting mechanism due to an energy level bandgap between light emitting materials according to another exemplary aspect of the present disclosure.

As shown in fig. 9, the OLED D4 of this aspect includes a first electrode 410 and a second electrode 430 facing each other, and an emission layer 420 having a single emission part disposed between the first electrode 410 and the second electrode 430. The organic light emitting display device 100 (fig. 2) may include a red pixel region, a green pixel region, and a blue pixel region, and the OLED D1 may be disposed in the green pixel region.

In one exemplary aspect, the emissive layer 420 having a single emissive portion includes three layers of EMLs 440. The emission layer 420 may include at least one of an HTL 460 disposed between the first electrode 410 and the EML 440 and an ETL 470 disposed between the second electrode 430 and the EML 440. In addition, the emission layer 420 may further include at least one of an HIL 450 disposed between the first electrode 410 and the HTL 460 and an EIL 480 disposed between the second electrode 430 and the ETL 470. Alternatively, the emissive layer 420 may further include an EBL 465 disposed between the HTL 460 and the EML 440, and/or an HBL 475 disposed between the EML 440 and the ETL 470. The configurations of the first and second electrodes 410 and 430 and other layers of the emission layer 420 except for the EML 440 may be substantially the same as the corresponding electrodes and layers of the OLEDs D1, D2, and D3.

The EML 440 includes a first EML (EML1, lower EML, first layer) 442, a second EML (EML2, middle EML, second layer) 444, and a third EML (EML3, lower EML, third layer) 446. EML 1442 is disposed between EBL 465 and HBL 475, EML 2444 is disposed between EBL 465 and EML 1442, and EML 3446 is disposed between EML 1442 and HBL 475.

EML 1442 comprises a second compound DF of a delayed fluorescent material, EML 2444 and EML 3446 each comprise a fifth compound FD1 (second dopant) and a seventh compound FD2 (third dopant) which may be fluorescent or phosphorescent materials, respectively. In addition, each of EML 1442, EML 2444, and EML 3446 may further include a first compound H1, a fourth compound H2, and a sixth compound H3, which may be first to third bodies, respectively.

According to this aspect, the singlet energy and the triplet energy of the second compound DF (i.e. delayed fluorescent material) in EML 442 may be transferred to the fifth compound FD1 and the seventh compound FD2 (i.e. fluorescent or phosphorescent materials) by FRET energy transfer mechanisms, which are respectively comprised in EML 2444 and EML 3446 disposed adjacent to EML 1442. Therefore, the final light emission occurs in the fifth compound FD1 and the seventh compound FD2 within EML 2444 and EML 3446.

In other words, the triplet exciton energy of the second compound DF having delayed fluorescence property in EML 1442 is converted up to its own singlet exciton energy by RISC mechanism, and then the singlet exciton energy of the second compound DF is transferred to the fifth compound FD1 and the seventh compound FD2 in EML 2444 and EML 3446 because of the excited singlet energy level S of the second compound DF₁ ^DFHigher than the excited singlet energy of each of the fifth compound FD1 and the seventh compound FD2Stage S₁ ^FD1And S₁ ^FD2(see FIG. 10).

Since the fifth and seventh compounds FD1 and FD2 in EML 2444 and EML 3446 can emit light using singlet and triplet exciton energies derived from the second compound DF, the OLED D4 can improve its light emitting efficiency. In addition, since the fifth compound FD1 and the seventh compound FD2 respectively have relatively narrow FWHM compared to the second compound DF, the OLED D4 may enhance its color purity. In particular, in the case of using the fifth compound FD1 and the seventh compound FD2 having a large overlap region of the abs spectrum and the PL spectrum of the second compound DF, exciton energy can be efficiently transferred from the second compound DF to the fifth compound FD1 and the seventh compound FD 2. In this case, although the second compound DF is used only to transfer exciton energy to the fifth compound FD1 and the seventh compound FD2, a large amount of light emission occurs in EML 2444 and EML 3446 including the fifth compound FD1 and the seventh compound FD 2.

In addition, the luminescent materials introduced into the EML 1442, EML 2444, and EML 3446 need to be adjusted in order to perform effective luminescence. Referring to fig. 10, excited singlet levels S of first, fourth and sixth compounds H1, H2 and H3 as first to third hosts, respectively₁ ^H1、S₁ ^H1And S₁ ^H3And excited triplet energy level T₁ ^H1、T₁ ^H2And T₁ ^H3Respectively higher than excited singlet level S of second compound DF₁ ^DFAnd excited triplet energy level T₁ ^DF。

In addition, exciton energy should be efficiently transferred from the second compound DF in EML 1442 (which is converted into an ICT complex state by RISC) to the fifth compound FD1 and the seventh compound FD2, which are fluorescent or phosphorescent materials in EML 2444 and EML 3446, respectively. For this purpose, the excited singlet level S of the second compound DF in EML 1442₁ ^DFHigher than excited singlet state energy level S of each of fifth compound FD1 and seventh compound FD2 in EML 2444 and EML 3446₁ ^FD1And S₁ ^FD2. Alternatively, EML1Excited triplet level T of second compound DF at 442₁ ^DFHigher than the excited triplet level T of each of the fifth compound FD1 and the seventh compound FD2 in EML 2444 and EML 3446₁ ^FD1And T₁ ^FD2。

In addition, in order to achieve efficient light emission, exciton energy transferred from the second compound DF of the delayed fluorescent material to the fifth compound FD1 and the seventh compound FD2 of the fluorescent or phosphorescent material should not be transferred to the fourth compound H2 and the sixth compound H3. For this reason, the excited singlet level S of the fourth compound H2 and the sixth compound H3, which are the second and third hosts, respectively₁ ^H2And S₁ ^H3Higher than respective excited singlet levels S of the fifth compound FD1 and the seventh compound FD2, which are fluorescent or phosphorescent materials, respectively₁ ^FD1And S₁ ^FD2. Alternatively, excited triplet level T of fourth compound H2 and sixth compound H3₁ ^H2And T₁ ^H3Can be higher than the respective excited triplet energy level T of the fifth compound FD1 and the seventh compound FD2₁ ^FD1And T₁ ^FD2。

As described above, each of EML 1442, EML 2444, and EML 3446 includes the first compound H1, the fourth compound H2, and the sixth compound H3 as the first to third bodies, respectively. The first compound H1, the fourth compound H2, and the sixth compound H3 may be the same as or different from each other. In one exemplary aspect, the first compound H1, the fourth compound H2, and the sixth compound H3 may be the same as the first compound H in the above aspect, respectively. The second compound DF of the delayed fluorescent material may be any organic compound having a structure of chemical formulas 1 to 11. The fifth compound FD1 and the seventh compound FD2 may be respectively the same as the third compound described in the second aspect.

In an exemplary aspect, the content of the second compound DF in EML 1442 may be greater than the content of each of the fifth compound FD1 and the seventh compound FD2 in EML 2444 and EML 3446. In this case, exciton energy is efficiently transferred from the second compound DF to the fifth compound FD and the seventh compound FD2 through a FRET mechanism. As an example, the content of the second compound DF in the EML 1442 may be about 1% to about 70% by weight, preferably about 10% to about 50% by weight, more preferably about 20% to about 50% by weight, but is not limited thereto. In contrast, EML 2444 and EML 3446 may comprise about 90% to about 99% by weight, preferably about 95% to about 99% by weight, of the fourth compound H2 or the sixth compound H3, and about 1% to about 10% by weight, preferably about 1% to about 5% by weight, of the fifth compound FD1 or the seventh compound FD2, respectively.

In one exemplary aspect, when the EML 2444 is disposed adjacent to the EBL 465, the fourth compound H2 in the EML 2444 can be the same material as the EBL 465. In this case, the EML 2444 may have an electron blocking function as well as an emission function. In other words, the EML 2444 may serve as a buffer layer blocking electron holes. In one aspect, the EBL 465 can be omitted where the EML 2444 can be an electron blocking layer as well as an emissive material layer.

When EML 3446 is disposed adjacent to HBL 475, sixth compound H3 in EML 3446 may be the same material as HBL 475. In this case, the EML 3446 may have a hole blocking function as well as an emission function. In other words, the EML 3446 may function as a buffer layer blocking holes. In one aspect, HBL 475 may be omitted where EML 3446 may be a hole blocking layer as well as an emissive material layer.

In another exemplary aspect, fourth compound H2 in EML 2444 may be the same material as EBL 455, and sixth compound H3 in EML 3446 may be the same material as HBL 475. In this regard, EML 2444 may have an electron blocking function and an emission function, and EML 3446 may have a hole blocking function and an emission function. In other words, EML 2444 and EML 3446 may each function as a buffer layer that blocks electrons or holes, respectively. In one aspect, EBL 465 and HBL 475 may be omitted when EML 2444 may be an electron blocking layer and an emissive material layer and when EML 3446 may be a hole blocking layer and an emissive material layer.

In an alternative aspect, the OLED may include a plurality of emission portions. Fig. 11 is a schematic cross-sectional view illustrating an OLED according to still another exemplary aspect of the present disclosure.

As shown in fig. 10, the OLED D5 includes a first electrode 510 and a second electrode 530 facing each other, and an emission layer 520 having two emission parts disposed between the first electrode 510 and the second electrode 530. The organic light emitting display device 100 (fig. 1) includes a red pixel region, a green pixel region, and a blue pixel region, and the OLED D5 may be disposed in the green pixel region. The first electrode 510 may be an anode, and the second electrode 530 may be a cathode.

