KR20060080282A - Anthracene based organic light-emitting compound and organic light-emitting diode including the same - Google Patents

Abstract

Disclosed are an anthracene-based organic light emitting compound that emits high efficiency and high quality and has excellent thermal stability, and an organic light emitting diode including 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, At least one organic compound layer located between.

In the above formula, R ₁ is a substituted or unsubstituted aryl group having 4 to 60 carbon atoms or a substituted or unsubstituted alkenyl group having 2 to 10 carbon atoms, R ₂ to R ₁₁ may be the same or different from each other, H, CN , Halogen, CO ₂ R, OR, NR ₂ , SR (R is H, alkyl, alkene, alkyne, aryl group, heteroaryl group or heterocyclic group), substituted or unsubstituted aryl having 4 to 24 carbon atoms Group, heteroaryl group, heterocyclic group or conjugated ring group.

Blue, light emitting organic compound, organic light emitting diode, heat resistance, stability

Description

Anthracene based organic light emitting compound and organic light emitting diode comprising 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 an organic light emitting compound and an organic light emitting diode (OLED) including the same, and more particularly to an anthracene-based organic light emitting compound having excellent thermal stability and film forming process, and an organic light emitting diode including the same. It is about.

Organic Light-Emitting Diodes (OLEDs), also commonly called EL (Electroluminescence Devices), are liquid crystal displays (LCDs), plasma display panels (PDPs), field emission displays (Field Emissions). As one of the representative flat panel display devices with Display: FED, etc., it does not need a backlight for light emission, it is possible to manufacture a device in a thin film and bendable form, and it is easy to form patterns and mass production by film manufacturing technology. There is this. 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 When the electrons combine in the organic light emitting layer, the organic light emitting layer uses the property of generating light. Various organic compounds for forming such an organic light emitting layer are known, for example, US Patent No. 6,455,720 discloses a 2,2- (diaryl) vinylphosphine-based light emitting compound In addition, Korean Patent Publication No. 2002-70333 discloses a blue light emitting compound in which a central portion has a diphenylanthracene structure and an aryl group is substituted at the terminal. See also J. Am. Chem. Soc. 2000. 122, pp. 5695-5109 (Shujun Wang, Warren J. Oldham Jr., Raymond A. Hudack, Jr., and Guillermo C. Bazan) describe the synthesis, properties, and optical properties of materials with tetrahedraloligo (phenylenevinylene) structures. And Angew. Chem. Int. Ed. 2001, 40, (21), pp. 4042-4045 (Jun Pang, Eric JP Marcotte, Corey Seward, R. Stephen Brown, Suning wang) discloses a star Zn ^II complex blue luminescent material, Chem. Mater . In 2004, vol 16, 1896-1877 (Junghyun Lee, Qin-De Liu, Michael Motala, Justin Dane, Jun Gao, Youngjin Kang, and Suning Wang) contained N-7-azaindoryl and 2,2'-dipyridyl. The fluorescence and electroluminescent properties of N-7-azaindolyl and 2,2'-dipyridylamino-functionalized Siloles compounds are disclosed, see Chem. Comn. 2002, pp 2424-2425. (Joseph Frey, Andrew D. Bond, and Andrew B. Holmes) include dithieno [3,2-b: 2 ', 3'd]. thiophene: DTT) and derivatives thereof are disclosed, and Macromolecules, 2001, 34, pp 5860-5867 (Jianping Lu, Kenji Miyatake, Antisar R. Hill and Allan S. Hay) disclose p-quaterphenyl Or poly (arylene ether) water-soluble fluorescent substance comprising 2,5-bis (4-phenylphenyl) triazole group. However, such a conventional blue organic light emitting compound has a disadvantage in that heat resistance is not sufficient, control of emission color is not easy, or the synthesis process is complicated. In addition, US Pat. Nos. 5,130,603 and 6,251,531 disclose arylene compounds and anthracene compounds, respectively, and are represented by trade names IDE-102 and IDE-105 of Idemitsukosan as arylene compounds disclosed in US Pat. The organic compound may not have sufficient thermal stability such as heat resistance, and may not emit high efficiency and high quality blue light.

