KR100754474B1 - Anthracene-based organic light emitting compound and organic light emitting diode comprising same - Google Patents

Abstract

Disclosed are a 9- [4- (10H-anthracene-9-ylidenemethyl) -phenyl] -anthracene-based organic light emitting compound which emits light of high efficiency and has excellent thermal stability and film forming process, and an organic light emitting diode comprising the same. The organic light emitting compound has the following formula, and the organic light emitting diode includes a first electrode having a high work function, a second electrode having a low work function, and the organic light emitting compound, It further includes at least one organic compound layer located between.

In the above formula, R ₁ to R ₈ are each independently hydrogen, substituted or unsubstituted aryl group having 4 to 30 carbon atoms or alkenyl group having 2 to 10 carbon atoms, and A ₁ , A ₂ , B ₁ and B ₂ are each Independently hydrogen, an alkyl group having 1 to 4 carbon atoms, a substituted or unsubstituted aryl group having 4 to 24 carbon atoms, a heteroaryl group or a heterocyclic group, L is a benzene group, a pyrene group, a naphthalene group, a perylene group, an anthracene group And fluorene groups.

Organic light emitting compound, organic light emitting diode, heat resistance, film forming, light emitting

Description

Anthracene based organic luminescent compound and organic light-emitting diode including the same}

1 is a cross-sectional view of an organic light emitting diode according to an embodiment of the present invention.

2 is a cross-sectional view of an organic light emitting diode according to another embodiment of the present invention.

The present invention relates to a novel organic light emitting compound and an organic light emitting diode including the same, and more particularly, 9- [4- (10H-anthracene-9-ylidene), which emits light of high efficiency and has excellent thermal stability and film forming processability. Methyl) -phenyl] -anthracene-based organic light emitting compound and an organic light-emitting diode (OLED) including the same.

Organic Light-Emitting Diodes (OLEDs), commonly referred to as EL (Electroluminescence Devices), are liquid crystal displays (LCDs), plasma display panels (PDPs), and field emission displays (Fields). Emission Display (FED) is one of the representative flat panel display devices, and it does not need backlight for emitting light, and it is possible to manufacture the device in the form of thin film and bend, and it is easy to form patterns and mass production by film manufacturing technology. There is an advantage. In addition, since EL is a spontaneous light emitting device, it has the advantage of excellent luminance and viewing angle characteristics, fast response speed, low driving voltage, and theoretically light emission of all colors in the visible region.

The organic light emitting diode forms an organic light emitting layer having a light emitting property between a transparent electrode such as ITO having a large work function and a metal electrode such as Mg having a small work function, and applies a voltage to the electrode to generate holes and electrons at each electrode. When the organic light emitting layer is bonded to the organic light emitting layer, the organic light emitting layer generates light. As the material capable of forming the organic light emitting layer of the organic light emitting diode, conductive, non-conductive or semiconducting organic monomolecules, oligomers, or polymers may be used. Conjugated organic host materials with conjugated rings and conjugated organic activators are known. Typical examples of the organic host material include naphthalene, anthracene, phenanthrene, pyrene, benzopyrene, chrisene, picene, carbazole (carbazole), fluorene, biphenyl, terphenyl, qurterphenyl, triphenylene oxide, dihalobiphenyl, transstilbene ), 1,4-diphenyl butadiene, and the like, anthracene, tetracene, pentacene, and the like are known. However, the light emitting layer formed by using such a typical light emitting organic single molecule has a disadvantage that the thickness of the light emitting layer is 1 μm or more, and the light emitting layer has a high resistance and a high driving voltage. Therefore, various types of organic monomolecules have been developed that can reduce the thickness of the light emitting layer and lower the resistance and driving voltage of the light emitting layer. Typically, alumina quinone (Alq ₃ ), BeBq ₂ , Almq, Metal complex compounds such as ZnPBO and Balq which luminesce in the blue region (460 nm), and 4- (dicymethylene) -2-methyl-6- (p-dimethylaminostyryl) which luminesces in the red region 590 nm -4H-pyran (4- (dicyanomethylene e) -2-methyl-6- (p-dimethyl aminostyryl) -4H-pyran (DCM)), a DC series of DC series which emits light at 630 nm, etc. are known. Recently, a color light emitting layer has been developed and used to improve the luminous efficiency and durability by forming a guest-host doping system by mixing a host material having sufficient electron, hole mobility, and luminescence with a dopant having various hues. have. However, the organic light emitting compounds are still required to improve thermal stability, film forming processability and electroluminescent efficiency.

