WO2014129869A1 - Organic field effect light-emitting device - Google Patents

Abstract

The present invention provides an organic field effect light-emitting device including: a cathode; an anode; and one or more organic layers interposed between the cathode and the anode, wherein at least one of the organic layers includes a first and a second host.

Description

Organic electroluminescent element

The present invention relates to an organic electroluminescent device comprising at least one organic material layer.

In the organic electroluminescent device, when a voltage is applied between two electrodes, holes are injected into the organic material layer at the anode, and electrons are injected into the organic material layer at the cathode. When the injected holes and electrons meet, excitons are formed, and when the excitons fall to the ground, they shine. The material used as the organic material layer may be classified into a light emitting material, a hole injection material, a hole transport material, an electron transport material, an electron injection material and the like according to its function.

In order to increase the luminous efficiency of the organic electroluminescent device, it is necessary to increase the color purity and to transfer energy. For this, a light emitting material mixed with a host material and a dopant material may be used.

The dopant material may be divided into a fluorescent dopant using an organic material and a phosphorescent dopant using a metal complex compound containing heavy atoms such as Ir and Pt. Since the phosphor can theoretically improve luminous efficiency up to four times as compared to the fluorescent material, much research has been conducted on phosphorescent dopants as well as phosphorescent hosts.

Currently, as a phosphorescent dopant material of the light emitting layer, metal complex compounds including Ir such as Firpic, Ir (ppy) ₃ , and (acac) Ir (btp) ₂ are known, and CBP is known as a phosphorescent host material.

However, the conventional materials are not satisfactory in terms of the lifespan of the organic EL device because the glass transition temperature is low thermal stability is not good. Therefore, there is a demand for the development of an organic EL device including a light emitting material having excellent performance.

In order to solve the above problems, an object of the present invention is to provide an organic electroluminescent device having improved characteristics such as driving voltage, luminous efficiency and lifetime.

In order to achieve the above object, the present invention is an anode; cathode; And one or more organic material layers interposed between the anode and the cathode, wherein at least one of the one or more organic material layers includes a first host and a second host, wherein the first host is represented by Formula 1 below. The second host is an organic electroluminescent device, characterized in that the HOMO-LUMO energy gap is equal to or greater than the compound represented by the following formula (1), or a compound having a large LUMO value.

[Formula 1]

In Chemical Formula 1,

Y ₁ to Y ₄ are each independently N or CR ₃ , and _one of Y ₁ and Y ₂ , Y ₂ and Y _3, or Y ₃ and Y ₄ forms a condensed ring represented by Formula 2 below,

[Formula 2]

In Chemical Formula 2,

The dotted line means a site where condensation occurs with the compound of Formula 1, and Y ₅ to Y ₈ are each independently N or CR ₄ ,

X ₁ and X ₂ are each independently selected from the group consisting of O, S, Se, N (Ar ₁ ), C (Ar ₂ ) (Ar ₃ ) and Si (Ar ₄ ) (Ar ₅ ), wherein At least one of X ₁ and X ₂ is N (Ar ₁ ),

R ₁ to R ₄ and Ar ₁ to Ar ₅ are each independently hydrogen, deuterium, halogen, cyano, nitro, amino, C ₁ -C ₄₀ alkyl group, C ₂ -C ₄₀ alkenyl group, C Alkynyl group of ₂ to C ₄₀ , cycloalkyl group of C ₃ to C ₄₀ , heterocycloalkyl group of 3 to 40 nuclear atoms, aryl group of C ₆ to C ₆₀ , heteroaryl group of 5 to 60 nuclear atoms, C ₁ ~ C ₄₀ alkyloxy group of, C ₆ ~ aryloxy C _60, C ₁ ~ C ₄₀ alkyl silyl group, C ₆ ~ aryl silyl group of C _60, C ₁ ~ C ₄₀ group of an alkyl boron, C ₆ is selected from ~ C ₆₀ aryl boron group, the group consisting of C ₆ ~ C ₆₀ aryl phosphine group, C ₆ ~ C ₆₀ aryl phosphine oxide group, and a C ₆ ~ C ₆₀ aryl group of an amine of,

R ₁ to R ₄ may be bonded to an adjacent group to form a condensed ring,

The alkyl group, alkenyl group, alkynyl group, cycloalkyl group, heterocycloalkyl group, aryl group, heteroaryl group, alkyloxy group, aryloxy group, alkylsilyl group, arylsilyl group of R ₁ to R ₄ and Ar ₁ to Ar ₅ , Alkyl boron group, aryl boron group, aryl phosphine group, aryl phosphine oxide group and arylamine group are each independently deuterium, halogen group, cyano group, nitro group, amino group, C ₁ ~ C ₄₀ alkyl group, C ₂ ~ C ₄₀ alkenyl group, C ₂ to C ₄₀ alkynyl group, C ₃ to C ₄₀ cycloalkyl group, nuclear atom 3 to 40 heterocycloalkyl group, C ₆ to C ₄₀ aryl group, nuclear atom 5 to 40 Heteroaryl group, C ₁ ~ C ₄₀ alkyloxy group, C ₆ ~ C ₆₀ aryloxy group, C ₁ ~ C ₄₀ alkylsilyl group, C ₆ ~ C ₆₀ arylsilyl group, C ₁ ~ C ₄₀ the alkyl boron group, the group consisting of C ₆ ~ C ₆₀ aryl group of boron, C ₆ ~ C ₆₀ aryl phosphine group, C ₆ ~ C ₆₀ aryl phosphine oxide group, and a C ₆ ~ C ₆₀ aryl amine of the The selected one or more species may be unsubstituted or substituted. In this case, the plurality of substituents may be the same or different from each other.

