JP2010040501A - Organic el device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce visibility of non-light-emitting ranges between organic layers arranged in parallel with a substrate in an organic electroluminescent (EL) device having the first organic layer 2, the second organic layer 3, and the third organic layer 5 which respectively emit light of different colors. <P>SOLUTION: A light-emitting range of the third organic layer 5 is located above or below the non-light-emitting ranges 200 existng between respective light-emitting ranges of the first organic layer 2 and the second organic layer 3 located in parallel with the substrate 10. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an organic EL device having two electrodes and an organic layer between the two electrodes, and a plurality of organic EL elements that emit light when a voltage is applied between the two electrodes. is there.

  An organic EL element generally comprises a hole transport layer, an organic layer, an electron transport layer, etc. as an organic layer between an anode made of a transparent conductive film (for example, ITO) and a cathode made of a metal (for example, Al). It becomes. The organic EL element emits electrons by recombining holes injected from the anode side and electrons injected from the cathode side in the organic layer via the hole transport layer and the electron transport layer, respectively. It is a device. As one of methods for manufacturing an organic EL device having a plurality of organic EL elements, a vacuum deposition method is known. An organic compound is placed in the crucible as a vapor deposition material, and the temperature of the crucible is heated in the vacuum apparatus to a temperature higher than the vaporization temperature of the vapor deposition material. Form a layer.

  On the other hand, in an organic EL device, as a method for realizing light emission of a plurality of colors, there are a configuration in which organic EL elements are arranged in parallel and a configuration in which the organic EL elements are stacked.

In particular, an organic EL device having a structure in which organic EL elements are stacked is disclosed in Patent Document 1. In Patent Document 1, one pixel is composed of a plurality of sub-pixels, and each of the plurality of sub-pixels has a configuration in which a plurality of organic EL elements that emit different colors are stacked.
Japanese Patent Laid-Open No. 2005-174639

  Not only the structure of the organic EL device as disclosed in Patent Document 1, but in the organic EL device, a pixel which is a unit for displaying a color image is composed of a plurality of adjacent subpixels. In order to prevent color mixing between adjacent sub-pixels during the formation of the organic layer, a partition wall for partitioning the sub-pixel is disposed between two adjacent sub-pixels, and this partition wall portion is a non-light emitting region. It becomes. The width of the partition wall between the two adjacent sub-pixels, that is, the width of the non-light-emitting region has a width that can be observed with the naked eye depending on the resolution of the organic EL device. For this reason, there is a concern that high resolution cannot be obtained depending on the displayed image.

  The organic EL device of the present invention has a plurality of pixels, and each of the pixels includes a first organic layer, a second organic layer, and a third organic layer that emit different colors. The first organic layer and the second organic layer are juxtaposed with respect to the substrate, the first organic layer and the third organic layer are stacked, and the second organic layer and the third organic layer are stacked. An organic layer is laminated, and the light emitting region of the third organic layer is a light emitting region of the first organic layer, a light emitting region of the second organic layer, the first organic layer, and the second organic layer. The third organic layer is formed so as to be located above or below the non-light-emitting region between them.

  According to the configuration of the present invention, even when the respective organic layers emit light simultaneously, the non-light emitting region between the light emitting regions of the organic layer is reduced, and higher resolution can be obtained.

  The best mode for carrying out the present invention will be described with reference to the drawings. For parts not specifically shown or described in the present specification, well-known or well-known techniques in the art are applied. Further, a top emission type organic EL device that extracts light to the side opposite to the substrate will be described as an example, but the organic EL device of the present invention is not limited to this.

  The light emitting region of the organic layer is a region where two electrodes and an organic layer sandwiched between the two electrodes are formed in a direction perpendicular to the substrate, and a partition is formed between the two electrodes. This is not an area. On the other hand, the non-light emitting region is a region where at least one of the two electrodes and the organic layer sandwiched between the two electrodes is not formed in the direction perpendicular to the substrate, or a partition wall is formed between the two electrodes. It is a region that is formed.

