KR100942826B1 - Light emitting layer composition for organic electroluminescent device and organic electroluminescent device using the same - Google Patents

Abstract

The present invention includes an asymmetric fluorene derivative ligand as a metal complex compound for an organic light emitting device represented by the following formula (1).

The metal complex compound according to the present invention can increase the solubility by increasing the molecular weight due to the introduction of bulk substituents, and can easily form a thin film by spin coating, inkjet printing, casting method and the like.

In addition, the metal complex compound can reduce the manufacturing cost of the organic light emitting display device, and the interaction between the molecules can be suppressed by the bulk substituent to improve the luminous efficiency.

Metal complex compounds, asymmetric fluorene derivative ligands, luminous efficiency

Description

LIGHT EMITTING LAYER COMPOSITION FOR ORGANIC ELECTROLUMINESCENT DEVICE AND ORGANIC ELECTROLUMINESCENT DEVICE USING THE SAME}

The present invention relates to a metal complex compound for an organic light emitting device and an organic light emitting display device employing the same as a light emitting dopant. More particularly, the present invention relates to a metal complex compound that can be used as a light emitting layer forming material of an organic light emitting device and an organic light emitting display device employing the same as a light emitting dopant.

Among the display devices, the organic light emitting display device (organic EL device) is a self-luminous display device capable of low voltage driving, a wide viewing angle, excellent contrast, and fast response speed. This has the advantage of being possible.

In 1987, Eastman Kodak Co., Ltd. developed for the first time an organic electroluminescent device using a low molecular weight aromatic diamine and an aluminum complex as a material for forming a light emitting layer [Appl. Phys. Lett. 51, 913, 1987]. In 1987, C. W. Tang et al. Reported the devices having practical performance for the first time (Applied Physics Letters, Vol. 51, No. 12, 913-915 (1987)). The document describes a structure in which a thin film (hole transport layer) of a diamine derivative and a thin film (electron transport light emitting layer) of Alq3 (tris (8-hydroxy-quinolate) aluminum) are laminated as an organic layer.

In general, an organic EL device has a structure formed on a glass substrate in order of an anode made of a transparent electrode, an organic thin film including a light emitting region, and a metal electrode.

In this case, the organic thin film may include a light emitting layer, a hole injection layer, a hole transport layer, an electron transport layer or an electron injection layer, and may further include an electron blocking layer or a hole blocking layer due to the light emission characteristics of the light emitting layer.

When an electric field is applied to the organic EL device having such a structure, holes and electrons are injected from the anode and the cathode, respectively, and the injected holes and electrons are recombined in the light emitting layer through the respective hole transport layer and the electron transport layer to emit light excitons. To form. The light emitting excitons formed emit light while transitioning to ground states. In this case, the light emitting layer (dopant) may be doped into the light emitting layer (host) to increase the efficiency and stability of the light emitting state.

In the organic EL device having the structure as described above, the light emitting material is classified into a fluorescent material using excitons in a singlet state and a phosphorescent material using a triplet state according to its light emitting mechanism.

Recently, phosphorescent as well as fluorescent light emitting materials can be used as light emitting materials for organic EL devices (DFO'Brien et al., Applied Physics Letters, 74 (3), 442-444, 1999; MA Baldo et al. , Applied Physics letters, 75 (1), 4-6,1999).

The phosphorescence emission is a mechanism in which electrons transfer from the ground state to the excited state, and then the singlet excitons are non-luminescently transferred to the triplet excitons through intersystem crossing, and then the triplet excitons are emitted to the ground state. Is done.

At this time, the lifetime of the triplet excitons cannot be transferred directly to the ground state (spin forbidden), so the process of transition to the ground state after the flipping of the electron spin proceeds, so the lifetime (luminescence time) is higher than that of fluorescence. It has a longer characteristic.

That is, the emission duration of fluorescence emission is only several nanoseconds, but the phosphorescence emission corresponds to several micro seconds, which is a relatively long time.

In addition, in quantum mechanical terms, when the holes injected from the anode and the electrons injected from the cathode recombine to form a light-emitting excitons, the formation ratio of the singlet and triplet is 1: 3, and the triplet in the EL device is generated. Luminescent excitons are generated about three times more than singlet luminescent excitons.

