KR20210046294A - The thermally activated delayed fluorescence dopant material and organic light emitting diode comprising the same - Google Patents

Abstract

The present invention relates to a fluorescent material having excellent lifespan characteristics due to excellent electrochemical and thermal stability, and having high luminous efficiency even at low driving voltage, and an organic light emitting diode including the same. In chemical formula 1, X is nitrogen, boron or phosphorus, Y1 to Y5 are independently CR6 or N, at least one of Y1 to Y5 is N, R1, R2 and R6 are independently selected from the group consisting of hydrogen, halogen, a substituted or unsubstituted C6 to C20 aryl group, a substituted or unsubstituted C5 to C20 heteroaryl group, and a substituted or unsubstituted C6 to C20 arylamine group.

Description

Fluorescent material and organic light emitting diode containing the same {THERMALLY ACTIVATED DELAYED FLUORESCENCE DOPANT MATERIAL AND ORGANIC LIGHT EMITTING DIODE COMPRISING THE SAME}

The present invention relates to a fluorescent material and an organic light-emitting diode comprising the same, and more particularly, a fluorescent material having excellent electrochemical and thermal stability, excellent lifespan characteristics, and high luminous efficiency even at a low driving voltage, and a fluorescent material including the same. It relates to an organic light emitting diode.

Organic light-emitting diodes are self-luminous devices that not only have a wide viewing angle and excellent contrast, but also have a fast response time, excellent luminance, driving voltage, and response speed characteristics, and are capable of multicolorization. .

A typical organic light emitting diode may include an anode and a cathode, and an organic layer interposed between the anode and the cathode. The organic layer may include an electron injection layer, a hole transport layer, a light emitting layer, an electron transport layer, and an electron injection layer. When a voltage is applied between the anode and the cathode, holes injected from the anode move to the emission layer via the hole transport layer, and electrons injected from the cathode move to the emission layer via the electron transport layer. Carriers such as holes and electrons recombine in the emission layer region to generate excitons, and the excitons change to a ground state to generate light.

In general, excitons generated when driving an organic light emitting diode are generated with a probability of 25% in a singlet state and 75% in a triplet state, and in the case of a fluorescent light emitting material, light emission by 25% of the excitons in the singlet state Is generated, and the internal quantum efficiency stays at the maximum level of 25%. In order to improve these characteristics, iridium or platinum complexes that can use triplet energy are used, and are known to have excellent quantum efficiency characteristics. However, these materials are expensive, and in particular, due to the instability of the blue light-emitting material, their application is limited.

In order to solve the above problem, a fluorescence material has been recently developed, and the difference between the singlet state and the triplet state of the excitons is 0.3 eV or less, and in this case, due to heat corresponding to room temperature or device driving temperature. It is reported that the quantum efficiency of 100% can theoretically be achieved by transitioning the triplet state to the singlet state.

However, the actual quantum efficiency of the fluorescent material developed so far is known to be a problem to be improved since the difference from the theoretical quantum efficiency is very large.

Accordingly, there is an urgent need to develop a fluorescent material and an organic light emitting diode including the same, which can effectively improve quantum efficiency by effectively enabling a transition from a triplet state to a singlet state.

Korean Patent Application Publication No. 2017-0113808

In order to solve the problems of the prior art as described above, the present invention provides a fluorescent material having excellent electrochemical and thermal stability, excellent lifespan, and high luminous efficiency even at a low driving voltage, and an organic light emitting diode including the same. It is aimed at.

All of the above and other objects of the present invention can be achieved by the present invention described below.

In order to achieve the above object, the present invention provides a fluorescent material, characterized in that represented by the following formula (1).

[Formula 1]

(In Formula 1, X is nitrogen (N), boron (B) or phosphorus (P), Y ₁ to Y ₅ are independently CR ₆ or N, and at least one of _{Y 1} to Y _{5 is N,} R ₁ , R ₂ and R ₆ are independently hydrogen, halogen, a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, a substituted or unsubstituted heteroaryl group having 5 to 20 carbon atoms, and a substituted or unsubstituted C 6 To 20 arylamine groups, and R ₃ to R ₅ are independently hydrogen, a substituted or unsubstituted C 1 to C 20 alkyl group, a substituted or unsubstituted C 1 to C 20 alkoxy group, substituted or unsubstituted Is selected from the group consisting of a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 5 to 30 carbon atoms, and a substituted or unsubstituted amine group having 1 to 20 carbon atoms, l and m are independently 0 Is an integer of 2, n is an integer of 1 to 3, and l+m+n is 3 or less.)

In addition, the present invention is a first electrode; A second electrode; And a light emitting layer positioned between the first electrode and the second electrode, wherein the light emitting layer includes the fluorescent material of the present invention.

According to the present invention, there is an effect of providing a fluorescent material having excellent electrochemical and thermal stability, excellent lifespan characteristics, and high luminous efficiency even at a low driving voltage, and an organic light emitting diode including the same.

Hereinafter, the fluorescent material of the present disclosure and an organic light emitting diode including the same will be described in detail.

The present inventors have confirmed that when various compounds are synthesized and applied to a fluorescent material, the actual quantum efficiency is excellent, which is close to the theoretical quantum efficiency, and as a result, it has not only high luminous efficiency even at a low driving voltage, but also excellent lifespan characteristics. Based on this, the present invention was completed by further focusing on research.

In the present description, "substituted" means a substituent or at least one hydrogen in the compound is a halogen, a nitro group, an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 30 carbon atoms, an aryl group having 6 to 40 carbon atoms, and having 5 to 40 carbon atoms. It means substituted with a heteroaryl group, an alkylene group having 1 to 20 carbon atoms, a cycloalkylene group having 5 to 20 carbon atoms, an arylene group having 6 to 20 carbon atoms, an ester group, an ester group, a carbonyl group, or a carbonate group.

