WO2013168212A1

WO2013168212A1 - Organic electroluminescent device

Info

Publication number: WO2013168212A1
Application number: PCT/JP2012/061665
Authority: WO
Inventors: 崇人小山田
Original assignee: パイオニア株式会社
Priority date: 2012-05-07
Filing date: 2012-05-07
Publication date: 2013-11-14

Abstract

An organic EL device having: a bottom-emission first EL element including a light-transmissive first substrate; and a light-transmissive second EL element formed upon the main surface on the opposite side to a first electrode layer of the first substrate. The second EL element includes a light-transmissive second organic layer that emits light in a second light-emitting band different from a first light-emitting band for a first organic layer of the first EL element, and is arranged such that all or part of the first and second organic layers form an overlapping area that overlaps in the thickness direction of the first substrate.

Description

Organic electroluminescence device

The present invention relates to an organic electroluminescence device including a plurality of light emitting portions.

An organic electroluminescent element is formed by, for example, sequentially laminating an anode, a hole transport layer, a light emitting layer, an electron transport layer, and a cathode on a glass substrate, and the organic layers of the hole transport layer, the light emitting layer, and the electron transport layer are formed. It is an organic light emitting diode that exhibits electroluminescence (hereinafter referred to as EL) by current injection between the sandwiched anode and cathode. The organic EL element is a self-luminous surface emitting device and is put into practical use in a display device or a lighting device.

A so-called tandem organic light-emitting diode device is known as an organic EL device (see Patent Document 1). A tandem organic light-emitting diode device is composed of a plurality of EL units arranged between an anode and a cathode, and an intermediate connection layer arranged between adjacent EL units, and the plurality of EL units are connected in series. It is a connected organic EL device.

Special table 2009-506513

In the organic EL device described in Patent Document 1, since the currents flowing through the EL units connected in series are equal, the output from the entire EL unit depends on the current luminance efficiency of each EL unit with respect to the common current density flowing through all the EL units. The chromaticity of the mixed color emission is determined. However, when this organic EL device is continuously used as a white light source of mixed colors of R (red), G (green), and B (blue), for example, the current luminance efficiency is increased due to the aging of the light emitting materials of each color of RGB. As a result of different changes, there is a problem that a desired white color cannot be maintained for a long time as a color mixture of each light emitting panel.

In the production of the organic EL device, for example, an intermediate connection layer is formed on a green EL unit, a red EL unit is formed thereon, an intermediate connection layer is formed thereon, and a blue EL unit is formed thereon. In order to prevent the EL unit stacked below from being altered, the EL unit stacked above must be formed under severe process conditions in which the temperature, solvent, and the like are more limited. Therefore, there is a problem that materials that can be used for each color EL unit of the tandem organic light emitting diode device are extremely limited.

Accordingly, an object of the present invention is to provide an organic EL device that can be toned and that can be manufactured under relaxed process conditions and can stabilize the color of the emitted light for a long time.

The organic EL device of the present invention includes a first electrode layer formed on a light-transmitting first substrate, a second electrode layer facing the first electrode layer, and a first electrode sandwiched between these electrode layers. An organic layer, and the first organic layer emits light in a first emission band according to an applied voltage between the first and second electrode layers and passes through the first electrode layer and the first substrate. A first EL element that emits light of an emission band;
A translucent second EL element formed on the main surface of the first substrate opposite to the first electrode layer,
The second EL element is sandwiched between two translucent electrode layers facing each other and the translucent electrode layer, and is different from the first light-emitting band according to the applied voltage between the two translucent electrode layers. A light-transmitting second organic layer that emits light in two light-emitting bands and emits light emitted in the second light-emitting band through the two light-transmitting electrode layers, and the first organic layer and the second organic layer A part or all of the layers are arranged so as to form an overlapping region in which the layers overlap in the thickness direction of the first substrate.

According to the organic EL device having the above-described configuration, it is possible to perform color adjustment by changing the luminance for each of the first and second EL elements, the color of the emission color can be stabilized, and the manufacturing process conditions for each element are reduced. The effect of expanding the selection range of materials that can be used in the entire organic EL device is obtained.

