JP2016503585A - Novel organic electroluminescent compound and organic electroluminescent device containing the same - Google Patents

Abstract

The present invention relates to a novel organic electroluminescent compound and an organic electroluminescent device including the same. The organic electroluminescent compounds according to the present invention provide higher luminous efficiency compared to conventional materials. In addition, OLED devices that use the organic electroluminescent compounds according to the present invention as light emitting host materials have lower drive voltages, resulting in higher power efficiency and improved power consumption, providing improved current efficiency To do. [Selection figure] None

Description

  The present invention relates to a novel organic electroluminescent compound and an organic electroluminescent device including the same.

  Electroluminescent devices (EL devices) are self-emitting devices that have advantages in providing a wider viewing angle, a larger contrast ratio, and a faster response time. Organic EL devices were first developed by Eastman Kodak by using small aromatic diamine molecules and aluminum complexes as materials for forming the emissive layer [Appl. Phys. Lett. 51, 913, 1987].

The most important factor that determines the luminous efficiency in the organic EL device is the luminescent material. To date, fluorescent materials have been widely used as luminescent materials. However, in consideration of the electroluminescent mechanism, the phosphorescent material theoretically improves the luminous efficiency by a factor of four compared to the fluorescent material. Therefore, the development of phosphorescent light emitting materials has been widely studied. The red, green, and blue materials are bis (2- (2′-benzothienyl) -pyridinate-N, C3 ′) iridium (acetylacetonate) ((acac) Ir (btp) ₂ ), tris (2- Iridium (III) complexes containing phenylpyridine) iridium (Ir (ppy) ₃ ) and bis (4,6-difluorophenylpyridinate-N, C2) picolinate iridium (Firpic) are widely known as phosphorescent materials It has been.

  A luminescent material (dopant) can be used in combination with a host material as the luminescent material to improve color purity, luminous efficiency, and stability. These choices are important when using a host material / dopant system as the luminescent material, since the host material greatly affects the efficiency and performance of the EL device.

  Currently, 4,4'-N, N'-dicarbazole-biphenyl (CBP) is the most widely known host material for phosphorescent materials. Recently, Pioneer (Japan) et al., As host materials, have been known as hole blocking layer materials, butocuproin (BCP) and aluminum (III) bis (2-methyl-8-quinolinate) (4-phenylphenolate) ( A high performance organic EL device using BAlq) has been developed.

  Although these phosphorous host materials provide good luminescent properties, they have the following disadvantages: (1) High temperatures in vacuum due to their low glass transition temperature and poor thermal stability Their degradation can occur during the deposition process. (2) The output efficiency of the organic EL device is given by [(π / voltage) × current efficiency], and the output efficiency is inversely proportional to the voltage. Organic EL devices that include phosphorescent host materials provide higher current efficiency (cd / A) than those that include fluorescent materials, but require significantly higher drive voltages. Therefore, there is no advantage from the viewpoint of output efficiency (lm / W). (3) Furthermore, the operation life of the organic EL device is short, and the light emission efficiency still needs to be improved.

  Meanwhile, copper phthalocyanine (CuPc), 4,4′-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (NPB), N, N′-diphenyl-N, N′-bis (3-methyl) Phenyl)-(1,1′-biphenyl) -4,4′-diamine (TPD), 4,4 ′, 4 ″ -tris (3-methylphenylphenylamino) triphenylamine (MTDATA), etc. It has been used as an injection and transport material.

  However, organic EL devices using these materials have problems in quantum efficiency and operating lifetime. This is because when an organic EL device is driven under a high current, thermal stress occurs between the anode and the hole injection layer. Thermal stress significantly reduces the operating life of the device. Furthermore, since the organic material used for the hole injection layer has a very high hole mobility, the hole-electron charge balance may be broken and the quantum yield (cd / A) may be reduced.

  Japanese Patent Application Publication Nos. 2007-194241 and 2009-194042 disclose compounds in which two carbazoles are bonded via an aryl, heteroaryl or fluorene group as compounds for organic EL devices.

  However, organic EL devices including the compounds disclosed in the above documents are not yet satisfactory with respect to output efficiency, light emission efficiency, quantum efficiency, lifetime, and the like.

  An object of the present invention is to provide an organic electroluminescent compound having higher luminous efficiency, output efficiency, and longer operating lifetime than conventional materials; and an organic electroluminescent device having high efficiency and longer lifetime using the compound. Is to provide.

  The present inventors have stated that the above object is expressed by the following formula 1:

(Where
L ₁ represents a substituted or unsubstituted (C6-C30) arylene group, or a substituted or unsubstituted 5-30 membered heteroarylene group;
L ₂ represents a single bond, a substituted or unsubstituted (C6-C30) arylene group, or a substituted or unsubstituted 5-30 membered heteroarylene group;
Ar ₁ represents a substituted or unsubstituted (C6-C30) aryl group, or a substituted or unsubstituted 5-30 membered heteroaryl group;
Each of A _{1 to} A ₅ independently represents CR or N, provided that at least one of Ar _{1 to} Ar ₅ represents N;
R is hydrogen, a substituted or unsubstituted (C1-C30) alkyl group, a substituted or unsubstituted (C6-C30) aryl group, a substituted or unsubstituted 5- to 30-membered heteroaryl group, or a substituted or unsubstituted (C3-C30) Represents a cycloalkyl group;

