JP2007214007A - Manufacturing method and manufacturing device of organic electroluminescent element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of an organic EL element having an organic EL layer constructed of a transparent conductive layer, a negative electrode layer opposed to the transparent conductive film, and one or a plurality of functional layers including an organic luminous layer interposed by both electrodes on a transparent substrate, in which, even when the organic EL layer is formed by a wet coating method, solvent is removed by a simple method and even if the solvent remains, deterioration of the characteristics of the EL layer does not occur and the high performance organic EL element can be manufactured. <P>SOLUTION: This is the manufacturing method of the organic EL element in which at least one layer of functional layers is arranged by a wet process method at the upper part of the transparent conductive layer and the functional layer is dried by a process in which the atmosphere space where the functional layer is placed is replaced by a dried inert gas and a process in which it is again replaced by the dried inert gas. After the functional layer is placed in a reduced pressure space, the functional layer is heated while the dried inert gas is filled in the space, and the atmosphere space is replaced by the heated inert gas. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for producing an organic electroluminescence element using an electroluminescence phenomenon of an organic thin film, particularly an organic electroluminescence element (hereinafter referred to as organic EL) used for producing an organic electroluminescence element containing a polymer material, and a printing member. About.

  An organic EL element is one in which an organic EL layer including an organic light emitting layer is formed between two opposing electrodes, and light is emitted by passing a current from between both electrodes to the organic EL layer. For this, the thickness of the organic EL layer is important, and it is necessary to form a thin film of about 100 to 1000 nm. Furthermore, in order to make this a display display, it is necessary to pattern with high definition. Organic light-emitting materials used in organic EL devices include low-molecular materials and high-molecular materials. Generally, low-molecular materials are formed into thin films by resistance heating vapor deposition or the like, and patterning is performed using a fine pattern mask at this time. However, this method has a problem that the larger the substrate is, the less the patterning accuracy is. Further, in the vapor deposition method, since the vapor deposition source is usually a point shape like a pinhole or a crucible of a boat, it is difficult to form a thin film layer with a uniform film thickness on a large-sized substrate.

  On the other hand, recently, a method of forming a thin film by a wet process method using a polymer material as an organic light emitting material and using a coating liquid (ink) in which the organic light emitting material is dissolved or dispersed in a solvent is tried. It is becoming. Examples of the wet coating method for forming a thin film include a spin coating method, a bar coating method, and a dip coating method. In particular, for patterning with high definition and for painting pixels in three colors of R (red), G (green), and B (blue), thin film formation by a printing method that specializes in painting and patterning is required. It is considered to be most effective (see Patent Documents 1 and 2).

  Thus, although the method of manufacturing an organic EL element by a wet coating method is very effective, in order to use a solvent, it is necessary to remove a solvent at a drying process. As the method, methods using a reduced pressure drying method (see Patent Document 3), a heat drying method (see Patent Document 4), and a pressure heating drying method (see Patent Document 5) have been proposed.

  However, in the case of manufacturing an organic EL device by these wet coating methods, in particular, a printing method or a droplet discharge method, a solvent having a very high boiling point of 200 ° C. or more is often used, and heating under atmospheric pressure or pressurized conditions. There is a possibility that the solvent cannot be sufficiently removed from the organic EL layer by drying, and as a result, the life of the organic EL element may be shortened. In addition, when a high temperature is applied for sufficient drying, there is a problem that the material constituting the organic EL element may be deteriorated.

  Therefore, in general, the coating film of the organic EL element is often dried in a state where the boiling point of the solvent is lowered under reduced pressure using a vacuum dryer. If some of the materials easily react with oxygen, drying under reduced pressure is performed in an inert gas atmosphere such as nitrogen. At that time, the pressure is reduced until the drying process is completed and the organic EL substrate is taken out. When a dry pump is used, the degree of vacuum is at most several Pa, and the solvent in the vacuum dryer and the organic EL element does not deteriorate the characteristics of the organic EL element no matter how long the drying time is reduced. Does not decrease.