Meanwhile, alkyl in the present invention is a monovalent substituent derived from a straight or branched chain saturated hydrocarbon having 1 to 40 carbon atoms, and examples thereof include methyl, ethyl, propyl, isobutyl, sec-butyl, pentyl, iso-amyl and hexyl. Etc. can be mentioned.

Alkenyl in the present invention is a monovalent substituent derived from a straight or branched chain unsaturated hydrocarbon having 2 to 40 carbon atoms having one or more carbon-carbon double bonds. Examples thereof include vinyl and allyl. ), Isopropenyl, 2-butenyl, and the like.

Alkynyl in the present invention is a monovalent substituent derived from a C2-C40 straight or branched chain unsaturated hydrocarbon having one or more carbon-carbon triple bonds. Examples thereof include ethynyl, 2- Propanyl (2-propynyl) etc. are mentioned.

Aryl in the present invention means a monovalent substituent derived from an aromatic hydrocarbon having 6 to 60 carbon atoms combined with a single ring or two or more rings. In addition, a form in which two or more rings are attached to each other (pendant) or condensed may also be included. Examples of such aryls include phenyl, naphthyl, phenanthryl, anthryl and the like.

Heteroaryl in the present invention means a monovalent substituent derived from monoheterocyclic or polyheterocyclic aromatic hydrocarbon having 5 to 60 nuclear atoms. At least one carbon in the ring, preferably 1 to 3 carbons, is substituted with a heteroatom such as N, O, S or Se. In addition, a form in which two or more rings are pendant or condensed with each other may also be included, and may also include a form condensed with an aryl group. Examples of such heteroaryl include 6-membered monocyclic rings such as pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, triazinyl, phenoxathienyl, indolinzinyl, indolyl ( polycyclic rings such as indolyl, purinyl, quinolyl, benzothiazole, carbazolyl, 2-furanyl, N-imidazolyl, 2-isoxazolyl , 2-pyridinyl, 2-pyrimidinyl, and the like.

Aryloxy in the present invention is a monovalent substituent represented by RO-, wherein R means aryl having 6 to 60 carbon atoms. Examples of such aryloxy include phenyloxy, naphthyloxy, diphenyloxy and the like.

Alkyloxy in the present invention is a monovalent substituent represented by R'O-, wherein R 'means 1 to 40 alkyl, and includes a linear, branched or cyclic structure It is interpreted as. Examples of such alkyloxy include methoxy, ethoxy, n-propoxy, 1-propoxy, t-butoxy, n-butoxy, pentoxy and the like.

Arylamine in the present invention means an amine substituted with aryl having 6 to 60 carbon atoms.

Cycloalkyl in the present invention means a monovalent substituent derived from a monocyclic or polycyclic non-aromatic hydrocarbon having 3 to 40 carbon atoms. Examples of such cycloalkyl include cyclopropyl, cyclopentyl, cyclohexyl, norbornyl, adamantine and the like.

Heterocycloalkyl in the present invention means a monovalent substituent derived from a non-aromatic hydrocarbon having 3 to 40 nuclear atoms, wherein at least one carbon in the ring, preferably 1 to 3 carbons is N, O, S or Substituted with a hetero atom such as Se. Examples of such heterocycloalkyl include morpholine, piperazine and the like.

Alkylsilyl in the present invention is silyl substituted with alkyl having 1 to 40 carbon atoms, arylsilyl means silyl substituted with aryl having 6 to 60 carbon atoms.

Condensed ring in the present invention means a condensed aliphatic ring, a condensed aromatic ring, a condensed heteroaliphatic ring, a condensed heteroaromatic ring or a combination thereof.

Hereinafter, the present invention will be described.

The compound used in the organic material layer should have a HOOC (highest occupied molecular orbital) between the organic material layer (especially the light emitting layer) and the anode to facilitate hole injection, and the organic material layer (especially the light emitting layer) to facilitate electron transfer. It should have a lower unoccupied molecular orbital (LUMO) that is halfway between the cathode and the cathode. In addition, compounds with large LUMO values can lower the barrier during electron transport and facilitate electron transfer. Therefore, when a compound having a high LUMO value is introduced into the organic material layer, holes and electrons flowing into the organic EL device may be balanced, thereby improving lifespan of the organic EL device.

Accordingly, the organic electroluminescent device of the present invention includes an anode, a cathode and one or more organic material layers interposed between the anode and the cathode to improve the characteristics of the device as described above, the one or more organic material layers At least one of which includes a first host and a second host, wherein the first host is a compound represented by the formula (1), the second host is equal to or more than the HOMO-LUMO energy gap than the compound represented by the formula (1) Or a compound having a large LUMO value.

The compound represented by Chemical Formula 1 used as the first host of the present invention has a condensed carbon ring or a condensed heterocyclic moiety linked to an indole-based skeleton, and the energy level is controlled by various substituents, thereby providing a wide energy band gap (sky blue to red). Therefore, when the compound represented by Chemical Formula 1 is used as the first host of the organic material layer of the organic EL device, the emission (phosphorescence) characteristics of the organic EL device may be improved and the electron and / or hole transport ability may be enhanced.

