WO2017158767A1

WO2017158767A1 - Light-emitting device

Info

Publication number: WO2017158767A1
Application number: PCT/JP2016/058360
Authority: WO
Inventors: 真滋中嶋; 田中　信介
Original assignee: パイオニア株式会社
Priority date: 2016-03-16
Filing date: 2016-03-16
Publication date: 2017-09-21
Also published as: JPWO2017158767A1

Abstract

An insulating layer (150) is formed of an inorganic material. An organic layer (120) includes a light-emitting layer (123) and a positive-hole injection layer (121). The positive-hole injection layer (121) is a transition metal oxide layer and, more specifically, is a molybdenum oxide (MoO_x) layer, for example. The positive-hole injection layer (121) is disposed between a first electrode (110) and the light-emitting layer (123). In this manner, the organic layer (120) includes a first transition metal oxide (transition metal oxide forming the positive-hole injection layer (121)) between the light-emitting layer (123) and the first electrode (110).

Description

Light emitting device

The present invention relates to a light emitting device.

In recent years, light emitting devices having an organic layer have been developed. Such a light-emitting device has a first electrode and a second electrode that face each other with an organic layer interposed therebetween. The organic layer includes a light emitting layer. Electrons and holes are recombined in the light emitting layer by the voltage between the first electrode and the second electrode. In this way, light is emitted from the light emitting layer.

As described in Patent Document 1, a hole injection layer may be provided between the first electrode and the light emitting layer. The hole injection layer of Patent Document 1 contains a transition metal oxide.

JP 2005-32618 A

In a light emitting device, an insulating layer for defining a light emitting part may be formed on a substrate. Such an insulating layer may contain a photosensitive resin (for example, polyimide). On the other hand, when the inventor examined, when the insulating layer contained photosensitive resin, it became clear that the substance which degrades a light emission part may have propagated through the insulating layer. In order to suppress such a substance from propagating through the insulating layer, the present inventor has studied to form the insulating layer from an inorganic material. However, as a result of studies by the present inventor, it has been clarified that when the insulating layer is made of an inorganic material, the luminance of the light emitting portion may be lowered due to the inorganic material of the insulating layer.

An example of a problem to be solved by the present invention is to suppress a decrease in luminance of the light emitting part even when the insulating layer defining the light emitting part is made of an inorganic material.

The invention described in claim 1
A substrate,
An insulating layer on the substrate and made of an inorganic material;
A light emitting part defined by the insulating layer on the substrate and having a first electrode, a second electrode, and an organic layer between the first electrode and the second electrode;
With
The organic layer is a light emitting device including a light emitting layer and a first transition metal oxide between the light emitting layer and the first electrode.

The above-described object and other objects, features, and advantages will be further clarified by a preferred embodiment described below and the following drawings attached thereto.

It is a top view which shows the light-emitting device which concerns on embodiment. It is the figure which removed the coating layer from FIG. FIG. 3 is a diagram in which a second conductive layer, a partition wall, and an insulating layer are removed from FIG. 2. FIG. 3 is a cross-sectional view taken along line AA in FIG. 2. FIG. 3 is a sectional view taken along line BB in FIG. FIG. 3 is a cross-sectional view taken along the line CC of FIG. FIG. 3 is a DD sectional view of FIG. 2. It is the figure which expanded the light emission part shown in FIG. 5 is a graph showing a result of a weather resistance test of a light emitting device according to an example, a result of a weather resistance test of a light emitting device according to comparative example 1, and a result of a weather resistance test of a light emitting device according to comparative example 2.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings, the same reference numerals are given to the same components, and the description will be omitted as appropriate.

FIG. 1 is a plan view showing a light emitting device 10 according to the embodiment. FIG. 2 is a view in which the covering layer 200 is removed from FIG. FIG. 3 is a diagram in which the second conductive layer 130a, the partition wall 160, and the insulating layer 150 are removed from FIG. 4 is a cross-sectional view taken along the line AA in FIG. 5 is a cross-sectional view taken along the line BB in FIG. 6 is a cross-sectional view taken along the line CC of FIG. 7 is a cross-sectional view taken along the line DD of FIG. FIG. 8 is an enlarged view of the light emitting unit 140 shown in FIG.

