KR20120110626A - Green phosphorescent host material comprising vinyl-type polynorbornene and green phosphorescent organic light-emitting diode using the same - Google Patents

Abstract

PURPOSE: A poly norbornene polymer - containing green phosphorescence host material and a green phosphorescence organic light-emitting device using the same are provided to display excellent external quantum efficiency and power efficiencies. CONSTITUTION: A green phosphorescent host material includes vinyl-type poly norbornene polymer represented by chemical formula 1. Here, R indicates functional group of below chemical formula 1 -a, 1 -b, 1 -c or 1 -d. The vinyl-type poly norbornene polymer is manufactured by vinyl addition polymerization of norbornene monomer. The green phosphorescence organic light emitting diode comprises positive electrode, negative electrode, and a light emitting layer between both electrodes. The host material is included in the light-emitting layer.

Description

Green phosphorescent host material comprising vinyl-type polynorbornene and green phosphorescent organic light-emitting diode using the same

The present invention relates to a green phosphorescent host material comprising a vinyl-type polynorbornene polymer and a green phosphorescent organic light emitting device using the same.

The cathode ray tube (CRT) was the mainstream until 2000, but with the increasing demand for lightweight, low power consumption, portable and flattened flat panel displays, the replacement with LCD (liquid crystal display) Currently, organic light emitting diodes (OLEDs) are attracting attention as next-generation flat panel displays. OLED is a display that can realize characters or images of various colors by emitting organic materials by itself when voltage is applied to organic material (polymer or low molecule) thin film. Self-emitting type, ultra thin type (1/3 of LCD), fast Its response speed (1000 times of LCD), low power consumption (1/2 of LCD), high sharpness and flexibility make it a spotlight as a small mobile display such as mobile phones and PDAs. After 2010, it is expected to develop into a display that is as simple and clear as a scroll TV.

OLED emits visible light by recombination of holes and electrons, and has a form in which a plurality of organic layers are stacked between a cathode and an anode. Generally, substrates for OLED devices are made of glass, but in some cases, bendable plastic or film types are used. The anode on the substrate mainly uses indium tin oxide (ITO) formed by vacuum deposition or sputtering, and the organic layer is vacuum deposited for low molecular weight compounds, spin coating for high molecular weight compounds, spin coating, or inkjet printing. A thin film is formed using such as. The cathode requires magnesium or lithium having a small work function, but aluminum is mainly used in consideration of stability with moisture and oxygen in the air.

Looking briefly at the structure of an OLED, an organic material with semiconductor characteristics has a sandwich structure existing between a cathode and an anode in the form of a thin film, and when a DC electric field is applied to both electrodes, electrons and holes are formed of an organic material. It is injected into the light emitting layer to emit light in the visible light region. In general, in order to improve the luminous efficiency of OLEDs, various kinds of organic materials are formed in a multilayer between a cathode and an anode. For example, a hole injection layer (HIL) is formed on the anode, followed by a hole transporting layer (HTL), an emitting layer (EML), an electron transporting layer (ETL), and an electron. An injection layer (EIL) and a cathode electrode are sequentially formed. In addition, the light emitting layer is generally composed of a host material and a dopant material, and light emission efficiency can be greatly improved by doping a small amount of dopant of 0.5 to 20%.

In general, organic light emitting diodes are widely used as a patterning technique using a vacuum deposition method using a fine metal mask. However, this vacuum deposition method was difficult to apply to large displays due to high process price and technical limitations. Accordingly, various patterning techniques that can replace the vacuum deposition method is being researched and developed. In particular, wet processes such as spin coating, inkjet printing, casting methods, etc. do not require vacuum technology, thereby reducing equipment costs, and easily fabricating devices without material loss.

However, wet process materials are not yet capable of achieving excellent device performance compared to vacuum deposition materials. In addition, when the organic thin film layer is formed by a wet process, a problem may occur in that the material of the lower layer that is already formed is melted by the organic solvent, and due to such a problem, it is difficult to stack the organic thin film layer in multiple layers and thus, excellent device performance cannot be realized. to be.

For example, the hydrophilic poly (3,4-ethylene dioxythiophene) / poly (4-styrenesulfonate) (PEDOT / PSS) layer used in a wet process is commonly used as a hole injection layer, but the hydrophilic hole The injection layer may be stacked together with the hydrophobic light emitting layer, which may cause a problem of poor interface characteristics. In addition, since the intrinsic material property of PEDOT / PSS is acidic, there is a problem such that the light emitting efficiency and lifespan of the device are degraded by damaging the cathode and the light emitting layer with time.

In order to solve the above problems, a polymer material is mainly used as a wet process material. These polymer materials are formed in a conjugated form in which aromatic substituents such as aryl groups and arylamine groups are extended by covalent bonds. In general, as the molecular length increases, the conjugate length also increases, in which case the energy bandgap of the molecule decreases. Although polymer materials are synthesized with various polymer materials having different energy band gaps according to the degree of polymerization, and polymer materials having various molecular weight distributions are synthesized in one reactor, the polymer material is used to have a specific energy band gap. It is very difficult to obtain a thin film layer.

Therefore, in order to provide an organic photoelectric device having excellent life and efficiency characteristics by using a wet process, which is easy to manufacture the device and has advantages in terms of size and size, the interface stability between the organic thin film layers and the energy band gap are excellent. The development of a new polymer that can easily control the situation is required.

On the other hand, the phosphorescent organic light emitting diode (PhOLED) based on heavy metal composites is of great interest because it can theoretically achieve 100% internal quantum efficiency by using both singlet and triplet excitation. (JAG Williams, Top. Curr. Chem., 2007, 281, 205-268 .; L. Flamigni, A. Barbieri, C. Sabatini, B. Ventura and F. Barigelletti, Top. Curr. Chem., 2007, 281, 143-20).

In order to prevent triplet-triplet extinction and termination of concentration, PhOLED generally employs an active layer, where the phosphor emitter is doped inside a suitable host material.

In general, PhOLED's host material should have a higher triplet energy level (E _T ) than phosphorescent emitters for efficient energy transfer from the host into the guest and confinement of triplet excitation of the guest material.

Although studies on carbazole derivative based low molecular host materials have been well established (V. Cleave, G. Yahioglu, P. Le Barny, RH Friend and N. Tessler, Adv. Mater., 1999, 11, 285-288. K. Brunner, A. van Dijken, H. Borner, JJAM Bastiaansen, NMM Kiggen and BMW Langeveld, J. Am. Chem. Soc., 2004, 126, 6035-6042. It is considered to be of interest because of its manufacturability, which can be useful for volume production of OLEDs using printing techniques in applications in electrical signals, light emission, and displays.