The emission layer 520 includes a first emission part 620 including a first EML (EML1)640 and a second emission part 720 including a second EML (EML2) 740. In addition, the emission layer 520 may further include a Charge Generation Layer (CGL)680 disposed between the first emission part 620 and the second emission part 720.

The CGL680 is disposed between the first emission layer 620 and the second emission part 720 such that the first emission part 620, the CGL680, and the second emission part 720 are sequentially disposed on the first electrode 510. In other words, the first emission part 620 is disposed between the first electrode 510 and the CGL680, and the second emission part 720 is disposed between the second electrode 530 and the CGL 680.

The first transmission part 620 includes an EML 1640. The first emission part 620 may further include at least one of a first HTL (HTL1)660 disposed between the first electrode 510 and the EML 1640, an HIL 650 disposed between the first electrode 510 and the HTL 1660, and a first ETL (ETL1)670 disposed between the EML 1640 and the CGL 680. Alternatively, the first emitting portion 620 may further include a first (EBL1)665 disposed between the HTL 1660 and the EML 1640 and/or a first HBL (HBL1)675 disposed between the EML 1640 and the ETL 1670.

The second emission part 720 includes an EML 2740. The second emission part 720 may further include at least one of a second HTL (HTL2)760 disposed between the CGL680 and the EML2740, a second ETL (ETL2)770 disposed between the EML2740 and the second electrode 530, and an EIL 780 disposed between the ETL 2770 and the second electrode 530. Alternatively, the second emission part 720 may further include a first (EBL1)765 disposed between the HTL 2760 and the EML2740 and/or a second HBL (HBL2)775 disposed between the EML2740 and the ETL 2770.

The CGL680 is disposed between the first and second transmission parts 620 and 720. The first and second transmission parts 620 and 720 are connected by a CGL 680. CGL680 may be a PN junction CGL that links N-type CGL (N-CGL)682 with P-type CGL (P-CGL) 684.

N-CGL 682 is disposed between ETL 1670 and HTL 2760, and P-CGL 684 is disposed between N-CGL 682 and HTL 2760. The N-CGL 682 transports electrons to the EML 1640 of the first emission portion 620, and the P-CGL 684 transports holes to the EML2740 of the second emission portion 720.

In this aspect, the EML 1640 and EML2740 may be green emitting material layers, respectively. For example, at least one of EML 1640 and EML2740 comprises a first compound of a host, a second compound of a delayed fluorescent material and optionally a third compound of a fluorescent or phosphorescent material.

When the EML 1640 includes the first compound, the second compound, and the third compound, the content of the first compound may be greater than the content of the second compound, and the content of the second compound may be greater than the content of the third compound. In this case, the exciton energy may be efficiently transferred from the second compound to the third compound. As an example, the contents of the first to third compounds in the EML 1640 may be about 60 wt% to about 75 wt%, about 20 wt% to about 40 wt%, and about 0.1 wt% to about 5 wt%, respectively, but are not limited thereto.

In one exemplary aspect, EML2740 may include a first compound of a host similar to EML 1640, a second compound of a delayed fluorescent material, and optionally a third compound of a fluorescent or phosphorescent material. Alternatively, the EML2740 may include another compound different from at least one of the second compound and the third compound in the EML 1640, and thus the EML2740 may emit light different from light emitted from the EML 1640, or may have different light emission efficiency from that of the EML 1640.

In fig. 11, EML 1640 and EML2740 each have a single-layer structure. Alternatively, each of the EML 1640 and the EML2740, which may respectively include the first to third compounds, may have a double-layer structure (fig. 7) or a triple-layer structure (fig. 8), respectively.

In OLED D5, the transfer of singlet exciton energy of the second compound of the fluorescent material to the third compound of the fluorescent material is delayed and the final emission occurs at the third compound. Therefore, the OLED D5 may have excellent luminous efficiency and color purity. In addition, the OLED D4 has a dual stack structure of green emitting material layers, and the OLE 4D 5 improves its color sense or optimizes its light emitting efficiency.

Fig. 12 is a schematic cross-sectional view illustrating an organic light emitting display device according to still another exemplary aspect of the present disclosure. As shown in fig. 12, the organic light emitting display device 800 includes a substrate 810 defining a first pixel region P1, a second pixel region P2, and a third pixel region P3, a thin film transistor Tr disposed on the substrate 810, and an OLED D disposed on and connected to the thin film transistor Tr. As an example, the first pixel region P1 may be a green pixel region, the second pixel region P2 may be a red pixel region, and the third pixel region P3 may be a blue pixel region.

The substrate 810 may be a glass substrate or a flexible substrate. For example, the flexible substrate may be any one of a PI substrate, a PES substrate, a PEN substrate, a PET substrate, and a PC substrate.

A buffer layer 812 is disposed on the substrate 810, and a thin film transistor Tr is disposed on the buffer layer 812. The buffer layer 812 may be omitted. As shown in fig. 12, the thin film transistor Tr includes a semiconductor layer, a gate electrode, a source electrode, and a drain electrode, and functions as a driving element.

A passivation layer 850 is disposed on the thin film transistor Tr. The passivation layer 850 has a flat top surface and a drain electrode contact hole 852 exposing the drain electrode of the thin film transistor Tr.

The OLED D is disposed on the passivation layer 850 and includes a first electrode 910 connected to a drain electrode of the thin film transistor Tr, and an emission layer 920 and a second electrode 930 respectively sequentially disposed on the first electrode 910. The OLED D is disposed in each of the first, second, and third pixel regions P1, P2, and P3, and emits different light in the respective pixel regions. For example, the OLED D in the first pixel region P1 may emit green light, the OLED D in the second pixel region P2 may emit red light, and the OLED D in the third pixel region P3 may emit blue light.

The first electrode 910 is formed for the first, second, and third pixel regions P1, P2, and P3, respectively, and the second electrode 930 is integrally formed corresponding to the first, second, and third pixel regions P1, P2, and P3.

The first electrode 910 may be one of an anode and a cathode, and the second electrode 930 may be the other of the anode and the cathode. In addition, one of the first and second electrodes 910 and 930 is a transmissive (or semi-transmissive) electrode, and the other of the first and second electrodes 910 and 930 is a reflective electrode.

For example, the first electrode 910 may be an anode, and may include a transparent conductive oxide layer of a conductive material having a relatively high work function value, i.e., a Transparent Conductive Oxide (TCO). The second electrode 930 may be a cathode and may include a metal material layer of a conductive material having a relatively low work function value, i.e., a low resistance metal. For example, the first electrode 910 may include any one of ITO, IZO, ITZO, SnO, ZnO, ICO, and AZO, and the second electrode 930 may include Al, Mg, Ca, Ag, alloys thereof, or combinations thereof.

When the organic light emitting display apparatus 800 is a bottom emission type, the first electrode 910 may have a single layer structure of a transparent conductive oxide layer.

Alternatively, when the organic light emitting display apparatus 800 is a top emission type, a reflective electrode or a reflective layer may be disposed under the first electrode 910. For example, the reflective electrode or reflective layer may include, but is not limited to, Ag or APC alloys. In the top-emitting OLED D, the first electrode 910 may have a triple-layered structure of ITO/Ag/ITO or ITO/APC/ITO. In addition, the second electrode 930 is thin to have a light transmitting (semi-light transmitting) characteristic.

A bank layer 860 is disposed on the passivation layer 850 to cover an edge of the first electrode 910. The bank layer 860 corresponds to each of the first, second, and third pixel regions P1, P2, and P3, and exposes the center of the first electrode 910.

The emission layer 920 is disposed on the first electrode 910. In one exemplary aspect, the emission layer 920 may have a single-layer structure of the EML. Alternatively, the emission layer 920 may include at least one of an HIL, an HTL, and an EBL sequentially disposed between the first electrode 910 and the EML and/or an HBL, an ETL, and an EIL sequentially disposed between the EML and the second electrode 930.

In one exemplary aspect, the EML of the emission layer 930 in the first pixel region P1 of the green pixel region may include a first compound of a host, a second compound of a delayed fluorescent material having a structure of chemical formulas 1 to 11, and a third compound of a fluorescent or phosphorescent material.

An encapsulation film 870 is disposed on the second electrode 930 to prevent external moisture from penetrating into the OLED D. The encapsulation film 870 may have, but is not limited to, a three-layer structure of a first inorganic insulating film, an organic insulating film, and a second inorganic insulating film.

In addition, the organic light emitting display device 800 may have a polarizer to reduce external light reflection. For example, the polarizer may be a circular polarizer. When the organic light emitting display apparatus 800 is a bottom emission type, a polarizer may be disposed under the substrate 810. Alternatively, when the organic light emitting display device 800 is a top emission type, a polarizer may be disposed over the encapsulation film 870.

Fig. 13 is a schematic cross-sectional view illustrating an OLED according to still another exemplary aspect of the present disclosure. As shown in fig. 13, the OLED D6 includes a first electrode 910, a second electrode 930 facing the first electrode 910, and an emission layer 920 disposed between the first electrode 910 and the second electrode 930.

The first electrode 910 may be an anode, and the second electrode 920 may be a cathode. As an example, the first electrode 910 may be a reflective electrode, and the second electrode 930 may be a transmissive (semi-transmissive) electrode.

The emissive layer 920 includes an EML 940. The emission layer 930 may include at least one of an HTL 960 disposed between the first electrode 910 and the EML 940 and an ETL 970 disposed between the second electrode 930 and the EML 940. In addition, the emission layer 920 may further include at least one of a HIL 950 disposed between the first electrode 910 and the HTL 960 and an EIL 980 disposed between the second electrode 930 and the ETL 970. Alternatively, the emissive layer 920 may also include an EBL 965 disposed between the HTL 960 and the EML 940 and/or an HBL 975 disposed between the EML 940 and the ETL 970.

