JPH0696858A - Organic thin film el element - Google Patents

Abstract

PURPOSE:To provide a long-life EL element preventing the deterioration due to oxygen or moisture by using the ion-plated film of a metal oxide or a metal fluoride for the sealing layer of the organic thin film EL element. CONSTITUTION:A sealing layer 8 is formed by the ion plating method in vacuum without exposing it to the atmosphere after a cathode is formed. For the preferable conditions of a sealing material, the solubility in water is made low, preferably 1(g) or below against the water of 100(g), and the vapor pressure is made sufficient for deposition at 1500 deg.C or below to prevent the heat deterioration of an organic material when the film is formed. A metal oxide or multiple mixtures, or a metal fluoride or multiple mixtures are used for the material. Deposition clusters are decomposed into fine deposition particles by the electron impact in plasma. The deposition particles are accelerated by the bias electric field, and a uniform, smooth, and pinhole-free sealing film having high adhesion due to a driving effect and having a high barrier property against oxygen or steam can be formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an EL device using electroluminescence, that is, EL (electroluminescence), and more specifically, at least an anode, a hole injecting and transporting layer, an organic electron transporting and emitting light. The present invention relates to an organic thin-film EL device including a layer, a cathode or an anode, a hole injecting and transporting layer, an organic light emitting layer, an electron injecting and transporting layer, and a cathode in this order.

[0002]

2. Description of the Related Art Most conventional EL elements are of AC drive type in which an insulating layer having a high resistance is provided between electrodes, and they are classified into a dispersion type EL element and a thin film type EL element. Distributed EL
The structure of the device is that an insulating layer is formed by coating a powder of high dielectric constant barium titanate or the like dispersed in a resin binder on an aluminum foil serving as a back electrode to a thickness of several tens of μm.
A zinc sulfide-based luminescent material layer dispersed in a resin binder is provided thereon, and a transparent electrode is further laminated thereon. This type of element is inexpensive and can obtain a surface light emitter having a large area and a thickness of 1 mm or less, and has applications such as a backlight for a liquid crystal display device, but its brightness is easily lowered.

A thin film EL element is a transparent electrode substrate having a glass plate coated with indium oxide to tin oxide (hereinafter referred to as ITO) or the like, and a dielectric thin film layer such as yttrium oxide having a thickness of several hundreds nm as an insulating layer formed by a sputtering method or the like. Then, a phosphor thin film of ZnS type, ZnSe type, SrS type, CaS type or the like is laminated thereon by electron beam vapor deposition, sputtering method or the like to have a thickness of about several hundred nm, and a dielectric thin film layer or a back electrode of aluminum or the like is formed. It has a structure in which layers are sequentially stacked. The film thickness between the electrodes is 1 to 2 μm or less. The thin film type EL device is suitable for applications such as a display for a portable computer because it has a long life and is capable of high-definition display, but it has a drawback that it is expensive.

In either type of EL element, an AC high voltage of 100 V or more is required to obtain sufficient brightness. For example, since a step-up transformer is required when the EL element emits light with a battery, it is difficult to reduce the thickness of the entire device incorporated even if the EL element is thin 1 mm or less.

Therefore, in recent years, research aiming at an unnecessary EL element of low voltage DC drive such as a step-up transformer has been conducted.
As one of them, researches on organic thin film EL devices have been conducted. JP-A-57-51781, JP-A-59-19
4393, JP-A-63-264692, JP-A-63-295695, Japanese. journal. of. Applied. Physics Vol. 25, No. 9, p. 773 (1986), Applied. Physics.
Letter Vol. 51, No. 12, p. 913 (1987), Journal. of. Applied. Physics Volume 65 Volume 9
According to No. 3610 (1989), etc., an organic thin film EL element of this type has been conventionally manufactured as follows.

