KR102104357B1 - Blue Fluorescence Compounds and Organic Light Emitting Diode Device using the same - Google Patents

Abstract

상기 화학식 1에서, X는 산소(O)원자 또는 황(S)원자이며, R₁은 수소 원자, C1~C25 알킬기, 또는 C3~C4 알킬기로 치환된 페닐기이고, R₂는 수소 원자 또는 C1~25의 알킬기이다.
이에 따라, 용액 공정이 가능한 신규한 형광 화합물 및 이를 포함하는 유기전계발광소자를 제공할 수 있다. The blue fluorescent compound according to an embodiment of the present invention may be represented by the following Chemical Formula 1.
[Formula 1]

In Formula 1, X is an oxygen (O) atom or a sulfur (S) atom, R ₁ is a hydrogen atom, a C1 ~ C25 alkyl group, or a phenyl group substituted with a C3 ~ C4 alkyl group, R ₂ is a hydrogen atom or C1 ~ 25 alkyl group.
Accordingly, a novel fluorescent compound capable of solution processing and an organic electroluminescent device including the same can be provided.

Description

Blue Fluorescence Compounds and Organic Light Emitting Diode Device using the same}

The present invention relates to a blue fluorescent compound and an organic electroluminescent device using the same.

An organic light emitting device, which is one of the new flat panel display devices, has an excellent viewing angle and contrast ratio compared to a liquid crystal display device (LCD), and requires no separate backlight, so that it can be lightweight and thin, and is also advantageous in terms of power consumption. In addition, DC low-voltage driving is possible, the response speed is fast, and in particular, there are advantages in terms of manufacturing cost.

In particular, the organic light emitting device is a self-emitting device that emits light while extinguishing after pairing electrons and holes when a charge is injected into a light emitting layer formed between a cathode serving as an electron injection electrode and an anode serving as a hole injection electrode.

The organic electroluminescent device is formed by sequentially vacuum-depositing an anode, a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, an electron injection layer, and a cathode. In addition, a mask is used to pattern the pixels of red (R), green (G), and blue (B). In the case of a large area, there is a problem that the mask sags as the size of the mask gradually increases.

In order to improve the problem of vacuum deposition as described above, a method of forming an organic layer through a solution process was introduced. The solution process can be coated on a large area without a mask through inkjet printing or nozzle printing, etc., and the material use rate is very high at 50 to 80% compared to vacuum deposition where the material use rate is 10% or less. In addition, the glass transition temperature is higher than that of vacuum deposition, and thus it has an advantage of excellent thermal stability and morphology characteristics.

Development of materials for the solution process can be divided into low-molecular and cross-linked polymers, and organic electroluminescent devices made using these materials have lower characteristics of 50% or less compared to devices made by vacuum deposition. Compared to this, there is a problem that the polymer series is relatively difficult to synthesize and purify.

Therefore, various studies are being conducted on the development of materials capable of solution processing.

The present invention is to solve the above problems, and relates to an organic electroluminescent device comprising a blue fluorescent compound capable of solution processing.

The blue fluorescent compound according to an aspect of the present invention for achieving the above object is represented by the following formula (1).

[Formula 1]

In this case, in Formula 1, X is an oxygen (O) atom or a sulfur (S) atom, R ₁ is a hydrogen atom, a C1 ~ C25 alkyl group, or a C3 ~ C4 alkyl group substituted phenyl group, R ₂ is a hydrogen atom or It is a C1-25 alkyl group.

An organic electroluminescent device according to another aspect of the present invention for achieving the above object is a first electrode; A second electrode facing the first electrode; A light emitting layer positioned between the first and second electrodes; A hole transport layer positioned between the first electrode and the emission layer; An electron transport layer positioned between the second electrode and the emission layer, and at least one of the emission layer, the hole transport layer, and the electron transport layer is a fluorescent compound represented by the following Chemical Formula 1.

[Formula 1]

At this time, in Formula 1, X is an oxygen (O) atom or sulfur (S) atom, R ₁ is a hydrogen atom, a C1 ~ C25 alkyl group, or a C3 ~ C4 alkyl group substituted phenyl group, R ₂ is a hydrogen atom ㄸ Or it is a C1-C25 alkyl group.

