KR20160087959A - Carbazole Derivatives and Organic light emitting device Comprising the Same - Google Patents

Abstract

The present invention relates to a carbazole derivative organic light emitting compound and an organic light emitting device comprising the same. In the compound disclosed in the present invention, a substituent introduced at the ortho position induces the steric distortion in the organic light emitting compound to disconnect the pie conjugation, thereby minimizing the expansion of the conjugation between substituents due to a high steric hindrance, thus maintaining excellent triplet energy, and a hole transport substituent and an electron transport substituent are respectively bound to a benzene ring, thereby exhibiting excellent hole injection transport and electron injection transport characteristics. The compound disclosed in the present invention has excellent blue and green phosphorescent characteristics together with superior quantum efficiency, current efficiency, and power efficiency, and thus can be favorably used as an efficient phosphorescent host material.

Description

[0001] The present invention relates to a carbazole derivative and an organic light emitting device including the same,

The present invention relates to a carbazole derivative and an organic light emitting device including the same.

Conventional materials for organic light emitting devices have been developed in various types of materials, but commercialization has been limited due to low charge mobility, luminous efficiency, and lifetime problems. Especially, blue and green phosphorescent devices must have higher triplet energies than metal complex type luminescent dopants to realize device characteristics with excellent efficiency. However, since the unit (core) with high triplet energy is limited, it meets various demands The development of materials to be used is inadequate. Therefore, in order to improve existing compounds, new types of compounds should be devised to improve the efficiency and improve the lifetime.

Organic light emitting diodes can be classified into fluorescent and phosphorescent devices according to a light emitting mechanism. In the case of phosphorescent devices, it is theoretically four times as efficient as a fluorescent device. The luminescent material (dopant material) for such a phosphorescent device is mainly an iridium metal complex, and red, green and blue materials have been developed. The triplet energies of the red, green, and blue dopant materials have triplet energies suitable for each emission region of about 2.3 eV, 2.5 eV, and 2.7 eV, respectively. Generally, an organic light emitting diode device constitutes a light emitting layer as a host / dopant system in order to improve the efficiency and the lifetime. Therefore, a host material suitable for hosting such a phosphorescent dopant material is required, and basically, it should have a higher triplet energy than the luminescent dopant material, so that the exciton energy transfer from the host to the dopant proceeds smoothly, . Since red requires a relatively low triplet energy, a variety of host materials have been developed and commercialized. However, since the host material for constituting the green and blue light emitting layers requires high triplet energy, the selection of the core structure of the host material is very limited. Generally, a core having a high triplet energy is a core in which a heteroaromatic compound such as pyridine, pyrimidine, etc., and a fused ring compound such as carbazole, dibenzofuran, dibenzothiophene, etc., . However, when various substituents are introduced into a core molecule having a high triplet energy, the conjugation length of the molecule is increased, and the triplet energy tends to drop sharply. Therefore, the molecular design is inevitably limited in developing an optimal phosphorescent host material.

Several host materials have been reported for better phosphorescence emission. Due to the charge conducting ability, photophysical properties and redox properties, sufficiently high triplet energy and carrier-transporting properties of the carbazole-based compounds, research on these carbazole-based compounds is actively underway.

For example, U.S. Patent Application Publication No. US 2003/205696 discloses a guest-host emission system suitable for use in an organic light-emitting device, wherein the host material comprises one carbon-containing electron- A sol core and a compound comprising an aromatic amine group or a carbazole group bonded to at least one carbon atom, said compound having a high band gap potential and a high energy triplet excited state. Such a material allows short wavelength phosphorescence by the related guest material, and a combination of the above material and a luminescent phosphorescent organic metal compound (for example, an iridium complex) is useful for the production of an organic light emitting device.

In the present invention, the structure of the carbazole derivative is devised as a core molecule capable of ensuring the diversity of the molecular design and obtaining the optimum characteristics. The carbazole derivative has a relatively high triplet energy and has the advantage of being able to appropriately control hole injecting / transporting and electron injecting / transporting characteristics of the host material by introducing molecules having different electrical characteristics into the phenyl group have.

