KR20230078620A - Organic compounds, organic light emitting diode and organic light emittid device having the compounds - Google Patents

Abstract

In the present invention, at least two carbazolyl moieties functioning as electron donors, and at least one cyano group functioning as electron acceptors, connected to the carbazolyl moiety through an aromatic linking group, It relates to organic compounds having triazine moieties linked by substituted aromatic rings. Since it contains both an electron donor and an electron acceptor moiety in one molecule, charge can easily move in the molecule and the luminous efficiency can be improved. The organic compound of the present invention can be used as a delayed fluorescence dopant, and by applying the organic compound of the present invention, organic light emitting devices such as organic light emitting diodes, display devices, and lighting devices having low driving voltage, excellent luminous efficiency and color purity can be utilized

Description

Organic compounds, organic light emitting diodes and organic light emitting devices containing the same

The present invention relates to an organic compound, and more particularly, to an organic compound that can be applied to a light emitting layer of an organic light emitting diode due to its excellent light emitting efficiency, an organic light emitting diode and an organic light emitting device including the organic compound.

Currently, the technology of organic light emitting diode devices is rapidly developing. Organic light emitting diodes (OLEDs) are formed of a thin organic thin film of less than 2000 Å, and can implement images in a single direction or in both directions depending on the configuration of electrodes used. In addition, an organic light emitting diode display, which is one of organic light emitting devices including organic light emitting diodes, can form elements on a flexible transparent substrate such as plastic, so that a flexible or foldable display device can be realized. In addition, the organic light emitting diode display can be driven at a low voltage and has excellent color purity, so it has great advantages over a liquid crystal display device (LCD).

An organic light emitting diode includes a hole injection electrode (anode), an electron injection electrode (cathode), and an organic light emitting layer formed between the anode and the cathode. In order to increase the luminous efficiency, the organic light emitting layer is a hole injection layer (HIL), a hole transport layer (HTL), a light emitting material layer (EML), an electron transport layer (ETL), and an electron injection layer (EIL) sequentially stacked on the hole injection electrode. ) may be included. At this time, holes injected from the anode and electrons injected from the cathode are combined in the light emitting material layer to form excitons (exciton) to enter an unstable energy state (excited state), and then to a stable ground state ( It returns to the ground state and emits light. External quantum efficiency (EQE; η _ext ) of the light emitting material applied to the light emitting material layer can be calculated by the following formula (1).

(η _S/T is the singlet/triplet ratio, г is the charge balance factor; Φ is the radiative quantum efficiency; η _out-coupling is the light-extraction efficiency (out- coupling efficiency)

Exciton generation efficiency (η _S/T ) is a rate at which generated excitons are converted into light, and has a limiting value of up to 0.25 in the case of fluorescent materials. Theoretically, when a hole and an electron meet to form an exciton, a singlet exciton in the form of paired spin and a triplet exciton in the form of unpaired spin are formed according to the arrangement of spins. It is produced in a ratio of 1:3. This is because in fluorescent materials, only singlet excitons participate in light emission, and the remaining 75% of triplet excitons do not participate in light emission.

The charge balance factor (г) means the balance of holes and electrons forming excitons, and generally has a value of '1' assuming a 1:1 matching of 100%. Radiant quantum efficiency (Φ) is a value related to the actual luminous efficiency of a light emitting material, and depends on the photoluminescence (PL) of a dopant in a host-dopant system.

Light-extraction efficiency (η _out-coupling ) is a ratio of light extracted to the outside among light emitted from a light emitting material. In general, when a thin film is formed by thermally depositing an isotropic light emitting material, individual light emitting molecules do not have a certain directionality and exist in a disordered state. Light-extraction efficiency in such a random orientation state is generally assumed to be 0.2. Therefore, when the four elements shown in Equation (1) are combined, the maximum luminous efficiency of the organic light emitting diode using the fluorescent material is only about 5%.

On the other hand, phosphorescent materials have a light-emitting mechanism that converts both singlet excitons and triplet excitons into light. Phosphorescent materials convert singlet excitons into triplets through intersystem crossing (ISC). Therefore, when a phosphorescent material using both singlet excitons and triplet excitons is used, the low luminous efficiency of the fluorescent material can be improved. When a metal complex containing a heavy metal such as Ir or Pt is used as a phosphorescent material, a transition from a triplet state to a singlet state is possible due to strong spin-orbit coupling by the heavy metal element. However, the color purity of the blue phosphor material is difficult to apply to display devices, and the lifetime is also very short, so it does not reach the level of commercialization.

In particular, the phosphorescent host should be higher than the triplet energy of the phosphorescent dopant material in order to prevent back energy transfer of the phosphorescent dopant to the host. However, when the organic aromatic compound has an increased conjugated structure or a fused ring, the triplet energy is drastically lowered, so organic molecules that can be used as phosphorescent hosts are extremely limited. In addition, in order to have a high triplet energy, the phosphorescent host is designed to have a fairly wide energy band gap. Charge injection and transport are delayed due to the phosphorescent host material having a wide energy bandgap, and accordingly, the driving voltage of the organic light-emitting diode increases, adversely affecting power consumption, and electrical stress is applied to the material constituting the light emitting layer. However, a problem occurred in that the lifetime characteristics of the device were deteriorated.

SUMMARY OF THE INVENTION An object of the present invention is to provide an organic light emitting diode and an organic light emitting device that can improve light emitting efficiency, reduce power consumption by lowering a driving voltage using the organic compound, and improve device lifetime.

According to one aspect of the present invention, at least two carbazolyl moieties that act as electron donors and at least two carbazolyl moieties that function as electron acceptors are bonded to the carbazolyl moiety through an aromatic linking group, An organic compound comprising a triazine moiety also linked to an aromatic ring substituted with at least one cyano group is provided.

The aromatic linking group between the electron donor and the electron acceptor may be a homo arylene group or a hetero arylene group.

According to another aspect of the present invention, the present invention provides an organic light emitting diode and an organic light emitting device in which the organic compound described above is applied to an organic light emitting layer.

For example, the organic compound may be applied to the light emitting material layer.

In one exemplary embodiment, the organic compound of the present invention may be used as a dopant of the light emitting material layer.

The organic compound according to the present invention is linked to at least two carbazolyl moieties that act as electron donors and carbazolyl moieties that function as electron acceptors through an appropriate aromatic linking group, and at least one contains a triazine moiety having an aromatic substituent substituted with a cyano group of

At least two carbazolyl moieties having a rigid structure function as electron donors, and a triazine moiety substituted with an aromatic ring substituted with at least one cyano group is used as an electron acceptor. As the steric hindrance between the triazine moieties, which are electron acceptors, increases, the dihedral angle between the electron donors and electron acceptors increases. As the formation of a conjugate structure between at least two carbazolyl moieties that function as electron donors and a triazine moiety that functions as an electron donor is restricted, the highest level occupied molecular orbital (HOMO) energy state and Luminous efficiency can be improved while being easily separated into the lowest level unoccupied molecular orbital (LUMO) energy state.

In addition, a dipole is formed from at least two carbazolyl moieties that function as electron donors to a triazine moiety that functions as an electron acceptor, so that the dipole moment inside the molecule increases. In particular, as the aromatic moiety substituted with at least one cyano group is connected to the triazine moiety, the dipole moment between the electron acceptor and the electron donor is further improved, and the luminous efficiency can be further improved.

In addition, at least two carbazolyl moieties functioning as electron donors are connected to a triazine moiety as an electron acceptor through an aromatic linking group such as an arylene group. Since the distance between the electron donor and the electron acceptor increases, the overlap between the HOMO and the LUMO decreases, and thus the difference between the triplet energy level and the singlet energy level (Δ _EST ) can be reduced.

Due to the steric hindrance between the electron donor and electron acceptor by the linking group, it is possible to minimize the red shift problem of light emitted from the organic light emitting layer including the organic compound according to the present invention.

Moreover, the carbazolyl moiety functioning as an electron donor is a condensed aromatic ring with a rigid structure, and the three-dimensional conformation of the molecule is greatly restricted. When the organic compound according to the present invention emits light, there is no energy loss due to a change in the three-dimensional structure of the molecule, and since the emission spectrum can be limited to a specific range, high color purity can be realized.

Therefore, by applying the organic compound of the present invention to a light emitting device, the light emitting efficiency is improved, green light emission of high color purity is realized, and the driving voltage of the light emitting diode can be lowered.

Therefore, by using the organic compound of the present invention as a dopant of an organic light emitting layer constituting an organic light emitting diode, for example, a light emitting material layer, the driving voltage of the light emitting device can be lowered and the light emitting efficiency can be improved. Since it can be driven at a low voltage, the material constituting the light emitting element is not thermally decomposed due to the heat generated at the high voltage, so the light emitting efficiency is improved, and the load when driving the light emitting element is reduced and the life of the element is increased.

As a result, by applying the organic compound according to the present invention, it is possible to implement an organic light emitting device such as an organic light emitting diode capable of emitting green light, an organic light emitting diode display device, and a lighting device with improved light emitting efficiency and device lifetime characteristics. .

1 is a schematic diagram for explaining a light emitting mechanism when an organic compound according to an exemplary embodiment of the present invention is used as a delayed fluorescent material.
2 is a cross-sectional view schematically illustrating an organic light emitting diode in which an organic compound is applied to an organic light emitting layer according to an exemplary embodiment of the present invention.
3 is a schematic diagram for explaining an energy level of a material used as a host when an organic compound according to an exemplary embodiment of the present invention is used as a delayed fluorescent material.
4 is a cross-sectional view schematically illustrating an organic light emitting diode in which an organic compound is applied to an organic light emitting layer according to another exemplary embodiment of the present invention.
5 is a cross-sectional view schematically illustrating an organic light emitting diode display as an example of an organic light emitting diode having an organic light emitting diode applied to an organic light emitting layer according to an exemplary embodiment of the present invention.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings when necessary.

