JPWO2017134748A1 - Light emitting device - Google Patents

Abstract

  When viewed in the thickness direction of the organic layer (120), the organic layer (120) includes a hole transport layer (122: first region) and a light emitting layer (124: second region). The hole transport layer (122) contains 50% or more of the first material (hole transport organic material). The light emitting layer (124) is positioned closer to the second electrode (130) than the hole transport layer (122), and the second material (host material of the light emitting layer) having a higher ionization potential than the first material is 50 Contain more than%. The light emitting layer (124) further includes the first material and the third material (the dopant of the light emitting layer). The third material has a lower ionization potential than the first material.

Description

  The present invention relates to a light emitting device.

  One of the light sources of light emitting devices such as lighting devices and display devices is an organic EL element. The organic EL element has a configuration in which an organic layer is disposed between the first electrode and the second electrode. The organic layer has a hole transport layer, a light emitting layer, and an electron transport layer. The light emitting layer may contain other materials in addition to the host material for the purpose of increasing the light emission efficiency. For example, Patent Document 1 describes that the light-emitting layer is formed using a light-emitting material (host material), an electron-transporting material, and a hole-transporting material.

JP 2013-239703 A

  One of materials added to the light-emitting layer is a light-emitting material (hereinafter referred to as a dopant material) having a higher light-emitting ability than a host material. In general, when the content of the dopant material in the light emitting layer is increased, carrier localization in the dopant material is suppressed, and thus the lifetime of the light emitting device is likely to be extended. However, as a result of studies by the present inventors, it has been found that if the content of the dopant material in the light emitting layer is excessively increased, the light emission efficiency is lowered.

  The reason for this will be described with reference to FIG. In order for the light emitting material to emit light, the light emitting material and the dopant material need to be in an excited state (exciton). However, when the concentration of the dopant material is increased, as shown in FIG. 1, a part of the dopant receives holes from the hole transport layer and becomes polaran. For this reason, interaction occurs between the dopant material that is exciton and the dopant material that is polaran, and quenches (quenches).

  An example of a problem to be solved by the present invention is to prevent the light emission efficiency of the light emitting layer from being lowered when the concentration of the dopant material of the light emitting layer is increased in order to extend the lifetime of the light emitting device.

The invention according to claim 1 is a first electrode;
A second electrode;
An organic layer positioned between the first electrode and the second electrode;
With
When viewed in the thickness direction, the organic layer is
A first region containing 50% or more of the first material;
A second region that emits light and includes 50% or more of a second material that is located closer to the second electrode than the first region and has a higher ionization potential than the first material;
With
The second region is a light emitting device that further includes the first material and a third material having an ionization potential smaller than that of the first material.

  The above-described object and other objects, features, and advantages will become more apparent from the preferred embodiments described below and the accompanying drawings.

It is a figure for demonstrating a subject. It is sectional drawing which shows the structure of the light-emitting device which concerns on embodiment. It is a schematic diagram of a chart when an organic layer is analyzed by TOF-SIMS. It is sectional drawing which shows the structure of the light-emitting device which concerns on a modification. It is a table | surface which shows the luminous efficiency and lifetime of a light-emitting device. It is a table | surface which shows the luminous efficiency and lifetime of a light-emitting device. 1 is a plan view of a light emitting device according to Example 1. FIG. It is the figure which removed the 2nd electrode from FIG. It is the figure which removed the organic layer and the insulating layer from FIG. It is AA sectional drawing of FIG. 6 is a plan view of a light emitting device according to Example 2. FIG. It is the figure which removed the partition, the 2nd electrode, the organic layer, and the insulating layer from FIG. It is BB sectional drawing of FIG. It is CC sectional drawing of FIG. It is DD sectional drawing of FIG.

  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.

