KR20180025900A - Organic light-emitting diode device using nitrogen-containing heterocyclic derivative and derivative thereof - Google Patents

Abstract

The present invention proposes an organic compound represented by formula (I) wherein derivatives of anthracene and anthracene obtain high performance materials through naphthyl and phenanthroline coupling . In addition, the present invention further proposes an electron material having a high triplet energy. By using the electron material as an electron transporting material of the organic light emitting diode luminescent layer, energy transfer in the luminescent layer is promoted, and the blue luminescent efficiency and service life While reducing the operating voltage.

Description

Organic light-emitting diode device using nitrogen-containing heterocyclic derivative and derivative thereof

The present invention relates to a nitrogen containing aromatic heterocyclic derivative and an organic light emitting diode (OLED) device, and more particularly, to a nitrogen containing aromatic heterocyclic derivative having a relatively high luminous efficiency due to high triplet energy and electron transporting performance, Containing aromatic heterocyclic derivatives.

In recent years, extensive research and development on organic electroluminescent devices has been under way. The basic structure of such a light emitting element consists of inserting a layer containing a light emitting material between a pair of electrodes and applying a voltage to the element to emit light derived from the light emitting material.

Since such a light emitting element is a self light emitting element, it is suitable for a flat display element because it has a great advantage in terms of high quality visibility and backlight demand in comparison with a liquid crystal display. The light emitting element is thin and light and has a remarkably fast response speed.

In addition, since the above-described light emitting element is formed in the form of a thin film, planar light can be emitted. Therefore, a large area element can be easily formed. This is a characteristic that can not be obtained with a point light source such as an incandescent lamp or LED, or a light source represented by a fluorescent lamp. Therefore, the light emitting element has a great potential when it is used as a planar light source or the like used for illumination.

The excited state formed through the organic compound may be singlet or triplet state. It is fluorescence emitted in singlet excited state (S ^* ), or phosphorescence emitted in triplet excited state (T ^* ). In addition, the statistical generation ratio in the light emitting element is S ^* : T ^* = 1: 3. In converting into a compound emitting an energy of singlet excited state, no emission of triplet excited state at room temperature was observed and only emission of singlet excited state was observed. Thus, the internal quantum efficiency of a light emitting element using a fluorescent compound has a theoretical limit of 25%, which is based on a ratio of S ^* to T ^* of 1: 3. Therefore, the organic electroluminescent material is an organic electroluminescent material having a high luminous efficiency and a high luminous brightness as a material that has recently attracted attention by people. It uses an originally forbidden triplet transition at room temperature through a method of introducing heavy metal atoms, Quantum efficiency can reach theoretically 100%, which is four times that of a single fluorescent material (1. Cao Y., Parker ID, Heeger J., Nature, 1999, 397: 414-417.2, Wohlgenann M., et al., Nature, 2001, 409: 494-497). Heavy metal atoms frequently used in organic field phosphorescent materials are many transition metals, in which iridium is the most widely used and most studied metal. This makes it possible for the color of the electroluminescent device to cover the entire visible range by controlling the emission wavelength by adjusting the ligand structure as well as emitting a relatively strong phosphorescence at room temperature with high efficiency of the metal iridium compound. Therefore, researching and synthesizing novel metal iridium compounds with high efficiency is of great importance in the development of phosphorescent materials.

However, the efficiency of the dopant is severely deteriorated due to the decaying effect, which limits the light emitting layer having the host dopant. Therefore, it is expected to form a light emitting material layer through a host having a dopant and higher thermal stability and triplet energy.

In an OLED device including a phosphorescent compound, electrons derived from the positive electrode and electrons derived from the negative electrode are bonded at the host of the light emitting material layer. A singlet state exciton of the host causes an energy transition to the singlet or triplet energy of the dopant, and a triplet exciton derived from the host causes energy transition to the triplet energy of the dopant. The exciton transited to the singlet energy of the dopant is again transited to the triplet energy of the dopant. When the excitons of the triplet energy of the dopant are transited to the bottom state, the light emitting layer emits light.

