JP5174577B2 - ORGANIC ELECTROLUMINESCENCE ELEMENT AND ITS MANUFACTURING METHOD, LIGHTING DEVICE, SURFACE LIGHT SOURCE, DISPLAY DEVICE - Google Patents

Description

  The present invention relates to an organic electroluminescence element, an illumination device using the organic electroluminescence element, a planar light source, and a display device.

  The organic electroluminescence element includes a pair of electrodes and an organic light emitting layer. When a voltage is applied to the organic electroluminescence element, holes and electrons are injected from each electrode, and light is emitted by recombination of the injected holes and electrons in the organic light emitting layer. Compared to inorganic EL elements, organic electroluminescence elements can be driven at a low voltage and have high luminance. For this reason, the use of organic electroluminescence elements in display devices and lighting devices has been studied.

  For example, in an active matrix drive type display device, a plurality of organic electroluminescence elements are provided on a TFT (Thin Film Transistor) substrate on which a drive circuit is formed. In a so-called bottom emission type organic electroluminescence element that extracts light from the substrate side, the light is blocked by a drive circuit or the like provided on the substrate, so that the aperture ratio is usually low. Therefore, so-called top emission type organic electroluminescence elements that take out light from the side opposite to the substrate are being studied in order to increase the aperture ratio regardless of the drive circuit that blocks light.

  In the top emission type organic electroluminescence element, the electrode provided on the side opposite to the substrate is constituted by a transparent electrode. For example, there is an organic electroluminescence element in which a transparent electrode is a cathode composed of three layers of first to third layers (for example, Patent Document 1). In this organic electroluminescence element, the first layer and the third layer are constituted by oxide thin film layers, and the second layer is constituted by a layer made of a metal thin film selected from Au, Ag, Cu, Pd and Pt. Yes. However, the organic electroluminescence element described in Patent Document 1 has a problem that the light emission efficiency is not always sufficient.

  Further, the transparent electrode has a higher electrical resistance than an opaque electrode made of a metal film or the like. In a display device or lighting device using an organic electroluminescence element, a transparent electrode having a large area is required as the light emitting area increases. When a transparent electrode having a large area is used, a voltage drop due to a high wiring resistance becomes large, and there is a problem that unevenness in light emission luminance due to the voltage drop becomes so large that it cannot be ignored.

  In order to solve the problem caused by the voltage drop of the transparent electrode, a planar light emitting device including an organic electroluminescence element in which an auxiliary electrode having a lower resistance than the transparent electrode is electrically connected to the transparent electrode is disclosed (for example, Patent Document 2). In this planar light emitting device, the auxiliary electrode is thickened at a portion near a connection terminal connected to a power source, and the auxiliary electrode is thinned at a portion far from the connecting terminal. In the area close to the connection terminal, the current value is high and the emission intensity is strong because of the thick auxiliary electrode, while the aperture ratio is small, and in the area far from the connection terminal, the current value is small due to the thin auxiliary electrode and light is emitted. While the strength is weak, the aperture ratio increases, and thus a planar light emitting device that suppresses unevenness in the overall light emission luminance is realized.

  In order to solve the problem caused by the voltage drop of the transparent electrode, a planar light emitting device including an organic electroluminescence element in which an auxiliary electrode having a lower resistance than the transparent electrode is electrically connected to the transparent electrode is disclosed (for example, Patent Document 2). In this planar light emitting device, the auxiliary electrode is thickened at a portion near a connection terminal connected to a power source, and the auxiliary electrode is thinned at a portion far from the connecting terminal. In the area close to the connection terminal, the current value is high and the emission intensity is strong because of the thick auxiliary electrode, while the aperture ratio is small, and in the area far from the connection terminal, the current value is small due to the thin auxiliary electrode and light is emitted. While the strength is weak, the aperture ratio increases, and thus a planar light emitting device that suppresses unevenness in the overall light emission luminance is realized.

  However, even when an organic electroluminescence element as described in Patent Document 2 is used, the current value becomes small at a portion far from the connection terminal, and thus unevenness in emission luminance cannot be sufficiently suppressed. . Moreover, since unevenness in light emission luminance is suppressed by adjusting the aperture ratio, there is a problem that the light use efficiency is lowered.

JP 2004-79422 A Japanese Patent Laid-Open No. 2004-14128

  The present invention has been made in view of the above-described problems of the prior art, and the problem is that even when the light emission area is large, unevenness in light emission luminance is sufficiently suppressed, and uniform light emission is possible, and the light emission efficiency is excellent. An organic electroluminescence element, an illumination device using the organic electroluminescence element, a planar light source, and a display device are provided.

  In order to solve the above-described problems, an organic electroluminescence element having a first configuration according to the present invention includes a first electrode that is one of an anode and a cathode, and the other of the anode and the cathode. A transparent second electrode that is an electrode, an electric resistance lower than that of the second electrode, and an auxiliary electrode that is provided in contact with the second electrode, and is disposed between the first electrode and the second electrode The transparent second electrode is composed of a three-layer laminate in which the first layer, the second layer, and the third layer are arranged in this order from the light emitting layer side, and the first layer is a metal A material selected from the group consisting of metal oxides, metal fluorides, and mixtures thereof, wherein the second layer includes a metal selected from the group consisting of calcium, aluminum, magnesium, and mixtures thereof; Possible for the third layer The light transmittance is 40% or more, and the auxiliary electrode is disposed within a frame-shaped first auxiliary electrode and a frame of the first auxiliary electrode, and is electrically connected to the first auxiliary electrode. And a second auxiliary electrode having a narrower line width than the first auxiliary electrode.

  In the above configuration, the first layer includes at least one of a metal oxide and a metal fluoride, and the material included in the second layer is a reducing agent for the material included in the first layer. Also good.

  In the above configuration, the first layer may include a metal, and the material included in the second layer may be a reducing agent for the metal oxide included in the first layer.

  An organic electroluminescence device having a second configuration according to the present invention includes a first electrode which is one of an anode and a cathode, and a transparent first electrode which is the other of the anode and the cathode. Two electrodes, an auxiliary electrode that has a lower electrical resistance than the second electrode and is provided in contact with the second electrode, and a light-emitting layer disposed between the first electrode and the second electrode. The transparent second electrode is composed of a three-layer laminate in which the first layer, the second layer, and the third layer are arranged in this order from the light emitting layer side, and the material contained in the second layer is the first layer. The material included in the layer has a reducing action, the visible light transmittance of the third layer is 40% or more, the auxiliary electrode includes a frame-shaped first auxiliary electrode, and the first auxiliary electrode And is electrically connected to the first auxiliary electrode, A second auxiliary electrode line width narrower than the auxiliary electrode, characterized by having a.

  In the above configuration, the first layer may include a material selected from the group consisting of a metal, a metal oxide, a metal fluoride, and a mixture thereof.

  In the above configuration, the second layer may include a metal selected from the group consisting of calcium, aluminum, magnesium, and a mixture thereof.

  In the organic electroluminescence device having the first and second configurations, the first layer includes an alkali metal, an alkaline earth metal, an alkali metal oxide, an alkaline earth metal oxide, an alkali metal fluoride, an alkali. It may comprise a material selected from the group consisting of earth metal fluorides and mixtures thereof.

  In the above configuration, the first layer may include a material selected from the group consisting of barium, barium oxide, barium fluoride, and a mixture thereof.

  In the above configuration, the first layer may include a material selected from the group consisting of sodium, sodium oxide, sodium fluoride, and a mixture thereof.

  In the above configuration, the first layer may include a material selected from the group consisting of rubidium, rubidium oxide, rubidium fluoride, and a mixture thereof.

  In any one of the above-described configurations, the third layer is made of a material selected from the group consisting of gold, silver, copper, tin, lead, nickel, indium, and alloys thereof, and the thickness of the third layer is It is preferably 5 nm or more and 30 nm or less.

  In any one of the configurations described above, it is preferable that the reflectance of the first electrode with respect to visible light is 80% or more.

  In any one of the configurations described above, it is preferable that a value obtained by dividing the line width of the second auxiliary electrode by the line width of the first auxiliary electrode is 1/1000 to 1/10.

  The illuminating device of this invention is equipped with the said organic electroluminescent element, It is characterized by the above-mentioned. Moreover, the planar light source of the present invention comprises the organic electroluminescence element. Furthermore, the display device of the present invention is characterized by comprising the organic electroluminescence element.

  In the organic electroluminescent element of the present invention, the transparent second electrode is composed of a three-layered structure in which the first layer, the second layer, and the third layer are arranged in this order from the light emitting layer side. The layer comprises a material selected from the group consisting of metals, metal oxides, metal fluorides, and mixtures thereof, and the second layer is a metal selected from the group consisting of calcium, aluminum, magnesium, and mixtures thereof The visible light transmittance of the third layer is 40% or more, or the transparent second electrode is arranged in the order of the first layer, the second layer, and the third layer from the light emitting layer side. It consists of a three-layer laminate, and the material contained in the second layer has a reducing action on the material contained in the first layer, and the visible light transmittance of the third layer is 40% or more. . With such a characteristic configuration, the organic electroluminescent element of the present invention can have high luminous efficiency by increasing the aperture ratio, and can be easily made into a top emission type element and device, and a good image can be obtained. Can be obtained, and the luminance half-life is also increased.

  In addition, according to the organic electroluminescence element of the present invention, since the auxiliary electrode made of a material having a lower electrical resistance value than the transparent electrode is provided in contact with the transparent electrode, the voltage due to the resistance of the transparent electrode Even when the light emission area is wide, the unevenness of the light emission luminance is sufficiently suppressed and uniform light emission is possible.

  That is, in the organic electroluminescent element of the present invention, more specifically, the frame-shaped first auxiliary electrode and the frame of the first auxiliary electrode are disposed on the surface of the second electrode made of a transparent electrode. And a second auxiliary electrode that is electrically connected to the first auxiliary electrode and has a narrower line width than the first auxiliary electrode. In addition to the second electrode, by providing such an auxiliary electrode having an electric resistance lower than that of the transparent electrode (first electrode), a voltage drop due to the resistance of the second electrode can be reduced.

