JP2790353B2 - Organic thin-film electroluminescence device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic thin-film electroluminescence device, and more particularly, to an organic thin-film electroluminescence device used as a luminous body of various display devices.

[Problems to be solved by conventional technology and invention]

Electroluminescence device (hereinafter referred to as EL device)
Is characterized by high visibility due to self-luminescence and excellent impact resistance because it is a completely solid-state device. Currently, various EL devices using inorganic and organic compounds for the light-emitting layer have been proposed. Has been attempted for practical use. Among these, various materials are being developed for the organic thin film EL element because the applied voltage can be greatly reduced.

On the other hand, a BN pn junction type light emitting diode has been realized at the laboratory level for ultraviolet light emitting solid-state devices (Sci.
ence, 238 , 181 (1987) and JSAP Catalog Number 881105
−03, p.916). This device can emit ultraviolet light having a wavelength of 200 to 400 nm. However, it is difficult to grow a large BN crystal, and at present, light emission is obtained only by a crystal as large as 1 mm. Therefore, practical application is extremely difficult, and surface light emission is impossible.

By the way, the organic thin-film EL element can obtain surface light of visible light by applying a voltage of several tens of volts with a relatively simple element configuration, but has not yet obtained light emission of ultraviolet light (Thin).
Solid Films, 94 , 171 (1982), JP-A-61-43682 to JP-A-61-43691, JP-A-59-194393, Appl. Phys.
Lett. 51 , 913 (1987) and US Patent No. 9720437).

Organic single-crystal EL devices emit ultraviolet light using crystals of p-terphenyl and naphthalene, but require an applied voltage of 100 V or more, and must use a single crystal. Poor and impractical (Z. Bursht
ein, Mol. Cryst. 60 , 207 (1980)).

[Means for solving the problem]

Therefore, the present inventors have solved the above-mentioned problems of the prior art, emit light with high luminance only by applying a low voltage, and have a simple structure and can be easily manufactured. We worked diligently to develop EL devices that can be manufactured.

As a result, they have found that by using a specific organic compound as a light emitting material, or by providing this organic compound between electrodes as desired, these conditions can be achieved, and furthermore, ultraviolet surface light emission can be realized. The present invention has been completed based on such findings. That is, the present invention provides a compound represented by the general formula (I): Or general formula (II) [Wherein, R ^{1 to} R ¹⁰ are each a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a hydroxyl group, a sulfonic acid group, a carbonyl group, a carboxyl group, an amino group, and a dimethylamino group. , A cyano group, a halogen atom, an acyloxy group, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an aminocarbonyl group or an acylamino group, and these R ^{1 to} R ¹⁰ are bonded to each other to be substituted or unsubstituted saturated. A 5-membered ring or a substituted or unsubstituted saturated 6-membered ring may be formed. n shows the integer of 2-5. Note that a plurality of R ^{4 to} R ⁶ may be the same or different. However, in formula (I), the case where all of R ^{1 to} R ⁹ represent a hydrogen atom and n represents 3 is excluded. ] It is intended to provide an organic thin film EL device characterized by using a compound represented by the formula (1) as a light emitting material.

In the present invention, the organic compound used as the light-emitting material is a compound represented by the above general formula (I) or (II), and this compound may be of various types depending on the types of the substituents R ^{1 to} R ^{10 in} the formula. can give. That is, R ^{1 to} R ¹⁰ are each a hydrogen atom, an alkyl group having 1 to 6 carbon atoms (methyl group, ethyl group, isopropyl group, tert-butyl group, etc.),
An alkoxy group having 1 to 6 carbon atoms (methoxy group, ethoxy group, propoxy group, butoxy group, etc.), hydroxyl group, sulfonic acid group, carbonyl group, carboxyl group, amino group, dimethylamino group, cyano group, halogen atom (chlorine, Fluorine, bromine, iodine), acyloxy group (acetoxy group, benzoyloxy group, etc.), acyl group (acetyl group, benzoyl group, etc.), alkoxycarbonyl group (methoxycarbonyl group, etc.), aryloxycarbonyl group (phenoxycarbonyl group, etc.) , An aminocarbonyl group or an acylamino group (acetamino group, benzamino group, etc.), and these R ^{1 to} R ¹⁰ are bonded to each other to form a substituted or unsubstituted saturated 5-membered ring or a substituted or unsubstituted saturated 6-membered ring.
A member ring may be formed. n shows the integer of 2-5. Further, the numbers R ^{4 to} R ⁶ corresponding to the number n may be the same or different. However, in the formula (I), compounds wherein all of R ^{1 to} R ⁹ represent a hydrogen atom and n represents 3 are excluded from the scope of the present invention.

Among such compounds of the present invention, particularly, the compound represented by the general formula (I)
Or phenylene group in (II) (substituted phenylene group)
Is bonded to adjacent groups on both sides at the p-position (in other words, a compound having a p-phenylene group (substituted p-phenylene group)) because a compound having good crystallinity and a smooth deposited film can be formed. preferable.

Specific examples of such a compound of the present invention are as follows.

In the EL device of the present invention, the thickness of the thin film made of the light-emitting material may be appropriately selected depending on the situation, but is usually
It may be about 5 nm to 5 μm. The EL device of the present invention has various configurations. Basically, a light-emitting layer made of the light-emitting material is provided between two electrodes (an anode and a cathode, at least one of which is transparent or translucent). As a sandwiched structure, another layer may be interposed as necessary. Specifically, (1) anode / light emitting layer / cathode, (2) anode / hole injection layer / light emitting layer / cathode, (3) anode / hole injection layer / light emitting layer / electron injection layer / cathode, 4) anode / light-emitting layer /
There are configurations such as an electron injection layer / cathode. In addition, these EL
The element is preferably formed on a supporting substrate.

