KR20110049554A - Blue color fluorescence compounds and organic light emitting diode comprising thereof - Google Patents

Abstract

PURPOSE: A blue color fluorescence compound and an organic light emitting diode comprising the same are provided to improve voltage, brightness, and color purity compared with conventional organic electroluminescence devices. CONSTITUTION: A blue color fluorescence compound is represented by chemical formula 1. In chemical formula 1, R1, R2 and R3 are independently substituted or unsubstituted C5-35 phenyl, biphenyl, naphthyl, terphenyl, pyrene, pyridine or quinoline. A substituent of R1, R2 and R3 is selected from aromatic compounds having alkyl, alkoxy, halogen, cyano and silyl group. R4 is substituted with hydrogen or deuterium.

Description

Blue fluorescent compound and organic light emitting device comprising the same {Blue Color Fluorescence Compounds And Organic Light Emitting Diode Comprising Thereof}

The present invention relates to an organic electroluminescent device, and more particularly, to an organic electroluminescent device comprising a novel blue fluorescent compound.

Recently, the importance of the flat panel display (FPD) has increased with the development of multimedia. In response, Liquid Crystal Display (LCD), Plasma Display Panel (PDP), Field Emission Display (FED), Organic Light Emitting Diode Display Device, etc. The same various displays are put to practical use.

Among these, the organic light emitting device is a self-light emitting device that emits light when electrons and holes are paired and extinguished when charge is injected into the organic light emitting layer formed between the cathode as the electron injection electrode and the anode as the hole injection electrode.

The organic light emitting diode can be formed on a flexible substrate such as plastic, and can be driven at a voltage lower than 10V, compared to a plasma display panel or an inorganic electroluminescent display, and consumes less power and has excellent color. Has the advantage. In addition, the organic light emitting display device may display three colors of red, green, and blue, and thus, is a next generation display device that expresses a rich color, and thus has been attracting many people's attention.

The blue organic light emitting diode may be formed by sequentially stacking 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 this case, although the light emitting layer uses a host-dopant system, conventionally used host materials exhibit relatively low luminance and low color purity.

Therefore, development of a host material having a new structure to implement an organic light emitting display device having high brightness and high color purity is required.

Accordingly, the blue fluorescent compound of the present invention and the organic light emitting display device including the same have an advantage of providing an organic light emitting display device which can exhibit high brightness and excellent color purity.

In order to achieve the above object, the blue fluorescent compound according to an embodiment of the present invention provides a blue fluorescent compound represented by the following formula (1).

[Formula 1]

In Formula 1, R ₁ , R ₂ and R ₃ are each independently substituted or unsubstituted phenyl, biphenyl, naphthyl, phenanthrenyl, terphenyl, pyrene, pyridine or quinoline having 5 to 35 carbon atoms It can be one.

In addition, the organic light emitting display device according to an embodiment of the present invention, in the organic light emitting device including 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, the first to the first The blue fluorescent compound of claim 6 may be included as a host of the emission layer.

The blue fluorescent compound of the present invention and an organic light emitting device including the same have an advantage of improving luminance and blue color purity.

Hereinafter, various embodiments of the present invention will be described in detail with reference to the accompanying drawings.

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

Referring to FIG. 1, an organic light emitting display device 100 according to an exemplary embodiment of the present invention includes an anode 110, a hole injection layer 120, a hole transport layer 130, a light emitting layer 140, and an electron transport layer 150. The electron injection layer 160 and the cathode 170 may be included.

The anode 110 may be any one of an indium tin oxide (ITO), indium zinc oxide (IZO), or zinc oxide (ZnO) having a high work function as an electrode for injecting holes. In addition, when the anode 110 is a reflective electrode, the anode 110 is a reflective layer made of any one of aluminum (Al), silver (Ag), or nickel (Ni) under a layer made of any one of ITO, IZO, or ZnO. It may further include.

The hole injection layer 120 may play a role of smoothly injecting holes from the anode 110 to the light emitting layer 140, and may include cupper phthalocyanine (CuPc), poly (3,4) -ethylenedioxythiophene (PEDOT), and PANI. (polyaniline) and NPD (N, N-dinaphthyl-N, N'-diphenyl benzidine) may be made of any one or more selected from the group consisting of, but 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 that the hole injection characteristics can be prevented from deteriorating. When the thickness of the hole injection layer 120 is too thick, the hole injection layer 120 is too thick. There is an advantage that can be prevented from increasing the driving voltage to improve.

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) It may be made of any one or more, but is not limited thereto.

