KR101790552B1 - Organic light compound and organic light device using the same - Google Patents

Abstract

More particularly, the present invention relates to an organic light emitting device capable of realizing excellent light emitting efficiency, light emission luminance, color purity, (ETM), a light emitting layer (EML), a hole transporting layer (HTM), and the like, which are used for an organic light emitting diode (OLED) And various organic layers between the first electrode and the second electrode. Among other things, the phosphorescent host material has an excellent charge transporting property and is superior in terms of luminous efficiency and luminous efficiency through a derivative having a good overlap with the absorption spectrum of the dopant. Low voltage driving and excellent color rendering.

Description

TECHNICAL FIELD [0001] The present invention relates to an organic light emitting diode (OLED)

The present invention relates to an organic luminescent compound and an organic photonic device using the same. More particularly, the present invention relates to an oxanthene derivative having good charge transport properties as a phosphorescent host material and having a good overlap with the absorption spectrum of dopant, A light emitting element or an optical element for solar power generation.

In 1987, Tang et al. Of Kodak developed a low-molecular-weight OLED display rapidly after discovering a green luminescence phenomenon with improved efficiency and stability by forming a bilayer low-molecular organic thin film of Alq ₃ and TPD as a light emitting layer and a charge transport layer, respectively lost. In the late 1980s, the structure of a low-molecular OLED device started from a simple structure of an anode (ITO), a hole transport layer (HTL), an emission layer (EML), and a cathode (Mg: Ag). In the case of fluorescent devices, Hole Injection Layer (HIL) such as CuPc was introduced, Al: Li was developed as cathode and electron injection layer material, and materials such as LiF were developed and the structure became complicated. As a result, the efficiency and the driving voltage of the electro-optical characteristic have been improved.

The phosphorescent structure is generally composed of an anode, a hole injection layer, a hole transport layer, a light emitting layer, an electron transfer layer (ETL), an electron injection layer (EIL), and a cathode Hole blocking layer (HBL) layer has been introduced as a layer but it is not necessarily a necessary layer.

The light emitting layer material is largely divided into a light emitting material for a fluorescent element and a light emitting material for a phosphorescent element, and is classified again according to a luminescent color. The light emitting layer material is divided into a host material and a dopant material. Host or Dopant materials can emit light, but their efficiency and brightness are very low due to their own quenching phenomenon. Due to self-aggregation phenomenon between molecules, Dopant is doped into the host to form a light emitting layer.

CBP, which is a bipolar material with hole mobility and electron mobility, has been widely used for phosphorescent host materials for Red and Green. Recently, however, it has been known that Balq, an electron transporting material, or a similar kind of Al complex material is useful as a phosphorescent red host. It is also known that CBP derivative and Artsi family substances have excellent properties as a material for blue phosphorescent host.

The characteristics required for the host material must first be excellent in charge transport properties. It is necessary to move the holes and electrons in the light emitting layer, so that the mobility is appropriately required. In addition, the host material must transfer the energy to the dopant, so that the emission spectrum of the host should be well overlapped with the absorption spectrum of the dopant so that the energy transfer occurs well. In terms of energy, the band gap of the host should be wider than the gap of the dopant, and the LUMO level of the host should be higher than the Dopant LUMO.

Therefore, in order to further improve the characteristics of the organic electroluminescent device, development of a more stable and efficient material that can be used as an electron transporting material in the organic electroluminescent device is continuously required.

SUMMARY OF THE INVENTION The present invention provides a novel organic optical compound that can be applied to an organic photonic device, particularly an organic electroluminescent device.

Another technical problem to be solved by the present invention is to develop an oxanthene derivative having a charge transport property as a phosphorescent host material and having a good overlap with the absorption spectrum of the dopant to improve the luminous efficiency and the low voltage driving, To provide a material.

The organic photocompound according to the present invention and the organic photon using the same are based on the organic photocompound of the following formula:

<Formula F>

Wherein X is O, S, Se or Si,

A1, A2, B1, B2, C1, C2, D1, D2, E1 and E2 are each independently

A C5-C40 aryl group, a C5-C40 heteroaryl group, a C5-C40 aryloxy group, a C1-C40 alkyloxy group, a C5-C40 arylamino group, A C 5 to C 40 aryl ketone group, a C 3 to C 40 cycloalkyl group, and a C 3 to C 40 heterocycloalkyl group, or a group selected from ; Or a fused aliphatic ring, a condensed aromatic ring, a condensed heteroaliphatic ring or a condensed heteroaromatic ring adjacent to the adjacent group (provided that when X is O, S or Se, A1 and A2 are 0, to be).