The known literature is described below.
JP 2003-17261 A Special table 2003-527955 gazette JP-A-9-97679 JP 2002-31567 A JP 2005-26000 A Kazuo Hata and Kenichi Watanabe "Basic Organic Chemistry Experiment" Maruzen (1966), p. 115

  Therefore, the present invention has been made in view of such circumstances, and even when the organic EL layer is formed by a wet coating method, the solvent is removed by a simple method, and the amount of the remaining solvent is a characteristic of the organic EL element. It is an object of the present invention to provide a production method that can produce a high-performance organic EL device.

The present invention has been made in view of the above problems, and by replacing the gas containing the solvent present in the vacuum dryer contaminated with the solvent at the time of solvent drying with an inert gas such as fresh nitrogen, We found that the above problems could be solved.

The invention according to claim 1 of the present invention includes a first electrode (transparent conductive layer), a second electrode (cathode layer) facing the first electrode (transparent conductive film), and an organic electroluminescence sandwiched between both electrodes. In the manufacturing method of an organic electroluminescence element (organic EL element) provided with a layer (organic EL layer),
The organic electroluminescence layer (organic EL layer) is composed of one or more functional layers including an organic light emitting layer, and at least one of the one or more functional layers constituting the organic electroluminescence layer (organic EL layer). The formation process of
Arranging the functional layer above the first electrode by a wet process method;
Replacing the atmosphere space in which the functional layer formed by the wet process method is placed with a dry inert gas;
Replacing the atmosphere space replaced with the inert gas in which the functional layer is placed, with the dried inert gas again;
It is a manufacturing method of the organic electroluminescent element (organic EL element) characterized by including.

  When manufacturing an organic EL device comprising an organic EL layer comprising a transparent electrode, a counter electrode, and an organic light emitting layer according to the invention of claim 1, when at least one of the organic EL layers is formed by a coating method, Provided is a production method in which an inert gas is replaced twice or more when the layer is dried to dilute a slight amount of the solvent remaining in the vacuum dryer, thereby enabling rapid drying.

  In the invention according to claim 2 of the present invention, the step of replacing the atmosphere space in which the functional layer is placed with the dried inert gas is performed after the functional layer is placed in a space under reduced pressure and then dried in the space. 2. The method for producing an organic electroluminescence element (organic EL element) according to claim 1, wherein an inert gas is filled.

  According to the second aspect of the present invention, there is provided a production method in which a gas in a vacuum dryer containing a solvent is quickly eliminated by having a pressure reducing step.

  In the invention according to claim 3 of the present invention, the step of replacing the atmosphere space in which the functional layer is placed with the dried inert gas replaces the atmosphere space with the inert gas while heating the functional layer. A method for producing an organic electroluminescence element (organic EL element) according to claim 1 or 2.

  According to the third aspect of the invention, by having a heating step of heating while controlling the temperature of the organic EL layer, volatilization of the solvent from the organic EL layer is promoted.

  In the invention according to claim 4 of the present invention, the step of replacing the atmosphere space in which the functional layer is placed with the dried inert gas replaces the atmosphere space with the dried and heated inert gas. It is a manufacturing method of the organic electroluminescent element (organic EL element) of any one of Claims 1 thru | or 3 characterized by the above-mentioned.

  According to the invention described in claim 4, by introducing a preheated inert gas into the dryer, it is possible to quickly volatilize the solvent from the organic EL layer without lowering the temperature of the vacuum dryer and the substrate. It becomes.

The invention according to claim 5 of the present invention includes a substrate, a first electrode formed on the substrate, a second electrode facing the first electrode, and an organic electroluminescence layer sandwiched between both electrodes, The electroluminescence layer is an apparatus for producing an organic electroluminescence element composed of one or more functional layers including an organic light emitting layer,
A functional layer forming mechanism capable of disposing a functional layer above the first electrode by a wet process method;
An airtight chamber capable of keeping the atmosphere space in which the substrate provided with the first electrode is placed in an airtight state;
A heating mechanism capable of heating the material in the hermetic chamber;
A pressure reducing mechanism capable of depressurizing the hermetic chamber, and a pressure adjusting mechanism including a gas introducing unit capable of introducing an arbitrary gas into the hermetic chamber;
A gas heating mechanism capable of heating the gas introduced into the hermetic chamber;
It is the manufacturing apparatus of the organic electroluminescent element characterized by including.

