KR20160027299A - Cyan Host Compound and Organic emitting Device Employing The Same - Google Patents

Abstract

The present invention relates to a cyan-based host compound displayed by chemical formula 1, and an organic light emitting diode adopting the same. In chemical formula 1, R refers to one selected among the group including C1-C12 aliphatic alkyl and C3-C12 cycloalkyl; and Ax and Ay independently refer to hydrogen (H) or cyan (CN). The chemical compound displayed by chemical formula 1 includes at least one cyan therein, wherein n refers to an integer ranging from 1 to 5, while a and b are independently integers ranging from 1 to 3, and a+b equals 4. The present invention is to provide a host chemical compound for an alkylsilane-based light-emitting material with enhanced light-emitting properties and thermal stability, and a blue organic light-emitting diode using the same.

Description

TECHNICAL FIELD The present invention relates to a cyan host compound and an organic light emitting device employing the cyan host compound.

TECHNICAL FIELD The present invention relates to a cyan host compound and an organic light emitting device employing the same, and more particularly, to a host compound for blue phosphorescence including cyan and an organic light emitting device employing the same.

A long pursued goal in the technical field of phosphorescent light emitting materials as organic light emitting devices is to develop materials that emit light with high efficiency, high color purity and long life. With respect to the phosphorescent light emitting material, research is continuously carried out to increase the amount of energy absorbed and emitted by a given luminescent material which emits light in the visible light region. A host-dopant system is used as a method for increasing the luminous efficiency, increasing the color purity and improving the stability of the device in the phosphorescent organic light emitting device. Phosphorescent dopants generally have a long excitation lifetime and exhibit triplet-triplet extinction, so it is common to use doping to the host. The singlet and triplet levels of the host must be higher than the phosphorescent dopant to prevent reverse energy transfer and to constrain the triplet exciton in the light emitting layer (L. Xiao., Et al., Advanced Materials 23, pp. 926-952 , 2011).

Firpic, a well - known blue phosphorescent dopant, has a triplet energy of 2.7 eV. As a material constituting such a host having a large triple energy, a carbazole-based compound, a triazole-based compound, a phenylpyridine-based compound, an oxdiazole-based compound, a benzimidazole-based compound, a silicon-based compound or a phosphine oxide- Compounds have a problem of low efficiency in an organic light emitting device, and in particular, a host material capable of realizing excellent efficiency in a blue organic light emitting device is very limited (SO Jeon, et al., J. Mater. Chem. , pp. 4233-4243, 2012). Therefore, the development of a new host with high efficiency is a very important task in the field of blue phosphorescent devices.

US Patent Application No. 0119367A1 filed a variety of host materials for blue phosphorescence containing both a carbazole-based and phosphine oxide-based compound by Professor Jun Yeob Lee of Dankook University. The patented technology of the device using the host material for blue phosphorescence filed by them has a quantum efficiency of 15.0 to 21.9% and a color coordinate property of (0.14, 0.17).

However, the blue light emitting host compound has a problem that the color purity and the quantum efficiency are relatively low. In addition, mCPPO1, a representative compound of the above patent, showed a glass transition temperature (Tg) of 120 ?. In the case of organic light emitting materials, very high thermal stability is required because the heat generated during device operation promotes thermal decomposition, resulting in thin film separation or deformation of the electrode and the organic layer, thereby degrading the lifetime and performance of the device . Therefore, it is required to develop a compound having a structure for improving heat stability and to develop an organic light emitting device using the same.

U.S. Published Patent Application No. 0119367A1

An object of the present invention is to provide a host compound for alkylsilane emission having improved luminescence properties and thermal stability and a blue organic light emitting device employing the same.

One aspect of the present invention provides a cyanide host compound represented by the following formula (1).

Formula 1

In Formula 1, R is any one selected from the group consisting of C ₁ -C ₁₂ aliphatic alkyl and C ₃ -C ₁₂ cycloalkyl; Ax and Ay are each independently hydrogen (H) or cyan (CN) Wherein the compound of formula 1 comprises at least one cyan (CN), n is an integer of 1 to 5, each of a and b is independently an integer of 1 to 3, and a + b is 4 .

