JP6640450B2 - Light emitting device - Google Patents

Description

  The present invention relates to a light emitting device.

  In recent years, an organic EL element has been increasingly used as a light source of a light emitting device or the like. The organic EL element has a configuration in which an organic layer is interposed between a first electrode and a second electrode. A light-transmitting conductive material is used for the first electrode. Generally, a light-transmitting conductive material has higher resistance than a metal. Therefore, in many cases, the first electrode is partially provided with a conductive layer (for example, an auxiliary electrode) made of a metal material.

  For example, Patent Literature 1 describes that by arranging auxiliary electrodes in a pattern similar or similar to the Fibonacci sequence, coloring and moiré fringes when external light is reflected can be suppressed.

  Further, in Patent Document 2, a thin film is formed on a substrate, a micro crack is generated in the thin film due to shrinkage or the like, and then the micro crack is filled with a conductive material to form a mesh-shaped conductive layer. It is described to form. Patent Document 2 describes that a mesh-shaped conductive layer can be formed by a plating method.

JP 2012-84535 A JP 2004-228057 A

  In a light-emitting device having an organic EL element, when a long time has passed since manufacturing, a portion (light-emitting portion) where light emission is partially reduced due to moisture or the like may be generated. In particular, when a resin substrate is used, even if a barrier film is used, pinholes are unavoidable, and a point-like non-light-emitting portion called a dark spot is generated due to moisture penetration from the pinholes. An example of the problem to be solved by the present invention is to make the non-light emitting portion inconspicuous.

The invention according to claim 1 includes a substrate,
A light emitting unit formed on the substrate and having a first electrode, a second electrode, and an organic layer located between the first electrode and the second electrode;
A plurality of conductive layers in contact with the first electrode and including a material that does not transmit visible light;
With
The first electrode transmits visible light;
The conductive layer is a light-emitting device that extends in a first direction, and a distance between at least one pair of adjacent conductive layers is different from a distance between another pair of adjacent conductive layers. .

The invention according to claim 2 includes a substrate,
A light emitting unit formed on the substrate and having a first electrode, a second electrode, and an organic layer located between the first electrode and the second electrode;
A plurality of conductive layers in contact with the first electrode and including a material that does not transmit visible light;
With
The first electrode transmits visible light;
The light emitting device, wherein the conductive layer extends in a first direction, and at least one pair of two adjacent conductive layers has a portion where a distance between the two conductive layers is changed. .

FIG. 2 is a plan view illustrating a configuration of the light emitting device according to the first embodiment. It is the figure which removed the 2nd electrode from FIG. FIG. 3 is a diagram in which an organic layer and an insulating layer are removed from FIG. 2. It is AA sectional drawing of FIG. It is a top view which shows the modification of FIG. It is a top view which shows the modification of FIG. FIG. 3 is a view of the light emitting device as viewed from a second surface side of the substrate. FIG. 11 is a plan view illustrating a layout of conductive layers in a light emitting device according to a modification. It is a top view which shows the modification of FIG. It is a top view which shows the modification of FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings, the same components are denoted by the same reference numerals, and description thereof will not be repeated.

  FIG. 1 is a plan view illustrating a configuration of a light emitting device 10 according to the first embodiment. FIG. 2 is a diagram in which the second electrode 130 is removed from FIG. FIG. 3 is a diagram in which the organic layer 120 and the insulating layer 150 are removed from FIG. FIG. 4 is a sectional view taken along line AA of FIG.

The light emitting device 10 according to the embodiment includes a substrate 100, a light emitting unit 140, and a plurality of conductive layers 180. The light emitting section 140 is formed on the substrate 100 and has a first electrode 110, a second electrode 130, and an organic layer 120. The first electrode 110 transmits visible light. The organic layer 120 is located between the first electrode 110 and the second electrode 130. The conductive layer 180 is in contact with the first electrode 110 and does not transmit visible light. The conductive layer 180 extends in the first direction (the y direction in FIG. 3). The distance between at least one pair of adjacent conductive layers 180 (for example, w _{1 in} FIG. 3) is different from the distance between another pair of adjacent conductive layers 180 (for example, w _{2 in} FIG. 3). The details will be described below.