According to the present invention, it is possible to provide a novel fluorescent compound capable of solution processing and an organic electroluminescent device comprising the same.

In addition, by using the fluorescent compound of the present invention, it has bipolar characteristics, and the electron-hole balance is improved, so that the luminous efficiency can be further improved, and high-color purity and high-brightness images can be realized under low voltage, and product life is It has an improved effect.

1 is a view showing an organic light emitting device according to an embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Throughout the specification, the same reference numbers refer to substantially the same components. In the following description, when it is determined that a detailed description of known contents or configurations related to the present invention may unnecessarily obscure the subject matter of the present invention, the detailed description is omitted.

1 is a view showing an organic light emitting device according to an embodiment of the present invention.

As shown in Figure 1, the organic light emitting device 100 according to an embodiment of the present invention, the anode 110, the hole injection layer 120, the hole transport layer 130, the light emitting layer 140, the electron transport layer The electron injection layer 160 and the cathode 170 may be included.

The anode 110 may be any one selected from Indium Tin Oxide (ITO), Indium Zinc Oxide (IZO), and Zinc Oxide (ZnO) as an electrode for injecting holes. In addition, when the anode 110 is a reflective electrode, the anode 110 further includes a reflective layer made of any one of aluminum (Al), silver (Ag), or nickel (Ni) under the layer made of any one of ITO, IZO, or ZnO. It can contain.

The hole injection layer 120 may serve to facilitate the injection of holes from the anode 110 to the light emitting layer 140, cupper phthalocyanine (CuPc), poly (3,4) -ethylenedioxythiophene (PEDOT), PANI It may be any one or more selected from (polyaniline) and NPD (N, N-dinaphthyl-N, N'-diphenyl benzidine), but the spirit of the present invention is not limited thereto.

The hole injection layer 120 may have a thickness of 1 to 150 nm. Here, when the thickness of the hole injection layer 120 is 1 nm or more, there is an advantage of preventing the hole injection characteristics from being deteriorated. If it is 150 nm or less, the thickness of the hole injection layer 120 is too thick. In order to improve movement, there is an advantage that the driving voltage can be prevented from rising.

The hole transport layer 130 serves to facilitate the transport of holes, NPD (N, N-dinaphthyl-N, N'-diphenyl benzidine), TPD (N, N'-bis- (3-methylphenyl)- N, N'-bis- (phenyl) -benzidine), s-TAD and MTDATA (4,4 ', 4 "-Tris (N-3-methylphenyl-N-phenyl-amino) -triphenylamine) However, the spirit of the present invention is not limited thereto.

The hole transport layer 130 may have a thickness of 1 to 150 nm. Here, when the thickness of the hole transport layer 130 is 5 nm or more, there is an advantage of preventing the hole transport properties from being deteriorated, and when 150 nm or less, the thickness of the hole transport layer 130 is too thick to improve the movement of holes In order to prevent the driving voltage from rising, there is an advantage.

The light emitting layer 140 may be made of a material that emits red, green, and blue colors, and may be formed using phosphorescent or fluorescent materials. Hereinafter, a fluorescent material emitting blue light will be described in detail in an embodiment of the present invention.

The light emitting layer 140 of the present invention may include a host and a dopant.

At this time, the host of the present invention is composed of a blue fluorescent compound represented by the following formula (1).

[Formula 1]

In Formula 1, X is an oxygen (O) atom or a sulfur (S) atom, R ₁ is a hydrogen atom, a C1 ~ C25 alkyl group, or a phenyl group substituted with a C3 ~ C4 alkyl group, R ₂ is a hydrogen atom or C1 ~ 25 alkyl group.

Here, R ₁ is a hydrogen atom or any one of the following Formulas 2 to 6, and R ₂ may be a hydrogen atom or any one of the following Formulas 2 to 4.

[Formula 2]

[Formula 3]

[Formula 4]

[Formula 5]

[Formula 6]

화학식 2 내지 화학식 6에서 별 표시는 결합되는 부분을 나타냄.

