KR20150089263A - Bipolar organic material and oled having the same - Google Patents

Abstract

The present invention provides a bipolar organic material and an organic light emitting diode comprising the same. The bipolar organic material can be represented as the chemical formula 1. According to an embodiment of the present invention, the bipolar organic material represented as the chemical formula 1 with excellent electronic movability and movability of a positive hole, is capable of improving efficiency of an organic light emitting diode and reducing the operation voltage, in the case of using in an organic light emitting diode.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a bipolar organic material and an organic light-

The present invention relates to a compound for an organic light emitting diode, and more particularly to a bipolar organic material which is a compound for an organic light emitting diode.

An organic light emitting diode (OLED) is a self-luminous type device having a wide viewing angle, excellent contrast, fast response time, excellent luminance, driving voltage and response speed characteristics, and multi-coloring.

A typical organic light emitting diode may include an anode and a cathode and an organic layer interposed between the anode and the cathode. The organic layer may include an electron injecting layer, a hole transporting layer, a light emitting layer, an electron transporting layer, and an electron injecting layer. When a voltage is applied between the anode and the cathode, holes injected from the anode move to the light emitting layer via the hole transporting layer, and electrons injected from the cathode move to the light emitting layer via the electron transporting layer. Carriers such as holes and electrons recombine in the light emitting layer region to generate an exiton, which is converted to a base state and light is generated.

The quantum efficiency of such an organic light emitting diode can be improved when electrons and holes injected into the light emitting layer are balanced. Generally, it is known that the electron mobility of the organic layer is not better than the hole mobility. Therefore, there is an attempt to develop an electron injecting layer, an electron transporting layer and the like with improved electron mobility as disclosed in Korean Patent Laid-Open Publication No. 2013-0007510.

However, there is a continuing need for materials that have better electron mobility and are suitable for each device. As such, a material having excellent electron mobility as well as hole mobility is referred to as a bipolar organic material.

The present invention provides a bipolar organic material having improved electron mobility as well as hole mobility and an organic light emitting diode containing the bipolar organic material.

In order to achieve the above object, one aspect of the present invention provides a bipolar organic material. The bipolar organic material may be represented by the following formula (1).

[Chemical Formula 1]

Wherein R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ and R ₈ each independently represent hydrogen, deuterium, an amine group, a substituted or unsubstituted C1 to C30 alkyl group , A substituted or unsubstituted carbazolyl group, a substituted or unsubstituted C2 to C30 arylalkyl group, a substituted or unsubstituted C1 to C30 alkoxy group, a substituted or unsubstituted C2 to C30 aryloxy group, A substituted or unsubstituted C2 to C30 arylamine group, a substituted or unsubstituted C2 to C30 arylsilyl group, a substituted or unsubstituted C2 to C30 arylthio group, and a substituted or unsubstituted C2 to C30 aryl And a seleno group. X may be oxygen. Y represents a halogen group, a cyano group, a substituted or unsubstituted C1 to C30 alkylcarbonyl group, a substituted or unsubstituted C1 to C30 alkylsulfinyl group, a substituted or unsubstituted C1 to C30 alkylsulfonyl group, A substituted C1 to C30 alkylphosphonyl group, and a substituted or unsubstituted C1 to C30 alkylphosphoryl group. m may be an integer of 1 or 2. l may be an integer of 0 or 1. n may be an integer of 1 or 2.

According to one aspect of the present invention, there is provided an organic light emitting diode. The organic light emitting diode includes an anode, a hole conduction layer, a light emitting layer, an electron conduction layer, and a cathode sequentially stacked. Either the hole transporting layer, the light emitting layer or the electron transporting layer includes the bipolar organic material of Formula 1.

The light emitting layer may include a host material and a dopant material, and the host material may include the bipolar organic material of Formula 1. The dopant material may be a delayed fluorescent light emitting material.

According to the embodiments of the present invention, the bipolar organic material represented by Chemical Formula 1 has excellent electron mobility as well as hole mobility, and when used for an organic light emitting diode, it is expected that the efficiency of the organic light emitting diode and the driving voltage decrease .

1 is a cross-sectional view illustrating an organic light emitting diode according to an exemplary embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described herein but may be embodied in other forms. Like reference numerals designate like elements throughout the specification.

As used herein, the term "substitution" means that at least one hydrogen in the group is substituted with one or more substituents selected from the group consisting of deuterium, a halogen group, a hydroxyl group, an amino group, a cyano group, a C1 to C20 amine group, Means an alkylsilyl group of C3 to C30, a cycloalkyl group of C6 to C30, a C2 to C30 heteroaryl group, a C1 to C20 alkoxy group, or a C1 to C10 trifluoroalkyl group.

A substituted or unsubstituted C 1 to C 30 alkyl group, a substituted or unsubstituted C 3 to C 30 aryl group, a substituted C 6 to C 30 aryl group, a substituted or unsubstituted C 2 to C 30 heteroaryl group, An aryl group, a C1 to C20 alkoxy group, or a C1 to C10 trifluoroalkyl group may be bonded to form a saturated or unsaturated ring.

As used herein, unless otherwise defined, the term "alkyl group" means an aliphatic hydrocarbon group. The alkyl group may be a "saturated alkyl group" which does not contain any double or triple bonds. The alkyl group may be an "unsaturated alkyl group" comprising at least one double bond or triple bond. The alkyl group, whether saturated or unsaturated, can be branched, straight chain or cyclic. The alkyl group may be a C1 to C30 alkyl group. More specifically, the alkyl group may be a C1 to C10 alkyl group or a C1 to C6 alkyl group. For example, the C1 to C4 alkyl group may be selected from the group consisting of methyl, ethyl, propyl, iso-propyl, n-butyl, iso-butyl, sec-butyl and t-butyl.