When the light emitting device 10 is a bottom emission type light emitting device, the substrate 100 is a light-transmitting substrate such as a glass substrate or a resin substrate. On the other hand, when the light-emitting device 10 is a top emission light-emitting device, the substrate 100 does not need to have a light-transmitting property. Further, the substrate 100 may have flexibility. In this case, the light emitting device 10 can be used in a state where the substrate 100 is curved. In the case where the substrate 100 has flexibility, the thickness of the substrate 100 is, for example, not less than 10 μm and not more than 1000 μm. The substrate 100 is, for example, a polygon such as a rectangle. When the substrate 100 is a resin substrate, the substrate 100 is formed using, for example, PEN (polyethylene naphthalate), PES (polyethersulfone), PET (polyethylene terephthalate), or polyimide. When the substrate 100 is a resin substrate, an inorganic barrier film such as SiN _x or SiON is formed on at least one surface (preferably, both surfaces) of the substrate 100 in order to suppress the transmission of moisture through the substrate 100. I have. Note that a flattening layer (for example, an organic layer) may be provided between the inorganic barrier film and the substrate 100.

  A light emitting unit 140 is provided on the first surface 102 of the substrate 100. The light emitting section 140 has a configuration in which the first electrode 110, the organic layer 120, and the second electrode 130 are stacked in this order.

  The first electrode 110 is a transparent electrode having optical transparency. The material of the transparent electrode is a metal-containing material, for example, a metal oxide such as ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide), IWZO (Indium Tungsten Zinc Oxide), or ZnO (Zinc Oxide). The thickness of the first electrode 110 is, for example, not less than 10 nm and not more than 500 nm. The first electrode 110 is formed using, for example, a sputtering method or an evaporation method. Note that the first electrode 110 may be a carbon nanotube or a conductive organic material such as PEDOT / PSS.

  The organic layer 120 has a light emitting layer. The organic layer 120 has, for example, a configuration in which a hole injection layer, a light emitting layer, and an electron injection layer are stacked in this order. A hole transport layer may be formed between the hole injection layer and the light emitting layer. Further, an electron transport layer may be formed between the light emitting layer and the electron injection layer. The organic layer 120 may be formed by an evaporation method. Further, at least one of the organic layers 120, for example, a layer in contact with the first electrode 110 may be formed by a coating method such as an inkjet method, a printing method, or a spray method. Note that, in this case, the remaining layers of the organic layer 120 are formed by an evaporation method. Further, all the layers of the organic layer 120 may be formed by using a coating method.

  The second electrode 130 is made of a material that does not transmit visible light, for example, a metal selected from the first group consisting of Al, Au, Ag, Pt, Mg, Sn, Zn, and In, or a metal selected from the first group. A metal layer comprising an alloy of the selected metal is included. In this case, the second electrode 130 has a light shielding property. The thickness of the second electrode 130 is, for example, not less than 10 nm and not more than 500 nm. However, the second electrode 130 may be formed using the material exemplified as the material of the first electrode 110. The second electrode 130 is formed using, for example, a sputtering method or an evaporation method.

  The materials of the first electrode 110 and the second electrode 130 described above are for the case where the light emitting device 10 is of a bottom emission type. When the light emitting device 10 is a top emission type, the material of the first electrode 110 and the material of the second electrode 130 are reversed. That is, the material of the second electrode 130 is used as the material of the first electrode 110, and the material of the first electrode 110 is used as the material of the second electrode 130.

  Then, as shown in FIG. 3, a plurality of conductive layers 180 are formed between the first electrode 110 and the organic layer 120. The conductive layer 180 functions as an auxiliary electrode and includes a material having a lower resistance than the first electrode 110, for example, a metal layer of Al or the like. By providing the conductive layer 180, the apparent resistance of the first electrode 110 is reduced. The conductor layer 180 may have a multilayer structure. In this case, the conductor layer 180 is, for example, a first conductive layer which is a metal layer such as Mo or Mo alloy, a second conductive layer which is a metal layer such as Al or Al alloy, and a metal layer such as Mo or Mo alloy. Are stacked in this order.

Width _{w 3} of the conductive layer 180 is, for example, 200μm or more. Therefore, when a person approaches the light emitting device 10 to some extent (for example, a distance enough to recognize the non-light emitting portion 142 described later, specifically, within 100 cm), the person can visually recognize the conductive layer 180.

In the example shown in this figure, the plurality of conductive layers 180 all extend in the first direction (the y direction in the figure), and also cross the second direction in the first direction (the x direction in the figure). ). The distance between adjacent conductive layers 180 is not constant. Therefore, as described above, the distance between at least one pair of adjacent conductive layers 180 (for example, w _{1 in} FIG. 3) is equal to the distance between another pair of adjacent conductive layers 180 (for example, w _{2 in} FIG. 3). Is different. In other words, in the light emitting device 10, there are a plurality of intervals between the conductive layers 180. Preferably, three or more of the above-mentioned intervals are different from each other. Moreover, selecting any of the three conductive layers 180 adjacent to each other, preferably to w ₁ and w ₂ described above are different from each other. In this case, since the intervals between the conductive layers 180 appear irregular, the shadow of the conductive layer 180 generated when the light emitting unit 140 emits light looks like a pattern.