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.

It is another object of the present invention to provide a blue organic light emitting compound and a light emitting organic light emitting diode including the same.

In order to achieve the above object, the present invention provides a novel organic light emitting compound having the structure of 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, and the organic compound may be used as a host or dopant material of the light emitting layer.

[Formula 1]

In Formula 1, R ₁ is a substituted or unsubstituted aryl group having 4 to 60 carbon atoms or a substituted or unsubstituted alkenyl group having 2 to 10 carbon atoms, R ₂ to R ₁₁ may be the same or different from each other, H, CN, halogen, CO ₂ R, OR, NR ₂ , SR (R is H, alkyl, alkene, alkyne, or substituted or unsubstituted aryl, heteroaryl or heterocyclic group having 4 to 24 carbon atoms.) , A substituted or unsubstituted aryl group, heteroaryl group, heterocyclic group or a conjugated ring group having 4 to 24 carbon atoms.

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

The organic light emitting compound according to the present invention is an anthracene-based compound which emits light by receiving energy generated by recombination of electron-holes, and has a structure represented by the following Chemical Formula 1.

In Formula 1, R ₁ is a substituted or unsubstituted aryl group having 4 to 60, preferably 6 to 36 carbon atoms or a substituted or unsubstituted alkenyl group having 2 to 10 carbon atoms, R ₂ to R ₁₁ are May be the same or different, H, CN, halogen, CO ₂ R, OR, NR ₂ , SR (R is H, alkyl of 1 to 20 carbon atoms, alkene or alkyne, or substituted or unsubstituted aryl of 4 to 24 carbon atoms) (aryl) group, heteroaryl group or heterocyclic group), substituted or unsubstituted aryl group having 4 to 24 carbon atoms, heteroaryl group, heterocyclic group or conjugate ring (fused ring) group.

Here, the substituent is an alkyl group having 1 to 24 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, aryloxy having 1 to 30 carbon atoms, alkyldioxy having 1 to 20 carbon atoms, alkyl or arylamine group having 1 to 30 carbon atoms, 6 carbon atoms An allyl thioxyl group having 30 to 30 carbon atoms, an arylalkyl group having 7 to 30 carbon atoms, a monocyclic group having 5 to 30 carbon atoms, a conjugated ring group having 10 to 30 carbon atoms, a heterocyclic group having 5 to 30 carbon atoms or a heteroaryl group, and carbon atoms As an alkenyl group or cyano group (CN) of 4-40, it may be substituted or unsubstituted.

Preferred examples of the organic light emitting compound according to the present invention are those having the structure of Formula 2 or 3.

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등을 예시할 수 있다. In Formula 2, R ^* is a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted arylamine group having 6 to 30 carbon atoms, or a substituted or unsubstituted alkenyl group having 2 to 10 carbon atoms, R ₂ to R ₁₁ and the substituents are as defined in the formula (1). Specific examples of the organic light emitting compound represented by Formula 2

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Etc. can be illustrated.

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(상기 식들에서, R은 H, 또는 포화 또는 불포화 탄화수소로서, 탄소수는 바람직하게는 1 내지 20개이다.) 등을 예시할 수 있다.In Chemical Formula 3, R ₂ to R ₁₁ are the same as defined in Chemical Formula 1, and L is a substituted or unsubstituted aryl group, heteroaryl group or conjugated ring having 4 to 60 carbon atoms, preferably 6 to 36 carbon atoms, as a linking group. Or a substituted or unsubstituted alkenyl group having 2 to 40 carbon atoms, and may include heterogeneous elements such as S, O, and N as necessary, and n is an integer of 2 to 4. Specific examples of the light emitting organic compound represented by Formula 3

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(In the above formula, R is H, or a saturated or unsaturated hydrocarbon, carbon number is preferably 1 to 20.) and the like.