The organic material layer including the compound represented by Formula 1 as a first host is preferably a hole transport layer, an electron transport layer, and a light emitting layer. In particular, since the compound represented by Formula 1 exhibits excellent characteristics as a phosphorescent host material compared to the conventional CBP due to the indole-based skeleton, the organic material layer including the first host is more preferably a light emitting layer.

Specifically, the compound represented by Formula 1 has various aromatic rings bonded to the indole-based skeleton as a substituent to significantly increase the molecular weight of the compound, thereby improving the glass transition temperature and thereby higher than the conventional CBP. May have thermal stability. In addition, since the whole molecule has a bipolar (bipolar) nature of the various aromatic ring substituents to increase the binding force between the hole and the electron, it can exhibit excellent properties as a phosphorescent host material of the light emitting layer compared to the conventional CBP.

In the compound represented by such formula (I), inde Y ₁ to Y ₄ is N or CR _3, it is of which does not form a condensed ring represented by the formula (2) is preferably all of CR _3. In this case, the plurality of R ₃ may be the same or different from each other. In addition, Y ₅ to Y ₈ in the condensed ring represented by the formula (2) is N or CR ₄ , preferably all CR ₄ . In this case, the plurality of R ₄ may be the same or different from each other.

On the other hand, considering the wide energy band gap (gap) and thermal stability of the compound represented by Formula 1, R ₁ to R ₄ are each independently hydrogen, an aryl group of C ₆ ~ C ₆₀ (e.g., phenyl, naph Butyl, bisphenyl) or heteroaryl groups having 5 to 60 nuclear atoms (e.g. pyridine).

The compound of Formula 1 used as the first host is preferably selected from the group consisting of compounds represented by the following Formulas 1a to 1f.

[Formula 1a]

[Formula 1b]

[Formula 1c]

[Formula 1d]

[Formula 1e]

[Formula 1f]

In Formulas 1a to 1f, X ₁ , X ₂ and R ₁ to R ₄ are the same as defined above. In this case, a plurality of R ₃ are the same as or different from each other, a plurality of R _{4 is} also the same or different from each other.

In consideration of characteristics such as luminous efficiency, driving voltage, and lifetime of the organic electroluminescent device, in Formula 1 used as the first host, X ₁ and X ₂ are each independently N (Ar ₁ ) or S. That is, it is preferable that X ₁ is N (Ar ₁ ) and X ₂ is S, X ₁ is S and X ₂ is N (Ar ₁ ), or both X ₁ and X ₂ are N (Ar ₁ ).

Such a compound of the formula (1) used as the first host of the present invention is specifically selected from the group consisting of compounds represented by the following formula (C1 to C66).

In Formulas C1 to C66, R ₁ to R ₄ are as defined above. Further, suppose described Ar ₁ to Ar ₅ is also as defined above, particularly C ₆ ~ C ₆₀ aryl group, the number of nuclear atoms of 5 to 60 heteroaryl group, and a C ₆ ~ C ₆₀ of which is selected from the group consisting of an aryl amine It is preferable. Specifically, Ar ₁ to Ar ₅ are each independently selected from the group consisting of the following substituents (functional groups) (S1-S206).

The HOMO value of the compound used as the first host of the present invention is in the range of -6.5 eV to -5.0 eV, and the LUMO value is in the range of -3.5 eV to -1.5 eV.

The compound used as the second host of the present invention is equal to or greater than the compound represented by Formula 1 and the HOMO-LUMO energy gap, or has a high LUMO value. At this time, the HOMO-LUMO energy gap means a difference between the HOMO value and the LUMO value.

Here, in consideration of characteristics such as luminous efficiency, driving voltage, and lifetime of the organic electroluminescent device, the compound used as the second host is triphenylene, phenyl, carbazole, acridine, indenocarbazole, indolocarba It is preferable that the compound contains a compound selected from the group consisting of sol, pyrrolocarbazole, indolotriphenylene, dibenzothiophene and dibenzofuran as a moiety in a molecule, and the compound is substituted or unsubstituted. Can be.

Specifically, the compound used as the second host of the present invention is more preferably selected from the group consisting of compounds represented by the following H1 to H54.

The compounds represented by H1 to H54 are only examples that can be used as the second host, and the second host is not limited to the compounds.

As such, the organic electroluminescent device of the present invention may have a long life because at least one of the plurality of organic material layers may balance holes and electrons injected into the device including the first host and the second host. Here, the mixing ratio of the first host and the second host is not particularly limited in manufacturing the organic layer, but the first host and the second host may be mixed in a ratio of 1:99 to 99: 1, and the use ratio of the second host may be used. This higher is preferred.

On the other hand, the organic material layer of the present invention including the first host and the second host is preferably a light emitting layer, wherein the light emitting layer of the present invention may include a dopant diagram with the first host and the second host.

Here, the material that can be used as the dopant included in the light emitting layer is not particularly limited, but it is preferable to use a metal complex compound containing iridium (Ir).

The method of manufacturing the light emitting layer including the first host, the second host and the dopant is not particularly limited as long as it is known in the art, and the following methods may be mentioned as non-limiting examples.