The organic optical compound according to the present invention and the organic optical device using the organic optical compound are based on organic optical compounds corresponding to the following Chemical Formulas 1 to 82.

The organic optical device according to the present invention provides high luminous efficiency, high luminance, high color purity and remarkably improved luminous lifetime,

In addition, the present invention provides organic light emitting devices and organic light emitting compounds, or organic photoconductors and optical compounds for solar power generation.

Hereinafter, the present invention will be described in detail.

While the present invention has been described in connection with certain embodiments, it is obvious that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the invention. It is to be understood, however, that the invention is not intended to be limited to the particular forms disclosed, but on the contrary, is intended to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In the present application, the term &quot; comprising &quot; or &quot; consisting of &quot;, or the like, refers to the presence of a feature, a number, a step, an operation, an element, a component, But do not preclude the presence or addition of one or more other features, integers, steps, operations, components, parts, or combinations thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the contextual meaning of the related art and are to be interpreted as either ideal or overly formal in the sense of the present application Do not.

The present invention has been developed especially for oxanthene derivatives and has been widely used for a variety of organic films such as an electron transport layer (ETM), a light emitting layer (EML), a hole transport layer (HTM) Possible materials, especially phosphorescent host materials, have excellent charge transport properties and exhibit a good overlap with the absorption spectra of dopants. They also improve the performance such as increasing the efficiency and reducing the driving voltage and maximizing the ability as OLED materials. .

In the present specification, the term "organic photocompound" means a compound used in an organic photonic device. The scope of the present invention is not limited to the organic luminescent layer. The scope of the present invention is not limited to the organic luminescent layer. Can be used for any layer constituting the substrate.

In this specification, the terms 'optical compound' and 'optical device' are used to cover the case where the present invention is applied to both an organic light emitting device and a device for solar power generation regardless of a dictionary or conventional definition It is a selected term.

An organic photonic device according to a first aspect of the present invention includes: a first electrode; A second electrode; And at least one organic film between the first electrode and the second electrode, wherein the organic film comprises an organic photo-compound represented by the following formula (F).

<Formula F>

In the derivatives of the above formula, X is O, S, Se or Si,

A1, A2, B1, B2, C1, C2, D1, D2, E1 and E2 are each independently

A C5-C40 aryl group, a C5-C40 heteroaryl group, a C5-C40 aryloxy group, a C1-C40 alkyloxy group, a C5-C40 arylamino group, A C 5 to C 40 aryl ketone group, a C 3 to C 40 cycloalkyl group, and a C 3 to C 40 heterocycloalkyl group, or a group selected from ; Or a fused aliphatic ring, a condensed aromatic ring, a condensed heteroaliphatic ring or a condensed heteroaromatic ring adjacent to the adjacent group (provided that when X is O, S or Se, A1 and A2 are 0, to be).

The inventors of the present invention have found that the substituent of the organic photocompound of the above formula (F) is selected from the group consisting of A1, A2, B1, B2, C1, C2, D1, D2, E1,

Various derivatives have been developed to form organic light compounds that can be used as various organic films between the first electrode and the second electrode such as an electron transport layer (ETM), a light emitting layer (EML), a hole transport layer (HTM)

We have developed an organic photonic device using it,

It has been found that when the organic electroluminescent device is used as an organic light emitting device, it is possible to improve the performance such as the efficiency increase and the driving voltage decrease, maximize the ability as the OLED material,

It is expected that excellent application efficiency will be obtained when applied to optical devices and optical compound fields for solar power generation.

Hereinafter, the organic photochemical compound of formula (F) will be described in relation to an organic light emitting device, but the present invention should not be construed as limiting.

The organic photo-compound of Formula F is suitable as a material for forming an organic film interposed between the first electrode and the second electrode of the organic optical device. The organic photocompound of Formula F is suitable for use in an organic layer of an organic light emitting device, particularly, a hole transport layer, a hole injection layer, or a light emitting layer, and is used not only as a host material but also as a dopant material. The organic photo compound of Formula F provides a color that is blue to green and is suitable for use in a white light emitting device.

