WO2010024572A2

WO2010024572A2 - Material for organic photoelectric device and organic photoelectric device including the same

Info

Publication number: WO2010024572A2
Application number: PCT/KR2009/004730
Authority: WO
Inventors: Nam-Soo Kim; Myeong-Soon Kang; Ho-Kuk Jung; Eui-Su Kang; Young-Sung Park; Mi-Young Chae; Jin-Seong Park
Original assignee: Cheil Industries Inc.
Priority date: 2008-08-25
Filing date: 2009-08-25
Publication date: 2010-03-04
Also published as: EP2315753A2; TWI423961B; US20110156014A1; KR101174090B1; KR20100024340A; EP2315753A4; JP2012501091A; EP2315753B1; JP5596687B2; CN102089288B; CN102089288A; WO2010024572A3; TW201016680A; US8470454B2

Abstract

Disclosed are a material for an organic photoelectric device including an asymmetric compound of Chemical Formula 1, and an organic photoelectric device including the same. The material for an organic photoelectric device can act as a hole injection, hole transport, light emitting, or electron injection and/or transport material, and also as a light emitting host along with an appropriate dopant in an organic photoelectric device such as an organic light emitting diode. When the material is applied to an organic photoelectric device such as an organic light emitting diode, an organic photoelectric device having excellent life-span, efficiency, driving voltage, electrochemical stability, and thermal stability can be obtained.

Description

[DESCRIPTION] [Invention Title]

MATERIAL FOR ORGANIC PHOTOELECTRIC DEVICE AND ORGANIC PHOTOELECTRIC DEVICE INCLUDING THE SAME

[Technical Field]

<i> The present invention relates to a material for an organic photoelectric device and an organic photoelectric device including the same. More particularly, the present invention relates to a material for an organic photoelectric device that is capable of improving life-span, efficiency, driving voltage, electrochemical stability, and thermal stability, and an organic photoelectric device including the same.

<2>

[Background Art]

<3> An organic photoelectric device is a device requiring a charge exchange between an electrode and an organic material by using a hole or an electron.

<4> An organic photoelectric device may be classified as follows in accordance with its driving principles. A first organic photoelectric device is an electron device driven as follows: excitons are generated in an organic material layer by photons from an external light source; the excitons are separated to electrons and holes; and the electrons and holes are transferred to different electrodes from each other as a current source (voltage source).

<5> A second organic photoelectric device is an electron device driven as follows: a voltage or a current is applied to at least two electrodes to inject holes and/or electrons into an organic material semiconductor positioned at an interface of the electrodes; and then the device is driven by the injected electrons and holes.

<6> As examples, the organic photoelectric device includes an organic light emitting diode (OLED), an organic solar cell, an organic photo- conductor drum, an organic transistor, an organic memory device, etc., and it requires a hole injecting or transporting material, an electron injecting or transporting material , or a light emitting material .

<7> Although the organic light emitting diode is mainly described in the following description, the hole injecting or transporting material, the electron injecting or transporting material, and the light emitting material react in similar principles in the organic photoelectric devices. <8> An organic light emitting diode (OLED) has recently drawn attention due to an increase in demand for flat panel displays. In general, organic light emission refers to transformation of electrical energy to photo-energy. <9> The organic light emitting diode transforms electrical energy into light by applying current to an organic light emitting material. It has a structure in which a functional organic material layer is interposed between an anode and a cathode. The organic material layer includes multi-layer including different materials from each other, for example a hole injection layer (HIL), a hole transport layer (HTL), an emission layer, an electron transport layer (ETL), and an electron injection layer (EIL), in order to improve efficiency and stability of an organic light emitting diode.

<io> In such an organic light emitting diode, when a voltage is applied between an anode and a cathode, holes from the anode and electrons from the cathode are injected to an organic material layer. The generated excitons generate light having certain wavelengths while shifting to a ground state.

<ii> In 1987, Eastman Kodak, Inc. firstly developed an organic light emitting diode including a low molecular aromatic diamine and aluminum complex as an emission-layer-forming material (Applied Physics Letters. 51, 913, 1987). CW Tang et al . firstly disclosed a practicable device as an organic light emitting diode in 1987 (Applied Physics Letters, 51 12, 913- 915, 1987).

<12> According to the reference, the organic layer has a structure in which a thin film (hole transport layer (HTL)) of a diamine derivative and a thin film of tris(8-hydroxy-quinolate)aluminum (Alqs) are stacked.

<i3> Recently, it is has become known that a phosphorescent light emitting material can be used for a light emitting material of an organic light emitting diode in addition to the fluorescent light emitting material (D. F. O'Brien et al . , Applied Physics Letters, 74 3, 442-444, 1999; M. A. Baldo et al . , Applied Physics letters, 75 1, 4-6, 1999). Such a phosphorescent material emits lights by transiting the electrons from a ground state to an exited state, non-radiance transiting of a singlet exciton to a triplet exciton through intersystem crossing, and transiting a triplet exciton to a ground state to emit light.

<14> As described above, in an organic light emitting diode, an organic material layer includes a light emitting material and a charge transport material, for example a hole injection material, a hole transport material, an electron transport material, an electron injection material, and so on.

<i5> The light emitting material is classified as blue, green, and red light emitting materials according to emitted colors, and yellow and orange light emitting materials to emit colors approaching natural colors.

<i6> When one material is used as a light emitting material, a maximum light emitting wavelength is shifted to a long wavelength or color purity decreases because of interactions between molecules, or device efficiency decreases because of a light emitting quenching effect. Therefore, a host/dopant system is included as a light emitting material in order to improve color purity and increase luminous efficiency and stability through energy transfer.