The first method is a co-deposition method in which a first host and a second host are positioned in the first and second heat sources, respectively, and a dopant is placed in the third heat source to simultaneously apply heat to form a light emitting layer. Specifically, at a vacuum degree of 1 × 10 ⁻⁰⁶ torr or less, a first host having high electron mobility and high electron injection efficiency is placed in the first heat source, and hole mobility is located in the second heat source. A method of co-depositing at a proper ratio by placing a second host having a high c) and having a good hole injection efficiency and adjusting the dopant of the third heat source and the evaporation rate per second. In this case, the number of co-deposited hosts may be two or more depending on the characteristics of the light emitting layer. The amount of the first host, the second host, and the dopant is not particularly limited, but the first host and the second host may be 70 to 99 wt%, and the dopant may be used at 1 to 30 wt%. Specifically, it is preferable to use 80 to 95 weight% of a 1st host and a 2nd host, and to use 5 to 20 weight% of a dopant.

In the second method, in order to reduce the number of heat sources used and to simplify the formation process, the first host and the second host used to form the light emitting layer are mixed at an appropriate ratio, placed in one heat source, and heated to form the light emitting layer. Vapor deposition method. Specifically, the host (first host + second host) mixed in the first heat source is placed at a vacuum degree of 1 × 10 ⁻⁰⁶ torr or less, and the dopant is placed in the second heat source to simultaneously control the evaporation rate per second and It is a method of forming. This method can reduce the error of the mixing ratio generated when using one or more hosts, and can form the light emitting layer with a small number of heat sources. In this case, the amount of the first host, the second host, and the dopant is not particularly limited, but the first host and the second host may be 70 to 99 wt%, and the dopant may be used at 1 to 30 wt%. Specifically, it is preferable to use 80 to 95 weight% of a 1st host and a 2nd host, and to use 5 to 20 weight% of a dopant.

The material usable as the anode included in the organic electroluminescent device of the present invention is not particularly limited, but non-limiting examples include metals such as vanadium, chromium, copper, zinc, gold or alloys thereof; Metal oxides such as zinc oxide, indium oxide, indium tin oxide (ITO) and indium zinc oxide (IZO); Combinations of metals and oxides such as ZnO: Al and SnO ₂ : Sb; Conductive polymers such as polythiophene, poly (3-methylthiophene), poly [3,4- (ethylene-1,2-dioxy) thiophene] (PEDT), polypyrrole and polyaniline; And carbon black.

The material that can be used as the cathode included in the organic electroluminescent device of the present invention is not particularly limited, but non-limiting examples include magnesium, calcium, sodium, potassium, titanium, indium, yttrium, lithium, gadolinium, aluminum, silver, tin, lead Metals such as these, alloys thereof, and multilayered structural materials such as LiF / Al and LiO ₂ / Al.

The structure of the organic EL device of the present invention is not particularly limited, but a non-limiting example is a structure in which a substrate, an anode, an organic material layer (hole injection layer-> hole transport layer-> light emitting layer-> electron transport layer) and a cathode are sequentially stacked. Can be. In this case, at least one of the hole injection layer, the hole transport layer, the light emitting layer, the electron transport layer and the electron injection layer may include the compound represented by Formula 1 as a first host.

On the other hand, the electron injection layer may be further stacked on the electron transport layer. In addition, the structure of the organic EL device according to the present invention may be a structure in which an insulating layer or an adhesive layer is inserted at the interface between the anode and cathode and the organic layer.

The organic electroluminescent device of the present invention may be formed using other materials and methods known in the art, except that one or more layers (eg, a light emitting layer) of the organic material layer are formed to include the first host and the second host. The organic material layer can be formed.

The substrate used in the manufacture of the organic electroluminescent device of the present invention is not particularly limited, but non-limiting examples include silicon wafers, quartz, glass plates, metal plates, plastic films, and the like.

Hereinafter, the present invention will be described in detail with reference to Examples, but the following Examples are merely illustrative of the present invention, and the present invention is not limited by the following Examples.

Preparation Example 1 Synthesis of IC-1

<Step 1> Synthesis of 5- (4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl) -1H-indole

5-bromo-1H-indole (25 g, 0.128 mol), 4,4,4 ', 4', 5,5, 5 ', 5'-octamethyl-2,2'-bi (1,3) under nitrogen stream , 2-dioxaborolane) (48.58 g, 0.191 mol), Pd (dppf) Cl ₂ (5.2 g, 5 mol), KOAc (37.55 g, 0.383 mol) and 1,4-dioxane (500 ml) were mixed and 130 ° C Stir at 12 h. After the reaction was completed, the mixture was extracted with ethyl acetate and then dried with MgSO ₄ , purified by column chromatography (Hexane: EA = 10: 1 (v / v)), and purified by 5- (4,4,5,5-tetramethyl). -1,3,2-dioxaborolan-2-yl) -1H-indole (22.32 g, yield 72%) was obtained.

¹ H-NMR: δ 1.24 (s, 12H), 6.45 (d, 1H), 7.27 (d, 1H), 7.42 (d, 1H), 7.52 (d, 1H), 7.95 (s, 1H), 8.21 ( s, 1 H)

<Step 2> Synthesis of 5- (2-nitrophenyl) -1H-indole

1-bromo-2-nitrobenzene (15.23 g, 75.41 mmol) under nitrogen stream and 5- (4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl) obtained in <Step 1> above -1H-indole (22 g, 90.49 mmol), NaOH (9.05 g, 226.24 mmol) and THF / H ₂ O (400 ml / 200 ml) were mixed and then Pd (PPh ₃ ) ₄ (4.36 g) at 40 ° C. , 5 mol%) was added and stirred at 80 ° C. for 12 hours.

