JP2009016693A - Host material, and organic el element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide high performance host materials for phosphorescence and to provide host materials suitable when forming a red phosphorescence light emitting layer in particular, and to provide a high performance organic EL element. <P>SOLUTION: The organic EL element 10 has host materials combined with a phosphorescence light emitting dopant to form phosphorescence materials, the host materials has a substituted or unsubstituted polycyclic condensed aromatic skeleton part, wherein the number of nucleus atoms of the polycyclic condensed aromatic skeleton part ranges from 14 to 30, and the lowest excitation triplet energy gap of the host materials is ≥1. 71 eV and ≤2. 09 eV. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an organic electroluminescence element (EL element). In particular, the present invention relates to an organic EL element including a light emitting layer that emits red light.

An organic electroluminescent device (organic EL device) that has an organic light emitting layer between an anode and a cathode, and emits light from exciton energy generated by recombination of holes and electrons injected into the organic light emitting layer It has been known.
Such an organic EL element is expected as a light emitting element excellent in luminous efficiency, image quality, power consumption, and thin design, taking advantage of the self-luminous element.

As a further improvement of organic EL devices, there is a point of luminous efficiency. In order to increase the internal quantum efficiency, phosphorescent materials that emit light from triplet excitons have been developed, and recently phosphorescent light emission has been used. Organic EL devices have been reported.
By using such a phosphorescent material, an internal quantum efficiency of 75% or more and theoretically close to 100% can be realized, and an organic EL element with high efficiency and low power consumption can be obtained.

In addition, when using a light emitting material in an organic EL element, a doping method is known in which a host material is doped with a dopant material.
In order to efficiently generate excitons from the injected energy and efficiently link the exciton energy to light emission, a configuration is adopted in which the exciton energy generated in the host is transferred to the dopant and light emission is obtained from the dopant. The

Here, in order to perform intermolecular energy transfer from the host to the dopant, the energy gap Eg _{H of the} host needs to be larger than the energy gap Eg _{D of the} dopant.
As a material having a large triplet energy gap, CBP (4,4′-bis (N-carbazolyl) biphenyl) is typically known.
When this CBP is used as a host, a highly efficient light-emitting element can be obtained by transferring energy between triplet excitons in a phosphorescent material exhibiting a predetermined emission wavelength (for example, green and red).

However, when CBP is used as a host, there is a problem that the device life is short and not suitable for practical use. (For example, 1000 nit and half-life 2000 hours)
This is presumably because the molecular structure of CBP is not very stable and the deterioration of the molecule that occurs when exposed to electric current is severe.

Furthermore, in recent years, it is necessary to increase color purity from application to various applications.
In particular, there is a demand for an organic EL device having a light emitting layer that emits deep red light. As a red phosphorescent material, for example, platinum (II) (2- (2 ′-(4 ′, 5′-benzothienyl) pyridinate N , C ³ ′) (acetylacetonate) (btp (Pt) acac) is disclosed (Patent Document 1).
Although CBP has a large Eg (T), Eg (S) is also large, and a large voltage is required for charge injection. Therefore, current efficiency is high, but power efficiency is low. In addition, since Eg (S) is larger than the surrounding material, it is difficult to confine the charge, the charge leaks to the surrounding material, energy transfer occurs, the efficiency is lowered, and the life is shortened due to the deterioration of the surrounding material.
Further, when the drive voltage is increased to increase the light emission luminance under inefficient energy efficiency, there are problems that the energy efficiency is not good and the deterioration rate of the element is increased.

  Therefore, in order to solve the above problems, the host of the phosphorescent material having a long wavelength emission is not CBP, for example, Balq (bis- (2-methyl-8-quinolinolate) -4- (phenylphenolate) aluminum) or alq ( It is disclosed that an organic EL element with improved performance is provided by using tris (8-quinolinol) aluminum (for example, Patent Document 2).

US application 2002/182441 publication WO 2004/060026 Publication

However, since Balq and alq are typical electron transporting materials, there is a limit to the performance when used as a host material of the light emitting layer. Specifically, there is a problem of an increase in driving voltage and deterioration of element lifetime. Occurs.
That is, when exciton generation is performed in the light emitting layer, electron injection and electron transport are easy, but it is difficult to inject holes into Balq or alq. In order to forcibly inject holes, the applied voltage must be increased, causing a problem of an increase in driving voltage.
In addition, since these materials have low hole resistance, there is a problem that molecular deterioration is severe when exposed to holes, leading to deterioration of device lifetime.

An object of the present invention is to provide a high-performance phosphorescent host material.
In particular, an object of the present invention is to provide a host material suitable for constituting a red phosphorescent light emitting layer.
Furthermore, a high performance organic EL element is provided using this host material.

The host material of the present invention is a host material that forms a phosphorescent material in combination with a phosphorescent dopant, and has a substituted or unsubstituted polycyclic fused aromatic skeleton that does not coordinate to a metal complex. The polycyclic fused aromatic skeleton has 14 to 30 nuclear atoms, and the host material has a lowest excited triplet energy gap of 1.71 eV to 2.09 eV.
For this reason, since the triplet energy gap Eg (T) of the host material of the present invention is 1.71 eV or more and 2.09 eV or less, the triplet exciton energy generated in the host material is a phosphorescent dopant. Intermolecular energy transfer is possible.
As a result, excitons can be generated efficiently, and a phosphorescent dopant can be efficiently emitted to obtain red phosphorescence.

Conventionally, CBP has been typically used as a host material for a phosphorescent light-emitting layer because of its large triplet energy gap, but the short-lived defect has been fatal.
In this respect, the host material of the present invention can be a host material with high molecular stability and a long lifetime.
And since the triplet energy gap of the host material of the present invention is 1.71 eV or more and 2.09 eV or less, it cannot be commonly used for a host of phosphorescent material having a short wavelength from green to red like CBP. Rather, it is very matched with Eg (T) of the red phosphorescent complex, and it becomes possible to construct a red light emitting layer with extremely high efficiency for efficient intermolecular energy transfer.
As described above, according to the host material of the present invention, a red phosphorescent light emitting layer having a longer life and higher efficiency than the conventional one can be formed.

Here, the triplet energy gap Eg of the host material is defined as an example based on the phosphorescence emission spectrum. For example, in the present invention, the triplet energy gap Eg is defined as follows.
That is, each material is dissolved at 10 μmol / L in an EPA solvent (diethyl ether: isopentane: ethanol = 5: 5: 2 by volume ratio) to obtain a sample for phosphorescence measurement.
Then, the phosphorescence measurement sample is put in a quartz cell, cooled to 77K, irradiated with excitation light, and the emitted phosphorescence is measured with respect to wavelength.
A triplet energy gap Eg is defined as a value obtained by drawing a tangent line to the short-wavelength rise of the obtained phosphorescence spectrum and converting the wavelength value into energy.
In addition, a commercially available measuring apparatus F-4500 (made by Hitachi) can be used for the measurement.
However, any value that can be defined as a triplet energy gap without departing from the gist of the present invention is acceptable, regardless of such rules.

  In the host material of the present invention, the host is preferably an anthracene derivative represented by the following formula (1) or a pyrene derivative represented by the following formula (2).

(In the formula (1), Ar ¹ and Ar ² are each independently a group derived from a substituted or unsubstituted aromatic ring having 6 to 20 nuclear carbon atoms. The aromatic ring is 1 or 2 The substituent may be substituted with the above-mentioned substituents: substituted or unsubstituted aryl group having 6 to 50 nuclear carbon atoms, substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, substituted or unsubstituted A cycloalkyl group having 3 to 50 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 50 carbon atoms, a substituted or unsubstituted aralkyl group having 6 to 50 nuclear carbon atoms, a substituted or unsubstituted nuclear atom number of 5 50 aryloxy groups, substituted or unsubstituted arylthio groups having 5 to 50 nucleus atoms, substituted or unsubstituted alkoxycarbonyl groups having 1 to 50 carbon atoms, substituted or unsubstituted silyl groups Selected from a group, a carboxyl group, a halogen atom, a cyano group, a nitro group and a hydroxy group, and when the aromatic ring is substituted with two or more substituents, the substituents may be the same or different. Alternatively, adjacent substituents may be bonded to each other to form a saturated or unsaturated cyclic structure.
R ¹ to R ⁸ are each a hydrogen atom, a substituted or unsubstituted aryl group having 6 to 50 nuclear carbon atoms, a substituted or unsubstituted heteroaryl group having 5 to 50 nuclear atoms, a substituted or unsubstituted carbon atom having 1 to 50 alkyl groups, substituted or unsubstituted cycloalkyl groups having 3 to 50 carbon atoms, substituted or unsubstituted alkoxy groups having 1 to 50 carbon atoms, substituted or unsubstituted aralkyl groups having 6 to 50 carbon atoms, substituted or Unsubstituted aryloxy group having 5 to 50 nucleus atoms, substituted or unsubstituted arylthio group having 5 to 50 nucleus atoms, substituted or unsubstituted alkoxycarbonyl group having 1 to 50 carbon atoms, substituted or unsubstituted silyl group Group, carboxyl group, halogen atom, cyano group, nitro group and hydroxy group. Further, adjacent substituents may be bonded to each other to form a saturated or unsaturated cyclic structure. )

(In Formula (2), Ar ^1a and Ar ^2a are each a substituted or unsubstituted aromatic ring group having 6 to 50 nuclear carbon atoms.
L is a substituted or unsubstituted phenylene group, a substituted or unsubstituted naphthalenylene group, a substituted or unsubstituted fluorenylene group, or a substituted or unsubstituted dibenzosilolylene group, respectively.
m is an integer from 0 to 2, nb is an integer from 1 to 4, s is an integer from 0 to 2, and t is an integer from 0 to 4.
L or Ar ^1a is bonded to any of the 1 to 5 positions of pyrene, and L or Ar ^2a is bonded to any of the 6 to 10 positions of pyrene.
However, when nb + t is an even number, Ar ^1a , Ar ^2a , and L satisfy the following (1) or (2).
(1) Ar ^1a ≠ Ar ^2a (where ≠ indicates a group having a different structure)
(2) When Ar ^1a = Ar ^2a
(2-1) m ≠ s and / or nb ≠ t, or
(2-2) When m = s and nb = t,
(2-2-1) L or pyrene are bonded to different bonding positions on Ar ^1a and Ar ^2a , respectively.
(2-2-2) When L or pyrene are bonded to the same bonding position on ^{Ar 1a} and ^{Ar 2a,}
There is no case where the substitution positions of L or Ar ^1a and Ar ^2a in pyrene are the 1st and 6th positions, or the 2nd and 7th positions. )

In the present invention, an anthracene derivative or a pyrene derivative is used as a host of a phosphorescent material having a wavelength region of 623 nm to 720 nm.
The anthracene derivative and pyrene derivative of the present invention have high molecular stability and can be a long-life host material.
In addition, since an anthracene derivative or a pyrene derivative exhibits sufficient mobility for holes and electrons, charge injection is efficiently performed, and exciton generation can be efficiently performed as a host material.

In the present invention, the anthracene derivative is preferably an asymmetric anthracene derivative represented by the following formula (3).

(In Formula (3), A ¹ and A ² are each independently a hydrogen atom or a substituted or unsubstituted aromatic ring group having 6 to 50 nuclear carbon atoms.
R ¹ to R ¹⁰ are each independently a hydrogen atom, a substituted or unsubstituted aromatic ring group having 6 to 50 nuclear carbon atoms, a substituted or unsubstituted aromatic heterocyclic group having 5 to 50 nuclear carbon atoms, substituted Or an unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted alkoxy group having 1 to 50 carbon atoms, a substituted or unsubstituted aralkyl group having 6 to 50 carbon atoms, Substituted or unsubstituted aryloxy group having 5 to 50 nucleus atoms, substituted or unsubstituted arylthio group having 5 to 50 nucleus atoms, substituted or unsubstituted alkoxycarbonyl group having 1 to 50 carbon atoms, substituted or unsubstituted Selected from silyl group, carboxyl group, halogen atom, cyano group, nitro group and hydroxyl group.
Ar ¹ , Ar ² , R ⁹ and R ¹⁰ may each be plural, and adjacent ones may form a saturated or unsaturated cyclic structure.
However, in Formula (3), there is no case where a group that is symmetrical with respect to the XY axis shown on the anthracene is bonded to the 9th and 10th positions of the central anthracene. )

In the present invention, the anthracene derivative is preferably a bisanthracene derivative represented by the following formula (4).