At least one of A1, A2, B1, B2, C1, C2, D1, D2, E1 and E2 is selected from the group consisting of C5 to C40 aryl, C5 to C40 heteroaryl, C5 to C40 arylamino, A diarylamino group, an arylalkyl group of C6 to C40, an arylketone group of C5 to C40, a cycloalkyl group of C3 to C40, and a heterocycloalkyl group of C3 to C40; Or a group forming an adjacent group and a fused aliphatic ring, a condensed aromatic ring, a condensed heteroaliphatic ring or a condensed heteroaromatic ring,

The C1 to C40 alkyl group, the C5 to C40 aryl group, the C5 to C40 heteroaryl group, the C5 to C40 aryloxy group, the C5 to C40 heteroaryl group, , A C 1 to C 40 alkyloxy group, a C 5 to C 40 arylamino group, a C 5 to C 40 diarylamino group, a C 6 to C 40 arylalkyl group, a C 5 to C 40 ketone group, a C 5 to C 40 aryl ketone group, The cycloalkyl group and the C3-C40 heterocycloalkyl group

A substituted or unsubstituted C1 to C40 alkyl group, a substituted or unsubstituted C1 to C40 alkoxy group, a substituted or unsubstituted C1 to C40 amino group, a substituted or unsubstituted C3 to C40 cycloalkyl group, C40 heterocycloalkyl group, C6-C40 aryl group, and C5-C40 heteroaryl group.

The C1 to C40 alkyl group, the C5 to C40 aryl group, the C5 to C40 heteroaryl group, the C5 to C40 aryloxy group, the C5 to C40 heteroaryl group, , A C 1 to C 40 alkyloxy group, a C 5 to C 40 arylamino group, a C 5 to C 40 diarylamino group, a C 6 to C 40 arylalkyl group, a C 5 to C 40 ketone group, a C 5 to C 40 aryl ketone group, The cycloalkyl group and the C3-C40 heterocycloalkyl group

A substituted or unsubstituted C1 to C40 alkyl group, a substituted or unsubstituted C1 to C40 alkoxy group, a substituted or unsubstituted C1 to C40 amino group, a substituted or unsubstituted C3 to C40 cycloalkyl group, C40 heterocycloalkyl group, C6-C40 aryl group, and C5-C40 heteroaryl group, and more preferably,

The above C1 to C40 alkyl group, C5 to C40 aryl group, C5 to C40 heteroaryl group, C5 to C40 aryloxyl groups of A1, A2, B1, B2, C1, C2, D1, D2, C40 alkyloxy group, C5-C40 arylamino group, C5-C40 diarylamino group, C6-C40 arylalkyl group, C5-C40 ketone group, C5-C40 aryl ketone group, C3-C40 And a substituent group introduced into the C3 to C40 heterocycloalkyl group

A substituted or unsubstituted C1 to C40 alkyl group, a substituted or unsubstituted C2 to C40 alkenyl group, a substituted or unsubstituted C1 to C40 alkoxy group, a substituted or unsubstituted C1 to C40 amino group, a C3 to C40 cycloalkyl group, a C3 to C40 heterocycloalkyl group, The heteroaryl group of C &lt;

A substituted or unsubstituted C1 to C40 alkyl group, a substituted or unsubstituted C1 to C40 alkoxy group, a substituted or unsubstituted C1 to C40 amino group, a substituted or unsubstituted C3 to C40 cycloalkyl group, At least one second substituent selected from the group consisting of a heterocycloalkyl group of C40, an aryl group of C6 to C40, and a heteroaryl group of C5 to C40; Or to form adjacent condensed aliphatic rings, condensed aromatic rings, condensed heteroaliphatic rings or condensed heteroaromatic rings or spiro bonds.