FIG. 1 is a schematic sectional view schematically showing a configuration of an organic EL device according to a first embodiment of the present invention. FIG. 2 is a schematic cross-sectional view schematically showing the configuration of the first EL element of the organic EL device shown in FIG. FIG. 3 is a schematic cross-sectional view schematically showing the configuration of an organic EL device according to the second embodiment of the present invention. FIG. 4 is a schematic cross-sectional view schematically showing the configuration of an organic EL device according to the third embodiment of the present invention. FIG. 5 is a schematic cross-sectional view schematically showing the configuration of an organic EL device which is a modification of the third embodiment of the present invention. FIG. 6 is a schematic sectional view schematically showing a configuration of an organic EL device according to the fourth embodiment of the present invention. FIG. 7 is a block diagram showing a schematic configuration of a light emitting apparatus including an organic EL device according to a fifth embodiment of the present invention. FIG. 8A shows an example of the spectral intensity distribution of the light emission regions of the three primary colors of the blue light emission region B of the first EL element and the red light emission region R and the green light emission region G of the second EL element 1t of the organic EL device of the embodiment. FIG. 8B is a graph, and FIG. 8B shows the color temperature of white light and the individual luminance R of the light emitting area when the white light is controlled under a constant luminance condition in the light emission color mixture of the whole organic EL device composed of the light emitting area groups of the three primary colors. It is a graph which shows an example of the relationship with the change of (k), G (k), B (k).

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

<First embodiment>
FIG. 1 shows the configuration of an organic EL device that is an embodiment of the present invention.

The organic EL device is a unit in which a first EL element 1 which is a bottom emission type organic EL panel and a light-transmitting second EL element 1t are stacked in parallel and integrated.

In the first EL element 1, a first organic layer 4 is formed on a first electrode layer 3 formed on a translucent first substrate 2, and a second electrode layer 5 that is a reflective electrode is formed thereon. Has been. With such a configuration, the first organic layer 4 sandwiched between the first electrode layer 3 and the second electrode layer 5 facing each other has a first voltage corresponding to the applied voltage between the first and

second electrode layers

3 and 5. Light is emitted in the light emission band, and the emitted light is emitted through the first electrode layer 3 and the first substrate 2. As described above, in the first EL element 1, the first light emitting portion 6 in the first light emission band including the first electrode layer 3, the first organic layer 4, and the second electrode layer 5 is formed on the translucent substrate 2. Has been.

In the first EL element 1, a sealing substrate 7 such as a glass plate is used as a sealing structure for the purpose of protecting the first light emitting unit 6 from oxygen and moisture in the air after the second electrode layer 5 is formed. The first light emitting unit 6 is hermetically protected by disposing a sealing unit 8 such as an adhesive around the first light emitting unit 6 between the first substrate 2 and the sealing substrate 7. For example, the sealing process is performed in a glove box substituted with nitrogen.

Instead of the sealing substrate, sealing is performed by bonding a sealing material such as a cap made of metal, glass, or the like that covers the first light emitting unit 6 separately as a sealing structure. May be. At this time, a desiccant (not shown) may be attached to the inner wall of the cap. Further, a so-called solid sealing may be performed by forming a sealing film (not shown) made of an organic compound or an inorganic compound so as to cover the first light emitting portion 6.

In the second EL element 1t shown in FIG. 1, the second EL element 1t is formed on the translucent electrode layer 3t formed on the main surface on the opposite side of the first electrode layer 3 of the first substrate 2 of the first EL element 1, that is, the main surface on the light extraction side. Two organic layers 4t are formed, and a translucent electrode layer 5t is formed thereon. With this configuration, the second organic layer 4t sandwiched between the

translucent electrode layers

3t and 5t facing each other emits light in the second emission band according to the applied voltage between the

translucent electrode layers

3t and 5t. The emitted light is radiated through the

translucent electrode layers

3t and 5t. As described above, in the second EL element 1t, the second light emitting unit 6t in the second light emission band including the translucent electrode layer 3t, the second organic layer 4t, and the translucent electrode layer 5t is formed on the first substrate 2. Is formed. Spectral components of the first light emission band of the first EL element 1 and the second light emission band of the second EL element 1t may overlap, but each light emitting portion has a different light emitting material so that the spectral distributions are different from each other. It is formed as a light emitting region containing

