JP2023026298A - Substrate for electronic element, organic electroluminescence element, display device, and lighting device - Google Patents

Abstract

Kind Code: A1 Abstract: A substrate for an electronic device is provided, which can suitably emit light when applied to an organic EL device even when a substrate having a rough surface is used.
Kind Code: A1 An electronic device substrate (1) comprising a substrate (2) having an electrode (3) on its surface and a conductive film (4) formed adjacent to an upper portion of the electrode (3), the substrate being perpendicular to the substrate (2). The maximum height roughness Rz of the shape of the electrode 3 in the direction is 300 nm or more and 1000 nm or less, and the thickness t of the conductive film 4 and the maximum height roughness Rz of the shape of the electrode 3 satisfy the formula (1): The relationship of maximum height roughness Rz (nm) of electrode shape-thickness t (nm) of conductive film≦230 nm is satisfied, and the conductive film 4 contains polyoxometalate containing tungsten. A substrate 1 for an electronic device is characterized.
[Selection drawing] Fig. 2

Description

TECHNICAL FIELD The present invention relates to a substrate for an electronic device, and an organic electroluminescence (hereinafter, electroluminescence (electroluminescence) may be abbreviated as “EL”) device, display device, and lighting device using the same.

Over the past 30 years, research and development of organic EL devices have been vigorously carried out, and they have been put to practical use in displays and lighting applications. Among them, the organic EL element has come to the stage of widespread use as a display element for smart phones and large-sized TVs, and further expansion of its use is expected in the future.
On the other hand, for lighting applications, the spread of organic EL elements has yet to be seen, and many problems remain. One major factor that hinders the widespread use of lighting is price, and organic EL lighting using organic EL elements is very expensive compared to other types of lighting such as fluorescent lamps and LED lighting. Lighting is more price-sensitive than display, and a breakthrough for lower prices is essential. One of the reasons why organic EL lighting is expensive is the use of an expensive transparent electrode-attached substrate. Therefore, it is important to make this substrate inexpensive.

As a low-cost substrate, the application of metal foil such as stainless steel foil and aluminum foil is being studied. The problem with metal foil is that it has a very rough surface. Using a metal foil as one electrode, an organic film is formed directly on the metal foil, and an upper electrode is provided on the organic film to produce an organic EL element. A short circuit occurs, and light emission from the organic EL element cannot be obtained. Therefore, it is generally necessary to smooth the metal foil to a surface roughness of 1 nm or less.
For example, in Patent Document 1 below, two types of insulating films, a methyl group-containing silica-based coating and a phenyl group-containing silica-based coating, are provided on a mirror-finished metal foil substrate to smooth it, and a new electrode is provided on the top thereof. A method has been reported. Further, Patent Document 2 below reports a process in which a copper foil is previously polished to smooth the surface roughness to 1 nm or less, and a high reflectance electrode for an organic EL device is formed thereon.
On the other hand, in Patent Document 3 below, a silver film is formed on a metal foil, and an organic EL element is formed thereon. In Patent Document 3, the effect of short circuits is suppressed by using a conductive organic layer with a thickness of 130 nm or more, and even with such a thick conductive organic layer, high conductivity is obtained. In addition, carrier doping technology is used.

JP 2018-10799 A JP 2013-157325 A U.S. Patent Application Publication No. 2007/0051946

However, the techniques of Patent Documents 1 and 2 use a complicated process of smoothing the surface shape of the metal foil itself and forming a smooth insulating film thereon in order to use the metal foil substrate. , resulting in high cost. In addition, in the technique of Patent Document 3, a thick organic layer is used to suppress short circuits, and the organic material used as the raw material for the organic layer is very expensive, resulting in an increase in cost. It's gone. Therefore, no report has been made so far of an organic EL device using a substrate such as a metal foil having an extremely rough surface, which is produced by a low-cost process.

Therefore, the present invention solves the above-mentioned problems of the prior art, even when using a substrate with a rough surface such as a metal foil whose surface smoothness is not controlled as used in a general kitchen An object of the present invention is to provide an electronic device substrate that can suitably emit light by applying it to an organic EL device.
Another object of the present invention is to provide an organic EL device using such an electronic device substrate, which can be manufactured at low cost, and a display device and a lighting device using the same.

The gist and configuration of the present invention for solving the above problems are as follows.

The electronic device substrate of the present invention is an electronic device substrate comprising a substrate having an electrode on its surface and a conductive film formed adjacent to the upper part of the electrode,
The maximum height roughness Rz of the shape of the electrode in the direction perpendicular to the substrate is 300 nm or more and 1000 nm or less,
The thickness t of the conductive film and the maximum height roughness Rz of the shape of the electrode are expressed by the following formula (1):
Maximum height roughness Rz (nm) of electrode shape−thickness t (nm) of conductive film≦230 nm (1)
satisfy the relationship of
The conductive film is characterized by containing a polyoxometalate containing tungsten.
Such a substrate for an electronic device of the present invention can suitably emit light by applying it to an organic EL device.

Further, in a preferred embodiment of the electronic device substrate of the present invention, the conductive film is a component obtained by performing Fourier transform (FFT) filtering to pass only components having a spatial frequency of 1,000,000/m or more in the surface shape. The surface average roughness Ra (FFT) obtained from is 1 nm or less. In this case, it is possible to more reliably prevent a short circuit between the electrode of the electronic device substrate and the upper electrode.

In another preferred embodiment of the electronic device substrate of the present invention, the conductive film has a thickness t of 210 nm or more. In this case, it is possible to more reliably prevent a short circuit between the electrode of the electronic device substrate and the upper electrode.

In another preferred embodiment of the electronic device substrate of the present invention, the substrate and the electrode are made of the same material and integrated. In this case, the electronic device substrate can be manufactured at a lower cost.

In another preferred embodiment of the electronic device substrate of the present invention, the conductive film further comprises dipyrazino[2,3-f:2′,3′-h]quinoxaline-2,3,6,7,10,11 - including hexacarbonitrile (HAT-CN). In this case, the smoothness of the surface of the conductive film can be improved.

In another preferred embodiment of the electronic device substrate of the present invention, an insulating tape is attached to a portion of the substrate having the electrode on the surface thereof, and a step formed by the substrate having the electrode on the surface and the insulating tape. is buried by a conductive film formed adjacent to the top of the electrode. In this case, when the substrate for an electronic device is applied to an organic EL device, an insulating portion can be formed by a simple process, a current can be supplied satisfactorily, and an electrical contact can be made with a strong force when the current is supplied. , it is possible to emit light satisfactorily.

In another preferred embodiment of the electronic device substrate of the present invention, the substrate having electrodes on its surface has a metal foil and a metal layer formed on the metal foil. In this case, the drive voltage of the electronic device can be reduced.

Further, the organic electroluminescence device of the present invention is characterized by comprising the electronic device substrate described above. Such an organic electroluminescence device of the present invention can be manufactured at low cost.

The organic electroluminescence device of the present invention preferably comprises the electronic device substrate, an upper electrode, and a plurality of light-emitting units located between the electronic device substrate and the upper electrode. In this case, a high emission intensity can be obtained at a low current density, and high luminance can be achieved.

A display device of the present invention is characterized by comprising the organic electroluminescence element described above. Such a display device of the present invention can be manufactured at low cost.

Further, a lighting device of the present invention is characterized by comprising the organic electroluminescence element described above. Such a lighting device of the present invention can be manufactured at low cost.

According to the present invention, even when using a substrate having a rough surface such as a metal foil whose surface smoothness is not controlled as used in a general kitchen, it can be applied to an organic EL element. It is possible to provide an electronic device substrate that can suitably emit light.
Further, according to the present invention, it is possible to provide an organic EL device using such an electronic device substrate, which can be manufactured at low cost, and a display device and a lighting device using the same.

Further, according to a preferred embodiment of the present invention, a metal foil or the like having an extremely rough surface shape, which could not be used as an electrode of an organic EL element in the past, can be used as an electrode of an organic EL element. It becomes possible. The metal foil is much cheaper than a substrate with a transparent electrode such as ITO, and is expected to reduce the cost of the organic EL device.
Further, the electronic device substrate of the present invention is not limited to organic EL devices, and similar effects can be expected by applying it to quantum dot EL devices, solar cell devices, and the like.

It is a surface shape profile of an example of a metal foil that can be used for the electronic device substrate of the present embodiment. BRIEF DESCRIPTION OF THE DRAWINGS It is a cross-sectional schematic diagram for demonstrating an example of the board|substrate for electronic devices of this embodiment. BRIEF DESCRIPTION OF THE DRAWINGS It is a cross-sectional schematic diagram for demonstrating an example of the organic EL element of this embodiment. 4 is a cross-sectional view taken along line IV-IV of FIG. 3; FIG. It is a cross-sectional schematic diagram for demonstrating another example of the organic EL element of this embodiment. FIG. 6 is a cross-sectional view taken along line VI-VI of FIG. 5; It is a modified example of a cross section along the IV-IV line in FIG. It is a modified example of a cross section along the IV-IV line in FIG. 11 is a light emission image of the organic EL element of Example 6. FIG. 10 is an emission image of the organic EL element of Example 10. FIG. 3 is a graph showing luminance-voltage characteristics of organic EL devices of Examples 11 and 12. FIG. 10 is a graph showing current density-voltage characteristics of organic EL devices of Examples 13 and 14. FIG. 10 is a graph showing luminance-voltage characteristics of organic EL devices of Examples 13 and 14. FIG. FIG. 12 is a top view of organic EL devices of Examples 15 and 16; FIG. 10 is an emission image of the organic EL element of Example 15. FIG. FIG. 10 is a luminescence image when the organic EL element of Example 15 is deformed. FIG. FIG. 10 is a luminescence image when the organic EL element of Example 15 is broken. FIG.

Hereinafter, the electronic device substrate, the organic electroluminescence device, the display device, and the lighting device of the present invention will be illustrated and explained in detail based on the embodiments thereof.

<Substrate for electronic device>
An electronic device substrate of the present invention comprises a substrate having an electrode on its surface, and a conductive film formed adjacent to an upper portion of the electrode. Here, the substrate and the electrode may be made of the same material and integrated, or may be made of different materials and composed of a substrate and an electrode covering the surface of the substrate.
Further, in the electronic device substrate of the present invention, the maximum height roughness Rz of the shape of the electrode in the direction perpendicular to the substrate is 300 nm or more and 1000 nm or less, and the thickness t of the conductive film, The maximum height roughness Rz of the shape of the electrode is expressed by the following formula (1):
Maximum height roughness Rz (nm) of electrode shape−thickness t (nm) of conductive film≦230 nm (1)
It is characterized by satisfying the relationship of

In the electronic device substrate of the present invention, an inexpensively available substrate having a relatively rough surface is used as the substrate having electrodes on its surface. Specifically, a substrate having an electrode on its surface and having a maximum height roughness Rz of the electrode shape in a direction perpendicular to the substrate of 300 nm or more and 1000 nm or less is used. As such a substrate, a metal foil (aluminum foil) having a very rough surface structure as shown in FIG. 1 can also be used. In the case of the metal foil (aluminum foil) shown in FIG. 1, the maximum height roughness Rz is 443 nm and the surface average roughness Ra is 91 nm. This is about the same value as the aluminum foil used in general kitchens.
In the electronic device substrate of the present invention, a conductive film is formed adjacent to the top of the electrode on the substrate having the electrode on the surface as described above, and the thickness t of the conductive film and the maximum height of the shape of the electrode are and the roughness Rz satisfy the relationship of the above formula (1), and furthermore, by using a material containing polyoxometalate containing tungsten for the conductive film, the concave portion of the electrode surface is filled and the conductive film is The surface of the substrate becomes smooth, and a short circuit between the electrode of the electronic device substrate and the upper electrode can be prevented.
Therefore, the electronic device substrate of the present invention can suitably emit light by applying it to an organic EL device even when a substrate having a rough surface is used.