R _{1 to} R ₄ are each independently hydrogen, deuterium, halogen, cyano group, substituted or unsubstituted (C1 to C30) alkyl group, substituted or unsubstituted (C6 to C30) aryl group, substituted or unsubstituted 5 -30 membered heteroaryl group, substituted or unsubstituted (C3-C30) cycloalkyl group, substituted or unsubstituted (C1-C30) alkoxy group, substituted or unsubstituted (C1-C30) alkylsilyl group, substituted or unsubstituted ( C6-C30) arylsilyl group, substituted or unsubstituted (C6-C30) aryl (C1-C30) alkylsilyl group, substituted or unsubstituted (C1-C30) alkylamino group, substituted or unsubstituted (C6-C30) aryl Amino group, or substituted or unsubstituted (C1-C30) alkyl (C6-C30) arylamino Or a monocyclic bond in which the carbon atom (s) may be substituted with at least one heteroatom selected from the group consisting of nitrogen, oxygen and sulfur in combination with adjacent substituent (s) Or form a polycyclic, 3-30 membered, alicyclic or aromatic ring;

a and c each independently represent an integer of 1 to 4; when each of a or c is 2 or more, each of R ₁ and each of R ₃ may be the same or different;
b and d each independently represent an integer of 1 to 3; when each of b or d is 2 or more, each of R ₂ and each of R ₄ may be the same or different; and a heteroarylene group and hetero Each aryl group independently contains at least one heteroatom selected from B, N, O, S, P (═O), Si and P)
It has been found that two carbazoles represented by can be achieved by compounds bonded via an aryl or hetero group and a nitrogen-containing aromatic ring bonded to the nitrogen atom of one carbazole.

  The organic electroluminescent compounds according to the invention have a high luminous efficiency, a power efficiency and a long operating life. In addition, organic electroluminescent devices using the compounds according to the invention provide excellent current efficiency, have a lower operating voltage, resulting in higher power efficiency and improved power consumption.

  Hereinafter, the present invention will be described in detail. However, the following description is intended to illustrate the invention and is in no way meant to limit the scope of the invention.

  The present invention relates to an organic electroluminescent compound of formula 1, an organic electroluminescent material comprising the compound, and an organic electroluminescent device comprising the material.

  The compound represented by Formula 1 above will be described in detail.

In the above formula 1, L ₁ represents a substituted or unsubstituted (C6-C30) arylene group, or a substituted or unsubstituted 5- to 30-membered heteroarylene group, preferably a substituted or unsubstituted (C6-C30) arylene group. , More preferably a (C6-C20) arylene group which is unsubstituted or substituted with (C1-C6) alkyl.

L ₂ represents a single bond, a substituted or unsubstituted (C6-C30) arylene group, or a substituted or unsubstituted 5- to 30-membered heteroarylene group, preferably a single bond, or a substituted or unsubstituted (C6-C30) arylene group And more preferably a single bond or an unsubstituted (C6-C20) arylene group.

Ar ₁ represents a substituted or unsubstituted (C6-C30) aryl group, or a substituted or unsubstituted 5-30 membered heteroaryl group, preferably a substituted or unsubstituted (C6-C30) aryl group, more preferably It represents an unsubstituted or deuterium, halogen, (C1-C6) alkyl, or (C6-C20) aryl group substituted with cyano; or an unsubstituted 5-20 membered heteroaryl group.

A _{1 to} A ₅ each independently represent CR or N under the condition that at least one of Ar _{1 to} Ar ₅ represents N.

  R is hydrogen, a substituted or unsubstituted (C1-C30) alkyl group, a substituted or unsubstituted (C6-C30) aryl group, a substituted or unsubstituted 5- to 30-membered heteroaryl group, or a substituted or unsubstituted (C3-C30) Represents a cycloalkyl group, preferably hydrogen, a substituted or unsubstituted (C6-C30) aryl group, or a substituted or unsubstituted 5-30 membered heteroaryl group, more preferably hydrogen; unsubstituted or deuterium; (C1-C6) alkyl, (C3-C20) cycloalkyl, (C6-C20) aryl, 5-20 membered heteroaryl, or (C6-C20) aryl group substituted with tri (C1-C6) alkylsilyl; Or an unsubstituted 5-20 membered heteroaryl group is represented.

R _{1 to} R ₄ are each independently hydrogen, deuterium, halogen, cyano group, substituted or unsubstituted (C1 to C30) alkyl group, substituted or unsubstituted (C6 to C30) aryl group, substituted or unsubstituted 5 -30 membered heteroaryl group, substituted or unsubstituted (C3-C30) cycloalkyl group, substituted or unsubstituted (C1-C30) alkoxy group, substituted or unsubstituted (C1-C30) alkylsilyl group, substituted or unsubstituted ( C6-C30) arylsilyl group, substituted or unsubstituted (C6-C30) aryl (C1-C30) alkylsilyl group, substituted or unsubstituted (C1-C30) alkylamino group, substituted or unsubstituted (C6-C30) aryl Amino group, or substituted or unsubstituted (C1-C30) alkyl (C6-C30) arylamino Or a monocyclic which may be substituted with at least one heteroatom selected from the group consisting of nitrogen, oxygen and sulfur in combination with adjacent substituent (s) Or a polycyclic, 3-30 membered, alicyclic or aromatic ring, preferably each independently hydrogen, substituted or unsubstituted (C1 to C30) alkyl group, substituted or unsubstituted (C6 to C30). ) Represents an aryl group, or a substituted or unsubstituted di (C6-C30) arylamino group; or combined with adjacent substituent (s) to form a monocyclic or polycyclic, 3-30 membered, alicyclic Form an aromatic ring, more preferably each independently hydrogen, unsubstituted (C1-C6) alkyl group, unsubstituted (C6-C20) aryl group, or unsubstituted di (C6-C20) aryl. An amino group; or bonded with an adjacent substituent (s), monocyclic, 3-20 membered, form an aromatic ring.

a and c each independently represent an integer of 1 to 4, preferably 1 or 2; when each of a or c is 2 or more, each of R ₁ and each of R ₃ may be the same or different .

b and d each independently represent an integer of 1 to 3, preferably an integer of 1 to 2; when each of b or d is 2 or more, each of R ₂ and each of R ₄ are the same or different obtain.