Therefore, in the case of fluorescence, the probability of singlet excited state is 25% (triple state 75%) and there is a limit of luminous efficiency, whereas phosphorescence can be used to triplet 75% and singlet excited state 25%. The internal quantum efficiency can be up to 100%. Therefore, in the case of using a phosphorescent light emitting material, there is an advantage that can achieve a three times higher luminous efficiency than the fluorescent light emitting material.

As a molecular structure that is easy to phosphorescence emission, it is a molecular structure that is easy to intercalate and introduces heavy metals such as Ir, Pt, Rh, and Pd into organic molecules. In this case, spin generated by heavy atom effect Spin-orbital coupling results in a mixture of triplet and singlet states, which allows forbidden transitions and effectively phosphorescent at room temperature.

Among these, the iridium organometallic complex has been attracting attention as a material having excellent phosphorescence efficiency, and phosphorescent materials using the same have been reported [Sergey Lamansky etc. Inorg. Chem., 40, 1704-1711, 2001 & J. Am. Chem. Soc. , 123, 4304-4312, 2001].

The phosphorescent organic metal complex has been mainly focused on the development of low-molecular materials that can form devices by vacuum evaporation, and in the case of polymer materials, the devices may be formed by wet processes such as spin coating, inkjet printing, and casting methods. Configure.

Wet processes using polymers are easier to fabricate devices than vacuum evaporation, and have more advantages in terms of cost and size, but have the disadvantage that polymer materials are lower than low molecular materials in terms of lifetime, luminous efficiency and color purity.

Therefore, in order to overcome such a problem, there is a demand for the development of a material capable of constituting a device by a wet process with low molecular weight and high solubility.

The technical problem to be achieved by the present invention is the solubility is improved due to the introduction of a bulk substituent, the metal complex compound for an organic electroluminescent device that can be easily manufactured by a wet process such as spin coating, inkjet printing, casting method And it is an object to provide an organic light emitting display device comprising the same.

According to an aspect of the present invention comprises a metal complex compound comprising an organic solvent, a low molecular or high molecular host and an asymmetric fluorene derivative ligand represented by the formula (1), wherein the host and the metal complex compound is an organic solvent It provides a light emitting layer composition for an organic electroluminescent device that can be dissolved in.

In Chemical Formula 1,

n is an integer of 1 to 3, a and b are each independently 0 or 1,

The ring of Formula 1 is each a ring containing a double bond or consisting of a single bond,

M is a metal forming an octahedral complex,

L is a bidentate ligand of a monovalent anion coordinated to M via sp ² carbon and a heteroatom, or a bidentate ligand coordinated via a non-covalent electron pair of a heteroatom and a heteroatom of a monovalent anion,

Y ¹ is a monodentate ligand coordinated via a non-covalent electron pair of heteroatoms, Y ² is a monodentate ligand coordinated with a nitrogen atom of sp ² carbon or monovalent anion,

X ¹ to X ⁸ represent each a carbon atom or a heteroatom, the X ¹ to X ⁸ any of the carbon atoms of R ¹ to R ⁸ are each the carbon atom bonded to X ¹ to X ⁸ representing the case representing a carbon atom of the Represents a substituted substituent, and X ¹ to X ⁸ Of which one indicates the R ¹ to R ⁸ is a lone pair, each coupled to the X ¹ to X ⁸ indicate a nitrogen, oxygen or sulfur atom, the substituent represented by R ¹ to R ⁸ are bonded to X ¹ to X ⁸ Done Can form a ring,

The substituents represented by R ¹ to R ⁸ are each independently one of a hydrogen atom, a functional group and a nitro group represented by the following Chemical Formula 2,

In Chemical Formula 2,

R ⁹ is Independently hydrogen, halogen, R ¹¹ , OR ⁴ , N (R ¹¹ ) ₂ , P (R ¹¹ ) ₂ , P (OR ¹¹ ) ₂ , POR ¹¹ , PO ₂ R ¹¹ , PO ₃ R ¹¹ , SR ¹¹ , Si (R ¹¹ ) ₃ , Si (CH ₃ ) ₂ R ¹¹ , Si (Ph) ₂ R ¹¹ , B (R ¹¹ ) ₂ , B (OR ¹¹ ) ₂ , C (O) R ¹¹ , C (O) OR ¹¹ , C (O) N (R ¹¹ ) ₂ , CN, NO ₂ , SO ₂ , SOR ¹¹ , SO ₂ R ¹¹ and SO ₃ R ¹¹ ,