As shown in FIG. 2, the light emitting device 10 includes a substrate 100, an insulating layer 150, and a light emitting unit 140. As shown in FIGS. 4 to 8, the insulating layer 150 is on the substrate 100. The insulating layer 150 is made of an inorganic material. As shown in FIGS. 2, 4, and 5, the light emitting unit 140 is defined on the substrate 100 by an insulating layer 150. As shown in FIGS. 4, 5, and 8, the light emitting unit 140 includes a first electrode 110, an organic layer 120, and a second electrode 130. The organic layer 120 is between the first electrode 110 and the second electrode 130. As shown in FIG. 8, the organic layer 120 includes a light emitting layer 123 and a hole injection layer 121. The hole injection layer 121 is a transition metal oxide layer, specifically, for example, a molybdenum oxide (MoO _x ) layer. The hole injection layer 121 is between the first electrode 110 and the light emitting layer 123. As described above, the organic layer 120 includes the first transition metal oxide (transition metal oxide constituting the hole injection layer 121) between the light emitting layer 123 and the first electrode 110. Details will be described below.

In the example shown in FIGS. 1 to 8, the light emitting device 10 is a display. The light emitting device 10 includes a substrate 100, a conductive layer 170, a conductive layer 180, an insulating layer 150, an organic layer 120a, a second conductive layer 130a, a partition wall 160, and a coating layer 200.

As shown in FIGS. 4 to 8, the substrate 100 has a first surface 102 and a second surface 104. The second surface 104 is on the opposite side of the first surface 102 and is the back surface of the substrate 100. In the example shown in FIGS. 1 to 3, the shape of the first surface 102 is a rectangle. However, the shape of the first surface 102 may be a polygon other than a rectangle, for example.

The light emitting device 10 may be either bottom emission or top emission. When the light emitting device 10 is bottom emission, light from the plurality of light emitting units 140 is emitted from the second surface 104 of the substrate 100. In this case, the substrate 100 is made of a translucent material (for example, glass or resin). On the other hand, when the light emitting device 10 is top emission, the light from the plurality of light emitting units 140 is emitted from above the first surface 102 of the substrate 100. In this case, the substrate 100 may be made of the above-described translucent material or may be made of a material that does not have translucency.

The substrate 100 may have flexibility or may not have flexibility. When 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. When the substrate 100 has flexibility and includes glass, the thickness of the substrate 100 is, for example, 200 μm or less. When the substrate 100 is flexible and includes a resin, the substrate 100 includes, for example, PEN (polyethylene naphthalate), PES (polyethersulfone), PET (polyethylene terephthalate), or polyimide. The first surface 102 (preferably both the first surface 102 and the second surface 104) of the substrate 100 may be covered with an inorganic barrier film (eg, SiN _x or SiON). In this case, even if the substrate 100 includes a material (for example, resin) having a high water vapor transmission rate, the water vapor is prevented from reaching the first surface 102 of the substrate 100.

As shown in FIGS. 1 to 3, the plurality of conductive layers 170 are on the first surface 102 of the substrate 100. The plurality of conductive layers 170 include a plurality of conductive layers 170a and a plurality of conductive layers 170b. Each conductive layer 170 a includes a first conductive layer 110 a and a first wiring 114. The first conductive layer 110a is a part of the conductive layer 170a. The first wiring 114 is another part of the conductive layer 170a. The first conductive layer 110a and the first wiring 114 are connected to each other. Each conductive layer 170 b includes a second wiring 134.

The first terminal 112 is located at one end of the first wiring 114. A potential is applied to the first terminal 112. Thereby, the potential of the first terminal 112 is applied to the first conductive layer 110a (first electrode 110) through the first wiring 114. The second terminal 132 is located at one end of the second wiring 134. A potential is applied to the second terminal 132. Thereby, the potential of the second terminal 132 is applied to the second conductive layer 130a (second electrode 130) through the second wiring 134.