(In the formula (4), Ant is an anthracene derivative and may be substituted.
R represents a hydrogen atom, a substituted or unsubstituted aryl group having 6 to 50 nuclear carbon atoms, a substituted or unsubstituted heteroaryl group having 5 to 50 nuclear atoms, or a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms. Substituted or unsubstituted cycloalkyl group having 3 to 50 carbon atoms, substituted or unsubstituted alkoxy group having 1 to 50 carbon atoms, substituted or unsubstituted aralkyl group having 6 to 50 carbon atoms, substituted or unsubstituted nucleus Aryloxy group having 5 to 50 atoms, substituted or unsubstituted arylthio group having 5 to 50 nuclear atoms, substituted or unsubstituted alkoxycarbonyl group having 1 to 50 carbon atoms, substituted or unsubstituted silyl group, carboxyl group , A halogen atom, a cyano group, a nitro group and a hydroxy group. Further, adjacent substituents may be bonded to each other to form a saturated or unsaturated cyclic structure.
K is an integer from 0 to 9. )

In the present invention, the anthracene derivative is preferably a benzanthracene derivative represented by the following formula (5).

(In Formula (5), A ¹ and A ² are each independently a substituted or unsubstituted aromatic ring group having 6 to 50 nuclear carbon atoms.
R ¹ to R ¹² are each independently a hydrogen atom, a substituted or unsubstituted aromatic ring group having 6 to 50 nuclear carbon atoms, a substituted or unsubstituted aromatic heterocyclic group having 5 to 50 nuclear carbon atoms, substituted Or an unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted alkoxy group having 1 to 50 carbon atoms, a substituted or unsubstituted aralkyl group having 6 to 50 carbon atoms, Substituted or unsubstituted aryloxy group having 5 to 50 nucleus atoms, substituted or unsubstituted arylthio group having 5 to 50 nucleus atoms, substituted or unsubstituted alkoxycarbonyl group having 1 to 50 carbon atoms, substituted or unsubstituted Selected from silyl group, carboxyl group, halogen atom, cyano group, nitro group and hydroxyl group. )
Ar ¹ , Ar ² , R ^11, and R ¹² may each be plural, and adjacent ones may form a saturated or unsaturated cyclic structure. )

The organic EL device of the present invention is an organic EL device including a light emitting layer containing a phosphorescent dopant and the above-described host material, and the phosphorescent dopant has a central metal of iridium, platinum, osmium, ruthenium, It is an organometallic complex of at least one of rhenium.
The phosphorescent dopant is usually one type, but a plurality of phosphorescent dopants may be added.

  Moreover, the organic EL device of the present invention includes a first light-emitting layer that is the above-described light-emitting layer, and a second light-emitting layer containing a second host material, and the second light-emitting layer includes the host material, It is preferable to contain a dopant that emits light at a wavelength different from that of the phosphorescent dopant. Examples of the fluorescent light-emitting dopant include an amine dopant or a fluoranthene dopant.

Furthermore, the organic EL device of the present invention includes a light emitting layer having the above host material and the above phosphorescent dopant, and the light emitting layer further contains a dopant that emits light at a wavelength different from that of the phosphorescent dopant. It is preferable.
That is, two or more dopants are contained in one light emitting layer. The dopant contained in the light emitting layer may be doped with one or more phosphorescent dopants and one or two or more fluorescent dopants.
In such a configuration, the above-described host material has a sufficiently wide singlet energy gap Eg (S) and is also suitable as a host material for a fluorescent light-emitting dopant.
Particularly, it is suitable as a host of a blue light emitting dopant. Here, when the fluorescent light emitting dopant is doped, when the fluorescent light emitting dopant is blue, the whole becomes white.
That is, a white element can be easily manufactured.

And in the organic EL element of this invention, it is preferable that the dopant light-emitted with a wavelength different from the said phosphorescent dopant light-emits with a shorter wavelength than the said phosphorescent dopant.
The dopant that emits light at a wavelength different from that of the phosphorescent dopant may be a fluorescent or a phosphorescent dopant.

  Hereinafter, embodiments of the present invention will be described.

(Configuration of organic EL element)
Hereinafter, the element configuration of the organic EL element will be described.
(1) Configuration of Organic EL Element As shown in FIG. 1, the organic EL element of the present embodiment includes an anode provided on a light-transmitting substrate, a hole injection layer, a light emitting layer, and an electron transport layer. A configuration in which the electron injection layer and the cathode are provided in this order is not limited thereto. For example
(1) Anode / light emitting layer / cathode
(2) Anode / hole injection layer / light emitting layer / cathode
(3) Anode / light emitting layer / electron injection layer / cathode
(4) Anode / hole injection layer / light emitting layer / electron injection layer / cathode
(5) Anode / organic semiconductor layer / light emitting layer / cathode
(6) Anode / organic semiconductor layer / electron barrier layer / light emitting layer / cathode
(7) Anode / organic semiconductor layer / light emitting layer / adhesion improving layer / cathode
(8) Anode / hole injection layer / hole transport layer / light emitting layer / electron injection layer / cathode (9) Anode / insulating layer / light emitting layer / insulating layer / cathode
(10) Anode / inorganic semiconductor layer / insulating layer / light emitting layer / insulating layer / cathode
(11) Anode / organic semiconductor layer / insulating layer / light emitting layer / insulating layer / cathode
(12) Anode / insulating layer / hole injection layer / hole transport layer / light emitting layer / insulating layer / cathode
(13) Structures such as anode / insulating layer / hole injection layer / hole transport layer / light emitting layer / electron injection layer / cathode can be mentioned.

  FIG. 1 is a diagram showing a schematic configuration of an organic EL element according to an embodiment of the present invention.

  In FIG. 1, the organic EL element 10 includes an anode 12 provided on a translucent substrate 11, a hole injection layer 13, a light emitting layer 14, an electron transport layer 15, an electron injection layer 16, and a cathode 17. With.

(2) Translucent substrate 11
The organic EL element is manufactured on a light-transmitting substrate. Here, the translucent substrate is a substrate that supports the organic EL element, and is preferably a smooth substrate having a light transmittance in the visible region of 400 to 700 nm of 50% or more.
Specifically, a glass plate, a polymer plate, etc. are mentioned.
Examples of the glass plate include soda lime glass, barium / strontium-containing glass, lead glass, aluminosilicate glass, borosilicate glass, barium borosilicate glass, and quartz.
Examples of the polymer plate include polycarbonate, acrylic, polyethylene terephthalate, polyether sulfide, and polysulfone.

(3) Anode 12
As the anode 12, it is preferable to use a metal, an alloy, an electrically conductive compound, or a mixture thereof having a high work function (for example, 4.0 eV or more). Specifically, one kind of indium tin oxide (ITO), indium zinc oxide, tin, zinc oxide, gold, platinum, palladium and the like can be used alone or in combination of two or more kinds.
Further, the thickness of the anode 12 is not particularly limited, but is preferably a value within the range of 10 to 1,000 nm, and more preferably within a range of 10 to 200 nm.

(4) Light emitting layer 14
The light emitting layer of the organic EL element has the following functions.
That is,
(1) Injection function; function that can inject holes from the anode or hole injection layer when an electric field is applied, and can inject electrons from the cathode or electron injection layer,
(2) Transport function: Function to move injected charges (electrons and holes) by the force of electric field,
(3) Light emission function: A function to provide a field for recombination of electrons and holes and connect it to light emission,
There is.
However, there may be a difference between the ease of hole injection and the ease of electron injection, and the transport capability represented by the mobility of holes and electrons may be large or small. It is preferable to move one charge.
As a method for forming the light emitting layer, for example, a known method such as an evaporation method, a spin coating method, or an LB method can be applied.
The light emitting layer is particularly preferably a molecular deposited film.
Here, the molecular deposition film is a thin film formed by deposition from a material compound in a gas phase state or a film formed by solidification from a material compound in a solution state or a liquid phase state. Can be classified from a thin film (accumulated film) formed by the LB method according to a difference in an agglomerated structure and a higher-order structure and a functional difference resulting therefrom.
Further, as disclosed in JP-A-57-51781, a binder such as a resin and a material compound are dissolved in a solvent to form a solution, and then this is thinned by a spin coating method or the like. In addition, a light emitting layer can be formed.
Furthermore, the thickness of the light emitting layer is preferably 5 to 50 nm, more preferably 6 to 50 nm. If the thickness is less than 5 nm, it is difficult to form a light emitting layer, and it may be difficult to adjust the chromaticity. If the thickness exceeds 50 nm, the driving voltage may increase.
The light emitting layer 14 is a phosphorescent light emitting layer containing a host material and a phosphorescent light emitting dopant.

Specific examples of the dopant for red phosphorescence include the following compounds in addition to PQIr (iridium (III) bis (2-phenylquinolyl-N, C ^{2 ′} ) acetylacetonate).

Specific examples of the dopant for green phosphorescence include, for example, Ir (ppy) ₃ (fac-tris (2-phenylpyridine) iridium) and the following compounds.

  The host material of this embodiment has Eg (T) of 1.71 eV to 2.09 eV and a wavelength region of 623 nm to 720 nm, and is combined with a dopant. Examples of such a host material include an anthracene derivative represented by the following formula (1).

(In the formula (1), Ar ¹ and Ar ² are each independently a group derived from a substituted or unsubstituted aromatic ring having 6 to 20 nuclear carbon atoms. The aromatic ring is 1 or 2 The substituent may be substituted with the above-mentioned substituents: substituted or unsubstituted aryl group having 6 to 50 nuclear carbon atoms, substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, substituted or unsubstituted A cycloalkyl group having 3 to 50 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 50 carbon atoms, a substituted or unsubstituted aralkyl group having 6 to 50 nuclear carbon atoms, a substituted or unsubstituted nuclear atom number of 5 50 aryloxy groups, substituted or unsubstituted arylthio groups having 5 to 50 nucleus atoms, substituted or unsubstituted alkoxycarbonyl groups having 1 to 50 carbon atoms, substituted or unsubstituted silyl groups Selected from a group, a carboxyl group, a halogen atom, a cyano group, a nitro group and a hydroxy group, and when the aromatic ring is substituted with two or more substituents, the substituents may be the same or different. Alternatively, adjacent substituents may be bonded to each other to form a saturated or unsaturated cyclic structure.
R ¹ to R ⁸ are each a hydrogen atom, a substituted or unsubstituted aryl group having 6 to 50 nuclear carbon atoms, a substituted or unsubstituted heteroaryl group having 5 to 50 nuclear atoms, a substituted or unsubstituted carbon atom having 1 to 50 alkyl groups, substituted or unsubstituted cycloalkyl groups having 3 to 50 carbon atoms, substituted or unsubstituted alkoxy groups having 1 to 50 carbon atoms, substituted or unsubstituted aralkyl groups having 6 to 50 carbon atoms, substituted or Unsubstituted aryloxy group having 5 to 50 nucleus atoms, substituted or unsubstituted arylthio group having 5 to 50 nucleus atoms, substituted or unsubstituted alkoxycarbonyl group having 1 to 50 carbon atoms, substituted or unsubstituted silyl group Group, carboxyl group, halogen atom, cyano group, nitro group and hydroxy group. Further, adjacent substituents may be bonded to each other to form a saturated or unsaturated cyclic structure. )

  Specific examples of such anthracene derivatives include 2a-49 to 2a-51 of the following chemical formulas 7 and 8.

  Further, the anthracene derivative represented by the formula (1) may be, for example, an asymmetric anthracene represented by the following formula (3).

(In Formula (3), A ¹ and A ² are each independently a hydrogen atom or a substituted or unsubstituted aromatic ring group having 6 to 50 nuclear carbon atoms.
R ¹ to R ¹⁰ are each independently a hydrogen atom, a substituted or unsubstituted aromatic ring group having 6 to 50 nuclear carbon atoms, a substituted or unsubstituted aromatic heterocyclic group having 5 to 50 nuclear carbon atoms, substituted Or an unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted alkoxy group having 1 to 50 carbon atoms, a substituted or unsubstituted aralkyl group having 6 to 50 carbon atoms, Substituted or unsubstituted aryloxy group having 5 to 50 nucleus atoms, substituted or unsubstituted arylthio group having 5 to 50 nucleus atoms, substituted or unsubstituted alkoxycarbonyl group having 1 to 50 carbon atoms, substituted or unsubstituted Selected from silyl group, carboxyl group, halogen atom, cyano group, nitro group and hydroxyl group.
Ar ¹ , Ar ² , R ⁹ and R ¹⁰ may each be plural, and adjacent ones may form a saturated or unsaturated cyclic structure.
However, in the formula (2), groups that are symmetrical with respect to the XY axis shown on the anthracene do not bond to the 9th and 10th positions of the central anthracene. )

  Examples of such an asymmetric anthracene derivative include the following.