Also in the second EL element 1t, a transparent sealing substrate 7t such as a glass plate is used for the purpose of protecting the second light emitting unit 6t from oxygen and moisture in the atmosphere after the transparent electrode layer 5t is formed. The second light emitting unit 6t is hermetically protected by disposing the second sealing unit 8t such as an adhesive around the second light emitting unit 6t between the first substrate 2 and the sealing substrate 7t. The second EL element 1t can also be hermetically sealed with an inert gas. Further, instead of sealing with an inert gas, liquid sealing using a light diffusing material such as oil that diffuses light by dispersing a plurality of fine particles in a liquid phase is also possible. That is, at least one of the first EL element 1 and the second EL element 1t shown in FIG. 1 is filled with the light diffusing material around the first organic layer 4 and the second organic layer 4t in the space Sp inside the sealing structure. It may be a structure.

As shown in FIG. 1, the first EL element 1 and the second EL element 1t are arranged such that their light emitting regions overlap, that is, the first organic layer 4 of the first EL element 1 and the second organic layer of the second EL element 1t. Both elements are overlapped so as to form an overlapping region OVL in which part or all of 4t overlaps in the thickness direction of the first substrate.

As shown in FIG. 2, the organic layer of the first EL element 1 typically has positive and negative electrodes in order from the anode to the cathode when the first electrode layer 3 is an anode and the second electrode layer 5 is a cathode. The hole injection layer 4a, the hole transport layer 4b, the light emitting layer 4c, the electron transport layer 4d, and the electron injection layer 4e are laminated. In addition, in the laminated structure of the 1st organic layer 4, it is also possible to laminate | stack components other than a board | substrate in reverse order. In any case, the first organic layer 4 is not limited to these laminated structures, and at least emits light, for example, by adding a hole blocking layer (not shown) between the light emitting layer 4c and the electron transport layer 4d. A layered structure including a charge transport layer that includes or can also be used as a layer is also included in the present invention. The first organic layer 4 may be configured by omitting the hole transport layer 4b, the hole injection layer 4a, or the hole injection layer 4a and the electron transport layer 4d from the stacked structure. It may be configured. Further, similarly to the first organic layer 4 of the first EL element 1, the second organic layer 4t of the second EL element 1t can also be configured by stacking each functional layer. The material for the charge transport layer of the organic layer can be appropriately selected from known materials in the right place.

For example, as the organic EL material of the light emitting layer 4c, for example, any known material such as a fluorescent material or a phosphorescent material can be applied.

Examples of fluorescent materials that emit blue light include naphthalene, perylene, and pyrene. Examples of fluorescent materials that give green light emission include quinacridone derivatives, coumarin derivatives, and aluminum complexes such as Alq3 (tris (8-hydroxy-quinoline) aluminum). Examples of fluorescent materials that give yellow light include rubrene and perimidone derivatives. Examples of fluorescent materials that give red light emission include DCM (4- (dicyanomethylene) -2-methyl-6- (p-dimethylaminostyryl) -4H-pyran) compounds, benzopyran derivatives, rhodamine derivatives, and the like. Examples of the phosphorescent material include ruthenium, rhodium, and palladium. Specific examples of the phosphorescent material include tris (2-phenylpyridine) iridium (so-called Ir (ppy) 3), tris (2-phenylpyridine) ruthenium, and the like.

As the material of the second electrode layer 5 that is the reflective electrode of the first EL element 1 shown in FIG. 1, for example, a metal such as aluminum or silver is used. The thickness of the second electrode layer 5 is not limited as long as it maintains the reflective action of the second electrode layer 5.

Each of the first electrode layer 3 of the first EL element 1 and the

translucent electrode layers

3t and 5t of the second EL element 1t have light transmissivity. For these, for example, ITO (Indium-tin-oxide) or FTO (fluorine-tin-oxide) is used as a light transmissive electrode material. Also, oxide materials such as ZnO, ZnO—Al ₂ O ₃ (so-called AZO), In ₂ O ₃ —ZnO (so-called IZO), SnO ₂ —Sb ₂ O ₃ (so-called ATO), RuO _2, etc. It can also be used.