  According to the method for producing an organic EL element of the present invention, even when the organic EL layer is formed by a wet coating method, the organic EL element accompanying the removal of the solvent can be obtained by completely removing the residual solvent in the organic EL layer. Thus, it is possible to provide a manufacturing method that makes it possible to manufacture a high-performance organic EL element that improves the initial characteristics and life characteristics of the organic EL element.

  An example of producing an organic EL device according to the present invention will be described with reference to FIG.

FIG. 1 shows a first electrode made of a transparent conductive layer (hereinafter referred to as a transparent conductive layer), a second electrode of an opposing cathode layer (hereinafter referred to as a cathode layer), and an organic electroluminescent layer (which is sandwiched between both electrodes). 1 illustrates an organic electroluminescence element (hereinafter referred to as an organic EL element) provided with an organic EL layer). The organic EL device of the present invention includes a transparent conductive layer on a light-transmitting substrate, an opposing cathode layer, and an organic EL layer sandwiched between both electrodes, and the organic EL layer includes one or more organic light-emitting layers. It consists of functional layers. Here, as an example, a bottom emission type organic EL element having a structure in which a transparent electrode layer is an anode, a cathode layer is a cathode, and light is extracted from the transparent conductive layer side is exemplified. FIG. 1 shows an organic EL device 10 having a transparent electrode layer 2 as an anode, an organic EL layer 3 composed of one or a plurality of functional layers 31 including an organic light emitting layer, and a cathode layer 4 as a cathode on a transparent substrate 1 to be supported. It is.

  Next, a method for forming a functional layer in the method for producing an organic EL element of the present invention will be described below.

  The organic EL layer is composed of one or a plurality of functional layers including an organic light emitting layer, and at least one of the one or a plurality of functional layers constituting the organic EL layer has a functional layer wet above the first electrode. Formed by process method. The wet process method uses a functional ink which is a liquid in which a functional material such as an organic light emitting material or a hole transport material is dissolved or dispersed, and is a transparent electrode to be formed by a method such as coating, spraying or printing. A thin film is formed by coating on the substrate on which is formed. Examples of the coating method include a spin coating method, a spray coating method, an ink jet method, and a relief printing method.

  The method for drying the functional layer of the present invention will be described below.

  After the atmosphere space on which the functional layer formed by the wet process method is placed is replaced with a dried inert gas, the atmosphere is dried in the atmosphere space, and after the predetermined time has passed, the atmosphere is dried. After replacing the space with the dried inert gas again, the functional layer is dried in the re-substituted atmosphere space. That is, in the functional layer drying method of the present invention, the functional layer is dried by substituting the atmosphere in which the functional layer formed by the wet process method is placed twice or more with a dried inert gas. In the method of replacing the atmosphere space with an inert gas, the atmosphere space is placed in a decompressed space, and then the dried inert gas is filled in the space.

  The inert gas to be filled is substituted into the atmosphere space using, for example, a dried and heated inert gas. Simultaneously with the filling of the inert gas, for example, the atmosphere space is replaced with the inert gas while heating the functional layer. In the functional layer drying method of the present invention, it is important to appropriately optimize the presence / absence of heating of the placed functional layer and the heating of the inert gas in the atmosphere space.

  Below, each layer which comprises the organic EL element of this invention is demonstrated.

  The translucent substrate 1 in the present invention is not limited as long as it is a base material that is translucent and has a certain degree of strength. Specifically, a glass substrate or a plastic film or sheet can be used. If a thin glass substrate of 0.2 mm to 1 mm is used, a thin organic EL element having a very high barrier property can be produced.

  If a flexible plastic film is used, the organic EL element can be manufactured by winding, and the organic EL element can be provided at low cost. As the plastic film, polyethylene terephthalate, polypropylene, cycloolefin polymer, polyamide, polyether sulfone, polymethyl methacrylate, polycarbonate and the like can be used. In addition, the barrier property can be improved by laminating other gas barrier films such as ceramic vapor-deposited film, polyvinylidene chloride, polyvinyl chloride, saponified ethylene-vinyl acetate copolymer on the side where the transparent conductive layer 2 is not formed. And it can be set as an organic EL element with a long lifetime.