Further, the anthracene derivative represented by the formula (1) may be a bisanthracene derivative represented by the following formula (4).

(In the formula, Ant is an anthracene derivative and may be substituted.
R represents a hydrogen atom, a substituted or unsubstituted aryl group having 6 to 50 nuclear carbon atoms, a substituted or unsubstituted heteroaryl group having 5 to 50 nuclear atoms, or a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms. Substituted or unsubstituted cycloalkyl group having 3 to 50 carbon atoms, substituted or unsubstituted alkoxy group having 1 to 50 carbon atoms, substituted or unsubstituted aralkyl group having 6 to 50 carbon atoms, substituted or unsubstituted nucleus Aryloxy group having 5 to 50 atoms, substituted or unsubstituted arylthio group having 5 to 50 nuclear atoms, substituted or unsubstituted alkoxycarbonyl group having 1 to 50 carbon atoms, substituted or unsubstituted silyl group, carboxyl group , A halogen atom, a cyano group, a nitro group and a hydroxy group. Further, adjacent substituents may be bonded to each other to form a saturated or unsaturated cyclic structure.
K is an integer from 0 to 9. )

  Examples of such bisanthracene derivatives include the following. Specifically, those represented by Chemical formulas 2a-41 to 2a-48, Chemical formulas 17 and Chemical formula 18 are shown.

Further, the anthracene derivative represented by the formula (1) may be a benzanthracene derivative represented by the following formula (5).

(In the formula, A ¹ and A ² are each independently a substituted or unsubstituted aromatic ring group having 6 to 50 nuclear carbon atoms.
R ¹ to R ¹² are each independently a hydrogen atom, a substituted or unsubstituted aromatic ring group having 6 to 50 nuclear carbon atoms, a substituted or unsubstituted aromatic heterocyclic group having 5 to 50 nuclear carbon atoms, substituted Or an unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted alkoxy group having 1 to 50 carbon atoms, a substituted or unsubstituted aralkyl group having 6 to 50 carbon atoms, Substituted or unsubstituted aryloxy group having 5 to 50 nucleus atoms, substituted or unsubstituted arylthio group having 5 to 50 nucleus atoms, substituted or unsubstituted alkoxycarbonyl group having 1 to 50 carbon atoms, substituted or unsubstituted Selected from silyl group, carboxyl group, halogen atom, cyano group, nitro group and hydroxyl group. )
Ar ¹ , Ar ² , R ^11, and R ¹² may each be plural, and adjacent ones may form a saturated or unsaturated cyclic structure. )

  Examples of such benzanthracene derivatives include the following.

The host material may be a pyrene derivative represented by the following formula (2).

(In the formula, Ar ^1a and Ar ^2a are each a substituted or unsubstituted aromatic ring group having 6 to 50 nuclear carbon atoms.
L is a substituted or unsubstituted phenylene group, a substituted or unsubstituted naphthalenylene group, a substituted or unsubstituted fluorenylene group, or a substituted or unsubstituted dibenzosilolylene group, respectively.
m is an integer from 0 to 2, nb is an integer from 1 to 4, s is an integer from 0 to 2, and t is an integer from 0 to 4.
L or Ar ^1a is bonded to any of the 1 to 5 positions of pyrene, and L or Ar ^2a is bonded to any of the 6 to 10 positions of pyrene.
However, when nb + t is an even number, Ar ^1a , Ar ^2a , and L satisfy the following (1) or (2).
(1) Ar ^1a ≠ Ar ^2a (where ≠ indicates a group having a different structure)
(2) When Ar ^1a = Ar ^2a
(2-1) m ≠ s and / or nb ≠ t, or
(2-2) When m = s and nb = t,
(2-2-1) or L or pyrene, has bonded to different bonding positions on ^{Ar 1a} and ^{Ar 2a} each,
(2-2-2) When L or pyrene is bonded to the same bonding position on Ar ^1a and Ar ^2a ,
There is no case where the substitution positions of L or Ar ^1a and Ar ^2a in pyrene are the 1st and 6th positions, or the 2nd and 7th positions. )

  Examples of such pyrene derivatives include the following.

The phosphorescent dopant combined with the host material having at least one of the anthracene derivatives, benzanthracene derivatives, and pyrene derivatives is an organic metal whose central metal is at least one of iridium, platinum, osmium, ruthenium, and rhenium It is a complex.
Examples of such organometallic complexes include the following.

(5) Hole injection layer 13
A hole injection layer 13 is provided between the anode 12 and the light emitting layer 14.
In addition to the hole injection layer 13, a hole transport layer, an organic semiconductor layer, or the like can be provided. The hole injection layer 13 or the hole transport layer is a layer that assists hole injection into the light emitting layer 14 and transports it to the light emitting region, and has a high hole mobility and a small ionization energy of usually 5.5 eV or less. . The hole injection layer 13 is provided to adjust the energy level, for example, to ease a sudden change in the energy level. The hole injection layer 13 or the hole transport layer is preferably a material that transports holes to the light emitting layer 14 with a lower electric field strength, and further has an electric field with a hole mobility of, for example, 10 4 to 10 6 V / cm. Those that are at least 10 −6 cm 2 / V · sec when applied are preferred.
Here, a specific example of a method for measuring hole mobility will be described.
A 25 mm × 75 mm × 1.1 mm glass substrate with an ITO transparent electrode (Asahi Glass) is subjected to ultrasonic cleaning in isopropyl alcohol for 5 minutes, and then UV ozone cleaning is performed for 30 minutes.
The glass substrate after washing is mounted on a substrate holder of a vacuum evaporation apparatus, and first, a measurement material is formed on the ITO transparent substrate electrode by 3 to 5 μm by resistance heating evaporation.
Subsequently, 10 nm of metal Al is deposited on this film to form a translucent electrode. The carrier (hole,) mobility in the electric field strength of 10 ⁴ to 10 ⁶ V / cm is measured by a time-of-flight measuring device TOF-401 manufactured by Optel Co., Ltd. with the element thus prepared.
Here, light from a nitrogen laser of 337 nm is used as excitation light.
The photocurrent (I) -time (t) curve is plotted in logarithm, and the obtained inflection point is tr, and the mobility μ can be obtained as mobility μ = L ² / (tr × V). Here, L is the sample film thickness, and V is the applied voltage.
Note that the mobility of electrons can also be measured by a similar method.

  The material for forming the hole injection layer 13 or the hole transport layer is not particularly limited as long as it has the above-mentioned preferable properties, and is conventionally used as a charge transport material for holes in optical transmission materials. Alternatively, any known one used for the hole injection layer of the organic EL element can be selected and used.

  Specific examples of the material for forming such a hole injection layer or a hole transport layer include, for example, triazole derivatives (see US Pat. No. 3,112,197, etc.), oxadiazole derivatives (US Pat. No. 3, 189,447, etc.), imidazole derivatives (see JP-B-37-16096, etc.), polyarylalkane derivatives (US Pat. Nos. 3,615,402, 3,820,989) No. 3,542,544, JP-B-45-555, JP-A-51-10983, JP-A-51-93224, JP-A-55-17105, JP-A-56-4148, No. 55-108667, No. 55-156953, No. 56-36656, etc.), pyrazoline derivatives and pyrazolone derivatives (US Pat. No. 3, 80,729, 4,278,746, JP-A-55-88064, 55-88065, 49-105537, 55-51086, 56 No.-80051, No. 56-88141, No. 57-45545, No. 54-112737, No. 55-74546, etc.), Phenylenediamine derivatives (US Pat. No. 3,615,404) , Japanese Patent Publication No. 51-10105, No. 46-3712, No. 47-25336, Japanese Unexamined Patent Publication No. 54-53435, No. 54-110536, No. 54-1119925, etc.) Arylamine derivatives (US Pat. Nos. 3,567,450, 3,180,703, 3,240,597) 3,658,520, 4,232,103, 4,175,961, 4,012,376, JP-B-49-35702 No. 39-27577, JP-A-55-144250, JP-A-56-119132, JP-A-56-22437, West German Patent No. 1,110,518, etc.), amino-substituted chalcone Derivatives (see US Pat. No. 3,526,501, etc.), oxazole derivatives (disclosed in US Pat. No. 3,257,203, etc.), styrylanthracene derivatives (Japanese Patent Laid-Open No. 56-46234) ), Fluorenone derivatives (see Japanese Patent Laid-Open No. 54-110837), hydrazone derivatives (US Pat. No. 3,717,462, Japanese Patent Laid-Open No. 54-59143). No. 55-52063, No. 55-52064, No. 55-46760, No. 55-85495, No. 57-11350, No. 57-148799, JP-A-2-311591. Stilbene derivatives (Japanese Patent Laid-Open Nos. 61-210363, 61-228451, 61-14642, 61-72255, 62-47646, 62- 36674, 62-10652, 62-30255, 60-93455, 60-94462, 60-174749, 60-175052, etc.), silazane Derivatives (U.S. Pat. No. 4,950,950), polysilanes (JP-A-2-204996), aniline Copolymer (JP-A-2-282263), an electroconductive oligomer (particularly a thiophene oligomer) disclosed in JP-A-1-211399 and the like.

As the material for the hole injection layer 13 or the hole transport layer, the above-mentioned materials can be used. Porphyrin compounds (disclosed in JP-A-63-295695 etc.), aromatic tertiary amines Compounds and styrylamine compounds (US Pat. No. 4,127,412, JP-A-53-27033, 54-58445, 54-149634, 54-64299, 55) -79450 publication, 55-144250 publication, 56-119132 publication, 61-295558 publication, 61-98353 publication, 63-295695 publication, etc.), aromatic tertiary amine compounds Can also be used. Further, for example, 4,4′-bis (N- (1-naphthyl) -N-phenylamino) biphenyl having two condensed aromatic rings described in US Pat. No. 5,061,569 in the molecule. 4,4 ′, 4 ″ -tris (N- (3-methylphenyl) -N-phenyl, in which three triphenylamine units described in JP-A-4-308688 are linked in a starburst type And amino) triphenylamine.
Further, hexaazatriphenylene derivatives described in Japanese Patent Publication Nos. 3614405, 3571977 or US Pat. No. 4,780,536 can also be suitably used as the hole injecting material.
Furthermore, in addition to the above-mentioned aromatic dimethylidin compounds shown as the material for the light emitting layer, inorganic compounds such as p-type Si and p-type SiC can also be used as the material for the hole injection layer 13 or the hole transport layer.
The hole injection layer 13 or the hole transport layer may be composed of one layer or two or more layers of the above-described materials, or may be a different type from the hole injection layer 13 or the hole transport layer. A hole injection layer or a hole transport layer made of a compound may be laminated. Although the film thickness of the positive hole injection layer 13 or a positive hole transport layer is not specifically limited, Preferably, it is 20-200 nm.
The organic semiconductor layer is a layer that assists hole injection or electron injection into the light emitting layer 14 and preferably has a conductivity of 10 −10 S / cm or more. As a material of such an organic semiconductor layer, a conductive oligomer such as a thiophene-containing oligomer or an arylamine oligomer described in JP-A-8-193191, a conductive dendrimer such as an arylamine dendrimer, or the like can be used. . Although the film thickness of an organic-semiconductor layer is not specifically limited, Preferably, it is 10-1,000 nm.