(Embodiment)
FIG. 2 is a cross-sectional view illustrating a configuration of the light emitting device 10 according to the embodiment. The light emitting device 10 according to the embodiment includes a first electrode 110, an organic layer 120, and a second electrode 130. The organic layer 120 is located between the first electrode 110 and the second electrode 130. When viewed in the thickness direction of the organic layer 120, the organic layer 120 includes a hole transport layer 122 (first region) and a light emitting layer 124 (second region). The hole transport layer 122 contains 50% or more of the first material (hole transportable organic material). The light emitting layer 124 is located closer to the second electrode 130 than the hole transport layer 122, and contains 50% or more of a second material (host material of the light emitting layer) having a higher ionization potential than the first material. The light emitting layer 124 further includes the first material described above and a third material (a dopant of the light emitting layer). The third material has a lower ionization potential than the first material. The light emitting layer 124 is defined as, for example, a region containing 50% or more of the second material, containing the first material or more with a reference value, and further containing the third material or more with a reference value. Here, the reference value of the content of the first material is, for example, 5%, and the reference value of the content of the third material is, for example, 10%. However, the reference value of the first material and the reference value of the third material are not limited to this. The content of each component in each layer is measured using, for example, TOF-SIMS (Time-of-Flight Secondary Mass Spectrometry). Details will be described below.

  The light emitting device 10 includes a light emitting unit 140. The light emitting unit 140 is formed on one surface of the substrate 100 and includes a first electrode 110, an organic layer 120, and a second electrode 130. The organic layer 120 is located between the first electrode 110 and the second electrode 130. The light emitting unit 140 may be a bottom emission type light emitting unit or a top emission type light emitting unit. The light emitting unit 140 may be a double-sided light emitting unit.

When the light emitting unit 140 is a bottom emission type, the substrate 100 is formed of a light-transmitting material such as glass or a light-transmitting resin, and the surface of the substrate 100 opposite to the first electrode 110 is used. Is the light extraction surface of the light emitting device 10. On the other hand, when the light emitting portion 140 is a top emission type, the substrate 100 may be formed of the above-described light-transmitting material or may be formed of a material that does not have light-transmitting properties. The substrate 100 is, for example, a polygon such as a rectangle. Further, the substrate 100 may have flexibility. 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. In particular, when the substrate 100 is made of a glass material and has flexibility, the thickness of the substrate 100 is, for example, 200 μm or less. In the case where the substrate 100 is made of a resin material and is flexible, the material of the substrate 100 includes, for example, PEN (polyethylene naphthalate), PES (polyethersulfone), PET (polyethylene terephthalate), or polyimide. Is formed. In the case where the substrate 100 includes a resin material, an inorganic barrier film such as SiN _x or SiON is formed on at least the light emitting surface (preferably both surfaces) of the substrate 100 in order to suppress moisture from passing through the substrate 100. ing.

  At least one of the first electrode 110 and the second electrode 130 is a transparent electrode having optical transparency. For example, when the light emitting unit 140 is a bottom emission type, at least the first electrode 110 is a transparent electrode. On the other hand, when the light emitting unit 140 is a top emission type, at least the second electrode 130 is a transparent electrode. Note that both the first electrode 110 and the second electrode 130 may be transparent electrodes. In this case, the light emitting unit 140 is a double-sided light emitting unit.

  The transparent conductive material constituting 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). is there. 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 a vapor deposition method. The first electrode 110 may be a carbon nanotube, a conductive organic material such as PEDOT / PSS, or a thin metal electrode.

  Of the first electrode 110 and the second electrode 130, the non-transparent electrode is selected from, for example, a first group consisting of Al, Au, Ag, Pt, Mg, Sn, Zn, and In. Or a metal layer made of an alloy of metals selected from the first group. This electrode is formed using, for example, a sputtering method or a vapor deposition method.

  When the light emitting unit 140 is a top emission type light emitting device, the first electrode 110 may have a structure in which a metal layer and a transparent conductive layer are laminated in this order.

  The organic layer 120 includes a hole transport layer 122, a light emitting layer 124, and an electron transport layer 126.

  The hole transport layer 122 is formed using a hole transporting organic material (first material). The hole transport layer 122 may be formed using a coating method, or may be formed using a vapor deposition method. The first material is, for example, NPB (N, N-di (naphthalene-1-yl) -N, N-diphenyl-benzidene), but also TAPC ([= 1,1-Bis [4- [N, N-di (p-tolyl) amino] phenyl] cyclohexane] or TCTA (4,4 ′, 4 ″ -Tri (9-carbazoyl) triphenylamine) may be used. For example, the hole transport layer 122 is a region where the content ratio of the first material is 50% or more in the analysis by the TOF-SIMS method, for example.