At present, there are relatively few electron transporting and injecting materials. Phosphorescent devices not only have to meet the high speed of electron transporting but also have to increase the energy of triplet and limit the excitons generated in the phosphorescent device to the light emitting layer. It is very important to develop materials with high speed. Since phenanthroline derivatives have low HOMO and LUMO, they can effectively transport electrons, block holes, and have an electron-to-electron ratio of up to 10 ^-4 . However, phenanthroline easily appears in crystals, and when used for a long time, crystals are converted, which can seriously affect the lifetime of the device. Therefore, it is necessary to perform structural adjustment to phenanthroline to avoid occurrence of crystal phenomenon and to obtain an amorphous material.

Phenanthroline has a large planar structure, which is beneficial for the transition of electrons. It has a structure of 4,7-diphenyl-1,10-phenanthroline (Bphen) and 4,7-diphenyl-2,9- 10-Phenanthroline (BCP) The electron transit rate can reach up to 10 ^-4 and the triplet state is around 3.0 eV, which can meet current phosphorescent requirements. However, these two materials are limited in use because crystals are easily generated and it is difficult to reach the lifetime at an industrially available level. Because of the high electron transitivity and triplet state of phenanthroline, other structures have already been introduced to obtain different performance materials. The electron transitivity of the obtained material can still maintain the transparency of phenanthroline, but it can only be used as an electron transporting material of a red light material since the triplet state is only 2.5ev because it is through a phenyl chain linkage (A in patent TW201329195 , B compound emission).

Although the compound can improve the performance of the material due to the adoption of the phenyl chain linking method, it can be used only as an electron transporting material of the red phosphorescent material because the triplet state (2.5ev) of the material is low. It can not be applied.

The present invention relates to an OLED device using a nitrogen-containing heterocyclic derivative and a nitrogen compound thereof, both of which basically solve one or more problems due to limitations and deficiencies of the prior art.

An object of the present invention is to propose an electron transporting material compound, and the electron transporting material has high triplet energy and high electron transporting ability.

Still another object of the present invention is to propose an OLED with improved luminous efficiency, which has a long service life and low operating voltage.

The nitrogen-containing heterocyclic derivative has the structure of formula (I).

Wherein one of R1-R10 is connected to a phenyl group through a chain linking method, and the remainder each independently represents a hydrogen atom, an aryl or heteroaryl group having a substituted or unsubstituted carbon atom number of 5-60, a substituted or unsubstituted carbon atom A naphthene group having 3-50 substituted or unsubstituted carbon atoms, an aralkyl group having 6-50 substituted or unsubstituted carbon atoms, or an aromatic ring formed by bonding in adjacent substituent groups And the value of n can be from 1 to 3;

One of R1a-R8a is connected to a phenyl group through a chain linkage, and the remainder each independently represents a hydrogen atom, aryl having a substituted or unsubstituted carbon atom number of 5-60, pyridyl having a substituent, quinolyl , Alkyl having a substituted or unsubstituted carbon atom number of 1 to 50, naphthene group having a substituted or unsubstituted carbon atom number of 3 to 50, aralkyl having a substituted or unsubstituted carbon atom number of 6 to 50, An arylsulfenyl having a substituted or unsubstituted carbon atom number of 5-50, or an alkoxycarbonyl having a substituted or unsubstituted carbon atom number of 1-50.

Preferably, one of R1a-R8a is linked to the phenyl through a chain linkage and the other is independently selected from hydrogen, C1-C4 alkyl substituted or unsubstituted phenyl, C1-C4 alkyl substituted or unsubstituted naphthyl, 1 to 3 phenyl substituted phenyl;

Wherein one of R1-R10 is connected to the phenyl and the chain through a chain linkage and the others are independently selected from the group consisting of a hydrogen atom, C1-C4 alkyl substituted or unsubstituted phenyl, C1-C4 alkyl substituted or unsubstituted naphthyl, C1 C4 alkyl substituted or unsubstituted anthryl, or phenyl substituted phenyl, phenyl substituted naphthyl or phenyl substituted anthryl, naphthyl substituted naphthyl, naphthyl substituted anthryl .