In view of this, much research is underway in the development of conjugated polymer hosts for phosphors. In particular, red PhOLED devices with high device efficiencies similar to vacuum deposited devices have been demonstrated by several groups (H. Zhen, C. Luo, W. Yang, W. Song, B. Du, J. Jiang, C.). Jiang, Y. Zhang and Y. Cao, Macromolecules, 2006, 39, 1693-1700 .; F.-I. Wu, P.-I. Shih, Y.-H. Tseng, G.-Y. Chen, C .-H. Chien, C.-F. Shu, Y.-L. Tung, Y. Chi and AK-Y. Jen, J. Phys. Chem. B, 2005, 109, 14000-14005.

However, there have been few reports of successful polymer host materials as green emitters, although it has recently been reported that high efficiencies are achieved through modification of the main chain polymer structure resulting from the increase in E _T (T. Fei). , G. Cheng, D. Hu, P. Lu and Y. Ma, J. Polym. Sci., Part A: Polym. Chem., 2009, 47, 4784-4792 .; H.-C. Yeh, C. -H. Chien, P.-I. Shih, M.-C. Yuan and C.-F.Shu, Macromolecules, 2008, 41, 3801-3807., Which is the most conjugated polymer (Z. Wu). , Y. Xiong, J. Zou, L. Wang, J. Liu, Q. Chen, W. Yang, J. Peng and Y. Cao, Adv. Mater., 2008, 20, 2359-2364. The energy is derived from the general green emitter fac-tris (2-phenylpyridine) iridium (III) (fac-Ir (ppy) ₃ , E _T = 2.41 eV) (AB Tamayo, BD Alleyne, PI Djurovich, S. Lamansky, I. Tsyba, NN Ho, R. Bau and ME Thompson, J. Am. Chem. Soc., 2003, 125, 7377-7387.

Alternatively, unbound side chain polymers such as poly (9-vinylcarbazole) (PVK) are often applied as polymer hosts because of their relatively high triplet energy (E _T = 2.5 eV) (KM Vaeth and CW Tang). , J. Appl. Phys., 2002, 92, 3447-3453.), Has a problem of low efficiency due to low charge transport transfer properties.

Therefore, in order to manufacture an efficient green phosphorescent organic light emitting device (PhOLED), a new host material is required.

Accordingly, it is an object of the present invention to provide a new host material which can utilize a wet process and exhibits efficient green phosphorescent activity.

Still another object of the present invention is to provide a green phosphorescent organic light emitting device (green PhOLED) including the new host material.

In order to achieve the above object, the present invention provides a green phosphorescent host material comprising a vinyl-type polynorbornene represented by the formula (1).

≪ Formula 1 >

,

(Wherein R is

,

또는

이며,

or

Is,

Wherein R ₁ is hydrogen, C _{1? 20} alkyl group, C _{1? 20} haloalkyl group or a C _{6? 20} aryl groups, C _{6? 20} aryl groups, C _{6? 20} alkylaryl group, C _{6? 20} of the a haloaryl group, wherein R ₂ is hydrogen, C _{1? 20} alkyl group, C _{1? 20} haloalkyl group or a C _{6? 20} aryl groups, C _6? arylalkyl group of _20, C _{6? 20} alkyl, aryl group, a C _6?, and haloaryl of ₂₀ group, wherein R ₃ is hydrogen, C _{1? 20} alkyl group, C _{1? 20} of a haloalkyl group or a C _{6? 20} aryl groups, C _6? arylalkyl group of _20, C _{6? 20} alkylaryl group, C _6? and ₂₀ haloaryl group, wherein R ₄ is hydrogen, C _{1? 20} alkyl group, C _{1? 20} of a haloalkyl group or a C _{6? 20} aryl groups, C _6? arylalkyl groups of _20, C _6? alkylaryl group of _20, C _{6? 20} aryl group of halo, n ₁ is 1 ~ 10,000, n ₂ is 1 ~ _3, n 3 is 1 to 20).

In one embodiment of the present invention, R is 9,9 '-(1,1'-biphenyl) -4,4'-diylbis-9H-carbazole (CBP), 9-phenyl-4-yl -9H-carbazole and 9-biphenyl-4-yl-9H-carbazole.

In one embodiment of the present invention, the vinyl type polynorbornene polymer may be prepared through a vinyl addition polymerization of the norbornene monomer.

In one embodiment of the present invention, the vinyl addition polymerization may be carried out by adding a norbornene monomer to the activated catalyst solution containing a palladium catalyst and adding 1-olefin.

In one embodiment of the present invention, the 1-olefin is added to 0.01 to 20 mol% with respect to the norbornene monomer may be carried out vinyl addition polymerization.

In addition, the present invention provides a green phosphorescent organic light emitting device (PhOLED) comprising the vinyl type polynorbornene polymer as a green phosphorescent host material in an organic light emitting device comprising a light emitting layer between an anode, a cathode and a positive electrode. .

In one embodiment of the present invention, the host material may further include a phosphorescent dopant.

In one embodiment of the present invention, the phosphorescent dopant is tris (2-phenylpyridinato-N, C2) ruthenium, bis (2-phenylpyridinato-N, C2) palladium, bis (2-phenylpyridina To-N, C2) platinum, tris (2-phenylpyridinato-N, C2) osmium, tris (2-phenylpyridinato-N, C2) renium, octaethyl platinum porphyrin, octaphenyl platinum porphyrin, octaethyl Palladium porphyrin, octaphenyl palladium porphyrin, iridium (III) bis [(4,6-difluorophenyl) -pyridinato-N, C2 '] picolinate (Firpic), tris (2-phenylpyridinato- N, C 2) iridium (Ir (ppy) ₃ ), fac- Ir (ppy) ₃ , bis- (2-phenylpyridinato-N, C 2) iridium (acetylacetonate) (Ir (ppy) ₂ (acac) ) And 2,3,7,8,12,13,17,18-octaethyl-21H, 23H-porphine platinum (II) (PtOEP).

In one embodiment of the present invention, it may be characterized by having a structure including a charge transport layer between the anode or cathode and the light emitting layer.

In one embodiment of the present invention, a transparent electrode (anode), a hole injection layer, a hole transporting layer, a light emitting layer, an electron transporting layer, an electron injection layer and a metal electrode (cathode) is a multi-layered structure sequentially stacked Can be.

Vinyl-type polynorbornene according to the present invention (vinyl-type polynorbornene) is combined with a polynorbornene backbone excellent in the R group fairness, the general organic solvent (for example chloroform, dichloromethane, tetrahydrofuran, And chlorobenzene) very well at room temperature and exhibit high heat resistance with high decomposition temperature (T _d5 > 451 ° C.) and glass transition temperature (Tg> 361 ° C.), and the general green phosphorescent emitter (fac-Ir (ppy). ) ₃ , E _T = 2.41 eV) triplet energy (E _T ) values higher than or equal to superior external quantum efficiency (η _EQE ) and power when compared to devices containing molecular hosts conventionally used in manufacturing devices Since device performance, such as efficiency (η _PE ), is shown, it can be usefully used as a green phosphorescent host material that can use a solution process.