There is a conductive layer 180 on the top surface of each conductive layer 170. The electric resistance of the conductive layer 180 is lower than the electric resistance of the conductive layer 170. Thereby, the voltage drop between the first terminal 112 and the first electrode 110 and the voltage drop between the second terminal 132 and the second electrode 130 can be suppressed. The conductive layer 180 is positioned so as not to overlap the light emitting unit 140. For this reason, the conductive layer 180 does not need to have translucency. Specifically, the conductive layer 180 is made of, for example, Al or Ag. As another example, the conductive layer 180 may include, for example, a Mo alloy layer on the top surface of the first conductive layer 110a, an Al alloy layer on the Mo alloy layer, and a Mo alloy layer on the Al alloy layer.

As shown in FIG. 3, the plurality of first conductive layers 110a are arranged in the first direction (X direction in the figure). Each first conductive layer 110a extends in a second direction (specifically, the Y direction in the figure) that intersects the first direction (specifically, orthogonal to the first direction).

As shown in FIGS. 4, 5 and 7, the insulating layer 150 is on the first surface 102 of the substrate 100 and on the plurality of first conductive layers 110a. The insulating layer 150 includes an inorganic material (for example, silicon oxide or silicon nitride). As shown in FIGS. 2 and 3, the insulating layer 150 has a plurality of openings 152. The plurality of openings 152 is an m × n matrix (this figure) including m rows arranged in the second direction (Y direction in the drawing) and n columns arranged in the first direction (X direction in the drawing). In the example shown in FIG. 4, m = 4 and n = 5). The planar shape of each opening 152 is a rectangle. As shown in FIGS. 4 and 5, in each opening 152, a part of the first conductive layer 110a (first electrode 110) and a part of the second conductive layer 130a (second electrode 130) overlap each other. . Thereby, the region surrounded by the edge of the opening 152 functions as the light emitting unit 140. That is, the insulating layer 150 defines the light emitting unit 140.

As shown in FIGS. 4 and 5, each side of the light emitting unit 140 is defined by the lower end of the inner surface of the opening 152. Specifically, as shown in FIG. 4, in the cross section perpendicular to the first direction (X direction in FIGS. 1 to 3), the opening 152 has a first inner surface and a second inner surface. The second inner surface is on the opposite side of the first inner surface. The first inner side surface of the opening 152 is inclined so that the upper end of the first inner side surface is located outside the lower end of the first inner side surface. The second inner side surface of the opening 152 is inclined so that the upper end of the second inner side surface is located outside the lower end of the second inner side surface. The first side of the light emitting unit 140 is defined by the lower end of the first inner side surface of the opening 152. The second side of the light emitting unit 140 is defined by the lower end of the second inner side surface of the opening 152. Similarly, as shown in FIG. 5, in the cross section perpendicular to the second direction (the Y direction in FIGS. 1 to 3), the opening 152 has a third inner surface and a fourth inner surface. The fourth inner surface is on the opposite side of the third inner surface. The third inner side surface of the opening 152 is inclined so that the upper end of the third inner side surface is located outside the lower end of the third inner side surface. The fourth inner side surface of the opening 152 is inclined so that the upper end of the fourth inner side surface is located outside the lower end of the fourth inner side surface. The third side of the light emitting unit 140 is defined by the lower end of the third inner side surface of the opening 152. The fourth side of the edge of the light emitting unit 140 is defined by the lower end of the fourth inner side surface of the opening 152.

The insulating layer 150 has an opening 154. As shown in FIG. 6, the second conductive layer 130 a is connected to the second wiring 134 through the opening 154.

As shown in FIGS. 4, 6, and 7, the partition wall 160 is on the insulating layer 150. The partition 160 includes a photosensitive resin (for example, polyimide). As shown in FIG. 2, the plurality of partition walls 160 are arranged in the second direction (Y direction in the figure). Each partition wall 160 extends in the first direction (X direction in the figure). 4 and 6, the width of the upper surface of the partition wall 160 in the cross section perpendicular to the direction in which the partition wall 160 extends, that is, the first direction (the X direction in FIGS. 1 to 3) is the lower surface of the partition wall 160. Wider than the width of. More specifically, in the cross section perpendicular to the first direction (the X direction in FIGS. 1 to 3), the partition wall 160 has a first side surface and a second side surface. The second side surface is on the opposite side of the first inner surface. The first side surface of the partition wall 160 is inclined so that the upper end of the first side surface is located outside the lower end of the first side surface. The second side surface of the partition wall 160 is inclined so that the upper end of the second side surface is located outside the lower end of the second side surface. Note that the number of the partition walls 160 on the insulating layer 150 is not limited to a plurality, and may be only one.