Preferably, R10 and R8a are chain linkages.

Preferably, R2a-R7a is hydrogen and R1a is hydrogen, phenyl, naphthyl, biphenyl or diphenyl substituted phenyl; Wherein R 1 -R 8 is hydrogen and R 9 is selected from the group consisting of hydrogen, phenyl, naphthyl, anthryl, biphenyl, diphenyl substituted phenyl, naphthyl substituted phenyl, phenyl substituted naphthyl, phenyl substituted anthryl, Substituted naphthyl, naphthyl substituted anthryl.

More preferably, R1a-R7a is hydrogen, wherein R1-R8 are hydrogen and R9 is hydrogen, phenyl, naphthyl, anthryl.

In the present application derivatives of anthracene and anthracene provide high performance materials through naphthyl and phenanthroline coupling. There are several ways to connect naphthyl.

Based on the foregoing description, this patent will be explained more clearly.

The organic light emitting diode device includes a cathode and an anode. After the cathode is deposited, the organic compound is deposited on the cathode.

The organic compound of the above claims is contained as an electron transporting material, and particularly as an electron transporting material of a phosphorescent device, and the device is a display device and a lighting device.

The examples listed in the present invention merely list the scope of the claims, but the patent is not limited by the present examples. All structures that satisfy the claims are within the scope of protection of the present invention.

The present application incorporates naphthyl based on the electron transition of phenanthroline to maintain high electron transitions as well as to ensure high triplet state and to prevent crystallization and maximize lifetime. Anthracene is an excellent material of electron transition, and in this application derivatives of anthracene and anthracene obtain high performance materials through naphthyl and phenanthroline coupling. The obtained material is easy to manufacture because of its simple structure and is suitable for industrial production.

Figure 1 is nuclear magnetic resonance (NMR) of compound 4;
Figure 2 is NMR of compound 8; And
3 is NMR of compound 2. Fig.

Example 1: Preparation of Compound 4

Synthesis of compound 2: The synthesis of compound 2 was synthesized using hydrated phenanthroline and 1,4-dibromonaphthalene reference Eur.J.Inorg. Chem., 2001, 1155-1166, Compound 2 A white solid can be easily obtained, the yield is 84%, and the spectrogram is as shown in FIG.

Synthesis of Compound 4:

(0.1 mol) of the product 2 obtained in the immediately preceding step was added to the reaction flask, 29.81 g (0.1 mol) of the compound 3 was added to the reaction flask, and 138 g of potassium carbonate and 500 L of water were added until complete dissolution Lt; / RTI > Nitrogen is charged for 30 minutes, 1 g tetrakis (triphenylphosphine) palladium is added, and the reflux reaction is carried out for 8 hours. Wait until the TLC detection reaction is complete, then cool to room temperature and filter to obtain a solid recrystallization, yielding a 40G target product. NMR is as shown in Fig. MODI-TOF: 558.67.

Example 2: Synthesis of Compound 6

Synthesis of Compound 2: The synthesis of Compound 2 was synthesized using hydrated phenanthroline and 1,4-dibromonaphthalene reference Eur.J.Inorg. Chem., 2001, 1155-1166, A white solid was obtained, the yield was 84%, and the spectrogram was as shown in Fig.

Synthesis of Compound 6:

(0.1 mol) of the product 2 obtained in the immediately preceding stage was added, 34.82 g (0.1 mol) of the compound 7 was added to the reaction flask, and 138 g of potassium carbonate and 500 L of water were added thereto Lt; / RTI > Nitrogen is charged for 30 minutes, 1 g tetrakis (triphenylphosphine) palladium is added, and the reflux reaction proceeds for 8 hours. Wait until the TLC detection reaction is complete, then cool to room temperature and filter to obtain solid recrystallization, yielding 42G target product. MODI-TOF: 608.71.