The electronic device substrate of the present invention differs from Patent Documents 1 and 2 in that even if the substrate has a rough surface, a substrate with an electrode, or an integrated body of the substrate and the electrode (aluminum foil, etc.), polishing or the like is required. The point is that a conductive film can be formed directly without going through a smoothing process. Here, the aluminum foil acts as an electrode. In addition, the electronic device substrate of the present invention differs from Patent Document 3 in that an inexpensive commercial product can be used to form the conductive film without using an expensive organic compound costing several tens of thousands of yen per gram. is.

Next, one embodiment of the electronic device substrate of the present invention will be described in detail with reference to the drawings. FIG. 2 is a schematic cross-sectional view for explaining an example of the electronic device substrate of the present embodiment.

(Electronic device substrate 1)
The electronic device substrate 1 of this embodiment shown in FIG. I get it.
In the electronic device substrate of the present invention, the substrate 2 and the electrode 3 may be made of the same material and integrated. foil, etc.) can be used. When the substrate and the electrode are made of the same material and integrated, the electronic device substrate can be manufactured at a lower cost.

(Substrate 2)
An example of the substrate 2 is a foil made of a conductive material such as metal. Examples of metals used for the foil include aluminum and stainless steel.
Another example of the substrate 2 is a non-conductive material such as glass, quartz, plastic, etc. on top of which an organic compound such as that used in US Pat. No. 9,318,705 is used to form a membrane surface. It is used as a substrate by forming unevenness on the substrate.
Another example of the substrate 2 is a microlens array structure used for extracting light from the backlight of an organic EL device or a liquid crystal display, a concave three-dimensional structure used for a light-condensing film, and a moth-eye structure used for antireflection. It is a substrate having a three-dimensional structure such as a structure or photonic crystal on its surface.

Although the roughness of the substrate 2 is not particularly limited, it is preferable that the maximum height roughness Rz is 300 nm or more and 1000 nm or less, and the surface average roughness Ra is 3 nm or more and 150 nm at the used portion of the substrate 2. The following are preferable.

(Electrode 3)
An electrode 3 made of a transparent material such as ITO or an electrode 3 made of an opaque material such as aluminum or silver is deposited on the substrate 2 . When an opaque electrode is used, it is preferable to use it with a film thickness at which the transmittance is 1% or less.
Here, the surface shape of the electrode 3 has a maximum height roughness Rz in the direction perpendicular to the substrate 2 of 300 nm or more and 1000 nm or less. The surface shape of the electrode 3 preferably has an average surface roughness Ra of 3 nm or more and 150 nm or less, more preferably 30 nm or more and 100 nm or less.
Here, the maximum height roughness Rz and surface average roughness Ra of the substrate 2 and the electrode 3 can be measured by a stylus type surface profile measuring device such as Dektak of Bruker, but other methods may be used. As for the surface shape measurement range, the present invention uses Rz and Ra at a measurement length of 50 μm.

The above measurement also includes a component with a small rate of change in the direction perpendicular to the planar direction of the substrate. Since a component with a small rate of change has little effect of causing electric field concentration, a method of excluding the effect of evaluation is also suitable for evaluating the likelihood of short-circuiting. The present invention uses a method using a Fourier transform (FFT) filter as such a method. A high-pass filter that passes only components with a spatial frequency of 1,000,000/m or more is used to extract components with a large percentage of change in the direction perpendicular to the planar direction from the obtained surface shape. By evaluating the Ra of the component, it is possible to evaluate the susceptibility to electric field concentration in the electronic device. Here, in the present invention, Ra evaluated in this way is called Ra(FFT), and treated separately from Ra when FFT filtering is not performed. In the present invention, we measure a length of 50 μm with a measurement resolution of 10 nm or less, obtain a data set and perform FFT processing.

Further, as described above, in the electronic device substrate of the present invention, the substrate 2 and the electrode 3 may be made of the same material and integrated. In this case, the electronic device substrate can be manufactured at a lower cost. Metal foil such as aluminum foil (aluminum foil) and stainless steel foil can be used as the substrate 2 and the electrode 3 integrated together.
Here, when the substrate 2 and the electrodes 3 are made of metal foil, large deformation is possible, and even if a part is broken, the continuity can be sufficiently secured. Therefore, by using a metal foil as a substrate having an electrode on its surface, it is possible to realize a foldable electronic element or an electronic element that can be attached in various shapes due to its high mechanical properties.

Further, in the electronic device substrate of the present invention, the substrate having electrodes on the surface thereof may be formed from a metal foil and a metal layer formed on the metal foil. The metal layer is preferably formed on the metal foil by vapor deposition or the like. When the substrate having electrodes on its surface has a metal foil and a metal layer formed on the metal foil, the influence of the oxide on the metal foil can be reduced, and the driving voltage of the electronic device can be reduced. . Here, examples of the metal foil include aluminum foil (aluminum foil) and stainless steel foil. Also, the material of the metal layer can be the same as the material of the metal foil used.

(Conductive film 4)
A conductive film 4 is provided on the electrode 3 . The conductive film 4 has a function as a smoothing layer for the entire surface of the electronic device substrate 1 and a function as a conductive layer. The average surface roughnesses Ra and Ra(FFT) of the conductive film 4 are preferably 5 nm or less, more preferably 1 nm or less, and within these ranges short circuits are more difficult to occur.
The average surface roughness Ra and Ra (FFT) of the conductive film 4 are measured in the same manner as the average surface roughness Ra and Ra (FFT) of the electrode 3 described above.

--Polyoxometalate--
The conductive film 4 contains polyoxometalate containing tungsten. When the conductive film 4 contains a polyoxometalate containing tungsten, it fills the recesses on the surface of the electrode 3 while having sufficient conductivity, the surface of the conductive film 4 becomes smooth, and the electrode of the electronic device substrate, A short circuit between the upper electrode and the can be prevented more reliably.

The tungsten-containing polyoxometalate is a cluster molecule composed of an anion formed by condensation of an oxoacid of a tungsten-containing metal and a cation such as a proton. Polyoxometalates containing tungsten are characterized by high solubility in polar solvents, unlike general metal oxides. In addition, in the sol-gel process normally used for forming metal oxide films, it is necessary to bake and oxidize the coating film at a high temperature of several hundred degrees, but polyoxometalates containing tungsten are originally oxidized. , no need to bake at high temperature. Therefore, in the case of a polyoxometalate containing tungsten, it is sufficient that the solvent in the film can be removed, and the heat-drying temperature may be about the boiling point of the solvent. Another commonly used technique is the application of nanoparticles, but there is the problem that it is difficult to produce nanoparticles with a particle size of the order of nanometers. On the other hand, tungsten-containing polyoxometalates are available on the market at low cost and can be easily obtained and used.

The polyoxometallate containing tungsten is preferably a heteropolyoxometallate containing tungsten. A heteropolyoxometalate containing tungsten has a structure centered on a heteroatom (P ⁵⁺ , Si ⁴⁺ , Ge ⁴⁺ , Bi ³⁺ , etc.) and a polyatom (W ⁶⁺ ) coordinated to the heteroatom via oxygen. It is a compound, and structures such as Keggin type and Dawson type are known.

Examples of polyoxometalates containing tungsten include phosphotungstic acid (PWA) and silicotungstic acid (SWA). Here, the phosphotungstic acid (PWA) includes phosphotungstic acid represented by the formula: H ₃ PW ₁₂ O ₄₀ , and formula: H ₃ PW ₁₂ O ₄₀ ·nH ₂ O (where n is an arbitrary ) can also be used.

The polyoxometalate is particularly preferably phosphotungstic acid represented by the formula: H ₃ PW ₁₂ O ₄₀ . Phosphotungstic acid has a particularly high solubility in solvents, and facilitates formation of a thick conductive film 4 .

The polyoxometalate containing tungsten is not particularly limited, but one with low crystallinity is preferable, and a commercially available product may be used, or a synthesized product may be used. Commercially available products include, for example, phosphotungstic acid (PWA) manufactured by MP Bio. Phosphotungstic acid (PWA) is an inexpensive material that can be purchased at a price of about 50 to 500 yen per gram. Phosphotungstic acid (PWA) is a cluster molecule composed of four tungsten trioxides and phosphoric acid, and has a known structure such as the Keggin type. Phosphotungstic acid (PWA) is highly soluble in polar solvents, for example, 1 g/mL or more can be dissolved in acetonitrile, so it is easy to form a thick film of several hundred nm or more.

The content of the polyoxometalate containing tungsten in the conductive film 4 is preferably 90% by mass or more, more preferably 95% by mass or more, and preferably 99.5% by mass or less, and further preferably 99% by mass or less. preferable.

--smoothing agent--
Moreover, the conductive film 4 preferably further contains a smoothing agent. The smoothing agent is an additive that smoothes the conductive film 4 by suppressing the formation of coarse particles due to the crystallization of polyoxometalate containing tungsten during the formation of the coating film.
As described above, the polyoxometalate containing tungsten has a very high solubility in a polar solvent, and can easily form the conductive film 4 with a thickness of several hundred nm or more. However, when the thickness is increased, there is a problem that the smoothness of the surface of the conductive film 4 formed by coating is deteriorated. This is probably because, for example, when the thin film (conductive film 4) is formed from the solution, the polyoxometalate containing tungsten crystallizes, forming large crystal grains and thus losing the smoothness. . On the other hand, the smoothness of the surface of the conductive film 4 can be improved by adding a smoothing agent to the conductive film 4 together with polyoxometalate containing tungsten. It is presumed that the addition of the smoothing agent controlled the crystallization behavior of the tungsten-containing polyoxometalate, suppressing the formation of coarse particles, thereby forming a smooth conductive film 4. be. This makes it possible to easily form the conductive film 4 having a smooth surface even with a thickness of several hundred nm or more.

で表されるジピラジノ［２，３－ｆ：２’，３’－ｈ］キノキサリン－２，３，６，７，１０，１１－ヘキサカルボニトリル（ＨＡＴ－ＣＮ）が特に好ましい。ＨＡＴ－ＣＮは、塗布膜形成時のタングステンを含むポリオキソメタレートの結晶化による粗大粒子の生成を防ぐ事ができ、形成される導電膜４の表面の平滑性を更に向上させることができる。平滑化のメカニズムの詳細は明らかでないが、ＨＡＴ－ＣＮは、ポリオキソメタレートとの相互作用が大きいため、結晶化の際に種として利用できるものと考えられる。また、ＨＡＴ－ＣＮは、平面状の分子であるため、結晶化の際にその平面をテンプレートとして結晶が面状に成長し、シート状の結晶が生成するため、三次元的な粗大粒子の生成が抑えられるものと考えられる。そして、シート状の結晶が生成するため、形成される導電膜４の平滑性が向上するものと考えられる。ここで、導電膜４の表面平均粗さＲａは、１ｎｍ以下が好ましい。 As the smoothing agent, any compound can be used that has the effect of suppressing the deterioration of the smoothness of the surface of the conductive film 4 by preventing the formation of coarse particles due to the crystallization of polyoxometalate containing tungsten. Among the smoothing agents having such action, the following structural formula:

Dipyrazino[2,3-f:2',3'-h]quinoxaline-2,3,6,7,10,11-hexacarbonitrile (HAT-CN) represented by is particularly preferred. HAT-CN can prevent the formation of coarse particles due to the crystallization of polyoxometalate containing tungsten during the formation of the coating film, and can further improve the smoothness of the surface of the conductive film 4 to be formed. Although the details of the smoothing mechanism are not clear, it is thought that HAT-CN can be used as a seed during crystallization because of its strong interaction with polyoxometalate. In addition, since HAT-CN is a planar molecule, the crystals grow in a planar manner using the planar surface as a template during crystallization, and sheet-like crystals are generated, resulting in the generation of three-dimensional coarse particles. is considered to be suppressed. Since sheet-like crystals are formed, the smoothness of the formed conductive film 4 is considered to be improved. Here, the average surface roughness Ra of the conductive film 4 is preferably 1 nm or less.

