KR102325673B1 - Organic compound and Light emitting diode and Organic light emitting diode display device using the same - Google Patents

Abstract

The present invention has a structure in which an electron withdrawing group is substituted for a core of benzothiophene, benzofuran or benzoselenophene, and has excellent hole injection characteristics and charge generation characteristics. compounds are provided.

Description

Organic compound and light emitting diode and organic light emitting diode display device using same

The present invention relates to an organic compound used in a light emitting diode, and in particular, an organic compound capable of lowering the driving voltage of a light emitting diode by being used as a hole injection layer and/or a charge generation layer, and the same It relates to a light emitting diode and an organic light emitting diode display device used.

Recently, as the display device becomes larger, the demand for a flat display device that occupies less space is increasing. One of these flat display devices includes a light emitting diode and an organic light emitting diode display, also called an organic electroluminescent device (OELD). 2. Description of the Related Art [0002] The technology of organic light emitting diode (OLED) display devices is developing at a rapid pace.

A light emitting diode is a device that emits light while electrons and holes are paired and then extinguished when electric charges are injected into an organic light emitting layer formed between an electron injection electrode (cathode) and a hole injection electrode (anode). Not only can the device be formed on a flexible transparent substrate such as plastic, but also it can be driven at a low voltage (10V or less), consumes relatively little power, and has excellent color purity.

The organic light emitting layer may have a single layer structure of a light emitting material layer or a multilayer structure to improve light emitting efficiency. For example, the organic light emitting layer may include a hole injection layer (HIL), a hole transporting layer (HTL), an emitting material layer (EML), an electron transporting layer (ETL) and It may have a multi-layered structure including an electron injection layer (EIL).

A brief overview of the manufacturing process of an organic light emitting diode is as follows:

(1) First, a material such as indium tin oxide (ITO) is deposited on a transparent substrate to form an anode.

(2) A hole injection layer (HIL) is formed on the anode to a thickness of 5 nm to 30 nm.

(3) Next, a hole transport layer is formed on the hole injection layer. The hole transport layer is formed by depositing 4,4'-bis[N-(1-naphthyl)-N-phenylamino]-biphenyl(NPB) to about 30 nm to 70 nm.

(4) Next, an emitting material layer (EML) is formed on the hole transport layer. The light emitting material layer may include a dopant.

(5) Next, an electron transport layer (ETL) and an electron injection layer (EIL) are formed on the light emitting material layer. For example, tris(8-hydroxy-quinolate)aluminum (Alq ₃ ) is used as the electron transport layer, and LiF is used as the electron injection layer. In the case of a phosphorescent device, in order to effectively confine triplet excitons in the light emitting material layer, a hole blocking layer may be formed before the electron transport layer is formed.

(6) Next, a cathode is formed on the electron injection layer.

In general, the hole injection layer is formed of DNTPD, CuPc, or HAT-CN, which are materials represented by Formula 1 below.

[Formula 1]

However, when the hole injection layer is formed using DNTPD, CuPc, or HAT-CN, hole injection becomes difficult due to the difference in the energy level of the Highest Occupied Molecular Orbital (HOMO) between the hole injection layer and the hole transport layer. There is a problem in that the driving voltage rises.

Meanwhile, in order to further improve the performance of the light emitting diode and to realize the white light emitting diode, a tandem type light emitting diode manufactured by stacking a plurality of unit elements has been proposed. The stacked light emitting diode includes a charge generation layer (CGL) disposed between each unit element to supply positive and negative charges to each unit element, respectively.

It has been proposed to use an indium-zinc-oxide (IZO) film or an indium-tin-oxide (ITO) film as the charge generating layer. However, when the IZO film and the ITO film are used as the charge generating layer, the lateral conductivity is high, so that the pixel crosstalk problem occurs. In addition, the IZO film and the ITO film is formed by a sputtering process, damage to the organic material layer occurs by the sputtering process.

An object of the present invention is to provide an organic compound that has excellent hole injection properties and can be used as a charge generating layer without damaging the organic layer.

In order to solve the above problems, the present invention provides an organic compound having a structure in which an electron withdrawing group is substituted in a core of benzothiophene, benzofuran or benzoselenophene. to provide.

In another aspect, the present invention is represented by the following formula (1), X is selected from sulfur (S), oxygen (O) or selenium (Se), R1 to R4 each is independently hydrogen, deuterium, -OH, - CN, -NO2, -CF3, fluoroalkyl group, halogen group, carboxyl group, carbonyl group, substituted or unsubstituted alkyl group, substituted or unsubstituted alkoxy group, substituted or unsubstituted aromatic group, substituted or An unsubstituted heteroaromatic group, a substituted or unsubstituted aryloxyl group, a substituted or unsubstituted heteroaryloxyl group, an amine group, an amine group including a substituted or unsubstituted aromatic group, a substituted or unsubstituted hetero selected from an amine group including an aromatic group, and each of R5 to R7 is independently hydrogen, deuterium, -OH, -CN, -NO2, -CF3, a fluoroalkyl group, a halogen group, a carboxyl group, and a carbonyl group , substituted or unsubstituted alkyl group, substituted or unsubstituted alkoxy group, substituted or unsubstituted aromatic group, substituted or unsubstituted aryloxyl group, substituted or unsubstituted heteroaromatic group, substituted or unsubstituted heteroaryl An organic compound selected from the oxyl group is provided.

[Formula 1]

[Formula 2]

In the organic compound of the present invention, at least one of R1 to R4 is a substituted or unsubstituted alkyl group, substituted or unsubstituted aromatic group, substituted or unsubstituted heteroaromatic group, amine group, substituted or unsubstituted aromatic group It is selected from an amine group including, an amine group including a substituted or unsubstituted heteroaromatic group, or an alkyl group.

The organic compound of the present invention is any one of the following compounds.

In another aspect, the present invention provides a light emitting unit including a first electrode, a second electrode facing the first electrode, and a light emitting material layer positioned between the first and second electrodes, and the first Provided is a light emitting diode positioned between an electrode and the light emitting unit and including a hole layer including the above-described organic compound.

In the light emitting diode of the present invention, the hole layer includes a hole transport layer, a hole injection layer that is located between the hole transport layer and the first electrode and is made of only the organic compound or the hole injection host material is doped with the organic compound. include

In the light emitting diode of the present invention, the hole layer includes a hole transport layer, a first hole injection that is positioned between the hole transport layer and the first electrode and is made of only the organic compound or the hole injection host material is doped with the organic compound and a second hole injection layer positioned between the first electrode and the first hole injection layer and made of a hole injection host material.

In the light emitting diode of the present invention, the hole layer includes a first hole transport layer formed by doping a hole transport host material with the organic compound.

In the light emitting diode of the present invention, the hole layer further includes a second hole transport layer positioned between the first hole transport layer and the light emitting unit and made of a hole transport host material.

In another aspect, the present invention provides a first light emitting unit comprising a first electrode, a second electrode facing the first electrode, and a first light emitting material layer positioned between the first and second electrodes; , a second light emitting unit located between the first light emitting unit and the first electrode and including a second light emitting material layer, and the organic compound of claims 1 to 4 located between the first and second light emitting units It provides a light emitting diode including a P-type charge generation layer comprising a.

In the light emitting diode of the present invention, the P-type charge generating layer is made of only the organic compound or the hole injection host material is doped with the organic compound.

In the light emitting diode of the present invention, the N-type charge generation layer is located between the P-type charge generation layer and the second light emitting unit and is an organic layer doped with an alkali metal or alkaline earth metal.

In the light emitting diode of the present invention, the first light emitting unit includes a first hole transport layer positioned between the first light emitting material layer and the P-type charge generating layer, and between the first light emitting material layer and the second electrode. It further comprises an electron injection layer and a first electron transport layer positioned, wherein the second light emitting unit, a second electron transport layer positioned between the N-type charge generation layer and the second light emitting material layer, the first electrode and It further includes a first hole injection layer and a second hole transport layer positioned between the second light emitting material layer.

