KR100936307B1 - Iridium Complex with Improved Luminescent Properties and Organic Electroluminescent Device Containing Iridium Complex - Google Patents

Abstract

The present invention provides an iridium complex in which a carbazole derivative and an aromatic quinoline derivative are introduced as a main ligand, and an organic electroluminescent device for phosphorescence containing the iridium complex as a dopant of a light emitting layer. The iridium complex compound synthesized by the main and secondary ligands introduced into the iridium according to the present invention not only greatly improved the solubility and thermal characteristics of the luminescent properties, but also formed the thin film by the solution process in the manufacturing process of the light emitting device. This possible device was obtained. By dope the iridium complex compound in the light emitting layer, it was possible to obtain a device that is greatly improved compared to the conventional in the emission spectrum and color purity. By dope the iridium complex compound in the light emitting layer, the device can be obtained a greatly improved luminous efficiency and the like compared with the conventional.

Iridium Complex, Triplet, Aromatic Quinoline, Carbazole, Organic Light Emitting Diode (OLED)

Description

Iridium Complex with Improved Luminescent Properties and Organic Electroluminescent Device Containing Iridium Complex}

The present invention relates to an iridium complex and an organic electroluminescent device comprising the same, and more particularly, to an iridium complex compound and an organic electroluminescent device comprising the same, which has greatly improved solubility and thermal characteristics luminous efficiency. By dope the iridium complex compound in the light emitting layer, it was possible to obtain a device that is greatly improved compared to the conventional in the emission spectrum and color purity.

Recently, as the size of display devices increases, the demand for flat display devices such as liquid crystal displays (LCDs) and plasma display panels (PDPs) is increasing. These flat display devices have slower response speeds and limited viewing angles compared to CRTs, and thus, researches on other display devices have been conducted. One of them is an electroluminescent device.

Conventional electroluminescent devices have mainly used inorganic electroluminescent devices using a light emitting image generated when an electric field is applied to an inorganic semiconductor made of a pn junction such as ZnS or Cas. However, in the case of an inorganic electroluminescent device, a driving voltage of 220 V or more is used. There is a problem that it is difficult to increase the size because the device is manufactured in a vacuum state, and in particular, it is difficult to obtain blue with high efficiency.

Due to these problems, research on organic light-emitting diodes (OLEDs) using organic materials is being conducted. An organic electroluminescent device is a display using an organic material that emits light by itself. When an electric field is applied to the organic material, electrons and holes are transferred from the cathode and the anode, respectively, and are combined in the organic material. Uses organic electroluminescence emitted by light. Compared with LCDs, organic light emitting diodes are attracting attention as next-generation display devices because they have a good viewing angle, low power consumption, and significantly improved response speeds to process high quality images.

The phenomenon of light emission in such an organic light emitting device can be classified into fluorescence and phosphorescence. When fluorescence is emitted from an organic molecule to a ground state from a singlet excited state, it emits light. Phosphorescence is a phenomenon in which organic molecules emit light when they fall from the triplet excited state to the ground state.

This will be described in detail as follows. Organic compounds doped in organic electroluminescent devices, including light emitting layers, share electrons between atomic carbon and other carbon atoms, or between atomic carbon and other atoms to form molecules through covalent bonds. State electron orbits (atomic orbital, AO) are converted to molecular orbitals (molecular orbital, MO). In molecular electron orbits, two pairs of atomic orbitals in the atomic state each participate to form a bonding orbital and an antibonding orbital, respectively. At this time, the band formed by many coupling orbits is called a valence band, and the die formed by many anti-bonding orbits is called a conduction band. The highest energy level of the valence band is called HOMO. The highest energy level of the conductive band is called Lowest Unoccupied Molecular Orbital (LUMO), and the energy difference between the energy of HOMO and LUMO is called the band gap.

However, electrons and holes injected into the organic light emitting layer constituting the organic light emitting device are recombined to form excitons, and the color of the color corresponding to the energy band gap of the light emitting layer in the process of converting the electrical energy of the excitons into light energy. Implement light. In this process, a single spin exciton with zero spin and triplet exciton with a spin of 1 are generated at a ratio of 1: 3. According to the selection rule for the electric dipole transition, the spin quantum number should not be changed when transitioning from the excited state to the ground state. Since the ground state of the organic molecule is the singlet state, the singlet excitons emit light and transition to the ground state. However, triplet excitons can't glow and transition. Therefore, in general, the maximum internal quantum efficiency of the organic light emitting diode doped with fluorescent dye is limited to 25%. However, when the spin-orbital coupling is large, the triplet excitons are phosphorescent to the ground state because the inter-system crossing occurs between the singlet and triplet states by mixing the singlet form and the triplet state. Can make a transition. After all, if the triplet excitons can be used to emit light, the internal quantum efficiency of the organic light emitting device can theoretically be improved to 100%.

As such, the phosphorescent organic electroluminescent device that can significantly improve the luminous efficiency of the organic light emitting device is S.R. Professor Forrest and M.E. of USC. It was developed by Thompson's team, especially since the spin-orbital bond is proportional to the square of the atomic number, and phosphorescent complexes of heavy atoms such as platinum (Pt), iridium (Ir), europium (Eu) and terbium (Tb) are phosphorescent. It is known that the efficiency is high. In the case of platinum complexes, the lowest triplet excitons are ligand-centered excitons (LC excitons), while the iridium complexes have the lowest energy triplet excitons. ligand charge transfer (MLCT). Thus, iridium complexes form larger spin-orbit bonds than platinum complexes, resulting in much shorter triplet exciton lifetimes and high phosphorescence efficiencies.

In this regard, C. Adachi et al. Described bis (2-phenylpyridine) iridium (III) acetylacetonate [(ppy) ₂ Ir (acac)], a green phosphorescent pigment with iridium as its central metal, with 3-phenyl-4- (1'- An organic electroluminescent device with a maximum luminous efficiency of 60 lm / W and a maximum internal quantum efficiency of 87% has been announced by doping naphthyl) -5-phenyl-1,2,4-triazole (TAZ). In addition, U.S. Universal Display Corp. (UDC) has announced that it has achieved high luminous efficiency of 82 lm / W by doping such a green phosphorescent dye into the light emitting layer and using a hole injection material developed by LG Chem.

As described above, phosphorescent organic light emitting diodes displaying blue, green and red colors have been developed, but until now, three primary colors of phosphorescent organic light emitting diodes having excellent luminous efficiency, color coordinates, and lifetime have not been developed. For example, FIrpic (Iridium (III) bis [2-2 ', 4'-difluorophenylpyridinato-N, C2'] picolinate, a phosphor that exhibits a blue emission color, and Ir (btp) ₂ (acac), which realizes a red emission color (Iridium (III) bis (2- (2'-benzothienyl) pyridinato-N, C2) (acetylacetonate) has been developed, but it has not been developed successfully in terms of color purity, efficiency and solubility. It is true.

The present invention has been proposed to solve the above problems, and an object of the present invention is to provide an iridium complex compound and a organic electroluminescent device including the same, which have greatly improved red light emission characteristics and luminous efficiency, particularly with respect to red. .

