KR102148239B1 - benzo(b)fluoranthene compounds and organic light emitting diode comprising the same - Google Patents

Abstract

The present invention relates to a benzofluoranthene-based compound and an organic electroluminescent device exhibiting excellent efficiency characteristics by including it in one or more organic layers.

Description

Benzofluoranthene compounds and organic light emitting diode comprising the same {benzo(b)fluoranthene compounds and organic light emitting diode comprising the same}

It is revealed that this application was processed with partial application fee support through the 2017 Regional Autonomous Program for Small and Medium Global Enterprises hosted by Gyeonggi-do Economics and Science Promotion Agency.
The present invention relates to a benzo( b )fluoranthene-based compound and an organic light emitting device including the same, and more particularly, to an N-type charge generation layer (n-type-charge generation layer, n- It relates to a compound capable of lowering a driving voltage, improving lifespan, and increasing efficiency by providing CGL), and an organic light emitting device including the same.

A white organic light emitting device that is widely used in a large area is being studied in a tandem structure in which a plurality of light emitting layers of the same or different colors are stacked to implement white. In a tandem type organic light emitting device, a plurality of light emitting units including a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, and an electron injection layer are stacked between the anode and the cathode. In a tandem type organic light-emitting device, an N-type charge generation layer and a P-type charge generation layer through which electrons and holes can be generated are formed between each light emitting unit. In this case, the charge generation layer should have good energy level and charge injection performance with the adjacent layer, should be transparent, and should have low surface resistance. In addition, it should be stably deposited so that the adjacent layer and the interface should fit well and be driven stably.

In general, charges are generated between the N-type charge generation layer and the P-type charge generation layer, and electrons are transferred to the electron injection layer adjacent to the N-type charge generation layer, and holes are transferred to the P-type charge generation layer and the adjacent hole injection layer. At this time, the device efficiency is determined according to the interface characteristics and energy level difference between the P-type charge generation layer and the N-type charge generation layer, and the interface characteristics and energy level difference between the N-type charge generation layer and the doped alkali metal. As the energy level difference between the N-type charge generation layer and the P-type charge generation layer increases, charges are generated at the interface between the P-type charge generation layer and the adjacent hole injection layer, making it difficult for electrons to be injected into the N-type charge generation layer. In addition, when the N-type charge generation layer is doped with an alkali metal, the alkali metal diffuses into adjacent layers such as the P-type charge generation layer, resulting in current leakage. Current leakage reduces the life of the device.

Korean Patent Publication No. 10-2016-0092059 (published on August 3, 2016)

An object of the present invention is to provide a benzofluoranthene-based compound having a new structure and an organic light emitting device including the same.

Another object of the present invention is to provide a material for an organic light-emitting device having high luminous efficiency, excellent heat resistance, and a long lifespan, and an organic light-emitting device using the same.

Another object of the present invention is to minimize the difference in the energy level between the N-type charge generation layer and the P-type charge generation layer to improve the amount of electrons injected into the light emitting unit, and the N-type charge generation layer is doped with an alkali metal or alkaline earth metal. Even in the case where the alkali metal is diffused into the P-type charge generation layer, a benzofluoranthene-based compound and an organic light-emitting device including the same are provided.

The object of the present invention is achieved by a benzofluoranthene (Benzo( b )fluoranthene)-based compound represented by the following Chemical Formula 1.

[Formula 1]

Formulas R ₁ to R ₃ are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 40 carbon atoms which may have a substituent, a heterocyclic group having 3 to 60 carbon atoms which may have a substituent, and 1 to carbon number which may have a substituent A 60 alkoxy group, an aryl group having 6 to 60 carbon atoms which may have a substituent, an aryloxy group having 6 to 60 carbon atoms which may have a substituent, an aralkyl group having 7 to 60 carbon atoms which may have a substituent, Alkenyl group having 2 to 60 carbon atoms, alkylamino group having 1 to 80 carbon atoms which may have a substituent, arylamino group having 6 to 80 carbon atoms which may have a substituent, aralkylamino group having 7 to 80 carbon atoms which may have a substituent, and a substituent May have an alkylsilyl group having 3 to 10 carbon atoms, an arylsilyl group having 6 to 30 carbon atoms or a cyano group which may have a substituent, and R ₁ to R ₃ may each be plural, and adjacent ones may be saturated or unsaturated Can form an annular structure of