(First embodiment)
FIG. 1 is a schematic diagram of an organic EL device according to this embodiment. In this organic EL device, a first organic layer 2 and a second organic layer 3 are formed on a first electrode 1, and a second electrode 4, a third organic layer 5, and a third electrode 6 are disposed thereon. Has been. Further, in this organic EL device, one pixel is composed of two sub-pixels arranged in parallel, and the two sub-pixels are composed of a plurality of organic layers that each emit light of different colors. The first subpixel has a first organic layer 2 and a third organic layer 5 stacked thereon, and the second subpixel has a second organic layer 3 and a third organic layer 5 stacked thereon. Here, the first organic layer 2, the second organic layer 3, and the third organic layer 5 emit different colors. In general, the combination of the emission colors of each organic layer is composed of three colors of blue, green, and red.

  In addition, the first organic layer 2 and the third organic layer 5 in one pixel are stacked via a common electrode (second electrode 4), and the second organic layer 3 and the third organic layer 5 are stacked. The layer 5 is laminated via the same common electrode (second electrode 4). The second electrode 4 is provided over a plurality of pixels. A common electrode is shared by both of the two organic EL elements stacked in one pixel, and is shared by a plurality of organic EL elements in a plurality of pixels by being provided across the plurality of pixels. Electrode.

  2 is an xy plan view of electrodes in the organic EL device according to the present embodiment, FIG. 3 is a cross-sectional view taken along the line AA ′ in FIG. 1, and FIG. 4 is along the line BB ′ in FIG. FIG. On the substrate 10, a gate insulating layer 11, a thin film transistor (hereinafter referred to as TFT) 18, a thin film transistor insulating layer 12, a planarizing layer 13, and a first electrode (1a, 1b, 1c) are arranged. On the first electrode, the first organic layer 2, the second organic layer 3, the second electrode 4, the third organic layer 5, the third electrode (6a, 6b, 6c), sealing means (not shown) ) Is formed. A partition wall 14 is provided between the first organic layer 2 and the second organic layer 3.

  2 and 3, two subpixels are arranged in parallel in the pixel 100, and a plurality of pixels are arranged on the substrate 10. In correspondence with the two subpixels in the pixel 100, the first electrode is formed by patterning the first electrodes 1a and 1b, and the third electrode is formed by patterning the third electrodes 6a and 6b.

  One subpixel includes an organic EL element including a first electrode 1a (1b), a first organic layer 2 (second organic layer 3), and a second electrode 4, and a second electrode 4 and a third organic layer. 5 and an organic EL element composed of the third electrode 6a (6b) are stacked. The second electrode 4 is shared by the two organic EL elements stacked in the sub-pixel as a common electrode, and is formed across the pixel 100 and the pixel 101. The second electrode 4 is provided over a plurality of pixels.

  The first electrode is preferably made of a highly reflective material such as Al or Ag so that the light generated from each organic layer can be reflected. In addition, on the first electrode, in order to improve the charge injection property to the first organic layer 2 and the second organic layer 3, a transparent conductive film such as ITO and IZO and a metal film made of a highly reflective material. It is good also as a laminated film structure. In addition, since these transparent conductive films such as ITO and IZO have optical transparency, they can be used as the second electrode 4. In addition, the second electrode 4 can be made of a metal such as Al or Ag by forming a thin film so as to have optical transparency.

  Each of the first organic layer 2 and the second organic layer 3 is formed in a desired region in the pixel by mask vapor deposition. The third organic layer 5 may be formed in a desired region in the pixel by mask vapor deposition, but it is preferable that the third organic layer 5 be formed integrally over a plurality of pixels by widening the opening of the mask. Furthermore, it is preferable that the third organic layer 5 is formed by vapor deposition over all pixels without using a mask.

  Organic layer is single layer type (light emitting layer), two layer type (hole transport layer / light emitting layer), three layer type (hole transport layer / light emitting layer / electron transport layer), four layer type (hole injection layer) / Hole transport layer / light emitting layer / electron injection layer), and any of the five-layer type (hole injection layer / hole transport layer / light emitting layer / electron transport layer / electron injection layer).

  Organic light-emitting materials constituting each light-emitting layer are triarylamine derivatives, stilbene derivatives, polyarylenes, aromatic condensed polycyclic compounds, aromatic heterocyclic compounds, aromatic heterocyclic condensed compounds, metal complex compounds, and the like alone. Oligobodies or composite oligobodies can be used. However, the structure of the present invention is not limited to these materials. In addition, the film thickness of a light emitting layer should be about 0.05 micrometer-0.3 micrometer, Preferably it is about 0.05-0.15 micrometer.