Numerous papers and patent documents are referenced and cited throughout this specification. The disclosures of the cited papers and patent documents are incorporated herein by reference in their entirety to better understand the state of the art to which the present invention pertains and the content of the present invention.

The present inventors have made intensive researches in order to find out an organic luminescent compound which has high triplet energy and can realize a device characteristic of excellent efficiency. As a result, the organic luminescent compound represented by the formula (1) of the present invention has a structure in which substituents introduced at the ortho position induce three-dimensional distortion in the organic luminescent compound to thereby interrupt the piconjugation, The substituent having a hole transporting property and the substituent having an electron transporting property are introduced into the phenyl group while maintaining the triplet energy, and thus it can be usefully used as an organic light emitting compound having excellent hole injection and transportation, electron injection and transport properties The present invention has been completed.

Accordingly, an object of the present invention is to provide an organic luminescent compound of a carbazole derivative.

Another object of the present invention is to provide an organic light emitting device including the organic light emitting compound.

The objects and advantages of the present invention will become more apparent from the following detailed description of the invention and claims.

According to one aspect of the present invention, there is provided a carbazole derivative organic electroluminescent compound represented by Formula 1:

Formula 1

In the above formulas, X is O, S, NR ₄ (R ₄ is hydrogen or C ₁ -C ₃ alkyl) or CR ₅ (R ₅ is hydrogen or C ₁ -C ₃ alkyl); R < _{1 >} is independently hydrogen or heteroarylphenyl of from 13 to 19 rings; And R ₂ and R ₃ are each independently hydrogen or C ₁ -C ₅ alkyl, or R ₂ and R ₃ together form a six-membered aryl ring.

The present inventors have discovered that an organic luminescent compound having high triplet energy and capable of realizing excellent efficiency characteristics can be obtained by substituting a substituent introduced at an ortho position to induce a three-dimensional distortion of an organic luminescent compound to thereby interrupt the piconjugation I tried my best to study. As a result, the organic luminescent compound represented by the above formula (1) has a high triplet energy due to the steric hindrance between each benzene ring, and a substituent having hole transporting property and a substituent having electron transporting property are introduced And can be usefully used as an organic light emitting compound having excellent hole injecting and transporting properties and electron injecting and transporting properties.

As used herein, the term " organic light emitting compound " refers to a compound that exhibits luminescent properties due to interaction between holes and electrons due to voltage loading due to conjugation of double bonds in organic compound molecules.

The organic light emitting compound is used as an organic material layer in an organic light emitting device and can be classified into a light emitting material and a charge transporting material such as a hole injecting material, a hole transporting material, an electron transporting material, and an electron injecting material depending on functions. The light emitting material may be classified into a fluorescent material derived from the singlet excitation state of electrons and a phosphorescent material derived from the triplet excited state of electrons according to a light emitting mechanism. The light emitting material may be classified into blue, green, and red light emitting materials . According to the present invention, the organic luminescent compound of the present invention can be usefully used as a phosphorescent material having high triplet energy.

As used herein, the term " alkyl " means a straight or branched saturated hydrocarbon group, including, for example, methyl, ethyl, propyl, isobutyl, pentyl or hexyl. C ₁ -C ₃ alkyl means an alkyl group having an alkyl unit having 1 to 3 carbon atoms, and when C ₁ -C ₃ alkyl is substituted, the number of carbon atoms of the substituent is not included.

According to a specific embodiment of the present invention, X is O, S, NR ₄ (R ₄ is hydrogen or C ₁ -C ₃ alkyl) or CR ₅ (R ₅ is Hydrogen or C ₁ -C ₃ alkyl), and more specifically X is O or S.

According to a specific embodiment of the present invention, in the organic luminescent compound represented by the formula (1) of the present invention, R ₂ and R ₃ are each independently hydrogen or C ₁ -C ₅ alkyl, or R ₂ and R ₃ together form a hexa ≪ / RTI > More specifically, the organic luminescent compound represented by Formula 1 of the present invention is an organic compound represented by Formulas 14 to 16 in which R ₂ and R ₃ together form a six-membered aryl ring.