In addition, the cyan host compound may provide a cyan host compound, which is at least one selected from the group consisting of the following compounds.

Another aspect of the present invention provides an organic light emitting device comprising an organic film provided between a pair of electrodes, wherein the organic film includes the cyanide host compound and the blue iridium phosphorescent compound of any one of claims 1 to 2 .

Also, the blue iridium phosphorescent compound may be at least one selected from the group consisting of the following structural formulas.

In addition, the blue iridium phosphorescent compound may include 0.1 to 90% by weight of the alkylsilane-based host compound.

According to one aspect of the present invention, a cyan host compound and a blue organic light emitting device employing the host material can provide a blue phosphorescent organic light emitting device having improved color coordinates and quantum efficiency and improved thermal stability .

FIG. 1 is a schematic diagram showing the structure of 9- (4- (3-cyanocarbazole) phenyl) dimethylsilyl) phenyl) -9- carbazole) is a nuclear magnetic resonance spectroscopy data.
FIG. 2 is a hydrogen nuclear magnetic resonance spectroscopic data of bis (4- (N-3-cyano-carbazolyl) phenyl) dimethyl silane.
Figure 3 shows the hydrogen nuclear magnetic resonance of bis (4- (N-3,6-dicyano-carbazolyl) phenyl) dimethylsilane It is a spectral data.
FIG. 4 is a graph showing the effect of the 9- (4- (3-cyanocarbazole) phenyl) dimethylsilyl) phenyl-9- carbazole) in a solution state, and a graph of optical emission at room temperature and low temperature.
FIG. 5 is a graph showing the results of a UV absorption graph in the solution state of a compound of bis (4- (N-3-cyano-carbazolyl) phenyl) dimethylsilane , And optical luminescence at room temperature and low temperature.
Figure 6 shows the solution state of a compound of bis (4- (N-3,6-dicyano-carbazolyl) phenyl) dimethylsilane (bis (4- (N-3,6-dicyano- , And graphs showing optical luminescence at room temperature and low temperature.
FIG. 7 is a graph showing the results of UV absorption in a solution state of a compound of (4- (N-3-cyano-carbazolyl) phenyl) trimethyl silane, And optical emission at low temperature.
FIG. 8 is a graph showing the UV absorbance in the solution state of a compound of tris (4- (N-3-cyano-carbazolyl) phenyl) dimethylsilane (tris , And optical luminescence at room temperature and low temperature.
9 is a diagrammatic view of the synthesis of 9,9 '- (4,4' - ((4- (3- (dicyanocarbazole) -9 hydrogen-carbazol-9yl) phenyl) (methyl) silanediyl) (9,9 '- (4,4' - ((4- (3- (dicyano carbazole) -9H-carbazol-9-yl) phenyl) methyl) silanediyl) bis (4,1-phenylene)) bis (9H-carbazole)) in solution state.
10 shows the structure of an OLED device fabricated in Examples 2, 3, and 4 using a cyanide host compound according to one aspect of the present invention.
11 is a curve of IVL characteristics of the device manufactured in Examples 2, 3 and 4 using a cyanide host compound according to one aspect of the present invention.
FIG. 12 is a graph showing the luminous efficiency characteristics of the devices fabricated in Examples 2, 3, and 4 using a cyanide host compound according to an aspect of the present invention.
13 is a graph showing EL spectrum characteristics of the devices fabricated in Examples 2, 3, and 4 using a cyanide host compound according to one aspect of the present invention.

One aspect of the present invention provides a cyanide host compound represented by the following formula (1).

Formula 1

In Formula 1, R is any one selected from the group consisting of C ₁ -C ₁₂ aliphatic alkyl and C ₃ -C ₁₂ cycloalkyl; Ax and Ay are each independently hydrogen (H) or cyan (CN) And n is an integer of 1 to 5, each of a and b is independently an integer of 1 to 3, and a + b is an integer of 1 to 3, and the compound of the formula 1 contains at least one cyanide (CN) 4.