As used herein, the term "aryl group" means a polycyclic aromatic compound composed of a monocyclic aromatic compound or a fused aromatic ring unless otherwise defined, and includes a heteroaryl group.

The term "heteroaryl group ", as used herein, unless otherwise defined, includes at least one heteroatom selected from the group consisting of N, O, S, Se, and P in at least one ring, Means a polycyclic aromatic compound consisting of a phosphorus, monocyclic aromatic compound or fused aromatic rings.

In the present specification, the "halogen group" is an element belonging to group 17, specifically, fluorine, chlorine, bromine, or an iodine group.

In the present specification, when "Cx to Cy" is described, it is to be interpreted that the number of carbon atoms corresponding to all integers between the number of carbon atoms x and the number of carbon atoms y is also described.

Bipolar organic material

The following Formula 1 represents a bipolar organic material according to an embodiment of the present invention.

In Formula 1,

Each of R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ and R ₈ is independently hydrogen, deuterium, an amine group, a substituted or unsubstituted C 1 to C 30 alkyl group, A substituted or unsubstituted C2 to C30 arylalkyl group, a substituted or unsubstituted C1 to C30 alkoxy group, a substituted or unsubstituted C2 to C30 aryloxy group, a substituted or unsubstituted C1 to C30 alkoxy group, A substituted or unsubstituted C2 to C30 arylamine group, a substituted or unsubstituted C2 to C30 arylsilyl group, a substituted or unsubstituted C2 to C30 arylthio group, and a substituted or unsubstituted C2 to C30 arylseleno group And substituents adjacent to each other among R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ and R ₈ may optionally be bonded to form a saturated Or an unsaturated ring. m may be an integer of 1 or 2.

X may be oxygen, and l may be an integer of 0 or 1.

Y is an electron-withdrawing substituent and is selected from the group consisting of a halogen group, a cyano group, a substituted or unsubstituted C1 to C30 alkylcarbonyl group, a substituted or unsubstituted C1 to C30 alkylsulfinyl group, a substituted or unsubstituted C1 to C30 alkyl A substituted or unsubstituted C1 to C30 alkylphosphonyl group, a substituted or unsubstituted C1 to C30 alkylphosphoryl group, and n may be an integer of 1 or 2.

Such a bipolar organic material may be a compound for an organic light emitting diode. Specifically, the bipolar organic material may be used as one of a hole injecting material, a hole transporting material, a light emitting host material, a light emitting dopant material, an electron injecting material, and an electron transporting material in an organic light emitting diode. More specifically, such a bipolar organic material may be a light emitting host material.

The bipolar organic material may include a carbazole group as an electron donating substituent and an electron donating substituent group as a substituent in biphenyl (when l = 0 in the formula 1) or dibenzofuran (when l = 1 in the formula 1) (Y in the formula (1)) are bonded to each other, and the electron mobility and hole mobility can be excellent. Accordingly, when such a bipolar organic material is applied to an organic light emitting diode, especially when it is used as a light emitting host material, the efficiency of the organic light emitting diode and the driving voltage can be reduced.

The bipolar organic material may have an energy gap (ΔEst) between the T ₁ and S ₁ levels of 0.3 eV or less, specifically 0 to 0.3 eV, further preferably 0.21 eV or less. Therefore, when the bipolar organic material is used as a light emitting host material and a phosphorescent material or a delayed fluorescent material is used as a dopant material, efficient energy transfer from the bipolar organic material to the dopant material, that is, S ₁ The energy transfer efficiency can be further improved because the energy transfer can be efficiently performed at the S ₁ and T ₁ levels of the phosphorescent material or the retarded fluorescent material at the T ₁ level, respectively.

A unit having a high electron density such as a phenyl unit substituted with a carbazole (for example, two carbazoles as shown in the following formula (2)) and a unit having a small electron density such as a phenyl unit substituted with an electron withdrawing unit The electron donor-electron acceptor structure is formed in the molecular structure, and the charge transfer complex form is formed in the molecular structure, so that the singlet energy and the band gap are reduced, resulting in a narrow △ Est.

Formula (2) represents a bipolar organic material according to one embodiment of the present invention.

In Formula _{2, R a1, R a2,} R a3, R a4, R a5, R a6, R a7, R a8, R b1, R b2, R b3, R b4, R b5, R b6, R b7, And R _b8 may each independently be any of the substituents described in relation to R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , and R _{8 in} Formula 1. R _b1 , R _b2 , R _b3 , R _b4 , R _b5 and R _b6 adjacent to each other among R _a1 , R _a2 , R _a3 , R _a4 , R _a5 , R _a6 , R _a7 and R _a8 , , R < _b7 >, and R < _b8 > may optionally bind to each other to form a saturated or unsaturated ring fused to the body. X, l, Y, and n may be the same as defined in formula (1).

Formula (3) represents a bipolar organic material according to one embodiment of the present invention.

In Formula _{3, R a1, R a2,} R a3, R a4, R a5, R a6, R a7, R a8, R b1, R b2, R b3, R b4, R b5, R b6, R b7, And R _b8 may each independently be any of the substituents described in relation to R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , and R _{8 in} Formula 1. R _b1 , R _b2 , R _b3 , R _b4 , R _b5 and R _b6 adjacent to each other among R _a1 , R _a2 , R _a3 , R _a4 , R _a5 , R _a6 , R _a7 and R _a8 , , R < _b7 >, and R < _b8 > may optionally bind to each other to form a saturated or unsaturated ring fused to the body. X and l may be the same as defined in formula (1). Y ₁ and Y ₂ may each independently be any one of the substituents described in relation to Y in the above formula (1).