After completion of the reaction, the mixture was extracted with methylene chloride, MgSO ₄ was added and filtered. After removing the solvent in the organic layer obtained was purified by column chromatography (Hexane: EA = 3: 1 (v / v)) to give 5- (2-nitrophenyl) -1H-indole (11.32 g, 63% yield).

¹ H-NMR: δ 6.47 (d, 1H), 7.25 (d, 1H), 7.44 (d, 1H), 7.53 (d, 1H), 7.65 (t, 1H), 7.86 (t, 1H), 7.95 ( s, 1H), 8.00 (d, 1H), 8.09 (t, 1H), 8.20 (s, 1H)

<Step 3> Synthesis of 5- (2-nitrophenyl) -1-phenyl-1H-indole

5- (2-nitrophenyl) -1H-indole (11 g, 46.17 mmol), iodobenzene (14.13 g, 69.26 mmol) obtained in the above <Step 2> under nitrogen stream, Cu powder (0.29 g, 4.62 mmol), K ₂ CO ₃ (6.38 g, 46.17 mmol), Na ₂ SO ₄ (6.56 g, 46.17 mmol) and nitrobenzene (200 ml) were mixed and stirred at 190 ° C. for 12 h.

After completion of the reaction, nitrobenzene was removed, the organic layer was separated with methylene chloride, and water was removed using MgSO ₄ . The solvent was removed from the organic layer, which was freed of water, and then purified by column chromatography (Hexane: MC = 3: 1 (v / v)) to give 5- (2-nitrophenyl) -1-phenyl-1H-indole (10.30 g, yield). 71%).

¹ H-NMR: δ 6.48 (d, 1H), 7.26 (d, 1H), 7.45 (m, 3H), 7.55 (m, 4H), 7.63 (t, 1H), 7.84 (t, 1H), 7.93 ( s, 1H), 8.01 (d, 1H), 8.11 (t, 1H)

Step 4 Synthesis of IC-1

5- (2-nitrophenyl) -1-phenyl-1H-indole (5 g, 15.91 mmol), triphenylphosphine (10.43 g, 39.77 mmol) and 1,2-dichlorobenzene (50 ml) obtained in <Step 3> under a nitrogen stream. ) Was mixed and stirred for 12 hours.

After the reaction was completed, 1,2-dichlorobenzene was removed and extracted with dichloromethane. Water was removed with MgSO ₄ and the resulting organic layer was purified by column chromatography (Hexane: MC = 3: 1 (v / v)) to obtain IC-1 (2.38 g, yield 53%).

¹ H-NMR: δ 6.99 (d, 1H), 7.12 (t, 1H), 7.27 (t, 1H), 7.32 (d, 1H), 7.41 (t, 1H), 7.50 (d, 1H), 7.60 ( m, 5H), 7.85 (d, 1H), 8.02 (d, 1H), 10.59 (s, 1H)

Preparation Example 2 Synthesis of IC-2

Step 1 Synthesis of 6- (4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl) -1H-indole

Except for using 6-bromo-1H-indole instead of 5-bromo-1H-indole by following the same procedure as in <Step 1> of Preparation Example 1 6- (4,4,5,5-tetramethyl- 1,3,2-dioxaborolan-2-yl) -1H-indole was obtained.

¹ H-NMR: δ 1.25 (s, 12H), 6.52 (d, 1H), 7.16 (d, 1H), 7.21 (d, 1H), 7.49 (d, 1H), 7.53 (s, 1H), 8.15 ( s, 1 H)

Step 2 Synthesis of 6- (2-nitrophenyl) -1H-indole

5- (4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl) -1H-indole instead of 6- (4,4,5,5-tetramethyl-1,3,2-dioxaborolan A 6- (2-nitrophenyl) -1H-indole was obtained by the same procedure as in <Step 2> of Preparation Example 1, except that 2-yl) -1H-indole was used.

¹ H-NMR: δ 6.57 (d, 1H), 7.07 (d, 1H), 7.24 (d, 1H), 7.35 (s, 1H), 7.43 (t, 1H), 7.50 (d, 1H), 7.58 ( t, 1H), 7.66 (d, 1H), 7.78 (d, 1H), 8.19 (s, 1H)

<Step 3> Synthesis of 6- (2-nitrophenyl) -1-phenyl-1H-indole

Except that 6- (2-nitrophenyl) -1H-indole is used instead of 5- (2-nitrophenyl) -1H-indole, 6- (2- nitrophenyl) -1-phenyl-1H-indole was obtained.

¹ H-NMR: δ 6.81 (d, 1H), 7.12 (t, 1H), 7.22 (t, 1H), 7.35 (s, 1H), 7.43 (d, 1H), 7.51 (m, 3H), 7.56 ( m, 2H), 7.62 (m, 2H), 7.85 (d, 1H), 8.02 (d, 1H)

Step 4 Synthesis of IC-2

The same procedure as in <Step 4> of Preparation Example 1, except that 6- (2-nitrophenyl) -1-phenyl-1H-indole is used instead of 5- (2-nitrophenyl) -1-phenyl-1H-indole Was carried out to obtain IC-2.

¹ H-NMR: δ 6.80 (d, 1H), 7.11 (t, 1H), 7.23 (t, 1H), 7.42 (d, 1H), 7.50 (m, 3H), 7.57 (m, 2H), 7.63 ( m, 2H), 7.86 (d, 1H), 8.03 (d, 1H), 9.81 (s, 1H)

Synthesis Example 1 Synthesis of Com-1

IC-1 (3 g, 10.63 mmol), 2- (3-chlorophenyl) -4,6-diphenyl-1,3,5-triazine (4.38 g, 12.75 mmol), Pd (OAc) ₂ (0.12) under nitrogen stream g, 5 mol%), NaO (t-bu) (2.04 g, 21.25 mmol), P (t-bu) ₃ (0.21 g, 1.06 mmol) and Toluene (100 ml) were mixed and stirred at 110 ° C. for 12 hours. Stirred.