The organic light emitting compound according to the present invention changes the emission wavelength and the electron / hole injection / transport characteristics according to the type of the substituent or linker substituted in the compound represented by the formula (1), so that by selecting the appropriate substituent or linker An organic compound layer having physical properties such as emission wavelength, charge transfer characteristics, and the like can be formed. The organic light emitting compound according to the present invention has excellent heat resistance and not only improves lifespan and productivity of the light emitting device, but also emits light of high efficiency and high quality. The luminescent anthracene-based compound according to the present invention can be prepared by various known organic synthesis methods, such as the Wittig reaction, the Grignard reaction as disclosed in US Patent No. 5,130,603, and the like.

1 is a cross-sectional view of an organic light emitting diode according to an exemplary embodiment of the present invention. As shown in FIG. 1, an organic light emitting diode has a hole formed in a first electrode 12 having a high work function on the substrate 10. A light emitting layer 14 including a light emitting organic compound according to the present invention is formed on the first electrode 12 and formed as a hole injection electrode (anode). In addition, the light emitting layer 14 may include a conventional host, a conventional light emitting compound, a fluorescent dye, and / or a dopant together with the light emitting organic compound according to the present invention. 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 based on the entire host / dopant. 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), or the like, and the second electrode 16 may be formed of a metal such as Al, Mg, Ca, or LiAl, It may be made of a metal alloy such as Mg-Ag.

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 ( The hole injection and transport layers 21 and 22 and the electron injection and transport layers 25 and 26 are further formed so as to be easily injected into 14), which is different from the organic light emitting diode shown in FIG. 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 of transporting, non-limiting but not limited chinoline derivatives, in particular, conventional electron injection and transport compounds such as tris (8-quinolinorate) aluminum (aluminaquinone, Alq3), LiF, form the electron transport layer 26. These layers 21, 22, 25, and 26 function to augment, confine, and combine holes and electrons injected into the light emitting layer 14, and to improve luminous efficiency. The thickness of the hole injection and transport layers 21 and 22 and the electron injection and transport layers 25 and 26 is not particularly limited, and depending on the formation method, the thickness is usually 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, and is particularly useful as a major injection layer. 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 electroluminescent device, and may be preferably formed by a vacuum deposition method. 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. Such structures of various organic light emitting diodes are disclosed in, for example, US Pat. Nos. 4,539,507, 5,151,629, 6,214,481, 6,387,544, and the like.

Next, preferred examples are provided to help understanding of the present invention. However, the following examples are intended to illustrate the invention, not to limit the invention. In the examples below all experiments were performed in an inert atmosphere such as a nitrogen atmosphere.

Example 1 Synthesis of Organic Light Emitting Compound

A. Synthesis of 7- (4-bromo-benzylidene) -7H-benzo [de] anthracene (7- (4-Bromo-benzylidene) -7H-benzo [de] anthracene: BBA)

To a solution of 6.26 g (257.43 mmol) of Mg in 100 ml of tetrahydrofuran (THF), a solution of 64.34 g (257.43 mmol) of 4-bromobenzylbromide in 300 ml of THF was dropped dropwise, followed by 55 ° C. The reaction was carried out for 1 hour at. Next, as shown in Scheme 1 below, benzanthrone 29.64 g (128.71 mmol, benzanthrone) was dissolved in 300 ml of THF and dropped dropwise, and reaction was performed at 40 ° C. for 14 hours when the dropping of benzanthrone was completed. After the reaction was completed, the temperature of the reaction solution was lowered to room temperature, filtered, and the filtered solid was stirred in 1 L of cold 10% NH ₄ Cl solution for 3 hours. The solid was filtered again, and 100 ml of toluene was added with 0.1 g of p-toluenesulfonic acid monohydrate, followed by reflux for 3 hours, and the reaction solution was cooled to room temperature, followed by 2% Na. _It was washed with ₂ CO ₃ and dried to give 7- (4-bromo-benzylidene) -7H-benzo [de] anthracene in a yield of 50%.