In addition, as a material for the cathode for supplying electrons, a metal having a low work function is preferable in order to perform electron injection efficiently, for example, a suitable metal such as tin, magnesium, indium, calcium, aluminum, silver, or an alloy thereof. Is used.

Each of the first electrode layer 3 and the

translucent electrode layers

3t and 5t is made of an electric conductor having an electric conductivity of 10 ⁶ S / m or more, and is about 360 nm or less of the shortest wavelength of visible light, that is, ultra soft X A thin film having a film thickness in the range from the line to the ultraviolet wavelength can be used by being stacked on the oxide material film. The material of the laminated thin film includes carbon such as metal, graphite, and graphene. The 20 nm-thick silver thin film as the laminated thin film has a transmittance of about 50%. For example, an Al film having a thickness of 10 nm as the thin film has a transmittance of 50%. The 20 nm-thick MgAg alloy film as the thin film has a transmittance of 50%. The translucent conductive thin film has a thickness of a thin film made of an electrical conductor and having a thickness in the range of ultra-soft X-ray to ultraviolet wavelength, and has a transmittance of at least 50% or a thickness of 20 nm or less. It is preferable to employ a thin film having

The first substrate 2 common to the first EL element 1 and the second EL element 1t shown in FIG. 1 is made of a highly light-transmitting material such as a resin film such as glass, polyester, polymethacrylate, polycarbonate, or polysulfone. The light emitted from the first light emitting unit 6 and the second light emitting unit 6t is reflected inside the first EL element 1 and the second EL element 1t, but is output to the outside through the first substrate 2 and the sealing substrate 7t. .

In order to increase the output light extraction efficiency, a light extraction film 9 is attached to the outer surface of the second EL element 1t shown in FIG. 1 so as to cover the overlapping region OVL.

In the organic EL device shown in FIG. 1, the first EL element 1 and the second EL element 1t are overlapped and integrated. However, the present invention is not limited to this, and the space between the external surface of the second EL element 1t and the light extraction film 9 is not limited thereto. One or more translucent second EL elements 1t may be stacked. That is, each of the second EL elements 1t has a second light emission different from the first light emission band depending on the applied voltage between the two light transmissive electrode layers sandwiched between the two light

transmissive electrode layers

3t and 5t facing each other. It is only necessary to form the second light-emitting portion 6t including the light-transmitting second organic layer 4t that emits light in the band and emits light in the second light-emitting band through the two light-

transmissive electrode layers

3t and 5t. .

<Second embodiment>
In the following, the differences between the second embodiment and the first embodiment will be mainly described. Elements indicated by the same reference numerals as those in the first embodiment are the same, and thus description thereof is omitted.

In the first embodiment, the second EL element 1t is formed using the main surface of the first EL element 1 on the light extraction side of the first substrate 2, but in the second embodiment, the first substrate 2 is used. After the second EL element 1t is manufactured individually, the first EL element 1 and the second EL element 1t are bonded together to achieve the integration of both elements.

As shown in FIG. 3, the second EL element 1t uses a translucent second substrate 2t such as a glass plate equivalent to the first substrate 2, and a translucent electrode layer 3t formed on the second substrate 2t. A second organic layer 4t is formed thereon, and a translucent electrode layer 5t is formed thereon. The second light emitting unit 6t is hermetically protected by disposing the second sealing unit 8t such as an adhesive around the second light emitting unit 6t between the sealing substrate 7t and the second substrate 2t. The first substrate 2 of the first EL element 1 and the second substrate 2t of the second EL element 1t are bonded to each other with a light-transmitting optical adhesive layer 10 interposed therebetween. When the first EL element 1 and the second EL element 1t are separately manufactured and bonded together, a light diffusing material such as fine particles can be uniformly mixed and dispersed in the translucent optical adhesive layer 10 to enhance the light extraction effect. That is, when the second substrate 2t is considered as an integral body with the first substrate 2, it is preferable that the first substrate 2 has a light-transmitting adhesive layer 10 containing a light diffusing material.

<Third embodiment>
In the following, the difference between the third embodiment and the second embodiment will be mainly described. Elements indicated by the same reference numerals as those in the second embodiment are the same, and thus description thereof is omitted.