In the light emitting diode of the present invention, the first light emitting unit further includes a second hole injection layer positioned between the first hole transport layer and the P-type charge generation layer.

In the light emitting diode of the present invention, the light emitting diode further includes a second hole injection layer positioned between the P-type charge generation layer and the N-type charge generation layer.

In the light emitting diode of the present invention, the first light emitting unit further comprises an electron injection layer and a first electron transport layer positioned between the first light emitting material layer and the second electrode, the second light emitting unit, A second electron transport layer positioned between the N-type charge generation layer and the second light emitting material layer, and a hole injection layer and a hole transport layer positioned between the first electrode and the second light emitting material layer, wherein the P The type charge generation layer is formed by doping the organic compound into a hole transport layer host material.

In another aspect, the present invention provides a base substrate; Provided is an organic light emitting diode display including an encapsulation substrate bonded to the substrate.

The present invention has a structure in which an electron withdrawing group is substituted in a core of benzothiophene, benzofuran or benzoselenophene, and has excellent hole injection properties and charge generation properties. compounds are provided. That is, a strong electron withdrawing group is substituted in the core of benzothiophene, benzofuran, or benzoselenophen to have a deep LUMO value, and hole transport characteristics and charge generation characteristics are improved.

Since the light emitting diode and the organic light emitting diode display including the electron injection layer made of the organic compound of the present invention can be driven by a low voltage, power consumption is reduced.

In addition, the light emitting diode and organic light emitting diode display having a stack structure including a charge generating layer made of an organic compound of the present invention have advantages of reducing power consumption by low voltage driving and realizing high purity white color.

1 is a schematic cross-sectional view of a light emitting diode according to a first embodiment of the present invention.
2 is a schematic cross-sectional view of a light emitting diode according to a second embodiment of the present invention.
3 is a schematic cross-sectional view of a light emitting diode according to a third embodiment of the present invention.
5 is a schematic cross-sectional view of a light emitting diode according to a fourth embodiment of the present invention.
5 is a schematic cross-sectional view of a light emitting diode according to a fifth embodiment of the present invention.
6 is a schematic cross-sectional view of a light emitting diode according to a sixth embodiment of the present invention.
7 is a schematic cross-sectional view of a light emitting diode according to a seventh embodiment of the present invention.
8 is a schematic cross-sectional view of a light emitting diode according to an eighth embodiment of the present invention.
9 is a schematic cross-sectional view of an organic light emitting diode display according to a ninth embodiment of the present invention.

Hereinafter, an organic compound according to the present invention and a light emitting diode and an organic light emitting diode display using the same will be described.

The organic compound of the present invention has a structure in which an electron withdrawing group is substituted in the core of a structure in which a ring containing sulfur, oxygen or selenium is condensed on a benzene ring, and has excellent hole injection properties and charge generation properties. , is represented by the following formula (2).

[Formula 2]

In Formula 2, X is selected from sulfur (S), oxygen (O) or selenium (Se), and R1 to R4 are each independently hydrogen, deuterium, -OH, -CN, -NO2, -CF3, a fluoroalkyl group Group, halogen group, carboxyl group, carbonyl group, C1 to C18 substituted or unsubstituted alkyl group, C1 to C18 substituted or unsubstituted alkoxy group, C6 or more (eg, C6 to C20) substitution or unsubstituted aromatic group, C5 or more (eg, C5~C20) substituted or unsubstituted heteroaromatic group, C6 or more (eg, C6~ C20) substituted or unsubstituted aryloxyl group, C5 More than (eg, C5~C20) substituted or unsubstituted heteroaryloxyl group, C1 to C18 amine group, amine group including a substituted or unsubstituted aromatic group, substituted or unsubstituted heteroaromatic It is selected from the amine group including a group, and at least one of R1 to R4 is a C1 to C18 substituted or unsubstituted alkyl group, a C6 or more (eg, C6 to C20) substituted or unsubstituted aromatic group, C5 or more (eg, C5-C20) substituted or unsubstituted heteroaromatic group, C1 to C18 amine group, amine group including substituted or unsubstituted aromatic group, substituted or unsubstituted heteroaromatic group It is selected from an amine group containing a group or a C1 to C27 alkyl group.

For example, when each of R1 to R4 is a substituted or unsubstituted aromatic group, charge generation characteristics are improved by reducing orbital overlap, and sublimation during the process can be minimized by increasing the molecular weight of the organic compound.

In Formula 2, Y and Z are the same or different from each other and are selected from Formula 3 below.

[Formula 3]

In Formula 3, each of R5 to R7 is independently hydrogen, deuterium, -OH, -CN, -NO2, -CF3, fluoroalkyl group, halogen group, carboxyl group, carbonyl group, C1 to C18 substituted or unsubstituted A cyclic alkyl group, a C1 to C18 substituted or unsubstituted alkoxy group, a C6 or more (eg, C6 to C20) substituted or unsubstituted aromatic group, C6 or more (eg, C6 to C20) substitution Or an unsubstituted aryloxyl group, C5 or more (eg, C5~ C20) substituted or unsubstituted heteroaromatic group, C5 or more (eg, C5~ C20) substituted or unsubstituted heteroaryloxyl group and R5 and R6 may be connected to each other to form a fused ring.

As described above, the organic compound of the present invention has a structure in which an electron withdrawing group is substituted in the core of a structure in which a ring containing sulfur, oxygen or selenium is condensed on a benzene ring, and has a deep LUMO value. Hole injection characteristics and charge generation characteristics are improved.

Accordingly, the organic compound of the present invention may be used as a hole injection layer, a doped hole transport layer, or a charge generation layer in a stacked structure light emitting diode, thereby increasing the light emitting efficiency of the light emitting diode and lowering the driving voltage.

For example, the organic compound of the present invention may be any one of the compounds of Formula 4 below.

[Formula 4]

Hereinafter, examples of synthesis and properties of the organic compound according to the present invention will be described.

1. Synthesis of compound A

(1) Synthesis of compound A-1

[Scheme 1-1]

In a 100ml 2-neck flask, potassium carbonate (1.46 g, 10.57 mmol) and potassium iodide (0.05 g, 0.29 mmol) were added and dissolved in dimethylsulfoxide (DMSO, 20 ml). 2,5-dimethoxythiophenol (1.0 g, 5.87 mmol) and bromoacetaldehyde diethyl acetal (1.27 g, 6.46 mmol) were added, and the mixture was stirred at 50°C for 2 hours. After extraction several times with a large amount of ethyl acetate and water, the compound obtained by distillation under reduced pressure was columned with dichloromethane and hexane to obtain compound A-1 (1.6 g). (Yield = 95%)

(2) Synthesis of compound A-2

[Scheme 1-2]

Compound A-1 (1.6 g, 5.6 mmol) and polyphosphoric acid (PPA, 3.2 g) were added to a 1000ml 2-neck flask, dissolved in xylene (40 ml), and stirred at 150°C for 1 hour. After extraction several times with a large amount of ethyl acetate and water, the compound obtained by distillation under reduced pressure was columned with dichloromethane and hexane to obtain compound A-2 (0.7 g). (Yield=65%)

(3) Synthesis of compound A-3

[Scheme 1-3]

Compound A-2 (2.77 g, 14.3 mmol) was placed in a 100 ml 2-neck flask and dissolved with acetonitrile (40 ml). An aqueous solution (40 ml) of Ammonium cerium(IV) nitrate (23.45 g, 42.8 mmol) was added, followed by stirring at room temperature for 2 hours. After extraction with chloroform and water, the product obtained by distillation under reduced pressure was columned with dichloromethane and hexane to obtain Compound A-3 (1.3 g). (Yield=57%)

(4) Synthesis of compound A

[Scheme 1-4]

Compound A-3 (1.3 g, 7.92 mmol) and malononitrile (5.2 g, 79.2 mmol) were placed in a 500ml 2-neck flask and dissolved in dichloromethane (250 ml). Titanium(IV) chloride (8.7 ml, 79.2 mmol) and pyridine (12.78 ml, 158.4 mmol) were slowly added dropwise sequentially at -78°C. Then, it was stirred at room temperature for 12 hours. Distilled water was added dropwise under an ice bath to terminate the reaction, followed by work up with distilled water and dichloromethane. By column using dichloromethane and hexane, compound A (0.89 g) was obtained. (Yield=43%)