The light emitting layer in the EL device of the present invention has the following three functions. Injection function When an electric field is applied, holes can be injected from the anode or the hole injection / transport layer, and electrons can be injected from the cathode or the electron injection / transport layer. Transport function Injected charges (electrons and holes) ) The function of moving the) by the force of an electric field. Light-emitting function Provides a field for recombination of electrons and holes, and connects it to light emission. However, there is a difference between the ease of hole injection and the ease of electron injection. Although the transport ability represented by the mobility of holes and electrons may be large or small, it is preferable to transfer either one of the charges.

However, here, in an electroluminescence device that emits near-ultraviolet light as in the present invention, since light in this wavelength range is absorbed by many organic compounds, it interacts with the material forming the light emitting layer in a broad sense. Is likely to occur, and it may be difficult to uniquely identify the light emitting region for the following reasons.

The excited state formed at the interface by the interaction between the light emitting layer and the hole injection layer (exciplex generation) emits light.
That is, the hole injection layer also contributes to light emission.

Near-ultraviolet light emitted from the light emitting layer excites the fluorescent hole injection layer to generate fluorescence.

In the EL device of the present invention, the compound of the general formula (I) or (II) used as a light-emitting material (light-emitting layer) has a relatively small ionization energy in terms of structure. It is easy to inject target holes.
Also, the electron affinity is relatively large, and if an appropriate cathode metal or cathode compound is selected, electrons can be relatively easily injected. Moreover, the electron and hole transport functions are excellent. Further, since the solid state fluorescence is strong, the ability to convert the excited state of the compound, its aggregate, crystal or the like formed at the time of recombination of electrons and holes into light is large.

The substrate that can be used in the EL device of the present invention is preferably a substrate having transparency, and generally, glass, transparent plastic, quartz, or the like is applied. The electrodes (cathode, cathode) may be made of a metal such as gold, aluminum, or indium, an alloy, a mixture, or a transparent material such as indium tin oxide (a mixed oxide of indium oxide and tin oxide; ITO), SnO ₂ , and ZnO. Preferably, it is used. Also, JP-A-63-2956
The alloy and mixture electrodes disclosed in Japanese Patent Publication No. 95 are preferred. A metal with a high work function or an electrically conductive compound is suitable for the anode, and a metal or an electrically conductive compound with a small work function is suitable for the cathode. It is preferable that at least one of these electrodes is transparent or translucent in order to increase the transmittance of light emission.

EL (1) EL composed of anode / light-emitting layer / cathode described above
In order to produce an element, for example, the following procedure may be followed. That is, first, an electrode is formed on a substrate by vapor deposition or sputtering. At this time, the thickness of the film-like electrode is generally 10 nm to 1 μm, and particularly preferably 200 nm or less, in order to increase the transmittance of light emission. Next, a light emitting material (compound of the general formula (I) or (II)) is formed on the electrode in a thin film to form a light emitting layer. The light-emitting material can be made into a thin film by spin coating, casting, vapor deposition, or the like, but vapor deposition is particularly preferred because a uniform film is easily obtained and pinholes are not generated. When using a vapor deposition method for thinning the light emitting material, the vapor deposition conditions include, for example, a boat heating temperature of 50 to 400 ° C., a degree of vacuum of 10 ⁻⁵ to 10 ⁻³ Pa, and a vapor deposition rate of 0.03 to 50 n.
m / sec, film thickness 5nm-5μm in substrate temperature range -50 ~ + 300 ℃
What is necessary is just to select. After forming this thin film, an EL element is formed by forming a counter electrode with a thickness of 50 to 200 nm by a vapor deposition method or a sputtering method. The conditions for forming the light emitting layer vary depending on the type of the compound of the general formula (I) or (II), the target crystal structure of the molecular deposition film, the association structure, and the like, and may vary in various ways. Is preferably maintained at a temperature at which the compound of the general formula (I) or (II) does not decompose.

Further, in order to form an EL device having the structure of (2) anode / hole injection layer / light emitting layer / cathode, first, electrodes are formed in the same manner as the EL device of (1), and then the hole injection material ( The hole transport compound is thinned on the electrode by an evaporation method to form a hole injection transport layer. The vapor deposition conditions at this time may be in accordance with the vapor deposition conditions for forming the thin film of the light emitting material. After that, the EL of (1) above
By forming a thin film of a light emitting material and forming a counter electrode in the same manner as in the case of fabricating the element, the desired configuration of (2) can be obtained
An EL element is created. In the EL device having the configuration (2), the order of manufacturing the hole injection layer and the light emitting layer may be reversed, and the electrode, the light emitting layer, the hole injection layer, and the electrode may be manufactured in this order.

Further, in order to prepare an EL device having the constitution of (3) anode / hole injection layer / light-emitting layer / electron injection layer / cathode, first, electrodes are formed in the same manner as in the above-mentioned EL device (1). A hole injection layer is formed in the same manner as in the above-mentioned EL element (2), and a thin film of a luminescent material is formed thereon in the same manner as in the case of forming the above-mentioned EL element (1). Thereafter, the electron injecting material (electron transfer compound) is thinned by an evaporation method to form an electron injecting layer on the light emitting layer, and finally, as in the case of producing the EL element of (1) above, By forming the counter electrode, the intended EL device having the above configuration (3) is manufactured. The fabrication of the EL device having the configuration (4) is the same as that of the configuration (1) up to the formation of the light-emitting layer, and then may be performed according to the fabrication method for the electron injection layer and the configuration (3). Here, the order of forming the hole injection layer, the light emitting layer, the electron injection layer or the light emitting layer and the electron injection layer may be reversed in the same order as in the element configuration (1) and (2).