[organic compound]

The organic compound according to the present invention functions as an electron donor and has at least two carbazolyl moieties having a rigid chemical structure, functions as an electron acceptor, and includes a carbazolyl moiety and an appropriate aromatic linking group ( linker) and includes a triazine moiety substituted with two aromatic rings substituted with at least one cyano group. The organic compound according to the present invention may be represented by Formula 1 below.

Formula 1

(In Formula 1, R ₁ to R ₃ are each independently an unsubstituted or substituted carbazolyl group or a condensed aromatic ring having a carbazolyl moiety; m is 0 or 1; Ar ₁ and Ar ₂ are each independently to C ₅ ~C ₃₀ aryl group, C ₄ ~C ₃₀ heteroaryl group, C ₅ ~C ₃₀ homo arylalkyl group, C ₄ ~C ₃₀ heteroarylalkyl group, C ₅ ~C ₃₀ homo aryloxyl group, C ₄ ~C ₃₀ hetero aryloxyl group, C ₅ ~ C ₃₀ selected from the group consisting of homo arylamine group and C ₄ ~ C ₃₀ hetero arylamine group; Ar ₃ is C ₅ ~ C ₃₀ arylene group, C ₄ ~ C ₃₀ hetero arylene group , C ₅ ~ C ₃₀ homo arylalkylene group, C ₄ ~ C ₃₀ hetero arylalkylene group, C ₅ ~ C ₃₀ selected from the group consisting of homo aryloxylene group and C ₄ ~ C ₃₀ heteroaryloxylene group; a and b is each independently 1 or 2)

In the present specification, 'unsubstituted' or 'unsubstituted' means that a hydrogen atom is substituted, and in this case, the hydrogen atom includes light hydrogen, heavy hydrogen, and tritium.

In the present specification, the substituent in 'substituted' is, for example, a C ₁ ~ C ₂₀ alkyl group unsubstituted or substituted with a halogen atom, a cyano group, and/or a nitro group, an unsubstituted or substituted with a halogen atom, a cyano group, and/or a nitro group. C ₁ ~C ₂₀ alkoxy group, halogen atom, cyano group, alkyl halide group such as -CF ₃ , hydroxy group unsubstituted or substituted with a halogen atom, cyano group and/or nitro group, carboxy group, carbonyl group, amine group , C ₁ ~C ₁₀ alkyl substituted amine group, C ₅ ~C ₃₀ aryl substituted amine group, C ₄ ~C ₃₀ heteroaryl substituted amine group, nitro group, hydrazyl group, sulfonic acid group, C ₁ ~C ₂₀ Alkyl silyl group, C ₁ ~C ₂₀ Alkoxy silyl group, C ₃ ~C ₃₀ Cycloalkyl silyl group, C ₅ ~C ₃₀ Aryl silyl group, C ₄ ~C ₃₀ Heteroaryl silyl group, C ₅ ~C ₃₀ Aryl group , C ₄ ~ C ₃₀ heteroaryl group, C ₅ ~ C ₃₀ homo aralkyl group, C ₄ ~ C ₃₀ hetero aralkyl group, C ₅ ~ C ₃₀ homo aralkoxy group or C ₄ ~ C ₃₀ hetero aralkoxy group, and the like. However, the present invention is not limited thereto.

In the present specification, 'heteroaromatic ring', 'heterocycloalkyl group', 'heteroaryl group', 'heteroarylalkyl group', 'heteroaryloxyl group', 'heteroarylamine group', 'heteroarylene group, heteroarylalkylene group' The term 'hetero' used in ', 'heteroaryloxylene group', etc. means that at least one of the carbon atoms constituting these aromatic or alicyclic rings, for example, 1 to 5 carbon atoms are N, O, S And means substituted with one or more heteroatoms selected from the group consisting of combinations thereof.

According to one exemplary embodiment, R ₁ to R ₃ in Formula 1 may form a carbazolyl moiety that can function as an electron donor. For example, R ₁ to R ₃ may each independently be a carbazolyl group and a polycyclic aromatic substituent in which an aromatic ring is fused to the carbazolyl moiety. For example, R ₁ to R ₃ are each independently substituted, C ₁ ~ C ₁₀ Alkyl group or aromatic ring (eg, carbazolyl group, etc.) substituted carbazolyl group, benzocarbazolyl group, dibenzocarbazolyl group group, indenocarbazolyl group, indolocarbazolyl group, spy bonded carbazolyl group (e.g., spiro[9H-fluorene-9,7'(12'H)-indeno[1,2-a ] carbazolyl group]) and the like.

Meanwhile, Ar ₁ and Ar ₂ that may be substituted on the triazine ring functioning as an electron donor are each independently an aromatic substituent substituted with one or two cyano groups. According to one exemplary embodiment, Ar ₁ and Ar ₂ directly linked to the triazine moiety in Formula 1 are each independently a phenyl group, a biphenyl group, a terphenyl group, a tetraphenyl group, a naphthyl group, an anthracenyl group, an indenyl group, and a phenyl group. uncondensed or fused homoaromatic rings such as nalenyl, phenanthrenyl, azulenyl, pyrenyl, fluorenyl, tetracenyl, indacenyl or spiro fluorenyl, and/or pyrrole; Ryl group, pyridinyl group, pyrimidinyl group, pyrazinyl group, pyridazinyl group, triazinyl group, tetrazinyl group, imidazolyl group, pyrazolyl group, indolyl group, carbazolyl group, benzocarbazolyl group, dibenzocarba Azoyl group, indolocarbazolyl group, indenocarbazolyl group, benzofuranocarbazolyl group, benzothienocarbazolyl group, quinolinyl group, isoquinolinyl group, phthalazinyl group, quinoxalinyl group, cinolinyl group , quinazolinyl group, phthalazinyl group, quinoxalinyl group, cynolinyl group, quinazolinyl group, benzoquinolinyl group, benzoisoquinolinyl group, benzoquinazolinyl group, benzoquinoxalinyl group, acridinyl group, phenanthrolinyl group , Furanyl group, pyranyl group, oxazinyl group, oxazolyl group, oxadiazolyl group, triazolyl group, dioxynyl group, benzofuranyl group, dibenzofuranyl group, thiopyranyl group, thiazinyl group, thiophenyl group, or It may be an uncondensed or condensed heteroaromatic ring such as an N-substituted spiro fluorenyl group.

For example, in Formula 1, Ar ₁ and/or Ar ₂ may each independently represent a homoaryl group such as a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, an anthracenyl group, a fluorenyl group, or a spirofluorenyl group, and/or Benzothiophenyl group, dibenzothiophenyl group, benzofuranyl group, dibenzofuranyl group, pyrrolyl group, pyridinyl group, pyrimidinyl group, pyrazinyl group, pyridazinyl group, triazinyl group, tetrazinyl group, imidazole Dibenzoyl group, pyrazolyl group, indole group, carbazolyl group, benzocarbazolyl group, dibenzocarbazolyl group, indolocarbazolyl group, indenocarbazolyl group, benzofuranocarbazolyl group, benzothienocarbazolyl group, Quinolinyl group, isoquinolinyl group, phthalazinyl group, quinoxalinyl group, cinolinyl group, quinazolinyl group, phthalazinyl group, quinoxalinyl group, cinolinyl group, quinazolinyl group, benzoquinolinyl group, benzoiso It may be a heteroaryl group such as a quinolinyl group, a benzoquinazolinyl group, or a benzoquinoxalinyl group.

In this case, the number of aromatic rings each constituting Ar ₁ and/or Ar ₂ in Formula 1 is 1 to 2, more preferably 1. When the number of aromatic rings each constituting Ar ₁ and/or Ar ₂ increases, the conjugated structure of the molecule is excessively lengthened and the band gap is excessively reduced and/or the triplet energy level of the molecule is lowered to realize desired luminous efficiency. may not be able to For example, in Formula 1, Ar ₁ and/or Ar ₂ are each independently a phenyl group, a biphenyl group, a naphthyl group, a biphenyl group, a pyrrole group, an imidazole group, a pyrazole group, a pyridinyl group, a pyrazinyl group, or a pyrimidinyl group. , It may be a pyridazinyl group, a furanyl group, or a thiophenyl group.

On the other hand, in one non-limiting embodiment, Ar ₃ as a linker in Formula 1 is an electron donor, at least two carbazolyl moieties (R ₁ to R ₃ ), and a triazine moiety functioning as an electron acceptor. It is an aromatic linking group that mediates t. For example, when Ar ₃ is a C ₅ ~C ₃₀ homoarylene group, Ar ₃ is a phenylene group, a biphenylene group, a terphenylene group, a tetraphenylene group, or an indenyl group. Indenylene, naphthylene, azulenylene, indacenylene, acenaphthylene, fluorenylene, spiro-fluorenylene , phenalenylene, phenanthrenylene, anthracenylene, fluoranthrenylene, triphenylenylene, pyrenylene, chrysenylene (chrysenylene), naphthacenylene, picenylene, perylenylene, pentaphenylene, and hexacenylene.

In another optional embodiment, when Ar ₃ is a C ₄ ~C ₃₀ heteroarylene group, Ar ₃ is a pyrrolylene group, an imidazolylene group, a pyrazolylene group, or a pyridinylene group ( pyridinylene), pyrazinylene, pyrimidinylene, pyridazinylene, isoindolylene, indolylene, indazolylene, purinyl Purinylene, quinolinylene, isoquinolinylene, benzoquinolinylene, phthalazinylene, naphthyridinylene, quinoxalinyl Quinoxalinylene, quinazolinylene, benzoquinolinylene, benzoisoquinolinylene, benzoquinazolinylene, benzoquinoxalinylene, cinnolinylene, phenanthridinylene (phenanthridinylene), acridinylene, phenanthrolinylene, phenazinylene, benzoxazolylene, benzimidazolylene, furanylene , benzofuranylene, thiophenylene, benzothiophenylene, thiazolylene, isothiazolylene, benzothiazolylene, isoxazolyl isoxazolylene, oxazolylene, triazolylene, tetrazolylene, oxadiazolylene, triazinylene, benzofuranylene, dibenzofuranylene, benzo Furodibenzofuranylene group, benzothienobenzofuranylene group, benzothienodibenzofuranylene group, benzothiophenylene group, dibenzothiophenylene group, benzothietobenzothiophenylene group, benzothienodibenzothio Phenylene group, carbazolylene group, benzocarbazolylene group, dibenzocarbazolylene group, indolocarbazolylene group, indenocarbazolylene group, benzofurocarbazolylene group, benzothienocarbazolylene group, imidazopyrimidinylene group (imidazopyrimidinylene) and an imidazopyridinylene group (imidazopyridinylene).