Formula (4) represents a bipolar organic material according to one embodiment of the present invention.

In Formula _{4, R a1, R a2,} R a3, R a4, R a5, R a6, R a7, R a8, R b1, R b2, R b3, R b4, R b5, R b6, R b7, And R _b8 may each independently be any of the substituents described in relation to R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , and R _{8 in} Formula 1. R _b1 , R _b2 , R _b3 , R _b4 , R _b5 and R _b6 adjacent to each other among R _a1 , R _a2 , R _a3 , R _a4 , R _a5 , R _a6 , R _a7 and R _a8 , , R < _b7 >, and R < _b8 > may optionally bind to each other to form a saturated or unsaturated ring fused to the body. X, l, and Y may be the same as defined in formula (1).

Formula (5) represents a bipolar organic material according to one embodiment of the present invention.

Formula (6) represents a bipolar organic material according to one embodiment of the present invention.

Formula (7) represents a bipolar organic material according to one embodiment of the present invention.

Organic light emitting diode

1 is a cross-sectional view illustrating an organic light emitting diode according to an exemplary embodiment of the present invention.

1, an organic light emitting diode includes an anode 10 and a cathode 70, a light emitting layer 40 disposed between the two electrodes, a hole conduction layer 20 disposed between the anode 10 and the light emitting layer 40, And an electron conduction layer 50 disposed between the light emitting layer 40 and the cathode 70. The hole transport layer 20 may include a hole transport layer 25 for transporting holes and a hole injection layer 23 for facilitating injection of holes. In addition, the electron conduction layer 50 may include an electron transport layer 55 for transporting electrons and an electron injection layer 53 for facilitating injection of electrons. In addition, a hole blocking layer (not shown) may be disposed between the light emitting layer 40 and the electron transporting layer 55. Further, an electron blocking layer (not shown) may be disposed between the light emitting layer 40 and the hole transporting layer 25. However, the present invention is not limited thereto, and the electron transport layer 55 may serve as a hole blocking layer, or the hole transport layer 25 may serve as an electron blocking layer.

When a forward bias is applied to the organic light emitting diode, holes are injected from the anode 10 into the light emitting layer 40, and electrons from the cathode 70 are injected into the light emitting layer 40. Electrons and holes injected into the light emitting layer 40 are combined with each other to form excitons, and light is emitted while the excitons transition to the ground state.

The light emitting layer 40 may be made of a single light emitting material, and may include a light emitting host material and a light emitting dopant material. When the light emitting layer 40 includes a light emitting host material and a light emitting dopant material, the electrons and holes injected into the light emitting layer 40 are combined at the light emitting host material to form an exciton, and then the exciton is transferred to the light emitting dopant material, Lt; / RTI > In this case, the efficiency of the organic light emitting diode can be improved when the electron transporting ability and the electron transporting ability are improved, for example, as the charge transporting ability of the luminescent host material. The light emitting layer 40 including the light emitting host material and the light emitting dopant material may be a phosphorescent light emitting layer or a fluorescent light emitting layer, for example, a delayed fluorescent light emitting layer.

On the other hand, the hole injection layer 23 and / or the hole transport layer 25 are layers having a HOMO level between the work function level of the anode 10 and the HOMO level of the light emitting layer 40, ) To enhance the injection or transport efficiency of holes. The electron injection layer 53 and / or the electron transport layer 55 are layers having a LUMO level between the work function level of the cathode 70 and the LUMO level of the light emitting layer 40, ) In order to increase the injection or transport efficiency of electrons. At this time, the hole transporting ability of the hole injecting layer 23 and / or the hole transporting layer 25 is improved and the electron transporting ability of the electron injecting layer 53 and / or the electron transporting layer 55 is improved, Improvement and drive voltage reduction.

A hole injecting material for forming the hole injecting layer 23, a hole transporting material for forming the hole transporting layer 25, a light emitting host material, a light emitting dopant material, and an electron injecting layer 53 are formed in the organic light emitting diode according to this embodiment And the electron transporting material forming the electron transporting layer 55 may be a bipolar derivative represented by any one of the above-described Formulas 1 to 7.

Specifically, the bipolar organic material represented by any one of formulas 1 to 7 may be a light emitting host material. The bipolar organic material may include a carbazole group as an electron donating substituent and an electron donating substituent group as a substituent in biphenyl (when l = 0 in the formula 1) or dibenzofuran (when l = 1 in the formula 1) (Y) are combined with each other to have excellent electron mobility as well as excellent hole mobility and excellent injection of electrons and electrons, so that the charge balance in the layer can be well matched. Therefore, when such a bipolar derivative is used as a light emitting host material, it is expected that the efficiency of the organic light emitting diode and the driving voltage are reduced.

In addition, the bipolar organic material represented by any one of the formulas 1 to 7 may also have high triplet energy. In one example, the energy gap between the T ₁ and S ₁ levels of the bipolar organic material may be 0.3 eV or less, specifically 0 to 0.3 eV, and more preferably 0.2 eV or less. Therefore, when the bipolar organic material is used as the light emitting host material, efficient energy transfer to the light emitting dopant material is enabled, and the light emitting efficiency can be improved.

In one embodiment, the bipolar organic material represented by any one of Chemical Formulas 1 to 7 is used as a light emitting host material, and a phosphorescent material or a retardation fluorescent material to be described later can be used as a light emitting dopant material. In this case, in addition to the driving voltage reduction described above, Δ Est of 0.3 eV or less of the bipolar organic material is determined by the S ₁ and T ₁ levels of the phosphorescent material or the delayed fluorescence material at the S ₁ and T ₁ levels of the bipolar organic material, _The energy transfer efficiency can be increased by _one level, and the luminous efficiency can be improved.