In the EL device of the present invention, the hole injection layer and the electron injection layer are not necessarily required, but the presence of these layers further improves the light emission performance. Here, the hole injection layer is made of a hole transport compound (hole injection material) and has a function of transmitting holes injected from the anode to the light emitting layer. By sandwiching this layer between the anode of the EL element and the light emitting layer, more holes are injected into the light emitting layer at a low voltage, and the luminance of the element is improved.

The hole transport compound of the hole injection layer used here is disposed between two electrodes to which an electric field is applied, and when holes are injected from the anode, the holes are appropriately transmitted to the light emitting layer. Is a compound that can be By sandwiching the hole injection layer between the anode and the light emitting layer, many holes are injected into the light emitting layer with a lower electric field. Furthermore, electrons injected from the cathode or the electron injection layer into the light emitting layer are accumulated near the interface in the light emitting layer due to the electron barrier existing at the interface between the light emitting layer and the hole injection layer, and the luminous efficiency is improved. Preferred hole transport compounds here have a hole mobility of at least 10 ^-6 cm ² / volt-second when the layer is placed between electrodes exposed to an electric field of 10 ⁴ to 10 ⁶ volts / cm. . Therefore, preferred examples include various compounds used as a hole charge transporting material in a photoconductive material.

Examples of such charge transport materials include the following.

Triazole derivatives described in U.S. Patent No. 3,112,197, etc., oxadiazole derivatives described in U.S. Patent No. 3,189,447, etc., imidazole derivatives described in JP-B-37-1696, etc. U.S. Patent Nos. 3615402, 3820989, 3542544 and JP-B-45-555, 51-10983, and JP-A-51-93224, 55-17105, 56-4148 , Id 55
Polyarylalkane derivatives described in JP-A-108667, JP-A-55-156953, JP-A-56-36656 and the like; U.S. Patent Nos. 3,180,729 and 4,278,746;
-88064, 55-88065, 49-105537, 55-51
Nos. 086, 56-80051, 56-88141, 57-45545
Pyrazoline derivatives and pyrazolone derivatives described in U.S. Pat. Nos. 6,115,105, 54-112637, 55-74546, and the like.
46-3712, 47-25336 and JP-A-54-534.
Phenylenediamine derivatives described in JP-A Nos. 35, 54-110536 and 54-119925; U.S. Pat. Nos. 3,567,450, 3,180,703, 3,240,597;
Nos. 3,658,520, 4,322,103, 4,117,961 and 4,012,376, and JP-B-49-35702, JP-A-39-27577, and JP-A-55-144250, JP-A-56-119132, and JP-A-56-119. 22437
JP-A No. 1110518, arylamine derivatives described in U.S. Pat.No. 3,235,501, amine-substituted chalcone derivatives described in U.S. Pat.No. 3,235,203, U.S. Pat. Oxazole derivatives, styryl anthracene derivatives described in JP-A-56-46234, etc., fluorenone derivatives described in JP-A-54-110837, etc., U.S. Pat. 54-59143, same
55-52063, 55-52064, 55-46760, 55-8
Hydrazone derivatives described in JP-A-5495, JP-A-57-11350, JP-A-57-148749 and the like; JP-A-61-210363, JP-A-61-228451, JP-A-61-14642
Nos. 61-72255, 62-47646, 62-36674,
No. 62-10652, No. 62-30255, No. 60-93445, No. 60
Stilbene derivatives and the like described in JP-A-94462, JP-A-60-174749, JP-A-60-175052 and the like can be listed.

More particularly preferred examples include a compound (aromatic tertiary amine) as a hole transport layer and a compound (porphyrin compound) as a hole injection zone disclosed in JP-A-63-295695. .

Further preferred examples of the hole transport compound are described in JP-A-53-27033, JP-A-54-58445, and JP-A-54-149634.
JP-A-54-64299, JP-A-55-79450, and 55
No. 144250, No. 56-119132, No. 61-295558, No. 61-98353, and U.S. Pat. No. 4,127,412. Examples of these are as follows.

The hole injecting layer is formed from these hole transporting compounds. The hole injecting layer may be composed of one layer, or a hole injecting layer using a compound different from the above one layer may be laminated. A preferred example is disclosed in JP-A-63-295695.

On the other hand, the electron injection layer has a function of transmitting electrons injected from the cathode to the light emitting layer.

Preferred examples of the electron transfer compound (electron injection material) for forming the electron injection layer include: Nitro-substituted fluorenone derivatives such as JP-A-57-149259, JP-A-58-55450 and JP-A-63-104061.
No. 3 (1988), p.68, anthraquinodimethane derivatives described in Japanese Unexamined Patent Publication No.
Listed in 1 etc. Diphenylquinone derivatives such as, Thiopyran dioxide derivatives such as those described in JJAPPl. Phys., 27, L269 (1988). A compound represented by the formula described in Appl. Phys. Lett. Vol. 55 (1989), p. Compounds represented by the following formulas: JP-A-60-69657, JP-A-61-143764, JP-A-61-148159
And the anthraquinodimethane derivatives and anthrone derivatives described in JP-A Nos. 61-225151 and 61-233750.

In the EL element of the present invention, when the applied voltage is AC (AC drive), light emission is observed only in a bias state in which a positive voltage is applied to the anode side. When the applied voltage is direct current (direct current drive), light emission is always observed by applying a positive voltage to the anode side.

〔Example〕

Next, the present invention will be described in more detail with reference to Examples and Comparative Examples.