It is another object of the present invention to provide an iridium complex compound having an improved solubility in organic solvents, significantly improved heat resistance and excellent interfacial properties with an electrode, and an organic electroluminescent device comprising the same.

Another object of the present invention is to provide a device that is greatly improved compared to the conventional in the emission spectrum and color purity by doping the iridium complex compound in the light emitting layer.

Other objects and advantages of the present invention will become more apparent from the following drawings and the configuration of the invention.

According to one aspect of the present invention having the above object, there is provided an iridium complex compound in which carbazole derivatives and aromatic quinylone derivatives are introduced into the main ligand.

Iridium complex compound synthesized according to a preferred embodiment of the present invention has a structure of formula (1).

Formula 1

는 피콜리닉산-N-oxide, 피라진산, 또는 피페콜리닉산이다.)In Formula 1, Ar is an aromatic ring; R ₁ is hydrogen, an alkyl group (C 1-20), an alkoxy group (C 1-20), a cyanide group, a nitro group, a halogen, or a carbazole group; R ₂ is hydrogen or carbon number 1-20 alkyl groups;

Is picolinic acid-N-oxide, pyrazine acid, or pipecolinic acid.)

In particular, the aromatic ring (Ar) connected to the quinoline of Formula 1 is a phenyl group, naphthalene group, carbazole group, fluorenyl group, phenazine group, phenanthroline group, phenanthridine group, permidine group, acridine group, cynoline group, In quinazoline group, quinoxaline group, naphthridin group, phthalazine group, quinolizine group, indole group, indazole group, pyridazine group, pyrazine group, pyrimidine group, pyridine group, pyrazole group, imidazole group, pyrrole group It may be selected, and preferably include a phenyl group, naphthalene group, carbazole group, fluorenyl group, the functional group (R ₁ ) substituted in the aromatic ring may be an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, The substituted halogen may include fluorine or chlorine.

On the other hand, according to another aspect of the present invention provides an organic electroluminescent device in which the iridium complex compound as described above is included in the light emitting layer.

An organic light emitting display device according to the present invention includes, for example, a first electrode functioning as an anode; And a second electrode formed to face the first electrode and functioning as a cathode, wherein the light emitting layer is stacked between the first electrode and the second electrode.

An organic light emitting display device according to a preferred embodiment may have a multilayer form further comprising a hole injection layer and a hole transport layer between the first electrode and the light emitting layer, and an electron transport layer between the light emitting layer and the second electrode.

The iridium complex is included in a concentration of 3 to 20% by weight based on the total amount of the light emitting layer, and is used as a dopant capable of interacting with other host materials.

The iridium complex compound synthesized according to the present invention has greatly improved light emission color and light emission efficiency compared to the known iridium-based light emitting materials, and can be easily dissolved in an organic solvent, thereby maintaining a large light emission area.

That is, the iridium complex of the present invention can realize pure red light emission color as compared with conventionally known iridium-based light emitting materials by introducing aromatic quinoline derivatives and carbazole derivatives as main ligands and acetylacetone, picolinic acid, etc. as auxiliary ligands. By using this material as a dopant of the light emitting layer, a red phosphorescent organic electroluminescent device can be manufactured.

In addition, the iridium complex compound of the present invention is soluble in a general organic solvent by introducing various types of substituents to the aromatic quinoline derivatives and carbazole derivatives introduced into the main ligand, improves heat resistance characteristics, and has excellent interface characteristics with electrodes. It can be used as a light emitting material having excellent thin film properties.

In addition, by doping the iridium complex compound of the present invention in the light emitting layer it was possible to obtain a device significantly improved compared to the conventional in the emission spectrum and color purity.

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

As described above, in the organic electroluminescent device, it is advantageous to use the light emitting material having the phosphorescent property rather than the light emitting material having the fluorescent property in terms of luminous efficiency. In the present invention, among the light emitting materials having such a phosphorescent property, not only the red light emitting property and the light emitting efficiency are improved, but also an organic electroluminescent device comprising an iridium complex compound and an iridium complex compound having excellent solubility or compatibility with various organic solvents in the light emitting layer. Developed. In addition, by dope the iridium complex compound in the light emitting layer, the device was greatly improved in the emission spectrum and color purity.

In the iridium complex according to the present invention, aromatic quinoline derivatives and carbazole derivatives are respectively introduced as main ligands, and thus red luminescence properties and luminescence efficiencies are improved, particularly in red light emission, which have improved solubility and thermal properties, emission spectrum and color purity. It is configured to indicate. According to a preferred embodiment, the iridium complex synthesized in the present invention has a structure of formula (1).

Formula 1

는 아세틸아세톤, 피콜리닉산, 피콜리닉산-N-옥사이드, 피라진산, 또는 피페콜리닉산이다.)In Formula 1, Ar is an aromatic ring; R ₁ is hydrogen, an alkyl group (C 1-20), an alkoxy group (C 1-20), a cyanide group (CN), a nitro group (NO ₂ ), a halogen, or a carbazole group R ₂ is hydrogen, an alkyl group having 1 to 20 carbon atoms;

Is acetylacetone, picolinic acid, picolinic acid-N-oxide, pyrazine acid, or pipecolic acid.)

As can be seen in the above formula (1), the iridium complex according to the present invention is an aromatic quinoline derivative and a carbazole derivative is introduced as the main ligand. In the iridium complex compound exhibiting the phosphorescence property as in the present invention, the main ligand is a main factor for determining the emission color, and in particular, the emission property may be converted according to the electron density of nitrogen (N) contained in the ligand. In the case of the aromatic quinoline derivatives and carbazole derivatives introduced into the main ligand according to the present invention, the electron density of nitrogen contained in the structure is greatly increased compared to the conventionally developed iridium complex compound, thereby showing pure red light emission.

Aromatic rings (Ar) which may be linked to quinoline in connection with the present invention include phenyl, naphthalene, carbazole, fluorene, phenazine, phenazine, phenanthroline, phenantri Phenanthridine, permidine, acridine, cynoline, quinazoline, quinoxaline, naphthydrine, phthalazine, phthalazine Quinolizine, indole, indazole, pyridazine, pyrazine, pyrimidine, pyridine, pyridine, pyrazole, Imidazole, pyrrole, and the like, preferably phenyl, naphthalene, carbazole, fluorene.

Meanwhile, the aromatic quinoline derivatives and carbazole derivatives introduced into the main ligands according to the present invention may be substituted by various substituents such as alkyl groups, alkoxy groups, cyanide groups, nitro groups, halogens, and the like. It can be used, and when applied to the organic light emitting device can improve the interface characteristics with the electrode. Particularly as the substituent which may be substituted in the aromatic ring connected to quinoline in the context of the present invention, for example, an alkyl group having 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms, preferably 1 to 20 carbon atoms, It contains an alkoxy group. Meanwhile, halogen such as fluorine (F), chlorine (Cl), bromine (Br), iodine (I) and the like may be used as a substituent of an aromatic ring connected to quinoline, and preferred halogen atoms include fluorine and chlorine.