In Formula 1, R ₁ to R ₃ are substituted or unsubstituted 5 to 60 members including one or more heteroatoms selected from hydrogen, substituted or unsubstituted aryl groups having 6 to 60 carbon atoms, nitrogen, oxygen and sulfur It is characterized in that any one selected from a heteroaryl group, an arylamine group, or a secondary amine group, and R ₁ to R ₃ may be represented by any one of the following formulas.

In the above formula, L ₁ to L ₂ may be a single bond, hydrogen, a substituted or unsubstituted arylene group having 6 to 20 carbon atoms, or a substituted or unsubstituted heteroarylene group having 4 to 20 carbon atoms.

Another object of the present invention is to include a first electrode, a first electrode, and an organic material layer positioned between the first electrode and the second electrode and emitting light, wherein the organic material layer consists of a plurality of layers, and at least one layer is the benzo It is achieved by an organic light emitting device comprising a fluoranthene compound.

At least one organic material layer may include a charge generation layer.

The charge generation layer may be N-type.

The organic material layer may include a first light emitting portion, a second light emitting portion positioned on the first light emitting portion, and a first charge generating layer positioned between the first light emitting portion and the second light emitting portion.

A third light emitting unit positioned on the second light emitting unit, and a second charge generating layer positioned between the second light emitting unit and the third light emitting unit may be further included.

At least one of the first charge generation layer and the second charge generation layer is doped with at least one of an alkali metal and an alkaline earth metal to a benzofluoranthene-based compound, and the doped alkali metal is Li, Na , K, Rb, and at least one of Cs, and the alkaline earth metal may be at least any one of Be, Mg, Ca, Sr, and Ba.

According to the present invention, a benzofluoranthene-based compound having a new structure and an organic light-emitting device including the same are provided.

According to the present invention, a compound capable of improving the driving voltage and efficiency by minimizing the difference in energy level between the N-type charge generation layer and the P-type charge generation layer to improve the amount of electrons injected into the light emitting unit, and an organic light-emitting device including the same are provided. do.

According to the present invention, even when the N-type charge generation layer is doped with an alkali metal or alkaline earth metal, the doped materials are firmly coordinated with the compound as a host material to minimize the diffusion of the alkali metal into the P-type charge generation layer. An organic light-emitting device comprising a compound capable of improving the lifespan of the light-emitting device is provided.

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

Advantages and features of the present invention, and a method of achieving them will become apparent with reference to embodiments described below in detail. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various forms different from each other, and only these embodiments make the disclosure of the present invention complete, and common knowledge in the technical field to which the present invention pertains. It is provided to completely inform the scope of the invention to those who have it, and the invention is only defined by the scope of the claims.

The size and thickness of each component shown in the drawings are illustrated for convenience of description, and the present invention is not limited to the size and thickness of the illustrated component.

Each of the features of the various embodiments of the present invention can be partially or entirely combined or combined with each other, and as a person skilled in the art can fully understand, technically various interlocking and driving are possible, and each of the embodiments may be independently implemented with respect to each other. It may be possible to do it together in a related relationship.

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

The compound used in the N-type charge generation layer in the embodiment of the present invention is represented by the following formula (1).

[Formula 1]

R ₁ to R ₃ are each independently a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C3 to C20 cycloalkyl group, a substituted or unsubstituted C3 to C20 heterocycloalkyl group, a substituted or unsubstituted C6 to C6 40 aryl group, substituted or unsubstituted heteroaryl group having 3 to 40 carbon atoms, substituted or unsubstituted alkoxy group having 1 to 30 carbon atoms, substituted or unsubstituted aryloxy group having 6 to 30 carbon atoms, substituted or unsubstituted 1 to carbon number 30 alkylamino group, substituted or unsubstituted C3-C20 cycloalkylamino group, substituted or unsubstituted C3-C20 heterocycloalkylamino group, substituted or unsubstituted C6-C30 arylamino group, substituted or unsubstituted C6-C30 Heteroarylamino group, substituted or unsubstituted aralkylamino group having 6 to 30 carbon atoms, substituted or unsubstituted alkylsilyl group having 1 to 30 carbon atoms, substituted or unsubstituted arylsilyl group having 6 to 30 carbon atoms, substituted or unsubstituted alkenyl group , Substituted or unsubstituted alkynyl group, cyano group, halogen group, selected from the group consisting of deuterium and hydrogen. In addition, _{one set} of neighboring substituents of R ₁ to R ₃ may be bonded to each other to form an aromatic ring.