When at least one of the hole injecting material, the hole transporting material, the electron injecting material, the electron transporting material, the light emitting host material, and the luminescent dopant material is a bipolar organic material represented by any one of Chemical Formulas 1 to 7, As shown in FIG.

The anode 10 may be a conductive metal oxide, a metal, a metal alloy, or a carbon material. The conductive metal oxide is indium tin oxide (indium tin oxide: ITO), fluorine tin oxide (fluorine tin oxide: FTO), antimony tin oxide (antimony tin oxide, ATO), fluorine-doped tin oxide (FTO), SnO _2, ZnO , Or a combination thereof. The metal or metal alloy suitable as the anode 10 may be Au and CuI. The carbon material may be graphite, graphene, or carbon nanotubes.

The hole injecting layer 23 or the hole transporting layer 25 may include a material commonly used as a hole transporting material and one layer may have a different hole transporting material layer. The hole-transporting material may be, for example, mCP (N, N-dicarbazolyl-3,5-benzene); PEDOT: PSS (poly (3,4-ethylenedioxythiophene): polystyrenesulfonate); NPD (N, N'-di (1-naphthyl) -N, N'-diphenylbenzidine); N, N'-diphenyl-N, N'-di (3-methylphenyl) -4,4'-diaminobiphenyl (TPD); N, N'-diphenyl-N, N'-dinaphthyl-4,4'-diaminobiphenyl; N, N, N'N'-tetra-p-tolyl-4,4'-diaminobiphenyl; N, N, N'N'-tetraphenyl-4,4'-diaminobiphenyl; Porphyrin compound derivatives such as copper (II) 1,10,15,20-tetraphenyl-21H, 23H-porphyrin and the like; TAPC (1,1-Bis [4- [N, N'-Di (p-tolyl) Amino] Phenyl] cyclohexane; Triarylamine derivatives such as N, N, N-tri (p-tolyl) amine and 4,4 ', 4'-tris [N- (3-methylphenyl) -N-phenylamino] triphenylamine; Carbazole derivatives such as N-phenylcarbazole and polyvinylcarbazole; Phthalocyanine derivatives such as nonmetal phthalocyanine and copper phthalocyanine; Starburst amine derivatives; Enamnstilbene derivatives; Derivatives of aromatic tertiary amines and styryl amine compounds; And polysilane. Such a hole transporting material may also serve as an electron blocking layer.

When the light emitting layer 40 is made of a single light emitting material, the light emitting layer 40 may be formed of Alq3 (8-trishydroxyquinoline aluminum), DSA (distyrylarylene), DSA derivative, DSB (distyrylbenzene), DSB derivative, DPVBi (4,4'- diphenyl vinyl) -1,1'-biphenyl, a DPVBi derivative, spiro-DPVBi or spiro-6P (spirosexyphenyl).

The dopant material or light emitting material in the light emitting layer 40 may be a fluorescent light emitting material, a phosphorescent light emitting material, or a retarded fluorescent light emitting material.

As a fluorescent light emitting material, for example, a red fluorescent light emitting material such as rubrene (5,6,11,12-tetraphenylnaphthacene); C545T (10- (2-benzothiazolyl) -1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H, 5H, 11H- [1] benzopyrano [ , 8-ij] quinolizine-11-one); Or ter-fluorene, 4,4'-bis [4- (di-p-tolylamino) styryl] biphenyl (DPAVBi), 2,5,8,11-tetra- (TBP), and the like.

The phosphorescent material may be a red phosphorescent material such as PtOEP (see the following chemical formula), Ir (piq) ₃ (see the following chemical formula), Btp2Ir (acac) A green phosphorescent material such as Ir (ppy) ₃ (ppy = phenylpyridine) (see the following chemical formula), Ir (ppy) ₂ (acac) (see the following chemical formula) and Ir (mpyp) ₃ Or a blue phosphorescent material such as F ₂ Irpic (see the following chemical formula), (F ₂ ppy) ₂ Ir (tmd) (see the following chemical formula) and Ir (dfppz) ₃

The retarded fluorescent light emitting material is a material that is thermally coupled between the T ₁ and S ₁ levels to such an extent that a reverse ISC (intersystem crossing) from a triplet state (T ₁ state) to a singlet state (S ₁ state) Is a material with a low energy gap (? Est). As an example, the retardation fluorescent dopant can have an energy gap (E _ST ) between the T ₁ and S ₁ levels of 0 to 0.5 eV. Such delayed fluorescent light emitting material is carbazolyl dicyanobenzene derivatives (CDCB derivatives), and examples thereof include 2,3,5,6-tetrakis (3,6-diphenylcarbazol- 9-yl) -1,4-dicyanobenzene (4CzTPN-Ph), 2,3,5,6-tetrakis (3,6-dimethylcarbazol- (Carbazol-9-yl) -1,4-dicyanobenzene (4CzPN), 3,4,5,6-tetrakis (carbazol- 4,6-tetrakis (carbazol-9-yl) -1,3-dicyanobenzene (4CzIPN), or 2,4,5-bis (carbazol-9-yl) -1,2-dicyanobenzene have.

On the other hand, the host of the light emitting layer 40 may be Alq3, CBP (4,4'-N, N'-dicarbazole-biphenyl), 9,10- (N-phenylbenzimidazole-2-yl) benzene), TBADN (3-tert-butyl-9,10-di (Naphth-2-yl) anthracene), E3 (see the following formula), or BeBq2 (see the following formula).

