JP4116764B2 - Method for producing organic electroluminescent device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to an organic electroluminescent device used for various displays, display devices, liquid crystal backlights, and the like.How to makeIt is about.
[0002]
[Prior art]
Organic electroluminescence devices using organic materials as light emitters, that is, organic electroluminescence devices, have attracted attention for a long time, and various studies have been conducted. It did not come. However, in 1987, Kodak's C.I. W. Tang et al. Proposed an organic electroluminescence having a functionally separated laminated structure in which an organic material is divided into two layers, a hole transport layer and a light emitting layer. In this case, although it has a low voltage of 10 V or less, it is 1000 cd / m.²It became clear that the above high luminance can be obtained. Since then, organic electroluminescence devices have begun to attract attention and active research has been conducted.
[0003]
As a result of such research and development, at present, the organic electroluminescence device has a low voltage of about 10 V and is 100 to 100,000 cd / m.²Surface light emission with a level of high brightness is possible, and light emission from blue to red is possible by selecting the type of fluorescent material.
[0004]
However, when the organic electroluminescence element is driven for a certain period, a non-light emitting portion called a dark spot occurs and grows, and there is a problem that the light emission characteristics deteriorate. The cause of the occurrence of such dark spots is considered to be the largest influence of moisture and oxygen, and particularly, the moisture is considered to have a great influence even in a very small amount.
[0005]
Therefore, it is necessary to seal the element by some method to shield the action of moisture, and various types of sealing with a protective film have been studied. What is conventionally known as the sealing by this protective film is that provided by an inorganic amorphous protective film containing carbon or silicon, which is provided in Japanese Patent Laid-Open No. 7-161474, and Japanese Patent Laid-Open No. 8-111286. Provided, SiO by ECR plasma CVD method₂Or Si_ThreeN_FourAnd a protective film formed by a room temperature reactive plasma CVD method provided in Japanese Patent Application Laid-Open No. 11-242994.
[0006]
[Problems to be solved by the invention]
However, in the method of sealing the element with the protective film as described above, pinholes often exist in the protective film, and cracks occur over time due to internal residual stress when the protective film is formed. There is a fear, a sufficient moisture shielding effect cannot be obtained, and it is difficult to maintain stable light emission characteristics over a long period of time.
[0007]
  The present invention has been made in view of the above points, and can obtain a sufficient moisture shielding effect and can maintain stable light emission characteristics over a long period of time.How to makeIs intended to provide.
[0008]
[Means for Solving the Problems]
  Organic electroluminescent device according to claim 1 of the present inventionHow to makeIs an organic electroluminescent device comprising a substrate 1, an anode 2 made of a transparent conductive film formed on the substrate 1, an organic light emitting layer 3 and a cathode 4 formed on the anode 2.How to makeAnd at least one water-absorbing film 5 on at least one of the outer surfaces of the anode 2 side and the cathode 4 side,On the outsideProtective film6bProvided,thisProtective film6bUsing low temperature plasma CVD with silane, nitrogen and ammonia as source gasesA silicon nitride film is formed, and another protective film 6a is formed between the water absorption film 5 and the protective film 6, and a silicon nitride film is formed by a low temperature plasma CVD method using silane and nitrogen as source gases. Formed byIt is characterized by that.
[0011]
  And claims2The invention of claim1In this case, a silicon nitride film produced by a low temperature plasma CVD method using silane and nitrogen as source gases is formed as another protective film 6 a inside the water absorption film 5.YouIt is characterized by that.
[0012]
  And claims3The invention of claim 1Or 2The sealing portion 7 made of an inorganic material is provided on the outermost surface of the protective film 6.TheFormationYouIt is characterized by that.
[0013]
  And claims4The invention of claim 1Or 2The sealing portion 7 made of an organic material is provided on the outermost surface of the protective film 6.TheFormationYouIt is characterized by that.
[0014]
  And claims5The invention of claim 1 to claim 14In any of the above, the water absorption film 5TheFormed by a water-absorbing agent that chemically adsorbs moistureYouIt is characterized by that.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below.