In one exemplary embodiment, when the number of aromatic rings constituting Ar ₃ increases, the conjugated structure in the entire organic compound becomes excessively long, and thus the band gap of the organic compound may be excessively reduced. Therefore, the number of aromatic rings constituting Ar ₃ is preferably 1 to 2, more preferably 1. In addition, with regard to charge injection and transfer characteristics, Ar ₃ may be a 5-membered ring or a 7-membered ring, particularly a 6-membered ring. It may be desirable to For example, Ar ₃ is a phenylene group, a biphenylene group, a pyrrolylene group, an imidazolylene group, a pyrazolylene group, a pyridinylene group, a pyrazinylene group, a pyrimidinylene group, a pyridazinylene group, a furanylene group, or thio It may be a phenylene group.

The organic compound represented by Formula 1 has 2-3 carbazolyl moieties that can function as electron donors, and functions as electron acceptors through an appropriate aromatic linking group, each containing 1-2 cyanoalkyl moieties. It is linked to a triazine moiety linked to an aromatic substituent substituted with a no group. Since the steric hindrance of the carbazolyl moiety consisting of three or more condensed aromatic rings is large, 3 of the organic compounds of the present invention synthesized by forming a chemical bond with these carbazolyl moieties located on one side of the molecule Dimensional conformation is limited. Accordingly, the organic compound according to the present invention has a rigid structure, thereby improving thermal stability. When the organic compound represented by Formula 1 emits light, there is no energy loss due to a change in the three-dimensional structure of the molecule, and since the emission spectrum can be limited to a specific range, good color purity can be implemented.

In particular, by using the organic compound according to the present invention, low-voltage driving is possible, so power consumption can be reduced, and a light emitting diode with improved lifespan can be realized. As an example, the organic compound according to the present invention can be used as a dopant of an organic light emitting layer constituting an organic light emitting diode, and in particular has so-called delayed florescence characteristics, which will be described.

1 is a schematic diagram for explaining a light emitting mechanism when an organic compound according to the present invention is used as a delayed fluorescent compound. Delayed fluorescence can be divided into thermally activated delayed fluorescence (TADF) and field activated delayed fluorescence (FADF). Triplet excitons are activated by heat or an electric field, and conventional fluorescence It is possible to realize so-called super-fluorescence that exceeds the maximum luminous efficiency in materials.

That is, in the delayed fluorescent compound, triplet excitons are activated by heat or an electric field generated when the device is driven, and the triplet excitons also participate in light emission. In general, a delayed fluorescent compound has both an electron donor moiety and an electron acceptor moiety, and thus can be converted into an intramolecular charge transfer (ICT) state. When a delayed fluorescence compound capable of ICT is used as a dopant, excitons having a singlet energy level (S ₁ ) and an exciton having a triplet energy level (T ₁ ) in the delayed fluorescence compound move to an intermediate ICT state, and the bottom State (ground state, S ₀ ) transitions (S ₁ → ICT←T ₁ ). Since excitons having a singlet energy level (S ₁ ) and excitons having a triplet energy level (T ₁ ) both participate in light emission, the internal quantum efficiency is improved, and thus the luminous efficiency is improved.

In conventional fluorescent materials, since the Highest Occupied Molecular Orbital (HOMO) and the Lowest Unoccupied Molecular Orbital (LUMO) are spread throughout the molecule, there is a transition between singlet and triplet states. Interchangeability is not possible (selection rule). However, since the overlapping of HOMO and LUMO orbitals in the compound having the ICT state is small, the interaction between the orbits of the HOMO state and the orbits of the LUMO state is small. Therefore, the spin state change of an electron does not affect other electrons, and a new charge transfer band (CT band) that does not follow the selection rule is formed.

That is, since the electron acceptor moiety and the electron donor moiety in the delayed fluorescent compound are spaced apart in the molecule, the dipole moment in the molecule exists in a large polarization state. In a state where the dipole moment is polarized, the interaction between the orbits of the HOMO and LUMO states becomes small, and a transition from the triplet state and the singlet state to the intermediate state (ICT) becomes possible. Accordingly, excitons having a singlet energy level (S ₁ ) as well as excitons having a triplet energy level (T ₁ ) participate in light emission. That is, when the light emitting device is driven, excitons having a singlet energy level (S ₁ ) of 25% and excitons having a triplet energy level (T ₁ ) of 75% are transitioned to an intermediate state (ICT) by heat or an electric field. Since light emission occurs while falling back to the ground state (S ₀ ), the internal quantum efficiency theoretically becomes 100%.

A dopant for realizing delayed fluorescence needs to have the following characteristics. The dopant must have an electron donor moiety and an electron acceptor moiety in one molecule at the same time to implement an ICT state. The dopant usually has the form of a complex in an ICT state (ICT complex), and has an electron-donor moiety and an electron-acceptor moiety in one bonsai at the same time, so electron transfer easily occurs in the molecule. That is, in the ICT complex, one electron moves from the electron-donor moiety to the electron-acceptor portion under specific conditions, and charge separation occurs within the molecule.

In addition, in order for energy transfer to occur in both the triplet state and the singlet state, the dopant for realizing delayed fluorescence has a difference (ΔE _ST ) between the singlet energy level (S ₁ ) and the triplet energy level (T ₁ ) of 0.3 eV or less, for example 0.05 to 0.3 eV. In this case, a material with a small energy difference between the singlet state and the triplet state not only exhibits fluorescence as intersystem crossing (ISC) occurs, in which energy is transferred from the singlet state to the triplet state, but also exhibits heat at room temperature. Reverse Inter System Crossing (RISC) is performed from a triplet state to a singlet state having higher energy by energy or an electric field, and delayed fluorescence is exhibited as the singlet state transitions to the ground state. In the case of delayed fluorescence, since efficiency of up to 100% can be obtained theoretically, internal quantum efficiency equivalent to that of conventional phosphorescent materials containing heavy metals can be realized.

ICT complexes capable of delayed fluorescence are formed by the external environment, which can be easily confirmed by comparing absorption wavelengths and emission wavelengths in a solution state using various solvents, which can be represented by the following formula (2).

In the above equation, Δν is a stock shift value, and ν _abs and ν _fl are wave numbers of the maximum absorption wavelength and maximum emission wavelength, respectively. In addition, h is Plank's constant, c is the velocity of light, a is the onsager cavity radius, and Δμ is the dipole moment of the excited state and the ground state ) represents the difference in dipole moment (Δμ = μ _e - μ _g ). Δf is a value representing the orientational polarizability of the solvent and is expressed by the dielectric constant (ε) and the refractive index (n) of the solvent as shown in Equation (3) below.

At this time, whether the ICT complex is formed can be confirmed by comparing the absorption wavelength and the emission wavelength of the solution state using various solvents. This is because the degree of polarization (ie, the magnitude of the dipole moment) when excited is determined by the polarity of the surroundings. Specifically, Δf, the directional polarization of the mixed solvent, can be used by calculating the directional polarization values of each pure solvent as a ratio of mole fractions, and the formation of ICT complexes can be determined by using the above equation (Lippert-Mataga equation). It can be judged by checking whether a linear relationship appears when plotting and Δν. That is, stabilization of the ICT complex occurs according to the directional polarization of the solvent, and the emission wavelength shifts to a longer wavelength according to the degree of stabilization. Therefore, when the ICT complex is formed, Δf and Δν form a linear graph, and conversely, when Δf and Δν form a linear graph, it can be seen that the light emitting material is an ICT complex.

The organic compound represented by Formula 1 has at least two carbazolyl moieties that function as electron donors and triazine moieties that are heteroaromatic rings that function as electron acceptors and are linked to aromatic substituents each substituted with 1-2 cyano groups. Because they coexist in one molecule, they can show delayed fluorescence characteristics. In particular, since the steric hindrance between the carbazolyl moiety, which is a condensed heteroaromatic ring, and the triazine ring is large, the formation of a conjugated structure is limited, and it is easily separated into HOMO and LUMO states. As dipoles are formed in the carbazolyl moiety and the triazine moiety, the dipole moment inside the molecule increases, thereby improving luminous efficiency. The electron donor and electron acceptor coexist in the molecule, reducing the overlap of the HOMO and LUMO of the molecule.

In addition, since 2-3 carbazolyl moieties and triazine moieties are connected through an appropriate aromatic linking group (represented by Ar ₃ ), the overlap of HOMO and LUMO is further reduced, so that the triplet energy level (T ₁ ) and A difference in energy levels (Δ _EST ) between singlet energy levels (S ₁ ) may be reduced. At this time, since it has a carbazolyl moiety, which is a condensed heteroaromatic ring having a solid chemical structure, on one side, the three-dimensional structure between the carbazolyl moiety and the triazine moiety is limited. There is no energy loss when emitting light, and good green light emission can be implemented.