The hole transport layer 130 may have a thickness of 1 to 150 nm. In this case, when the thickness of the hole transport layer 130 is 5 nm or more, there is an advantage of preventing the hole transport property from being lowered. When the thickness of the hole transport layer 130 is less than or equal to 150 nm, 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 emission layer 140 may be formed of a material emitting red, green, and blue, and may be formed using a phosphorescent or fluorescent material. In the present embodiment, a material emitting blue light will be described.

The emission layer 140 may include a host and a dopant material. Here, the dopant material may be BD-A represented by the following formula, but is not limited thereto.

The host material of the emission layer 140 may be a blue fluorescent compound represented by Formula 1 below.

[Formula 1]

In Formula 1, R ₁ , R ₂ and R ₃ are each independently substituted or unsubstituted phenyl, biphenyl, naphthyl, phenanthrenyl, terphenyl, pyrene, pyridine or quinoline having 5 to 35 carbon atoms It can be one.

The substituents of R ₁ , R ₂ and R ₃ may be any one selected from aromatic compounds having alkyl, alkoxy, halogen, cyano and silyl groups.

The substituents of R ₁ , R ₂ and R ₃ may each independently be any one selected from the group consisting of methyl, ethyl, propyl, isopropyl, butyl, methoxy, ethoxy, butoxy, trimethylsilyl, fluorine and chlorine. have.

R ₄ may be phenyl substituted with hydrogen or deuterium.

The blue fluorescent compound may be any one selected from compounds shown below.

Doping concentration of the dopant may be 0.5 to 10 parts by weight.

The electron transport layer 150 serves to facilitate the transport of electrons, made of one or more selected from the group consisting of Alq3 (tris (8-hydroxyquinolino) aluminum), PBD, TAZ, spiro-PBD, BAlq and SAlq. But it is not limited thereto.

The thickness of the electron transport layer 150 may be 1 to 50nm. In this case, when the thickness of the electron transport layer 150 is 1 nm or more, there is an advantage of preventing the electron transport characteristics from being lowered. When the thickness of the electron transport layer 150 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 may be Alq3 (tris (8-hydroxyquinolino) aluminum), PBD, TAZ, spiro-PBD, BAlq or SAlq, but is not limited thereto.

The electron injection layer 160 may have a thickness of about 1 nm to about 50 nm. Here, when the thickness of the electron injection layer 160 is 1 nm or more, there is an advantage that the electron injection characteristics may be prevented from being lowered. There is an advantage that can be prevented from increasing the driving voltage to improve.

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. 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 double-sided light emitting structure, and may reflect light when the organic light emitting device is a rear light emitting structure. It can form thick enough.

Hereinafter, the synthesis examples of the blue fluorescent compound of the present invention and the organic electroluminescent device including the compound will be described in detail in the following Synthesis Examples and Examples. However, the following examples are merely to illustrate the present invention is not limited to the following examples.

Synthetic example

1) Synthesis of 9-phenylanthracene

In a two-necked round bottom flask, 1-bromoanthracene (2 g, 7.81 mmol) and phenylboronic acid (1.05 g, 8.59 mmol) were added to 80 ml of anhydrous tetrahydrofuran and stirred. Tetrakis (triphenylphosphine) palladium (0.45g, 5mol%), potassium carbonate (20g) and 80ml of distilled water were added and refluxed at 100 ° C for 24 hours. After the reaction is completed, tetrahydrofuran is removed and the solids produced are filtered out. Recrystallization using dichloromethane and methanol gave 1-phenylanthracene (1.81 g, 91%).

2) Preparation of 9-phenyl-10-bromoanthracene

1-phenylanthracene (2 g, 7.86 mmol) and 50 mL of chloroform were added to a two necked round bottom flask and stirred. Bromine (1.27 g, 7.94 mmol) is slowly dropped for 30 minutes and then stirred at room temperature for 8 hours. After the reaction, 100 mL of distilled water was added and stirred. The resulting solids were filtered off and washed with 50 mL of distilled water and 50 mL of ethanol to obtain 1-phenyl-9-bromoanthracene (2.1 g, 80%).