The content of the smoothing agent in the conductive film 4 is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, and preferably 10 parts by mass or less with respect to 100 parts by mass of the polyoxometalate. , 3 parts by mass or less is more preferable. When the content of the smoothing agent is 0.5 parts by mass or more with respect to 100 parts by mass of the polyoxometalate, the smoothness of the surface of the conductive film 4 is further improved. Further, when the content of the smoothing agent is 10 parts by mass or less with respect to 100 parts by mass of the polyoxometalate, the conductivity is improved.

--Thickness of conductive film--
The thickness t of the conductive film 4 and the maximum height roughness Rz of the electrode 3 are expressed by the following formula (1):
Maximum height roughness Rz (nm) of electrode shape−thickness t (nm) of conductive film≦230 nm (1)
It is necessary to satisfy the relationship of If the thickness t of the conductive film 4 and the maximum height roughness Rz of the electrode 3 do not satisfy the relationship of the formula (1), that is, the maximum height roughness Rz of the electrode 3 determines the thickness of the conductive film 4 If the value after subtracting t exceeds 230 nm, the electrode 3, which has a rough surface underneath, cannot be sufficiently covered and a short circuit occurs. The thickness t of the conductive film 4 is preferably thicker than the maximum height roughness Rz of the electrode 3 . When the thickness t of the conductive film 4 is greater than the maximum height roughness Rz of the electrode 3, the conductive film 4 reliably covers the electrode 3 having a rough surface underneath, and short circuits can be prevented more reliably.
In one embodiment, the thickness t of the conductive film 4 is about several hundred nm to 1 μm. In another embodiment, the thickness t of the conductive film 4 is preferably 210 nm or more, more preferably 300 nm or more, even more preferably 400 nm or more, and 1200 nm or less. It is preferably 1000 nm or less, and more preferably 1000 nm or less. When the thickness t of the conductive film 4 is 210 nm or more, the concave portions of the electrode surface are further filled, the surface of the conductive film becomes smoother, and the short circuit between the electrode of the electronic device substrate and the upper electrode is further prevented. can be reliably prevented. Further, when the thickness t of the conductive film 4 is 400 nm or more, the effect of smoothing the surface is enhanced. Further, when the thickness t of the conductive film 4 is 1000 nm or less, the conductive film 4 is less likely to crack.
In the present invention, the thickness t of the conductive film 4 is defined as the distance from the deepest portion of the valley of the surface shape of the electrode 3 to the surface of the conductive film 4 immediately above it. The thickness t of the conductive film 4 can be measured by a method such as SEM observation of the cross section.

Also, the thick conductive film 4 containing polyoxometalate containing tungsten exhibits a negative differential resistance (NDR) characteristic in which the current value decreases when the voltage is increased within a certain voltage range. Such NDR characteristics also contribute to the prevention of short circuits in electronic elements. The conductive paths in the conductive film 4 need not be uniform and may have a conductive filament structure such as found in resistive memory elements.

<Organic electroluminescence element>
An organic electroluminescence device of the present invention is characterized by comprising the electronic device substrate described above. Since the organic EL device of the present invention includes the electronic device substrate, it can be manufactured at low cost.

Further, the organic electroluminescence device of the present invention preferably comprises the above-described electronic device substrate, an upper electrode, and a plurality of light-emitting units positioned between the electronic device substrate and the upper electrode. A so-called tandem structure organic EL element is preferable.
In order to drive an organic EL element with a tandem structure in which a plurality of light emitting units are connected in series, the sum of the driving voltages of the respective light emitting units is required to obtain the same current value. A higher voltage is required than an organic EL element composed of a light-emitting unit. However, since the intensity of emitted light obtained at the same current value is several times that of the light-emitting unit, the emitted light intensity obtained per unit power is equivalent to that of an ordinary organic EL device consisting of one light-emitting unit. In addition, the current value required to obtain the same brightness as that of an ordinary organic EL element composed of one light emitting unit is (1/the number of light emitting units) times smaller in the tandem structure organic EL element. Since only a small amount of current is required, the driving life of the tandem-structured organic EL element can be greatly improved.
Therefore, in the tandem-structured organic EL element, high emission intensity can be obtained at a low current density, and high luminance can be realized.

The organic EL device of the present invention can be produced, for example, by directly forming an EL functional layer such as a charge transport layer constituting the organic EL device on the above substrate for an electronic device, and then providing an upper electrode. . The organic EL device manufactured in this manner emits light well without short circuit.
For example, if the opaque metal foil described above is used as the lower electrode, the upper electrode must be transparent. On the other hand, when a transparent substrate and material are used for the lower electrode, the upper electrode may be transparent or opaque. Cross-sectional views of these element structures are shown in FIGS.

The organic EL element of the present invention differs from the above-mentioned Patent Documents 1 and 2 in that a smoothing layer (conductive film) is directly coated on an aluminum foil or the like having a rough surface without going through a smoothing process such as polishing. The smoothing layer (conductive film) is electrically conductive and sandwiched between the electrodes of the organic EL element. Here, the aluminum foil acts as an electrode. In addition, the organic EL device of the present invention differs from the above-mentioned Patent Document 3 in that it can be manufactured using inexpensive commercial products without using expensive organic compounds costing tens of thousands of yen or more per gram. .

Next, embodiments of the organic EL element of the present invention will be described in detail with reference to the drawings. FIG. 3 is a schematic cross-sectional view for explaining an example of the organic EL element of this embodiment. 4 is a cross-sectional view along line IV-IV in FIG.

(Organic EL element 10)
The organic EL element 10 of the present embodiment shown in FIG. 3 is an example of a so-called forward structure element among the organic EL elements of the present invention.

The organic EL element 10 of this embodiment shown in FIG. It comprises an EL functional layer 50 and an electrode 60 (upper electrode) formed thereon. Among them, as shown in FIG. 4, the EL function layer 50 includes a hole injection layer 51, a hole transport layer 52, a light emitting layer 53, an electron transport layer 54, an electron It is divided into injection layers 55 . The structure of the organic EL element of the present invention is not limited to this, and it is sufficient that at least one light-emitting layer is included between the electrode-attached substrate 20 and the electrode 60 . Also, a sealing portion 70 is provided to shield the organic EL element from the air.

(Substrate 20 with electrodes)
In FIG. 3, the electrode-attached substrate 20 is composed of the substrate 2 and the electrodes 3 of the electronic device substrate 1 . One example of the electrode-attached substrate 20 is a foil made of a conductive material such as metal. The roughness of the foil is not particularly limited as long as the organic EL device functions. The average surface roughness Ra is preferably 3 nm or more and 150 nm or less, more preferably 30 nm or more and 100 nm or less.

Another example of an electroded substrate 20 is a non-conductive material such as glass, quartz, plastic, etc., on which organic compounds such as those used in US Pat. It is also possible to use the one in which the unevenness is formed and covered with a conductive material such as a metal or a transparent conductive film. Here, the surface roughness of the electrode-attached substrate 20 is not particularly limited as long as the organic EL device functions. The average surface roughness Ra is preferably 3 nm or more and 150 nm or less, more preferably 30 nm or more and 100 nm or less.

Another example of the electrode-attached substrate 20 is a microlens array structure used for extracting light from an organic EL device, a concave three-dimensional structure used for a light-condensing film, a moth-eye structure used for antireflection, and a photonic structure. A substrate having a three-dimensional structure such as a crystal on its surface and coated with a conductive material such as a metal or a transparent conductive film can be used. Here, the surface roughness of the electrode-attached substrate 20 is not particularly limited as long as the organic EL element functions. and the average surface roughness Ra is preferably 3 nm or more and 150 nm or less, more preferably 30 nm or more and 100 nm or less.

(Insulating portion 30)
The insulating part 30 has a role of preventing a short circuit between the electrode of the electrode-attached substrate 20 and the electrode 60 . A region sandwiched between the electrode-attached substrate 20 and the electrode 60 does not emit light. An insulating film such as SiO ₂ can be provided between the electrode of the electrode-attached substrate 20 and the electrode 60 (upper electrode). good. For example, an organic insulating film may be formed by a coating method, or an insulating tape such as a polyester tape may be attached.

(Smoothing layer and conductive layer 40)
In FIG. 3, the smoothing layer and conductive layer 40 is made of the conductive film 4 of the electronic device substrate 1 .
For the smoothing layer/conductive layer 40, as described in the section of the conductive film 4 of the electronic device substrate 1, a polyoxometalate containing tungsten is used, and a smoothing agent such as HAT-CN is added. It can also be used by adding. The smoothing agent such as HAT-CN has the role of suppressing the formation of coarse particles due to crystallization during the formation of a coating film of polyoxometalate containing tungsten. The surface becomes smooth. The additive is not limited to HAT-CN, and any smoothing agent can be used as long as the surface of the formed smoothing layer-conducting layer 40 is smooth. The content of the smoothing agent in the smoothing layer/conductive layer 40 is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, or 10 parts by mass with respect to 100 parts by mass of the polyoxometalate. parts by mass or less is preferable, and 3 parts by mass or less is more preferable. When the content of the smoothing agent is 0.5 parts by mass or more with respect to 100 parts by mass of the polyoxometalate, the smoothness of the surface of the smoothing layer/conductive layer 40 is further improved. Further, when the content of the smoothing agent is 10 parts by mass or less with respect to 100 parts by mass of the polyoxometalate, the conductivity is improved.
The average surface roughness Ra of the smoothing layer/conductive layer 40 is preferably 1 nm or less, more preferably 0.5 nm or less.

The thickness of the smoothing layer and conductive layer 40 must be sufficiently thick. If it is not thick enough, the electrode-attached substrate 20 having a rough surface at the bottom cannot be sufficiently covered, causing a short circuit and causing an organic EL. It does not function as an element. Specifically, the thickness t of the smoothing layer and conductive layer 40 and the maximum height roughness Rz of the electrode-attached substrate 20 are expressed by the following formula (1′):
Maximum height roughness Rz (nm) of electrode-attached substrate-thickness t (nm) of smoothing layer and conductive layer ≤ 230 nm (1')
It is necessary to satisfy the relationship of
In one embodiment, the thickness t of the smoothing and conductive layer 40 is preferably 210 nm or more, more preferably 300 nm or more, even more preferably 400 nm or more, and 1200 nm or less. It is preferably 1000 nm or less, and more preferably 1000 nm or less. When the thickness t of the smoothing layer/conductive layer 40 is 400 nm or more, the effect of smoothing the surface is enhanced. Further, when the thickness t of the smoothing layer-cum-conductive layer 40 is 1000 nm or less, the smoothing layer-cum-conductive layer 40 is less likely to crack.
In the present invention, the thickness t of the smoothing layer-cum-conductive layer 40 is the distance from the deepest part of the valley of the surface shape of the electrode-attached substrate 20 to the surface of the smoothing layer-cum-conductive layer 40 immediately above it. and The thickness of the smoothing layer/conductive layer 40 can be measured by a method such as SEM observation of the cross section.