In particular, when the organic compound represented by Chemical Formula 1 is used as a dopant of the light emitting material layer, the triplet energy level of the organic compound represented by Chemical Formula 1 is lower than that of conventional phosphorescent materials, and the energy band gap of conventional phosphorescent materials is narrower than the material. The organic host used together with the organic compound represented by Formula 1 does not need to have a triplet energy level as high as when using a conventional phosphorescent material, and it does not need to have a wide band gap. Therefore, it is not necessary to use an organic compound having a high triplet energy, which has been a limitation when applying a conventional phosphorescent material, as a host, and a phosphorescent host having a wide energy bandgap is not necessarily used. Due to the use of a host having a wide energy bandgap, charge injection and transport are delayed, and accordingly, the driving voltage of the light emitting diode increases, power consumption increases, and lifespan characteristics of the device decrease.

In one exemplary embodiment, the organic compound according to the present invention includes an organic compound represented by Formula 2 below.

Formula 2

(In Formula 2, a, b and m are each the same as defined in Formula 1)

More specifically, the organic compound according to the present invention may be any one compound represented by Formula 3 below.

Formula 3

The organic compound represented by Formulas 2 to 3 functions as an electron donor, has at least two carbazolyl moieties consisting of a rigid condensed heteroaromatic ring, and has a triazine moiety that functions as a carbazolyl moiety and an electron acceptor. are connected by a phenylene ring having an appropriate conjugated structure. At least two carbazolyl moieties as electron donors and triazine moieties as electron acceptors are present in one molecule to increase the dipole moment, and the HOMO and LUMO are easily separated to increase the dipole moment. Therefore, the organic compounds represented by Chemical Formulas 2 to 3 can be applied as delayed fluorescent materials, and the organic compounds represented by Chemical Formulas 2 to 3 can be used to improve the light emitting efficiency and color purity of the organic light emitting diode. . In addition, by applying the organic compounds represented by Chemical Formulas 2 to 3 to the organic light emitting diode, the driving voltage of the organic light emitting diode can be lowered to reduce power consumption, and electrical stress to organic materials constituting the light emitting layer can be reduced to reduce the electrical stress of the device. Life characteristics can be improved.

[Organic Light-Emitting Diode and Organic Light-Emitting Device]

As described above, by applying the organic compounds represented by Chemical Formulas 1 to 3 to the organic light-emitting layer constituting the organic light-emitting diode, it is possible to obtain a particularly high-purity emission color and reduce power consumption by lowering the driving voltage, A light emitting device with improved lifespan characteristics and luminous efficiency can be implemented. explain this. 2 is a cross-sectional view schematically illustrating an organic light emitting diode in which an organic compound is applied to an organic light emitting layer according to an exemplary embodiment of the present invention.

As shown in FIG. 2 , the organic light emitting diode 100 according to the first embodiment of the present invention includes a first electrode 110 and a second electrode 120 facing each other, and the first and second electrodes 110 , 120) and an organic light emitting layer 130 positioned between them. In an exemplary embodiment, the organic light emitting layer 130 may include a hole injection layer (HIL) 140 sequentially stacked from the first electrode 110, a hole transfer layer (HTL) 150, and a light emitting material. It includes an emissive material layer (EML) 160, an electron transfer layer (ETL) 170 and an electron injection layer (EIL) 180.

The first electrode 110 may be an anode supplying holes to the light emitting material layer 160 . The first electrode 110 is preferably formed of a conductive material having a relatively high work function value, for example, transparent conductive oxide (TCO). In an exemplary embodiment, the first electrode 110 is indium-tin-oxide (ITO), indium-zinc-oxide (IZO), or indium-tin-zinc-oxide. (indium-tin-zinc oxide; ITZO), tin oxide (SnO), zinc oxide (ZnO), indium-copper-oxide (ICO) and aluminum:zinc oxide (Al:ZnO; AZO). It can be done.

The second electrode 120 may be a cathode supplying electrons to the light emitting material layer 160 . The second electrode 120 is formed of a conductive material having a relatively small work function value, for example, aluminum (Al), magnesium (Mg), calcium (Ca), silver (Ag), or an alloy or combination thereof having reflective properties. It can be made of good material.

The hole injection layer 140 is positioned between the first electrode 110 and the hole transport layer 150, and improves interface characteristics between the inorganic first electrode 110 and the organic hole transport layer 150. In one exemplary embodiment, the hole injection layer 140 is 4,4 ', 4 "-tris (3-methylphenylamino) triphenylamine (4,4 ', 4 "-Tris (3-methylphenylamino) triphenylamine; MTDATA), 4,4', 4"-tris (N, N-diphenyl-amino) triphenylamine (4,4', 4 "-Tris (N, N-diphenyl-amino) triphenylamine; NATA), 4 ,4',4"-tris(N-(naphthalene-1-yl)-N-phenyl-amino)triphenylamine(4,4',4"-Tris(N-(naphthalene-1-yl)-N -phenyl-amino)triphenylamine; 1T-NATA), 4,4',4"-tris(N-(naphthalen-2-yl)-N-phenyl-amino)triphenylamine(4,4',4"- Tris (N- (naphthalene-2-yl) -N-phenyl-amino) triphenylamine; 2T-NATA), copper phthalocyanine (CuPc), tris (4-carbazolyl-9yl-phenyl) amine (Tris ( 4-carbazoyl-9-yl-phenyl)amine; TCTA), N,N'-diphenyl-N,N'-bis(1-naphthyl)-1,1'-biphenyl-4,4"-diamine (N,N'-Diphenyl-N,N'-bis(1-naphthyl)-1,1'-biphenyl-4,4"-diamine; NPB; NPD), 1,4,5,8,9,11 -Hexaazatriphenylenehexacarbonitrile (1,4,5,8,9,11-Hexaazatriphenylenehexacarbonitrile, Dipyrazino[2,3-f:2'3'-h]quinoxaline-2,3,6,7,10 ,11-hexacarbonitrile; HAT-CN), 1,3,5-tris [4- (diphenylamino) phenyl] benzene (1,3,5-tris [4- (diphenylamino) phenyl] benzene; TDAPB), poly (3,4-ethylenedioxythiophene)polystyrene sulfonate (poly(3,4-ethylenedioxythiophene)polystyrene sulfonate (PEDOT/PSS) and/or N-(biphenyl-4-yl)-9,9-dimethyl-N -(4-(9-phenyl-9H-carbazol-3-yl)phenyl)-9H-fluoren-2-amine (N-(biphenyl-4-yl)-9,9-dimethyl-N-(4 -(9-phenyl-9H-carbazol-3-yl)phenyl)-9H-fluoren-2-amine) and the like. Depending on the characteristics of the organic light emitting diode 100, the hole injection layer 140 may be omitted.

The hole transport layer 150 is positioned adjacent to the light emitting material layer 160 between the first electrode 110 and the light emitting material layer 160 . In one exemplary embodiment, the hole transport layer 150 is N,N'-diphenyl-N,N'-bis(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine (N ,N'-Diphenyl-N,N'-bis(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine; TPD), NPB, 4,4'-bis(N-carbazolyl)- 1,1'-biphenyl (4,4'-bis (N-carbazolyl) -1,1'-biphenyl; CBP), poly [N, N'-bis (4-butylphenyl) -N, N'- Bis (phenyl) -benzidine] (Poly [N, N'-bis (4-butylpnehyl) -N, N'-bis (phenyl) -benzidine]; Poly-TPD), poly [(9,9-dioxylflu Orenyl-2,7-diyl)-co-(4,4'-(N-(4-sec-butylphenyl)diphenylamine))](Poly[(9,9-dioctylfluorenyl-2,7-diyl )-co-(4,4'-(N-(4-sec-butylphenyl)diphenylamine))], TFB), di-[4-(N,N-di-p-tolyl-amino)phenyl]cyclohexane (Di-[4-(N,N-di-p-tolyl-amino)-phenyl]cyclohexane; TAPC), N-(biphenyl-4-yl)-9,9-dimethyl-N-(4-( 9-phenyl-9H-carbazol-3-yl) phenyl) -9H-fluoren-2-amine (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-carbazole-3 -yl) phenyl) biphenyl) -4-amine (N- (biphenyl-4-yl) -N- (4- (9-phenyl-9H-carbazol-3-yl) phenyl) biphenyl-4-amine), etc. It may consist of a compound selected from the group consisting of, but the present invention is not limited thereto.

The light emitting material layer 160 may be formed by doping a host with a dopant. For example, the light emitting material layer 160 may have a dopant added to the host in an amount of about 1 to 50% by weight, and may emit green light.

In one exemplary embodiment, organic compounds represented by Chemical Formulas 1 to 3 may be used as a dopant of the light emitting material layer 160 . Meanwhile, the dopant, which is an organic compound represented by Chemical Formulas 1 to 3 used in the light emitting material layer 160, may be a dopant having delayed fluorescence characteristics.

As described above, the compound having delayed fluorescence is activated by heat or an electric field and has an intermediate energy state such as an ICT complex. Since both excitons having a singlet energy level and excitons having a triplet energy level are involved in light emission, the light emitting efficiency of the organic light emitting diode 100 can be improved.

The difference (ΔE _ST ) between the singlet energy level (S ₁ ) and the triplet energy level (T ₁ ) of the organic compounds represented by Chemical Formulas 1 to 3 may be 0.3 eV or less, for example, 0.05 to 0.3 eV. When the difference (ΔE _ST ) between the singlet energy level (S ₁ ) and the triplet energy level (T ₁ ) of organic compounds represented by Formulas 1 to 3 that can be used as delayed fluorescence dopants is 0.3 eV or less, these energy levels The quantum efficiency of the dopant may be improved while transitioning to an intermediate energy state and finally falling to the ground state. That is, the luminous efficiency may increase as ΔE _ST decreases, and when the difference between the singlet energy level (S ₁ ) and the triplet energy level (T ₁ ) of the dopant is 0.3 eV or less, the singlet state is generated by heat or an electric field. Excitons and triplet state excitons can transition to an intermediate ICT complex state (ΔE _ST ≤ 0.3).