R ₁ to R ₃ of the benzofluoranthene-based compound of Formula 1 according to the present invention includes at least one heteroatom selected from hydrogen, a substituted or unsubstituted aryl group having 6 to 60 carbon atoms, nitrogen, oxygen, and sulfur. It may be selected from a substituted or unsubstituted 5 to 60 membered heteroaryl group, an arylamine group, or a secondary amine group, and R ₁ to R ₃ may be represented by any one of the following formulas.

At this time, in the above formula, L ₁ to L ₂ may be selected from a single bond, hydrogen, or a substituted or unsubstituted arylene group having 6 to 20 carbon atoms or a substituted or unsubstituted heteroarylene group having 4 to 20 carbon atoms.

The benzofluoranthene-based compound according to the present invention may be any one selected from the following compounds.

Substituents including “alkyl”, “alkoxy” and other “alkyl” moieties described in the present invention include all straight chain or branched forms.

The'aryl' described in the present invention is an organic radical derived from an aromatic hydrocarbon by the removal of one hydrogen, and a single or fused ring containing 4 to 7, preferably 5 or 6 ring atoms suitably in each ring It includes a system, and includes a form in which a plurality of aryls are connected by a single bond. Specific examples include phenyl, naphthyl, biphenyl, anthryl, indenyl, fluorenyl, phenanthryl, triphenylenyl, pyrenyl, peryleneyl, chrysenyl, naphthacenyl, fluoranthenyl, and the like, It is not limited to this. The naphthyl includes 1-naphthyl and 2-naphthyl, anthryl includes 1-anthryl, 2-anthryl and 9-anthryl, and fluorenyl is 1-fluorenyl, 2- Fluorenyl, 3-fluorenyl, 4-fluorenyl and 9-fluorenyl are all included.

The'heteroaryl' described in the present invention includes 1 to 4 heteroatoms selected from B, N, O, S, P(=O), Si and P as an aromatic ring skeleton atom, and the remaining aromatic ring skeleton atoms are carbon It refers to a phosphorus aryl group, a 5 to 6 membered monocyclic heteroaryl, and a polycyclic heteroaryl condensed with one or more benzene rings, and may be partially saturated.

The following shows the structural formula and band gap of each compound.

Aromatic compounds rich in electrons, such as anthracene, pyrene, and fluoranthene, provide a certain bandgap to organic materials and play a role in setting the framework of HOMO and LUMO. However, since aromatic macro compounds such as pyrene absorb blue light in a tandem method and adversely affect efficiency, an aromatic compound having an appropriate band gap is required.

The benzofluoranthene compound contained in the charge generation layer according to the present invention can contribute to suppressing light absorption in the light emitting layer and improving the injection of electric charges, thereby providing an organic light emitting device having an excellent lifespan.

The compound according to the present invention can be represented by schematically as follows.

Here, Moiety 1 in the schematic diagram represents pyridyl, alkylpyridyl, halopyridyl, cyanopyridyl, alkoxypyridyl, silylpyridyl, pyrimidyl, halopyrimidyl, which are substituents of the benzofluoranthene compound according to the present invention. Cyanopyrimidyl, alkoxypyrimidyl, quinolinyl, isoquinolinyl, quinoxalinyl, pyrazinyl, quinazolinyl, bipyridyl, terpyridyl, phenanthrolinyl.