2. Synthesis of compound B

[Scheme 2]

Compound A-3 (1.3 g, 7.9 mmol), 4-(cyanomethyl)-2,3,5,6-tetrafluorobenzonitrile (16.4 g, 79.2 mmol) was placed in a 500ml 2-neck flask and dissolved in dichloromethane (300 ml). Titanium(IV) chloride (8.7 ml, 79.2 mmol) and pyridine (12.78 ml, 158.4 mmol) were slowly added dropwise sequentially at -78°C. It was stirred at reflux for 16 hours. Distilled water was added dropwise under an ice bath to terminate the reaction, and work-up was performed with distilled water and dichloromethane. By column using dichloromethane and hexane, compound B (1.4 g) was obtained. (Yield=32%)

3. Synthesis of compound C

[Scheme 3]

Compound A-3 (1.5 g, 9.1 mmol) and malononitrile (0.9 g, 13.7 mmol) were added to a 250ml 2-neck flask and dissolved in dichloromethane (150 ml). Titanium(IV) chloride (1.5 ml, 13.7 mmol) and pyridine (2.2 ml, 27.4 mmol) were slowly added dropwise sequentially at -78°C. Stirred at room temperature for 12 hours. Distilled water was added dropwise under an ice bath to terminate the reaction, and work-up was performed with distilled water and dichloromethane. By column using dichloromethane and hexane, compound C (0.87 g) was obtained. (Yield=45%)

4. Synthesis of compound D

[Scheme 4]

Compound C (0.8 g, 3.8 mmol) and 4-(cyanomethyl)-2,3,5,6-tetrafluorobenzonitrile (1.2 g, 5.65 mmol) were placed in a 500ml 2-neck flask and dissolved in dichloromethane (250 ml). Titanium(IV) chloride (0.6 ml, 5.65 mmol) and pyridine (0.9 ml, 11.3 mmol) were slowly added dropwise sequentially at -78°C. It was stirred at reflux for 16 hours. Distilled water was added dropwise under an ice bath to terminate the reaction, and work-up was performed with distilled water and dichloromethane. By column using dichloromethane and hexane, compound D (0.57 g) was obtained. (Yield=37%)

5. Synthesis of compound E

(1) Synthesis of compound E-1

[Scheme 5-1]

Compound A-3 (10 g, 60.9 mmol) was added to a 100 ml 2-neck flask and dissolved in acetic acid (60 ml). Bromine (4.06 ml, 79 mmol) was added slowly at 50° C. for 15 minutes and stirred for 12 hours. The resulting solid compound was filtered and washed with acetic acid (6 ml) and water. The product was extracted with dichloromethane and sodium thiosulfate aqueous solution to obtain compound E-1 (2.8 g). (Yield = 19%)

(2) Synthesis of compound E-2

[Scheme 5-2]

Compound E-1 (5.0 g, 20.6 mmol), 2,4-bis(trifluoromethyl)phenylboronic acid (5.3 g, 20.6 mmol), potassium carbonate (8.5 g, 61.7 mmol), tetrakis(triphenylphosphine) in a 500ml 2-neck flask Palladium(0) (1.19 g, 1.0 mmol) was added, dissolved in 1,4-dioxane (200 ml) and water (70 ml), and stirred at room temperature for 1 hour. After stirring at 90° C. for an additional hour, extraction was performed with dichloromethane and brine, and the solvent was distilled under reduced pressure. By column using dichloromethane and hexane, compound E-2 (4.7 g) was obtained. (Yield = 61%)

(3) Synthesis of compound E

[Scheme 5-3]

Compound E-2 (2.0 g, 5.3 mmol) and malononitrile (3.5 g, 53.2 mmol) were added to a 500ml 2-neck flask and dissolved in dichloromethane (250 ml). Titanium(IV) chloride (5.8 ml, 53.2 mmol) and pyridine (8.58 ml, 106.3 mmol) were slowly added dropwise sequentially at -78°C. Stirred at room temperature for 12 hours. Distilled water was added dropwise under an ice bath to terminate the reaction, and work-up was performed with distilled water and dichloromethane. By column using dichloromethane and hexane, compound E (1.0 g) was obtained. (Yield=40%)

6. Synthesis of compound F

[Scheme 6]

Compound E-2 (2.0 g, 5.3 mmol) and 4-(cyanomethyl)-2,3,5,6-tetrafluorobenzonitrile (11.4 g, 53.2 mmol) were placed in a 500ml 2-neck flask and dissolved in dichloromethane (300 ml). Titanium(IV) chloride (5.8 ml, 53.2 mmol) and pyridine (8.58 ml, 106.3 mmol) were slowly added dropwise sequentially at -78°C. Then, the mixture was stirred under reflux for 16 hours. Distilled water was added dropwise under an ice bath to terminate the reaction, and work-up was performed with distilled water and dichloromethane. By column using dichloromethane and hexane, compound F (1.3 g) was obtained. (Yield=33%)

The organic compound of the present invention has a structure in which one condensed ring (eg, thiophene) is bonded to a benzene ring, compared to a compound having a structure in which a condensed ring (eg, thiophene) is bonded to both sides of the benzene ring. It has a low LUMO value. (deep LUMO)

That is, as shown in Table 1 below, the LUMO value is lowered by about 0.3 eV.

1 is a schematic cross-sectional view of a light emitting diode according to a first embodiment of the present invention.

As shown in FIG. 1 , the light emitting diode 100 according to the first embodiment of the present invention includes a first electrode 110 and a second electrode 120 facing each other, and the first and second electrodes 110 , 120) between the light emitting unit 130, the first electrode 110 and the light emitting unit 130, the hole injection layer 140, and between the light emitting unit 130 and the hole injection layer 140 and a hole transport layer 150 located in

The first electrode 110 is made of a conductive material having a relatively large work function value and is an anode. For example, the first electrode 110 may be made of indium-tin-oxide (ITO) or indium-zinc-oxide (IZO).

The second electrode 120 is made of a conductive material having a relatively small work function value and is a cathode. For example, the second electrode 120 may be made of aluminum (Al), magnesium (Mg), calcium (Ca), silver (Ag), or an alloy thereof.

The light emitting unit 130 includes a light emitting material layer 132 , an electron transport layer 134 , and an electron injection layer 136 . The electron transport layer 134 is positioned between the second electrode 120 and the light emitting material layer 132 , and the electron injection layer 136 is positioned between the second electrode 120 and the electron transport layer 134 .

The light emitting material layer 132 may be formed by doping a host material with a dopant. For example, when the light-emitting material layer 132 emits blue (B) light, the light-emitting material layer 132 is made of an anthracene derivative, a pyrene derivative, and a perylene derivative. At least one fluorescent host material selected from the group may be doped with a fluorescent dopant. In addition, when the light-emitting material layer 132 emits green (G) light, the light-emitting material layer 132 may be formed by doping a phosphorescent host material made of a carbazole-based compound or a metal complex with a phosphorescent dopant. In addition, when the light-emitting material layer 132 emits red (R) light, the light-emitting material layer 132 may be formed by doping a phosphorescent host material made of a carbazole-based compound or a metal complex with a phosphorescent dopant.

The electron transport layer 134 may be made of an electron transport material such as oxadiazole, triazole, phenanthroline, benzoxazole, or benzthiazole. However, the present invention is not limited thereto.

Also, the electron injection layer 136 may be formed of an electron injection material such as LIF or lithium quinolate (LiQ). However, the present invention is not limited thereto.

The hole transport layer 150 is positioned adjacent to the light emitting material layer 132 of the light emitting unit 130 and is located between the first electrode 110 and the light emitting unit 130 .

For example, the hole transport layer 150 is TPD (N,N'-diphenyl-N,N'-bis(3-methylphenyl)-1,1'-bi-phenyl-4,4'-diamine) or NPB (NPB). N,N'-di(naphthalen-1-yl)-N,N'-diphenylbenzidine), but is not limited thereto.