R ¹¹ is independently hydrogen, a linear or branched alkyl group having 1 to 30 carbon atoms, an alkenyl group having 1 to 30 carbon atoms, an alkynyl group having 1 to 30 carbon atoms, a heteroalkyl group having 1 to 30 carbon atoms, and an aryl group having 3 to 40 carbon atoms. And a heteroaryl group having 3 to 40 carbon atoms, wherein R ¹¹ is substituted by one or more substituents Z,

Z is independently hydrogen, halogen, R ¹² , OR ¹² , N (R ¹² ) ₂ , P (R ¹² ) ₂ , P (OR ¹² ) ₂ , POR ¹² , PO ₂ R ¹² , PO ₃ R ¹² , SR ¹² , Si (R ¹² ) ₃ , Si (CH ₃ ) ₂ R ¹² , Si (Ph) ₂ R ¹² , B (R ¹² ) ₂ , B (OR ¹² ) ₂ , C (O) R ¹² , C ( O) OR ¹² , C (O) N (R ¹² ) ₂ , CN, NO ₂ , SO ₂ , SOR ¹² , SO ₂ R ^12, and SO ₃ R ¹² ,

R ¹² is Independently Hydrogen, a straight or branched alkyl group having 1 to 30 carbon atoms, an alkenyl group having 1 to 30 carbon atoms, an alkynyl group having 1 to 30 carbon atoms, a heteroalkyl group having 1 to 30 carbon atoms, an aryl group having 3 to 40 carbon atoms, and a 3 to 40 carbon atoms One of the heteroaryl groups.

In the light emitting layer composition for an organic light emitting device, when a and b are pentagonal rings with a = b = 0 when 0 and a = b = 1 or a = 0, b = 1 or a = 1 when 1 , b = 0 may be a hexagonal ring.

The asymmetric fluorene derivative ligand represented by Formula 1 may include an aromatic ring.

L may be any one selected from the following ligands.

The metal atom (M) forming the octahedral complex in Formula 1 may be iridium.

According to another aspect of the present invention, a first electrode formed on the substrate, an organic thin film layer formed on the first electrode and formed of the light emitting layer composition for the organic light emitting device and a second electrode formed on the organic thin film layer It provides an organic electroluminescent device comprising.

The organic thin film layer is formed on the first electrode layer and at least one of a first buffer layer for injecting and transporting holes, a light emitting layer formed on the first buffer layer, and a second buffer layer formed on the light emitting layer and injecting and transporting electrons. It may comprise a layer.

The first electrode may be a transparent conductive metal oxide selected from ITO and IZO.

The substrate may be a glass substrate or a flexible substrate.

The light emitting layer may be formed by one of a spin coating method, an ink jet method, a casting method, and a vacuum deposition method.

Other specific details of embodiments of the present invention are included in the following detailed description.

The metal complex compound for an organic light emitting device according to the present invention introduces a molecule having a bulk three-dimensional structure as a ligand of the metal complex compound, thereby inhibiting intermolecular interactions and thereby improving solubility.

In addition, when the organic light emitting display device is manufactured using the metal complex compound for the organic light emitting device, it can be easily manufactured by a wet process such as spin coating, inkjet printing, and casting, thereby reducing the manufacturing cost of the organic light emitting device. .

Metal complex compound for an organic light emitting device for achieving the present invention is characterized in that it comprises an asymmetric fluorene derivative ligand represented by the following formula (1).

n = 1 to 3, and a and b are each independently 0 or 1.

The ring of formula 1 is each a ring containing a double bond or consisting of a single bond,

Where

M is a metal forming an octahedral complex,

L is a bidentate ligand of a monovalent anion coordinated to M through sp ² carbon and a heteroatom, or a bidentate ligand coordinated via a non-covalent electron pair of heteroatom and heteroatom of monovalent anion,

Y ¹ is a monodentate ligand coordinated via a non-covalent electron pair of heteroatoms, Y ² is a monodentate ligand coordinated with a nitrogen atom of sp ² carbon and monovalent anion,

X ¹ to X ⁸ each represents a carbon atom or a hetero atom, X ¹ to X ⁸ in the case specified to the shown carbon atom, the R ¹ to R ⁸ are each the carbon atom bonded to X ¹ to X ⁸ represents a carbon atom Substituent bonded to is shown. When X ¹ to X ⁸ specific to the shown nitrogen, oxygen or sulfur atom, represents a R ¹ to R ⁸ is a lone pair, each coupled to the X ¹ to X ^8, the substituent represented by R ¹ to R ⁸ are X Bound to ¹ to X ⁸ May form a ring.