In the present description, “aryl group” means any functional group or substituent derived from an aromatic hydrocarbon ring unless otherwise defined.

In the present description, "hetero" means that one functional group contains 1 to 3 heteroatoms selected from the group consisting of O, N, S and P, and the rest is carbon or hydrogen unless otherwise defined. do.

In the present description, the term "heteroaryl group" means that the aryl group contains 1 to 3 heteroatoms selected from the group consisting of N, O, S, and P, and the remainder is carbon or hydrogen. When the heteroaryl group is a fused ring, each ring may contain 1 to 3 heteroatoms.

As used herein, the term "arylamine group" means a functional group or a substituent in which an aromatic hydrocarbon ring is bonded to a nitrogen atom unless otherwise defined.

In the present description, "alkyl group" means an aliphatic hydrocarbon group unless otherwise defined.

In the present description, "*" means a part connected to a carbon atom or an atom other than carbon, that is, a part to which a substituent or a functional group is connected.

Fluorescent material

The fluorescent material of the present invention is characterized in that it is represented by the following formula (1), and in this case, it is possible to realize the luminous colors of red, green, and blue, and has an effect of lowering the difference between singlet energy and triplet energy to 0.3 Ev or less.

The smaller the difference between the singlet energy and the triplet energy, the higher the luminous efficiency even at a low driving voltage, and the lifespan characteristics are improved.

In addition, the difference between the singlet energy and the triplet energy has a level similar to that of the triplet energy, and when a fluorescent material having a similar level is applied to the organic light emitting diode, there is an effect of lowering the driving voltage.

[Formula 1]

(In Formula 1, X is nitrogen (N), boron (B) or phosphorus (P), Y ₁ to Y ₅ are independently CR ₆ or N, and at least one of _{Y 1} to Y _{5 is N,} R ₁ , R ₂ and R ₆ are independently hydrogen, halogen, a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, a substituted or unsubstituted heteroaryl group having 5 to 20 carbon atoms, and a substituted or unsubstituted C 6 To 20 arylamine groups, and R ₃ to R ₅ are independently hydrogen, a substituted or unsubstituted C 1 to C 20 alkyl group, a substituted or unsubstituted C 1 to C 20 alkoxy group, substituted or unsubstituted Is selected from the group consisting of a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 5 to 30 carbon atoms, and a substituted or unsubstituted amine group having 1 to 20 carbon atoms, wherein R ₁ to R ₅ , CN and the functional group having a cyclic form are independently substituted with any one of the hydrogens bonded in the spanning benzene ring, l and m are independently an integer of 0 to 2, n is an integer of 1 to 3, and l+ m+n is 3 or less.)

을 의미하며, 여기서 Y₁ 내지 Y₅는 독립적으로 CR₆ 또는 N이고, 상기 Y₁ 내지 Y₅ 중 적어도 하나는 N이다.The functional group having a cyclic form in Formula 1

Means, wherein Y ₁ to Y ₅ are independently CR ₆ or N, and at least one of _{Y 1} to Y _{5 is N.}

As a specific example, in Chemical Formula 1, X may be nitrogen (N) and n may be 1, and in this case, charge transport performance is improved, and luminous efficiency and lifespan characteristics are excellent.

As another example, in Formula 1, X may be nitrogen (N), and l+m may be an integer of 0 to 2. In this case, there is an effect of having high luminous efficiency even at a low driving voltage and improving lifespan characteristics. .

_{Substituents that may be introduced into the aryl group, heteroaryl group, and arylamine group of R 1} , R ₂ and R ₆ in Formula 1 are for example, independently containing an aryl group having 6 to 20 carbon atoms and 1 to 3 N It may be selected from the group consisting of a C5 to C20 heteroaryl group.

As a specific example, the substituents each of which may be introduced into the aryl group, heteroaryl group, and arylamine group of _{R 1} , R ₂ and R _{6 are independently phenyl group, biphenyl group, terfuryl group, naphthyl group, anthracenyl group, phenathrene group} , Pyrenyl group, triphenylene group perylenyl group, chrysenyl group, carbazole group, thiophene group, furan group, pyrrole group, imidazole group, thiazole group, oxazole group, oxadiazole group, triazole group, pyridyl group, pyra It may be selected from the group consisting of a chopped group, a quinolinyl group, an isoquinoline group, and an acridyl group.

In Formula 1, Y ₁ to Y ₅ are, for example, independently CR ₆ or N, _{at least one of Y 1} to Y ₅ is N, and R ₆ is an aryl group having 6 to 18 carbon atoms, or a substituted or unsubstituted It may be a heteroaryl group having 6 to 18 carbon atoms, and in this case, charge mobility is high and there is a thermally very stable effect.

As a specific example, in Chemical Formula 1, ₁ to 3 of Y 1 to Y ₅ may be N, and the rest may be CR _{6. In} this case, since it has a high glass transition temperature and a decomposition temperature, it is thermally excellent, so that the stability of driving is improved. There is an improved effect.

In a preferred example, R ₆ is a phenyl group, a biphenyl group, a terpenyl group, a naphthyl group, an anthracenyl group, a phenathrene group, a pyrenyl group, a triphenylene group perylenyl group, a chrysenyl group, a carbazole group, a thiophene group, a furan group , A pyrrole group, an imidazole group, a thiazole group, an oxazole group, an oxadiazole group, a triazole group, a pyridyl group, a pyrazazine group, a quinolinyl group, an isoquinoline group, and an acridyl group.