Specific examples of the formula (1) may include at least one selected from the group consisting of the following compounds, although it is not particularly limited as long as it is a cyanide host compound conforming to the formula (1).

When three substituents such as a silicon group, a carbazole group and a cyan group are simultaneously introduced in the substituent group, it is possible to use a conventional carbazole-based compound, triazole-based compound, phenylpyridine-based compound, oxydiazole-based compound, benzimidazole- It is possible to have a higher triplet energy as compared with the case where the oxide compound is used alone. In particular, thermal stability can be achieved by not only superposition of the p-d orbital function of the carbon-silicon bond of the alkyl-silane with the cyan substituent having strong C-N bond, but also strong coupling by the orbital superposition of p-σ *. In addition, energy can be efficiently transferred to the blue phosphorescent light emitting compound by a high triplet energy and a strong electron attracting group of the cyan system, thereby improving the quantum efficiency and color purity and enabling light emission in a deep blue color.

In addition, the organic light emitting device according to an aspect of the present invention includes an organic film provided between a pair of electrodes, and the organic film may include an alkylsilane-based host compound and a blue iridium phosphorescent compound.

The structure of the organic light emitting device may be the same as that of the conventional organic light emitting device, and the organic film included between the electrodes may include the organic light emitting device according to one aspect of the present invention. When the alkylsilane-based host compound of the above formulas (1), (2) and (3) is used together with the iridium compound for blue phosphorescence, the blue light emitting material is excellent in luminous efficiency and may be useful as a coloring material for an organic light emitting device. The blue iridium phosphorescent compound allows the blue light to emit more efficiently with the alkylsilane based host compound.

The blue iridium phosphorescent compound may be at least one selected from the group consisting of the following structural formulas.

The mixed weight ratio of the cyan host compound and the blue iridium phosphorescent compound of the above structural formula may be 99 (host): 1 (dopant) to 60:40. Here, when the content of the blue cyanide host to the blue light emitting compound exceeds the above range and the content of the blue cyan host is less than the above range, the light emitting efficiency may tend to decrease.

Further, one aspect of the present invention can provide an organic light emitting device employing the above light emitting compound as a coloring material. That is, in an organic light emitting device including an organic film provided between a pair of electrodes, the organic film may include an iridium phosphorescent compound or a mixture of the two.

Hereinafter, a method of manufacturing an organic light emitting diode according to an embodiment of the present invention will be described.

First, an anode electrode material is coated on the substrate. Here, a substrate used in a conventional organic light emitting device is used as a substrate, and a glass substrate or a plastic substrate having excellent transparency, surface smoothness, ease of handling, and waterproofness can be used. As the material for the anode electrode, indium tin oxide (ITO), tin oxide (SnO ₂ ), zinc oxide (ZnO), indium zinc oxide (IZO) and antimony tin oxide (ATO) .

A hole transport layer may be formed by vacuum evaporation or spin-coating a material for forming a hole transport layer on the anode. An iridium phosphorescent compound may be vacuum deposited on the hole transport layer to form a light emitting layer.

The hole transport layer material is not particularly limited, but it is preferable that the hole transport layer material is selected from the group consisting of N, N'-bis (3-methylphenyl) -N, N'-diphenyl- [1,1'- TPD), N, N'-di (naphthalen-1-yl) -N, N'-diphenyl-benzidine (? -NPD), 9,9- N'-bis (phenyl) -benzidine (PAPB), di- [(4-fluorophenyl) N, N ', N', N'-tetra-naphthalene-benzidine (α-TNB) and the like can be used.

A metal for forming a cathode is vacuum-deposited on the light emitting layer to form a cathode, thereby completing the organic EL device. Here, the cathode forming metal is selected from the group consisting of Li, Mg, Al-Li, Ca-Al, LiF- Mg-In, Mg-Ag, Ba-Al, Au, Ag, and Cu may be used.