According to a specific embodiment of the present invention, R ₁ of formula (1) of the present invention is independently carbazole C ₆ -C ₁₀ aryl which is unsubstituted or substituted by C ₁ -C ₃ alkyl. / RTI >

,

,

,

,

,

,

,

,

,

,

,

,

,

또는

인 것을 특징으로 하는 유기발광 화합물이다. According to a more specific embodiment of the invention, R ₁ of general formula (I) of the present invention are each independently

,

,

,

,

,

,

,

,

,

,

,

,

,

or

≪ / RTI >

According to a more specific embodiment of the present invention, the organic electroluminescent compound represented by Formula 1 of the present invention is selected from the group consisting of the following compounds represented by Formulas 2 to 16:

(2)

(4)

(6)

(8)

(10)

(12)

(14)

Formula 16

According to another aspect of the present invention, there is provided an organic light emitting device comprising the organic light emitting compound of the present invention.

Since the organic luminescent compound used in the present invention has already been described above, the description thereof is omitted in order to avoid excessive overlapping.

As used herein, the term " organic light-emitting device " refers to a thin film light-emitting device in which a light-emitting layer is made of an organic compound. An organic light emitting device using an organic light emitting phenomenon generally has a structure including an anode, a cathode, and an organic material layer therebetween. Here, in order to enhance the efficiency and stability of the organic light emitting device, the organic material layer may have a multi-layered structure composed of different materials and may include a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, and an electron injection layer. When a voltage is applied between the two electrodes in the structure of such an organic light emitting device, holes are injected in the anode, electrons are injected into the organic layer in the cathode, excitons are formed when injected holes and electrons meet, When it falls back to the ground state, the light comes out.

According to a specific embodiment of the present invention, the organic light emitting element of the present invention is a blue or green phosphor element. The organic light emitting material constituting the organic light emitting device can be classified into blue, green and red light emitting materials depending on the luminescent color. Of these, the blue and green phosphorescent devices are required to have higher triplet energy than the metal complex type luminescent dopant material Thereby realizing the device characteristics of efficiency. According to the present invention, the organic light emitting device of the present invention is a compound wherein two groups of molecules having different terminal characteristics due to the steric hindrance characteristic induce a three-dimensionally distorted substituent introduced into the organic light emitting compound at the ortho position are relatively independent The electrical properties of the host material can be easily controlled, and the extension of the conjugation can be minimized, thereby preventing the degradation of the triplet energy. Therefore, the compound of the present invention exhibits excellent properties as a luminescent host of green and blue phosphorescent devices due to high triplet energy.

The features and advantages of the present invention are summarized as follows:

(a) The present invention provides a carbazole derivative organic light emitting compound and an organic light emitting device containing the same.

(b) The organic luminescent compound disclosed in the present invention has a structure in which a substituent introduced at an ortho position induces a three-dimensional distortion in an organic luminescent compound to thereby interrupt the piconjugation, And a hole transport substituent and an electron transport substituent are bonded to the both terminal benzene rings, respectively, so that the hole injection / transport and electron injection / transport properties are excellent.

(c) The compounds disclosed in the present invention have excellent blue and green phosphorescence characteristics together with excellent quantum efficiency, current efficiency and power efficiency, and can be usefully used as an efficient phosphorescent host material.

Figs. 1A, 1B, and 1C are diagrams showing 3D structures that a compound (a) may have through 3D simulation.
2 is a diagram showing ¹ H NMR (400 MHz) of the compound (a).
3 is a graph showing mass spectrometry (MS) experimental data of compound (b).
Figure 4 is a diagram showing the cyclic voltametry of compound (k).
Figure 5 shows the UV and PL spectra of compound (j).
Fig. 6 is a graph showing the quantum efficiency QE and the power efficiency (PE) according to the luminance L of the compound (g).

Hereinafter, the present invention will be described in more detail with reference to Examples. It is to be understood by those skilled in the art that these embodiments are only for describing the present invention in more detail and that the scope of the present invention is not limited by these embodiments in accordance with the gist of the present invention .