In addition, the emissive layer 920 may also include an ancillary hole transport layer (ancillary HTL)962 disposed between the HTL 960 and the EBL 965. The auxiliary HTL962 may include a first auxiliary HTL962 a in the first pixel region P1, a second auxiliary HTL962 b in the second pixel region P2, and a third auxiliary HTL962c in the third pixel region P3.

The first sub HTL962 a has a first thickness, the second sub HTL962 b has a second thickness, and the third sub HTL962c has a third thickness. The first thickness is less than the second thickness and greater than the third thickness. Therefore, the OLED D6 has a microcavity structure.

Since the first, second, and third sub HTLs 962a, 962b, and 962c have different thicknesses from each other, a distance between the first and second electrodes 910 and 930 in the first pixel region P1 emitting light (green light) in the first wavelength range is smaller than a distance between the first and second electrodes 910 and 930 in the second pixel region P2 emitting light (red light) in the second wavelength range, which is longer than the first wavelength range, and a distance between the first and second electrodes 910 and 930 in the first pixel region P1 is larger than a distance between the first and second electrodes 910 and 930 in the third pixel region P3 emitting light (blue light) in the third wavelength range, which is shorter than the first wavelength range. Therefore, the OLED D6 has improved luminous efficiency.

In fig. 13, a third subordinate HTL962c is located in the third pixel region P3. Alternatively, OLED D6 may implement a microcavity structure without the third subordinate HTL962 c. In addition, a cover layer may be provided on the second electrode to improve the out-coupling of the light emitted from the OLED D5.

The EML 940 includes a first EML (EML1)942 located in the first pixel region P1, a second EML (EML2)944 located in the second pixel region P2, and a third EML (EML3)946 located in the third pixel region P3. The EML 1942, EML 2944, and EML 3946 may each be green EML, red EML, and blue EML, respectively.

In one exemplary aspect, the EML 1942 located in the first pixel region P1 may include a first compound of a host, a second compound of a delayed fluorescent material having a structure of chemical formulas 1 to 11, and a third compound of a fluorescent or phosphorescent material. In this case, the EML 1942 may have a single-layer structure, a double-layer structure (fig. 7), or a triple-layer structure (fig. 9).

When the EML 1942 includes the first compound, the second compound, and the third compound, the content of the first compound may be greater than the content of the second compound, and the content of the second compound is greater than the content of the third compound. In this case, the exciton energy may be efficiently transferred from the second compound to the third compound. As an example, the contents of the first to third compounds in the EML 1942 may be about 60 wt% to about 75 wt%, about 20 wt% to about 40 wt%, and about 0.1 wt% to about 5 wt%, respectively, but are not limited thereto.

The EML 2944 located in the second pixel region P2 may include a host and a red dopant, and the EML 3946 located in the third pixel region P3 may include a host and a blue dopant. For example, the host in the EML 2944 and the EML 3946 may include the first compound, and the red dopant and the blue dopant may include at least one of a red or blue phosphorescent material, a red or blue fluorescent material, and a red or blue delayed fluorescent material, respectively.

For example, the host in EML 2944 may include, but is not limited to, 9 ' -diphenyl-9H, 9 ' H-3, 3' -bicarbazole (BCzPh), CBP,1, 3, 5-tris (carbazol-9-yl) benzene (TCP), TCTA, 4' -bis (carbazol-9-yl) -2, 2' -dimethylbiphenyl (CDBP), 2, 7-bis (carbazol-9-yl) -9, 9-dimethylfluorene (DMFL-CBP), 2', 7,7 ' -tetrakis (carbazol-9-yl) -9, 9-spirofluorene (spiro-CBP), DPEPO, 4' - (9H-carbazol-9-yl) biphenyl-3, 5-dicarbonitrile (PCzB-2CN), 3' - (9H-carbazol-9-yl) biphenyl-3, 5-dicyan-2 (mCZB-2CN), 3, 6-bis (carbazol-9-yl) -9- (2-ethyl-hexyl) -9H-carbazole (TCz1), Bepp₂Bis (10-hydroxybenzo [ h ]]Quinoline) beryllium (Bebq)₂)1,3, 5-tris (1-pyrenyl) benzene (TPB3), and combinations thereof.

Additionally, red dopants in EML 2944 may include, but are not limited to, red phosphorescent dopants and/or red fluorescent dopants, such as [ bis (2- (4, 6-dimethyl) phenylquinoline)]Iridium (III) (2,2,6, 6-tetramethylhepta-3, 5-diketonate), (bis [2- (4-n-hexylphenyl) quinoline]Iridium (III) (Hex-Ir (phq))₂(acac)), tris [2- (4-n-hexylphenyl) quinoline]Iridium (III) (Hex-Ir (phq)₃) Tris [ 2-phenyl-4-methylquinoline ]]Iridium (III) (Ir (Mphq)₃) Bis (2-phenylquinoline) (2,2,6, 6-tetramethylhepta-3, 5-diketonic acid) iridium (III) (Ir (dpm) PQ₂) Bis (phenylisoquinoline) (2,2,6, 6-tetramethylheptan-3, 5-dionate) iridium (III) (Ir (dpm) (piq)₂) Di [ (4-positive)Hexylphenyl) isoquinoline]Iridium (III) (Hex-Ir (piq))₂(acac)), tris [2- (4-n-hexylphenyl) quinoline]Iridium (III) (Hex-Ir (piq)₃) Tris (2- (3-methylphenyl) -7-methyl-quinoline) iridium (Ir (dmpq)₃) Bis [2- (2-methylphenyl) -7-methyl-quinoline]Iridium (III) (Ir (dmpq))₂(acac)), bis [2- (3, 5-dimethylphenyl) -4-methyl-quinoline]Iridium (III) (Ir (mphmq))₂(acac)), tris (dibenzoylmethane) -1, 10-phenanthroline europium (III) (Eu (dbm)₃(phen)) and combinations thereof.

The host in EML 3946 may include, but is not limited to, mCP-CN, mCBP, CBP-CN, 9- (3- (9H-carbazol-9-yl) phenyl) -3- (diphenylphosphoryl) -9H-carbazole (mCPPO1), 3, 5-bis (9H-carbazol-9-yl) biphenyl (Ph-mCP), TSPO1, 9- (3'- (9H-carbazol-9-yl) - [1, 1' -diphenyl ] -3-yl) -9H-pyrido [2,3-b ] indole (CzBPCb), bis (2-methylphenyl) diphenylsilane (UGH-1), 1, 4-bis (triphenylsilyl) benzene (UGH-2), 1, 3-bis (triphenylsilyl) benzene (UGH-3), 9, 9-spirobifluoren-2-yl-diphenyl-phosphine oxide (SPPO1), 9' - (5- (triphenylsilyl) -1, 3-phenylene) bis (9H-carbazole) (SimCP), and combinations thereof.

The blue dopant in EML 3946 may include, but is not limited to, blue phosphorescent dopants and/or blue fluorescent dopants, such as perylene, 4' -bis [4- (di-p-tolylamino) styryl]Biphenyl (DPAVBi), 4- (di-p-tolylamino) -4-4' - [ (di-p-tolylamino) styryl]Diphenylethylene (DPAVB), 4' -bis [4- (diphenylamino) styryl]Biphenyl (BDAVBi), 2, 7-bis (4-diphenylamino) styryl) -9, 9-spirofluorene (spiro-DPVBi), [1, 4-bis [2- [4- [ N, N-bis (p-tolyl) amino group]Phenyl radical]Vinyl radical]Benzene (DSB), 1-4-bis [4- (N, N-diphenyl) amino]Styrylbenzenes (DSA), 2,5,8, 11-tetra-tert-butylphthalene (TBPe), bis (2-hydroxyphenyl) -pyridine) beryllium (Bepp)₂) 9- (9-Phenylcarbazol-3-yl) -10- (naphthalen-1-yl) anthracene (PCAN), mer-tris (1-phenyl-3-methylimidazolidin-2-ylidene-C, C (2)' Iridium (III) (mer-Ir (pmi))₃) Fac-tris (1, 3-diphenyl-benzimidazol-2-ylidene-C, C (2)' Iridium (III) (fac-Ir (dpbic)₃) Bis (3,4, 5-trifluoro-2- (2-pyridyl) phenyl- (2-carboxypyridyl) iridium (III))(Ir(tfpd)₂pic), tris (2- (4, 6-difluorophenyl) pyridine)) iridium (III) (Ir (Fppy)₃) Bis [2- (4, 6-difluorophenyl) pyridine-C²,N]Iridium (iii) (picoline) (FIrpic) and combinations thereof.

The OLEDs D6 emit green, red, and blue light in the first, second, and third pixel regions P1, P2, and P3, respectively, so that the organic light emitting display device 800 (fig. 12) can realize a full color image.

The organic light emitting display device 800 may further include color filter layers corresponding to the first, second, and third pixel regions P1, P2, and P3 to improve color purity of light emitted from the OLED D. As an example, the color filter layers may include a first color filter layer (green color filter layer) corresponding to the first pixel region P1, a second color filter layer (red color filter layer) corresponding to the second pixel region P2, and a third color filter layer (blue color filter layer) corresponding to the third pixel region P3.

When the organic light emitting display apparatus 800 is a bottom emission type, a color filter layer may be disposed between the OLED D and the substrate 810. Alternatively, when the organic light emitting display device 800 is a top emission type, a color filter layer may be disposed on the OLED D.