First, copper phthalocyanine, poly-3-methylthiophene, as a hole injecting and transporting layer is first formed on the anode of a transparent conductive film of gold or ITO formed on a transparent insulating substrate such as glass by vapor deposition or sputtering. Alternatively, 1,1-bis (4-di-para-tolylaminophenyl) cyclohexane represented by the following (Chemical formula 1) (melting point 181.4
℃ ~ 182.4 ℃), represented by (Chemical Formula 2), N, N'-
Diphenyl-N, N'-bis (3-methylphenyl)-
1,1'-biphenyl-4,4'-diamine (melting point 15
(9 ° C. to 163 ° C.) or the like, and a layer of a tetraphenyldiamine derivative is formed by vapor deposition, electrolytic polymerization or the like to have a thickness of about 1 μm or less in a single layer or laminated.

[0007]

[Chemical 1]

[0008]

[Chemical 2]

Next, on the hole injecting and transporting layer, tetraphenyl butadiene, anthracene, perylene, coronene, 12
-Phthaloperinone derivative, tris (8-quinolinol)
An organic phosphor such as aluminum is vapor-deposited or dispersed in a resin binder for coating to form an electron-transporting light-emitting layer with a thickness of about 1.0 μm or less. Finally, on top of that, Mg, In, Al element metals as cathodes,
Alternatively, an alloy of Mg and Ag (atomic ratio 10: 1) or the like is deposited.

In the device manufactured as described above, holes and electrons are injected into the light emitting layer by applying a direct current low voltage of 20 to 30 V or less with the transparent electrode side as an anode, and light is emitted by recombination thereof.

In addition, applied. Physics. According to Letter 57, No. 6, page 531 (1990), etc., Adachi et al.
N'-diphenyl-N, N'-bis (3-methylphenyl) -1,1'-biphenyl-4,4'-diamine, 1- [4-N, N-bis (P-methoxy) as an organic light emitting layer (Phenyl) aminostyryl] naphthalene, 2- (4-biphenyl) -5- (4-t-butylphenyl) -1,3,4-oxadiazole (hereinafter B
PBD) and an organic thin film EL device obtained by sequentially stacking MgAg alloy as a cathode, and similarly, EL light emission of 1000 cd / m ² or more is obtained at a DC low voltage of 20 to 30 V or less.

However, in this type of organic thin film EL device, in order to obtain a high brightness of 1000 cd / m ² or more at a low voltage of about 10 V or less, electrons are efficiently injected from the cathode to the organic electron transporting light emitting layer. There is a need to. For that purpose, it is necessary to use a low work function cathode having a high Fermi level equal to or higher than the energy level of the lowest unoccupied molecular orbital (hereinafter referred to as LUMO) of the organic phosphor used for the organic electron transporting light emitting layer.

The LUMO energy level of tris (8-quinolinol) aluminum, which is known as a typical organic electron-transporting light-emitting material capable of obtaining the highest brightness, is the work function value measured by a photoelectron emission method in the atmosphere. When calculated by subtracting the optical energy gap (2.75 eV) from, it is about 3.1 eV. In the case of BPBD used as an electron injecting and transporting material, it is 2.7 eV.
As a low work function metal having a work function of 3.1 eV or less and a high Fermi level, Li (work function 2.4e
V), Na (2.3 eV in the same), K (2.3 eV in the same)
Alkali metals such as Mg (the same 3.2 eV), Ca (the same 2.9 eV), Sr (the same 2.7 eV), Ba (the same)
There is an alkaline earth metal such as 2.5 eV), but except Mg, it cannot be used as a cathode as a single metal because it is extremely easy to oxidize in air and unstable.

In addition, C.I. W. Tang et al. Used a MgAg alloy (atomic ratio 10: 1, work function 3.8 eV) as a cathode, and applied a direct current applied voltage of about 10 V at 1000 cd /
An organic thin film EL device having a brightness of m ² or more has been realized. However, by mixing Ag (work function 4.6 eV), Mg
Since the work function of the Ag alloy is lower than the LUMO energy level of tris (8-quinolinol) aluminum, there is a drawback that electrons are hard to be injected.