A hole barrier layer and an electron transport layer may be formed on the emission layer before forming the cathode. The hole blocking layer and the electron transporting layer may use a material for forming a hole blocking layer electron transporting layer.

The organic light emitting device according to an aspect of the present invention may further include an intermediate layer for improving characteristics between two layers selected from an anode, a hole transporting layer, a light emitting layer, an electron transporting layer, and a cathode. For example, a hole injection layer (HIL) may be further formed between the anode and the hole transport layer. When the hole injection layer is formed as described above, the hole transport layer (e.g., alpha -NPD) and the anode It is possible to improve adhesion and to help inject holes from the anode into the hole transport layer.

The material for forming the hole injection layer is not particularly limited. However, the material for forming the hole injection layer is not limited to a specific one, but examples thereof include phthalocyanine (CuPc), 4,4 ', 4 "-tris (3- ethylphenylphenylamino) tris (3-ethylphenylphenylamino) triphenylamine, m-MTDATA), 4,4 ', 4 "-tris (N- (1-naphthyl) tris [2-naphthyl (phenyl) amino] -triphenylamine (4, 4 ' 4,4 ', 4 "-tris [2-naphthyl (phenyl) amino] -triphenylamine, 2T-NATA, dipyrjino [2,3-f: 2', 3'-h] , 6,7,10,11-hexacarbonitrile (Dipyrazino [2,3-f: 2 ', 3'-h] quinoxaline-2,3,6,7,10,11-hexacarbonitrile HAT- (N, N'-diphenyl-N, N'-di- [4- (N N, N ', N'-tetrakis (4-methoxyphenyl) benzidine and N, N'- methoxyphenyl) benzidine, MeO-TPD), at least one selected from the group consisting of Can be used.

The organic light emitting device may be manufactured in the order as described above, that is, in the order of anode / hole transporting layer / light emitting layer / hole blocking layer / electron transporting layer / cathode, / Hole transport layer / anode.

The following is an actual synthesis example of an alkylsilane-based host compound according to one aspect of the present invention. It is to be understood that the scope of the present invention is not limited thereto and that the scope of the present invention includes all ranges that can be easily derived by a person having ordinary skill in the art.

Preparation of cyan base blue host compound

Synthesis Example 1 Synthesis of Compound 1

Phenyl) -9H-carbazole) of 9- (4- (3-cyano-carbazole) phenyl) dimethylsilyl) synthesis

Scheme 1

As shown in Scheme 1, a reaction vessel was charged with 9- (4 - ((4-bromophenyl) dimethylsilyl) phenyl-9-hydrogen- (1.20 g, 29 mmol), 3-cyano-carbazole (4.61 g, 24 mmol), copper iodide (9.30 g, 49 mmol), potassium carbonate (13.10 g, 95 mmol) and 1,2-dichlorobenzene were heated at 210 ° C. for 12 hours. After completion of the reaction, the reaction mixture was extracted with dichloromethane, and the organic solvent was evaporated with a rotary vacuum evaporator The resulting product was purified by silica gel column chromatography to obtain a white solid in a yield of 65% (10.70 g). The results are shown in FIG.

_{1H-NMR (CDCl 3, 400MHz} ) δ (ppm) = 8.47 (s, 1H), 8.16 (d, 2H), 7.86 (t, 4H), 7.63 (d, 2H), 7.58 (d, 2H), 7.49 (m, 6H), 7.42 (t, 4H), 7.28 (t, 2H), 0.75 (s, 6H).

Synthesis Example 2 Synthesis of Compound 2

Synthesis of bis (4- (N-3-cyano-carbazolyl) phenyl) dimethyl silane) Synthesis of bis (4- (N-3-cyano-carbazolyl) phenyl) dimethylsilane

Scheme 2

As shown in Reaction Scheme 2, bis (4-bromophenyl) dimethyl silane (5.34 g, 14.5 mmol), 3-cyano-carbazole ), Potassium iodide (9.30 g, 49 mmol), potassium carbonate (13.10 g, 95 mmol) and 1,2-dichlorobenzene were heated at 210 ° C Lt; / RTI > for 12 hours. After completion of the reaction, the reaction mixture was extracted with dichloromethane, and the organic solvent was evaporated using a rotary vacuum evaporator. The resultant was subjected to silica gel column chromatography to obtain a white solid in a yield of 55% (9.45 g). The results are shown below and are shown in FIG.