The hole blocking layer serves to prevent triplet excitons or holes from diffusing toward the cathode 70 when the light emitting layer 40 is a phosphorescent light emitting layer, and may be selected arbitrarily from known hole blocking materials. For example, oxadiazole derivatives, triazole derivatives, phenanthroline derivatives, and the like can be used.

The electron transporting layer 55 may be formed of a material selected from the group consisting of diphenylphosphine oxide-4- (triphenylsilyl) phenyl, tris (8-quinolinolate) aluminum (Alq3), 2,5- diarylsilole derivative (PyPySPyPy), perfluorinated compound PF-6P), COTs (Octasubstituted cyclooctatetraene), TAZ (see the following chemical formula), Bphen (4,7-diphenyl-1,10-phenanthroline) (See the following formula), or Balq (see the following formula).

The electron injection layer 53 may be, for example, LiF, NaCl, CsF, Li2O, BaO, BaF2, or Liq (lithium quinolate).

The cathode 70 is a conductive film having a lower work function than the anode 70 and is made of a metal such as aluminum, magnesium, calcium, sodium, potassium, indium, yttrium, lithium, May be formed using a combination of two or more of them.

The anode 10 and the cathode 70 may be formed using a sputtering method, a vapor deposition method, or an ion beam deposition method. The hole injecting layer 23, the hole transporting layer 25, the light emitting layer 40, the hole blocking layer, the electron transporting layer 55 and the electron injecting layer 53 are formed by a vapor deposition method or a coating method, , Spin coating, dipping, printing, doctor blading, or electrophoresis.

The organic light emitting diode may be disposed on a substrate (not shown), which may be disposed under the anode 10 or above the cathode 70. In other words, the anode 10 may be formed on the substrate before the cathode 70, or the cathode 70 may be formed before the anode 10.

The substrate may be a light-transmissive substrate as a flat plate member, in which case the substrate may be glass; Ceramics material; And may be made of a polymer material such as polycarbonate (PC), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyimide (PI), polypropylene (PP) However, the present invention is not limited to this, and the substrate may be a metal substrate capable of light reflection.

Hereinafter, exemplary embodiments of the present invention will be described in order to facilitate understanding of the present invention. It should be understood, however, that the following examples are intended to aid in the understanding of the present invention and are not intended to limit the scope of the present invention.

[Experimental Examples; Examples]

Synthesis Example 1: Synthesis of Intermediates 1 and 2

[Reaction Scheme 1]

(5.0 g, 15.0 mmol), Cooper (I) iodide (CuI, 0.7 g, 3.6 mmol), potassium carbonate (4.9 g, 35.7 mmol) and 1,10-phenanthroline (0.6 g, 3.6 mmol) were dissolved in DMF. The temperature was raised in a nitrogen stream and the mixture was refluxed for 12 hours. The reaction solution was extracted with MC and then subjected to column chromatography using an MC / Hexane mixed solvent as an eluent to obtain about 2 g of Intermediate 1. Intermediate 1 (4 g, 8.2 mmol) and 4,4,4 ', 4', 5,5,5 ', 5'-octamethyl-2,2'-by (1,3,2-dioxaborane (3.1 g, 12.3 mmol), potassium acetate (2.4 g, 24.0 mmol) and 1,1'-bis (diphenylphosphino) ferrocene (0.2 g, 0.2 mmol) (1,4-dioxane) was dissolved in a nitrogen stream, and the mixture was refluxed and stirred for 24 hours. The reaction was terminated by pouring distilled water and extracted with MC. And then subjected to column chromatography using an MC / Hexane mixed solvent developing solvent to obtain 3 g of Intermediate 2.

Intermediate 2: Mass Spec (FAB) m / z 534 [(M + H) <^+> ]. _{^{1 H NMR (400 MH Z,}} CDCl 3): δ 8.17-8.11 (m, 6H), 7.87 (s, 1H), 7.54-7.40 (m, 9H), 7.34-7.30 (m, 3H), 1.36 (s , 12H).

Synthesis Example 2: Synthesis of Intermediate 3

[Reaction Scheme 2]

To a solution of Intermediate 2 (2 g, 3.7 mmol), 1,3,5-tribromobenzene (5.9 g, 18.7 mmol) and tetrakis (triphenylphosphine) palladium (0) (0.1 g, 0.1 mmol) Dissolved in a nitrogen stream. Potassium carbonate (1 M, 30 ml) was added and the temperature was raised and stirred at reflux for 24 hours. After extraction with MC and distilled water, column chromatography was carried out using MC / Hexane mixed solvent as eluent to obtain 1.3 g of Intermediate 3.

Intermediate 3: Mass Spec (FAB) m / z 642 [(M + H) <^+> ]. _{^{1 H NMR (400 MH Z,}} CDCl 3): δ8.17 (d, 4H), 7.85-7.70 (m, 6H), 7.58-7.28 (m, 12H).

Synthesis Example 3: Synthesis of Intermediate 4

[Reaction Scheme 3]

The compound of Intermediate 4 was obtained in a yield of 55% in a similar manner to the preparation of Intermediate 3 compound, except that 1,4-dibromobenzene was used instead of 1,3,5-tribromobenzene.

Intermediate 4: Mass Spec (FAB) m / z 564 [(M + H) &lt; ⁺ & gt ^; ]. _{^{1 H NMR (400 MH Z,}} CDCl 3): 8.14 (d, 4H), 7.75-7.63 (m, 8H), 7.32-7.22 (m, 11H).