4 to 6, the organic layer 120a is on the first surface 102 of the substrate 100, on the plurality of first conductive layers 110a, and on the insulating layer 150. As shown in FIG. 4, the plurality of organic layers 120a are arranged in the second direction (Y direction in FIGS. 1 to 3). The organic layers 120a adjacent to each other face each other with the partition wall 160 interposed therebetween. As shown in FIGS. 4 and 5, a part of the organic layer 120a overlaps a part (first electrode 110) of the first conductive layer 110a. This part of the organic layer 120 a functions as the organic layer 120 of the light emitting unit 140.

As shown in FIGS. 4 and 6, the organic layer 120 a is not in contact with the partition wall 160. In this case, a substance that degrades the organic layer 120a can be prevented from propagating from the partition wall 160 to the organic layer 120a. In detail, the partition 160 may contain a substance (for example, water) that degrades the organic layer 120a. In this case, if the organic layer 120 a is in contact with the partition wall 160, this material may propagate from the organic layer 120 a to the partition wall 160. On the other hand, in the example shown in FIGS. 4 and 6, even if the partition 160 includes the above-described substance, it is possible to suppress the propagation of the substance to the organic layer 120a.

As shown in FIGS. 4, 6, and 7, the organic layer 120 b is on the upper surface of the partition wall 160. The material included in the organic layer 120b is the same as the material included in the organic layer 120a. The organic layer 120 a and the organic layer 120 b are formed by depositing an organic layer on the first surface 102 of the substrate 100 and the partition 160. In this case, the organic layer is separated into the organic layer 120 a and the organic layer 120 b by the partition wall 160.

As shown in FIG. 8, the organic layer 120a includes a hole injection layer 121a, a hole transport layer 122a, a light emitting layer 123a, an electron transport layer 124a, and an electron injection layer 125a. Part of the hole injection layer 121a (hole injection layer 121), part of the hole transport layer 122a (hole transport layer 122), part of the light emitting layer 123a (light emitting layer 123), one of the electron transport layers 124a The part (electron transport layer 124) and a part of the electron injection layer 125a (electron injection layer 125) are located in a region (light emitting part 140) defined by the insulating layer 150, and constitute the organic layer 120. Yes. The total thickness of the organic layer 120 is, for example, not less than 50 nm and not more than 200 nm.

The hole injection layer 121a is a transition metal oxide layer. Specifically, for example, a molybdenum oxide (MoO _x ) layer, a tungsten oxide (WO _x ) layer, a vanadium oxide (V _x O _y ) layer, or a ruthenium oxide ( a RuO _x) layer, and more specifically, for example, molybdenum trioxide (MoO ₃₎ layer, molybdenum dioxide (MoO ₂₎ layer, tungsten trioxide (WO ₃₎ layer, tungsten dioxide (WO ₂₎ layer, pentoxide A vanadium (V ₂ O ₅ ) layer, a ruthenium tetroxide (RuO ₄ ) layer, or a ruthenium dioxide (RuO ₂ ) layer, preferably a molybdenum trioxide (MoO ₃ ) layer. The thickness of the hole injection layer 121a is extremely thin and is about 10 nm at most. For this reason, the atoms contained in the hole injection layer 121a may not form a layer. In other words, in this case, there is a transition metal oxide at the interface between the upper surface of the first electrode 110 and the lower surface of a part of the hole transport layer 122a (hole transport layer 122), and the surface of the insulating layer 150 and the hole transport. The transition metal oxide is present at the interface with the lower surface of the other part of the layer 122a (the part around the hole transport layer 122).

The transition metal oxide (hole injection layer 121) functions to improve the hole injection efficiency between the first electrode 110 and the light emitting layer 123. Accordingly, when there is a transition metal oxide (hole injection layer 121) between the first electrode 110 and the light emitting layer 123, the luminance of the light emitting unit 140 is improved. As a result of studies by the present inventor, the improvement in luminance due to the transition metal oxide (hole injection layer 121) is maintained even when the insulating layer 150 is made of an inorganic material. As described above, when the insulating layer 150 is made of an inorganic material, the luminance of the light emitting unit 140 may deteriorate. On the other hand, in this embodiment, even when the insulating layer 150 is made of an inorganic material, it is possible to suppress a decrease in luminance of the light emitting unit 140.