Fig. 14 is a schematic cross-sectional view illustrating an organic light emitting display device according to still another exemplary aspect of the present disclosure. As shown in fig. 14, the organic light emitting display device 1010 includes a substrate 1010 defining a first pixel region P1, a second pixel region P2, and a third pixel region P3, a thin film transistor Tr disposed on the substrate 1010, an OLED D disposed on the thin film transistor Tr and connected to the thin film transistor Tr, and a color filter layer 1020 corresponding to the first pixel region P1, the second pixel region P2, and the third pixel region P3. As an example, the first pixel region P1 may be a green pixel region, the second pixel region P2 may be a red pixel region, and the third pixel region P3 may be a blue pixel region.

The substrate 1010 may be a glass substrate or a flexible substrate. For example, the flexible substrate may be any one of a PI substrate, a PES substrate, a PEN substrate, a PET substrate, and a PC substrate. The thin film transistor Tr is located on the substrate 1010. Alternatively, a buffer layer may be disposed on the substrate 1010, and the thin film transistor Tr may be disposed on the buffer layer. As shown in fig. 2, the thin film transistor Tr includes a semiconductor layer, a gate electrode, a source electrode, and a drain electrode, and functions as a driving element.

The color filter layer 1020 is on the substrate 1010. As an example, the color filter layers 1020 may include a first color filter layer 1022 corresponding to the first pixel region P1, a second color filter layer 1024 corresponding to the second pixel region P2, and a third color filter layer 1026 corresponding to the third pixel region P3. The first color filter layer 1022 may be a green color filter layer, the second color filter layer 1024 may be a red color filter layer, and the third color filter layer 1026 may be a blue color filter layer. For example, the first color filter layer 1022 may include at least one of a green dye or a green pigment, the second color filter layer 1024 may include at least one of a red dye or a red pigment, and the third color filter layer 1026 may include at least one of a blue dye or a blue pigment.

A passivation layer 1050 is disposed on the thin film transistor Tr and the color filter layer 1020. The passivation layer 1050 has a flat top surface and a drain electrode contact hole 1052 exposing the drain electrode of the thin film transistor Tr.

The OLED D is disposed on the passivation layer 1050 and corresponds to the color filter layer 1020. The OLED D includes a first electrode 1110 connected to a drain electrode of the thin film transistor Tr, and an emission layer 1120 and a second electrode 1130 respectively sequentially disposed on the first electrode 1110. The OLEDs D emit white light in the first, second, and third pixel regions P1, P2, and P3.

The first electrode 1110 is formed with respect to the first, second, and third pixel regions P1, P2, and P3, respectively, and the second electrode 1130 corresponds to the first, second, and third pixel regions P1, P2, and P3 and is integrally formed.

The first electrode 1110 may be one of an anode and a cathode, and the second electrode 1130 may be the other of the anode and the cathode. In addition, the first electrode 1110 may be a transmissive (or semi-transmissive) electrode, and the second electrode 1130 may be a reflective electrode.

For example, the first electrode 1110 may be an anode, and may include a transparent conductive oxide layer of a conductive material having a relatively high work function value, i.e., a Transparent Conductive Oxide (TCO). The second electrode 1130 may be a cathode, and may include a metal material layer of a conductive material having a relatively low work function value, i.e., a low-resistance metal. For example, the transparent conductive oxide layer of the first electrode 1110 may include any one of ITO, IZO, ITZO, SnO, ZnO, ICO, and AZO, and the second electrode 1130 may include Al, Mg, Ca, Ag, an alloy thereof (e.g., Mg — Ag), or a combination thereof.

The emission layer 1120 is disposed on the first electrode 1110. The emission layer 1120 includes at least two emission portions emitting different colors. Each emission part may have a single-layer structure of the EML. Alternatively, each emission part may include at least one of a HIL, a HTL, an EBL, a HBL, an ETL, and an EIL. In addition, the emission layer 1120 may further include CGLs disposed between the emission parts.

At least one of the at least two emission parts may include a first compound of a host, a second compound of a delayed fluorescence material having a structure of chemical formulas 1 to 11, and optionally a third compound of a fluorescent or phosphorescent material.

A bank layer 1060 is disposed on the passivation layer 1050 to cover an edge of the first electrode 1110. The bank layer 1060 corresponds to each of the first, second, and third pixel regions P1, P2, and P3 and exposes the center of the first electrode 1110. As described above, since the OLED D emits white light in the first, second, and third pixel regions P1, P2, and P3, the emission layer 1120 may be formed as one common layer without being separated in the first, second, and third pixel regions P1, P2, and P3. The bank layer 1060 is formed to prevent current from leaking from the edge of the first electrode 1110, and the bank layer 1060 may be omitted.

In addition, the organic light emitting display device 1000 may further include an encapsulation film disposed on the second electrode 1130 to prevent external moisture from penetrating into the OLED D. In addition, the organic light emitting display device 1000 may further include a polarizer disposed under the substrate 1010 to reduce external light reflection.

In the organic light emitting display device 1000 in fig. 14, the first electrode 1110 is a transmissive electrode, the second electrode 1130 is a reflective electrode, and the color filter layer 1020 is disposed between the substrate 1010 and the OLED D. In other words, the organic light emitting display apparatus 1000 is a bottom emission type. Alternatively, the first electrode 1110 may be a reflective electrode, the second electrode 1120 may be a transmissive electrode (or a semi-transmissive electrode), and the color filter layer 1020 may be disposed on the OLED D in the organic light emitting display device 1000.

In the organic light emitting display device 1000, the OLEDs D located in the first, second, and third pixel regions P1, P2, and P3 emit white light, and the white light passes through each of the first, second, and third pixel regions P1, P2, and P3, so that green, red, and blue light are respectively displayed in the first, second, and third pixel regions P1, P2, and P3.

A color conversion film may be disposed between the OLED D and the color filter layer 1020. The color conversion films correspond to the first, second, and third pixel regions P1, P2, and P3, and include a green conversion film, a red conversion film, and a blue conversion film, each of which can convert white light emitted from the OLED D into green, red, and blue light, respectively. For example, the color conversion film may include quantum dots. Accordingly, the organic light emitting display device 1000 may further enhance its color purity. Alternatively, the color conversion film may replace the color filter layer 1020.

Fig. 15 is a schematic cross-sectional view illustrating an OLED according to still another exemplary aspect of the present disclosure. As shown in fig. 15, the OLED D7 includes a first electrode 1110 and a second electrode 1120 facing each other, and an emission layer 1120 disposed between the first electrode 1110 and the second electrode 1120. For example, the first electrode 1100 may be a transmissive electrode, and the second electrode 1120 may be a reflective electrode.

The emission layer 1120 includes a first emission part 1220 including a first EML (EML1)1240, a second emission part 1320 including a second EML (EML2)1340, and a third emission part 1420 including a third EML (EML3) 1440. In addition, the emission layer 1120 may further include a first charge generation layer (CGL1)1280 disposed between the first emission part 1220 and the second emission part 1320, and a second charge generation layer (CGL2)1380 disposed between the second emission part 1320 and the third emission part 1420. Accordingly, the first emission part 1220, the CGL 11280, the second emission part 1320, the CGL 21380, and the third emission part 1420 are sequentially disposed on the first electrode 1110.

The first emission part 1220 may further include at least one of a first HTL (HTL1)1260 disposed between the first electrode 1110 and the EML11240, an HIL 1250 disposed between the first electrode 1110 and the HTL 11260, and a first ETL (ETL1)1270 disposed between the EML11240 and the CGL 1280. Alternatively, the first emitting part 1220 may further include a first (EBL1)1265 disposed between the HTL 11260 and the EML11240 and/or a first HBL (HBL1)1275 disposed between the EML11240 and the ETL 11270.

The second emitting part 1320 may further include at least one of a second HTL (HTL2)1360 disposed between the CGL 1280 and the EML 21340 and a second ETL (ETL2)1370 disposed between the EML 21340 and the CGL 21380. Alternatively, the second emitter 1320 may further include a second EBL (EBL2)1365 disposed between the HTL 21360 and the EML 21340 and/or a second HBL (HBL2)1375 disposed between the EML 21340 and the ETL 21370.

The third emission part 1420 may further include at least one of a third HTL (HTL3)1460 disposed between the CGL 21380 and the EML 31440, a third ETL (ETL3)1470 disposed between the EML 31440 and the second electrode 1130, and an EIL 1480 disposed between the ETL 31470 and the second electrode 1130. Alternatively, the third emitting portion 1420 may further include a third EBL (EBL3)1465 disposed between the HTL 31460 and the EML 31440, and/or a third HBL (HBL3)1475 disposed between the EML 31440 and the ETL 31470.

The CGL 11280 is disposed between the first and second emitting portions 1220 and 1320. The first and second emitting parts 1220 and 1320 are connected through the CGL 11280. The CGL 11280 may be a PN junction CGL that connects a first N-type CGL (N-CGL1)1282 with a first P-type CGL (P-CGL1) 1284.

An N-CGL 11282 is disposed between the ETL 11270 and the HTL 21360, and a P-CGL 11284 is disposed between the N-CGL 11282 and the HTL 21360. The N-CGL 11282 delivers electrons to the EML11240 of the first emission portion 1220, and the P-CGL 11284 delivers holes to the EML 21340 of the second emission portion 1320.