In the present invention, since the first auxiliary electrode has a wide line width and can pass a sufficient current, even the portion far from the connection terminal is hardly affected by the voltage drop due to the wiring resistance.
In addition, since the second auxiliary electrode has a narrow line width, the second auxiliary electrode has a small amount of blocking light emitted from the organic layer, and has little influence on the light use efficiency. The second auxiliary electrode is easily affected by a voltage drop due to wiring resistance due to its narrow line width. In the present invention, the second auxiliary electrode is disposed within the frame of the first auxiliary electrode. In addition, since it has an electrical connection structure in which it is electrically connected to the first auxiliary electrode that is hardly affected by the voltage drop due to the wiring resistance, the wiring resistance even in the auxiliary electrode far from the connection terminal The voltage drop due to is reduced.

  Therefore, according to the organic electroluminescent element of the present invention, the voltage drop due to the resistance of the transparent electrode is reduced, and even when the light emitting area is wide, unevenness in the light emission luminance is sufficiently suppressed, and uniform light emission is possible.

As described above, according to the present invention, the luminous efficiency can be increased by increasing the aperture ratio, and a top-emission type element and device can be easily obtained. Can be obtained, and an organic electroluminescence device having a long luminance half-life can be provided. According to the present invention, it is possible to provide an organic electroluminescence device capable of reducing the voltage drop due to the resistance of the transparent electrode, sufficiently suppressing unevenness in light emission luminance even when the light emission area is large, and capable of uniform light emission. It becomes.
Therefore, the organic electroluminescence element of the present invention can be preferably used as a display device such as a lighting device, a planar light source as a backlight, and a flat panel display.

  Hereinafter, the organic electroluminescence element of the present invention will be described in detail in accordance with preferred embodiments thereof. Note that the scale of each member in the drawings shown in the following description may differ from the actual scale.

  The organic electroluminescence device according to the present invention includes a first electrode that is one of an anode and a cathode, a transparent second electrode that is the other of the anode and the cathode, and the second electrode. An auxiliary electrode having an electrical resistance lower than that of the electrode and provided in contact with the second electrode; and a light emitting layer disposed between the first electrode and the second electrode, wherein the transparent second electrode comprises: It consists of a laminate of three layers arranged in the order of the first layer, the second layer and the third layer from the light emitting layer side, and the first layer is made of metal, metal oxide, metal fluoride, and a mixture thereof. A material selected from the group, the second layer includes a metal selected from the group consisting of calcium, aluminum, magnesium, and mixtures thereof, and the visible light transmittance of the third layer is 40%. And the above The auxiliary electrode is disposed within the frame-shaped first auxiliary electrode and the frame of the first auxiliary electrode, and is electrically connected to the first auxiliary electrode, and the line width is narrower than the first auxiliary electrode. And a second auxiliary electrode.

  In addition, another organic electroluminescence device according to the present invention includes a first electrode that is one of an anode and a cathode, and a transparent second electrode that is the other of the anode and the cathode. And an auxiliary electrode provided in contact with the second electrode, and a light emitting layer disposed between the first electrode and the second electrode, wherein the transparent first electrode The two electrodes are composed of a three-layer laminate in which the first layer, the second layer, and the third layer are arranged in this order from the light emitting layer side, and the material included in the second layer is included in the first layer The third layer has a visible light transmittance of 40% or more, and the auxiliary electrode is disposed in a frame-shaped first auxiliary electrode and the frame of the first auxiliary electrode. And is electrically connected to the first auxiliary electrode and connected to the first auxiliary electrode. Is characterized by also having a second auxiliary electrode line width is narrow, the.

  An organic electroluminescence device according to an embodiment of the present invention having such a basic configuration is shown in FIG. In the following description, one side in the thickness direction of the support substrate 1 may be referred to as upper (or upper), and the other in the thickness direction of the support substrate 1 may be referred to as lower (or lower). The notation of this hierarchical relationship is set for convenience of explanation, and is not necessarily applied to the process and the situation where the organic electroluminescence element is actually manufactured.

An anode (first electrode) 5 is disposed on the support substrate 1. A light emitting unit 6 is disposed on the anode (first electrode) 5, and a transparent cathode (second electrode) 7 is disposed thereon. The transparent second electrode 7 is composed of a three-layer laminate. The three-layer laminate includes three layers, a first layer 7a, a second layer 7b, and a third layer 7c, which are sequentially laminated from the light emitting unit 6 side.
Usually, a protective layer (sometimes referred to as an upper sealing film) 8 is provided in order to protect the light emitting function part including the anode 5, the light emitting part 6 and the cathode 7 disposed on the support substrate 1. An auxiliary electrode 4 having a first auxiliary electrode 2 and a second auxiliary electrode 3 is formed on the surface of the transparent second electrode 7 on the protective layer 8 side. The light emitting unit 6 includes a light emitting layer 10, a layer 9 provided as needed between the anode (first electrode) 5 and the light emitting layer 10, and a space between the light emitting layer 10 and the cathode (second electrode) 7. It is comprised from the layer 11 provided as needed.
In the present embodiment, the first electrode 5 is an anode and the transparent second electrode 7 is a cathode. However, the order of stacking the light emitting function units is reversed, the first electrode is a cathode, and the second electrode You may comprise the organic EL element which is an anode.

  Below, the three-layer structure of the 2nd electrode 7 which is the characteristic structure of this invention is demonstrated first, and the auxiliary electrode provided in contact with the transparent 2nd electrode 7 is demonstrated after that. Thereafter, other components will be described.

(Second electrode)
In this embodiment, the 2nd electrode 7 is comprised from the laminated body of 3 layers. The three-layer laminate includes three layers, a first layer 7a, a second layer 7b, and a third layer 7c, which are sequentially laminated from the light emitting unit 6 side.

  In this embodiment, the first layer 7a of the second electrode 7 includes a material selected from the group consisting of metals, metal oxides, metal fluorides, and mixtures thereof, and the second layer 7b is calcium, aluminum, And a metal selected from the group consisting of magnesium and mixtures thereof. In this embodiment, the first layer 7a contains a metal oxide and / or a metal fluoride, and the material contained in the second layer 7b is a reducing agent for the material contained in the first layer 7a. Alternatively, it is preferable that the first layer 7a contains a metal, and the material contained in the second layer 7b is a reducing agent for the metal oxide contained in the first layer 7a.

  In still another embodiment of the present invention, the material of the second layer 7b of the second electrode 7 has a reducing action on the material of the first layer 7a. In this embodiment, the first layer 7a preferably includes a material selected from the group consisting of metals, metal oxides, metal fluorides, and mixtures thereof, and the second layer 7b includes calcium, aluminum, It is preferred to include a metal selected from the group consisting of magnesium and mixtures thereof.

  In the above embodiment, when the first layer 7a includes a material selected from the group consisting of metals, metal oxides, metal fluorides, and mixtures thereof, the first layer 7a is substantially composed of these materials. Layer. Of the metals, metal oxides, metal fluorides, and mixtures thereof, metals are preferred. Examples of the metal constituting the metal, metal oxide, metal fluoride, and mixture thereof contained in the first layer 7a include alkali metals and / or alkaline earth metals. More specifically, for example, lithium, sodium, potassium, rubidium, cesium, beryllium, magnesium, calcium, strontium, barium and the like can be mentioned, and barium, sodium and rubidium are particularly preferable. When the material which comprises the 2nd layer 7b contains calcium or magnesium, it is preferable that the metal which comprises the 1st layer 7a is a metal other than this.

  When the second layer 7b includes a metal selected from the group consisting of calcium, aluminum, magnesium, and mixtures thereof, the second layer 7b includes these metals, oxides of these metals, fluorides of these metals Or a layer consisting essentially of any of these mixtures. In particular, it is preferable to consist essentially only of these metals.

  The member A (for example, metal) “consists essentially of” means that other elements different from the member A mixed in the manufacturing process such as vapor deposition and the process of oxidation during use may be included. Specifically, the content ratio of the member A can be 90 mol% or more.

  When the material contained in the second layer 7b is a reducing agent for the material contained in the first layer 7a, the material contained in the second layer 7b is a reducing agent for the metal oxide contained in the first layer 7a. In the case where the material contained in the second layer 7b has a reducing action on the material contained in the first layer 7a, the presence / absence / degree of the reducing ability between the materials is, for example, the bond dissociation energy (ΔrH °) can be determined from. That is, in the reduction reaction of the material constituting the second layer 7b with respect to the material constituting the first layer 7a, when the combination is such that the bond dissociation energy is positive, the material of the second layer 7b is the first layer 7a. It can be said that this material has reducing ability.

The bond dissociation energy can be referred to, for example, in Electrochemical Handbook 5th Edition (Maruzen, 2000), Thermodynamic Database MALT (Science and Technology, 1992), and the like. For example, in the combination of LiF and Al,
3LiF + Al → 3Li + AlF ₃ , ΔrH ° = −36.28
Thus, since it is an endothermic reaction, Al does not have a reducing ability for LiF. Moreover, in the combination of LiF and Ca,
2LiF + Ca → 2Li + CaF ₂ , ΔrH ° = + 38.58
Since Ca is a heat dissipation reaction, Ca has a reducing ability for LiF.