Moiety 1 represents the characteristics of the N-type charge generation layer by bonding with alkali metal or alkaline earth metal doped to the N-type charge generation layer as a core. Here, the cores are bound with alkali metals (Li, Cs) doped in the charge generation layer to form a gap state, and electrons are transferred from the N-type charge generation layer to the electron transport layer by the formed gap state. Delivery can be smooth. In addition, by combining nitrogen with the metal contained in the N-type charge generation layer, it is possible to improve the lifespan by preventing diffusion to the adjacent layer over time.

Moiety 2 adjusts HOMO and LUMO and improves N-type or P-type characteristics by controlling HOMO and LUMO, and by giving the characteristics of holes or electrons depending on the substituent, it can facilitate the transfer of electrons from the N-type charge generation layer to the electron transport layer. In addition, by preventing the point of attack between the molecular moiety reactions, the stability of the molecule is increased and the glass transition temperature is increased. In addition, Moiety 2 can increase stability by dispersing electrons concentrated on the N-type moiety such as phenanthroline by attaching a strong electron attractor such as pyridine or pyrimidine.

The linker controls the charge mobility. Through fine conjugation control, it acts as a pathway to reach the rich electrons of benzofluoranthene of schematic diagram 1 to Moiety 1, and regulates HOMO (highest occupied molecular orbital) and LUMO (lowest unoccupied molecular orbital).

Benzofluoranthene is an aromatic macrocycle that improves pi (π)-electron density, helps to form a stable interface with adjacent layers, and serves to hold the main framework of HOMO and LUMO. Accordingly, the charge mobility of the N-type charge generation layer can be improved to facilitate transfer of electrons from the N-type charge generation layer to the electron transport layer.

The compound according to the present invention has excellent thermal stability, a glass transition temperature of 150°C or higher, and a melting temperature of 330°C or higher. Accordingly, it is possible to implement a highly efficient organic light emitting device.

In particular, in an organic light-emitting device having a tandem structure, an aromatic moiety having an appropriate band gap without absorbing the light of the blue layer is required. The benzo( b )fluoranthene-based compound used in the charge generation layer of the organic light-emitting device according to the present invention suppresses the absorption of light in the light-emitting layer and contributes to improving the effect of charge injection, thereby providing excellent device life. An organic light-emitting device may be provided.

The benzofluoranthene-based compound according to the present invention is rich in electrons and has high electron mobility to facilitate electron transport. Therefore, the organic light-emitting device of the present invention can efficiently transfer electrons transferred from the N-type charge generation layer to the light-emitting layer by using a benzofluoranthene-based compound in at least one of several electron transport layers included in the light-emitting unit. The efficiency of the device can be improved.

1 is a cross-sectional view of an organic light emitting device according to an embodiment of the present invention. Referring to FIG. 1, the organic light-emitting device 1 has a tandem structure, with a first electrode (anode, 110), a second electrode (cathode, 120), a first light-emitting unit 210, and a second light-emitting unit 220. And a charge generation layer 230.

The first light-emitting part 210, the second light-emitting part 220, and the charge generation layer 230 are organic material layers and are positioned between the first electrode 110 and the second electrode 120, and the charge generation layer 230 is It is positioned between the first light-emitting unit 210 and the second light-emitting unit 220.

The first light emitting part 210 is composed of a hole injection layer 211, a first hole transport layer 212, a first light emitting layer 213, and a first electron transport layer 214, and the second light emitting part 220 is 2 It consists of a hole transport layer 221, a second light emitting layer 222, a second electron transport layer 223, and an electron injection layer 224.

The charge generation layer 230 includes an N-type charge generation layer 231 and a p-type charge generation layer 232. The n-type charge generation layer 231 may be doped with an alkali metal.

The compound according to the present invention may be included in the first electron transport layer 212, the second electron transport layer 223, and the charge generation layer 230, and may be particularly used in the N-type charge generation layer 231.

The described organic light emitting device 1 can be variously modified. Some organic layers may be omitted or added, may not be in a tandem form, and may be in a tandem form having three or more light emitting units.

Hereinafter, Preparation Examples of Compounds 1-1 and 1-7 and Comparative Examples of Examples 1 and 2 of the organic light emitting device? will be described. However, the manufacturing examples and examples described below are only for specifically exemplifying or explaining the present invention, and should not be interpreted as limiting the present invention by the manufacturing examples and examples described below.