On the other hand, in order to implement delayed fluorescence, the host included in the light emitting material layer 160 should be able to induce excitons in the triplet state generated from the dopant to participate in light emission without quenching. . 3 is a schematic diagram for explaining an energy level with a delayed fluorescent compound when an organic compound according to an exemplary embodiment of the present invention is used as a host.

As shown in FIG. 3, the energy level of the host for realizing delayed fluorescence needs to be appropriately adjusted with the dopant. First, the triplet energy level of the host (T ₁ ^H ) must be higher than the triplet energy level of the dopant (T ₁ ^D ). If the triplet energy level of the host (T ₁ ^H ) is not sufficiently higher than the triplet energy level of the dopant (T ₁ ^D ), the triplet state excitons of the dopant cross over to the triplet energy level of the host (T ₁ ^H ). and since the triplet excitons of the dopant eventually disappear into non-emission, the triplet state excitons of the dopant do not contribute to luminescence.

In addition, it is necessary to properly adjust the HOMO energy level and the LUMO energy level of the host and the dopant. For example, the difference between the highest occupied molecular orbital energy level of the host (HOMO ^H ) and the highest occupied molecular orbital energy level of the dopant (HOMO ^D ) (|HOMO ^H -HOMO ^D |) or the lowest unoccupied molecular orbital of the host It may be preferable that the difference between the energy level (LUMO ^H ) and the lowest unoccupied molecular orbital energy level (LUMO ^D ) of the dopant (|LUMO ^H -LUMO ^D |) is 0.5 eV or less, for example, 0.1 to 0.5 eV or less. there is. Accordingly, the charge transfer efficiency from the host to the dopant is improved, and finally, the light emitting efficiency of the light emitting diode 100 may be improved.

In one exemplary embodiment, the host of the light emitting material layer 160 is 9-(3-(9H-carbazol-9-yl)phenyl)-9H-carbazole-3-carbonitrile (9-(3- (9H-carbazol-9-yl)phenyl)-9H-carbazole-3-carbonitrile; mCP-CN), CBP, 3,3'-bis(N-carbazolyl)-1,1'-biphenyl (3, 3'-bis (N-carbazolyl) -1,1'-biphenyl; mCBP), 1,3-bis (carbazol-9-yl) benzene (1,3-Bis (carbazol-9-yl) benzene; MCP ), (Oxybis (2,1-phenylene)) bis (diphenylphosphine oxide) (Oxybis (2,1-phenylene)) bis (diphenylphosphine oxide; DPEPO), 2T-NATA, TCTA, 1,3, 5-tri[(3-pyridyl)-phen-3-yl]benzene (1,3,5-Tri[(3-pyridyl)-phen-3-yl]benzene; TmPyPB), 2,6-di( 9H-carbazol-9-yl)pyridine (2,6-Di(9H-carbazol-9-yl)pyridine; PYD-2Cz), 3', 5'-di(carbazol-9-yl)-[1 ,1'-biphenyl] -3,5-dicarbonitrile (3',5'-Di (carbazol-9-yl) - [1,1'-bipheyl] -3,5-dicarbonitrile; DCzTPA), 4 '-(9H-carbazol-9-yl)biphenyl-3,5-dicarbonitrile(4'-(9H-carbazol-9-yl)biphenyl-3,5-dicarbonitrile; pCzB-2CN), 3'-(9H- Carbazol-9-yl) biphenyl-3,5-dicarbonitrile (3'-(9H-carbazol-9-yl)biphenyl-3,5-dicarbonitrile; mCzB-2CN), 9-(4-(9H -Carbazol-9-yl)phenyl)-9H-3,9'-bicarbazole (9-(4-(9H-carbazol-9-yl)phenyl)-9H-3,9'-bicarbazole), 9 -(3-(9H-carbazol-9-yl)phenyl)-9H-3,9'-bicarbazole (9-(3-(9H-carbazol-9-yl)phenyl)-9H-3,9 '-bicarbazole) and/or 4-(3-triphenylene-2-yl)phenyl)dibenzo[b,d]thiophene (4-(3-(triphenylene-2-yl)-phenyl)dibenzo[b , d] thiophene) and the like, but the present invention is not limited thereto.

Referring back to FIG. 2 , an electron transport layer 170 and an electron injection layer 180 may be sequentially stacked between the light emitting material layer 160 and the second electrode 120 . A material constituting the electron transport layer 170 requires high electron mobility, and electrons are stably supplied to the light emitting material layer 160 through smooth electron transport.

In one exemplary embodiment, the electron transport layer 170 is imidazole, oxadiazole, triazole, phenanthroline, benzoxazole, benzothiazole ( benzothiazole), benzimidazole, and triazine derivatives. For example, the electron transport layer 170 is tris (8-hydroxyquinoline) aluminum (tris- (8-hydroxyquinoline aluminum; Alq ₃ ), 2-biphenyl-4-yl-5- (4-tert-butylphenyl ) -1,3,4-oxadiazole (2-biphenyl-4-yl-5- (4-t-butylphenyl) -1,3,4-oxadiazole; PBD), spiro-PBD, lithium quinolate ( lithium quinolate; Liq), 1,3,5-tris (N-phenylbenzimidazol-2-yl) benzene (1,3,5-Tris (N-phenylbenzimidazol-2-yl) benzene; TPBi), bis ( 2-methyl-8-quinolinolato-N1,O8)-(1,1'-biphenyl-4-olato)aluminum (Bis(2-methyl-8-quinolinolato-N1,O8)-(1, 1'-biphenyl-4-olato)aluminum; BAlq), 4,7-diphenyl-1,10-phenanthroline; Bphen), 2,9-bis( Naphthalen-2-yl) 4,7-diphenyl-1,10-phenanthroline (2,9-Bis (naphthalene-2-yl) 4,7-diphenyl-1,10-phenanthroline; NBphen), 2, 9-dimethyl-4,7-diphenyl-1,10-phenanthroline (2,9-Dimethyl-4,7-diphenyl-1,10-phenathroline; BCP), 3-(4-biphenyl)-4 -Phenyl-5-tert-butylphenyl-1,2,4-triazole (3-(4-Biphenyl)-4-phenyl-5-tert-butylphenyl-1,2,4-triazole; TAZ), 4- (Naphthalen-1-yl)-3,5-diphenyl-4H-1,2,4-triazole (4-(Naphthalen-1-yl)-3,5-diphenyl-4H-1,2,4- triazole; NTAZ), 1,3,5-Tri(p-pyrid-3-yl-phenyl)benzene; TpPyPB), 2 ,4,6-tris(3'-(pyridin-3-yl)biphenyl-3-yl)1,3,5-triazine(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)-alt-2,7-(9, 9-dioctylfluorene)](Poly[9,9-bis(3'-((N,N-dimethyl)-N-ethylammonium)-propyl)-2,7-fluorene]-alt-2,7- (9,9-dioctylfluorene)]; PFNBr) and/or tris(phenylquinoxaline; TPQ), etc., but the present invention is not limited thereto.

The electron injection layer 180 is positioned between the second electrode 120 and the electron transport layer 170, and the life of the device can be improved by improving the characteristics of the second electrode 120. In one exemplary embodiment, as a material of the electron injection layer 180, an alkali halide-based material such as LiF, CsF, NaF, BaF ₂ , and/or lithium quinolate (Liq), lithium benzoate, sodium Organometallic materials such as stearate (sodium stearate) may be used, but the present invention is not limited thereto.

The organic light emitting diode 100 according to an exemplary embodiment of the present invention has a dopant, which is an organic compound represented by Chemical Formulas 1 to 3 having delayed fluorescence, in the light emitting material layer 160 constituting the organic light emitting layer 130. there is. Since excitons in singlet energy states and excitons in triplet energy states of the organic compounds represented by Chemical Formulas 1 to 3 are involved in light emission, the luminous efficiency is improved.

Since the electron-donor moiety (carbazolyl moiety) and the electron-acceptor moiety (triazine moiety) coexist in the organic compounds represented by Formulas 1 to 3, the dipole moment increases, and HOHO and LUMO are easily separated. , because it has a structure in which the dipole moment can increase, it has delayed fluorescence characteristics. In addition, since the three-dimensional structure between a carbazolyl moiety composed of three or more condensed aromatic rings having a rigid structure and a triazine moiety is greatly restricted, it is possible to realize good green light emission while reducing energy loss during light emission.

In addition, compared to the case of using a conventional phosphorescent material containing a heavy metal, the organic host included in the light emitting material layer (EML, 160) together with the organic compound represented by Formulas 1 to 3 has a high triplet energy level. It does not have to have, and the band gap does not have to be wide. Therefore, problems caused by using an organic host having a wide energy bandgap, that is, charge injection and transport are delayed, and accordingly, the driving voltage of the light emitting diode 100 increases, power consumption increases, and device lifespan A deterioration of properties can be prevented.

Meanwhile, the organic light emitting diode according to the present invention may further include one or more exciton blocking layers. 4 is a schematic cross-sectional view of an organic light emitting diode to which a phosphorescent compound is applied according to a second exemplary embodiment of the present invention. As shown in FIG. 4, the organic light emitting diode 200 according to the second embodiment of the present invention includes a first electrode 210 and a second electrode 220 facing each other, and the first and second electrodes 210 , 220) and an organic light emitting layer 230 positioned between them.

In an exemplary embodiment, the organic light emitting layer 230 includes a hole injection layer 240, a hole transport layer 250, a light emitting material layer 260, an electron transport layer 270, and electron transport layer 270 sequentially stacked from the first electrode 210. An injection layer 280 is included. In addition, the organic light emitting layer 230 includes an electron blocking layer (EBL, 255) and/or a first exciton blocking layer positioned between the hole transport layer 250 and the light emitting material layer 260 and/or the light emitting material layer 260 ) and a hole blocking layer (HBL, 265) as a second exciton blocking layer located between the electron transport layer 270.