[0016]
  FIG. 1 illustrates the present invention.Reference exampleAn anode 2 made of a transparent conductive film is laminated on the surface of the substrate 1, an organic light emitting layer 3 is laminated on the surface of the anode 2 via a hole transport layer 11, and organic light emission is further performed. The cathode 4 is laminated on the surface of the layer 3 via the electron transport layer 12. An organic electroluminescence element, that is, an organic electroluminescence element (organic EL element) can be formed based on this structure. When a positive voltage is applied to the anode 2 and a negative voltage is applied to the cathode 4, the electron transport layer 12 is formed. The electrons injected into the organic light emitting layer 3 through the hole and the holes injected into the organic light emitting layer 3 through the hole transport layer 11 are recombined in the organic light emitting layer 3 to emit light. .
[0017]
As said board | substrate 1, transparent glass substrates, such as soda-lime glass and an alkali free glass, a transparent plastic substrate, etc. can be used. As the anode 2 which is an electrode for injecting holes into the element, it is preferable to use an electrode material made of a metal, an alloy, an electrically conductive compound, or a mixture thereof having a large work function, and the work function is particularly 4 eV or more. It is preferable to use the electrode material. Specific examples of such an electrode material include metals such as gold, CuI, ITO (indium tin oxide), SnO.₂And conductive transparent materials such as ZnO. For example, the anode 2 can be formed as a thin film by depositing these electrode materials on the substrate 1 by a method such as vacuum deposition or sputtering.
[0018]
Here, when a transparent substrate is used as the substrate 1 and light emitted from the organic light emitting layer 3 is transmitted through the anode 2 and irradiated from the substrate 1 to the outside, the light transmittance of the anode 2 is preferably 10% or more. . The sheet resistance of the anode 2 is preferably several hundred Ω / □ or less, and particularly preferably 100 Ω / □ or less. Further, the film thickness of the anode 2 varies depending on the material in order to control the light transmittance, sheet resistance and other characteristics of the anode 2 as described above, but is usually 500 nm or less, and preferably in the range of 10 to 200 nm. .
[0019]
On the other hand, the cathode 4 which is an electrode for injecting electrons into the organic light emitting layer 3 is preferably made of an electrode material made of a metal, an alloy, an electrically conductive compound and a mixture thereof having a small work function, and the work function is It is preferable to use an electrode material of 5 eV or less. Such electrode materials include sodium, sodium-potassium alloy, lithium, magnesium, aluminum, magnesium-silver mixture, magnesium-indium mixture, aluminum-lithium alloy, Al / Al₂O_ThreeA mixture, an Al / LiF mixture, etc. can be mentioned. For example, the cathode 4 can be produced by forming these electrode materials into a thin film by a method such as vacuum deposition or sputtering. In addition, when the light emitted from the organic light emitting layer 3 is transmitted through the cathode 4 and irradiated outside, the cathode 4 preferably has a light transmittance of 10% or more. Here, the film thickness of the cathode 4 varies depending on the material in order to control the characteristics such as the light transmittance of the cathode 4 as described above, but is usually 500 nm or less, and preferably in the range of 100 to 200 nm.
[0020]
In addition, as the light emitting material or doping material that can be used for the organic light emitting layer 3 in the present invention, anthracene, naphthalene, pyrene, tetracene, coronene, perylene, phthaloperylene, naphthaloperylene, diphenylbutadiene, tetraphenylbutadiene, coumarin, oxadiazole, bisbenzo Xazoline, bisstyryl, cyclopentadiene, quinoline metal complex, tris (8-hydroxyquinolinato) aluminum complex, tris (4-methyl-8-quinolinato) aluminum complex, tris (5-phenyl-8-quinolinato) aluminum complex, Aminoquinoline metal complex, benzoquinoline metal complex, tri- (p-terphenyl-4-yl) amine, 1-aryl-2,5-di (2-thienyl) pyrrole derivative, pyran, quinacridone, Examples include, but are not limited to, rubrene, distilbenzene derivatives, distilarylene derivatives, and various fluorescent dyes. It is also preferable to include 90 to 99.5 parts by mass of a light emitting material selected from these compounds and 0.5 to 10 parts by mass of a doping material. The thickness of the organic light emitting layer 3 is preferably 0.5 to 500 nm, particularly preferably 0.5 to 200 nm.