Example 1 ITO was deposited on a 25 mm × 75 mm × 1.1 mm glass substrate by vapor deposition.
A transparent support substrate was formed with a thickness of 100 nm. This transparent support substrate is supplied to a commercially available vapor deposition device (Nihon Vacuum Technology Co., Ltd.)
200 mg of 3,5,3 ', 5'-tetrabutyl kinkphenyl (TBQ) was placed in a molybdenum resistance heating boat, and the pressure in the vacuum chamber was reduced to 1 × 10 ^-4 Pa.

Thereafter, the boat was heated to 270 to 290 ° C., and TBQ was deposited on the transparent support substrate at a deposition rate of 0.2 to 0.5 nm / sec to obtain a 0.7 μm-thick crystalline luminescent thin film. The substrate temperature at this time was 150 ° C. Take this out of the vacuum chamber, place a stainless steel mask on the phosphor thin film,
It was fixed to the substrate holder again.

Next, 20 mg of gold was placed in a molybdenum resistance heating boat, and the pressure in the vacuum chamber was reduced to 2 × 10 ⁻⁴ Pa.

Thereafter, the boat was heated to 1400 ° C., and a gold electrode having a thickness of 50 nm was formed on the luminous body thin film to form a counter electrode.

This device uses a direct current 6 with the gold electrode as the positive electrode and the ITO electrode as the negative electrode.
0 V was applied. As a result, a current of 50 μA flowed, and on-plane light emission was obtained from the near-ultraviolet region to the visible light blue region and from the entire region sandwiched between the two electrodes visible in the dark. As a result of spectrometry, the emission wavelength range was distributed from 380 nm to 500 nm, and the maximum wavelength was 435 nm. When measuring the light emission intensity with a photodiode
0.02 mW / cm ² .

Example 2 ITO was deposited on a 25 mm × 75 mm × 1.1 mm glass substrate by vapor deposition.
A transparent support substrate was formed with a thickness of 100 nm. This transparent support substrate is supplied to a commercially available vapor deposition device (Nihon Vacuum Technology Co., Ltd.)
) Substrate holder and a molybdenum resistance heating boat, N, N'-diphenyl-N, N'-bis (3-methylphenyl)-[1,1'-biphenyl] -4,4'- 200 mg of diamine (TPDA) was put, and 200 mg of TBQ was put into another molybdenum boat in the same manner as in Example 1, and the vacuum chamber was set to 1 × 10 ⁻⁴ Pa
The pressure was reduced to

Thereafter, the boat containing TPDA was heated to 215 to 220 ° C., and TPDA was deposited on the transparent support substrate at a deposition rate of 0.1 to 0.3 nm / sec to form a hole injection layer having a thickness of 90 nm. The substrate temperature at this time was room temperature. Without taking it out of the vacuum chamber, place the TB on the hole injection layer from another boat.
Q was deposited and deposited as a light emitting layer so as to have a thickness of 70 nm.
The deposition conditions were the same as in Example 1 except that the substrate temperature was room temperature.
Is the same as This was taken out of the vacuum chamber, a stainless steel mask was placed on the light emitting layer, and fixed again to the substrate holder.

Next, 1 g of a magnesium ribbon was placed in a molybdenum resistance heating boat, and a copper pellet was mounted as a target of an electron gun for electron beam evaporation located below the substrate holder in the center of the vacuum chamber. Thereafter, the pressure in the vacuum chamber was reduced to 2 × 10 ⁻⁴ Pa, and then copper was deposited by an electron beam evaporation method at 0.03 to 0.08 nm.
At the same time, magnesium was vapor-deposited from the molybdenum boat at a deposition rate of 1.7 to 2.8 nm / sec by the resistance heating method. The emission current of the filament of the electron gun was 230-250 mA, and the accelerating voltage was 4 kV. The temperature of the boat was about 500 ° C. Under the above conditions, a 90-nm mixed metal electrode of magnesium and copper was deposited on the light-emitting layer to form a counter electrode.

Applying a direct current of 20 V to this device using the ITO electrode as the anode and the mixed metal electrode of magnesium and copper as the cathode, the current becomes 50
Light emission from μA and visible light blue to blue light was obtained.
As a result of spectrometry, the emission wavelength range was distributed from 380 nm to 500 nm, and the maximum wavelength was 435 nm. The emission intensity obtained in the same manner as in Example 1 was 0.08 mW / cm ² .

Example 3 ITO was deposited on a 25 mm × 75 mm × 1.1 mm glass substrate by vapor deposition.
A transparent support substrate was formed with a thickness of 100 nm. This transparent support substrate is supplied to a commercially available vapor deposition device (Nihon Vacuum Technology Co., Ltd.)
200 mg of p-quarterphenyl (PQP) was placed in a molybdenum resistance heating boat, and the pressure in the vacuum chamber was reduced to 1 × 10 ⁻⁴ Pa.

Thereafter, the boat was heated to 230 to 250 ° C., and PQP was deposited on the transparent support substrate at a deposition rate of 0.2 to 0.5 nm / sec to obtain a crystalline luminescent thin film having a thickness of 0.4 μm. At this time, the substrate temperature was room temperature. This was taken out of the vacuum chamber, a stainless steel mask was set on the luminous body thin film, and fixed again to the substrate holder.

Next, 20 mg of gold was placed in a molybdenum resistance heating boat, and the pressure in the vacuum chamber was reduced to 2 × 10 ⁻⁴ Pa.

Thereafter, the boat was heated to 1400 ° C., and a gold electrode having a thickness of 50 nm was formed on the luminous body thin film to serve as a counter electrode.