  The light-emitting layer 124 is formed using a material that emits light when electrons and holes are recombined. The emission color of the light emitting layer 124 (that is, the emission color of the light emitting unit 140) may be any color, for example, blue, green, or red. The material of the light emitting layer 124 may be anything as long as it is a light emitting organic material. Part of the light emission of the light emitting layer 124 is derived from delayed fluorescence, and the other part of the light emission of the light emitting layer 124 is derived from phosphorescence.

  The light emitting layer 124 includes a light emitting host material (second material) and a light emitting dopant (third material). The ionization potential of the host material is larger than the ionization potential of the first material (the material constituting the hole transport layer 122). On the other hand, the ionization potential of the dopant is smaller than the ionization potential of the first material. In the light emitting layer 124, the content of the host material is 50% or more, and the content of the dopant is, for example, 10% or more. However, substantially, the material constituting the light-emitting layer 124 is almost always a host material, a dopant, and a hole-transporting organic material (first material: details will be described later). Therefore, in most cases, the content (%) of the host material in the light emitting layer 124 is regarded as a value obtained by subtracting the content (%) of the dopant and the content (%) of the hole transporting organic material from 100. be able to.

  The host material described above may be a material having an anthracene skeleton such as ADN (9,10-di (naphth-2-yl) anthracene). Examples of the dopant include DPAVBi (4,4 ′-[bis (di-p-triamino) styryl] biphenyl), but are not particularly limited.

  In addition to the host material and the dopant described above, the light emitting layer 124 includes a hole transporting organic material (first material) used for the hole transport layer 122. The content of the first material is, for example, 5% or more.

  The electron transport layer 126 is formed using a material (electron transporting organic material) through which electrons move. Examples of such materials include nitrogen-containing aromatic heterocyclic derivatives, aromatic hydrocarbon ring derivatives, dibenzofuran derivatives, dibenzothiophene derivatives, and silole derivatives. The thickness of the electron transport layer 126 is, for example, not less than 5 nm and not more than 100 nm.

  FIG. 3 shows a schematic diagram of a chart when the organic layer 120 is analyzed by TOF-SIMS. In this chart, only the host material (second material) and dopant (third material) of the light emitting layer 124 and the hole transporting material (first material) are shown. The layer in contact with the surface on the second electrode 130 side of the light emitting layer 124 (in this embodiment, the electron transport layer 126) includes a hole transporting material, a host material, and a dopant in the vicinity of the interface with the light emitting layer 124. It is out. On the other hand, the light emitting layer 124 contains 50% or more of the host material and contains a small amount of a dopant and a hole transporting material. The hole transport layer 122 contains a small amount of a dopant and a host material in the vicinity of the interface with the light emitting layer 124, but is formed of a hole transport material in other portions.

  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 vapor deposition method or a sputtering method. Next, the hole transport layer 122 is formed on the first electrode 110. The hole transport layer 122 is formed using, for example, a vapor deposition method or a coating method such as spin coating or an inkjet method.

  Next, the light emitting layer 124 is formed on the hole transport layer 122. The organic material for forming the light emitting layer 124 includes a dopant and a hole transporting material used for forming the hole transport layer 122 in addition to the host material. For this reason, the light emitting layer 124 has the composition described above. The light emitting layer 124 is formed using, for example, a vapor deposition method or a coating method such as spin coating or an ink jet method.

  Next, the electron transport layer 126 is formed on the light emitting layer 124. The electron transport layer 126 is formed using, for example, a vapor deposition method or a coating method such as spin coating or an inkjet method. In this way, the organic layer 120 is formed.

  Then, the second electrode 130 is formed on the organic layer 120. The second electrode 130 is formed using, for example, a vapor deposition method or a sputtering method.

  In this embodiment, the light emitting layer 124 of the organic layer 120 contains a hole transporting material constituting the hole transport layer 122 in addition to the host material and the dopant. For this reason, even if the concentration of the dopant is increased in order to extend the lifetime of the light emitting portion 140, the holes move in the light emitting layer 124 through the hole transporting material instead of the dopant. Therefore, it can be suppressed that a part of the dopant receives holes and becomes a polaran. Therefore, even if the dopant concentration in the light emitting layer 124 is increased, the light emission efficiency of the light emitting layer 124 is unlikely to decrease. Further, depending on the combination of materials, the light emission efficiency of the light emitting layer 124 is improved by increasing the dopant concentration.