[0021]
The hole transport material constituting the hole transport layer 11 has the ability to transport holes, has a hole injection effect from the anode 2, and has an excellent hole injection effect for the organic light emitting layer 3 or the light emitting material. And a compound that prevents the electrons from moving to the hole transport layer 11 and has an excellent ability to form a thin film. Specifically, phthalocyanine derivatives, naphthalocyanine derivatives, porphyrin derivatives, N, N′-bis (3-methylphenyl)-(1,1′-biphenyl) -4,4′-diamine (TPD), 4,4 ′ -Aromatic diamine compounds such as bis [N- (naphthyl) -N-phenyl-amino] biphenyl (α-NPD), oxazole, oxadiazole, triazole, imidazole, imidazolone, stilbene derivative, pyrazoline derivative, tetrahydroimidazole, poly Arylalkanes, butadiene, 4,4 ′, 4 ″ -tris (N- (3-methylphenyl) N-phenylamino) triphenylamine (m-MTDATA), and polyvinylcarbazole, polysilane, polyethylenedioside thiophene (PEDOT) ) Polymers such as conductive polymers Fees including without being limited thereto.
[0022]
The electron transport material constituting the electron transport layer 12 has the ability to transport electrons, has an electron injection effect from the cathode 4, and has an excellent electron injection effect for the organic light emitting layer 3 or the light emitting material. And a compound that prevents holes from moving to the electron transport layer 12 and has an excellent ability to form a thin film. Specifically, fluorene, bathophenanthroline, bathocuproine, anthraquinodimethane, diphenoquinone, oxazole, oxadiazole, triazole, imidazole, anthraquinodimethane, etc. and their compounds, metal complex compounds or nitrogen-containing five-membered ring derivatives is there. Specifically, examples of the metal complex compound include tris (8-hydroxyquinolinate) aluminum, tri (2-methyl-8-hydroxyquinolinato) aluminum, tris (8-hydroxyquinolinato) gallium, bis ( 10-hydroxybenzo [h] quinolinato) beryllium, bis (10-hydroxybenzo [h] quinolinato) zinc, bis (2-methyl-8-quinolinato) (o-cresolate) gallium, bis (2-methyl-8-quinolinato) ) (1-naphtholato) aluminum, but is not limited thereto. The nitrogen-containing five-membered ring derivative is preferably an oxazole, thiazole, oxadiazole, thiadiazole or triazole derivative. Specifically, 2,5-bis (1-phenyl) -1,3,4-oxazole, 2,5-bis (1-phenyl) -1,3,4-thiazole, 2,5-bis (1 -Phenyl) -1,3,4-oxadiazole, 2- (4′-tert-butylphenyl) -5- (4 ″ -biphenyl) 1,3,4-oxadiazole, 2,5-bis (1-naphthyl) -1,3,4-oxadiazole, 1,4-bis [2- (5-phenylthiadiazolyl)] benzene, 2,5-bis (1-naphthyl) -1,3, Examples include, but are not limited to, 4-triazole, 3- (4-biphenylyl) -4-phenyl-5- (4-tert-butylphenyl) -1,2,4-triazole. Furthermore, the polymer material used for a polymer organic electroluminescent element can also be used. For example, polyparaphenylene and derivatives thereof, fluorene and derivatives thereof, and the like.
[0023]
In the organic EL device of FIG. 1, the anode 2 side and the cathode of the laminated structure of the anode 2, the hole transport layer 11, the organic light emitting layer 3, the electron transport layer 12 and the cathode 4 stacked on the substrate 1. A water absorption film 5 and a protective film 6 are formed on at least one of the four outer surfaces. In the embodiment of FIG. 1, the water absorbing film 5 and the protective film are formed so as to cover the exposed surface of the anode 2, the hole transport layer 11, the organic light emitting layer 3, the electron transport layer 12, and the cathode 4 on the outer surface on the cathode 4 side. 6 is formed.
[0024]
The water-absorbing film 5 is formed by a water-absorbing agent that chemically adsorbs moisture, and the water-absorbing film 5 absorbs moisture that has entered a minute amount from the outside and moisture that has emerged from the inside of the element. It is possible to prevent deterioration of characteristics. Although the film thickness of the water absorption film | membrane 5 is not specifically limited, It is preferable to set to the range of 0.01-100 micrometers.
