KR101495154B1 - Organic electroluminescent device and display apparatus - Google Patents

Abstract

The present invention relates to a red light emitting organic electroluminescent device. The organic electroluminescent device includes a cathode; cathode; And an organic layer including a light emitting layer, wherein the light emitting layer contains a host material made of a polycyclic aromatic hydrocarbon compound having a red luminescent guest material and a skeleton of 4 to 7 rings, and contains a luminescent guest material for generating green light And a photosensitizer layer is provided adjacent to the light emitting layer.

An organic electroluminescent element, a guest material, a host material, a light emitting layer,

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an organic electroluminescent device,

The present invention relates to an organic electroluminescent device and a display device. In particular, the present invention relates to an organic electroluminescent device emitting red light and a display device using the same.

Cross-reference to related application

The present invention includes objects related to Application Nos. JP 2006-346063 and JP 2007-152330 filed with the Japanese Patent Office on Dec. 22, 2006 and Jun. 8, 2007, respectively, Are included in the invention.

2. Description of the Related Art Recently, a display device using an organic electroluminescence device (so-called organic EL device) as a lightweight and highly efficient flat panel display device has attracted attention.

An organic electroluminescent device composed of such a display device is prepared, for example, by being provided on a substrate made of transparent glass, and laminating an anode, an organic layer and a cathode composed of ITO (indium tin oxide: transparent electrode) in order from the substrate layer. The organic layer has a form in which a hole injection layer, a hole transport layer, and an electron transporting light emitting layer are sequentially stacked from the anode side. In the thus constructed organic electroluminescent device, the electrons injected from the cathode and the holes injected from the anode are recombined in the light emitting layer, and light generated in such recombination is drawn out from the substrate side through the anode.

In addition to the organic electroluminescent device having the above-described configuration, the organic electroluminescent device is constituted by sequentially laminating a cathode, an organic layer and an anode sequentially from the substrate side, and an electrode (anode or anode Called top emission type in which light is emitted from the side of the upper electrode on the opposite side of the substrate. Particularly, in an active matrix type display device in which a thin film transistor (TFT) is provided on a substrate, a so-called top emission structure in which a top emission type organic electroluminescence device is provided on a substrate on which TFTs are formed Is advantageous in improving the aperture ratio of the light emitting portion.

However, considering the practical use of the organic EL display, there is a need to improve the light emission efficiency of the organic electroluminescent device as well as to enhance the light extraction by widening the opening of the organic electroluminescent device. Thus, various materials and layer constructions for improving the luminous efficiency have been examined.

For example, as far as the red light emitting device is concerned, a configuration has been proposed in which a naphthacene derivative (including a rubrene derivative) is used as a dopant material as a new red light emitting material instead of a conventionally known pyran derivative represented by DCJTB See, for example, patent documents JP-A-2000-26334 and JP-A-2003-55652, especially paragraphs [0353] to [0357] and table 11.

Patent Document JP-A-2003-55652 also discloses a structure in which white luminescence is obtained by laminating a second luminescent layer containing a phenylene derivative and an anthracene derivative in a first luminescent layer using a rubrene derivative as a dopant material .

Further, a structure in which white luminescence is obtained by doping a rubrene derivative to an electron transporting layer or a hole transporting layer adjacent to the blue luminescent layer has also been proposed (see Patent Document JP-A-2004-134396).

In order to perform full-color display in the above-described display device, organic electroluminescent elements of respective colors emitting light of three primary colors (red, green, and blue) may be arranged and used, A color filter of each color or a color conversion layer is used in combination. Among them, from the viewpoint of drawing efficiency of emitted light, it is advantageous to use an organic electroluminescent element which emits light of each color.

However, the current efficiency of the red light emitting device using the naphthacene derivative (rubrene derivative) was about 6.7 cd / A, and the luminescent color was orange light rather than red light.

In view of such circumstances, the present invention aims to provide an organic electroluminescent device with red light emission and a display device using the organic electroluminescent device, the luminescent efficiency and the color purity being sufficiently satisfactory.

An organic electroluminescent device according to an embodiment of the present invention includes: a cathode; cathode; And an organic layer including a light emitting layer. This luminescent layer contains a red luminescent guest material and a host material composed of a polycyclic aromatic hydrocarbon compound having a skeleton of 4 to 7 rings. Further, a photosensitizing layer containing a luminescent guest material for generating green light is provided adjacent to this luminescent layer.

As described in detail in the following embodiments, in the organic electroluminescent device having the above-described structure, the current efficiency is increased as compared with the structure in which the photosensitivity layer is not provided, Only the red light generated in the light emitting layer is extracted from the device without being influenced by the light emitting layer.

According to an embodiment of the present invention, there is provided a display device in which a plurality of organic electroluminescent devices having the above-described configuration are arranged on a substrate.

In such a display device, as described above, a display device using an organic electroluminescent device having a high luminance and high color purity as a red light emitting device is constituted. Thus, by combining with other green light emitting devices and blue light emitting devices, - Color display can be implemented.

As described above, according to the organic electroluminescent device according to the embodiment of the present invention, the luminous efficiency of the red light can be improved while maintaining the color purity.

In addition, according to the display device of the embodiment of the present invention, as described above, the organic electroluminescent device as a red light emitting device having high color purity and luminous efficiency, and the green light emitting device and the blue light emitting device as one set By configuring the pixels, a full-color display with high color reproducibility can be realized.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings in the order of an organic electroluminescent device and a display device using the same.

&Quot; Organic electroluminescent device-1 "

1 is a cross-sectional view schematically showing an organic electroluminescent device of the present invention. 1, an organic electroluminescent element 11 is formed by laminating an anode 13, an organic layer 14 and a cathode 15 on a substrate 12 in this order. Among them, the organic layer 14 includes, for example, a hole injection layer 14a, a hole transport layer 14b, a light emitting layer 14c, a photosensitizing layer 14d, and an electron transport layer 14e in this order from the anode 13 side. .

In the embodiment according to the present invention, the structure of the light-emitting layer 14c and the structure in which the photosensitizing layer 14d is provided in contact with the light-emitting layer 14c are provided. Hereinafter, it is assumed that the organic electroluminescent device 11 having such a laminated structure is constituted as a top-emitting type device for extracting light from the opposite side to the substrate 12, and details of each layer in this case Are described in order from the substrate 12 side.

<Substrate>

The substrate 12 is a support on which the organic electroluminescent elements 11 are arranged on the main surface side thereof. The substrate 12 can be made of a known material, and examples thereof include a film or sheet made of quartz, glass, metal foil, or resin. Of these, quartz and glass are preferable, and in the case of resin, methacrylic resin typified by polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutyl Polyesters such as rhenaphthalate (PBN), and polycarbonate resins. It is important to utilize a laminate structure or surface treatment to control moisture permeability and gas permeability.

<Anode>

As the anode 13, an electrode material having a large work function from the vacuum level of the electrode material for injecting holes with good efficiency is used. Examples thereof include metals and alloys of aluminum (Al), chromium (Cr), molybdenum (Mo), tungsten (W), copper (Cu), silver (Ag) An alloy of tin oxide (SnO ₂ ) and antimony (Sb), an alloy of ITO (indium tin oxide), InZnO (zinc oxide tin), zinc oxide (ZnO) and aluminum (Al) Or an oxide of an alloy. These materials are used singly or in a mixed state.

The anode 13 may have a laminated structure of a first layer having excellent light reflectivity and a second layer having a light permeability and a large work function provided thereon.

The first layer is made of an alloy containing aluminum as a main component. The subcomponent thereof may contain at least one element having a relatively smaller work function than aluminum, which is the main component. As such a subcomponent, a lanthanoid-based element is preferable. Although the work function of the lanthanoid-based element is not large, the stability of the anode is improved by including such an element, and the hole injection property of the anode is also satisfied. In addition to the lanthanoid-based element, for example, silicon (Si), copper (Cu), or the like may be contained as a subcomponent.

The content of the subcomponent in the aluminum alloy layer constituting the first layer is preferably about 10 wt% or less in total in the case of, for example, Nd, Ni, or Ti stabilizing aluminum. Thus, while maintaining the reflectance in the aluminum alloy layer, the aluminum alloy layer can be stably maintained in the manufacturing process of the organic electroluminescent device, and the hole precision and chemical stability can also be obtained. Also, the conductivity of the anode 13 and the adhesion to the substrate 12 can be improved.

As the second layer, a layer composed of at least one of an oxide of an aluminum alloy, an oxide of molybdenum, an oxide of zirconium, an oxide of chromium, and an oxide of tantalum can be exemplified. Here, for example, when the second layer is an oxide layer (including a natural oxide film) of an aluminum alloy containing a lanthanoid-based element as a subcomponent, since the transmittance of the oxide of the lanthanide-based element is high, The transmittance of the transparent substrate is improved. Therefore, it is possible to maintain a high reflectance on the surface of the first layer. The second layer may be a transparent conductive layer such as ITO (indium tin oxide) or IZO (indium zinc oxide). These conductive layers can improve the electron injection characteristics of the anode (13).

A conductive layer for improving the adhesion between the anode 13 and the substrate 12 may be provided on the side of the anode 13 in contact with the substrate 11. [ Examples of such a conductive layer include transparent conductive layers such as ITO and IZO.

When the driving method of the display device using the organic electroluminescence element 11 is an active matrix method, the anode 13 is patterned for each pixel and connected to the driving thin film transistor provided on the substrate 12 Respectively. In this case, an insulating film (not shown) is provided on the anode 13, and the surface of the anode 13 of each pixel is exposed from the opening of the insulating film.

<Hole injection layer>

The hole injection layer 14a is for increasing the hole injection efficiency into the light emitting layer 14c. As the material of the hole injection layer 14a that can be used, for example, a material such as benzene, styrylamine, triphenylamine, porphyrin, triphenylene, azatriphenylene, tetracyanoquinodimethane, triazole, imidazole , Oxadiazole, polyarylalkane, phenylenediamine, arylamine, oxazole, fluorene, anthracene, fluorenone, hydrazine, stilbene or derivatives thereof, or polysilane compounds, vinylcarbazole compounds, thiophene compounds A conjugated monomer, an oligomer or a polymer such as a compound or an aniline compound may be used.

More specific examples of the hole injection layer 14a include α-naphthylphenylphenylenediamine, porphyrin, metal tetraphenylporphyrin, metal naphthalocyanine, C60, C70, hexacyanoazatriphenylene, Tetracyanoquinodimethane (TCNQ), 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane (F4-TCNQ), tetracyano- N, N ', N'-tetrakis (p-tolyl) -p-phenylenediamine, N, N, N', N'- (P-phenylenevinylene), poly (thiophene), poly (thiophene), poly Poly (2,2'-thienylpyrrole), and the like, but are not limited thereto.

&Lt; Hole transport layer &

The hole transporting layer 14b is for enhancing the efficiency of injecting holes into the light emitting layer 14c in the same manner as the hole injecting layer 14a. Such a hole transport layer 14b is formed using a material selected from the same materials as the above-mentioned hole injection layer 14a.

<Light Emitting Layer>

The light emitting layer 14c is a region where holes injected from the anode 13 and electrons injected from the cathode 15 are recombined when a voltage is applied to the anode 13 and the cathode 15. [ In this embodiment, the structure of the light-emitting layer 14c is a feature. That is, the light-emitting layer 14c uses a polycyclic aromatic hydrocarbon compound having a skeleton of 4 to 7 rings as a host material, and the host material is doped with a red luminescent guest material, and as a result, red light is generated.

Of these, the host material constituting the light-emitting layer 14c is a polycyclic aromatic hydrocarbon compound having a skeleton of 4 to 7-membered rings, and is a pyrene, benzoprene, chrysene, naphthacene, benzonaphthacene, dibenzonaphthacene, perylene , Coronene.

The host material constituting the light-emitting layer 14c is a polycyclic aromatic hydrocarbon compound having a skeleton of 4 to 7-membered ring and is a pyrene, benzoprene, .

Among them, it is preferable to use a naphthacene derivative represented by the following general formula (1) as a host material.

Wherein R ¹ to R ⁸ each independently represent hydrogen, halogen, a hydroxyl group, a substituted or unsubstituted carbonyl group having 20 or less carbon atoms, a substituted or unsubstituted carbonyl ester group having 20 or less carbon atoms , A substituted or unsubstituted alkyl group having 20 or less carbon atoms, a substituted or unsubstituted alkenyl group having 20 or less carbon atoms, a substituted or unsubstituted alkoxyl group having 20 or less carbon atoms, a cyano group, a nitro group, A substituted or unsubstituted aryl group having 30 or less carbon atoms, a substituted or unsubstituted heterocyclic group having 30 or less carbon atoms, a substituted or unsubstituted aryl group having 30 or less carbon atoms, Substituted amino group.