This device has a direct current of 4 with the gold electrode as the positive electrode and the ITO electrode as the negative electrode.
0 V was applied. As a result, a current of 3.2 mA flowed, and dark visible light emission from near-ultraviolet region to visible light blue region was obtained. As a result of spectrometry, the emission wavelength range was distributed from 360 nm to 550 nm, and the maximum wavelength was 440 nm and 470 nm. The emission intensity obtained in the same manner as in Example 1 was 0.03 mW / cm ² .

Example 4 ITO was deposited on a 25 mm × 75 mm × 1.1 mm glass substrate by vapor deposition.
A transparent support substrate was formed with a thickness of 100 nm. This transparent support substrate is supplied to a commercially available vapor deposition device (Nihon Vacuum Technology Co., Ltd.)
) Substrate holder and a molybdenum resistance heating boat, N, N'-diphenyl-N, N'-bis (3-methylphenyl)-[1,1'-biphenyl] -4,4'- 200 mg of diamine (TPDA) was put, and 200 mg of PQP was put in another molybdenum boat in the same manner as in Example 3, and the vacuum chamber was set to 1 × 10 ^-4 Pa
The pressure was reduced to

Thereafter, the boat containing TPDA was heated to 215 to 220 ° C., TPDA was deposited on the transparent support substrate at a deposition rate of 0.1 to 0.3 nm / sec, and a hole injection transport layer having a thickness of 95 nm was formed. . The substrate temperature at this time was room temperature. Without taking this out of the vacuum chamber, PQP was deposited as a light emitting layer from another boat so as to have a thickness of 60 nm on the hole injecting and transporting layer. The deposition conditions are the same as in Example 3. This was taken out of the vacuum chamber, a stainless steel mask was placed on the light emitting layer, and fixed again to the substrate holder.

Next, 1 g of a magnesium ribbon was placed in a molybdenum resistance heating boat, and a copper pellet was mounted as a target of an electron gun for electron beam evaporation located below the substrate holder in the center of the vacuum chamber. Thereafter, the pressure in the vacuum chamber was reduced to 2 × 10 ⁻⁴ Pa, and then copper was deposited at 0.03 to 0.08 nm / cm by electron beam evaporation.
At the same time, magnesium was vapor-deposited from the Molbden boat at a deposition rate of 1.7 to 2.8 nm / sec by the resistance heating method. The emission current of the filament of the electron gun was 230-250 mA, and the accelerating voltage was 4 kV. The temperature of the boat was about 500 ° C. Under the above conditions, a mixed metal electrode of magnesium and copper was deposited on the light emitting layer in a thickness of 130 nm to form a counter electrode.

When an ITO electrode is used as an anode and a mixed metal electrode of magnesium and copper is used as a cathode, a current of 3.5
mA emission and emission ranging from near ultraviolet to visible blue were obtained. The emission wavelength range is distributed from 360 nm to 500 nm as a result of spectroscopic measurement,
The maximum wavelength was 420 nm. The emission intensity obtained in the same manner as in Example 1 was 0.2 mW / cm ² .

Example 5 ITO was deposited on a 25 mm × 75 mm × 1.1 mm glass substrate by vapor deposition.
A transparent support substrate was formed with a thickness of 100 nm. This transparent support substrate is supplied to a commercially available vapor deposition device (Nihon Vacuum Technology Co., Ltd.)
) And a molybdenum resistance heating boat and N, N'-diphenyl-N, N'-bis (3-methoxyphenyl)-[1,1'-biphenyl] -4,4'- 200 mg of diamine (MPDA) was charged, and 200 mg of PQP was placed in another molybdenum boat, and the pressure in the vacuum chamber was reduced to 1 × 10 ⁻⁴ Pa.

Thereafter, the boat containing MPDA is heated to 220 ° C.
A was deposited on the transparent support substrate at a deposition rate of 0.1 to 0.3 nm / sec to form a 60-nm thick hole injection layer. The substrate temperature at this time was room temperature. Without removing this from the vacuum chamber, PQP was deposited as a light emitting layer on the hole injection layer in a thickness of 60 nm. The deposition conditions are boat temperature 218 ° C and deposition rate 0.3.
0.5 nm / sec, and the substrate temperature was room temperature. This was taken out from the vacuum chamber, a stainless steel mask was placed on the above-mentioned light emitting layer, and fixed again to the substrate holder.

Next, put 1g of magnesium ribbon into a molybdenum resistance heating boat and indium into another molybdenum boat.
500 mg was attached. Thereafter, the pressure in the vacuum chamber was reduced to 2 × 10 ⁻⁴ Pa, and then indium was vapor-deposited at a deposition rate of 0.1 nm / sec.
Deposition started at a deposition rate of ~ 2.8 nm / sec. The temperature of the boat was about 800 ° C and 500 ° C for indium and magnesium, respectively.

Under the above conditions, a mixed metal electrode of magnesium and indium was deposited in a thickness of 150 nm on the light emitting layer to form a counter electrode.

When a direct current of 7.5 V was applied to the device using an ITO electrode as an anode and a mixed metal electrode of magnesium and indium as a cathode, a current of 7 mA / cm ² flowed, and light-visible blue-violet light was obtained.

The detailed emission wavelength range was 380 to 600 nm by spectrometry, and the peak wavelength was 436 nm. The light emission intensity was 0.03 mW / cm ² under the above conditions from the power measurement by the photodiode measurement.