  The heteroarylene group and the heteroaryl group each independently contain at least one heteroatom selected from B, N, O, S, P (═O), Si and P.

According to an embodiment of the present invention, in Formula 1, L ₁ represents a substituted or unsubstituted (C6-C30) arylene group; L ₂ represents a single bond or a substituted or unsubstituted (C6-C30) arylene group. Ar ₁ represents a substituted or unsubstituted (C6-C30) aryl group; A _{1 to} A ₅ each independently represents CR or N, provided that at least one of Ar _{1 to} Ar ₅ represents N. R represents hydrogen, a substituted or unsubstituted (C6-C30) aryl group, or a substituted or unsubstituted 5- to 30-membered heteroaryl group; R _{1 to} R ₄ each independently represent hydrogen, substituted or unsubstituted (C1-C30) represents an alkyl group, a substituted or unsubstituted (C6-C30) aryl group, or a substituted or unsubstituted di (C6-C30) arylamino group; Combined with a substituent (s) to form a monocyclic or polycyclic, 3 to 30 membered, alicyclic or aromatic ring; a and c are each independently an integer of 1 to 2 And b and d each independently represents an integer of 1 to 2.

According to another embodiment of the present invention, in the above formula 1, _{L 1} represents a unsubstituted or is (C1 -C6) substituted with an alkyl (C6 to C20) arylene group; _{L 2} represents a single bond, or Represents an unsubstituted (C6-C20) arylene group; Ar ₁ is an unsubstituted or substituted (C6-C20) aryl group with deuterium, halogen, (C1-C6) alkyl, or cyano; or unsubstituted 5 Represents a 20-membered heteroaryl group; A ₁ -A ₅ each independently represent CR or N, provided that at least one of Ar ₁ -Ar ₅ represents N; R is hydrogen; unsubstituted (C6-C6) alkyl, (C3-C20) cycloalkyl, (C6-C20) aryl, 5-20 membered heteroaryl, or substituted with tri (C1-C6) alkylsilyl (C6 It represents or unsubstituted 5-20 membered heteroaryl _group;; C20) aryl groups R 1 to R ₄ are each independently hydrogen, unsubstituted (C1 -C6) alkyl group, unsubstituted (C6 to C20) aryl group Or an unsubstituted di (C6-C20) arylamino group; or combined with adjacent substituent (s) to form a monocyclic, 3-20 membered, aromatic ring; Each independently represents an integer of 1-2; b and d each independently represent an integer of 1-2.

  Formula 1 may be represented by the following formulas (1-1) to (1-4).

In the formula, L ₁ , L ₂ , Ar ₁ , A _{1 to} A ₅ , R _{1 to} R ₄ , a, b, c, and d are as defined in Formula 1.

Construction,

  May represent pyridine, pyrimidine, triazine, pyrazine or pyridazine.

  In the present specification, “(C1-C30) alkyl” means a linear or branched alkyl having 1 to 30 carbon atoms, wherein the number of carbon atoms is preferably 1 to 30. 10 and includes methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, etc .; “(C3-C30) cycloalkyl” is a monocyclic ring having 3 to 30 carbon atoms. Or a polycyclic hydrocarbon, wherein the number of carbon atoms is preferably 3-20, more preferably 3-7, including cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, etc .; (C6-C30) aryl (ene) "is a monocyclic or fused ring derived from an aromatic hydrocarbon having 6-30 carbon atoms, wherein the carbon atom Is preferably 6-15, and includes phenyl, biphenyl, terphenyl, naphthyl, fluorenyl, phenanthrenyl, anthracenyl, indenyl, triphenylenyl, pyrenyl, tetracenyl, perylenyl, chrycenyl, naphthacenyl, fluoranthenyl and the like; “30-membered heteroaryl (ene)” means at least one, preferably 1-4 heteroatoms selected from the group consisting of B, N, O, S, P (═O), Si and P, and 5- An aryl having 30 ring skeleton atoms; a monocyclic ring or a condensed ring fused with at least one benzene ring; preferably having 5 to 15 ring skeleton atoms; Well; at least one heteroary or aryl group to a heteroaryl group with a single bond (s) Furyl, thiophenyl, pyrrolyl, imidazolyl, pyrazolyl, thiazolyl, thiadiazolyl, isothiazolyl, isoxazolyl, oxazolyl, oxadiazolyl, triazinyl, tetrazinyl, triazolyl, tetrazolyl, furazanyl, pyridyl, pyrazinyl Monocyclic ring heteroaryls, including, Benzoxazolyl, isoindolyl, indolyl, indazolyl, benzothiadiazolyl, quinolyl, isoquinolyl, cinnolinyl, quinazo Examples include fused ring heteroaryls including linyl, quinoxalinyl, carbazolyl, phenoxazinyl, phenanthridinyl, benzodioxolyl and the like. Further, “halogen” includes F, Cl, Br and I.