In Chemical Formulas 2 to 6, the asterisk indicates a portion to be joined.

The blue fluorescent compound may be any one selected from the following compounds.

In the case of the dopant mixed with the host in the light emitting layer 140 of the present invention, it may be an iridium compound such as FCNIr or FIrpic. In addition, in the light emitting layer 140 of the present invention, the dopant may be included in an amount of 0.1 to 20% by weight relative to 100% by weight of the host.

The electron transport layer 150 serves to facilitate the transport of electrons, and may be one or more selected from Alq3 (tris (8-hydroxyquinolino) aluminum), PBD, TAZ, spiro-PBD, BAlq, and SAlq, Thoughts are not limited to this.

The electron transport layer 150 may have a thickness of 1 to 50 nm. Here, when the thickness of the electron transport layer 150 is 1 nm or more, there is an advantage of preventing the electron transport properties from deteriorating, and when it is 50 nm or less, the thickness of the electron transport layer 150 is too thick to improve the movement of electrons In order to prevent the driving voltage from rising, there is an advantage.

The electron injection layer 160 serves to facilitate the injection of electrons, and Alq3 (tris (8-hydroxyquinolino) aluminum), PBD, TAZ, spiro-PBD, BAlq or SAlq can be used, but the idea of the present invention Is not limited to this.

The electron injection layer 160 may have a thickness of 1 to 50 nm. Here, when the thickness of the electron injection layer 160 is 1 nm or more, there is an advantage of preventing the electron injection characteristics from deteriorating, and when it is 50 nm or less, the thickness of the electron injection layer 150 is too thick to move electrons. In order to improve, there is an advantage that the driving voltage can be prevented from rising.

The cathode 170 is an electron injection electrode, and may be made of magnesium (Mg), calcium (Ca), aluminum (Al), silver (Ag), or an alloy thereof having a low work function. Here, the anode 170 may be formed to a thickness thin enough to transmit light when the organic light emitting device is a front or both sides light emitting structure, and when the organic light emitting device is a back light emitting structure, it may reflect light. It can be formed to be thick enough.

Hereinafter, the synthesis examples of the blue fluorescent compound of the present invention and the properties of the compounds will be described in the following synthesis examples and examples. However, the following examples are merely illustrative of the present invention, and the present invention is not limited to the following examples.

Synthetic example

1) Preparation of 2,6-di-tetra-butylanthracene (2,6-di-tert-butylanthracene)

Anthracene (33mmol), 2-methylpropan-2-ol (110mmol) and TFA (50 ml) were added to a two-neck round bottom flask and stirred at room temperature for 72 hours. . Subsequently, while washing with acetic acid remaining in water and hexane, the filter was filtered to obtain 6.0 g of a solid.

2) Preparation of 2,6-di-tetra-butyl-9,10-diboromoanthracene (2,6-di-tert-butyl-9,10-diboromoanthracene)

2,6-ditetrabutyl anthracene (14mmol) and chloroform (30ml) were added to the two-neck round bottom flask, stirred, and then bromine (42 mmol) was added. I put it in slowly. Subsequently, after stirring for 72 hours, the reaction was quenched with sodium thio sulfate dissolved in purified water (DI water), and 4.5 g of powder was used with dichloromethane and methanol. Got.

3) Preparation of 2,6-di-tetra-butyl-9-dibenzothiophenyl-10-bromoanthracene (2,6-di-tert-butyl-9-dibenzothiopenyl-10-bromoanthracene)

2,6-di-tetra-butyl-9,10-dibromoanthracene (2,6-di-tert-butyl-9,10-diboromoanthracene) (10mmol) and 3-dibenzothio in a 2-neck round bottom flask Phenyl boronic acid (3-dibenzothiopenyl boronic acid) and tetrakis (triphenylphosphine) palladium (0.5 mmol) and potassium carbonate (12 g) toluene (30 ml) , Dissolved in water (H ₂ O) (10 ml), and stirred at 100 ° C. for 24 hours. After the reaction was completed, toluene was removed, extraction was performed using ethyl ether and water, and distillation was performed under reduced pressure. Subsequently, after silica gel column, the solvent was distilled under reduced pressure, recrystallized with dichloromethane and petroleum ether, and then filtered to obtain 4.0 g of a solid. Did.