Comparative Example: Preparation of Compound 8

Synthesis of Compound 2: The synthesis of Compound 2 was synthesized using hydrated phenanthroline and 1,4-dibromonaphthalene reference Eur.J.Inorg. Chem., 2001, 1155-1166, A white solid was obtained, the yield was 84%, and the spectrogram was as shown in Fig.

Synthesis of Compound 8:

(0.1 mol) of the product 2 obtained in the previous step was added to the reaction flask, 24.81 g (0.1 mol) of the compound 5 was added to the reaction flask, and 138 g of potassium carbonate and 500 L of water were added until completely dissolved Lt; / RTI > Nitrogen is charged for 30 minutes, 1 g tetrakis (triphenylphosphine) palladium is added, and the reflux reaction proceeds for 8 hours. Wait until the TLC detection reaction is complete, then cool to room temperature and filter to obtain solid recrystallization, yielding 45 G target product. NMR is as shown in Fig. MODI-TOF: 506.59.

The ultraviolet absorption spectrum and the optical luminescence of the three materials prepared according to the synthesis example of the present invention and the materials of the comparative examples represented by the following formula were measured at a low temperature (for example, 77 K) The following table shows.

UV PL energy LUMO HOMO Triplet energy 4 363 424 3.43 -2.85 -6.28 2.84 5 360 434 3.50 -2.75 -6.25 2.85 6 355 424 3.46 -2.70 -5.66 2.83

As can be seen from Table 1, since all of the compounds 4 to 6 are higher than 2.82 eV, the requirements of the blue phosphorescence device can be met.

Hereinafter, a production example of an organic light emitting diode using the blue phosphorescent compound formed by the compound 4 and the compound 6 and the material of the comparative compound 8 as a blue electronic material will be described.

Preparation Example 1:

Patterning is performed on the ITO substrate to make the light emitting area 3 mm x 3 mm, and then cleaning is performed. Place the ITO substrate in a vacuum chamber and set the bottom pressure to 1 × 10 ^-6 Torr. Subsequently, HATCN having a thickness of about 50 angstroms was formed on the ITO layer to form a positive electrode. The HATCN layer was used for the hole injection layer, and NPD having a thickness of about 550 angstroms was formed on the hole transport layer. (TAPC) is used for the hole injection layer, and a host material PH having a thickness of about 300 angstroms is formed (US20140151647), and fac-Ir (mpim) ₃ having a doping concentration of 15% is used for the light emitting layer. Compound 4 having a thickness of 400 angstroms is then formed on the electron transport layer to form LiF having a thickness of about 5 angstroms and used in the electron injection layer to form an Al layer cathode having a thickness of 1100 angstroms. Then, a packaging process is performed using a UV curable packaging agent and a moisture absorbent to form a light emitting diode.

Production Example 2

The only difference is that the organic light emitting diode is manufactured by adopting the same manufacturing process as described above, but the compound 6 is used as an electronic material.

Comparative Example 1

The only difference is that the same process as in Production Example 1 is employed to produce an organic light emitting diode, but the compound 8 is used as an electronic material.

Voltage
(volt) Luminous efficiency Quantum efficiency
(%) Color coordinates Service life
(T50,700 nit) Cd / A Im / W CIE_x CIE_y Compound 8 3.0 71 60 20 0.154 0.274 1000 Compound 4 1.8 78 67 30 0.154 0.253 4000 Compound 6 2.0 76 65 29 0.154 0.255 3500

As can be seen from Table 2, the organic light emitting diodes manufactured in Example 1 exhibited improved luminous efficiency, quantum efficiency, and service life when displaying the same color coordinates as those of Comparative Example 1. [ In particular, the service life of the organic light emitting diode is maximized.