After completion of the reaction, the mixture was extracted with ethyl acetate and then water was removed with MgSO ₄ , and purified by column chromatography (Hexane: EA = 2: 1 (v / v)) to obtain the title compound Com-1 (4.89 g, yield 78 %) Was obtained.

GC-Mass (Theoretical value: 589.23 g / mol, Measured value: 589 g / mol)

Synthesis Example 2 Synthesis of Com-2

The above synthesis except that 2- (3-chlorophenyl) -4,6-diphenylpyrimidine (4.36 g, 12.75 mmol) was used instead of 2- (3-chlorophenyl) -4,6-diphenyl-1,3,5-triazine. The same procedure as in Example 1 was performed to obtain Com-2 (4.68 g, yield 75%) as a target compound.

GC-Mass (Theoretical value: 588.23 g / mol, Measured value: 588 g / mol)

Synthesis Example 3 Synthesis of Com-3

The above synthesis except that 2- (3-chlorophenyl) -4,6-diphenylpyridine (4.34 g, 12.75 mmol) was used instead of 2- (3-chlorophenyl) -4,6-diphenyl-1,3,5-triazine. The same procedure as in Example 1 was carried out to obtain Com-3 (4.36 g, yield 70%) as a target compound.

GC-Mass (Theoretical value: 587.23 g / mol, Measured value: 587 g / mol)

Synthesis Example 4 Synthesis of Com-4

2- (3-chloro-5-methylphenyl) -4,6-diphenyl-1,3,5-triazine (4.55 g instead of 2- (3-chlorophenyl) -4,6-diphenyl-1,3,5-triazine , 12.75 mmol) was prepared in the same manner as in Synthesis Example 1 to obtain Com-4 (4.81 g, yield 75%) as a target compound.

GC-Mass (Theoretical value: 603.24 g / mol, Measured value: 603 g / mol)

Synthesis Example 5 Synthesis of Com-5

Except for using IC-2 (3 g, 10.63 mmol) instead of IC-1 was carried out in the same manner as in Synthesis Example 1 to obtain the target compound Com-5 (4.81 g, yield 75%).

GC-Mass (Theoretical value: 589.23 g / mol, Measured value: 589 g / mol)

Synthesis Example 6 Synthesis of Com-6

Except for using 2-chloro-4,6-diphenyl-1,3,5-triazine (3.40 g, 12.75 mmol) instead of 2- (3-chlorophenyl) -4,6-diphenyl-1,3,5-triazine Then, the same procedure as in Synthesis Example 1 was performed, to obtain Com-6 (3.98 g, yield 73%) as a target compound.

GC-Mass (Theoretical value: 513.20 g / mol, Measured value: 513 g / mol)

Synthesis Example 7 Synthesis of Com-7

Same as Synthesis Example 1, except that 2-chloro-4,6-diphenylpyrimidine (3.40 g, 12.75 mmol) was used instead of 2- (3-chlorophenyl) -4,6-diphenyl-1,3,5-triazine. The procedure was carried out to obtain the title compound Com-7 (3.81 g, yield 70%).

GC-Mass (Theoretical value: 512.20 g / mol, Measured value: 512 g / mol)

Synthesis Example 8 Synthesis of Com-8

Same as Synthesis Example 1, except that 2-chloro-4,6-diphenylpyridine (3.38 g, 12.75 mmol) was used instead of 2- (3-chlorophenyl) -4,6-diphenyl-1,3,5-triazine. The procedure was carried out to obtain the title compound Com-8 (4.07 g, yield 75%).

GC-Mass (Theoretical value: 511.20 g / mol, Measured value: 511 g / mol)

Synthesis Example 9 Synthesis of Com-9

Use IC-2 (3 g, 10.63 mmol) instead of IC-1, 2-chloro-4,6-diphenyl- instead of 2- (3-chlorophenyl) -4,6-diphenyl-1,3,5-triazine Except for using 1,3,5-triazine (3.38 g, 12.75 mmol) was carried out the same procedure as in Synthesis Example 1 to obtain the target compound Com-9 (3.92 g, 72% yield).

GC-Mass (Theoretical value: 513.20 g / mol, Measured value: 513 g / mol)

[Examples 1 to 9] Fabrication of Organic Electroluminescent Device

The glass substrate coated with ITO (Indium tin oxide) with a thickness of 1500Å was ultrasonically washed with distilled water. After washing the distilled water, ultrasonic cleaning with a solvent such as isopropyl alcohol, acetone, methanol, dried and transferred to a UV OZONE cleaner (Power sonic 405, Hwasin Tech), and then wash the substrate using UV for 5 minutes The substrate was transferred to a vacuum evaporator.

On the ITO transparent substrate prepared as above, using Com-1 as the first host and the compounds represented by H1, H3, H9, H13, H18, H30, H34, H46, H51 as the second host, respectively, -MTDATA (60 nm) / TCTA (80 nm) / 90% of the first and second host + 10% Ir (ppy) ₃ (300nm) / BCP (10 nm) / Alq ₃ (30 nm) / LiF ( 1 nm) / Al (200 nm) was laminated in order to manufacture an organic EL device.