In the second embodiment, the organic layers of the light emitting regions of both the first EL element 1 and the second EL element are uniformly laminated in a predetermined area. However, in the device of the third embodiment, the organic layer of at least one EL element. Is formed as a light emitting region divided so as to include a plurality of light emitting layers juxtaposed in a stripe shape, for example.

As shown in FIG. 4, a light emitting region B including a blue light emitting layer is formed over the first organic layer 4 of the first EL element 1, and red light is formed in the second organic layer 4t of the second EL element 1t. The light emitting regions R and G each including a green light emitting layer and a green light emitting layer are juxtaposed in a state of being separated from each other by an insulating film BK. By these light emitting regions R, G, and B, color mixing is performed when the device emits light, and, for example, white light emission can be achieved. Although not shown, a bus line for supplying current may be formed along the insulating film BK between the insulating film BK and the translucent electrode layer 3t. Needless to say, the first EL element 1 and the second EL element 1t are electrically connected to the driving portions by predetermined wirings (not shown) so that they can be driven independently for each light emitting region.

As shown in FIG. 4, a plurality of insulating films BK (banks extending in parallel with the normal direction to the paper surface) that partition the stripe-like light emitting layers R and G of the second EL element 1t are previously formed on the second substrate 2t. Thus, it is possible to reliably achieve application of the predetermined organic material between the adjacent banks BK using an ink jet application method or the like.

In the case of forming a light emitting region that is subdivided so as to include a plurality of light emitting layers by using an ink jet coating method or the like, an insulating film (bank) is not necessarily required, and so-called pins of the ink droplets applied to the ink jet are themselves. The stopping phenomenon can be used. For example, in the manufacturing process of the second EL element, a light emitting layer is individually formed by ink-jet coating on each of the translucent electrode layers 3t arranged in a stripe shape, and as shown in FIG. An organic EL device including the second EL element 1t having the stripe-shaped light emitting regions R and G without a bank) can also be manufactured.

In this embodiment, the light emitting region of the second organic layer 4t of the second EL element 1t is subdivided into stripes for each color, but the divided light emitting region is also formed in the first organic layer 4 of the first EL element 1. You can also That is, at least one of the first organic layer 4 of the first EL element 1 and the second organic layer 4t of the second EL element 1t can be configured to have a plurality of light emitting layers juxtaposed in a stripe shape.

<Fourth embodiment>
In the following, the difference between the fourth embodiment and the second embodiment will be mainly described. Elements indicated by the same reference numerals as those in the second embodiment are the same, and thus description thereof is omitted.

In the first EL element 1 of the second embodiment, the second electrode layer 5 (FIG. 3), which is a reflective electrode, is formed on the first organic layer 4 on the translucent first substrate 2. In the device of the fourth embodiment, as shown in FIG. 6, instead of the reflective electrode, a translucent electrode layer 5t is formed on the first organic layer 4, and the reflective film 5A such as Al is sealed. It is formed in the inner wall facing the 1st light emission part 6 of sealing structures, such as the board | substrate 7, with the area exceeding the superimposition area | region OVL. Thereby, a part of the light emission in the predetermined light emission band of the first organic layer 4 is radiated through the translucent electrode layer 5t, but the reflective film 5A not only emits the light from the first organic layer 4, but also the second light emission. All the light from the part 6t is also reflected toward the second substrate 2t. As described above, by further including the reflective film 5A spaced from the translucent electrode layer 5t of the second electrode layer of the first EL element 1, the same light extraction effect as that of the above embodiment can be obtained.

<Fifth embodiment>
Hereinafter, as an example of the present invention, for example, a light emitting device using an organic EL device will be described.

FIG. 7 is a block diagram showing a schematic configuration of such a light emitting device. This light emitting device includes a drive unit 12 connected to the control unit 11 and an organic EL device shown in FIG. 4 connected to the drive unit. Further, the light emitting device includes an operation unit 13 connected to the control unit 11.

Such an organic EL device includes a blue light emitting region B of the first EL element 1 and a plurality of sets of a red light emitting region R and a green light emitting region G of the second EL element 1t as shown in FIG.

