KR20110072040A - Blue fluorescent compound and organic light emitting device using same - Google Patents

Abstract

The present invention relates to a blue fluorescent compound capable of achieving high brightness and high efficiency and an organic light emitting device using the same, wherein the blue fluorescent compound is represented by the following Chemical Formula 1,

[Formula 1]

R1, R2 and R3 may be selected from hydrogen, deuterium, C1 to C6 alkyl group, substituted or unsubstituted C6 or more aryl group or fluorine group, at least one of R1, R2, R3 comprises fluorine, and The other includes a substituted or unsubstituted C6 or more aryl group, R4, R5, R6, R7, R8 are hydrogen, deuterium, an alkyl group from C1 to C6, a C6 or more substituted or unsubstituted aryl group, florin, cyanine, The trifluoromethyl or trimethylsilyl group is selected.

Description

Blue fluorescent compound and organic electroluminescent device using the same {Blue Fluorescence Compound and Organic Electroluminescence Device using The Same}

The present invention relates to a blue fluorescent compound and an organic light emitting device using the same, and more particularly, to a blue fluorescent compound capable of achieving high brightness and high efficiency and an organic light emitting device using the same.

Video display devices that realize various information as screens are the core technologies of the information and communication era, and are developing in a direction of thinner, lighter, portable and high performance.

With the development of the information society in recent years, various forms of display devices have increased, and flat displays such as liquid crystal display (LCD), plasma display panel (PDP), electro luminescent display (ELD), and field emission display (FED) There is an active research on the device.

The organic light emitting device is a device that emits light by dissipating electrons and holes after pairing when electrons are injected into the organic light emitting layer formed between the electron injection electrode (cathode) and the hole injection electrode (anode).

The organic light emitting diode can be formed on a flexible transparent substrate such as plastic, and can be driven at a lower voltage and consumes less power than a plasma display panel or an inorganic electroluminescent display. It has a small and excellent color.

The organic light emitting layer may exhibit red, green, or blue color depending on the organic compound included in the light emitting layer. The known organic compound has a lack of lifespan, luminous efficiency, and luminance, and is particularly difficult to realize a clear blue color due to low color purity of blue. It is difficult to implement full color display.

The present invention is to solve the above problems, and an object of the present invention is to provide a blue fluorescent compound that can achieve high brightness and high efficiency and an organic EL device using the same.

The blue fluorescent compound according to the present invention is represented by the following formula (1),

[Formula 1]

R1, R2 and R3 may be selected from hydrogen, deuterium, C1 to C6 alkyl group, substituted or unsubstituted C6 or more aryl group or fluorine group, at least one of R1, R2, R3 comprises fluorine, and The other includes a substituted or unsubstituted C6 or more aryl group, R4, R5, R6, R7, R8 are hydrogen, deuterium, an alkyl group from C1 to C6, a C6 or more substituted or unsubstituted aryl group, florin, cyanine, The trifluoromethyl or trimethylsilyl group is selected.

In an organic light emitting device using a blue fluorescent compound according to the present invention, an organic light emitting device including a light emitting layer between a cathode and an anode, wherein the light emitting layer includes a dopant material and a host material, and the dopant material is represented by Chemical Formula 1 do.

The C1 to C6 alkyl group is selected from the group consisting of methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl and t-butyl, wherein the C6 or more aryl group is substituted with phenyl, deuterium Deuterium substituted phenyl, biphenyl, naphthyl, phenanthrene, terphenyl, fluorenyl and their substituents.

The organic light emitting device using the blue fluorescent compound further includes a hole injection layer and a hole transport layer sequentially formed between the anode and the light emitting layer, and an electron transport layer and an electron injection layer sequentially formed between the light emitting layer and the cathode.

The dopant material may be contained in an amount of 0.1 wt% to 50 wt% based on the total weight of the host material and the dopant material.

The blue fluorescent compound according to the present invention substitutes diphenyl amine in the pyrene skeleton and introduces a florin group and an aryl group in the diphenyl amine, so that the organic light emitting device using the blue fluorescent compound can be driven at low voltage and improve color purity. do.

In addition, the present invention improves the lifetime and has a high luminous efficiency.

Hereinafter, a blue fluorescent compound and an organic light emitting device using the same according to the present invention will be described in detail with reference to the accompanying drawings.

The blue fluorescent compound according to the present invention is represented by the following formula (1).