The hole injection layer 140 is positioned between the hole transport layer 150 and the first electrode 110 , and may be formed of the material represented by Formula 2 or may be formed by doping the hole injection host material with the material of Formula 2 .

When the hole injection layer 140 includes a host material and an organic compound of Formula 2, the host material is MTDATA (4,4',4"-tris(3-methylphenylphenylamino)triphenylamine), CuPc (copper phthalocyanine), or PEDOT/ PSS (poly(3,4-ethylenedioxythiphene)polystyrene sulfonate) may be used, and the organic compound of Formula 2 may be doped in an amount of about 0.1 to 50% by weight, but is not limited thereto.

In other words, the light emitting diode 100 according to the first embodiment of the present invention is positioned between the first and second electrodes 110 and 120 facing each other and the first and second electrodes 110 and 120 . It includes a light emitting unit 130 and a hole layer positioned between the first electrode 110 and the light emitting unit 130 and consisting of a hole injection layer 140 and a hole transport layer 150, and the hole injection layer 140 has the formula The organic compound of Formula 2 may be formed alone or may be formed by doping the hole injection host material with the organic compound of Formula 2.

As described above, the organic compound of the present invention has a structure in which an electron withdrawing group is substituted in the core of benzothiophene, benzofuran, or benzoselenophene, and has excellent hole injection properties has

Accordingly, when the hole injection layer 140 is formed of the organic compound of Chemical Formula 2 or the host material is doped with the organic compound of Chemical Formula 2, the light emitting efficiency of the light emitting diode 100 is increased.

2 is a schematic cross-sectional view of a light emitting diode according to a second embodiment of the present invention.

As shown in FIG. 2 , the light emitting diode 200 according to the second embodiment of the present invention includes a first electrode 210 and a second electrode 220 facing each other, and the first and second electrodes 210 , 220), the light emitting unit 230 positioned between, and the hole injection layer 240 positioned between the first electrode 210 and the light emitting unit 230 and including the first and second layers 242 and 244, and , and a hole transport layer 250 positioned between the light emitting unit 230 and the hole injection layer 240 .

As described above, the first electrode 210 is an anode and is made of a conductive material having a relatively large work function value, and the second electrode 220 is a cathode and is made of a conductive material having a relatively small work function value.

The light emitting unit 230 includes a light emitting material layer 232 , an electron transport layer 234 , and an electron injection layer 236 . The electron transport layer 234 is positioned between the second electrode 220 and the light emitting material layer 232 , and the electron injection layer 236 is positioned between the second electrode 220 and the electron transport layer 234 .

The light emitting material layer 232 may be formed by doping a host material with a dopant. The electron transport layer 234 is made of an electron transport material such as oxadiazole, triazole, phenanthroline, benzoxazole, or benzthiazole, and the electron The injection layer 236 may be formed of an electron injection material such as LIF or lithium quinolate (LiQ).

The hole transport layer 250 is located adjacent to the light emitting material layer 232 of the light emitting unit 230 and is located between the first electrode 210 and the light emitting unit 230 . For example, the hole transport layer 250 is TPD (N,N'-diphenyl-N,N'-bis(3-methylphenyl)-1,1'-bi-phenyl-4,4'-diamine) or NPB (NPB). N,N'-di(naphthalen-1-yl)-N,N'-diphenylbenzidine).

The hole injection layer 240 includes a first layer 242 and a second layer 244 sequentially stacked on the first electrode 210 . That is, the first layer 242 is positioned between the first electrode 210 and the second layer 244 .

The first layer 242 is made of a hole injection material such as MTDATA, CuPc, or PEDOT/PSS, and the second layer 244 is made of a material represented by Formula 2 or a hole injection host material is doped with a material of Formula 2 it can be done

When the second layer 244 of the hole injection layer 240 includes a host material and an organic compound of Formula 2, the host material may be MTDATA, CuPc, or PEDOT/PSS, and the organic compound of Formula 2 contains about 0.1 to 50 It may be doped in wt%. However, the present invention is not limited thereto.

In contrast, the first layer 242 is made of the material represented by Formula 2 or the hole injection host material is doped with the material of Formula 2, and the second layer 244 is formed of MTDATA, CuPc, or PEDOT/PSS. It may be made of only a hole injection material.

That is, in the light emitting diode 200 according to the second embodiment of the present invention, the hole injection layer 240 is made of a layer made of only a hole injection material and an organic compound of Formula 2, or an organic compound of Formula 2 is added to the hole injection material. It has a double-layer structure of doped layers.

In other words, the light emitting diode 200 according to the second embodiment of the present invention is positioned between the first and second electrodes 210 and 220 facing each other, and the first and second electrodes 210 and 220 . It includes a light emitting unit 230 and a hole layer (hole injection layer) positioned between the first electrode 210 and the light emitting unit 230 and consisting of first and second layers 242 and 244 , The second layer 244 may be formed using only the organic compound of Chemical Formula 2 or may be formed by doping the hole injection host material with the organic compound of Chemical Formula 2.

As described above, the organic compound of the present invention has a structure in which an electron withdrawing group is substituted for a core of benzothiophene, benzofuran or benzoselenophene, and has excellent hole injection properties.

Accordingly, the luminous efficiency of the light emitting diode 200 including the hole injection layer 240 made of the organic compound of Formula 2 or including a layer formed by doping the organic compound of Formula 2 into a host material increases.

3 is a schematic cross-sectional view of a light emitting diode according to a third embodiment of the present invention.

As shown in FIG. 3 , the light emitting diode 300 according to the third embodiment of the present invention includes first and second electrodes 310 and 320 facing each other, first and second electrodes 310 , It includes a light emitting unit 330 positioned between the 320 and a doped hole transport layer (doped-HTL) 350 positioned between the first electrode 310 and the light emitting unit 330 .

As described above, the first electrode 310 is an anode and is made of a conductive material having a relatively large work function value, and the second electrode 320 is a cathode and is made of a conductive material having a relatively small work function value.

The light emitting unit 330 includes a light emitting material layer 332 , an electron transport layer 334 , and an electron injection layer 336 . The electron transport layer 334 is positioned between the second electrode 320 and the light emitting material layer 332 , and the electron injection layer 336 is positioned between the second electrode 320 and the electron transport layer 334 .

The light emitting material layer 332 may be formed by doping a host material with a dopant. The electron transport layer 334 is made of an electron transport material such as oxadiazole, triazole, phenanthroline, benzoxazole, or benzthiazole, and the electrons The injection layer 336 may be formed of an electron injection material such as LIF or lithium quinolate (LiQ).

The doped hole transport layer 350 is formed by doping a hole transport host material with an organic compound of Formula 2 . For example, the hole transport host material may be TPD or NPB, and the organic compound of Formula 2 may be doped in an amount of about 0.1 to 50 wt%. However, the present invention is not limited thereto.

In other words, the light emitting diode 300 according to the third embodiment of the present invention is positioned between the first and second electrodes 310 and 320 facing each other, and the first and second electrodes 310 and 320 . The light emitting unit 330 is positioned between the first electrode 310 and the light emitting unit 330 and includes a single hole layer, the hole layer doping formed by doping the hole transport host material with the organic compound of Formula 2 hole transport layer 350 .

As described above, since the organic compound of the present invention has excellent hole injection properties, the doped hole transport layer 350 formed by doping the hole transport host material with the organic compound of Formula 2 serves as a hole injection layer and a hole transport layer. can be combined with Accordingly, even if only the doped hole transport layer 350 exists between the light emitting unit 330 and the first electrode 310 , hole injection and hole transport characteristics can be sufficiently obtained. That is, in the light emitting diode 300 according to the third embodiment of the present invention, one surface of the doped hole transport layer 350 is in contact with the first electrode 310 and the other surface is the light emitting material layer 332 of the light emitting unit 330 . ) and located in contact with

4 is a schematic cross-sectional view of a light emitting diode according to a fourth embodiment of the present invention.