Accordingly, an object of the present invention is to provide an organic light emitting compound having excellent thermal stability and film forming processability, and an organic light emitting diode including the same.

Another object of the present invention is to provide an organic light emitting compound which emits light of high efficiency and an organic light emitting diode including the same.

In order to achieve the above object, the present invention provides an organic light emitting compound represented by the following formula (1). The present invention also includes a first electrode having a high work function, a second electrode having a low work function, and the organic light emitting compound, and including at least one organic compound layer positioned between the first and second electrodes. It provides an organic light emitting diode. The organic compound layer may be a light emitting layer, a hole injection layer, a hole transport layer, an electron injection layer or an electron transport layer, the organic light emitting compound may be used as a host or dopant material of the light emitting layer.

[Formula 1]

In Formula 1, R ₁ to R ₈ are each independently hydrogen, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms or an alkenyl group having 2 to 10 carbon atoms, and A ₁ , A ₂ , B ₁ and B ₂ are Each independently hydrogen, an alkyl group having 1 to 4 carbon atoms, a substituted or unsubstituted aryl group having 6 to 24 carbon atoms, a heteroaryl group having 4 to 24 carbon atoms or a heterocyclic group, OR, NR ₂ or SR (R = hydrogen, halogen, alkyl having 1 to 12 carbon atoms, aromatic ring, substituted or unsubstituted aryl group having 6 to 24 carbon atoms, heteroaryl group having 4 to 24 carbon atoms or heterocylic group) Heterocyclic group, L is a benzene group, a pyrene group, a naphthalene group, a perylene group, an anthracene group, 9,9'-spirobifluorene ( 9,9'-Spirobifluorene) or fluorene group.

Hereinafter, with reference to the accompanying drawings, described in detail the present invention.

The organic light emitting compound according to the present invention is 9- [4- (10H-anthracene-9-ylidenemethyl) -phenyl] -anthracene {9- [4- (which emits light by receiving energy generated by recombination of electron-holes. 10H-Anthracen-9-ylidenemethyl) -phenyl] -anthracene} -based compound having the structure of Formula 1.

In Formula 1, R ₁ to R ₈ are each independently hydrogen, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms or an alkenyl group having 2 to 10 carbon atoms, and A ₁ , A ₂ , B ₁ and B ₂ are Each independently hydrogen, an alkyl group having 1 to 4 carbon atoms, a substituted or unsubstituted aryl group having 6 to 24 carbon atoms, a heteroaryl group having 4 to 24 carbon atoms or a heterocyclic group, OR, NR ₂ or SR is hydrogen, halogen, alkyl having 1 to 12 carbon atoms, alkene, aromatic ring, substituted or unsubstituted aryl group having 6 to 24 carbon atoms, heteroaryl group having 4 to 24 carbon atoms or Heterocyclic group, adjacent A ₁ and A ₂ may be bonded to each other to form a ring, wherein L is a benzene group, a pyrene group, a naphthalene group, a perylene group , Anthracene groups, 9,9'-spirobifluorene (9,9'-Spir It is an obifluorene group or a fluorene group.

The substituents of R ₁ to R ₈ may be substituted or unsubstituted alkyl group having 1 to 24 carbon atoms, alkoxy group having 1 to 20 carbon atoms, aryloxy group having 1 to 30 carbon atoms, alkyldioxy group having 1 to 20 carbon atoms, and 6 to 6 carbon atoms. An arylthioxy group having 30, an arylalkyl group having 7 to 30 carbon atoms, a monocyclic group having 5 to 30 carbon atoms, a condensed polycyclic group having 10 to 30 carbon atoms, a heteroaryl or heteroalkyl group having 5 to 30 carbon atoms, or an alkenyl group having 4 to 40 carbon atoms to be. In addition, the L may be substituted with a substituent, if necessary, for example, the substituent of the fluorene is preferably methyl, butyl, t-butyl, isopropyl or phenyl, the substituent of the benzene is a diarylamine Substituents are preferred.