As a more preferred example, R ₆ may be selected from the group consisting of a phenyl group, a biphenyl group, a carbazole group and a furan group, and the furan group may be a dibenzofuran group as an example.

In Chemical Formula 1, R ₁ and R ₂ may be independently selected from the group consisting of hydrogen, an aryl group having 6 to 18 carbon atoms, and a heteroaryl group having 6 to 18 carbon atoms, in which case charge transport performance is improved and luminous efficiency And there is an effect of excellent life characteristics.

In a specific example, R ₁ and R ₂ are independently a phenyl group, a biphenyl group, a terfuryl group, a naphthyl group, an anthracenyl group, a phenatrene group, a pyrenyl group, a triphenylene group, a perylenyl group, a chrysenyl group, a carbazole group, and a thi. To be selected from the group consisting of an ofene group, a furan group, a pyrrole group, an imidazole group, a thiazole group, an oxazole group, an oxadiazole group, a triazole group, a pyridyl group, a pyrazazine group, a quinolinyl group, an isoquinoline group, and an acridyl group. In this case, there is an effect of having high luminous efficiency even at a low driving voltage and improving life characteristics.

As a preferred example, the R ₁ and R ₂ may independently be a phenyl group or a carbazole group, and in this case, the desired effect of the present invention is best revealed.

In Formula 1, R ₃ to R ₅ may be independently hydrogen, or one of the following Formulas 2-1 to 2-21, in this case, reducing the difference between the singlet energy and the triplet energy, so that even at a low driving voltage There is an effect of having luminous efficiency.

As a preferred example, in Formula 1, R ₃ to R ₅ may independently be hydrogen, or one of the following Formulas 2-1, 2-19, and 2-21, and in this case, electrochemical and thermal stability are excellent, resulting in lifetime characteristics. It has an excellent effect of excellent luminous efficiency even at a low driving voltage.

[Formula 2-1]

[Formula 2-2]

[Formula 2-3]

[Formula 2-4]

[Formula 2-5]

[Formula 2-6]

[Formula 2-7]

[Formula 2-8]

[Formula 2-9]

[Formula 2-10]

[Chemical Formula 2-11]

[Formula 2-12]

[Formula 2-13]

[Formula 2-14]

[Formula 2-15]

[Formula 2-16]

[Formula 2-17]

[Formula 2-18]

[Chemical Formula 2-19]

[Formula 2-20]

[Formula 2-21]

Formula 1 may be, for example, one of Formulas 1-1 to 1-16, but is not limited thereto. In this case, the exciton of the triplet is a singlet due to the difference between the singlet energy and the triplet energy. The moving reverse intersystem crossing (RISC) effect is excellent, so that the luminous efficiency is very excellent and the lifespan characteristics are improved.

[Formula 1-1]

[Formula 1-2]

[Formula 1-3]

[Formula 1-4]

[Formula 1-5]

[Formula 1-6]

[Formula 1-7]

[Formula 1-8]

[Formula 1-9]

[Formula 1-10]

[Formula 1-11]

[Formula 1-12]

[Formula 1-13]

[Formula 1-14]

[Formula 1-15]

[Formula 1-16]

The fluorescent material may be, for example, a thermally active delayed fluorescent material, and in this case, the difference between singlet energy and triplet energy is small, so that the inverse interphase transition occurs well, thereby improving the delayed fluorescence effect, thereby exhibiting excellent luminous efficiency. There is this.

The fluorescent material of the present disclosure may, for example, have a difference between singlet energy and triplet energy (ΔE _ST ) of 0.3 eV or less, 0.01 to 0.3 eV, or 0.01 to 0.2 eV, and emit light even at a low driving voltage within this range. There is an effect of excellent efficiency.

The △E _ST is a UV-vis measurement using an Agilent Technologies (company) Cary 8454 UV-Vis Diode Array system device to measure the Energy Gap (eV), and the PL measurements using a PerkinElmer (company) LS55 Luminescence Spectrometer, T1 ( eV) was measured.

Organic light emitting diode

The organic light emitting diode of the present disclosure includes, for example, a first electrode; A second electrode; And a light-emitting layer positioned between the first electrode and the second electrode, wherein the light-emitting layer may include the fluorescent material of the present disclosure. In this case, when a forward bias is applied, holes are transferred from the first electrode to the light-emitting layer. Electrons flow into the light emitting layer from the second electrode, and electrons and holes introduced into the light emitting layer are combined to form excitons, and light is emitted as the excitons transition to the ground state, so that the viewing angle is wide, the response time is fast, and the luminance, driving The voltage and response speed characteristics are excellent.

The emitted light may embody red, green, and blue luminous colors, and in particular, there is an effect of excellent green color.

The light emitting layer may have a thickness of 1 to 100 nm, 10 to 70 nm, 15 to 65 mm, or 30 to 50 nm, for example, and exhibit excellent light emission characteristics without a substantial increase in driving voltage within this range.

Between the first electrode and the light-emitting layer, for example, a hole-conducting layer may be included, and the hole-conducting layer may include, for example, a fluorescent material of the present disclosure, and in this case, there is an effect of excellent luminous efficiency and lifetime characteristics. .

The hole conductive layer may include, for example, a hole transport layer for transporting holes and a hole injection layer for injection of holes, and the hole transport layer and the hole injection layer are HOMO between the work function level of the anode and the HOMO level of the light emitting layer. It is a layer having a level, and in this case, there is an effect of increasing the efficiency of injecting or transporting holes from the anode to the light emitting layer.

The hole transport layer is preferably bis(N-(1-naphthyl-n-phenyl))benzidine (α-NPD), N'-di(naphthalen-1-yl)-N,N'-biphenyl-benzidine ( NPB) and N,N'-biphenyl-N,N'-bis(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine (TPD) In this case, there is an effect of increasing the transport efficiency of holes from the anode to the light emitting layer.