As shown in FIG. 4 , the light emitting diode 400 according to the fourth embodiment of the present invention includes a first electrode 410 and a second electrode 420 facing each other, and the first and second electrodes 410 , The light emitting unit 430 positioned between the 420 and the hole including the first electrode 410 and the light emitting unit 430 between the first layer (doped-HTL, 452) and the second layer 454 and a transport layer 450 .

As described above, the first electrode 410 is an anode and is made of a conductive material having a relatively large work function value, and the second electrode 420 is a cathode and is made of a conductive material having a relatively small work function value.

The light emitting unit 430 includes a light emitting material layer 432 , an electron transport layer 434 , and an electron injection layer 436 . The electron transport layer 434 is positioned between the second electrode 420 and the light emitting material layer 432 , and the electron injection layer 436 is positioned between the second electrode 420 and the electron transport layer 434 .

The light emitting material layer 432 may be formed by doping a host material with a dopant. The electron transport layer 434 is made of an electron transport material such as oxadiazole, triazole, phenanthroline, benzoxazole or benzthiazole, The injection layer 436 may be formed of an electron injection material such as LIF or lithium quinolate (LiQ).

The hole transport layer 450 includes a first layer 452 and a second layer 454 sequentially stacked on the first electrode 410 . That is, the first layer 452 is positioned between the first electrode 410 and the second layer 454 .

The first layer 452 is formed by doping a hole transporting host material such as TPD or NPB with an organic compound of Formula 2 . In this case, the organic compound of Formula 2 may be doped in an amount of about 0.1 to 50 wt%. Meanwhile, the second layer 454 is made of only a hole transport material such as TPD or NPB.

That is, compared with the light emitting diode 300 shown in FIG. 3 , in the light emitting diode 400 according to the fourth embodiment of the present invention, the first layer 452 which is a doped hole transport layer and the light emitting unit 430 are A second layer 454 made of only a hole transport material is further formed between the light emitting material layers 432 .

In other words, the light emitting diode 400 according to the fourth embodiment of the present invention is positioned between the first and second electrodes 410 and 420 facing each other, and the first and second electrodes 410 and 420 . The light emitting unit 430 and the first electrode 410 and a hole layer positioned between the light emitting unit 430, the first layer 452, which is a hole transport layer doped with the hole layer, and the light emitting unit 430 A second layer 454 made of only a hole transport material is formed between the light emitting material layers 432 .

As described above, since the organic compound of the present invention has excellent hole injection properties, the first layer 452 of the doped hole transport layer 450 formed by doping the hole transport host material with the organic compound of Formula 2 is a hole It may serve as both an injection layer and a hole transport layer. In addition, since the hole transport layer 450 further includes a second layer 454 made of only a hole transport material between the light emitting material layer 432 and the first layer 452 , hole transport to the light emitting material layer 432 . characteristics are further improved.

5 is a schematic cross-sectional view of a light emitting diode according to a fifth embodiment of the present invention.

As shown in FIG. 5 , the light emitting diode 500 according to the fifth embodiment of the present invention includes first and second electrodes 510 and 520 facing each other, first and second electrodes 510 , A first light emitting unit 530 positioned between 520, a second light emitting unit 540 positioned between the first electrode 510 and the first light emitting unit 530, and first and second light emitting units ( and a charge generation layer 550 positioned between 530 and 540 .

As described above, the first electrode 510 is an anode and is made of a conductive material having a relatively large work function value, and the second electrode 520 is a cathode and is made of a conductive material having a relatively small work function value.

The first light emitting unit 530 includes a first hole transport layer 532 , a first light emitting material layer 534 , a first electron transport layer 536 , and an electron injection layer 538 . The first light emitting material layer 534 is positioned between the first hole transport layer 532 and the second electrode 520 , and the first electron transport layer 536 is formed between the first light emitting material layer 534 and the second electrode 520 . The electron injection layer 538 is positioned between the first electron transport layer 536 and the second electrode 520 .

In addition, the second light emitting unit 540 includes a hole injection layer 542 , a second hole transport layer 544 , a second light emitting material layer 546 , and a second electron transport layer 548 .

The hole injection layer 542 is positioned between the first electrode 510 and the second hole transport layer 544 , and the second hole transport layer 544 is between the hole injection layer 542 and the second light emitting material layer 546 . The second light emitting material layer 546 is positioned between the second hole transport layer 544 and the second electron transport layer 548 .

Each of the first and second light emitting material layers 534 and 546 may be formed by doping a host material with a dopant, and may emit different colors.

For example, the second light-emitting material layer 546 may emit blue light, and the first light-emitting material layer 534 may emit green, yellowgreen, or orange color having a longer wavelength than blue.

Each of the first and second hole transport layers 532 and 544 may be formed of a hole transport host such as TPD or NPB. The first and second hole transport layers 532 and 544 may be made of the same material or different materials. Also, the hole injection layer 542 may be formed of a hole injection material such as MTDATA, CuPc, or PEDOT/PSS.

Each of the first and second electron transport layers 536 and 548 includes electrons such as oxadiazole, triazole, phenanthroline, benzoxazole, or benzthiazole. It is made of a transport material, and the electron injection layer 538 may be made of an electron injection material such as LIF or lithium quinolate (LiQ). The first and second electron transport layers 536 and 548 may be made of the same material or different materials.

The charge generation layer 550 is positioned between the first light emitting unit 530 and the second light emitting unit 540 , and includes the N-type charge generation layers N-CGL and 552 adjacent to the second light emitting unit 540 . and a P-type charge generation layer (P-CGL) 554 adjacent to the first light emitting unit 530 .

The N-type charge generation layer 552 injects electrons into the second light emitting unit 540 , and the P type charge generation layer 554 injects holes into the first light emitting unit 530 .

The N-type charge generation layer 552 may be an organic layer doped with an alkali metal such as Li, Na, K, or Cs or an alkaline earth metal such as Mg, Sr, Ba, or Ra.

The P-type charge generation layer 554 may be formed of an organic material of Formula 2 or may be formed by doping a hole injection host material with an organic compound of Formula 2 . When the P-type charge generating layer 554 includes a hole injection host material and an organic compound of Formula 2, the hole injection host material may be MTDATA, CuPc, or PEDOT/PSS, and the organic compound of Formula 2 contains about 0.1 to 50 weight % can be doped. However, the present invention is not limited thereto.

As described above, the organic compound of the present invention has a structure in which an electron withdrawing group is substituted for a core of benzothiophene, benzofuran, or benzoselenophene, and has excellent hole injection properties and charge generation properties.

Accordingly, a stacked structure light emitting diode comprising a charge generation layer 540 comprising a P-type charge generation layer 544 formed of an organic compound of Formula 2 or formed by doping a host material with an organic compound of Formula 2 ( 500) is used for white light emission and the luminous efficiency is increased.

6 is a schematic cross-sectional view of a light emitting diode according to a sixth embodiment of the present invention.

As shown in FIG. 6 , the light emitting diode 600 according to the sixth embodiment of the present invention includes first and second electrodes 610 and 620 facing each other, first and second electrodes 610 , A first light emitting unit 630 positioned between 620, a second light emitting unit 640 positioned between the first electrode 610 and the first light emitting unit 630, and first and second light emitting units ( and a charge generation layer 650 positioned between 630 and 640 .

As described above, the first electrode 610 is an anode and is made of a conductive material having a relatively large work function value, and the second electrode 620 is a cathode and is made of a conductive material having a relatively small work function value.

The first light emitting unit 630 includes a first hole injection layer 631 , a first hole transport layer 633 , a first light emitting material layer 635 , a first electron transport layer 637 , and an electron injection layer ( 538).

The first hole transport layer 633 is positioned between the first hole injection layer 631 and the second electrode 620 , and the first light emitting material layer 635 includes the first hole transport layer 633 and the second electrode 620 . located between The first electron transport layer 637 is positioned between the first light emitting material layer 635 and the second electrode 620 , and the electron injection layer 639 is between the first electron transport layer 637 and the second electrode 620 . located in

In addition, the second light emitting unit 640 includes a second hole injection layer 642 , a second hole transport layer 644 , a second light emitting material layer 646 , and a second electron transport layer 648 .