Further, Ito et al. Succeeded in providing a cathode having a low work function and relatively stable by using an alloy containing an alkali metal and an alkaline earth metal such as MgLi and AlLi.

In this type of organic thin film EL element, it is necessary to provide a sealing layer in order to prevent oxidation of the cathode. However, since the sealing layer of metal oxides and metal fluorides by the conventional vapor deposition method has many pinholes, the transmittance of oxygen and water vapor is still high, and the deterioration of the cathode cannot be completely stopped. .

[0017]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention uses an ion plating method capable of forming a pinhole-free film as compared with a conventionally used vapor deposition method and uses a sealing layer. The purpose of the present invention is to provide a high-brightness organic thin film EL device that is stable against deterioration due to oxygen or water when formed.

[0018]

That is, the present invention provides at least an anode, a hole injecting and transporting layer, an organic electron transporting and emitting layer,
In an organic thin film EL device composed of a cathode or an anode, a hole injecting and transporting layer, an organic light emitting layer, an electron injecting and transporting layer, and a cathode in this order, a sealing layer such as a metal oxide or a metal fluoride is formed on the cathode. It is characterized by using an ion plating film.

Hereinafter, the case where the organic thin film EL element according to the present invention is formed on the substrate 1 in the order of the anode 2, the hole injecting and transporting layer 3, the organic electron transporting and emitting layer 4, and the cathode 7 will be described. It is also possible to sequentially form the cathode 7 on the substrate 1. (See FIG. 1) Also, the organic electron transporting light emitting layer 4
May be functionally separated into an organic light emitting layer 5 and an electron injecting and transporting layer 6, and the anode 2, the hole injecting and transporting layer 3, the organic light emitting layer 5, the electron injecting and transporting layer 6, and the cathode 7 may be formed on the substrate 1 in this order. it can.
(See Figure 2)

The anode 2 is a transparent insulating substrate 1 such as glass.
A transparent electrode with a surface resistance of 10-50 Ω / square and visible light transmittance of 80% or more coated with a transparent conductive material such as ITO or zinc aluminum oxide by vacuum deposition or a sputtering method, or gold or platinum is thinly vapor-deposited. A semitransparent electrode is desirable.

However, in other cases, the anode 2 is opaque, and a metal plate such as gold, platinum, nickel, or the like having a large work function that facilitates the injection of holes into the electron-transporting light-emitting layer, silicon, gallium phosphide, amorphous silicon carbide, or the like. Has a work function of 4.
It is also possible to use a semiconductor substrate having a voltage of 8 eV or more, or an anode 2 in which a metal or semiconductor thereof is coated on an insulator substrate 1, and the cathode can be a transparent electrode or a semitransparent electrode. When the cathode 7 is also opaque, at least one end of the light emitting layer 4 needs to be transparent.

Next, the hole injecting and transporting layer 3 is formed on the transparent anode 2. Preferred conditions for the hole injecting and transporting material are stable to oxidation, high hole mobility, and ionizing energy of the anode material. It is necessary to have a good film-forming property and be substantially transparent at least in the fluorescence wavelength region of the light emitting layer material. A phthalocyanine such as copper phthalocyanine or metal-free phthalocyanine, or a tetraphenyldiamine derivative is used as a single layer or a laminated layer. Typical materials for the tetraphenyldiamine derivative are 1,
1-bis (4-di-para-tolylaminophenyl) cyclohexane, N, N'-diphenyl-N, N'-bis (3-methylphenyl) -1,1'-biphenyl-4,
4'-diamine, N, N'-diphenyl-N, N'-bis (para-tolyl) -1,1'-biphenyl-4,4 '
-Diamine, N, N, N'N'-tetra (para-tolyl) -4,4'-diaminobiphenyl and the like can be mentioned, but not limited to the above examples.