Examples of the aryl group represented by R ¹ to R ⁸ in the general formula (1) include a phenyl group, a 1-naphthyl group, a 2-naphthyl group, a fluorenyl group, a 1-anthryl group, 1-naphthacenyl group, 2-naphthacenyl group, 9-naphthacenyl group, 2-naphthacenyl group, 2-naphthacenyl group, 2-naphthacenyl group, 2-fluorenyl group, 2-fluorenyl group, 2-fluorenyl group, 2-fluorenyl group, 2-fluorenyl group, 2-fluorenyl group, 3-biphenyl group, 4-biphenyl group, o-tolyl group, m-tolyl group, p-tolyl group, p-t-butylphenyl group and the like.

The heterocyclic group represented by R ¹ to R ⁸ includes a 5-membered or 6-membered aromatic heterocyclic group having 2 to 20 carbon atoms and a condensed polycyclic aromatic heterocyclic group containing 0, N or S as a hetero atom. Examples of the aromatic heterocyclic group and the condensed polycyclic aromatic heterocyclic group include a thienyl group, a furyl group, a pyrrolyl group, a pyridyl group, a quinolyl group, a quinoxalyl group, an imidazopyridyl group and a benzothiazole group. Representative examples include 1-pyrrolyl, 2-pyrrolyl, 3-pyrrolyl, pyrazinyl, 2-pyridinyl, 3-pyridinyl, 4- pyridinyl, Isoindolyl group, 3-isoindolyl group, 3-isoindolyl group, 4-isoindolyl group, 4-indolyl group, 4-indolyl group, Isoindolyl group, 2-furyl group, 3-furyl group, 2-benzofuranyl group, 3-benzofuranyl group, 4-benzoyl group, 6-benzofuranyl, 7-benzofuranyl, 1-isobenzofuranyl, 3-isobenzofuranyl, 4-isobenzofuranyl, 5-isobenzofuranyl, 6-benzofuranyl, An isobenzofuranyl group, a 7-isobenzofuranyl group, a quinolyl group, a 3-quinolyl group, a 4-quinolyl group, a 5-quinolyl group, Isoquinolyl group, 8-isoquinolyl group, 8-isoquinolyl group, 4-isoquinolyl group, 5-isoquinolyl group, Carbazolyl group, 3-carbazolyl group, 4-carbazolyl group, 9-carbazolyl group, 2-quinoxalinyl group, And examples thereof include a carbazolyl group, a 1-phenanthridinyl group, a 2-phenanthridinyl group, a 3-phenanthridinyl group, a 4-phenanthridinyl group, a 6-phenanthridinyl group, An acridinyl group, a 9-acridinyl group, a 9-acridinyl group, a 9-acridinyl group, a 2-acridinyl group, .

The amino group represented by R ¹ to R ⁸ may be any of an alkylamino group, an arylamino group, and an aralkylamino group. It is preferable that these have an aliphatic and / or 1 to 4 ring aromatic carbon ring having 1 to 6 carbon atoms in total. Examples of such groups include a dimethylamino group, a diethylamino group, a dibutylamino group, a diphenylamino group, a ditolylamino group, a bisphenylamino group and a dinaphthylamino group.

Two or more of the above substituents may form a condensed ring or may further have a substituent.

In particular, the naphthacene derivative represented by the above general formula (1) is preferably a rubrene derivative represented by the following general formula (1a).

In formula (1a), R ¹¹ to R ¹⁵ , R ²¹ to R ²⁵ , R ³¹ to R ³⁵ , and R ⁴¹ to R ⁴⁵ each independently represent a hydrogen atom, an aryl group, a heterocyclic group, An alkyl group or an alkenyl group. R ¹¹ to R ¹⁵ , R ²¹ to R ²⁵ , R ³¹ to R ³⁵ , and R ⁴¹ to R ⁴⁵ are preferably the same as each other.

In the general formula (1a), R ⁵ to R ⁸ each independently represent a hydrogen atom, an aryl group which may have a substituent, or an alkyl or alkenyl group which may have a substituent.

Preferable examples of the aryl group, heterocyclic group and amino group in the general formula (1a) may be the same as those of R ¹ to R ^{8 in} the general formula (1). When R ¹¹ to R ¹⁵ , R ²¹ to R ²⁵ , R ³¹ to R ³⁵ , and R ⁴¹ to R ⁴⁵ are amino groups, they are alkylamino groups, arylamino groups, or aralkylamino groups. These are preferably aliphatic or monocyclic to tetracyclic aromatic carbocyclic rings having 1 to 6 carbon atoms in total. Examples of such groups include a dimethylamino group, a diethylamino group, a dibutylamino group, a diphenylamino group, a ditolylamino group and a bisphenylamino group.

Another more specific example of the naphthacene derivative preferably used as the host material of the light emitting layer 14c includes rubrene of the following compound (1) -1, which is one of the rubrene derivatives of the formula (1a) The following compounds (1) -2 to (1) -4 are exemplified.

Examples of the red luminescent guest material constituting the light emitting layer 14c include the following perylene derivatives of the general formula (5), diketopyrrolopyrrole derivatives of the general formula (6), pyromethene complexes of the general formula (7) , The pyran derivative of the formula (8), or the styryl derivative of the formula (9). Hereinafter, details of the red luminescent guest material will be described.

- Perylene derivatives -

As the red luminescent guest material, for example, a compound represented by the following general formula (5) (diindeno [1,2,3-cd] perylene derivative) is used.

In the general formula (5), X ^{1 to} X ²⁰ each independently represent a hydrogen atom, a halogen atom, a hydroxyl group, a substituted or unsubstituted carbonyl group having 20 or less carbon atoms, a substituted or unsubstituted Carbonyl ester group, substituted or unsubstituted alkyl group having 20 or less carbon atoms, substituted or unsubstituted alkenyl group having 20 or less carbon atoms, substituted or unsubstituted alkoxyl group having 20 or less carbon atoms, cyano group, nitro , A substituted or unsubstituted silyl group having 30 or less carbon atoms, a substituted or unsubstituted aryl group having 30 or less carbon atoms, a substituted or unsubstituted heterocyclic group having 30 or less carbon atoms, Substituted or unsubstituted amino group.

Examples of the aryl group represented by X ¹ to X ²⁰ in the general formula (5) include a phenyl group, a 1-naphthyl group, a 2-naphthyl group, a fluorenyl group, a 1-anthryl group, Naphthacenyl groups, 9-anthryl groups, 1-phenanthryl groups, 2-phenanthryl groups, 3-phenanthryl groups, Naphthacenyl group, a 1-pyrenyl group, a 2-pyrenyl group, a 4-pyrenyl group, a 1-chrysenyl group, a 6-crescenyl group, a 2-fluoranthienyl group, a 3-fluoranthienyl group, , 3-biphenyl group, 4-biphenyl group, o-tolyl group, m-tolyl group, p-tolyl group, p-t-butylphenyl group and the like.

The heterocyclic group represented by X ¹ to X ²⁰ includes a 5-membered or 6-membered aromatic heterocyclic group having 2 to 20 carbon atoms and a condensed polycyclic aromatic heterocyclic group containing 0, N or S as a hetero atom. Examples of the aromatic heterocyclic group and the condensed polycyclic aromatic heterocyclic group include a thienyl group, a furyl group, a pyrrolyl group, a pyridyl group, a quinolyl group, a quinoxalyl group, an imidazopyridyl group and a benzothiazole group. Representative examples include 1-pyrrolyl, 2-pyrrolyl, 3-pyrrolyl, pyrazinyl, 2-pyridinyl, 3-pyridinyl, 4- pyridinyl, Isoindolyl group, 3-isoindolyl group, 3-isoindolyl group, 4-isoindolyl group, 4-indolyl group, 4-indolyl group, Isoindolyl group, 2-furyl group, 3-furyl group, 2-benzofuranyl group, 3-benzofuranyl group, 4-benzoyl group, 6-benzofuranyl, 7-benzofuranyl, 1-isobenzofuranyl, 3-isobenzofuranyl, 4-isobenzofuranyl, 5-isobenzofuranyl, 6-benzofuranyl, An isobenzofuranyl group, a 7-isobenzofuranyl group, a 1-quinolyl group, a 3-quinolyl group, a 4-quinolyl group, a 5-quinolyl group, Isoquinolyl group, 8-isoquinolyl group, 3-isoquinolyl group, 4-isoquinolyl group, 5-isoquinolyl group, The Carbazolyl group, 3-carbazolyl group, 4-carbazolyl group, 9-carbazolyl group, 2-quinoxalinyl group, And examples thereof include a carbazolyl group, a 1-phenanthridinyl group, a 2-phenanthridinyl group, a 3-phenanthridinyl group, a 4-phenanthridinyl group, a 6-phenanthridinyl group, An acridinyl group, a 3-acridinyl group, a 4-acridinyl group, a 9-acridinyl group, and the like can be given to the compound .

The amino group represented by X ^{1 to} X ²⁰ may be any of an alkylamino group, an arylamino group, and an aralkylamino group. It is preferable that these have an aliphatic and / or 1 to 4 ring aromatic carbon ring having 1 to 6 carbon atoms in total. Examples of such groups include a dimethylamino group, a diethylamino group, a dibutylamino group, a diphenylamino group, a ditolylamino group, a bisphenylamino group and a dinaphthylamino group.

Two or more of the above substituents may form a condensed ring and may further have a substituent.

Specific examples of the diindeno [1,2,3-cd] perylene derivatives preferably used as a red luminescent guest material in the light emitting layer 14c include the following compounds (5) -1 to (5) - 8 &lt; / RTI &gt; However, the present invention is not limited thereto.

- diketopyrrolopyrrole derivatives -

As the red luminescent guest material, for example, a compound represented by the following general formula (6) (diketopyrrolopyrrole derivative) is used.

In the general formula (6), Y ¹ and Y ² each independently represent an oxygen atom or a substituted or unsubstituted imino group. Y ^{3 to} Y ⁸ each independently represent hydrogen, halogen, a substituted or unsubstituted alkyl group having 20 or less carbon atoms, a substituted or unsubstituted alkenyl group having 20 or less carbon atoms, a substituted An unsubstituted aryl group, a substituted or unsubstituted heterocyclic group having 30 or less carbon atoms, or a substituted or unsubstituted amino group having 30 or less carbon atoms.

In the general formula (6), Ar ¹ and Ar ² represent a divalent group selected from a substituted or unsubstituted aromatic hydrocarbon group and a substituted or unsubstituted aromatic heterocyclic group.

And, in the formula (6), Y ³ heterocyclic group, and an amino group represented by Y ³ ~Y ⁸ ~Y ⁸ is an aryl group, Y ³ ~Y ⁸ of the substituted or unsubstituted shown illustrating the general formula ( 5). &Lt; / RTI &gt; Two or more of the above substituents may form a condensed ring or may further have a substituent.

Specific examples of the diketopyrrolopyrrole derivatives preferably used as a red luminescent guest material in the light-emitting layer 14c include the following compounds (6) -1 to (6) -14. However, the present invention is not limited thereto.

- pyromethene complex -

As the red luminescent guest material, for example, a compound represented by the following general formula (7) (pyromethene complex) is used.

In the general formula (7), each of Z ^{1 to} Z ⁹ independently represents a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group having 20 or less carbon atoms, a substituted or unsubstituted alkenyl group having 20 or less carbon atoms, A cyano group, a nitro group, a substituted or unsubstituted silyl group having 30 or less carbon atoms, a substituted or unsubstituted aryl group having 30 or less carbon atoms, a substituted or unsubstituted aryl group having 30 or less carbon atoms Or a substituted or unsubstituted amino group having 30 or less carbon atoms.

And, general formula (7), Z ¹ ~Z a substituted or unsubstituted ⁹ represents an aryl group, a heterocyclic group Z1~Z9 represented in, and Z ¹ ~Z ⁹ represents an amino group, the general formula (5) Lt; / RTI &gt; Two or more of the above substituents may form a condensed ring or may further have a substituent.

Specific examples of the pyromethene complexes preferably used as the red luminescent guest material in the light emitting layer 14c include the following compounds (7) -1 to (7) -69. However, the present invention is not limited thereto.

- pyran derivatives -

As the red luminescent guest material, for example, a compound represented by the following general formula (8) (a pyran derivative) is used.

In the general formula (8), L ^{1 to} L ⁶ each independently represent hydrogen, a substituted or unsubstituted alkyl group having 20 or less carbon atoms, a substituted or unsubstituted alkenyl group having 20 or less carbon atoms, A cyano group, a nitro group, a substituted or unsubstituted silyl group having 30 or less carbon atoms, a substituted or unsubstituted aryl group having 30 or less carbon atoms, a substituted or unsubstituted aryl group having 30 or less carbon atoms A substituted or unsubstituted heterocyclic group, or a substituted or unsubstituted amino group having 30 or less carbon atoms. In addition, L ¹ and L ⁴ or L ² and L ³ may take a cyclic structure through a hydrocarbon.

And, in the formula (8), L ¹ ~L substituted or unsubstituted aryl group represented by ^6, L ¹ ~L ⁶ is a heterocyclic group, an amino group, and L ¹ ~L ⁶ is shown illustrating the general formula ( 5). &Lt; / RTI &gt; L ¹ and L ^4, or L ² and L ³ may have a cyclic structure through a hydrocarbon, and two or more of the substituents may form a condensed ring or may further have a substituent.