Meanwhile, according to the present invention, the functional group (R ₂ ) which may be substituted with the carbazole derivative introduced into the iridium complex of the iridium complex together with the aromatic quinoline derivative is hydrogen or an alkyl group having 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms. Is an alkyl group. Due to the alkyl group which can be substituted for carbazole, the solubility or compatibility of the iridium complex according to the present invention to the organic solvent can be improved.

)로는 아세틸아세톤(acetyl acetone,

), 피콜리닉산(picolinic acid,

); 피콜리닉산-N-옥사이드(picolinic acid N-oxide,

); 피라진산(pyrazine-2-carboxylic acid,

); 또는 피페콜리닉산(pipecolinic acid,

) 등이 포함될 수 있으나, 본 발명이 이들 보조리간드로만 한정되는 것은 아니다. On the other hand, the iridium complex synthesized according to the preferred embodiment of the present invention is an ancillary ligand (ancillary ligand) is introduced separately from the above-described main ligand. The auxiliary ligands are selected to adjust the fine color in the luminescence properties of the synthesized complex, and in particular, it is preferable that the conjugated structure is less formed so that the iridium complex of the present invention exhibits a purer red color. Secondary ligand that can be selected in connection with the present invention (

Acetyl acetone (acetyl acetone,

Picolinic acid,

); Picolinic acid N-oxide (picolinic acid N-oxide,

); Pyrazine-2-carboxylic acid,

); Or pipecolinic acid,

) May be included, but the present invention is not limited to these auxiliary ligands.

Next, the synthesis | combining process of the iridium complex compound which concerns on this invention is demonstrated. 1 is a schematic diagram illustrating a process of synthesizing the iridium complex of Chemical Formula 1 according to an embodiment of the present invention.

As shown, first, aluminum chloride, carbon disulfide, and the like are added to a carbazole ((1)) substituted with an alkyl group having 1 to 20 carbon atoms, and then acetyl chloride is mixed to form an alkyl carbazole ((2)) substituted with a ketone. Create Subsequently, the aromatic quinolin-alkylcarbazole ((4)) can be obtained by mixing the aminophenone ((3)) substituted by aromatic with the obtained ketone substituted alkyl carbazole ((2)). The aromatic aminophenone ((3)) used in the present process according to the present invention is converted into a quinoline derivative in this process. The process for synthesizing aromatic aminophenone ((3)) as a precursor for producing aromatic quinoline according to the present invention is well known. For example, aminophenone having an aromatic ring as a phenyl group may be obtained by the process shown in Scheme 1 below. Can be.

Scheme 1

In addition, amino quinones in which the aromatic ring is substituted by two or more aromatic rings such as naphthalene, carbazole, fluorene, and the like may be synthesized through the process of Scheme 2 below.

Scheme 2

Subsequently, a mixture of the aromatic quinoline-alkylcarbazole ((4)) and the iridium chloride hydrate (IrCl ₃ -3H ₂ O) obtained is dissolved in an appropriate solvent and mixed, followed by chlorine-crosslinked dimer ( (5)) can be synthesized Finally, the chlorine-crosslinked dimer ((5)) can be mixed with an auxiliary ligand and an appropriate solvent to finally synthesize the iridium complex ((6)). It was confirmed that the iridium complex compound synthesized through exhibited a maximum emission peak at approximately 625 nm, as can be seen from the emission measurement result of FIG. 4, to have pure red emission characteristics.

The iridium complex compound synthesized through the above-described method is a phosphorescent light emitting material having excellent light emission characteristics, and when used as a dopant of a light emitting layer of an organic light emitting diode, for example, pure red light emission can be obtained. An organic electroluminescent device to which a complex compound can be applied will be described. 2A schematically illustrates an organic light emitting display device 1000 in a single layer type to which the above-described iridium complex compound may be applied according to an embodiment of the present invention. The single layer organic light emitting diode 1000 has a structure in which the substrate 1100, the first electrode 1110, the light emitting layer 1140, and the second electrode 1170 are sequentially stacked. The substrate 1100 may be made of a material such as, for example, glass or plastic.

Meanwhile, the first electrode 1110 and the second electrode 1170, for example, function as an anode and a cathode, respectively, and the first electrode 1110 is one part of the second electrode 1170. Use materials with large work functions. In particular, in relation to the present invention, the first electrode 1110 is an effective material for injecting a hole, which is a positive-charged carrier, and is a metal, a mixed metal, an alloy, a metal oxide, or a mixed metal oxide or a conductive polymer. Can be. Specifically, the first electrode 1110 may be indium-tin oxide (ITO), fluorine doped tin oxide (FTO), ZnO-Ga ₂ O ₃ , or ZnO-Al ₂ O ₃ , SnO ₂ -Sb ₂ O ₃ Materials such as mixed metal oxides, conductive polymers such as polyaniline, polythiophene, and the like may be used, and according to a preferred embodiment, ITO.

In contrast, the second electrode 1170 may be a material effective for injecting electrons, which are negative-charged carriers, as gold, aluminum, copper, silver, or alloys thereof; Aluminum, indium, calcium, barium, magnesium and alloys thereof, such as calcium / aluminum alloys, magnesium / silver alloys, aluminum / lithium alloys, and the like; Or in some cases, may be selected from metals belonging to rare earths, lanthanides, actinides, preferably aluminum, or aluminum / calcium alloys.

Meanwhile, in the emission layer 1140 stacked between the first electrode 1110 and the second electrode 1170, the above-described iridium complex compound synthesized according to the present invention is used as a dopant. In this regard, the light emitting layer 1140 includes a host, which is a light emitting material, to increase luminous efficiency by suppressing energy loss processes such as color purity change and quenching. In particular, in the case of the iridium complex synthesized according to the present invention, since almost pure red light is emitted, the host may be selected so that the energy emitted from the host included in the light emitting layer 1140 may be well transferred to the iridium complex which is a dopant. According to the present invention, the host included in the light emitting layer 1140 may include both a host having a fluorescent property and a host having a phosphorescent property, but a host having a phosphorescent property. Specifically, the host, which is a light emitting material in the red region, may be, for example, a poly (phenylenevinylene), a polyvinyl fluoride (poly (fluorene)) system, or a polyparaphenylene (poly (para-phenylene) system. ), PPP), polyalkylalkylthiophene, polypyridine, PPy, polymer materials such as distyrylbenzene (DSB) and distyrylbenzene derivatives (PESB) ), Distyrylarylene (DSA), distyrylarylene derivatives, 1,2,3,4,5-pentaphenyl-1,3-cyclopentadiene (1,2,3,4,5-pentaphenyl Cyclopentadiene derivatives such as -1,3-cyclopentadiene, PPCP), DPVBi (4,4'-bis (2,2'-diphenyl vinyl) -1,1'-biphenyl), DPVBi derivatives, spiro-DPVBi And the like.

