KR102069555B1 - Hole transport material and organic light emitting diode comprising the same - Google Patents

Abstract

상기 화학식 1에서, 상기 R₁, R₂, R₃ 및 R₄가 각각 독립적으로 C5 내지 C30의 치환 또는 비치환된 아릴기, C3 내지 C30의 치환 또는 비치환된 포화 또는 불포화된 환(polycyclic aromatic hydrocarbon group or aromatic heterocyclic organic group)으로부터 선택되고, 상기 R₃ 및 R₄ 중 적어도 하나는 가교결합 특성을 갖는 트리플루오로메틸에테르(trifluoromethylether group)을 포함하는 치환기를 가진다.Hole transport material according to an embodiment of the present invention is characterized in that represented by the formula (1).
[Formula 1]

In Formula 1, R ₁ , R ₂ , R ₃ and R ₄ are each independently a substituted or unsubstituted aryl group of C5 to C30, a substituted or unsubstituted saturated or unsaturated ring of C3 to C30 (polycyclic aromatic) hydrocarbon group or aromatic heterocyclic organic group), and at least one of R ₃ and R ₄ has a substituent including a trifluoromethylether group having crosslinking properties.

Description

Hole transport material and organic electroluminescent device comprising same {HOLE TRANSPORT MATERIAL AND ORGANIC LIGHT EMITTING DIODE COMPRISING THE SAME}

The present invention relates to an organic light emitting display device, and more particularly, to a low molecular hole transport material including a crosslinking having high synthesis yield and easy purification, and an organic light emitting display device including the same.

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

Among these, the organic light emitting device is a self-light emitting device that emits light when electrons and holes are paired and extinguished when charge is injected into the organic light emitting layer formed between the cathode as the electron injection electrode and the anode as the hole injection electrode. The organic light emitting diode can be formed on a flexible substrate such as plastic, and can be driven at a voltage lower than 10V, compared to a plasma display panel or an inorganic electroluminescent display, and consumes less power and has excellent color. There is an advantage. In addition, the organic light emitting display device can display three colors of red, green, and blue, and thus, has become a target of many people as a next-generation display device for expressing rich colors.

In order to secure the competitiveness of the organic light emitting device, a large area of the manufacturing process is required. Increasing the size of the input substrate can lead to diversification of productivity and the product range produced. This requires a large area of manufacturing equipment, process technology development, and material development.

Large area by vacuum deposition requires many improvements in the composition of organic or metal sources, metal masks, glass substrates and mask transfer systems, and equipment. In the case of the solution process, various methods are proposed, but the materials, equipment, and processes of the solution process are only low levels, and for this purpose, further research on the technology is required.

The organic light emitting device based on low molecular weight can be deposited by layer by layer deposition through vacuum deposition. Masking is required for R, G, and B pixel patterning, but the size of the fine metal mask (FMM) increases as the area becomes larger, which causes a problem of mask sag. The solution process can be patterned and coated on a large area without a mask through inkjet printing or nozzle printing, and the use rate of the material is very high, such as 50 to 80%, compared to vacuum deposition having a material use rate of 10% or less. In addition, the glass transition temperature (glass transition temperature) is higher than the vacuum deposition thin film has excellent thermal stability and morphology (morphology) characteristics.

The material development of the hole transport layer for the solution process can be divided into low molecular and cross-linked polymers. US Pat. No. 7,736,534 discloses a low molecular hole transport material having a cross-linkable group that can crosslink to a moiety having hole transport properties. U. S. Patent No. 6,107, 452 discloses a polymer-based material in which heat or optical crosslinking occurs. U. S. Patent No. 6,596, 450 discloses a charge transport material having a crosslink. A method of depositing a material for fabricating an organic light emitting display device and a material that can be used therein are disclosed. In addition, US Patent No. 7,365,230 discloses a polymer having a crosslink, US Patent No. 7,592,414 discloses a polymer having an oxetane group, US Patent No. 7,659,009 is a thermal crosslinkable boronic Disclosed are a material having a bronic acid derivatie and an organic field device using the same.