(Modification)
FIG. 4 is a cross-sectional view illustrating a configuration of a light emitting device 10 according to a modification. The light emitting device 10 according to this modification has the same configuration as the light emitting device 10 according to the embodiment except that the organic layer 120 includes a hole injection layer 121 and an electron injection layer 127. The hole injection layer 121 is located between the first electrode 110 and the hole transport layer 122, and the electron injection layer 127 is located between the electron transport layer 126 and the second electrode 130.

  The hole injection layer 121 is in contact with the first electrode 110 and is formed using a material in which holes move (a hole transporting organic material). The thickness of the hole injection layer 121 is, for example, not less than 20 nm and not more than 100 nm. The hole injection layer 121 is formed using a vapor deposition method or a coating method such as inkjet or spin coating.

  The electron injection layer 127 is in contact with the second electrode 130 and is represented by, for example, an alkaline earth metal compound such as LiF, a metal oxide typified by aluminum oxide, or lithium 8-hydroxyquinolate (Liq). It is formed using a metal complex. The electron injection layer 127 is formed by using, for example, a vapor deposition method. The thickness of the electron injection layer 127 is, for example, not less than 0.1 nm and not more than 10 nm.

  The organic layer 120 may further have an electron blocking layer. The electron blocking layer is located between the hole transport layer 122 and the light emitting layer 124 and suppresses electrons penetrating the light emitting layer 124 from reaching the hole transport layer 122 and the hole injection layer 121. The electron blocking layer is formed using, for example, at least one of materials in which holes move (hole transporting organic material). The thickness of the electron block layer is, for example, 5 nm or more and 50 nm or less.

  The organic layer 120 may further have a hole blocking layer. The hole blocking layer is located between the light emitting layer 124 and the electron transporting layer 126 and suppresses the holes that have penetrated the light emitting layer 124 from reaching the electron transporting layer 126 or the electron injection layer 127. The hole blocking layer is formed using, for example, a material (electron transporting organic material) that can move electrons. The thickness of the hole blocking layer is, for example, not less than 5 nm and not more than 50 nm.

  Also in this modified example, the light emitting layer 124 of the organic layer 120 contains a hole transporting material constituting the hole transporting layer 122 in addition to the host material and the dopant. Therefore, as in the embodiment, even if the dopant concentration in the light emitting layer 124 is increased in order to extend the life of the light emitting unit 140, the light emission efficiency of the light emitting layer 124 is unlikely to decrease. Further, depending on the combination of materials, the light emission efficiency of the light emitting layer 124 is improved by increasing the dopant concentration.

FIG. 5 shows the luminous efficiencies of the light emitting device 10 (samples 1 and 2) according to this modification, the light emitting device 10 according to comparative example 1, the light emitting device 10 according to comparative example 2, and the light emitting device 10 according to comparative example 3. It is a table | surface which shows each of an external quantum efficiency) and lifetime. The external quantum efficiency is a value when the light emitting unit 140 emits light at a current density of ^2.5 mA / cm ² . The lifetime is a time until the luminance is reduced by 10% when the light emitting unit 140 continues to emit light under the condition that the initial luminance is 1000 cd / m ² .

  In any example, the first electrode 110 is an ITO film having a thickness of 170 nm, the hole injection layer 121 is CuPc (copper phthalocyanine) having a thickness of 30 nm, and the electron transport layer is an Alq3 having a thickness of 35 nm. (Tris (8-hydroxyquinolinato) aluminum), and the electron injection layer 127 is LiF having a thickness of 1 nm. In any example, the thickness of the hole transport layer 122 is 15 nm, and the thickness of the light emitting layer 124 is 30 nm. That is, in each example, the difference is the material of the hole transport layer 122 and the material of the light emitting layer 124. Further, the light emitting unit 140 is sealed by a sealing member (for example, a sealing member having a can sealing structure), and a desiccant is disposed inside the sealing member.

  In Sample 1, the hole transport layer 122 is NPB (first material: ionization potential is 5.4 eV), and the light-emitting layer 124 is 72% ADN (second material: ionization potential is 5.6 eV), 10% DPAVBi (third material: ionization potential is 5.3 eV), and 18% NPB mixed layer. That is, the ionization potential decreases in the order of the second material, the first material, and the third material.