As can be seen from the above description, the method of the present invention has produced an electronic material having high triplet state energy, and by using the electronic material as an electron transporting material of the organic light emitting diode luminescent layer, The blue light emission efficiency and the service life of the light emitting layer were improved while the operating voltage was lowered.

The embodiments of the present invention have already been described with reference to numerous embodiments thereof. Those skilled in the art to which the present invention pertains may design other improvements and implementations within the scope of the principles disclosed herein. More specifically, it is possible to proceed with various changes and improvements in terms of components and / or arrangements which are disclosed in the present invention and which combine and arrange subjects within the scope of the attached drawings and claims. For those skilled in the art to which the invention pertains, substitutional applications as well as variations and / or improvements in the configuration and / or arrangement aspects are also readily conceivable.

Claims (8)

Having the structure of formula (I)

Wherein one of R1-R10 is connected to a phenyl group through a chain linking method, and the remainder each independently represents a hydrogen atom, an aryl or heteroaryl group having a substituted or unsubstituted carbon atom number of 5-60, a substituted or unsubstituted carbon atom A naphthene group having 3-50 substituted or unsubstituted carbon atoms, an aralkyl group having 6-50 substituted or unsubstituted carbon atoms, or an aromatic ring formed by bonding in adjacent substituent groups And the value of n can be from 1 to 3;
One of R1a-R8a is connected to a phenyl group through a chain linkage, and the remainder each independently represents a hydrogen atom, aryl having a substituted or unsubstituted carbon atom number of 5-60, pyridyl having a substituent, quinolyl , Alkyl having a substituted or unsubstituted carbon atom number of 1 to 50, naphthene group having a substituted or unsubstituted carbon atom number of 3 to 50, aralkyl having a substituted or unsubstituted carbon atom number of 6 to 50, Arylsulfenyl having a substituted or unsubstituted carbon atom number of 5 to 50, alkoxycarbonyl having a substituted or unsubstituted carbon atom number of 1 to 50, a nitrogen-containing heterocyclic ring derivative. The method according to claim 1,
One of R1a-R8a is linked via a chain linkage to phenyl and the other is independently selected from hydrogen, C1-C4 alkyl substituted or unsubstituted phenyl, C1-C4 alkyl substituted or unsubstituted naphthyl, Phenyl substituted phenyl;
Wherein one of R1-R10 is connected to the phenyl and the chain through a chain linkage and the others are independently selected from the group consisting of a hydrogen atom, C1-C4 alkyl substituted or unsubstituted phenyl, C1-C4 alkyl substituted or unsubstituted naphthyl, C1 -C4 alkyl substituted or unsubstituted anthryl, or represents phenyl substituted phenyl, phenyl substituted naphthyl or phenyl substituted anthryl, naphthyl substituted naphthyl, naphthyl substituted anthryl And a nitrogen-containing heterocyclic derivative. The method according to claim 1 or 2,
Lt; 10 > and R < 8a > are a chain-linking system. The method of claim 3,
R2a-R7a is hydrogen and R1a is hydrogen, phenyl, naphthyl, biphenyl or diphenyl substituted phenyl; R1-R8 are hydrogen and R9 is hydrogen, phenyl, naphthyl, anthryl, biphenyl, diphenyl substituted phenyl, naphthyl substituted phenyl, phenyl substituted naphthyl, phenyl substituted anthryl, Naphthyl, and naphthyl-substituted anthryl. 5. The method of claim 4,
Wherein R1a-R7a is hydrogen, wherein R1-R8 are hydrogen and R9 is hydrogen, phenyl, naphthyl, anthryl. The method according to claim 1,
A compound having the following structure

A nitrogen-containing heterocyclic derivative. The organic light-emitting diode device according to any one of claims 1 to 6, wherein the nitrogen-containing heterocyclic compound is deposited on the top surface of the cathode after the cathode is deposited. 8. The method of claim 7,
The organic light-emitting diode device according to any one of claims 1 to 6, which comprises the nitrogen-containing heterocyclic compound as an electron transporting material, wherein the device is a display device and a lighting device.

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