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등을 예시할 수 있다. 여기서, C₁ 및 C₂는 각각 독립적으로 수소, 메틸, 부틸, t-부틸, 이소프로필 또는 페닐기이다.Preferred examples of the organic light emitting compound according to the present invention are

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Etc. can be illustrated. Wherein C ₁ and C ₂ are each independently hydrogen, methyl, butyl, t-butyl, isopropyl or a phenyl group.

In the organic light emitting compound according to the present invention, since the emission wavelength and charge / hole injection / transport characteristics change according to the substituents substituted in the basic skeleton of the compound represented by Chemical Formula 1, the desired emission wavelength and charge transfer characteristics by appropriately selecting the substituents The organic compound layer which has physical properties, such as these, can be formed. The organic light emitting compound according to the present invention has excellent thermal stability and film forming processability, which not only improves the lifespan and productivity of the light emitting device, but also emits light of high efficiency and high quality.

The organic light emitting compound according to the present invention is a Suzuki coupling of 9- [4- (10H-anthracene-9-ylidenemethyl) -phenyl] -10-bromo-anthracene derivative and boronic acid compound. Can be synthesized. The 9- [4- (10H-anthracene-9-ylidenemethyl) -phenyl] -10-bromo-anthracene derivative may be prepared by various organic synthesis methods, for example, a Grignard reaction. Mg and 4-bromobenzylbromide were reacted to obtain 4-bromobenzylmagnesium bromide, which was reacted with anthrone, followed by a dehydration reaction, and the obtained product was reacted with trimethyl borate to give 9- (4 -Boronic acid-benzylidene) -9,10-dihydro-anthracene can be synthesized, and then obtained again by a Suzuki reaction with 9,10-dibromoanthracene.

1 illustrates a cross-sectional view of an organic light emitting diode according to an embodiment of the present invention. As shown in FIG. 1, the organic light emitting diode includes a first electrode 12 having a high work function on the substrate 10. It is formed as a hole injection electrode (anode), and the light emitting layer 14 including the organic light emitting compound according to the present invention is formed on the first electrode 12. In addition to the organic light emitting compound according to the present invention, the light emitting layer 14 may further include a conventional organic light emitting compound such as Alq ₃ , a conventional fluorescent dye and / or a dopant. When the compound of the present invention is used as a dopant with a conventional host material such as 9,10-di (2-naphthyl) anthracene (9,10-di (2-naphthyl) anthracene: ADN), the dopant The content of is preferably 1 to 20% by weight, more preferably 5 to 10% by weight relative to the entire host / dopant mixture. A second electrode 16 having a low work function is formed on the emission layer 14 so as to face the first electrode 12 as an electron injection electrode (cathode). When voltage is applied to the first and second electrodes 12 and 16 of the organic light emitting diode, holes and electrons generated in the first and second electrodes 12 and 16 are injected into the light emitting layer 14, and the light emitting layer In the molecular structure of (14), electrons and holes are combined to emit light, and the emitted light passes through the first electrode 12 and the substrate 10 made of a transparent material to display an image. The substrate 10 of the organic light emitting diode is electrically insulative, and in particular, when fabricating a device emitting light toward the first electrode 12, the substrate 10 is made of a transparent material, preferably made of glass or transparent plastic film. The first electrode 12 may be made of indium tin oxide (ITO), polyaniline, silver (Ag), and the like, and the second electrode 16 may be made of Al, Mg, Ca, or LiAl, Mg-Ag. It may be made of a metal alloy such as.