  Further, in the example shown in FIG. 3, the width of one conductive layer 180 is constant. However, as shown in FIG. 5, at least one conductive layer 180 may have a portion where the width is changed. By doing so, a pattern emerges in the light emitting section 140 due to the conductive layer 180. Therefore, the shadow of the conductive layer 180 generated when the light emitting unit 140 emits light looks more like a pattern.

  Further, as shown in FIG. 6, the light emitting device 10 may further include at least one dot-shaped conductive layer 180. This is because the non-light-emitting portion 142 described later is often formed in a dot shape. Further, at least one of the conductive layers 180 over the dots may overlap with the conductive layer 180 in a stripe shape. When the dot-shaped conductive layer 180 is formed, the diameter of the conductive layer 180 is preferably, for example, 200 μm or more. The non-light-emitting portion 142 may be formed in various sizes, large and small, and may not be visible to human eyes. However, it is only necessary to make the non-light emitting portion invisible to human eyes. is there.

  Note that the conductive layer 180 may be formed between the first electrode 110 and the substrate 100. In this case, the conductive layer 180 is in contact with the surface of the first electrode 110 facing the substrate 100.

  The edge of the first electrode 110 is covered with the insulating layer 150. The insulating layer 150 defines a region of the first electrode 110 to be the light emitting unit 140. In other words, the insulating layer 150 surrounds the light emitting unit 140. A part of the insulating layer 150 is located between the light emitting unit 140 and the first terminal 112. The insulating layer 150 is formed of, for example, a photosensitive resin material such as polyimide, and surrounds a portion of the first electrode 110 that becomes a light emitting region of the light emitting unit 140. By providing the insulating layer 150, a short circuit between the first electrode 110 and the second electrode 130 at the edge of the first electrode 110 can be suppressed. The insulating layer 150 is formed by applying a coating material to be the insulating layer 150 and then exposing and developing the coating material. The insulating layer 150 may cover a part (for example, an edge part) of the conductive layer 180. In this way, a short circuit at the edge of the conductive layer 180 (as a normally used auxiliary electrode) is prevented.

  The light emitting device 10 has a first terminal 112 and a second terminal 132. The first terminal 112 is connected to the first electrode 110, and the second terminal 132 is connected to the second electrode 130. The first terminal 112 and the second terminal 132 have, for example, a layer formed of the same material as the first electrode 110. Further, at least a part of at least one of the first terminal 112 and the second terminal 132 may include a metal having lower resistance than the first electrode 110 on this layer. A layer formed of the same material as the first electrode 110 among the first terminal 112 and the second terminal 132 is formed in the same step as the first electrode 110. Therefore, the first electrode 110 is integrated with at least a part of the layer of the first terminal 112. Note that an extraction wiring may be provided between the first terminal 112 and the first electrode 110. In addition, a lead wiring may be provided between the second terminal 132 and the second electrode 130.

  The positive terminal of the control circuit is connected to the first terminal 112 via a conductive member such as a bonding wire or a lead terminal, and the second terminal 132 is connected to the control circuit via a conductive member such as a bonding wire or a lead terminal. The negative terminal is connected.

  Note that the plurality of conductive layers 180 illustrated in FIGS. 3, 5, and 6 may be connected to each other on the first terminal 112.

  Further, the light emitting device 10 may have a sealing member. This sealing member has translucency, and is formed using, for example, glass or resin. The sealing member has a polygonal or circular shape similar to that of the substrate 100, and has a shape provided with a concave portion at the center. The edge of the sealing member is fixed to the substrate 100 with an adhesive. Thus, the space surrounded by the sealing member and the substrate 100 is sealed. The light emitting unit 140 is located in a sealed space. Note that the sealing member may be a film formed by an ALD method or a film formed by a CVD method.

  Next, a method for manufacturing the light emitting device 10 will be described. First, the first electrode 110 is formed on the substrate 100 by using, for example, a sputtering method. At this time, the first electrode 110 is formed into a predetermined pattern by using a mask or using wet etching. At this time, the first terminal 112 and the second terminal 132 are also formed.

  Next, a conductive layer 180 is formed over the first electrode 110 by using, for example, a sputtering method. At this time, the conductive layer 180 is formed into the above-described pattern using a mask, wet etching, or the like.

  Next, a coating material to be the insulating layer 150 is applied on the edge of the first electrode 110. Next, the coating material is cured. Thereby, the insulating layer 150 is formed. Note that when the insulating layer 150 is formed using a photosensitive material, the coating material to be the insulating layer 150 is also applied to a region other than the edge of the first electrode 110. Then, the insulating layer 150 is formed on the edge of the first electrode 110 by performing the exposure step and the development step.