_{1H-NMR (CDCl 3, 400MHz} ) δ (ppm) = 8.48 (s, 2H), 8.18 (d, 2H), 7.87 (d, 4H), 7.65 (d, 2H), 7.60 (d, 4H), 7.50 (m, 6 H), 7.39 (t, 2 H), 0.77 (s, 6 H).

Synthesis Example 3 Synthesis of Compound 3

Synthesis of bis (4- (N-3,6-dicyano-carbazolyl) phenyl) dimethyl silane) Synthesis of bis (4- (Nitrogen-3,6-dicyano-carbazolyl) phenyl)

Scheme 3

As shown in Reaction Scheme 3, bis (4-bromophenyl) dimethyl silane (5.34 g, 14.5 mmol), 3,6-dicyano-carbazole -dicyano-carbazole (5.21g, 24mmol), copper iodide (9.30g, 49mmol), potassium carbonate (13.10g, 95mmol), 1,2- dichlorobenzene ) Is heated to 210 < 0 > C for 12 hours. After completion of the reaction, the reaction mixture was extracted with dichloromethane, and the organic solvent was evaporated using a rotary vacuum evaporator. The resultant was subjected to silica gel column chromatography to obtain a white solid in a yield of 53% (9.87 g). The results are shown in FIG.

_{1H-NMR (CDCl 3, 400MHz} ) δ (ppm) = 8.49 (s, 4H), 7.89 (d, 4H), 7.74 (d, 4H), 7.57 (d, 4H), 7.50 (d, 4H), 0.77 (s, 6 H).

Synthesis Example 4 Synthesis of Compound 4

Synthesis of (4- (N-3-cyano-carbazolyl) phenyl) trimethyl silane Synthesis of 4- (N-3-cyano-carbazolyl)

Scheme 4

(4-bromophenyl) trimethyl silane (6.61 g, 29 mmol), 3-cyano-carbazole (4.61 g, g, 24 mmol), copper iodide (9.30 g, 49 mmol), potassium carbonate (13.10 g, 95 mmol) and 1,2-dichlorobenzene Lt; / RTI > After completion of the reaction, the reaction mixture was extracted with dichloromethane, and the organic solvent was evaporated using a rotary vacuum evaporator. The resultant was subjected to silica gel column chromatography to obtain a white solid in a yield of 65% (6.41 g). The results are as follows.

_{1H-NMR (CDCl 3, 400MHz} ) δ (ppm) = 8.58 (s, 1H), 8.34 (d, 1H), 7.65 (d, 1H), 7.60 (d, 1H), 7.50 (d, 1H), 7.45 (t, 1 H), 7.23 (t, 1 H), 0.76 (s, 9 H).

≪ Synthesis Example 5 &

Synthesis of tris (4- (N-3-cyano-carbazolyl) phenyl) methyl silane) Synthesis of tris (4- (N-3-cyano-carbazolyl) phenyl)

Scheme 5

As shown in Reaction Scheme 5, tris (4-bromophenyl) methyl silane (4.93 g, 9.7 mmol), 3-cyano-carbazole ), Potassium iodide (9.30 g, 49 mmol), potassium carbonate (13.10 g, 95 mmol) and 1,2-dichlorobenzene were heated at 210 ° C Lt; / RTI > for 12 hours. After completion of the reaction, the reaction mixture was extracted with dichloromethane, and the organic solvent was evaporated using a rotary vacuum evaporator. The resultant was subjected to silica gel column chromatography to obtain a white solid in a yield of 49% (4.01 g). The results are as follows.