Example 6 ITO was deposited on a 25 mm × 75 mm × 1.1 mm glass substrate by vapor deposition.
A transparent support substrate was formed with a thickness of 100 nm. This transparent support substrate is supplied to a commercially available vapor deposition device (Nihon Vacuum Technology Co., Ltd.)
200 mg of 1,1-bis (4-di-para-tolylaminophenyl) cyclohexane (TPAC) in a molybdenum resistance heating boat, and 200 mg of PQP in another molybdenum boat Put vacuum chamber 1 × 10
^The pressure was reduced to ^-4 Pa.

After that, the boat containing TPAC is heated to 220 ° C,
C was deposited on the transparent support substrate at a deposition rate of 0.1 to 0.3 nm / sec to form a 60-nm thick hole injection layer. The substrate temperature at this time was room temperature. Without removing this from the vacuum chamber, PQP was deposited as a light emitting layer on the hole injection layer in a thickness of 60 nm. The deposition conditions are boat temperature 218 ° C and deposition rate 0.3.
0.5 nm / sec, and the substrate temperature was room temperature. This was taken out from the vacuum chamber, a stainless steel mask was placed on the above-mentioned light emitting layer, and fixed again to the substrate holder.

Next, put 1g of magnesium ribbon into a molybdenum resistance heating boat and indium into another molybdenum boat.
500 mg was attached. Thereafter, the pressure in the vacuum chamber was reduced to 2 × 10 ⁻⁴ Pa, and then indium was vapor-deposited at a deposition rate of 0.1 nm / sec.
Deposition started at a deposition rate of ~ 2.8 nm / sec. The temperature of the boat was about 800 ° C and 500 ° C for indium and magnesium, respectively.

Under the above conditions, a mixed metal electrode of magnesium and indium was deposited in a thickness of 150 nm on the light emitting layer to form a counter electrode.

When a direct current of 15 V was applied to the device using an ITO electrode as an anode and a mixed metal electrode of magnesium and indium as a cathode, a current of 8.4 mA / cm ² flowed, and a bright blue-violet light was obtained.

The detailed emission wavelength range was 380 to 600 nm by spectrometry, and the peak wavelength was 450 nm. The emission intensity at this time was 0.05 mW / cm ^{2 as} measured by a photodiode.

Example 7 ITO was deposited on a 25 mm × 75 mm × 1.1 mm glass substrate by vapor deposition.
A transparent support substrate was formed with a thickness of 100 nm. This transparent support substrate is supplied to a commercially available vapor deposition device (Nihon Vacuum Technology Co., Ltd.)
N, N'-diphenyl-N, N'-bis (2-methylphenyl)-[1,1'-biphenyl] -4,4'-diamine on a molybdenum resistance heating boat 200 mg of (TPDA ') was added, and 200 mg of PQP was placed in another molybdenum boat, and the pressure in the vacuum chamber was reduced to 1 × 10 ⁻⁴ Pa.

Thereafter, the boat containing TPDA 'is heated to 220 ° C.
PDA 'was deposited on the transparent support substrate at a deposition rate of 0.1 to 0.3 nm / sec to form a 60-nm thick hole injection layer. The substrate temperature at this time was room temperature. Without removing this from the vacuum chamber, PQP was deposited as a light emitting layer on the hole injection layer in a thickness of 60 nm. The evaporation conditions are boat temperature 218 ° C and evaporation rate
The substrate temperature was 0.3 to 0.5 nm / sec and the room temperature was room temperature. This was taken out from the vacuum chamber, a stainless steel mask was placed on the above-mentioned light emitting layer, and fixed again to the substrate holder.

Next, put 1g of magnesium ribbon into a molybdenum resistance heating boat and indium into another molybdenum boat.
500 mg was attached. Thereafter, the pressure in the vacuum chamber was reduced to 2 × 10 ⁻⁴ Pa, and then indium was vapor-deposited at a deposition rate of 0.1 nm / sec.
Deposition started at a deposition rate of ~ 2.8 nm / sec. The temperature of the boat was about 800 ° C and 500 ° C for indium and magnesium, respectively.

Under the above conditions, a mixed metal electrode of magnesium and indium was deposited in a thickness of 150 nm on the light emitting layer to form a counter electrode.

When a direct current of 10 V was applied to this device using an ITO electrode as an anode and a mixed metal electrode of magnesium and indium as a cathode, a current of 4.2 mA / cm ² flowed, and a bright blue-violet light was emitted.

The detailed emission wavelength range was 380 to 700 nm by spectrometry, and the peak wavelength was 430 nm. Light emission was observed in a wide wavelength range from the near ultraviolet region to a long wavelength region. The emission intensity is
It was 0.05 mW / cm ^{2 as} measured by a photodiode.

Example 8 ITO was deposited on a 25 mm × 75 mm × 1.1 mm glass substrate by vapor deposition.
A transparent support substrate was formed with a thickness of 100 nm. This transparent support substrate is supplied to a commercially available vapor deposition device (Nihon Vacuum Technology Co., Ltd.)
And 200mg of 1,1'-bis (4-di-para-tolylaminophenyl) cyclohexane (TPAC) in a molybdenum resistance heating boat. 200 mg of 5,3,5'-tetrabutyl kink phenyl (TBQ) is charged and the vacuum chamber is set to 1 × 10 ^-4
The pressure was reduced to Pa.

After that, the boat containing TPAC is heated to 220 ° C,
C was deposited on the transparent support substrate at a deposition rate of 0.1 to 0.3 nm / sec to form a 60-nm thick hole injection layer. The substrate temperature at this time was room temperature. Without taking this out of the vacuum chamber, TBQ was deposited as a light emitting layer to a thickness of 60 nm on the hole injection layer. The deposition conditions were as follows: boat temperature 220 ° C, deposition rate 0.3
0.5 nm / sec, and the substrate temperature was room temperature. This was taken out from the vacuum chamber, a stainless steel mask was placed on the above-mentioned light emitting layer, and fixed again to the substrate holder.