  In the present specification, the term “substituted” in the expression “substituted or unsubstituted” means that a hydrogen atom in a functional group is substituted with another atom or group, that is, a substituent.

In the above formula 1, in L ₁ , L ₂ , Ar ₁ , R, and R _{1 to} R ₄ , substituted alkyl, substituted alkoxy, substituted alkylsilyl, substituted arylsilyl group, substituted arylalkylsilyl, substituted alkylamino, substituted aryl The substituents of amino, substituted alkylarylamino, substituted cycloalkyl, substituted aryl (ene) and substituted heteroaryl (ene) are each independently deuterium, halogen, cyano, carboxyl, nitro, hydroxyl, (C1-C30 ) Alkyl, halo (C1-C30) alkyl, (C2-C30) alkenyl, (C2-C30) alkynyl, (C1-C30) alkoxy, (C1-C30) alkylthio, (C3-C30) cycloalkyl, (C3- C30) cycloalkenyl, 3-7 membered heterocycloalkyl, C6-C30) aryloxy, (C6-C30) arylthio, unsubstituted or (C6-C30) aryl-substituted 5-30 membered heteroaryl, unsubstituted or substituted with 5-30 membered heteroaryl (C6-C30) aryl, tri (C1-C30) alkylsilyl, tri (C6-C30) arylsilyl, di (C1-C30) alkyl (C6-C30) arylsilyl, (C1-C30) alkyldi (C6- C30) arylsilyl, amino, mono or di (C1-C30) alkylamino, mono or di (C6-C30) arylamino, (C1-C30) alkyl (C6-C30) arylamino, (C1-C30) alkylcarbonyl , (C1-C30) alkoxycarbonyl, (C6-C30) arylcarbonyl Di (C6-C30) aryl boronyl, di (C1-C30) alkyl boronyl, (C1-C30) alkyl (C6-C30) aryl boronyl, (C6-C30) aryl (C1-C30) alkyl, and ( C1-C30) at least one selected from the group consisting of alkyl (C6-C30) aryl, preferably each independently, deuterium, halogen, cyano, (C1-C30) alkyl, (C3-C30) It is at least one selected from the group consisting of cycloalkyl, 5-30 membered heteroaryl, (C6-C30) aryl, and tri (C1-C30) alkylsilyl.

  Representative compounds of the present invention include the following compounds:

  The compounds of the invention can be prepared by synthetic methods known to those skilled in the art. For example, they can be prepared according to Reaction Scheme 1 below.

  [Reaction Scheme 1]

In the formula, L ₁ , L ₂ , Ar ₁ , A _{1 to} A ₅ , R _{1 to} R ₄ , and a to d are as defined in Formula 1 above, and Hal represents halogen.

  Another embodiment of the present invention provides an organic electroluminescent material comprising an organic electroluminescent compound of Formula 1 and an organic electroluminescent device comprising the material.

  The organic electroluminescent device includes a first electrode; a second electrode; and at least one organic layer between the first and second electrodes. Said organic layer comprises at least one compound of formula 1 according to the invention.

  One of the first and second electrodes is an anode and the other is a cathode. The organic layer includes a light emitting layer and at least one layer selected from the group consisting of a hole injection layer, a hole transport layer, an electron transport layer, an electron injection layer, an intermediate layer, and a hole block layer.

  The compound represented by Formula 1 may be included in the light emitting layer. When used in the light emitting layer, the compound represented by Formula 1 can be included as a host material. Preferably, the emissive layer can further comprise at least one dopant and, if necessary, a compound other than the compound represented by Formula 1 can additionally be included as the second host material.

  The second host material can comprise any known phosphorescent dopant. In particular, a phosphorescent dopant selected from the group consisting of compounds of the following formulas 2 to 6 is preferable from the viewpoint of luminous efficiency.

  In which Cz represents the following structure;

X represents O or S;
R _{21 to} R ₂₄ are each independently hydrogen, deuterium, halogen, substituted or unsubstituted (C 1 -C 30) alkyl, substituted or unsubstituted (C 6 -C 30) aryl, substituted or unsubstituted 5 to 30 membered heteroaryl Or R ₂₅ R ₂₆ R ₂₇ Si—; R _{25 to} R ₂₇ each independently represents a substituted or unsubstituted (C1-C30) alkyl, or a substituted or unsubstituted (C6-C30) aryl; L ₄ represents a single bond, substituted or unsubstituted (C6-C30) arylene, or substituted or unsubstituted 5-30 membered heteroarylene; M is substituted or unsubstituted (C6-C30) aryl, or substituted or unsubstituted 5 represents a 30-membered heteroaryl; _{Y 1} and _{Y 2} each independently have as _{Y 1} and _{Y 2} is absent at the same time In condition, -O -, - S -, - N (R 31) - or _{-C (R 32) (R 33} ) - are _expressed; R 31 _{to R 33} each independently represent a substituted or unsubstituted (C1 -C30) alkyl, substituted or unsubstituted (C6 to C30) aryl or a substituted or unsubstituted 5 to 30 membered _{heteroaryl,, R 32} and _{R 33} may be the same or different; h and i are each, independently, Represents an integer of 1 to 3; j, k, l, and m each independently represent an integer of 0 to 4; and h, i, j, k, l, or m is an integer of 2 or more , (Cz-L ₄ ), (Cz), R ₂₁ , R ₂₂ , R ₂₃ , or R ₂₄ , respectively, may be the same or different.

  In particular, preferred examples of the second host material are as follows.