In one embodiment, the insulating portion 30 is made of an insulating tape such as a polyester tape, and the insulating tape (insulating portion 30) is attached to a part of the substrate 20 with electrodes. 30) is formed adjacent to the upper portion of the substrate 20 with electrodes (more specifically, the upper portion of the substrate 20 with electrodes to which the insulating tape is not attached) as a smoothing layer and conductive layer. It is filled with layer 40 .
When forming the insulating part 30 by providing an insulating film such as SiO ₂ on the substrate 20 with electrodes, the insulating film such as SiO ₂ must be formed by sputtering, which increases the process load and increases the process load. ₂ or the like is provided with an electrode 60, and when a power source is connected to the electrode 60 for evaluation, if the electrode of the evaluation device is strongly pressed against the electrode 60 (eg, sandwiched with an alligator clip), Since the electrode-attached substrate 20 at the bottom is electrically connected, it is necessary to press the electrode of the evaluation device with a weak force, resulting in unstable contact, and furthermore, there is a step between the electrode-attached substrate 20 and the insulating portion 30 . is formed, and when the EL functional layer 50 and the upper electrode 60 are formed on the substrate 20 with the electrode and the insulating portion 30 by vapor deposition, the EL functional layer 50 and the upper electrode 60 are cut off at the step portion, resulting in in-plane It is possible that the current cannot be supplied to the LED and it does not emit light.
On the other hand, if the insulating portion 30 is formed from an insulating tape, the insulating portion 30 can be formed by a simple process of sticking the insulating tape. Further, after the insulating portion 30 is formed at the edge of the substrate 20 with electrodes, the steps formed by the substrate 20 with electrodes and the insulating tape (insulating portion 30) are filled with the smoothing layer/conductive layer 40 to fill the steps. By forming the EL functional layer 50 and the upper electrode 60 on the upper part of the smoothing layer and conductive layer 40, the EL functional layer 50 and the upper electrode 60 are not interrupted at the step portion, which is good. In-plane current can be supplied to Furthermore, even when the organic EL element 10 having such a structure is electrically contacted with the electrode 60 with a strong force (for example, when sandwiched with an alligator clip), the electrode-attached substrate 20 below does not conduct. , it is possible to emit light satisfactorily.

(EL functional layer 50)
As shown in FIG. 4, the EL functional layer 50 of the organic EL element 10 shown in FIG. Although it is divided into an electron transport layer 54 and an electron injection layer 55, the structure of the organic EL element of the present invention is not limited to this.

--hole injection layer 51--
For the hole injection layer 51, materials commonly used for hole injection layers of organic EL elements can be used. The hole injection layer 51 is preferably made of a material having a strong charge acceptor property, and may be made of an organic material or an inorganic material.

When the hole injection layer 51 is an organic material, the material of the hole injection layer 51 may be tetrafluorotetracyanoquinodimethane (F4TCNQ) and/or 1,4,5,8,9,12-hexaaza, for example. Triphenylene-2,3,6,7,10,11-hexacarbonitrile (HAT-CN) and the like can be used. Among these, HAT-CN is particularly preferred.

On the other hand, when the hole injection layer 51 is an inorganic material, the material of the hole injection layer 51 may be vanadium oxide (V ₂ O ₅ ), molybdenum oxide (MoO ₃ ), ruthenium oxide (RuO ₂ ), or the like. can. Among these, _MoO3 is particularly preferred.

Although the average thickness of the hole injection layer 51 is not particularly limited, it is preferably 1 to 100 nm, more preferably 5 to 50 nm.

--hole transport layer 52--
For the hole transport layer 52, materials commonly used for hole transport layers of organic EL elements can be used.
Materials for the hole transport layer 52 include N4,N4′-bis(dibenzo[b,d]thiophen-4-yl)-N4,N4′-diphenylbiphenyl-4,4′-diamine (DBTPB), 1, Arylcycloalkane compounds such as 1-bis(4-di-para-tolylaminophenyl)cyclohexane, 1,1′-bis(4-di-para-tolylaminophenyl)-4-phenyl-cyclohexane, etc., 4 ,4′,4″-trimethyltriphenylamine, N,N,N′,N′-tetraphenyl-1,1′-biphenyl-4,4′-diamine, N,N′-diphenyl-N,N′ -bis(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine (TPD1), N,N'-diphenyl-N,N'-bis(4-methoxyphenyl)-1,1'-biphenyl-4,4'-diamine (TPD2), N,N,N',N'-tetrakis(4-methoxyphenyl)-1,1'-biphenyl-4,4'-diamine (TPD3), N, arylamine compounds such as N'-di(1-naphthyl)-N,N'-diphenyl-1,1'-biphenyl-4,4'-diamine (α-NPD) and triphenylamine tetramer (TPTE); N,N,N',N'-tetraphenyl-para-phenylenediamine, N,N,N',N'-tetra(para-tolyl)-para-phenylenediamine, N,N,N',N'- Phenylenediamine compounds such as tetra(meta-tolyl)-meta-phenylenediamine (PDA), carbazole compounds such as carbazole, N-isopropylcarbazole, N-phenylcarbazole, stilbene, 4-di-para-tolylaminostilbene, etc. stilbene compounds, oxazole compounds such as OxZ, triphenylmethane, triphenylmethane compounds such as m-MTDATA, pyrazoline compounds such as 1-phenyl-3-(para-dimethylaminophenyl)pyrazoline, benzine (cyclo hexadiene) compounds, triazole compounds such as triazole, imidazole compounds such as imidazole, 1,3,4-oxadiazole, 2,5-di(4-dimethylaminophenyl)-1,3,4,-oxa Oxadiazole compounds such as diazole, anthracene compounds such as anthracene, 9-(4-diethylaminostyryl)anthracene, fluorenone, 2,4,7,-trinitro-9-fluorenone, 2,7-bis(2- hydroxy- Fluorenone compounds such as 3-(2-chlorophenylcarbamoyl)-1-naphthylazo)fluorenone, aniline compounds such as polyaniline, silane compounds, 1,4-dithioketo-3,6-diphenyl-pyrrolo-(3,4- c) pyrrole compounds such as pyrrolopyrrole, fluorene compounds such as fluorene, porphyrins, porphyrin compounds such as metal tetraphenylporphyrin, quinacridone compounds such as quinacridone, phthalocyanine, copper phthalocyanine, tetra(t-butyl)copper phthalocyanine, Metal or metal-free phthalocyanine compounds such as iron phthalocyanine, metal or metal-free naphthalocyanine compounds such as copper naphthalocyanine, vanadyl naphthalocyanine, monochlorogallium naphthalocyanine, N,N'-di(naphthalen-1-yl) -N,N'-diphenyl-benzidine, N,N,N',N'-tetraphenylbenzidine and other benzidine compounds, and the like, and one or more of these can be used. Among these, arylamine compounds such as α-NPD are preferred.

Although the average thickness of the hole transport layer 52 is not particularly limited, it is preferably 5 to 150 nm, more preferably 10 to 100 nm.

--Light emitting layer 53--
For the light-emitting layer 53, materials generally used for light-emitting layers of organic EL elements can be used. A material used for the light-emitting layer 53 may be a low-molecular compound, a high-molecular compound, or a mixture thereof.

Examples of the polymer compound forming the light-emitting layer 53 include polyacetylene-based compounds such as trans-polyacetylene, cis-polyacetylene, poly(di-phenylacetylene) (PDPA), and poly(alkylphenylacetylene) (PAPA); para-phenylene vinylene) (PPV), poly(2,5-dialkoxy-para-phenylene vinylene) (RO-PPV), cyano-substituted-poly(para-phenylene vinylene) (CN-PPV), poly(2- Dimethyloctylsilyl-para-phenylene vinylene) (DMOS-PPV), poly(2-methoxy, 5-(2'-ethylhexoxy)-para-phenylene vinylene) (MEH-PPV) and other polyparaphenylene vinylene compounds; Polythiophene compounds such as (3-alkylthiophene) (PAT) and poly(oxypropylene) triol (POPT); poly(9,9-dialkylfluorene) (PDAF) and poly(dioctylfluorene-alto-benzothiadiazole) (F8BT) ), α,ω-bis[N,N′-di(methylphenyl)aminophenyl]-poly[9,9-bis(2-ethylhexyl)fluorene-2,7-diyl] (PF2/6am4), poly( 9,9-dioctyl-2,7-divinylenefluorenyl-alto-co(anthracene-9,10-diyl)) and other polyfluorene compounds; poly(para-phenylene) (PPP), poly(1, Polyparaphenylene compounds such as 5-dialkoxy-para-phenylene) (RO-PPP); polycarbazole compounds such as poly(N-vinylcarbazole) (PVK); poly(methylphenylsilane) (PMPS), poly Polysilane-based compounds such as (naphthylphenylsilane) (PNPS) and poly(biphenylylphenylsilane) (PBPS); compounds and the like.

Low-molecular compounds forming the light-emitting layer 53 include 8-hydroxyquinoline aluminum (Alq ₃ ), tris[1-phenylisoquinoline-C2,N]iridium (III) (Ir(piq) ₃ ), fac-tris(3 -methyl-2-phenylpyridinato-N,C2′-)iridium (III) (Ir(mppy) ₃ ), bis[2-(o-hydroxyphenylbenzothiazole]zinc(II) (Zn(BTZ) ₂ ) tris(4-methyl-8-quinolinolate) aluminum (III) (Almq ₃ ), zinc 8-hydroxyquinoline (Znq ₂ ), (1,10-phenanthroline)-tris-(4,4,4-trifluoro- 1-(2-thienyl)-butane-1,3-dionate)europium(III) (Eu(TTA) ₃ (phen)), 2,3,7,8,12,13,17,18-octaethyl-21H , 23H-porphine platinum (II) and other metal complexes; benzene-based compounds such as distyrylbenzene (DSB) and diaminodistyrylbenzene (DADSB); naphthalene-based compounds such as naphthalene and Nile Red; phenanthrene-based compounds such as phenanthrene. , chrysene, chrysene compounds such as 6-nitrochrysene, perylene, N,N'-bis(2,5-di-t-butylphenyl)-3,4,9,10-perylene-di-carboximide (BPPC ) and other perylene compounds, coronene compounds such as coronene, anthracene compounds such as anthracene and bisstyrylanthracene, pyrene compounds such as pyrene, 4-(di-cyanomethylene)-2-methyl-6-(para- dimethylaminostyryl)-4H-pyran (DCM) and other pyran-based compounds, acridine-based compounds such as acridine, stilbene-based compounds such as stilbene, 4,4'-bis[9-dicarbazolyl]-2,2'-biphenyl ( CBP), carbazole compounds such as 4,4′-bis(9-ethyl-3-carbazovinylene)-1,1′-biphenyl (BCzVBi), 2,4-diphenyl-6-bis(12-phenylindolo) [2,3-a]carbazol-11-yl)-1,3,5-triazine (DIC-TRZ) and other triazine compounds, 2,5-dibenzoxazolethiophene and other thiophene compounds, benzoxazole and other benzoxazole oxazole compounds, benzimidazole compounds such as benzimidazole, 2,2 Benzothiazole compounds such as '-(para-phenylenedivinylene)-bisbenzothiazole, butadiene compounds such as bistyryl (1,4-diphenyl-1,3-butadiene) and tetraphenylbutadiene, naphthalimides such as naphthalimide coumarin-based compounds such as coumarin, perinone-based compounds such as perinone, oxadiazole-based compounds such as oxadiazole, aldazine-based compounds, 1,2,3,4,5-pentaphenyl-1,3-cyclo Cyclopentadiene compounds such as pentadiene (PPCP), quinacridone compounds such as quinacridone and quinacridone red, pyridine compounds such as pyrrolopyridine and thiadiazolopyridine, 2,2′,7,7′-tetraphenyl-9,9 Examples include spiro compounds such as '-spirobifluorene, metal or metal-free phthalocyanine compounds such as phthalocyanine (H ₂ Pc) and copper phthalocyanine, and one or more of these can be used.

Although the average thickness of the light-emitting layer 53 is not particularly limited, it is preferably 5 to 150 nm, more preferably 10 to 100 nm.