FIG. 2 is a cross-sectional view of an organic light emitting diode according to another embodiment of the present invention. In the organic light emitting diode illustrated in FIG. 2, holes and electrons generated in the first and second electrodes 12 and 16 are respectively formed in the light emitting layer 14. The hole injection and transport layers 21 and 22 and the electron injection and transport layers 25 and 26 are further formed so that they can be easily injected into the? The hole injection and transport layers 21 and 22 have a function of facilitating the injection of holes from the hole injection electrode 12 and a function of stably transporting the holes, and the hole injection layer 21 is not limited to the US. Porphyrinic compounds such as phthalocyanine copper disclosed in patent 4,356,429, for example m-MTDATA (4,4 ', 4 "-tris (3-methylphenylphenylamino) triphenylamine), The hole transport layer 22 is NPB (N, N'-diphenyl-N, N'-bis (1-naphthyl) -1,1'-biphenyl) -4,4'-diamine), triphenyldiamine Derivatives, styrylamine derivatives, α-NPD (N, N'-diphenyl-N, N'-bis (α-naphthyl)-[1,1'-biphenyl] 4,4'-diamine) It can be formed using a conventional amine derivative having an aromatic condensed ring The electron injection and transport layer (25, 26) has a function to facilitate the injection of electrons from the electron injection electrode 16 and to stabilize the electrons. As a function to transport, without limitation, keys Quinoline derivatives, in particular, the conventional compounds such as tris (8-kinol Reno rate) aluminum (alumina quinone, Alq ₃₎ may be used to form the electron transport layer 26 These layers 21, 22, 25, and 26 function to augment, confine, and combine the holes and electrons injected into the light emitting layer 14. The light emitting layer 14, the hole injection and transport layer The thicknesses of the 21 and 22 and the electron injection and transport layers 25 and 26 are not particularly limited and vary depending on the formation method, but usually have a thickness of about 5 to 500 nm.

The organic light emitting compound according to the present invention may be used as a host or dopant material of the light emitting layer 14, and according to the potential difference with other layers, the hole injection and transport layers 21 and 22 and / or the electron injection and transport layer ( 25, 26), it may also function to inject / transport electrons and holes. The organic layers may be formed by a vacuum deposition method, a spin coating method, or the like, which is commonly used for fabricating an organic light emitting diode. The organic light emitting compound of the present invention can be applied not only to the organic light emitting diode having the structure shown in FIG. 1 or 2 but also to organic electroluminescent devices and various semiconductor devices having various structures that exhibit light emission by hole-electron coupling. The structure of such various organic light emitting diodes is disclosed, for example, in US Pat. Nos. 4,539,507, 5,151,629, and the like.

Next, a preferred embodiment for helping understanding of the present invention is presented. However, the following examples are intended to illustrate the invention, not to limit the invention.

Example 1 Synthesis of Organic Light Emitting Compound

end. Synthesis of 9- (4-bromo-benzylidene) -9,10-dihydro-anthracene

As shown in Scheme 1, 6.26 g (257.43 mmol) of magnesium (Mg) and 100 ml of tetrahydrofuran (THF) were added to a reactor in a nitrogen atmosphere, and 64.34 g (4-bromobenzylbromide) of 64.34 g (257.43 mmol) was added. ) Was added dropwise to 300 ml of THF, and then reacted at 55 ° C. for 1 hour. After the reaction was completed, a mixture of 25 g (128.71 mmol) of anthrone was dissolved in 300 ml of THF, and then reacted at 40 ° C. for 14 hours. After the reaction was completed, the reaction was cooled to room temperature, filtered and the remaining solid was placed in 1 L of cold 10% NH ₄ Cl solution, stirred at room temperature for 3 hours, and the reaction was filtered again. filtered and put into the reaction (B) of the rest of the solid in toluene (toluene) 100ml, p - toluene sulphonic Acid mono hydrate (p -toluenesulfonic acid (PTSA) monohydrate ) 0.1g , and refluxed for 3 hours (reflux) After reaction, the refluxed reaction was filtered. The filtered reaction was washed with 2% Na ₂ CO ₃ and dried to give 9- (4-bromo-benzylidene) -9,10-dihydro-anthracene (9- (4-Bromo-benzylidene) -9,10 -dihydro-anthracene) was synthesized in 50% yield.