Examples of combinations of materials of the first layer 7a and the second layer 7b when the material of the second layer 7b has a reducing ability with respect to the material of the first layer 7a are listed below. In the following formula, the left side material on the left side is the material of the first layer 7a, the right side material on the left side is the material of the second layer 7b, and the right side material on the left side is the reducing agent for the left side material on the left side. .
(1) 2BaO + Al → 2Ba + AlO ₂ , ΔrH ° = + 197.6
(2) BaO + Ca → Ba + CaO, ΔrH ° = + 172.4
(3) BaO + Mg → Ba + MgO, ΔrH ° = + 217.2
(4) BaF + Ca → Ba + CaF, ΔrH ° = + 55.2
(5) 2BaF + Ca → 2Ba + CaF ₂ , ΔrH ° = + 51.0
(6) BaF + Mg → Ba + MgF, ΔrH ° = + 135.9
(7) 2BaF + Mg → 2Ba + MgF ₂ , ΔrH ° = + 139.3
(8) 2LiF + Ca → 2Li + CaF ₂ , ΔrH ° = + 38.5
(9) CsF + Ca → Cs + CaF, ΔrH ° = + 14.7
(10) CsF + Ag → Cs + AgF, ΔrH ° = + 158.0
(11) Cs ₂ CO ₃ + Al → 2Cs + AlO + CO ₂ , ΔrH ° = + 303.0
(12) Cs ₂ CO ₃ + Ca → 2Cs + CaO + CO ₂ , ΔrH ° = + 431.6
(13) Cs ₂ CO ₃ + Ag → 2Cs + AgO + CO ₂ , ΔrH ° = + 595.4
(14) 2Na ₂ O + Al → 4Na + AlO ₂ , ΔrH ° = + 41.7
(15) 2Rb ₂ O + Al → 4Rb + AlO ₂ , ΔrH ° = + 41.7
(16) Rb ₂ O + Ca → 2Rb + CaO, ΔrH ° = + 94.4

In the present embodiment, when the material of the first layer 7a is substantially composed only of a metal that is not an oxide or fluoride, the material of the second layer 7b has a reducing action on the oxide of the metal. Or the material of the second layer 7b has a reducing action on the metal fluoride, or the material of the second layer 7b has a reducing action on both the metal oxide and the metal fluoride. In the present invention, this corresponds to the case where “the material of the second layer has a reducing action on the material of the first layer”. Even when the organic electroluminescence element is manufactured with the material of the first layer 7a substantially consisting of only metal, it is oxidized by a small amount of oxygen, moisture, etc. mixed in the first layer 7a during the manufacturing process. Product, fluoride, etc. may be generated. When the material of the second layer 7b has a reducing action on the oxide, fluoride, etc., the effect of the present invention can be obtained. Therefore, the material of the second layer 7b preferably has a reducing action on both the metal oxide and the fluoride constituting the first layer 7a.
In this case, as listed above, calcium, aluminum, and magnesium can be suitably used as the material of the second layer 7b.

In the present embodiment, the third layer 7c constituting the second electrode 7 has a visible light transmittance of usually 40% or more, preferably 50% or more. By setting it as such visible light transmittance, the 2nd electrode 7 can be made into a transparent electrode.
The material constituting the third layer 7c is preferably selected from the group consisting of gold, silver, copper, tin, lead, nickel, indium, and alloys thereof.

  The thicknesses of the first layer 7a, the second layer 7b, and the third layer 7c constituting the second electrode 7 are not particularly limited, but are appropriately set particularly in view of the visible light transmittance. It is preferable that the thickness is 5 to 10 nm, the second layer 7b is 0.5 to 10 nm, and the third layer 7c is 5 to 30 nm. Further, the visible light transmittance of light passing through all layers of the second electrode 7 is preferably 40% or more in order to improve the optical characteristics of the organic electroluminescence element.

  As a method of forming the first layer 7a, the second layer 7b, and the third layer 7c, a vapor deposition method such as a vacuum vapor deposition method is preferable because damage to the light emitting layer and the like can be avoided. When forming the second electrode by the vacuum deposition method, the substrate is placed in the chamber of the vacuum deposition apparatus to reduce the pressure and maintain the vacuum from the viewpoint of ease of operation and prevention of quality deterioration due to contamination with foreign matter. The first layer 7a, the second layer 7b, and the third layer 7c are preferably formed in succession.

Further, for the purpose of improving the light transmittance of the second electrode 7, an antireflection layer can be provided after the auxiliary electrode 4 described later is provided on the third layer 7 c of the second electrode 7. Preferably having a refractive index of about (n) is 1.8 to 3.0 as a material used for the antireflection layer, for example, ZnS, ZnSe, etc. WO ₃ and the like. The thickness of the antireflection layer varies depending on the combination of materials, but is usually in the range of 10 nm to 150 nm.
For example, when the second electrode 7 has a structure in which Ba is 5 nm for the first layer 7 a, Al is 1 nm for the second layer 7 b, and Ag is 15 nm for the third layer 7 c, the auxiliary electrode is formed on the third layer 7 c. 4, when WO ₃ is laminated to a thickness of 21 nm as an antireflection layer, the light transmittance from the light emitting layer 10 side is improved by 10%.

(Auxiliary electrode)
In the organic electroluminescence element of this embodiment, the auxiliary electrode 4 is arranged on the surface of the anode (first electrode) 5 and is a frame-shaped first auxiliary electrode electrically connected to the first electrode. 2 and a second auxiliary electrode 3 disposed within the frame of the first auxiliary electrode 2 and electrically connected to the first auxiliary electrode 2 and having a line width narrower than that of the first auxiliary electrode 2. Prepare.
In the present embodiment, the first auxiliary electrode 2 and the second auxiliary electrode 3 are arranged on the surface of the second electrode 7 in the above-described manner, so that even when the light emitting area of the organic electroluminescence element is large, light emission is performed. Brightness unevenness can be sufficiently suppressed. Further, for example, in an active matrix display device, a transparent cathode common to a plurality of organic electroluminescence elements can be constituted by one second electrode 7. Even when the light emitting area of each organic electroluminescence element is small, the influence of the voltage drop of the second electrode 7 can be reduced by the auxiliary electrode 4, and the luminance unevenness between the pixels can be suppressed.

  An example of the arrangement form of the auxiliary electrode 4 composed of the first auxiliary electrode 2 and the second auxiliary electrode 3 is shown in FIGS.

  In the arrangement form shown in FIG. 2, the auxiliary electrode 4 formed on the third layer 7c of the second electrode 7 is arranged within a rectangular frame-shaped first auxiliary electrode 2a and the frame of the first auxiliary electrode 2a. The second auxiliary electrode 3a is formed integrally with the first auxiliary electrode 2a. The second auxiliary electrode 3a has a narrower line width than the first auxiliary electrode 2a, and the plurality of second auxiliary electrodes 3a are arranged in a lattice shape intersecting at right angles to each other.

  In the arrangement form shown in FIG. 3, the auxiliary electrode 4 formed on the third layer 7c of the second electrode 7 is arranged within a rectangular frame-shaped first auxiliary electrode 2b and the frame of the first auxiliary electrode 2b. In addition, the second auxiliary electrode 3b is formed integrally with the first auxiliary electrode 2a. The second auxiliary electrode 3b has a narrower line width than the first auxiliary electrode 2b, and the plurality of second auxiliary electrodes 3b are arranged in parallel to each other.

  In the arrangement form shown in FIG. 4, the auxiliary electrode 4 formed on the third layer 7c of the second electrode 7 is arranged in a rectangular frame-shaped first auxiliary electrode 2c and the frame of the first auxiliary electrode 2c. In addition, the second auxiliary electrode 3c is formed integrally with the first auxiliary electrode 2a. The second auxiliary electrode 3c has a narrower line width than the first auxiliary electrode 2c, and each of the plurality of second auxiliary electrodes 3c is arranged so as to constitute each side of each hexagon of the honeycomb structure.

  In the arrangement form shown in FIG. 5, the auxiliary electrode 4 formed on the third layer 7c of the second electrode 7 is arranged in a rectangular frame-shaped first auxiliary electrode 2d and the frame of the first auxiliary electrode 2d. In addition, the second auxiliary electrode 3d is formed integrally with the first auxiliary electrode 2a. The second auxiliary electrode 3d is composed of two types of fine line electrodes whose line width is narrower than that of the first auxiliary electrode 2d. That is, the second auxiliary electrode 3d includes a plurality of main thin-line electrodes 3d-1 intersecting at right angles to each other and the inside of the region surrounded by the first thin-line electrodes 3d-1, It consists of a second thin wire electrode 3d-2 formed inside a region surrounded by the first auxiliary electrode 2d and the first thin wire electrode 3d-1.

In the arrangement form shown in FIG. 5, the first thin wire electrodes 3d-1 are arranged in a lattice shape, and a plurality of second thin wire electrodes 3d-2 are arranged in a lattice shape in each lattice-shaped frame. . The second thin wire electrode 3d-2 is usually preferably formed to be thinner than the first thin wire electrode 3d-1.
By taking such an arrangement form of the auxiliary electrodes, the effect of the present invention can be obtained even in an element having a larger light emitting area.

  Here, the frame shape of the frame-shaped first auxiliary electrode 2 is not particularly limited as long as the second auxiliary electrode 3 can be formed in the frame of the first auxiliary electrode 2. A circular shape or the like is possible. The first auxiliary electrode 2 is preferably provided so as to surround a main region through which light is transmitted. The line width of the first auxiliary electrode 2 can be appropriately selected according to the electric resistance and the light emitting area of the organic electroluminescence element, and is preferably in the range of 1 to 50 mm, and more preferably in the range of 3 to 20 mm. More preferred.

  Since the inside of the frame of the first auxiliary electrode 2 where the second auxiliary electrode 3 is provided is a main region through which light from the light emitting unit 6 is transmitted, the line width of the second auxiliary electrode 3 does not hinder the transmission of light. Such dimensions are preferred. From this point of view, the line width of the thin wire electrode constituting the second auxiliary electrode 3 (hereinafter referred to as “line width of the second auxiliary electrode”) is in the range of 1 to 200 μm from the viewpoint of light utilization efficiency. Preferably, it is in the range of 10 to 100 μm.

  In the first embodiment, the value obtained by dividing the line width of the second auxiliary electrode by the line width of the first auxiliary electrode is more preferably 1/1000 to 1/10. If the ratio of the line widths is within the above range, the light utilization efficiency is further improved, and unevenness in the light emission luminance tends to be further suppressed.

The material of the first auxiliary electrode 2 and the second auxiliary electrode 3 is preferably higher in electrical conductivity (lower electrical resistance value) than the transparent second electrode 7, and is usually 10 ⁷ S / cm or more. A conductive material having conductivity is used. Specific examples of such a conductive material include metal materials such as aluminum, silver, chromium, gold, copper, and tantalum. Among these, aluminum, chromium, copper, and silver are more preferable from the viewpoint of high electrical conductivity and ease of material handling.

  The area where the auxiliary electrode 4 composed of the first auxiliary electrode 2 and the second auxiliary electrode 3 is in contact with the third layer 7c of the second electrode 7 is wider if it is wide for the purpose of reducing the voltage drop due to the resistance of the first electrode 5. Moderately good. Therefore, when a metal is used as the material of the first auxiliary electrode 2 and the second auxiliary electrode 3, the auxiliary electrode 4 becomes the second electrode when converted to the ratio of the area covered by the auxiliary electrode 4 to the light emitting area of the element. 7 is preferably at least 20%, more preferably 30% or more, in contact with the third layer 7c.