Synthesis Example 4: Compound I (Formula 5)

[Reaction Scheme 4]

Intermediate 3 (4.0 g, 6.2 mmol) and Cooper (I) cyanide (CuCN, 1.4 g, 15.5 mmol) were added to N-methyl-2-pyrrolidone and dissolved in a nitrogen stream. The temperature of the reaction was raised and stirred at reflux for 18 hours. The reaction was terminated by the addition of 10% sodium hydride aqueous solution and extracted with distilled water and MC. The reaction product was subjected to column chromatography using a mixed solvent of MC / Hexane as a developing solvent, and finally purified through sublimation purification to obtain 1.5 g of a pure white solid compound 1 in 45% yield.

Compound 1: Mass Spec (FAB) m / z 534 [(M + H) <^+> ]. _{^{1 H NMR (400 MH Z,}} CDCl 3): δ 8.13-8.12 (m, 4H), 8.11 (s, 2H), 7.93 (t, 1H), 7.86 (d, 2H), 7.82 (t, 1H), 7.56 (s, 2H), 7.54 (s, 2H), 7.41-7.43 (m, 4H), 7.33-7.29 (m, 4H). _{^{13 H NMR (100 MH Z,}} CDCl 3): δ 142.2, 140.9, 140.5, 134.7, 134.6, 126.6, 126.1, 124.2, 124.0, 121.0, 120.9, 116.5, 115.1, 109.6. Elemental analysis: Theory C ₃₈ H ₂₂ N ₄ = C, 85.37; H, 4.15; N, 10.48. Measured = C, 85.30; H, 4.02; N, 10.47. T _g , 151 ° C

Synthesis Example 5: Compound II (Formula 6)

[Reaction Scheme 5]

Compound II of formula (VI) was obtained in a yield of 54% in a similar manner to the preparation of compound (5), except that Intermediate 4 was used instead of Intermediate 3.

Compound II: mass spectrometry (FAB) m / z 509 [(M + H) &lt; ⁺ & gt ^; ]. _{^{1 H NMR (400 MH Z,}} CDCl 3): δ 8.02-7.98 (m, 4H), 7.83 (s, 1H), 7.76-7.49 (m, 12H), 7.32-7.21 (m, 6H). _{^{13 H NMR (100 MH Z,}} CDCl 3): δ 140.1, 139.7, 138.2, 137.6, 135.7, 134.3, 125.6, 124.4, 124.1, 123.0, 121.7, 120.2, 117.5, 116.1, 110.3. Elemental analysis: Theory C ₃₇ H ₂₃ N ₃ = C, 87.21; H, 4.55; N, 8.25. Measured = C, 87.24; H, 4.53; N, 8.23.

Synthesis Example 6: Synthesis of Compound III (Formula 7)

[Reaction Scheme 6]

(2-iodo-1,3-dicyanobenzene) was used instead of 1,3,5-tribromobenzene in a similar manner to the preparation of the intermediate 3 compound, Of Compound &lt; RTI ID = 0.0 &gt; III &lt; / RTI &gt;

Compound III: mass spectrometry (FAB) m / z 534 [(M + H) <^+> ]. _{^{1 H NMR (400 MH Z,}} CDCl 3): δ 8.23 (d, 4H), 7.83-7.65 (m, 12H), 7.42 (t, 2H), 7.41-7.38 (m, 4H). _{^{13 H NMR (100 MH Z,}} CDCl 3): δ 145.6, 134.2, 131.3, 131.1, 130.3, 128.3, 122.6, 122.4, 121.1, 120.0, 119.7, 119.5, 115.5, 114.1, 113.3. Elemental analysis: Theory C ₃₈ H ₂₂ N ₄ = C, 85.37; H, 4.15; N, 10.48. Measured = C, 85.74; H, 4.12; N, 10.47.

Production Example 1: Production of retarded fluorescent organic light emitting diode

(ITO / PEDOT: PSS / TAPC / mCP / Compound I: 4CzIPN / TSPO1 / LiF / Al)

The anode ITO substrate was cleaned with ultrasonic waves for 30 minutes using pure water and isopropyl alcohol. The cleaned ITO substrate was surface-treated with ultraviolet light of short wavelength and then PEDOT: PSS (poly (3,4-ethylenedioxythiophene): poly (styrenesulfonate)) was spin-coated to a thickness of 60 nm. After spin coating, a hole injection or transport material, TAPC (1,1-Bis [4- [N, N'-Di (p-tolyl) Amino] Phenyl] Cyclohexane was added at a pressure of 1 × 10 ^-6 torr at 0.1 nm / s To form a hole transporting layer having a thickness of 20 nm. Thereafter, an electron blocking material, mCP (N, N-dicarbazolyl-3,5-benzene) was deposited at a pressure of 1 x 10 ^-6 torr at a rate of 0.1 nm / s to form a 10 nm exciton blocking layer. Thereafter, Compound I (Formula 5) synthesized as Synthesis Example 1 as a retarded fluorescent host material under a pressure of ¹ x 10 ^-6 torr was irradiated at a rate of 0.1 nm / s with 4CzIPN as a retardation fluorescent dopant material at a rate of 0.01 nm / s To form a light emitting layer. As an electron transport material, TSPO1 (diphenylphosphine oxide-4- (triphenylsilyl) phenyl) was deposited at a pressure of 1 x 10 ^-6 torr at a rate of 0.1 nm / s to form an electron transport layer of 35 nm. Thereafter, LiF as an electron injecting material was vapor-deposited at a pressure of ¹ x 10 ^-6 torr at a rate of 0.01 nm / s to form an electron injecting layer of 1 nm. Thereafter, Al was vapor-deposited at a rate of 0.5 nm / sec under a pressure of ¹ x 10 ^-6 torr to form a cathode of 100 nm, thereby forming an organic light-emitting diode. After the device was formed, the device was sealed using a CaO wetting agent and a glass cover glass.