Hole injecting and transporting layer 3 using these compounds
The film is formed mainly on the anode 2 of the transparent electrode by vapor deposition, but it is formed by dispersing it in a resin such as polyester, polycarbonate, polymethylphenylsilane, etc. and coating it by a method such as spin coating. It is also possible.

The thickness of the hole injecting and transporting layer 3 is 1 μm or less, preferably 0.03 to 0.1 μm even when it is formed as a single layer or a laminated layer. When a hole injecting and transporting material that melts by heating, such as a tetraphenyldiamine derivative, is used, defects in the deposited film may be removed during or after vapor deposition of the hole injecting and transporting material in a vacuum or in an inert gas atmosphere. In order to remove it, the substrate heat treatment may be performed at a temperature equal to or lower than the melting point. Further, when a hole injecting and transporting material such as copper phthalocyanine that is crystalline and the surface of the deposited film is likely to have irregularities is used, the substrate can be cooled during the deposition to obtain an amorphous deposited film.

Next, the organic electron transporting light emitting layer 4 is formed on the hole injecting and transporting layer 3. The phosphor used for the organic electron transporting light emitting layer 4 has fluorescence in the visible region and is formed by an appropriate method. Any phosphor that can be filmed can be used. For example, anthracene, salicylate, pyrene, coronene, perylene, tetraphenylbutadiene, 9,10-bis (phenylethynyl) anthracene, tris (8-quinolinol) aluminum, bis (8-quinolinol) zinc, tris (5-fluoro-). Examples include 8-quinolinol) aluminum complex, bis [8- (para-tosyl) aminoquinoline] zinc, and cadmium complex.

As the phosphors in the organic electron transporting light emitting layer 4, two or more kinds of phosphors are mixed in order to convert emission wavelength and improve light emission efficiency, or two or more light emitting layers of various kinds of phosphors are laminated. One of them may exhibit fluorescence in the infrared region or the ultraviolet region. The film formation method of the organic electron transporting light emitting layer 4 is performed by a vacuum vapor deposition method, a cumulative film method, or a method in which the organic electron transport light emitting layer 4 is dispersed in an appropriate resin binder and coated by spin coating or the like.

The film thickness of the organic electron transporting light emitting layer 4 is 1 μm or less, preferably 0.03 to 0.1 μm even when it is formed as a single layer or a laminated layer.

Next, when the organic electron transporting light emitting layer 4 is functionally separated into the organic light emitting layer 5 and the electron injecting and transporting layer 6 as shown in FIG. 2, a preferable condition of the electron injecting and transporting material is electron transfer. And the LUMO energy level is intermediate between the LUMO energy level of the organic light emitting material and the Fermi level of the cathode material, and the film forming property is good.
Further, in the element in which the anode 2 is opaque and the light is extracted from the transparent or semitransparent cathode 7, it is necessary that the anode 2 is substantially transparent at least in the fluorescence wavelength region of the organic light emitting layer material. Examples include BPBD, 3,4,9,10-
Examples thereof include perylene tetracarboxyl-bis-benzimidazole, but are not particularly limited to the above examples.

The electron injecting and transporting layer 6 is formed by a vacuum vapor deposition method, a cumulative film method, or a method of dispersing the electron injecting and transporting layer 6 in an appropriate resin binder and coating it by spin coating or the like. The thickness of the electron injecting and transporting layer 6 is 1 μm or less, preferably 0.01 to 0.1 μm.

When the organic electron transporting light emitting layer 4 or the organic light emitting layer 5 and the electron injecting and transporting layer 6 are formed by the vacuum deposition method, the non-electron attracting property such as hydrogen and ammonia or the electron donating property is provided during or immediately after the deposition. It is also possible to introduce a volatile gas into the vacuum chamber and allow it to adsorb to the organic molecules, which prevents the organic molecules from adsorbing oxygen in the air and increasing the electrical resistance of the membrane.