  On the other hand, since the auxiliary electrode 4 is provided in contact with the transparent second electrode 7 that transmits the light from the light emitting portion 6, it is preferable that the area occupied by the auxiliary electrode 4 is as small as possible so as not to block the light as much as possible. From this point of view, the ratio of the area covered by the auxiliary electrode 4 to the light emitting area of the element is preferably 90% or less, and more preferably 80% or less.

  Taking these into consideration, the ratio of the area covered by the auxiliary electrode 4 to the light emitting area of the element is preferably 20% or more and 90% or less, preferably 30% or more and 80% or less. More preferred.

  Further, the thicknesses of the first auxiliary electrode 2 and the second auxiliary electrode 3 can be appropriately selected so that the sheet resistance has a desired value, and is, for example, 10 to 500 nm, preferably 20 to 300 nm. Yes, more preferably 50 to 150 nm.

  Furthermore, in the organic electroluminescence element of the present embodiment, the first auxiliary electrode 2 and the second auxiliary electrode 3 are surfaces of the transparent second electrode 7 on the light emitting unit 6 side (first layer). 7a) may be arranged, but from the viewpoint of ensuring the electrical connection between the transparent second electrode 7 and the first auxiliary electrode 2 and the second auxiliary electrode 3, light emission It is preferable to be disposed on the surface opposite to the portion 6.

  As a method of forming the first auxiliary electrode 2 and the second auxiliary electrode 3, for example, after forming a film made of the constituent material of the auxiliary electrode by a vacuum deposition method, a sputtering method, or a laminating method in which a metal thin film is thermocompression bonded. And a method of forming a pattern by an etching method using a photoresist. Note that the auxiliary electrode can be patterned without etching. For example, the auxiliary electrode having a predetermined pattern can be formed by performing vacuum vapor deposition a plurality of times using one or a plurality of masks in which openings corresponding to the shape of the auxiliary electrode are formed. Depending on the material constituting the second electrode, the second electrode may be damaged by the etchant. However, by forming the auxiliary electrode using a mask, the auxiliary electrode can be applied to the second electrode having low resistance to the etchant. Can be formed.

As described above, the organic electroluminescence element of the present embodiment is characterized in that the transparent second electrode 7 has a three-layer structure, and an auxiliary electrode having a specific shape while being electrically connected to the transparent second electrode. 4 is arranged. The details of the transparent second electrode 7 having a three-layer structure and the auxiliary electrode 4 are as described above.
Subsequently, components of the organic electroluminescence element other than the second electrode 7 and the auxiliary electrode 4 will be described in detail below.

(substrate)
The support substrate 1 may be any substrate that does not change in the step of forming the organic electroluminescence element, that is, any substrate that does not change when the electrode is formed and the organic layer is formed, and may be a rigid substrate or a flexible substrate. For example, a glass plate, a plastic plate, a polymer film and a silicon plate, and a laminated plate obtained by laminating these are preferably used. Further, a plastic, a polymer film or the like that has been subjected to a low water permeability treatment can also be used. A commercially available substrate can be used as the substrate. Moreover, the said board | substrate can also be manufactured by a well-known method.

  When the organic electroluminescence element of the present embodiment constitutes a pixel of a display device, a circuit for driving a pixel may be provided on the substrate 1, or a planarizing film is provided on the drive circuit. It may be. When a planarizing film is provided, it is preferable that the average roughness (Ra) on the center line of the planarizing film satisfies Ra <10 nm.

(First electrode)
In the present embodiment, the first electrode 5 is usually provided on the substrate 1 directly or via another layer as necessary. The first electrode 5 is usually provided as a reflective electrode that reflects light from the light emitting layer 10 toward the second electrode 7. The first electrode 5 is preferably provided connected to a circuit for an active matrix driving method. For example, the first electrode may be formed on a TFT substrate on which an active matrix driving circuit is formed.

  The first electrode 5 preferably has a reflectance with respect to visible light of 80% or more. By having such a reflectance, it can be advantageously used as a reflective electrode in a top emission type display element.

  The first electrode 5 is preferably provided as an anode. From the viewpoint of the ability to supply holes to organic semiconductor materials used in an interlayer such as a hole injection layer and a hole transport layer described later, and a light emitting layer, the work function of the surface of the first electrode 5 on the light emitting layer 10 side is used. Is preferably 4.0 eV or more.

  As such a material for the first electrode, a material having a small work function and easy electron injection into the light emitting layer and / or a material having a high electric conductivity and / or a material having a high visible light reflectivity are preferable. Specific examples of such cathode materials include metals, metal oxides, alloys, graphite or graphite intercalation compounds, and inorganic semiconductors such as zinc oxide (ZnO).

  As the metal, an alkali metal, an alkaline earth metal, a transition metal, a group 13 metal of the periodic table, or the like can be used. Specific examples of these metals include lithium, sodium, potassium, rubidium, cesium, beryllium, magnesium, calcium, strontium, barium, gold, silver, platinum, copper, manganese, titanium, cobalt, nickel, tungsten, tin, and aluminum. , Scandium, vanadium, zinc, yttrium, indium, cerium, samarium, europium, terbium, ytterbium, and the like.

  Examples of the alloy include an alloy containing at least one of the above metals. Specifically, a magnesium-silver alloy, a magnesium-indium alloy, a magnesium-aluminum alloy, an indium-silver alloy, a lithium-aluminum alloy, Examples thereof include a lithium-magnesium alloy, a lithium-indium alloy, and a calcium-aluminum alloy.

  The first electrode 5 is made transparent as necessary, and examples thereof include indium oxide, zinc oxide, tin oxide, ITO (Indium Tin Oxide), and IZO (Indium Zinc Oxide). Conductive oxides such as zinc oxide); conductive organic substances such as polyaniline or derivatives thereof, polythiophene or derivatives thereof.

  Note that the first electrode 5 may have a laminated structure of two or more layers. The film thickness of the first electrode 5 can be appropriately selected in consideration of electrical conductivity and durability, but is, for example, 10 nm to 10 μm, preferably 20 nm to 1 μm, and more preferably 50 nm to 500 nm.

  Further, when the first electrode 5 is provided as a reflecting electrode and an anode, a multilayer structure in which a light reflecting layer made of a highly light reflecting metal and a high work function material layer made of a material having a work function of 4.0 eV or more are combined. preferable.

As specific examples of the configuration of the first electrode, the following (1) to (15) can be exemplified.
(1) Al
(2) Ag
(3) Ag-MoO ₃
(4) Alloy of Ag, Pd and Cu-ITO
(5) Alloy of Al and Nd-ITO
(6) Alloy of Mo and Cr-ITO
(7) Cr-Al-Cr-ITO
(8) Cr-Ag-Cr-ITO
(9) Cr—Ag—Cr—ITO—MoO ₃
(10) Ag—Pd—Cu alloy—IZO
(11) Al-Nd alloy-IZO
(12) Alloy of Mo and Cr-IZO
(13) Cr-Al-Cr-IZO
(14) Cr-Ag-Cr-IZO
(15) Cr—Ag—Cr—IZO—MoO ₃
In addition, in the description of said (3)-(15), symbol "-" represents the interface between each lamination | stacking, and the left side of description is a board | substrate side. In order to obtain a sufficient light reflectance, the film thickness of the highly light-reflective metal layer such as Al, Ag, Al alloy, or Ag alloy is preferably 50 nm or more, and more preferably 80 nm or more. The film thickness of the high work function material layer such as ITO or IZO is usually in the range of 5 nm to 500 nm.

Further, from the viewpoint of preventing poor electrical connection such as short circuit, it is desirable that the center line average roughness (Ra) of the surface of the first electrode 5 on the light emitting layer 10 side satisfies Ra <5 nm, and more preferably Ra <. 2 nm.
Ra can be measured with reference to JIS-B0651 to JIS-B0656, JIS-B0671-1, etc. based on JIS-B0601-2001 of Japanese Industrial Standard JIS.

  Examples of the method for forming the first electrode 5 include a vacuum deposition method, a sputtering method, and a laminating method in which a metal thin film is thermocompression bonded.

(Layer provided between the anode and the light emitting layer)
In the present embodiment, examples of the layer 9 provided as necessary between the anode (first electrode 5) and the light emitting layer 10 include a hole injection layer, a hole transport layer, and an electron block layer.

The hole injection layer is a layer having a function of improving the hole injection efficiency from the anode (first electrode) 5.
The hole transport layer is a layer having a function of improving hole injection from an anode, a hole injection layer, or a hole transport layer closer to the anode.
The electron blocking layer is a layer having a function of blocking electron transport. In the case where the hole injection layer and / or the hole transport layer has a function of blocking electron transport, these layers may also serve as an electron blocking layer.
The fact that the electron blocking layer has a function of blocking electron transport makes it possible, for example, to produce an element that allows only electron current to flow and confirm the blocking effect by reducing the current value.

(Hole injection layer)
The hole injection layer can be provided between the anode and the hole transport layer or between the anode and the light emitting layer. As a material constituting the hole injection layer, a known material can be appropriately used, and there is no particular limitation. For example, phenylamine, starburst amine, phthalocyanine, hydrazone derivative, carbazole derivative, triazole derivative, imidazole derivative, oxadiazole derivative having amino group, vanadium oxide, tantalum oxide, tungsten oxide, molybdenum oxide, ruthenium oxide And oxides such as aluminum oxide, amorphous carbon, polyaniline, polythiophene derivatives, and the like.

  As a film formation method of the hole injection layer, for example, film formation from a solution containing a material (hole injection material) that becomes the hole injection layer can be mentioned. The solvent used for film formation from a solution is not particularly limited as long as it dissolves the hole injection material. Chlorine solvents such as chloroform, methylene chloride and dichloroethane, ether solvents such as tetrahydrofuran, toluene, Mention may be made of aromatic hydrocarbon solvents such as xylene, ketone solvents such as acetone and methyl ethyl ketone, ester solvents such as ethyl acetate, butyl acetate and ethyl cellosolve acetate, and water.

  As a film forming method from a solution, a spin coating method, a casting method, a micro gravure coating method, a gravure coating method, a bar coating method, a roll coating method, a wire bar coating method, a dip coating method, a spray coating method, a screen printing method, Examples of the application method include a flexographic printing method, an offset printing method, and an ink jet printing method.

  The thickness of the hole injection layer is preferably about 5 to 300 nm. If the thickness is less than 5 nm, the production tends to be difficult. On the other hand, if the thickness exceeds 300 nm, the driving voltage and the voltage applied to the hole injection layer tend to increase.