Specific examples of the pyran derivative preferably used as the red luminescent guest material in the light emitting layer 14c include the following compounds (8) -1 to (8) -7. However, the present invention is not limited thereto.

- styryl derivatives -

As the red luminescent guest material, for example, a compound represented by the following general formula (9) (styryl derivative) is used.

In the general formula (9), T ^{1 to} T ³ represent a substituted or unsubstituted aryl group having 30 or less carbon atoms or a substituted or unsubstituted heterocyclic group having 30 or less carbon atoms. T ⁴ represents a substituted or unsubstituted phenylene moiety which may have a cyclic structure with T ² and T ³ .

In the formula (9), T ¹ ~T ³ is a heterocyclic group represented by aryl groups, T ¹ ~T ³ represents a substituted or non-substituted, the same groups in the perylene derivatives of the general formula (5).

Two or more of the above substituents may form a condensed ring or may further have a substituent. In this case, examples of the group substituted for T ^{1 to} T ⁴ include hydrogen, a halogen, a hydroxyl group, a substituted or unsubstituted carbonyl group having 20 or less carbon atoms, a substituted or unsubstituted group having 20 or less carbon atoms A substituted or unsubstituted alkyl group having 20 or less carbon atoms, a substituted or unsubstituted alkenyl group having 20 or less carbon atoms, a substituted or unsubstituted alkoxyl group having 20 or less carbon atoms, a cyano group , A nitro group, and an amino group. In addition, as the amino group, any of an alkylamino group, an arylamino group, and an aralkylamino group can be used. It is preferable that these have an aliphatic and / or 1 to 4 ring aromatic carbon ring having 1 to 6 carbon atoms in total. Examples of such groups include a dimethylamino group, a diethylamino group, a dibutylamino group, a diphenylamino group, a ditolylamino group, a bisphenylamino group and a dinaphthylamino group.

Specific examples of the styryl derivative preferably used as the red luminescent guest material in the light emitting layer 14c include the following compounds (9) -1 to (9) -35. However, the present invention is not limited thereto.

The perylene derivatives of the general formula (5), the diketopyrrolopyrrole derivatives of the general formula (6) and the pyromethene derivatives of the general formula (7), which are used as the red luminescent guest material in the luminescent layer (14c) The complex, the pyran derivative of the general formula (8), or the styryl derivative of the general formula (9) preferably has a molecular weight of 2000 or less, more preferably 1,500 or less, and particularly preferably 1,000 or less. The reason for this is that if the molecular weight is large, there is a fear that the vapor deposition property is deteriorated in the production of the device by vapor deposition.

&Lt; Optical sensitization layer &

The photosensitizer layer 14d is a layer for transferring energy to the light emitting layer 14c and improving the light emitting efficiency in the light emitting layer 14c. In this embodiment, it is also a feature that such a photosensitizer layer 14d is provided in contact with the light-emitting layer 14c. Such a photosensitizer layer 14d is a host material doped with a luminescent guest material for generating green light.

As the luminescent guest material, an organic luminescent material such as a material having a high luminous efficiency, such as a low molecular weight fluorescent dye, a fluorescent polymer, or a metal complex, is used.

Here, the green luminescent guest material refers to a compound having a peak within a wavelength range of light emission of about 490 nm to 580 nm. Examples of such compounds include naphthalene derivatives, anthracene derivatives, pyrene derivatives, naphthacene derivatives, fluoranthene derivatives, perylene derivatives, coumarin derivatives, quinacridone derivatives, indeno [1,2,3- cd] perylene derivatives, bis (Azinyl) methene boron complex, pyran-based dye, and the like are used. Among these, an aminoanthracene derivative, a fluoranthene derivative, a coumarin derivative, a quinacridone derivative, an indeno [1,2,3-cd] perylene derivative, and a bis (azinyl) methane boron complex are preferable.

The host material of the photosensitizing layer 14d is an organic material comprising an aromatic hydrocarbon derivative having 6 to 60 carbon atoms, or a combination thereof. Specific examples thereof include a naphthalene derivative, an indene derivative, a phenanthrene derivative, a pyrene derivative, a naphthacene derivative, a triphenylene derivative, an anthracene derivative, a perylene derivative, a picene derivative, a fluoranthene derivative, (8-quinolinolato) aluminum complexes, bis (benzoquinolinolato) beryllium complexes, and the like can be used as the cobalt complexes.

As the above-mentioned host material, a host material having the highest luminous efficiency for each luminescent guest material is selected and used.

It is important that the photosensitizing layer 14d having such a structure is provided in contact with the light emitting layer 14c. The light enhancement layer 14d is not limited to be provided between the light emitting layer 14c and the cathode 15 as described above and may be formed between the light emitting layer 14c and the anode 13 by the light emitting layer 14c Or the like.

<Electron transport layer>

The electron transport layer 14e is for transporting electrons injected from the cathode 15 to the light-emitting layer 14c. Examples of the material of the electron transporting layer 14e include quinoline, perylene, phenanthroline, bisstyryl, pyrazine, triazole, oxazole, oxadiazole, fluorenone, and derivatives and metal complexes thereof have. Specifically, there may be mentioned tris (8-hydroxyquinoline) aluminum (abbreviated to Alq3), anthracene, naphthalene, phenanthrene, pyrene, anthracene, perylene, butadiene, coumarin, acridine, stilbene, Or a derivative thereof or a metal complex thereof.

The organic layer 14 is not limited to such a layer structure and may include at least a light emitting layer 14c and a light enhancement layer 14d in contact with the light emitting layer 14c. have.

The light emitting layer 14c may be provided in the organic electroluminescent element 11 as a hole transporting light emitting layer, an electron transporting light emitting layer, or a positive charge transporting light emitting layer. Each of the layers constituting the organic layer 14, for example, the hole injecting layer 14a, the hole transporting layer 14b, the light emitting layer 14c, the photosensitizing layer 14d, and the electron transporting layer 14e, Or may be a laminated structure in which each layer is composed of a plurality of layers.

<Cathode>

Next, the cathode 15 provided on the organic layer 14 having the above-described structure is, for example, a two-layer structure in which the first layer 15a and the second layer 15b are stacked in this order from the organic layer 14 side Structure.

The first layer 15a is made of a material having a small work function and a good light transmittance. Examples of such materials include cesium carbonate (Cs ₂ CO ₃ ), which is a composite oxide of lithium oxide (Li ₂ O) or cesium (Cs), which is an oxide of lithium (Li), and a mixture of oxides and complex oxides Can be used. The first layer 15a is not limited to such a material but may be an alkali earth metal such as calcium (Ca) or barium (Ba), an alkali metal such as lithium or cesium, or a metal such as indium (In) (Mg), oxides and complex oxides of these metals, fluorides, and the like can be used alone. In addition, a mixture or alloy of these metals, oxides or complex oxides and fluorides may be used with increased stability.

The second layer 15b is made of a thin film using a light-transmitting layer such as MgAg. The second layer 15b may also be a mixed layer containing an organic light emitting material such as an aluminum quinoline complex, a styrylamine derivative, or a phthalocyanine derivative. In this case, it is also possible to additionally have a light-transmitting layer such as MgAg as the third layer.

When the driving method of the display device using the organic electroluminescent element 11 is an active matrix method, the cathode 15 is formed by the organic layer 14 and the above-described insulating film (Not illustrated in FIG. 1) in the form of a solid film on the substrate 12 while being insulated from the anode 13, and is used as a common electrode of each pixel.

It is needless to say that the cathode 15 is not limited to the above-described laminated structure, but may have an optimal combination and laminated structure depending on the structure of the device to be manufactured. For example, the structure of the cathode 15 of the above embodiment is the same as that of the first embodiment except that the function of the electrode layers, that is, the inorganic layer (the first layer 15a) which promotes the injection of electrons into the organic layer 14, And the inorganic layer (second layer 15b) are separated. However, the inorganic layer that promotes the injection of electrons into the organic layer 14 may also serve as an inorganic layer that serves as an electrode, and these layers may be formed as a single layer structure. It is also possible to adopt a laminated structure in which transparent electrodes such as ITO are formed on the single-layer structure.

The current to be applied to the organic electroluminescent element 11 having the above-described configuration is usually a direct current, but a pulse current or alternating current may be used. The value of the current and the value of the voltage are not particularly limited as far as they are within the range that the element is not destroyed. However, considering the power consumption and lifetime of the organic electroluminescent element, it is preferable to emit light with a good efficiency with as little electric energy as possible.

When the organic electroluminescent device 11 has a cavity structure, the cathode 15 is formed of a material that is semi-transmitting and semi-reflecting. Light emitted by multiple interferences between the light reflecting surface on the anode 13 side and the light reflecting surface on the cathode 15 side is drawn out from the cathode 15 side. In this case, the optical distance between the light reflection surface on the anode 13 side and the light reflection surface on the cathode 15 side is defined by the wavelength of the light to be drawn, and the film thickness of each layer Respectively. In this top emission type organic electroluminescent device, by using this cavity structure positively, it is possible to improve the light extraction efficiency to the outside and control the emission spectrum.

Although not shown here, the organic electroluminescent device 11 having such a structure is used in a state of being covered with a passivation layer in order to prevent deterioration of an organic material by moisture, oxygen, or the like in the air . As the passivation film, for example, a silicon nitride (typically Si ₃ N ₄ ) film, a silicon oxide (typically SiO ₂ ) film, a silicon nitride oxide (SiN _x O _y : composition ratio X> Y) (SiO _x N _y : composition ratio X> Y) film, a thin film mainly composed of carbon such as DLC (diamond-like carbon), CN (carbon nanotube) film, or the like is used. These films preferably have a single layer or a laminated structure. Among them, the passivation layer made of nitride is preferably used since it has a dense film quality and an extremely high blocking effect on moisture, oxygen, and other impurities adversely affecting the organic electroluminescence device 11.

In the above embodiments, the present invention has been described in detail with reference to the case where the organic electroluminescent device is a top emission type. However, the organic electroluminescent device of the present invention is not limited to the application to the top emission type, and can be widely applied to a structure in which an organic layer having at least a light emitting layer is provided between the anode and the cathode. Therefore, the organic electroluminescent device according to the present invention is a device having a structure in which a cathode, an organic layer, and an anode are laminated in order from the substrate side, or an electrode (a lower electrode as a cathode or an anode) And an electrode (an upper electrode as a cathode or an anode) located on the opposite side of the substrate is made of a reflective material so that light can be extracted only from the lower electrode side.

Further, the organic electroluminescent device according to the embodiment of the present invention may be an element formed by a pair of electrodes (anode and cathode) and an organic layer provided between the electrodes. Therefore, the present invention is not limited to a structure comprising only a pair of electrodes and an organic layer, and it is not excluded that other components (for example, an inorganic compound layer or an inorganic component) coexist within a range in which the effect of the present invention is not impaired.

In the organic electroluminescent element 11 constructed as described above, it was confirmed that the current efficiency was increased as compared with the element in which the photosensitivity layer 14d was not provided, as will be described in detail in the following embodiments .

Further, although the red light emitting layer 14c has a structure in which a light enhancement layer 14d that emits green light is laminated, even if an electric field is applied, color mixing due to light emission from the light enhancement layer 14d does not occur, Can be obtained. This is because, in the photosensitivity layer 14d, even if holes injected through the red light-emitting layer 14c and electrons injected through the electron-transporting layer 14e are recombined, the energy released by the recombination is reduced to the adjacent red And serves to excite electrons of the host material constituting the light emitting layer 14c of the red light emitting layer 14c and contributes to light emission in the red light emitting layer 14c. Such a phenomenon can be explained as a comparative example to the following examples. In the case where the photosensitizing layer 14d is composed only of a host material, the phenomenon in which the intended red luminescent layer does not substantially emit light can do.

As described above, according to the organic electroluminescent element 11 having the above-described structure, it is possible to improve the luminous efficiency of the red light while maintaining the color purity.

In addition, such a significant improvement in the luminous efficiency can improve the luminance lifetime of the organic electroluminescent element 11 and reduce the power consumption.

&Quot; Organic electroluminescent device -2 &quot;

2 is a cross-sectional view schematically showing another example of the organic electroluminescent device of the present invention. The organic electroluminescent device 11 'shown in FIG. 2 is different from the organic electroluminescent device 11 described with reference to FIG. 1 in the structure of the hole transporting layer 14b, and the other structures are the same. Next, the structure of the hole transporting layer 14b in the organic electroluminescence element 11 'will be described.

&Lt; Hole transport layer &

The hole transporting layer 14b is for enhancing the efficiency of injecting holes into the light emitting layer 14c in the same manner as the hole injecting layer 14a. Here, in particular, the hole transport layer 14b has a laminated structure made of different materials, and at least the first hole transport layer 14b-1 on the side of the hole injection layer 14b and the second hole transport layer 14b- 14b-2.

Among them, the first hole transporting layer 14b-1 is formed using a material selected from the same materials as the above-mentioned hole injection layer 14a. The first hole transport layer 14b-1 itself may have a laminated structure.