Substituents represented by R ¹ to R ⁸ are each independently a hydrogen atom, a substituted or unsubstituted C 6 or more aryl group, a substituted or unsubstituted C 2 or more heteroaryl group, a substituted or unsubstituted C 1 or more alkyl group , Substituted or unsubstituted C2 or more amino group, substituted or unsubstituted C1 or more alkoxy group, halogen atom, nitro group, substituted or unsubstituted C6 or more arylene group, substituted or unsubstituted C2 or more heteroaryl group A ethylene group, a substituted or unsubstituted alkylene group having 1 or more carbon atoms.

And Chemical Formula 1 is an aromatic ring.

In addition, the metal atom (M) forming the octahedral complex in the formula (1) is characterized in that the iridium.

Herein, the substituents represented by R ¹ to R ⁸ in Chemical Formula 1 may be specifically selected from fluorene structures of Chemical Formulas 2 and 3 below.

R ⁹ is Independently hydrogen, halogen, R ¹¹ , OR ⁴ , N (R ¹¹ ) ₂ , P (R ¹¹ ) ₂ , P (OR ¹¹ ) ₂ , POR ¹¹ , PO ₂ R ¹¹ , PO ₃ R ¹¹ , SR ¹¹ , Si (R ¹¹ ) ₃ , Si (CH ₃ ) ₂ R ¹¹ , Si (Ph) ₂ R ¹¹ , B (R ¹¹ ) ₂ , B (OR ¹¹ ) ₂ , C (O) R ¹¹ , C (O) OR ¹¹ , C (O) N (R ¹¹ ) ₂ , CN, NO ₂ , SO ₂ , SOR ¹¹ , SO ₂ R ¹¹ And SO ₃ R ¹¹ Any one of

R ¹¹ is independently Hydrogen, a straight or branched alkyl group of 1 to 30 carbon atoms, an alkenyl group of 1 to 30 carbon atoms, an alkynyl group of 1 to 30 carbon atoms, a heteroalkyl group of 1 to 30 carbon atoms, an aryl group of 3 to 40 carbon atoms, and a 3 to 40 carbon atoms Is any of a heteroaryl group, wherein R ¹¹ is optionally substituted by one or more substituents Z,

Z is independently hydrogen, halogen, R ¹² , OR ¹² , N (R ¹² ) ₂ , P (R ¹² ) ₂ , P (OR ¹² ) ₂ , POR ¹² , PO ₂ R ¹² , PO ₃ R ¹² , SR ¹² , Si (R ¹² ) ₃ , Si (CH ₃ ) ₂ R ¹² , Si (Ph) ₂ R ¹² , B (R ¹² ) ₂ , B (OR ¹² ) ₂ , C (O) R ¹² , C ( O) OR ¹² , C (O) N (R ¹² ) ₂ , CN, NO ₂ , SO ₂ , SOR ¹² , SO ₂ R ¹² or SO ₃ R ¹² ,

R ¹² is independently hydrogen, a straight or branched alkyl group having 1 to 30 carbon atoms, an alkenyl group having 1 to 30 carbon atoms, an alkynyl group having 1 to 30 carbon atoms, a heteroalkyl group having 1 to 30 carbon atoms, an aryl group having 3 to 40 carbon atoms, Any of heteroaryl group having 3 to 40 carbon atoms,

R ¹⁰ is a substituted or unsubstituted aryl group having 6 or more carbon atoms, a substituted or unsubstituted heteroaryl group having 2 or more carbon atoms, a substituted or unsubstituted C1 or more alkyl group, a substituted or unsubstituted C2 or more amino group, a substituted or unsubstituted Any one of an alkoxy group having 1 or more carbon atoms, a halogen atom, a nitro group, a substituted or unsubstituted arylene group having 6 or more carbon atoms, a substituted or unsubstituted heteroarylene group having 2 or more carbon atoms, or a substituted or unsubstituted alkyl group having 1 or more carbon atoms. .