Further, the C1 to C40 alkyl group, the C5 to C40 aryl group, the C5 to C40 heteroaryl group, the C5 to C40 aryloxyl group, the C5 to C40 heteroaryl group, and the C5 to C40 heteroaryl groups of A1, A2, B1, B2, C1, C2, D1, D2, C40 alkyloxy group, C5-C40 arylamino group, C5-C40 diarylamino group, C6-C40 arylalkyl group, C5-C40 ketone group, C5-C40 aryl ketone group, C3-C40 And the substituent which is introduced into the C3-C40 heterocycloalkyl group is

A phenanthryl group, a phenanthryl group, an anthracenyl group, a benzoanthracenyl group, an azranyl group, an acenaphthylenyl group, a phenanthryl group, a phenanthryl group, a phenanthryl group, A phenanthryl group, a phenanthrenyl group, a phenanthrenyl group, a phenanthrenyl group, a pyrenyl group, a chrysenyl group, a picenyl group, a perylenyl group, a chloroperylenyl group, a pentaphenyl group, A phenyl group, a hexacenyl group, a rubicenyl group, a coronenyl group, a trinaphthylenyl group, a heptaphenyl group, a heptacenyl group, a fluorenyl group, a pyranthrenyl group, an obenyl group, a carbazolyl group, a dibenzofuranyl group, A thiophenyl group, a thiophenyl group, an indolyl group, a purinyl group, a benzimidazolyl group, a quinolizinyl group, a quinolinyl group, a benzothiophenyl group, a parathiazinyl group, a pyrrolyl group, a pyrazolyl group, an imidazolyl group, , Thiazolyl group, triazolyl group, tetrazolyl group, oxadiazolyl group, A pyridinyl group, a pyridazinyl group, a pyrimidinyl group, a pyrazinyl group, a thianthrenyl group, a cyclopentyl group, a cyclohexyl group, an oxiranyl group, a pyrrolidinyl group, a pyrazolidinyl group, (C6-C50 aryl) amino group, silyl group, and derivatives thereof are preferable.

The aryl group is a monovalent group having an aromatic ring system and may include two or more ring systems, and the two or more ring systems may exist in a bonded or condensed form to each other. The heteroaryl group refers to a group in which at least one carbon of the aryl group is substituted with at least one member selected from the group consisting of N, O, S, P, Si and Se.

On the other hand, the cycloalkyl group refers to an alkyl group having a ring system, and the heterocycloalkyl group refers to a group in which at least one carbon in the cycloalkyl group is substituted with at least one member selected from the group consisting of N, O, S, P, Si and Se .

When at least one hydrogen of the aryl group and the heteroaryl group is substituted, the substituent is a C1-C50 alkyl group; A C1-C50 alkoxy group; A C6-C50 aryl group unsubstituted or substituted with a C1-C50 alkyl group or a C1-C50 alkoxy group; A C2-C50 heteroaryl group unsubstituted or substituted with a C1-C50 alkyl group or a C1-C50 alkoxy group; A C5-C50 cycloalkyl group which is unsubstituted or substituted by a C1-C50 alkyl group or a C1-C50 alkoxy group and a C5-C50 heterocycloalkyl group which is unsubstituted or substituted by a C1-C20 alkyl group or a C1-C20 alkoxy group, &Lt; / RTI &gt;

An organic photonic device according to a first aspect of the present invention includes: a first electrode; A second electrode; And at least one organic film between the first electrode and the second electrode.

The organic photo-compound used in the organic photonic device of the present invention may have, but is not limited to, the structures of the following formulas (1) to (82)

The organic photo-compound according to the present invention represented by the above formula (F) can be synthesized by a conventional synthesis method, and a more detailed synthesis route of the compound will be described with reference to the reaction formulas of the following synthesis examples. The compound of Formula F is suitable for use in an organic film of an organic optical device, particularly a hole transporting layer, a hole injecting layer, or a light emitting layer. The structure of the organic light emitting device according to the present invention is very diverse. The organic EL device may further include at least one layer selected from the group consisting of a hole injecting layer, a hole transporting layer, a hole blocking layer, an electron blocking layer, an electron transporting layer, and an electron injecting layer between the first electrode and the second electrode.

More specifically, an embodiment of an organic light emitting device according to the present invention

First, the organic light emitting device may have a structure including a first electrode / a hole injection layer / a light emitting layer / an electron transport layer / an electron injection layer / a second electrode,

The organic light emitting device may have a structure including a first electrode / a hole injection layer / a hole transport layer / a light emitting layer / an electron transport layer / an electron injection layer / a second electrode,

Further, the organic light emitting device may have a structure of a first electrode / a hole injection layer / a hole transport layer / a light emitting layer / a hole blocking layer / an electron transport layer / an electron injection layer / a second electrode.

At this time, one or more of the hole transporting layer, the hole injecting layer, and the light emitting layer may include a compound according to the present invention.