The transparent conductive layer 2 is not particularly limited as long as it is a conductive substance capable of forming a transparent or translucent electrode. Specifically, a composite oxide of indium and tin (hereinafter referred to as ITO) can be preferably used. A film can be formed on the translucent substrate 1 by vapor deposition or sputtering. Alternatively, a precursor such as indium octylate or indium acetone can be formed on the base material by a coating pyrolysis method in which an oxide is formed by thermal decomposition. Alternatively, a material in which a metal such as aluminum, gold, or silver is vapor-deposited in a translucent state can be used. Alternatively, an organic semiconductor such as polyaniline can also be used.

  The transparent conductive layer 2 may be activated on the surface by etching, patterning, UV treatment, plasma treatment, or the like, if necessary.

  The organic EL layer 3 in the present invention is not limited to a single layer structure having only an organic light emitting layer, but includes a plurality of hole injection layers, hole transport layers, electron block layers, hole block layers, electron transport layers, electron injection layers, and the like. These layers may be laminated. Although the thickness of each layer is arbitrary, it is preferably 10 nm to 100 nm, and the total film thickness of the organic EL layer 3 is preferably 100 nm to 1000 nm.

  The hole injection layer, the hole transport layer, and the electron block layer are layers having a material having a hole transport property and / or an electron block property, and holes are injected from the transparent conductive layer 2 to the organic EL layer 3 respectively. It is a layer that plays a role of preventing holes from passing through the transparent conductive layer 2 while moving holes injected from the transparent conductive layer 2 toward the cathode layer 4 and preventing electrons from traveling toward the transparent conductive layer 2 while passing through the holes. .

  The material used for these layers may be any material generally used as a hole transport material, such as copper phthalocyanine and derivatives thereof, 1,1-bis (4-di-p-tolylaminophenyl) cyclohexane, N, N′-diphenyl-N, N′-bis (3-methylphenyl) -1,1′-biphenyl-4,4′-diamine, N, N′-di (1-naphthyl) -N, N ′ Although low molecular weight compounds such as aromatic amines such as diphenyl-1,1′-biphenyl-4,4′-diamine can be used, polyaniline derivatives, polythiophene derivatives, polyvinylcarbazole (PVK) derivatives, poly (3, A polymer material such as a mixture of 4-ethylenedioxythiophene) and polystyrene sulfonic acid is preferable from the viewpoint of film formability. In addition, polyamines such as polyparaphenylene (PPP), polyarylene vinylenes such as polyphenylene vinylene (PPV), conductive polymers such as polyarylene vinylene (PPV), or polymers such as polystyrene (PS), arylamines, carbazole derivatives, aryl You may use the thing which mixed the material which shows low molecular hole transport property and electron block property, such as sulfides, a thiophene derivative, and a phthalocyanine derivative.

  An organic light emitting layer is a layer having a light emitting material. Examples of the phosphor used in the organic light emitting layer include coumarin, perylene, pyran, anthrone, porphyrene, quinacridone, N, N′-dialkyl substituted quinacridone, naphthalimide, N, N′-diaryl substituted pyrrolo. Low molecular luminescent dyes such as pyrrole, iridium complex, platinum complex, and europium complex are dissolved in polymers such as polystyrene, polymethyl methacrylate, polyvinyl carbazole, and polyarylene and polyarylene vinylenes. Polymer light emitters such as polyfluorene and polyfluorene can be used.

  The hole blocking layer and the electron transporting layer are layers having a material having an electron transporting property and / or a hole blocking property, and each of the electrons injected from the cathode layer 4 advances toward the transparent conductive layer 2. It is a layer that plays a role of preventing holes from traveling in the direction of the cathode layer 4 while passing through.

Materials used for these layers include charge transfer complexes of 7,7,8,8-tetracyanoquinodimethane (TCNQ) derivatives, silole derivatives, arylboron derivatives, pyridine derivatives such as bisphenanthroline, and perfluorinated products. Low molecular weight compounds such as oligophenylene derivatives and oxadiazole derivatives may be used, but from the viewpoint of film-forming properties, polymers having electron transport properties such as electron transport polysilanes, polysiloles, and boron-containing polymers. The system type is preferred. Also, a material obtained by mixing the above-described material having electron transport property or hole blocking property with a conductive polymer such as polyarylene such as PPP, polyarylene vinylene such as PPV, or a polymer such as polystyrene (PS). May be used.