(6) Electron transport layer 15 and electron injection layer 16
An electron injection layer 15 and an electron transport layer 16 are provided between the cathode 17 and the light emitting layer 14. The electron injection layer 15 and the electron transport layer 16 are layers that assist injection of electrons into the light emitting layer 14 and have a high electron mobility. The electron injection layer 15 is provided to adjust the energy level, for example, to ease a sudden change in the energy level. As a material used for the electron injection layer 15 and the electron transport layer 16, 8-hydroxyquinoline or a metal complex of its derivative, an oxadiazole derivative, and a nitrogen-containing heterocyclic derivative are suitable. As a specific example of the metal complex of 8-hydroxyquinoline or a derivative thereof, a metal chelate oxinoid compound containing a chelate of oxine (generally 8-quinolinol or 8-hydroxyquinoline), for example, tris (8-quinolinol) aluminum is used. Can do. And as an oxadiazole derivative, the following general formula [6]-[8]

(In the formulas (6) to (8), Ar ¹⁷ , Ar ¹⁸ , Ar ¹⁹ , Ar ²¹ , Ar ²² and Ar ²⁵ each represent an aryl group having or not having a substituent, and Ar ¹⁷ , Ar ¹⁸ , Ar ¹⁹ and Ar ²¹ , Ar ²² and Ar ²⁵ may be the same or different, Ar 20, Ar ²³ and Ar ²⁴ each represent an arylene group with or without a substituent, and Ar ²³ and Ar ²⁴ are , Which may be the same or different from each other). Examples of the aryl group in the general formulas (6) to (8) include a phenyl group, a biphenyl group, an anthranyl group, a perylenyl group, and a pyrenyl group. Examples of the arylene group include a phenylene group, a naphthylene group, a biphenylene group, an anthranylene group, a peryleneylene group, and a pyrenylene group. And as a substituent to these, a C1-C10 alkyl group, a C1-C10 alkoxy group, a cyano group, etc. are mentioned. As this electron transfer compound, those having good thin film forming properties are preferably used. Specific examples of these electron transfer compounds include the following.

含窒素複素環誘導体としては、以下の一般式（９）または（１０）を有する有機化合物からなる含窒素複素環誘導体であって、金属錯体でない含窒素化合物が挙げられる。例えば、（９）に示す骨格を含有する５員環もしくは６員環である。

Examples of the nitrogen-containing heterocyclic derivative include nitrogen-containing heterocyclic derivatives that are organic compounds having the following general formula (9) or (10) and are not metal complexes. For example, it is a 5-membered or 6-membered ring containing the skeleton shown in (9).

(In the formula, X represents a carbon atom or a nitrogen atom. Z ₁ and Z ₂ each independently represents an atomic group capable of forming a nitrogen-containing heterocycle.)

  The nitrogen-containing heterocyclic derivative is preferably an organic compound having a nitrogen-containing aromatic polycyclic group consisting of a 5-membered ring or a 6-membered ring, and having a skeleton at a bonding position that is not adjacent when there are a plurality of nitrogen atoms. Furthermore, in the case of such a nitrogen-containing aromatic polycyclic group having a plurality of nitrogen atoms, the nitrogen-containing aromatic polycyclic organic compound having a skeleton obtained by combining the above (9) and (10) or (9) and (11) But you can.

The nitrogen-containing groups of the compounds represented by the formulas (9) to (11) are, for example, the following general formulas (12) to (34)

(In the formulas (12) to (34), R is an aryl group having 6 to 40 carbon atoms, a heteroaryl group having 3 to 40 carbon atoms, an alkyl group having 1 to 20 carbon atoms, or an alkoxy group having 1 to 20 carbon atoms. N is an integer of 0 to 5, and when n is an integer of 2 or more, a plurality of Rs may be the same or different from each other. It is a nitrogen-containing heterocyclic derivative.

  Furthermore, a preferred specific compound is a nitrogen-containing heterocyclic derivative represented by the following general formula (35).

(In Formula (35), HAr is a nitrogen-containing heterocycle having 3 to 40 carbon atoms which may have a substituent, and L is a single bond or 6 to 6 carbon atoms which may have a substituent. 40 arylene group or heteroarylene group having 3 to 40 carbon atoms which may have a substituent, Ar ₁ is a divalent aromatic carbon atom having 6 to 40 carbon atoms which may have a substituent It is a hydrogen group, and Ar ₂ is an aryl group having 6 to 40 carbon atoms which may have a substituent or a heteroaryl group having 3 to 40 carbon atoms which may have a substituent.

HAr

A nitrogen-containing heterocyclic derivative selected from the group consisting of

L is

A nitrogen-containing heterocyclic derivative selected from the group consisting of

Ar2 is

A nitrogen-containing heterocyclic derivative selected from the group consisting of

Ar ₁ represents the general formula (36) or (37)

(In formulas (36) and (37), R ^{1 to} R ¹⁴ each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or 6 to 6 carbon atoms. 40 aryloxy group, an aryl group having 6 to 40 carbon atoms which may have a substituent or a heteroaryl group having 3 to 40 carbon atoms, and Ar ₃ is a carbon which may have a substituent. It is a nitrogen-containing heterocyclic derivative having an arylanthranyl group represented by an aryl group having 6 to 40 carbon atoms or a heteroaryl group having 3 to 40 carbon atoms.

Further, in Ar ₁ , a nitrogen-containing heterocyclic derivative in which R _{1 to} R ₈ are all hydrogen atoms may be used.

In addition, as described in JP-A-9-3448

Wherein R _{1 to} R ₄ are each independently a hydrogen atom, a substituted or unsubstituted aliphatic group, a substituted or unsubstituted aliphatic cyclic group, a substituted or unsubstituted carbocyclic aromatic ring group Represents a substituted or unsubstituted heterocyclic group, and X ₁ and X ₂ each independently represents an oxygen atom, a sulfur atom or a dicyanomethylene group), or JP-A-2000-173774

[In the general formula (38), R ¹ , R ² , R ³ and R ⁴ are the same or different groups, and are aryl groups represented by the following general formula (39).

(However, in the general formula (39), R ⁵ , R ⁶ , R ⁷ , R ⁸ and R ⁹ are the same or different from each other, and a hydrogen atom or at least one of them is saturated or unsaturated alkoxyl. A group, an alkyl group, an amino group or an alkylamino group.)]
And the like, and organic compounds that satisfy the above-mentioned element constituent conditions.

Further, it may be a polymer compound containing the nitrogen-containing heterocyclic group or nitrogen-containing heterocyclic derivative.
Although the film thickness of the electron injection layer 16 or the electron carrying layer 15 is not specifically limited, Preferably, it is 1-100 nm.
It is preferable that the light emitting layer or the first organic layer which is the organic layer closest to the anode 12 contains an oxidizing agent. A preferred oxidizing agent contained in the light emitting layer or the hole injection layer is an electron withdrawing or electron acceptor. Preferred are Lewis acids, various quinone derivatives, dicyanoquinodimethane derivatives, and salts formed with aromatic amines and Lewis acids. Particularly preferred Lewis acids are iron chloride, antimony chloride, aluminum chloride and the like.
It is preferable that the light emitting layer or the second organic layer which is the organic layer closest to the cathode 17 contains a reducing agent. Preferred reducing agents are alkali metals, alkaline earth metals, alkali metal oxides, alkaline earth oxides, rare earth oxides, alkali metal halides, alkaline earth halides, rare earth halides, alkali metals and aromatic compounds. It is a complex formed. Particularly preferred alkali metals are Cs, Li, Na and K.

(7) Inorganic compound layer An inorganic compound layer may be further provided in contact with the anode 12 and / or the cathode 17. The inorganic compound layer functions as an adhesion improving layer. Preferred inorganic compounds used in the inorganic compound layer include alkali metal oxides, alkaline earth oxides, rare earth oxides, alkali metal halides, alkaline earth halides, rare earth halides, SiOX, AlOX, SiNX, and SiON. , AlON, GeOX, LiOX, LiON, TiOX, TiON, TaOX, TaON, TaNX, C, and other oxides, nitrides, and oxynitrides. In particular, as a component of the layer in contact with the anode, SiOX, AlOX, SiNX, SiON, AlON, GeOX, and C are preferable to form a stable injection interface layer. In particular, LiF, MgF2, CaF2, MgF2, and NaF are preferred as the components of the layer in contact with the cathode. Although the film thickness of an inorganic compound layer is not specifically limited, Preferably, it is 0.1 nm-100 nm.

  The method for forming each organic layer and inorganic compound layer including the light-emitting layer is not particularly limited, and known methods such as a vapor deposition method, a spin coating method, a casting method, and an LB method can be applied. In addition, since the characteristics of the obtained organic EL element become uniform and the manufacturing time can be shortened, the electron injection layer and the light emitting layer are preferably formed by the same method. For example, the electron injection layer is formed by vapor deposition. In this case, it is preferable to form the light emitting layer by vapor deposition.

(8) Cathode 17
For the cathode 17, it is preferable to use a metal, an alloy, an electrically conductive compound, or a mixture thereof having a low work function (for example, less than 4.0 eV). Specifically, one kind of magnesium, aluminum, indium, lithium, sodium, silver and the like can be used alone or in combination of two or more kinds. The thickness of the cathode 17 is not particularly limited, but is preferably a value in the range of 10 to 1000 nm, and more preferably in the range of 10 to 200 nm. At least one of the anode 12 and the cathode 17 is substantially transparent so that the light emitted from the light emitting layer 14 can be effectively extracted to the outside. More specifically, the light transmittance is 10% or more. It is preferable that The anode 12 or the cathode 17 can be manufactured by vacuum deposition, sputtering, ion plating, electron beam deposition, CVD, MOCVD, plasma CVD, or the like.

[Modification of Embodiment]
It should be noted that the present invention is not limited to the above-described embodiment, and modifications, improvements, and the like within the scope that can achieve the object of the present invention are included in the present invention.

  In the present embodiment, the host material is at least one of anthracene derivatives, pyrene derivatives, and benzanthracene derivatives, but is not limited thereto. For example, a phenanthrene derivative, a triphenylene derivative, a perylene derivative, or the like may be used.

In the present embodiment, the organic EL element 10 shows the light emitting layer 14 having the host material and the red phosphorescent dopant, but is not limited thereto. For example, in addition to the light emitting layer 14, a second light emitting layer having a second host material and a fluorescent light emitting dopant may be further provided.
In this case, an example of the fluorescent dopant is an amine dopant represented by the following formula (40).

In the formula (40), P represents a substituted or unsubstituted aromatic hydrocarbon group having 6 to 40 nuclear carbon atoms, a substituted or unsubstituted heterocyclic group having 3 to 40 nuclear atoms, or substituted or unsubstituted styryl. It is a group. k is an integer of 1 to 3.
Ar ^{1 to} Ar ⁴ are each independently a substituted or unsubstituted aromatic hydrocarbon group having 6 to 40 nuclear carbon atoms or a substituted or unsubstituted heterocyclic group having 3 to 40 nuclear atoms, and s is It is an integer of 0-4.
Two adjacent substituents arbitrarily selected from Ar ¹ , Ar ² , and P may be bonded to each other to form a ring. When k is 2 or more, P may be the same or different.

  Examples of the aromatic hydrocarbon group and heterocyclic group of P include a substituted or unsubstituted aromatic hydrocarbon group having 6 to 40 nuclear carbon atoms and a substituted or unsubstituted heterocyclic ring having 3 to 40 nuclear atoms, respectively. Groups such as benzene, biphenyl, terphenyl, naphthalene, phenanthrene, fluoranthene, anthracene, pyrene, perylene, coronene, chrysene, picene, dinaphthyl, trinaphthyl, phenylanthracene, diphenylanthracene, fluorene, triphenylene, rubicene, benz Examples include anthracene, dibenzanthracene, acenaphthofluoranthene, tribenzopentaphene, fluoranthenofluoranthene, benzodifluoranthene, benzofluoranthene, and diindenoperylene, especially naphthalene, phenanthrene. Fluoranthene, anthracene, pyrene, perylene, chrysene, phenylanthracene, residues and residues that combines several of these diphenyl anthracene are preferable.

In the formula (20), Ar ^{1 to} Ar ⁴ are each independently a substituted or unsubstituted aromatic hydrocarbon group having 6 to 40 nuclear carbon atoms or a substituted or unsubstituted heterocyclic group having 3 to 40 nuclear atoms. S is an integer of 0-4.
Examples of the aromatic hydrocarbon group of Ar ^{1 to} Ar ⁴ include a phenyl group, a 1-naphthyl group, a 2-naphthyl group, a 1-anthryl group, a 2-anthryl group, a 9-anthryl group, a 1-phenanthryl group, 2 -Phenanthryl group, 3-phenanthryl group, 4-phenanthryl group, 9-phenanthryl group, 1-naphthacenyl group, 2-naphthacenyl group, 9-naphthacenyl group, 1-pyrenyl group, 2-pyrenyl group, 4-pyrenyl group, 2 -Biphenylyl group, 3-biphenylyl group, 4-biphenylyl group, p-terphenyl-4-yl group, p-terphenyl-3-yl group, p-terphenyl-2-yl group, m-ter Phenyl-4-yl group, m-terphenyl-3-yl group, m-terphenyl-2-yl group, o-tolyl group, m-tolyl group, p-tolyl group, pt-butyl Enyl group, p- (2-phenylpropyl) phenyl group, 3-methyl-2-naphthyl group, 4-methyl-1-naphthyl group, 4-methyl-1-anthryl group, 4′-methylbiphenylyl group, 4 "-T-butyl-p-terphenyl-4-yl group and the like.