--Electron transport layer 54--
For the electron transport layer 54, materials generally used for electron transport layers of organic EL elements and host materials for the light-emitting layers described above can be used.
Examples of materials for the electron transport layer 54 include bis[2-(o-hydroxyphenylbenzothiazole]zinc(II) (Zn(BTZ) ₂ ), tris(8-hydroxyquinolinato)aluminum (Alq ₃ ), and the like. Representative various metal complexes, boron-containing compounds, pyridine derivatives such as tris-1,3,5-(3′-(pyridin-3″-yl)phenyl)benzene (TmPyPhB), 2-(3-(9- Quinoline derivatives such as carbazolyl)phenyl)quinoline (mCQ), pyrimidine derivatives such as 2-phenyl-4,6-bis(3,5-dipyridylphenyl)pyrimidine (BPyPPM), pyrazine derivatives, phenanthrolines such as bathophenanthroline (BPhen) derivatives, 2,4-bis(4-biphenyl)-6-(4′-(2-pyridinyl)-4-biphenyl)-[1,3,5]triazine (MPT), 2,4-diphenyl-6- Triazine derivatives such as bis(12-phenylindolo)[2,3-a]carbazol-11-yl)-1,3,5-triazine (DIC-TRZ), 3-phenyl-4-(1′-naphthyl) )-5-phenyl-1,2,4-triazole (TAZ) and other triazole derivatives, oxazole derivatives, 2-(4-biphenylyl)-5-(4-tert-butylphenyl-1,3,4-oxazide oxadiazole derivatives such as azole) (PBD); , naphthalene, aromatic ring tetracarboxylic anhydrides such as perylene, 2,5-bis(6′-(2′,2″-bipyridyl))-1,1-dimethyl-3,4-diphenylsilole (PyPySPyPy), etc. One or more of these may be used, among which 2,4-diphenyl-6-bis(12-phenylindolo) [ 2,3-a]carbazol-11-yl)-1,3,5-triazine (DIC-TRZ) is preferred.

Although the average thickness of the electron transport layer 54 is not particularly limited, it is preferably 5 to 100 nm, more preferably 10 to 80 nm.

-- electron injection layer 55 --
For the electron injection layer 55, materials commonly used for electron injection layers of organic EL elements can be used. For example, the electron injection layer 55 may include an alkali metal salt such as lithium fluoride, an alkaline earth metal salt, an alkali metal complex such as 8-hydroxyquinolinolatritium, an alkaline earth metal complex, a basic material containing amine, Ionic materials such as ammonium salts can be used.
Although the average thickness of the electron injection layer 55 is not particularly limited, it is preferably 0.5 to 100 nm, more preferably 1 to 60 nm.

(Electrode 60)
For the electrode 60 (upper electrode), in the case of the bottom emission type, an electrode material with high reflectance such as aluminum or silver can be used.
On the other hand, in the case of the top emission type or bitransparent type, electrode materials generally used in top emission type elements can be used. For example, an alloy of Mg:Ag or a material with high transparency and high conductivity such as IZO can be used.
The film thickness of the electrode 60 may be different between the light-emitting portion and the non-light-emitting portion of the EL element. In the case of the top emission structure, it is preferable that the film thickness of the electrode 60 is reduced to 20 nm or less to suppress light absorption loss in order to extract light to the outside in the light emitting portion. On the other hand, it is preferable that the film thickness is thicker in the portions other than the light emitting portion in order to reduce the wiring resistance.

(sealing structure 70)
For the sealing structure 70, in the case of the bottom emission type, a hollow sealing structure using a glass cap, a solid sealing structure in which a gas barrier substrate with an adhesive is attached to the element, or the like is used.
On the other hand, in the case of the top emission type, it is possible to use a film sealing structure or the like made of a highly transparent material.

(Organic EL element 110)
FIG. 5 is a schematic cross-sectional view for explaining another example of the organic EL element of this embodiment. The organic EL element 110 shown in FIG. 5 is an example of a so-called inverted structure element among the organic EL elements of the present invention. The organic EL element 110 shown in FIG. 5 is the same as the organic EL element 10 shown in FIG. 3 except for the EL functional layer 150 . 6 is a cross-sectional view along line VI-VI in FIG.

The organic EL element 110 shown in FIG. 5 includes a substrate 120 with electrodes, an insulating portion 130 formed thereon, a smoothing layer and conductive layer (conductive film) 140, and an EL functional layer 150 formed thereon. , and an electrode 160 formed thereon. Among them, as shown in FIG. 6, the EL function layer 150 includes an electron injection layer 151, an electron transport layer 152, a light emitting layer 153, a hole transport layer 154, a hole It is divided into injection layers 155 . The embodiment of the present invention is not limited to this, and may include at least one light-emitting layer between the electrode-attached substrate 120 and the electrode 160 . Also, a sealing portion 170 is provided to shield the organic EL element from the air.

(Substrate with electrodes 120)
As the electrode-equipped substrate 120 of the organic EL element 110, the same substrate as the electrode-equipped substrate 20 of the organic EL element 10 shown in FIG. 3 can be used.

(Insulator 130)
For the insulating portion 130 of the organic EL element 110, the same insulating portion 30 of the organic EL element 10 shown in FIG. 3 can be used.

(Smoothing layer and conductive layer 140)
As the smoothing layer/conducting layer 140 of the organic EL element 110, the same material as the smoothing layer/conducting layer 40 of the organic EL element 10 shown in FIG. 3 can be used.
A film of a material such as aluminum or silver that lowers the work function may be formed on the upper portion of the smoothing layer/conductive layer 140 . At this time, it is preferable to form the film as thin as possible with a film thickness of 3 nm or less, which does not impair the transparency and keeps the conductivity in the lateral direction low.

(EL functional layer 150)
The EL functional layer 150 of the organic EL element 110 shown in FIG. 5 includes an electron injection layer 151, an electron transport layer 152, a light emitting layer 153, a hole Although it is divided into a transport layer 154 and a hole injection layer 155, the structure of the organic EL element of the present invention is not limited to this.

-- electron injection layer 151 --
The electron injection layer 151 contains electrons of an organic EL device having a reverse structure, such as alkali metals, alkaline earth metals, complex compounds thereof, coordinating materials such as phenanthroline derivatives and bipyridine derivatives, and basic materials such as amine derivatives. A material generally used for the injection layer can be used. Further, the electron injection layer 151 may be made of the same material as the electron injection layer 55 shown in FIG. 4, and may have the same thickness.

-- electron transport layer 152 --
For the electron transport layer 152, materials commonly used for electron transport layers of organic EL elements can be used. For example, the electron transport layer 152 can be made of the same material as the electron transport layer 54 shown in FIG. 4, and can have the same thickness.

--light-emitting layer 153--
Materials generally used for organic EL elements can be used for the light-emitting layer 153 . For example, the light-emitting layer 153 can be made of the same material as the light-emitting layer 53 shown in FIG. 4, and can have the same thickness.

--hole transport layer 154--
For the hole transport layer 154, materials commonly used in organic EL devices having an inverted structure, such as arylamine compounds such as α-NPD, can be used. Further, the hole transport layer 154 may be made of the same material as the hole transport layer 52 shown in FIG. 4, and may have the same thickness.

--hole injection layer 155--
For the hole injection layer 155, a material generally used in an organic EL element having an inverted structure, such as an electron acceptor material such as MoO ₃ or HAT-CN, can be used. Further, the same material as the hole injection layer 51 shown in FIG. 4 can be used for the hole injection layer 155, and the thickness and the like can be the same.

(Electrode 160)
For the electrode 160 (upper electrode), in the case of the bottom emission type, an electrode material with high reflectance such as aluminum or silver can be used.
On the other hand, in the case of the top emission type or bitransparent type, electrode materials generally used in top emission type elements can be used. For example, an alloy of Mg:Ag or a material with high transparency and high conductivity such as IZO can be used.

(sealing structure 170)
For the sealing structure 170, in the case of the bottom emission type, a hollow sealing structure using a glass cap, a solid sealing structure in which a gas barrier substrate with an adhesive is attached to the element, or the like is used.
On the other hand, in the case of the top emission type, it is possible to use a film sealing structure or the like made of a highly transparent material.

(EL functional layer 210)
FIG. 7 is a schematic cross-sectional view for explaining an EL functional layer of an organic EL element having n light-emitting units (so-called tandem structure), specifically, taken along line IV-IV in FIG. It is a modified example of the cross section.

The EL function layer 210 shown in FIG. 7 is laminated with a light-emitting unit 220 ₁ , a charge-generating layer 230 ₁ , a light-emitting unit 220 ₂ , and a charge-generating layer 230 ₂ in order from the upper layer side of the smoothing layer-cum-conductive layer 40 in FIG. Then, the charge generation layer 230 _n−1 and the light emitting unit 220 _n are laminated (where n is an integer of 2 or more).
In other words, the organic EL element having the EL functional layer 210 shown in FIG. _{, 220 n and charge generating layers 230 1 , 230 2 , .} Here, a charge generation layer is provided between each light emitting unit.
Although the number of light-emitting units is not limited, organic EL elements having a tandem structure in which the value of n is 2 or 3 are preferable so that the driving voltage is not too high and the element fabrication is not too complicated.
In an _organic EL device having a plurality of light-emitting units 220 ₁ , 220 ₂ , . Emission intensity can be obtained, and high brightness can be realized.

-- Light-emitting units 220 ₁ , 220 ₂ , . . . , 220 _n --
Each of the light-emitting units 220 ₁ , 220 _{2 ,} . It can include a transport layer, an electron-injection layer (not shown), and have any of the layers other than the light-emitting layer (i.e., hole-injection layer, hole-transport layer, electron-transport layer, electron-injection layer). It doesn't have to be.
Alternatively, charges may be generated between a hole injection layer having charge acceptor properties and a hole transport layer having charge donating properties. The hole transport layer functions as a charge generating layer.
These hole injection layer, hole transport layer, light emitting layer, electron transport layer and electron injection layer include the hole injection layer 51, the hole transport layer 52, the light emitting layer 53 and the electrons of the organic EL element 10 shown in FIG. Materials similar to those of the transport layer 54 and the electron injection layer 55 can be used.

--Charge generating layers 230 ₁ , 230 ₂ , . . . , 230 _n−1 --
As described above, when generating charges between a hole injection layer with charge acceptor properties and a hole transport layer with charge donor properties, a hole injection layer with charge acceptor properties and a hole transport layer with charge donor properties function as charge generation layers 230 ₁ , 230 ₂ , . . . , 230 _n−1 .
. _. , 230 _{n−1 of} the EL functional layer 210 may be made of a highly reflective material such as aluminum or silver, an alloy of Mg:Ag, or IZO. It is also possible to use a layer (metal-containing layer) made of a material having high transparency and high electrical conductivity such as .

(EL functional layer 310)
FIG. 8 is a schematic cross-sectional view for explaining an EL functional layer of an organic EL element having two light-emitting units (so-called tandem structure), specifically, a cross-section taken along line IV-IV in FIG. It is a modification of

The EL functional layer 310 shown in FIG. 8 includes a hole injection layer 320 ₁ , a hole transport layer 330 ₁ , a light emitting layer 340 ₁ , an electron transport layer _350-1 , electron-injection layer _360-1 , metal-containing layer 370, hole-injection layer _320-2 , hole-transport layer _330-2 , light-emitting layer _340-2 , electron-transport layer _350-2 , electron injection It has a laminated structure in which layers ₃₆₀₂ are formed in this order.
Here, the hole-injection layer _320-1 , the hole-transport layer _330-1 , the light-emitting layer _340-1 , the electron-transport layer _350-1 , and the electron-injection layer _360-1 constitute one light-emitting unit _380-1 , A hole injection layer 320 ₂ , a hole transport layer 330 ₂ , a light emitting layer 340 ₂ , an electron transport layer 350 ₂ and an electron injection layer 360 ₂ constitute another light emitting unit 380 ₂ .
When the hole injection layer ₃₂₀₂ has a charge acceptor property and the hole transport layer ₃₃₀₂ has a charge donor property, charges are generated between the hole injection layer ₃₂₀₂ and the hole transport layer ₃₃₀₂ . In this case, the metal-containing layer 370, the hole-injecting layer ₃₂₀₂ , and the hole-transporting layer ₃₃₀₂ can be considered charge generating layers.
In an organic EL device having two light-emitting units 380 ₁ and 380 ₂ between the smoothing layer/conductive layer 40 and the electrode (upper electrode) 60, high light emission intensity can be obtained at a low current density. brightness can be achieved.