The thickness of the hole transport layer may be, for example, 10 to 200 nm, 20 to 150 nm, 40 to 100 mm, or 60 to 80 nm, and within this range, there is an effect of improving hole transport characteristics without an increase in driving voltage.

The hole injection layer is, for example, copper phthalocyanine (CuPc), 4,4',4"-tris(3-methylphenylamino)triphenylamine (m-MTDATA), 4,4',4"-tris(3-methylphenyl). Amino)phenoxybenzene (m-MTDAPB), starburst type amines 4,4',4"-tri(N-carbazolyl)triphenylamine (TCTA), 4,4',4"-tris (N-(2-naphthyl)-N-phenylamino)-triphenylamine (2-TNATA), N'-di(naphthalen-1-yl)-N,N'-biphenyl-benzidine (NPB) and It may be one or more selected from the group consisting of 1,4,5,8,9,11-Hexaazatriphenylene hexacarbonitrile (HAT-CN), and in this case, there is an effect of increasing the injection efficiency of holes from the anode to the light emitting layer.

The thickness of the hole injection layer may be 1 to 50 nm, 1 to 30 nm, or 5 to 20 nm, for example, and within this range, there is an effect of improving hole injection characteristics without an increase in driving voltage.

An electron conductive layer may be included between the second electrode and the light emitting layer as an example, and the electron conductive layer may include a fluorescent material of the present invention as an example, and in this case, there is an effect of excellent lifespan characteristics and luminous efficiency. .

The conductive conductive layer may include, for example, an electron transport layer for transporting electrons and an electron injection layer for injection of electrons, and the electron transport layer and the electron injection layer are LUMO between the work function level of the cathode and the LUMO level of the light emitting layer. It is a layer having a level, and in this case, there is an effect of increasing the efficiency of injecting or transporting electrons from the cathode to the light emitting layer.

The electron transport layer is, for example, tris(8-hydroxyquinolinolato)aluminum (Alq3), PBD(2-(4-biphenylyl)-5-(4-t-butylphenyl)-1,3,4 -Oxadiazole), TNF (2,4,7-trinitro fluorenone), may be one or more selected from the group consisting of BMD and BND, in this case, there is an effect of increasing the electron transport efficiency from the cathode to the light emitting layer.

The thickness of the electron transport layer may be 1 to 100 nm, 10 to 70 nm, 15 to 65 mm, or 30 to 50 nm, for example, and within this range, electron transport characteristics may be improved without a substantial increase in driving voltage.

The electron injection layer is not particularly limited as long as it is commonly used in the art, but for example, it may be at _{least one selected from the group consisting of LiF, NaCl, CsF, Li 2} O, BaO, BaF ₂ , and Liq (lithium quinolate). In this case, there is an effect of increasing the injection efficiency of electrons from the cathode to the light emitting layer.

The thickness of the electron injection layer may be, for example, 0.01 to 10 nm, 0.01 to 5 nm, 0.05 to 3 nm, or 1 to 3 nm, and within this range, there is an effect of improving electron injection characteristics without increasing the driving voltage. .

The light-emitting layer may include, for example, a dopant material, a host material, or both, and in this case, there is an advantage in that luminous efficiency is greatly improved.

For example, when the dopant material includes the fluorescent material of the present disclosure, the host material is mCP (N,N-dicarbazolyl-3,5-benzene), DPEPO ((bis 2-(diphenylphosphino)phenyl] ether oxide), Alq3 (tris (8-quinolinolate) aluminum), CBP (4,4'-N,N'-dicarbazol-biphenyl), 9,10-di (naphthalen-2-yl) anthracene, TPBI (1,3, 5-tris(N-phenylbenzimidazole-2-yl)benzene)), TBADN(3-tert-butyl-9,10-di(naphth-2-yl) anthracene) and mCBP(3,3'-Di(9H It may be one or more selected from the group consisting of -carbazol-9-yl)-1,1'-biphenyl), and in this case, the luminous colors of red, green, and blue can be implemented, and the luminous efficiency is improved even at a low driving voltage. There is.

As another example, when the host material includes the fluorescent material of the present disclosure, the dopant material may be a fluorescent dopant, and the fluorescent dopant is not particularly limited as long as it is commonly used in the art, for example, but green fluorescence It is preferable that it is a fluorescent green dopant that emits light, and in this case, the organic light emitting diode may be a Hyper Fluorescence (HF) device.

Examples of the fluorescent dopant include perylene, TBPe (2,5,8,11-tetra-tert-butylperylene), BCzVB (1,4-bis[2-(3-N-ethylcarbazoryl)vinyl]benzene) , BCzVBi(4,4'-bis(9-ethyl-3-carbazovinylene)-1,1'-biphenyl), BDAVBi(4,4'-bis[4-diphenylamino]styryl)biphenyl), DPAVB(4-( di-p-tolylamino)-4'-[(di-p-tolylamino)styryl]stilbene), DPAVBi(4,4'-bis[4-(di-p-tolylamino)styryl]bipnehyl), DSA-Ph( 1-4-di-[4-(N,N-diphenyl)amino]styryl-benzene), C545T(2,3,6,7-tetrahydro-1,1,7,7,-tetramethyl-1H, 5H,11H-10(2-benzothiazolyl)quinozino-[9,9a,1gh]coumarin), DMQA(N,N'-dimethyl-quinacridone), TPA(9,10-bis[phenyl( m-tolyl) -amino] anthracene) , BA-TTB (N 10, N 10, N 10 ', N 10'-tetra-tolyl-9,9'-bianthracene-10,10'-diamine), DCM (4 -(dicyanomethylene)-2-methyl-6-[p-(dimethylamino)styryl]-4H-pyran), DCJTB(4-(Dicyanomethylene)-2-tert-butyl-6-(1,1,7,7, -tetramethyljulolidyl-9-enyl)-4H-pyran), AAAP(6-methyl-3-[3-(1,1,6,6-tetramethyl-10-oxo-2,3,5,6-tetrahydro-1H ,4H,10H-11-oxa-3a-azabenzo[de]-anthracen-9-yl)acryloyl]pyran-2,4-dione), BSN(1,10-dicyano-substituted bis-styrylnaphthalene derivat ive) DBP (tetraphenyldibenzoperiflanthene) and rubrene may be one or more selected from the group consisting of, but is not limited thereto.