1 to 3 are each a schematic cross-sectional view of an organic light emitting device according to the present invention.
4 is the UV-Vis absorption (left) and PL (right) spectra of the compound of Formula 1 prepared in the Examples of the present invention in diluted CH ₂ Cl ₂ solution.
5 is a cyclic voltammogram of the vinyl-based polynorbornene compound prepared in the embodiment of the present invention.
6 is a schematic structural cross-sectional view of an organic light emitting device manufactured in an embodiment of the present invention.
7 is an EL spectrum of the organic light emitting device manufactured in the embodiment of the present invention.
8 is a graph showing the external quantum efficiency (η _EQE , FIG. 8A) and the power efficiency (η _PE , FIG. 8B) of the organic light emitting diode manufactured in the embodiment of the present invention.
9 is a graph of (a) current density-emitting-applied voltage (JVL), and (b) external quantum efficiency-emitting curves of organic light emitting diodes manufactured in an embodiment of the present invention.

The present invention provides a green phosphorescent host material including a vinyl-type polynorbornene polymer represented by Formula 1 below.

≪ Formula 1 >

,

, Wherein R is

,

,

또는

이며,

or

Is,

Wherein R ₁ is hydrogen, C _{1? 20} alkyl group, C _{1? 20} haloalkyl group or a C _{6? 20} aryl groups, C _{6? 20} aryl groups, C _{6? 20} alkylaryl group, C _{6? 20} of the a haloaryl group, wherein R ₂ is hydrogen, C _{1? 20} alkyl group, C _{1? 20} haloalkyl group or a C _{6? 20} aryl groups, C _6? arylalkyl group of _20, C _{6? 20} alkyl, aryl group, a C _6?, and haloaryl of ₂₀ group, wherein R ₃ is hydrogen, C _{1? 20} alkyl group, C _{1? 20} of a haloalkyl group or a C _{6? 20} aryl groups, C _6? arylalkyl group of _20, C _{6? 20} alkylaryl group, C _6? and ₂₀ haloaryl group, wherein R ₄ is hydrogen, C _{1? 20} alkyl group, C _{1? 20} of a haloalkyl group or a C _{6? 20} aryl groups, C _6? arylalkyl groups of _20, C _6? alkylaryl group of _20, C _{6? 20} aryl group of halo, n ₁ is 1 ~ 10,000, n ₂ is 1 ~ _3, n 3 is 1 to 20.

Preferably, R is 9,9 '-(1,1'-biphenyl) -4,4'-diylbis-9H-carbazole (CBP), 9-phenyl-4-yl-9H-carbazole And 9-biphenyl-4-yl-9H-carbazole.

That is, the vinyl polynorbornene polymer according to the present invention may have a backbone having a structure in which a norbornene monomer or an alkyl group is polymerized and may have various R groups capable of emitting green phosphorescence.

Polynorbornene polymers of the vinyl type according to the invention are very well soluble at room temperature in common organic solvents (e.g. chloroform, dichloromethane, tetrahydrofuran, and chlorobenzene), ¹ H and ¹³ C NMR spectra and mass spectrometry It is a vinyl type polynorbornene by the form of a short-lived structure in which there is no double bond in a polynorbornene structure. Thus, the "vinyl-based polynorbornene polymer" according to the present invention is a new polymer having a different structure bonded in a completely different manner from the previously known double-bonded polynorbornene polymer, and examples of using it as a host material There was no until.

The polynorbornene polymer according to the present invention is green phosphorescence by a substituted R group, by providing a host material having a vinyl-based polynorbornene backbone prepared through a unique vinyl addition polymerization reaction, a conventional polymer host It has a function as a green phosphorescent host material which is much better than the material. Specifically, the host material containing the vinyl-type polynorbornene polymer according to the present invention has a high decomposition temperature (T _d5). > 451 ° C) and high heat resistance with glass transition temperature (Tg> 361 ° C) and higher triplet energy (E _T ) than common green phosphorescent emitters (fac-Ir (ppy) ₃ , E _T = 2.41 eV) Value, and the excellent performance of the solution process, including the excellent external quantum efficiency (η _EQE ) and power efficiency (η _PE ) of the device when compared to a device containing a conventional molecular host when manufacturing an organic light emitting device It is characterized by having.

On the other hand, the polynorbornene polymer of the vinyl type of Formula 1 according to the present invention can be prepared through the vinyl addition polymerization of the norbornene monomer (vinyl addition polymerization).

Specifically, the vinyl addition polymerization may be performed by adding a norbornene monomer to a solution of an activated catalyst including a pd catalyst and adding 1-olefin. In this case, the 1-olefin is preferably added in 0.01 to 20 mol% based on the norbornene monomer.

In one example, R is 9,9 '-(1,1'-biphenyl) -4,4'-diylbis-9H-carbazole (9,9- (1,1-biphenyl) -4,4- In the case of diylbis-9H-carbazole, CBP), the vinyl polynorbornene compound according to the present invention may be prepared as shown in Scheme 1, but not limited thereto.

Reacting the compound of Formula 2 with the compound of Formula 3 to prepare a halogen substituted CBP compound of Formula 4 (step 1);

Reacting the compound of formula 4 prepared in step 1 with 5-norbornene-2-alkyl halide and lithium salt to prepare a norbornene monomer substituted with a CBP substituent of formula 5 (step 2); And

Preparing a norbornene monomer of Formula 5 prepared in step 2 into a polynorbornene polymer substituted with a CBP substituent of Formula 1 through a vinyl addition polymerization using a palladium catalyst and a 1-olefin (step 3) It can be prepared by a manufacturing method, in the reaction scheme n of the polynorbornene may be 1 to 10,000.

<Reaction Scheme 1>

Specifically, to explain in detail step by step the preparation method of Scheme 1, step 1 is a step of preparing a halogen-substituted CBP compound of Formula 4 by reacting the compound of Formula 2 and the compound of Formula 3.

In this step, as a step of preparing a CBP group for binding to the norbornene backbone, 3-bromocarbazole of Formula 2 and 4-iodo-4-carbazolylbiphenyl of Formula 3 by coupling a reaction under an organic solvent and a base A halogen-substituted CBP compound of Formula 4 may be prepared.

In this case, the compounds of Formulas 2 and 3 as starting materials may be purchased commercially, or may be prepared by methods commonly used in the art, and the organic solvent may be 1,2-dichlorobenzene, chlorobenzene, toluene, xylene And the like, and as the base, K ₂ CO ₃ , Na ₂ CO ₃ , Cs ₂ CO _3, etc. may be used together with 18-crown-6 or alone, but is not limited thereto.

The coupling reaction can also be carried out using conventional methods in the field of organic chemistry. For example, after dissolving the compounds of Formulas 2 and 3 in 1,2-dichlorobenzene, by adding Cu, K ₂ CO ₃ and 18-crown-6 and heating to reflux temperature and then stirred for 30 to 36 hours A halogen-substituted CBP compound of Formula 4 may be prepared.