As described above, the first electrode 210 may be an anode and may be made of ITO, IZO, ITZO, SnO, ZnO, ICO, and AZO, which are conductive materials having a relatively high work function value. The second electrode 220 may be a cathode and may be made of Al, Mg, Ca, Ag, or an alloy or combination thereof, which is a conductive material having a relatively low work function value.

The hole injection layer 240 is positioned between the first electrode 210 and the hole transport layer 22 . The hole injection layer 240 is made of MTDATA, NATA, 1T-NATA, 2T-NATA, CuPc, TCTA, NPB (NPD), HAT-CN, TDAPB, PEDOT/PSS and/or N-(biphenyl-4-yl) -9,9-dimethyl-N-(4-(9-phenyl-9H-carbazol-3-yl)phenyl)-9H-fluoren-2-amine and the like. Depending on the structure of the organic light emitting diode 200, the hole injection layer 240 may be omitted.

The hole transport layer 250 is positioned adjacent to the light emitting material layer 260 between the first electrode 210 and the light emitting material layer 260 . Hole transport layer 250 is TPD, NPD (NPB), CBP, Poly-TPD, TFB, TAPC, 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-carbazole-3 -yl) phenyl) biphenyl) -4-amine and other aromatic amine compounds.

The light emitting material layer 260 may be formed by doping a host with a dopant. For example, the light emitting material layer 260 may have a dopant added to the host in an amount of about 1 to 50% by weight, and may emit blue light. For example, organic compounds represented by Chemical Formulas 1 to 3 are used as dopants of the light emitting material layer 260, and mCP-CN, CBP, mCBP, MCP, DPEPO, 2T-NATA, TCTA, TmPyPB, PYD-2Cz, DCzTPA, pCzB-2CN, mCzB-2CN, 9-(4-(9H-carbazol-9-yl)phenyl)-9H-3,9′-bicarbazole, 9-(3-(9H-carbazole- Compounds such as 9-yl)phenyl)-9H-3,9'-bicarbazole and/or 4-(3-triphenylen-2-yl)phenyl)dibenzo[b,d]thiophene are light emitting materials It can be used as a host for layer 260.

The electron transport layer 270 is positioned between the light emitting material layer 260 and the electron injection layer 280 . For example, the electron transport layer 270 may include oxadiazole, triazole, phenanthroline, benzoxazole, benzothiazole, benzimidazole, triazine, and the like. may be a derivative. For example, the electron transport layer 270 may be made of Alq ₃ , PBD, spiro-PBD, Liq, BAlq, Bphen, NBphen, BCP, TAZ, NTAZ, TpPyPB, TmPPPyTz, PFNBr, and/or TPQ, but The invention is not limited thereto.

The electron injection layer 280 is positioned between the second electrode 220 and the electron transport layer 270 . Alkali halide-based materials such as LiF, CsF, NaF, and BaF ₂ and/or organometallic materials such as Liq, lithium benzoate, and sodium stearate may be used as the material of the electron injection layer 280, but the present invention It is not limited.

On the other hand, when holes move through the light emitting material layer 260 to the second electrode 220 or when electrons pass through the light emitting material layer 260 and go to the first electrode 210, the lifetime and efficiency of the device may be reduced. can To prevent this, in the organic light emitting diode 200 according to the second exemplary embodiment of the present invention, at least one exciton blocking layer is positioned adjacent to the light emitting material layer 260 .

For example, the organic light emitting diode 200 according to the second embodiment of the present invention has an electron blocking layer capable of controlling or preventing the movement of electrons between the hole transport layer 250 and the light emitting material layer 260. layer, EBL, 255) is located.

For example, the electron blocking layer 255 is TCTA, tris [4- (diethylamino) phenyl] amine (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, mCP, mCBP, CuPC, N,N'- Bis[4-[bis(3-methylphenyl)amino]phenyl]-N,N'-diphenyl-[1,1'-biphenyl]-4,4'-diamine (N,N'-bis[4- [bis(3-methylphenyl)amino]phenyl]-N,N'-diphenyl-[1,1'-biphenyl]-4,4'-diamine; DNTPD) and/or TDAPB.

In addition, a hole blocking layer 265 is positioned as a second exciton blocking layer between the light emitting material layer 260 and the electron transport layer 270 to prevent movement of holes between the light emitting material layer 260 and the electron transport layer 270 do. In one exemplary embodiment, as a material for the hole blocking layer, imidazole, oxadiazole, triazole, phenanthroline, or benzos that may be used in the electron transport layer 270 may be used. Derivatives such as benzoxazole, benzothiazole, benzimidazole, and triazine may be used.

For example, the hole blocking layer 265 may be formed of BCP, BAlq, Alq3, PBD, or spiro- which has a lower HOMO (highest occupied molecular orbital) energy level compared to the material used in the light emitting material layer 260. PBD, Liq and/or bis-4,6-(3,5-di-3-pyridylphenyl)-2-methylpyrimidine (bis-4,6-(3,5-di-3-pyridylphenyl)- 2-methylpyrimidine; B3PYMPM) and combinations thereof.

The organic light emitting diode 200 according to the second embodiment of the present invention has a dopant, which is an organic compound represented by Chemical Formulas 1 to 3 having a delayed fluorescence characteristic, in the light emitting material layer 160 . Organic compounds represented by Formulas 1 to 3 have an electron donor moiety (carbazolyl moiety) and an electron acceptor moiety (triazine moiety) coexist in one molecule, increasing the dipole moment and easily separating HOHO and LUMO. And, since it has a structure in which the dipole moment can increase, it has delayed fluorescence characteristics. In addition, the three-dimensional structure between at least two carbazolyl moieties constituting the electron donor and the triazine moiety constituting the electron acceptor is limited. Accordingly, when the organic compounds represented by Chemical Formulas 1 to 3 are used as dopants of the light emitting device, the light emitting efficiency is improved and the organic light emitting diode 200 having good color purity can be manufactured. Since there is no need to use an organic host having high triplet energy and a wide bandgap, power consumption can be reduced by lowering the driving voltage of the light emitting diode 200 and lifespan of the device can be improved. In addition, since the organic light emitting diode 200 according to the second embodiment of the present invention includes at least one exciton blocking layer 255 or 265, the charge transport layers 250 or 270 adjacent to the light emitting material layer 260 By preventing light emission at the interface with the organic light emitting diode 200, the light emitting efficiency and lifetime of the organic light emitting diode 200 can be further improved.

The organic light emitting diode according to the present invention may be applied to an organic light emitting device such as an organic light emitting diode display device or a lighting device to which the above organic light emitting diode is applied. As an example, a display device to which the organic light emitting diode of the present invention is applied will be described. 5 is a schematic cross-sectional view of an organic light emitting diode display device according to an exemplary embodiment of the present invention.

As shown in FIG. 5 , the organic light emitting diode display 300 includes a driving thin film transistor Td as a driving element, a planarization layer 360 covering the driving thin film transistor Td, and a planarization layer 360 on and an organic light emitting diode 400 connected to the driving thin film transistor Td as a driving element. The driving thin film transistor (Td) includes a semiconductor layer 310, a gate electrode 330, a source electrode 352, and a drain electrode 354. In FIG. 3, the driving thin film has a coplanar structure. Indicates the transistor Td.

The substrate 302 may be a glass substrate, a thin flexible substrate, or a polymeric plastic substrate. For example, flexible substrates include polyimide (PI), polyethersulfone (PES), polyethylenenaphthalate (PEN), polyethylene terephthalate (PET) and polycarbonate (PC). It can be formed by any one of them. The driving thin film transistor (Td), which is a driving element, and the substrate 302 on which the organic light emitting diode 400 are positioned form an array substrate.

A semiconductor layer 310 is formed on the substrate 302 . For example, the semiconductor layer 310 may be made of an oxide semiconductor material. In this case, a light-shielding pattern (not shown) and a buffer layer (not shown) may be formed under the semiconductor layer 310, and the light-shielding pattern prevents light from entering the semiconductor layer 310 so that the semiconductor layer 310 is not exposed to light. prevent degradation by Alternatively, the semiconductor layer 310 may be made of polycrystalline silicon, and in this case, both edges of the semiconductor layer 310 may be doped with impurities.

A gate insulating film 320 made of an insulating material is formed on the entire surface of the substrate 302 on the semiconductor layer 310 . The gate insulating layer 320 may be formed of an inorganic insulating material such as silicon oxide (SiO ₂ ) or silicon nitride (SiNx).

A gate electrode 330 made of a conductive material such as metal is formed on the top of the gate insulating film 320 to correspond to the center of the semiconductor layer 310 . In addition, a gate wiring (not shown) and a first capacitor electrode (not shown) may be formed on the gate insulating layer 320 . The gate wiring may extend along the first direction, and the first capacitor electrode may be connected to the gate electrode 330 . Meanwhile, although the gate insulating film 320 is formed on the entire surface of the substrate 302 , the gate insulating film 320 may be patterned in the same shape as the gate electrode 330 .

An interlayer insulating film 340 made of an insulating material is formed on the entire surface of the substrate 302 above the gate electrode 330 . The interlayer insulating film 340 may be formed of an inorganic insulating material such as silicon oxide (SiO ₂ ) or silicon nitride (SiNx), or an organic insulating material such as benzocyclobutene or photo-acryl. there is.

The interlayer insulating film 340 has first and second semiconductor layer contact holes 342 and 344 exposing top surfaces of both sides of the semiconductor layer 310 . The first and second semiconductor layer contact holes 342 and 344 are spaced apart from the gate electrode 330 on both sides of the gate electrode 330 . Here, the first and second semiconductor layer contact holes 342 and 344 are also formed in the gate insulating layer 320 . In contrast, when the gate insulating film 320 is patterned in the same shape as the gate electrode 330, the first and second semiconductor layer contact holes 342 and 344 are formed only in the interlayer insulating film 340.