The fluorescent material may include, for example, 10 to 90% by weight, 10 to 80% by weight, or 10 to 70% by weight based on the total 100% by weight of the light emitting layer, and in this case, there is an effect of excellent efficiency.

The first electrode is an anode as an example, and the second electrode may be a cathode as an example. In this case, holes are injected from the anode to move to the emission layer, and electrons are injected from the cathode to move to the emission layer, and the holes and electrons Is combined in the emission layer to generate excitons, and has excellent effect of realizing red, green, and blue emission colors.

The anode may include, for example, one or more from the group consisting of a conductive metal oxide, a metal, and carbon.

The conductive metal oxide is, for example, indium tin oxide (ITO), fluorine tin oxide (FTO), aluminum zinc oxide (AZO), galium zinc oxide (GZO), antimony tin oxide (ATO), indium zinc oxide (IZO), and ZnO. It may be one or more selected from the group consisting of (zinc oxide) and OMO (oxide/metal/oxide), and in this case, there is an excellent effect of transparency.

The metal is not particularly limited as long as it is commonly used in the art, for example.

The carbon may be one or more selected from the group consisting of graphite, graphene, and carbon nanotubes, for example.

The cathode is not particularly limited as long as it is commonly used in the art, for example, but may include at least one selected from the group consisting of aluminum, magnesium, calcium, sodium, potassium, indium, lithium, silver, lead, and cesium. have.

The organic light emitting diode may include, for example, a first electrode; Hole injection layer; Hole transport layer; Light-emitting layer; Electron transport layer; Electron injection layer; And a second electrode; may be sequentially stacked, preferably an electron blocking layer between the first electrode and the emission layer, and a hole blocking layer between the second electrode and the emission layer.

For example, the organic light emitting diode may have an emission luminance of 4,000 cd/m ² or more, 4,000 to 7,000 cd/m ² , or 4,200 to 5,500 cd/m ² , and has an advantage of obtaining excellent luminous efficiency within this range.

For example, the organic light emitting diode may have a luminous efficiency of 40 cd/A or higher, 40 to 70 cd/A, or 42 to 60 cd/A.

In the present description, the luminance and luminous efficiency are values evaluated based on ^{10 mA/cm 2.}

Hereinafter, preferred synthesis examples and examples are presented to aid the understanding of the present invention, but the following synthesis examples and examples are only illustrative of the present invention, and various changes and modifications are possible within the scope and spirit of the present invention. It is obvious to those skilled in the art, and it is natural that such modifications and modifications fall within the appended claims.

[Synthesis Example]

[Compound 1]

Synthesis of compound 1-1

4,5-dibromo-2-chlorobenzonitrile 20g (67.7 mmol), 11,12-dihydroindolo[2,3-a]carbazole 17.4g (67.7 mmol), sodium tertiarybutoxide 26g ( 270.8 mmol), Pd ₂ (dba) ₃ 6.2 g (6.8 mmmol), triturateylphosphine (50% in toluene) 6.6 ml (13.5 mmol) were suspended in 350 ml of toluene and stirred under reflux for 12 hours. Extracted with dichloromethane and distilled water, and the organic layer was filtered with silica gel. The organic solution was removed and subjected to silica gel column to obtain compound 1, 10.5g (yield: 40%).

Synthesis of compound 1-2

Compound 1-1 10.5g (26.9 mmol), bis(pinacolato) _{diborone 10.8g (40.4 mmol), Pd(dba) 2} 0.8g (1.3 mmol), potassium acetate 5.3g (53.9 mmmol), tricyclohexyl Phosphine 1.8 g (6.5 mmol) was suspended in 150 ml of 1,4-dioxane and stirred at 80 °C for 12 hours. After completion of the reaction, the mixture was filtered through Celite. The filtrate was distilled under reduced pressure and then subjected to silica gel column to obtain Compound 1-2, 10.3 g (yield: 80%).

Synthesis of compound 1

Compound 1-2 7g (14.5 mmol), 2-chloro-4,6-diphenyl-1,3,5-triazine 3.9g (14.5 mmol), Pd(PPh ₃ ) ₄ 0.8g (0.7 mmol), potassium 4.0 g (29.1 mmmol) of carbonate was suspended in 75 ml of toluene, 15 ml of ethyl alcohol, and 15 ml of distilled water, and then stirred under reflux for 12 hours. After the reaction was completed, the mixture was extracted with dichloromethane and distilled water, and the organic layer was distilled under reduced pressure and then subjected to silica gel column to obtain Compound 1, 5.9 g (yield: 70%).

[Compound 2]

Synthesis of compound 2

Compound 1-2 7g (14.5 mmol), 4-chloro-2,6-diphenylpyrimidine 3.9g (14.5 mmol), Pd(PPh ₃ ) ₄ 0.8g (0.7 mmol), potassium carbonate 4g (29.1 mmmol) After suspending in 75 ml of toluene, 15 ml of ethyl alcohol, and 15 ml of distilled water, the mixture was stirred under reflux for 12 hours. After the reaction was completed, the mixture was extracted with dichloromethane and distilled water, and the organic layer was distilled under reduced pressure and then subjected to silica gel column to obtain Compound 2, 6.4 g (yield: 75%).