Next, step 2 is a norbornene monomer substituted with a CBP substituent of Formula 5 by reacting a lithium salt or Grignard reagent with 5-norbornene-2-alkyl halide to the compound of Formula 4 prepared in Step 1 To prepare a step. Specifically, the compound of formula 4 is added to an organic solvent such as tetrahydrofuran (THF), dimethoxyethane, diethyl ether, and the like to add lithium salt or magnesium to prepare a lithium salt or magnesium salt of the compound of formula 4, 5- The norbornene monomer in which the CBP group of the formula (5) is bonded to the norbornene mother nucleus may be prepared by adding and reacting norbornene-2-alkyl halide. In this case, t-BuLi, s-BuLi, n-BuLi, or the like may be used as the lithium salt, and preferably t-BuLi may be used. The 5-norbornene-2-alkyl halide is not limited thereto, but 5-norbornene-2-methyl iodine, 5-norbornene-2-methyl bromide, 5-norbornene-2-ethyl bromide, 5-novo Nene-2-propyl bromide, 5-norbornene-2-butyl bromide, 5-norbornene-2-pentyl bromide, 5-norbornene-2-hexyl bromide, 5-norbornene-2-heptyl bromide, 5-novo Nene-2-octyl bromide, 5-norbornene-2-nonyl bromide, 5-norbornene-2-decyl bromide or 5-norbornene-2-dodecyl bromide, etc., Preferably 5-norbornene 2-butyl bromide, 5-norbornene-2-pentyl bromide, 5-norbornene-2-hexyl bromide or 5-norbornene-2-octyl bromide can be used.

In this step, the lithium salt is preferably added at a low temperature of -75 ~ -80 ℃, the 5-norbornene-2-alkyl halide may be added in the vicinity of -5 ~ 5 ℃, preferably 0 ℃. . For example, after dissolving the compound of Chemical Formula 2 prepared in Step 1 in THF, t-BuLi is slowly added at -78 ° C, 5-norbornene-2-alkyl halide is slowly added at 0 ° C, and then reaction By heating the mixture to room temperature and then stirring overnight, a norbornene monomer in which the CBP group of Formula 5 is bonded to the norbornene parent nucleus may be prepared.

Next, Step 3 is a step of preparing a polynorbornene polymer substituted with a CBP substituent of Chemical Formula 1 by performing a polymerization reaction using the palladium catalyst of the monomer of Formula 5 prepared in Step 2 above. Specifically, the polymerization of step 3 may be performed by adding the norbornene monomer of Formula 5 prepared in step 2 to the activated catalyst solution including the palladium catalyst and adding 1-olefin.

In this case, the activated catalyst solution may be prepared by dissolving a palladium catalyst and a weakly coordinating anion promoter or a weakly coordinating boron Lewis acid promoter in an organic solution, preferably chlorobenzene. Specific examples of the weakly coordinated anion compound include trityl tetrakis (pentafluorophenyl) borate, sodium tetrakis (pentafluorophenyl) borate, lithium tetrakis (pentafluorophenyl) borate, N, N-dimethylanilinium Tetrakis (pentafluorophenyl) borate, silver tetrafluoroborate, silver hexafluoroantimonate, silver hexachloroantimonate, silver hexafluorophosphate, and the like. Specific examples of the above coordination boron Lewis acid Examples include triphenyl borane, tris (pentafluorophenyl) borane, tris (3,5-bis (trifluoromethyl) phenyl) borane, and the like, preferably silver hexachloro antimonate. (AgSbF ₆ ) Or a lithium tetrakis (pentafluorophenyl) borate (LiB (C ₆ F ₅ ) ₄ ) promoter. The palladium catalyst is preferably a cationic Pd (II) catalyst derived from an N-heterocyclic carbene complex reaction. Specific examples of the N-heterocyclic carbene include N, N′-bis (2,6- Diisopropylphenyl) -imidazol-2-ylidene) (NHC), N, N'-bis (2,6-diisopropylphenyl) dihydro-imidazole-2-ylidene), etc. are mentioned. More preferably [(NHC) Pd (η ³ -allyl) Cl].

At this time, it is preferable that [monomer] / [Pd] mixed is 10-10,000, More preferably, 100-1,000 are used. Propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-heptene, 1-decene, styrene and the like may be used for the 1-olefin, and it is preferable to add 0.01 to 20 mol% based on the monomer. More preferably, 0.05-10 mol% is used.

Under these conditions, the monomer of Formula 5 polymerizes to produce a polynorbornene polymer substituted with a CBP substituent of Formula 1.

The vinyl type polynorbornene polymer of the formula (1) prepared according to the above method is combined with the polynorbornene backbone with good R process (e.g., CBP substituent), and a general organic solvent (e.g., chloroform , Dichloromethane, tetrahydrofuran, and chlorobenzene) very well at room temperature and high decomposition temperature (T _d5 > 451 ° C.) and glass transition temperature (Tg> 361 ° C.), in particular, the glass transition temperature is a polynorbornene comprising NPB and a polymer host material with conjugated and side chains reported to date. Highest glass transition temperature (T _g ). In addition, it exhibits a large triplet energy (E _T ) of about 2.60 eV, which has a higher triplet energy (E _T ) value than typical green phosphorescent emitters (fac-Ir (ppy) ₃ , ET = 2.41 eV). The polynorbornene polymer of the vinyl type of the general formula (1) according to the present invention can be usefully used as a green phosphorescent host material that can use a solution process (see Examples).

In addition, the present invention provides organic light-emitting diodes (OLEDs) including the polynorbornene polymer of the vinyl type of Formula 1 in a light emitting layer as a green phosphorescent host material.

The organic light emitting device according to the present invention is a monolayer comprising a light emitting layer including the compound of Formula 1 as a light emitting host material as one structural unit between an anode, a cathode and two electrodes, or an anode together with a charge transport layer, the formula 1 It has a multi-layered structure in which the light emitting layer and the cathode containing a compound of the light emitting material in order.

In general, a multilayer device having a combination of a light emitting layer and a charge transporting layer exhibits superior characteristics, rather than a single layered device consisting of only one light emitting layer, which is an energy barrier when charge is injected from an electrode by properly combining the light emitting material and the charge transporting material. This is because the charge transport layer binds the holes or electrons injected from the electrode to the light emitting layer region to balance the number density of the holes and electrons injected. In particular, in the case of a phosphorescent light emitting device, since the emission duration of the phosphorescent material is long, in order to increase efficiency, it is necessary to trap holes in the light emitting layer so that the holes remain in the light emitting layer for a long time to show excellent phosphorescence properties. More preferred.

A schematic cross-sectional view of the organic light emitting device of the present invention is shown in FIGS. As shown in FIG. 1, the basic organic light emitting device of the present invention has a structure in which a transparent electrode (anode), a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, an electron injection layer, and a metal electrode (cathode) are sequentially stacked. 2, a hole blocking layer is provided between the light emitting layer and the electron transporting layer as shown in FIG. 2, or as shown in FIG. 3, or a hole blocking layer between the light emitting layer and the electron transporting layer and between the light emitting layer and the hole transporting layer, respectively. And an electron blocking layer.