The light-emitting layer of the organic optical device according to the present invention may include a phosphorescent or fluorescent dopant including red, green, blue or white. The phosphorescent dopant may be an organometallic compound containing at least one element selected from the group consisting of Ir, Pt, Os, Ti, Zr, Hf, Eu, Tb and Tm. In addition, the compound according to the present invention can also be used as a fluorescent dopant in the light emitting layer.

Hereinafter, a method of manufacturing an organic optical device according to the present invention will be described with reference to an organic optical device. First, a first electrode material having a high work function is formed on a substrate by a vapor deposition method, a sputtering method, or the like to form a first electrode. The first electrode may be an anode. Here, the substrate used in a typical organic optical device is preferably a glass substrate or a transparent plastic substrate having excellent mechanical strength, thermal stability, transparency, surface smoothness, ease of handling, and waterproofness. As the material for the first electrode, indium tin oxide (ITO), indium zinc oxide (IZO), tin oxide (SnO2), zinc oxide (ZnO) or the like is used which is transparent and excellent in conductivity.

Next, a hole injection layer (HIL) may be formed on the first electrode by various methods such as a vacuum deposition method, a spin coating method, a casting method, and an LB method.

When the hole injection layer is formed by the vacuum deposition method, the deposition conditions vary depending on the compound used as the material of the hole injection layer, the structure and the thermal characteristics of the desired hole injection layer, and the like. In general, A degree of vacuum of 10 &lt; ^-5 &gt; to 10 &lt; ^-3 &gt; torr, a deposition rate of 0.01 to 100 A / sec and a film thickness of 100 to 1 mu m.

When the hole injection layer is formed by the spin coating method, the coating conditions vary depending on the compound used as the material of the hole injection layer, the structure and the thermal properties of the desired hole injection layer, but the coating speed is preferably from about 2000 rpm to 5000 rpm , And the heat treatment temperature for removing the solvent after coating is suitably selected within a temperature range of about 80 캜 to 200 캜.

The hole injection layer material may be a compound having the formula a as described above.

Alternatively, phthalocyanine compounds such as copper phthalocyanine disclosed in U.S. Patent No. 4,356,429 or starburst amine derivatives such as TCTA, m-MTDATA, and m-MTDATA described in Advanced Material, 6, p.677 (1994) MTDAPB, 2-TNATA (4,4 ', 4 "-tris (N- (2-naphthyl) -N-phenylamino) triphenylamine: 4,4,4- (Polyaniline / dodecylbenzenesulfonic acid) or PEDOT / PSS (poly (3,4-ethylenedioxythiophene) / poly (4-styrenesulfonate)), which is a soluble conductive polymer, Styrene sulfonate), PANI / CSA (polyaniline / camphor sulfonic acid) or PANI / PSS (polyaniline / camphor sulfonic acid)

(Polyaniline) / poly (4-styrenesulfonate): polyaniline) / poly (4-styrenesulfonate)) and the like can be used.

The thickness of the hole injection layer may be about 100 Å to 10000 Å, preferably 100 Å to 1000 Å. If the thickness of the hole injection layer is less than 100 angstroms, the hole injection characteristics may be degraded. If the thickness of the hole injection layer exceeds 10000 angstroms, the driving voltage may increase.

Alternatively, the hole injection layer may be formed by a vacuum vapor deposition method. The specific deposition conditions vary depending on the compound used, but are selected from substantially the same range of conditions as the formation of a general hole injection layer. For example, DNTPD (N, N-bis- [4- (di-m-tolylamino) phenyl] -N, N-diphenylbiphenyl-4,4-diamine) may be used.

Next, a hole transport layer (HTL) may be formed on the hole injection layer by various methods such as a vacuum deposition method, a spin coating method, a casting method, and an LB method. In the case of forming the hole transporting layer by the vacuum deposition method and the sputtering method, the deposition conditions and the coating conditions vary depending on the compound used, but are generally selected from substantially the same range of conditions as the formation of the hole injection layer.

The hole transport layer material may comprise a compound of formula (a) as described above. Or carbazole derivatives such as N-phenylcarbazole, polyvinylcarbazole and the like, N, N'-bis (3-methylphenyl) -N, N'- diphenyl- [ Amine having an aromatic condensed ring such as N, N'-tetramethyldisiloxane, -4,4'-diamine (TPD) and N, N'-di (naphthalen- The hole transporting layer may have a thickness of about 50 Å to 1000 Å, preferably 100 Å to 600 Å. When the thickness of the hole transporting layer is less than 50 Å, the hole transporting property may be degraded. When the thickness of the hole transporting layer is more than 1000 Å, the driving voltage may increase.