4) Preparation of the first host: Preparation of 2,6-di-tetra-butyl-9-dibenzothiophenyl-10-naphthalene (2,6-di-tert-butyl-9-dibenzothiopenyl-10-naphthalene)

2,6-di-tetra-butyl-9,10-diboromoanthracene (2,6-di-tert-butyl-9,10-diboromoanthracene) (7mmol), 2-naphthalene boronic in a 2-neck round bottom flask 2-naphthaleneboronic acid (8.7 mmol), tetrakis (triphenylphosphine) palladium (0.5 mmol), and potassium carbonate (9 g) toluene (27 ml) And H ₂ O (9 ml), followed by stirring at 100 ° C. for 24 hours. After the reaction was completed, toluene was removed, followed by extraction using ethyl ether and water, distillation under reduced pressure, recrystallization using dichloromethane and hexane, and then filter. This gave 3.8 g of a solid.

Hereinafter, Experimental Example 1 to Experimental Example 3 for manufacturing an organic electroluminescent device using the blue fluorescent compound according to the embodiment of the present invention described above, and a comparative example for manufacturing an organic electroluminescent device using a conventional fluorescent compound Through, the performance of the blue fluorescent compound of the present invention and the organic electroluminescent device using the same will be described.

Experimental Example 1

The indium-tin-oxide (ITO) layer on the substrate was patterned to have a light emitting area of 3 mm X 3 mm, and then washed. After mounting the substrate in a vacuum chamber, the process pressure (base pressure) is 1X10 ^-6 torr, and then the organic material is placed on the ITO layer DNTPD (700Å), NPD (300Å), first host (250Å) + dopant DPAVBi (4 %), Alq3 (350 kPa), LiF (5 kPa), and Al (1000 kPa) in order.

[First host]

As a result of the experiment, it showed 725 cd / m2 (4.3 V) at 10 mA / cm2, where CIEx = 0.142 and CIEy = 0.203. The half-life is 1210 hr at 3000 cd / m2.

Experimental Example 2

The indium-tin-oxide (ITO) layer on the substrate was patterned to have a light emitting area of 3 mm X 3 mm, and then washed. After mounting the substrate in a vacuum chamber, the process pressure (base pressure) is 1X10 ^-6 torr, and then the organic material is placed on the ITO layer DNTPD (700Å), NPD (300Å), second host (250Å) + dopant DPAVBi (4 %), Alq3 (350 kPa), LiF (5 kPa), and Al (1000 kPa) in order.

[Second Host]

As a result of the experiment, 720cd / m2 (4.5V) was displayed at 10mA / cm2, and CIEx = 0.143 and CIEy = 0.204. The half-life is 1158 hr at 3000 cd / m2.

Experimental Example 3

The indium-tin-oxide (ITO) layer on the substrate was patterned to have a light emitting area of 3 mm X 3 mm, and then washed. After mounting the substrate in a vacuum chamber, the process pressure (base pressure) was 1X10 ^-6 torr, and then the organic material was placed on the ITO layer DNTPD (700Å), NPD (300Å), third host (250Å) + dopant DPAVBi (4 %), Alq3 (350 kPa), LiF (5 kPa), and Al (1000 kPa) in order.

[3rd host]

As a result of the experiment, it showed 726 cd / m2 (4.7V) at 10 mA / cm2, and CIEx = 0.142 and CIEy = 0.203. The half-life is 950 hr at 3000 cd / m2.

Comparative example

The indium-tin-oxide (ITO) layer on the substrate was patterned to have a size of 3 mm X 3 mm, and then washed. After mounting the substrate in a vacuum chamber, the process pressure (base pressure) is 1X10 ^-6 torr, and then the organic material is placed on the ITO layer DNTPD (700Å), NPD (300Å), a-AND (250Å) which is a conventional fluorescent material. + Film formation was performed in the order of dopant DPAVBi (4%), Alq3 (350 kPa), LiF (5 kPa), and Al (1000 kPa).