And L is any one selected from the following ligands.

On the other hand, the metal complex compound for an organic light emitting device according to the present invention is characterized in that the general formula 1 is represented by the following general formula (1a) or 1b, but the present invention is not limited to the following representative examples.

[Formula 1a]

[Formula 1b]

[Formula 1c]

[Formula 1d]

[Formula 1e]

[Formula 1f]

*

[Formula 1g]

An organic electroluminescent display device for achieving the present invention comprises a first electrode formed on a substrate; An organic thin film layer formed on the first electrode and formed of a metal complex compound for an organic light emitting device; It includes a second electrode formed on the organic thin film layer.

Herein, the organic thin film layer is formed on the first electrode layer and includes a first buffer layer for injecting and transporting holes, a light emitting layer formed on the first buffer layer, and a second buffer layer formed on the light emitting layer and injecting and transporting electrons. It is characterized by including any one or more layers.

The first electrode may be a transparent conductive metal oxide selected from indium-tin-oxide (ITO) and indium-zinc-oxide (IZO).

The substrate is characterized in that the glass substrate or a flexible substrate.

The light emitting layer is formed by one of spin coating, ink jet, and casting.

Hereinafter, it demonstrates more concretely based on the Example of this invention. However, the following examples are provided to help the understanding of the present invention, and the scope of the present invention is not limited thereto.

Preparation Example 1 Synthesis of Chemical Formula 1a

14.0 g (1.1 eq, 61.1 mmol) of 1,3-dibromobenzene was dissolved in 200 ml of tetrahydrofuran. After the reaction temperature was lowered to -78 ° C, 39.8 ml (1.15eq, 63.8 mmol) of n-butyllithium (1.6M in n-Hexane) was slowly added dropwise.

After stirring for 30 minutes, 10.0 g (1.0eq, 55.5 mmol) of fluorenone dissolved in 100 ml of tetrahydrofuran was slowly added dropwise. The reaction temperature is raised to room temperature and stirred for 12 hours under nitrogen gas.

After completion of the reaction, the mixture was extracted with diethyl ether. The organic layer may be dried over anhydrous magnesium sulfate, concentrated, and separated by silica gel column chromatography to obtain 9- (3-bromophenyl) -9H-fluorene-9-ol.

5.0 g (1.0 eq, 14.8 mmol) of 9- (3-bromophenyl) -9H-fluorene-9-ol and 2.5 g (1.1 eq, 21.0 mmol) of 4-isobutylbenzene were dissolved in dichloromethane. Catalytic amount of methanesulfonic acid diluted in dichloromethane is added dropwise, followed by stirring at room temperature for 12 hours.

After the completion of the reaction, the mixture was extracted with dichloromethane and the organic layer was dried over anhydrous magnesium sulfate, concentrated, and separated by silica gel column chromatography to obtain 2- (3- (9- (4-isobutylphenyl) -9H-fluorene-9 -Yl) phenyl) bromide was obtained.

After dissolving 4.0 g (1.0eq, 8.8 mmol) of 3- (9- (4-isobutylphenyl) -9H-fluoren-9-yl) phenyl bromide in 50 ml of THF, the temperature of the reactor was reduced to -78 ° C. Lower and slowly dropwise add 9.73 ml (1.2 eq, 11 mmol) of n-butyllithium (1.6 M in Hexane).

After stirring the material for 30 minutes, 1.96 g (1.3 eq, 11.5 mmol) of 2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane was slowly added to the material. Add it down. The reaction temperature is raised to room temperature and stirred for 12 hours.

The reaction is terminated and extracted with diethyl ether. The organic layer was dried and concentrated, and then obtained Intermediate 3 by silica gel column chromatography.

Ligand a was synthesized by the Suzuki coupling reaction. 2 g (1 eq, 4 mmol) and 0.59 g (0.9 eq, 3.6 mmol) of 1-chloroisoquinoline were dissolved in 10 ml of a 2 molar concentration aqueous potassium carbonate solution and 20 ml of THF, followed by tetrakis (triphenylphosphino) under nitrogen stream. ) Add 0.1 g (2 mol%) of palladium (0 oxide) and reflux for 12 hours.

After completion of the reaction, tetrakis (triphenylphosphino) palladium was removed through celite filtration, and then extracted with diethyl ether. The organic layer was dried and concentrated, and then ligand a was obtained by silica gel column chromatography.