<17> In order to implement the above excellent performance of an organic light emitting diode, a material constituting an organic material layer, for example a hole injection material, a hole transport material, a light emitting material, an electron transport material, an electron injection material, and a light emitting material such as a host and/or a dopant should be stable and have good efficiency. However, development of an organic material layer forming material for an organic light emitting diode has not been satisfactory up to now and thus there is a need for a novel material. This material development is also required for other organic photoelectric devices. <18>

[Disclosure] [Technical Problem] <i9> An exemplary embodiment of the present invention provides a novel material that can act as a hole injection, hole transport, light emitting, or electron injection and/or transport material, and also as a light emitting host along with an appropriate dopant. <20> Another embodiment of the present invention provides an organic photoelectric device including the material for an organic photoelectric device, and having improved life-span, efficiency, driving voltage, electrochemical stability, and thermal stability. <2i> The embodiments of the present invention are not limited to the above technical purposes, and a person of ordinary skill in the art can understand other technical purposes.

<22>

[Technical Solution]

<23> According to one embodiment of the present invention, a material for an organic photoelectric device including an asymmetric compound represented by the following Chemical Formula 1 is provided: <24> [Chemical Formula 1]

<26> wherein, in the above Chemical Formula 1,

<27> Ar₁ is selected from the group consisting of hydrogen and a substituted or unsubstituted aryl , provided that when Ari is a substituted aryl , the substituent of Ar₁ is not the same as Ar₂, <28> Ar₂ and Ar3 are independently selected from the group consisting of a substituted or unsubstituted carbazolyl, a substituted or unsubstituted C2 to C30 heteroaryl, a substituted or unsubstituted C2 to C30 arylamine, and a substituted or unsubstituted C2 to C30 heteroarylamine, <29> Li and L₂ are independently selected from the group consisting of substituted or unsubstituted phenylene, a substituted or unsubstituted naphthylene, and a substituted or unsubstituted anthracene, and

<30> m and n are integers ranging from 1 to 4.

<3i> According to another embodiment of the present invention, an organic photoelectric device is provided that includes an anode, a cathode, and an organic thin layer disposed between the anode and cathode. The organic thin layer includes the material for the organic photoelectric device.

<32> According to a further embodiment of the present invention, a display device including the organic photoelectric device is provided.

<33> Hereinafter, further embodiments of the present invention will be described in detail.

<34> The material for an organic photoelectric device according to one embodiment has an asymmetric structure with respect to a pyrimidine core. Such asymmetric structure including a pyrimidine core reinforces amorphous characteristics and thereby suppresses crystallization, improving life-span characteristics of an organic photoelectric device when an organic photoelectric device is driven. Therefore, an organic photoelectric device having excellent efficiency, driving voltage, electrochemical stability, and thermal stability is provided. [Advantageous Effects]

<36> The novel material according to one embodiment of the present invention can act as a hole injection, hole transport, light emitting, or electron injection and/or transport material, and also as a light emitting host along with an appropriate dopant in an organic photoelectric device such as an organic light emitting diode.

<37>

[Description of Drawings] <38> FIGS. 1 to 5 are cross-sectional views showing organic light emitting diodes including compounds according to various embodiments of the present invention. <39> FIG. 6 is a graph showing Differential Scanning Calorimetry (DSC) measurement result of the compound according to Synthesis Example 1. <40> description of Reference Numerals Indicating Primary Elements in the

Drawings>

<4i> 100: organic photoelectric device 110: cathode <42> 120: anode 105: organic thin layer

<43> 130: emission layer 140: hole transport layer (HTL)

<44> 150: electron transport layer (ETL) 160: electron injection layer (EIL) <45> 170: hole injection layer (HIL) <46> 230: emission layer + electron transport layer (ETL)

<47>

[Best Mode]

<48> Exemplary embodiments of the present invention will hereinafter be described in detail. However, these embodiments are only exemplary, and the present invention is not limited thereto.

<49> As used herein, when specific definition is not provided, the term "substituted" refers to one substituted with at least a substituent selected from the group consisting of a Cl to C30 alkyl , a Cl to ClO heteroalkyl , a C3 to C30 cycloalkyl, a C6 to C30 aryl , a Cl to C30 alkoxy, a fluoro, and a cyano. <50> As used herein, when specific definition is not provided, the term

"hetero" refers to one including 1 to 3, including N, 0, S, P, or Si, and remaining carbons in one ring. <5i> According to one embodiment of the present invention, a material for an organic photoelectric device including an asymmetric compound represented by the following Chemical Formula 1 is provided: <52> [Chemical Formulal]

<54> wherein, in the above Chemical Formula 1,

<55> Ari is selected from the group consisting of hydrogen and a substituted or unsubstituted aryl , provided that when An is a substituted aryl , the substituent of An is not the same as Ar2, <56> Ar2 and Ar₃ are independently selected from the group consisting of a substituted or unsubstituted carbazolyl, a substituted or unsubstituted C2 to C30 heteroaryl , a substituted or unsubstituted C2 to C30 arylamine, and a substituted or unsubstituted C2 to C30 heteroarylamine, <57> L₁ and L₂ are independently selected from the group consisting of a substituted or unsubstituted phenylene, a substituted or unsubstituted naphthylene, and a substituted or unsubstituted anthracene, and

<58> m and n are integers ranging from 1 to 4.

<59> In the above Chemical Formula 1, it is preferable that Ari is an aryl or an aryl substituted aryl. Examples of the aryl are phenyl, naphthyl , anthracenyl , phenanthrenyl , pyrenyl , perylenyl , chrysenyl , and the like. <60> Ar₁ is substituted with a substituent selected from the group consisting of a Cl to C30 alkyl, a Cl to ClO heteroalkyl , a C3 to C30 cycloalkyl, a C6 to C30 aryl , a Cl to C30 alkoxy, a fluoro, and a cyano. Examples of the aryl include one selected from the group consisting of phenyl, naphthyl , anthracenyl , phenanthrenyl , pyrenyl , perylenyl, and chrysenyl . Examples of the heteroalkyl include alkylsilyl. However, the aryl and heteroalkyl are not limited to the above described. <6i> When Ari is a substituted aryl, the substituent of Ari is not the same as Ar₂. When Ari is a substituted aryl and the substituent of Ari is not the same as Ar₂, an asymmetric structure with respect to a pyrimidine core can be obtained. The material for an organic photoelectric device having such an asymmetric structure suppresses crystallization, and thus improves life-span characteristics of an organic photoelectric device. <62> In the above Chemical Formula 1, the heteroaryl represented by Ar₂ and