  In Sample 2, the hole transport layer 122 is NPB, and the light-emitting layer 124 is a mixed layer of 76% ADN (host material), 5% DPAVBi (dopant), and 19% NPB.

  On the other hand, in Comparative Example 1, the hole transport layer 122 is NPB, and the light emitting layer 124 is a mixed layer of 95% ADN (host material) and 5% DPAVBi (dopant). That is, in Comparative Example 1, the light emitting layer 124 does not contain the first material (the material constituting the hole transport layer 122).

  In Comparative Example 2, the hole transport layer 122 is NPB, and the light emitting layer 124 is a mixed layer of 90% ADN (host material) and 10% DPAVBi (dopant). That is, also in Comparative Example 2, the light emitting layer 124 does not contain the first material (the material constituting the hole transport layer 122).

  In Comparative Example 3, the hole transport layer 122 is NPB, and the light emitting layer 124 is 72% ADN (host material), 10% DPAVBi (dopant), and 18% TPD (N, N′-Diphenyl-N , N'-di (m-tolyl) benzidine). That is, in Comparative Example 3, the light emitting layer 124 includes a hole transporting material different from that of the hole transport layer 122.

  In the table shown in FIG. 5, the external quantum efficiency and the lifetime are both converted into relative values with respect to Comparative Example 1.

  The dopant concentration of Sample 1 is the same as that of Comparative Example 1. And as shown in Table 1, the external quantum efficiency of the sample 1 was 1.23 times, and the lifetime was 2.21 times.

  Further, the dopant of Sample 2 is halved compared to Comparative Example 1. Despite this, as shown in Table 1, the external quantum efficiency of Sample 2 was reduced only by 7%. In addition, the life of Sample 2 was 1.32 times that of Comparative Example 1.

  On the other hand, in Comparative Example 2, since the dopant concentration was the same as that of Sample 1, the lifetime was not significantly reduced compared to Sample 1. However, the external quantum efficiency decreased. In Comparative Example 3, since the light-emitting layer 124 contained a hole transporting material different from that of the hole transport layer 122, the lifetime was improved even though the dopant concentration was the same as that of the sample 1. The effect was lower than Sample 1. Also, the external quantum efficiency was lowered.

  From the above, by including the same hole transporting material as the hole transport layer 122 in the light emitting layer 124, even if the dopant concentration in the light emitting layer 124 is increased, the light emission efficiency of the light emitting layer 124 is lowered. It was shown that it was difficult. In addition, it was shown that the luminous efficiency of the light emitting layer 124 increases when the dopant concentration in the light emitting layer 124 is increased at least in the combination of the above materials.

  FIG. 6 is a table showing the external quantum efficiency and lifetime of the light emitting device 10 according to the reference example and the light emitting device 10 according to the comparative example 4. The definitions of external quantum efficiency and lifetime are the same as in FIG. In the table shown in FIG. 6, the external quantum efficiency and the lifetime are both converted into relative values with respect to the reference example.

  Reference examples are comparative examples except that TCTA (4,4 ′, 4 ″ -Tri (9-carbazoyl) triphenylamine: first material: ionization potential is 5.7 eV) is used for the hole transport layer 122. 1 is the same configuration. Further, Comparative Example 4 has the same configuration as Sample 1 except that TCTA is used instead of NPB. That is, in Comparative Example 4, the hole transport layer 122 is TCTA, and the light emitting layer 124 is 72% ADN (second material: ionization potential is 5.6 eV), 10% DPAVBi (third material ionization potential is 5). 3 eV), and 18% TCTA (first material) mixed layer. The ionization potential decreases in the order of the first material, the second material, and the third material.

  In Comparative Example 4, the external quantum efficiency and lifetime are both lower than those in the reference example. This is considered because the ionization potential of ADN (second material) is smaller than the ionization potential of TCTA (first material). Therefore, in order not to reduce the light emission efficiency, the ionization potential of the second material is larger than the ionization potential of the first material, and the ionization potential of the third material is smaller than the ionization potential of the first material. It is considered necessary.

(Example 1)
FIG. 7 is a plan view of the light emitting device 10 according to the first embodiment. FIG. 8 is a view in which the second electrode 130 is removed from FIG. FIG. 9 is a diagram in which the organic layer 120 and the insulating layer 150 are removed from FIG. 10 is a cross-sectional view taken along line AA in FIG. The light emitting device 10 according to the present embodiment is a lighting device, and a light emitting unit 140 is formed on almost the entire surface of the substrate 100.