In the organic light emitting device according to the present invention, the transparent electrode (anode) and the metal electrode (cathode) are conventional electrode materials, for example, the transparent electrode is indium tin oxide (ITO) or SnO ₂ , and the metal electrode is It may be formed of a metal such as Li, Mg, Ca, Ag, Al and In or an alloy thereof, and the metal electrode may have a single layer or a multilayer structure of two or more layers.

The light emitting layer may include the compound of Chemical Formula 1 of the present invention as a light emitting host material, and may have a single layer or a multilayer structure of two or more layers. In this case, the compound of Formula 1 may further include a phosphorescent dopant, the phosphorescent dopant is commonly used in the art, tris (2-phenylpyridinato-N, C2) ruthenium, bis (2-phenylpyrido Dinato-N, C2) palladium, bis (2-phenylpyridinato-N, C2) platinum, tris (2-phenylpyridinato-N, C2) osmium, tris (2-phenylpyridinato-N, C2) rhenium, octaethyl platinum porphyrin, octaphenyl platinum porphyrin, octaethyl palladium porphyrin, octaphenyl palladium porphyrin, iridium (III) bis [(4,6-difluorophenyl) -pyridinato-N, C2 '] Picolinate (Firpic), Tris (2-phenylpyridinato-N, C2) Iridium (Ir (ppy) 3), fac- Ir (ppy) ₃ , Bis- (2-phenylpyridinato-N, C2 Iridium (acetylacetonate) (Ir (ppy) 2 (acac)) and 2,3,7,8,12,13,17,18-octaethyl-21H, 23H-phosphine platinum (II) (PtOEP) One selected from the group consisting of can be used.

The hole transport layer is a conventional hole transport material such as 4,4-bis [N- (1-naphthyl) -N-phenyl-amine] biphenyl (α-NPD), N, N-diphenyl-N, N-bis (3-methylphenyl) -1,1-biphenyl-4,4-diamine (TPD) and poly- (N-vinylcarbazole) (PVCz) may be used alone or in combination of two or more thereof. It can also be laminated | stacked 2 or more layers as a separate layer.

The hole blocking layer has a low unoccupied molecular orbital (LUMO) value between 5.5 and 7.0, and is composed of a material having excellent electron transport ability with a significant drop in hole transport capacity. Such materials include bastocuproine (BCP), 3- (4-biphenylyl) -4-phenyl-5- (4-t-butylphenyl) -1,2,4-triazole (TAZ) and bis (8-hydroxy-2-methylquinolinato ) -Aluminum biphenoxide (BAlq) and the like are suitable. In addition, a material having a large LUMO value is generally used as the electron blocking layer, and iridium (III) tris (1-phenylpyrazole-N, C 2 ′) (Ir (ppz) ₃ ) is suitable.

The electron transporting layer (electron transporting emissive layer) may be composed of a conventional electron transporting material such as tris (8-quinolinolato) aluminum (Alq ₃ ), rubrene, or the like alone or in combination of two or more thereof. Two or more separate layers may be stacked.

In addition, in order to improve device characteristics such as luminous efficiency and lifetime, a conventional hole injection layer including, for example, copper phthalocyanine (CuPc) may be inserted between the anode and the hole transport layer, and the cathode and the electron transport layer may be inserted. In between, for example, a conventional electron injection layer containing LiF can be inserted.

The anode, cathode, light emitting layer, transport layer, injection layer and blocking layer may be formed by a conventional deposition method.

Thus, the vinyl-type polynorbornene polymer compound of Formula 1 according to the present invention is included as a host material in the organic light emitting device to exhibit a stable green light emission, excellent external quantum efficiency (power quantum efficiency) and power efficiency (power efficiency) It can be usefully used for green phosphorescent organic light emitting device (phOLED).

Hereinafter, the present invention will be described in detail with reference to examples. However, these examples are intended to illustrate the present invention in more detail, and the scope of the present invention is not limited to these examples.

&Lt; Example 1 >

Preparation of Vinyl Type Polynorbornene Polymer

All work was performed under inert nitrogen atmosphere using standard Schlenk and glove box techniques. Anhydrous solvent (Aldrich) was dried by passing through an activated alumina column and stored in an active molecular sieve (5 cc). Spectrophotometer grade dichloromethane was used from Aldrich. Commercial reagents (carbazole, N-bromosuccinimide, 4,4'-dioodobiphenyl, copper, potassium carbonate, 18-crown-6, t-butyllithium (1.7 M (solution in pentane))) and strost Rem (AgSbF ₆ )) was purchased from Aldrich and used without further purification. 3-bromocarbazole (K. Smith, DM James, AG Mistry, MR Bye and DJ Faulkner, Tetrahedron, 1992, 48, 7479-7488.), 4-iodo-4- (carbazolyl) biphenyl (BE Koene , DE Loy and ME Thompson, Chem. Mater., 1998, 10, 2235-2250), 5-norbornene-2-pentyl bromide (AJ Gabert, E. Verploegen, PT Hammond and RR Schrock, Macromolecules, 2006, 39 , 3993-4000.) (Endo / exo = 2: 1) and allylchloro [N, N'-bis (2,6-diisopropylphenyl) -imidazole-2-ylidene] palladium (II) ([ (NHC) Pd (η ³ -allyl) Cl]) (MS Viciu, O. Navarro, RF Germaneau, RA Kelly, III, W. Sommer, N. Marion, ED Stevens, L. Cavallo and SP Nolan, Organometallics, 2004 , 23, 1629-1635.) Was prepared by the method disclosed in the literature.

Step 1: Preparation of 9- [4'-carbazol-9-yl-biphenyl-4-yl] -3-bromo-9H-carbazole (4)

_3- broken in a slurry of copper (0.42 g, 6.6 mmol), 18-crown-6 (0.87 g, 3.3 mmol) and K ₂ CO ₃ (5.53 g, 40.0 mmol) dissolved in o-dichlorobenzene (50 mL). A solution in which mocarbazole (2.46 g, 10.0 mmol) and 4-iodo-4- (carbazolyl) biphenyl (5.34 g, 12.0 mmol) was dissolved in o-dichlorobenzene was added at room temperature. The reaction mixture was heated to reflux and then stirred for 30-36 hours. After cooling to room temperature, the reaction mixture was filtered over silica and the filtrate was evaporated to give a dry product. The crude product was washed three times with acetone (30 mL). The washed product was recrystallized in chloroform to give the product as a white powder (yield: 2.54 g, yield: 45%).

mp = 253-255 ° C.