Next, the cathode 7 is formed on the organic electron transporting light emitting layer 4 or the electron injecting transporting layer 6. Preferred conditions for the cathode material have a work function as low as or lower than the LUMO level of the organic electron transporting light emitting material or the electron injecting transporting material,
It is relatively stable against oxidation, and a vapor pressure sufficient for vapor deposition can be obtained even at a low temperature of about 1200 ° C. or lower in order to prevent thermal deterioration of an organic material during film formation. M alone
Examples of g and In include MgAg for increasing the stability. Materials with lower work function include MgLi and AlL
Examples thereof include alloys such as i, MgSr, and AlSr, but are not particularly limited to the above examples, and alkali metal (L
i, Na) and alkaline earth metals (Ca, Sr, Ba) and other metals (Ag, Al, In, Sn, etc.) in any combination are conceivable.

The cathode 7 is formed by co-evaporation from different vapor deposition sources for each component under a pressure of 10 ^-5 Torr order or less by a resistance heating system or an electron gun system. While controlling each component independently with a plurality of crystal oscillator type film thickness meters, the film thickness is controlled to about 0.1 to 0.3 μm. Further, an ion plating method may be used to obtain a uniform and smooth cathode having high adhesion. If the target can be easily prepared and stored, the sputtering method may be able to achieve the same effect. .

Finally, to prevent the oxidation of the organic layers and electrodes of the device,
The sealing layer 8 is formed for this purpose. The sealing layer 8 is formed in the shape of the cathode 7.
After completion, it is desirable to continuously perform it in a vacuum without exposing it to the atmosphere.
Good The preferred condition for the encapsulating material is its solubility in water.
Low, preferably about 1 g or less per 100 g of water,
About 1500 ℃ to prevent thermal deterioration of organic materials during film formation
A vapor pressure that is practically sufficient for vapor deposition can be obtained even at low temperatures below
And. GeO, SiO, MoO₃, B₂O₃, Pb
O, Sb₂O₃, SnO, SnO₂ Metal oxides such as
RuF, a mixture of these materials, MgF₂，
LiF, BaF ₂, AlF₃, CaF₂, MnF₂,etc
Metal fluorides, or a mixture of
Examples thereof include, but are not particularly limited to the above examples
Absent.

A method for forming the sealing layer 8 according to the present invention will be described with reference to the ion plating apparatus shown in FIG. The chamber 11 is once evacuated to a vacuum of the order of 10 ^-6 Torr or less, and then O ₂ gas or an inert gas such as Ar or Ne is introduced through the gas introduction valve 12 to obtain a pressure of 10 ^-4 to 10 ^-10.
Stabilize at a pressure of ^-3 Torr. Plasma is generated by applying high-frequency power to the coil electrode 15 from the RF power source 13 via the matching circuit 14.

While monitoring with a crystal oscillator type film thickness meter,
The resistance heating vapor deposition source 16 is vapor-deposited on the substrate 17 to form an ion plating film. However, if an electron beam vapor deposition source or a microwave power source is used, plasma can be generated even on the order of 10 ⁻⁵ Torr. In addition, the substrate bias power source 18
By applying a negative voltage from the substrate to the substrate 17, the implantation of the charged vapor deposition particles can be promoted, but the implantation effect by the sheath bias generated near the substrate 17 can be expected without positively applying the bias. .

After the sealing layer 8 is formed, a glass plate or the like can be adhesively sealed by using a low hygroscopic UV-curable adhesive, epoxy adhesive or the like in order to prevent further infiltration of moisture.
The organic thin-film EL element configured as described above emits light when the anode 2 is positive and a DC voltage is applied. Even when an AC voltage is applied, the organic thin film EL element emits light while the anode 2 is positively applied. .

[0037]

In the conventional vacuum vapor deposition, some of the metal oxides or metal fluorides are GeO, SiO, Mo.
Many are deposited as clusters such as O ₃ , MgF ₂ , LiF, and AlF ₃ . Therefore, many pinholes were present in the formed sealing film, and the barrier properties against oxygen and water vapor were poor. .