  In the case of using a hole transport layer, phthalocyanine compounds, triarylamine compounds, conductive polymers, perylene compounds, Eu complexes, and the like can be used as the materials. It is not limited. As the material for using the electron transport layer, Alq3 in which an 8-hydroxyquinoline trimer is coordinated to aluminum, an azomethine zinc complex, a distyrylbiphenyl derivative system, and the like can be used. It is not limited to.

  In the pixel 100, the first electrodes 1a, 1b, the second electrode 4, and the third electrodes 6a, 6b are individually connected to the TFT 18, and each organic EL element can be driven independently. In particular, as shown in FIG. 4, the third electrode 6 a is connected to the TFT 18 through a contact hole 17 formed after the third organic layer 5 is formed on the second electrode 4. More specifically, the third electrode 6 a is connected to the conductive member 15 separated from the first electrode through the contact hole 17, and the conductive member 15 is connected to the TFT 18 through the contact hole 16. . Further, the TFT 18 is provided according to the arrangement of each organic layer, but is desirably provided below the organic layer.

  As a method for forming this contact hole, laser processing is preferable, and known methods generally used for thin film processing such as YAG laser (including SHG and THG) and excimer laser can be used. A predetermined pattern is formed on the first organic layer 2 or the third organic layer 5 by scanning with these laser beams reduced to several μm, or by using a planar light source through a mask that transmits the contact hole portion. It is possible to form a contact hole at a desired position by irradiating with.

  Then, the third electrode formed on the third organic layer 5 may be formed by patterning by the above-described laser processing or the like after forming the base electrode material, or may be selected using a metal mask. It may be formed automatically. The electrode material is preferably a highly transmissive material, and a transparent conductive film such as ITO or IZO can be used. Similarly to the second electrode 4, the third electrode may be formed of a light-transmitting metal thin film such as Al or Ag.

  As shown in FIG. 3, in the pixel 100, the first organic layer 2 and the second organic layer 3 are juxtaposed with respect to the substrate 10. Further, the first organic layer 2 and the third organic layer 5, and the second organic layer 3 and the third organic layer 5 are stacked. The light emitting region of the first organic layer 2 is defined by the first electrode 1 a, the second electrode 4, and the partition wall 14, and the light emitting region of the second organic layer 3 is the first electrode 1 b, the second electrode 4, and the partition wall 14. It is prescribed by. In other words, a region where the partition wall 14 is formed becomes a non-light emitting region 200 between the light emitting region of the first organic layer 2 and the light emitting region of the second organic layer 3. The third organic layer 5 defined by the second electrode 4 and the third electrode 6a is formed on the non-light emitting region 200 and on the respective light emitting regions of the first organic layer 2 and the second organic layer 3. The third organic layer 5 is formed so that the light emitting region is located. Further, since the third electrodes 6a and 6b are separated from each other, the third organic layer 5 in the region where the third electrode is separated does not emit light, and the region where the third electrode is separated is the first. 3 becomes the non-light-emitting region 200 of the organic layer 5. Under the non-light emitting region 200 of the third organic layer 5, the light emitting region of the second organic layer 3 is located. For this reason, when each organic layer of the pixel 100 emits light simultaneously, the possibility that each non-light-emitting region 200 in the pixel 100 is visually observed is reduced.

  The pixel 100 is also formed on the non-light emitting region 200 between the pixels between the light emitting region of the second organic layer 3 formed in the pixel 100 and the light emitting region of the first organic layer 2 formed in the pixel 101. The light emitting region of the third organic layer 5 formed in is located. On the other hand, a region where the third electrodes 6b and 6c are separated from each other is a non-light-emitting region 200 of the third organic layer 5 between the pixels 100 and 101. Below the non-light-emitting region 200, the pixel The light emitting region of the first organic layer 2 101 is located. Due to this configuration, when the organic layers of the pixels 100 and 101 are caused to emit light at the same time, it is possible to reduce the non-light emitting region 200 between the pixels being visually observed.

  Sealing means (not shown) is formed to protect the organic EL element composed of each organic layer, each electrode, and the like. In general, an ultraviolet curable resin or the like is applied to the outermost peripheral portion of the organic EL element, and is blocked from the outside air by a sealing glass.