Example

Synthesis of intermediates

1. Intermediates (I-V)

[Synthesis Example]

Methanol (800 ml) was added to the aniline derivative (183.3 mmol) and dissolved at 45 占 폚. 2-Bromobenzaldehyde (183.3 mmol) was added to the reaction solution, followed by stirring at room temperature for about 24 hours. After completion of the reaction, methanol was removed using a concentrator. 2,3-Dichloro-5,6-dicyano-para-benzoquinone (219.9 mmol) and methylene chloride (1200 ml) were added to the concentrated compound and stirred at room temperature for 24 hours. The reaction solution was filtered, and the filtrate was removed using a concentrator. The concentrated compound was subjected to column chromatography using an eluting solvent of ethyl acetate / hexane as a developing solvent to obtain each intermediate (I to V).

Intermediate (I): Yield ^{60.1%, 1 H NMR (400MHz} , CDCl3) δ 7.30 ~ 7.45 (m, 4H), 7.58 ~ 7.61 (m, 1H), 7.74 (d, 1H, J = 8.0), 7.84 ~ 7.86 (m, 1 H), 8.06 (d, 1 H, J = 8.0).

& Lt; ¹ > H NMR (400 MHz, CDCl3) [delta] 2.52 (s, 3H), 7.20 (m, 2H), 7.71 (d, 1H, J = 8.0), 7.76 (d, 1H, J = 8.4), 8.06 (d, 1H, J = 7.6).

Intermediate (Ⅲ): Yield ^{58.9%, 1 H NMR (400MHz} , DMSO) δ 7.47 ~ 7.58 (m, 4H), 7.86 (d, 1H, J = 8.0), 8.01 (d, 1H, J = 7.2), 8.12 (d, 1H, J = 8.4), 8.19 (d, 1H, J = 7.6).

Intermediate (Ⅳ): Yield ^{59.3%, 1 H NMR (400MHz} , CDCl3) δ 2.50 (s, 3H), 7.20 (d, 1H, J = 8.0), 7.34 (t, 1H, J = 7.6), 7.42 ~ 7.47 (m, 2H), 7.63 (s, 1H), 7.75 (d, 1H, J = 8.0), 8.05 (d, 1H, J = 8.0).

Intermediate (Ⅴ): Yield ^{54.8%, 1 H NMR (400MHz} , CDCl3) δ 7.36 (t, 1H, J = 7.6), 7.48 (t, 1H, J = 7.6), 7.56 (t, 1H, J = 7.6) , 7.68 (d, IH, J = 8.0), 8.16 (d, IH, J = = 8.0), 8.60 (d, 1H, J = 8.4).

Synthesis of compounds

The intermediate (I, II, III, IV, V) (7.3 mmol) and the boronic acid derivative (1,2,3) (8.0 mmol) were dissolved in 1,4-dioxane (18 ml) To remove oxygen in the solution. Tetraquistriphenylphosphinopalladium (0.4 mmol), sodium carbonate (21.9 mmol) and water (6 ml) were added to the reaction solvent, and oxygen was removed through nitrogen bubbling for about 30 minutes. After refluxing for about 3 to 4 hours, the reaction mixture was cooled to room temperature. After filtration through Celite, the organic layer was extracted from the filtrate using dichloromethane and water. After removal of moisture using magnesium sulfate, the mixture was concentrated to obtain a solid. Column chromatography was carried out using a developing solvent of ethyl acetate / hexane as a developing solvent to obtain a total of 15 compounds of the respective compounds (a) to (o).

Compound (a): Yield ^{67.1%, 1 H NMR (400MHz} , DMSO) δ 7.05 (m, 4H), 7.18 (t, 2H, J = 7.0), 7.34 (s, 1H), 7.44 (m, 2H), 2H, J = 6.6), 7.62-7.67 (m, 3H), 7.71-7.82 (m, 3H), 8.10 (d, .

Mass spectrometry TOF MS 437.1

Compound (b): Yield ^{69.9%, 1 H NMR (400MHz} , DMSO) δ 7.29 (t, 2H, J = 7.6), 7.35 (d, 2H, J = 8), 7.38 ~ 7.46 (m, 4H), 7.52 2H), 7.75 (m, 2H), 8.14 (d, 1H, J = 8), 8.25 (d, 2H, J = 7.6).

Mass spectrometry TOF MS 437.1

Compound (c): Yield ^{67.9%, 1 H NMR (400MHz} , DMSO) δ 7.02 (s, 1H), 7.13 (d, 2H, J = 8.4), 7.27 ~ 7.73 (m, 13H), 7.78 (d, 1H , J = 7.6), 7.96 (d, 1H, J = 7.2), 8.23-8.25 (m, 2H).