The organic light emitting diode manufactured through Production Example 1 exhibited a maximum quantum efficiency of 26% at a voltage of 4.5 V and exhibited excellent efficiency characteristics. The driving voltage of this device was measured at 5.1V. In addition, the half life of this device was about 200 hours based on 1,000 cd / m ² .

Production Example 2: Production of retarded fluorescent organic light emitting diode

(ITO / PEDOT: PSS / TAPC / mCP / Compound II: 4CzIPN / TSPO1 / LiF / Al)

An organic light emitting diode was prepared and sealed in the same manner as in Production Example 1, except that Compound (II) (6) synthesized through Synthesis Example 2 was used as a retarded fluorescent host material in the light emitting layer.

The organic light emitting diode manufactured through Production Example 2 exhibited a maximum quantum efficiency of 24% at a voltage of 4.5 V and exhibited excellent efficiency characteristics. The driving voltage of this device was measured at 5.3 V. In addition, the half-life of this device was about 180 hours based on 1,000 cd / m ² .

Production Example 3: Production of retarded fluorescent organic light emitting diode

(ITO / PEDOT: PSS / TAPC / mCP / Compound III: 4CzIPN / TSPO1 / LiF / Al)

An organic light emitting diode was prepared and sealed in the same manner as in Production Example 1, except that Compound (III) synthesized through Synthesis Example 3 (Formula 7) was used as a retarded fluorescent host material in the light emitting layer.

The organic light emitting diode manufactured through Production Example 2 exhibited a maximum quantum efficiency of 25% at a voltage of 4.5 V and exhibited excellent efficiency characteristics. The driving voltage of this device was measured at 5.5 V. In addition, the half life of this device was 170 hours at 1,000 cd / m ² .

Comparative Example: Manufacture of retarded fluorescent organic light emitting diode

(ITO / PEDOT: PSS / TAPC / mCP / CBP: 4CzIPN / TSPO1 / LiF / Al)

An organic light emitting diode was prepared and sealed in the same manner as in Production Example 1 except that CBP was used as a retarded fluorescent host material in the light emitting layer.

The organic light emitting diode manufactured through the comparative example exhibited a maximum quantum efficiency of 15% at a voltage of 4.0V. The driving voltage of this device was measured at 8.5V. In addition, the half life of this device is shown to be within 10 hours based on 1,000 cd / m ² .

When the above results are referenced, it can be seen that the retarded fluorescent organic light emitting diodes according to Production Examples 1 to 3 have improved quantum efficiency and lifetime as well as reduced driving voltage as compared with the organic light emitting diode according to the comparative example.

The following Table 1 shows the energy values according to known measuring methods of Compounds I, II, and III respectively prepared according to Synthesis Examples 1 to 3.

Compound I Compound II Compound III CBP 4CzIPN Bg (eV) 2.88 2.97 2.94 3.50 2.58 S ₁ (eV) 2.86 2.93 2.89 3.36 2.44 T ₁ (eV) 2.71 2.72 2.72 2.60 2.4 ? E _ST (eV) 0.15 0.21 0.17 0.76 0.04 HOMO level (eV) -6.14 -6.12 -6.10 -5.90 -5.80 LUMO level (eV) -3.26 -3.15 -3.19 -2.40 -3.40

Referring to Table 1, it can be seen that the compounds I, II, and III exhibit ΔE Est of 0.3 eV or less and further 0.21 eV or less. Because of this property, the compounds, i.e., the S ₁ level of compounds I, II, and III and the T ₁ S ₁ 4CzIPN level of the delayed fluorescence material in the light emitting level and T ₁ It can be predicted that the luminous efficiency is improved by increasing the energy transfer efficiency to each level.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, This is possible.

Claims (11)

A bipolar organic material represented by the following formula (1): &lt; EMI ID =
[Chemical Formula 1]

In Formula 1,
Each of R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ and R ₈ is independently hydrogen, deuterium, an amine group, a substituted or unsubstituted C 1 to C 30 alkyl group, A substituted or unsubstituted C2 to C30 arylalkyl group, a substituted or unsubstituted C1 to C30 alkoxy group, a substituted or unsubstituted C2 to C30 aryloxy group, a substituted or unsubstituted C1 to C30 alkoxy group, A substituted or unsubstituted C2 to C30 arylamine group, a substituted or unsubstituted C2 to C30 arylsilyl group, a substituted or unsubstituted C2 to C30 arylthio group, and a substituted or unsubstituted C2 to C30 arylseleno group , &Lt; / RTI &gt;
X is oxygen,
Y represents a halogen group, a cyano group, a substituted or unsubstituted C1 to C30 alkylcarbonyl group, a substituted or unsubstituted C1 to C30 alkylsulfinyl group, a substituted or unsubstituted C1 to C30 alkylsulfonyl group, A substituted or unsubstituted C1 to C30 alkylphosphonyl group, and a substituted or unsubstituted C1 to C30 alkylphosphoryl group,
m is an integer of 1 or 2,
l is an integer of 0 or 1,
n is an integer of 1 or 2; The method according to claim 1,
Wherein the bipolar organic material is a bipolar organic material represented by the following formula:
(2)

In Formula 2,
R _b1 , R _b2 , R _b3 , R _b4 , R _b5 , R _b6 , R _b7 , and R _b8 are each independently selected from the group consisting of R _a1 , R _a2 , R _a3 , R _a4 , R _a5 , R _a6 , R _a7 , R _a8 , R _b1 , A substituted or unsubstituted C1 to C30 alkyl group, a substituted or unsubstituted carbazolyl group, a substituted or unsubstituted C2 to C30 arylalkyl group, a substituted or unsubstituted C1 to C30 alkyl group, Substituted or unsubstituted C2 to C30 aryloxy groups, substituted or unsubstituted C2 to C30 aryloxy groups, substituted or unsubstituted C2 to C30 arylamine groups, substituted or unsubstituted C2 to C30 arylsilyl groups, substituted or unsubstituted An arylthio group of C2 to C30, and a substituted or unsubstituted arylseleno group of C2 to C30,
X, l, Y, and n are the same as defined in formula (1). The method according to claim 1,
Wherein the bipolar organic material is a bipolar organic material represented by the following formula:
(3)