[Compound 3]

Synthesis of compound 3

Compound 1-2 7g (14.5 mmol), 2-([1,1'-diphenyl]-3-yl-4-chloro-6-phenyl-1,3,5-triazine 5g (14.5 mmol), Pd (PPh ₃ ) ₄ 0.8 g (0.7 mmol), potassium carbonate 4 g (29.1 mmmol) were suspended in 75 ml of toluene, 15 ml of ethyl alcohol, and 15 ml of distilled water, and then stirred under reflux for 12 hours. And extracted with distilled water, the organic layer was distilled under reduced pressure, and then subjected to silica gel column to obtain Compound 3, 6.7 g (yield: 70%).

[Compound 4]

Synthesis of compound 4-1

2,3-dibromo-4-chlorobenzonitrile 20g (67.7 mmol), 11,12-dihydroindolo[2,3-a]carbazole 17.4g (67.7 mmol), sodium tertiarybutoxide 26g ( 270.8 mmol), Pd ₂ (dba) ₃ 6.2 g (6.8 mmmol), triturateylphosphine (50% in toluene) 6.6 ml (13.5 mmol) were suspended in 350 ml of toluene and stirred under reflux for 12 hours. Extracted with dichloromethane and distilled water, and the organic layer was filtered with silica gel. The organic solution was removed and subjected to silica gel column to obtain compound 4, 11.9 g (yield: 45%).

Synthesis of compound 4-2

Compound 4-1 11.9g (30.5 mmol), bis(pinacolato)diborone 12.2g (45.8 mmol), Pd(dba) ₂ 0.9g (1.5 mmol), potassium acetate 6g (61 mmmol), tricyclohexylphos Pin 2g (7.3 mmol) was suspended in 150 ml of 1,4-dioxane and stirred at 80 °C for 12 hours. After completion of the reaction, the mixture was filtered through Celite. The filtrate was distilled under reduced pressure and then subjected to silica gel column to obtain compound 4-2, 12.5 g (yield: 85%).

Synthesis of compound 4

Compound 4-2 7g (14.5 mmol), 2-chloro-4,6-diphenyl-1,3,5-triazine 3.9g (14.5 mmol), Pd(PPh ₃ ) ₄ 0.8g (0.7 mmol), potassium 4 g (29.1 mmmol) of carbonate was suspended in 70 ml of toluene, 15 ml of ethyl alcohol, and 15 ml of distilled water, and then stirred under reflux for 12 hours. After the reaction was completed, the mixture was extracted with dichloromethane and distilled water, and the organic layer was distilled under reduced pressure and then subjected to silica gel column to obtain Compound 4, 5.9g (yield: 70%).

[Compound 5]

Synthesis of compound 5-1

2,3-dibromo-5-chloro-4,6-difluorobenzonitrile 20g (60.4 mmol), 11,12-dihydroindolo[2,3-a]carbazole 15.4g (60.4 mmol) , Sodium tertiary butoxide 23.2g (241.4 mmol), Pd ₂ (dba) ₃ 5.5g (6 mmmol), tritertiary phosphine (50% in toluene) 5.85 ml (12.1 mmol) suspended in 300 ml of toluene Then, the mixture was stirred under reflux for 12 hours. Extracted with dichloromethane and distilled water, and the organic layer was filtered with silica gel. The organic solution was removed and subjected to silica gel column to obtain compound 5, 10.3 g (yield: 40%).

Synthesis of compound 5-2

Compound 5-1 10.3g (24.2 mmol), carbazole 8.5g (50.8 mmol), cesium carbonate 33.1g (101.6 mmol) were suspended in 120 ml of dimethylformamide and then stirred at 150 °C for 16 hours. After the reaction was completed, the mixture was extracted with dichloromethane and distilled water, and the organic layer was distilled under reduced pressure and then subjected to silica gel column to obtain Compound 5-2, 10.4g (yield: 60%).

Synthesis of compound 5-3

Compound 5-2 10.4g (14.5 mmol), bis(pinacolato)diborone 5.8g (21.6 mmol), Pd(dba) ₂ 0.4g (0.7 mmol), potassium acetate 2.8g (28.9 mmmol), tricyclohexyl 1 g (3.5 mmol) of phosphine was suspended in 75 ml of 1,4-dioxane, and then stirred at 80 °C for 12 hours. After completion of the reaction, the mixture was filtered through Celite. The filtrate was distilled under reduced pressure and then subjected to silica gel column to obtain compound 5-3, 8.2g (yield: 70%).

Synthesis of compound 5

Compound 5-3 7g (8.6 mmol), 2-chloro-4,6-diphenyl-1,3,5-triazine 2.3g (8.6 mmol), Pd(PPh ₃ ) ₄ 0.5g (0.4 mmol), potassium After suspending 2.4 g (17.2 mmmol) of carbonate in 45 ml of toluene, 9 ml of ethyl alcohol, and 9 ml of distilled water, the mixture was stirred under reflux for 12 hours. After the reaction was completed, the mixture was extracted with dichloromethane and distilled water, and the organic layer was distilled under reduced pressure and then subjected to silica gel column to obtain Compound 5, 5.5g (yield: 70%).