Next, a light emitting layer (EML) may be formed on the hole transporting layer by a method such as a vacuum evaporation method, a spin coating method, a casting method, or an LB method. When a light emitting layer is formed by a vacuum deposition method and a spin coating method, the deposition conditions vary depending on the compound used, but generally, the conditions are substantially the same as those for forming the hole injection layer.

The luminescent layer may comprise a compound of formula (a) according to the invention as described above. At this time, the compound of the formula (a) can be used together with a suitable known host material or can be used together with a known dopant material.

It is also possible to use the compound of formula (a) alone. In the case of the host material, for example, Alq3 (tris (8-hydroxy-quinolatealuminium) or CBP (4,4'-N, N'-dicarbazole- ) Can be used.

In the case of the dopant material, IDE102, IDE105 and IDE55 available from Idemitsu Co., Ltd. and C545T available from Hayashibara Co., Ltd. can be used. As the phosphorescent dopant, red phosphorescent dopant PtOEP, UDC RD61, green phosphorescent dopant Ir (PPy) 3 (PPy = 2-phenylpyridine), a blue phosphorescent dopant F2Irpic, and a red phosphorescent dopant RD 61 manufactured by UDC. MQD (N-methylquinacridone), coumarine derivatives and the like can also be used.

The doping concentration is not particularly limited, but the content of the dopant is usually 0.01 to 15 parts by weight based on 100 parts by weight of the host. The thickness of the light emitting layer may be about 100 Å to 1000 Å, preferably 200 Å to 600 Å.

When the thickness of the light emitting layer is less than 100 Å, the light emitting characteristics may be degraded. If the thickness of the light emitting layer is more than 1000 Å, the driving voltage may increase.

When a luminescent compound is used in combination with a phosphorescent dopant in the luminescent layer, a method such as vacuum deposition, spin coating, casting, or LB method is applied on the luminescent layer to prevent the triplet excitons or holes from diffusing into the electron transporting layer The hole blocking layer HBL can be formed. In the case of forming the hole blocking layer by the vacuum deposition method and the spin coating method, the conditions vary depending on the compound used, but are generally selected from substantially the same range of conditions as the formation of the hole injection layer. Known hole blocking materials which can be used, for example, oxadiazole derivatives, triazole derivatives, phenanthroline derivatives, BCP, and the like.

The thickness of the hole blocking layer may be about 50 Å to 1000 Å, preferably 100 Å to 300 Å. If the thickness of the hole blocking layer is less than 50 angstroms, the hole blocking characteristics may be deteriorated. If the thickness of the hole blocking layer exceeds 1000 angstroms, the driving voltage may be increased. An organic light emitting element having the structure shown in FIG. 1B is obtained.

Next, an electron transport layer (ETL) is formed by various methods such as a vacuum evaporation method, a spin coating method, and a casting method.

In the case of forming the electron transporting layer by the vacuum deposition method and the spin coating method, the conditions vary depending on the compound used, but generally, the conditions are substantially the same as those for forming the hole injection layer. The electron transport layer material serves to stably transport electrons injected from an electron injection electrode, and is a quinoline derivative, particularly a known material such as tris (8-quinolinolate) aluminum (Alq3), TAZ, Balq, Materials may also be used.

The thickness of the electron transporting layer may be about 100 ANGSTROM to 1000 ANGSTROM, preferably 200 ANGSTROM to 500 ANGSTROM. When the thickness of the electron transporting layer is less than 100 angstroms, the electron transporting characteristics may be deteriorated. When the thickness of the electron transporting layer exceeds 1000 angstroms, the driving voltage may increase.

Further, an electron injection layer (EIL), which is a material having a function of facilitating the injection of electrons from the cathode, may be laminated on the electron transporting layer, which is not particularly limited.

As the electron injection layer, any material known as an electron injection layer forming material such as LiF, NaCl, CsF, Li2O, BaO, or the like can be used. The deposition conditions of the electron injection layer vary depending on the compound used, but are generally selected from substantially the same range of conditions as the formation of the hole injection layer.