In the example shown in FIG. 8, a part of the hole injection layer 121a (first part: hole injection layer 121) is on the first electrode 110 and the other part (second part) of the hole injection layer 121a. ) Is on the insulating layer 150 around the hole injection layer 121. In this way, the organic layer 120a (first organic layer) includes the first transition metal oxide (transition metal oxide constituting the hole injection layer 121a) and the insulation between the light emitting layer 123a and the first electrode 110. The second transition metal oxide (transition metal oxide constituting the hole injection layer 121a) on the layer 150 is included. The first transition metal oxide (transition metal oxide constituting the hole injection layer 121a) is the same material as the second transition metal oxide (transition metal oxide constituting the hole injection layer 121a). May be.

When the inventor examined, when the transition metal oxide (hole injection layer 121a) is located between the hole transport layer 122a and the insulating layer 150, the hole transport layer 122a (organic material layer) is formed in the melt process. It has been clarified that repelling from the insulating layer 150 (inorganic material layer) is suppressed. Specifically, after forming the hole injection layer 121a and the hole transport layer 122a, the first conductive layer 110a may be heated to a high temperature in the melt process. In the present embodiment, the insulating layer 150 is made of an inorganic material. In this case, the insulating layer 150 may have high water repellency. In this case, the hole injection layer 121a and the hole transport layer 122a melted in the melt process may be repelled from the surface of the insulating layer 150. For this reason, the hole injection layer 121a and the hole transport layer 122a may not be formed in a part of the periphery of the light emitting unit 140. For this reason, a phenomenon occurs in which a part of the light emitting part 140 defined in the insulating layer 150 does not emit light normally. On the other hand, when the transition metal oxide (hole injection layer 121a) is located between the surface of the molten hole transport layer 122a and the insulating layer 150, the transition metal oxide (hole injection) melted in the melt process. It was confirmed that the layer 121a) and the hole transport layer 122a were not repelled from the surface of the insulating layer 150, and all of the light emitting portions 140 defined in the insulating layer 150 emitted light normally. From this, it has been clarified by the present inventors that the transition metal oxide (hole injection layer 121a) may function to adhere the hole transport layer 122a to the insulating layer 150. .

The hole transport layer 122a is made of an organic material, for example, α-NPD. The thickness of the hole transport layer 122a is, for example, not less than 20 nm and not more than 50 nm.

The light emitting layer 123a is made of an organic material, for example, Alq3 (tris (8-quinolinolato) aluminum). Between the first electrode 110 and the second electrode 130, electrons and holes are recombined in the light emitting layer 123a (light emitting layer 123). Thereby, light is emitted from the light emitting layer 123. The color of light from the light emitting layer 123 is, for example, white, red, green, or blue.

Electrons are transported between the first electrode 110 and the second electrode 130 in the electron transport layer 124a (electron transport layer 124). The thickness of the electron transport layer 124 is, for example, 5 nm or more and 100 nm or less.

The electron injection layer 125a is made of an alkali metal compound (for example, LiF), a metal oxide (for example, aluminum oxide) or a metal complex (for example, lithium 8-hydroxyquinolate (Liq)). The thickness of the electron injection layer 125a is, for example, not less than 0.1 nm and not more than 10 nm.

Note that one of the electron transport layer 124a and the electron injection layer 125a may be omitted.

As shown in FIGS. 4 to 6, the second conductive layer 130a is on the organic layer 120a. As shown in FIG. 2, a plurality of second conductive layers 130a are arranged in the second direction (Y direction in the figure). Each second conductive layer 130a extends in the first direction (X direction in the figure). The second conductive layers 130a adjacent to each other are opposed to each other with the partition wall 160 interposed therebetween. In other words, the second conductive layers 130 a adjacent to each other are separated from each other along the partition 160. As shown in FIGS. 4 and 5, a part of the second conductive layer 130a overlaps a part of the first conductive layer 110a (first electrode 110). This part of the second conductive layer 130 a functions as the second electrode 130 of the light emitting unit 140.