I. Synthesis of 9- (4-boronic acid-benzylidene) -9,10-dihydro-anthracene

As shown in Scheme 2 below, 2.2 g (7.12 mmol) of 9- (4-bromo-benzylidene) -9,10-dihydro-anthracene was dissolved in 40 ml of tetrahydrofuran (THF), and at -90 ° C. 5.34 ml of n-butyllithium (n-BuLi) was added and then stirred for 30 minutes. After the reaction was completed, 2.2 ml (21.36 mmol) of trimethyl borate was added dropwise to the reaction, stirred at −90 ° C. for 20 minutes, and ether / water (ether / H ₂ O) was added thereto, and the organic layer was added. 9- (4-boronic acid-benzylidene) -9,10-dihydro-anthracene (9- (4-boronic acid-benzylidene) -9,10-dihydro-anthracene) was obtained in 70% yield. Synthesized.

All. Synthesis of 9- [4- (10H-anthracene-9-ylidenemethyl) -phenyl] -10-bromo-anthracene

As shown in Scheme 3 below, 0.42 g (1.26 mmol) of 9,10-dibromoanthracene (9,10-dibromoanthracene), 0.072 g of palladium catalyst (Pd (PPh ₃ ) ₄ ), and a phosphorus compound ((t-Bu) ) ₃ P, Bu = butyl) was dissolved in 20 ml of dimethyl ether (DME) and stirred at room temperature for 30 minutes. After stirring was completed, 0.47 g (1.51 mmol) of 9- (4-boronic acid-benzylidene) -9,10-dihydro-anthracene and 0.6 ml of Na ₂ CO ₃ (2M in water) were added to the stirring solution, It was refluxed for overnight. After the reaction was completed, the reaction was cooled to room temperature and sublimated at 160 ° C. to yield 9- [4- (10H-anthracene-9-ylidenemethyl) -phenyl] -10-broken as a pale yellow solid. Mo-anthracene (9- [4- (10H-Anthracen-9-ylidenemethyl) -pheny l] -10-bromo-anthracene) was synthesized in 60% yield.

la. Synthesis of 9- [4- (10H-anthracene-9-ylidenemethyl) -phenyl] -10-naphthalen-2-yl-anthracene

9- [4- (10H-anthracene-9-ylidenemethyl) -phenyl] -10-bromo-anthracene (0.9 g, 1.72 mmol), as in the Suzuki coupling method shown in Scheme 4 below, 0.057 g of palladium catalyst (Pd (PPh ₃ ) ₄ ) and 0.04 g of phosphorus compound ((t-Bu) ₃ P, Bu = butyl) were dissolved in 20 ml of dimethyl ether (DME) and stirred at room temperature for 30 minutes. After stirring was completed, 0.36 g (2.1 mmol) of Naphthyl boronic acid and 0.6 ml of Na ₂ CO ₃ (2M in water) were added to the stirring solution, and the mixture was refluxed for 12 hours. After the reaction was completed, the reaction was cooled to room temperature and sublimated at 270 ° C. to give 9- [4- (10H-anthracene-9-ylidenemethyl) -phenyl] -10-naphthalen-2-yl- Anthracene (9- [4- (10H-Anthracen-9-ylidenemethyl) -phenyl] -10-naphalen-2-yl-anthracene) was synthesized in 70% yield (molecular weight (GC / Mess): 570).