(Hole transport layer)
The material constituting the hole transport layer is not particularly limited. For example, N, N′-diphenyl-N, N′-di (3-methylphenyl) 4,4′-diaminobiphenyl (TPD), 4 , 4′-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (NPB) and other aromatic amine derivatives, polyvinylcarbazole or derivatives thereof, polysilane or derivatives thereof, aromatic amines in the side chain or main chain Polysiloxane derivative having pyrazole, pyrazoline derivative, arylamine derivative, stilbene derivative, triphenyldiamine derivative, polyaniline or derivative thereof, polythiophene or derivative thereof, polyarylamine or derivative thereof, polypyrrole or derivative thereof, poly (p-phenylene vinylene) Or its derivatives, or poly (2,5-thienylene vinylene) or a derivative thereof is exemplified.

  Among these, as the hole transport material used for the hole transport layer, polyvinyl carbazole or a derivative thereof, polysilane or a derivative thereof, a polysiloxane derivative having an aromatic amine compound group in a side chain or a main chain, polyaniline or a derivative thereof, Polymeric hole transport materials such as polythiophene or derivatives thereof, polyarylamine or derivatives thereof, poly (p-phenylene vinylene) or derivatives thereof, or poly (2,5-thienylene vinylene) or derivatives thereof are preferred, and more preferred Is polyvinyl carbazole or a derivative thereof, polysilane or a derivative thereof, and a polysiloxane derivative having an aromatic amine in the side chain or main chain. In the case of a low-molecular hole transport material, it is preferably used by being dispersed in a polymer binder.

  The aromatic amine compound is preferably a tertiary amine, and specifically includes a compound containing a repeating unit represented by the following general formula (1).

式中、Ａｒ^１、Ａｒ^２、Ａｒ^３及びＡｒ^４は、それぞれ独立に、置換基を有していてもよいアリーレン基または置換基を有していてもよい２価の複素環基を表し、Ａｒ^５、Ａｒ^６及びＡｒ^７は置換基を有していてもよいアリール基または置換基を有していてもよい１価の複素環基を表し、ｎ及びｍはそれぞれ独立に、０又は１を表し、０≦ｎ＋ｍ≦２である。

In the formula, Ar ¹ , Ar ² , Ar ³ and Ar ⁴ each independently represent an arylene group which may have a substituent or a divalent heterocyclic group which may have a substituent, Ar ⁵ , Ar ⁶ and Ar ⁷ represent an aryl group which may have a substituent or a monovalent heterocyclic group which may have a substituent, and n and m are each independently 0 or 1 And 0 ≦ n + m ≦ 2.

  In formula (1), the hydrogen atom on the aromatic ring is a halogen atom, alkyl group, alkyloxy group, alkylthio group, aryl group, aryloxy group, arylthio group, arylalkyl group, arylalkyloxy group, arylalkylthio group, alkenyl. Group, alkynyl group, arylalkenyl group, arylalkynyl group, acyl group, acyloxy group, amide group, acid imide group, imine residue, substituted amino group, substituted silyl group, substituted silyloxy group, substituted silylthio group, substituted silylamino group, Selected from cyano group, nitro group, monovalent heterocyclic group, heteroaryloxy group, heteroarylthio group, alkyloxycarbonyl group, aryloxycarbonyl group, arylalkyloxycarbonyl group, heteroaryloxycarbonyl group and carboxyl group Be It may be substituted by a substituent.

  Substituents include vinyl, acetylene, butenyl, acrylic, acrylate, acrylamide, methacryl, methacrylate, methacrylamide, vinyl ether, vinylamino, silanol, and small rings (for example, cyclo A propyl group, a cyclobutyl group, an epoxy group, an oxetane group, a diketene group, an episulfide group, etc.), a lactone group, a lactam group, or a cross-linking group such as a group containing a structure of a siloxane derivative. In addition to the above groups, combinations of groups capable of forming an ester bond or an amide bond (for example, an ester group and an amino group, an ester group and a hydroxyl group, etc.) can be used as a crosslinking group.

In addition, as an aromatic amine compound which comprises a positive hole transport layer, in the repeating unit represented by the said General formula (1), Ar < ² > and Ar < ³ > are direct or bivalent, such as -O- and -S-. It may be a compound containing a repeating unit having a structure bonded via the group.

Examples of the arylene group include a phenylene group, and examples of the divalent heterocyclic group include a pyridinediyl group. These groups may have a substituent.
Examples of the aryl group include a phenyl group and a naphthyl group, and examples of the monovalent heterocyclic group include a pyridyl group. These groups may have a substituent.

The polymer containing the repeating unit containing the structure of the aromatic tertiary amine compound may further have another repeating unit. Other repeating units include arylene groups such as a phenylene group and a fluorenediyl group.
Of these polymers, those containing a crosslinking group are more preferred.

  The method for forming the hole transport layer is not particularly limited, but in the case of a low molecular hole transport material, film formation from a mixed solution containing a polymer binder and a hole transport material can be exemplified. Examples of molecular hole transport materials include film formation from a solution containing a hole transport material.

The solvent used for film formation from a solution is not particularly limited as long as it dissolves the hole transport material, and is a chlorine-based solvent such as chloroform, methylene chloride, dichloroethane, an ether-based solvent such as tetrahydrofuran, toluene, Examples thereof include aromatic hydrocarbon solvents such as xylene, ketone solvents such as acetone and methyl ethyl ketone, and ester solvents such as ethyl acetate, butyl acetate, and ethyl cellosolve acetate.
Examples of the film forming method from a solution include the same coating method as the above-described film forming method of the hole injection layer.

  As the polymer binder to be mixed, those that do not extremely inhibit charge transport are preferable, and those that weakly absorb visible light are preferably used. For example, polycarbonate, polyacrylate, polymethyl acrylate, polymethyl methacrylate, polystyrene, poly Examples thereof include vinyl chloride and polysiloxane.

  The thickness of the hole transport layer is not particularly limited, but can be appropriately changed according to the intended design, and is preferably about 1 to 1000 nm. If the thickness is less than the lower limit value, production tends to be difficult or the effect of hole transport is not sufficiently obtained. On the other hand, if the thickness exceeds the upper limit value, the driving voltage and the hole transport layer are increased. There is a tendency that the voltage applied to is increased. Therefore, the thickness of the hole transport layer is preferably 1 to 1000 nm as described above, more preferably 2 nm to 500 nm, and still more preferably 5 nm to 200 nm.

(Light emitting layer)
The light emitting layer 10 usually includes an organic material that mainly emits fluorescence or phosphorescence. The light emitting layer 10 contains a low molecular compound and / or a high molecular compound as an organic substance. Further, a dopant material may be included. Examples of the material for forming the light emitting layer that can be used in this embodiment include the following. A plurality of light emitting layers may be arranged between the anode 5 and the cathode 7 without being limited to a single light emitting layer.

(Dye material)
Examples of dye-based materials include cyclopentamine derivatives, tetraphenylbutadiene derivative compounds, triphenylamine derivatives, oxadiazole derivatives, quinacridone derivatives, coumarin derivatives, pyrazoloquinoline derivatives, distyrylbenzene derivatives, distyrylarylene derivatives, Examples include pyrrole derivatives, thiophene ring compounds, pyridine ring compounds, perinone derivatives, perylene derivatives, oligothiophene derivatives, trifumanylamine derivatives, oxadiazole dimers, and pyrazoline dimers.

(Metal complex materials)
Examples of the metal complex material include metal complexes that emit light from triplet excited states such as iridium complexes and platinum complexes, aluminum quinolinol complexes, benzoquinolinol beryllium complexes, benzoxazolyl zinc complexes, benzothiazole zinc complexes, azomethyls. Zinc complex, porphyrin zinc complex, europium complex, etc., which has Al, Zn, Be, etc. as the central metal or rare earth metals such as Tb, Eu, Dy, etc., and oxadiazole, thiadiazole, phenylpyridine, phenylbenzo as ligands Examples thereof include metal complexes having an imidazole or quinoline structure.

(Polymer material)
Polymeric materials include polyparaphenylene vinylene derivatives, polythiophene derivatives, polyparaphenylene derivatives, polysilane derivatives, polyacetylene derivatives, polyfluorene derivatives, polyvinylcarbazole derivatives, and polymerized chromophores and metal complex light emitting materials. Etc.

Among the light emitting materials, examples of the material that emits blue light include distyrylarylene derivatives, oxadiazole derivatives, and polymers thereof, polyvinylcarbazole derivatives, polyparaphenylene derivatives, and polyfluorene derivatives. Of these, polymer materials such as polyvinyl carbazole derivatives, polyparaphenylene derivatives, and polyfluorene derivatives are preferred.
Examples of materials that emit green light include quinacridone derivatives, coumarin derivatives, and polymers thereof, polyparaphenylene vinylene derivatives, polyfluorene derivatives, and the like. Of these, polymer materials such as polyparaphenylene vinylene derivatives and polyfluorene derivatives are preferred.
Examples of materials that emit red light include coumarin derivatives, thiophene ring compounds, and polymers thereof, polyparaphenylene vinylene derivatives, polythiophene derivatives, and polyfluorene derivatives. Among these, polymer materials such as polyparaphenylene vinylene derivatives, polythiophene derivatives, and polyfluorene derivatives are preferable.

(Dopant material)
A dopant can be added to the light emitting layer for the purpose of improving the light emission efficiency and changing the light emission wavelength. Examples of such dopants include perylene derivatives, coumarin derivatives, rubrene derivatives, quinacridone derivatives, squalium derivatives, porphyrin derivatives, styryl dyes, tetracene derivatives, pyrazolone derivatives, decacyclene, phenoxazone, and the like. In addition, the thickness of such a light emitting layer is about 20-2000 mm normally.

(Light-emitting layer deposition method)
As a method for forming a light emitting layer containing an organic substance, a method including applying a solution containing a light emitting material on the surface of the light emitting layer forming region, a method of depositing the surface of the light emitting layer forming region using a vacuum evaporation method, a predetermined method A method of applying a solution containing a light emitting material on a substrate, forming this coating film, and transferring the obtained film to the light emitting layer region can be used. Specific examples of the solvent used for the film formation from the solution include the same solvents as those for dissolving the hole transport material when forming the hole transport layer from the above solution.