-- hole injection layers 320 ₁ , 320 ₂ --
For the hole injection layers 320 ₁ and 320 ₂ of the EL function layer 310, the same material as the hole injection layer 51 of the organic EL element 10 shown in FIG. 3 can be used.

-- hole transport layers 330 ₁ , 330 ₂ --
For the hole transport layers 330 ₁ and 330 ₂ of the EL functional layer 310, the same material as the hole transport layer 52 of the organic EL element 10 shown in FIG. 3 can be used.

-- Light-emitting layers 340 ₁ , 340 ₂ --
For the light emitting layers 340 ₁ and 340 ₂ of the EL functional layer 310, the same material as the light emitting layer 53 of the organic EL element 10 shown in FIG. 3 can be used.

-- electron transport layers 350 ₁ , 350 ₂ --
As the electron transport layers 350 ₁ and 350 ₂ of the EL functional layer 310, the same material as the electron transport layer 54 of the organic EL element 10 shown in FIG. 3 can be used.

-- electron injection layers 360 ₁ , 360 ₂ --
For the electron injection layers 360 ₁ and 360 ₂ of the EL function layer 310, the same material as the electron injection layer 55 of the organic EL element 10 shown in FIG. 3 can be used.

--metal-containing layer 370--
For the metal-containing layer (charge generation layer) 370 of the EL function layer 310, a material having high reflectance such as aluminum or silver can be used, or a highly transparent material such as Mg:Ag alloy or IZO can be used. , a material with high electrical conductivity can also be used.

(Formation method)
In the organic EL elements 10 and 110 shown in FIGS. 3 to 8, the method of forming all the layers is not particularly limited, and chemical vapor deposition methods such as plasma CVD, thermal CVD, laser CVD, etc., which are vapor deposition methods ( CVD), vacuum deposition, sputtering, ion plating, and other dry plating methods, thermal spraying methods, and liquid phase deposition methods such as electrolytic plating, immersion plating, and electroless plating, sol-gel methods, and MOD methods. , a spray pyrolysis method, a doctor blade method using a fine particle dispersion, a spin coating method, an ink jet method, a printing technique such as a screen printing method, etc. can be used, and an appropriate method can be selected and used according to the material. can be done.
These methods are preferably selected according to the characteristics of the material of each layer, and the manufacturing method may be different for each layer.

<Display device>
A display device of the present invention is characterized by comprising the organic electroluminescence element described above. Since the display device of the present invention includes the organic electroluminescence element described above, it can be manufactured at low cost.
The display device can be formed by combining a TFT circuit generally used for driving an organic EL display and the organic EL element of the present invention.

<Lighting device>
A lighting device of the present invention is characterized by comprising the organic electroluminescence element described above. Since the lighting device of the present invention includes the organic electroluminescence element described above, it can be manufactured at low cost.
The lighting device can be formed by incorporating the organic EL element of the present invention into a lighting fixture that is generally used for organic EL lighting.

<Other uses>
The electronic device substrate of the present invention can be used for the above-described organic EL device, display device, lighting device, solar cell, and the like. For example, a solar cell according to the present invention is characterized by comprising the electronic device substrate described above. Such a solar cell can be manufactured at a low cost because it includes the electronic device substrate.

EXAMPLES The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples.

<Manufacturing Method of Electronic Device Substrate 1>
The electronic device substrate 1 configured as described above was manufactured as follows.
As the aluminum foil, a non-glossy surface of clean room/vacuum aluminum foil UHVF-03 manufactured by T-Support Co., Ltd. was used. The surface shape is the one shown in FIG. 1, with a maximum height roughness Rz of 435 nm and an average surface roughness Ra of 91 nm.

A piece of aluminum foil was cut out and pasted on one side of a film with adhesive layers on both sides. The other side was attached to a glass substrate of 25 mm×35 mm. The attached aluminum foil and adhesive film were cut with scissors along the shape of the 25 mm×35 mm glass substrate.

After dust on the surface of the glass substrate with aluminum foil was blown off with an air gun, it was treated with UV ozone and moved into a glove box filled with nitrogen. A solution was prepared by adding 1 part by mass of HAT-CN to 100 parts by mass of phosphotungstic acid (PWA) adjusted to a predetermined concentration so as to obtain a desired film thickness. The solution was dropped onto a glass substrate with aluminum foil fixed on the spin table of a spin coater, and was spun at 5000 rpm for 180 seconds to form a coating film. The film thickness of the produced film (conductive film) is 1 μm. Next, heat treatment was performed at 150° C. for 10 minutes under nitrogen to remove the solvent. Thus, an electronic device substrate was produced.

<Manufacturing Method of Organic EL Element 10>
The organic EL element 10 configured as described above was manufactured as follows.
The molecular structures of the materials used are as follows.

As the aluminum foil, a non-glossy surface of clean room/vacuum aluminum foil UHVF-03 manufactured by T-Support Co., Ltd. was used. The surface shape is the one shown in FIG. 1, with a maximum height roughness Rz of 435 nm and an average surface roughness Ra of 91 nm.

A piece of aluminum foil was cut out and pasted on one side of a film with adhesive layers on both sides. The other side was attached to a glass substrate of 25 mm×35 mm. The attached aluminum foil and adhesive film were cut with scissors along the shape of the 25 mm×35 mm glass substrate.

After dust on the surface of the glass substrate with aluminum foil was blown off with an air gun, a mask was attached and the glass substrate was introduced into a sputtering apparatus to deposit 400 nm of SiO ₂ as an insulating film.

After dust on the surface of the glass substrate with aluminum foil was blown off with an air gun, it was treated with UV ozone and moved into a glove box filled with nitrogen. A solution was prepared by adding 1 part by mass of HAT-CN to 100 parts by mass of phosphotungstic acid (PWA) adjusted to a predetermined concentration so as to obtain a desired film thickness. The solution was dropped onto a glass substrate with aluminum foil fixed on the spin table of a spin coater, and was spun at 5000 rpm for 180 seconds to form a coating film. The film thickness of the produced film (smoothing layer and conductive layer) was 173 nm (Comparative Example 1), 200 nm (Comparative Example 2), 250 nm (Example 1), 400 nm (Example 2), 1 μm (Example 3). is. Next, heat treatment was performed at 150° C. for 10 minutes under nitrogen to remove the solvent.

Next, the substrate was transferred into a vacuum chamber, and HAT-CN as a hole injection layer was deposited to a thickness of 10 nm at a deposition rate of 0.3 Å/sec.
Next, α-NPD as a hole transport layer was vapor-deposited to a thickness of 20 nm at a film formation rate of 0.4 Å/sec.
Next, DIC-TRZ as the host material of the light-emitting layer was deposited at a deposition rate of 0.376 Å/sec, and Ir(mppy) ₃ as the guest material was deposited at a deposition rate of 0.024 Å/sec to a thickness of 25 nm. bottom.
Next, DIC-TRZ was deposited as an electron transport layer to a thickness of 40 nm at a deposition rate of 0.376 Å/sec.
Subsequently, Py-hpp ₂ was deposited as an electron injection layer to a thickness of 1.5 nm at a deposition rate of 0.3 Å/sec.
Next, a co-evaporation film of Mg and Ag (Mg:Ag=9:1) was vapor-deposited at a film-forming rate of 1 Å/sec to form a cathode with a thickness of 15 nm.
Subsequently, the substrate was taken out from the vacuum chamber into a glove box filled with nitrogen, and the element portion was covered with a UV curing adhesive on a glass tube with a desiccant, and was irradiated with UV for hollow sealing. The area of the fabricated device is 150 mm ² .

<Method for Manufacturing Organic EL Element 110>
The organic EL element 110 configured as described above was manufactured as follows.
The molecular structures of the materials used are as follows.

As the aluminum foil, a non-glossy surface of clean room/vacuum aluminum foil UHVF-03 manufactured by T-Support Co., Ltd. was used. The surface shape is the one shown in FIG. 1, with a maximum height roughness Rz of 435 nm and an average surface roughness Ra of 91 nm.

A piece of aluminum foil was cut out and pasted on one side of a film with adhesive layers on both sides. The other side was attached to a glass substrate of 25 mm×35 mm. The attached aluminum foil and adhesive film were cut with scissors along the shape of the 25 mm×35 mm glass substrate.

After dust on the surface of the glass substrate with aluminum foil was blown off with an air gun, a mask was attached and the glass substrate was introduced into a sputtering apparatus to deposit 400 nm of SiO ₂ as an insulating film.

After dust on the surface of the glass substrate with aluminum foil was blown off with an air gun, it was treated with UV ozone and moved into a glove box filled with nitrogen. A solution was prepared by adding 1 part by mass of HAT-CN to 100 parts by mass of phosphotungstic acid (PWA) adjusted to a predetermined concentration so as to obtain a desired film thickness. The solution was dropped onto a glass substrate with aluminum foil fixed on the spin table of a spin coater, and was spun at 5000 rpm for 180 seconds to form a coating film. The film thickness of the produced film (smoothing layer and conductive layer) was 173 nm (Comparative Example 3), 200 nm (Comparative Example 4), 250 nm (Example 4), 400 nm (Example 5), 1 μm (Example 6). is. Next, heat treatment was performed at 150° C. for 10 minutes under nitrogen to remove the solvent.

Next, the substrate was transferred into a vacuum chamber, and aluminum was deposited to a thickness of 1.5 nm at a deposition rate of 0.2 Å/sec.
Then, spB- _BPy2 was co-evaporated at a deposition rate of 0.38 Å/s and Py- _hpp2 at a deposition rate of 0.02 Å/s for a total deposition rate of 0.4 Å/s for 10 nm electron deposition. An injection layer was deposited by vapor deposition.
Subsequently, Zn(BTZ) ₂ was deposited at a deposition rate of 0.4 Å/sec to form a 10 nm electron transport layer.
Subsequently, Zn(BTZ) ₂ was co-deposited at a deposition rate of 0.376 Å/sec and Ir(piq) ₃ at a deposition rate of 0.024 Å/sec, for a total deposition rate of 0.4 Å/sec. A 20 nm light-emitting layer was deposited by vapor deposition.
Subsequently, α-NPD was vapor-deposited to form a hole transport layer of 50 nm at a film formation rate of 0.4 Å/sec.
Subsequently, HAT-CN was vapor-deposited to form a hole injection layer of 10 nm at a film formation rate of 0.4 Å/sec.
Subsequently, a co-evaporation film of Mg and Ag (Mg:Ag=9:1) was vapor-deposited at a film-forming rate of 1 Å/sec to form an anode with a thickness of 15 nm.
Subsequently, the substrate was taken out from the vacuum chamber into a glove box filled with nitrogen, and the element portion was covered with a UV curing adhesive on a glass tube with a desiccant, and was irradiated with UV for hollow sealing. The area of the fabricated device is 150 mm ² .

<Measurement results for verification>
Using the aluminum foils of the devices of Comparative Examples 1, 2, and Examples 1 to 3 as anodes and co-deposited films of Mg and Ag as cathodes, a voltage was applied to confirm whether or not a luminescent image was obtained. In the element of Comparative Example 1, when the voltage was increased, a short circuit occurred in the element portion, small sparks were observed, and light emission was not obtained. In the device of Comparative Example 2, although light was emitted, a uniform light emitting surface was not obtained due to a large short circuit. On the other hand, in the devices of Examples 1 to 3, uniform light emission was observed when the voltage was increased. Table 1 shows the results.