Next, put 1g of magnesium ribbon into a molybdenum resistance heating boat and indium into another molybdenum boat.
500 mg was attached. Thereafter, the pressure in the vacuum chamber was reduced to 2 × 10 ⁻⁴ Pa, and then indium was vapor-deposited at a deposition rate of 0.1 nm / sec.
Deposition started at a deposition rate of ~ 2.8 nm / sec. The temperature of the boat was about 800 ° C and 500 ° C for indium and magnesium, respectively.

Under the above conditions, a mixed metal electrode of magnesium and indium was deposited in a thickness of 150 nm on the light emitting layer to form a counter electrode.

When a direct current of 15 V was applied to this device using an ITO electrode as an anode and a mixed metal electrode of magnesium and indium as a cathode, a current of 11 mA / cm ² flowed, and light was emitted in visible light. The emission wavelength range was from 400 nm to longer wavelengths than the spectral measurement. The light emission intensity under the above conditions was 0.02 mW / cm ^{2 as} measured by a photodiode.

Example 9 ITO was deposited on a 25 mm × 75 mm × 1.1 mm glass substrate by vapor deposition.
A transparent support substrate was formed with a thickness of 100 nm. This transparent support substrate is supplied to a commercially available vapor deposition device (Nihon Vacuum Technology Co., Ltd.)
And 200mg of 1,1'-bis (4-di-meta-tolylaminophenyl) ether (ETPA) in a molybdenum resistance heating boat. 200 mg of 5,3,5'-tetrabutyl kinkphenyl (TBQ) was charged, and the pressure in the vacuum chamber was reduced to 1 × 10 ⁻⁴ Pa.

Thereafter, the boat containing ETPA is heated to 210 ° C.
A was deposited on the transparent support substrate at a deposition rate of 0.1 to 0.3 nm / sec to form a 60-nm thick hole injection layer. The substrate temperature at this time was room temperature. Without taking this out of the vacuum chamber, TBQ was deposited as a light emitting layer to a thickness of 60 nm on the hole injection layer. The deposition conditions were as follows: boat temperature 220 ° C, deposition rate 0.3
0.5 nm / sec, and the substrate temperature was room temperature. This was taken out from the vacuum chamber, a stainless steel mask was placed on the above-mentioned light emitting layer, and fixed again to the substrate holder.

Next, put 1g of magnesium ribbon into a molybdenum resistance heating boat and indium into another molybdenum boat.
500 mg was attached. Thereafter, the pressure in the vacuum chamber was reduced to 2 × 10 ⁻⁴ Pa, and then indium was vapor-deposited at a deposition rate of 0.1 nm / sec.
Deposition started at a deposition rate of ~ 2.8 nm / sec. The temperature of the boat was about 800 ° C and 500 ° C for indium and magnesium, respectively.

Under the above conditions, a mixed metal electrode of magnesium and indium was deposited in a thickness of 150 nm on the light emitting layer to form a counter electrode.

When a direct current of 15 V was applied to the device using an ITO electrode as an anode and a mixed metal electrode of magnesium and indium as a cathode, a current of 1.5 mA / cm ² flowed, and a bright visible violet emission was obtained. Emission of near-ultraviolet components was confirmed in the emission wavelength range from 360 nm to 600 nm by spectrometry. The light emission intensity under the above conditions was 0.06 mW / cm ^{2 as} measured by a photodiode.

Example 10 ITO was deposited on a 25 mm x 75 mm x 1.1 mm glass substrate by vapor deposition.
A transparent support substrate was formed with a thickness of 100 nm. This transparent support substrate is supplied to a commercially available vapor deposition device (Nihon Vacuum Technology Co., Ltd.)
) And a molybdenum resistance heating boat and N, N'-diphenyl-N, N'-bis (2-methylphenyl)-[1,1'-biphenyl] -4,4'- Add 200mg of diamine (TPDA ') and add 3,5,3,5'-tetrabutyl kinkphenyl (TBQ) to another molybdenum boat
Was placed in a vacuum tank, and the pressure in the vacuum chamber was reduced to 1 × 10 ⁻⁴ Pa.

Thereafter, the boat containing TPDA ′ is heated to 210 ° C.
PDA 'was deposited on the transparent support substrate at a deposition rate of 0.1 to 0.3 nm / sec to form a 60-nm thick hole injection layer. The substrate temperature at this time was room temperature. Without taking this out of the vacuum chamber, TBQ was deposited as a light emitting layer to a thickness of 60 nm on the hole injection layer. The evaporation conditions are boat temperature 220 ° C and evaporation rate
The substrate temperature was 0.3 to 0.5 nm / sec and the room temperature was room temperature. This was taken out from the vacuum chamber, a stainless steel mask was placed on the above-mentioned light emitting layer, and fixed again to the substrate holder.

Next, put 1g of magnesium ribbon into a molybdenum resistance heating boat and indium into another molybdenum boat.
500 mg was attached. Thereafter, the pressure in the vacuum chamber was reduced to 2 × 10 ⁻⁴ Pa, and then indium was vapor-deposited at a deposition rate of 0.1 nm / sec.
Deposition started at a deposition rate of ~ 2.8 nm / sec. The temperature of the boat was about 800 ° C and 500 ° C for indium and magnesium, respectively.

Under the above conditions, a mixed metal electrode of magnesium and indium was deposited in a thickness of 150 nm on the light emitting layer to form a counter electrode.