The CGL 21380 is disposed between the second transmitting part 1320 and the third transmitting part 1420. The second and third transmitting portions 1320 and 1420 are connected by a CGL 21380. CGL 21380 may be a PN junction CGL that connects a second N-type CGL (N-CGL2)1382 with a second P-type CGL (P-CGL2) 1384.

N-CGL 21382 is disposed between ETL 21370 and HTL 31460, and P-CGL 21384 is disposed between N-CGL 21382 and HTL 31460. The N-CGL 21382 transports electrons to the EML 21340 of the second emission part 1320, and the P-CGL 21384 transports holes to the EML 31440 of the third emission part 1420.

In this aspect, one of the first, second, and third EMLs 1240, 1340, and 1440 may be a blue EML, another of the first, second, and third EMLs 1240, 1340, and 1440 may be a green EML, and a third of the first, second, and third EMLs 1240, 1340, and 1440 may be a red EML.

As an example, EML11240 may be a blue EML, EML 21340 may be a green EML, and EML 31440 may be a red EML. Alternatively, the EML11240 may be a red EML, the EML 21340 may be a green EML, and the EML 31440 may be a blue EML.

The EML11240 may include a host and a blue dopant (or a red dopant), and the EML 31340 may include a host and a red dopant (or a blue dopant). As an example, the host in each of the EML11240 and the EML 31440 may include the above-described red or blue host, and the blue or red dopant in each of the EML11240 and the EML 31440 may include at least one of the above-described red or blue phosphorescent material, red or blue fluorescent material, and red or blue delayed fluorescent material.

The EML 21340 may include a first compound of the host, a second compound of the delayed fluorescence material having the structure of chemical formulas 1 to 11, and an optional third compound. The EML 21340 including the first to third compounds may have a single layer structure, a double layer structure, or a triple layer structure.

When EML 21340 includes the first compound, the second compound, and the third compound, the content of the first compound may be greater than the content of the second compound, and the content of the second compound is greater than the content of the third compound. In this case, the exciton energy may be efficiently transferred from the second compound to the third compound. As an example, the content of the first to third compounds in the EML 21340 may be about 60 wt% to about 75 wt%, about 20 wt% to about 40 wt%, and about 0.1 wt% to about 5 wt%, respectively, but is not limited thereto.

The OLED D7 emits white light in the first, second, and third pixel regions P1, P2, and P3, respectively, and the white light passes through the color filter layers 1020 disposed in the first, second, and third pixel regions P1, P2, and P3, respectively (fig. 14). Thus, the OLED D7 can realize a full color image.

Fig. 16 is a schematic cross-sectional view illustrating an OLED according to still another exemplary aspect of the present disclosure. As shown in fig. 16, the OLED D8 includes a first electrode 1110 and a second electrode 1120 facing each other, and an emission layer 1120A disposed between the first electrode 1110 and the second electrode 1120. The first electrode 1110 may be an anode, and the second electrode 1120 may be a cathode. For example, the first electrode 1100 may be a transmissive electrode, and the second electrode 1120 may be a reflective electrode.

The emission layer 1120A includes a first emission part 1520 including an EML 11540, a second emission part 1620 including an EML 21640, and a third emission part 1720 including an EML 31740. In addition, the emission layer 1120 may further include a CGL 11580 disposed between the first emission part 1520 and the second emission part 1620, and a CGL 21680 disposed between the second emission part 1620 and the third emission part 1720. Accordingly, the first emission part 1520, the CGL 11580, the second emission part 1620, the CGL 21680, and the third emission part 1720 are sequentially disposed on the first electrode 1110.

The first emission part 1520 may further include at least one of an HTL 11560 disposed between the first electrode 1110 and the EML 11540, an HIL 1550 disposed between the first electrode 1110 and the HTL 11560, and an ETL 11570 disposed between the EML 11540 and the CGL 1580. Alternatively, the first emitting portion 1520 may further include an EBL 11565 disposed between the HTL 11560 and the EML 11540 and/or an HBL 11575 disposed between the EML 11540 and the ETL 11570.

The EML 21640 of the second emitting part 1620 includes a lower EML 1642 and an upper EML 1644. The lower EML 1642 is disposed adjacent to the first electrode 1110, and the upper EML 1644 is disposed adjacent to the second electrode 1130. In addition, the second emitting part 1620 may further include at least one of an HTL 21660 disposed between the CGL 11580 and the EML 21640 and an ETL 21670 disposed between the EML 21640 and the CGL 21680. Alternatively, the second emission part 1620 may further include an EBL 21665 disposed between the HTL 21660 and the EML 21640, and/or an HBL 21675 disposed between the EML 21640 and the ETL 21670.

The third emission part 1720 may further include at least one of an HTL 31760 disposed between the CGL 21680 and the EML31740, an ETL 31770 disposed between the EML31740 and the second electrode 1130, and an EIL 1780 disposed between the ETL 31770 and the second electrode 1130. Alternatively, the third emission portion 1720 may further include an EBL 31765 disposed between the HTL 31760 and the EML31740, and/or an HBL 31775 disposed between the EML31740 and the ETL 31770.

The CGL 11380 is disposed between the first transmitting part 1520 and the second transmitting part 1620. The first and second emitting portions 1520 and 1620 are connected by a CGL 11580. CGL 11580 may be a PN junction CGL that connects N-CGL 11582 with P-CGL 11584. An N-CGL 11582 is disposed between the ETL 11570 and the HTL 21660, and a P-CGL 11584 is disposed between the N-CGL 11582 and the HTL 21560.

The CGL 21680 is disposed between the second emission part 1620 and the third emission part 1720. In other words, the second emission part 1620 and the third emission part 1720 are connected by the CGL 21680. The CGL 21680 may be a PN junction CGL, which links the N-CGL 21682 with the P-CGL 21684. An N-CGL 21682 is disposed between the ETL 21570 and the HTL 31760, and a P-CGL 21684 is disposed between the N-CGL 21682 and the HTL 31760.

In this regard, EML 11540 and EML31740 may each be a blue EML. Each of EML 11540 and EML31740 may include a host and a blue dopant, respectively. The host of each of the EMLs 11540 and 31740 may independently include the above blue host, and the blue dopant of each of the EMLs 11540 and 31740 may independently include at least one of the above blue phosphorescent material, blue fluorescent material, and blue delayed fluorescent material. At least one of the host and the blue dopant in the EML 11540 may be the same as or different from at least one of the host and the blue dopant in the EML 31740. As an example, the blue dopant in EML 11540 may be different from the dopant in EML31740 in terms of luminous efficiency and/or emission wavelength.

One of the lower EML 1642 and the upper EML 1644 in the EML 21640 may be a green EML, and the other of the lower EML 1642 and the upper EML 1644 in the EML 21640 may be a red EML. The green EML and the red EML are sequentially disposed to form an EML 21640.

In one exemplary aspect, the lower EML 1642, which is a green EML, may include a first compound of a host, a second compound of a delayed fluorescence material having a structure of chemical formulas 1 to 11, and an optional third compound of a fluorescent or phosphorescent material.

In addition, the upper EML 1644, which is a red EML, may include a host and a red dopant. The host in the upper EML 1644 may include the above-described red host, and the red dopant in the upper EML 1644 may include at least one of the above-described red phosphorescent material, red fluorescent material, and red delayed fluorescent material.

For example, when the lower EML 1642 includes the first compound, the second compound, and the third compound, the content of the first compound may be greater than the content of the second compound, and the content of the second compound may be greater than the content of the third compound. In this case, the exciton energy may be efficiently transferred from the second compound to the third compound. As an example, the contents of the first to third compounds in the lower EML 1642 may be about 60 wt% to about 75 wt%, about 20 wt% to about 40 wt%, and about 0.1 wt% to about 5 wt%, respectively, but are not limited thereto.

The OLED D8 emits white light in the first, second, and third pixel regions P1, P2, and P3, respectively, and the white light passes through the color filter layers 1020 disposed in the first, second, and third pixel regions P1, P2, and P3, respectively (fig. 14). Accordingly, the organic light emitting display device 1000 (fig. 13) can realize a full color image.

In fig. 16, an OLED D8 has a three-stack structure including a first emitting part 1520, a second emitting part 1620, and a third emitting part 1720, which include EMLs 11540 and 31740 as blue EMLs. Alternatively, the OLED D8 may have a dual stack structure in which one of the first and third emission portions 1520 and 1720, which respectively include EML 11540 and EML31740 as blue EMLs, is omitted.

Synthesis example 1: synthesis of Compound 1-1

(1) Synthesis of intermediate A

[ reaction formula 1-1]

2-chloro-4, 6-diphenyl-1, 3, 5-triazine (50g,186.8mmol), 3-cyano-4-fluorophenylboronic acid (33.9g,205.4mmol), tetrakis (triphenylphosphine) palladium (0) (Pd (PPh)₃)₄10.8g,9.3mmol) and potassium carbonate (51.6g,373.5mmol) were suspended in a mixed solvent of toluene (200mL), ethanol (200mL) and deionized water (200mL), and the solution was refluxed for 12 hours with stirring. After completion of the reaction, the organic layer was extracted with dichloromethane and deionized water and distilled under reduced pressure. The obtained crude product was purified by silica gel column chromatography to obtain intermediate A (46g, yield: 70%).

(2) Synthesis of intermediate B

[ reaction formulae 1-2]

4, 6-dibromo dibenzo [ b, d ]]Furan (30g,92mmol), 2-nitrophenylboronic acid (16.9g,101.2mmol), Pd (PPh)₃)₄(5.3g,4.6mmol) and potassium carbonate (25.4g,184mmol) were suspended in a mixed solution of toluene (460mL), ethanol (92mL) and deionized water (92mL), and the solution was refluxed for 12 hours with stirring. After completion of the reaction, the organic layer was extracted with dichloromethane and deionized water and distilled under reduced pressure. The obtained crude product was purified by silica gel column chromatography to obtain intermediate B (30.2g, yield: 80%).