  The dopant contained in the organic electroluminescent device according to the present invention may be selected from the group consisting of compounds of the following formulas 7-9.

  Where L is selected from the following structure:

R ₁₀₀ represents hydrogen, substituted or unsubstituted (C1-C30) alkyl, or substituted or unsubstituted (C3-C30) cycloalkyl;

R ₁₀₀ to R ₁₀₉ and _R 111 _{to R 123} are each independently hydrogen; deuterium, halogen, have been (C1-C30) alkyl unsubstituted or substituted with halogen (s); a substituted or unsubstituted ( C3 to C30) cycloalkyl, cyano, or substituted or unsubstituted (C1-C30) _alkoxy; adjacent substituents R 120 _{to R 123} may form fused rings, such as quinoline bonded to each other;

R _{124 to} R ₁₂₇ each independently represent hydrogen, deuterium, halogen, substituted or unsubstituted (C 1 -C 30) alkyl, or substituted or unsubstituted (C 6 -C 30) aryl; R ₁₂₄ -R ₁₂₇ is aryl If a group, adjacent substituents can be joined together to form a fused ring, such as fluorene;

R _{201 to} R ₂₁₁ are each independently hydrogen, deuterium, halogen, (C1-C30) alkyl which is unsubstituted or substituted with halogen (s), or substituted or unsubstituted (C3-C30) cyclo. Represents alkyl;

f and g each independently represent an integer from 1 to 3; when f or g is an integer greater than or equal to 2, each of R ₁₀₀ may be the same or different; and

  n is an integer of 1 to 3.

  In particular, dopant materials include:

  In another embodiment of the present invention, a material for use in an organic electroluminescent device is provided. The material comprises a compound according to the invention as a host material. When the compound according to the invention is included as a host material, the material may additionally contain a second host material, wherein the ratio of the first host material to the second host material is from 1:99 to 99: May be in the range of 1.

  In addition, the organic electroluminescent device according to the present invention comprises a first electrode; a second electrode; and at least one organic layer between the first and second electrodes. Said organic layer comprises the material used for the organic electroluminescent device according to the invention.

  The organic electroluminescent device according to the present invention may further include at least one compound selected from the group consisting of an arylamine-based compound and a styrylarylamine-based compound in addition to the compound represented by Formula 1.

  In the organic electroluminescent device according to the present invention, the organic layer comprises a group 1 metal of the periodic table, a group 2 metal, a transition metal of the fourth period, a transition metal of the fifth period, an organic metal of a lanthanide and a d transition element, Alternatively, at least one metal selected from the group consisting of at least one complex compound containing the metal may be further included. The organic layer may further include a light emitting layer and a charge generation layer.

  In addition, the organic electroluminescent device according to the invention comprises, in addition to the compound according to the invention, at least one light-emitting layer comprising a blue electroluminescent compound, a red electroluminescent compound or a green electroluminescent compound known in the art By further including, it is possible to emit white light. Also, if necessary, a yellow or orange light emitting layer can be included in the device.

According to the present invention, at least one layer (hereinafter “surface layer”) is preferably disposed on the inner surface (s) of one or both electrode (s); chalcogenide layer, metal halide layer and metal Selected from oxide layers. In particular, a chalcogenide (including oxide) layer of silicon or aluminum is preferably disposed on the anode surface of the electroluminescent medium layer, and a metal halide layer or metal oxide layer is on the cathode surface of the electroluminescent medium layer. Are preferably arranged. Such a surface layer provides operational stability for the organic electroluminescent device. Preferably, the chalcogenide includes SiO _X (1 ≦ X ≦ 2), AlO _X (1 ≦ X ≦ 1.5), SiON, SiAlON, etc .; the metal halide includes LiF, MgF ₂ , CaF ₂ , Including rare earth metal fluorides; and the metal oxides include Cs ₂ O, Li ₂ O, MgO, SrO, BaO, CaO, and the like.

  In the organic electroluminescent device according to the present invention, the mixed region of the electron transport compound and the reducing dopant or the mixed region of the hole transport compound and the oxidizing dopant is preferably arranged on at least one surface of the pair of electrodes. Is done. In this case, the electron transport compound is reduced to an anion, thus facilitating the injection and transport of electrons from the mixed region to the electroluminescent medium. Furthermore, the hole transport compound is oxidized to cations, thus further facilitating the injection and transport of holes from the mixed region to the electroluminescent medium. Preferably, the oxidizing dopant includes various Lewis acids and acceptor compounds; the reducing dopant includes alkali metals, alkali metal compounds, alkaline earth metals, rare earth metals, and mixtures thereof. A reducing dopant layer can be used as a charge generation layer to prepare an electroluminescent device having two or more electroluminescent layers and emitting white light.

  In order to form each layer of the organic electroluminescent device according to the present invention, dry film forming methods such as vacuum evaporation, sputtering, plasma, and ion plating methods, or wet film forming methods such as spin coating, dip coating, and flow coating are used. Can be used.

  When using a wet film forming method, a thin film can be formed by dissolving or diffusing the material forming each layer in any suitable solvent such as ethanol, chloroform, tetrahydrofuran, dioxane, and the like. The solvent can be any solvent in which the material forming each layer can be dissolved or diffused and there is no problem in the ability to form the layer.

  Hereinafter, the organic electroluminescent compound, the method for preparing the compound, and the light emission characteristics of the device will be described in detail with reference to the following examples.