  The electron injection layer is a layer having a material having an electron injection property, and is a layer that plays a role of lowering an electron injection barrier from the cathode layer 4 to the organic EL layer 3. In addition to the same material as that used for the electron transport layer, the material used for this layer is a salt or oxide of an alkali metal or alkaline earth metal such as lithium fluoride or lithium oxide, or PS. You may use the thing mixed with polymer materials, such as.

  For the formation of these layers, spin coating, curtain coating, bar coating, wire coating, slit coating, letterpress printing, intaglio printing, screen printing, gravure printing, flexographic printing, offset printing Wet coating method such as coating method or wet process method by printing method can also be used. For example, if high patterning accuracy and film thickness uniformity are not required in layers other than the organic light emitting layer, the film is formed by vapor deposition. Also good.

  Further, when these layers are prepared by a wet process method, as a solvent for dissolving or dispersing these materials, toluene, xylene, mesitylene, anisole, monochlorobenzene, p-cymene, diethylbenzene, cyclohexylbenzene, Examples thereof include those obtained by introducing a substituent into an aromatic ring such as dodecylbenzene, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, cyclohexanone, methanol, ethanol, isopropyl alcohol, ethyl acetate, butyl acetate, and water. These solvents may be used alone or in combination, if necessary, and surfactants, antioxidants, viscosity modifiers, ultraviolet absorbers and the like may be added as necessary.

  After coating and forming the organic EL layer, the substrate is placed in a vacuum dryer and dried. Usually, the organic EL element is produced in a clean room in order to prevent impurities from being mixed. In order to prevent mixing of oil into the organic EL layer and contamination of the clean room environment, the pump used for vacuum drying is preferably a dry pump rather than a general oil rotary pump.

  Some organic EL materials cause an oxidation reaction when heated in the presence of oxygen. When such a material is used, it is necessary to replace the inside of the vacuum dryer with an inert gas such as nitrogen several times before heating the vacuum dryer.

  After substituting with an inert gas, drying under reduced pressure is performed at an arbitrary pressure and temperature. At that time, in order to remove the solvent contained in the organic EL layer as much as possible, it is preferable to apply a temperature higher than the boiling point of the solvent. However, if a too high temperature is applied to the organic EL layer, the material constituting the organic EL element may be thermally deteriorated. Therefore, it is preferable to lower the boiling point of the solvent by lowering the atmospheric pressure. In addition, the boiling point of the solvent under reduced pressure can be calculated by an estimation based on a boiling point conversion table (Non-patent Document 1), an estimation based on the Clausius-Clapeyron formula, or an estimation based on a pressure-boiling point nomograph (FIG. 2) (non-patent) Reference 1).

  As described above, the heat drying is often performed under the reduced pressure conditions as much as possible. However, there is a limit to the ultimate pressure, and even if heat is applied in such a state that the material constituting the organic EL element does not undergo thermal deterioration, complete removal of the solvent cannot be achieved. This is because the amount of the solvent that volatilizes from the organic EL layer and the amount by which the solvent remaining as a gas in the vacuum dryer at the ultimate pressure is adsorbed to the organic EL layer reach an equilibrium state. In a vacuum dryer using a normal dry pump, the pressure that can be reached over several minutes to several hours is about 10 Pa. Under such conditions, a significant amount of high boiling solvent having a boiling point at atmospheric pressure exceeding 200 ° C. remains in the dryer. As a result, the solvent remains in the order of ppm in the organic EL layer. This residual solvent adversely affects the characteristics of the organic EL element.

  In order to quickly reduce the residual solvent, there is a method in which vacuum drying is temporarily interrupted, an inert gas not contaminated with the solvent is introduced, and the solvent atmosphere in the vacuum dryer is diluted by evacuating again. It is valid. This inert gas replacement may be performed as many times as necessary. Further, a fan may be attached and rotated in the vacuum dryer for the purpose of diffusing the solvent in the vicinity of the substrate and stirring the gas in the vacuum dryer during and after filling with the inert gas. Furthermore, when a preheated inert gas is introduced, the temperature of the vacuum dryer and the substrate can be prevented from decreasing, and the drying time can be shortened.

  After drying, an annealing treatment may be performed by heating the substrate above the glass transition point of the material constituting the organic EL layer, if necessary.