Mass spectrometry TOF MS 437.1

Compound (d): Yield ^{63.9%, 1 H NMR (400MHz} , DMSO) δ 2.43 (s, 3H), 7.07 (m, 4H), 7.18 (m, 2H), 7.23 (d, 1H, J = 8.4), 1H, J = 7.6 (d, 2H, J = 7.6), 7.68-7.76 (m, 2H), 8.06 = 7.6), 8.14 (d, 2H, J = 7.2).

Mass spectrometry TOF MS 451.1

Compound (e): Yield ^{60.6%, 1 H NMR (400MHz} , DMSO) δ 2.41 (s, 3H), 7.19 (d, 1H, J = 8.4), 7.27 ~ 7.35 (m, 5H), 7.43 (t, 2H 1H, J = 7.6), 7.50 (d, 2H, J = 8.4), 7.57 (d, 1H, J = 8.4), 7.61-7.74 d, 2H, J = 8.0).

Mass spectrometry TOF MS 451.1

Compound (f): 60.4%, ¹ H NMR (400 MHz, DMSO)? 2.35 (s, 3H), 7.03 (s, 1H), 7.04-7.20 (m, 3H), 7.26-7.30 2H), 7.32-7.42 (m, 4H), 7.54-7.58 (m, 1H), 7.62-7.70 (m, 3H), 7.92 (d, 1H, J = 6.8), 8.22 (d, 2H, J = 8).

Mass spectrometry TOF MS 451.1

Compound (g): Yield 54%, ¹ H NMR (400 MHz, DMSO)? 7.17 (s, 1H), 7.23-7.25 (m, 2H), 7.29-7.45 (m, 8H), 7.50-7.66 ), 7.96 (d, 2H, J = 8), 8.03 (d, 1H, J = 8), 8.24 ~ 8.28 (m, 2H).

Mass spectrometry TOF MS 453.1

Compound (h): Yield ^{65.4%, 1 H NMR (400MHz} , DMSO) δ 7.28 (t, 2H, J = 8.0), 7.34 ~ 7.69 (m, 12H), 8.01 (t, 2H, J = 8.0), 8.06 (d, 1 H, J = 7.2), 8.23 (d, 2H, J = 8).

Mass spectrometry TOF MS 453.1

Compound (i): 60% yield, ¹ H NMR (400 MHz, DMSO)? 7.17 (s, 1H), 7.24-7.64 (m, 14H), 7.96 (d, 2H, J = , J = 8), 8.25-8.28 (m, 2H).

Mass spectrometry TOF MS 453.1

Compound (j): Yield ^{67.2%, 1 H NMR (400MHz} , DMSO) δ 2.46 (s, 3H), 7.07 ~ 7.09 (m, 4H), 7.18 ~ 7.22 (m, 2H), 7.25 (d, 1H, J = 7.6), 7.34 (m, IH), 7.42 (s, IH), 7.51 (d, IH, J = 8.4), 7.56-7.67 (m, 6H), 7.71-7.78 , 1H, J = 7.2), 8.16 (d, 2H, J = 8).

Mass spectrometry TOF MS 451.1

Compound (k): Yield ^{50.1%, 1 H NMR (400MHz} , DMSO) δ 2.40 (s, 3H), 7.19 (d, 1H, J = 8.4), 7.26 ~ 7.75 (m, 15H), 8.10 (d, 1H , J = 7.2), 8.23 ~ 8.25 (d, 2H, J = 8).

Mass spectrometry TOF MS 451.1

Compound (l): Yield ^{50.3%, 1 H NMR (400MHz} , DMSO) δ 2.34 (s, 3H), 7.06 (d, 1H, J = 8.4), 7.18 ~ 7.30 (m, 4H), 7.36 ~ 7.43 (m 1H, J = 7.6), 7.47 (s, 1H), 7.49-7.52 (m, , 8.25 (s, 1 H)

Mass spectrometry TOF MS 451.1

Compound (m): Yield ^{64.5%, 1 H NMR (400MHz} , DMSO) δ 6.79 (t, 2H, J = 7.2), 7.03 (d, 2H, J = 8), 7.07 (t, 2H, J = 7.2) 1H, J = 9.2), 8.08 (d, 2H, J = 7.6), 8.12 (d, 1H, J = 8), 7.36 (m, 1H), 7.57-7.82 8.18 (d, 1H, J = 7.2), 8.23 (d, 1H, J = 7.6).