In Formula 1 above, hydrogen, deuterium, an alkyl group from C1 to C6, a substituted or unsubstituted C6 or more aryl group or florin group may be selected as R1. As R2, hydrogen, deuterium, an alkyl group of C1 to C6, a substituted or unsubstituted C6 or more aryl group or florin group may be selected. R 3 may be selected from hydrogen, deuterium, C 1 -C 6 alkyl groups, substituted or unsubstituted C 6 or more aryl groups, or florin groups.

Wherein at least one of R1, R2, R3 comprises a fluorine, and the other must contain a substituted or unsubstituted C6 or higher aryl group.

R 4 may be selected from hydrogen, deuterium, C 1 -C 6 alkyl groups, C 6 or more substituted or unsubstituted aryl groups, florin, cyanine, trifluoromethyl or trimethylsilyl groups. R 5 may be selected from hydrogen, deuterium, C 1 -C 6 alkyl groups, C 6 or more substituted or unsubstituted aryl groups, florin, cyanine, trifluoromethyl or trimethylsilyl groups.

R 6 may be selected from hydrogen, deuterium, C 1 -C 6 alkyl groups, C 6 or more substituted or unsubstituted aryl groups, florin, cyanine, trifluoromethyl or trimethylsilyl groups. R 7 may be selected from hydrogen, deuterium, C 1 -C 6 alkyl groups, C 6 or more substituted or unsubstituted aryl groups, florin, cyanine, trifluoromethyl or trimethylsilyl groups. R 8 may be selected from hydrogen, deuterium, C 1 -C 6 alkyl groups, C 6 or more substituted or unsubstituted aryl groups, florin, cyanine, trifluoromethyl or trimethylsilyl groups.

The alkyl group of C1 to C6 may be selected from the group consisting of methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl and t-butyl. C6 and higher aryl groups are phenyl, deuterium substituted phenyl, biphenyl, naphthyl, phenanthrene, terphenyl and fluorenyl And their substituents.

Specific examples of the phenyl moiety including R1, R2 and R3 may be represented by the following compounds, at least one of which includes fluorine and another of which includes a substituted or unsubstituted C6 or more aryl group do. However, the present invention is not limited thereto.

Specific examples of the phenyl moiety including R 4, R 5, R 6, R 7 and R 8 may be represented by the following compounds. However, the present invention is not limited thereto.

The blue fluorescent compound represented by Chemical Formula 1 may be specifically represented by the following compounds of D-1 to D-144. However, the present invention is not limited thereto.

Hereinafter, a method for synthesizing the blue fluorescent compound of the present invention will be described by taking the compound represented by D-2 among the blue fluorescent compounds according to the present invention as an example.

[Synthesis Example]

1) Synthesis of 3-bromo-5-Fluorobiphenyl

In a round flask, 1,3-dibromo-5-fluorobenzene (20 mmol), phenylboronic acid (22 mmol), tetrakis (triphenylphosphine) palladium (0) (1 mmol) and Potassium carbonate (15 g) were added to THF (50 mL), H ₂ O ( 40 mL), and then stirred in a 100 ° C. bath for 24 hours. After the reaction was completed, the THF was removed, extracted with dichloromethane and water, distilled under reduced pressure, and then the silica gel column was distilled under reduced pressure to obtain 3.7 g of 3-bromo-5-Fluorobiphenyl.

2) Preparation of 3-Fluoro-5-phenyl-N-phenylbenzenamine

3-bromo-5-Fluorobipheny (10mmol), aminobenzene (11mmol), Tris (dibenzylideneacetone) dipalladium (0) (0.2mmol), (±) -2,2'-Bis (diphenylphosphino) -1,1 'in round flask Dissolve -binaphthalene (0.3 mmol) and sodium tert-butoxide (14 mmol) in toluene (50 mL), stir for 24 hours in a 100 ° C bath, remove the toluene when the reaction is complete, remove dichloromethane and water. Extract using. After distillation under reduced pressure, the solvent was distilled off under reduced pressure after silica gel column, recrystallized with dichloromethane and petroleum ether, and filtered to obtain 2.2 g of 3-Fluoro-5-phenyl-N-phenylbenzenamine solid.

3) N1, N6-bis (3-fluoro-5-phenyl) -N1, N6-diphenylpyrene-1,6-diamine (D-2)

In a round flask, 3-Fluoro-5-phenyl-N-phenylbenzenamine (8 mmol), 1,6-dibromopyrene (4 mmol), Tris (dibenzylideneacetone) dipalladium (0) (0.15 mmol), tri-tert-butylphosphine (0.2 mol) Sodium tert-butoxide (12 mmol) was dissolved in toluene (30 mL), and then stirred in a 100 ° C. bath for 24 hours. After the reaction is completed, toluene is removed, extracted with dichloromethane and water, and then distilled under reduced pressure. After silica gel columm, the solvent was distilled off under reduced pressure, and then recrystallized and filtered using dichloromethane and acetone to give a compound D-2.