The thickness of the electron injection layer may be about 1 A to 100 A, preferably 5 A to 50 A. If the thickness of the electron injection layer is less than 1 angstrom, the electron injection characteristics may be deteriorated. If the thickness of the electron injection layer exceeds 100 angstroms, the driving voltage may increase.

Finally, the second electrode can be formed on the electron injection layer by a vacuum evaporation method, a sputtering method, or the like.

The second electrode may be used as a cathode. As the metal for forming the second electrode, a metal, an alloy, an electrically conductive compound having a low work function, or a mixture thereof may be used. Specific examples thereof include lithium (Li), magnesium (Mg), aluminum (Al), aluminum-lithium (Al-Li), calcium (Ca), magnesium-indium (Mg-In), magnesium- . Also, a transmissive cathode using ITO or IZO may be used to obtain a front light emitting element.

The organic electroluminescent compound according to another embodiment of the present invention may be represented by the above formula (a), and more specifically, it may be represented by the above formulas (1) to (82). The details of the compounds are the same as those described for the organic foot and the device described above.

Hereinafter, the reaction examples and comparative examples of the present invention will be specifically described, but the present invention is not limited to the following synthesis examples and examples. In the following reaction examples, the intermediate compounds are indicated by adding the serial number to the final product number. For example, Compound 1 is represented by the compound [1], and the intermediate compound of the above compound is represented by [1-1] or the like. In the present specification, the chemical number is represented by the chemical number. For example, the compound represented by the formula (1) is represented by the compound (1).

[Reaction Example 1] Synthesis of Compound [35]

Preparation of intermediate compound [35-1]

19.0 g (0.101 mol) of 2-bromothiophenol and 27.8 g (0.201 mol) of potassium carbonate were stirred in a 1 L reaction flask with 300 mL of N, N-dimethylformamide in a nitrogen atmosphere. 14.6 mL (0.12 mol) of 2'-fluoroacetophenone was added dropwise at room temperature, and the mixture was heated and stirred at 100 ° C for 12 hours. The reaction mixture was cooled to room temperature and poured into 800 mL of a saturated ammonium chloride aqueous solution to separate the organic layer. The organic layer is dried over anhydrous magnesium sulfate and filtered. The filtrate was concentrated under reduced pressure and recrystallized from dichloromethane and hexane to obtain 22.0 g (72%) of intermediate compound [35-1].

Preparation of intermediate compound [35-2]

21.5 g (69.98 mmol) of the intermediate compound [35-1] was added to the flask and stirred with 300 mL of anhydrous tetrahydrofuran in a nitrogen atmosphere. 75 mL (1.4 M, 0.104 mol) of methylmagnesium bromide is slowly added dropwise at 5 占 폚. After stirring at the same temperature for 1 hour, the reaction solution was poured into 500 mL of a saturated ammonium chloride aqueous solution and extracted with 300 mL of ethyl acetate. The organic layer was separated, dried over anhydrous magnesium sulfate and filtered. The filtrate was concentrated under reduced pressure and purified by silica gel column chromatography to obtain 20.0 g (93%) of the intermediate compound [35-2] as a colorless oil.

Preparation of intermediate compound [35-3]

20 g (61.87 mmol) of the intermediate compound [35-2] and 400 ml of methanesulfonic acid are placed in a flask and stirred at 60 캜. After completion of the reaction, the reaction solution is slowly added to a constant volume of 1 L while stirring, and the resulting solid is filtered under reduced pressure. The resulting solid was recrystallized from dichloromethane and methanol, and the product was purified by column chromatography to obtain 9.6 g (51%) of an intermediate compound [35-3] as a white solid.

Preparation of intermediate compound [35-4]

To the flask, 9.1 g (29.81 mmol) of the intermediate compound [35-3] and 150 ml of tetrahydrofuran are added, and the mixture is completely dissolved by stirring under N ₂ . 14.3 ml (35.77 mmol) of 2.5M n-butyllithium was slowly added dropwise at -78 ° C, and 3.99 ml (35.77 mmol) of trimethylborate was added dropwise at the same temperature for 30 minutes. After completion of the reaction, the reaction mixture was poured into 1N hydrochloric acid aqueous solution at room temperature and extracted with ethyl acetate. The organic layer was separated and recrystallized from dichloromethane and normal hexane to obtain 4.7 g (59%) of an intermediate compound [35-4] as a white solid.