Examples of the heterocyclic group represented by Ar ^{1 to} Ar ⁴ include 1-pyrrolyl group, 2-pyrrolyl group, 3-pyrrolyl group, pyrazinyl group, 2-pyridinyl group, 3-pyridinyl group, 4-pyridinyl group, and 1-indolyl group. Group, 2-indolyl group, 3-indolyl group, 4-indolyl group, 5-indolyl group, 6-indolyl group, 7-indolyl group, 1-isoindolyl group, 2-isoindolyl group, 3-isoindolyl group, 4-isoindolyl group Group, 5-isoindolyl group, 6-isoindolyl group, 7-isoindolyl group, 2-furyl group, 3-furyl group, 2-benzofuranyl group, 3-benzofuranyl group, 4-benzofuranyl group, 5-benzofuranyl group, 6-benzofuranyl group Group, 7-benzofuranyl group, 1-isobenzofuranyl group, 3-isobenzofuranyl group, 4-isobenzofuran group Group, 5-isobenzofuranyl group, 6-isobenzofuranyl group, 7-isobenzofuranyl group, quinolyl group, 3-quinolyl group, 4-quinolyl group, 5-quinolyl group, 6-quinolyl group, 7-quinolyl group, 8-quinolyl group, 1-isoquinolyl group, 3-isoquinolyl group, 4-isoquinolyl group, 5-isoquinolyl group, 6-isoquinolyl group, 7-isoquinolyl group, 8-isoquinolyl group, 2-quinoxalinyl group, 5-quinoxalinyl group, 6-quinoxalinyl group, 1-carbazolyl group, 2-carbazolyl group, 3-carbazolyl group, 4-carbazolyl group, 9-carbazolyl group, 1-phenanthridinyl group, 2-phenanthridinyl group 3-phenanthridinyl group, 4-phenanthridinyl group, 6-phenanthridinyl group, 7-phenanthridinyl group, 8-phena Thridinyl group, 9-phenanthridinyl group, 10-phenanthridinyl group, 1-acridinyl group, 2-acridinyl group, 3-acridinyl group, 4-acridinyl group, 9-acridinyl group, 1,7-phenanth Lorin-2-yl group, 1,7-phenanthrolin-3-yl group, 1,7-phenanthrolin-4-yl group, 1,7-phenanthrolin-5-yl group, 1,7- Phenanthrolin-6-yl group, 1,7-phenanthrolin-8-yl group, 1,7-phenanthrolin-9-yl group, 1,7-phenanthrolin-10-yl group, 1, 8-phenanthrolin-2-yl group, 1,8-phenanthrolin-3-yl group, 1,8-phenanthrolin-4-yl group, 1,8-phenanthrolin-5-yl group, 1,8-phenanthrolin-6-yl group, 1 , 8-phenanthroline-7-yl group, 1,8-phenanthrolin-9-yl group, 1,8-phenanthrolin-10-yl group, 1,9-phenanthrolin-2-yl group 1,9-phenanthroline-3-yl group, 1,9-phenanthrolin-4-yl group, 1,9-phenanthrolin-5-yl group, 1,9-phenanthrolin-6- Yl group, 1,9-phenanthroline-7-yl group, 1,9-phenanthrolin-8-yl group, 1,9-phenanthrolin-10-yl group, 1,10-phenanthroline- 2-yl group, 1,10-phenanthrolin-3-yl group, 1,10-phenanthrolin-4-yl group, 1,10-phenanthrolin-5-yl group, 2,9-phenance Lorin-1-yl group, 2,9-phenanthrolin-3-yl group, 2,9-fur Nansulolin-4-yl group, 2,9-phenanthrolin-5-yl group, 2,9-phenanthrolin-6-yl group, 2,9-phenanthrolin-7-yl group, 2,9- Phenanthrolin-8-yl group, 2,9-phenanthrolin-10-yl group, 2,8-phenanthrolin-1-yl group, 2,8-phenanthrolin-3-yl group, 2, 8-phenanthroline-4-yl group, 2,8-phenanthrolin-5-yl group, 2,8-phenanthrolin-6-yl group, 2,8-phenanthrolin-7-yl group, 2,8-phenanthroline-9-yl group, 2,8-phenanthrolin-10-yl group, 2,7-phenanthrolin-1-yl group, 2,7-phenanthrolin-3-yl Group, 2,7-phenanthrolin-4-yl group, 2,7-phenanthroline- -Yl group, 2,7-phenanthroline-6-yl group, 2,7-phenanthrolin-8-yl group, 2,7-phenanthrolin-9-yl group, 2,7-phenanthroline -10-yl group, 1-phenazinyl group, 2-phenazinyl group, 1-phenothiazinyl group, 2-phenothiazinyl group, 3-phenothiazinyl group, 4-phenothiazinyl group, 10-phenothiazinyl group, 1-phenoxazinyl group 2-phenoxazinyl group, 3-phenoxazinyl group, 4-phenoxazinyl group, 10-phenoxazinyl group, 2-oxazolyl group, 4-oxazolyl group, 5-oxazolyl group, 2-oxadiazolyl group, 5-oxadiazolyl group, 3-flazanyl group 2-thienyl group, 3-thienyl group, 2-methylpyrrol-1-yl group, 2-methylpyrrol-3-yl Group, 2-methylpyrrol-4-yl group, 2-methylpyrrol-5-yl group, 3-methylpyrrol-1-yl group, 3-methylpyrrol-2-yl group, 3-methylpyrrol-4-yl Group, 3-methylpyrrol-5-yl group, 2-t-butylpyrrol-4-yl group, 3- (2-phenylpropyl) pyrrol-1-yl group, 2-methyl-1-indolyl group, 4- Methyl-1-indolyl group, 2-methyl-3-indolyl group, 4-methyl-3-indolyl group, 2-t-butyl 1-indolyl group, 4-t-butyl 1-indolyl group, 2-t-butyl 3-indolyl group, 4-t-butyl 3-indolyl group and the like can be mentioned.

  Specific examples of the amine compound represented by the formula (20) are condensed aromatic amine, styrylamine, benzidine and the like, but are not limited thereto. Me represents a methyl group.

  Moreover, the compound containing the following carbazole groups may be sufficient.

  Moreover, the fluorescent substance dopant may be a fluoranthene derivative represented by any of the following formulas (41) to (44).

In formulas (41) to (44), X ^{1 to} X ⁵² are each independently a hydrogen atom, a halogen atom, a substituted or unsubstituted linear, branched or cyclic alkyl group having 1 to 30 carbon atoms, a substituted group Or an unsubstituted straight chain, branched or cyclic alkoxy group having 1 to 30 carbon atoms, a substituted or unsubstituted straight chain, branched or cyclic alkylthio group having 1 to 30 carbon atoms, a substituted or unsubstituted straight chain Branched or cyclic alkenyl groups having 2 to 30 carbon atoms, substituted or unsubstituted straight chain, branched or cyclic alkenyloxy groups having 2 to 30 carbon atoms, substituted or unsubstituted straight chain, branched or cyclic An alkenylthio group having 2 to 30 carbon atoms, a substituted or unsubstituted aralkyl group having 7 to 30 carbon atoms, a substituted or unsubstituted aralkyl group having 7 to 30 carbon atoms A ruoxy group, a substituted or unsubstituted aralkylthio group having 7 to 30 carbon atoms, a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 20 carbon atoms, A substituted or unsubstituted arylthio group having 6 to 20 carbon atoms, a substituted or unsubstituted amino group having 2 to 30 carbon atoms, a cyano group, a silyl group, a hydroxyl group, a —COOR ^1e group (wherein R ^1e is a hydrogen atom) Atom, substituted or unsubstituted linear, branched or cyclic alkyl group having 1 to 30 carbon atoms, substituted or unsubstituted linear, branched or cyclic alkenyl group having 2 to 30 carbon atoms, substituted or unsubstituted an aralkyl group having 7 to 30 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 30 carbon atoms), and - in ^{COR 2e} group ^{(group, R 2e} is Elementary atom, substituted or unsubstituted linear, branched or cyclic alkyl group having 1 to 30 carbon atoms, substituted or unsubstituted linear, branched or cyclic alkenyl group having 2 to 30 carbon atoms, substituted or unsubstituted Represents a substituted aralkyl group having 7 to 30 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or an amino group, and a -OCOR ^3e group (wherein R ^3e is substituted or unsubstituted) A linear, branched or cyclic alkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted linear, branched or cyclic alkenyl group having 2 to 30 carbon atoms, a substituted or unsubstituted carbon atom having 7 to 7 carbon atoms 30 represents an aralkyl group, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms), and among X ^{1 to} X ⁵² , an adjacent group and a substituent of each group are To form a substituted or unsubstituted carbocycle.

  As such a fluoranthene derivative, the following are mentioned, for example.

  Further, the fluorescent light-emitting dopant may be a boron compound represented by the following formula (45).

Wherein A and A ′ represent an independent azine ring system corresponding to a 6-membered aromatic ring containing one or more nitrogen, wherein Xa and ^Xb are each independently selected substituents, The two can combine to form a fused ring for A or A ′, m and n each independently represent 0 to 4 and Z ^a and Z ^b are each independently selected; And 1, 2, 3, 4, 1 ′, 2 ′, 3 ′ and 4 ′ are independently selected as either a carbon atom or a nitrogen atom. In the azine ring, 1, 2, 3, 4, 1 ′, 2 ′, 3 ′ and 4 ′ are all carbon atoms, m and n are 2 or more, and X ^a and X ^b are aromatic It is preferably a quinolinyl or isoquinolinyl ring that represents two or more carbon substituents that are joined to form a ring. Z ^a and Z ^b are preferably fluorine atoms.

In a preferred embodiment, the two fused ring systems are quinoline or isoquinoline systems, the aryl or heteroaryl substituent is a phenyl group, two X ^a groups and two bonded to form a 6-6 fused ring At least X ^b groups are present, and the fused ring system is fused at the 1-2, 3-4, 1'-2 'or 3'-4' position, respectively, and one or both of the fused rings are phenyl Further included are boron compounds represented by the following formulas 14, 15 or 16 substituted with groups.

In the above formulas (46) to (48), X ^c , X ^d , X ^e , X ^f , X ^g and X ^h are hydrogen or an independently selected substituent, one of which is an aryl group or Must be a heteroaryl group.

In the azine ring, 1, 2, 3, 4, 1 ′, 2 ′, 3 ′ and 4 ′ are all carbon atoms, m and n are 2 or more, and X ^a and X ^b are aromatic rings Preferably it is a quinolinyl ring or an isoquinolinyl ring, which represents two or more carbon substituents that are bonded to form, and one is an aryl or substituted aryl group. Z ^a and Z ^b are preferably fluorine atoms.

  A boron compound complexed with two ring nitrogens of a deprotonated bis (azinyl) amine ligand, the two ring nitrogens being different 6,6 condensed ring systems, at least one of which is Illustrate boron compounds that are members of those containing aryl or heteroaryl substituents.

In addition, the host material of the light emitting layer 14 of this embodiment and the second host material of the second light emitting layer may be the same or different.
And when dividing a light emitting layer into plurality, each dopant may contain one dopant and a plurality of dopants may be contained. As an example in which a plurality of dopants are provided, various combinations such as a blue dopant / green dopant, a red dopant / blue dopant, and a green dopant / red dopant can be considered.

Moreover, although the light emitting layer 14 showed the structure containing a host material and a phosphorescent dopant in this embodiment, it is not restricted to this.
For example, the light emitting layer 14 may further contain a fluorescent light emitting dopant.
That is, two or more dopants are contained in one light emitting layer 14. The light emitting layer 14 may be doped with one or more phosphorescent dopants and one or more fluorescent dopants. When a fluorescent luminescent dopant is doped, when the fluorescent luminescent dopant is blue, the whole is white.

Here, a configuration for obtaining white light emission with high efficiency using a phosphorescent light emitting layer containing a phosphorescent dopant and a fluorescent light emitting layer containing a fluorescent light emitting dopant will be described.
In order to prevent charges from being trapped by the phosphorescent layer and reducing the amount of charge injected into the fluorescent layer, the phosphorescent dopant is preferably 10% or less by mass with respect to the phosphorescent host. More preferably, it is 5% or less. Even when a plurality of phosphorescent dopants are present in the same layer, the doping concentration is preferably 10% or less, preferably 5% or less as a whole.