As described above, the present invention may improve color purity, lifetime, and luminous efficiency by substituting at least one florin and aryl group at R1, R2, and R3 positions in the general formula (1). In addition, by replacing the florin group, trifluoro methyl group, trimethylsilyl group or cyanine group in the positions R4, R5, R6, R7, R8, it is possible to improve the high luminous efficiency, color purity and lifespan.

As shown in FIG. 1, the organic light emitting device 130 using the blue fluorescent compound according to the present invention is formed between the opposite anode 132, the cathode 138, and the anode 132 and the cathode 138. An emission layer (EML) 135 including a host material and a dopant material is included. The dopant material of the emission layer 135 is a structure represented by Formula 1 above.

In Formula 1, each of R1, R2, and R3 may be selected from hydrogen, deuterium, an alkyl group up to C1 to C6, a substituted or unsubstituted C6 or more aryl group, or a fluorine group. Wherein at least one of R1, R2, R3 comprises a fluorine, and the other must contain a substituted or unsubstituted C6 or higher aryl group.

Each of R4, R5, R6, R7, R8 may be selected from hydrogen, deuterium, C1 to C6 alkyl group, C6 or more substituted or unsubstituted aryl group, florin, cyanine, trifluoromethyl or trimethylsilyl group.

The alkyl group of C1 to C6 may be selected from the group consisting of methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl and t-butyl. C6 and higher aryl groups are phenyl, deuterium substituted phenyl, biphenyl, naphthyl, phenanthrene, terphenyl and fluorenyl And their substituents.

The dopant material constituting the light emitting layer 135 may be specifically represented by the blue fluorescent compound of D-1 to D-144. However, the present invention is not limited thereto. The dopant material selected from the compounds D-1 to D-144 is contained in the light emitting layer 0.1wt% to 50wt% based on the total weight of the host material and the dopant material.

The host material constituting the emission layer 135 together with the dopant material selected from D-1 to D-144 is 9,10-bis (1-naphthyl) anthracene (9,10-) represented by Chemical Formula 2 below. Bis (1-naphthyl) anthracene; α-ADN) may be used. However, the present invention is not limited thereto, and a known host material may be used.

The organic light emitting device 130 further includes a hole injection layer (HIL) 133 and a hole transport layer (HTL) 134 between the anode 132 and the light emitting layer 135, or between the light emitting layer 135 and the cathode 138. An electron transport layer (ETL) 136 and an electron injection layer (EIL) 137 may be further included.

Indium tin oxide (ITO) may be commonly used as the anode 132, and as the hole injection layer 133, N, N′-diphenyl-N, N′-bis- [ 4- (phenyl-m-cttolyl-amino) -phenyl] -biphenyl 1-4,4'-diamine (N, N'-diphenyl-N, N'-bis- [4- (phenyl-m-tolyl -amino) -phenyl] -biphenyl-4,4'-diamine; DNTPD) can be used. However, the present invention is not limited thereto, and known hole injection materials may be used.

As the hole transport layer 134, 4,4'-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (4,4'-bis [N- (1- naphthyl) -N-phenylamino] -biphenyl; NPB) is used. However, the present invention is not limited thereto, and a known hole transport material may be used.

As the electron transport layer 136, tris (8-hydroxy-quinolate) aluminum (Alq ₃ ) represented by Formula 5 below is used. However, the present invention is not limited thereto, and a known electron transport material may be used.

LiF may be used as the electron injection layer 137. However, the present invention is not limited thereto, and a known electron injection material may be used. As the cathode 138, a known metal is used.

By using a blue fluorescent compound selected from D-1 to D-144 as the dopant material in the light emitting layer 135 of the organic light emitting device 130, the present invention has high luminous efficiency, excellent heat resistance, long life, and color. A blue fluorescent organic electroluminescent device excellent in purity can be obtained.

In the method of manufacturing an organic light emitting device using a blue fluorescent compound according to the present invention, an anode is formed on a substrate, and a cathode is formed by sequentially forming a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, and an electron injection layer on the anode. Form. In this case, the emission layer includes a host material and a dopant material.