0.1 g (0.2 mmol) of iridium acetylacetonate and 0.46 g (4.5 eq, 0.9 mmol) of the ligand a are dissolved in glycerol, and then heated and stirred at 200 ° C. for 24 hours under a nitrogen stream.

After the completion of the reaction, the reaction product was poured into distilled water, filtered, and then dissolved in chloroform to obtain Compound 1a having a bulk particle structure, that is, a bulk ligand, an asymmetric fluorene derivative ligand, using silica gel column chromatography.

Preparation Examples 2 to 5: Synthesis of Chemical Formulas 1b to 1e

A procedure similar to Preparation Example 1 was carried out to prepare ligands b to ligand e and compounds 1b to 1e.

Preparation Example 6 Synthesis of Chemical Formula 1f

A ligand f was prepared by following a similar procedure to Preparation Example 1. 0.2 g (0.33 mmol) of Ir (ppy) 2 (acac) and 0.3 g (2 eq, 0.66 mmol) of the ligand f are dissolved in glycerol, and then heated and stirred at 200 ° C. for 24 hours under a nitrogen stream.

After completion of the reaction, the reaction product was poured into distilled water, filtered, and then dissolved in chloroform to obtain Compound 1f having a bulk particle structure, that is, a bulk ligand, an asymmetric fluorene derivative ligand, using silica gel column chromatography.

Preparation Example 7 Synthesis of Chemical Formula 1g

A ligand g was prepared by following a similar procedure to Preparation Example 1. 0.2 g (0.33 mmol) of Ir (ppy) 2 (acac) and 0.65 g (2 eq, 0.66 mmol) of the ligand g were dissolved in glycerol, and then heated and stirred at 200 ° C. for 24 hours under a nitrogen stream.

After completion of the reaction, the reaction product was poured into distilled water, filtered, and then dissolved in chloroform to obtain 1 g of a compound having a bulk particle structure, that is, a bulk ligand, an asymmetric fluorene derivative ligand, using silica gel column chromatography.

OLED  Device Characterization

The organic electroluminescent device can be fabricated using the metal complex compound for an organic electroluminescent device obtained from the present invention as a light emitting dopant.

1 is a view showing an organic light emitting display device according to the present invention.

Referring to FIG. 1, an organic light emitting display device 1 includes a first electrode 20 made of a transparent conductive metal oxide, an organic thin film layer 100 including a light emitting region, and a second electrode 30 of a second electrode. It can be formed in a structure formed on the substrate 10 in order.

The substrate 10 may be used as a glass substrate or a flexible substrate having flexibility. The substrate is a Corning (15Ω / ㎠) (1200Å), the first electrode 20 on the substrate 10 to form a 20mm x 20mm x 0.7mm size.

The first electrode 20 may use indium-tin-oxide (ITO) or indium-zn-oxide (IZO) as a transparent conductive metal oxide.

The substrate 10 on which the first electrode 20 is formed is ultrasonically cleaned in isopropyl alcohol and pure water for 5 minutes, and then UV ozone cleaned for 30 minutes.

PEDOT (poly (ethylenedioxy) thiophene) is spin coated to form the organic thin film layer 100 on the first electrode 20. In this case, the organic thin film layer 100 may include a light emitting layer 120, a first buffer layer 110, and a second buffer layer 130.

The first and second buffer layers 110 and 130 may include at least one layer selected from a hole injection layer, a hole transport layer, an electron transport layer, or an electron injection layer, and may have an electron blocking layer or a hole blocking layer due to light emission characteristics of the light emitting layer 120. And the like may be further included.

Here, an embodiment will be described in which a hole blocking layer and an electron transporting layer are formed in the second buffer layer 130 without introducing the first buffer layer 110.

The light emitting layer 120 is formed on the PEDOT (poly (ethylenedioxy) thiophene). The light emitting layer may be formed by a wet process such as spin coating, inkjet printing, or casting, and in the present invention, the light emitting layer is formed by spin coating. Explain.

The light emitting layer host may form TMM038 (Merck, low molecular weight) or PVK (poly vinylcarbazole) or PVK / CBP (4,4'-N, N'-dicarbazolebiphenyl) (45:55 or 1: 1). Using the metal complex compound according to the invention as a dopant (1% to 30%, preferably 7%), spin coating to a thickness of 500 kPa.