[0025]
Examples of the water-absorbing agent that forms the water-absorbing film 5 include alkali metal oxides such as calcium oxide and barium oxide, organic substances, and the like, and organic substances having an isocyanate group can be used. As shown in the following reaction formula, this organic compound having an isocyanate group has a high ability to chemically adsorb moisture, and also maintains a solid state after moisture absorption, and liquefies. There is no.
[0026]
R-NCO + H₂O → R-NH₂  + CO₂
Specific examples of the organic substance having an isocyanate group include naphthylene diisocyanate, 4,4-diphenylmethane diisocyanate (MDI), paraphenylene diisocyanate, isopropylidenebis (4-cyclohexyl isocyanate) (IPC), cyclohexyl diisocyanate, and tolidine diisocyanate. Lysine diisocyanate, tetramethylxylylene diisocyanate, tolylene diisocyanate (TDI), xylylene diisocyanate, hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, isophorone diisocyanate, hydrogenated xylylene diisocyanate, etc. It is not limited. Among these organic substances having an isocyanate group, those having a melting point of 50 ° C. or higher are particularly preferable from the viewpoint of heat resistance. Moreover, the polymer obtained by superposing | polymerizing the organic substance which has the above-mentioned isocyanate group can be used, and it is preferable also in this case that a glass transition temperature is 50 degreeC or more from a heat resistant point.
[0027]
  In the organic EL element of FIG. 1, the protective film 6 is formed so as to cover the entire outer surface of the water absorbing film 5. This protective film 6 has a function of blocking moisture and oxygen, and is formed of a silicon nitride film. The silicon nitride film has a high function of blocking moisture and oxygen, and is formed by low temperature plasma CVD performed at a low temperature of about room temperature.TheTherefore, by forming the protective film 6 with a silicon nitride film produced by low temperature plasma CVD, the organic light emitting layer 3 is not deteriorated by a high temperature action. When forming a silicon nitride film,originalSilane, nitrogen, and ammonia are used as source gasesAndLineYeah.The thickness of the protective film 6 is not particularly limited, but is preferably set in the range of 0.01 to 100 μm.
[0028]
Either the water absorbing film 5 or the protective film 6 may be on the outside or the inside, and the water absorbing film 5 and the protective film 6 may be formed of a plurality of layers in addition to a single layer. In the organic EL element shown in FIG. 1 formed by providing the water absorption film 5 and the protective film 6, the water absorption by the water absorption film 5 and the moisture blocking by the protective film 6 prevent the moisture from acting on the element. The generation and growth of non-light emitting portions called dark spots can be prevented. Moreover, even if pinholes and cracks exist in the protective film 6 and the moisture cannot be completely blocked, if the water-absorbing film 5 is provided inside the protective film 6, the water passing through the protective film 6 absorbs water. It is possible to prevent water from being absorbed by the film 5 and preventing moisture from acting on the inside of the device, and it is possible to prevent the generation and growth of non-light emitting portions without sealing the entire device using a glass plate or the like. It can be done. In order to reliably block the passage of moisture, the water absorption film 5 and the protective film 6 are preferably formed in a plurality of layers.
[0029]
  FIG. 2 shows the present invention.The fruitForm of applicationExampleThe protective film 6 provided so as to cover the water absorption film 5 is formed in a plurality of layers. Other configurations are the same as those in FIG. In forming the protective film 6 with a silicon nitride film formed by low-temperature plasma CVD, there are a method using silane and nitrogen as source gases and a method using silane, nitrogen and ammonia as source gases. In the case where the protective films 6a and 6b are formed in two layers as in the embodiment, a silicon nitride film is first formed by using silane and nitrogen as source gases to form the protective film 6a, and then silane and nitrogen are formed thereon. A protective film 6b is formed by forming a silicon nitride film using ammonia and a raw material gas. A silicon nitride film formed using silane, nitrogen, and ammonia as source gases has fewer pinholes and has a function as a film that blocks moisture than a silicon nitride film formed using silane and nitrogen as source gases. However, since ammonia in the source gas may reduce the light emission characteristics of the device, it is preferable to form the silicon nitride film in the above order and form the protective film 6 in a plurality of layers.