[Comparative compound 1]

Synthesis of Comparative Compound 1-1

Compound 5-1 20g (74 mmol), 11,12-dihydroindolo[2,3-a]carbazole 19g (74 mmol), sodium tertiarybutoxide 28.4g (295.9 mmol), Pd ₂ (dba) ₃ 6.8g (7.4 mmmol), tritertiary phosphine (50% in toluene) 7.2 ml (14.8 mmol) were suspended in 370 ml of toluene and stirred under reflux for 12 hours. Extracted with dichloromethane and distilled water, and the organic layer was filtered with silica gel. The organic solution was removed and subjected to silica gel column to obtain compound 1, 13.5g (yield: 50%).

Synthesis of Comparative Compound 1-2

Compound 1-1 13.5g (37 mmol), bis(pinacolato) _{diborone 14.8g (55.5 mmol), Pd(dba) 2} 1.1g (1.8 mmol), potassium acetate 7.3g (74 mmmol), tricyclohexyl Phosphine 2.5 g (8.9 mmol) was suspended in 185 ml of 1,4-dioxane and stirred for 12 hours at 80 °C. After completion of the reaction, the mixture was filtered through Celite. The filtrate was distilled under reduced pressure and then subjected to silica gel column to obtain Comparative Compound 1-2, 13.5 g (yield: 80%).

Synthesis of Comparative Compound 1

Compound 1-2 7g (15.3 mmol), 2-chloro-4,6-diphenyl-1,3,5-triazine 4.1g (15.3 mmol), Pd(PPh ₃ ) ₄ 0.9g (0.8 mmol), potassium 4.2 g (30.7 mmmol) of carbonate was suspended in 75 ml of toluene, 15 ml of ethyl alcohol, and 15 ml of distilled water, followed by reflux agitation 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 silica gel column to obtain Comparative Compound 1, 5.6 g (yield: 65%).

[Comparative compound 2]

Synthesis of Comparative Compound 2

In a nitrogen atmosphere, 10 g (39 mmol) of 11,12-dihydroindolo[2,3-a]carbazole was suspended in 270 ml of tetrahydrafuran, and 3.4 g (85.8 mmol) of sodium hydride (60%) was added in a small amount. It was added in increments. After the addition was completed, the mixture was stirred at room temperature for 1 hour. Then, 6 g (43 mmol) of 3,4-difluorobenzonitrile dissolved in 80 ml of tetrahydrofuran was slowly added. After the addition was complete, the mixture was stirred at 55°C for 12 hours. After the reaction was completed, an excess of distilled water was added and stirred, followed by extraction with dichloromethane and distilled water. The organic layer was distilled under reduced pressure and then subjected to silica gel column to obtain Comparative Compound 2, 9g (yield: 65%).

[Comparative compound 3]

Preparation of Comparative Compound 3-1

2-chloro-4,6-diphenyl-1,3,5-triazine 20 g (74.7 mmol), (4-fluorophenyl) boronic acid 11.5 g (82.2 mmol), Pd(PPh ₃ ) ₄ 4.3 g (3.7 mmol) and potassium carbonate 20.6 g (149.4 mmol) were suspended in 380 ml of toluene, 75 ml of ethyl alcohol, and 75 ml of distilled water, followed by reflux stirring 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 purified by a silica gel column to obtain Comparative Compound 3-1, 19.6 g (yield: 80%).

Synthesis of Comparative Compound 3

Comparative compound 3-1 1.96 g (5.99 mmol), 1-bromo-9H-carbazole 1.0 g (5.99 mmol), cesium carbonate 3.9 g (11.97 mmol) were suspended in 30 ml of dimethylformamide and then 190 for 16 hours. Stirred under °C. After the reaction was completed, extraction was performed with dichloromethane and distilled water, and the organic layer was distilled under reduced pressure and purified by a silica gel column to obtain Comparative Compound 3, 2.1 g (yield: 75%).

[Example]

Example 1 (Manufacture of organic light emitting diode)

ITO (Indium Tin Oxide) glass used as an anode was ultrasonically cleaned for 30 minutes using IPA and distilled water, dried in an oven at 100° C. for 30 minutes, and then transferred to a vacuum deposition apparatus chamber.

Next, on the ITO substrate in turn, a hole injection layer (HIL), a hole transport layer (HTL), an electron blocking layer (EBL), an organic emission layer (OEL), and electrons A transport layer (ETL) and an electron injection layer (EIL) were sequentially deposited (0.5 to 1.0Å/sec, 1 × 10 ^-7 to 4 × 10 ^-7 torr), and an Al layer as a cathode. Was deposited. The organic emission layer was prepared to contain a dopant (Compound 1) on a host (mCP; N,N-dicarbazolyl-3,5-benzene) in a weight ratio of 60:40.

After vacuum deposition, the substrate was transferred to a glove box and encapsulated to manufacture an organic light-emitting device. The sealing member may be provided as a glass cap with a getter using BaO inside, and an epoxy sealant for sealing is applied and UV irradiation (curing) to block oxygen and moisture penetration into the deposition surface. Was prevented.

Components used in Example 1 are shown in Table 1 below.

layer material Thickness (nm) Cathode Al 100 EIL LiF One ETL LGC201 (LG Chem) 35 OEL Host: mCBP, CBP, or mCP
Dopant: Compounds 1 to 5 or Comparative Compounds 1 and 2
Host: Dopant = 60: 40 weight ratio 35 EBL TCTA 15 HTL NPB 75 HIL NPB: HAT-CN = 90: 10 weight ratio 10 Anode ITO 150

Example 2 to 7 and Comparative example 1 to 5

In Example 1, except that the host material and the dopant material of Table 2 were used, it was carried out in the same manner as in Example 1.