[Production Example]

1. Compound 1-1

2-(4-(benzo[e]acephenanthrylen-3-yl)naphthalen-1-yl)-1,10-phenanthroline represented by compound 1-1 was prepared using the following reactions.

(Suzuki reaction)

In a round bottom flask, phenanthren-9-ylboronic acid (44.4 g, 200 mmol), 1,2-dibromobenzene (60 g, 320 mmol), tetrakis (triphenylphosphine) palladium (0) (11.6 g, 10 mmol) , Potassium carbonate (70 g), 400 mL of toluene, 200 mL of ethanol, and 200 mL of water were added and stirred under reflux for 12 hours. After the reaction was completed, the reaction solution was concentrated to obtain a crude product. The crude was dissolved by heating in MC, filtered under reduced pressure on silica gel, concentrated and recrystallized to obtain 47 g of 9-(2-bromophenyl)phenanthrene.

(Heck reaction)

In a round-bottom flask, 9-(2-bromophenyl)phenanthrene (31.4 g, 94.2 mmol), Pd(PPh ₃ ) ₂ Br ₂ (3.72 g, 118 mmol) and DBU (44 g, 283 mmol) were added to 300 mL of DMF. Stir at reflux for 48 hours. After the reaction was completed, 1 liter of water was added, stirred, filtered, dried, followed by silica gel column, and recrystallized to obtain 25 g of benzo[e]acephenanthrylene.

(Bromination)

In a round-bottom flask, benzo[e]acephenanthrylene (18 g, 71.4 mmol) was dissolved in 500 mL of MC, stirred, and 1.2 equivalent of Br ₂ was added thereto, followed by refluxing for 42 hours. After the reaction was completed, 50 mL of a saturated NaOH aqueous solution was added to remove residual Br ₂ , dried, and then filtered under reduced pressure to obtain a crude product. The filtered crude was recrystallized after a silica column to obtain 14 g of 3-bromobenzo[e]acephenanthrylene. (The isomer expected to be the following compound occurs as an impurity, but recrystallization is difficult, so it is separated in the next reaction)

(Borylation)

2-(benzo[e]acephenanthrylen-3-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (11 g, 33.2 mmol), pinacoldiborane (10.1 g, 39.8 mmol) in a round bottom flask ), Pd(dppf)Cl ₂ (1.2 g, 1.66 mmol) and potassium acetate (9.8 g, 99.6 mmol) were added to 300 mL of dioxane and stirred under reflux for 24 hours. After the reaction was completed, the reaction solution was prepared in a Celite/Silica/Celite column (50 g/50 g/50 g), filtered, and 1 liter of dioxane solution was further poured, and then concentrated to 10.3 g of 2-(benzo [e]acephenanthrylen-3-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane was obtained.

(Suzuki reaction)

In a round bottom flask, 2-(benzo[e]acephenanthrylen-3-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (10 g, 26.4 mmol), 2-(4-bromonaphthalen- 1-yl)-1,10-phenanthroline (11 g, 28.5 mmol), tetrakis (triphenylphosphine) palladium (0) (1.73 g, 1.5 mmol), potassium carbonate (10.35 g, 75 mmol), toluene 200 mL, 100 mL of ethanol, and 100 mL of water were added and stirred under reflux for 12 hours. After completion of the reaction, water was removed and the reaction solution was filtered to obtain a crude product. The concentrated crude was dissolved by heating in MC, filtered under reduced pressure on silica gel, concentrated and recrystallized to obtain 11 g of a compound. The isomer was not completely removed and the purity was low.

2. Compound 1-7

2-(5-(10-phenylanthracen-9-yl)-4'-(pyrimidin-2-yl)-[1,1'-biphenyl]-3-yl)-1,10- represented by compound 1-7 phenanthroline was prepared using the following reactions.