  Next, the organic layer 120 is formed. A layer of the organic layer 120 formed by a coating method such as an inkjet method is formed by positioning a coating material in a region of the first electrode 110 surrounded by the insulating layer 150. Next, a second electrode 130 is formed. The second electrode 130 is also formed in a predetermined pattern using, for example, a mask. After that, the light emitting unit 140 is sealed using a sealing member.

  FIG. 7 is a view of the light emitting device 10 as viewed from the second surface 104 side of the substrate 100. When the light emitting device 10 emits light, no light is emitted from the portion of the second surface 104 where the conductive layer 180 is formed, as described above. For this reason, a shadow occurs in a portion of the light emitting device 10 where the conductive layer 180 is located.

On the other hand, the organic layer 120 is vulnerable to moisture and the like. For this reason, when a long time has passed since the manufacture of the light emitting device 10, the non-light emitting portion 142 may be generated in the light emitting portion 140 of the light emitting device 10. However, in the present embodiment, the distance between at least one pair of adjacent conductive layers 180 (for example, w _{1 in} FIG. 3) is different from the distance between another pair of adjacent conductive layers 180 (for example, w _{2 in} FIG. 3). . For this reason, the non-light-emitting portion 142 is more invisible to the shadow caused by the conductive layer 180 than in a case where the conductive layers 180 are arranged at equal intervals, and thus is less noticeable.

  In particular, in the case where the substrate 100 is formed of a material containing a resin, even if a barrier film for moisture prevention is provided on the substrate 100, pinholes may be generated in the barrier film. It is difficult to completely prevent intrusion, and the occurrence of the non-light emitting portion 142 is remarkable. Also in this case, by setting the width of the conductive layer 180 to at least 200 μm or more, the non-light emitting portion 142 can be made inconspicuous. Further, since the conductive layers 180 are formed at intervals in the light emitting region, the flexibility of the substrate 100 is not impaired.

(Modification)
FIG. 8 is a plan view illustrating a layout of the conductive layer 180 in the light emitting device 10 according to the modification. The light emitting device 10 according to the present modification has the same configuration as the light emitting device 10 according to the embodiment except for the layout of the conductive layer 180.

  In this modification, the conductive layer 180 has a pattern. For this reason, at least one set of two adjacent conductive layers 180 has a portion where the distance between the two conductive layers 180 is changed. In the example shown in this drawing, the interval between the conductive layers 180 changes in all places.

  In the example shown in FIG. 8, the conductive layer 180 has a pattern similar to a watermelon skin. However, the conductive layer 180 may have a zebra-like pattern as shown in FIG. 9 or may have a woodgrain pattern as shown in FIG.

  Also in this modification, since the conductive layer 180 draws a pattern, the non-light emitting portion 142 is inconspicuous for the same reason as in the embodiment.

  As described above, the embodiments and examples have been described with reference to the drawings. However, these are examples of the present invention, and various configurations other than those described above can be adopted.

Reference Signs List 10 light emitting device 100 substrate 110 first electrode 120 organic layer 130 second electrode 140 light emitting unit 150 insulating layer 180 conductive layer

Claims (5)

Board and
A light emitting unit formed on the substrate and having a first electrode, a second electrode, and an organic layer located between the first electrode and the second electrode;
A plurality of conductive layers in contact with the first electrode and including a material that does not transmit visible light;
With
The first electrode transmits visible light;
The conductive layer has a stripe-like portion extending in a dot-like portion and the first direction,
Of the stripe portion of the conductive layer, the interval of the stripe portion adjacent at least one pair are Unlike interval of the stripe portions adjacent the other set,
A light-emitting device in which a region overlapping with the conductive layer is a non-light-emitting region . Board and
A light emitting unit formed on the substrate and having a first electrode, a second electrode, and an organic layer located between the first electrode and the second electrode;
A plurality of conductive layers in contact with the first electrode and including a material that does not transmit visible light;
With
The first electrode transmits visible light;
The conductive layer has a dot-shaped portion and a stripe-shaped portion extending in the first direction;
Wherein one of the stripe of the conductive layer, possess at two of the stripe portion adjacent at least one set, a portion where the interval of the two stripe portion is changed,
A light-emitting device in which a region overlapping with the conductive layer is a non-light-emitting region . The light emitting device according to claim 1, wherein
A light emitting device wherein the diameter of the dot- shaped portion is 200 μm or more. The light-emitting device according to any one of claims 1 to 3,
A light emitting device wherein at least one of the conductive layers has a portion having a variable width. The light emitting device according to any one of claims 1 to 4,
A light emitting device wherein the substrate is formed of a resin substrate having at least one barrier film.

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