In Formula 3,
R _b1 , R _b2 , R _b3 , R _b4 , R _b5 , R _b6 , R _b7 , and R _b8 are each independently selected from the group consisting of R _a1 , R _a2 , R _a3 , R _a4 , R _a5 , R _a6 , R _a7 , R _a8 , R _b1 , A substituted or unsubstituted C1 to C30 alkyl group, a substituted or unsubstituted carbazolyl group, a substituted or unsubstituted C2 to C30 arylalkyl group, a substituted or unsubstituted C1 to C30 alkyl group, Substituted or unsubstituted C2 to C30 aryloxy groups, substituted or unsubstituted C2 to C30 aryloxy groups, substituted or unsubstituted C2 to C30 arylamine groups, substituted or unsubstituted C2 to C30 arylsilyl groups, substituted or unsubstituted An arylthio group of C2 to C30, and a substituted or unsubstituted arylseleno group of C2 to C30,
Y ₁ and Y ₂ are each independently a halogen group, a cyano group, a substituted or unsubstituted C1 to C30 alkylcarbonyl group, a substituted or unsubstituted C1 to C30 alkylsulfinyl group, a substituted or unsubstituted C1 to C30 An alkylsulfonyl group, a substituted or unsubstituted C1 to C30 alkylphosphonyl group, and a substituted or unsubstituted C1 to C30 alkylphosphoryl group,
X and l are the same as defined in formula (1). The method according to claim 1,
Wherein the bipolar organic material is a bipolar organic material represented by the following Formula 4:
[Chemical Formula 4]

In Formula 4,
R _b1 , R _b2 , R _b3 , R _b4 , R _b5 , R _b6 , R _b7 , and R _b8 are each independently selected from the group consisting of R _a1 , R _a2 , R _a3 , R _a4 , R _a5 , R _a6 , R _a7 , R _a8 , R _b1 , A substituted or unsubstituted C1 to C30 alkyl group, a substituted or unsubstituted carbazolyl group, a substituted or unsubstituted C2 to C30 arylalkyl group, a substituted or unsubstituted C1 to C30 alkyl group, Substituted or unsubstituted C2 to C30 aryloxy groups, substituted or unsubstituted C2 to C30 aryloxy groups, substituted or unsubstituted C2 to C30 arylamine groups, substituted or unsubstituted C2 to C30 arylsilyl groups, substituted or unsubstituted An arylthio group of C2 to C30, and a substituted or unsubstituted arylseleno group of C2 to C30,
X, l, and Y are the same as defined in formula (1). The method according to claim 1,
Wherein the bipolar organic material is a bipolar organic material represented by the following formula:
[Chemical Formula 5]

The method according to claim 1,
Wherein the bipolar organic material is a bipolar organic material represented by the following Formula 6:
[Chemical Formula 6]

The method according to claim 1,
Wherein the bipolar organic material is a bipolar organic material represented by the following formula:
(7)

A bipolar organic material represented by any of the following formulas 1 to 7:
[Chemical Formula 1]

(2)

(3)

[Chemical Formula 4]

[Chemical Formula 5]

[Chemical Formula 6]

(7)

In the above _{formula, R 1, R 2, R} 3, R 4, R 5, R 6, R 7, R 8, R a1, R a2, R a3, R a4, R a5, R a6, R a7, R _a8, R _b1, R _b2, R _b3, R an alkyl group _b4, R _b5, R _b6, R _b7, and R _b8 is C1 to C30 each independently hydrogen, deuterium, an amine group, a substituted or unsubstituted, substituted Or a substituted or unsubstituted carbazolyl group, a substituted or unsubstituted C2 to C30 arylalkyl group, a substituted or unsubstituted C1 to C30 alkoxy group, a substituted or unsubstituted C2 to C30 aryloxy group, An unsubstituted C 2 to C 30 arylamine group, a substituted or unsubstituted C 2 to C 30 arylsilyl group, a substituted or unsubstituted C 2 to C 30 arylthio group, and a substituted or unsubstituted C 2 to C 30 arylseleno group , And one of the groups selected from the group consisting of
X is oxygen,
Y, Y ₁ and Y ₂ are each independently a halogen group, a cyano group, a substituted or unsubstituted C1 to C30 alkylcarbonyl group, a substituted or unsubstituted C1 to C30 alkylsulfinyl group, a substituted or unsubstituted C1 A substituted or unsubstituted C1 to C30 alkylphosphonyl group, and a substituted or unsubstituted C1 to C30 alkylphosphoryl group,
m is an integer of 1 or 2,
l is an integer of 0 or 1,
n is an integer of 1 or 2; An organic light emitting diode comprising an anode, a hole conduction layer, a light emitting layer, an electron conduction layer, and a cathode sequentially stacked,
Wherein one of the hole transporting layer, the light emitting layer, and the electron transporting layer comprises the bipolar organic material according to claim 1 or claim 8. The method of claim 9,
Wherein the light emitting layer comprises a host material and a dopant material,
Wherein the host material comprises the bipolar organic material of claim 1 or claim 8. The method of claim 10,
Wherein the dopant material is a delayed fluorescent light emitting material.

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