The second hole transporting layer 14b-2 is a layer provided in contact with the light emitting layer 14c and is made of a material different from the material constituting the first hole transporting layer 14b-1. As the material constituting the second hole transporting layer 14b-2, a trillylamine derivative of the general formula (2), a fluorene derivative of the general formula (3), a carbazole derivative of the general formula (4) Is used. Hereinafter, the material constituting the second hole transporting layer 14b-2 will be described in detail.

- triarylamine derivatives -

As the material constituting the second hole transporting layer 14b-2, for example, a triarylamine derivative represented by the following general formula (2) is used.

In the general formula (2), A ^{1 to} A ³ each independently represent an aryl group or a heterocyclic group, and each of them may be unsubstituted or substituted. Each of A ^{1 to} A ³ may have a plurality of rings connected through a conjugated bond to form a stretch structure, but preferably has a total carbon number of 30 or less. Examples of the substituent bonded on the aryl group or heterocyclic group include hydrogen, halogen, a hydroxyl group, a substituted or unsubstituted carbonyl group having 20 or less carbon atoms, a substituted or unsubstituted carbonyl ester having 20 or less carbon atoms A substituted or unsubstituted alkyl group having 20 or less carbon atoms, a substituted or unsubstituted alkenyl group having 20 or less carbon atoms, a substituted or unsubstituted alkoxyl group having 20 or less carbon atoms, a cyano group, a nitro group, or And a substituted or unsubstituted amino group having 30 or less carbon atoms.

Specific examples of such a thrylarylamine derivative include the following compounds (2) -1 to (2) -48.

- Fluorene derivatives -

As a material constituting the second hole transporting layer 14b-2, for example, a fluorene derivative containing a pyrrolidyl skeleton represented by the following general formula (3) is used.

In the general formula (3), A ^{1 to} A ⁴ bonded to the pyrrolidyl skeleton and Z ¹ and Z ² bonded to the fluorene skeleton are each independently selected from the group consisting of hydrogen, a halogen, a hydroxyl group, a carbonyl group, A carbonyl ester group, an alkyl group, an alkenyl group, an alkoxyl group, a cyano group, a nitro group and an amino group. Of these, the carbonyl group, the carbonyl ester group, the alkyl group, the alkenyl group and the alkoxyl group may be further substituted with another substituent, and have 20 or fewer carbon atoms. The amino group may be further substituted with another substituent and has 30 or fewer carbon atoms.

A ^{1 to} A ⁴ bonded to the pyrrolidyl skeleton may form an annular structure at adjacent positions.

Here, specific examples of the pyrrolidyl skeleton are shown below.

Ar ¹ and Ar ² in the general formula (3) each independently represent an aryl group or a heterocyclic group. These aryl groups or heterocyclic groups may be monosubstituted or polysubstituted by halogen, alkyl group, alkoxy group, or aryl group, but may be an aryl group (carbocyclic aromatic group) having a total of 6 to 20 carbon atoms, Heterocyclic group (heterocyclic aromatic group).

Each of Ar ¹ and Ar ² is preferably an unsubstituted or substituted or unsubstituted alkyl group having 1 to 14 carbon atoms, an alkoxy group having 1 to 14 carbon atoms, or an aryl group having 6 to 10 carbon atoms, An aryl group having 6 to 20 carbon atoms in total.

Each of Ar ¹ and Ar ² is more preferably unsubstituted or monosubstituted or polysubstituted by halogen, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or an aryl group having 6 to 10 carbon atoms An aryl group having 6 to 16 carbon atoms in total.

B ¹ and B ² in the general formula (3) represent hydrogen, an alkyl group, an aryl group, or a heterocyclic group. The alkyl group may be straight-chain, branched or cyclic. The aryl group may be a substituted or unsubstituted aryl group having 20 or less carbon atoms. The heterocyclic group may be a heterocyclic group having 20 or less carbon atoms.

Specific examples of the substituted or unsubstituted aryl group constituting the general formula (3) include a phenyl group, a 1-naphthyl group, a 2-naphthyl group, a 2-anthryl group, a 9- A thienyl group, a 2-thiazolyl group, a 2-thienyl group, a 2-thienyl group, a 2-thienyl group, a 2-thiazolyl group, Oxazolyl group, 2-benzothiazolyl group, 2-benzoimidazolyl group, and the like, but are not limited thereto.

Specific examples of the alkyl group constituting the general formula (3) include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec- N-hexyl group, 3-methylbutyl group, cyclohexyl group, n-heptyl group, cyclohexylmethyl group, n-pentyl group, n-decyl group, n-dodecyl group, n-tetradecyl group, and n-hexadecyl group. Of these groups, But is not limited thereto.

Specific examples of the fluorene derivatives as described above include the following compounds (3) -1 to (3) -20.

- carbazole derivatives -

As a material constituting the second hole transporting layer 14b-2, for example, a carbazole derivative represented by the following general formula (4) is used.

In the general formula (4), Ar ¹ and Ar ² each independently represent an aryl group or a heterocyclic group, and they may have a substituent.

Examples of the aryl group represented by Ar ¹ and Ar ² include a group consisting of a monocyclic ring or a 2 to 5-condensed ring of a benzene ring. Specific examples thereof include a phenyl group, a naphthyl group, an anthryl group, a phenanthryl group, , Perylenyl group and the like. Examples of the heterocyclic group include a monocyclic ring of a 5-membered ring or a 6-membered ring, or a 2-to 5-condensed ring. Specific examples thereof include a pyridyl group, a triazinyl group, a pyrazinyl group, a quinoxalinyl group and a thienyl group have.

Examples of the substituent that the aryl group or heterocyclic group may have include an alkyl group (e.g., a linear or branched alkyl group having 1 to 6 carbon atoms such as a methyl group and an ethyl group), an alkenyl group (e.g., , A linear or branched alkenyl group having 1 to 6 carbon atoms), an alkoxycarbonyl group (e.g., a linear or branched alkoxycarbonyl group having 1 to 6 carbon atoms such as a methoxycarbonyl group or an ethoxycarbonyl group), an alkoxy group (Such as an alkoxy group having 6 to 10 carbon atoms, such as a phenoxy group or a naphthoxy group), an aralkyloxy group (such as a methoxy group, an ethoxy group, Examples thereof include aryl groups having 7 to 13 carbon atoms, such as benzyloxy groups, aryl groups having 2 to 20 carbon atoms, such as a secondary or tertiary amino group (e.g., a dialkyl group having a linear or branched alkyl group having 2 to 20 carbon atoms, such as diethylamino group and diisopropylamino group A halogen atom (a fluorine atom, a chlorine atom, a bromine atom or an iodine atom), an aromatic group (for example, a fluorine atom, a bromine atom or an iodine atom), an amino group, a diarylamino group such as a diphenylamino group or a phenylnaphthylamino group, A 5-membered or 6-membered monocyclic or bicyclic ring such as a hydrocarbon ring (for example, an aromatic hydrocarbon ring group having 6 to 10 carbon atoms such as a phenyl group or a naphthyl group) and an aromatic heterocyclic group (for example, a thienyl group or a pyridyl group) Aromatic heterocyclic group), and the like.

Of these, alkyl, alkoxy, alkylamino, arylamino, arylalkylamino, halogen, aryl (aromatic hydrocarbon ring), and heterocyclic Do.

When Ar ¹ and Ar ² each have three or more aromatic groups connected through two or more direct bonds, for example, a terphenyl group or the like, a hole having an arylamino group represented by -NAr ¹ Ar ² There is a possibility of deteriorating the transportation ability. Therefore, in order not to impair the properties of the compound according to the present invention, Ar ¹ and Ar ² are both groups in which at least three aryl groups or heterocyclic groups are not directly bonded, or are bonded in series via short- It is important that this is not done.

In the general formula (4), R ¹ to R ⁸ are each independently selected from the group consisting of hydrogen, halogen, alkyl, aralkyl, alkenyl, cyano, amino, acyl, alkoxycarbonyl, carboxyl, alkoxy, An alkylsulfonyl group, a hydroxyl group, an amide group, an aryl group, or a heterocyclic group, and may form a cyclic structure at an adjacent site. Also, where possible, R ¹ to R ⁸ may each be further substituted with another substituent.

Examples of R ¹ to R ⁸ are halogen (fluorine, chlorine, bromine or oxo); An alkyl group (e.g., a linear or branched alkyl group having 1 to 6 carbon atoms such as a methyl group or an ethyl group; a cycloalkyl group having 5 to 8 carbon atoms such as a cyclopentyl group or a cyclohexyl group); An aralkyl group (e.g., an aralkyl group having 7 to 13 carbon atoms, such as a benzyl group or a phenethyl group); An alkenyl group (e.g., a straight or branched alkenyl group having 2 to 7 carbon atoms, such as a vinyl group or an allyl group); Cyano; Amino groups, particularly tertiary amino groups (for example, dialkylamino groups having a straight chain or branched alkyl group having 2 to 20 carbon atoms such as diethylamino group and diisopropylamino group, dianhydrides such as diphenylamino group and phenylnaphthylamino group, An arylamino group having 7 to 20 carbon atoms, such as a methylamino group, a reylamino group, and a methylphenylamino group); An acyl group (for example, an acyl group containing a straight chain, branched or cyclic hydrocarbon group portion of 1 to 20 carbon atoms such as an acetyl group, a propionyl group, a benzoyl group or a naphthoyl group); An alkoxycarbonyl group (for example, a linear or branched alkoxycarbonyl group having 2 to 7 carbon atoms, such as a methoxycarbonyl group or an ethoxycarbonyl group); A carboxyl group; An alkoxy group (e.g., a linear or branched alkoxy group having 1 to 6 carbon atoms, such as a methoxy group or an ethoxy group); An aryloxy group (for example, an aryloxy group having 6 to 10 carbon atoms such as a phenoxy group and a benzyloxy group); An alkylsulfonyl group (for example, an alkylsulfonyl group having 1 to 6 carbon atoms such as a methylsulfonyl group, an ethylsulfonyl group, a propylsulfonyl group, a butylsulfonyl group and a hexylsulfonyl group); A hydroxyl group; An amide group (for example, an alkylamide group having 2 to 7 carbon atoms, such as a methylamide group, a dimethylamide group or a diethylamide group; an arylamide group such as a benzylamide group or a dibenzylamide group); An aryl group (for example, an aromatic hydrocarbon ring group comprising a monocyclic ring of a benzene ring or a 2 to 4 condensed ring such as a phenyl group, a naphthyl group, an anthryl group, a phenanthryl group or a pyrenyl group); Or an aromatic heterocyclic group consisting of a monocyclic or bicyclic condensed ring of a 5-membered or 6-membered ring such as a carbazolyl group, a pyridyl group, a triazyl group, a pyrazyl group, a quinoxalyl group or a thienyl group, )to be.

More preferably, R ¹ to R ⁸ are a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an aryl group (aromatic hydrocarbon ring group), or a heterocyclic group (aromatic heterocyclic group).

As the examples of R ¹ to R ⁸ , the groups described above may further have a substituent. Examples of such a substituent include a halogen atom (fluorine atom, chlorine atom, bromine atom or oxo atom); An alkyl group (for example, a linear or branched alkyl group having 1 to 6 carbon atoms such as a methyl group and an ethyl group); An alkenyl group (e.g., a linear or branched alkenyl group having 1 to 6 carbon atoms, such as a vinyl group or an allyl group); An alkoxycarbonyl group (for example, a linear or branched alkoxycarbonyl group having 1 to 6 carbon atoms, such as a methoxycarbonyl group or an ethoxycarbonyl group); An alkoxy group (e.g., a linear or branched alkoxy group having 1 to 6 carbon atoms, such as a methoxy group or an ethoxy group); An aryloxy group (for example, an aryloxy group having 6 to 10 carbon atoms, such as a phenoxy group or a naphthoxy group); A dialkylamino group (e.g., a dialkylamino group having a straight chain or branched alkyl group having 2 to 20 carbon atoms, such as diethylamino group and diisopropylamino group); Diarylamino groups (for example, diarylamino groups such as diphenylamino group and phenylnaphthylamino group); Aromatic hydrocarbon ring group (for example, aromatic hydrocarbon ring group such as phenyl group); An aromatic heterocyclic group (for example, an aromatic heterocyclic group comprising a monocyclic ring of a 5-membered ring or a 6-membered ring such as a thienyl group or a pyridyl group); An acyl group (for example, a linear or branched acyl group having 1 to 6 carbon atoms, such as an acetyl group or a propionyl group); A haloalkyl group (e.g., a straight or branched haloalkyl group having 1 to 6 carbon atoms, such as a trifluoromethyl group); And cyano group. Of these, a halogen atom, an alkoxy group and an aromatic hydrocarbon ring group are more preferable.