The control unit 11 includes a microcomputer including a CPU, a ROM, a RAM, an internal timer, and the like that execute program codes such as processing procedures for generating various signals including a luminance designation signal, and the luminance of each light emitting area of the organic EL device. And a lighting control routine for controlling lighting / extinguishing. The control unit 11 generates a luminance designation signal for each color for driving each light emitting area and supplies it to the driving unit 12.

The driving unit 12 includes a red driving unit 12R, a green driving unit 12G, and a blue driving unit 12B, which are driving circuits for RGB light emission connected to the light emitting regions R, G, and B, respectively. In response to the luminance designation signal supplied from the control unit 11, the red driving unit 12R, the green driving unit 12G, and the blue driving unit 12B are driven individually to the light emitting regions R, G, and B or for each of the R group, the G group, and the B group. Power is supplied and each emits light at a specified brightness. The drive unit 12 is a light source color (light color) such as white by mixing light emission of a predetermined luminance in the light emitting regions R, G, and B in various lighting modes of the organic EL device according to the luminance designation signal of each color from the control unit 11. Toning. The light color white light is “color temperature” when the chromaticity is on the black body radiation locus indicated by the XYZ color system of the CIE chromaticity diagram, and “correlated color temperature” when the chromaticity is not within that range. (Unit: K (Kelvin)).

The operation unit 13 is a device such as a remote controller including an open / close switch or a wired module attached in the room. The operation unit 13 supplies the control unit 11 with an operation command such as a command for turning on or off the light emitting device by the user, and a command for switching to a lighting mode such as normal lighting or night light.

Next, as an example, the light emitting region of the organic EL device in which only the color temperature of white light changes due to the light emission color mixture of the R, G, B organic EL element group even if the normal lighting brightness of the entire organic EL device is constant An example of toning when color temperature luminance data of each luminance value is used will be described.

The color temperature luminance data includes a red driving unit 12R, a green driving unit 12G, and a green driving unit 12G for emitting white light of various color temperatures of the organic EL device by mixing the light emitting regions R, G, and B with a specific luminance. It is table | surface data of the luminance value (luminance designation | designated signal) for every light emission area | region sent to the blue drive part 12B.

FIG. 8A shows an example of the spectral intensity distribution of the light emission regions of the three primary colors of the blue light emission region B of the first EL element 1 and the red light emission region R and the green light emission region G of the second EL element 1t. FIG. 8B shows the color temperature of the white light and the individual luminance R (k) of the light emitting region when the white light luminance is controlled under a constant condition in the light emission color mixture of the entire organic EL device composed of the light emitting region group of the three primary colors. An example of the relationship with changes in G (k) and B (k) is shown. When the three primary color (RGB) light emitting regions R, G, and B used adopt the spectral intensity distribution shown in FIG. 8A (an example calculated by normalizing the maximum value of each spectral intensity to 1), the device In order to emit light with constant white light brightness, the light emitting regions R (k), G (k), B for the color temperature (1500K to 5000K) range of white light as shown in FIG. A set of individual luminances (k) is required.

As is clear from the color temperature luminance curves R (k), G (k), and B (k) of the light emitting regions R, G, and B in FIG. 8B, for example, to obtain white light of 2000K, the light emitting region. R, G, separate luminance output of B is required ^{7000cd / m 2, 3000cd / m} 2, 10cd / m 2, in order to obtain white light 4500K is ^{3500cd / m 2, 5000cd / m} 2, Indicates that 2000 cd / m ² is required. Therefore, based on the color temperature luminance curves R (k), G (k), and B (k) of the light emitting regions R, G, and B in FIG. From one to the other, for example, every 100K, it is divided into a plurality of color temperature steps in order, and luminance designation signals (color temperature luminance curves R (k), G (k) for each light emitting region R, G, B for each color temperature 100K. , B (k) and the luminance value at the intersection point) are prepared in advance.