As the dopant material of the light emitting layer, a compound represented by Chemical Formula 1 is used, and specifically, a compound selected from the above D-1 to D-144 compounds is used. The dopant material selected from the D-1 to D-144 compounds may be included in the light emitting layer in an amount of 0.1 wt% to 50 wt% based on the total weight of the host material and the dopant material.

As the host material, α-ADN represented by Chemical Formula 2 may be used, and as the hole injection layer, DNTPD represented by Chemical Formula 3 may be used. NPB represented by Formula 4 may be used as the hole transport layer, Alq ₃ represented by Formula 5 may be used as the electron transport layer, and LiF may be used as the electron injection layer.

However, the hole injection layer, the hole transport layer, the electron transport layer and the electron injection layer is not limited to the above-described formula and materials, and known hole injection materials, known hole transport materials, known electron transport materials and known electron injection materials Can be used.

Hereinafter, a method of manufacturing an organic light emitting diode using a blue fluorescent compound according to the present invention will be described with reference to the following examples. However, the present invention is not limited to the following examples.

Example 1

The light emitting area of the ITO glass is patterned to have a size of 3 mm x 3 mm and then cleaned. After mounting the substrate in the vacuum chamber, the base pressure was 1X10-6torr, and the organics were placed on the ITO DNTPD (700Å), NPB (300Å), host α-ADN (250Å) + dopant D-2 (4%), Alq. _An organic light emitting display device is manufactured by forming a film in the order of ₃ (350 Hz), LiF (5 Hz), and Al (1000 Hz). The organic light emitting device manufactured as described above exhibited 681 cd / m ² (4.5 V) at 10 mA / cm ² , where CIE x = 0.133 and y = 0.156. The half life is 2020hr at 3000cd / m ² .

[Example 2]

The light emitting area of the ITO glass is patterned to have a size of 3 mm x 3 mm and then cleaned. After mounting the substrate in the vacuum chamber, the base pressure is 1X10-6torr, and the organic material is placed on the ITO DNTPD (700Å), NPB (300Å), host α-ADN (250Å) + dopant D-52 (4%), Alq _An organic light emitting display device is manufactured by forming a film in the order of ₃ (350 Hz), LiF (5 Hz), and Al (1000 Hz). The organic light emitting device manufactured as described above exhibited 834 cd / m ² (4.6 V) at 10 mA / cm ² , where CIE x = 0.135 and y = 0.170. The half life is 2230 hr at 3000 cd / m ² .

Example 3

The light emitting area of the ITO glass is patterned to have a size of 3 mm x 3 mm and then cleaned. After mounting the substrate in the vacuum chamber, the base pressure is 1X10-6torr and the organics are placed on the ITO DNTPD (700Å), NPB (300Å), host α-ADN (250Å) + dopant D-99 (4%), Alq _An organic light emitting display device is manufactured by forming a film in the order of ₃ (350 Hz), LiF (5 Hz), and Al (1000 Hz). The organic light emitting diode manufactured as described above exhibited 645 cd / m ² (4.6V) at 10 mA / cm ² , where CIE x = 0.141 and y = 0.113. The half life is 1400 hr at 3000 cd / m ² .

Example 4

The light emitting area of the ITO glass is patterned to have a size of 3 mm x 3 mm and then cleaned. After mounting the substrate in the vacuum chamber, the base pressure was 1X10-6torr, and the organics were placed on the ITO. _An organic light emitting display device is manufactured by forming a film in the order of ₃ (350 Hz), LiF (5 Hz), and Al (1000 Hz). The organic light emitting device manufactured as described above exhibited 608 cd / m ² (4.7 V) at 10 mA / cm ² , where CIE x = 0.140 and y = 0.102. The half life is 1550hr at 3000cd / m ² .

Comparative Example 1

The light emitting area of the ITO glass is patterned to have a size of 3 mm x 3 mm and then cleaned. After mounting the substrate in the vacuum chamber, the basic pressure was 1X10-6torr, and the organic material was placed on the ITO DNTPD (700Å), NPB (300Å), host α-ADN (250Å) + dopant DPAVBi (4,4'-bis [ 2- (4- (N, N-diphenylamino) phenyl) vinyl] biphenyl; 4%), Alq ₃ (350 Pa), LiF (5 Pa), and Al (1000 Pa) were formed in the following order to manufacture an organic EL device. In this case, 724cd / m ² (5.4 V) was shown at 10 mA / cm ² , where CIE x = 0.144 and y = 0.205. The half life is 650 hrs at 3000 cd / m ² .