3) Preparation of 9-phenyl-10-meth-terphenylanthracene

In a two-neck round bottom flask, 1-phenyl-9-bromoanthracene (2 g, 6.00 mmol) and meta-terphenyl boronic acid (1.81 g, 6.60 mmol) were added to 80 mL of anhydrous tetrahydrofuran and stirred. Tetrakis (triphenylphosphine) palladium (0.35g, 5mol%), potassium carbonate (K ₂ CO ₃ , 20g) and 80mL of distilled water were added and refluxed at 100 ° C for 24 hours. After the reaction is completed, the tetrahydrofuran is removed and the resulting solids are filtered out. Recrystallization using dichloromethane and methanol gave 1-phenyl-10-meth-terphenylanthracene (2.49 g, 86%).

Example

Hereinafter, the Example which produced the organic electroluminescent element using the blue fluorescent compound of this invention represented by BH1, BH11, BH205, and BH308 mentioned above as a blue host is described.

≪ Example 1 >

The light emitting area of the ITO glass was patterned to have a size of 3 mm x 3 mm and then washed. After mounting the substrate in a vacuum chamber, the base pressure was 1 × 10 ⁻⁶ torr, and then CuPC, a hole injection layer, was deposited to a thickness of 200 kPa on the anode ITO, NPD, a hole transport layer, was deposited to a thickness of 400 kPa, and the light emitting layer was formed. As a result, 200 Å of compound represented by BH1 as a host and BD-A 50 인 of dopant were formed at a weight of 1 part by weight of the dopant. Next, Alq ₃ as an electron transport layer was formed to a thickness of 350 kW, LiF as an electron injection layer was formed to a thickness of 5 kW, and Al as a cathode was formed to a thickness of 1000 kW to fabricate an organic light emitting device.

<Example 2>

Under the same conditions as in Example 1, an organic light emitting diode was manufactured by using only a host material as a compound represented by BH11.

<Example 3>

Under the same conditions as in Example 1, an organic light emitting diode was manufactured by using only a host material as a compound represented by BH205.

<Example 4>

Under the same conditions as in Example 1, an organic light emitting diode was manufactured by using only a host material as a compound represented by BH308.

Comparative Example

Under the same conditions as in Example 1, an organic light emitting diode was manufactured by using only a host material as a DPBVi compound.

The voltage, current, brightness and color coordinates of the organic light emitting diodes manufactured according to Examples 1 to 4 and Comparative Examples were measured and shown in Table 1 below.

Voltage (v) Current (mA)
Luminance
(cd / ㎡) Color coordinates CIE (X) CIE (Y) Example 1 4.30 0.9 574 0.146 0.103 Example 2 4.58 0.9 608 0.147 0.109 Example 3 4.42 0.9 603 0.148 0.114 Example 4 4.78 0.9 638 0.144 0.138 Comparative Example 1 6.7 0.9 526 0.136 0.188

As shown in Table 1, it can be seen that the organic light emitting display device manufactured according to Examples 1 to 4 exhibited better color coordinates in the comparative example, and the voltage and luminance characteristics were significantly improved compared to the comparative example. Can be.

Accordingly, the blue fluorescent compound and the organic light emitting device including the same according to an embodiment of the present invention have an advantage of improving voltage, luminance, and color coordinate characteristics as compared to the conventional organic light emitting device.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It will be understood that the invention may be practiced. Therefore, the embodiments described above are to be understood as illustrative and not restrictive in all aspects. In addition, the scope of the present invention is shown by the claims below, rather than the above detailed description. Also, it is to be construed that all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts are included in the scope of the present invention.

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

Claims (7)

Blue fluorescent compound represented by the following formula (1).

In Formula 1, R ₁ , R ₂ and R ₃ are each independently substituted or unsubstituted phenyl, biphenyl, naphthyl, phenanthrenyl, terphenyl, pyrene, pyridine or quinoline having 5 to 35 carbon atoms It can be one. The method of claim 1, The substituent of R ₁ , R ₂ and R ₃ is any one selected from aromatic compounds having alkyl, alkoxy, halogen, cyano and silyl groups. 3. The method of claim 2, Substituents of R ₁ , R ₂ and R ₃ are each independently selected from the group consisting of methyl, ethyl, propyl, isopropyl, butyl, methoxy, ethoxy, butoxy, trimethylsilyl, fluorine and chlorine Fluorescent compounds. The method of claim 1, R ₄ is a blue fluorescent compound which is phenyl substituted with hydrogen or deuterium. The method according to claim 1 and 4, The blue fluorescent compound is any one selected from among the compounds shown below.

The method of claim 5, The compound is a blue fluorescent compound in which hydrogen of phenyl 9 of anthracene is substituted with deuterium. In the organic light emitting device comprising 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, An organic light emitting display device comprising the blue fluorescent compound of claim 1 as a host of the light emitting layer.

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