(Suzuki reaction)

In a round bottom flask, phenanthren-9-ylboronic acid (15.39 g, 69.3 mmol), 2-bromo-4-chloro-1-iodobenzene (20 g, 63 mmol), tetrakis (triphenylphosphine) palladium (0) ( 3.6 g, 3.1 mmol), potassium carbonate (30 g), 100 mL of toluene, 50 mL of ethanol, and 100 mL of water were added and stirred at 50 ^o C for 36 hours. After the reaction was completed, the reaction solution was concentrated to obtain a crude product. The crude was dissolved by heating in MC, filtered under reduced pressure on silica gel, and concentrated. 20 g of 9-(2-bromophenyl)phenanthrene was obtained.

(Heck reaction)

In a round bottom flask, add 9-(2-bromo-4-chlorophenyl)phenanthrene (20 g, 54.4 mmol), Pd(PPh ₃ ) ₂ Br ₂ (2.2 g, 2.72 mmol) and DBU (25 g, 163.2 mmol) in DMF. Put in 200 mL and stirred under reflux for 48 hours. After completion of the reaction, 1 liter of water was added, stirred, filtered, dried, followed by silica gel column, and recrystallized to obtain 12 g of 11-chlorobenzo[e]acephenanthrylene.

(Borylation)

In a round bottom flask, 11-chlorobenzo[e]acephenanthrylene (8.6 g, 30 mmol), pinacoldiborane (9.15 g, 36 mmol), Pd(OAc) ₂ (0.4 g, 1.5 mmol) and SPhos (1.23 g, 3 mmol), Potassium phosphate (17.2 g, 90 mmol) was added to 300 mL of dioxane and stirred under reflux for 24 hours. After the reaction was completed, the reaction solution was prepared in a Celite/Silica/Celite column (50 g/50 g/50 g), filtered, and 1 liter of dioxane solution was further poured, and then concentrated to 11.35 g of 2-(benzo [e]acephenanthrylen-11-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane was obtained.

(Suzuki reaction)

In a round bottom flask, 2-(benzo[e]acephenanthrylen-11-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (11.35 g, 30 mmol), 2-(4-bromonaphthalen- 1-yl)-1,10-phenanthroline (13.87 g, 36 mmol), tetrakis (triphenylphosphine) palladium (0) (1.73 g, 1.5 mmol), potassium carbonate (10.35 g, 75 mmol), toluene 200 mL, 100 mL of ethanol, and 100 mL of water were added and stirred under reflux for 12 hours. After completion of the reaction, water was removed and the reaction solution was filtered to obtain a crude product. The concentrated crude was dissolved by heating in MC, filtered under reduced pressure on silica gel, concentrated and recrystallized to obtain 10 g of 2-(4-(benzo[e]acephenanthrylen-11-yl)naphthalen-1-yl)-1,10 -phenanthroline was obtained.

The NMR data of the synthesized compounds are as follows.

compound 1H NMR (CDCl ₃ ) MS

Compound 1-1

1H δ
1H NMR (500 MHz, cdcl3) δ 9.24-9.23 (1H, d), 8.72-8.71 (1H, d), 8.53-8.51 (1H, d), 8.42-8.41 (1H, d), 8.34 (1H, s ), 8.34-8.30 (1H, d), 8.21-8.11 (5H, m), 8.07-8.05 (1H, d), 8.03-8.01 (1H, d), 7.96-7.87 (3H, m), 7.83-7.80 (1H, t), 7.73-7.65 (4H, m), 7.62-7.60 (1H, d), 7.50-7.48 (2H, m) 557.2
Compound 1-7

1H δ
1H NMR (500 MHz, cdcl3) δ 9.24-9.23 (1H, d), 8.72-8.71 (1H, d), 8.53-8.51 (1H, d), 8.42-8.41 (1H, d), 8.34 (1H, s ), 8.34-8.30 (1H, d), 8.21-8.11 (5H, m), 8.07-8.05 (1H, d), 8.03-8.01 (1H, d), 7.96-7.87 (3H, m), 7.83-7.80 (1H, t), 7.73-7.65 (4H, m), 7.62-7.60 (1H, d), 7.50-7.48 (2H, m) 557.2

[Measurement of glass transition temperature]