[0030]
  FIG. 3 illustrates the present invention.Other reference examplesThe protective film 6 is formed in two layers, and the protective film 6a, the water absorption film 5 and the protective film 6b are laminated in this order. Other configurations are the same as those in FIG. Also in this case, a silicon nitride film is formed using silane and nitrogen as source gases to form an inner protective film 6a, and a silicon nitride film is formed using silane, nitrogen and ammonia as source gases to form an outer protective film 6b. Form.
[0031]
  FIG. 4 shows still another embodiment of the present invention.Reference exampleThe sealing portion 7 is provided so as to cover the outermost surface of the water absorption film 5 and the protective film 6. Other configurations are the same as those in FIG. By sealing the organic light emitting layer 3 and the like of the element with the sealing portion 7 in this way, it is possible to completely prevent moisture and oxygen from entering from the outside, and to stabilize the light emission characteristics over a long period of time. It can be done.
[0032]
The material for forming the sealing portion 7 is not particularly limited as long as it can fill a pinhole existing in the protective film 6 and can block moisture and oxygen. For example, examples of the inorganic substance include metals such as aluminum, silver, and gold, and metal oxides such as silicon oxide, magnesium oxide, and titanium oxide. In addition, as an organic material, polyparaxylylene, Teflon-based polymer, polyimide, polymer materials such as epoxy and acrylic thermosetting resins and photo-curing resins, and organic electroluminescent elements are used, and excellent in film forming properties. 4 ', 4 "-tris (N- (3-methylphenyl) N-phenylamino) triphenylamine (m-MTDATA), tris (8-hydroxyquinolinato) aluminum, and other low molecular materials that can be vacuum deposited Furthermore, in order to give mechanical strength, a glass plate, a stainless steel plate, or the like may be bonded together, and the thickness of the sealing portion 7 is not particularly limited, but is 0.01 μm. It is preferable to set in the range of ˜5 mm.
[0033]
【Example】
Next, the present invention will be specifically described with reference to examples.
[0034]
Example 1
ITO glass (Sanyo Vacuum Co., Ltd.) formed on a glass substrate 1 having a thickness of 0.7 mm by sputtering ITO (indium-tin oxide) and providing an anode 2 made of a transparent electrode having a sheet resistance of 7Ω / □. Made). This ITO glass substrate was subjected to ultrasonic cleaning with acetone, pure water, and isopropyl alcohol for 15 minutes, dried, and further UV ozone cleaned.
[0035]
Next, this ITO glass substrate is set in a vacuum deposition apparatus, and 1 × 10^-6Torr (1.33 × 10^-FourUnder reduced pressure of Pa), 4,4′-bis [N- (naphthyl) -N-phenyl-amino] biphenyl (manufactured by Dojindo Laboratories Co., Ltd.) is formed to a thickness of 400 mm at a deposition rate of 1 to 2 mm / s. The hole transport layer 11 was formed on the anode 2 by vapor deposition.
[0036]
Next, tris (8-hydroxyquinolinate) aluminum complex (manufactured by Dojindo Laboratories Co., Ltd.) was deposited at a deposition rate of 1 to 2 cm / s to a thickness of 400 mm, and an organic light emitting layer was formed on the hole transport layer 11. 3 and an electron transport layer 12 were formed.
[0037]
Next, the organic light emitting layer 3 and the electron transport layer are formed by first depositing LiF at a deposition rate of 0.5 to 1.0 mm and a thickness of 5 mm, and subsequently depositing Al at a thickness of 1500 mm at a deposition rate of 10 mm / s. The cathode 4 was formed on the layer serving as 12.
[0038]
Thereafter, naphthylene diisocyanate was deposited on the cathode 4 by a vacuum deposition method to form a water absorption film 5 having a thickness of 1 μm.
[0039]
Further, a protective film 6 was formed on the water absorption film 5 by a low temperature plasma CVD method. At this time, a silicon nitride film 6a having a thickness of 0.4 μm is first formed using silane and nitrogen as source gases, and then a silicon nitride film 6b having a thickness of 0.6 μm is formed using silane, nitrogen and ammonia as source gases. A protective film 6 was formed by forming a film with a thickness.