The second hole injection layer 642 is positioned between the first electrode 610 and the second hole transport layer 644 , and the second hole transport layer 644 includes the second hole injection layer 642 and the second light emitting material layer. 646 , and a second layer of emissive material 646 is positioned between the second hole transport layer 644 and the second electron transport layer 648 .

Each of the first and second light emitting material layers 635 and 646 may be formed by doping a host material with a dopant, and may emit different colors.

For example, the second light-emitting material layer 646 may emit blue light, and the first light-emitting material layer 635 may emit green, yellowgreen, or orange color having a longer wavelength than blue.

Each of the first and second hole transport layers 633 and 644 may be formed of a hole transport host such as TPD or NPB. The first and second hole transport layers 633 and 644 may be made of the same material or different materials. In addition, the first and second hole injection layers 631 and 642 may be formed of a hole injection material such as MTDATA, CuPc, or PEDOT/PSS. The first and second hole injection layers 631 and 642 may be made of the same material or different materials.

Each of the first and second electron transport layers 637 and 648 includes electrons such as oxadiazole, triazole, phenanthroline, benzoxazole, or benzthiazole. It is made of a transport material, and the electron injection layer 639 may be made of an electron injection material such as LIF or lithium quinolate (LiQ). The first and second electron transport layers 637 and 648 may be made of the same material or different materials.

The charge generation layer 650 is positioned between the first light emitting unit 630 and the second light emitting unit 640 , and includes the N-type charge generation layers N-CGL and 652 adjacent to the second light emitting unit 640 . and a P-type charge generation layer (P-CGL) 654 adjacent to the first light emitting unit 630 .

The N-type charge generation layer 652 injects electrons into the second light emitting unit 640 , and the P type charge generation layer 654 injects holes into the first light emitting unit 630 .

The N-type charge generation layer 652 may be an organic layer doped with an alkali metal such as Li, Na, K, or Cs or an alkaline earth metal such as Mg, Sr, Ba, or Ra.

The P-type charge generation layer 654 may be formed of an organic material of Formula 2 or may be formed by doping a hole injection host material with an organic compound of Formula 2 . When the P-type charge generating layer 654 includes a hole injection host material and an organic compound of Formula 2, the hole injection host material may be MTDATA, CuPc, or PEDOT/PSS, and the organic compound of Formula 2 contains about 0.1 to 50 weight % can be doped. However, the present invention is not limited thereto.

As described above, the organic compound of the present invention has a structure in which an electron withdrawing group is substituted for a core of benzothiophene, benzofuran, or benzoselenophene, and has excellent hole injection properties and charge generation properties.

Accordingly, a stacked structure light emitting diode comprising a charge generation layer 640 comprising the P-type charge generation layer 644 formed of the organic compound of Formula 2 or by doping the host material with the organic compound of Formula 2 ( 600) increases the luminous efficiency.

7 is a schematic cross-sectional view of a light emitting diode according to a seventh embodiment of the present invention.

As shown in FIG. 7 , the light emitting diode 700 according to the seventh embodiment of the present invention includes first and second electrodes 710 and 720 facing each other, first and second electrodes 710 , A first light emitting unit 730 positioned between 720, a second light emitting unit 740 positioned between the first electrode 710 and the first light emitting unit 730, and first and second light emitting units ( and a charge generation layer 750 positioned between 730 and 740 .

As described above, the first electrode 710 is an anode and is made of a conductive material having a relatively large work function value, and the second electrode 720 is a cathode and is made of a conductive material having a relatively small work function value.

The first light emitting unit 730 includes a first hole transport layer 732 , a first light emitting material layer 734 , a first electron transport layer 736 , and an electron injection layer 738 . The first light emitting material layer 734 is positioned between the first hole transport layer 732 and the second electrode 720 , and the first electron transport layer 736 is formed between the first light emitting material layer 734 and the second electrode 720 . The electron injection layer 738 is located between the first electron transport layer 736 and the second electrode 720 .

In addition, the second light emitting unit 740 includes a first hole injection layer 742 , a second hole transport layer 744 , a second light emitting material layer 746 , and a second electron transport layer 748 .

The first hole injection layer 742 is positioned between the first electrode 710 and the second hole transport layer 744 , and the second hole transport layer 744 includes the first hole injection layer 742 and the second light emitting material layer. 746 , and the second light emitting material layer 746 is positioned between the second hole transport layer 744 and the second electron transport layer 748 .

Each of the first and second light emitting material layers 734 and 746 may be formed by doping a host material with a dopant, and may emit different colors.

For example, the second light-emitting material layer 746 may emit blue light, and the first light-emitting material layer 734 may emit green, yellowgreen, or orange color having a longer wavelength than blue.

Each of the first and second hole transport layers 732 and 744 may be formed of a hole transport host such as TPD or NPB. The first and second hole transport layers 732 and 744 may be made of the same material or different materials. Also, the first hole injection layer 742 may be formed of a hole injection material such as MTDATA, CuPc, or PEDOT/PSS.

Each of the first and second electron transport layers 736 and 748 includes electrons such as oxadiazole, triazole, phenanthroline, benzoxazole, or benzthiazole. It is made of a transport material, and the electron injection layer 738 may be made of an electron injection material such as LIF or lithium quinolate (LiQ). The first and second electron transport layers 736 and 744 may be made of the same material or different materials.

The charge generation layer 750 is positioned between the first light emitting unit 730 and the second light emitting unit 740 , and includes N-type charge generation layers N-CGL and 752 adjacent to the second light emitting unit 740 . , a P-type charge generation layer (P-CGL) 754 adjacent to the first light emitting unit 730 , and a second hole injection positioned between the N-type charge generation layer 752 and the P-type charge generation layer 754 . layer 756 .

The N-type charge generation layer 752 injects electrons into the second light emitting unit 740 , and the P type charge generation layer 754 injects holes into the first light emitting unit 730 .

The N-type charge generation layer 752 may be an organic layer doped with an alkali metal such as Li, Na, K, or Cs or an alkaline earth metal such as Mg, Sr, Ba, or Ra.

The P-type charge generation layer 754 may be formed of an organic material of Formula 2 or may be formed by doping a hole injection host material with an organic compound of Formula 2 . When the P-type charge generation layer 754 includes a hole injection host material and an organic compound of Formula 2, the hole injection host material may be MTDATA, CuPc, or PEDOT/PSS, and the organic compound of Formula 2 contains about 0.1 to 50 weight % can be doped. However, the present invention is not limited thereto.

In addition, the second hole injection layer 756 is made of a hole injection material. For example, the second hole injection layer 756 may be formed of MTDATA, CuPc, or PEDOT/PSS.

As described above, the organic compound of the present invention has a structure in which an electron withdrawing group is substituted for a core of benzothiophene, benzofuran, or benzoselenophene, and has excellent hole injection properties and charge generation properties.

Accordingly, a stacked structure light emitting diode including a charge generation layer 740 comprising a P-type charge generation layer 744 formed of an organic compound of Formula 2 or formed by doping a host material with an organic compound of Formula 2 ( 700) increases the luminous efficiency.

8 is a schematic cross-sectional view of a light emitting diode according to an eighth embodiment of the present invention.

As shown in FIG. 8 , the light emitting diode 800 according to the eighth embodiment of the present invention includes first and second electrodes 810 and 820 facing each other, and first and second electrodes 810 , A first light emitting unit 830 positioned between 820, a second light emitting unit 840 positioned between the first electrode 810 and the first light emitting unit 830, and first and second light emitting units ( and a charge generation layer 850 positioned between 830 and 840 .

As described above, the first electrode 810 is an anode and is made of a conductive material having a relatively large work function value, and the second electrode 820 is a cathode and is made of a conductive material having a relatively small work function value.