The adjacent groups of R ¹ to R ⁸ may be bonded to each other to form a ring condensed on the N-carbazolyl group. Of the rings R ¹ to R ⁸ , the ring formed by bonding adjacent groups to each other is usually a 5- to 8-membered ring, but is preferably a 5-membered ring or a 6-membered ring, more preferably a 6-membered ring. The ring may be an aromatic ring or a non-aromatic ring, but is preferably an aromatic ring. The ring may be an aromatic hydrocarbon ring or an aromatic heterocyclic ring, but is preferably an aromatic hydrocarbon ring.

In the N-carbazolyl group of the formula (4), examples of forming a condensed ring in which any one of R ¹ to R ⁸ is bonded to the N-carbazolyl group is as follows.

Wherein R ¹ ~R ⁸ are, in particular, of preferably, both injeuk hydrogen atom, N- carbazolyl group being unsubstituted), or structure, or R ¹ ~R at least one of the ^eight methyl groups, a phenyl group, or a methoxy group And the other is a hydrogen atom.

X in the general formula (4) represents a divalent aromatic ring group. For example, a linking group comprising 1 to 4 divalent alicyclic groups or divalent heterocyclic groups, and may be further substituted.

Such a connecting group X ^{is, -Ar 3 -, -Ar 4 -Ar} 5 -, -Ar 6 -Ar 7 -Ar 8 - is represented by -, or ^{-Ar 9 -Ar 10 -Ar 11 -Ar 12} .

Ar ³ , Ar ⁴ , Ar ⁵ , Ar ⁶ , Ar ⁸ , Ar ^9, and Ar ¹² constituting the terminal portion of the linking group X represent a divalent group consisting of a monocyclic aromatic ring or a 2-5 condensed ring having 5 to 6 atoms as the raw water , Or may be substituted.

Specific examples of such Ar ³ , Ar ⁴ , Ar ⁵ , Ar ⁶ , Ar ⁸ , Ar ⁹ and Ar ¹² include divalent aromatic hydrocarbon ring groups (for example, phenylene group, naphthylene group, anthrylene, phenanthrylene group, A perylene group, a perylene group); And a divalent aromatic heterocyclic group (e.g., a pyridylene group, a triazylene group, a pyrazylene group, a quinoxaline group, a thienyl group, and an oxadiazolylene group).

Ar ⁷ , Ar ¹⁰ and Ar ¹¹ constituting the middle part of the linking group X may be the same bivalent aromatic group as Ar ³ or the like or a divalent arylamino group. However, in the case of a divalent arylamino group, the aryl group is an aromatic group of a 5-membered or 6-membered ring, and includes, for example, a phenyl group, a naphthyl group, an anthryl group, a phenanthryl group, a thienyl group, a pyridyl group, , They may have a substituent.

Ar ^{3, which} is the smallest linking group as the linking group X, is preferably at least a tri-condensed ring to improve the rigidity of the compound and the heat resistance caused thereby.

Ar ⁴ , Ar ⁵ , Ar ⁶ , Ar ⁸ , Ar ⁹ and Ar ¹² constituting the end of the linking group X are preferably a monocyclic or bicytoctylated ring, and more preferably a monocyclic or bicyclic ring.

Examples of the substituent substituted on the aromatic ring constituting the above linking group X include the same groups as described above as the substituent which may be substituted for each of R ¹ to R ⁸ . Among them, an alkyl group, an alkoxy group, an aromatic hydrocarbon ring group or an aromatic heterocyclic group is particularly preferable.

Specific examples of such carbazole derivatives include the following compounds (4) -1 to (4) -26.

The second hole transporting layer 14b-2 as described above may be composed of a plurality of compounds in the organic materials represented by the general formulas (2) to (4), or may have a laminated structure per se.

In the case where the second hole transporting layer 14b-2 is constituted by using the general formula (3) or (4) in the organic electroluminescence device 11 'provided with the second hole transporting layer 14b-2 described above, , And the photosensitizing layer 14d preferably contains a hole trapping property compound. Examples of the hole trapping compound include amino naphthalene derivatives, aminoanthracene derivatives, aminocrysene derivatives, aminopyrene derivatives, styrylamine derivatives, and bis (azinyl) methane boron complexes.

In the organic electroluminescent device 11 'having the second hole transporting layer 14b-2 made of the above-described material, as described in detail in the following embodiments, The initial deterioration of the luminance lifetime is remarkably improved while maintaining the luminous efficiency and the color purity, as compared with the structure including the hole transport layer of the single-layer structure made of the material of the hole transport layer.

As a result, the organic electroluminescent element 11 'can improve the luminance lifetime and reduce the power consumption by providing the light enhancement layer 14d in the same manner as the organic electroluminescent element 11 described with reference to Fig. 1 In addition, by specifying the lamination structure of the hole transport layer 14b, it is possible to improve the luminance lifetime and reduce the power consumption.

<< Schematic Configuration of Display Device >>

3 (A) and 3 (B) are views showing an example of a display device 10 according to an embodiment of the present invention. FIG. 3 (A) is a schematic structural view, and FIG. 3 FIG. Here, an embodiment in which the present invention is applied to the active matrix type display device 10 using the organic electroluminescence element 11 as the light emitting element will be described.

As shown in Fig. 3 (A), a display region 12a and its peripheral region 12b are set on the substrate 12 of the display device 10. Fig. The display region 12a is configured as a pixel array portion in which a plurality of signal lines 23 are wired in a longitudinal and a horizontal direction with a plurality of scanning lines 21 and one pixel a is provided corresponding to each intersection portion. One of the organic electroluminescence elements 11R (11), 11G, and 11B is provided for each pixel a . In the peripheral region 12b, a scanning line driving circuit b for scanning-driving the scanning line 21 and a signal line driving circuit c for supplying a video signal (that is, an input signal) according to luminance information to the signal line 23 are arranged.

As shown in Fig. 3 (B), the pixel circuit provided in each pixel a includes, for example, one of the organic electroluminescence elements 11R (11), 11G and 11B, the driving transistor Tr1, A transistor (sampling transistor) Tr2, and a storage capacitor Cs. The video signal recorded from the signal line 23 through the recording transistor Tr2 is held in the storage capacitor Cs by driving by the scanning line driving circuit b and the current corresponding to the held signal amount is supplied to each organic field Are supplied to the light emitting elements 11R (11), 11G, and 11B, and the organic electroluminescence elements 11R (11), 11G, and 11B emit light with the brightness corresponding to the current values.

The above-described configuration of the pixel circuit is merely an example. If necessary, a capacitor element may be provided in the pixel circuit, or a plurality of transistors may be provided to constitute the pixel circuit. In the peripheral region 2b, a necessary driving circuit is added in accordance with the change of the pixel circuit.

«Sectional configuration of display device -1»

4 shows a first example of a sectional configuration of a main part in the display area of the display device 10. [

In the display region of the substrate 12 on which the organic electroluminescence devices 11R (11), 11G and 11B are provided, a driving transistor, a scanning transistor, a scanning line, and a signal line (See Fig. 3), and an insulating film is provided so as to cover them.

Organic electroluminescence devices 11R (11), 11G and 11B are arranged on a substrate 12 covered with this insulating film. Each of the organic electroluminescence devices 11R (11), 11G, and 11B is configured as a top emission type device for extracting light from the opposite side of the substrate 12.

The anode 13 of each of the organic electroluminescent elements 11R (11), 11G, and 11B is pattern-formed for each element. Each of the positive electrodes 13 is connected to a driving transistor of the pixel circuit through a connection hole formed in an insulating film covering the surface of the substrate 12. [

The periphery of each anode 13 is covered with an insulating film 30 and the central portion of the anode 13 is exposed in the opening portion formed in the insulating film 30. [ The organic layer 14 is patterned to cover the exposed portion of the anode 13 and the cathode 15 is provided as a common layer covering each organic layer 14. [

Among these organic electroluminescence devices 11R (11), 11G and 11B, in particular, the red light emitting device 11R is configured as the organic electroluminescence device 11 of the embodiment described with reference to Fig. On the other hand, the green light emitting element 11G and the blue light emitting element 11B may have a common device structure.

That is, in the red light emitting element 11R (11), the organic layer 14 provided on the anode 13 includes, for example, the hole injection layer 14a, the hole transport layer 14b A red light emitting layer 14c-R (14c) using a naphthacene derivative as a host material, a photosensitizing layer 14d formed by doping a luminescent guest material for generating green light into a host material, and an electron transport layer 14e .

On the other hand, the organic layers in the green light emitting element 11G and the blue light emitting element 11B are formed by sequentially stacking the hole injection layer 14a, the hole transport layer 14b, (14c-G, 14c-B), and an electron transport layer (14e).

The light enhancement layer 14d in the red light emitting element 11R (11) is doped with a green luminescent guest material. For example, the green light emitting layer 14c- G) may be the same configuration (material). Each layer other than the light-emitting layers 14c-R, 14c-G and 14c-B and the photosensitizing layer 14d includes the positive electrode 13 and the negative electrode 15, The elements 11R, 11G, and 11B may be made of the same material, or may be formed using the respective materials described with reference to Fig.

The plurality of organic electroluminescence elements 11R (11), 11G, and 11B provided as described above are covered with a passivation film. The passivation film is provided so as to cover the entire display region provided with the organic electroluminescence elements 11R, 11G, and 11B.

Each layer from the anode 13 to the cathode 15 constituting the red light emitting element 11R (11), the green light emitting element 11G and the blue light emitting element 11B is formed by a vacuum vapor deposition method, ), A molecular beam epitaxy (MBE) method, a sputtering method, or an organic vapor phase deposition (OVPD) method.

If the organic layer is involved, in addition to the above methods, a wet process such as a coating method (e.g., laser transfer method, spin coating method, dipping method, doctor blade method, ejection coating method, spray coating method) , Ink jet method, offset printing method, convex printing method, concave printing method, screen printing method, micro gravure coating method). Depending on the properties of each organic layer and each member, a dry method and a wet method may be used together It is possible.

As described above, the organic layer 14 formed in a pattern for each of the organic electroluminescence elements 11R (11), 11G, and 11B is formed by, for example, a vapor deposition method or a transfer method using a mask.

In the display device 10 of the first example configured as described above, the organic electroluminescent element 11 having the structure according to the embodiment of the present invention described with reference to Fig. 1 is used as the red light emitting element 11R. The red light emitting element 11R (11) has a high light emitting efficiency while maintaining the red light emitting color as described above. For this reason, by combining the green light emitting element 11G and the blue light emitting element 11B together with the red light emitting element 11R (11), it becomes possible to perform full-color display with high color expression.

Further, by using the organic electroluminescent element 11 having a high luminous efficiency, it is possible to improve the luminance lifetime and the power consumption of the display device 10. Therefore, the display device 10 can be preferably used as a flat panel display such as a wall-hung TV or a flat light-emitting device, and can be applied to a light source such as a copying machine or a printer, a light source such as a liquid crystal display or a meter, .

«Sectional configuration of display device -2»

5 shows a second example of the cross-sectional configuration of the main portion in the display area of the display device 10. As shown in Fig.

The display device 10 of the second example shown in Fig. 5 is different from the first example shown in Fig. 4 in that the photosensitivity layer 14d (14c-G) and the luminescent layer 14c- The electron transport layer 14e is formed as a common continuous pattern in the elements 11R (11), 11G and the electron transport layer 14e is formed as a continuous pattern of the common layer in all the pixels, and the other structures may be the same.

Even the display device 10 of the second example configured as described above can bring about the same effect as that of the first example. The light-enhancement layer 14d (14c-G) and the light-emitting layer 14c-G are formed as a common layer in a continuous pattern in each of the organic electroluminescence devices 11R (11) and 11G, 14e can be formed simultaneously with all the pixels. Therefore, the manufacturing process of the display device 10 can be simplified.

«Sectional configuration of display device -3»

6 shows a third example of the sectional configuration of the main part in the display area of the display device 10. In Fig.

In the display device 10 of the third example shown in Fig. 6, the anode 13 and the light-emitting layers 14c-R, 14c-G, and 14c-14 in the respective organic electroluminescence devices 11R (11) B are used as the common layer, the other constitution may be the same as the second example shown in Fig. That is, contrary to the second example of FIG. 5, the hole injection layer 14a and the hole transport layer 14b, which are lower than the light emitting layer, are also used as a common layer.

Also in the display device 10 of the third example configured as described above, the same effects as those of the second example can be obtained, and the manufacturing process can be further simplified as compared with the second example.

«Sectional configuration of display device -4»

7 shows a fourth example of the cross-sectional configuration of the main portion in the display area of the display device 10. Fig.

7, each of the organic electroluminescence elements 11R, 11G, and 11B can be formed as a common layer above the light-emitting layers 14c-R and 14c-B. In this case, A green luminescent layer 14c-G serving also as a sensitizing layer 14d, an electron transport layer 14e and a cathode 15 are formed in common in all the display regions and the other layers are used as a patterned layer.