Mass spectrometry TOF MS 487.1

Compound (n): 53.3% Yield ¹ H NMR (400 MHz, DMSO)? 7.28 (t, 2H, J = 8), 7.34-7.43 (m, 4H), 7.57-7.78 1H, J = 8.8), 8.08-8.10 (d, 1H, J = 8), 8.23-8.25 (m, 3H), 8.28 (d, 1H, J = 8.8).

Mass spectrometry TOF MS 487.1

Compound (o): Yield ^{52.3%, 1 H NMR (400MHz} , DMSO) δ 6.96 ~ 7.03 (m, 5H), 7.16 ~ 7.20 (m, 2H), 7.20 ~ 7.27 (m, 1H), 7.34 ~ 7.38 (m 2H), 7.58-7.63 (m, 3H), 7.71-7.74 (m, 3H), 7.86 (d, 1H, J = 8.8), 8.02 J = 8.4), 8.20 ~ 8.25 (m, 2H) 8.32 (d, 1H, J = 8.4).

Mass spectrometry TOF MS 487.1

Physical properties of compounds compound Band gap
(eV) HOMO
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(eV) LUMO
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(eV) Triplet
energy
(eV) Singlet
energy
(eV) Usage Remarks (a) 3.56 -5.62 -2.06 2.84 2.93 Green phosphorescent host Example 1 (b) 3.54 -5.67 -2.13 2.78 2.94 Green phosphorescent host Example 2 (c) 3.39 -5.64 -2.25 2.63 3.02 Green phosphorescent host Example 3 (d) 3.57 -5.67 -2.10 2.82 2.99 Green phosphorescent host Example 4 (e) 3.55 -5.64 -2.09 2.75 2.98 Green phosphorescent host Example 5 (f) 3.40 -5.64 -2.24 2.61 3.08 Green phosphorescent host Example 6 (g) 3.40 -5.64 -2.24 2.79 2.86 Green phosphorescent host Example 7 (h) 3.54 -5.67 -2.13 2.65 2.88 Green phosphorescent host Example 8 (i) 3.41 -5.65 -2.24 2.57 2.84 Green phosphorescent host Example 9 (j) 3.56 -5.64 -2.08 2.82 2.96 Green phosphorescent host - (k) 3.54 -5.64 -2.10 2.75 2.96 Green phosphorescent host - (l) 3.47 -5.65 -2.18 2.61 2.92 Green phosphorescent host - (m) 3.40 -5.68 -2.28 2.59 3.11 Red phosphorescent host - (n) 3.41 -5.67 -2.26 2.55 2.98 Red phosphorescent host - (o) 3.38 -5.69 -2.31 2.59 3.01 Red phosphorescent host -

Example 1  : Preparation of green phosphorescent device using compound (a)

The compound (a) synthesized in the present invention was applied as a light emitting host material of a green phosphorescent device to produce a green phosphorescent device. The device was laminated with a back-light-emitting structure, and the materials used were as follows:

(3,4-ethylenedioxythiophene) -Polystyrenesulfonate (PEDOT-PSS) was used as the hole injection layer and the hole transport layer material, while the substrate and the anode were organic substrate deposited with indium tin oxide (ITO) And di- [4- (N, N-ditolylamino) -phenyl] cyclohexane (TAPC), respectively. The light emitting dopant material used was tris [2-phenylpyridinato-C2, N] (picolinate) iridium (III) (Ir (ppy) ₃ ), and the electron transport layer material was diphenylphosphine oxide- (Triphenylsilyl) phenyl (TSPO1) was used. Lithium fluoride (LiF) and aluminum (Al) were used as the cathode material. Further, N, N'-dicarbazolyl-3,5-benzene (mCP) was used as an exciton blocking layer between the light emitting layer and the hole transporting layer. As a result, the structure of the device was ITO / PEDOT-PSS / TAPC / mCP / compound (a): Ir (ppy) ₃ / TSPO1 / LiF / Al.