Example 1: Preparation of compound H-3

Preparation of Compound 1-1 9-phenyl-9H-carbazol-3-yl-boronic acid (30 g, 104 mmol), 1-bromo-4-iodobenzene (22.7 g, 80 mmol), tetrakis (triphenylphosphine) palladium [ Pd (PPh ₃ ) ₄ ] (2.8 g, 2.4 mmol), Na ₂ CO ₃ (22 g, ₂₀₀ mmol), toluene 400 mL, ethanol (EtOH) 100 mL, and H ₂ O 100 mL were added to the flask and the mixture was then refluxed. Stir for 5 hours. After the reaction was complete, the mixture was extracted with dichloromethane (DCM) and H ₂ O and the DCM layer was dried over MgSO ₄ and filtered. The obtained solid was separated by a column to obtain Compound 1-1 (17.9 g, 45%).

Preparation of Compound 1-2 After dissolving Compound 1-1 (17.9 g, 44.8 mmol) in 200 mL of tetrahydrofuran (THF), the mixture was cooled to −78 ° C. and 2.5 M n-butyllithium (23 mL, 58.3 mmol) was slowly added to the mixture and the mixture was stirred for 1 hour. Then isopropyl borate (15.5 mL, 67.2 mmol) was added to the mixture and the mixture was slowly heated and stirred at room temperature for 17 hours. After the reaction was complete, the mixture was extracted with ethyl acetate (EA) and H ₂ O and the EA layer was dried over MgSO ₄ and concentrated to give compound 1-2 (5.02 g, 31%).

Preparation of Compound 1-3 Compound 1-3 (5 g, 13.7 mmol), 3-bromocarbazole (3.72 g, 15.1 mmol), Pd (PPh ₃ ) ₄ (791 mg, 0.7 mmol), K ₂ CO ₃ (3.8 g, 27.4 mmol), 80 mL of toluene, 30 mL of EtOH, and 30 mL of H ₂ O were added to the flask, and then the mixture was stirred at reflux for 5 hours. After the reaction was complete, the mixture was extracted with DCM and H ₂ O and the DCM layer was dried over MgSO ₄ and filtered. The obtained solid was separated by a column to obtain compound 1-3 (3.4 g, 53%).

Preparation of Compound H-3 Compound 1-3 (3.4 g, 7 mmol), 2-chloro-4,6-diphenyl-1,3,5-triazine (2.2 g, 8.4 mmol), dimethylaminopyridine (DMAP) ) (427 mg, 3.5 mmol), K ₂ CO ₃ (2.4 g, 17.5 mmol), and 80 mL of dimethylformamide (DMF) were added to the flask, and then the mixture was stirred under reflux for 3 hours. After the reaction was complete, methanol (MeOH) was added to the mixture to produce a solid and the solid was filtered. Next, the obtained solid was separated with a column to obtain Compound H-3 (2.7 g, 53%).

  Detailed data of the compound prepared in Example 1 and the compound that can be prepared by the same method as Example 1 is shown in Table 1 below.

Device Example 1: Preparation of an OLED device using an organic electroluminescent compound according to the present invention An OLED device was manufactured using a compound according to the present invention. Transparent electrode indium tin oxide (ITO) thin film (15Ω / sq) on glass substrate for organic light emitting diode (OLED) device (Samsung Corning, Republic of Korea) was used in succession with trichlorethylene, acetone, ethanol and distilled water Subjected to ultrasonic cleaning and then stored in isopropanol. Next, the ITO substrate was attached to the substrate holder of the vacuum evaporation apparatus. ^{N 1, N 1 '- (} [1,1'- biphenyl] -4,4'-diyl) bis ^{(N 1} - ^{(naphthalen-1-yl)} -N ^{4, N} 4 - diphenyl-1,4 Diamine) was introduced into the cell of the vacuum deposition apparatus, and then the pressure in the chamber of the apparatus was controlled to 10 ⁻⁶ torr. Thereafter, an electric current was applied to the cell to evaporate the introduced substance, thereby forming a hole injection layer having a thickness of 60 nm on the ITO substrate. Next, N, N′-di (4-biphenyl) -N, N′-di (4-biphenyl) -4,4′-diaminobiphenyl is introduced into another cell of the vacuum deposition apparatus, and a current is supplied to the cell. Evaporation was applied to form a hole transport layer having a thickness of 20 nm on the hole injection layer. Thereafter, Compound H-3 as a host material was introduced into one cell of the vacuum deposition apparatus, and Compound D-1 as a dopant was introduced into another cell. The two materials were evaporated at different rates and deposited with a doping amount of 15% by weight based on the total amount of host and dopant to form a light emitting layer having a thickness of 30 nm on the hole transport layer. Then, 2- (4- (9,10-di (naphthalen-2-yl) anthracen-2-yl) phenyl) -1-phenyl-1H-benzo [d] imidazole was introduced into one cell, and lithium quino The rate was introduced into another cell. The two materials were evaporated at the same rate and each deposited with a doping amount of 50% by weight to form an electron transport layer having a thickness of 30 nm on the light emitting layer. Next, lithium quinolate was deposited on the electron transport layer as an electron injection layer having a thickness of 2 nm, and then an Al cathode having a thickness of 150 nm was deposited on the electron injection layer by another vacuum evaporation apparatus. . Thus, an OLED device was manufactured. All materials used to manufacture OLED devices were purified by vacuum sublimation at ^10-6 torr before use.

The manufactured OLED device showed a green emission with a luminance of 930 cd / m ² and a current density of 2.28 mA / cm ² at a driving voltage of 2.6 V and an output efficiency of 49.31 m / W.