[Test Example]

For the organic light emitting diodes prepared in Examples 1 to 7 and Comparative Examples 1 to 5, luminance and luminous efficiency based on ^{10 mA/cm 2 using Keithley sourcemeter “2635B” and HORIBA Spectrometer “PR-655”} And the emission peaks were evaluated, respectively, and the results are shown in Table 2 below. The samples showed peak values of green emission in the range of 530 to 540 nm.

division Emissive layer (host) Light-emitting layer (dopant) Luminance [cd/m ² ] Luminous efficiency
[cd/A] Emission peak [nm] Example 1 mCP Compound 1 5083 50.8 532 Example 2 mCP Compound 2 4261 42.6 536 Example 3 mCBP Compound 3 5139 51.4 532 Example 4 CBP Compound 4 4352 43.5 536 Example 5 mCP Compound 5 5251 52.5 536 Example 6 CBP Compound 1 5039 50.4 540 Example 7 CBP Compound 5 5213 52.1 532 Comparative Example 1 mCP Comparative compound 1 3752 37.5 536 Comparative Example 2 mCP Comparative compound 2 3913 39.1 532 Comparative Example 3 CBP Comparative compound 1 3811 38.1 536 Comparative Example 4 CBP Comparative compound 2 4084 40.8 540 Comparative Example 5 mCP Comparative compound 3 3993 39.9 532

As shown in Table 1, it was confirmed that the organic light emitting diodes of Examples 1 to 7 of the present invention have excellent luminance and luminous efficiency.

On the other hand, in the case of the organic light-emitting diodes of Comparative Examples 1 to 5 that do not contain the dopant material of the present invention, it was confirmed that both the luminance and luminous efficiency were lowered compared to the organic light-emitting diodes of Examples 1 to 7.

Claims (10)

Fluorescent material, characterized in that represented by the following formula (1).
[Formula 1]

(In Formula 1, X is nitrogen (N), boron (B) or phosphorus (P), Y ₁ to Y ₅ are independently CR ₆ or N, and at least one of _{Y 1} to Y _{5 is N,} R ₁ , R ₂ and R ₆ are independently hydrogen, halogen, a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, a substituted or unsubstituted heteroaryl group having 5 to 20 carbon atoms, and a substituted or unsubstituted C 6 To 20 arylamine groups, and R ₃ to R ₅ are independently hydrogen, a substituted or unsubstituted C 1 to C 20 alkyl group, a substituted or unsubstituted C 1 to C 20 alkoxy group, substituted or unsubstituted Is selected from the group consisting of a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heteroaryl group having 5 to 30 carbon atoms, and a substituted or unsubstituted amine group having 1 to 20 carbon atoms, l and m are independently 0 Is an integer of 2, n is an integer of 1 to 3, and l+m+n is 3 or less.)
The method of claim 1,
In Formula 1, X is nitrogen (N), and n is a fluorescent material, characterized in that 1.
The method of claim 1,
In Formula 1, Y ₁ to Y ₅ are independently CR ₆ or N, _{at least one of Y 1} to Y ₅ is N, and R ₆ is an aryl group having 6 to 18 carbon atoms, or a substituted or unsubstituted carbon number A fluorescent material characterized in that it is a 6 to 18 heteroaryl group.
The method of claim 1,
In Formula 1, R ₁ and R ₂ are independently selected from the group consisting of hydrogen, an aryl group having 6 to 18 carbon atoms, and a heteroaryl group having 6 to 18 carbon atoms.
The method of claim 1,
In Formula 1, R ₃ to R ₅ are independently hydrogen or one of the following Formulas 2-1 to 2-21.
[Formula 2-1]

[Formula 2-2]

[Formula 2-3]

[Formula 2-4]

[Formula 2-5]

[Formula 2-6]

[Formula 2-7]

[Formula 2-8]

[Formula 2-9]

[Formula 2-10]

[Chemical Formula 2-11]

[Formula 2-12]

[Formula 2-13]

[Formula 2-14]

[Formula 2-15]

[Formula 2-16]

[Formula 2-17]

[Formula 2-18]

[Chemical Formula 2-19]

[Formula 2-20]

[Formula 2-21]

The method of claim 1,
Formula 1 is a fluorescent material, characterized in that one of formulas 1-1 to 1-16.
[Formula 1-1]

[Formula 1-2]

[Formula 1-3]

[Formula 1-4]

[Formula 1-5]

[Formula 1-6]

[Formula 1-7]

[Formula 1-8]

[Formula 1-9]

[Formula 1-10]

[Formula 1-11]

[Formula 1-12]

[Formula 1-13]

[Formula 1-14]

[Formula 1-15]

[Formula 1-16]

A first electrode; A second electrode; And a light emitting layer positioned between the first electrode and the second electrode,
An organic light-emitting diode comprising the fluorescent material according to any one of claims 1 to 6 in the light-emitting layer.
The method of claim 7,
The light emitting layer is an organic light emitting diode comprising a dopant material, a host material, or both.
The method of claim 7,
The emission layer is mCP (N,N-dicarbazolyl-3,5-benzene), DPEPO ((bis 2-(diphenylphosphino)phenyl] ether oxide), Alq3 (tris (8-quinolinolate) aluminum), CBP (4, 4'-N,N'-dicarbazol-biphenyl), 9,10-di(naphthalen-2-yl)anthracene, TPBI(1,3,5-tris(N-phenylbenzimidazole-2-yl)benzene)), TBADN (3-tert-butyl-9,10-di(naphth-2-yl) anthracene) and mCBP(3,3'-Di(9H-carbazol-9-yl)-1,1'-biphenyl) Organic light-emitting diode, characterized in that at least one selected from the group.
The method of claim 7,
The fluorescent material is an organic light-emitting diode comprising 10 to 90% by weight based on the total 100% by weight of the emission layer.