When the phosphorescent light emitting layer is disposed on the anode side with respect to the fluorescent light emitting layer, it is preferable that the hole mobility of the phosphorescent host material is large. Thereby, it is possible to easily inject holes into the fluorescent light emitting layer which is an exciton generation layer through the phosphorescent light emitting layer, and to increase the probability of charge recombination. In this case, the hole mobility of the phosphorescent host material is preferably 1 × 10 ⁻⁵ cm ² / Vs or more in an electric field of 1.0 × 10 ^{4 to} 1.0 × 10 ⁶ V / cm. Furthermore, it is preferably 10 ⁻⁴ cm ² / Vs or more, and more preferably 10 ⁻³ cm ² / Vs or more.
When the phosphorescent light emitting layer is disposed on the cathode side with respect to the fluorescent light emitting layer, it is preferable that the electron mobility of the phosphorescent host material is large. Thus, electrons can be easily injected into the fluorescent light emitting layer that is the exciton generation layer through the phosphorescent light emitting layer, and the recombination probability of charges can be increased. In this case, the electron mobility of the phosphorescent host material is preferably 1 × 10 ⁻⁵ cm ² / Vs or more in an electric field of 1.0 × 10 ^{4 to} 1.0 × 10 ⁶ V / cm. Furthermore, it is preferably 10 ⁻⁴ cm ² / Vs or more, and more preferably 10 ⁻³ cm ² / Vs or more.

When a fluorescent light emitting layer and a phosphorescent light emitting layer are provided, and both the fluorescent light emitting layer and the phosphorescent light emitting layer emit light with charge recombination energy by charge injection, the thickness of the fluorescent light emitting layer is larger than that of the phosphorescent light emitting layer. Thickness is preferred.
Since fluorescence emission is inferior in quantum efficiency compared to phosphorescence emission, it is preferable to make the fluorescence emission layer thicker and the phosphorescence emission layer thinner in order to balance the overall chromaticity.
On the other hand, in the case where the phosphorescent light emitting layer and the phosphorescent light emitting layer are provided, and the exciton energy (triplet exciton energy) generated in the fluorescent light emitting layer is transferred to the phosphorescent light emitting layer to cause the phosphorescent light emitting layer to emit light. It is preferable to make the phosphorescent light emitting layer thicker by making the fluorescent light emitting layer thinner.
This is because the fluorescent light-emitting layer is preferably thin in order to move triplet excitons generated by the host of the fluorescent light-emitting layer to the phosphorescent light-emitting layer, while the phosphorescent light-emitting layer diffuses from the fluorescent light-emitting layer. This is because it is preferable to have a thickness because it is necessary to receive triplet energy. Further, by reducing the thickness of the fluorescent light emitting layer, the charge recombination probability in the fluorescent light emitting layer can be increased.
At this time, in order to further increase the exciton generation probability in the fluorescent light emitting layer, an intermediate layer for confining carriers in the fluorescent light emitting layer may be disposed adjacent to the fluorescent light emitting layer.
When the intermediate layer is disposed on the anode side with respect to the fluorescent light emitting layer, it is preferable that the affinity level of the intermediate layer is small because the intermediate layer functions as an electron blocking layer. It is preferably less than 7 eV, more preferably less than 2.5 eV.

Further, when the intermediate layer is disposed on the anode side with respect to the fluorescent light emitting layer, it is preferable from the viewpoint of carrier (hole) injection into the fluorescent light emitting layer that the intermediate layer does not become a hole trap. It is preferable that the hole mobility of the layer is large. As a result, it is possible to easily inject holes into the fluorescent light-emitting layer that is the exciton generation layer through the intermediate layer, and the charge recombination probability can be increased. In this case, the hole mobility of the intermediate layer is preferably 1 × 10 ⁻⁵ cm ² / Vs or more in an electric field of 1.0 × 10 ^{4 to} 1.0 × 10 ⁶ V / cm. Furthermore, it is preferably 10 ⁻⁴ cm ² / Vs or more, and more preferably 10 ⁻³ cm ² / Vs or more.
Similarly, when the intermediate layer is disposed on the cathode side with respect to the fluorescent light emitting layer, it is preferable that the intermediate layer has a high ionization potential in order to function as a hole blocking layer. It is preferably greater than .6 eV, more preferably greater than 5.8 eV.

Furthermore, when the intermediate layer is disposed on the cathode side with respect to the fluorescent light emitting layer, it is preferable from the viewpoint of carrier (electron) injection into the fluorescent light emitting layer that the intermediate layer does not become an electron trap. The electron mobility is preferably large. As a result, it is possible to easily inject electrons into the fluorescent light-emitting layer that is the exciton generation layer through the intermediate layer, and to increase the probability of charge recombination. In this case, the electron mobility of the intermediate layer is preferably 1 × 10 ⁻⁵ cm ² / Vs or more in an electric field of 1.0 × 10 ^{4 to} 1.0 × 10 ⁶ V / cm. Furthermore, it is preferably 10 ⁻⁴ cm ² / Vs or more, and more preferably 10 ⁻³ cm ² / Vs or more.
In addition, when the phosphorescent dopant and the fluorescent dopant are contained in the same light emitting layer, it is preferable to inject charges into this light emitting layer to promote exciton generation. Can do. Then, since the amount of the luminescent dopant can be increased, the load applied to one molecule of the luminescent dopant is reduced, and as a result, a light-emitting element with high luminance and a long lifetime can be obtained.

  In addition, specific materials and treatments in the implementation of the present invention may be other materials and treatments as long as the object of the present invention can be achieved.

  The present invention will be described in more detail with reference to examples and comparative examples. In addition, this invention is not restrict | limited to the description content of these Examples at all.

[Example 1]
In Example 1, the organic EL device includes anode / hole injection layer / light emitting layer / electron transport layer / electron injection layer / cathode in this order.
Specifically, a glass substrate with a transparent electrode of 25 mm × 75 mm × 1.1 mm (manufactured by Geomatic) was subjected to ultrasonic cleaning for 5 minutes in isopropyl alcohol, and further subjected to UV ozone cleaning for 30 minutes. did.
The glass substrate with the transparent electrode thus washed is attached to the substrate holder of the vacuum evaporation apparatus, and first, on the surface of the glass substrate on which the transparent electrode line is formed, the transparent electrode is covered, NPD was vapor-deposited with a thickness of 600 nm to obtain a hole injection layer.
On this hole transport layer, 2a-1 which is a host for red phosphorescence and PtTPP which is a dopant for red phosphorescence and represented by Chemical Formula 25 were co-evaporated at a thickness of 250 nm to obtain a light emitting layer. The concentration of PtTPP was 4% by mass.

Next, Alq was vapor-deposited with a thickness of 350 nm on this red phosphorescent light emitting layer to obtain an electron transport layer.
On this electron transport layer, 1 nm thick LiF and 100 nm thick metal Al were sequentially laminated to obtain a cathode.
The deposition rates of anode / hole injection layer / light emitting layer / electron injection layer / cathode are 1 / 1.04 / 1/1/5, respectively.

[Example 2 to Example 13]
In Examples 2 to 13, organic EL elements were produced in the same manner as in Example 1 except that the host shown in Table 1 was used.
Note that TPPy in Example 9 is an abbreviation for tetraphenylpyrene.

[Comparative Example 1 to Comparative Example 4]
In Comparative Examples 1 to 4, organic EL elements were produced in the same manner as in Example 1 except that the host shown in Table 1 was used. The structure of TDbN used in Comparative Example 4 is shown below.

[Example 14 to Example 26]
In Examples 14 to 26, organic EL elements were prepared in the same manner as in Examples 1 to 13, except that PtTaNP shown in Chemical formula 28 was used as the dopant and that shown in Table 2 was used as the host. Produced.

[Example 27 to Example 39]
In Examples 27 to 39, organic EL elements were produced in the same manner as in Examples 1 to 13, except that PtTNP shown in Chemical formula 28 was used as the dopant and that shown in Table 3 was used as the host. did.
PtTNP has a triplet energy gap of 1.77 eV and an emission wavelength of 700 nm.

[Example 40 to Example 52]
In Example 40 to Example 52, Niq2Ir (acac). Organic EL devices were prepared in the same manner as in Examples 1 to 13 except that (Please tell us the compound name) and the host shown in Table 4 was used.

[Example 53 to Example 65]
In Examples 53 to 65, organic EL elements were produced in the same manner as in Examples 1 to 13, except that PtOEt shown in Chemical formula 28 was used as the dopant and that shown in Table 5 was used as the host. did.

[Example 66 to Example 78]
In Examples 66 to 78, organic EL elements were produced in the same manner as in Examples 1 to 13, except that PtTPBP shown in Chemical formula 28 was used as the dopant and that shown in Table 6 was used as the host. did.

[Example 79 to Example 82]
Examples 79 to 82 are the same as Examples 1, 7, 9, and 12 except that Ir (PQ) 2acac shown in Chemical formula 28 is used as the dopant and that shown in Table 7 is used as the host. Thus, an organic EL element was produced.
Ir (PQ) 2acac has a triplet energy gap of 2.08 eV and an emission wavelength of 595 nm.

[Example 83]
In Example 83, an organic EL device was produced in the same manner as in Example 1 except that a hole blocking layer was provided between the light emitting layer and the electron injection layer.
Specifically, the organic EL device of Example 83 includes an anode / hole injection layer / light emitting layer / hole blocking layer / electron transport layer / electron injection layer / cathode in this order.
The composition of the anode / hole injection layer / light emitting layer / hole blocking layer / electron transport layer / electron injection layer / cathode is 2a-1 / 2 as a host containing 4% by mass of ITO / NPD / PtTPP as a dopant. , 9-dimethyl-4,7-diphenyl-1,10-phenanthroline (hereinafter abbreviated as “BCP”) / Alq / LiF / Al. The film thicknesses are 600 mm / 250 mm / 100 mm / 250 mm / 1 mm / 100 mm, respectively. The vapor deposition rates are 1 / 1.04 / 1/1/1/5, respectively.

[Example 84]
In Example 84, an organic EL device was produced in the same manner as in Example 1 except that the electron transporting light emitting layer was replaced with a hole blocking layer.
Specifically, the organic EL device of Example 84 includes an anode / a hole injection layer / a light emitting layer / a hole blocking layer / an electron injection layer / a cathode in this order.
The composition of the anode / hole injection layer / light emitting layer / hole blocking layer / electron injection layer / cathode is 2a-1 / Balq / LiF / Al as a host containing 4% by mass of ITO / NPD / PtTPP as a dopant. It is. The film thicknesses are 600 mm / 250 mm / 350 mm / 1 mm / 100 mm, respectively. The deposition rate is 1 / 1.04 / 1/1/5, respectively.

[Example 85]
In Example 85, an organic EL device was produced in the same manner as in Example 84 except that an electron blocking layer was provided between the hole injection layer and the light emitting layer.
Specifically, the organic EL device of Example 84 includes anode / hole injection layer / electron blocking layer / light emitting layer / hole blocking layer / electron injection layer / cathode in this order.
The composition of the anode / hole injection layer / electron blocking layer / light emitting layer / hole blocking layer / electron injection layer / cathode was ITO / NPD / fac-tris- (1-phenylpyrazolate, N, C2 ′) iridium ( III) (Irppz) / 2a-1 / Balq / LiF / Al as a host containing 4 mass% of 26PtTPP as a dopant. The film thicknesses are 550 mm / 50 mm / 250 mm / 350 mm / 10 mm / 1500 mm, respectively. The deposition rates are 1/1 / 1.04 / 1/1/5, respectively.

[Example 86]
In Example 86, an organic EL device was produced in the same manner as in Example 1 except that the electron transport layer was not provided, a plurality of dopants were used for the light emitting layer, and the compound J shown in Table 9 was used for the electron injection layer. did.
The light emitting layer contains 2a′-59 as a host material shown in Table 9, a blue dopant shown in Table 9, and a red dopant shown in Table 9. Blue dopant and red dopant are 2% and 0.1%, respectively, by mass ratio with respect to 2a′-59.
The film thicknesses of anode / hole injection layer / light emitting layer / electron injection layer / cathode are 550 mm / 400 mm / 200 mm / 10 mm / 1500 mm, respectively. The deposition rates are 1/1 / 1.02 / 1/3, respectively.