However, the organic electroluminescent device made using this material is lower than the device made by vacuum deposition at the level of 50% or less. In addition, there is a problem that the polymer series is relatively synthesized and purified compared to the low molecules.

The present invention provides a low molecular hole transport material having a high synthetic yield and easy to purify a crosslink, and an organic light emitting device including the same.

In order to achieve the above object, the hole transport material according to an embodiment of the present invention is characterized by the following formula (1).

[Formula 1]

In Formula 1, R ₁ , R ₂ , R ₃ and R ₄ are each independently a substituted or unsubstituted aryl group of C5 to C30, a substituted or unsubstituted saturated or unsaturated ring of C3 to C30 (polycyclic aromatic) hydrocarbon group or aromatic heterocyclic organic group), and at least one of R ₃ and R ₄ has a substituent including a trifluoromethylether group having crosslinking properties.

At least one substituent of R ₃ and R ₄ is phenyl, biphenyl, naphthyl, phenanthryl, terphenyl, pyridyl and bipyridyl It is characterized in that any one selected from (bipyridyl).

The substituted or unsubstituted aryl group of C5 to C30 is a phenyl group, 2-methylphenyl group, 3-methylphenyl group, 4-methylphenyl group, pentaduthiumphenyl group, 2-trimethylsilylphenyl group, 3-trimethylsilylphenyl group, 4-trimethylsilyl Selected from phenyl group, 3,5-difluorophenyl group, 4-ethylphenyl group, biphenyl group, 4-menylbiphenyl group, 4-ethylbiphenyl group, 4-cyclohexylbiphenyl group and terphenyl group, 3,5-dichlorophenyl group The substituted or unsubstituted saturated or unsaturated ring of any one of C3 to C30 may be a naphthyl group, 1-methylnaphthyl group, 2-methylnaphthyl group, acenaphthyl group, anthracenyl group, pulloenyl group, phenanyl group, or phenane It is characterized in that it is any one selected from srenyl group and pyrenyl group.

Substituents for R ₁ , R ₂ , R _3, and R ₄ include methyl, ethyl, n-propyl, i-propyl, n-butyl (n- C1-C6 alkyl groups such as butyl, i-butyl and t-butyl, cyanyl, trimethylsilyl, fluorine, It is characterized in that any one selected from trifluoromethyl (trifluoromethyl) and deuterium (deuterium).

The hole transport material represented by Formula 1 is characterized in that any one of the following compounds.

In addition, the organic light emitting display device according to an embodiment of the present invention, the organic light emitting device including an anode, a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, an electron injection layer and a cathode, the hole transport material comprises Characterized in that.

The hole transport material is formed by any one method selected from spin coating, inkjet printing, slit coating and screen printing.

The hole transport material and the organic light emitting device including the same according to an embodiment of the present invention has the advantage that can improve the current efficiency, power efficiency and life characteristics compared to the conventional organic light emitting device.

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

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

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

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

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

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

The hole injection layer 120 may have a thickness of about 1 nm to about 150 nm. In this case, when the thickness of the hole injection layer 120 is 1 nm or more, there is an advantage of preventing the hole injection characteristic from deteriorating. When the thickness of the hole injection layer 120 is too thick, the hole injection layer 120 is too thick. There is an advantage that can be prevented from increasing the driving voltage to improve.

The hole transport layer 130 has a crosslinking property and may be made of a material represented by the following Chemical Formula 1.

[Formula 1]

In Formula 1, R ₁ , R ₂ , R ₃ and R ₄ are each independently a substituted or unsubstituted aryl group of C5 to C30, a substituted or unsubstituted saturated or unsaturated ring of C3 to C30 (polycyclic aromatic) hydrocarbon group or aromatic heterocyclic organic group), and at least one of R ₃ and R ₄ has a substituent including a trifluoromethylether group having crosslinking properties. Here, at least one substituent of R ₃ and R ₄ is phenyl, biphenyl, naphthyl, phenanthryl, terphenyl, pyridyl and birid. It is any one selected from pyridyl.