Ar3 includes imidazolyl, thiazolyl, oxazolyl, oxadiazolyl, triazolyl, pyridinyl, pyridazine, quinolinyl, isoquinolinyl , acridyl, imidazopyridinyl , imidazopyrimidinyl , and the like. <63> In the above Chemical Formula 1, the heteroarylamine represented by Ar₂ and Ar3 includes diphenyl amine, dinaphthyl amine, dibiphenyl amine, phenyl naphthyl amine, phenyl diphenyl amine, ditolyl amine, phenyl tolyl amine, carbazoyl , triphenylamine, dipyridyl amine, and the like. <64> Each substituent represented by Ar₂ and Ar₃ in the above Chemical

Formula 1 may be substituted or unsubstituted. When Ar₂ and Ar3 are substituted, they may be substituted with one selected from the group consisting of a Cl to C30 alkyl, a Cl to ClO heteroalkyl, a C3 to C30 cycloalkyl, a C6 to C30 aryl, a Cl to C30 alkoxy, a fluoro, and a cyano. Examples of the aryl include one selected from the group consisting of phenyl, naphthyl, anthracenyl, phenanthrenyl, pyrenyl, perylenyl, and chrysenyl. Examples of the heteroalkyl include alkylsilyl. However, the aryl and heteroalkyl are not limited to the above described. <65> In the above Chemical Formula 1, Li and L₂ are preferably phenylene.

<66> The compound of the above Chemical Formula 1 according to the present invention includes a pyrimidine core and substituents of Ari to Ar3.

Pyrimidine is an aromatic compound and has an electron structure such as benzene. The pyrimidine has thermal stability or relatively high resistance to oxidation, but it can synthesize an asymmetric compound by the reactivity difference with respect to 2~, 4-, and 6- positions.

<67> According to one embodiment, the pyrimidine core is substituted with substituents that are not identical to each other, and forms an asymmetric structure. The amorphous characteristic can be enhanced in the pyrimidine core structure having an asymmetric substituent, and the crystallization is suppressed to improve the life-span characteristic while driving the organic photoelectric device. On the other hand, the symmetric compound having the same substituents is easily crystallized, so it may cause shortening of the life-span characteristic of an organic light emitting diode.

<68> The various substituents (An to Ar₃) are introduced to the pyrimidine having the above-mentioned characteristic to provide the organic photoelectric device with the required characteristics.

<69> For example, it is possible to synthesize a thermally electrically stable n-type material by introducing a substituent having a p-type property such as a pyridinyl group, a quinolinyl group, and an isoquinolinyl group to Ar₂ and Ar₃, and it is possible to synthesize a p-type material by introducing substituents having the p-type property.lt is also possible to provide an amphiphilic material having both n-type and p-type properties by introducing both an n-type substituent and a p-type substituent.

<70> The n-type property means a property of a conductive characteristic depending upon the LUMO level, so as to have an anionic characteristic due to the electron formation. The p-type property means a property of a conductive characteristic depending upon the HOMO level, so as to have a cationic characteristic due to the hole formation. <7i> The compound represented by Chemical Formula 1 is introduced with the various substituents, so the total molecular property thereof may be further enriched into an n-type or a p-type. In other words, when a certain substituent is introduced to the substituting part in Chemical Formula 1 to enrich the property of a chemical represented by Chemical Formula 1 to either one, the compound represented by Chemical Formula 1 can become a compound that further satisfies the conditions for the material for hole injection, hole transport, light emitting, electron injection, or electron transport.

<72> For example, when Ar₂ and Ar₃ is substituted with a heteroarylamine group, the compound represented by Chemical Formula 1 has wider application fields such as a material for a hole injection layer (HIL) and a hole transport layer (HTL). <73> On the other hand, when Ar₂ and Ar₃ are substituted with materials having an excellent electron affinity such as a hetero aryl group, the compound represented by Chemical Formula 1 may be applied to a material for an electron injection layer or an electron transport layer (ETL). <74> Furthermore, when Ar₁ is substituted with a substituent such as a phenyl group, a naphthyl group, an anthracenyl group, a phenanthrenyl group, a pyrenyl group, a perylenyl group, a chrysenyl group, and so on, it is possible to increase the thermal stability or the resistance to oxidation; and when Ar₂ or Ar₃ are simultaneously substituted with substituents of a heteroarylamine group and a heteroaryl group, respectively, it is possible to provide an amphiphilic material and to apply the material for an emission 1ayer .

<75> As described above, it is possible to synthesize a compound having the various energy band gaps by introducing the various substituents in the Ar₁ to

Ar₃ position in Chemical Formula 1.

<76> Thereby, the compound represented by Chemical Formula 1 may become a compound satisfying the condition required for a hole injection layer (HIL), a hole transport layer (HTL), an emission layer, an electron injection layer, and a transport layer. <77> It is possible to accomplish a device having a low driving voltage and high photo efficiency by selecting a compound having a suitable energy level depending upon the substituent of Compound 1 and applying it to an organic electronic device. <78> Specific examples of the compound represented by the above Chemical

Formula 1 include the following compounds (1) to (90) or combinations thereof, but are not limited thereto.

<79>

<80>

<8I>

<82>

<83>

<85> <86> The material for an organic photoelectric device including the above compounds can play a role of hole injection, hole transport, light emitting, or electron injection and/or transport, and also as a light emitting host with an appropriate dopant. According to the embodiment of the present invention, a compound for an organic photoelectric device can improve lifespan and electrochemical and thermal stability, and decrease the driving voltage for improving the life-span and efficiency characteristics of an organic photoelectric device when included in an organic thin layer.