Device Example 2: Production of an OLED device using an organic electroluminescent compound according to the invention In the same manner as Device Example 1, except that Compound H-3 is used as the host for the luminescent material and Compound D-102 is used as the dopant. An OLED device was manufactured.

The manufactured OLED device showed green emission with a luminance of 2420 cd / m ² and a current density of 5.76 mA / cm ² at a driving voltage of 2.7 V, and an output efficiency of 48.91 m / W.

Device Example 3: Production of an OLED device using an organic electroluminescent compound according to the invention In the same manner as Device Example 1, except that Compound H-56 is used as the host for the luminescent material and Compound D-1 is used as the dopant. An OLED device was manufactured.

The manufactured OLED device showed a green emission with a luminance of 1110 cd / m ² and a current density of 3.34 mA / cm ² at a driving voltage of 2.7 V and an output efficiency of 38.71 m / W.

Device Example 4: Production of an OLED device using an organic electroluminescent compound according to the invention In the same manner as Device Example 1, except that Compound H-11 is used as the host for the luminescent material and Compound D-1 is used as the dopant. An OLED device was manufactured.

The manufactured OLED device showed a green emission with a luminance of 770 cd / m ² and a current density of 2.56 mA / cm ² and a power efficiency of 36.31 m / W at a driving voltage of 2.6V.

Device Example 5: Production of an OLED device using an organic electroluminescent compound according to the invention In the same manner as Device Example 1 except that compound H-63 is used as the host for the luminescent material and compound D-1 is used as the dopant. An OLED device was manufactured.

The manufactured OLED device showed green emission with a luminance of 1970 cd / m ² and a current density of 5.38 mA / cm ² at a driving voltage of 3.0 V, and an output efficiency of 38.31 m / W.

Device Example 6: Production of an OLED device using an organic electroluminescent compound according to the invention In the same manner as Device Example 1 except that compound H-85 is used as the host for the luminescent material and compound D-1 is used as the dopant. An OLED device was manufactured.

The manufactured OLED device showed green emission with a luminance of 1240 cd / m ² and a current density of 2.86 mA / cm ² at a driving voltage of 2.6 V and an output efficiency of 52.41 m / W.

Comparative Example 1: Production of OLED device using conventional luminescent material 4-4′-N, N′-dicarbazole-biphenyl as host and compound D-86 as dopant with 30 nm on hole transport layer Except depositing a light emitting layer having a thickness; and depositing aluminum (III) bis (2-methyl-8-quinolinato) 4-phenylphenolate to form a hole blocking layer having a thickness of 10 nm, An OLED device was manufactured in the same manner as in Device Example 1.

The manufactured OLED device showed a green emission with a luminance of 3000 cd / m ² and a current density of 8.57 mA / cm ² at a driving voltage of 5.8 V, and an output efficiency of 18.961 m / W.

Comparative Example 2: Production of OLED Device Using Conventional Luminescent Material Holes Using 4-4′-bis (9-phenyl-9H-carbazol-3-yl) biphenyl as Host and Compound D-86 as Dopant An OLED device was fabricated in the same manner as Device Example 1 except that a light emitting layer having a thickness of 30 nm was deposited on the transport layer.

The manufactured OLED device showed green emission with a luminance of 1320 cd / m ² and a current density of 11.66 mA / cm ² at a driving voltage of 5.9 V, and an output efficiency of 6.031 m / W.

  The organic electroluminescent compound according to the present invention provides higher luminous efficiency compared to conventional materials. In addition, OLED devices that use the organic electroluminescent compounds according to the present invention as light emitting host materials have a lower drive voltage, resulting in higher power efficiency and improved power consumption, resulting in improved current efficiency. provide.

Claims (8)