In particular, hosts having phosphorescent properties that can be used in connection with the present invention include aryl amines, carbazoles, and spiros. Specifically, 4,4-N, N-dicarbazole-biphenyl (4,4-N, N-dicarbazole-biphenyl, CBP), N, N-dicarbazoyl-3,5-benzene (N, N- dicarbazoyl-3,5-benzene, mCP), poly (vinylcarbazole, PVK), polyfluorene, 4,4'-bis [9- (3,6biphenylcarbazolyl)]-1- 1,1'-biphenyl4,4'-bis [9- (3,6-biphenylcarbazolyl)]-1-1,1'-biphenyl, 9,10-bis [(2 ', 7' -t-butyl) -9 ', 9' '-spirobifluorenyl anthracene, tetrafluorene (tetrafluorene) and the like may be included, preferably CBP and mCP may be used.

According to a preferred embodiment, the light emitting layer 1170 is laminated on top of the first electrode 1110 with a thickness of approximately 5 to 200 nm, preferably 50 to 10 nm, wherein the iridium complex synthesized according to the present invention is a dopant. It is included in a concentration of 3 to 20% by weight, preferably 5 to 10% by weight with respect to the light emitting layer 1170.

On the other hand, the iridium complex synthesized according to the present invention is not only the organic light emitting device 1000 in the form of a single layer described above, but also a multi-layer organic field provided with a separate layer for electron / hole transport between the light emitting layer and the electrode. 2B is a schematic cross-sectional view of an organic light emitting diode 2000 having a multi-layer type to which an iridium complex compound synthesized according to the present invention can be applied. As shown, the organic light emitting diode 2000 includes a substrate 2100, a first electrode 2110, a hole injection layer (HIL) 2120, a hole transporting layer (HTL) 2130. The light emitting layer 2140, the electron transporting layer (ETL) 2150, the electron injection layer (EIL) 2160, and the second electrode 2170 are sequentially stacked.

In the multilayer organic light emitting device 2000 having the above-described structure, the hole injection layer 2120 stacked between the first electrode 2110 and the light emitting layer 2140 may be formed of ITO and holes used as the first electrode 2100. In addition to improving the interfacial properties between the organic materials used as the transfer layer 2130, the surface is applied on top of the uneven ITO to serve to smooth the surface of the ITO. In particular, the hole injection layer 2120 has a work function level of ITO and a hole transport layer 2130 in order to control the difference between the work function level of ITO that can be used as the first electrode 2110_ and the HOMO level of the hole transport layer 2130. In particular, a material having an appropriate conductivity is selected as a material having a median value of HOMO level of C. In the present invention, a material forming the hole injection layer 2120 includes copper phthlalocyanine (CuPc) and N, N′-dinaphthyl. -N, N'-phenyl- (1,1'-biphenyl) -4,4'-diamine, NPD), 4,4 ', 4' '-tris [methylphenyl (phenyl) amino] triphenyl amine (m-MTDATA ), 4,4 ', 4' '-tris [1-naphthyl (phenyl) amino] triphenyl amine (1-TNATA), 4,4', 4 ''-tris [2-naphthyl (phenyl) amino] triphenyl amine Aromatic amines such as (2-TNATA), 1,3,5-tris [N- (4-diphenylaminophenyl) phenylamino] benzene (p-DPA-TDAB), and poly (3,4-, polythiophene derivatives as conductive polymers. ethylenedioxythiophene) -poly (styrnesulfonate) (PEDOT) may be used, which in the embodiment of the present invention DOT was used. The hole injection layer 2120 may be coated on the upper portion of the first electrode 2110 to a thickness of 20 to 200Å.

Meanwhile, a hole transport layer 2130 is formed on the hole injection layer 2120 to stably supply the holes introduced through the hole injection layer 2120 to the light emitting layer 2140, and the holes may be smoothly transported and transferred. The material of which the HOMO level of the hole transport layer 2130 is higher than the HOMO level of the light emitting layer 2140 is selected. The material that can be used in the hole transport layer 2130 in accordance with the present invention is N, N'-bis (3-methylphenyl) -N, N'-diphenyl- [1,1'-diphenyl-4,4'- diamine (TPD), N, N'-bis (1-naphthyl) -N, N'-biphenyl- [1,1'-biphenyl] -4,4'-diamine (TPB), N, N'-di ( naphthalene-1-yl) -N, N'-diphenyl-benzidene (NPB), triphenylamine (TPA), bis [4- (N, N-diethylamino) -2-methylphenyl] (4-methylphenyl) methane (MPMP ), N, N, N ', N'-tetrakis (4-methylphenyl)-(1,1'-biphenyl) -4,4-diamine (TTB), N, N'-bis (4-methylphenyl) -N Low molecular hole transport materials such as, N'-bis (4-ethylphenyl)-[1,1 '-(3,3'-dimethyl) biphenyl] -4,4'-diamine (ETPD); Polymer hole transport materials such as polyvinylcarbazole, polyaniline, (phenylmenyl) polysilane, and the like can be used. According to an embodiment of the present invention, NPB was used as the hole transport layer 2130, and the hole injection layer 2130 may be deposited on the hole injection layer 2120 at a thickness of about 10 to 100 nm.

Meanwhile, according to the present invention, the electron injection layer 2160 and the electron transport layer 2150, which may correspond to the hole injection layer 2120 and the hole transport layer 2130, are disposed between the emission layer 2140 and the second electrode 2170. Is formed. The electron injection layer 2160 is used to induce smooth electron injection. Unlike other charge transfer layers, an alkali metal or alkaline earth metal ion form is used, such as LiF, BaF ₂ , CsF, and the like. And may be capable of inducing doping for 2150.

On the other hand, the electron transport layer 2150 is mainly composed of a material containing a chemical component that attracts electrons, for which high electron mobility is required, and stably supplies electrons to the light emitting layer 2140 through smooth electron transport. In this case, the particularly strong electron-receiver component may quench the electrons, so it is preferable to use an appropriate electron-receiving component to improve electron mobility. Electron transport layers that may be used in accordance with the present invention include Alq ₃ and oxadizole components. Specifically, Tris (8-hydroxyquinolinato) aluminum (Alq ₃ ); 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (DDPA); 2- (4-biphenyl) -5- (4-tert-butyl) -1,3,4-oxadizole (PBD), 3- (4-biphenyl) -4-phenyl-5- (4-tert-butyl) Azole compounds such as -1,2,4-triazole (TAZ); phenylquinozaline and the like. In the embodiment of the present invention, Alq ₃ was used as the electron transport layer 2150, and the electron transport layer 2150 may be stacked on the light emitting layer 2140 to a thickness of 5 to 150 nm.

On the other hand, although not shown in the drawings, when the holes introduced through the hole injection layer 2120 and the hole transport layer 2130 passes through the light emitting layer 2140 to the second electrode 2170 and the lifetime of the device Since the efficiency may be reduced, a hole blocking layer (HBL) having a very low HOMO level may be formed between the emission layer 2140 and the electron transport layer 2150. Materials that can be used in the hole blocking layer in the context of the present invention include 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), and the light emitting layer (2140) having a thickness of approximately 5 ~ 150 nm It may be deposited on top of).