¹ H NMR (CDCl ₃ , 400 MHz): δ 7.27-7.36 (m, 4H), 7.40-7.53 (m, 7H), 7.63-7.73 (m, 4H), 7.88-7.93 (m, 4H) , 8.10 (d, J = 7.7 Hz, 1 H), 8.15 (d, J = 7.4, 2 H), 8.27 (d, J = 1.8 Hz, 1 H).

Step 2: Preparation of Norbornene Monomer (5) of Vinyl Type Substituted with CBP Substituent

To the slurry of the compound of formula 2 prepared in step 1 (2.35 g, 4.0 mmol) in THF (50 mL) was slowly added 2 equivalents of t-BuLi (4.7 mL) at -78 ° C. The reaction mixture was stirred at this temperature for 2 hours and then raised to room temperature. Next, a solution (10 mL) in which 5-norbornene-2-pentyl bromide (1.17 g, 4.8 mmol) was dissolved in THF was slowly added at 0 ° C. through a cannula. The reaction mixture was raised to room temperature and then stirred overnight. Then saturated aqueous solution of NH ₄ Cl (30 mL) was added, the organic layer was separated, and the aqueous layer was further extracted with ether (2 × 30 mL). The organic layers were combined, dried under MgSO ₄ , filtered and evaporated to give an oil residue. The crude product was purified by silica column chromatography (eluent: CH ₂ Cl ₂ / n-hexane = 1/4) to obtain the title compound as a white solid (amount: 1.79 g, yield: 69%, endo and exo isomers ( 2/1)).

mp = 96-99 ° C.

1 H NMR (CDCl ₃ ): δ 0.48-0.54 (m), 1.02-1.47 (m) (10H), 1.67-2.05 (m, 3H), 2.53 (s), 2.72-2.88 (m) (4H), 5.94 (dd, J = 5.9 / 2.7 Hz, H _endo ), 6.03 (dd, J = 5.9 / 2.7 Hz, H _exo ), 6.09-6.11 (m, H _exo ), 6.12 (dd, J = 5.9 / 3.0 Hz, H _endo ) (2H), 7.26-7.37 (m, 4H), 7.41-7.56 (m, 7H), 7.70 (d, J = 8.2 Hz, 4H), 7.85-7.93 (m, 4H), 7.98 (s, 1H), 8.16 (d, J = 8.0 Hz, 1H), 8.19 (d, J = 8.1 Hz, 2H).

Step 3: CBP  Of vinyl type with substituent Polynorbornene  Preparation of Polymer (1)

To the mixture of [(NHC) Pd (η ³ -allyl) Cl] and 1.5 equiv AgSbF ₆ , chlorobenzene (6.0 mL) was added and a series of stirring for 2 hours at room temperature gave an activated catalyst solution (2.0 μM). It was. After filtering the activated catalyst solution, the filtered activated catalyst solution (1.5 μmol) was added to the monomer prepared in step 2 (1.5 mmol, [monomer] / [Pd] = 1,000) and 1-octene (0.1 for the monomer). The polymerization reaction was initiated by introducing into a chlorobenzene solution containing mol%). The polymerization was carried out at 25 ° C. for 20 hours. The mixture was poured into a large amount of methanol oxide (5% v / v, 300 mL) to precipitate the polymer. After stirring for 1 hour, the precipitated polymer was collected by filtration and washed with methanol (3 x 50 mL). The polymer was purified by dissolving CHCl ₃ and repeating the process of reprecipitation in methanol / acetone (v / v = 4/1) three times. Finally, the obtained polymer was put in a vacuum oven and dried to a content weight at 70 ° C. to obtain a target compound.

¹ H NMR (CDCl ₃ ): δ 0.5-2.0 (br, 15H), 2.1-3.1 (br, 4H), 7.21 (bs, 8H), 7.31 (bs, 11H), 7.83 (bs, 2H), 8.07 ( bs, 2H).

¹³ C NMR (CDCl ₃ ): δ 26.4-49.6 (br), 109.7, 120.0, 120.3, 123.4, 125.9, 126.9, 127.1, 128.1, 134.6, 136.9, 137.1, 138.4, 138.9, 140.6.

(Molecular weight (Mw), molecular weight distribution (Mw / Mn)), thermal properties (thermogravimetric analysis (TGA) and differential scanning calorie (DSC)), optical physical properties and electrochemical properties Were measured.

Specifically, the molecular weight (Mw) and molecular weight distribution (Mw / Mn) of the polymer of formula (1) were Viscotek T60A equipped with UV and RI detectors, calibrated at 35 ° C. using THF as eluent and using a narrow polystyrene standard as reference. Analyze by gel permeation chromatography on. Thermogravimetric analysis (TGA) was performed using a TA Instrument Q500 at a heating rate of 20 ° C./min from 50 ° C. to 800 ° C. under N ₂ atmosphere. Differential scanning calorimetry (DSC) method was performed on TA Instrument Q100. The first heating of the samples at any temperature history at 20 ° C./min in the polymer of Formula 1 did not measure the temperature history, and then recorded a second DSC scan at 10 ° C./min until the decomposition temperature.

UV-Vis and emission spectra were dissolved in CH ₂ Cl ₂ in 1-cm square cuvettes. At room temperature, measurements were made with a Jasco V-530 and Spex Fluorog-3 luminescent spectrophotometer, respectively. Cyclic voltammetry experiments were performed using the AUTOLAB / PGSTAT12 system. Specifically, cyclic voltammetry was performed at room temperature using a three-electrode cell environment consisting of a platinum working electrode, a counter electrode and an Ag / AgNO ₃ (0.1 N in CH ₃ CN) reference electrode. The solvent was CH ₂ Cl ₂ and 0.1 M tetrabutylammonium hexafluorophosphate was used as the support electrode. Oxidation potential was recorded at a scanning rate of 50 mV / s and reported for ferrocene / ferrocenium (Fc / Fc ⁺ ) redox couples using baseline.

Each measurement result is shown in Table 1 and FIGS. 4 to 5.

division Molecular properties Molecular Weight Mw (g / mol) 413 × 10 ³ Molecular weight distribution (Mw / Mn) 2.51 Decomposition Temperature (℃) 451 Glass transition temperature (캜) 361 Absorption Wavelength λ _abs (nm) (logε) 295 (4.52), 325 (4.42) Emission Wavelength λ _em (nm) 391 λ _phos (nm) 476 Optical Bandgap E _g (eV) 3.34 Triplet Energy E _T (eV) 2.60 Oxidation Energy E _ox (eV) 0.68 HOMO / LUMO (eV) -5.48 / -2.14

4 is a UV-Vis absorption (left) and PL (right) spectra of a compound of the present invention in diluted CH ₂ Cl ₂ solution, and FIG. 5 is a cyclic voltammetry of the compound of the present invention.

As shown in Table 1, the polynorbornene polymer of the vinyl type of Formula 1 according to the present invention was shown to have a high thermal stability having a decomposition temperature (T _d5 ) of 450 ℃ or more.

In particular, DSC analysis showed a high glass transition temperature (T _g ) of 361 ° C., which was the highest glass transition temperature (T _g ) among the conjugated and side chained polymer host materials reported so far.