[0040]
The organic electroluminescent device as shown in FIG. 2 was produced as described above, and the organic electroluminescent device was 10 mA / cm.²A continuous light emission test was conducted for 500 hours with a constant current of. As a result, no dark spot generation growth was observed, and 400 cd / m equivalent to the initial luminance.²Was obtained.
[0041]
  (Reference example 1)
  In the same manner as in Example 1, ITO glass (manufactured by Sanyo Vacuum Co., Ltd.) was used, and a hole transport layer 11, a layer that shared the organic light emitting layer 3 and the electron transport layer 12, and the cathode 4 were formed on the anode 2, respectively. .
[0042]
Next, a silicon nitride film 6a having a thickness of 0.5 μm was formed on the cathode 4 by low temperature plasma CVD using silane and nitrogen as source gases. Next, calcium oxide was deposited by a vacuum deposition method to form a water absorption film 5 having a thickness of 1 μm on the silicon nitride film 6a. Further, a silicon nitride film 6b having a thickness of 0.5 μm was formed on the water absorption film 5 by low temperature plasma CVD using silane, nitrogen and ammonia as source gases.
[0043]
The organic electroluminescent device as shown in FIG. 3 was prepared as described above, and the organic electroluminescent device was 10 mA / cm.²A continuous light emission test was conducted for 500 hours with a constant current of. As a result, no generation and growth of dark spots were observed, and 395 cd / m equivalent to the initial luminance.²Was obtained.
[0044]
  (Example2)
  In Example 1, after forming the silicon nitride film 6b, aluminum was formed by sputtering, and the sealing portion 7 having a thickness of 10 μm was provided on the silicon nitride film 6b.
[0045]
As described above, an organic electroluminescent element having the sealing portion 7 provided in FIG. 4 as shown in FIG. 4 was prepared. The organic electroluminescent element was 10 mA / cm.²A continuous light emission test was conducted for 500 hours with a constant current of. As a result, no generation and growth of dark spots were observed, and 410 cd / m equivalent to the initial luminance.²Was obtained.
[0046]
  (Reference example 2)
  Reference example 1Then, after the silicon nitride film 6b was formed, polyparaxylylene was formed by the CVD method, and the sealing portion 7 having a thickness of 10 μm was provided on the silicon nitride film 6b.
[0047]
As described above, an organic electroluminescent element having the sealing portion 7 provided in FIG. 3 as shown in FIG. 4 was prepared, and the organic electroluminescent element was 10 mA / cm.²A continuous light emission test was conducted for 500 hours with a constant current of. As a result, no generation and growth of dark spots were observed, and 410 cd / m equivalent to the initial luminance.²Was obtained.
[0048]
(Comparative Example 1)
In the same manner as in Example 1, ITO glass (manufactured by Sanyo Vacuum Co., Ltd.) was used, and a hole transport layer 11, a layer that shared the organic light emitting layer 3 and the electron transport layer 12, and the cathode 4 were formed on the anode 2, respectively. . Then, using a mixed gas of silane and nitrogen as a source gas, low temperature plasma CVD was performed in the same manner as in Example 1 to form a silicon nitride film having a thickness of 1.0 μm on the cathode 4 to form the protective film 6. .
[0049]
An organic electroluminescent element having the same configuration as that shown in FIG. 1 except that the water absorbing film was not formed as described above was prepared. The organic electroluminescent element was 10 mA / cm.²A continuous light emission test was conducted for 500 hours with a constant current of. As a result, the generation and growth of dark spots were confirmed, and 100 cd / m²Was obtained.