As described above, the iridium complex synthesized according to the present invention exhibits a wavelength corresponding to the pure red region. The electroluminescent device applying the improved iridium complex as a dopant of the light emitting layer is about 625 nm as shown in FIG. 4. It was confirmed that light emission was shown in the red region.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited by the following examples.

Example  One. Ethylcarbazole - Phenylquinoline Juri Gand  Acetylacetone Secondary ligand  Synthesis of Iridium Complexes Having

1) Preparation of 1- (9-ethylcarbazol-3-yl) -ethanone

Into a three-necked flask, 5.0 g (25.6 mmol) of ethyl carbazole ((1) of FIG. 1) was added, 5.12 g (38.4 mmol) of aluminum chloride (AlCl ₃ ) and 40 mL of carbon disulfide (CS ₂ ) were added thereto, followed by a nitrogen atmosphere. Stirred at. 2.36 mL (33.2 mmol) of acetyl chloride was added to the reaction mixture, stirred at room temperature for 2 hours, distilled water was added to terminate the reaction, and the product was extracted twice with 30 mL of ethyl acetate. The organic layer containing the product was dried using magnesium sulfate, separated by column chromatography using hexane and ethyl acetate, and then purified by 1- (9-ethylcarbazol-3yl) -ethanone (1- (9- 3.0 g (yield 49%) of ethylcarbazole-3-yl) -ethanone (FIG. 1 (2)) were obtained, and NMR results for the obtained composite were shown below.

¹ H-NMR (CDCl ₃ ): (ppm) 1.54-1.59 (t, 3H, C H ₃ CH ₂ N), 2.84 (s, 3H, C H ₃ CO), 4.49-4.54 (q, 2H, CH ₃ C H ₂ N), 7.42-7.66 (m, 4H, aromatic proton), 8.23-8.29 (m, 2H, aromatic proton), 8.66 (s, 1H, aromatic proton).

2) Preparation of 9-ethyl-3- (4-phenylquinolin-2-yl) carbazole

1- (9-ethylcarbazol-3-yl) ethanone (Fig. 1 (2)) 2.7 g (11.3 mmol), 2-aminobenzophenone (2-aminobenzophenone (3)) 2.46 obtained above g (12.5 mmol), 3.41 g (13.6 mmol) of diphenylphosphate, and 8.0 mL of methacresol were placed in a three-necked flask, and the mixture was stirred at room temperature for 20 minutes in a nitrogen atmosphere, and then refluxed for 12 hours. After the three-necked flask was cooled to room temperature, 60 mL of methylene chloride and 10% aqueous sodium hydroxide (NaOH) solution were added thereto, and the organic layer was separated. The obtained organic layer was washed several times with distilled water, dried over magnesium sulfate, separated by column chromatography using hexane and ethyl acetate, and then introduced into iridium 9-ethyl-3- (4). 3.5 g (yield 77%) of -phenylquinolin-2-yl) carbazole (9-ethyl-3- (4-phenylquinoline-2-yl) -carbazole, (4) of FIG. 1) was obtained. The NMR results for the resulting composites are shown below.

¹ H-NMR (CDCl ₃ ): (ppm) 0.96 (t, 3H, C H ₃ (CH ₂ ) ₇ N), 1.33-1.77 (m, CH ₃ (C H ₂ ) ₆ CH ₂ N) 2.55 (s , 3H, C H ₃ CO), 3.85 (q, 2H, CH ₃ (CH ₂ ) ₆ C H ₂ N), 7.42-7.66 (m, 4H, aromatic proton), 8.23-8.29 (m, 2H, aromatic proton ), 8.66 (s, 1 H, aromatic proton).

3) Preparation of chloride-bridged dimer

300 mg (0.75 mmol) of 9-ethyl-3- (4-phenylquinolin-2-yl) carbazole obtained above and 264 mg of iridium chloride hydrate (IrCl ₃ -3H ₂ O) (0.75 mol) were 2-ethoxyethanol. The solution dissolved in 3.0 mL and 1.3 mL of distilled water was stirred at 120 ° C. for 24 hours. After cooling the stirred solution to room temperature, the resulting yellow solid was filtered and washed well with water-ethanol (3: 1) to give 300 mg (yield of the desired product chlorine-crosslinked dimer (5 in Fig. 1) 93%). The melting point of the product obtained was 213 ~ 215 ℃, NMR results are shown below.

¹ H-NMR (CDCl ₃ ); δ 1.39 (m, 12H), 4.31 (m, 8H), 7.07-7.18 (m, 4H), 7.26-8.03 (m, 44H), 8.20 (m, 4H), 8.45 (m, 4H), 8.71 (m , 4H), 8.94 (m, 4H).

4) Preparation of Complex Compound Having Acetyl Acetone as Secondary Ligand

To 100 mg (0.048 mmol) of chlorine-crosslinked dimer obtained above, 12.6 μL (0.12 mmol) of acetylacetone, and 15.5 mg (0.15 mmol) of Na ₂ CO ₃ were added 1.5 mL of 2-ethoxyethanol, followed by stirring for 30 minutes, followed by 20 hours. It was refluxed. The refluxed solution was cooled to room temperature, and the resulting solid was filtered and washed well with water-ethanol (3: 1) to obtain an iridium complex compound (FIG. 1 (6)) into which acetylacetone was introduced as a secondary ligand. Hereinafter, the iridium complex compound obtained through this example is abbreviated as "Ir (IsoQ-Cvz-2) ₂ (acac)". The melting point of the iridium complex compound obtained according to the present example was 199 to 210 ° C, and the NMR results are shown below.

¹ H-NMR (CDCl ₃ ); δ 1.46 (m, 6H), 4.71 (m, 4H), 6.30 (s, 1H), 6.78 (m, 1H), 7.01 (s, 1H), 7.14-8.24 (m, 24H), 8.62 (s, 1H ), 8.77 (s, 1 H), 8.90-8.94 (m, 2 H), 9.62 (m, 1 H).

Example  2. Ethylcarbazole - Phenylquinoline Juri Gand Picolinic Secondary ligand  Synthesis of Iridium Complexes Having

In this example, the iridium complex was synthesized by repeating the same conditions and procedures as in Example 1 except that picolinic acid was introduced as an auxiliary ligand. 1.5 mL of 2-ethoxyethanol was added to 100 mg (0.048 mmol) of chlorine-crosslinked dimers (FIG. 1 (5)), and 15 mg (0.12 mmol) of picolinic acid, which were produced through the procedure of Example 1 above. It was refluxed for 20 hours after the addition. After the refluxed solution was cooled to room temperature, the resulting solid was filtered and washed well with water-ethanol (3: 1) to obtain 77 mg (yield 71%) of iridium complex in which picolinic acid was introduced as a secondary ligand. Hereinafter, the iridium complex compound obtained through this example is abbreviated as "Ir (IsoQ-Cvz-2) ₂ (pic)". The melting point of the iridium complex compound obtained according to this example was 221 to 223 ° C, and the NMR results are shown below.