As shown in FIGS. 4, 6, and 7, the conductive layer 130 b is provided on the upper surface of the partition wall 160. The material included in the conductive layer 130b is the same as the material included in the second conductive layer 130a. The second conductive layer 130 a and the conductive layer 130 b are formed by depositing a conductive layer on the first surface 102 and the partition 160 of the substrate 100. In this case, the conductive layer is separated into the second conductive layer 130 a and the conductive layer 130 b by the partition 160.

When the light emitting device 10 is bottom emission, the first conductive layer 110a is a conductive layer having translucency. In this case, the second conductive layer 130a does not need to have translucency. On the other hand, when the light emitting device 10 is top emission, the second conductive layer 130a is a light-transmitting conductive layer. In this case, the first conductive layer 110a does not need to have translucency.

In the case where the first conductive layer 110a and the second conductive layer 130a are light-transmitting conductive layers, the first conductive layer 110a and the second conductive layer 130a include, for example, a metal oxide, and more specifically, for example, It contains ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide), IWZO (Indium Tungsten Zinc Oxide) or ZnO (Zinc Oxide).

In the case where the first conductive layer 110a and the second conductive layer 130a are conductive layers that do not have translucency, the first conductive layer 110a and the second conductive layer 130a include, for example, Al, Au, Ag, Pt, Mg, Sn, A metal selected from the first group consisting of Zn and In or an alloy of a metal selected from the first group is included.

4 to 7, the covering layer 200 covers the insulating layer 150, the plurality of light emitting portions 140, and the plurality of partition walls 160. Thereby, the coating layer 200 seals the insulating layer 150, the plurality of light emitting units 140, and the plurality of partition walls 160. More specifically, in the example shown in the figure, the covering layer 200 is formed by ALD (Atomic Layer Deposition). Accordingly, the covering layer 200 continuously covers the side surfaces and the upper surface of the insulating layer 150, the light emitting unit 140, and the partition wall 160. The covering layer 200 includes, for example, an insulating material, more specifically, for example, a metal oxide. The covering layer 200 includes, for example, a titanium oxide layer and an aluminum oxide layer. In this case, the aluminum oxide layer is on the titanium oxide layer or below the titanium oxide layer. The thickness of the coating layer 200 is, for example, not less than 50 nm and not more than 300 nm.

The covering layer 200 may be formed by, for example, CVD (Chemical Vapor Deposition) or sputtering. In this case, the covering layer 200 includes, for example, a SiO ₂ layer or a SiN layer. In this case, the film thickness of the coating layer 200 is, for example, not less than 10 nm and not more than 1000 nm.

The covering layer 200 may be covered with a resin layer. The resin layer is provided to protect the covering layer 200. The resin layer contains, for example, an epoxy resin or an acrylic resin.

Next, a method for manufacturing the light emitting device 10 will be described. First, a conductive layer is formed on the first surface 102 of the substrate 100, and this conductive layer is patterned. Thus, a plurality of conductive layers 170 (first conductive layer 110a, first wiring 114, and second wiring 134) are formed. Next, a conductive layer 180 is formed on the upper surface of each conductive layer 170.

Next, the insulating layer 150 is formed on the first surface 102 of the substrate 100 and the plurality of conductive layers 170. Next, a plurality of openings 152 and a plurality of openings 154 are formed in the insulating layer 150.

Next, a plurality of partition walls 160 are formed on the insulating layer 150.

Next, an organic layer is formed on the insulating layer 150 and the plurality of partition walls 160. Accordingly, the organic layer is separated into the organic layer 120a and the organic layer 120b by the partition 160.

Specifically, first, a transition metal oxide layer is formed on the insulating layer 150 and the plurality of partition walls 160 by, for example, sputtering or vapor deposition. The transition metal oxide layer is separated into a plurality of hole injection layers 121 a by the partition wall 160. Next, an organic material layer is formed over the insulating layer 150 and the plurality of partition walls 160. The organic material layer is separated into a plurality of hole transport layers 122a by the partition 160. Next, the first electrode 110 is heated to a high temperature (melt process). As described above, in this melt process, even if the insulating layer 150 (inorganic material layer) has high water repellency, the transition metal oxidation may cause the molten hole transport layer 122a to be repelled from the surface of the insulating layer 150. It is suppressed by the object (hole injection layer 121a).