  In the above-described configuration, the third electrode is patterned to form the third electrodes 6a and 6b so that the third organic layer 5 can independently emit light in the sub-pixels. The third electrode may be connected. Also in this case, not only on the respective light emitting regions of the first organic layer 2 and the second organic layer 3, but also between the light emitting region of the first organic layer 2 and the light emitting region of the second organic layer 3. The third organic layer 5 is also formed on the non-light emitting region 200 in such a manner that the light emitting region of the third organic layer 5 is located. For this reason, there exists an effect of the present invention.

  Further, since the third organic layer 5 has an area twice as large as that of the first organic layer 2 and the second organic layer 3 in each pixel, the third organic layer 5 has blue, green and red colors. Among them, it is preferable to arrange an organic layer that emits green light with the highest visibility.

  In the case of a bottom emission type organic EL device that extracts light from the substrate 10 side, the first electrode is preferably a highly transmissive material, for example, ITO or IZO, and the third electrode is made of Al, Ag, or the like. A highly reflective material is desirable.

<Equivalent circuit of the organic EL device of the present invention>
An example of an equivalent circuit of the organic EL device of the present invention is shown in FIG. Each pixel includes switching TFTs 301a, 301b, 301c, and 301d, organic EL elements stacked with driving TFTs 302a, 302b, 302c, and 302d, and capacitors 303a, 303b, 303c, and 303d.

  Here, the gate electrodes of the switching TFTs 301 a, 301 b, 301 c, and 301 d are connected to the gate signal line 304. The source regions of the switching TFTs 301a, 301b, 301c, and 301d are connected to the source signal lines 305a, 305b, 305c, and 305d, and the drain regions are connected to the gate electrodes of the driving TFTs 302a, 302b, 302c, and 302d. .

  Further, the source regions of the driving TFTs 302a, 302b, 302c, and 302d are connected to the power supply line 306, and the respective drain regions are electrodes (first electrode 1a, third electrode 6a, first electrode) of one end of the organic EL element. 1b and the third electrode 6b).

  One of the two terminals of each of the capacitors 303a, 303b, 303c, and 303d is connected to the gate electrode of each of the driving TFTs 302a, 302b, 302c, and 302d, and the other is connected to the power supply line 306.

  In this manner, the driving TFTs 302a, 302b, 302c, and 302d and the organic EL element are connected in series. The current flowing in the organic EL element is controlled by the driving TFTs 302a, 302b, 302c, and 302d in accordance with the data signal supplied from the source signal lines 305a, 305b, 305c, and 305d, so that the light emission of each organic EL element is independent. Controlled.

  A hole transport layer, a light emitting layer, and an electron injection layer are formed in this order on the first electrode 1a (1b) as the first organic layer 2 (second organic layer 3). The organic layer 5 is formed in the order of an electron transport layer, a light emitting layer, and a hole transport layer. For this reason, as shown in FIG. 5, the rectification characteristics are reversed between the first organic layer 2 (second organic layer 3) and the third organic layer 5. The order of layers in the organic layer is not limited to this, and the first organic layer 2 (second organic layer 3) and the third organic layer 5 are formed so that the rectification characteristics are in the same direction. Is also possible.

(Second Embodiment)
A schematic diagram of the organic EL device of this embodiment is shown in FIG. The organic EL device of the present embodiment is different from the organic EL device of the first embodiment in the direction perpendicular to the substrate, and the first organic layer 2 and the second organic layer 3 and the substrate of the third organic layer 5 However, it is different in that it is configured in the reverse stacking order. That is, in the organic EL device of the present embodiment, the third organic layer 5 is provided on the substrate, and the first organic layer 2 and the second organic layer 3 are formed on the substrate via the second electrode 4 thereon. On the other hand, the structure laminated | stacked in the state juxtaposed is taken.

  As shown in FIG. 6, in the pixel, the light emitting region of the third organic layer 5 is below the light emitting regions of the first organic layer 2 and the second organic layer 3, and the light emitting region of the first organic layer 2. The third organic layer 5 is formed so as to be located under the non-light emitting region 200 between the light emitting region of the second organic layer 3 and the second organic layer 3. Further, the light emitting region of the first organic layer 2 or the second organic layer 3 is located on the non-light emitting region 200 of the third organic layer 5. Therefore, the effect of the present invention is achieved in the pixel.