  Specifically, the first electrode 110, the first terminal 112, and the second terminal 132 are formed on one surface of the substrate 100. The first terminal 112 and the second terminal 132 have a layer formed using the same material as the first electrode 110. This layer is formed in the same process as the first electrode 110. In addition, a layer formed of the same material as the first electrode 110 in the first terminal 112 is integrated with the first electrode 110. On the other hand, the second terminal 132 is separated from the first electrode 110.

  Further, the first terminal 112 and the second terminal 132 are located on opposite sides of the first electrode 110. In the example shown in the figure, the substrate 100 is rectangular. The first terminal 112 is formed along one side of the substrate 100, and the second terminal 132 is formed along the side opposite to the first terminal 112 among the four sides of the substrate 100.

  A region of the substrate 100 where the organic layer 120 is to be formed is surrounded by an insulating layer 150. The insulating layer 150 is formed using a photosensitive material such as polyimide, and is formed in a predetermined shape through exposure and development processes. The insulating layer 150 is formed after the first electrode 110 is formed and before the organic layer 120 is formed. However, the insulating layer 150 may not be formed.

  The organic layer 120 is formed inside a region surrounded by the insulating layer 150. The configuration of the organic layer 120 is as shown in the embodiment or the modification. A second electrode 130 is formed on the organic layer 120. A part of the second electrode 130 extends over the second terminal 132 across the insulating layer 150.

  According to the present example, the organic layer 120 has the configuration shown in the embodiment or the modification. For this reason, even if the dopant concentration in the light emitting layer 124 is increased, the light emission efficiency of the light emitting layer 124 is unlikely to decrease. Further, depending on the combination of materials, the light emission efficiency of the light emitting layer 124 is improved by increasing the dopant concentration.

(Example 2)
FIG. 11 is a plan view of the light emitting device 10 according to the second embodiment. 12 is a view in which the partition 170, the second electrode 130, the organic layer 120, and the insulating layer 150 are removed from FIG. 13 is a cross-sectional view taken along line BB in FIG. 11, FIG. 14 is a cross-sectional view taken along line CC in FIG. 11, and FIG. 15 is a cross-sectional view taken along line DD in FIG.

  The light emitting device 10 according to the second embodiment is a display, and includes a substrate 100, a first electrode 110, a light emitting unit 140, an insulating layer 150, a plurality of openings 152, a plurality of openings 154, a plurality of lead wires 114, an organic layer 120, a first layer. It has two electrodes 130, a plurality of lead wires 134, and a plurality of partition walls 170.

  The first electrode 110 extends in a line shape in the first direction (Y direction in FIG. 11). The end portion of the first electrode 110 is connected to the lead wiring 114.

  The lead wiring 114 is a wiring that connects the first electrode 110 to the first terminal 112. In the example shown in the drawing, one end side of the lead wiring 114 is connected to the first electrode 110, and the other end side of the lead wiring 114 is the first terminal 112. In the example shown in the figure, the first electrode 110 and the lead-out wiring 114 are integrated. A conductor layer 180 is formed on the first terminal 112 and the lead wiring 114. The conductor layer 180 is formed using a metal having a lower resistance than that of the first electrode 110, such as Al or Ag. A part of the lead wiring 114 is covered with an insulating layer 150.

  As shown in FIGS. 11 and 13 to 15, the insulating layer 150 is formed on the plurality of first electrodes 110 and in a region therebetween. A plurality of openings 152 and a plurality of openings 154 are formed in the insulating layer 150. The plurality of second electrodes 130 extend in parallel to each other in a direction intersecting the first electrode 110 (for example, a direction orthogonal to the X direction in FIG. 11). A partition wall 170, which will be described in detail later, extends between the plurality of second electrodes 130. The opening 152 is located at each intersection of the first electrode 110 and the second electrode 130 in plan view. The plurality of openings 152 are arranged to form a matrix.