The green light emitting layer 14c-G which is a common layer over all the pixels is provided as the light enhancement layer 14d in the red light emitting element 11R (11). On the other hand, a green light emitting layer 14c-G is also laminated on the blue light emitting element 11B. Even in such a configuration, when the film thickness of the blue luminescent layer 14c-B is sufficiently thick or when the blue luminescent center locally exists at the interface of the hole transporting layer 14b, It is sufficiently possible to obtain good blue light emission. In the respective organic electroluminescence devices 11R (11), 11G and 11B, since the structure of the organic layer is formed as a cavity structure for drawing out the emitted light of each color, only the blue light from the blue light emitting device 11B Or the like.

In manufacturing the display device 10 having such a configuration, each layer in the upper layer from the green light-emitting layer 14c-G (the light enhancement layer 14d) is displayed using an area mask of a large diameter So that the manufacturing process of the display device 10 can be simplified.

In the fourth example, it is also possible to use the hole injection layer 14a and the hole transport layer 14b below the light emitting layer as a common layer (continuous pattern) in the entire display region. With this configuration, the manufacturing process of the new display device 10 can be simplified.

In the first to fourth examples as described above, an embodiment in which the present invention is applied to an active matrix type display device has been described. However, the display device of the present invention can be applied to a passive matrix type display device, and the same effect can be obtained.

The display device according to the present invention as described above also includes a module shape having a sealed configuration as shown in Fig. For example, a sealing portion 31 is provided so as to surround the display region 12a, which is a pixel array portion. While the sealing portion 31 is used as an adhesive, an opposing portion such as a transparent glass 32) of the display module. The transparent sealing substrate 32 may be provided with a color filter, a passivating film, a light shielding film, or the like. A flexible printed circuit board 33 for inputting and outputting signals from the outside to the display area 12a (pixel array part) may be provided on the substrate 12 as a display module in which the display area 12a is formed .

In the above-described display device, each of the red light emitting elements 11R may be the organic electroluminescent element 11 'described with reference to Fig. In this case, the hole transporting layers of the other green light emitting element 11G and the blue light emitting element 11B may have the same lamination structure as the red light emitting element 11R (11 ').

By using the organic electroluminescent element 11 'having the structure according to the embodiment of the present invention described with reference to Fig. 2 as the red electroluminescent element 11R, the red electroluminescent element 11R (11' The initial deterioration of the luminance lifetime can be suppressed to a low level while maintaining the light emitting efficiency and the color purity. Therefore, by combining the green light emitting element 11G and the blue light emitting element 11B together with the red light emitting element 11R (11 '), it becomes possible to perform full color display with high color expression, and at the same time, ) Can be prevented.

Further, by using the organic electroluminescent device 11 'having a high luminous efficiency, it is possible to improve the luminance lifetime and the power consumption of the display device 10. Therefore, it can be suitably used as a flat panel display such as a wall-mounted TV or a flat light emitting device, and can be applied to a light source such as a copying machine or a printer, a light source such as a liquid crystal display or instrument, a display panel, and a cover.

«Application example»

The display device according to the embodiment of the present invention as described above can be applied to various electronic devices as shown in Figs. 9 to 13, for example, a portable terminal device such as a digital camera, a notebook type personal computer, The present invention can be applied to a display device of an electronic device in all fields that displays a video signal input to an electronic device or a video signal generated in an electronic device as an image or an image. Hereinafter, an example of an electronic apparatus to which the present invention is applied will be described.

9 is a perspective view showing a television receiver to which an embodiment according to the present invention is applied. The television receiver according to the present application example includes an image display screen unit 101 composed of a front panel 102, a filter glass 103 and the like, and the image display screen unit 101 is used as an example of the present invention By using a display device according to the present invention.

Fig. 10 is a perspective view of the digital camera to which the present invention is applied. Fig. 10 (A) is a perspective view as seen from the front side, and Fig. 10 (B) is a perspective view as seen from the rear side. The digital camera according to this application example includes a flash light emitting unit 111, a display unit 112, a menu switch 113, a shutter button 114, and the like. By using a display device according to the present invention.

11 is a perspective view showing a notebook-type personal computer to which the present invention is applied. The notebook type personal computer according to this application example includes a keyboard 122 that is operated when a character or the like is input to the main body 121, a display unit 123 that displays an image, and the like. Lt; / RTI &gt; is used.

12 is a perspective view showing a video camera to which the present invention is applied. The video camera according to this application example includes a main body 131, a lens 132 for photographing a subject on the side facing forward, a start / stop switch 133 for photographing, a display 134, (134). &Lt; / RTI &gt;

13A to 13G are views showing a portable terminal device to which the present invention is applied, for example, a cellular phone. Fig. 13A is a front view in an open state, Fig. 13B 13 (D) is a left side view, Fig. 13 (E) is a right side view, Fig. 13 (F) is a top view, Is a bottom view. The mobile phone according to this application example includes an upper housing 141, a lower housing 142, a connecting portion (hinge portion in this case) 143, a display 144, a sub-display 145, a picture light 146, 147 and the like, and is manufactured by using the display device according to the embodiment of the present invention as the display 144 or the sub-display 145.

The procedure of manufacturing the organic electroluminescent device of the specific examples and the comparative examples of the present invention will be described with reference to Fig. 1, and the evaluation results thereof will be described.

Example  1 to 4

An organic electroluminescent device was manufactured using a perylene derivative as a red luminescent guest material in the light emitting layer (see Table 1).

First, an ITO transparent electrode of 12.5 nm was laminated on an Ag alloy (reflective layer) having a thickness of 190 nm as a cathode 13 on a substrate 12 made of a glass plate of 30 mm x 30 mm, Cell was prepared.

Next, as a hole injection layer 14a of the organic layer 14, a film made of m-MTDATA represented by the following structural formula (101) was formed to a thickness of 12 nm (deposition rate: 0.2 to 0.4 nm / sec) . Here, m-MTDATA means 4,4 ', 4 "-tris (phenyl-m-tolylamino) triphenylamine.

Subsequently, a film made of? -NPD represented by the following structural formula (102) was formed as a hole transporting layer 14b with a film thickness of 12 nm (deposition rate: 0.2 to 0.4 nm / sec). Here,? -NPD means N, N'-bis (1-naphthyl-N, N'-diphenyl [1,1'-biphenyl] -4,4'-diamine.

Next, on the hole transport layer 14b, a luminescent layer 14c with a film thickness of 30 nm was deposited by evaporation. At this time, rubrene of the following compound (1) -1 was used as a host material, and dibenzo [f, f '] diindeno [1,2,3- cd: 1 ', 2', 3'-1m] perylene derivative was doped with a relative film thickness ratio of 1% as a red luminescent guest material.

On the thus-formed light-emitting layer 14c, a 25 nm-thick light-enhancement layer 14d was deposited by vapor deposition. At this time, 9,10-di- (2-naphthyl) anthracene (ADN) represented by the following structural formula (103) was used as a host material, and a diaminoanthracene derivative represented by the following structural formula (104) As a luminescent guest material. The green luminescent guest material was doped in the doping amounts (relative film thickness ratio) of 2%, 5%, 10% and 15% in Examples 1 to 4, respectively.

Subsequently, Alq3 (8-hydroxyquinoline aluminum) represented by the following structural formula (105) was vapor-deposited as the electron transport layer 14e to a thickness of 10 nm.

After forming the organic layer 14 in which the hole injecting layer 14a, the hole transporting layer 14b, the light emitting layer 14c, the photosensitizing layer 14d and the electron transporting layer 14e are stacked in this order, A film made of LiF was formed to a thickness of about 0.3 nm (evaporation rate: 0.01 nm / sec) by a vacuum evaporation method as the first layer 15a of the film 15. Finally, a MgAg film having a thickness of 10 nm was formed as the second layer 15b of the negative electrode 15 on the first layer 15a by the vacuum vapor deposition method.

Thus, the organic electroluminescent devices of Examples 1 to 4 were produced.

Example  5 to 9

In the formation of the photosensitivity layer 14d in the manufacturing procedure of the organic electroluminescent device described in Examples 1 to 4, the materials shown by the structural formulas (106) to (110) as the green luminescent guest materials were used, Thereby forming a sensitizing layer 14d. The doping amount of the guest material was 5% in the relative film thickness ratio in Example 5 and 1% in the relative film thickness ratio in Examples 6 to 9. The other procedures were the same as in Examples 1 to 4.

Comparative Example  One

Instead of forming the photosensitizing layer 14d in the manufacturing procedure of the organic electroluminescent device described in Examples 1 to 4, the film thickness of the electron transporting layer made of Alq3 (8-hydroxyquinoline aluminum) was changed to 45 nm Thickness. The other procedures were the same as in Examples 1 to 4.

Comparative Example  2

In forming the photosensitizing layer 14d in the manufacturing procedure of the organic electroluminescent device described in Examples 1 to 4, the photosensitizing layer 14d was formed only of the host material without doping the green luminescent guest material. The other procedures were the same as in Examples 1 to 4.

&Lt; Evaluation result &gt;

Each of the organic electroluminescent devices manufactured in Examples 1 to 9 and Comparative Examples 1 and 2 was tested for the driving voltage (V), current efficiency (cd / A), and color at the current density of 10 mA / The coordinates (x, y) were measured. The obtained results are shown in Table 1 below.

As shown in Table 1, in any of the organic electroluminescent devices of Examples 1 to 9 to which the present invention was applied, the same driving voltage as that of the organic electroluminescent devices of Comparative Examples 1 and 2, to which the present invention was not applied, The current efficiency is almost twice as high. This shows that the energy recombined in the photosensitizing layer 14d composed of the host material ADN and the luminescent guest material brings about the effect of the light increase (light amount increase) in the light emitting layer 14c.

In addition, in the organic electroluminescent devices of Examples 1 to 9, even though the photosensitivity layer 14d doped with a green luminescent guest was laminated on the red luminescent layer 14c, the color coordinates of the luminescent light were 0.64 , 0.34) was observed, and the influence of the color mixture derived from the green emission was not observed. Particularly, in all of the organic electroluminescent devices of Examples 4 to 9 in which the type of the luminous guest material to be doped was changed in the photosensitivity layer 14d, the color coordinates of the emitted light were (0.64, 0.34). From this fact, it has been confirmed that, according to the constitution of the present invention, the red light emission generated in the red light emitting layer 14c is drawn out regardless of the luminescent guest material of the photosensitizer layer 14d.

Example  10 to 13

An organic electroluminescent device was produced using a diketopyrrolopyrrole derivative as a red luminescent guest material in the light emitting layer (see Table 2 below).

The diketopyrrolopyrrole derivative represented by the following formula (6) -5 as a red luminescent guest material in the formation of the light emitting layer 14c in the manufacturing procedure of the organic electroluminescent device described in Examples 1 to 4 was mixed with 1% Doped with a relative film thickness ratio. The other procedures were the same as in Examples 1 to 4.

Example  14 to 18

In forming the photosensitizing layer 14d in the manufacturing procedure of the organic electroluminescent device described in Examples 10 to 13, the materials represented by the structural formulas (106) to (110) are used as the green luminescent guest materials Thereby forming a photosensitizer layer 14d. The doping amount of the guest material was 5% in the relative film thickness ratio in Example 14 and 1% in the relative film thickness ratio in Examples 15 to 18. The other procedures were the same as in Examples 10 to 13.

Comparative Example  3

Instead of forming the photosensitizing layer 14d in the manufacturing procedures of the organic electroluminescent device described in Examples 10 to 13, the film thickness of the electron transporting layer made of Alq3 (8-hydroxyquinoline aluminum) was changed to 45 nm . The other procedures were the same as in Examples 10 to 13.

Comparative Example  4

In forming the photosensitizing layer 14d in the manufacturing procedures of the organic electroluminescent device described in Examples 10 to 13, the photosensitizing layer 14d was formed only of the host material without doping the green luminescent guest material. The other procedures were the same as in Examples 10 to 13.

&Lt; Evaluation result &gt;

Each of the organic electroluminescent devices manufactured in Examples 10 to 18 and Comparative Examples 3 and 4 was tested for driving voltage (V), current efficiency (cd / A), color The coordinates (x, y) were measured. The obtained results are shown in Table 2 above.

As shown in Table 2, in all of the organic electroluminescent devices of Examples 10 to 18 to which the present invention was applied, the same driving voltage as that of the organic electroluminescent devices of Comparative Examples 3 and 4, The current efficiency is almost twice as high. This shows that the energy recombined in the photosensitizing layer 14d composed of the host material ADN and the luminescent guest material brings about the effect of the light increase (light amount increase) in the light emitting layer 14c.

Further, in the organic electroluminescent devices of Examples 10 to 18, even though the photosensitivity layer 14d doped with a guest luminescent green in the host was laminated on the red luminescent layer 14c, Luminescence was observed and the influence of the color mixture derived from the emission of green was not observed. Particularly, in all of the organic electroluminescent devices of Examples 14 to 18, in which the kind of the luminous guest material to be doped was changed in the photosensitivity layer 14d, red luminescence was confirmed and the luminous guest material of the photosensitivity layer 14d It was confirmed that the red light emitted from the red light emitting layer 14c was drawn out.

Example  19 to 22

An organic electroluminescent device was prepared using a pyromethene complex as a red luminescent guest material in the light emitting layer (see Table 3 below).