B. Synthesis of 7- (4-boronic acid-benzylidene) -7H-benzo [de] -anthracene (7- (4-boronic acid-benzylidene) -7H-benzo [de] anthracene)

As shown in Scheme 2 below, 2.7 g (7.12 mmol) of 7- (4-bromo-benzylidene) -7H-benzo [de] anthracene obtained in Step A was dissolved in 40 ml of THF, and 5.34 ml of n-butyllithium (BuLi) was added and then stirred at the same temperature for 30 minutes. 2.2 ml (21.36 mmol) of trimethyl borate was added dropwise to the solution, followed by stirring at −90 ° C. for 20 minutes. Next, an ether / water (volume ratio: 50/50) mixture was added, and the organic layer was immediately separated and used in the next reaction, wherein 7- (4-boronic acid-benzylidene) -7H-benzo [de] -anthracene The yield of was 70%.

C. Synthesis of Organic Light Emitting Compound (BBA-dimer)

As shown in Scheme 3 below, 3.3 g (8.64 mmol) of 7- (4-bromo-benzylidene) -7H-benzo [de] anthracene obtained in Step A, 7- (4-boro obtained in Step B) Nixane-benzylidene) -7H-benzo [de] -anthracene 3.61 g (10.37 mmol), Pd (PPh ₃ ) ₄ 0.36 g (0.3 mmol) and 6.5 ml of 2M Na ₂ CO ₃ aqueous solution were mixed with 24 ml of toluene and 4 ml of ethanol. The solution was placed in a solution, reacted at 90 ° C. for 8 hours, and then the resulting solid was filtered and washed with a methylene chloride solution to synthesize an organic light emitting compound in a yield of 75%.

Example 2 Synthesis of Organic Light Emitting Compound (Spiro-BBA)

0.5 g (1.26 mmol) of 2-bromo-spiro-9,9-fluorene, 0.072 g of Pd (PPh ₃ ) ₄ and 0.05 g of (t-Bu) ₃ P are dissolved in 20 ml of dimethyl ether (DME), and at room temperature. After stirring for 30 minutes, 0.57 g (1.51 mmol) of 7- (4-boronic acid-benzylidene) -7H-benzo [de] -anthracene obtained in Step B of Example 1, as shown in Scheme 4 below. Was slowly added, 0.6 ml of a 2M Na ₂ CO ₃ aqueous solution was added, and then refluxed overnight. After the reaction was completed, the temperature of the reaction solution was lowered to room temperature, and column chromatography was performed with ethyl acetate (EA) / hexane (Hexane) eluent to obtain a pale green target compound (solid) in a yield of 80%.

Example 3 Synthesis of Organic Light Emitting Compound (BBA-diphenyl amine)

As shown in Scheme 5 below, 0.48 g (1.25 mmol) of 7- (4-bromo-benzylidene) -7H-benzo [de] anthracene obtained in Step A of Example 1, 0.25 g (1.50) of diphenylamine mmol), and 0.14 g (1.5 mmol) of (CH ₃ ) ₃ CONa were dissolved in 20 ml of o-xylene and stirred at room temperature for 5 minutes. Next, 0.02 g (0.07 mmol) of Pd (OAc) ₂ and 0.056 g (0.28 mmol) of tri-t-butylphosphine were added and refluxed for 5 hours, and when the reaction was completed, water and methylene chloride (MC) were added. ) Was added to quench the reaction, followed by extraction, and then subjected to column chromatography with ethyl acetate (EA) / hexane (Hexane) eluent to give the title compound (solid) as a pale yellow in 60% yield.