  As a method of applying a solution containing a light emitting material on the surface of the light emitting layer forming region or on a substrate for forming a transfer film, a spin coating method, a casting method, a micro gravure coating method, a gravure coating method, Bar coating method, roll coating method, wire bar coating method, dip coating method, slit coating method, capillary coating method, spray coating method, nozzle coating method and other coating methods, gravure printing method, screen printing method, flexographic printing method, offset A coating method such as a printing method such as a printing method, a reverse printing method, and an ink jet printing method can be used. A printing method such as a gravure printing method, a screen printing method, a flexographic printing method, an offset printing method, a reversal printing method, and an ink jet printing method is preferable in that pattern formation and multi-coloring are easy. In the case of a sublimable low-molecular compound, a vacuum deposition method can be used. Furthermore, a method of forming a light emitting layer only at a desired place by laser transfer or thermal transfer can be used.

(Layer provided between the cathode and the light emitting layer)
A layer 11 such as an electron injection layer, an electron transport layer, or a hole blocking layer is laminated between the light emitting layer 10 and the second electrode (cathode) 7 as necessary.

When both the electron injection layer and the electron transport layer are provided between the cathode 7 and the light emitting layer 10, the layer in contact with the cathode is referred to as an electron injection layer, and the layers other than the electron injection layer are referred to as an electron transport layer. .
The electron injection layer is a layer having a function of improving electron injection efficiency from the cathode.
The electron transport layer is a layer having a function of improving electron injection from the cathode, the electron injection layer, or the electron transport layer closer to the cathode.
The hole blocking layer is a layer having a function of blocking hole transport. In the case where the electron injection layer and / or the electron transport layer have a function of blocking hole transport, these layers may also serve as the hole blocking layer.
The fact that the hole blocking layer has a function of blocking hole transport makes it possible, for example, to produce an element that allows only a hole current to flow, and confirm the blocking effect by reducing the current value.

(Electron injection layer)
As described above, the electron injection layer is provided between the electron transport layer and the second electrode 7 or between the light emitting layer 10 and the second electrode 7. Depending on the type of the light emitting layer 10, the electron injection layer may be an alkali metal, an alkaline earth metal, an alloy containing one or more of the metals, an oxide, halide and carbonate of the metal, A mixture etc. are mentioned.

  Examples of the alkali metal or its oxide, halide, carbonate include lithium, sodium, potassium, rubidium, cesium, lithium oxide, lithium fluoride, sodium oxide, sodium fluoride, potassium oxide, potassium fluoride, oxide Examples include rubidium, rubidium fluoride, cesium oxide, cesium fluoride, and lithium carbonate.

  Examples of the alkaline earth metals or oxides, halides and carbonates thereof include magnesium, calcium, barium, strontium, magnesium oxide, magnesium fluoride, calcium oxide, calcium fluoride, calcium fluoride, barium oxide, fluorine. Barium fluoride, strontium oxide, strontium fluoride, magnesium carbonate and the like.

  Furthermore, a metal, a metal oxide, an organometallic compound doped with a metal salt, an organometallic complex compound, or a mixture thereof can also be used as a material for the electron injection layer.

This electron injection layer may have a stacked structure in which two or more layers are stacked. Specifically, Li / Ca etc. are mentioned. This electron injection layer is formed by vapor deposition, sputtering, printing, or the like.
The thickness of the electron injection layer is preferably about 1 nm to 1 μm.

(Electron transport layer)
As the material for forming the electron transport layer, known materials can be used, such as oxadiazole derivatives, anthraquinodimethane or derivatives thereof, benzoquinone or derivatives thereof, naphthoquinone or derivatives thereof, anthraquinones or derivatives thereof, tetracyanoanthraquinodi. Examples include methane or its derivatives, fluorenone derivatives, diphenyldicyanoethylene or its derivatives, diphenoquinone derivatives, or metal complexes of 8-hydroxyquinoline or its derivatives, polyquinoline or its derivatives, polyquinoxaline or its derivatives, polyfluorene or its derivatives, etc. The

  Of these, oxadiazole derivatives, benzoquinone or derivatives thereof, anthraquinones or derivatives thereof, or metal complexes of 8-hydroxyquinoline or derivatives thereof, polyquinoline or derivatives thereof, polyquinoxaline or derivatives thereof, polyfluorene or derivatives thereof are preferred, 2- (4-biphenylyl) -5- (4-t-butylphenyl) -1,3,4-oxadiazole, benzoquinone, anthraquinone, tris (8-quinolinol) aluminum, and polyquinoline are more preferable.

  The electron injection layer and the hole injection layer may be collectively referred to as a charge injection layer, and the electron transport layer and the hole transport layer may be collectively referred to as a charge transport layer.

(Second electrode)
The second electrode 7 is as described in detail above.

In the organic EL element of the present embodiment, a combination example of layer configurations from the anode 5 to the cathode 7 is shown below.
a) anode / light emitting layer / cathode b) anode / hole injection layer / light emitting layer / cathode c) anode / hole injection layer / light emitting layer / electron injection layer / cathode e) anode / hole injection layer / light emitting layer / Electron transport layer / cathode f) anode / hole injection layer / light emitting layer / electron transport layer / electron injection layer / cathode d) anode / hole transport layer / light emitting layer / cathode e) anode / hole transport layer / light emitting layer / Electron injection layer / cathode f) anode / hole transport layer / light emitting layer / electron transport layer / cathode g) anode / hole transport layer / light emitting layer / electron transport layer / electron injection layer / cathode h) anode / hole Injection layer / hole transport layer / light emitting layer / cathode i) anode / hole injection layer / hole transport layer / light emitting layer / electron injection layer / cathode j) anode / hole injection layer / hole transport layer / light emitting layer / Electron transport layer / cathode k) anode / hole injection layer / hole transport layer / light emitting layer / electron transport layer / electron injection layer / cathode l) anode / light emitting layer / electron injection layer / cathode m) anode / Photo layer / electron transport layer / cathode n) anode / light emitting layer / electron transport layer / electron injection layer / cathode (here, the symbol “/” indicates that each layer sandwiching the symbol “/” is laminated adjacently) The same shall apply hereinafter.)

In addition, the organic EL device of the present embodiment may have two or more light emitting layers, and examples of the organic EL device having two light emitting layers include the layer configuration shown in the following q). Can do.
q) Anode / charge injection layer / hole transport layer / light emitting layer / electron transport layer / charge injection layer / charge generation layer / charge injection layer / hole transport layer / light emitting layer / electron transport layer / charge injection layer / cathode Specifically, as an organic EL device having three or more light-emitting layers, (charge generation layer / charge injection layer / hole transport layer / light-emitting layer / electron transport layer / charge injection layer) is one repeating unit. Examples of the layer structure include two or more repeating units shown in the following r).
r) Anode / charge injection layer / hole transport layer / light emitting layer / electron transport layer / charge injection layer / (the repeating unit) / (the repeating unit) /... / cathode In the above layer configurations p) and q) Each layer other than the anode, the electrode, the cathode, and the light emitting layer can be deleted as necessary.
Here, the charge generation layer is a layer that generates holes and electrons by applying an electric field. Examples of the charge generation layer include a thin film made of vanadium oxide, ITO, molybdenum oxide, or the like.
In an organic EL element, an anode is usually disposed on the substrate side, but a cathode may be disposed on the substrate side.

  In the organic EL element of the present embodiment, an insulating layer having a thickness of 2 nm or less may be provided adjacent to the electrode in order to further improve the adhesion to the electrode and the charge injection property from the electrode. In addition, a thin buffer layer may be inserted between each of the aforementioned layers in order to improve adhesion at the interface or prevent mixing.

(Protective layer)
After the second electrode (cathode) 7 is formed as described above, the light emitting function includes the first electrode (anode) 5-light emitting portion 6-second electrode (cathode) 7-auxiliary electrode 4 as a basic structure. In order to protect the portion, a protective layer (upper sealing film) 8 for sealing the light emitting function portion is formed. The protective layer 8 usually has at least one inorganic layer and at least one organic layer. The number of stacked layers is determined as necessary. Basically, inorganic layers and organic layers are alternately stacked.

  Note that the plastic substrate has higher permeability of gases such as oxygen and water than the glass substrate. Since a light emitting substance such as the light emitting layer 10 is easily oxidized and easily deteriorates by contact with oxygen, water, or the like, when a plastic substrate is used as the substrate 1, a treatment for improving gas barrier properties is applied to the substrate in advance. It is preferable to apply. For example, it is preferable to stack a lower sealing film having a high barrier property against gas or the like on a plastic substrate, and then stack the light emitting function part on the lower sealing film. The lower sealing film is usually formed with the same configuration and the same material as the protective layer (upper sealing film).

  In the apparatus using the organic electroluminescence element of this embodiment, the auxiliary electrode 4 is electrically connected to the second electrode 7. The first electrode opposed to the second electrode 7 is electrically connected to a circuit for realizing the active matrix driving method. For example, as described above, an active matrix drive type display device can be realized by forming a plurality of organic electroluminescent elements on a TFT substrate on which an active matrix drive type circuit is formed.

  The apparatus using the organic electroluminescence element of this embodiment further includes an optional filter for constituting a display device such as a filter such as a color filter or a fluorescence conversion filter, a circuit and wiring necessary for driving a pixel, if necessary. Can have the following components:

  In the apparatus using the organic electroluminescence element of this embodiment, the first electrode 5 is a reflective electrode, the second electrode 7 is a transmissive electrode, and a top emission type apparatus that emits light from a surface opposite to the substrate 1 is used. be able to. By adopting such a configuration, the first electrode 5 can be used as a drive electrode, and the aperture ratio can be increased while ensuring the degree of freedom in designing the drive circuit. As a result, display quality, drive performance, luminance half life, etc. The display device can be made excellent. However, the apparatus using the organic electroluminescence element of the present embodiment is not necessarily limited to this. For example, both the surfaces may be transparent or semi-transparent electrodes, and the light may be emitted from both surfaces. In addition, as a device using the organic electroluminescence element of the present embodiment, a lighting device, a planar light source, and the like are also possible.

  Hereinafter, although this invention is demonstrated more concretely based on a manufacture example and a reference example, this invention is not limited to the following illustrations.