  The opening 154 is located in a region overlapping with one end side of each of the plurality of second electrodes 130 in plan view. The openings 154 are arranged along one side of the matrix formed by the openings 152. When viewed in a direction along this one side (for example, the Y direction in FIG. 11, that is, the direction along the first electrode 110), the openings 154 are arranged at a predetermined interval. A part of the lead wiring 134 is exposed from the opening 154. The lead wiring 134 is connected to the second electrode 130 through the opening 154.

  The lead wiring 134 is a wiring that connects the second electrode 130 to the second terminal 132, and has a layer made of the same material as the first electrode 110. One end side of the lead wiring 134 is located below the opening 154, and the other end side of the lead wiring 134 is led out of the insulating layer 150. In the example shown in the figure, the other end side of the lead-out wiring 134 is the second terminal 132. A conductor layer 180 is also formed on the second terminal 132 and the lead wiring 134. A part of the lead wiring 134 is covered with an insulating layer 150.

  In the region overlapping with the opening 152, the organic layer 120 is formed. The configuration of the organic layer 120 is as shown in the embodiment or the modification. The light emitting unit 140 is located in each of the regions overlapping with the opening 152.

  In the example shown in FIGS. 13 and 14, the layers constituting the organic layer 120 are shown to protrude to the outside of the opening 152. The organic layer 120 may be formed continuously between the adjacent openings 152 in the direction in which the partition wall 170 extends, or may not be formed continuously. However, as shown in FIG. 15, the organic layer 120 is not formed in the opening 154.

  As shown in FIGS. 11 and 13 to 15, the second electrode 130 extends in a second direction (X direction in FIG. 11) that intersects the first direction. A partition wall 170 is formed between the adjacent second electrodes 130. The partition wall 170 extends in parallel to the second electrode 130, that is, in the second direction. The base of the partition 170 is, for example, the insulating layer 150. The partition 170 is, for example, a photosensitive resin such as a polyimide resin, and is formed in a desired pattern by being exposed and developed. The partition wall 170 may be made of a resin other than a polyimide resin, for example, an inorganic material such as an epoxy resin, an acrylic resin, or silicon dioxide.

  The partition wall 170 has a trapezoidal cross-sectional shape (reverse trapezoidal shape). That is, the width of the upper surface of the partition wall 170 is larger than the width of the lower surface of the partition wall 170. Therefore, if the partition wall 170 is formed before the second electrode 130, the second electrode 130 is formed on one surface side of the substrate 100 by using an evaporation method or a sputtering method, so that the plurality of second electrodes 130 are formed. It can be formed in a lump.

  Next, a method for manufacturing the light emitting device 10 in this embodiment will be described. First, the first electrode 110 and the lead wires 114 and 134 are formed on the substrate 100. These forming methods are the same as the method of forming the first electrode 110 in the embodiment.

  Next, the conductor layer 180 is formed on the lead wiring 114, on the first terminal 112, on the lead wiring 134, and on the second terminal 132. Next, the insulating layer 150 is formed, and further the partition 170 is formed. Next, each layer of the organic layer 120 is formed. Next, the second electrode 130 is formed.

  Also in the present example, the organic layer 120 has the configuration shown in the embodiment or the modification. For this reason, even if the dopant concentration in the light emitting layer 124 is increased, the light emission efficiency of the light emitting layer 124 is unlikely to decrease. Further, depending on the combination of materials, the light emission efficiency of the light emitting layer 124 is improved by increasing the dopant concentration.

  As mentioned above, although embodiment and the Example were described with reference to drawings, these are illustrations of this invention and can also employ | adopt various structures other than the above.

Claims (4)

A first electrode;
A second electrode;
An organic layer positioned between the first electrode and the second electrode;
With
When viewed in the thickness direction, the organic layer is
A first region containing 50% or more of the first material;
A second region that emits light and includes 50% or more of a second material that is located closer to the second electrode than the first region and has a higher ionization potential than the first material;
With
The second region further includes the first material and a third material having a lower ionization potential than the first material. The light-emitting device according to claim 1.
In the second region, the light emitting device includes 5% or more of the first material and 10% or more of the third material. The light-emitting device according to claim 1 or 2,
The light emitting device wherein the first material is a hole transporting material, the second material is a host material of the light emitting layer, and the third material is a dopant of the light emitting layer. In the light-emitting device as described in any one of Claims 1-3,
The light from the second region includes light emitted from phosphorescence and light emitted from delayed fluorescence.

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