The fabrication of the device was performed in the following manner.

The ITO substrate was cleaned with pure water and isopropyl alcohol for 30 minutes using ultrasound. The ITO substrate was surface-treated with ultraviolet light of short wavelength and vacuum was deposited on the ITO substrate under a pressure of 1 × 10 ^-6 torr. The hole injection layer PEDOT-PSS was coated to a thickness of 60 nm using a spin coater. TAPC, mCP and TSPO1 were deposited at a rate of 0.1 nm / s to deposit 20 nm, 10 nm, and 35 nm, respectively. The compound (a), which is a green phosphorescent host material, was formed in a thickness of 25 nm by vacuum evaporation at the same time as Ir (ppy) ₃ , which is a phosphorescent dopant material. The deposition rate was 0.1 nm / s, Ir (ppy) ₃ was 0.005 nm / s. LiF was formed to a thickness of 1 nm at a rate of 0.01 nm / s, and Al was formed to a thickness of 100 nm at a deposition rate of 0.5 nm / sec. After the device was formed, the device was sealed using a CaO wetting agent and a glass cover glass.

The above compound (a) was applied as a light emitting host material of a green phosphorescent device and quantum efficiency of 25.6%, current efficiency of 78.8 Cd / A, power efficiency of 39.1 lm / W at a voltage of 7 V and x = 0.29, y = 0.62, indicating excellent green phosphorescent emission characteristics. The driving voltage (1000nit voltage) of this device was measured at 7.1V.

Example 2  : Preparation of Organic Electroluminescent Device Using Compound (b)

The manufacturing process of the device was the same as that of Example 1 except that the compound (b) was applied to the green host material.

The above compound (b) was applied as a light emitting host material of a green phosphorescent device and quantum efficiency of 25.4%, current efficiency of 77.9 Cd / A, power efficiency of 36.1 lm / W at a voltage of 7.5 V and x = 0.29, y = 0.62, indicating excellent green phosphorescent emission characteristics. The driving voltage (1000nit voltage) of this device was measured at 7.6V.

Example 3  : Preparation of Organic Electroluminescent Device Using Compound (c)

The manufacturing process of the device was the same as that of Example 1 except that the compound (c) was applied to the green host material.

The above compound (c) was applied as a light emitting host material of a green phosphorescent device and quantum efficiency of 22.5%, current efficiency of 71.6 Cd / A, power efficiency of 45.2 lm / W at a voltage of 5.5 V and x = 0.28 based on CIE 1931 color coordinates, y = 0.63, indicating excellent green phosphorescent emission characteristics. The driving voltage (1000nit voltage) of this device was measured at 5.6V.

Example 4  : Preparation of Organic Electroluminescent Device Using Compound (d)

The manufacturing process of the device was the same as that of Example 1 except that the compound (d) was applied to the green host material.

The above compound (d) was applied as a light emitting host material of a green phosphorescent device and quantum efficiency of 25.3%, current efficiency of 78.3 Cd / A, power efficiency of 41.8 lm / W at a voltage of 6.5 V and x = 0.29, y = 0.62, indicating excellent green phosphorescent emission characteristics. The driving voltage (1000nit voltage) of this device was measured to be 6.6V.

Example 5  : Preparation of Organic Electroluminescent Device Using Compound (e)

The manufacturing process of the device was the same as that of Example 1 except that the compound (e) was applied to the green host material.

The above compound (e) was applied as a light emitting host material of a green phosphorescent device and quantum efficiency of 23.1%, current efficiency of 73.9 Cd / A, power efficiency of 46.6 lm / W at a voltage of 5.5 V and x = 0.28, y = 0.63, indicating excellent green phosphorescent emission characteristics. The driving voltage (1000nit voltage) of this device was measured at 5.6V.

Example 6  : Preparation of Organic Electroluminescent Device Using Compound (f)

The manufacturing process of the device was the same as that of Example 1 except that the compound (f) was applied to the green host material.