Preparation of intermediate compound [35-5]

(15.54 mmol) of intermediate compound [35-4], 4.4 g (15.54 mmol) of 1-bromo-3-iodobenzene, 2.79 g (20.21 mmol) of calcium carbonate, 0.18 g (0.15 mmol) of palladium was added, and the mixture was refluxed under stirring in toluene and purified water for 12 hours. After completion of the reaction, the reaction mixture was extracted with ethyl acetate at room temperature, and the organic layer was dried over anhydrous magnesium sulfate and filtered. The obtained solid was separated and purified by column chromatography to obtain 3.7 g (63%) of an intermediate compound [35-5] as a white solid .

Preparation of compound [35]

To the flask was added 3.3 g (8.65 mmol) of the intermediate compound [35-5], 2.6 g (9.52 mmol) of 2-triphenyleneboronic acid, 1.55 g (11.25 mmol) of calcium carbonate, 0.1 g of tetrakis (triphenylphosphine) palladium 0.08 mmol) were added, and the mixture was refluxed under stirring in toluene and purified water for 12 hours. After completion of the reaction, the reaction mixture was filtered under reduced pressure at room temperature, and the resulting solid was recrystallized from dichloromethane and methanol, and then separated and purified by column chromatography to obtain 3.4 g (76%) of the target compound [35] as a white solid.

Compounds 1 to 82 were prepared in the same manner as in Reaction Example 1, and the results are shown in the first group (first group).

[First group (group)]

Comparative Example 1

A compound represented by the following formula (a) is used as a phosphorescent blue host, and a compound represented by the following formula (b) is used as a phosphorescent blue dopant and 2-TNATA (4,4 ' -yl) -N-phenylamino) -triphenylamine was used as a hole injection layer material and α-NPD (N, N'-di (naphthalene-1-yl) -N, N'-diphenylbenzidine) (30 nm) / Alq3 (30 nm) / LiF (0.5 nm) / compound a + compound (30 nm) / ITO / 2-TNATA / Al (60 nm).

An anode was prepared by cutting Corning's 15 Ω / cm ² (1000 Å) ITO glass substrate into 50 mm × 50 mm × 0.7 mm size, ultrasonically cleaning it in acetone isopropyl alcohol and pure water for 15 minutes each, Washed and used. 2-TANATA was vacuum-deposited on the substrate to form a hole injection layer having a thickness of 80 nm. On top of the hole injection layer,? -NPD was vacuum deposited to form a hole transport layer having a thickness of 30 nm. A compound represented by the formula (a) and a compound represented by the formula (b) (8% doping) were vacuum deposited on the hole transport layer to form a 30 nm thick light emitting layer. Then, an Alq3 compound was vacuum deposited on the light emitting layer to a thickness of 30 nm to form an electron transporting layer. LiF 0.5 nm (electron injecting layer) and Al 60 nm (cathode) were sequentially vacuum-deposited on the electron transporting layer to form an organic light emitting device as shown in Table 3. This is referred to as Comparative Sample 1.

In this comparative example and the following comparative examples and embodiments, devices were fabricated by using an EL evaporator manufactured by DeVoiste.

(Formula a) < Formula b >

Examples 1 to 82

In the same manner as in Comparative Example 1 except that Compound 1 was replaced with Compound 1 as a phosphorescent host compound in the light emitting layer in Comparative Example 1, An organic material having a structure of ITO / 2-TNATA (80 nm) /? -NPD (30 nm) / [phosphorescent host compound 1-82] (30 nm) / Alq3 (30 nm) / LiF (0.5 nm) / Al Thereby preparing a light emitting device. These are referred to as Samples 1 to 81, respectively.

Evaluation Example 1: Evaluation of luminescence characteristics of Comparative Sample 1 and Samples 1 to 82

Comparative Example 1 and Samples 1 to 82 were evaluated for light emission luminance, luminous efficiency and emission peak using Keithley SMU 235 and PR650, respectively, and the results are shown in the following [second group (group)]. The samples showed green emission peak values in the range of 516 to 524 nm.

[Second group (group)]

Samples 1 to 82 exhibited improved luminescence properties as compared to Comparative Sample 1, as shown in [second set of group (s)].

In the above description, the conventional well-known technique is omitted, but a person skilled in the art can easily guess, deduce and reproduce it.

Claims (4)

The organic electroluminescent compound according to any one of claims 1 to 61 and 82,

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