Next, an organic material layer is formed on the insulating layer 150 and the plurality of partition walls 160. The organic material layer is separated into a plurality of light emitting layers 123 a by the partition 160. Next, an organic material layer is formed over the insulating layer 150 and the plurality of partition walls 160. The organic material layer is separated into a plurality of electron transport layers 124 a by the partition 160. Next, for example, a metal oxide layer is formed over the insulating layer 150 and the plurality of partition walls 160. The metal oxide layer is separated into a plurality of electron injection layers 125 a by the partition 160.

Next, a conductive layer is formed over the insulating layer 150 and the plurality of partition walls 160. Accordingly, the conductive layer is separated into the second conductive layer 130a and the conductive layer 130b by the partition 160.

Next, the coating layer 200 is formed by ALD on the first surface 102 of the substrate 100, the insulating layer 150, and the plurality of partition walls 160. As a result, the insulating layer 150, the plurality of light emitting units 140, and the plurality of partition walls 160 are sealed by the covering layer 200.

As described above, according to the present embodiment, there is a transition metal oxide (hole injection layer 121) between the first electrode 110 and the light emitting layer 123. The transition metal oxide functions to improve the hole injection efficiency between the first electrode 110 and the light emitting layer 123. For this reason, even if the insulating layer 150 (inorganic material) functions to deteriorate the luminance of the light-emitting portion 140, the luminance deterioration due to the insulating layer 150 (inorganic material) can be suppressed.

Furthermore, in the present embodiment, there is a transition metal oxide (hole injection layer 121a) between the hole transport layer 122a and the surface of the insulating layer 150 on the surface of the insulating layer 150. As a result of studies by the inventors, when the hole transport layer 122a has a transition metal oxide (hole injection layer 121a) between the insulating layers 150, the hole transport layer 122a is firmly bonded to the surface of the insulating layer 150. To come. For this reason, even if the first electrode 110 is heated to a high temperature in the melting step, the molten hole transport layer 122a is suppressed from being repelled from the insulating layer 150.

FIG. 9 is a graph showing the results of the weather resistance test of the light emitting device 10 according to the example, the results of the weather resistance test of the light emitting device 10 according to Comparative Example 1, and the results of the weather resistance test of the light emitting device 10 according to Comparative Example 2. It is. In the weather resistance test according to the example shown in the figure, the light emitting device 10 was driven at a temperature of 70 ° C.

The light emitting device 10 according to this example was the same as the light emitting device 10 shown in FIGS. Specifically, in this embodiment, the hole injection layer 121a includes a molybdenum trioxide (MoO ₃ ) layer. The insulating layer 150 is made of an inorganic material. The inorganic material of the insulating layer 150 was silicon oxide. In the example shown in this figure, two light emitting devices 10 according to this example were tested. In the present embodiment, for each of the two light emitting devices 10, the luminance at the initial time (0 hour), the luminance at the time of 260 hours, the luminance at the time of 381 hours, the luminance at the time of 547 hours, and the luminance at the time of 1000 hours. Luminance was measured. Further, for the two light emitting devices 10, the average value of luminance at the initial (0 hour) time point, the average value of luminance at the time point of 260 hours, the average value of luminance at the time point of 381 hours, the average value of luminance at the time point of 547 hours Value and the average value of luminance at the time of 1000 hours were calculated.

The light emitting device 10 according to Comparative Example 1 was the same as the light emitting device 10 according to this example, except that the hole injection layer 121a did not contain a transition metal oxide. In the example shown in this figure, two light emitting devices 10 according to Comparative Example 1 were tested. In this comparative example, for each of the two light emitting devices 10, the luminance at the initial time (0 hour), the luminance at the time of 260 hours, the luminance at the time of 381 hours, the luminance at the time of 547 hours, and the luminance at the time of 1000 hours. Luminance was measured. Further, for the two light emitting devices 10, the average value of luminance at the initial (0 hour) time point, the average value of luminance at the time point of 260 hours, the average value of luminance at the time point of 381 hours, the average value of luminance at the time point of 547 hours Value and the average value of luminance at the time of 1000 hours were calculated.