[Example 87]
In Example 87, an organic EL device was produced in the same manner as in Example 86 except that the blue dopant B shown in Table 8 was used instead of the blue dopant and red dopant of Example 86.
Blue dopant B is contained in a mass ratio of 2% with respect to 2a′-59.
The thicknesses of the anode / hole injection layer / light emitting layer / electron injection layer / cathode are 550 mm / 400 mm / 200 mm / 10 mm / 1500 mm, respectively. The deposition rates are 1/1 / 1.03 / 1/3, respectively.

[Example 88]
In Example 88, an organic EL element was produced in the same manner as in Example 86, except that a plurality of light emitting layers were provided between the hole injection layer and the electron injection layer.
The organic EL element includes a hole injection layer / first light emitting layer / second light emitting layer / electron injection layer in this order. The first light emitting layer contains 2a′-59 as a host material and a blue dopant shown in Table 9. The blue dopant is 2% by mass with respect to 2a′-59.
The second light emitting layer contains 2a′-59 as a host material and a red dopant shown in Table 9. The red dopant is 2% by mass with respect to 2a′-59.
The thicknesses of the anode / hole injection layer / first light emitting layer / second light emitting layer / electron injection layer / cathode are 550 mm / 100 mm / 300 mm / 200 mm / 10 mm / 1500 mm, respectively.

[Example 89]
In Example 89, an organic EL device was manufactured in the same manner as in Example 88 except that a blue dopant was used instead of the red dopant in the second light emitting layer of Example 88, and Alq3 was used instead of compound J in the electron transport layer. Produced.
In the second light emitting layer, the blue dopant is 2% by mass with respect to 2a′-59.
The thicknesses of the anode / hole injection layer / first light emitting layer / second light emitting layer / electron injection layer / cathode are 550 mm / 100 mm / 300 mm / 200 mm / 10 mm / 1500 mm, respectively.

[Example 90]
In Example 90, an organic EL element was produced in the same manner as in Example 86, except that a plurality of light emitting layers were provided between the hole injection layer and the electron injection layer in Example 86.
The organic EL element includes an anode / a hole injection layer / a first light emitting layer / an intermediate layer as a second light emitting layer / a third light emitting layer / an electron transport layer in this order. The first light emitting layer contains 2a′-59 as a host material and a blue dopant shown in Table 9. The blue dopant is 2% by mass with respect to 2a′-59. The intermediate layer contains 2a′-59. The third light emitting layer contains 2a′-59 as a host material and a red dopant shown in Table 9. The red dopant is 1% by mass with respect to 2a′-59.
The thicknesses of the anode / hole injection layer / first light emitting layer / intermediate layer / third light emitting layer / electron injection layer / cathode are 550 mm / 100 mm / 50 mm / 300 mm / 200 mm / 10 mm / 1500 mm.

[Example 91]
In Example 91, red dopant is used in place of the blue dopant in the first light emitting layer of Example 90, 2b-9 and blue dopant are used in place of 2a′-59 in the intermediate layer, and 2a in the third light emitting layer is used. An organic EL device was produced in the same manner as in Example 90 except that 2b-9 and a green dopant were used in place of '-59 and the red dopant.
In the first light emitting layer, the red dopant is 1% by mass with respect to 2a′-59. In the intermediate layer, the blue dopant is 2% by mass with respect to 2b-9. In the third light emitting layer, the green dopant is 3% by mass with respect to 2b-9.
The thicknesses of the anode / hole injection layer / first light emitting layer / intermediate layer / third light emitting layer / electron injection layer / cathode are 550/50 mm / 100 mm / 100 mm / 200 mm / 10 mm / 1500 mm.

[Example 92]
In Example 92, a red dopant was used instead of the blue dopant in the first light emitting layer of Example 88, and 2a′-59 and 2b-9 instead of the red dopant in the second light emitting layer were combined with the blue dopant and the green dopant. An organic EL device was produced in the same manner as in Example 88 except that it was used.
In the first light emitting layer, the red dopant is 1% by mass with respect to 2a′-59. In the second light emitting layer, the blue dopant and the green dopant are 2% and 0.5%, respectively, by mass ratio with respect to 2a′-59.
The thicknesses of the anode / hole injection layer / first light emitting layer / second light emitting layer / electron injection layer / cathode are 550/50 mm / 100 mm / 200 mm / 10 mm / 1500 mm, respectively.

[Example 93]
In Example 93, an organic EL element was produced in the same manner as in Example 86 except that a green dopant was further used in the light emitting layer of Example 86.
In a light emitting layer, a blue dopant, a green dopant, and a red dopant are 2%, 0.5%, and 0.1% by mass ratio with respect to 2a'-59, respectively.
The thicknesses of the anode / hole injection layer / light emitting layer / electron injection layer / cathode are 550 mm / 400 mm / 200 mm / 10 mm / 1500 mm, respectively.

[Example 94]
In Example 94, a red dopant was further used for the first light-emitting layer of Example 88, CBP and green dopant B were used in place of 2a′-59 and the red dopant in the second light-emitting layer, and the second light-emitting layer and the electrons were used. An organic EL device was produced in the same manner as in Example 88 except that Compound I was used as an electron transport layer between the injection layer and the injection layer.
In the first light emitting layer, the blue dopant and the red dopant are 2% and 0.1%, respectively, by mass ratio with respect to 2a′-59. In the second light emitting layer, the green dopant B is 5% by mass with respect to CBP.
The thicknesses of anode / hole injection layer / first light emitting layer / second light emitting layer / electron transport layer / electron injection layer / cathode are 550 mm / 300 mm / 100 mm / 200 mm / 100 mm / 10 mm / 1500 mm, respectively.

[Example 95]
In Example 95, a blue dopant is further used in the second light emitting layer of Example 90, CBP and green dopant B are used in place of 2a′-59 and the green dopant in the third light emitting layer, and the third light emitting layer An organic EL device was produced in the same manner as in Example 90 except that Compound I was used as an electron transport layer between the electron injection layer and the electron injection layer.
In the first light emitting layer, the red dopant is 1% by mass with respect to 2a′-59. In the second light emitting layer, the blue dopant is 2% by mass with respect to 2a′-59. In the third light emitting layer, the green dopant B is 5% by mass with respect to CBP.
Regarding the film thickness, the anode / hole injection layer / first emission layer / second emission layer / third emission layer / electron transport layer / electron injection layer / cathode are 550 mm / 50 mm / 100 mm / 100 mm / 200 mm / 100 mm, respectively. / 10cm / 1500mm.

[Example 96]
In Example 96, an organic EL element was produced in the same manner as in Example 95, except that 2b-9 was used instead of 2a′-59 in the second light emitting layer of Example 95.
In the first light emitting layer, the red dopant is 1% by mass with respect to 2a′-59. In the second light emitting layer, the blue dopant is 2% by mass with respect to 2b-9. In the third light emitting layer, the green dopant is 5% by mass with respect to CBP.
Regarding the film thickness, the anode / hole injection layer / first emission layer / second emission layer / third emission layer / electron transport layer / electron injection layer / cathode are 550 mm / 50 mm / 100 mm / 100 mm / 200 mm / 100 mm, respectively. / 10cm / 1500mm.

[Example 97]
Example 97 uses red dopant instead of blue dopant in the first light-emitting layer of Example 88, and 4a'-bis (9-carbazolyl) instead of 2a′-59 and red dopant in the second light-emitting layer. -2,2'-dimethyl-biphenyl (hereinafter abbreviated as "CDBP") and bis {2- [3,5-bis (trifluoromethyl) phenyl] -pyridinate-N, C2 '} iridium (III) picolinate Example 89 except that [(CF3ppy) 2Ir (pic)] (hereinafter abbreviated as “FIrpic”) was used and Compound I was used as an electron transport layer between the second light-emitting layer and the electron injection layer. Similarly, an organic EL device was produced.
In the second light emitting layer, CDBP is 8% by mass with respect to FIrpic.
The thickness of the anode / hole injection layer / first light emitting layer / second light emitting layer / electron transporting layer / electron injection layer / cathode is 550 mm / 100 mm / 300 mm / 200 mm / 100 mm / 10 mm / 1500 mm. .

[Example 98]
In Example 98, CBP and green dopant B were used instead of 2a′-59 and blue dopant in the second light emitting layer of Example 95, and CDBP and FIrpic were used instead of CBP and green dopant in the third light emitting layer. Except for the above, an organic EL device was produced in the same manner as in Example 95.
In the second light emitting layer, the green dopant B is 5% by mass with respect to CBP. In the third light emitting layer, FIrpic is 8% by mass with respect to CDBP.
As for film thickness, anode / hole injection layer / first light emitting layer / second light emitting layer / third light emitting layer / electron transport layer / electron injection layer / cathode are 550Å / 100Å / 50Å / 300Å / 200Å / 100 respectively. / 10cm / 1500mm.

[Evaluation of organic EL elements]
Each of the organic EL devices fabricated in Examples 1 to 85 and Comparative Examples 1 to 4 was caused to emit light by a direct current of 1 mA / cm ² , and an applied voltage (V) and chromaticity (CIE) (x , Y), external quantum efficiency (%), and half-life (L50 @ 1000 mit) were measured. The results are shown in Tables 1 to 7 and Table 9.
Moreover, each organic EL element produced in Examples 86 to 98 was made to emit light by a direct current of 1 mA / cm ² , and the external quantum efficiency (%) and the half life (L50 @ 1000 mit) were measured. The results are shown in Table 10.

As can be seen from Table 1, in Example 1 and Example 2, the organic EL device provided with the symmetric anthracene derivative was more than the case where Balq, Alq, CBP, and TDbN were provided in Comparative Example 1 to Comparative Example 4. Low voltage, good external quantum efficiency and long half-life.
Further, in Examples 3 to 5 using the bisanthracene derivative, the half-life was longer than that in Examples 1 and 2.
In Examples 6 to 8 using the asymmetric anthracene derivative, the external quantum efficiency was improved and the half life was longer than those in Examples 1 and 2.
Furthermore, in Examples 9 to 11 using a pyrene derivative, the external quantum efficiency was improved and the half-life was longer than those in Examples 1 and 2.
Moreover, in Example 12 and Example 13 using a benzanthracene derivative, the external quantum efficiency was further improved and the half-life was further increased as compared with Examples 1 and 2.
In Examples 1 to 13, PtTPP has a triplet energy gap of 1.85 eV, an emission wavelength of 670 nm, and chromaticity coordinates (CIE color system) (x, y) = It exhibited red light emission of (0.718, 0.283).
In Comparative Example 4, the chromaticity coordinates are (x, y) = (0.580, 0.440) and are not PtTPP light emission.

In Example 14 to Example 26, as shown in Table 2, even when PtTaNP was used as the phosphorescent dopant, good external quantum efficiency and long lifetime were exhibited.
In the case of Examples 14 to 26, PtTaNP has a triplet energy gap of 1.82 eV, an emission wavelength of 680 nm, and chromaticity coordinates (x, y) = (0.723, 0.277). A red luminescence was exhibited.
As shown in Table 3, particularly in Examples 32 to 34, even when PtTNP was used as the phosphorescent dopant, good external quantum efficiency and long lifetime were exhibited.
In Examples 27 to 39, PtTNP has a triplet energy gap of 1.77 eV, an emission wavelength of 700 nm, and chromaticity coordinates (x, y) = (0.728, 0.272). A red light was emitted.
Furthermore, as shown in Table 4, in Example 49 to Example 52, Niq2Ir (acac). Even when was used, good external quantum efficiency and long lifetime were exhibited.
In the case of Examples 40 to 52, Niq2Ir (acac). Had a triplet energy gap of 1.91 eV, an emission wavelength of 650 nm, and red emission of chromaticity coordinates (x, y) = (0.6835, 0.3155).

Further, as shown in Table 5, in Examples 53 to 65, even when PtOEt was used as the phosphorescent dopant, the lifetime was long.
In Examples 53 to 65, PtOEt has a triplet energy gap of 1.91 eV, an emission wavelength of 650 nm, and chromaticity coordinates (x, y) = (0.6735, 0.3055). A red light was emitted.
As shown in Tables 6 and 7, in Examples 66 to 82, when PtTPBP and Ir (PQ) 2acac were used as the phosphorescent dopant, good external quantum efficiency was not obtained and the lifetime was short. It was.
In Examples 66 to 78, PtTPBP had a triplet energy gap of 1.61 eV and an emission wavelength of 770 nm.
In Examples 79 to 82, Ir (PQ) 2acac had a triplet energy gap of 2.08 eV and an emission wavelength of 595 nm.