A source electrode 352 and a drain electrode 354 made of a conductive material such as metal are formed on the interlayer insulating film 340 . In addition, a data wire (not shown), a power supply wire (not shown), and a second capacitor electrode (not shown) may be formed on the interlayer insulating film 340 and extend along the second direction.

The source electrode 352 and the drain electrode 354 are spaced apart from each other with respect to the gate electrode 330, and both sides of the semiconductor layer 310 and each other through the first and second semiconductor layer contact holes 342 and 344, respectively. make contact Although not shown, the data line extends along the second direction and intersects the gate line to define a pixel area, and the power line supplying a high potential voltage is spaced apart from the data line. The second capacitor electrode is connected to the drain electrode 354 and overlaps the first capacitor electrode, so that the interlayer insulating film 340 between the first and second capacitor electrodes serves as a dielectric layer to form a storage capacitor.

Meanwhile, the semiconductor layer 310, the gate electrode 330, the source electrode 352, and the drain electrode 354 form a driving thin film transistor Td. The driving thin film transistor Td illustrated in FIG. 5 has a coplanar structure in which a gate electrode 330 , a source electrode 352 , and a drain electrode 354 are positioned on a semiconductor layer 310 . Alternatively, the driving thin film transistor Td may have an inverted staggered structure in which a gate electrode is positioned below the semiconductor layer and a source electrode and a drain electrode are positioned above the semiconductor layer. In this case, the semiconductor layer may be made of amorphous silicon.

In addition, a switching thin film transistor (not shown), which is a switching element having substantially the same structure as the driving thin film transistor Td, is further formed on the substrate 302 . The gate electrode 330 of the driving thin film transistor (Td) is connected to the drain electrode (not shown) of the switching thin film transistor (not shown), and the source electrode 352 of the driving thin film transistor (Td) is connected to a power wiring (not shown). Connected. In addition, the gate electrode (not shown) and the source electrode (not shown) of the switching thin film transistor (not shown) are respectively connected to the gate wiring and the data wiring.

Meanwhile, the organic light emitting diode display 300 may include a color filter (not shown) absorbing light generated by the organic light emitting diode 400 . For example, a color filter (not shown) may absorb red (R), green (G), blue (B), and white (W) light. In this case, red, green, and blue color filter patterns that absorb light may be separately formed for each pixel area, and each of these color filter patterns is an organic light emitting diode (OLED) that emits light of a wavelength band to be absorbed. 400) may be disposed to overlap each other with the organic light emitting layer 430. By adopting a color filter (not shown), the organic light emitting diode display 300 can implement full-color.

For example, when the organic light emitting diode display device 300 is a bottom emission type, a color filter (not shown) absorbing light may be positioned above the interlayer insulating layer 340 corresponding to the organic light emitting diode 400. . In an optional embodiment, when the organic light emitting diode display device 300 is a top emission type, the color filter may be positioned above the organic light emitting diode 400, that is, above the second electrode 420.

A planarization layer 360 is formed on the entire surface of the substrate 302 on the source electrode 352 and the drain electrode 354 . The planarization layer 360 has a flat upper surface and has a drain contact hole 362 exposing the drain electrode 354 of the driving thin film transistor Td. Here, the drain contact hole 362 is illustrated as being formed right above the second semiconductor layer contact hole 344, but may be formed spaced apart from the second semiconductor layer contact hole 344.

The light emitting diode 400 includes a first electrode 410 positioned on the planarization layer 360 and connected to the drain electrode 354 of the driving thin film transistor Td, and an organic layer sequentially stacked on the first electrode 410. A light emitting layer 430 and a second electrode 420 are included.

One electrode 410 is formed separately for each pixel area. The first electrode 410 may be an anode and may be made of a conductive material having a relatively high work function value. For example, the first electrode 410 may be made of a transparent conductive material such as ITO, IZO, ITZO, SnO, ZnO, ICO, and AZO.

Meanwhile, when the organic light emitting diode display 300 of the present invention is a top-emission type, a reflective electrode or a reflective layer may be further formed below the first electrode 310 . For example, the reflective electrode or the reflective layer may be made of an aluminum-palladium-copper (APC) alloy.

In addition, a bank layer 370 covering an edge of the first electrode 410 is formed on the planarization layer 360 . The bank layer 370 exposes the center of the first electrode 410 corresponding to the pixel area.

An organic emission layer 430 is formed on the first electrode 410 . In one exemplary embodiment, the organic light-emitting layer 430 may have a single-layer structure of light-emitting material layers. Alternatively, as shown in FIGS. 2 and/or 4 , the organic light emitting layer 430 includes a hole injection layer, a hole transport layer, an electron blocking layer, a light emitting material layer, a hole blocking layer, an electron transport layer, and/or an electron injection layer. It may also consist of a plurality of organic material layers.

A second electrode 420 is formed on the substrate 302 on which the organic light emitting layer 430 is formed. The second electrode 420 is located on the entire surface of the display area and is made of a conductive material having a relatively low work function value and can be used as a cathode. For example, the second electrode 420 is made of any one of aluminum (Al), magnesium (Mg), calcium (ca), silver (Ag), or an alloy or combination thereof such as an aluminum-magnesium alloy (AlMg). can

An encapsulation film 380 is formed on the second electrode 420 to prevent penetration of external moisture into the organic light emitting diode 400 . The encapsulation film 380 may have a stacked structure of a first inorganic insulating layer 382, an organic insulating layer 384, and a second inorganic insulating layer 386, but is not limited thereto.

As described above, the organic light emitting diode 400 is represented by Chemical Formulas 1 to 3 in the organic light emitting layer 430 and an organic compound having a delayed fluorescence property is used as a dopant to improve light emitting efficiency.

Organic compounds represented by Chemical Formulas 1 to 3 have delayed fluorescence characteristics because at least two carbazolyl moieties as electron donors and triazine moieties as electron acceptors coexist in one molecule. In addition, the three-dimensional structure between the triazine moiety and at least two carbazolyl moieties consisting of three or more rigidly structured condensed aromatic rings is restricted. Accordingly, when the organic compounds represented by Chemical Formulas 1 to 3 are used as dopants of the light emitting device, the light emitting efficiency is improved and the organic light emitting diode 400 having good color purity can be manufactured. Since there is no need to use an organic host having high triplet energy and a wide bandgap, power consumption can be reduced by lowering the driving voltage of the light emitting diode 400 and the organic light emitting diode display device 300 including the same. can improve the lifespan of

Hereinafter, the present invention will be described through exemplary embodiments, but the present invention is not limited to the technical idea described in the following examples.

Synthesis Example 1: Synthesis of Compound 1

(1) Synthesis of Intermediate Compound 1-1

A suspension was prepared by suspending 6.68 g (275 mmol) of magnesium and 1.39 g (5.5 mmol) of iodine in 55 mL of anhydrous tetrahydrofuran solvent in a nitrogen atmosphere, and 50 g (275 mmol) of 4-bromobenzonitrile was added to anhydrous hydrofuran. A solution diluted in 100 mL was slowly added dropwise to the suspension, and the mixture was heated to reflux for 5 hours. After cooling the mixture to room temperature, a solution of 18.7 g (101 mmol) of 1,3,5-trichlorotriazine in 100 mL of anhydrous hydrofuran was slowly added dropwise to the mixture, followed by refluxing and stirring for about 7 hours. After the reaction was completed, extraction was performed with dichloromethane and distilled water, and the organic layer was distilled under reduced pressure and subjected to a silica gel column to obtain 22.4 g of compound 1-1 (yield: 70%).

(2) Synthesis of Intermediate Compound 1-2

After suspending 50 g (259 mmol) of 1-bromo-3,5-difluorobenzene, 86.6 g (518 mmol) of carbazole, and 253 g (777 mmol) of cesium carbonate in 1300 mL of dimethylformamide, the mixture was heated to 190 °C for 16 hours. It was stirred at °C. After the reaction is over, the stirring solution is filtered under reduced pressure, and the solid is put into methyl alcohol and stirred at room temperature. After filtering under reduced pressure, compound 1-2, 64g (yield: 51%) was obtained.

(3) Synthesis of Intermediate Compound 1-3

Compound 1-2 64 g (131 mmol), bis (pinacolato) diboron 50 g (197 mmol), Pd (dppf) Cl ₂ ([1,1'-Bis (diphenylphosphine) ferrocene] dichloropalladium (II)), 4.8 g (6.55 mmol) and 25.7 g (262 mmol) of potassium acetate were suspended in 500 mL of 1,4-dioxane, followed by refluxing and stirring for 12 hours. Extraction was performed with dichloromethane and distilled water, and the organic layer was filtered through silica gel. The organic solution was removed and recrystallized to obtain compound 1-3, 37.1g (yield: 53%).

(4) Compound 1 synthesis

Compound 1-1 3.3g (10 mmol), Compound 1-3 6g (11 mmol), Pd (PPh ₃ ) ₄ (Tetrakis (triphenylphosphine) palladium (0)) 0.6g (0.5 mmol), potassium carbonate 2.8g (20 mmmol) was suspended in a mixed solvent of 100 mL of toluene, 20 mL of ethyl alcohol, and 20 mL of distilled water, and then refluxed and stirred for 12 hours. After the reaction was completed, extraction was performed with dichloromethane and distilled water, and the organic layer was distilled under reduced pressure and then subjected to a silica gel column to obtain Compound 1, 4.3g (yield: 62%).

Synthesis Example 2: Synthesis of Compound 2

(1) Synthesis of Intermediate Compound 2-1

50 g (237 mmol) of 1-bromo-3,4,5-difluorobenzene, 119 g (711 mmol) of carbazole, and 309 g (948 mmol) of cesium carbonate were suspended in 1200 mL of dimethylformamide for 16 hours. Stir at 190 °C. After the reaction is over, the stirring solution is filtered under reduced pressure, and the solid is put into methyl alcohol and stirred at room temperature. After filtering under reduced pressure, compound 2-1, 77g (yield: 50%) was obtained.