The light emitting device 10 according to Comparative Example 2 was the same as the light emitting device 10 according to Comparative Example 1 except that the insulating layer 150 was made of an organic material. In the example shown in the figure, two light emitting devices 10 according to Comparative Example 2 were tested. In this comparative example, the luminance at the initial time (0 hour), the luminance at the time of 260 hours, the luminance at the time of 381 hours, the luminance at the time of 547 hours, and the luminance at the time of 1000 hours were measured. Further, for the two light emitting devices 10, the average value of luminance at the initial (0 hour) time point, the average value of luminance at the time point of 260 hours, the average value of luminance at the time point of 381 hours, the average value of luminance at the time point of 547 hours Value and the average value of luminance at the time of 1000 hours were calculated.

In the light emitting device 10 according to this example, the luminance at the time of 260 hours, the luminance at the time of 381 hours, the luminance at the time of 547 hours, and the luminance at the time of 1000 hours are almost the same as the luminance at the initial time (0 hour). The luminance did not decrease and became about 90% of the luminance at the initial time (0 hour). Similarly, in the light emitting device 10 according to Comparative Example 2, the luminance at the time of 260 hours, the luminance at the time of 381 hours, the luminance at the time of 547 hours, and the luminance at the time of 1000 hours are the initial (0 hour) time points. There was almost no decrease from the luminance at, and it was approximately 90% of the luminance at the initial time (0 hour). On the other hand, in the light emitting device 10 according to Comparative Example 1, the luminance at the time of 260 hours, the luminance at the time of 381 hours, the luminance at the time of 547 hours, and the luminance at the time of 1000 hours are initial (0 hours). The brightness greatly decreased from the brightness at ½, and became less than half of the brightness at the initial time (0 hour).

The results of Comparative Example 1 and Comparative Example 2 suggest that the insulating layer 150 (inorganic material) functions to deteriorate the luminance of the light emitting unit 140.

As a result of this example and Comparative Example 1, the luminance degradation due to the insulating layer 150 (inorganic material) is suppressed by the transition metal oxide (molybdenum trioxide (MoO ₃ )) in the hole injection layer 121a. Suggests that.

As mentioned above, although embodiment and the Example were described with reference to drawings, these are the illustrations of this invention, Various structures other than the above are also employable.

Claims

A substrate,
An insulating layer on the substrate and made of an inorganic material;
A light emitting part defined by the insulating layer on the substrate and having a first electrode, a second electrode, and an organic layer between the first electrode and the second electrode;
A covering layer covering at least a part of the insulating layer and the light emitting part;
With
The organic layer includes a light emitting layer and a first transition metal oxide between the light emitting layer and the first electrode.
The light-emitting device according to claim 1.
A first organic layer comprising a first portion on the first electrode and a second portion around the first portion;
The first portion of the first organic layer is the organic layer of the light emitting unit;
The second portion of the first organic layer is on the insulating layer;
A light emitting device comprising a second transition metal oxide on the insulating layer.
The light-emitting device according to claim 2.
The first organic layer includes a transition metal oxide layer,
The transition metal oxide layer is a light emitting device including the first transition metal oxide and the second transition metal oxide.
The light emitting device according to any one of claims 1 to 3,
Comprising a partition on the insulating layer;
A light emitting device in which the second electrode is divided along the partition.
The light-emitting device according to claim 4.
In the cross section perpendicular to the direction in which the partition extends, the partition has a lower surface and an upper surface having a width wider than a width of the lower surface.
The light emitting device according to claim 4 or 5,
A light emitting device comprising the covering layer that continuously covers side surfaces and an upper surface of the insulating layer, the light emitting unit, and the partition.
The light-emitting device according to claim 6.
The covering layer is a light emitting device including a titanium oxide layer and an aluminum oxide layer.
The light emitting device according to any one of claims 1 to 7,
A plurality of first conductive layers arranged in a first direction;
A plurality of second conductive layers arranged in a second direction orthogonal to the first direction on the substrate and the plurality of first conductive layers;
With
The first conductive layer includes a portion overlapping the second conductive layer,
The second conductive layer includes a portion overlapping the first conductive layer,
The first electrode is the portion of the first conductive layer;
The light emitting device, wherein the second electrode is the portion of the second conductive layer.
The light emitting device according to any one of claims 1 to 8,
The light emitting device wherein the first transition metal oxide is molybdenum oxide.