In addition, the substituted or unsubstituted aryl group of C5 to C30 is a phenyl group, 2-methylphenyl group, 3-methylphenyl group, 4-methylphenyl group, pentaduthiumphenyl group, 2-trimethylsilylphenyl group, 3-trimethylsilylphenyl group, 4- Trimethylsilylphenyl group, 3,5-difluorophenyl group, 4-ethylphenyl group, biphenyl group, 4-menylbiphenyl group, 4-ethylbiphenyl group, 4-cyclohexylbiphenyl group and terphenyl group, 3,5-dichlorophenyl group Any one selected from among C3 to C30 substituted or unsubstituted saturated or unsaturated ring is naphthyl group, 1-methylnaphthyl group, 2-methylnaphthyl group, acenaphthyl group, anthracenyl group, pulloenyl group, phenalyl group , Phenanthrenyl group and pyrenyl group.

In addition, the substituents of the R ₁ , R ₂ , R ₃ and R ₄ is methyl (methyl), ethyl (ethyl), n-propyl (n-propyl), i-propyl (i-propyl), n-butyl ( C1-C6 alkyl groups such as n-butyl, i-butyl and t-butyl, cyanyl, trimethylsilyl and fluorine ), Trifluoromethyl and deuterium.

The hole transport material represented by Formula 1 may be any one of the following compounds.

Referring to the following schematic diagram of the hole transport material of the present invention described above,

[Schematic diagram]

The core portion has a high singlet energy (E _T1 ) in a twisted biphenyl structure, and improves solubility with high steric hindrance. The hole transport unit has a symmetry structure to improve hole transportability, a ladder type to improve hole mobility, and has an amorphous structure by increasing molecular weight. The crosslinking unit improves interfacial properties by introducing a thermal cross-linked type functional group and introducing a trifluoromethyl ether.

Meanwhile, the p-type dopant may be doped into the hole transport layer 130 of the present invention. As the p-type dopant, F4TCNQ, which is a material having excellent electron affinity, may be used, and metals such as Mo, W, and V oxide may be used to improve hole injection. The hole transport layer 130 is formed by any one method selected from spin coating, inkjet printing, slit coating, and screen printing.

As described above, the hole transport material of the present invention is an organic solvent at the time of crosslinking by introducing a twisted biphenyl (diphenylamine) and a diarylamine (diarylamine) derivative and a substituent capable of crosslinking at least one in the diarylamine It is excellent in resistance, has high hole transporting ability, and can improve luminous efficiency, color purity and lifespan when applied as hole transporting layer of organic light emitting device.

The light emitting layer 140 may emit red (R), green (G), and blue (B), and may be formed of a phosphor or a fluorescent material.

When the emission layer 140 is red, it includes a host material including CBP (carbazole biphenyl) or mCP (1,3-bis (carbazol-9-yl), and PIQIr (acac) (bis (1-phenylisoquinoline) acetylacetonate Phosphorescent light containing a dopant containing any one or more selected from the group consisting of iridium), PQIr (acac) (bis (1-phenylquinoline) acetylacetonate iridium), PQIr (tris (1-phenylquinoline) iridium) and PtOEP (octaethylporphyrin platinum) It may be made of a material, and alternatively may be made of a fluorescent material including PBD: Eu (DBM) ₃ (Phen) or perylene, but is not limited thereto.

When the light emitting layer 140 is green, it may include a host material including CBP or mCP, and may be made of a phosphor including a dopant material including Ir (ppy) 3 (fac tris (2-phenylpyridine) iridium). Alternatively, the composition may be made of a fluorescent material including Alq3 (tris (8-hydroxyquinolino) aluminum), but is not limited thereto.