The first light emitting unit 830 includes a first light emitting material layer 832 , a first electron transport layer 834 , and an electron injection layer 836 . The first electron transport layer 834 is positioned between the first light emitting material layer 832 and the second electrode 820 , and the electron injection layer 836 is between the first electron transport layer 834 and the second electrode 820 . located in

In addition, the second light emitting unit 840 includes a hole injection layer 842 , a hole transport layer 844 , a second light emitting material layer 846 , and a second electron transport layer 848 .

The hole injection layer 842 is located between the first electrode 810 and the hole transport layer 844 , and the hole transport layer 844 is located between the hole injection layer 842 and the second light emitting material layer 846 , The second light emitting material layer 846 is positioned between the hole transport layer 844 and the second electron transport layer 848 .

Each of the first and second light emitting material layers 832 and 846 may be formed by doping a host material with a dopant, and may emit different colors.

For example, the second light-emitting material layer 846 may emit blue light, and the first light-emitting material layer 832 may emit green, yellowgreen, or orange color having a longer wavelength than blue.

The hole transport layer 844 may be formed of a hole transport host such as TPD or NPB. Also, the hole injection layer 842 may be formed of a hole injection material such as MTDATA, CuPc, or PEDOT/PSS.

Each of the first and second electron transport layers 834 and 848 includes electrons such as oxadiazole, triazole, phenanthroline, benzoxazole, or benzthiazole. It is made of a transport material, and the electron injection layer 836 may be made of an electron injection material such as LIF or lithium quinolate (LiQ). The first and second electron transport layers 834 and 848 may be made of the same material or different materials.

The charge generation layer 850 is positioned between the first light emitting unit 830 and the second light emitting unit 840 , and the N-type charge generation layer (N-CGL, 852) adjacent to the second light emitting unit 840 and and a P-type charge generation layer (P-CGL) 854 adjacent to the first light emitting unit 830 .

The N-type charge generation layer 852 injects electrons into the second light emitting unit 840 , and the P type charge generation layer 854 injects holes into the first light emitting unit 830 .

The N-type charge generation layer 852 may be an organic layer doped with an alkali metal such as Li, Na, K, or Cs or an alkaline earth metal such as Mg, Sr, Ba, or Ra.

The P-type charge generating layer 854 may be formed of an organic material of Formula 2 or may be formed by doping a hole transporting host material with an organic compound of Formula 2 . When the P-type charge generating layer 854 includes a hole transport host material and an organic compound of Formula 2, the hole transport host material may be TPD or NPB, and the organic compound of Formula 2 may be doped in an amount of about 0.1 to 50% by weight. can However, the present invention is not limited thereto.

As described above, the organic compound of the present invention has a structure in which an electron withdrawing group is substituted for a core of benzothiophene, benzofuran, or benzoselenophene, and has excellent hole injection properties and charge generation properties.

Accordingly, the light-emitting layer structure including the charge generation layer 840 including the P-type charge generation layer 844 made of the organic compound of Formula 2 or formed by doping the hole transporting host material with the organic compound of Formula 2 The luminous efficiency of the diode 800 is increased.

In addition, although it has been described that the P-type charge generating layer includes the organic compound of Formula 2 in FIGS. 5 to 8 , the hole injection layer or the hole transport layer may include the organic compound of Formula 2 as in FIGS. 1 to 4 . have.

In addition, although it has been described that the first and second light emitting units are stacked and the charge generating layer is positioned between them in FIGS. 5 to 8 , a charge generating layer positioned between the additional light emitting unit and the light emitting units may be further included. have.

Hereinafter, the performance of the light emitting diode using the organic compound of the present invention will be compared and described through the experimental examples and comparative examples for manufacturing a light emitting diode using the organic compound of the present invention.

[Light Emitting Diode]

After patterning so that the emission area of the indium-tin-oxide (ITO) layer on the substrate has a size of 3 mm X 3 mm, it was washed. A hole transport layer doped with α-NPB on the ITO layer at a pressure of about 1*10 ^-6 torr in a vacuum chamber (25 wt%, 100 Å), α-NPB (600 Å), a material of Formula 5 below ( A film was formed in the order of host) + a material of formula 6 below (dopant, 4 wt%) (250 _{Å), Alq 3} (300 Å), LiF (10 Å), and Al (800 Å).

[Experimental Example 1]

Compound A was used as a dopant of the doped hole transport layer.

[Experimental Example 2]

Compound B was used as a dopant of the doped hole transport layer.

[Experimental Example 3]

Compound C was used as a dopant of the doped hole transport layer.

[Experimental Example 4]

Compound D was used as a dopant of the doped hole transport layer.

[Experimental Example 5]

Compound E was used as a dopant of the doped hole transport layer.

[Experimental Example 6]

Compound F was used as a dopant of the doped hole transport layer.

[Comparative example]

HAT-CN was used as a dopant of the doped hole transport layer.

[Formula 5]

[Formula 6]

The results of the above-described Experimental Examples 1 to 6 (Ex1 to Ex6) and Comparative Example (Ref) are shown in Table 2 below.

As shown in Table 2, when compared with the light emitting diodes (Ref) constituting the HAT-CN doped hole transport layer, the driving voltage is higher in the light emitting diodes (Ex1 to Ex6) constituting the hole transport layer doped with the organic compound of the present invention. decreased and the luminous efficiency increased.

9 is a schematic cross-sectional view of an organic light emitting diode display according to a ninth embodiment of the present invention.

As shown in FIG. 9 , the light emitting diode display 900 includes a driving thin film transistor Td, a planarization layer 960 covering the driving thin film transistor Td, and a driving thin film positioned on the planarization layer 960 . and a light emitting diode E connected to the transistor Td.

The driving thin film transistor Td includes a semiconductor layer 940 , a gate electrode 944 , a source electrode 956 , and a drain electrode 958 .

Specifically, the semiconductor layer 940 is formed on the substrate 901 made of glass or plastic. For example, the semiconductor layer 940 may be formed of an oxide semiconductor material. In this case, a light blocking pattern (not shown) and a buffer layer (not shown) may be formed under the semiconductor layer 140 , and the light blocking pattern prevents light from being incident on the semiconductor layer 940 to prevent the semiconductor layer 940 from being incident on the semiconductor layer 940 . It prevents deterioration by this light. Alternatively, the semiconductor layer 940 may be made of polycrystalline silicon, and in this case, both edges of the semiconductor layer 940 may be doped with impurities.

A gate insulating layer 942 made of an insulating material is formed on the entire surface of the substrate 901 on the semiconductor layer 940 . The gate insulating layer 942 may be made of an inorganic insulating material such as silicon oxide or silicon nitride.

A gate electrode 944 made of a conductive material such as metal is formed on the gate insulating layer 942 to correspond to the center of the semiconductor layer 940 . Also, a gate wiring (not shown) and a first capacitor electrode (not shown) may be formed on the gate insulating layer 942 . The gate wiring may extend along the first direction, and the first capacitor electrode may be connected to the gate electrode 944 .

Meanwhile, although the gate insulating layer 942 is formed on the entire surface of the substrate 901 , the gate insulating layer 942 may be patterned to have the same shape as the gate electrode 944 .

An interlayer insulating film 950 made of an insulating material is formed on the entire surface of the substrate 901 on the gate electrode 944 . The interlayer insulating layer 950 may be formed of an inorganic insulating material such as silicon oxide or silicon nitride, or an organic insulating material such as benzocyclobutene or photo-acryl.

The interlayer insulating layer 950 has first and second contact holes 952 and 954 exposing top surfaces of both sides of the semiconductor layer 940 . The first and second contact holes 952 and 954 are positioned at both sides of the gate electrode 944 to be spaced apart from the gate electrode 944 . Here, the first and second contact holes 952 and 954 are also formed in the gate insulating layer 942 . Alternatively, when the gate insulating layer 942 is patterned to have the same shape as the gate electrode 944 , the first and second contact holes 952 and 954 are formed only in the interlayer insulating layer 950 .

A source electrode 956 and a drain electrode 958 are formed on the interlayer insulating layer 950 using a conductive material such as a metal. In addition, a data line (not shown), a power line (not shown), and a second capacitor electrode (not shown) extending in the second direction may be formed on the interlayer insulating layer 950 .