Using the aluminum foils of the devices of Comparative Examples 3, 4, and Examples 4 to 6 as cathodes and co-deposited films of Mg and Ag as anodes, a voltage was applied to confirm whether or not a luminescent image was obtained. In the element of Comparative Example 3, when the voltage was increased, a short circuit occurred in the element portion, small sparks were observed, and light emission was not obtained. In the device of Comparative Example 4, although light was emitted, a uniform light emitting surface was not obtained due to a large short circuit. On the other hand, in the devices of Examples 4 to 6, uniform light emission was observed when the voltage was increased. Table 1 shows the results. FIG. 9 shows how the device of Example 6 emits light.

The reason why the organic EL device of the example was able to emit light is that the coating with a sufficiently thick smoothing layer and conductive layer (PWA) relieved the concentration of the electric field on the convex portions of the surface, thereby suppressing the short circuit. Conceivable. In addition, since the PWA film with a thickness of several hundred nm or more has a negative differential resistance characteristic, an increase in current value is suppressed with respect to an increase in voltage. It is considered that this negative differential resistance characteristic was also effective in suppressing short circuits.

<Evaluation of Ra (FFT) of electronic device substrate 1>
As the aluminum foil, a non-glossy surface of clean room/vacuum aluminum foil UHVF-03 manufactured by T-Support Co., Ltd. was used. The surface shape is the one shown in FIG. 1, with a maximum height roughness Rz of 435 nm and an average surface roughness Ra of 91 nm.
A piece of aluminum foil was cut out and pasted on one side of a film with adhesive layers on both sides. The other side was attached to a glass substrate of 25 mm×35 mm. The attached aluminum foil and adhesive film were cut with scissors along the shape of the 25 mm×35 mm glass substrate.
After dust on the surface of the glass substrate with aluminum foil was blown off with an air gun, it was treated with UV ozone and moved into a glove box filled with nitrogen. A solution was prepared by adding 1 part by mass of HAT-CN to 100 parts by mass of phosphotungstic acid (PWA) adjusted to a predetermined concentration so as to obtain a desired film thickness. The solution was dropped onto a glass substrate with aluminum foil fixed on the spin table of a spin coater, and was spun at 5000 rpm for 180 seconds to form a coating film. The film thicknesses of the produced films (conductive films) are 250 nm (Example 7), 400 nm (Example 8), and 600 nm (Example 9). Next, heat treatment was performed at 150° C. for 10 minutes under nitrogen to remove the solvent. Thus, an electronic device substrate was produced.

Regarding the surface shape of the aluminum foil (Comparative Example 5) and the electronic device substrate produced as described above, the surface shape was measured with a Dektak, and a high-pass filter was used to pass only components with a spatial frequency of 1,000,000/m or more. , Fourier transform (FFT) filtering was performed to evaluate the surface average roughness Ra (FFT). Table 2 shows the results. In addition, the numerical value used what averaged the measurement result of 5 points|pieces.

From Table 2, it can be seen that by forming a conductive film (PWA: 100 parts by mass + HAT-CN: 1 part by mass) on the aluminum foil, sharp changes in the surface shape are greatly reduced. It is considered that this reduction effect was also effective in suppressing the short circuit.

<Production of organic EL element using insulating tape>
(Example 10)
Although SiO ₂ was used for the insulating portion in the above example, an insulating tape was used as the insulating portion instead. Polyester film adhesive tape 633L (thickness: 9 μm) manufactured by Teraoka Seisakusho was used as the insulating tape. An organic EL device was fabricated in the same manner as in Example 1 above, except that the SiO ₂ film formation portion was changed to the insulating tape attachment. The film thickness of PWA was set to 250 nm.

Both the anode and the cathode of the devices of Examples 1 and 10 were clamped with alligator clips, and light emission was evaluated.
In the device of Example 1, the alligator clip broke through SiO ₂ and reached the lower aluminum foil, short-circuiting the anode and cathode, and the organic EL device could not emit light.
On the other hand, in the device of Example 10, since the alligator clip did not break through the insulating tape, no short circuit occurred and good light emission was obtained. As described above, as an insulating part, attaching an insulating tape is more useful than forming a film of SiO ₂ by sputtering because the process can be simplified and the insulating properties can be improved.

Here, there is a sharp step of 9 μm between the aluminum foil and the insulating tape, but the step between the aluminum foil and the insulating tape can be smoothed by coating the smoothing layer and conductive layer 40 . can be done. By forming the EL function layer 50 and the upper electrode 60 after that, the film was not interrupted at the step portion, and the current could be supplied satisfactorily. In the organic EL element thus produced, even when the electrode 60 is sandwiched with an alligator clip and electrical contact is made with a strong force, the electrode-attached substrate 20 does not conduct to the lower electrode-attached substrate 20 and emits light well. FIG. 10 shows how the device of Example 10 emits light.

As described above, the film thickness of the upper electrode may not be uniform. A thick PWA film can fill the step and make the step smooth, but the upper electrode is likely to break at the step. Therefore, it is preferable that the electrode at the stepped portion formed by the insulating tape be as thick as possible. In the element of this example, a thick electrode (approximately 150 nm) was formed so as to protrude slightly inside the light emitting element from the step. Since the light-emitting portion needs to be thin in order to extract light, the electrode was formed in two steps to form a thin portion and a thick portion.

<Verification of effect of vapor deposition of metal layer>
In addition to or in place of the materials used in the above examples, materials having the molecular structures shown below were used to fabricate organic EL devices.

As the aluminum foil, a non-glossy surface of clean room/vacuum aluminum foil UHVF-03 manufactured by T-Support Co., Ltd. was used. The surface shape is the one shown in FIG. 1, with a maximum height roughness Rz of 435 nm and an average surface roughness Ra of 91 nm.
As the insulating tape, polyester film adhesive tape 633L (thickness: 9 μm) manufactured by Teraoka Seisakusho was used.

Before attaching the insulating tape, an aluminum foil substrate was not coated with aluminum by vapor deposition over the entire surface (Example 11), and an aluminum foil substrate was coated with aluminum to a thickness of 30 nm by vapor deposition over the entire surface (Example 11). 12) and were prepared.
Next, for Example 11, an insulating tape was attached to the top of the aluminum foil substrate, and a thin film of 250 nm consisting of only PWA was formed on the aluminum foil substrate to which the insulating tape was attached in a glove box filled with nitrogen. and dried at 150° C. for 10 minutes to produce an electronic device substrate (composite of aluminum foil substrate, insulating tape, and PWA film).
On the other hand, in Example 12, an insulating tape was attached to the top of the evaporated aluminum film, and a thin film of 250 nm consisting of only PWA was formed on the evaporated aluminum film to which the insulating tape was attached in a glove box filled with nitrogen. , and dried at 150° C. for 10 minutes to prepare an electronic device substrate (a composite of an aluminum foil substrate, an aluminum deposition film, an insulating tape, and a PWA film).

Next, the substrate was transferred into a vacuum chamber, and HAT-CN as a hole injection layer was deposited to a thickness of 5 nm at a deposition rate of 0.3 Å/sec.
Next, α-NPD as a hole transport layer was vapor-deposited to a thickness of 20 nm at a film formation rate of 0.4 Å/sec.
Next, TCTA as the host material of the first light-emitting layer was co-deposited at a deposition rate of 0.34 Å/sec, and Ir(mppy) ₃ as the guest material was co-evaporated to a thickness of 5 nm at a deposition rate of 0.06 Å/sec. filmed.
Next, DIC-TRZ as a host material of the second light-emitting layer was deposited at a deposition rate of 0.34 Å/sec, and Ir(mppy) ₃ as a guest material was deposited at a deposition rate of 0.06 Å/sec to form a 15 nm film. A film was formed by vapor deposition.
Next, B3PYMPM was deposited as an electron transport layer to a thickness of 50 nm at a deposition rate of 0.4 Å/sec.
Subsequently, Liq was deposited as an electron injection layer to a thickness of 1.2 nm at a deposition rate of 0.15 Å/sec.
Next, an Al deposition film was deposited at a deposition rate of 1 Å/sec to form a first cathode (a thin portion of the electrode 60) with a thickness of 5 nm.
Next, a second cathode (thick part of the electrode 60) of 150 nm was formed by vapor deposition of Al at a film formation rate of 1 to 10 Å/sec.
Next, α-NPD as a capping layer was deposited to a thickness of 40 nm at a deposition rate of 0.4 Å/sec.
Subsequently, the substrate was taken out from the vacuum chamber into a glove box filled with nitrogen, a UV curing adhesive was applied to the glass tube, and the device portion was covered with UV irradiation to effect hollow sealing. The area of the fabricated device is 150 mm ² .

A voltage was applied to each device of Examples 11 and 12, and luminance was measured. FIG. 11 shows the results after aging by applying a voltage of 7V.
It was found that the driving voltage can be reduced by using an aluminum foil on which 30 nm of aluminum is vapor-deposited (Example 12). Looking at the driving voltage at 100 cd/m ² , the device without vapor-deposited aluminum (Example 11) was 6.0 V, while the device with vapor-deposited aluminum (Example 12) was 3.6 V. . The reason why the driving voltage was reduced is not clear, but it is because the aluminum foil has a thick oxide film on its surface, whereas the vapor-deposited aluminum has a thin oxide film, making it more difficult to block electron conduction. it is conceivable that.

<Verification of effect of tandem structure>
In addition to or in place of the materials used in the above examples, materials having the molecular structures shown below were used to fabricate organic EL devices.

As the aluminum foil, a non-glossy surface of clean room/vacuum aluminum foil UHVF-03 manufactured by T-Support Co., Ltd. was used. The surface shape is the one shown in FIG. 1, with a maximum height roughness Rz of 435 nm and an average surface roughness Ra of 91 nm.
As the insulating tape, polyester film adhesive tape 633L (thickness: 9 μm) manufactured by Teraoka Seisakusho was used.

A device was fabricated in the same manner as in Example 12, except that the device configuration was changed. Specifically, after vapor-depositing 30 nm of aluminum on the entire surface of the aluminum foil, an insulating tape was attached. After that, a 250 nm PWA layer was applied and dried by heating at 150° C. for 10 minutes. In Example 13, an organic EL device having one light emitting unit was fabricated, and in Example 14, a tandem structure organic EL device having two light emitting units was fabricated.

(Example 13: 1 unit element)
An electronic device substrate (a composite of an aluminum foil substrate, an aluminum deposition film, an insulating tape, and a PWA film) was transferred into a vacuum chamber, and HAT-CN as a hole injection layer was applied at a rate of 0.3 Å/sec. A 5 nm film was formed by vapor deposition at a film formation rate.
Next, α-NPD as a hole transport layer was vapor-deposited to a thickness of 20 nm at a film formation rate of 0.4 Å/sec.
Next, TCTA as the host material of the first light-emitting layer was co-deposited at a deposition rate of 0.34 Å/sec, and Ir(mppy) ₃ as the guest material was co-evaporated to a thickness of 5 nm at a deposition rate of 0.06 Å/sec. filmed.
Next, DIC-TRZ as a host material of the second light-emitting layer was deposited at a deposition rate of 0.34 Å/sec, and Ir(mppy) ₃ as a guest material was deposited at a deposition rate of 0.06 Å/sec to form a 15 nm film. A film was formed by vapor deposition.
Next, DPPyA was deposited as an electron transport layer to a thickness of 50 nm at a deposition rate of 0.4 Å/sec.
Subsequently, Liq was deposited as an electron injection layer to a thickness of 1.2 nm at a deposition rate of 0.15 Å/sec.
Next, an Al deposition film was deposited at a deposition rate of 1 Å/second to form the first cathode (the thin portion of the electrode 60) with a thickness of 5 nm.
Next, a second cathode (the thick portion of the electrode 60) of 150 nm was deposited by depositing an Al deposition film at a deposition rate of 1 to 10 Å/sec.
Next, α-NPD as a capping layer was deposited to a thickness of 40 nm at a deposition rate of 0.4 Å/sec.
Subsequently, the substrate was taken out from the vacuum chamber into a glove box filled with nitrogen, a UV curing adhesive was applied to the glass tube, the device part was covered with UV irradiation, and hollow sealing was performed. The area of the fabricated device is 150 mm ² .