When the light emitting layer 140 is blue, the light emitting layer 140 may include a host material including CBP or mCP, and may be formed of a phosphor including a dopant material including (4,6-F ₂ ppy) ₂ Irpic. spiro-DPVBi, spiro-6P, distilbenzene (DSB), distriarylene (DSA), PFO-based polymer and may be composed of a fluorescent material including any one selected from the group consisting of PPV polymer. .

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

The thickness of the electron transport layer 150 may be 1 to 50nm. In this case, when the thickness of the electron transport layer 150 is 1 nm or more, there is an advantage of preventing the electron transport property from deteriorating. When the thickness of the electron transport layer 150 is 50 nm or less, the thickness of the electron transport layer 150 is too thick to improve the movement of electrons. In order to prevent the driving voltage from rising, there is an advantage.

The electron injection layer 160 serves to facilitate the injection of electrons, and may be Alq3 (tris (8-hydroxyquinolino) aluminum), PBD, TAZ, spiro-PBD, BAlq or SAlq, but is not limited thereto.

The electron injection layer 160 may have a thickness of about 1 nm to about 50 nm. In this case, when the thickness of the electron injection layer 160 is 1 nm or more, there is an advantage that the electron injection characteristics may be prevented from being lowered. When the thickness of the electron injection layer 160 is 50 nm or less, the thickness of the electron injection layer 150 may be too thick to move electrons. There is an advantage that can be prevented from increasing the driving voltage to improve.

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

Hereinafter, a synthesis example of the hole transport material of the present invention and an organic light emitting device including the same will be described in detail in the following synthesis examples and examples. However, the following examples are merely to illustrate the present invention is not limited to the following examples.

Synthesis Example

1) Synthesis of 2,2'-biphenydilboronic acid

2,2'-dibromobiphenyl (10g, 0.03mol) and 100mL of ether (stirring) is added to a two-necked flask. The temperature was lowered to -78 ° C. in a dry ice bath, and slowly added dropwise 2.5 M n-BuLi (26.9 mL, 0.067 mol) for 1 hour at room temperature. The temperature was lowered to -78 ° C with a dry ice bath, and triethylborate (19.5g, 0.13mol) was slowly added dropwise and stirred at room temperature for 4 hours. 100 mL of 2N HCl is added and quenched, and the solvent is evaporated. The resulting solid was filtered and washed 3-4 times with distilled water and hexane to give 2,2'-biphenyldibromic acid (5.4 g, yield: 70%).

2) Synthesis of 2,2'-bis (4'-bromophenyl) biphenyl (2,2'-bis (4'-bromophenyl) biphenyl)

2,2'-biphenyl dibromic acid (5 g, 0.02 mol), 1-bromo-4-iodobenzene (12.9 g, 0.045 mol), tetrakis (tri Phenylphosphine) palladium (Pd (PPh ₃ ) ₄ ) (0.1 g, 0.9 mmol), potassium carbonate (K ₂ CO ₃ ) and 90 mL of toluene / ethanol (3: 1) were added and refluxed for 12 hours. . After cooling to room temperature, the mixture was extracted with methylene chloride, the solvent was evaporated, and purified by silica gel column to give 2,2'-bis (4'-bromophenyl) biphenyl (7.8 g, yield: 80%).

3) Synthesis of 4-trifluoromethyletherdiphenylamine

Aniline (5 g, 0.05 mol), 4-bromo-1-trifluoromethyletherbenzene (13.6 g, 0.05 mol), palladium acetate (Pd) OAc) 2 ₎ , tertbutylphosphorus (P (t-Bu) ₃ ), NaOBu and toluene were added and refluxed at 130 ° C. for 18 hours. After cooling to room temperature, the mixture was purified by methylene chloride, the solvent was evaporated, and purified by a silica gel column to obtain 4-trifluoromethyl ether diphenylamine (10 g, yield: 70%).