<87> According to another embodiment of the present invention, an organic photoelectric device including the material for the organic photoelectric device is provided. The organic photoelectric device includes an organic light emitting diode, an organic solar cell, an organic transistor, an organic photo-conductor drum, an organic memory device, and the like.

<88> As for an organic solar cell, the new compound of the present invention is included in an electrode or an electrode buffer layer and can thereby improve quantum efficiency. As for an organic transistor, it can be used as an electrode material in a gate, a source-drain electrode, and the like.

<89> Hereinafter, an organic light emitting diode is illustrated in more detail. According to another embodiment of the present invention, an organic light emitting diode including an anode, a cathode, and at least one organic thin layer disposed between the anode and cathode is provided. The organic thin layer includes the material for an organic photoelectric device.

<90> The organic thin layer is selected from the group consisting of an emission layer! and a hole transport layer (HTL), a hole injection layer (HIL), an electron transport layer (ETL), an electron injection layer (EIL), a hole blocking layer, and combinations thereof. At least one layer includes a material for an organic photoelectric device according to the present invent ion.

<9i> FIGS. 1 to 5 are cross-sectional views showing an organic light emitting diode including the material for an organic photoelectric device according to one embodiment of the present invention.

<92> Referring to FIGS. 1 to 5, organic light emitting diodes 100, 200, 300, 400, and 500 according to embodiments includes at least one organic thin layer 105 interposed between an anode 120 and a cathode 110.

<93> The anode 120 includes an anode material laving a large work function to help hole injection into an organic thin layer. The anode material includes a metal such as nickel, platinum, vanadium, chromium, copper, zinc, and gold, or alloys thereof; a metal oxide such as zinc oxide, indium oxide, indium tin oxide (ITO), and indium zinc oxide (IZO); a combined metal and oxide such as Zn0:Al or Snθ2:Sb; or a conductive polymer such as poly(3- methylthiophene), poly[3,4-(ethylene-l,2-dioxy)thiophene] (PEDT), polypyrrole, and polyaniline, but is not limited thereto. It is preferable to include a transparent electrode including ITO (indium tin oxide) as an anode .

<94> The cathode 110 includes a cathode material having a small work function to help electron injection into an organic thin layer. The cathode material includes a metal such as magnesium, calcium, sodium, potassium, titanium, indium, yttrium, lithium, gadolinium, aluminum, silver, tin, and lead, or alloys thereof; or a multi-layered material such as LiF/Al, Liq/Al, Li(VAl, LiF/Ca, LiF/Al, and BaF₂/Ca, but is not limited thereto. It is preferable to include a metal electrode including aluminum as a cathode.

<95> Referring to FIG. 1, the organic photoelectric device 100 includes an organic thin layer 105 including only an emission layer 130.

<96> Referring to FIG. 2, a double-layered organic photoelectric device 200 includes an organic thin layer 105 including an emission layer 230 including an electron transport layer (ETL), and a hole transport layer (HTL) 140. The emission layer 130 also functions as an electron transport layer (ETL), and the hole transport layer (HTL) 140 layer has an excellent binding property with a transparent electrode such as ITO or an excellent hole transporting property.

<97> Referring to FIG. 3, a three-layered organic photoelectric device 300 includes an organic thin layer 105 including an electron transport layer (ETL) 150, an emission layer 130, and a hole transport layer (HTL) 140. The emission layer 130 is independently installed, and layers having an excellent electron transporting property or an excellent hole transporting property are separately stacked.

<98> As shown in FIG. 4, a four-layered organic photoelectric device 400 includes an organic thin layer 105 including an electron injection layer (EIL) 160, an emission layer 130, a hole transport layer (HTL) 140, and a hole injection layer (HIL) 170 for binding with the cathode of ITO. <99> As shown in FIG. 5, a five layered organic photoelectric device 500 includes an organic thin layer 105 including an electron transport layer (ETL) 150, an emission layer 130, a hole transport layer (HTL) 140, and a hole injection layer (HIL) 170, and further includes an electron injection layer (EIL) 160 to achieve a low voltage.

<ioo> In FIGS. 1 to 5, the organic thin layer 105 including at least one selected from the group consisting of an electron transport layer (ETL) 150, an electron injection layer (EIL) 160, an emission layer 130 and 230, a hole transport layer (HTL) 140, a hole injection layer (HIL) 170, and combinations thereof includes a material for an organic photoelectric device. The material for the organic photoelectric device may be used for an electron transport layer (ETL) 150 including the electron transport layer (ETL) 150 or electron injection layer (EIL) 160. When it is used for the electron transport layer (ETL), it is possible to provide an organic photoelectric device having a more simple structure because it does not require an additional hole blocking layer (not shown).

<ioi> Furthermore, when the material for an organic photoelectric device is included in the emission layer 130 and 230, the material for the organic photoelectric device may be included as a phosphorescent or fluorescent host or a fluorescent blue dopant.

<iO2> The organic light emitting diode may be fabricated by forming an anode on a substrate; forming an organic thin layer in accordance with a dry coating method such as an evaporation, a sputtering, a plasma plating, and an ion plating or a wet coating method such as spin coating, dipping, and flow coating; and providing a cathode thereon.

<103> Another embodiment of the present invention provides a display device including the organic photoelectric device according to the above embodiment.

<104>

[Mode for Invention]

<105> The following examples illustrate the present invention in more detail. However, it is understood that the present invention is not limited by these examples.

<106> (Preparing Material for Organic Photoelectric Device) <107> Synthesis Example 1: Synthesis of Compound (1) <108> For the specific example of the material for an organic photoelectric device, the compound (1) was synthesized in accordance with the following Reaction Scheme 1 in two steps.