When a direct current of 15 V was applied to the device using an ITO electrode as an anode and a mixed metal electrode of magnesium and indium as a cathode, a current of 27 mA / cm ² flowed, and a bright visible violet emission was obtained. In the emission wavelength region, near-ultraviolet emission components were confirmed in the range of 360 nm to 550 nm by spectrometry. The emission intensity under the above conditions is
1.0V when applying 20V from power measurement by photodiode
mW / cm ² .

Example 11 ITO was deposited on a 25 mm x 75 mm x 1.1 mm glass substrate by vapor deposition.
A transparent support substrate was formed with a thickness of 100 nm. This transparent support substrate is supplied to a commercially available vapor deposition device (Nihon Vacuum Technology Co., Ltd.)
) And a molybdenum resistance heating boat and N, N'-diphenyl-N, N'-bis (3-methoxyphenyl)-[1,1'-biphenyl] -4,4'- Add 200mg of diamine (MPDA) and add 3,5,3,5'-tetrabutyl kinkphenyl (TBQ) to another molybdenum boat
Was placed in a vacuum tank, and the pressure in the vacuum chamber was reduced to 1 × 10 ⁻⁴ Pa.

Thereafter, the boat containing MPDA is heated to 220 ° C.
A was deposited on the transparent support substrate at a deposition rate of 0.1 to 0.3 nm / sec to form a 60-nm thick hole injection layer. The substrate temperature at this time was room temperature. Without taking this out of the vacuum chamber, TBQ was deposited as a light emitting layer to a thickness of 60 nm on the hole injection layer. The deposition conditions were as follows: boat temperature 220 ° C, deposition rate 0.3
0.5 nm / sec, and the substrate temperature was room temperature. This was taken out from the vacuum chamber, a stainless steel mask was placed on the above-mentioned light emitting layer, and fixed again to the substrate holder.

Next, put 1g of magnesium ribbon into a molybdenum resistance heating boat and indium into another molybdenum boat.
500 mg was attached. Thereafter, the pressure in the vacuum chamber was reduced to 2 × 10 ⁻⁴ Pa, and then indium was vapor-deposited at a deposition rate of 0.1 nm / sec.
Deposition started at a deposition rate of ~ 2.8 nm / sec. The temperature of the boat was about 800 ° C and 500 ° C for indium and magnesium, respectively.

Under the above conditions, a mixed metal electrode of magnesium and indium was deposited in a thickness of 150 nm on the light emitting layer to form a counter electrode.

When a direct current of 15 V was applied to the device using an ITO electrode as an anode and a mixed metal electrode of magnesium and indium as a cathode, a current of 12 mA / cm ² flowed, and a bright visible violet emission was obtained. The emission wavelength range has a peak at 430 nm from the spectroscopic measurement, 370 to 550 n
m. This confirmed the presence of near-ultraviolet light-emitting components. The light emission intensity was 0.7 mW / cm ² at the time of applying 20 V from power measurement by a photodiode.

〔The invention's effect〕

As described above, the EL device of the present invention can obtain high luminance only by applying a low voltage, has a simple configuration, and can be easily manufactured. Further, according to this EL device, it is possible to achieve light emission in the near-ultraviolet region to the blue region with high luminance and high efficiency, which has been conventionally difficult. Since light in this region has large energy, it is possible to obtain lower energy, that is, long wavelength blue, green, and red visible light by a certain energy conversion, for example, fluorescence.

In addition, there are few defects such as pinholes, and it is easy to enlarge the area, high productivity, and EL for display of various devices
It is possible to provide an inexpensive and stable product as an element.

Claims (4)

(57) [Claims] 1. The compound of the general formula (I) Or general formula (II) [Wherein, R ^{1 to} R ¹⁰ are each a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a hydroxyl group, a sulfonic acid group, a carbonyl group, a carboxyl group, an amino group, and a dimethylamino group. , A cyano group, a halogen atom, an acyloxy group, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an aminocarbonyl group or an acylamino group, and these R ^{1 to} R ¹⁰ are bonded to each other to be substituted or unsubstituted saturated. A 5-membered ring or a substituted or unsubstituted saturated 6-membered ring may be formed. n shows the integer of 2-5. Note that a plurality of R ^{4 to} R ⁶ may be the same or different. However, in formula (I), the case where all of R ^{1 to} R ⁹ represent a hydrogen atom and n represents 3 is excluded. ] An organic thin-film electroluminescence device, characterized by using a compound represented by the following formula: 2. An organic thin-film electroluminescent device, wherein at least one of the light-emitting materials comprising the compound according to claim 1 is sandwiched between two transparent or translucent electrodes. 3. An organic thin-film electroluminescence comprising a laminate of a light-emitting material layer comprising the compound of claim 1 and a hole injection layer, at least one of which is sandwiched between two transparent or translucent electrodes. element. 4. A cathode of the general formula (I) Or general formula (II) [Wherein, R ^{1 to} R ¹⁰ are each a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a hydroxyl group, a sulfonic acid group, a carbonyl group, a carboxyl group, an amino group, and a dimethylamino group. , A cyano group, a halogen atom, an acyloxy group, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an aminocarbonyl group or an acylamino group, and these R ^{1 to} R ¹⁰ are bonded to each other to be substituted or unsubstituted saturated. A 5-membered ring or a substituted or unsubstituted saturated 6-membered ring may be formed. n shows the integer of 2-5. Note that a plurality of R ^{4 to} R ⁶ may be the same or different. However, in formula (I), the case where all of R ^{1 to} R ⁹ represent a hydrogen atom and n represents 3 is excluded. ] An organic thin-film electroluminescent device comprising a compound represented by the following formula, an aromatic tertiary amine compound, an anode and a substrate laminated in this order.