The CBP molecule itself exhibits a relatively low glass transition temperature of 62 ° C. (M.-H. Tsai, Y.-H. Hong, C.-H. Chang, H.-C. Su, C.- C. Wu, A. Matoliukstyte, J. Simokaitiene, S. Grigalevicius, JV Grazulevicius and C.-P. Hsu, Adv. Mater., 2007, 19, 862-866.), Glass transition temperature of the compound of Formula 1 It can be seen that is greatly increased by the immobilized polynorbornene backbone.

In addition, as shown in Figure 4, according to the UV-Vis absorption and PL spectrum, the compound of formula 1 exhibited a main absorption band of 295 and 325 nm by the π → π ^* transition of the chain carbazole group, The optical bandgap (E _g ) measured from the absorption start wavelength (371 nm) was measured to be about 3.34 eV, and when excited at 332 nm, the PL spectrum of the compound of Formula 1 at 298 K was approximately at the central axis in solution. Strong emission was shown at 390 nm.

Furthermore, when compared with the spectrum of the monomer of formula (5), the polymer compound of formula (1) of the present invention exhibited almost identical absorption and emission characteristics with the monomer, and there was no aggregation or excimer formation between the side chain CBP substituents in the polymer. In addition, the spectral characteristics of the polymer compounds of Formula 1 appear to match very well with those of the CBP molecules, indicating that the polynorbornene backbone does not affect the photophysical properties of the CBP substituents.

The PL spectrum obtained at 77K was useful for measuring the triplet energy (E _T ) of the polymer compound of formula (1). When compared with the triplet energy (2.56 eV) of the CBP molecule by selecting the highest energy phosphorescence peak as the transition from T1 → S0, the triplet energy (E _T ) of the polymer compound of Formula 1 was measured at about 2.60 eV. Since it has a triplet energy (E _T ) value higher than a general green phosphorescent emitter ( fac -Ir (ppy) ₃ , E _T = 2.41 eV), the polymer compound of Formula 1 is suitable as a host material for green light emitters. .

In addition, the cyclic voltammetry of the polymer compound of formula 1 of the present invention exhibits the irreversible oxidation characteristics commonly observed in 3,6-position deprotected carbazole derivatives (see FIG. 5), optical and electrochemical From the data, the HOMO and LUMO levels were calculated to be about -5.5 eV and -2.1 eV, respectively. Observed oxidation behavior and energy levels were reported for CBP molecules (C.-H. Chien, F.-M. Hsu, C.-F. Shu and Y. Chi, Org. Electron., 2009, 10, 871-876 .; TJ Park, WS Jeon, JJ Park, SY Kim, YK Lee, J. Jang and JH Kwon, Thin Solid Films, 2008, 517, 896-900.

<Example 2>

Fabrication of Organic Light-Emitting Device comprising Vinyl Type Polynorbornene Polymer as Organic Phosphorescent Host

An organic light emitting device including the compound of Chemical Formula 1 of the present invention as shown in FIG. 6 was manufactured by the following method.

Specifically, 150 nm-thick ITO was pre-coated on a glass substrate, and then washed with soapy water, deionized water, acetone, and isopropyl alcohol in an ultrasonic bath, followed by an air plasma using a plasma cleaner (PDC-32G, Harrick Plasma). Treated with.

Next, an aqueous dispersion of PEDOT: PSS (Baytron AI4083, HC Starck) was spun at 2500 rpm on the substrate for 30 seconds. The samples were then dried for 10 minutes on a hotplate (140 ° C.). Thereafter, 1 wt% of fac- Ir (ppy) ₃ was doped into the compound of Formula 1 prepared in Example 1, which was spin-coated from the chlorobenzene solution (0.9 wt%) to 3,000 ppm, followed by N _2. Dry at 80 ° C. for 10 minutes on a hotplate in a glove box filled with. The film thickness of the spin coated layer was measured using AFM, and as a result, about 50 nm.

After the drying step, the sample coated with the compound of Formula 1 was brought into a thermal deposition chamber (HS-1100, Digital Optics & Vacuum) surrounded by a glove box filled with N ₂ . A 50 nm thick CBP layer was co-deposited with Ir (ppy) ₃ using an optional shadow mask on the sample deposited with PEDOT: PSS. Next, the shadow mask was changed to having an opening. In this way, BCP (12 nm), Bphen (35 nm), LiF (1 nm), and Al (100 nm) layers were placed on top of the light emitting layer (polymer of formula 1 doped using Ir (ppy) ₃ ). As successfully deposited. Then vacuum deposition under high vacuum (˜7 × 10 ⁻⁷ torr) and the following deposition rates: 0.5-1.0 dl / s (BCP and Bphen), 0.5 dl / s (LiF), and 3 dl / s (Al electrode) Was performed. Thus compound of formula 1 doped with ITO / PEDOT: PSS (40 nm) / Ir (ppy) ₃ (50 nm) / BCP (12 nm) / Bphen (35 nm) / LiF (1 nm) / Al (100 nm A device consisting of a layer was fabricated.

Wherein PEDOT: PSS is poly (3,4-ethylenedioxythiophene: poly- (styrenesulfonate), BCP is 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline; Bphen is 4,7-diphenyl-1,10-phenanthroline.

<Examples 3 to 5>

An organic light emitting diode was manufactured according to the same method as Example 2 except that the concentration of Ir (ppy) ₃ doped into the compound of Formula 1 was 2, 4, or 6 wt%, respectively.

<Comparative Example 1-2>

An organic light emitting diode was manufactured according to the same method as Example 2 except for using a PVK polymer and a CBP molecular host doped with 4 wt% and 7 wt%, respectively, instead of the compound of Formula 1.

Experimental Example 1 EL Spectrum Observation

The EL spectra of the devices manufactured in Examples 2-5 and Comparative Examples 1 (PVK) and 2 (CBP) were observed and shown in FIG. 7, and the EL spectra were N ₂ atmosphere using an optical fiber spectrometer (EPP2000, StellarNet). Measured in

As shown in FIG. 7, all devices fabricated in the Examples and Comparative Examples emitted almost the same green phosphorescence with a maximum emission wavelength λ _em of 512 nm, indicating that the emission is complete from the host to the guest. It can be seen that by energy transfer only the phosphorescent dopant fac-Ir (ppy) ₃ is derived.

Experimental Example 2 Device Performance Measurement

The performance of the devices manufactured in Example 2-5 and Comparative Examples 1 (PVK) and 2 (CBP) were measured and shown in Table 2 and FIGS. 8-9.

Current-voltage (J-V) and emission-voltage (L-V) characteristics were measured with a source meter unit (SMU, Keithley 2400) and calibrated photodiode (FDS100, Thorlab).