In addition, Balq is vacuum-deposited on the light emitting layer 120 to form a hole blocking layer having a thickness of 50 Å. Subsequently, Alq3 is vacuum deposited on the hole blocking layer to form an electron transport layer having a thickness of 200 kHz.

LiF 10kV (electron injection layer) and Al 1000kV (cathode) are sequentially vacuum deposited on the electron transport layer to form the second electrode 30 of LiF / Al metal to manufacture the organic light emitting display device 1. Can be.

When holes and electrons are injected from the first electrode 20 and the second electrode 30 when an electric field is applied to the organic light emitting display device 1, the injected holes and electrons are electrons of the organic thin film layer 100. The light emitting excitons may be formed by recombination in the light emitting layer 120 through the transport layer.

The light emitter can emit light while transitioning to ground states.

In the present invention, in the organic light emitting display device 1 in which the organic thin film layer 100 including the metal complex compound of Chemical Formula 1 as a light emitting material is disposed between the first electrode 20 and the second electrode 30. At least one of the constituent layers of the organic thin film layer 100 includes the metal complex compound according to the present invention.

As described above, in order to grasp the characteristics of the organic light emitting display device 1 manufactured, the initial turn-on voltage, the maximum luminance (cd / m 2), and the luminance of 1000 cd / m 2 are obtained. The driving voltages (V), current efficiency (cd / A) and power efficiency (lm / W) at were measured, and these results are shown in [Table 1].

TABLE 1

As described above, although the metal complex compound used in the organic thin film layer 100 of the present invention is an organic electroluminescent display device (1) manufactured by spin coating, which is a wet process rather than a vacuum deposition method, color coordinates are x, y = It can emit light corresponding to the pure red color of [0.67, 0.33].

In addition, the initial driving voltage was measured to 2.8 ~ 5.0 V, the maximum brightness can be confirmed that the electrical stability is also improved to 3,847 cd / ㎡ to 12,700 cd / ㎡.

In addition, unlike Ir (piq) ₃ or Ir (piq) ₂ (acac), which are known to be effective among red phosphorescent organometallic complexes, organic solvents such as toluene, chloroform, and chlorobenzene are caused by the decrease of intermolecular van derwaltz forces. Excellent solubility characteristics make it easy to manufacture devices by wet process.

As such, by introducing a bulky substituent in the metal complex compound according to the present invention, the intermolecular distance is increased, and thus, the crystallinity is reduced and the solubility is increased. That is, the intermolecular interaction can be suppressed to improve luminous efficiency and electrical characteristics.

Therefore, the metal complex of the present invention is expected to be useful as a phosphorescent material of an organic light emitting display device.

1 is a view showing an organic light emitting display device according to the present invention.

<Explanation of symbols for the main parts of the drawings>

1 organic light emitting display device 10 substrate

20: first electrode 30: second electrode

100 organic thin film layer 110 first buffer layer

120: second buffer layer

Claims (10)

Organic solvents; Low molecular or polymeric hosts; And It includes a metal complex compound containing an asymmetric fluorene derivative ligand represented by the formula (1), Wherein the host and the metal complex compound are soluble in an organic solvent, the light emitting layer composition for an organic light emitting device:

In Chemical Formula 1, n is an integer of 1 to 3, a and b are each independently 0 or 1, The ring of Formula 1 is each a ring containing a double bond or consisting of a single bond, M is a metal forming an octahedral complex, L is a bidentate ligand of a monovalent anion coordinated to M via sp ² carbon and a heteroatom, or a bidentate ligand coordinated via a non-covalent electron pair of a heteroatom and a heteroatom of a monovalent anion, Y ¹ is a monodentate ligand coordinated via a non-covalent electron pair of heteroatoms, Y ² is a monodentate ligand coordinated with a nitrogen atom of sp ² carbon or monovalent anion, X ¹ to X ⁸ represent each a carbon atom or a heteroatom, the X ¹ to X ⁸ any of the carbon atoms of R ¹ to R ⁸ are each the carbon atom bonded to X ¹ to X ⁸ representing the case representing a carbon atom of the When any one of X ¹ to X ⁸ represents a nitrogen, oxygen or sulfur atom, R ¹ to R ⁸ bonded to X ¹ to X ⁸ each represent a non-covalent electron pair, and R ¹ to R ⁸ Substituents represented are bonded to X ¹ to X ⁸ Can form a ring, The substituents represented by R ¹ to R ⁸ are each independently one of a hydrogen atom, a functional group and a nitro group represented by Formula 2, and at least one of the substituents represented by R ¹ to R ⁸ is represented by Formula 2 below. The functional group is represented by:

In Chemical Formula 2, R ⁹ is Independently hydrogen, halogen, R ¹¹ , OR ⁴ , N (R ¹¹ ) ₂ , P (R ¹¹ ) ₂ , P (OR ¹¹ ) ₂ , POR ¹¹ , PO ₂ R ¹¹ , PO ₃ R ¹¹ , SR ¹¹ , Si (R ¹¹ ) ₃ , Si (CH ₃ ) ₂ R ¹¹ , Si (Ph) ₂ R ¹¹ , B (R ¹¹ ) ₂ , B (OR ¹¹ ) ₂ , C (O) R ¹¹ , C (O) OR ¹¹ , C (O) N (R ¹¹ ) ₂ , CN, NO ₂ , SO ₂ , SOR ¹¹ , SO ₂ R ¹¹ and SO ₃ R ¹¹ , R ¹¹ is independently hydrogen, a linear or branched alkyl group having 1 to 30 carbon atoms, an alkenyl group having 1 to 30 carbon atoms, an alkynyl group having 1 to 30 carbon atoms, a heteroalkyl group having 1 to 30 carbon atoms, and an aryl group having 3 to 40 carbon atoms. And a heteroaryl group having 3 to 40 carbon atoms, wherein R ¹¹ is substituted by one or more substituents Z, Z is independently hydrogen, halogen, R ¹² , OR ¹² , N (R ¹² ) ₂ , P (R ¹² ) ₂ , P (OR ¹² ) ₂ , POR ¹² , PO ₂ R ¹² , PO ₃ R ¹² , SR ¹² , Si (R ¹² ) ₃ , Si (CH ₃ ) ₂ R ¹² , Si (Ph) ₂ R ¹² , B (R ¹² ) ₂ , B (OR ¹² ) ₂ , C (O) R ¹² , C ( O) OR ¹² , C (O) N (R ¹² ) ₂ , CN, NO ₂ , SO ₂ , SOR ¹² , SO ₂ R ^12, and SO ₃ R ¹² , R ¹² is Independently Hydrogen, a straight or branched alkyl group having 1 to 30 carbon atoms, an alkenyl group having 1 to 30 carbon atoms, an alkynyl group having 1 to 30 carbon atoms, a heteroalkyl group having 1 to 30 carbon atoms, an aryl group having 3 to 40 carbon atoms, and a 3 to 40 carbon atoms It is either of heteroaryl groups. The method of claim 1, A and b are pentagonal rings with a = b = 0 when 0, and with 1 being a hexagonal ring with a = b = 1 or a = 0, b = 1 or a = 1, b = 0. The light emitting layer composition for organic electroluminescent elements which are used. The method of claim 1, The asymmetric fluorene derivative ligand represented by the formula (1) is an organic light emitting device light emitting layer composition, characterized in that it comprises an aromatic ring. The method of claim 1, Wherein L is any one selected from the ligands of the organic light emitting device, characterized in that the light emitting layer composition:

. The method of claim 1, The metal atom (M) forming the octahedral complex in Formula 1 is iridium light emitting layer composition for an organic light emitting device. A first electrode formed on the substrate; An organic thin film layer formed on the first electrode and formed of a light emitting layer composition for an organic light emitting device according to any one of claims 1 to 5; And An organic electroluminescent device comprising a second electrode formed on the organic thin film layer. The method of claim 6, The organic thin film layer A first buffer layer formed on the first electrode layer and injecting and transporting holes, a light emitting layer formed on the first buffer layer, and a second buffer layer formed on the light emitting layer and injecting and transporting electrons. An organic light emitting display device, characterized in that. The method of claim 6, The first electrode is an organic electroluminescent device, characterized in that the transparent conductive metal oxide selected from ITO and IZO. The method of claim 6, The substrate is an organic light emitting display device, characterized in that the glass substrate or a flexible substrate. The method of claim 6, The light emitting layer is an organic electroluminescent device, characterized in that formed by one of spin coating method, inkjet method and casting method.

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