_{1H-NMR (CDCl 3, 400MHz} ) δ (ppm) = 8.17 (s, 1H), 8.13 (d, 2H), 7.93 (m, 4H), 7.85 (d, 2H), 7.76 (m 6H), 7.65 ( m, 8H), 7.40 (m 6H), 7.29 (m, 4H), 1.09 (s, 3H)

≪ Synthesis Example 6 &

9,9 '- (4,4' - ((4- (3- (dicyanocarbazole) -9 hydrogen-carbazol-9-yl) phenyl) (methyl) silanediyl) (9,9 '- (4,4' - ((4- (3- (dicyano carbazole) -9H-carbazol-9-yl) phenyl) (methyl) silanediyl ) bis (4,1-phenylene)) bis (9H-carbazole)

Scheme 6

As shown in Scheme 6, a reaction vessel was charged with 9,9 '- (4,4'- ((4-bromophenyl) (methyl) silanediyl) bis (4,1- Carbazole) (19.78g, 29mmol), (9,9 '- (4,4'- (4-bromophenyl) (methyl) silanediyl) bis 3,3-dicyano-carbazole (5.21 g, 24 mmol), copper iodide (9.30 g, 49 mmol), potassium carbonate (13.10 g, 95 mmol) , And 1,2-dichlorobenzene are heated at 210 占 폚 for 12 hours. After completion of the reaction, the reaction mixture was extracted with dichloromethane, and the organic solvent was evaporated using a rotary vacuum evaporator. The resultant was subjected to silica gel column chromatography to obtain a white solid in a yield of 67% (15.92 g). The results are as follows.

_{1H-NMR (CDCl 3, 400MHz} ) δ (ppm) = 8.17 (s, 2H), 8.12 (d, 2H), 7.94 (m, 4H), 7.70 (m 6H), 7.64 (m, 8H), 7.43 ( m 8H), 7.29 (m, 4H), 1.10 (s, 3H).

1 to 13, the results are shown in FIGS. 1 to 3, which are hydrogen nuclear magnetic resonance spectroscopic data of the resultant product, and FIGS. 4 to 9 show the results of the hydrogen silicate- Optical absorption at room temperature, optical emission, and optical emission at low temperature.

Example 1: Comparison of thermal stability of cyan host compounds prepared

(9- (9H-Carbazol-9-yl) phenyl) -3- (diphenylphosphoryl) benzoate, which is a representative compound of compounds 1, 2, 3, 4, 5 and 6 according to one aspect of the present invention, -9H carbazole] were analyzed by differential scanning calorimetry (DSC) analysis in a nitrogen atmosphere, and the results are shown in Table 1 below.

compound The glass transition temperature (Tg) Compound 1 162 ° C Compound 2 240 ℃ Compound 3 270 ℃ Compound 4 151 C Compound 5 212 ° C Compound 6 176 ° C mCPPO1 120 DEG C

As shown in Table 1, compounds 1, 2, 3, 4, 5, and 6 according to one aspect of the present invention have a glass transition temperature of about 150 to about 150 when compared with the conventional compound mCPPO1 ? It can be seen that the temperature is high. This may mean that the thermal stability is higher than the conventional compound.

≪ Example 2 > Preparation of organic luminescent device employing Compound 1

The organic light emitting device according to one aspect of the present invention is fabricated as a single blue light emitting structure for evaluating a blue phosphorescent host. Each layer of the device is as follows. First, ITO (Indium Tin Oxide) was deposited on a substrate with a thickness of 150 nm as a hole injecting layer by using 10 nm thick dipyrinose ([2,3-f: 2 ', 3'-h] quinoxaline-2,3 , 6,7,10,11-hexacarbonitrile) was used as a hole transport layer and TACP (di- [4- (N, N-ditolyl-amino) -phenyl] cyclohexane MCP (1,3-bis (9-carbazolyl) benzene) is used as a light emitting layer, and Compound 1 of the present invention is used as a cyan host compound and a dopant for blue iridium phosphorescence is doped as a light emitting layer, Compound 1 synthesized in the present invention was used as a phosphorescent host and 10% doped with blue phosphorescent dopant using Ir (dfCF3pepy). The electron transport layer was composed of 30 nm thick TSPO1 (Diphenyl -4-triphenylsilylphenyl-phosphine oxide, and 3 nm-thick Liq (8-hydroxyquinolinolato-lithium) was used for the electron injection layer. After the moisture is absorbed into the gap glass, the cover glass is bonded with the UV bond and the device is manufactured. do.