<109> [Reaction Scheme 1]

o<y<

(A) (B)

<1 10> <1 1 1> First Step: Synthesizing Intermediate Product (A)

<1 12> 75.0 g (409 mmol) of 2,4,6-trichloropyrimidine, 54.8 g (450 mmol) of phenylboronic acid, and 11.8 g (10 mmol) of tetrakis- (triphenylphosphine)palladium were suspended in a mixed solvent of 450 ml of tetrahydrofuran and 300 ml of toluene to provide a suspension. The suspension was added to a solution in which 113.0 g (818 mmol) of potassium carbonate was dissolved in 300 ml of water, and the obtained mixture was heated and refluxed for 9 hours. After separating the reaction fluid into two layers, an organic layer was washed with a saturated sodium chloride aqueous solution and dried with anhydrous sodium sulfate.

<ii3> The organic solvent was disti Hated and removed under reduced pressure, and then the residue was recrystallized with toluene. The obtained crystal was separated by filtration and washed with toluene to obtain 64.7 g (yield: 70.3 %) of intermediate product (A).

<ii4> Second Step: Synthesizing Compound (1)

<ii5> 2.3 g (10 mmol) of intermediate product (A), 6.3 g (22 mmol) of 2-(4- (4,4,5,5-tetramethyl-l,3,2-dioxaborolan-2-yl)phenyl)pyridine (B), and 0.6 g (0.5 mmol) of tetrakis-(triphenylphosphine)palladium were suspended in a mixed solvent of 70 ml of tetrahydrofuran and 50 ml of toluene to provide a suspension. The suspension was added to a solution in which 5.7 g (41 mmol) of potassium carbonate was dissolved in 50 ml of water. The obtained mixture was heated and refluxed for 12 hours. After separating the reaction fluid into two layers, an organic layer was washed with a saturated sodium chloride aqueous solution and dried with anhydrous sodium sulfate.

<ii6> The organic solvent was distillated and removed under reduced pressure, and then the residue was recrystallized with toluene. The obtained crystal was separated by filtration and washed with toluene to obtain 3.9 g (yield: 67.9 %) of compound (1).

<ii7> ¹H NMR (300MHz, CDCl₃) 8.85 (d,2H), 8.75 (d,2H), 8.45 (d,2H), 8.34

(d,2H), 8.21 (m,4H), 8.08 (s.lH), 7.80 (m,4H), 7.60 Gn₁3H), 7.27 (m,2H);

MS[M+1] 463.

<ii8> Synthesis Example 2: Synthesizing Compound (2) <ii9> For the specific example of the material for an organic photoelectric device, compound (2) was synthesized in accordance with the following

Reaction Scheme 2 in two steps. <i20> [React ion Scheme 2]

(C) (B)

<122> First Step: Synthesizing Intermediate Product (C)

<123> 75.0 g (409 mmol) of 2,4,6-trichloropyrimidine, 77.3 g (450 mmol) of naphthylboronic acid, and 11.8 g (10 mmol) of tetrakis- (triphenylphosphine)palladium were suspended in a mixed solvent of 450 ml of tetrahydrofuran and 300 ml of toluene to provide a suspension. The suspension was added to a solution in which 113.0 g (818 mmol) of potassium carbonate was dissolved in 300 ml of water, and the obtained mixture was heated and refluxed for 9 hours. After separating the reaction fluid into two layers, an organic layer thereof was washed with a saturated sodium chloride aqueous solution and dried with anhydrous sodium sulfate.

<124> The organic solvent was disti Hated and removed under reduced pressure, and then the residue was recrystaliized with toluene. The obtained crystal was separated by filtration and washed with toluene to obtain 80.0 g (yield: 71.1 %) of intermediate product (C).

<125> Second Step: Synthesizing Compound (2) <!26> 3.2 g (12 mmol) of intermediate product (C), 7.2 g (26 mmol) of 2-(4- (4,4,5,5-tetramethyl-l,3,2-dioxaborolan-2-yl)phenyl)pyridine (B), and 0.7 g (0.6 mmol) of tetrakis-(triphenylρhosphine)palladium were suspended in a mixed solvent of 100 ml of tetrahydrofuran and 65 ml of toluene to provide a suspension. The suspension was added to a solution in which 6.4 g (47 mmol) of potassium carbonate was dissolved in 65 ml of water. The obtained mixture was heated and refluxed for 12 hours. After separating the reaction fluid into two layers, an organic layer thereof was washed with a saturated sodium chloride aqueous solution and dried with anhydrous sodium sulfate.

<127> The organic solvent was disti Hated and removed under reduced pressure, and then the residue was recrystallized with toluene. The extracted crystal was separated by filtration and washed with toluene to obtain 4.1 g (yield: 69.0 %) of compound (2).

<128> ¹H NMR (300MHz, CDCl₃) 8.85 (d,2H), 8.76 (d,2H), 8.45 (m,3H), 8.20

(m,4H), 8.01 (m,3H), 7.80 (m,5H), 7.61 (m,3H), 7.27 (m,2H); MS[M+1] 513.

<129> Synthesis Example 3: Synthesizing Compound (10) <130> For the specific example of the material for organic photoelectric device, the compound (10) was synthesized in accordance with the following Reaction Scheme 3.

<131> [Reaction Scheme 3]

<133> 2.3 g (10 mmol) of intermediate product (A), 7.5 g (22 mmol) of l-(4- (4,4,5,5-tetramethyl-l,3,2-dioxaborolan-2-yl)phenyl)isoquinoline (D), and 0.6 g (0.5 mmol) of tetrakis-(triphenylphosphine)palladium were suspended in a mixed solvent of 70 ml of tetrahydrofuran and 50 ml of toluene to provide a suspension. The suspension was added to a solution in which 5.7 g (41 mmol) of potassium carbonate was dissolved in 50 ml of water. The obtained mixture was heated and refluxed for 12 hours. After separating the reaction fluid into two layers, an organic layer thereof was washed with a saturated sodium chloride aqueous solution and dried with anhydrous sodium sulfate. <134> The organic solvent was disti Hated and removed under reduced pressure, and then the residue was recrystallized with toluene. The extracted crystal was separated by filtration and washed with toluene to obtain 3.9 g (yield- 68.0 %) of compound (10).