The source electrode 956 and the drain electrode 958 are spaced apart from the gate electrode 944 and contact both sides of the semiconductor layer 940 through the first and second contact holes 952 and 954, respectively. . Although not shown, the data line extends along the second direction and intersects the gate line to define a pixel area, and the power line for supplying a high potential voltage is spaced apart from the data line. The second capacitor electrode is connected to the drain electrode 958 and overlaps the first capacitor electrode to form a storage capacitor using the interlayer insulating film 950 between the first and second capacitor electrodes as a dielectric layer.

On the other hand, the semiconductor layer 940 , the gate electrode 944 , the source electrode 956 , and the drain electrode 958 form a driving thin film transistor Td, and the driving thin film transistor Td is the semiconductor layer 940 . It has a coplanar structure in which a gate electrode 944 , a source electrode 956 , and a drain electrode 958 are positioned thereon.

Alternatively, the driving thin film transistor Td may have an inverted staggered structure in which a gate electrode is disposed under a semiconductor layer and a source electrode and a drain electrode are disposed above the semiconductor layer. In this case, the semiconductor layer may be made of amorphous silicon.

In addition, a switching thin film transistor (not shown) having substantially the same structure as the driving thin film transistor Td is further formed on the substrate 901 . The gate electrode 944 of the driving thin film transistor Td is connected to the drain electrode (not shown) of the switching thin film transistor Ts, and the source electrode 956 of the driving thin film transistor Td is a power supply line (not shown). is connected to In addition, a gate electrode (not shown) and a source electrode (not shown) of the switching thin film transistor Ts are respectively connected to a gate line and a data line.

A planarization layer 960 is formed over the entire surface of the substrate 901 on the source electrode 956 and the drain electrode 958 . The planarization layer 960 has a flat top surface and has a drain contact hole 962 exposing the drain electrode 958 of the driving thin film transistor Td. Here, the drain contact hole 962 is illustrated as being formed directly above the second contact hole 954 , but may be formed to be spaced apart from the second contact hole 954 .

The light emitting diode E is disposed on the planarization layer 960 and includes a first electrode 910 connected to the drain electrode 958 of the driving thin film transistor Td, and an organic layer sequentially stacked on the first electrode 910 . The light emitting layer 120 and the second electrode 930 are included.

As described above, the first electrode 910 may be made of a material having a relatively large work function value to serve as an anode, and the second electrode 930 may be made of a material having a relatively small work function value to serve as a cathode.

In addition, an encapsulation substrate (not shown) covering the light emitting diode E may be bonded to the substrate 101 . In this case, a barrier layer may be formed between the encapsulation substrate and the light emitting diode (E) by bonding the substrates and preventing moisture or oxygen from penetrating into the light emitting diode (E).

The organic light emitting layer 920, as described with reference to the embodiments of FIGS. 1 to 8, the hole injection layer, the hole transport layer, or the charge generating layer includes a layer made of only the organic compound of Chemical Formula 2 or the organic compound of Chemical Formula 2 in the host material. It comprises a layer formed by doping the compound.

Although not shown, when the light emitting diode E has a stacked structure as in FIGS. 5 to 8 and is used for white light emission, a color filter may be formed.

As described above, the organic compound of the present invention has a structure in which an electron withdrawing group is substituted for a core of benzothiophene, benzofuran or benzoselenophene, and has excellent hole injection and charge generation properties. Accordingly, the organic light emitting diode display including the organic compound of the present invention has advantages in that the driving voltage is reduced and the luminous efficiency is improved.

Although the above has been described with reference to the preferred embodiment of the present invention, those skilled in the art can variously modify and change the present invention within the scope without departing from the spirit and scope of the present invention described in the claims below. You will understand that it can be done.

110, 210, 310, 410, 510, 610, 710, 810, 910: first electrode
120, 220, 320, 420, 520, 620, 720, 820, 920: second electrode
130, 230, 330, 430, 530, 540, 630, 640, 730, 740, 830, 840: light emitting unit
132, 232, 332, 432, 534, 546, 635, 646, 734, 746, 832, 846: light emitting material layer
134, 234, 334, 434, 536, 548, 637, 648, 736, 748, 834, 848: electron transport layer
136, 236, 336, 436, 538, 639, 738, 836: electron injection layer
140, 240, 542, 631, 642, 742, 756, 842: hole injection layer
150, 250, 350, 450, 532, 544, 633, 644, 732, 744, 844: hole transport layer
550, 650, 750, 850: charge generation layer
552, 652, 752, 852: N-type charge generation layer
554, 654, 754, 854: P-type charge generation layer

Claims (18)

delete delete delete An organic compound which is any one of the following compounds.

a first electrode;
a second electrode facing the first electrode;
a light emitting unit positioned between the first and second electrodes and including a light emitting material layer;
A hole layer positioned between the first electrode and the light emitting unit and comprising the organic compound of claim 4
A light emitting diode comprising a.
6. The method of claim 5,
The hole layer includes a hole transport layer, and a hole injection layer positioned between the hole transport layer and the first electrode and comprising only the organic compound or a hole injection host material doped with the organic compound.
6. The method of claim 5,
The hole layer is
a hole transport layer;
a first hole injection layer disposed between the hole transport layer and the first electrode and made of only the organic compound or doped with the organic compound into a hole injection host material;
and a second hole injection layer disposed between the first electrode and the first hole injection layer and made of a hole injection host material.
6. The method of claim 5,
The hole layer is a light emitting diode including a first hole transport layer formed by doping a hole transport host material with the organic compound.
9. The method of claim 8,
The hole layer is positioned between the first hole transport layer and the light emitting unit and further comprises a second hole transport layer made of a hole transport host material.
a first electrode;
a second electrode facing the first electrode;
a first light emitting unit positioned between the first and second electrodes and including a first light emitting material layer;
a second light emitting unit positioned between the first light emitting unit and the first electrode and including a second light emitting material layer;
A P-type charge generation layer positioned between the first and second light emitting units and comprising the organic compound of claim 4
A light emitting diode comprising a.
11. The method of claim 10,
The P-type charge generation layer is a light emitting diode made of only the organic compound or doped with the organic compound in a hole injection host material.
11. The method of claim 10,
and an N-type charge generation layer positioned between the P-type charge generation layer and the second light emitting unit and which is an organic layer doped with an alkali metal or alkaline earth metal.
13. The method of claim 12,
The first light emitting unit includes a first hole transport layer positioned between the first light emitting material layer and the P-type charge generating layer, an electron injection layer positioned between the first light emitting material layer and the second electrode, and a first Further comprising an electron transport layer,
The second light emitting unit may include a second electron transport layer positioned between the N-type charge generating layer and the second light emitting material layer, and a first hole injection layer positioned between the first electrode and the second light emitting material layer. and a second hole transport layer.
14. The method of claim 13,
The first light emitting unit may further include a second hole injection layer positioned between the first hole transport layer and the P-type charge generation layer.
13. The method of claim 12,
The light emitting diode further comprising a second hole injection layer positioned between the P-type charge generation layer and the N-type charge generation layer.
13. The method of claim 12,
The first light emitting unit further includes an electron injection layer and a first electron transport layer positioned between the first light emitting material layer and the second electrode,
The second light emitting unit may include a second electron transport layer positioned between the N-type charge generating layer and the second light emitting material layer, and a hole injection layer and a hole positioned between the first electrode and the second light emitting material layer. further comprising a transport layer,
The P-type charge generating layer is a light emitting diode formed by doping the organic compound into a hole transport layer host material.
a base substrate;
a driving thin film transistor positioned on the base substrate;
The light emitting diode of any one of claims 5 to 16, which is located on the base substrate and is connected to the driving thin film transistor;
An encapsulation substrate that covers the light emitting diode and is bonded to the base substrate
An organic light emitting diode display comprising a.
14. The method of claim 13,
One of the first and second hole transport layers and the first hole injection layer is a light emitting diode including the organic compound of claim 4 .

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