(3) Synthesis of intermediate C

[ reaction formulae 1 to 3]

Intermediate B (30.2g,73.6mmol) and triphenylphosphine (57.9g,220.8mmol) were suspended in 1, 2-dichlorobenzene (370mL) under a nitrogen atmosphere, and the solution was refluxed for 12 hours with stirring. The organic layer was distilled under reduced pressure, and then the resulting crude product was purified by silica gel column chromatography to obtain intermediate C (20.4g, yield: 80%).

(4) Synthesis of intermediate D

[ reaction formulae 1 to 4]

Intermediate C (20.4g,58.9mmol), bromobenzene (8.3g,53mmol), tris (dibenzylideneacetone) dipalladium (0) (Pd (dba)₃5.4g,5.9mmol), tri-tert-butylphosphine (50% in toluene, 5.9mmol) and sodium tert-butoxide (11.3g,117.8mmol) were suspended in toluene (300mL) and the solution was refluxed for 12 hours with stirring. After completion of the reaction, the organic layer was extracted with dichloromethane and deionized water and distilled under reduced pressure. The resulting crude product was purified by silica gel column chromatography to obtain intermediate D (16.2g, yield: 65%).

(5) Synthesis of Compound 1-1

[ reaction formulae 1 to 5]

Intermediate a (4.6g,13mmol), intermediate D (5g,11.8mmol) and cesium carbonate (7.7g,23.7mmol) were suspended in dimethylformamide (DMF,60mL) and the solution was stirred at 190 ℃ for 16 h. After completion of the reaction, the organic layer was extracted with dichloromethane and deionized water and distilled under reduced pressure. The obtained crude product was purified by silica gel column chromatography to obtain compound 1-1(7.1g, yield: 80%).

Synthesis example 2: synthesis of Compound 2-1

(1) Synthesis of intermediate E

[ reaction formula 2-1]

3-bromobiphenyl (50g,233.11mmol), bis (valeryl) diboron (81.7g,321.7mmol)[1, 1' -bis (diphenylphosphino) ferrocene]Palladium (II) dichloride (Pd (dppf) Cl₂7.8g,10.7mmol) and potassium acetate (42.1g,429mmol) were suspended in 1, 4-dioxane (1100mL) and the solution was refluxed for 12 hours with stirring. After completion of the reaction, the mixed liquid was filtered through celite. The filtrate was distilled under reduced pressure and purified by silica gel column chromatography to obtain intermediate E (36g, yield: 60%).

(2) Synthesis of intermediate F

[ reaction formula 2-2]

2, 4-dichloro-6-phenyl-1, 3, 5-triazine (29.1g,128.7mmol), intermediate E (36g,128.7mmol), Pd (PPh)₃)₄(7.43g,6.43mmol) and potassium carbonate (35.5g,257.3mmol) were suspended in a mixed solution of toluene (650mL), ethanol (130mL) and deionized water (130mL), and the solution was refluxed for 12 hours with stirring. After completion of the reaction, the organic layer was extracted with dichloromethane and deionized water and distilled under reduced pressure. The resulting crude product was purified by silica gel column chromatography to obtain intermediate F (30.1g, yield: 68%).

(3) Synthesis of intermediate G

[ reaction formulae 2 to 3]

Intermediate F (30.1g,87.5mmol), 3-cyano-4-fluorophenylboronic acid (15.9g,96.3mmol), Pd (PPh)₃)₄(5.06g,4.4mmol) and potassium carbonate (24.2g,175.1mmol) were suspended in a mixed solvent of toluene (440mL), ethanol (90mL) and deionized water (900mL), and then the solution was refluxed for 12 hours with stirring. After completion of the reaction, the organic layer was extracted with dichloromethane and deionized water and distilled under reduced pressure. The resulting crude product was purified by silica gel column chromatography to obtain intermediate G (26.2G, yield: 70%).

(4) Synthesis of Compound 2-1

[ reaction formulae 2 to 4]

Intermediate G (5.6G,13mmol), intermediate D (5G,11.8mmol) and cesium carbonate (7.7G,23.7mmol) were suspended in dimethylformamide (DMF,60mL) and the solution was stirred at 190 ℃ for 16 h. After completion of the reaction, the organic layer was extracted with dichloromethane and deionized water and distilled under reduced pressure. The obtained crude product was purified by silica gel column chromatography to obtain compound 2-1(8g, yield: 82%).

Synthesis example 3: synthesis of Compound 2-2

(1) Synthesis of intermediate H

[ reaction formula 3-1]

Reacting 3-bromo-6-iododibenzo [ b, d ]]Furan (30g,80.4mmol), 2-nitrophenylboronic acid (12.1g,72.4mmol), Pd (PPh)₃)₄(4.6g,4mmol) and potassium carbonate (22.2g,160.9mmol) were suspended in a mixed solvent of toluene (400mL), ethanol (80mL) and deionized water (80mL), and then the solution was refluxed for 12 hours with stirring. After completion of the reaction, the organic layer was extracted with dichloromethane and deionized water and distilled under reduced pressure. The resulting crude product was purified by silica gel column chromatography to obtain intermediate H (20.7g, yield: 70%).

(2) Synthesis of intermediate I

[ reaction formula 3-2]

Intermediate H (20.7g,56.3mmol) and triphenylphosphine (44.3g,168.8mmol) were suspended in 1, 2-dichlorobenzene (280mL) under a nitrogen atmosphere and the solution was refluxed for 12 hours with stirring. The organic layer was distilled under reduced pressure, and then the resulting crude product was purified by silica gel column chromatography to obtain intermediate I (13.6g, yield: 72%).

(3) Synthesis of intermediate J

[ reaction formula 3-3]

Intermediate I (13.6g,40.5mmol), fluorobenzene (6.2g,64.1mmol) and cesium carbonate (38g,116.6mmol) were suspended in DMF (290mL) and the solution was stirred at 150 ℃ for 12 h. After completion of the reaction, the organic layer was extracted with dichloromethane and deionized water and distilled under reduced pressure. The resulting crude product was purified by silica gel column chromatography to obtain intermediate J (12.5g, yield: 75%).

(4) Synthesis of intermediate K

[ reaction formulae 3 to 4]

Intermediate J (12.5g,30.3mmol), 2-nitrophenylboronic acid (5.6g,33.3mmol), Pd (PPh)₃)₄(1.7g,1.5mmol) and potassium carbonate (8.4g,60.6mmol) were suspended in a mixed solvent of toluene (150mL), ethanol (30mL) and deionized water (30mL), and then the solution was refluxed for 12 hours with stirring. After completion of the reaction, the organic layer was extracted with dichloromethane and deionized water and distilled under reduced pressure. The obtained crude product was purified by silica gel column chromatography to obtain intermediate K (9.6g, yield: 70%).

(5) Synthesis of intermediate L

[ reaction formulae 3 to 5]

Intermediate K (9.6g,21.1mmol) and triphenylphosphine (16.6g,63.4mmol) were suspended in 1, 2-dichlorobenzene (105mL) and the solution was refluxed for 12 hours with stirring. The organic layer was distilled under reduced pressure, and then the resulting crude product was purified by silica gel column chromatography to obtain intermediate L (5.8g, yield: 65%).

(6) Synthesis of Compound 2-2

[ reaction formulae 3 to 6]

Intermediate G (5.6G,13mmol), intermediate L (5G,11.8mmol) and cesium carbonate (7.7G,23.7mmol) were suspended in DMF (60mL) and the solution was stirred at 190 ℃ for 16 h. After completion of the reaction, the organic layer was extracted with dichloromethane and deionized water and distilled under reduced pressure. The obtained crude product was purified by silica gel column chromatography to obtain compound 2-2(6.3g, yield: 71%).

Synthesis example 4: synthesis of Compounds 2-30

(1) Synthesis of intermediate M

[ reaction formula 4-1]

Reacting 3-bromo-6-iododibenzo [ b, d ]]Furan (30g,80.4mmol), 2-nitrophenylboronic acid (13.4g,80.4mmol), Pd (PPh)₃)₄(4.6g,4mmol) and potassium carbonate (22.2g,160.9mmol) were suspended in a mixed solvent of toluene (400mL), ethanol (80mL) and deionized water (80mL), and then the solution was refluxed for 12 hours with stirring. After completion of the reaction, the organic layer was extracted with dichloromethane and deionized water and distilled under reduced pressure. The resulting crude product was purified by silica gel column chromatography to obtain intermediate M (24.6g, yield: 83%).

(2) Synthesis of intermediate N

[ reaction formula 4-2]

Intermediate M (24.6g,66.7mmol) and triphenylphosphine (52.6g,200.4mmol) were suspended in 1, 2-dichlorobenzene (335mL) under a nitrogen atmosphere, and the solution was refluxed for 12 hours with stirring. The organic layer was distilled under reduced pressure, and then the resulting crude product was purified by silica gel column chromatography to obtain intermediate N (19.1g, yield: 85%).

(3) Synthesis of intermediate O

[ reaction formula 4-3]

Intermediate N (19.1g,56.8mmol), fluorobenzene (6g,62.5mmol) and cesium carbonate (37g,113.6mmol) were suspended in DMF (285mL) and the solution was stirred at 150 ℃ for 12 h. After completion of the reaction, the organic layer was extracted with dichloromethane and deionized water and distilled under reduced pressure. The obtained crude product was purified by silica gel column chromatography to obtain intermediate O (21.1g, yield: 90%).