<135> ¹H NMR (300MHz, CDCl₃) 8.94 (d,2H), 8.68 (d,2H), 8.52 (d,2H), 8.39

(d,2H), 8.21 (d,2H), 8.16 (s,lH), 7.94 (m,6H), 7.72 (m,4H), 7.61 (m,5H); MS[M+1] 563.

<136> Synthesis Example 4: Synthesizing Compound (11)

<137> For a specific example of the material for organic photoelectric device, the compound (11) was synthesized in accordance with the following Reaction Scheme 4.

<138> [Reaction Scheme 4]

<140> 2.7 g (10 mmol) of intermediate product (C), 7.2 g (22 mmol) of l-(4- (4,4,5,5~tetramethyl-l,3,2-dioxaborolan-2-yl)phenyl)isoquinoline (D), and 0.6 g (0.5 mmol) of tetrakis-(triphenylphosphine)palladium were suspended in a mixed solvent of 80 ml of tetrahydrofuran and 55 ml of toluene to provide a suspension. The suspension was added to a solution in which 5.4 g (391 mmol) of potassium carbonate was dissolved in 55 ml of water. The obtained mixture was heated and refluxed for 12 hours. After separating the reaction fluid into two layers, an organic layer thereof was washed with a saturated sodium chloride aqueous solution and dried with anhydrous sodium sulfate.

<141> The organic solvent was distillated and removed under reduced pressure, and then the residue was recrystallized with toluene. The extracted crystal was separated by filtration and washed with toluene to obtain 4.5 g (yield: 65.0 %) of compound (11). <142> H NMR (300MHz, CDCl₃) 8.93 (d,2H), 8.67 (d,2H), 8.53 (d,2H), 8.45

(d.lH), 8.21 (d,2H), 7.96 (m,10H), 7.72 (m,5H), 7.64 (m,4H); MS[M+1] 613.

<143> Synthesis Example 5". Synthesizing Compound (19) <144> For a specific example of the material for organic photoelectric device, the compound (19) was synthesized in accordance with the following Reaction Scheme 5.

<145> [Reaction Scheme 5]

<147> 4.0 g (18 mmol) of intermediate product (A), 13.0 g (39 mmol) of 3-(4- (4,4,5,5-tetramethyl-l,3,2-dioxaborolan-2-yl)phenyl)quinoline (E), and 1.0 g (0.9 mmol) of tetrakis-(triphenylphosphine)palladium were suspended in a mixed solvent of 120 ml of tetrahydrofuran and 80 ml of toluene to provide a suspension. The suspension was added to a solution in which 9.8 g (71 mmol) of potassium carbonate was dissolved in 80 ml of water. The obtained mixture was heated and refluxed for 12 hours. After separating the reaction fluid into two layers, an organic layer thereof was washed with a sodium chloride saturated aqueous solution and dried with anhydrous sodium sulfate.

<148> The organic solvent was disti Hated and removed under reduced pressure, and then the residue was recrystallized with toluene. The extracted crystal was separated by filtration and washed with toluene to obtain 6.5 g (yield: 64.7 %) of compound (19).

<149> ¹H NMR (300MHz, CDCl₃) 9.31 (d,2H), 8.89 (d,2H), 8.40 (m,6H), 8.17

(d,2H), 8.09 (s,lH), 7.92 (m,6H), 7.75 (m,2H), 7.59 (m,5H); MS[M+1] 563.

<150> Synthesis Example 6: Synthesizing Compound (63) <151> For the specific example of the material for an organic photoelectric device, the compound (63) was synthesized in accordance with the following Reaction Scheme 6.

<152> [Reaction Scheme 6]

<154> First Step: Synthesizing Intermediate Product (F)

<155> 50.8 g (304 mmol) of carbazole, 71.6 g (304 ramol) of 1,4- dibromobenzene, 3.76 g (38 mmol) of cuprous chloride, and 83.9 g (607 mmol) of potassium carbonate were suspended in 322 ml of dimethyl sulfoxide and refluxed for 8 hours under nitrogen atmosphere while heating. The obtained reaction fluid was cooled to room temperature, and recrystallized using methanol .

<156> The obtained crystal was separated by filtration, and the resulting product was purified using a silica gel column chromatography to obtain 55.9 g (61.3%) of intermediate product (F).

<I 57> Second Step: Synthesizing Intermediate Product (G) <158> 37.8 g (117 mmol) of the intermediate product (F) was dissolved in 378 ml of tetrahydrofuran, 100.5 ml (lδlmmol) of 1.6M n-butyl lithium hexane solution was added at -70 ° C under argon atmoshhere, and then the resulting solution was agitated at -70 ° C to -40 C for 1 hour. The reaction fluid was cooled to -70 ° C and 47.9 ml (235 mmol) of isopropyl tetramethyl dioxaboloane was added in a dropwise fashion. After the resulting solution was agitated at -70 °C for 1 hour, the temperature increased to a room temperature and agiting was performed for 6 hours. 200 ml of water was added to the resulting solution and then agitated for 20 minutes.

<159> After separating the reaction fluid into two layers, an organic layer was washed with a saturated sodium chloride aqueous solution and dried with anhydrous sodium sulfate.

<i60> The organic solvent was distillated and removed under reduced pressure, and then the residue was recrystallized with toluene. The obtained crystal was separated by filtration and washed with toluene to obtain 28.9 g (yield- 66.7 %) of intermediate product (G).

<i6i> Third Step: Synthesizing Intermediate Product (H)

<162> 26.8 g (73 mmol) of the intermediate product (G), 20.0 g (73 mmol) of the compound (C), and 2.1 g (1.8 mmol) of tetrakis- (triphenylphosphine)palladium were suspended in a mixed solvent of 600 ml of tetrahydrofuran and 400 ml of toluene to provide a suspension. The suspension was added to a solution in which 20.1 g (154 mmol) of potassium carbonate was dissolved in 400 ml of water. The obtained mixture was heated and refluxed for 8 hours. After separating the reaction fluid into two layers, an organic layer was washed with a saturated sodium chloride aqueous solution and dried with anhydrous sodium sulfate.