Hereinafter, the glass transition ionicity and melting temperature of Bphen mainly used in Preparation Examples 1 to 2 and the charge generation layer were measured, and are shown in Table 2 below.

matter Tg( ^o C) Tm( ^o C) Comparative Example 1 BPhen 64 220 Manufacturing Example 1 Compound 1-1 156.20 330.1 Manufacturing Example 2 Compound 1-7 166.10 334.5

As shown in Table 2, it can be seen that the compounds of Preparation Examples 1 to 2 according to the present invention have a much higher glass transition temperature and melting temperature than Comparative Example 1. Accordingly, it can be seen that the benzofluoranthene-based compound according to the present invention has improved stability compared to Comparative Example 1.

Hereinafter, an organic light-emitting device was manufactured and tested using Bphen and the compound according to the present invention, respectively, in the charge generation layer.

[Manufacture of organic light emitting device 1: single layer structure]

1. Comparative Example 2

After patterning the ITO substrate so that the luminous area was 2 mm × 2 mm in size, each was cleaned with isopropyl alcohol and UV ozone. Thereafter, the ITO substrate was mounted on the substrate holder of the vacuum evaporation apparatus, and pressure was formed so that the degree of vacuum was 1×10 ^-7 torr.

First, the HAT-CN compound was vacuum deposited to form a 5 nm thickness. This compound acts as a hole injection layer. On this, an NPB material was formed to a thickness of 35 nm as a hole transport layer.

Thereafter, a yellow light emitting layer was formed by co-depositing a CPB material as a host and an Ir compound as a dopant to a thickness of about 10% at a thickness of 30 nm.

An electron transport layer was formed on the light-emitting layer with a TmPyPB compound having a thickness of 25 nm. Thereafter, a charge generation layer was formed by co-depositing a Li material to a BPhen material in a thickness of 10 nm so as to have a 2% mass ratio. Thereafter, Al was deposited to a thickness of 100 nm to form a cathode to fabricate an organic light emitting device.

2. Example 1

In the same manner as in Comparative Example 2 described above, only the material of the charge generation layer was changed to Compound 1-40 to produce an organic light-emitting device.

[Manufacture of organic light emitting device 2: two-layer structure]

1. Comparative Example 3

After patterning the ITO substrate so that the luminous area was 2 mm × 2 mm in size, each was cleaned with isopropyl alcohol and UV ozone. Thereafter, the ITO substrate was mounted on the substrate holder of the vacuum evaporation apparatus, and the pressure was held so that the degree of vacuum was 1×10 ^-7 torr.

First, the HAT-CN compound was vacuum deposited to form a 5 nm thickness. This compound acts as a first hole injection layer. On this, an NPB material was formed to a thickness of 35 nm as a first hole transport layer.

Thereafter, a CPB material as a host and an Ir compound as a dopant were co-deposited to a thickness of 30 nm so as to have a mass ratio of about 10% to form a yellow first emission layer.

An electron transport layer was formed on the light-emitting layer with a TmPyPB compound having a thickness of 25 nm. Thereafter, an N-type charge generation layer was formed by co-depositing a Li material to a BPhen material in a thickness of 10 nm so as to have a 2% mass ratio. Thereafter, a HAT-CN compound was vacuum deposited to a thickness of 5 nm as a P-type charge generation layer. The foreign material is also used as the second hole injection layer. On this, an NPB material was formed to a thickness of 35 nm as a second hole transport layer.

Thereafter, the CPB material as a host and the Ir compound as a dopant were co-deposited to a thickness of 30 nm so as to have a mass ratio of about 10% to form a yellow second light emitting layer. A second electron transport layer was formed on the light-emitting layer with a TmPyPB compound having a thickness of 25 nm. Thereafter, the LiF material was vacuum deposited as an electron injection layer to a thickness of 1 nm. Finally, Al was deposited to a thickness of 100 nm to form a cathode to fabricate an organic light emitting device.

2. Example 2

In the same manner as in Comparative Example described above, only the organic material of the N-type charge generation layer was changed to Compound 1-1 to manufacture an organic light-emitting device.