Example 4 Fabrication of Organic Light Emitting Diode

The glass substrate coated with indium tin oxide (ITO) was ultrasonically cleaned, washed again with deionized water, then degreased with toluene gas and dried. Next, a hole injection layer was formed by vacuum evaporation of m-MTDATA on the ITO electrode at a 500 kW thickness, and a hole transport layer was formed by vacuum evaporation of α-NPD at a thickness of 200 kW on the hole injection layer. The organic light emitting compound synthesized in Example 1 was deposited on the hole transport layer to a thickness of 300 kHz as a host, and then Alq3 was deposited to a thickness of 200 Å as the electron transport layer. An electron injection layer was formed by vacuum depositing LiF to a thickness of 10 μm on the electron transport layer, and then an Al was deposited to a thickness of 1200 μm on the electron injection layer to form a cathode, thereby manufacturing an organic light emitting diode. The light emitting color coordinates of the manufactured organic light emitting diodes were (0.19, 0.24), and the light emitting efficiency was 1.54 cd / A at 10 mA / cm ^2. The organic light emitting diodes produced high quality blue light, and showed excellent light emitting efficiency.

As described above, the organic light emitting compound according to the present invention is not only excellent in heat resistance, thermal stability and luminous efficiency, but also has an advantage of displaying blue light of high quality and various wavelengths depending on substituents. The organic light emitting compound according to the present invention is useful for the production of full color organic light emitting diodes, and is a field effect transistor, a photodiode, a photovoltaic cell, a solar cell, and an organic laser. It can be widely applied to various organic semiconductor devices such as a laser and a laser diode.

Claims (7)

An organic light emitting compound having the structure of Formula 1. [Formula 1]

In Formula 1, R ₁ is a substituted or unsubstituted aryl group having 4 to 60 carbon atoms or a substituted or unsubstituted alkenyl group having 2 to 10 carbon atoms, R ₂ to R ₁₁ may be the same or different from each other, H, CN, halogen, CO ₂ R, OR, NR ₂ , SR (R is H, alkyl, alkene, alkyne, or substituted or unsubstituted aryl, heteroaryl or heterocyclic group having 4 to 24 carbon atoms.) , A substituted or unsubstituted aryl group, heteroaryl group, heterocyclic group or a conjugated ring group having 4 to 24 carbon atoms. The organic light emitting compound of claim 1, wherein the organic compound has a structure of Formula 2 below. [Formula 2]

In Formula 2, R ^* is a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted arylamine group having 6 to 30 carbon atoms, or a substituted or unsubstituted alkenyl group having 2 to 10 carbon atoms, R ₂ to R ₁₁ and the substituents are as defined in the formula (1). The method of claim 2, wherein the organic light emitting compound

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And

An organic light emitting compound selected from the group consisting of. The organic light emitting compound of claim 1, wherein the organic light emitting compound has a structure represented by Formula 3 below. [Formula 3]

In Chemical Formula 3, R ₂ to R ₁₁ are the same as defined in Chemical Formula 1, and L is a substituted or unsubstituted aryl group having 4 to 60 carbon atoms, a heteroaryl group or a conjugated ring group, or a substituted or unsubstituted group. It is a C2-C40 alkenyl group, and it can contain heterogeneous elements, such as S, O, N, as needed, and n is an integer of 2-4. The method of claim 4, wherein the organic light emitting compound

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(Wherein R is H, saturated or unsaturated hydrocarbon). 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 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 is a substituted or unsubstituted aryl group having 4 to 60 carbon atoms or a substituted or unsubstituted alkenyl group having 2 to 10 carbon atoms, R ₂ to R ₁₁ may be the same or different from each other, H, CN, halogen, CO ₂ R, OR, NR ₂ , SR (R is H, alkyl, alkene, alkyne, or substituted or unsubstituted aryl, heteroaryl or heterocyclic group having 4 to 24 carbon atoms.) , A substituted or unsubstituted aryl group, heteroaryl group, heterocyclic group or a conjugated ring group having 4 to 24 carbon atoms. The organic light emitting diode of claim 6, 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, and an electron transport layer.

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