4) Synthesis of 2,2'-bis (4 "-trifluoromethyletherdiphenylamine) biphenyl (2,2'-bis (4" -trifluoromethyletherdiphenylamine) biphenyl) (Compound A-01)

2,2'-bis (4'-bromophenyl) biphenyl (1.5g, 3.2mmol), 4'-trifluoromethyletherdiphenylamine (2.1g, 8.1mmol), Pd ₂ ( dba) ₃ , P (t-Bu) ₃ , NaOBu and toluene were added and refluxed at 130 ° C. for 18 hours. After cooling to room temperature, the mixture was purified by methylene chloride, the solvent was evaporated and purified by a silica gel column to give 2,2'-bis (4 "-trifluoromethyletherdiphenylamine) biphenyl (1.8 g, yield: 70%).

5) Synthesis of 4'-trifluoromethyletherphenyl-1-naphthylamine

1-aminonaphthalene (5 g, 0.035 mol), 4-bromo-1-trifluoromethyletherbenzene (8.8 g, 0.035 mol), Pd (OAc) ₂ , P (t) -Bu) ₃ , NaOBu and toluene were added and refluxed at 130 ° C. for 18 hours. After cooling to room temperature, the mixture was purified by methylene chloride, the solvent was evaporated, and purified by silica gel column to obtain 4'-trifluoromethyletherphenyl-1-naphthylamine (7.7 g, yield: 70%).

6) 2,2'-bis (4 "-trifluoromethyletherphenyl-1'-naphthylamine) biphenyl (2,2'-bis (4" -trifluoromethyletherphenyl-1'-naphthylamine) biphenyl) (compound Synthesis of A-02)

2,2'-bis (4'-bromophenyl) biphenyl (1.5 g, 3.2 mmol), 4'-trifluoromethyletherphenyl-1-naphthylamine (2.5 g, 8.1 mmol) in a two-neck flask , Pd ₂ (dba) ₃ , P (t-Bu) ₃ , NaOBu, toluene was added and refluxed at 130 ° C. for 18 hours. The temperature was cooled to room temperature, then purified by methylene chloride, the solvent was evaporated and purified by silica gel column to give 2,2'-bis (4 "-trifluoromethyletherphenyl-1'-naphthylamine) biphenyl ( 1.9 g, yield: 65%).

7) Synthesis of 4'-trifluoromethyletherphenyl-4-biphenylamine

4-aminobiphenyl (5 g, 0.03 mol), 4-bromo-1-trifluoromethyletherbenzene (7.5 g, 0.03 mol), Pd (OAc) ₂ , P ( t-Bu) ₃ , NaOBu and toluene were added and refluxed at 130 ° C. for 18 hours. After cooling to room temperature, the mixture was purified by methylene chloride, the solvent was evaporated, and purified by a silica gel column to obtain 4'-trifluoromethyletherphenyl-4-biphenylamine (7.2 g, yield: 70%).

8) 2,2 '-(4 "-trifluoromethyletherphenyl-4'-biphenylamine) biphenyl (compound A- (2,2'-(4" -trifluoromethyletherphenyl-4'-biphenylamine) biphenyl) 05) Synthesis

2,2'-bis (4'-bromophenyl) biphenyl (2,2'-bis (4'-bromophenyl) biphenyl) (1.5 g, 3.2 mmol), 4'-trifluoromethyl Etherphenyl-4-biphenylaminenaphthylamine (4'-trifluoromethyletherphenyl-4-biphenylaminenaphthylamine (2.8g, 8.1mmol), Pd ₂ (dba) ₃ , P (t-Bu) ₃ , NaOBu, toluene Reflux for 8 hours at room temperature, then cooled to room temperature, purified by methylene chloride, evaporated solvent and purified by silica gel column to give 2,2 '-(4 "-trifluoromethyletherphenyl-4'-bi. Phenylamine) biphenyl (2.1 g, yield: 65%) was obtained.