As shown in Table 8, in Example 83, by providing a hole blocking layer having BCP between the light emitting layer and the electron transporting layer, good external quantum efficiency was obtained, and the lifetime was also extended. .
Further, in Example 84, by providing an electron transport layer having Balq instead of Alq, good external quantum efficiency was obtained and the lifetime was extended.
In Example 85, an electron blocking layer having Irppz was provided between the hole injection layer and the light emitting layer, and an electron transport layer having Balq was provided between the light emitting layer and the electron injection layer. As a result, the external quantum efficiency was improved and the lifetime was extended.

When anthracene derivatives and pyrene derivatives are used as hosts for phosphorescent dopants, it has been found that the external quantum efficiency is improved and the lifetime is increased as compared with CBP and the like.
Further, it was found that the external quantum efficiency is further improved in the configuration including the hole blocking layer and the electron blocking layer.

In Example 86, as compared with Example 7, the organic EL device may further have a half-life by including a blue dopant in the light emitting layer and using Compound J instead of Alq in the electron transport layer. I understood.
In Example 87, it was found that 2a′-59 can be combined with blue dopant B, and the half-life of the organic EL device is further increased.
In Example 88, it was found that by providing a plurality of light emitting layers, the external quantum efficiency of the organic EL element was improved and the half-life was further increased.

In Example 89, compared with Example 88, the constituent material of the first light emitting layer of Example 89 is the same as the constituent material of the second light emitting layer of Example 88, and the configuration of the second light emitting layer of Example 89 is the same. The material is the same as the constituent material of the first light emitting layer of Example 88. That is, in Example 89 and Example 88, the order of the first light emitting layer and the second light emitting layer is reversed. Also, the electron transport layer is different.
As a result, in Example 89, it was found that the external quantum efficiency was lower than that in Example 88, but the half-life was increased.

  Example 90 includes a first light-emitting layer, a second light-emitting layer, and a third light-emitting layer. Compared to Example 88, the first light-emitting layer of Example 88 and the second light-emitting layer are interposed between them. The light emitting layer provided with 2a′-59 is provided. It was found that even with such a difference in configuration, the external quantum efficiency and the half-life are hardly different.

In Example 91, three light emitting layers are provided, and it can be seen that the external quantum efficiency is significantly improved as compared with the case where one light emitting layer is provided or two light emitting layers are provided. It was.
In Example 92, compared with Example 89, the external light emission efficiency was improved by further containing a green dopant in the second light emitting layer and using compound J in place of Alq3 in the electron transport layer.

In Example 93, as compared with Example 86, the half-life was increased by further containing a green dopant in the light emitting layer.
In Example 94, as compared with Example 86, the external quantum efficiency was greatly improved by further including a light-emitting layer containing CBP and green dopant B and an electron transport layer containing Compound I.
In Example 95, as compared with Example 89, the compound J was used in place of Alq3 in the electron transport layer, and a light emitting layer containing CBP and green dopant B and an electron transport layer containing compound I were further provided. The external quantum efficiency has been greatly improved.
In Example 96, compared with Example 95, even if the host material of the second light-emitting layer was different between 2a′-59 and 2b-9, there was no significant difference in external quantum efficiency and half life.

In Example 97, compared with Example 1, the external quantum efficiency was significantly improved by further including a light emitting layer having CDBP and FIrpic and an electron transporting layer containing Compound I.
In Example 98, as compared with Example 97, a half-life is increased by further providing a light-emitting layer having CBP and green dopant B between the first light-emitting layer and the second light-emitting layer of Example 97. I understood that.

It has been found that the organic EL device having a light emitting layer having a plurality of dopants has a longer half-life than that of a light emitting layer having one dopant.
Moreover, it turned out that the external quantum efficiency improves significantly in the organic EL element provided with two or more light emitting layers compared with the case where a light emitting layer consists of one.

The present invention can be used, for example, as an organic EL element used in a thin display device.

It is a figure which shows the structure of the organic EL element of this embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Organic EL element 12 ... Anode 14 ... Light emitting layer 17 ... Cathode

Claims (9)

A host material comprising a phosphorescent material in combination with a phosphorescent dopant,
Having a substituted or unsubstituted polycyclic fused aromatic skeleton that is not coordinated to the metal complex, the number of nuclear atoms of the polycyclic fused aromatic skeleton is 14 to 30;
The lowest excited triplet energy gap of the host material is 1.71 eV or more and 2.09 eV or less,
A host material characterized by that. The host material according to claim 1, wherein the host material is an anthracene derivative represented by the following formula (1) or a pyrene derivative represented by the following formula (2).

(In the formula (1), Ar ¹ and Ar ² are each independently a group derived from a substituted or unsubstituted aromatic ring having 6 to 20 nuclear carbon atoms. The aromatic ring is 1 or 2 The substituent may be substituted with the above-mentioned substituents: substituted or unsubstituted aryl group having 6 to 50 nuclear carbon atoms, substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, substituted or unsubstituted A cycloalkyl group having 3 to 50 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 50 carbon atoms, a substituted or unsubstituted aralkyl group having 6 to 50 nuclear carbon atoms, a substituted or unsubstituted nuclear atom number of 5 50 aryloxy groups, substituted or unsubstituted arylthio groups having 5 to 50 nucleus atoms, substituted or unsubstituted alkoxycarbonyl groups having 1 to 50 carbon atoms, substituted or unsubstituted silyl groups Selected from a group, a carboxyl group, a halogen atom, a cyano group, a nitro group and a hydroxy group, and when the aromatic ring is substituted with two or more substituents, the substituents may be the same or different. Alternatively, adjacent substituents may be bonded to each other to form a saturated or unsaturated cyclic structure.
R ¹ to R ⁸ are each a hydrogen atom, a substituted or unsubstituted aryl group having 6 to 50 nuclear carbon atoms, a substituted or unsubstituted heteroaryl group having 5 to 50 nuclear atoms, a substituted or unsubstituted carbon atom having 1 to 50 alkyl groups, substituted or unsubstituted cycloalkyl groups having 3 to 50 carbon atoms, substituted or unsubstituted alkoxy groups having 1 to 50 carbon atoms, substituted or unsubstituted aralkyl groups having 6 to 50 carbon atoms, substituted or Unsubstituted aryloxy group having 5 to 50 nucleus atoms, substituted or unsubstituted arylthio group having 5 to 50 nucleus atoms, substituted or unsubstituted alkoxycarbonyl group having 1 to 50 carbon atoms, substituted or unsubstituted silyl group Group, carboxyl group, halogen atom, cyano group, nitro group and hydroxy group. Further, adjacent substituents may be bonded to each other to form a saturated or unsaturated cyclic structure. )

(In Formula (2), Ar ^1a and Ar ^2a are each a substituted or unsubstituted aromatic ring group having 6 to 50 nuclear carbon atoms.
L is a substituted or unsubstituted phenylene group, a substituted or unsubstituted naphthalenylene group, a substituted or unsubstituted fluorenylene group, or a substituted or unsubstituted dibenzosilolylene group, respectively.
m is an integer from 0 to 2, nb is an integer from 1 to 4, s is an integer from 0 to 2, and t is an integer from 0 to 4.
L or Ar ^1a is bonded to any of the 1 to 5 positions of pyrene, and L or Ar ^2a is bonded to any of the 6 to 10 positions of pyrene.
However, when nb + t is an even number, Ar ^1a , Ar ^2a , and L satisfy the following (1) or (2).
(1) Ar ^1a ≠ Ar ^2a (where ≠ indicates a group having a different structure)
(2) When Ar ^1a = Ar ^2a
(2-1) m ≠ s and / or nb ≠ t, or
(2-2) When m = s and nb = t,
(2-2-1) L or pyrene are bonded to different bonding positions on Ar ^1a and Ar ^2a , respectively.
(2-2-2) When L or pyrene is bonded to the same bonding position on Ar ^1a and Ar ^2a ,
There is no case where the substitution positions of L or Ar ^1a and Ar ^2a in pyrene are the 1st and 6th positions, or the 2nd and 7th positions. ) The host material according to claim 1,
The anthracene derivative is an asymmetric anthracene derivative represented by the following formula (3).

(In Formula (3), A ¹ and A ² are each independently a hydrogen atom or a substituted or unsubstituted aromatic ring group having 6 to 50 nuclear carbon atoms.
R ¹ to R ¹⁰ are each independently a hydrogen atom, a substituted or unsubstituted aromatic ring group having 6 to 50 nuclear carbon atoms, a substituted or unsubstituted aromatic heterocyclic group having 5 to 50 nuclear carbon atoms, substituted Or an unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted alkoxy group having 1 to 50 carbon atoms, a substituted or unsubstituted aralkyl group having 6 to 50 carbon atoms, Substituted or unsubstituted aryloxy group having 5 to 50 nucleus atoms, substituted or unsubstituted arylthio group having 5 to 50 nucleus atoms, substituted or unsubstituted alkoxycarbonyl group having 1 to 50 carbon atoms, substituted or unsubstituted Selected from silyl group, carboxyl group, halogen atom, cyano group, nitro group and hydroxyl group.
Ar ¹ , Ar ² , R ⁹ and R ¹⁰ may each be plural, and adjacent ones may form a saturated or unsaturated cyclic structure.
However, in Formula (3), there is no case where a group that is symmetrical with respect to the XY axis shown on the anthracene is bonded to the 9th and 10th positions of the central anthracene. ) The host material according to claim 1,
The anthracene derivative is a bisanthracene derivative represented by the following formula (4).

(In the formula (4), Ant is an anthracene derivative and may be substituted.
R represents a hydrogen atom, a substituted or unsubstituted aryl group having 6 to 50 nuclear carbon atoms, a substituted or unsubstituted heteroaryl group having 5 to 50 nuclear atoms, or a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms. Substituted or unsubstituted cycloalkyl group having 3 to 50 carbon atoms, substituted or unsubstituted alkoxy group having 1 to 50 carbon atoms, substituted or unsubstituted aralkyl group having 6 to 50 carbon atoms, substituted or unsubstituted nucleus Aryloxy group having 5 to 50 atoms, substituted or unsubstituted arylthio group having 5 to 50 nuclear atoms, substituted or unsubstituted alkoxycarbonyl group having 1 to 50 carbon atoms, substituted or unsubstituted silyl group, carboxyl group , A halogen atom, a cyano group, a nitro group and a hydroxy group. Further, adjacent substituents may be bonded to each other to form a saturated or unsaturated cyclic structure.
K is an integer from 0 to 9. ) The host material according to claim 1,
The anthracene derivative is a benzanthracene derivative represented by the following formula (5).

(In Formula (5), A ¹ and A ² are each independently a substituted or unsubstituted aromatic ring group having 6 to 50 nuclear carbon atoms.
R ¹ to R ¹² are each independently a hydrogen atom, a substituted or unsubstituted aromatic ring group having 6 to 50 nuclear carbon atoms, a substituted or unsubstituted aromatic heterocyclic group having 5 to 50 nuclear carbon atoms, substituted Or an unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted alkoxy group having 1 to 50 carbon atoms, a substituted or unsubstituted aralkyl group having 6 to 50 carbon atoms, Substituted or unsubstituted aryloxy group having 5 to 50 nucleus atoms, substituted or unsubstituted arylthio group having 5 to 50 nucleus atoms, substituted or unsubstituted alkoxycarbonyl group having 1 to 50 carbon atoms, substituted or unsubstituted Selected from silyl group, carboxyl group, halogen atom, cyano group, nitro group and hydroxyl group. )
Ar ¹ , Ar ² , R ^11, and R ¹² may each be plural, and adjacent ones may form a saturated or unsaturated cyclic structure. ) An organic EL device comprising a light-emitting layer containing a phosphorescent dopant and the host material according to any one of claims 1 to 5,
The organic EL device, wherein the phosphorescent dopant is an organometallic complex whose central metal is at least one of iridium, platinum, osmium, ruthenium, and rhenium. A first light emitting layer which is the light emitting layer according to claim 6;
A second light emitting layer containing a second host material, wherein the second light emitting layer contains a dopant that emits light at a wavelength different from that of the host material and the phosphorescent dopant. . A light emitting layer comprising the host material according to any one of claims 1 to 5 and the phosphorescent dopant according to claim 6,
The light emitting layer further contains a dopant that emits light at a wavelength different from that of the phosphorescent dopant. In the organic EL device according to claim 7 or 8,
The organic EL device, wherein the dopant that emits light at a wavelength different from that of the phosphorescent dopant emits light at a shorter wavelength than the phosphorescent dopant.

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