In this case, the structures of m-MTDATA, TCTA, Ir (ppy) ₃ , BCP, and Com-1 used were as follows, and the mixing ratio of the first host and the second host was 3: 7.

Examples 10 to 18 Fabrication of Organic Electroluminescent Device

Example 1 On the prepared ITO transparent substrate, m-MTDATA (60 nm) / TCTA (80 nm) / 90 using the following Com-1 to Com-9 as the first host and the compound represented by the H54 as the second host % First host and second host + 10% Ir (ppy) ₃ (300nm) / BCP (10 nm) / Alq ₃ (30 nm) / LiF (1 nm) / Al (200 nm) stacked in order An electroluminescent device was produced.

At this time, the structure of the used Com-1 to Com-9 is as follows, m-MTDATA, TCTA, Ir (ppy) ₃ , the structure of the BCP is the same as in Example 1, the first host and the second host The mixing ratio was 3: 7.

Examples 19 to 27 Fabrication of Organic Electroluminescent Device

Example 1 On the prepared ITO transparent substrate, m-MTDATA (60 nm) / TCTA (80 nm) / 90% first using Com-1 as the first host and the compound represented by H43 as the second host The organic electroluminescent device was formed by stacking a host and a second host + 10% Ir (ppy) ₃ (300 nm) / BCP (10 nm) / Alq ₃ (30 nm) / LiF (1 nm) / Al (200 nm). Produced.

At this time, the structure of m-MTDATA, TCTA, Ir (ppy) ₃ , BCP and Com-1 used was the same as in Example 1, the mixing ratio of the first host and the second host was adjusted as shown in Table 2.

Comparative Example 1 Fabrication of Organic Electroluminescent Device

An organic electroluminescent device was manufactured in the same manner as in Example 1, except that 90% CBP + 10% Ir (ppy) ₃ was used to form the emission layer. At this time, the structure of the CBP used is as follows.

Comparative Example 2 Fabrication of Organic Electroluminescent Device

An organic EL device was manufactured in the same manner as in Example 1, except that 90% of the first host (Com-1) + 10% Ir (ppy) ₃ was used to form the emission layer.

Experimental Example 1 HOMO and LUMO Measurement

Com-1 and the second host used as the first host by methods known in the art. HOMO values and LUMO values of H1 and H3 used were measured, and the results are shown in Table 1 below.

Table 1

	compound	HOMO	LUMO	HOMO-LUMO Energy Gap (Band Gap)
First host	Com-1	-5.39	-1.86	3.53
2nd host	H1	-5.82	-2.29	3.53
	H3	-5.80	-2.03	3.77

Looking at Table 1, it was confirmed that the HOMO-LUMO energy gap of the compound used as the second host of the present invention is equal to or greater than the HOMO-LUMO energy gap of the compound used as the first host.

Experimental Example 2

For each of the organic EL devices manufactured in Examples 1 to 27 and Comparative Examples 1 and 2, the driving voltage and the current efficiency at the current density of 10 mA / cm 2 were measured, and the results are shown in Table 2 below.

TABLE 2

Sample	Host Usage Rate	Driving voltage (V)	Current efficiency (cd / A)
Example 1	30% Com-1 + 70% H1	6.50	42.9
Example 2	30% Com-1 + 70% H3	6.45	42.8
Example 3	30% Com-1 + 70% H9	6.45	42.8
Example 4	30% Com-1 + 70% H13	6.40	42.9
Example 5	30% Com-1 + 70% H18	6.50	42.5
Example 6	30% Com-1 + 70% H30	6.55	42.6
Example 7	30% Com-1 + 70% H34	6.55	42.5
Example 8	30% Com-1 + 70% H46	6.40	42.9
Example 9	30% Com-1 + 70% H51	6.45	43.0
Example 10	30% Com-1 + 70% H54	5.90	42.7
Example 11	30% Com-2 + 70% H54	5.95	42.9
Example 12	30% Com-3 + 70% H54	5.95	42.5
Example 13	30% Com-4 + 70% H54	5.90	43.2
Example 14	30% Com-5 + 70% H54	5.90	43.0
Example 15	30% Com-6 + 70% H54	5.95	42.9
Example 16	30% Com-7 + 70% H54	5.95	43.1
Example 17	30% Com-8 + 70% H54	6.00	43.3
Example 18	30% Com-9 + 70% H54	6.05	43.0
Example 19	10% Com-1 + 90% H43	6.15	42.8
Example 20	20% Com-1 + 80% H43	6.10	42.9
Example 21	30% Com-1 + 70% H43	6.00	43.0
Example 22	40% Com-1 + 60% H43	6.20	43.2
Example 23	50% Com-1 + 50% H43	6.10	43.0
Example 24	60% Com-1 + 40% H43	6.15	42.7
Example 25	70% Com-1 + 30% H43	6.25	42.5
Example 26	80% Com-1 + 20% H43	6.20	42.3
Example 27	90% Com-1 + 10% H43	6.25	42.4
Comparative Example 1	100% CBP	6.93	38.2
Comparative Example 2	100% Com-1	6.55	41.0

Looking at Table 2, the organic electroluminescent device (Examples 1 to 27) of the present invention using the light emitting layer comprising the first host and the second host is a conventional light emitting layer using CBP or Com-1 as a single host material It was confirmed that the organic electroluminescent device (Comparative Example 1 and Comparative Example 2) showed superior performance in terms of current efficiency and driving voltage.