Example

Hereinafter, an embodiment of fabricating an organic light emitting display device using the hole transport material of the present invention represented by A-01, A-02, and A-05 described above as a hole transport layer will be described.

<Example 1>

The light emitting area of the ITO glass was patterned to have a size of 3 mm x 3 mm and then washed. The substrate is mounted on a spin coater, followed by spin coating PEDOT: PSS (500 kPa, spin coating: 3000 rpm, drying condition: 150 ° C. for 10 minutes) on the ITO, followed by drying. After spin-coating an ink (300Å, spin coating: 3000 rpm, baking condition: 200 ° C., 30 minutes) in which hole transport material A-01 was dissolved in xylene, dried at 100 ° C. for 10 minutes on a hot plate. Then crosslinked. Then, DPAVBi (4%) was spin-coated with (300 kPa, 3000 rpm, drying condition: 100 ° C, 10 minutes) with AND and dopant as a host and dried. After mounting in a vacuum chamber, the base pressure was 1 × 10 ⁻⁶ torr, and then formed in the order of Alq ₃ (350 Pa), LiF (5 Pa), and Al (500 Pa) to fabricate an organic light emitting display device. .

<Example 2>

Under the same conditions as in Example 1, the organic light emitting diode was manufactured by using only the hole transport material A-02.

<Example 3>

Under the same conditions as in Example 1, the organic light emitting diode was manufactured by using only the hole transport material A-05.

Comparative Example

Under the same conditions as in Example 1, an organic light emitting diode was manufactured by using only 2-NPD as a hole transport material.

The voltage, current, current efficiency, power efficiency, color coordinates, and lifespan of the organic light emitting diodes manufactured according to Examples 1 to 3 and Comparative Examples are shown in Table 1 below.

Voltage (V)
Current (mA)
Current efficiency (cd / A) Power efficiency (lm / W) Color coordinates Lifespan (T50, 1000 nits) CIE_x CIE_y Example 1 5.0 0.9 6.25 3.92 0.136 0.242 680 Example 2 5.1 0.9 6.51 4.01 0.137 0.241 730 Example 3 5.1 0.9 6.42 3.95 0.137 0.241 720 Comparative example 5.5 0.9 4.22 2.41 0.137 0.241 640

As shown in Table 1, the organic light emitting display device manufactured according to Examples 1 to 3 shows color coordinates equivalent to those of Comparative Example, and it was confirmed that the voltage was lowered and the current efficiency, power efficiency, and lifespan were significantly improved. have.

Therefore, the hole transport material and the organic light emitting device including the same according to an embodiment of the present invention has the advantage that can improve the current efficiency, power efficiency and life characteristics compared to the conventional organic light emitting device.

Although the embodiments of the present invention have been described above with reference to the accompanying drawings, the technical configuration of the present invention described above may be modified in other specific forms by those skilled in the art to which the present invention pertains without changing its technical spirit or essential features. It will be appreciated that it may be practiced. Therefore, the exemplary embodiments described above are to be understood as illustrative and not restrictive in every respect. In addition, the scope of the present invention is represented by the following claims rather than the detailed description. Also, it is to be understood that all changes or modifications derived from the meaning and scope of the claims and the equivalent concepts shall be included in the scope of the present invention.

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

Claims (9)

A hole transport material, characterized in that any one of the following compounds.

delete delete delete delete In the organic light emitting device comprising an anode, a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, an electron injection layer and a cathode,
An organic light emitting device comprising the hole transport material according to claim 1.
The method of claim 6,
The hole transport material is an organic electroluminescent device, characterized in that formed by any one method selected from spin coating, inkjet printing, slit coating and screen printing. The method of claim 6,
The hole transport material is an organic light emitting device, characterized in that included in the hole transport layer.
The method of claim 8,
The hole transport layer further comprises a p-type dopant,
The p-type dopant is an organic light emitting device, characterized in that any one selected from Mo, W, V or oxides thereof and F4TCNQ.

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