(Example 14: 2-unit tandem element)
An electronic device substrate (a composite of an aluminum foil substrate, an aluminum vapor deposition film, an insulating tape, and a PWA film) was transferred into a vacuum chamber, and HAT-CN as a hole injection layer of the first unit was added to 0.00. A 5 nm deposition film was formed at a film formation rate of 3 Å/sec.
Next, α-NPD as the hole transport layer of the first unit was vapor-deposited to a thickness of 20 nm at a film formation rate of 0.4 Å/sec.
Next, TCTA as the host material of the first light-emitting layer of the first unit was deposited at a deposition rate of 0.34 Å/sec, and Ir(mppy) ₃ was deposited as the guest material at a deposition rate of 0.06 Å/sec. A 5 nm co-evaporation film was formed.
Next, DIC-TRZ as a host material of the second light-emitting layer of the first unit was deposited at a deposition rate of 0.34 Å/sec, and Ir(mppy) ₃ as a guest material was deposited at a deposition rate of 0.06 Å/sec. A film of 15 nm was co-deposited at a rate of 15 nm.
Next, as the electron transport layer of the first unit, DPPyA was vapor-deposited to a thickness of 60 nm at a film formation rate of 0.4 Å/sec.
Subsequently, as the electron injection layer of the first unit, Liq was deposited to a thickness of 1.2 nm at a deposition rate of 0.15 Å/sec.
Next, an Al deposition film was deposited to a thickness of 1 nm at a deposition rate of 0.2 Å/sec.

Next, HAT-CN as a hole injection layer of the second unit was vapor-deposited to a thickness of 5 nm at a film formation rate of 0.3 Å/sec.
Next, α-NPD as a hole transport layer of the second unit was vapor-deposited to a thickness of 60 nm at a film formation rate of 0.4 Å/sec.
Next, TCTA as the host material of the first light-emitting layer of the second unit was deposited at a deposition rate of 0.34 Å/sec, and Ir(mppy) ₃ was deposited as the guest material at a deposition rate of 0.06 Å/sec. A 5 nm co-evaporation film was formed.
Next, DIC-TRZ as a host material of the second light-emitting layer of the second unit was deposited at a deposition rate of 0.34 Å/sec, and Ir(mppy) ₃ as a guest material was deposited at a deposition rate of 0.06 Å/sec. A film of 15 nm was co-deposited at a rate of 15 nm.
Next, as the electron transport layer of the second unit, DPPyA was vapor-deposited to a thickness of 60 nm at a deposition rate of 0.4 Å/sec.
Subsequently, as the electron injection layer of the second unit, Liq was vapor-deposited to a thickness of 1.2 nm at a deposition rate of 0.15 Å/sec.
Next, an Al deposition film was deposited at a deposition rate of 1 Å/sec to form a first cathode (a thin portion of the electrode 60) with a thickness of 5 nm.
Next, a second cathode (thick part of the electrode 60) of 150 nm was formed by vapor deposition of Al at a film formation rate of 1 to 10 Å/sec.
Next, α-NPD as a capping layer was deposited to a thickness of 40 nm at a deposition rate of 0.4 Å/sec.
Subsequently, the substrate was taken out from the vacuum chamber into a glove box filled with nitrogen, a UV curing adhesive was applied to the glass tube, and the device portion was covered with UV irradiation to effect hollow sealing. The area of the fabricated device is 150 mm ² .

The organic EL element of Example 13 was aged by applying a maximum voltage of 9 V in advance, and the organic EL element of Example 14 was aged by applying twice the voltage of 18 V (two times the number of light emitting units). , the current density-voltage characteristics after aging are shown in FIG. 12, and the luminance-voltage characteristics are shown in FIG. These devices were subjected to aging with this voltage as the upper limit, since the leak current increased when a voltage higher than this was applied.
In the element of Example 13, due to the characteristics of PWA used in the conductive layer, the increase in current was limited and did not reach 1000 cd/m ² . On the other hand, the element of Example 14 also reached 1000 cd/m ² at 8.6 V, although the current increase was limited. It can be said that such a high brightness was obtained because the tandem structure provided a higher emission intensity with a lower current density.

<Fabrication of large area element>
(Example 15, Example 16)
An organic EL device was produced with the same device configuration as in Example 13, except that the size of the substrate was changed. FIG. 14 shows the dimensions of the device. In FIG. 14, an insulating tape (insulating portion) was attached to the outer portion of the light emitting portion.
Example 15 is a hollow-sealed device. In Example 16, light was emitted while crumpling and tearing in the glove box.

A 10 cm×10 cm piece of aluminum foil was cut out and attached to one side of a film having adhesive layers on both sides. The other side was attached to a glass substrate of 10 cm×10 cm. The attached aluminum foil and adhesive film were cut with scissors along the shape of the 10 cm x 10 cm glass substrate.
After that, it was transferred to a vapor deposition chamber, and 30 nm of aluminum was vapor-deposited on the entire surface.
Next, an insulating tape with a width of 1 cm was pasted along the edges of two opposite sides of the substrate.
Next, a 250 nm PWA film was formed by coating in a glove box filled with nitrogen, and dried by heating at 150° C. for 10 minutes.

Next, the substrate was transferred into a vacuum chamber, and HAT-CN as a hole injection layer was deposited to a thickness of 5 nm at a deposition rate of 0.3 Å/sec.
Next, α-NPD as a hole transport layer was vapor-deposited to a thickness of 20 nm at a film formation rate of 0.4 Å/sec.
Next, TCTA as the host material of the first light-emitting layer was co-deposited at a deposition rate of 0.34 Å/sec, and Ir(mppy) ₃ as the guest material was co-evaporated to a thickness of 5 nm at a deposition rate of 0.06 Å/sec. filmed.
Next, DIC-TRZ as a host material of the second light-emitting layer was deposited at a deposition rate of 0.34 Å/sec, and Ir(mppy) ₃ as a guest material was deposited at a deposition rate of 0.06 Å/sec to form a 15 nm film. A film was formed by vapor deposition.
Next, DPPyA was deposited as an electron transport layer to a thickness of 50 nm at a deposition rate of 0.4 Å/sec.
Subsequently, Liq was deposited as an electron injection layer to a thickness of 1.2 nm at a deposition rate of 0.15 Å/sec.
Next, an Al deposition film was deposited at a deposition rate of 1 Å/sec to form a first cathode (a thin portion of the electrode 60) with a thickness of 5 nm.
Next, a second cathode (thick part of the electrode 60) of 150 nm was formed by vapor deposition of Al at a film formation rate of 1 to 10 Å/sec.
Next, α-NPD as a capping layer was deposited to a thickness of 40 nm at a deposition rate of 0.4 Å/sec.

(Example 15)
Subsequently, the substrate was taken out from the vacuum chamber into a glove box filled with nitrogen, and in the device of Example 15, a UV curing adhesive was applied to the glass tube, the device portion was covered, and UV irradiation was performed to seal the hollow. bottom. The area of the fabricated device is 64 cm ² .
Next, a voltage was applied to the fabricated device to cause it to emit light. Although light emission unevenness related to in-plane unevenness in the film thickness of the thin film formed in the organic EL element was observed, the light emission was generally uniform. FIG. 15 shows how the device of Example 15 emits light.
In general, it is difficult to uniformly emit light from such a large-area device because a voltage drop occurs when there is a defect somewhere on the substrate surface or when the resistance of the electrode is high. However, the emission image of this device was generally uniform. It is believed that this is because the thick PWA film covers the surface defects and the high electrical conductivity of the aluminum foil.

(Example 16)
After the organic EL element was produced, the aluminum foil on which the organic EL element was formed was peeled off from the adhesive film, and a voltage was applied to emit light in a glove box. As shown in FIG. 16, the device was crumpled while emitting light. Further, as shown in FIG. 17, the device was broken while emitting light. In either case, the light emitting surface was not cracked and the light emission continued without any problem.
In this way, it was found that the device can emit light even if it is deformed, which cannot be done with a device using an ordinary flexible film. Normally, an element using an oxide cracks when deformed, but PWA contains phosphoric acid and is soft.

By applying the electronic device substrate of the present invention to an organic EL device, it can contribute to cost reduction of the organic EL device. Moreover, by incorporating such an organic EL element into a display device or a lighting device, it becomes possible to reduce the price of the display device or the lighting device.

1: Substrate for electronic device 2: Substrate 3: Electrode 4: Conductive film 10, 110: Organic EL element 20, 120: Substrate with electrode 30, 130: Insulator 40, 140: Smoothing layer and conductive layer (conductive film)
50, 150, 210, 310: EL functional layer 51, 155, 320 ₁ , 320 ₂ : hole injection layer 52, 154, 330 ₁ , 330 ₂ : hole transport layer 53, 153, 340 ₁ , 340 ₂ : light emission Layers 54, 152, 350 ₁ , 350 ₂ : electron transport layers 55, 151, 360 ₁ , 360 ₂ : electron injection layers 60, 160: electrodes (upper electrodes)
70, 170: sealing portion 220 ₁ , 220 ₂ , 220 _n , 380 ₁ , 380 ₂ : light emitting unit 230 ₁ , 230 ₂ , 230 _n−1 : charge generation layer 370: metal-containing layer

Claims (11)

An electronic device substrate comprising: a substrate having an electrode on its surface; and a conductive film formed adjacent to an upper portion of the electrode,
The maximum height roughness Rz of the shape of the electrode in the direction perpendicular to the substrate is 300 nm or more and 1000 nm or less,
The thickness t of the conductive film and the maximum height roughness Rz of the shape of the electrode are expressed by the following formula (1):
Maximum height roughness Rz (nm) of electrode shape−thickness t (nm) of conductive film≦230 nm (1)
satisfy the relationship of
A substrate for an electronic device, wherein the conductive film contains a polyoxometalate containing tungsten. The conductive film has a surface average roughness Ra (FFT) of 1 nm or less obtained from components obtained by Fourier transform (FFT) filtering that allows only components with a spatial frequency of 1,000,000/m or more to pass from the surface shape. The electronic device substrate according to claim 1, wherein 3. The electronic device substrate according to claim 1, wherein the conductive film has a thickness t of 210 nm or more. 4. The electronic device substrate according to claim 1, wherein said substrate and said electrode are made of the same material and integrated. Claim 1, wherein the conductive film further comprises dipyrazino[2,3-f:2',3'-h]quinoxaline-2,3,6,7,10,11-hexacarbonitrile (HAT-CN). 5. The electronic device substrate according to any one of 1 to 4. An insulating tape is attached to a part of the substrate having an electrode on its surface, and a step formed by the substrate having an electrode on its surface and the insulating tape is formed adjacent to an upper portion of the electrode. The electronic device substrate according to any one of claims 1 to 5, which is filled with The electronic device substrate according to any one of claims 1 to 6, wherein the substrate having electrodes on its surface has a metal foil and a metal layer formed on the metal foil. An organic electroluminescence device comprising the electronic device substrate according to any one of claims 1 to 7. 9. The organic electroluminescence device according to claim 8, comprising the electronic device substrate, an upper electrode, and a plurality of light emitting units positioned between the electronic device substrate and the upper electrode. 10. A display device comprising the organic electroluminescence device according to claim 8 or 9. 10. A lighting device comprising the organic electroluminescence device according to claim 8 or 9.

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