The organic electroluminescent device of the present invention includes an organic material layer including a first host and a second host, and since the compound represented by Chemical Formula 1 is used as the first host, driving voltage, luminous efficiency and lifetime may be improved. Can be. Therefore, when the display panel is manufactured using the organic EL device of the present invention, it is possible to provide a display panel having improved performance and lifespan.

Claims (6)

1. anode; cathode; And one or more organic material layers interposed between the anode and the cathode,

   At least one of the one or more organic material layers includes a first host and a second host,

   The first host is a compound represented by the following formula (1),

   The second host is an organic electroluminescent device, characterized in that the HOMO-LUMO energy gap is equal to or greater than the compound represented by the formula (1) or a compound having a larger LUMO value.

   [Formula 1]

   

   In Chemical Formula 1,

   Y ₁ to Y ₄ are each independently N or CR ₃ , and _one of Y ₁ and Y ₂ , Y ₂ and Y _3, or Y ₃ and Y ₄ forms a condensed ring represented by Formula 2 below,

   [Formula 2]

   

   In Chemical Formula 2,

   The dotted line means a site where condensation occurs with the compound of Formula 1, and Y ₅ to Y ₈ are each independently N or CR ₄ ,

   X ₁ and X ₂ are each independently selected from the group consisting of O, S, Se, N (Ar ₁ ), C (Ar ₂ ) (Ar ₃ ) and Si (Ar ₄ ) (Ar ₅ ), wherein At least one of X ₁ and X ₂ is N (Ar ₁ ),

   R ₁ to R ₄ and Ar ₁ to Ar ₅ are each independently hydrogen, deuterium, halogen, cyano, nitro, amino, C ₁ -C ₄₀ alkyl group, C ₂ -C ₄₀ alkenyl group, C Alkynyl group of ₂ to C ₄₀ , cycloalkyl group of C ₃ to C ₄₀ , heterocycloalkyl group of 3 to 40 nuclear atoms, aryl group of C ₆ to C ₆₀ , heteroaryl group of 5 to 60 nuclear atoms, C ₁ ~ C ₄₀ alkyloxy group of, C ₆ ~ aryloxy C _60, C ₁ ~ C ₄₀ alkyl silyl group, C ₆ ~ aryl silyl group of C _60, C ₁ ~ C ₄₀ group of an alkyl boron, C ₆ is selected from ~ C ₆₀ aryl boron group, the group consisting of C ₆ ~ C ₆₀ aryl phosphine group, C ₆ ~ C ₆₀ aryl phosphine oxide group, and a C ₆ ~ C ₆₀ aryl group of an amine of,

   R ₁ to R ₄ may be bonded to an adjacent group to form a condensed ring,

   The alkyl group, alkenyl group, alkynyl group, cycloalkyl group, heterocycloalkyl group, aryl group, heteroaryl group, alkyloxy group, aryloxy group, alkylsilyl group, arylsilyl group of R ₁ to R ₄ and Ar ₁ to Ar ₅ , Alkyl boron group, aryl boron group, aryl phosphine group, aryl phosphine oxide group and arylamine group are each independently deuterium, halogen group, cyano group, nitro group, amino group, C ₁ ~ C ₄₀ alkyl group, C ₂ ~ C ₄₀ alkenyl group, C ₂ to C ₄₀ alkynyl group, C ₃ to C ₄₀ cycloalkyl group, nuclear atom 3 to 40 heterocycloalkyl group, C ₆ to C ₄₀ aryl group, nuclear atom 5 to 40 Heteroaryl group, C ₁ ~ C ₄₀ alkyloxy group, C ₆ ~ C ₆₀ aryloxy group, C ₁ ~ C ₄₀ alkylsilyl group, C ₆ ~ C ₆₀ arylsilyl group, C ₁ ~ C ₄₀ the alkyl boron group, the group consisting of C ₆ ~ C ₆₀ aryl group of boron, C ₆ ~ C ₆₀ aryl phosphine group, C ₆ ~ C ₆₀ aryl phosphine oxide group, and a C ₆ ~ C ₆₀ aryl amine of the The selected one or more species may be unsubstituted or substituted.
2. The method of claim 1,

   The compound represented by Chemical Formula 1 is selected from the group consisting of compounds represented by the following Chemical Formulas 1a to 1f.

   [Formula 1a]

   

   [Formula 1b]

   

   [Formula 1c]

   

   [Formula 1d]

   

   [Formula 1e]

   

   [Formula 1f]

   

   In Formulas 1a to 1f, X ₁ , X ₂ and R ₁ to R ₄ are the same as defined above, and a plurality of R ₃ are the same as or different from each other, and a plurality of R ₄ are also the same as or different from each other.
3. The method of claim 1,

   The second host is in the group consisting of triphenylene, phenyl, carbazole, acridine, indenocarbazole, indolocarbazole, pyrrolocarbazole, indolotriphenylene, dibenzothiophene and dibenzofuran An organic electroluminescent device, characterized in that the compound comprising a selected compound as a moiety.
4. The method of claim 1,

   The second host is an organic electroluminescent device, characterized in that selected from the group consisting of compounds represented by H1 to H54.

   

   

   

   
5. The method of claim 1,

   The organic electroluminescent device comprising the first host and the second host is an emission layer.
6. The method of claim 5,

   The light emitting layer includes a dopant,

   The dopant is an organic electroluminescent device, characterized in that the metal complex compound.