[0050]
【The invention's effect】
  As described above, the organic electroluminescent device according to claim 1 of the present invention.How to makeIs an organic electroluminescent device comprising a substrate, an anode made of a transparent conductive film formed on the substrate, an organic light emitting layer and a cathode formed on the anodeHow to makeAnd at least one water-absorbing film on at least one of the outer surface of the anode side and the cathode sideOn the outsideProvide a protective film,thisThe protective film is made of low temperature plasma CVD using silane, nitrogen and ammonia as source gases.By forming a silicon nitride film, forming another protective film between the water absorption film and the protective film, and forming a silicon nitride film by low temperature plasma CVD using silane and nitrogen as source gasesSince it was formed, water absorption by the water absorption film and moisture blocking by the protective film can prevent moisture from acting inside the element, and even if there are pinholes and cracks in the protective film, Water passing therethrough can be absorbed by the water absorption film to prevent moisture from acting on the inside of the device, and the light emission characteristics can be stably maintained over a long period of time. In addition, the protective film formed of a silicon nitride film has a high barrier property against moisture and oxygen, and can stably maintain the light emission characteristics over a longer period. That is, since the protective film is formed of a silicon nitride film produced by a low temperature plasma CVD method using silane, nitrogen and ammonia as source gases, the protective film can be formed at a low temperature of about room temperature. Thus, the organic light emitting layer is not deteriorated by the above action, and a silicon nitride film with few pinholes can be formed by forming a film using silane, nitrogen and ammonia as source gases.In addition, another protective film is formed between the water-absorbing film and the protective film by a silicon nitride film formed by a low temperature plasma CVD method using silane and nitrogen as raw material gases, so that ammonia in the raw material gas is used as the element. Thus, there is no such thing as deteriorating the light emission characteristics.
[0053]
  And claims2In this invention, a silicon nitride film produced by low-temperature plasma CVD method using silane and nitrogen as source gases is formed as another protective film inside the water absorption film, so that ammonia in the source gas is the emission characteristic of the device It is a thing that does not lower the value.
[0054]
  And claims3According to the invention, since the sealing portion made of an inorganic substance is formed on the outermost surface of the protective film, it is possible to completely prevent the entry of moisture and oxygen from the outside by the sealing portion, and further, Thus, the light emission characteristics can be stabilized.
[0055]
  And claims4According to the invention, since the sealing portion made of an organic substance is formed on the outermost surface of the protective film, entry of moisture and oxygen from the outside can be completely prevented by the sealing portion. Thus, the light emission characteristics can be stabilized.
[0056]
  And claims5In the invention of the present invention, the water absorption film is formed by a water absorbing agent that chemically adsorbs moisture, so that the water absorption capability of the water absorption film can be obtained and the moisture acting on the element can be effectively removed, The light emission characteristics can be stably maintained over a longer period.
[Brief description of the drawings]
FIG. 1 of the present inventionReference exampleIt is sectional drawing which shows an example.
FIG. 2 shows an embodiment of the present invention.OneIt is sectional drawing which shows an example.
FIG. 3 of the present inventionReference exampleIt is sectional drawing which shows another example.
FIG. 4 of the present inventionReference exampleIt is sectional drawing which shows another example of these.
[Explanation of symbols]
  1 Substrate
  2 Anode
  3 Organic light emitting layer
  4 Cathode
  5 Water absorption membrane
  6 Protective film
  6a Protective film
  6b Protective film
  7 Sealing part

Claims (5)

In a method for manufacturing an organic electroluminescent device comprising a substrate, an anode made of a transparent conductive film formed on the substrate, an organic light emitting layer and a cathode formed on the anode, at least one of an outer surface on the anode side and the cathode side In addition, at least one water-absorbing film and a protective film on the outside thereof are provided, and this protective film is formed by forming a silicon nitride film by a low-temperature plasma CVD method using silane, nitrogen, and ammonia as source gases. method for manufacturing an organic electroluminescent element according to the water-absorption layer and another protective layer between the protective film, silane and nitrogen, wherein that you formed by making a silicon nitride film at a low temperature plasma CVD method as a material gas . Method for manufacturing an organic electroluminescent device according to claim 1 silane and nitrogen characterized that you forming a silicon nitride film formed by low temperature plasma CVD method as a raw material gas as the other protective film to the inside of the water film . The outermost surface of the protective film, a method for manufacturing an organic electroluminescent device according to claim 1 or 2, characterized that you form a sealing portion made of an inorganic substance. The outermost surface of the protective film, a method for manufacturing an organic electroluminescent device according to claim 1 or 2, characterized that you form a sealing portion made of organic matter. The water-absorption layer, a manufacturing method of an organic electroluminescent device according to any one of claims 1 to 4, characterized that you formed by water-absorbing agent to chemically adsorb moisture.

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