¹ H-NMR (CDCl ₃ ); δ 1.46 (m, 6H), 4.71 (m, 4H), 6.30 (s, 1H), 6.78 (m, 1H), 7.01 (s, 1H), 7.14-8.24 (m, 24H), 8.62 (s, 1H ), 8.77 (s, 1 H), 8.90-8.94 (m, 2 H), 9.62 (m, 1 H).

Example  3. Ethylcarbazole - Phenylquinoline Juri Gand Picolinic acid -N- oxide of Secondary ligand  Synthesis of Iridium Complexes Having

In this example, the iridium complex in which picolinic acid-N-oxide was introduced into the secondary ligand according to the same procedure as in Example 2 except that picolinic acid N-oxide was used in the same molar ratio instead of picolinic acid as the secondary ligand. Was synthesized.

Example  4. Ethylcarbazole - Phenylquinoline Juri Gand Pyrazine Secondary ligand  Synthesis of Iridium Complexes Having

In this example, an iridium complex in which pyrazine acid was introduced into the secondary ligand was synthesized according to the same procedure as in Example 2, except that pyrazinic acid was used instead of picolinic acid as the secondary ligand.

Example  5. Ethylcarbazole - Phenylquinoline Juri Gand Pipecolinic acid Secondary ligand  Synthesis of Iridium Complexes Having

In this example, an iridium complex in which pipecolinic acid was introduced into the secondary ligand was synthesized according to the same procedure as in Example 2, except that pipecolinic acid was used instead of picolinic acid as the auxiliary ligand.

Example  6. Ethylcarbazole - Phenylquinoline Juri Gand  Acetylacetone Secondary ligand  Synthesis of Iridium Complexes Having

In this example, the same procedure as in Example 1 was repeated except that 2-aminobenzo (p-methylphenone) was used instead of 2-aminobenzophenone, which was used to introduce an aromatic quinoline, which is a main ligand, and was substituted with a methyl group. Iridium complexes into which phenylquinoline was introduced into the main ligand were synthesized.

Example  7. Ethylcarbazole - Phenylquinoline Juri Gand  Acetylacetone Secondary ligand  Synthesis of Iridium Complexes Having

In this example, the same procedure as in Example 1 was repeated except that 2-aminobenzo (p-octylphenone) was used instead of 2-aminobenzophenone used to introduce the aromatic quinoline, which is a main ligand. An iridium complex in which phenylquinoline substituted with a group was introduced into the main ligand was synthesized.

Example  8. Ethylcarbazole - Phenylquinoline Juri Gand  Acetylacetone Secondary ligand  Synthesis of Iridium Complexes Having

The same procedure as in Example 1 was repeated except that 2-aminobenzo (p-methoxyphenone) was used instead of 2-aminobenzophenone which was used to introduce aromatic quinoline, which is a main ligand. An iridium complex in which phenylquinoline substituted with was introduced into the main ligand was synthesized.

Example  9. Ethylcarbazole - Phenylquinoline Juri Gand  Acetylacetone Secondary ligand  Synthesis of Iridium Complexes Having

In this example, the same procedure as in Example 1 was repeated, except that 2-aminobenzo (p-octyloxyphenone) was used instead of 2-aminobenzophenone which was used to introduce the aromatic quinoline, which is a main ligand. An iridium complex in which phenylquinoline substituted with a group was introduced into the main ligand was synthesized.

Example  10. Ethylcarbazole - Phenylquinoline Juri Gand  Acetylacetone Secondary ligand  Synthesis of Iridium Complexes Having

In this example, the same procedure as in Example 1 was repeated except that 2-aminobenzo (p-cyanophenone) was used instead of 2-aminobenzophenone which was used to introduce an aromatic quinoline, which is a main ligand. An iridium complex in which phenylquinoline substituted with a group was introduced into the main ligand was synthesized.

Example  11. Ethylcarbazole - Phenylquinoline Juri Gand  Acetylacetone Secondary ligand  Synthesis of Iridium Complexes Having

The same procedure as in Example 1 was repeated except that 2-aminobenzo- (p-nitrophenone) was used instead of 2-aminobenzophenone which was used to introduce the aromatic quinoline, which is a main ligand. An iridium complex in which substituted phenylquinoline was introduced into the main ligand was synthesized.

Example  12. Ethylcarbazole - Phenylquinoline Juri Gand  Acetylacetone Secondary ligand  Synthesis of Iridium Complexes Having

In this example, the same procedure as in Example 1 was repeated except that 2-aminobenzo- (p-chlorophenone) was used instead of 2-aminobenzophenone used to introduce the aromatic quinoline, which is a main ligand. An iridium complex in which substituted phenylquinoline was introduced into the main ligand was synthesized.

Example  13. Ethylcarbazole - Phenylquinoline Juri Gand  Acetylacetone Secondary ligand  Synthesis of Iridium Complexes Having

In this example, the same procedure as in Example 1 was repeated except that 2-amino- (p-carbazolephenone) was used instead of 2-aminobenzophenone which was used to introduce the aromatic quinoline, which is a main ligand. An iridium complex in which quinoline substituted with was introduced into the main ligand was synthesized.

Example  14. Ethylcarbazole - Phenylquinoline Juri Gand  Acetylacetone Secondary ligand  Synthesis of Iridium Complexes Having

In this example, quinoline substituted with naphthyl group using 2-amino- (p-naphthylphenone) instead of 2-aminobenzophenone, which was used to introduce aromatic quinoline, which is a ligand in Example 1, was used as the main ligand. The introduced iridium complex was synthesized.

Example  15. Octylcarbazole - Phenylquinoline Juri Gand  Acetylacetone Secondary ligand  Synthesis of Iridium Complexes Having

In this example, the iridium complex was synthesized by repeating the same procedure as in Example 1 except that octylcarbazole was used instead of ethyl carbazole as a starting material having carbazole introduced into the ligand.

1) Synthesis of 1- (9-octylcarbazol-3-yl) ethanone

Repeating the same procedure under the same conditions as in Example 1 using 7.14 g (25.6 mmol) of octylcarbazole as starting material, 1- (9-octylcarbazole-3-yl) ethanone (1- (9-octylcarbazole- 4.03 g (yield 49%) of 3-yl) ethanone ((2) of FIG. 1) were obtained, and the NMR results for the obtained composite were shown below.

¹ H-NMR (CDCl ₃ ): (ppm) 0.96 (t, 3H, CH ₃ (CH ₂ ) ₇ N), 1.33-1.77 (m, CH ₃ (CH ₂ ) ₆ CH ₂ N) 2.55 (s, 3H , CH ₃ CO), 3.85 (q, 2H, CH ₃ (CH ₂ ) ₆ CH ₂ N), 7.42-7.66 (m, 4H, aromatic proton), 8.23-8.29 (m, 2H, aromatic proton), 8.66 ( s, 1H, aromatic proton).

2) Synthesis of 9-octyl-3- (4-phenylquinolin-2-yl) -carbazole

9-octyl-3- (4-phenylquinoline was repeated under the same conditions as in Example 1 using 3.6 g (11.3 mmol) of 1- (9-octylcarbazol-3-yl) -ethanone obtained above. 2-yl) -carbazole (9-octyl-3- (4-phenylquinoline-2-yl) carbazole, (4)) of FIG. 1 was obtained (yield 77%), and the NMR result of the obtained compound was obtained. Is shown below.