In the formation of the light emitting layer 14c in the manufacturing procedure of the organic electroluminescence device described in Examples 1 to 4, the pyromethene complex represented by the following compound (7) -21 was used as the red luminescent guest material in 1% relative Doped with a film thickness ratio. The other procedures were the same as in Examples 1 to 4.

Example  23 to 27

In the formation of the photosensitivity layer 14d in the manufacturing procedure of the organic electroluminescent device described in Examples 19 to 22, the materials represented by the structural formulas (106) to (110) were used as the green luminescent guest materials, respectively Thereby forming a photosensitizer layer 14d. The doping amount of the guest material was 5% in the relative film thickness ratio in Example 23 and 1% in the relative film thickness ratio in Examples 24-27. The other procedures were the same as in Examples 19 to 22.

Comparative Example  5

Instead of forming the photosensitizing layer 14d in the manufacturing procedure of the organic electroluminescent device described in Examples 19 to 22, the film thickness of the electron transporting layer made of Alq3 (8-hydroxyquinoline aluminum) was changed to 45 nm . The other procedures were the same as in Examples 19 to 22.

Comparative Example  6

In forming the photosensitizing layer 14d in the manufacturing procedure of the organic electroluminescent device described in Examples 19 to 22, the photosensitizing layer 14d was formed only of the host material without doping the green luminescent guest material. The other procedures were the same as in Examples 19 to 22.

&Lt; Evaluation result &gt;

Each of the organic electroluminescent devices manufactured in Examples 19 to 27 and Comparative Examples 5 and 6 was tested for the driving voltage (V), current efficiency (cd / A), and color during driving at a current density of 10 mA / The coordinates (x, y) were measured. The obtained results are shown in Table 3 above.

As shown in Table 3, in all of the organic electroluminescent devices of Examples 19 to 27 to which the present invention was applied, the organic electroluminescent devices of Comparative Examples 5 and 6, to which the present invention was not applied, The current efficiency is 2.5 times or more. This shows that the energy recombined in the photosensitizing layer 14d composed of the host material ADN and the luminescent guest material brings about the effect of the light increase (light amount increase) in the light emitting layer 14c.

In addition, in the organic electroluminescent devices of Examples 19 to 27, even though the photosensitivity layer 14d doped with a guest luminescent green in the host was laminated on the red luminescent layer 14c, Luminescence was observed and the influence of the color mixture derived from the emission of green was not observed. Particularly, in all of the organic electroluminescent devices of Examples 23 to 27 in which the type of the luminous guest material to be doped was changed in the photosensitivity layer 14d, red luminescence was confirmed, and the luminescent guest material of the photosensitivity layer 14d It was confirmed that the red light emitted from the red light emitting layer 14c was drawn out.

Example  28 to 31

An organic electroluminescent device was prepared using a pyran derivative as a red luminescent guest material in the light emitting layer (see Table 4 below).

(8) -2 was used as a red luminescent guest material in the formation of the light emitting layer 14c in the manufacturing procedure of the organic electroluminescent device described in Examples 1 to 4, I was doped with rain. The other procedures were the same as in Examples 1 to 4.

Example  32 to 36

In forming the photosensitizing layer 14d in the manufacturing procedures of the organic electroluminescent device described in Examples 28 to 31, the materials represented by the structural formulas (106) to (110) were used as the green luminescent guest materials, Thereby forming a photosensitizer layer 14d. The doping amount of the guest material in Example 32 was 5% as a relative film thickness ratio, and the relative film thickness ratio in Examples 33 to 36 was 1%. The other procedures were the same as in Examples 28 to 31.

Comparative Example  7

Instead of forming the photosensitizing layer 14d in the manufacturing procedures of the organic electroluminescent device described in Examples 28 to 31, the film thickness of the electron transporting layer made of Alq3 (8-hydroxyquinoline aluminum) was changed to 45 nm . The other procedures were the same as in Examples 28 to 31.

Comparative Example  8

In forming the photosensitizing layer 14d in the manufacturing procedures of the organic electroluminescent device described in Examples 28 to 31, the photosensitizing layer 14d was formed only of the host material without doping with the green luminescent guest material. The other procedures were the same as in Examples 28 to 31.

&Lt; Evaluation result &gt;

The driving voltage (V), the current efficiency (cd / A) and the color at the time of driving at a current density of 10 mA / cm 2 were measured for each of the organic EL devices manufactured in Examples 28 to 36 and Comparative Examples 7 and 8 The coordinates (x, y) were measured. The obtained results are shown in Table 4 above.

As shown in Table 4, in all of the organic electroluminescent devices of Examples 28 to 36 to which the present invention was applied, the organic electroluminescent devices of Comparative Examples 7 and 8, to which the present invention was not applied, The current efficiency shows a high value of three times or more. This shows that the energy recombined in the photosensitizing layer 14d composed of the host material ADN and the luminescent guest material brings about the effect of the light increase (light amount increase) in the light emitting layer 14c.

In addition, in the organic electroluminescent devices of Examples 28 to 36, even though the photosensitivity layer 14d doped with a guest luminescent green in the host was laminated on the red luminescent layer 14c, Luminescence was observed and the influence of the color mixture derived from the emission of green was not observed. Particularly, in all of the organic electroluminescent devices of Examples 32 to 36, in which the type of the luminous guest material to be doped was changed in the photosensitivity layer 14d, red luminescence was confirmed, and the relationship with the luminescent guest material of the photosensitivity layer 14d It was confirmed that red light emission generated in the red light emitting layer 14c was drawn out.

Example  37 to 40

An organic electroluminescent device was produced using a styryl derivative as a red luminescent guest material in the light emitting layer (see Table 5 below).

In the formation of the light emitting layer 14c in the manufacturing procedure of the organic electroluminescent device described in Examples 1 to 4, the styryl derivative represented by the following compound (9) -21 was added as a red luminescent guest material to 1% Lt; / RTI &gt; The other procedures were the same as in Examples 1 to 4.

Example  41 to 45

In the formation of the photosensitivity layer 14d in the manufacturing procedures of the organic electroluminescent device described in Examples 37 to 40, the materials represented by the structural formulas (106) to (110) were used as the green luminescent guest materials, respectively Thereby forming a photosensitizer layer 14d. The doping amount of the guest material was 5% in the relative film thickness ratio in Example 41 and 1% in the relative film thickness ratio in Examples 42 to 45. [ The other procedures were the same as in Examples 37 to 40.

Comparative Example  9

Instead of forming the photosensitizing layer 14d in the manufacturing procedures of the organic electroluminescent device described in Examples 37 to 40, the film thickness of the electron transporting layer made of Alq3 (8-hydroxyquinoline aluminum) was changed to 45 nm . The other procedures were the same as in Examples 37 to 40.

Comparative Example  10

In forming the light-shielding layer 14d in the manufacturing procedures of the organic electroluminescent device described in Examples 37 to 40, the photosensitizing layer 14d was formed only of the host material without doping the green luminescent guest material. The other procedures were the same as in Examples 37 to 40.

&Lt; Evaluation result &gt;

The driving voltage (V), the current efficiency (cd / A), and the driving voltage (Vdd) during driving at a current density of 10 mA / cm 2 were measured for each of the organic EL devices manufactured in Examples 37 to 45 and Comparative Examples 9 and 10 The coordinates (x, y) were measured. The results obtained are shown in Table 5 above.

As shown in Table 5, in all of the organic electroluminescent devices of Examples 37 to 45 to which the present invention was applied, the organic electroluminescent devices of Comparative Examples 9 and 10, to which the present invention was not applied, The current efficiency shows a high value almost twice. This shows that the energy recombined in the photosensitizing layer 14d composed of the host material ADN and the luminescent guest material brings about the effect of the light increase (light amount increase) in the light emitting layer 14c.

In addition, in the organic electroluminescent devices of Examples 37 to 45, even though the photosensitivity layer 14d doped with a guest luminescent green in the host was laminated on the red luminescent layer 14c, Luminescence was observed and the influence of the color mixture derived from the emission of green was not observed. Particularly, in all of the organic electroluminescent devices of Examples 41 to 45 in which the kind of the luminescent guest material to be doped was changed in the photosensitivity layer 14d, the red luminescence was confirmed and the luminescent guest material of the photosensitivity layer 14d It was confirmed that the red light emitted from the red light emitting layer 14c was drawn out.

From the evaluation results of each of the examples and comparative examples described above, a material selected from organic materials known as a host material and an impurity material constituting the red light emitting layer 14c is used, and various kinds of green It has been confirmed that the structure according to the embodiment of the present invention in which the photosensitivity layer 14d containing the chromatic guest is provided can significantly improve the luminous efficiency (current efficiency) while maintaining the color purity of red .

This shows that it is possible to realize a full-color display with high color reproducibility by constituting pixels by using a pair of a green light emitting element and a blue light emitting element together with such organic electroluminescent elements.

Example  46 to 57

The above-described organic electroluminescent device was manufactured with reference to FIG. Here, in the manufacturing procedures of the organic electroluminescent device described in Examples 1 to 4, the hole transport layer 14b was formed as the following laminated structure, and the other procedures were the same as those of Examples 1 to 4. In the photosensitizer layer 14d, the doping amount of the guest material made of the structural formula (104) was set to 5% as a relative film thickness ratio as in Example 2. [

That is, in forming the hole transporting layer 14b, a film made of? -NPD shown by the above-mentioned structural formula (102) as the first hole transporting layer 14b-1 is formed to a thickness of 6 nm (deposition rate: 0.2 to 0.4 nm / sec).

Then, a film made of 12 kinds of the following compounds selected from the compounds (2) -1 to (2) -48 as the second hole transporting layer 14b-2 was formed to a thickness of 6 nm (deposition rate: 0.2 to 0.4 nm / sec) .

&Lt; Evaluation result &gt;

(Cd / A) and color coordinates (x, y) at the time of driving at a current density of 10 mA / cm 2 were measured for each of the organic electroluminescent devices manufactured in Examples 46 to 57, Were measured. In addition, the luminance reduction rate after 100 hours of elapse of driving at a current density of 30 mA / cm &lt; 2 &gt; and a duty of 75% was measured as an index of sealing. These results are shown in Table 6 below. Table 6 also shows the measurement results of Example 2 having the same structure as Examples 46 to 57 except that the hole transporting layer 14b has a single layer structure instead of the laminated structure.

As shown in Table 6, in all of the organic electroluminescent devices of Examples 46 to 57 in which the hole transport layer 14b was formed as the specific lamination structure using the material of the general formula (2), the hole transport layer 14b had a single layer structure The luminance reduction rate after a lapse of 100 hours in the duty 75% driving is low while maintaining the current efficiency at substantially the same driving voltage. This shows that the charge balance due to the recombination of holes and electrons in the light emitting layer 14c is adjusted, and the effect of preventing a temporal decrease in luminance is obtained.

In the organic electroluminescent devices of Examples 46 to 57, even though the photosensitivity layer 14d doped with a green luminescent guest was laminated on the red luminescent layer 14c, the color coordinates of the luminescent light were 0.64 , 0.34) was observed, and the influence of the color mixture derived from the green emission was not observed. Based on this fact, it has been confirmed that, according to the constitution of the embodiment of the present invention, the red light emission generated in the red light emitting layer 14c is drawn out regardless of the guest material of the light emission enhancing layer 14d.

From the above, it can be seen that the initial deterioration of the luminance lifetime can be greatly improved while maintaining the luminous efficiency and color purity by constructing the hole transport layer 14b by applying the present invention to a specific laminated structure using the material of the general formula (2) .

Example  58 to 62

The organic electroluminescent device described with reference to FIG. 2 was fabricated. Here, in the manufacturing procedures of the organic electroluminescent device described in Examples 1 to 4, the hole transport layer 14b was formed as the following laminated structure, and the other procedures were the same as those of Examples 1 to 4. The doping amount of the guest material made of the structural formula (104) in the photosensitizer layer 14d was 5% in terms of the relative film thickness ratio as in Example 2.

That is, in the formation of the hole transporting layer 14b, a film made of? -NPD shown by the above-described structural formula (102) as the first hole transporting layer 14b-1 is formed to a thickness of 6 nm (deposition rate: 0.2 to 0.4 nm / sec).

Subsequently, a film composed of the following five compounds selected from the compounds (3) -1 to (3) -20 in Examples 58 to 62 as the second hole transporting layer 14b-2 was formed to a thickness of 6 nm (deposition rate: 0.2 To 0.4 nm / sec), respectively.

&Lt; Evaluation result &gt;

(Cd / A) and color coordinates (x, y) at the time of driving at a current density of 10 mA / cm 2 were measured for each of the organic EL devices manufactured in Examples 58 to 62. [ Were measured. In addition, as an indicator of sealing, the luminance reduction rate after 100 hours of operation at a current density of 30 mA / cm 2 and a duty of 75% was measured. The results obtained are shown in Table 7 below. Table 7 also shows the measurement results of Example 2 having the same structure as Examples 46 to 57 except that the hole transporting layer 14b has a single layer structure instead of the lamination structure.