When the ion plating method is used for film formation, the vapor deposition clusters are decomposed by electron impact in plasma to form fine vapor deposition particles. In addition, since the vapor deposition particles are accelerated by the bias electric field, a uniform and smooth pinhole-free sealing film having a high barrier property against oxygen and water vapor can be obtained by the implantation effect.

[0039]

【Example】

Example 1 An example of the EL device of the present invention will be described below with reference to FIG. First, a 1.1 mm-thick glass plate was used as the transparent insulating substrate 1, and 0.12 μm of ITO was coated on the glass plate to form the anode 2. This transparent conductive glass substrate was washed with alcohol and then heated at about 400 ° C. for 10 minutes to degrease it. Next, as the hole injecting and transporting layer 3, N,
N′-diphenyl-N, N′-bis (3-methylphenyl) -1,1′-biphenyl-4,4′-diamine was vapor-deposited at 0.075 μm. Then, tris (8-quinolinol) aluminum is used as the organic electron transporting light-emitting layer 4 in an amount of 0.0
75 μm was vapor-deposited, and a MgAg alloy (thickness ratio 13: 1) was formed as a cathode 7 on the upper surface by co-evaporation to a film thickness of 0.2 μm. Finally, a GeO ion plating film was deposited as a sealing layer 8 by 0.7 μm. The plasma conditions were O ₂ plasma with an atmospheric pressure of 3 × 10 ⁻⁴ Torr and RF power of 50 W.

When this EL device was stored in an environment of a temperature of 40 ° C. and a humidity of 90% and the brightness at a constant voltage drive of DC 10 V was measured at regular intervals, the half-life was about 55 minutes.

Comparative Example 1 As in Example 1, a hole injecting and transporting layer 3, an organic electron transporting and emitting layer 4, and a cathode 7 were sequentially deposited on a transparent conductive glass substrate, and GeO was used as a sealing layer 8. 0.7 μm was vapor-deposited. When this EL device was stored in an environment of a temperature of 40 ° C. and a humidity of 90% and the brightness at constant voltage drive of DC 10 V was measured at regular intervals, the half-life was about 35 minutes. In addition, many non-light emitting areas which are considered to be caused by the deterioration of the cathode 7 were observed.

<Embodiment 2> As in Embodiment 1, a hole injecting and transporting layer 3, an organic electron transporting and emitting layer 4 and a MgAg alloy (film thickness ratio 10: 1) are used as a cathode 7 on a transparent conductive glass substrate. A 0.2 μm film was formed by vapor deposition. Finally, as the sealing layer 8, an SiO ion plating film was vapor-deposited by 0.2 μm. Plasma conditions are atmospheric pressure 3 × 10 ^-4 Torr, R
It was O ₂ plasma with F power of 50 W.

When this EL device was stored in an environment of a temperature of 40 ° C. and a humidity of 90% and the brightness at a constant voltage drive of DC 10 V was measured at regular intervals, the half-life was about 70 minutes.

Comparative Example 2 As in Example 2, the hole injecting and transporting layer 3, the organic electron transporting and emitting layer 4 and the cathode 7 were sequentially deposited on the transparent conductive glass substrate, and SiO 2 was used as the sealing layer 8. 0.2 μm was deposited. When this EL device was stored in an environment of an air temperature of 40 ° C. and a humidity of 90% and the brightness at a constant voltage drive of DC 10 V was measured at regular intervals, the half-life was about 25 minutes. In addition, many non-light emitting areas which are considered to be caused by the deterioration of the cathode 7 were observed.

<Example 3> As in Example 2, the hole injecting and transporting layer 3, the organic electron transporting and emitting layer 4, and the cathode 7 were sequentially deposited on the transparent conductive glass substrate, and then LiF was used as the sealing layer 8. An ion plating film was deposited by 0.3 μm. Plasma conditions are atmospheric pressure 3 × 10 ^-4 Torr, RF power 5
It was 0 W of Ar plasma.