The above compound (f) was applied as a light emitting host material of a green phosphorescent device and quantum efficiency of 18.4%, current efficiency of 58.3 Cd / A, power efficiency of 40.5 lm / W at a voltage of 5 V and x = 0.31, y = 0.62. The driving voltage (1000nit voltage) of this device was measured at 5.1V.

Example 7  : Preparation of Organic Electroluminescent Device Using Compound (g)

The manufacturing process of the device was the same as that of Example 1 except that the compound (g) was applied to the green host material.

The above compound (g) was applied as a light emitting host material of a green phosphorescent device and quantum efficiency of 22.6%, current efficiency of 69.5 Cd / A, power efficiency of 30.2 lm / W at a voltage of 8 V and x = 0.30 and y = 0.61, indicating excellent green phosphorescent emission characteristics. The driving voltage (1000nit voltage) of this device was measured at 8.2V.

Example 8  : Preparation of Organic Electroluminescent Device Using Compound (h)

The manufacturing process of the device was the same as that of Example 1 except that the compound (h) was applied to the green host material.

The above compound (h) was applied as a light emitting host material of a green phosphorescent device and quantum efficiency of 19.6%, current efficiency of 60.8 Cd / A, power efficiency of 26.4 lm / W at a voltage of 8 V and x = 0.32, y = 0.61. The driving voltage (1000nit voltage) of this device was measured at 7.9V.

Example 9  : Preparation of Organic Electroluminescent Device Using Compound (i)

The manufacturing process of the device was the same as in Example 1 except that the compound (i) was applied to the green host material.

The above compound (i) was applied as a light emitting host material of a green phosphorescent device and quantum efficiency 17.9%, current efficiency 55.2 Cd / A, power efficiency 22.5 lm / W at a voltage of 8.5 V and x = 0.30 based on CIE 1931 color coordinates, y = 0.61. The driving voltage (1000nit voltage) of this device was measured at 8.2V.

Comparative Example  : Preparation of organic electroluminescent device using 4,4'-bis (N-carbazolyl) -1,1'-biphenyl (CBP)

In order to compare the characteristics of the compounds synthesized in the present invention, CBP was applied as a green phosphorescent host material to fabricate a gas-phase electroluminescent device. The manufacturing process of the device was the same as that of Example 1 except that the compound CBP was applied to the green host material.

The CBP was applied as a light emitting host material of a green phosphorescent device, and quantum efficiency of 21.0%, current efficiency of 67.5 Cd / A, power efficiency of 39.1 lm / W at a voltage of 6 V and x = 0.30 and y = 0.62 based on CIE 1931 color coordinates And showed excellent green phosphorescence characteristics. The driving voltage (1000nit voltage) of this device was measured at 5.9V.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the same is by way of illustration and example only and is not to be construed as limiting the scope of the present invention. Accordingly, the actual scope of the present invention will be defined by the appended claims and their equivalents.

Claims (6)

An organic luminescent compound represented by the following formula (1):
Formula 1

In the above formulas, X is O, S, NR ₄ (R ₄ is hydrogen or C ₁ -C ₃ alkyl) or CR ₅ (R ₅ is hydrogen or C ₁ -C ₃ alkyl); R < _{1 >} is independently hydrogen or heteroarylphenyl of from 13 to 19 rings; And R ₂ and R ₃ are each independently hydrogen or C ₁ -C ₅ alkyl, or R ₂ and R ₃ together form a six-membered aryl ring.
The organic electroluminescent compound according to claim 1, wherein R ₁ in the formula (1) is independently carbazole C ₆ -C ₁₀ aryl which is unsubstituted or substituted with C ₁ -C ₃ alkyl.
The method of claim 2, wherein, R ₁ of Formula 1 are each independently

,

,

,

,

,

,

,

,

,

,

,

,

,

or

≪ / RTI >
The organic electroluminescent compound according to claim 1, wherein the organic electroluminescent compound represented by Formula 1 is selected from the group consisting of compounds represented by Formulas 2 to 16:
(2)

(4)

(6)

(8)

(10)

(12)

(14)

Formula 16

An organic light-emitting device comprising an organic light-emitting compound according to any one of claims 1 to 4.
The organic light emitting diode according to claim 5, wherein the organic light emitting device is a blue or green phosphorescent device.

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