[a-AND]

As a result of the experiment, it showed 724 cd / m2 (5.4V) at 10 mA / cm2, and CIEx = 0.144 and CIEy = 0.205. The half-life is 650 hr at 3000 cd / m2.

Here, each of the DNTPD, the NPD, the DPVBi, and the Alq3 is represented as follows.

[DNTPD]

[NPD]

[DPAVBi]

[Alq3]

Table 1 shows the comparison results of Experimental Examples 1 to 3 and Comparative Examples described above. Here, the voltage unit is V, the current unit is mA / cm2, the luminance unit is cd / m2, and the lifetime unit is time (h).

As shown in Table 1, Experimental Example 1 to Experimental Example 3 showed that the CIEy value was lowered and the color purity was improved while driving at low voltage was possible when compared with the comparative example.

device Voltage
(V) electric current
(mA) Luminance
(cd / m2) Current efficiency
(cd / A) Power efficiency
(lm / W) CIEx CIEy life span
(h) Experimental Example 1 4.3 0.9 725 8.9 6.5 0.142 0.203 1210 Example 2 4.5 0.9 720 9.1 6.3 0.143 0.204 1158 Example 3 4.7 0.9 726 7.8 5.2 0.142 0.203 950 Comparative example 5.4 0.9 724 7.2 4.2 0.144 0.205 650

Therefore, the blue fluorescent compound and the organic light emitting device including the same according to an embodiment of the present invention have the advantage of being capable of solution processing, while improving the current efficiency, power efficiency, color purity and lifespan characteristics than the conventional organic light emitting device. You can.

Those skilled in the art to which the present invention pertains will understand that the above-described present invention can be implemented in other specific forms without changing its technical spirit or essential features.

Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive. The scope of the present invention is indicated by the following claims rather than the above detailed description, and it should be interpreted that all changes or modifications derived from the meaning and scope of the claims and equivalent concepts are included in the scope of the present invention. do.

100: organic electroluminescent element 110: anode
120: hole injection layer 130: hole transport layer
140: light emitting layer 150: electron transport layer
160: electron injection layer 170: cathode

Claims (9)

A blue fluorescent compound represented by Formula 1 below.
[Formula 1]

In Formula 1, X is an oxygen (O) atom or a sulfur (S) atom, R _1a is any one of the following Formula 5 or Formula 6, R _1b is any one of the following Formula 2 to Formula 6 And R ₂ is any one of the following Chemical Formulas 2 to 4.
[Formula 2]

[Formula 3]

[Formula 4]

[Formula 5]

[Formula 6]

In Chemical Formulas 2 to 6, the asterisk indicates a portion to be joined. delete According to claim 1,
The blue fluorescent compound,
Blue fluorescent compound, characterized in that any one selected from the compounds shown below.

According to claim 1,
The blue fluorescent compound,
Blue fluorescent compound, characterized in that any one selected from the compounds shown below.

A first electrode;
A second electrode facing the first electrode;
A light emitting layer positioned between the first and second electrodes;
A hole transport layer positioned between the first electrode and the emission layer;
And an electron transport layer positioned between the second electrode and the light emitting layer,
At least one of the light emitting layer, the hole transport layer and the electron transport layer, characterized in that it comprises a fluorescent compound represented by the formula (1), an organic electroluminescent device.
[Formula 1]

In Formula 1, X is an oxygen (O) atom or a sulfur (S) atom, R _1a is any one of the following Formula 5 or Formula 6, R _1b is any one of the following Formula 2 to Formula 6 And R ₂ is any one of the following Chemical Formulas 2 to 4.
[Formula 2]

[Formula 3]

[Formula 4]

[Formula 5]

[Formula 6]

In Chemical Formulas 2 to 6, the asterisk indicates a portion to be joined. delete The method of claim 5,
The fluorescent compound,
Organic electroluminescent device, characterized in that any one selected from the compounds shown below.

The method of claim 5,
The fluorescent compound,
Organic electroluminescent device, characterized in that any one selected from the compounds shown below.

The method of claim 5,
The light emitting layer is an organic light emitting device that emits blue light.

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