Based on the acquired color temperature luminance data, the control unit 11 changes the light emission regions R, G, and B at a predetermined timing for compensating for the user's operation timing or the secular change of the light emission region from the lower one to the higher one of the color temperature steps. The luminance value for each is sent to the red drive unit 12R, the green drive unit 12G, and the blue drive unit 12B as luminance designation signals R (t), G (t), and B (t). As described above, the control unit 11 transmits the luminance designation signals R (t), G (t), and B (t) that define white light having a desired color temperature to the red drive unit 12R, the green drive unit 12G, and the blue drive, respectively. This is sent to the unit 12B, and the luminance of the light emitting regions R, G, B is controlled to adjust the light color of the organic EL device. That is, the control unit 11 controls the light color and color temperature of the organic EL device by individually adjusting the light emission intensity (luminance) of each light emitting region of the organic EL device, for example, according to the operation of the user. Thus, white light such as a light bulb color and daylight color can be emitted, or white light can be corrected at a predetermined timing for compensating for secular change in a light emitting area stored in a ROM or the like.

According to the organic EL device having the above-described configuration, for example, two color gradations can be obtained by driving two panels by sticking together two organic EL panels that are formed on the entire surface (solid). By combining the emission color, white (W) emission color of the RG / B stack and the B emission color, it is possible to adjust the warm white to cool white. In addition, if three organic EL panels of R, G, and B emission colors are stacked, color matching equivalent to the juxtaposed stripe is possible. Furthermore, if two W light emitting color panels are bonded together and driven in series, the voltage is improved and the efficiency is improved as in the tandem type. If the light extraction is optimized, in principle, the efficiency is doubled at twice the driving voltage.

A translucent organic EL panel and a bottom emission type organic EL panel were each formed by a coating method, and both organic EL panels were bonded together to produce an organic EL device.

First, in the first step, on the glass substrate (plate thickness: 0.7 mm), an anode (ITO: film thickness 112 nm) is formed into a pattern within a specified range, and a photolithography process is performed on them. A bus line (AlNd: film thickness of 200 nm) was formed into a pattern in a stripe shape (discontinuous).

Next, in the second step, an insulating film was formed in a pattern by a photolithography process so as to cover the AlNd bus line on the glass substrate and expose the ITO anode. The insulating film defines a light emitting area.

Next, in the third step, the surface of the ITO anode is treated with ultraviolet light / ozone, and then PEDOT: PSS (Poly (3,4-ethylenedioxythiophene) (poly (styrenesulfonate)) with a solid content concentration of 1 wt% is applied with an inkjet device. Then, it was vacuum-dried at 0.1 Pa to 50 Pa for 2 minutes and fired at 230 ° C. for 1 hour to form a hole injection layer.

Next, in the fourth step, 1 wt% -Hex-Ir (phq) 3 (Tris (2-phenylquinoline) iridium of a red dopant having a solid content concentration of 2 wt% in a xylene solvent on the fired PEDOT: PSS hole injection layer. DCIII (4,4'-Bis (N-carbazolyl)-containing (III)) and 9% of the green dopant-Ir (mppy) 3 (Tris (3-methyl-2-phenylpyridine) iridium (III)) 1,1′-biphenyl) ink was applied, vacuum dried at 0.1 Pa to 50 Pa for 2 minutes, and fired at 130 ° C. for 10 minutes to form a red-green light emitting layer.

Next, in the fifth step, BCP (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline) is used as a hole blocking layer by vacuum deposition on the fired red and green light emitting layer having a thickness of 40 nm. Was formed to a thickness of 15 nm. Furthermore, 30 nm thick Alq3 (tris (8-hydroxyquinolite) aluminum), which is an electron transport layer, is formed on the hole blocking layer by vacuum deposition, and then LiF with a thickness of 1 nm is formed on the electron injection layer. Finally, an Ag cathode having a thickness of 10 nm was formed, and liquid-sealed to produce a light-transmitting organic EL panel. The translucent cathode is preferably made of Ag or Al and has a thickness of 20 nm or less. Furthermore, since the resistance increases when the translucent electrode is oxidized, it is preferable to provide an antioxidant film.

Next, a bottom emission type organic EL panel was produced as follows.

First, the above first to third steps were similarly performed to prepare a glass substrate having a hole injection layer.

Next, 5% -DPAVBi (4,4′-Bis [4- (di-p-tolylamino) styryl) of blue dopant having a solid content concentration of 2 wt% in a xylene solvent on the hole injection layer of the baked PEDOT: PSS ], a host PAND (2-Phenyl-9,10-di (naphthalen-2-yl) -anthracene) ink containing biphenyl) was applied, vacuum dried at 0.1 Pa-50 Pa for 2 minutes, and 10 minutes, A blue light emitting layer was formed by baking at 130 ° C.