  In Production Examples 1 to 5 shown below, an auxiliary electrode is disposed on the surface of the transparent second electrode opposite to the light emitting layer in order to confirm the effect when the transparent second electrode is composed of three layers. The organic electroluminescent element which comprised the transparent 2nd electrode from specific 3 layers was manufactured.

(Production Example 1)
(A: Formation of the first electrode (anode))
A silver layer having a thickness of 100 nm, which is the first electrode (anode), was formed on the glass substrate by vacuum deposition. This silver layer is a light reflecting anode having a reflectance of 90%. Furthermore, a 10 nm thick MoO ₃ layer was further formed as a hole injection layer on the light reflecting anode while maintaining the vacuum.

(B: Formation of hole transport layer)
A hole transporting polymer material and xylene were mixed to obtain a 0.7 wt% xylene solution of the hole transporting polymer material (composition for forming a hole transport layer).

The substrate having the anode and the hole injection layer obtained in the above (A) was taken out from the vacuum apparatus, and the composition for forming the hole transport layer was applied onto the hole injection layer by a spin coating method, and the film thickness was 20 nm. Coating film was obtained.
The substrate provided with this coating film was heated at 190 ° C. for 20 minutes to insolubilize the coating film, and then naturally cooled to room temperature to obtain a hole transport layer.

(C: Formation of light emitting layer)
The light-emitting polymer material and xylene were mixed to obtain a 1.4 wt% xylene solution (a composition for forming a light-emitting layer) of the light-emitting polymer material.

On the hole transport layer of the substrate having the anode, the hole injection layer, and the hole transport layer obtained in (B) above, a composition for forming a light emitting layer was applied by spin coating, and the film thickness was 80 nm. A coating film was obtained.
The substrate provided with this coating film was heated at 130 ° C. for 20 minutes to evaporate the solvent and then naturally cooled to room temperature to obtain a light emitting layer.

(D: Formation of second electrode (cathode))
On the light emitting layer of the substrate having the anode, hole injection layer, hole transport layer and light emitting layer obtained in (C) above, 5 nm which is the first layer of the second electrode (cathode) by vacuum deposition The Ba layer, the 5 nm Ca layer as the second layer, and the 15 nm Sn—Ag alloy layer (molar ratio: Sn: Ag = 96: 4) as the third layer were successively formed to form the first layer. A cathode composed of a third layer was formed.

(E: Sealing)
The substrate obtained by the above (D), on which the light emitting function unit is laminated, is taken out from the vacuum deposition apparatus, and the light emitting function unit on the substrate is sealed with a sealing glass and a two-component mixed epoxy resin in a nitrogen atmosphere, An organic electroluminescence device 1 was obtained.

(F: Evaluation)
A voltage of 0 V to 12 V was applied to the device obtained in (E) above, and the maximum luminous efficiency was measured. Further, the half-life of the luminance was measured by applying a current at an initial luminance of 6000 cd / m ² and applying a constant current. The results are shown in (Table 1).

(Production Example 2)
The organic electroluminescence element 2 was obtained and evaluated in the same manner as in Production Example 1 except that a 15 nm Cu layer was formed as the third layer of the second electrode (cathode). The results are shown in (Table 1).

(Production Example 3)
An organic electroluminescence element 3 was produced in the same manner as in Production Example 1 except that a 1 nm Al layer was formed as the second layer of the second electrode (cathode) and a 15 nm Cu layer was formed as the third layer. The organic electroluminescence element 3 was evaluated in the same manner as in Production Example 1. The results are shown in (Table 1).

(Production Example 4)
An organic electroluminescence element 4 was produced in the same manner as in Production Example 3 except that a 15 nm Ag layer was formed as the third layer of the second electrode (cathode), and the obtained organic electroluminescence element 4 was produced in Production Example 1. And evaluated in the same manner. The results are shown in (Table 1).
When the 3rd layer of the above preparation examples 1-4 is each formed in said film thickness with said material, the visible light transmittance of the 3rd layer of each manufacture example will be 40% or more, respectively.

(Reference Example 1)
The organic electroluminescence element 5 was produced in the same manner as in Production Example 1 except that the Ca layer of the second electrode (cathode) was not formed, but a 15 nm Sn—Ag alloy layer was formed directly on the first layer. The obtained organic electroluminescence device 5 was evaluated in the same manner as in Production Example 1. The results are shown in (Table 1).

(Reference Example 2)
An organic electroluminescence element 6 was produced in the same manner as in Production Example 1 except that the Ca layer of the second electrode (cathode) was not formed and a Cu layer of 15 nm was formed directly on the first layer. The organic electroluminescence element 6 was evaluated in the same manner as in Production Example 1. The results are shown in (Table 1).

As apparent from reference to Production Example 1 and Reference Example 1, when a cathode composed of three layers of a first layer of Ba, a second layer of Ca, and a third layer of Sn—Ag alloy is used, the second Luminous efficiency was remarkably excellent compared with the case where the layer was omitted and a cathode composed of only two layers of Ba and Sn—Ag alloy was used. In addition, the luminance half life was remarkably excellent.
In addition, as apparent from reference to Preparation Example 2, Preparation Example 3, and Reference Example 2, when a cathode composed of three layers of a first layer of Ba, a second layer of Ca or Al, and a third layer of Cu is used. The luminous efficiency was superior compared to the case where the second layer was omitted and a cathode composed of only two layers of the Ba layer and the Cu layer was used. In addition, the luminance half-life was excellent.
Furthermore, as shown in Production Example 4, when a layer made of only Ag is used as the third layer in addition to the first layer of Ba and the second layer of Al, both the luminous efficiency and the luminance half-life are the most. It was excellent.

(Production Example 5)
The same operation as in Production Example 1 was performed except that a 3.5 nm LiF layer as the first layer of the second electrode (cathode), a 4 nm Ca layer as the second layer, and a 15 nm Ag layer as the third layer were formed. The organic electroluminescence element 7 was obtained and evaluated. The results are shown in (Table 2).

(Reference Example 3)
Except that the LiF layer of 3.5 nm was formed as the first layer of the second electrode (cathode), the Ag layer of 15 nm was formed directly on the first layer without forming the Ca layer, It operated similarly and obtained and evaluated the organic electroluminescent element 8. FIG. The results are shown in (Table 2).

  As is apparent from reference to Production Example 5 and Reference Example 3, when a cathode composed of three layers of a first layer of LiF, a second layer of Ca, and a third layer of Ag is used, the second layer is omitted. As compared with the case of using a cathode composed of only two layers of LiF and Ag, the luminous efficiency was remarkably excellent. In addition, the luminance half life was remarkably excellent.

In Production Example 6 shown below, in order to confirm the effect when the auxiliary electrode is formed on the transparent first electrode, the organic electroluminescent layer has a single-layer structure and the auxiliary electrode is disposed on the surface of the transparent anode on the substrate side. A luminescence element was manufactured.
In addition, the compounds A to C represented by the following structural formulas (A) to (C) used in Synthesis Examples 1 and 2 were synthesized according to the method described in International Publication No. 2000/046321 pamphlet.

(Synthesis Example 1)
Polymer compound 1 represented by the following general formula (2) was synthesized by the following method.

  First, 0.91 g of methyl trioctyl ammonium chloride (trade name: Aliquat 336, manufactured by Aldrich), 5.23 g of the above compound A, and 4.55 g of the above compound C were charged into a reaction vessel (200 mL separable flask), and then reacted. The system was replaced with nitrogen gas. Thereafter, 70 mL of toluene was added, 2.0 mg of palladium acetate and 15.1 mg of tris (o-tolyl) phosphine were added, and the mixture was refluxed to obtain a mixed solution.

  To the obtained mixed solution, 19 mL of an aqueous sodium carbonate solution was added dropwise and stirred overnight under reflux, then 0.12 g of phenylboric acid was added and stirred for 7 hours. Thereafter, 300 ml of toluene was added, the reaction solution was separated, and the organic phase was washed with an aqueous acetic acid solution and water, and then an aqueous sodium N, N-diethyldithiocarbamate solution was added and stirred for 4 hours.

Next, after the mixed solution after stirring is separated, it is passed through a silica gel-alumina column, washed with toluene, dropped into methanol to precipitate a polymer, and then the obtained polymer is filtered and dried under reduced pressure. Dissolved in. The obtained toluene solution was again added dropwise to methanol to form a precipitate. The precipitate was filtered and dried under reduced pressure to obtain 6.33 g of polymer compound 1. The obtained polymer compound 1 had a polystyrene equivalent weight average molecular weight Mw of 3.2 × 10 ⁵ and a polystyrene equivalent number average molecular weight Mn of 8.8 × 10 ⁴ .

(Synthesis Example 2)
Polymer compound 2 represented by the following general formula (3) was synthesized by the following method.

  First, 22.5 g of compound B and 17.6 g of 2,2′-bipyridyl were charged into a reaction vessel, and the inside of the reaction system was replaced with nitrogen gas. Thereafter, 1500 g of tetrahydrofuran (dehydrated solvent) previously deaerated by bubbling with an argon gas was added to obtain a mixed solution. To the obtained mixed solution, 31 g of bis (1,5-cyclooctadiene) nickel (0) was added, stirred at room temperature for 10 minutes, and reacted at 60 ° C. for 3 hours. The reaction was performed in a nitrogen gas atmosphere.

  Next, after cooling the obtained reaction solution, a mixed solution of 25% by mass of ammonia water 200 mL / methanol 900 mL / ion-exchanged water 900 mL was poured into this solution and stirred for about 1 hour. Thereafter, the produced precipitate was collected by filtration, and this precipitate was dried under reduced pressure and then dissolved in toluene. And after filtering the obtained toluene solution and removing an insoluble matter, this toluene solution was refine | purified by passing through the column filled with the alumina.

  Next, the purified toluene solution was washed with a 1N aqueous hydrochloric acid solution, allowed to stand and separated, and then the toluene solution was recovered. And this toluene solution was wash | cleaned with about 3 mass% ammonia water, and after leaving still and liquid-separating, the toluene solution was collect | recovered. Thereafter, this toluene solution was washed with ion-exchanged water, allowed to stand and separated, and the washed toluene solution was recovered.

Next, the washed toluene solution was poured into methanol to form a precipitate. The precipitate was washed with methanol and then dried under reduced pressure to obtain polymer compound 2. The obtained polymer compound 2 had a polystyrene equivalent weight average molecular weight of 8.2 × 10 ⁵ and a polystyrene equivalent number average molecular weight of 1.0 × 10 ⁵ .