  Furthermore, between two adjacent pixels, between the pixels between the light emitting region of the second organic layer 3 formed in one pixel and the light emitting region of the first organic layer 2 formed in the other pixel. The light emitting region of the third organic layer 5 is also located under the non-light emitting region 200. On the other hand, the light emitting region of the first organic layer 2 or the second organic layer 3 is located on the non-light emitting region 200 of the third organic layer 5 between the two adjacent pixels. . Therefore, the effect of the present invention is also achieved between two adjacent pixels.

(Third embodiment)
FIG. 7 shows a schematic diagram of the organic EL device of the present embodiment. As shown in FIG. 7, the first organic layer 2 is formed as a common layer with a pixel adjacent to the pixel 102 (a pixel located in the negative direction with respect to the pixel 102 in the X direction). Further, the second organic layer 3 is formed as a common layer with a pixel adjacent to the pixel 102 (a pixel located in a positive direction with respect to the pixel 102 in the X direction) on the side opposite to the adjacent pixel. . This configuration is different from the organic EL device of the first embodiment. In this configuration, the opening of the mask can be widened, and the rib width between the openings can also be widened. Deterioration is less likely to occur.

  Even in this configuration, in the pixel, the light emitting region of the third organic layer 5 is above the non-light emitting region 200 between the light emitting region of the first organic layer 2 and the light emitting region of the second organic layer 3. Since the 3rd organic layer 5 is formed so that it may be located also, there exists an effect of this invention.

  Further, of two adjacent pixels, non-light emission between the light emitting region of the second organic layer 3 formed in one pixel and the light emitting region of the first organic layer 2 formed in the other pixel On the region 200, the light emitting region of the third organic layer 5 is located. The non-light-emitting region 200 refers to a region including the non-light-emitting region 200 formed between the pixels of the first organic layer 2 or the second organic layer 3 and formed in common with two adjacent pixels. Therefore, the effect of the present invention is also achieved between two adjacent pixels.

  1, 3, 6, and 7, in the X direction, above or below the non-light-emitting region between the sub-pixels and between the light-emitting regions of the organic layer between two adjacent pixels, Although the structure in which the light emitting region of the stacked organic layer is located is shown, the present invention is not limited to this structure. 1, 3, 6, and 7, for example, the same configuration can be adopted in the Y direction (direction perpendicular to the paper surface).

1 is a schematic diagram illustrating an organic EL device according to a first embodiment. It is an xy plan view of an electrode of the organic EL device according to the first embodiment. It is sectional drawing corresponding to the AA 'line of FIG. It is sectional drawing corresponding to the BB 'line of FIG. 1 is an equivalent circuit diagram of an organic EL device according to a first embodiment. It is a schematic diagram which shows the organic EL apparatus of 2nd Embodiment. It is a schematic diagram which shows the organic electroluminescent apparatus which concerns on 3rd Embodiment.

Explanation of symbols

1, 1a, 1b, 1c 1st electrode 2 1st organic layer 3 2nd organic layer 4 2nd electrode 5 3rd organic layer 6, 6a, 6b, 6c 3rd electrode 10 Substrate 11 Gate insulating layer 12 Thin film transistor Insulating film 13 Planarizing film 14 Partition 15 Conductive member 16, 17 Contact hole 18 Thin film transistor (TFT)
100, 101, 102 pixels 200 non-light emitting area

Claims (3)

And an organic EL device having a first organic layer, a second organic layer, and a third organic layer that emit different colors.
The first organic layer and the second organic layer are juxtaposed to a substrate;
The first organic layer and the third organic layer are laminated,
The second organic layer and the third organic layer are laminated,
The light emitting region of the third organic layer is a light emitting region of the first organic layer, a light emitting region of the second organic layer, a light emitting region of the first organic layer, and a light emitting region of the second organic layer. An organic EL device, which is located above or below a non-light emitting region between the two.   The third organic layer is formed over a plurality of pixels. Of the two adjacent pixels, the second organic layer formed in one pixel and the first pixel formed in the other pixel. The organic EL device according to claim 1, wherein the light emitting region of the third organic layer is located above or below the non-light emitting region between the light emitting region of the organic layer.   A common electrode provided over a plurality of pixels, wherein the first organic layer and the third organic layer are stacked via the common electrode; and the second organic layer and the third organic layer are stacked. The organic EL device according to claim 1, wherein the organic layer is stacked via the common electrode.

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