<163> The organic solvent was distillated and removed under reduced pressure, and then the residue was recrystallized with toluene. The obtained crystal was separated by filtration and washed with toluene to obtain 23.0 g (yield: 65.4 %) of intermediate product (H).

<164> Fourth Step: Synthesizing Compound (63)

<165> 6.0 g (12 mmol) of the intermediate product (H), 4.5 g (14 mmol) of the compound (E), and 0.36 g (0.3 mmol) of tetrakis-(triphenylphosphine)palladium were suspended in a mixed solvent of 180 ml of tetrahydrofuran and 120 ml of toluene to provide a suspension. The suspension was added to a solution in which 3.4 g (25 mmol) of potassium carbonate was dissolved in 120 ml of water. The obtained mixture was heated and refluxed for 12 hours. After separating the reaction fluid into two layers, an organic layer was washed with a saturated sodium chloride aqueous solution and dried with anhydrous sodium sulfate.

<166> The organic solvent was disti Hated and removed under reduced pressure, and then the residue was recrystallized with toluene. The obtained crystal was separated by filtration and washed with toluene to obtain 7.2 g (yield¹- 88.3 %) of compound (63).

<167> ¹H NMR(300MHz, CDCl₃) 9.3Ks₁IH), 8.92(d,2H), 8.62(d,2H), 8.45(m,2H), 8.19(d,3H), 7.71(m,20H); MS[M+1] 651.

<168>

<I69> The synthesized compounds were measured to determine glass transition temperature and thermal decomposition temperature by differential scanning calorimetry (DSC) and thermogravimetry (TGA). The results of the compound (1) according to Synthesis Example 1 are shown in FIG. 6.

<i70> (Fabricating Organic Photoelectric Device)

<i7i> Example 1

<i72> A 15 Ω/cm (1200 A ITO glass substrate (Corning Inc.) was provided to have a size of 50 mm x 50 mm x 0.7 mm, and was cleaned in isopropyl alcohol and pure water for 5 minutes, respectively, and then washed with UV and ozone for 30 minutes.

<173> N,N'-diphenyl-N,N'-bis-[4-(phenyl-m-tolylamino)-phenyl)]-bipheny1-4,4'- diamine (N,N'-diphenyl-N,N'-bis-[4-(phenyl-m-tolyl-amino)-phenyl]-biphenyl- 4,4'-diamine: DNTPD) (40 nm) , N,N'-di(l-naphthyl)-N,N'-diphenylbenzidine (NPB) (10 nm), EB-46 (fluorescent blue dopant, manufactured by E-Ray Optoelectronics Technology Co., Ltd): EB-512 (fluorescent blue host, manufactured by E-Ray Optoelectronics Technology Co., Ltd) 6 % (40 nm), and the compound (1) (10 nm) obtained from Synthesis Example 1 were sequentially thermal-evaporated on the surface of glass substrate to provide a hole injection layer (HIL), a hole transfer layer (HTL), an emission layer, and an electron transport layer (ETL).

<174> As an electron injection layer (EIL), LiF was evaporated on the ETL to a thickness of 0.5 nm, and Al was evaporated to a thickness of 100 nm to provide a LiF/Al electrode. The structure of the obtained organic photoelectric device is shown in FIG. 5.

<i75> Example 2

<176> An organic photoelectric device was fabricated in accordance with the same procedure as in Example 1, except that compound (2) (10 nm) obtained from Synthesis Example 2 was used instead of compound (1).

<i77> Example 3

<178> An organic photoelectric device was fabricated in accordance with the same procedure as in Example 1, except that compound (10) (10 nm) obtained from Synthesis Example 3 was used instead of compound (1).

<i79> Example 4

<i80> An organic photoelectric device was fabricated in accordance with the same procedure as in Example 1, except that compound (11) (10 nm) obtained from Synthesis Example 4 was used instead of compound (1).

<i8i> Example 5

<i82> An organic photoelectric device was fabricated in accordance with the same procedure as in Example 1, except that compound (19) (10 nm) obtained from Synthesis Example 5 was used instead of compound (1).

<i83> Example 6

<184> An organic photoelectric device was fabricated in accordance with the same procedure as in Example 1, except that compound (63) (10 nm) obtained from Synthesis Example 6 was used instead of compound (1).

<i85> Comparative Example 1

<I86> An organic photoelectric device was fabricated in accordance with the same procedure as in Example 1, except that the compound of AIq₃ (10 nm) represented by Chemi cal Formula 2 was used instead of compound (1) <187> [Chemical Formula 2]

<189> Performance Measurement of the Organic Photoelectric Device

<i90> Each organic photoelectric device according to Examples 1 to 6 and

Comparative Example 1 was measured regarding luminous efficiency according to a voltage. The measurement method is as follows.

<i9i> 1) Measurement of Current Density Change Depending on Voltage Change <i92> The prepared organic photoelectric devices according to Examples 1 to 6 and Comparative Example 1 were increased in voltage from OV to 14V and measured regarding a current value in a unit device by using a current- voltage device (Keithley 2400 ). Then, their current densities were measured by dividing the current value by area.

<i93> 2) Measurement of Luminance Change Depending on Voltage Change <194> The organic photoelectric devices according to Examples 1 to 6 and Comparative Example 1 were increased in voltage from OV to 14V and measured regarding luminance using a luminance meter (Minolta Cs-IOOOA). <195> 3) Measurement of Electric Power Efficiency (Luminous Efficiency) <196> Electric power efficiency was calculated from the current density and the luminance measured from the "I) Measurement of current density change depending on voltage change" and "2) Measurement of luminance change, depending on voltage change," and voltage (V). The results are shown in the following Table 1. <i97> [Table 1] <198>

<199> Referring to Table 1, it is confirmed that the organic photoelectric devices according to Examples 1 to 6 in which the electron transport layer was formed with the material for an organic photoelectric device according to the present invention had excellent electric power efficiency (Lm/W) performance together with a low driving voltage, compared to the case of using the electron transport layer of Alq3 according to Comparative Example 1.