3. Example 3

It was constructed in the same manner as in Comparative Example described above, but only the organic material of the N-type charge generation layer was changed to Compound 1-7 to manufacture an organic light-emitting device.

In the case of PIN OLED, low-voltage high-efficiency driving is realized through electrical doping of the charge transport layer in the OLED structure. The P-doped layer is doped with an organic material or metal oxide having rare electrons in the hole transport material, and the N-doped layer is doped with an alkali metal such as lithium or cesium having a low work function on the electron transport material. The doped layer facilitates charge injection from adjacent layers by reducing the surface resistance of the organic material during driving. A buffer layer is introduced on the doped anode layer to realize a low voltage by energy banding, and a low voltage driving technology using a material with high charge mobility is known, and high efficiency is obtained by fabricating a fluorescent and phosphorescent material in a stacked structure.

The tandem structure is a structure in which EL units including a doped hole transport layer and an electron transport layer are vertically stacked, and the current emission efficiency increases in proportion to the stacked number. At this time, the CGL (change generation layer) layer is a concept of transparent PN bonding, and it can be understood as a concept in which the unit PIN OLED light emitting part is stacked in a plurality of layers. Therefore, the efficiency and voltage of the stack structure can be predicted even with a single-layer PIN OLED embodiment, and the efficiency and voltage of a three-layer structure can be predicted even with a two-layer structure embodiment.

Hereinafter, the current density, driving voltage, current efficiency, and external quantum efficiency of the organic light emitting device of Examples 2 to 3 were measured and shown in Table 3 below.

Classification matter Driving current
J(mA/cm ² ) Driving voltage
(Voltage) Current efficiency
(cd/A) Luminous efficiency
(lm/W) EQE(%) Comparative example BPhen 10 9.4 107.8 36.0 35 Example 2 1-1 10 8.6 128.5 46.9 39.7 Example 3 1-7 10 8.5 130.2 48.1 40.6

As shown in Table 3, in terms of driving voltage (V), current efficiency (cd/A), and external quantum efficiency (QE) affecting the organic light emitting device, Examples 1 to 2 were compared with Comparative Examples. When done, it can be seen that the size is greatly improved. Accordingly, it can be seen that the organic light-emitting device including the benzofluoranthene-based compound according to the present invention has improved lifespan and improved efficiency compared to the organic light-emitting device including the conventional compound.

The present invention is not necessarily limited to these embodiments, and various modifications may be made without departing from the spirit of the present invention. Accordingly, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention, but to explain the technical idea, and the scope of the technical idea of the present invention is not limited by these embodiments. Therefore, it should be understood that the embodiments described above are illustrative and non-limiting in all respects. The scope of protection of the present invention should be interpreted by the following claims, and all technical ideas within the scope equivalent thereto should be interpreted as being included in the scope of the present invention.

Claims (9)

A benzofluoranthene-based compound represented by any one selected from the compounds shown below.

delete delete A first electrode;
A second electrode; And
An organic material layer disposed between the first electrode and the second electrode and emitting light,
The organic material layer is made of a plurality of layers, at least one of the organic light emitting device comprising the benzofluoranthene compound according to claim 1. The method of claim 4,
The organic light emitting device, characterized in that the at least one organic material layer includes a charge generation layer. The method of claim 5,
The organic light emitting device, characterized in that the charge generation layer is N-type. The method of claim 4,
The organic material layer,
A first light emitting unit;
A second light-emitting unit positioned on the first light-emitting unit; and
A first charge generation layer positioned between the first light-emitting part and the second light-emitting part;
An organic light-emitting device comprising a. The method of claim 7,
A third light-emitting unit positioned on the second light-emitting unit;
A second charge generation layer positioned between the second light-emitting part and the third light-emitting part;
An organic light-emitting device, characterized in that it further comprises. The method of claim 8,
At least one of the first charge generation layer and the second charge generation layer,
At least one of an alkali metal and an alkaline earth metal is doped and bonded to the benzofluoranthene-based compound,
The doped alkali metal is at least one of Li, Na, K, Rb and Cs,
The alkaline earth metal is an organic light-emitting device, characterized in that at least one of Be, Mg, Ca, Sr, and Ba.

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