¹ H-NMR (CDCl ₃ ): (ppm) 0.96 (t, 3H, C H ₃ (CH ₂ ) ₇ N), 1.33-1.77 (m, CH ₃ (C H ₂ ) ₆ CH ₂ N) 2.55 (s , 3H, C H ₃ CO), 3.85 (q, 2H, CH ₃ (CH ₂ ) ₆ C H ₂ N), 7.25-8.41 (m, 16H, aromatic proton), 8.95 (s, 1H, aromatic proton).

3) Synthesis of chlorine-crosslinked dimers

300 mg (0.62 mmol) of 9-octyl-3- (4-phenylquinolin-2-yl) -carbazole obtained above and 91.7 mg (0.26 mmol) of iridium chloride hydrate (IrCl ₃ -3H ₂ O) were 2-ethoxy The same procedure as in Example 1 was repeated except that 2.2 mL of ethanol was dissolved in 0.8 mL of distilled water to obtain 300 mg (yield 97%) of chlorine crosslinked dimer ((5) of FIG. 1). Melting point of the resulting chlorine-crosslinked dimer was 151 ~ 153 ℃, NMR measurement results are shown below.

¹ H-NMR (CDCl ₃ ); δ 0.70-1.21 (m, 52H), 1.82-2.02 (m, 8H), 4.21-4.22 (m, 8H), 5.39 (s, 8H), 6.86-7.99 (m, 32H), 8.13-8.19 (m, 8H), 8.51 (m, 8H), 8.79 (m, 4H), 9.08 (m, 4H).

4) Synthesis of Iridium Complex

To 60 mg (0.025 mmol) of chlorine-crosslinked dimer obtained above, 6.9 μL (0.06 mmol) of acetylacetone, and 8 mL (0.08 mmol) of Na ₂ CO ₃ were added 1 mL of 2-ethoxyethanol to carry out the same procedure as in Example 1. An iridium complex in which acetylacetone was introduced as a secondary ligand was repeatedly synthesized. Hereinafter, the iridium complex compound obtained through this Example is abbreviated as "Ir (IsoQ-Cvz-8) ₂ (acac)". The melting point of the iridium complex compound obtained according to the present example was 83 to 85 ° C., and the NMR results are shown below.

¹ H-NMR (500 MHz, CDCl ₃ ); δ 0.80-0.86 (m, 6H), 1.09-1.59 (m, 20H), 1.90 (t, 4H, J = 6.81), 4.34 (t, 4H, J = 7.03), 4.78 (s, 1H), 6.54 ( s, 1H), 7.10 (d, 2H, J = 8.11), 7.69-7.98 (m, 18H), 8.21-8.22 (m, 3H), 8.28 (d, 2H, J = 8.38), 8.38 (d, 2H , J = 8.42), 8.60 (s, 1 H), 8.68 (d, 1 H, J = 8.36), 8.94 (s, 2H).

Example  16. Octylcarbazole - Phenylquinoline Juri Gand  Acetylacetone Secondary ligand  Synthesis of Iridium Complexes Having

In this example, the iridium complex was synthesized by repeating the same conditions and procedures as in Example 6 except that picolinic acid was introduced as an auxiliary ligand. 1 mL of 2-ethoxyethanol was added to 80 mg (0.034 mmol) of chlorine-crosslinked dimers (FIG. 1 (5)) and 10.3 mg (0.09 mmol) of picolinic acid, which were formed in the middle of the process of Example 6. It was refluxed for 20 hours after the addition. After the refluxed solution was cooled to room temperature, the resulting solid was filtered and washed well with water-ethanol (3: 1) to obtain 75 mg (yield 86%) of iridium complex having picolinic acid introduced into the secondary ligand. Hereinafter, the iridium complex compound obtained through this example is abbreviated as "Ir (IsoQ-Cvz-8) ₂ (pic)". The melting point of the iridium complex compound obtained according to the present example was 145 to 147 ° C, and the NMR results are shown below.

¹ H-NMR (500 MHz, CDCl ₃ ); δ 0.79-1.37 (m, 26H), 1.85-1.87 (m, 4H), 4.29 (t, 4H, J = 6.23), 6.21 (s, 1H), 6.77 (t, 1H, J = 7.17), 6.94 ( s, 1H), 7.08-8.25 (m, 26H), 8.61 (s, 1H), 8.74 (s, 1H), 8.95-8.96 (m, 1H).

Example  17. Octylcarbazole - Phenylquinoline Juri Gand  Acetylacetone Secondary ligand  Synthesis of Iridium Complexes Having

In this example, the same procedure as in Example 15 was repeated except that 2-aminobenzo (p-methylphenone) was used instead of 2-aminobenzophenone which was used to introduce an aromatic quinoline, which is a main ligand, and substituted with a methyl group. Iridium complexes into which phenylquinoline was introduced into the main ligand were synthesized.

Example  18. Octylcarbazole - Phenylquinoline Juri Gand  Acetylacetone Secondary ligand  Synthesis of Iridium Complexes Having

The same procedure as in Example 1 was repeated except that 2-aminobenzo (p-methoxyphenone) was used instead of 2-aminobenzophenone which was used to introduce aromatic quinoline, which is a main ligand. An iridium complex in which phenylquinoline substituted with was introduced into the main ligand was synthesized.

Example  19. Octylcarbazole - Phenylquinoline Juri Gand  Acetylacetone Secondary ligand  Synthesis of Iridium Complexes Having

In this example, the same procedure as in Example 1 was repeated except that 2-aminobenzo (p-cyanophenone) was used instead of 2-aminobenzophenone which was used to introduce an aromatic quinoline, which is a main ligand. An iridium complex in which phenylquinoline substituted with cyanide group was introduced into the ligand was synthesized.

Example  20. Octylcarbazole - Phenylquinoline Juri Gand  Acetylacetone Secondary ligand  Synthesis of Iridium Complexes Having

The same procedure as in Example 15 was repeated except that 2-aminobenzo- (p-nitrophenone) was used instead of 2-aminobenzophenone which was used to introduce the aromatic quinoline in this example. An iridium complex in which phenylquinoline was introduced into the main ligand was synthesized.

Example  21. Octylcarbazole - Phenylquinoline Juri Gand  Acetylacetone Secondary ligand  Synthesis of Iridium Complexes Having

In this example, the same procedure as in Example 15 was repeated except that 2-aminobenzo- (p-chlorophenone) was used instead of 2-aminobenzophenone used to introduce the aromatic quinoline. An iridium complex in which quinoline was introduced into the jurigan was synthesized.

Example  22. Octylcarbazole - Phenylquinoline Juri Gand  Acetylacetone Secondary ligand  Synthesis of Iridium Complexes Having

In this example, the same procedure as in Example 15 was repeated except that 2-amino- (p-carbazolephenone) was used instead of 2-aminobenzophenone used to introduce the aromatic quinoline, which was substituted with a carbazole group. An iridium complex in which quinoline was introduced into the jurigan was synthesized.