As shown in Table 7, in all of the organic electroluminescent devices of Examples 58 to 62 in which the hole transport layer 14b was formed as a specific lamination structure using the material of the general formula (3), the hole transport layer 14b had a single layer structure The luminance reduction rate after a lapse of 100 hours in the duty 75% driving is low while maintaining the current efficiency at substantially the same driving voltage. This indicates that the charge balance due to the recombination of holes and electrons in the light emitting layer 14c is adjusted, and the effect of preventing a temporal decrease in luminance is obtained.

In the organic electroluminescent devices of Examples 58 to 62, even though the photosensitivity layer 14d doped with a green luminescent guest was laminated on the red luminescent layer 14c, the color coordinates of the luminescent light were 0.64 , 0.34) was observed, and the influence of the color mixture derived from the green emission was not observed. Based on this fact, it has been confirmed that, according to the constitution of the embodiment of the present invention, the red light emission generated in the red light emitting layer 14c is drawn out regardless of the guest material of the light emission enhancing layer 14d.

From the above, it can be seen that the initial deterioration of the luminance lifetime can be greatly improved while maintaining the luminous efficiency and color purity by constructing the hole transport layer 14b by applying the present invention to a specific laminated structure using the material of the general formula (3) .

Example  63 to 69

The organic electroluminescent device described with reference to FIG. 2 was fabricated. Here, in the manufacturing procedures of the organic electroluminescent device described in Examples 1 to 4, the hole transporting layer 14b was formed as the following laminated structure, and the other procedures were the same as those of Examples 1 to 4. [ In the photosensitizer layer 14d, the doping amount of the guest material of the structural formula (104) was 5% in the same relative film thickness ratio as in Example 2. [

That is, in forming the hole transporting layer 14b, a film made of? -NPD shown by the above-mentioned structural formula (102) as the first hole transporting layer 14b-1 is formed to a thickness of 6 nm (deposition rate: 0.2 to 0.4 nm / sec).

Next, films of the following seven compounds selected from the compounds (4) -1 to (4) -26 in Examples 63 to 69 as the second hole transporting layer 14b-2 were formed to a thickness of 6 nm (deposition rate: 0.2 To 0.4 nm / sec), respectively.

&Lt; Evaluation result &gt;

(Cd / A) and color coordinates (x, y) at the time of driving at a current density of 10 mA / cm 2 were measured for each of the organic EL devices manufactured in Examples 63 to 69, Were measured. In addition, as an indicator of sealing, the luminance reduction rate after 100 hours of operation at a current density of 30 mA / cm 2 and a duty of 75% was measured. These results are shown in Table 8 below. Table 8 also shows the measurement results of Example 2 having the same configuration as Examples 46 to 57 except that the hole transporting layer 14b has a single layer structure instead of the lamination structure.

As shown in Table 8, in all of the organic electroluminescent devices of Examples 63 to 69 in which the hole transporting layer 14b was formed as a specific lamination structure using the material of the general formula (4), the hole transporting layer 14b had a single- The luminance reduction rate after a lapse of 100 hours in the duty 75% driving is low while maintaining the current efficiency at substantially the same driving voltage. This indicates that the charge balance due to the recombination of holes and electrons in the light-emitting layer 14c is adjusted, and the effect of preventing a temporal decrease in luminance is obtained.

In the organic electroluminescent devices of Examples 63 to 69, even though the photosensitivity layer 14d doped with a green luminescent guest was laminated on the red luminescent layer 14c, the color coordinates of the luminescent light were 0.64 , 0.34) was observed, and the influence of the color mixture derived from the green emission was not observed. Based on this fact, it has been confirmed that, according to the constitution of the embodiment of the present invention, the red light emission generated in the red light emitting layer 14c is drawn out regardless of the guest material of the light emission enhancing layer 14d.

From the above, it can be seen that the initial deterioration of the luminance lifetime can be greatly improved while maintaining the luminous efficiency and color purity by constructing the hole transport layer 14b by applying the present invention to a specific laminated structure using the material of the general formula (4) .

Example  70 to 73

A display device using the same organic electroluminescent device as those of Examples 46, 52, 58 and 63 was produced by the following method (see Fig. 6).

First, the anode 13 was patterned on the display region of the substrate 12, and an insulating film 30 having openings exposing the centers of the respective anodes 13 was formed. Subsequently, after the hole injection layer 14b is formed by using a mask with a large hole having an opening corresponding to the entire surface of the display area, the same hole transport layer 14b as in Example 46 is formed in Example 70 , The same hole transport layer 14b as in Example 52 was formed in Example 71, and the same hole transport layer 14a as in Example 58 was formed in Example 72. In Example 73, the same hole transport layer 14b ).

Next, a stripe-shaped mask having openings corresponding to the formation regions (red regions) of the red light emitting elements was used to form the light emitting layers 14c and 14c-R in the same manner as in Example 1, Respectively. Further, the light emitting layer 14c-B in the blue region was formed by using a stripe-type mask having an opening corresponding to the formation region (blue region) of the blue light emitting element.

After forming the red light-emitting layers 14c and 14c-R, a stripe-shaped mask having an intermediate hole having openings corresponding to the red region and the green region was used to form the light enhancement layer 14d, A green light emitting layer 14c-G serving as a light emitting layer was also formed.

Subsequently, an electron transport layer 14e was formed in the same manner as in Example 1, and a cathode 15 having a two-layer structure was formed by using a large hole mask having an opening corresponding to the entire surface of the display region .

As described above, in Example 70, the organic electroluminescent device of Example 46 in which the configuration according to the embodiment of the present invention is applied to the red region is formed as a red light emitting device, a green light emitting device is formed in the green region, A display device having a blue light emitting element formed thereon was obtained.

In Example 71, the organic electroluminescent element of Example 52 to which the structure according to the embodiment of the present invention was applied in the red region was formed as a red light emitting element, a green light emitting element was formed in the green region, A display device having a blue light emitting element formed thereon was obtained.

In Example 72, the organic electroluminescent device of Example 58, in which the configuration according to the embodiment of the present invention is applied to the red region, is formed as a red light emitting element, a green light emitting element is formed in the green region, A display device having a device formed thereon was obtained.

In Example 73, the organic electroluminescent device of Example 63 in which the configuration according to the embodiment of the present invention was applied to the red region was formed as a red light emitting element, a green light emitting element was formed in the green region, A display device having a device formed thereon was obtained.

A specific fixed screen was displayed using this display device, and evaluation of red coloring was evaluated. As a result, the display was not confirmed in all of the display devices of Examples 70 to 73.

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

2 is a cross-sectional view showing another example of an organic electroluminescent device according to an embodiment of the present invention.

3 (A) and 3 (B) are diagrams showing an example of the circuit configuration of the display device according to the embodiment of the present invention.

4 is a view showing a first example of a sectional configuration of a main part in a display device according to an embodiment of the present invention.

5 is a view showing a second example of a sectional configuration of a main part in a display device according to an embodiment of the present invention.

6 is a view showing a third example of the sectional configuration of the main part in the display device according to the embodiment of the present invention.

7 is a view showing a fourth example of a sectional configuration of a main part in a display device according to an embodiment of the present invention.

8 is a configuration diagram showing a module-shaped display device of a sealed configuration to which an embodiment according to the present invention is applied.

9 is a perspective view showing a television receiver to which an embodiment according to the present invention is applied.

Fig. 10 shows a digital camera to which an embodiment according to the present invention is applied. Fig. 10 (A) is a perspective view from the front side, and Fig. 10 (B) is an attempt from a rear side.

11 is a perspective view showing a notebook-type personal computer to which an embodiment according to the present invention is applied.

12 is a perspective view showing a video camera to which an embodiment according to the present invention is applied.

13A to 13G are views showing a portable terminal device, for example, a mobile phone to which the embodiment according to the present invention is applied. Fig. 13A is a front view in the open state, Fig. 13 (B) is a side view thereof, Fig. 13 (C) is a front view in a closed state, Fig. 13 (D) is a left side view, (G) is a bottom view.

Claims (13)

Anode; A cathode; And An organic layer including a light emitting layer provided between the anode and the cathode Wherein the red light emitting organic electroluminescent device comprises: Wherein the light emitting layer contains a host material comprising a red luminescent guest material and a polycyclic aromatic hydrocarbon compound having a skeleton of 4 to 7 rings, A photosensitizing layer containing a luminescent guest material for generating green light is provided in contact with the light emitting layer, As the host material contained in the light-emitting layer, rubrene represented by the following formula (1) -1 is used, (5) -1, (6) -5, (7) -21, (8) -2 or (9) - 21, 9,10-di- (2-naphthyl) anthracene (ADN) represented by the following structural formula (103) is used as a host material contained in the photosensitizer layer, The luminous guest material that generates green light contained in the photosensitizer layer is a diaminoanthracene selected from the following structural formulas (104), (106) to (110) Wherein the hole transporting layer provided adjacent to the light emitting layer comprises a plurality of layers each made of a different material and the layer adjacent to the light emitting layer comprises an organic material represented by the following general formula (2), (3) or (4) Configured to use, Organic electroluminescent device.

(In the above formula, A ^{1 to} A ³ each independently represent an aryl group or a heterocyclic group.)

A ^{1 to} A ⁴ , Z ¹ and Z ² each independently represent a hydrogen atom, a halogen atom, a hydroxyl group, a carbonyl group, a carbonyl ester group, an alkyl group, an alkenyl group, an alkoxyl group, , Ar ¹ and Ar ² each independently represent an aryl group or a heterocyclic group, and B ¹ and B ² each represent an aryl group or a heterocyclic group, respectively, and A ^{1 to} A ⁴ may form a cyclic structure at adjacent positions, Hydrogen, an alkyl group, an aryl group, or a heterocyclic group.

(Wherein, Ar ¹ and Ar ² are, each independently, an aryl group or represents a heterocyclic group, R ¹ ~R ⁸ are, each independently, hydrogen, halogen, an alkyl group, an aralkyl group, an alkenyl group, a cyano group, an amino group An amide group, an aryl group, or a heterocyclic group, and may form a cyclic structure at an adjacent site, and X may be a divalent aromatic group such as a divalent aromatic group, Indicates ventilation.) delete delete The method according to claim 1, Wherein the light enhancement layer is provided between the light emitting layer and the cathode adjacent to the light emitting layer. The method according to claim 1, Wherein the red light generated in the light emitting layer interferes with multiple layers between any one of the anode and the cathode and is drawn out from either the anode or the cathode. delete delete delete delete A display device comprising a plurality of red light emitting organic electroluminescent devices including a positive electrode, a negative electrode, and an organic layer including a light emitting layer on a substrate, Wherein the light emitting layer contains a host material composed of a red luminescent guest material and a polycyclic aromatic hydrocarbon compound having a skeleton of 4 to 7 rings, A light enhancement layer containing a luminescent guest material for generating green light is provided in contact with the light emitting layer, As the host material contained in the light-emitting layer, rubrene represented by the following formula (1) -1 is used, (5) -1, (6) -5, (7) -21, (8) -2 or (9) - 21, 9,10-di- (2-naphthyl) anthracene (ADN) represented by the following structural formula (103) is used as a host material contained in the photosensitizer layer, The luminous guest material that generates green light contained in the photosensitizer layer is a diaminoanthracene selected from the following structural formulas (104), (106) to (110) Wherein the hole transporting layer provided adjacent to the light emitting layer comprises a plurality of layers each made of a different material and the layer adjacent to the light emitting layer comprises an organic material represented by the following general formula (2), (3) or (4) Configured to use, Organic electroluminescent device.

(In the above formula, A ^{1 to} A ³ each independently represent an aryl group or a heterocyclic group.)

A ^{1 to} A ⁴ , Z ¹ and Z ² each independently represent a hydrogen atom, a halogen atom, a hydroxyl group, a carbonyl group, a carbonyl ester group, an alkyl group, an alkenyl group, an alkoxyl group, , Ar ¹ and Ar ² each independently represent an aryl group or a heterocyclic group, and B ¹ and B ² each represent an aryl group or a heterocyclic group, respectively, and A ^{1 to} A ⁴ may form a cyclic structure at adjacent positions, Hydrogen, an alkyl group, an aryl group, or a heterocyclic group.

(Wherein, Ar ¹ and Ar ² are, each independently, an aryl group or represents a heterocyclic group, R ¹ ~R ⁸ are, each independently, hydrogen, halogen, an alkyl group, an aralkyl group, an alkenyl group, a cyano group, an amino group An amide group, an aryl group, or a heterocyclic group, and may form a cyclic structure at an adjacent site, and X may be a divalent aromatic group such as a divalent aromatic group, Indicates ventilation.) 11. The method of claim 10, Wherein the organic electroluminescent element is provided in a part of pixels of a plurality of pixels as a red light emitting element. 12. The method of claim 11, Wherein the photosensitizing layer of the organic electroluminescent element covers a plurality of pixels so as to function as a common light emitting layer. 12. The method of claim 11, A blue light emitting organic electroluminescent element and a green light emitting organic electroluminescent element are provided on the substrate together with the red light emitting element.

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