  After the organic EL layer is dried, a cathode layer is formed. As the cathode layer 4 which is a counter electrode, a single metal such as Mg, Al, Yb, or a compound such as Li or LiF is sandwiched by about 1 nm at the interface in contact with the light emitting medium material, and Al or Cu having high stability and conductivity is placed. Laminated and used. Alternatively, in order to achieve both electron injection efficiency and stability, an alloy system of a metal having a low work function and a stable metal, for example, an alloy such as MgAg, AlLi, or CuLi can be used. As a method for forming the cathode, a resistance heating vapor deposition method, an electron beam method, or a sputtering method can be used depending on the material. The thickness of the cathode is preferably about 10 nm to 1000 nm.

  Finally, in order to protect these organic EL layers from external oxygen and moisture, an organic EL element can be obtained by hermetically sealing with a glass cap and an adhesive. Moreover, when a translucent board | substrate has flexibility, sealing sealing is performed using a sealing agent and a flexible film.

  The organic EL device manufacturing apparatus of the present invention includes a substrate, an electrode of a transparent conductive layer formed on the substrate, an electrode of a cathode layer facing the electrode of the transparent conductive layer, and an organic light emitting layer sandwiched between both electrodes In accordance with a method for manufacturing an organic EL element having a multilayer structure of one or a plurality of functional layers including the above, a manufacturing apparatus that sequentially processes in that order, the atmosphere space in which the substrate provided with the first electrode is placed in an airtight state An airtight chamber that can be maintained; a heating mechanism capable of heating the substance in the airtight chamber; a pressure reducing unit capable of depressurizing the airtight chamber; and a pressure adjusting mechanism including a gas introduction unit capable of introducing an arbitrary gas into the airtight chamber; An organic electroluminescence element manufacturing apparatus comprising: a gas heating mechanism capable of heating a gas introduced into an airtight chamber.

  In the decompression section capable of decompressing the hermetic chamber, first, the hermetic chamber is placed in a decompressed space, and then a decompression operation is performed to fill the hermetic chamber with the dried inert gas. In the first procedure, after the decompressed space is depressurized to a predetermined pressure or lower, a depressurizing operation is performed in which the predetermined inert gas is filled and returned to the predetermined pressure in the next procedure.

  In the gas introduction part, for example, there is a method of circulating an arbitrary gas. A predetermined inert gas is sucked into the hermetic chamber and simultaneously the same amount of the predetermined inert gas is circulated by a method of exhausting from the hermetic chamber. Of the predetermined inert gas exhausted from the hermetic chamber, for example, 90 %, The predetermined inert gas of the return is mixed with a new predetermined inert gas, and introduced again into the hermetic chamber. In other words, the exhaust gas is circulated by a pressure difference (differential pressure) between the intake port and the exhaust port while renewing a part of the inert gas to a new inert gas.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto.

  Examples of the present invention will be described below.

  A glass substrate with ITO was prepared, and the ITO was etched into a predetermined pattern. Next, a liquid in which a mixture of poly (3,4-ethylenedioxythiophene) and polystyrenesulfonic acid was dispersed in water was applied onto the ITO pattern by a spin coating method on the etched transparent conductive layer. The substrate was dried at 200 ° C. for 3 minutes in the air, and further dried in a 10 Pa nitrogen atmosphere for 10 minutes. The thickness after drying was 50 nm.

  In addition, poly (2- (2-ethylhexyloxymethoxy) -5-methoxy-1,4-phenylenevinylene: glass transition temperature of 196 ° C.), which is a polyarylene vinylene polymer light-emitting material, was dissolved in toluene (boiling point at atmospheric pressure). (111 ° C.) 50% and cyclohexylbenzene (boiling point 240 ° C. at atmospheric pressure) 50% in a mixed solvent was applied to the substrate by spin coating.

  The substrate coated with the organic light-emitting ink was placed in a vacuum dryer, and the pressure was reduced to 10 Pa, followed by replacement with dry nitrogen three times. Further, after reducing the pressure to 10 Pa again, drying was performed at 150 ° C. for 1 hr. Thereafter, the vacuum was temporarily stopped, nitrogen gas heated by a heater was introduced into the vacuum dryer, and the pressure was reduced to 100,000 Pa. Then, the pressure was again reduced to 10 Pa, and drying was performed at 150 ° C. for 1 hr. Thereafter, this substitution step was further performed twice to obtain a substrate in which the hole injection layer and the light emitting layer were laminated on the ITO electrode transparent electrode. The light emitting layer had a thickness of 70 nm.