(4) Synthesis of intermediate P

[ reaction formula 4-4]

Intermediate O (21.1g,51.2mmol), 2-nitrophenylboronic acid (9.4g,56.3mmol), Pd (PPh)₃)₄(2.9g,2.6mmol) and potassium carbonate (14.1g,102.3mmol) were suspended in a mixed solvent of toluene (255mL), ethanol (50mL) and deionized water (50mL), and then the solution was refluxed for 12 hours with stirring. After completion of the reaction, the organic layer was extracted with dichloromethane and deionized water and distilled under reduced pressure. The resulting crude product was purified by silica gel column chromatography to obtain intermediate P (18.6g, yield: 80%).

(5) Synthesis of intermediate Q

[ reaction formulae 4 to 5]

Intermediate P (18.6g,40.9mmol) and triphenylphosphine (32.2g,122.8mmol) were suspended in 1, 2-dichlorobenzene (205mL) and the solution was refluxed for 12 hours with stirring. The organic layer was distilled under reduced pressure, and then the resulting crude product was purified by silica gel column chromatography to obtain intermediate Q (12.1g, yield: 70%).

(6) Synthesis of Compounds 2-30

[ reaction formulae 4 to 6]

Intermediate G (5.6G,13mmol), intermediate L (5G,11.8mmol) and cesium carbonate (7.7G,23.7mmol) were suspended in DMF (60mL) and the solution was stirred at 190 ℃ for 16 h. After completion of the reaction, the organic layer was extracted with dichloromethane and deionized water and distilled under reduced pressure. The obtained crude product was purified by silica gel column chromatography to obtain compounds 2 to 30(7.1g, yield: 72%).

Synthesis example 5: synthesis of Compound 3-1

(1) Synthesis of intermediate R

[ reaction formula 5-1]

9H-carbazole (20g,119.6mmol) was suspended in DMF (840mL) at 0 deg.C, sodium hydride (60%, 5.7g,143.5mmol) was slowly added to the solution, and the solution was stirred at 0 deg.C for 1 hour. 2, 4-dichloro-6-phenyl-1, 3, 5-triazine (29.7g,131.6mmol) dissolved in DMF (250mL) was slowly added to the solution, and then the mixed solution was stirred at 0 ℃ for 1 hour and then at room temperature for 12 hours. After completion of the reaction, an excess amount of water was added to the mixture, and then the organic layer was extracted with dichloromethane and deionized water and distilled under reduced pressure. The resulting crude product was purified by silica gel column chromatography to obtain intermediate R (34.1g, yield: 80%).

(2) Synthesis of intermediate S

[ reaction formula 5-2]

Intermediate R (34.1g,95.6mmol), 3-cyano-4-fluorophenylboronic acid (173g,105.1mmol), Pd (PPh)₃)₄(5.5g,4.8mmol) and potassium carbonate (26.4g,191.1mmol) were suspended in a mixed solvent of toluene (480mL), ethanol (95mL) and deionized water (95mL), and the solution was refluxed for 12 hours with stirring. After completion of the reaction, the organic layer was extracted with dichloromethane and deionized water and distilled under reduced pressure. The obtained crude product was purified by silica gel column chromatography to obtain intermediate S (35g, yield: 83%).

(3) Synthesis of Compound 3-1

[ reaction formulae 5-3]

Intermediate S (5.7g,13mmol), intermediate D (5g,11.8mmol) and cesium carbonate (7.7g,23.7mmol) were suspended in DMF (60mL) and the solution was stirred at 190 ℃ for 16 h. After completion of the reaction, the organic layer was extracted with dichloromethane and deionized water and distilled under reduced pressure. The obtained crude product was purified by silica gel column chromatography to obtain compound 3-1(7.5g, yield: 75%).

Synthesis example 6: synthesis of Compound 3-2

[ reaction formula 6]

Intermediate S (5.7g,13mmol), intermediate L (5g,11.8mmol) and cesium carbonate (7.7g,23.7mmol) were suspended in DMF (60mL) and the solution was stirred at 190 ℃ for 16 h. After completion of the reaction, the organic layer was extracted with dichloromethane and deionized water and distilled under reduced pressure. The obtained crude product was purified by silica gel column chromatography to obtain compound 3-2(6.8g, yield: 68%).

Synthesis example 7: synthesis of Compounds 3-30

[ reaction formula 7]

Intermediate S (5.7g,13mmol), intermediate Q (5g,11.8mmol) and cesium carbonate (7.7g,23.7mmol) were suspended in DMF (60mL) and the solution was stirred at 190 ℃ for 16 h. After completion of the reaction, the organic layer was extracted with dichloromethane and deionized water and distilled under reduced pressure. The obtained crude product was purified by silica gel column chromatography to obtain compounds 3 to 30(7g, yield: 70%).

Experimental example 1: measurement of energy level

HOMO-LUMO level bandgaps (Eg, eV) and excited triplet levels (T, T) of the compounds 1-1, 2-2, 2-30, 3-1, 3-2 and 3-20 synthesized in Synthesis examples 1 to 7 and comparative examples 1 and 2 were simulated for comparison₁). Table 1 below shows the measurement results.

[ reference Compound ]

Table 1: energy level simulation of organic compounds

Compound (I)	Bandgap energy (Eg)	Ti(eV)
			Ref.1	2.71	2.68
Ref.2	2.66	2.58
			1-1	2.69	2.61
2-1	2.71	2.60
			2-2	2.66	2.55
2-30	2.69	2.60
			3-1	2.70	2.59
3-2	2.61	2.55
			3-30	2.58	2.48

As shown in table 1, the organic compounds synthesized in the synthesis examples have energy band gaps and triplet state energy levels suitable for dopants in EMLs.

Example 1 (ex.1): fabrication of OLEDs

An OLED was fabricated in which compound 1-1 was applied as a delayed fluorescence material to the EML. The ITO (50nm) attached glass substrate was washed with ozone and loaded in a vacuum system and then transferred to a vacuum deposition chamber for deposition of other layers on the substrate. At 10^-7Under support and set the deposition rate to

The organic layers were deposited by evaporation from a heated boat in the following order.

ITO (50 nm); HIL (HAT-CN; 7 nm); HTL (NPB,55 nm); EBL (mCBP,10 nm); EML (4- (3- (2-triphenylen-2-yl) phenyl) -dibenzothiophene (host): compound 1-1 (dopant) ═ 65:35 (by weight), 50 nm); HBL (B3PYMPM,10 nm); ETL (TPBi,20 nm); EIL (LiF; 1.0 nm); and a cathode (Al; 100 nm).

Then, a capping layer (CPL) was deposited on the cathode and the device was encapsulated with glass. After the deposition of the emission layer and the cathode, the OLED was transferred from the deposition chamber to a dry box for film formation, and then encapsulated with an ultraviolet curable epoxy resin and a moisture absorbent.

Examples 2 to 7(ex.2 to ex.7): fabrication of OLEDs

An OLED was manufactured using the same material as example 1, except that compound 2-1(ex.2), compound 2-2(ex.3), compound 2-30(ex.4), compound 3-1(ex.5), compound 3-2(ex.6), or compound 3-30(ex.7) was applied to the EML as a delayed fluorescence material instead of compound 1-1.

Comparative examples 1 to 2(com.1 to com.2): fabrication of OLEDs

An OLED was manufactured using the same material as example 1, except that ref.1 compound (com.1) or ref.2 compound (com.2) was applied to the EML as a delayed fluorescence material instead of compound 1-1.

Experimental example 2: measurement of light emission properties of OLED

Each of the OLEDs manufactured according to examples 1 to 7 and comparative examples 1 to 2 was connected to an external power source, and then a constant current source (KEITHLEY) and a photometer were used at room temperaturePR650 evaluates the light emitting properties of all diodes. In particular, the drive voltage (V), current efficiency (cd/A), external quantum efficiency (EQE,%), 10mA/cm were measured²Maximum electroluminescence wavelength (EL lambda) at current density_maxNm) and T at 8000nit₉₅(period of 95% brightness from initial brightness, hours). The results are shown in table 2 below.

Table 2: luminescent properties of OLEDs

Sample (I)	Dopant agent	V	cd/A	EQE	ELλmax	T95
							Com.1	Ref.1	5.01	43.3	13.04	524	30
Com.2	Ref.2	4.03	37.3	11.54	548	80
							Ex.1	1-1	3.93	50.0	15.21	544	120
Ex.2	2-1	3.83	37.6	11.71	540	200
							Ex.3	2-2	4.19	48.5	14.78	544	250
Ex.4	2-30	3.94	40.8	12.73	540	200
							Ex.5	3-1	4.03	46.2	14.05	540	210
Ex.6	3-2	4.07	49.6	15.25	544	160
							Ex.7	3-30	3.95	46.1	14.03	544	230

As shown in table 2, the driving voltage of the OLEDs in examples 1 to 7 was reduced by at most 23.6% and the current efficiency, EQE and emission lifetime were improved by at most 34.0%, 32.1% and 733.3%, respectively, compared to the OLEDs of comparative examples 1 and 2 in which the conventional triazine-based delayed fluorescent material was applied to the EML.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present disclosure without departing from the technical concept or scope of the disclosure. Thus, it is intended that the present disclosure cover the modifications and variations of this disclosure provided they come within the scope of the appended claims and their equivalents.