Accordingly, the organic compound according to one embodiment of the present invention had high thermal stability, a low driving voltage, and high luminous efficiency as shown in the performance result of the organic photoelectric device, so it is anticipated that it can improve the life-span of an organic photoelectric device. It is considered that the asymmetry of the material for an organic photoelectric device enriched the amorphous characteristic, so it suppressed the crystallization resulting in improved life-span of the device.

<200> 4) Measurement of Thermal Characteristic <201> A first analysis was carried out with the compounds obtained from Synthesis Examples 1 to 6 by differential scanning calorimetry (DSC), and then a second analysis was carried out with the compounds, thereby completing the first analysis. The analysis results for the compound according to Synthesis Example 1 are shown in FIG. 6. Referring to FIG. 6, the compound according to Synthesis Example 1 showed a melting point peak in the first analysis, but it did not show a melting point peak in the second analysis. From the results, it is confirmed that the compound according to Synthesis Example 1 was present in the stable asymmetric state.

<202> In addition, it is confirmed that the compounds according to Synthesis Examples 2 to 6 were present in the amorphous state in accordance with the same method. Accordingly, it is anticipated that the organic light emitting diode including each compound according to Synthesis Examples 1 to 6 was not affected by Jouleτl heat during the driving, and the life-span characteristic was more improved compared to the conventional organic photoelectric device.

<203> The present invention is not limited to the embodiments, but can be fabricated into various modifications and equivalent arrangements included within the spirit and scope of the appended claims by a person who is ordinarily skilled in this field. Therefore, the aforementioned embodiments should be understood to be exemplary but not limiting the present invention in any way.

Claims

[CLAIMS] [Claim 1] <205> A material for an organic photoelectric device comprising an asymmetric compound represented by the following Chemical Formula 1: <206> [Chemical Formulal]

<208> wherein, in the above Chemical Formula 1,

<209> Ari is selected from the group consisting of hydrogen and a substituted or unsubstituted aryl , provided that when Ari is a substituted aryl , the substituent of Ari is not the same as Ar₂, <2io> Ar₂ and Ar₃ are independently selected from the group consisting of a substituted or unsubstituted carbazolyl, a substituted or unsubstituted C2 to C30 heteroaryl, a substituted or unsubstituted C2 to C30 arylamine, and a substituted or unsubstituted C2 to C30 heteroarylamine, <2ii> Li and L₂ are independently selected from the group consisting of a substituted or unsubstituted phenylene, a substituted or unsubstituted naphthylene, and a substituted or unsubstituted anthracene, and

<2i2> m and n are integers ranging from 1 to 4.

[Claim 2]

<2i3> The material of claim 1, wherein Ari is selected from the group consisting of phenyl, naphthyl , anthracenyl , phenanthrenyl , pyrenyl , perylenyl, and chrysenyl .

[Claim 3] <2i4> The material of claim 1, wherein Ari is substituted with a substituent selected from the group consisting of a Cl to C30 alkyl , a Cl to ClO heteroalkyl, a C3 to C30 cycloalkyl, a C6 to C30 aryl , a Cl to C30 alkoxy, a fluoro, and a cyano.

[Claim 4] <2i5> The material of claim 1, wherein Ar₂ and Ar3 are independently selected from the group consisting of imidazolyl, thiazolyl, oxazolyl, oxadiazolyl, triazolyl, pyridinyl, pyridazine, quinolinyl, isoquinolinyl , acridyl, imidazopyridinyl , imidazopyrimidinyl , diphenyl amine, dinaphthyl amine, dibiphenyl amine, phenyl naphthyl amine, phenyl diphenyl amine, ditolyl amine, phenyl tolyl amine, carbazoyl , triphenylamine, and dipyridylamine.

[Claim 5] <2i6> The material of claim 1, wherein Li and L₂ are phenylene.

[Claim 6]

<2i7> The material of claim 1, wherein the compound represented by the above Chemical Formula 1 comprises the following compounds (1) to (90), or combinations tehreof:

<2l8>

<219>

<22l>

<222>

<223>

<225>

[Claim 7]

<226> An or_ganic photoelectric device comprising an anode, a cathode, and at least one organic thin layer interposed between the anode and cathode,

<227> wherein at least one of the organic thin layer comprises the material for an organic photoelectric device according to one of claims 1 to 6.

[Claim 8]

<228> The organic photoelectric device of claim 7, wherein the organic thin layer comprises an emission layer; and at least one layer selected from the group consisting of a hole transport layer (HTL), a hole injection layer (HIL), an electron injection layer (EIL), a hole blocking layer, and combinations thereof.

[Claim 9]

<229> The organic photoelectric device of claim 7, wherein the material for an organic photoelectric device is included in an electron transport layer (ETL) or an electron injection layer (EIL).

[Claim 10]

<230> The organic photoelectric device of claim 7, wherein the material for an organic photoelectric device is included in an emission layer.

[Claim 11]

<23i> The organic photoelectric device of claim 7, wherein the material for an organic photoelectric device is included in an emission layer as a phosphorescent or fluorescent host.

[Claim 12]

<232> The organic photoelectric device of claim 7, wherein the material for an organic photoelectric device is included in an emission layer as a fluorescent blue dopant.

[Claim 13]

<233> The organic photoelectric device of claim 7, wherein the organic photoelectric device is selected from the group consisting of an organic light emitting diode, an organic solar cell, an organic transistor, an organic photo-conductor drum, and an organic memory device.

[Claim 14] <234> A display device comprising the organic photoelectric device according to claim 7.