When this EL device was stored in an environment of a temperature of 40 ° C. and a humidity of 90%, and the brightness at a constant voltage drive of DC 10 V was measured at regular intervals, the half-life was about 55 minutes.

Comparative Example 3 As in Example 2, the hole injecting and transporting layer 3, the organic electron transporting and emitting layer 4, and the cathode 7 were sequentially deposited on the transparent conductive glass substrate, and LiF was used as the sealing layer 8. 0.3 μm was vapor-deposited. When this EL device was stored in an environment of a temperature of 40 ° C. and a humidity of 90% and the brightness at a constant voltage drive of DC 10 V was measured at regular intervals, the half-life was about 40 minutes. In addition, many non-light emitting areas which are considered to be caused by the deterioration of the cathode 7 were observed.

Example 4 Similar to Example 2, the hole injecting and transporting layer 3, the organic electron transporting and emitting layer 4, and the cathode 7 were sequentially deposited on the transparent conductive glass substrate, and then MgF ₂ was formed as the sealing layer 8.
The ion plating film of 0.2 μm was vapor-deposited. The plasma conditions were Ar plasma with an atmospheric pressure of 3 × 10 ⁻⁴ Torr and an RF power of 50 W.

When this EL device was stored in an environment of a temperature of 40 ° C. and a humidity of 90% and the brightness at a constant voltage drive of DC 10 V was measured at regular intervals, the half-life was about 60 minutes.

<Comparative Example 4> As in Example 2, the hole injecting and transporting layer 3, the organic electron transporting and emitting layer 4, and the cathode 7 were sequentially deposited on the transparent conductive glass substrate, and MgF ₂ was used as the sealing layer 8.
Was vapor-deposited by 0.2 μm. This EL element is stored in an environment of temperature 40 ° C and humidity 90%, and DC 10V at regular intervals.
The half-life was about 35 minutes as a result of measuring the luminance of the device under constant voltage driving. In addition, many non-light emitting areas which are considered to be caused by the deterioration of the cathode 7 were observed.

[0051]

As described above, by using the metal oxide or metal fluoride ion plating film as the sealing layer of the organic thin film EL element, the adhesion is higher than that of the conventionally used vapor deposition film. Since a uniform and smooth pinhole-free sealing film can be obtained, a sealing layer with a high barrier property against oxygen and water vapor can be obtained. Thin film EL
It is effective in obtaining an element.

[0052]

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an example of an organic thin film EL element of the present invention.

FIG. 2 is an explanatory view showing another embodiment of the organic thin film EL element of the present invention.

FIG. 3 is an explanatory view of an apparatus for forming an ion plating thin film sealing layer in the organic thin film EL element of the present invention.

[Explanation of symbols]

 1 Substrate 2 Anode 3 Hole Injecting and Transporting Layer 4 Organic Electron Transporting and Emitting Layer 5 Organic Emitting Layer 5 Electron Injecting and Transporting Layer 7 Cathode 8 Sealing Layer 11 Chamber 12 Gas Introducing Valve 13 RF Power Supply 14 Matching Circuit 15 Coil Electrode 16 Resistance Heating Vapor Deposition Source 17 Substrate 18 Substrate bias power supply

Claims (2)

[Claims] 1. At least an anode, a hole injecting and transporting layer, an organic electron transporting and emitting layer, a cathode, or an anode, a hole injecting and transporting layer,
In an organic thin film EL device composed of an organic light emitting layer, an electron injecting and transporting layer, and a cathode in this order, an ion plating film mainly composed of a metal oxide or a mixture of a plurality of metal oxides as a sealing layer on the cathode. An organic thin film EL element characterized by using. 2. The sealing layer is formed of an ion plating film containing a metal fluoride or a mixture of a plurality of metal fluorides as a main component instead of the metal oxide or a mixture of a plurality of metal oxides. The organic thin film EL element according to claim 1, wherein