Next, the fifth step was carried out in the same manner, and a BCP film having a thickness of 15 nm was formed as a hole blocking layer on the fired blue light-emitting layer by vacuum deposition. Further, an Alq3 film having a thickness of 30 nm, which is an electron transport layer, is formed by vacuum vapor deposition. Next, LiF film having a thickness of 1 nm is formed as an electron injection layer, and finally an Ag cathode having a thickness of 80 nm is formed. A bottom emission type organic EL panel was produced by liquid sealing.

Next, the glass substrate sides of the two produced organic EL panels were bonded to each other using a light-transmitting organic EL panel and a light-transmitting adhesive containing a diffusing material. In order to reduce light loss from the light-transmitting organic EL panel, the thickness of the light-transmitting adhesive layer including the thickness of the light-transmitting adhesive layer is 1 mm or less, and both glass substrates are 1 mm or less in thickness. The material is preferably transparent, thin and excellent in light transmission. As a result, the toning was possible with a slight loss of light.

In these produced sealing steps, a translucent organic EL panel having a translucent cathode transmits light of a bottom emission type organic EL panel having a reflective electrode, and therefore a structure that uses oil that diffuses light is used. It was.

A light extraction film (trade name STE manufactured by Kimoto Co., Ltd.) was attached to the translucent organic EL panel side of the produced organic EL device to improve the light extraction efficiency. Since the light extraction film has a variety of microlenses, pyramid structures, and the like, it is not limited to any one.

DESCRIPTION OF SYMBOLS 1 1st EL element 1t 2nd EL element 2 1st board | substrate 2t 2nd board | substrate 3 1st electrode layer 3t Translucent electrode layer 4 1st organic layer 4a Hole injection layer 4b Hole transport layer 4c Light emitting layer 4d Electron transport layer 4e Electron injection layer 4t Second organic layer 5 Second electrode layer 5A Reflective film 5t Translucent electrode layer 6

Light emitting part

7, 7t Sealing substrate 8 Sealing part 11 Control part 12 Driving part 13 Operation part G, B, R Light emission Region BK Insulating film

Claims

A first electrode layer formed on a light-transmitting first substrate, the second electrode layer facing the first electrode layer, and a first organic layer sandwiched between the electrode layers, A first organic layer emits light in a first light emission band according to an applied voltage between the first and second electrode layers, and emits light in the first light emission band through the first electrode layer and the first substrate. 1 EL element;
A translucent second EL element formed on the main surface of the first substrate opposite to the first electrode layer,
The second EL element is sandwiched between two translucent electrode layers facing each other and the translucent electrode layer, and is different from the first light-emitting band according to the applied voltage between the two translucent electrode layers. A light-transmitting second organic layer that emits light in two light-emitting bands and emits light emitted in the second light-emitting band through the two light-transmitting electrode layers, and the first organic layer and the second organic layer An organic EL device, wherein a part or all of the layers are arranged so as to form an overlapping region in which the layers overlap in the thickness direction of the first substrate.
The organic EL device according to claim 1, wherein the first substrate has a light-transmitting adhesive layer containing a light diffusing material.
3. The organic EL device according to claim 2, wherein at least one of the first organic layer of the first EL element and the second organic layer of the second EL element has a plurality of light emitting layers juxtaposed in a stripe shape. .
The organic EL device according to claim 2, wherein the first EL element and the second EL element have a sealing structure for protecting the first organic layer and the second organic layer.
The organic EL device according to claim 4, wherein a light diffusing material is filled around the first organic layer and the second organic layer inside the sealing structure.
6. The organic EL device according to claim 5, wherein at least one of the two translucent electrode layers includes a thin film made of Ag, Al or an alloy containing these metals having a thickness of 20 nm or less.
The organic EL device according to claim 2, further comprising a light extraction film attached to an external surface of the second EL element.
The organic EL device according to claim 2, wherein the second electrode layer of the first EL element is a reflective electrode layer.
The organic material according to claim 2, further comprising a reflective film spaced apart from the second electrode layer of the first EL element, wherein the second electrode layer of the first EL element is a translucent electrode layer. EL device.