(2) Synthesis of Intermediate Compound 2-2

Compound 2-1 77g (118 mmol), bis (pinacolato) diboron 44.9g (177 mmol), Pd (dppf) Cl ₂ 4.3g (5.9 mmol), potassium acetate 34.7g (354 mmol) 1,4 - After suspending in 600 mL of dioxane, it was refluxed and stirred for 12 hours. Extraction was performed with dichloromethane and distilled water, and the organic layer was filtered through silica gel. The organic solution was removed and recrystallized to obtain compound 2-2, 47g (yield: 57%).

(3) Synthesis of Compound 2

Compound 1-1 4g (12.6 mmol), compound 2-2 9.7g (13.9 mmol), Pd (PPh ₃ ) ₄ 0.7g (0.6 mmol), potassium carbonate 3.48g (25.2 mmol) toluene 100 mL, ethyl alcohol 20 After suspension in a mixed solvent of 20 mL of distilled water and 20 mL of distilled water, the mixture was refluxed and stirred for 12 hours. After the reaction was completed, extraction was performed with dichloromethane and distilled water, and the organic layer was distilled under reduced pressure and subjected to silica gel column to obtain compound 2, 6.5g (yield: 60%).

Synthesis Example 3: Synthesis of Compound 3

(1) Synthesis of Intermediate Compound 3-1

A suspension was prepared by suspending 6.68 g (275 mmol) of magnesium and 1.39 g (5.5 mmol) of iodine in 55 mL of anhydrous tetrahydrofuran solvent in a nitrogen atmosphere, and 50 g (275 mmol) of 3-bromobenzonitrile was added to anhydrous hydrofuran. A solution diluted in 100 mL was slowly added dropwise to this suspension, and the mixture was heated and refluxed for 5 hours. After cooling the mixture to room temperature, a solution of 18.7 g (101 mmol) of 1,3,5-trichlorotriazine in 100 mL of anhydrous hydrofuran was slowly added dropwise to the mixture, followed by refluxing and stirring for about 7 hours. After the reaction was completed, extraction was performed with dichloromethane and distilled water, and the organic layer was distilled under reduced pressure and subjected to silica gel column to obtain compound 3-1, 20.5g (yield: 64%).

(2) Synthesis of Compound 3

Compound 3-1 4g (12.6 mmol), compound 2-2 9.7g (13.9 mmol), Pd (PPh ₃ ) ₄ 0.7g (0.6 mmol), potassium carbonate 3.48g (25.2 mmol) toluene 100 mL, ethyl alcohol 20 After suspension in a mixed solvent of 20 mL of distilled water and 20 mL of distilled water, the mixture was refluxed and stirred for 12 hours. After the reaction was completed, extraction was performed with dichloromethane and distilled water, and the organic layer was distilled under reduced pressure and subjected to silica gel column to obtain compound 3, 6.4g (yield: 59%).

Example 1: Manufacturing of Light-Emitting Diodes

An organic light emitting diode was manufactured by applying Compound 1 synthesized in Synthesis Example 1 as a dopant of the light emitting material layer. First, a 40 mm x 40 mm x 0.5 mm thick ITO (including reflector) electrode-attached glass substrate was ultrasonically cleaned with isopropyl alcohol, acetone, and DI water for 5 minutes, and then dried in an oven at 100 °C. After cleaning the substrate, it was treated with O ₂ plasma for 2 minutes in a vacuum state and transferred to a deposition chamber to deposit other layers thereon. Organic layers were deposited in the following order by evaporation from a heating boat under a vacuum of about 10 ⁻⁷ Torr.

Hole injection layer (HIT; HAT-CN, 7 nm), hole transport layer (HTL; NPB, 55 nm), electron blocking layer (EBL; mCBP, 10 nm), light emitting material layer (EML; 4-(3-triphenyl) Ren-2-yl) phenyl) dibenzo [b, d] thiophene was used as a host, Compound 1 was doped with 30 wt%, 35 nm), a hole blocking layer (HBL; B3PYMPM, 10 nm), an electron transport layer ( ETL; TPBi, 20 nm), electron injection layer (EIL; LiF), cathode (Al).

After forming a capping layer (CPL), it was encapsulated with glass. After deposition of these layers, they were transferred from the deposition chamber into a dry box for film formation and subsequently encapsulated using UV curing epoxy and a moisture getter.

Example 2: Fabrication of light emitting diode

A light emitting diode was manufactured by repeating the procedure of Example 1, except that Compound 2 synthesized in Synthesis Example 2 was used instead of Compound 1 as the dopant of the light emitting material layer.

Example 3: Fabrication of Light-Emitting Diodes

A light emitting diode was manufactured by repeating the procedure of Example 1, except that Compound 3 synthesized in Synthesis Example 3 was used instead of Compound 1 as the dopant of the light emitting material layer.

Comparative Examples 1 to 3: Manufacturing of light emitting diodes

Light emitting diodes were fabricated by repeating the procedure of Example 1, except that each of the compounds shown below was used instead of Compound 1 as the dopant of the light emitting material layer.

Experimental Example: Measurement of Light Emission Characteristics of Organic Light-Emitting Diodes

Physical properties were measured for the organic light emitting diodes manufactured in Examples 1 to 3 and Comparative Examples 1 to 3, respectively. Each organic light emitting diode having an emission area of 9 mm 2 was connected to an external power source, and device characteristics were evaluated at room temperature using a current source (KEITHLEY) and a photometer (PR 650). Driving voltage (V), current efficiency (cd/A), power efficiency (lm/W), external quantum efficiency (EQE, %) of each light emitting diode measured at a current density of 10 ㎃/㎠, The CIE color coordinate measurement results are shown in Table 1 below.

Evaluating light emitting characteristics of light emitting diodes Sample V cd/A lm/W EQE (%) CIE Comparative Example 1 3.9 7.9 6.2 4.0 (0.189, 0.336) Comparative Example 2 4.1 21.5 16.2 9.8 (0.200, 0.410) Comparative Example 3 4.7 9.0 6.0 5.87 (0.159, 0.230) Example 1 4.3 32.4 23.4 11.4 (0.381, 0.575) Example 2 3.6 46.5 40.6 14.7 (0.318, 0.628) Example 3 4.1 46.1 35.8 15.7 (0.335, 0.596)

As shown in Table 1, as in Comparative Example 1, compared to the case where a compound having two carbazolyl groups but two phenyl groups in which the cyano group is not substituted is used as a dopant for the light emitting material layer, When the organic compound synthesized according to the present invention was used as the dopant of the light emitting material layer, the driving voltage was reduced by up to 7.7%, and the current efficiency, power efficiency, and external quantum efficiency were improved by up to 488.6%, 554.8%, and 292.5%, respectively.

In addition, as in Comparative Example 2, compared to the case where a compound having three carbazolyl groups but two phenyl groups in which the cyano group is not substituted is used as a dopant for the light emitting material layer, the compound synthesized according to the present invention is connected to a triazine ring. When the organic compound was used as the dopant of the light emitting material layer, the driving voltage was reduced by up to 12.2%, and the current efficiency, power efficiency, and external quantum efficiency were improved by up to 116.3%, 150.6%, and 60.2%, respectively.

In addition, compared to the case of using a compound having one carbazolyl group as a dopant of the light emitting material layer as in Comparative Example 3, when the organic compound synthesized according to the present invention is used as a dopant of the light emitting material layer, the driving voltage is It decreased by 23.4%, and current efficiency, power efficiency, and external quantum efficiency improved by up to 416.7%, 576.7%, and 167.5%, respectively. In particular, the compounds used in Comparative Examples 1 to 3 emitted blue light, but the organic compounds synthesized according to the present invention emitted green light, and had different light emission characteristics. As a result, by applying the organic compound of the present invention to the light emitting layer, the driving voltage can be significantly lowered, and an organic light emitting diode with good light emitting efficiency can be manufactured. Accordingly, the organic light emitting diode to which the organic compound of the present invention is applied may be used for an organic light emitting diode display device and/or a lighting device to improve light emitting efficiency and reduce power consumption.

In the above, the present invention has been described based on exemplary embodiments and examples of the present invention, but the present invention is not limited to the technical idea described in the above embodiments and examples. Rather, those skilled in the art to which the present invention belongs can easily make various modifications and changes based on the above-described embodiments and examples. However, it is clear from the appended claims that all of these modifications and changes fall within the scope of the present invention.

100, 200, 400: organic light emitting diode
110, 210, 410: first electrode 120, 220, 420: second electrode
130, 230, 430: organic light emitting layer 140, 240: hole injection layer
150, 250: hole transport layer 160, 260: light emitting material layer
170, 270: electron transport layer 180, 280: electron injection layer
255, 265: exciton blocking layer 300: organic light emitting diode display

Claims (7)

Organic compounds shown below.

a first electrode and a second electrode facing each other; and
An organic light emitting layer positioned between the first electrode and the second electrode,
The organic light emitting layer is an organic light emitting diode including an organic compound shown below.

According to claim 2,
wherein the organic light emitting layer includes a light emitting material layer including a light emitting material, and the light emitting material layer includes the organic compound.
According to claim 3,
The light emitting material layer includes a host and a dopant, and the dopant includes the organic compound.
According to claim 4,
The dopant is a green dopant organic light emitting diode.
According to claim 4,
The difference between the highest occupied molecular orbital energy level of the host (HOMO _Host ) and the highest occupied molecular orbital energy level of the dopant (HOMO _Dopant ) (|HOMO _Host -HOMO _Dopant |) or the lowest unoccupied molecular orbital of the host An organic light emitting diode in which a difference (|LUMO _Hos t-LUMO _Dopant |) between an energy level (LUMO _Host ) and a lowest unoccupied molecular orbital energy level (LUMO _Dopant ) of the dopant is 0.5 eV or less.
An organic light emitting device comprising the organic light emitting diode according to any one of claims 2 to 6.

Images