Example  23. Octylcarbazole - Phenylquinoline Juri Gand  Acetylacetone Secondary ligand  Synthesis of Iridium Complexes Having

In this example, the same procedure as in Example 1 was repeated except that 2-amino- (p-naphthylphenone) was used instead of 2-aminobenzophenone used to introduce the aromatic quinoline, which was substituted with a naphthyl group. An iridium complex in which quinoline was introduced into the jurigan was synthesized.

Example  24. Iridium Of complex compounds  Absorption Spectrum Measurement

In the present embodiment, the iridium complexes Ir (IsoQ-Cvz-2) ₂ (acac), Ir (IsoQ-Cvz-2) ₂ (pic), which are synthesized through the procedures of Examples 1, 2, 15, and 16, respectively, UV-visible absorption spectra were measured using a Shimadzu UV-3100 spectrometer with Ir (IsoQ-Cvz-8) ₂ (acac) and Ir (IsoQ-Cvz-8) ₂ (pic) luminescent materials dissolved in chloroform. .

FIG. 3 is a graph illustrating UV-visible absorption spectrum measurement results for an Ir (IsoQ-Cvz-2) ₂ (acac) light emitting material which is a iridium complex synthesized in Example 1. FIG. Looking at the UV absorption peak of the iridium complex synthesized according to the present invention, the transition phenomenon of phenylquinoline and carbazole derivatives occurs at a wavelength of about 247, 298 nm, the center metal of single and triplet at a wavelength of about 371-571 nm- It can be seen that the state of charge transfer between ligands occurs.

Example  25. Iridium Complex in Solution photoluminescence  ( PL ) Measure

In this embodiment, Ir (IsoQ-Cvz-2) ₂ (acac), Ir (IsoQ-Cvz-2) ₂ (pic), and Ir (IsoQ, which are the light emitting materials synthesized in Examples 1, 2, 15, and 16, respectively, PL was measured with Hitachi F-4500 while -Cvz-8) ₂ (acac) and Ir (IsoQ-Cvz-8) ₂ (pic) were dissolved in chloroform. PL was measured using the UV maximum absorption wavelength measured in each iridium-based light emitting material as an excitation wavelength. In FIG. 4, in particular, the iridium complex compound Ir (IsoQ-Cvz-2) ₂ (acac) synthesized in Example 1 was measured. The PL measurement results are shown graphically. As shown, the iridium complex synthesized according to an embodiment of the present invention can be seen that the maximum emission peak is formed at approximately 625nm to exhibit a pure red emission color.

Comparative Example : Ir ( btp ) ₂ (acac) Dopant  Measurement of Physical Properties of Phosphorescent Organic Electroluminescent Device of Red Light Emitting Using

In this embodiment, Ir (btp) ₂ (acac) (Iridium (III) bis (2- (2'-benzothienyl) pyridinato-N, C2) (acetylacetonate) disclosed in U.S. Patent No. 7,250,512 is used as a dopant of the light emitting layer. EL intensity was measured for the organic light emitting diodes used, and the measurement results are shown in Fig. 5. As illustrated, Ir (btp) ₂ (acac) reported as a red phosphorescent compound of the prior art was about 620. The maximum emission peak was shown at nm and the emission peak was shown at 675 nm, indicating that the red emission characteristics and color purity were inferior to those of the iridium complex synthesized according to the present invention.

In the above, the present invention has been described based on the preferred embodiments of the present invention. However, the present invention is only intended to illustrate the present invention, but the present invention is not limited thereto. Rather, one of ordinary skill in the art to which the present invention pertains will be able to easily make various modifications and changes with reference to the embodiments described above. However, it will be apparent from the scope of the following claims that such modifications and variations fall within the scope of the present invention without departing from the spirit of the present invention.

1 is a schematic diagram illustrating a mechanism in which iridium complexes in which carbazole and aromatic quinoline are introduced into a jurigan are prepared according to one embodiment of the present invention;

2A and 2B are cross-sectional views schematically illustrating an organic EL device having a single layer type and an organic EL device having a multilayer type to which an iridium complex compound synthesized according to the present invention is applied, respectively;

Figure 3 is a graph showing the UV-visible absorption spectrum measurement results for the iridium complex synthesized according to an embodiment of the present invention;

4 is a graph showing the results of measuring the intensity of photoluminescence (PL) for the iridium complex synthesized according to an embodiment of the present invention;

FIG. 5 is a graph showing electroluminescence (EL) intensity measurement results for an electroluminescent device using Flrpic, an iridium complex compound known to exhibit red light, as a dopant of a light emitting layer; FIG.

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

1000, 2000: organic light emitting display device 1100, 2100: substrate

1110 and 2110: first electrode 2120: hole injection layer

2130: hole transport layer 1140, 2140: light emitting layer

2150 electron transport layer 2160 electron injection layer

1170, 2170: second electrode

Claims (10)

Iridium complex compound having a structure of formula (1). Formula 1

In Formula 1, Ar is an aromatic ring; R ₁ is hydrogen, an alkyl group (C 1-20), an alkoxy group (C 1-20), a cyanide group, a nitro group, a halogen, or a carbazole group; R ₂ is hydrogen or carbon number 1-20 alkyl groups;

Is picolinic acid-N-oxide, pyrazinic acid, or pipelinic acid.) The method of claim 1, Ar of Formula 1 is a phenyl group, naphthalene group, carbazole group, fluorenyl group, phenazine group, phenanthroline group, phenanthridine group, permidine group, acridine group, cynoline group, quinazoline group, quinoxaline group, naphthydrine Iridium characterized in that the aromatic ring selected from the group, phthalazine group, quinolyzine group, indole group, indazole group, pyridazine group, pyrazine group, pyrimidine group, pyridine group, pyrazole group, imidazole group, pyrrole group Complex. The method of claim 1, Ar of Formula 1 is an iridium complex, characterized in that the aromatic ring selected from phenyl group, naphthalene group, carbazole group, fluorenyl group. The method of claim 1, R ₁ of Formula 1 is an iridium complex compound, characterized in that an alkyl group having 1 to 20 carbon atoms or alkoxy group having 1 to 20 carbon atoms. The method of claim 1, R ₁ of Formula 1 is an iridium complex, characterized in that the halogen selected from fluorine or chlorine. An organic electroluminescent device in which the iridium complex compound according to any one of claims 1 to 5 is contained in a light emitting layer. The method of claim 6, The organic light emitting diode includes a first electrode and a second electrode formed to face the first electrode, and the light emitting layer is stacked between the first electrode and the second electrode. device. The method of claim 7, wherein And a hole injection layer and a hole transport layer between the first electrode and the light emitting layer, and an electron transport layer between the light emitting layer and the second electrode. The method of claim 6, The iridium complex compound is an organic electroluminescent device, characterized in that included as a dopant of the light emitting layer. The method of claim 6, The iridium complex compound is an organic light emitting device, characterized in that contained in a concentration of 3 to 20% by weight based on the total amount of the light emitting layer.

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