Claims (20)

1. An organic compound having a structure of the following chemical formula 1:

[ chemical formula 1]

Wherein R is₁To R₁₂Each independently selected from hydrogen, halogen, cyano, unsubstituted or substituted C₁-C₂₀Alkyl, unsubstituted or substituted C₁-C₂₀Alkoxy, unsubstituted or substituted C₁-C₂₀Alkylamino radical, unsubstituted or substituted C₆-C₃₀Aryl and unsubstituted or substituted C₃-C₃₀Heteroaryl or R₁To R₁₂Two adjacent groups in (a) form an unsubstituted or substituted C₆-C₂₀Aromatic ring or unsubstituted or substituted C₃-C₃₀Heteroaromatic ring, wherein R₁To R₄Is cyano; r₁₃To R₁₅Each independently selected from hydrogen, unsubstituted or substituted C₁-C₂₀Alkyl, unsubstituted or substituted C₁-C₂₀Alkoxy, unsubstituted or substituted C₁-C₂₀Alkylamino radical, unsubstituted or substituted C₆-C₃₀Aryl and unsubstituted or substituted C₃-C₃₀Heteroaryl groups; and a is a fused heteroaromatic ring having the structure of the following chemical formula 2:

[ chemical formula 2]

Wherein R is₂₁To R₂₄Each independently selected from hydrogen, halogen, cyano, unsubstituted or substituted C₁-C₂₀Alkyl, unsubstituted or substituted C₁-C₂₀Alkoxy, unsubstituted or substituted C₁-C₂₀Alkylamino radical, unsubstituted or substituted C₆-C₃₀Aryl and unsubstituted or substituted C₃-C₃₀Heteroaryl or R₂₁To R₂₄Two adjacent groups in (a) form an unsubstituted or substituted C₆-C₂₀Aromatic ring or unsubstituted or substituted C₃-C₃₀A heteroaromatic ring; x is NR₂₅Oxygen (O) or sulfur (S), wherein R₂₅Selected from hydrogen, unsubstituted or substituted C₁-C₂₀Alkyl, unsubstituted or substituted C₁-C₂₀Alkoxy, unsubstituted or substituted C₁-C₂₀Alkylamino radical, unsubstituted or substituted C₆-C₃₀Aryl and unsubstituted or substituted C₃-C₃₀Heteroaryl groups.

2. The organic compound according to claim 1, wherein the organic compound has a structure of the following chemical formula 3:

[ chemical formula 3]

Wherein R is₁To R₁₅Each of which is the same as defined in chemical formula 1, R₂₁And R₂₂Each is the same as defined in chemical formula 2; and B is a fused heteroaromatic ring having the structure of the following chemical formula 4:

[ chemical formula 4]

Wherein R is₂₃、R₂₄And X are each the same as defined in chemical formula 2.

3. The organic compound according to claim 1, wherein the organic compound has a structure of the following chemical formula 5:

[ chemical formula 5]

Wherein R is₁To R₁₅Each of which is the same as defined in chemical formula 1, R₂₁And R₂₂Each is the same as defined in chemical formula 2; and B is a fused heteroaromatic ring having the structure of the following chemical formula 6:

[ chemical formula 6]

Wherein R is₂₃、R₂₄And X are each the same as defined in chemical formula 2.

4. The organic compound of claim 1, wherein the organic compound has a structure of the following chemical formula 7:

[ chemical formula 7]

Wherein R is₁To R₁₅Each of which is the same as defined in chemical formula 1, R₂₁And R₂₂Each is the same as defined in chemical formula 2; and B is a fused heteroaromatic ring having the structure of the following chemical formula 8:

[ chemical formula 8]

Wherein R is₂₃、R₂₄And X are each the same as defined in chemical formula 2.

5. The organic compound according to claim 1, wherein the organic compound comprises any organic compound having a structure of the following chemical formula 9:

[ chemical formula 9]

6. The organic compound according to claim 1, wherein the organic compound comprises any organic compound having a structure of the following chemical formula 10:

[ chemical formula 10]

7. The organic compound according to claim 1, wherein the organic compound comprises any organic compound having a structure of the following chemical formula 11:

[ chemical formula 11]

8. An organic light emitting diode, comprising:

a first electrode;

a second electrode facing the first electrode; and

a layer of emissive material disposed between the first electrode and the second electrode,

wherein the emitting material layer comprises a structure having the following chemical formula 1:

[ chemical formula 1]

Wherein R is₁To R₁₂Each independently selected from hydrogen, halogen, cyano, unsubstituted or substituted C₁-C₂₀Alkyl, unsubstituted or substituted C₁-C₂₀Alkoxy, unsubstituted or substituted C₁-C₂₀Alkylamino radical, unsubstituted or substituted C₆-C₃₀Aryl and unsubstituted or substituted C₃-C₃₀Heteroaryl or R₁To R₁₂Two adjacent groups in (a) form an unsubstituted or substituted C₆-C₂₀Aromatic ring or unsubstituted or substituted C₃-C₃₀Heteroaromatic ring, wherein R₁To R₄Is cyano; r₁₃To R₁₅Each independently selected from hydrogen, unsubstituted or substituted C₁-C₂₀Alkyl, unsubstituted or substituted C₁-C₂₀Alkoxy, unsubstituted or substituted C₁-C₂₀Alkylamino radical, unsubstituted or substituted C₆-C₃₀Aryl and unsubstituted or substituted C₃-C₃₀Heteroaryl groups; and a is a fused heteroaromatic ring having the structure of the following chemical formula 2:

[ chemical formula 2]

Wherein R is₂₁To R₂₄Each independently selected from hydrogen, halogen, cyano, unsubstituted or substituted C₁-C₂₀Alkyl, unsubstituted or substituted C₁-C₂₀Alkoxy, unsubstituted or substituted C₁-C₂₀Alkylamino, unsubstituted or substitutedC of substituent group₆-C₃₀Aryl and unsubstituted or substituted C₃-C₃₀Heteroaryl or R₂₁To R₂₄Two adjacent groups in (a) form an unsubstituted or substituted C₆-C₂₀Aromatic ring or unsubstituted or substituted C₃-C₃₀A heteroaromatic ring; x is NR₂₅Oxygen (O) or sulfur (S), wherein R₂₅Selected from hydrogen, unsubstituted or substituted C₁-C₂₀Alkyl, unsubstituted or substituted C₁-C₂₀Alkoxy, unsubstituted or substituted C₁-C₂₀Alkylamino radical, unsubstituted or substituted C₆-C₃₀Aryl and unsubstituted or substituted C₃-C₃₀Heteroaryl groups.

9. The organic light emitting diode of claim 8, wherein the organic compound has a structure of the following chemical formula 3:

[ chemical formula 3]

Wherein R is₁To R₁₅Each of which is the same as defined in chemical formula 1, R₂₁And R₂₂Each is the same as defined in chemical formula 2; and B is a fused heteroaromatic ring having the structure of the following chemical formula 4:

[ chemical formula 4]

Wherein R is₂₃、R₂₄And X are each the same as defined in chemical formula 2.

10. The organic light emitting diode of claim 8, wherein the organic compound has a structure of the following chemical formula 5:

[ chemical formula 5]

Wherein R is₁To R₁₅Each of which is the same as defined in chemical formula 1, R₂₁And R₂₂Each is the same as defined in chemical formula 2; and B is a fused heteroaromatic ring having the structure of the following chemical formula 6:

[ chemical formula 6]

Wherein R is₂₃、R₂₄And X are each the same as defined in chemical formula 2.

11. The organic light emitting diode of claim 8, wherein the organic compound has a structure of the following chemical formula 7:

[ chemical formula 7]

Wherein R is₁To R₁₅Each of which is the same as defined in chemical formula 1, R₂₁And R₂₂Each is the same as defined in chemical formula 2; and B is a fused heteroaromatic ring having the structure of the following chemical formula 8:

[ chemical formula 8]

Wherein R is₂₃、R₂₄And X are each the same as defined in chemical formula 2.

12. The organic light emitting diode of claim 8, wherein the emissive material layer comprises a first compound and a second compound, and wherein the second compound comprises the organic compound.

13. The organic light emitting diode of claim 12, wherein the excited triplet level of the first compound is higher than the excited triplet level of the second compound.

14. The organic light emitting diode of claim 12, the emitting material layer further comprising a third compound.

15. The organic light emitting diode of claim 14, wherein the excited singlet level of the third compound is lower than the excited singlet level of the second compound.

16. The organic light emitting diode of claim 12, wherein the emission material layer comprises a first emission material layer disposed between the first electrode and the second electrode, and a second emission material layer disposed between the first electrode and the first emission material layer or between the first emission material layer and the second electrode, wherein the first emission material layer comprises the first compound and the second compound, and wherein the second emission material layer comprises a fourth compound and a fifth compound.

17. The organic light-emitting diode of claim 16, wherein the excited triplet level of the fourth compound is higher than the excited triplet level of the second compound, and wherein the excited singlet level of the fifth compound is lower than the excited singlet level of the second compound.

18. The organic light emitting diode of claim 16, the emissive material layer further comprising a third emissive material layer disposed opposite the second emissive material layer relative to the first emissive material layer, wherein the third emissive material layer comprises a sixth compound and a seventh compound.

19. The organic light-emitting diode of claim 18, wherein an excited triplet level of the sixth compound is higher than an excited triplet level of the second compound, and wherein an excited singlet level of the seventh compound is lower than an excited singlet level of the second compound.

20. An organic light-emitting device, comprising:

a substrate; and

an organic light emitting diode according to claim 8 on said substrate.

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