Furthermore, 0.5 nm and 200 nm of lithium and aluminum were provided on the above-described substrate by vacuum vapor deposition, respectively, to obtain an organic EL element. When a voltage of 8 V was applied to the obtained organic EL device, it showed 100 cd / m ² patterned light emission. Further, when the luminance half-life at the time of constant current driving was measured at an initial luminance of 100 cd / m ² , the luminance half-life was 3000 hr.

  Example 2 will be described as a comparative example of the present invention.

  In Example 2, an organic EL device was prepared by the same method as in Example 1 except that the nitrogen substitution after the start of heating and drying was not performed, and the total drying time was the same in 4 hours.

As a result, when a voltage of 12 V was applied to the obtained EL element, it showed 100 cd / m ² patterned light emission. In addition, when the luminance half-life at the time of constant current driving was measured at an initial luminance of 100 cd / m ² , the luminance half-life was 300 hr.

  It is the result of measuring the amount of solvent remaining in the organic EL layer when the drying time and the number of times of nitrogen replacement were changed with a mass spectrometer. The results are shown in Table 1 below.

In addition, 2 is the same conditions as in Example 2, only the drying time is shortened,
3 shows the result of reducing only the number of nitrogen substitutions under the same conditions as in Example 1.

  In the evaluation results, Example 1 of the present invention obtained good results.

It is sectional drawing of the polymer organic EL element of this invention. It is a barometric pressure-boiling point nomograph.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Translucent substrate 2 ... (Anode) transparent conductive layer (1st electrode)
3 ... Organic EL layer (one or more functional layers including an organic light emitting layer)
4 ... (cathode) cathode layer (second electrode)
10 ... Organic EL element 31 ... Functional layer

Claims (5)

In the method of manufacturing an organic electroluminescence element including the first electrode, the second electrode facing the first electrode, and the organic electroluminescence layer sandwiched between both electrodes,
The organic electroluminescence layer is composed of one or more functional layers including an organic light emitting layer, and the step of forming at least one of the one or more functional layers constituting the organic electroluminescence layer includes:
Arranging the functional layer above the first electrode by a wet process method;
Replacing the atmosphere space in which the functional layer formed by the wet process method is placed with a dry inert gas;
Replacing the atmosphere space replaced with the inert gas in which the functional layer is placed, with the dried inert gas again;
A method for producing an organic electroluminescence element, comprising:   The step of replacing the atmosphere space in which the functional layer is placed with a dry inert gas is characterized in that the functional layer is placed in a space under reduced pressure and then the dry inert gas is filled in the space. The manufacturing method of the organic electroluminescent element of Claim 1.   3. The step of replacing the atmosphere space in which the functional layer is placed with a dried inert gas replaces the atmosphere space with an inert gas while heating the functional layer. The manufacturing method of organic electroluminescent element of this.   4. The step of replacing the atmosphere space in which the functional layer is placed with a dried inert gas replaces the atmosphere space with a dried and heated inert gas. The manufacturing method of the organic electroluminescent element of any one. A substrate, a first electrode formed on the substrate, a second electrode facing the first electrode, and an organic electroluminescence layer sandwiched between both electrodes, wherein the organic electroluminescence layer includes a single or an organic light emitting layer An apparatus for manufacturing an organic electroluminescence element composed of a plurality of functional layers,
A functional layer forming mechanism capable of disposing a functional layer above the first electrode by a wet process method;
An airtight chamber capable of keeping the atmosphere space in which the substrate provided with the first electrode is placed in an airtight state;
A heating mechanism capable of heating the material in the hermetic chamber;
A pressure reducing mechanism capable of depressurizing the hermetic chamber, and a pressure adjusting mechanism including a gas introducing unit capable of introducing an arbitrary gas into the hermetic chamber;
A gas heating mechanism capable of heating the gas introduced into the hermetic chamber;
An apparatus for manufacturing an organic electroluminescence element, comprising:

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