(Production Example 6)
In Production Example 6, in order to confirm the effect when the auxiliary electrode was formed on the transparent first electrode, an organic electroluminescence element in which the auxiliary electrode was disposed on the substrate side surface of the transparent anode was manufactured.

  A glass substrate (100 mm × 100 mm) was used as the support substrate. The temperature of the supporting substrate was set to 120 ° C., and Cr having a film thickness of 1000 nm was deposited on the supporting substrate by a DC sputtering method using a Cr target and Ar as a sputtering gas. The film forming pressure at this time was 0.5 Pa, and the sputtering power was 2.0 kW. A photoresist was applied on the Cr film and further baked at 110 ° C. for 90 seconds. Next, in a square frame-shaped opening composed of lines with a line width of 20 mm and the frame of the opening, the vertical and horizontal pitches are 300 μm × 100 μm, and the vertical and horizontal line widths are 70 μm × 30 μm, respectively. The film was exposed at an energy of 200 mJ through a photomask having a lattice-type opening made of, developed with 0.5% by weight aqueous potassium hydroxide solution, and post-baked at 130 ° C. for 110 seconds. Next, the resist residue is peeled off by immersing in Cr etching solution at 40 ° C. for 120 seconds, patterning Cr, and then immersing in a 2% by mass aqueous potassium hydroxide solution. 1 auxiliary electrode and 2nd auxiliary electrode) were formed.

Next, a first electrode was formed on the substrate on which the auxiliary electrode was formed. Specifically, an ITO film having a thickness of 3000 nm was deposited by a DC sputtering method using a substrate temperature of 120 ° C., an ITO firing target as a first electrode material, and Ar as a sputtering gas. The film forming pressure at this time was 0.25 Pa, and the sputtering power was 0.25 kW. Thereafter, annealing was performed in an oven at 200 ° C. for 40 minutes. Thereafter, the substrate on which the first electrode is formed is ultrasonically cleaned using a weak alkaline detergent at 60 ° C., cold water, and hot water at 50 ° C., pulled up from the hot water at 50 ° C. and dried, and then washed with UV / O _{3 for} 20 minutes. Went.

  Next, using a 0.45 μm diameter filter and a 0.2 μm diameter filter, respectively, a suspension of poly (3,4) ethylenedioxythiophene / polystyrene sulfonic acid (trade name: BaytronP CH8000, manufactured by Starck Vitech). The suspension is filtered in two stages, and a thin film with a thickness of 80 nm is formed on the washed substrate by spin coating using the solution filtered in the second stage, and is heated at 200 ° C. on a hot plate in an air atmosphere. Heat treatment was performed for 15 minutes to form a hole injection layer.

  Subsequently, the polymer compound 1 and the polymer compound 2 obtained in Synthesis Examples 1 and 2 were weighed at a weight ratio of 1: 1 and dissolved in toluene to prepare a 1% by mass polymer solution. The prepared polymer solution is formed on the substrate on which the hole injection layer is formed to a thickness of 80 nm by spin coating, and then heat-treated on a hot plate in a nitrogen atmosphere at 130 ° C. for 60 minutes to emit light. A layer was formed.

Thereafter, the substrate on which the light-emitting layer was formed was introduced into a vacuum vapor deposition machine, and LiF, Ca, and Al were sequentially deposited at a thickness of 2 nm, 5 nm, and 200 nm as a cathode to form a second electrode. In this vapor deposition step, metal deposition was started after the degree of vacuum reached 1 × 10 ⁻⁴ Pa or less.

  Finally, in an inert gas, the surface of the second electrode on the substrate on which the second electrode is formed is covered with a glass plate, and further, the four sides are covered with a photo-curing resin, and then the photo-curing resin is cured to protect it. A layer was formed to obtain an organic electroluminescence element.

(Reference Example 4)
In Production Example 6, the photomask for forming the auxiliary electrode was the same as that in Production Example 6 except that a photomask having only a square frame-shaped opening composed of lines with a line width of 20 mm was used. Thus, an organic electroluminescence element for comparison with the organic electroluminescence element of Production Example 6 was produced.

(Reference Example 5)
In the above manufacturing example 6, as a photomask for forming the auxiliary electrode, a photomask having a lattice-type opening having a vertical and horizontal pitch of 300 μm × 100 μm and a vertical and horizontal line width of 70 μm × 30 μm, respectively. An organic electroluminescence device for comparison with the organic electroluminescence device of Production Example 6 was produced in the same manner as Production Example 6 except that the mask was used.

(Evaluation of auxiliary electrode formation effect)
The light emission characteristics of the organic electroluminescence elements obtained in Production Example 6 and Reference Examples 4 and 5 were evaluated. Specifically, the light emission luminance when a voltage of 8 V was applied to the entire device was measured, and the state of the light emitting surface was visually observed. The obtained results are shown below (Table 3).

（表３）に示した結果から明らかなように、補助電極が設けられた有機エレクトロルミネッセンス素子においては、発光面積が大きい場合でも発光輝度のムラが十分に抑制され、均一発光が可能であることが確認された。

As is apparent from the results shown in Table 3, in the organic electroluminescent element provided with the auxiliary electrode, even when the light emitting area is large, unevenness in light emission luminance is sufficiently suppressed and uniform light emission is possible. Was confirmed.

It is sectional drawing of the organic electroluminescent element of one Embodiment of this invention. It is a top view which shows roughly an example of the positional relationship of the 1st auxiliary electrode and the 2nd auxiliary electrode in an organic electroluminescent element. It is a top view which shows roughly an example of the positional relationship of the 1st auxiliary electrode and the 2nd auxiliary electrode in an organic electroluminescent element. It is a top view which shows roughly an example of the positional relationship of the 1st auxiliary electrode and the 2nd auxiliary electrode in an organic electroluminescent element. It is a top view which shows roughly another example of the positional relationship of the 1st auxiliary electrode and the 2nd auxiliary electrode in an organic electroluminescent element.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Support substrate 2, 2a, 2b, 2c, 2d 1st auxiliary electrode 3, 3a, 3b, 3c, 3d 2nd auxiliary electrode 4 Auxiliary electrode 5 1st electrode (anode)
6 Light emitting part 7 Transparent second electrode (cathode)
7a First layer of second electrode 7b Second layer of second electrode 7c Third layer of second electrode 8 Protective film (upper sealing film)
9 Layer provided between anode and light emitting layer 10 Light emitting layer 11 Layer provided between cathode and light emitting layer

Claims (15)

A first electrode that is one of an anode and a cathode;
A transparent second electrode which is the other of the anode and the cathode;
An auxiliary electrode having a lower electrical resistance than the second electrode and provided in contact with the second electrode;
A light emitting layer disposed between the first electrode and the second electrode,
The transparent second electrode is composed of a three-layer laminate in which the first layer, the second layer, and the third layer are arranged in this order from the light emitting layer side,
The first layer comprises a material selected from the group consisting of metals, metal oxides, metal fluorides, and mixtures thereof;
The second layer comprises a metal selected from the group consisting of calcium, aluminum, and magnesium;
The visible light transmittance of the third layer is 40% or more,
The auxiliary electrode is
A frame-shaped first auxiliary electrode;
Together are positioned within the frame of the first auxiliary electrode is electrically connected to the first auxiliary electrode, have a, and a narrow second auxiliary electrode line width than the first auxiliary electrode,
The first layer includes at least one of a metal oxide and a metal fluoride;
The material contained in the second layer, the reducing agent der Ru organic electroluminescence device for the material contained in the first layer. The first layer comprises a metal;
The organic electroluminescent element according to claim 1, wherein the material contained in the second layer is a reducing agent for the metal oxide contained in the first layer. A first electrode that is one of an anode and a cathode;
A transparent second electrode which is the other of the anode and the cathode;
An auxiliary electrode that is lower in electrical resistance than the second electrode and is provided in contact with the second electrode;
A light emitting layer disposed between the first electrode and the second electrode,
The transparent second electrode is composed of a three-layer laminate in which the first layer, the second layer, and the third layer are arranged in this order from the light emitting layer side,
The material contained in the second layer has a reducing action on the material contained in the first layer;
The visible light transmittance of the third layer is 40% or more,
The auxiliary electrode is
A frame-shaped first auxiliary electrode;
An organic electroluminescence device comprising: a second auxiliary electrode disposed within a frame of the first auxiliary electrode, electrically connected to the first auxiliary electrode, and having a line width narrower than the first auxiliary electrode . The organic electroluminescence device according to claim 3, wherein the first layer includes a material selected from the group consisting of metals, metal oxides, metal fluorides, and mixtures thereof . The organic electroluminescent device according to claim 3 or 4, wherein the second layer contains a metal selected from the group consisting of calcium, aluminum, magnesium, and a mixture thereof . The first layer is made of a group consisting of an alkali metal, an alkaline earth metal, an alkali metal oxide, an alkaline earth metal oxide, an alkali metal fluoride, an alkaline earth metal fluoride, and a mixture thereof. The organic electroluminescent element of any one of Claims 1-5 containing the material selected . The organic electroluminescence device according to claim 6, wherein the first layer includes a material selected from the group consisting of barium, barium oxide, barium fluoride, and a mixture thereof . The organic electroluminescence device according to claim 6, wherein the first layer includes a material selected from the group consisting of sodium, sodium oxide, sodium fluoride, and a mixture thereof . The organic electroluminescence device according to claim 6, wherein the first layer includes a material selected from the group consisting of rubidium, rubidium oxide, rubidium fluoride, and a mixture thereof . The third layer is made of a material selected from the group consisting of gold, silver, copper, tin, lead, nickel, indium, and alloys thereof;
The organic electroluminescence device according to any one of claims 1 to 9, wherein the film thickness of the third layer is 5 nm or more and 30 nm or less . The organic electroluminescence device according to claim 1, wherein the first electrode has a reflectance of 80% or more with respect to visible light . 12. The organic electroluminescence element according to claim 1, wherein a value obtained by dividing the line width of the second auxiliary electrode by the line width of the first auxiliary electrode is 1/1000 to 1/10 . An illuminating device comprising the organic electroluminescence element according to claim 1 . A planar light source comprising the organic electroluminescence element according to claim 1 . A display device comprising the organic electroluminescence element according to claim 1 .

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