Formula 1:
(Where
L ₁ represents a substituted or unsubstituted (C6-C30) arylene group, or a substituted or unsubstituted 5-30 membered heteroarylene group;
L ₂ represents a single bond, a substituted or unsubstituted (C6-C30) arylene group, or a substituted or unsubstituted 5-30 membered heteroarylene group;
Ar ₁ represents a substituted or unsubstituted (C6-C30) aryl group, or a substituted or unsubstituted 5-30 membered heteroaryl group;
Each of A _{1 to} A ₅ independently represents CR or N, provided that at least one of Ar _{1 to} Ar ₅ represents N;
R is hydrogen, a substituted or unsubstituted (C1-C30) alkyl group, a substituted or unsubstituted (C6-C30) aryl group, a substituted or unsubstituted 5- to 30-membered heteroaryl group, or a substituted or unsubstituted (C3-C30) Represents a cycloalkyl group;
R _{1 to} R ₄ are each independently hydrogen, deuterium, halogen, cyano group, substituted or unsubstituted (C1 to C30) alkyl group, substituted or unsubstituted (C6 to C30) aryl group, substituted or unsubstituted 5 -30 membered heteroaryl group, substituted or unsubstituted (C3-C30) cycloalkyl group, substituted or unsubstituted (C1-C30) alkoxy group, substituted or unsubstituted (C1-C30) alkylsilyl group, substituted or unsubstituted ( C6-C30) arylsilyl group, substituted or unsubstituted (C6-C30) aryl (C1-C30) alkylsilyl group, substituted or unsubstituted (C1-C30) alkylamino group, substituted or unsubstituted (C6-C30) aryl Amino group, or substituted or unsubstituted (C1-C30) alkyl (C6-C30) arylamino Or a monocyclic bond in which the carbon atom (s) may be substituted with at least one heteroatom selected from the group consisting of nitrogen, oxygen and sulfur in combination with adjacent substituent (s) Or form a polycyclic, 3-30 membered, alicyclic or aromatic ring;
a and c each independently represent an integer of 1 to 4; when each of a or c is 2 or more, each of R ₁ and each of R ₃ may be the same or different;
b and d each independently represent an integer of 1 to 3; when each of b or d is 2 or more, each of R ₂ and each of R ₄ may be the same or different; and the heteroarylene group and Each heteroaryl group independently comprises at least one heteroatom selected from B, N, O, S, P (═O), Si and P)
An organic electroluminescent compound represented by: In L ₁ , L ₂ , Ar ₁ , R, and R _{1 to} R ₄ , the substituted alkyl, the substituted alkoxy, the substituted alkylsilyl, the substituted arylsilyl group, the substituted arylalkylsilyl, the substituted alkylamino, The substituted arylamino, the substituted alkylarylamino, the substituted cycloalkyl, the substituted aryl (ene), and the substituted heteroaryl (ene) are each independently substituted with deuterium, halogen, cyano, carboxyl, nitro. , Hydroxyl, (C1-C30) alkyl, halo (C1-C30) alkyl, (C2-C30) alkenyl, (C2-C30) alkynyl, (C1-C30) alkoxy, (C1-C30) alkylthio, (C3-C30 ) Cycloalkyl, (C3-C30) cycloalkene R, 3-7 membered heterocycloalkyl, (C6-C30) aryloxy, (C6-C30) arylthio, unsubstituted or (C6-C30) aryl-substituted 5-30 membered heteroaryl, unsubstituted (C6-C30) aryl, tri (C1-C30) alkylsilyl, tri (C6-C30) arylsilyl, di (C1-C30) alkyl (C6-C30) aryl substituted with 5-30 membered heteroaryl Silyl, (C1-C30) alkyldi (C6-C30) arylsilyl, amino, mono- or di (C1-C30) alkylamino, mono- or di (C6-C30) arylamino, (C1-C30) alkyl (C6-C30) Arylamino, (C1-C30) alkylcarbonyl, (C1-C30) alkoxycarbonyl (C6-C30) arylcarbonyl, di (C6-C30) arylboronyl, di (C1-C30) alkylboronyl, (C1-C30) alkyl (C6-C30) arylboronyl, (C6-C30) aryl ( The organic electroluminescent compound according to claim 1, which is at least one selected from the group consisting of C1-C30) alkyl and (C1-C30) alkyl (C6-C30) aryl. L ₁ represents a substituted or unsubstituted (C6-C30) arylene group;
L ₂ represents a single bond, or a substituted or unsubstituted (C6-C30) arylene group;
Ar ₁ represents a substituted or unsubstituted (C6-C30) aryl group;
Each of A _{1 to} A ₅ independently represents CR or N, provided that at least one of Ar _{1 to} Ar ₅ represents N;
R represents hydrogen, a substituted or unsubstituted (C6-C30) aryl group, or a substituted or unsubstituted 5-30 membered heteroaryl group;
R _{1 to} R ₄ are each independently hydrogen, substituted or unsubstituted (C1-C30) alkyl group, substituted or unsubstituted (C6-C30) aryl group, or substituted or unsubstituted di (C6-C30) arylamino Represents a group; or combines with adjacent substituent (s) to form a monocyclic or polycyclic, 3-30 membered, alicyclic or aromatic ring;
a and c each independently represents an integer of 1 to 2;
The organic electroluminescent compound of Claim 1 in which b and d represent the integer of 1-2 each independently. L ₁ represents a unsubstituted or is (C1 -C6) substituted with an alkyl (C6 to C20) arylene group; _{L 2} represents a single bond, or unsubstituted (C6 to C20) arylene group;
Ar ₁ represents an unsubstituted or deuterium, halogen, (C1-C6) alkyl, or (C6-C20) aryl group substituted with cyano; or an unsubstituted 5-20 membered heteroaryl group;
Each of A _{1 to} A ₅ independently represents CR or N, provided that at least one of A _{1 to} A ₅ represents N;
R is hydrogen; unsubstituted or deuterium, (C1-C6) alkyl, (C3-C20) cycloalkyl, (C6-C20) aryl, 5- to 20-membered heteroaryl, or tri (C1-C6) alkylsilyl A (C6-C20) aryl group substituted with or represents an unsubstituted 5-20 membered heteroaryl group;
R _{1 to} R ₄ each independently represent hydrogen, an unsubstituted (C ₁ -C 6) alkyl group, an unsubstituted (C 6 -C 20) aryl group, or an unsubstituted di (C 6 -C 20) arylamino group; or adjacent In combination with the substituent (s) to form a monocyclic, 3-20 membered, aromatic ring;
a and c each independently represents an integer of 1 to 2;
The organic electroluminescent compound of Claim 1 in which b and d represent the integer of 1-2 each independently. Formula 1 represents the following formulas (1-1) to (1-4):
Wherein L ₁ , L ₂ , Ar ₁ , A ₁ -A ₅ , R ₁ -R ₄ , a, b, c, and d are as defined in claim 1.
The organic electroluminescent compound of claim 1 represented by: The structure,
The organic electroluminescent compound according to claim 1, wherein represents pyridine, pyrimidine, triazine, pyrazine or pyridazine. Said compound represented by Formula 1 is:
The organic electroluminescent compound according to claim 1, wherein the organic electroluminescent compound is selected from the group consisting of:   An organic electroluminescent device comprising the organic electroluminescent compound according to claim 1.