FIG. 8 shows the external quantum efficiency (η _EQE , FIG. 8A) and power efficiency (η _PE , FIG. 8B) data of the devices, and FIG. 9 shows (a) the current density-emitting-applied voltage (JVL) of the devices. Graph, and (b) external quantum efficiency-luminescence curve.

device Host fac -Ir (ppy) ₃ concentration CIE (x, y) V _{turn - on}
(V) L _max
(cd / m ² ) EQE _max
(%) PE _max
(lm / W) D1
(Example 2) The compound of formula (1) 1 wt% 0.289, 0.631 4.7 8400 7.1 11 D2
(Example 3) The compound of formula (1) 2 wt% 0.287, 0.633 4.9 9300 7.2 11 D3
(Example 4) The compound of formula (1) 4 wt% 0.287, 0.638 5.0 6600 6.5 10 D4
(Example 5) The compound of formula (1) 6 wt% 0.298,0.632 4.9 8000 5.8 8 D5
(Comparative Example 1) PVK 4 wt% 0.289, 0.631 5.1 7500 5.4 8 D6
(Comparative Example 2) CBP 7 wt% 0.269, 0.643 3.3 66000 9.3 ^* 14 * D6 is less than the maximum external quantum efficiency (EQE) of conventional CBP host-based PhOLEDs because it does not include hole transport layers (HTLs).

As shown in Table 2 and FIG. 8, the external quantum efficiency (η _EQE ) and power efficiency (η _PE ) of the device containing the compound of formula 1 according to the present invention were 5.8-7.2% and 8-11 lm / W, respectively. Equivalent to the value of the molecular CBP host (D6), especially when the concentration of fac -Ir (ppy) ₃ is 2% by weight (D2), the quantum efficiency (η _EQE ) and power efficiency (η _PE ) are the highest. appear. This efficiency was found to be 32% higher than PVK based device (D5), the most commonly used polymer host physics.

In addition, the doping concentration of the device according to the present invention exhibiting maximum quantum efficiency is much lower than the value of CBP of D6. This difference in optimal doping concentration requires a smaller number of CBP substituents per unit weight of the compound host of Formula 1 according to the present invention than D6 because fac-Ir (ppy) ₃ of less than D6 is required for high efficiency. .

In addition, as shown in Figure 9, the device (D2) comprising the compound according to the present invention is a PVK-based device (D5) is the most commonly used polymer host physics for light emission and external quantum efficiency at a wide range of applied voltages Shows better performance than).

Accordingly, the device containing the compound of formula 1 according to the present invention exhibits device performance such as excellent external quantum efficiency (η _EQE ) and power efficiency (η _PE ), which is equal to or higher than that of a device including a molecular host. Therefore, it can be usefully used as an organic electroluminescent device.

So far I looked at the center of the preferred embodiment for the present invention. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. Therefore, the disclosed embodiments should be considered in an illustrative rather than a restrictive sense. The scope of the present invention is defined by the appended claims rather than by the foregoing description, and all differences within the scope of equivalents thereof should be construed as being included in the present invention.

Claims (10)

A green phosphorescent host material including a vinyl-type polynorbornene polymer represented by Formula 1;
&Lt; Formula 1 >

(Wherein R is

,

or

Is,
Wherein R ₁ is hydrogen, C _{1? 20} alkyl group, C _{1? 20} haloalkyl group or a C _{6? 20} aryl groups, C _{6? 20} aryl groups, C _{6? 20} alkylaryl group, C _{6? 20} of the a haloaryl group, wherein R ₂ is hydrogen, C _{1? 20} alkyl group, C _{1? 20} haloalkyl group or a C _{6? 20} aryl groups, C _6? arylalkyl group of _20, C _{6? 20} alkyl, aryl group, a C _6?, and haloaryl of ₂₀ group, wherein R ₃ is hydrogen, C _{1? 20} alkyl group, C _{1? 20} of a haloalkyl group or a C _{6? 20} aryl groups, C _6? arylalkyl group of _20, C _{6? 20} alkylaryl group, C _6? and ₂₀ haloaryl group, wherein R ₄ is hydrogen, C _{1? 20} alkyl group, C _{1? 20} of a haloalkyl group or a C _{6? 20} aryl groups, C _6? arylalkyl groups of _20, C _6? alkylaryl group of _20, C _{6? 20} aryl group of halo, n ₁ is 1 ~ 10,000, n ₂ is 1 ~ _3, n 3 is 1 to 20). The method of claim 1,
Wherein R is 9,9 '-(1,1'-biphenyl) -4,4'-diylbis-9H-carbazole (CBP), 9-phenyl-4-yl-9H-carbazole and 9-bi Green phosphorescent host material, characterized in that selected from the group consisting of phenyl-4-yl-9H-carbazole. The method of claim 1,
The vinyl-type polynorbornene polymer is a green phosphorescent host material, characterized in that prepared through the vinyl addition polymerization (vinyl addition polymerization) of the norbornene monomer. The method of claim 3,
The vinyl addition polymerization is performed by adding a norbornene monomer to an activated catalyst solution including a palladium catalyst and adding 1-olefin to react the green phosphorescent host material. The method of claim 4, wherein
The 1-olefin is added to 0.01 to 20 mol% based on the norbornene monomer, green phosphorescent host material, characterized in that to perform a vinyl addition polymerization. In an organic light emitting device comprising a light emitting layer between an anode, a cathode and a positive electrode,
A green phosphorescent organic light emitting diode comprising the host material of claim 1 in a light emitting layer. The method according to claim 6,
The organic light emitting device of claim 1, further comprising a phosphorescent dopant in the host material. The method of claim 7, wherein
The phosphorescent dopant is tris (2-phenylpyridinato-N, C2) ruthenium, bis (2-phenylpyridinato-N, C2) palladium, bis (2-phenylpyridinato-N, C2) platinum, tris (2-phenylpyridinato-N, C2) osmium, tris (2-phenylpyridinato-N, C2) rhenium, octaethyl platinum porphyrin, octaphenyl platinum porphyrin, octaethyl palladium porphyrin, octaphenyl palladium porphyrin, iridium (III) bis [(4,6-difluorophenyl) -pyridinato-N, C2 '] picolinate (Firpic), tris (2-phenylpyridinato-N, C2) iridium (Ir (ppy ) ₃ ), fac- Ir (ppy) ₃ , bis- (2-phenylpyridinato-N, C2) iridium (acetylacetonate) (Ir (ppy) ₂ (acac)) and 2,3,7,8 , 12, 13, 17, 18- octaethyl-21H, 23H- porphine platinum (II) (PtOEP) organic light emitting device, characterized in that selected from the group consisting of. The method according to claim 6,
An organic light emitting device, characterized in that consisting of a structure comprising a charge transport layer between the anode or cathode and the light emitting layer. 10. The method of claim 9,
An organic light emitting device comprising a multi-layered structure in which transparent electrodes (anodes), hole injection layers, hole transport layers, light emitting layers, electron transport layers, electron injection layers, and metal electrodes (cathodes) are sequentially stacked.

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