Example 2 Fabrication of Organic Light Emitting Diode

The glass substrate coated with indium tin oxide (ITO) was ultrasonically cleaned, and again washed with deionized water, then degreased with toluene gas and dried. Next, m-MTDATA was deposited on the ITO electrode to form a hole injection layer by vacuum deposition at a thickness of 300 kW, and α-NPD was vacuum deposited on the hole injection layer to a thickness of 300 kW to form a hole transport layer. 9- [4- (10H-anthracene-9-ylidenemethyl) -phenyl synthesized in Example 1 as a host and 9,10-di (2-naphthyl) anthracene as a host on top of the hole transport layer. After mixing -10-naphthalen-2-yl-anthracene (mixing amount: 5% by weight), the film was deposited at a thickness of 300 kPa, and Alq ₃ was deposited at a thickness of 200 kPa as an electron transporting layer on top of the organic light emitting layer thus formed. Further, an organic light emitting diode was manufactured by forming an electron injection layer by vacuum depositing LiF to a thickness of 10 μm on the electron transport layer, and forming a cathode by depositing Al to 1200 μm thickness on the electron injection layer. The light emitting color coordinates of the manufactured organic light emitting diodes were (0.14, 0.14), and the luminous efficiency was 2.1 lm / W at 10 mA / cm ^2. The organic light emitting diodes produced high quality blue light, and showed excellent luminous efficiency. Differential Scanning Calorimetry (DSC) was Tm = 300.09 ° C., which showed excellent thermal stability.

As described above, the organic light emitting compound according to the present invention not only has excellent thermal stability and film forming processability, but also improves the lifetime and productivity of the light emitting device, and has the advantage of high efficiency and high quality light emission. The organic light emitting compound according to the present invention is particularly useful for the production of full color organic light emitting diodes, and includes field effect transistors, photodiodes, photovoltaic cells, solar cells, and organic lasers. Organic laser), laser diode (Laser Diode) and the like can be widely applied to the manufacture of various semiconductor devices.

Claims (5)

An organic light emitting compound represented by Formula 1 below. [Formula 1]

In Formula 1, R ₁ to R ₈ are each independently hydrogen, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms or an alkenyl group having 2 to 10 carbon atoms, and A ₁ , A ₂ , B ₁ and B ₂ are Each independently hydrogen, an alkyl group having 1 to 4 carbon atoms, a substituted or unsubstituted aryl group having 6 to 24 carbon atoms, a heteroaryl group having 4 to 24 carbon atoms, or a heterocyclic group, OR, NR ₂ or SR (R = hydrogen, Halogen, an alkyl group having 1 to 12 carbon atoms, an alkene group, an aromatic ring, a substituted or unsubstituted aryl group having 6 to 24 carbon atoms, a heteroaryl group having 4 to 24 carbon atoms or a heterocyclic group), and L is a benzene group or a pyrene Group, naphthalene group, perylene group, anthracene group, 9,9'-spirofluorene group, or fluorene group. The method of claim 1, wherein the organic light emitting compound

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And

Wherein C ₁ and C ₂ are each independently hydrogen, methyl, butyl, t-butyl, isopropyl or phenyl. A first electrode having a high work function;  A second electrode having a low work function; And An organic light emitting diode comprising an organic light emitting compound of Formula 1 and comprising at least one organic compound layer positioned between the first and second electrodes. [Formula 1]

In Formula 1, R ₁ to R ₈ are each independently hydrogen, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms or an alkenyl group having 2 to 10 carbon atoms, and A ₁ , A ₂ , B ₁ and B ₂ are Each independently hydrogen, an alkyl group having 1 to 4 carbon atoms, a substituted or unsubstituted aryl group having 6 to 24 carbon atoms, a heteroaryl group having 4 to 24 carbon atoms, or a heterocyclic group, OR, NR ₂ or SR (R = hydrogen, Halogen, an alkyl group having 1 to 12 carbon atoms, an alkene group, an aromatic ring, a substituted or unsubstituted aryl group having 6 to 24 carbon atoms, a heteroaryl group having 4 to 24 carbon atoms or a heterocyclic group), and L is a benzene group or a pyrene Group, naphthalene group, perylene group, anthracene group, 9,9'-spirofluorene group, or fluorene group. The organic light emitting diode of claim 3, wherein the organic compound layer is selected from the group consisting of a light emitting layer, a hole injection layer, a hole transport layer, an electron injection layer, or an electron transport layer. The organic light emitting diode of claim 3, wherein the organic light emitting compound is used as a host or dopant material of the light emitting layer.

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