The prepared organic light emitting device was prepared by mixing ITO / HAT-CN (10 nm) / TAPC (40 nm) / mCP (10 nm) / Compound 1: Ir (dfCF3pepy) 10% / TSPO1 (30 nm) / Liq ] Are laminated in order from bottom to top. The effects are shown in Table 2 below.

≪ Example 3 > Preparation of organic light emitting device employing Compound 2

Was prepared in the same manner as in Example 2, except that a cyanide host in the light emitting layer was used as Compound 2 synthesized in the present invention.

The prepared organic light emitting device was prepared by mixing 10% ITO / HAT-CN (10 nm) / TAPC (40 nm) / mCP (10 nm) / Compound 2: blue phosphorescent dopant Ir (dfCF3pepy) Al (100 nm)] are laminated in order from bottom to top. The effects are shown in Table 2 below.

Example 4 Production of Organic Light Emitting Device Employing Compound 3

The cyan host of the light emitting layer is used as Compound 3 synthesized in the present invention.

The prepared organic light emitting device was prepared by mixing 10% ITO / HAT-CN (10 nm) / TAPC (40 nm) / mCP (10 nm) / Compound 3: blue phosphorescent dopant Ir (dfCF3pepy) Al (100 nm)] are laminated in order from bottom to top. The effects are shown in Table 2 below.

Quantum efficiency
(%) Luminous efficiency
(cd / A) Power efficiency
(lm / W) Color coordinates Remarks Example 2
Compound 1 25.2 24.0 18.0 (0.15, 0.15) MAX Example 3
Compound 3 23.0 22.1 15.5 (0.15, 0.15) MAX Example 4
Compound 3 22.5 19.1 10.9 (0.15, 0.15) Max mCPPO1 21.9 (0.14, 0.17) Max

As shown in Table 2, the compounds 1, 2 and 3 according to one aspect of the present invention were evaluated as unit elements, and as a result, 25.2% of Compound 1, 23.0% of Compound 2 and 22.5% of Compound 3 The efficiency of quantum efficiency was shown to be as high as 21.9% when mCPPO1, a representative material of the prior art, was used. In addition, the color coordinates of 0.15 and 0.15 were shown, which showed better color coordinates than the conventional blue alkylsilane host mCPPO1 in color purity. Therefore, it can be seen that the compound 1 according to one aspect of the present invention in the luminescent layer has improved properties as a host and the electron mobility is improved in a balanced manner.

Claims (5)

A cyanide host compound represented by the following formula (1).
Formula 1

In Formula 1,
R is any one selected from the group comprising C ₁ -C ₁₂ aliphatic alkyl and C ₃ -C ₁₂ cycloalkyl,
Ax and Ay are each independently hydrogen (H) or cyan (CN)
Wherein the compound of Formula 1 comprises at least one cyan (CN), n is an integer of 1 to 5,
Each of a and b is independently an integer of 1 to 3, and a + b is 4; The method according to claim 1,
Wherein the cyan host compound is at least one selected from the group consisting of the following compounds.

And an organic film provided between the pair of electrodes,
Wherein the organic film comprises the cyanide host compound and the blue iridium phosphorescent compound of any one of claims 1 to 2. The method of claim 3,
Wherein the blue iridium phosphorescent compound is at least one selected from the group consisting of the following structural formulas.

The method of claim 3,
Wherein the blue iridium phosphorescent compound comprises 0.1 to 90% by weight of the alkylsilane based compound.

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