The results of Examples 1 to 4 and Comparative Example 1 are shown in Table 1 below.

device Voltage
(V) electric current
(mA) Luminance
(cd / m ² ) Current efficiency
(cd / A) Power efficiency
(lm / W) Internal quantum
efficiency (%) life span
(at3000cd / m ² ) CIE
(X) CIE
(Y) Example 1 4.5 0.9 681 6.8 4.7 6.2 2020 0.133 0.156 Example 2 4.6 0.9 834 8.3 5.6 6.1 2230 0.135 0.170 Example 3 4.6 0.9 645 6.4 4.4 6.8 1400 0.141 0.113 Example 4 4.7 0.9 608 6.1 4.1 7 1550 0.140 0.102 Comparative Example 1 5.4 0.9 724 7.2 4.2 5.1 650 0.144 0.205

As shown in the above embodiments, the present invention introduces a compound represented by Formula 1 above and selected from D-1 to D-144 as the dopant material of the light emitting layer. In other words, it can be seen that the present invention is driven at a lower voltage than DPAVBi (Comparative Example 1), which has been conventionally used, by introducing a florin group and an aryl group into phenyl amine as a dopant material, and has a much improved lifetime. Furthermore, in one embodiment of the present invention, it can be seen that the CIE coordinates are lower than the CIE coordinates of Comparative Example 1, thereby improving color purity.

The above-described techniques represent presently preferred embodiments, and the present invention is not limited to the above-described embodiments and the accompanying drawings. Modifications and other uses of the embodiments will be apparent to those skilled in the art, and such changes and other uses are defined by the scope of the claims contained within or appended to the spirit of the invention.

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

Claims (10)

It is represented by the following formula (1), [Formula 1]

(In Formula 1, R1, R2 and R3 may be selected from hydrogen, deuterium, C1 ~ C6 alkyl group, substituted or unsubstituted C6 or more aryl group or florin group, R4, R5, R6, R7, R8 are selected from hydrogen, deuterium, an alkyl group from C1 to C6, a C6 or more substituted or unsubstituted aryl group, florin, cyanine, trifluoromethyl or trimethylsilyl group.) At least one of the R1, R2, R3 comprises a fluorine, and another blue substituted compound, characterized in that containing a substituted or unsubstituted C6 or more aryl group. According to claim 1, wherein the alkyl group of C1 to C6 is selected from the group consisting of methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl and t-butyl, The C6 or more aryl group is phenyl, phenyl substituted with deuterium, biphenyl, biphenyl, naphthyl, phenanthrene, terphenyl, fluorenyl ) And their substituents. The blue fluorescent compound according to claim 1, wherein the phenyl moiety including R1, R2 and R3 is selected from the following compounds.

The blue fluorescent compound according to claim 1, wherein the phenyl moiety including R4, R5, R6, R7, and R8 is selected from the following compounds.

The blue fluorescent compound of claim 1, wherein Chemical Formula 1 is represented by a compound selected from Compounds D-1 to D-144.

In the organic light emitting device comprising a light emitting layer between the cathode and the anode, The emission layer includes a dopant material and a host material, The dopant material is represented by the following Formula 1, [Formula 1]

(In Formula 1, R1, R2 and R3 is selected from hydrogen, deuterium, C1 ~ C6 alkyl group, substituted or unsubstituted C6 or more aryl group or fluorine group, R4, R5, R6, R7, R8 are selected from hydrogen, deuterium, an alkyl group from C1 to C6, a C6 or more substituted or unsubstituted aryl group, florin, cyanine, trifluoromethyl or trimethylsilyl group.) At least one of the R1, R2, R3 comprises a fluorine, and another is an organic electroluminescent device using a blue fluorescent compound, characterized in that containing a substituted or unsubstituted C6 or more aryl group. The organic electroluminescent device using a blue fluorescent compound according to claim 6, wherein the dopant material is formed of a compound selected from compounds D-1 to D-144 according to claim 5. The blue fluorescent compound of claim 6, further comprising a hole injection layer and a hole transport layer sequentially formed between the anode and the light emitting layer, and an electron transport layer and an electron injection layer sequentially formed between the light emitting layer and the cathode. Organic electroluminescent device using. The organic light emitting device of claim 6, wherein the dopant material is present in an amount of about 0.1 wt% to about 50 wt% based on the total weight of the host material and the dopant material. 7. The compound of claim 6, wherein the phenyl moiety comprising R1, R2 and R3 is selected from the compounds of claim 3, The phenyl moiety including R4, R5, R6, R7, and R8 is selected from the compounds of claim 4, wherein the organic light emitting device using a blue fluorescent compound.

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