JPWO2013051071A1 - Light emitting device and method for manufacturing light emitting device - Google Patents

Abstract

  The light-emitting element includes a first electrode, a light-emitting functional layer formed on the first electrode and having a conductive layer as an uppermost layer, and an undesired opening in a portion corresponding to a partial region of the conductive layer. A second electrode formed on the upper surface of the conductive layer; and a sealing layer formed on the second electrode except for a peripheral surface constituting the opening of the second electrode. The partial region of the conductive layer is oxidized. The light emitting functional layer includes an organic light emitting layer, and the conductive layer is on the organic light emitting layer.

Description

  The present invention relates to a light emitting element including a first electrode, a light emitting functional layer, a second electrode, and a sealing layer, and a method for manufacturing the light emitting element.

  Some light-emitting elements have a structure in which a light-emitting functional layer including a light-emitting layer and a conductive layer is sandwiched between an anode corresponding to a first electrode and a cathode corresponding to a second electrode.

  The light emitting layer and the cathode are affected by a gas such as moisture and oxygen (hereinafter also simply referred to as “gas such as moisture” and “gas”). Specifically, the light emitting layer has light emitting characteristics that are degraded by, for example, moisture, and the lifetime of the device is shortened. The electrical characteristics of the cathode change due to, for example, oxygen. When the change in the electrical characteristics is large, electrons cannot be supplied to the light emitting layer, and light emission does not occur (so-called display defect).

  For this reason, in order to protect a light emitting layer and a cathode from gas, such as a water | moisture content, ie, in order to barrier invasion of gas, the sealing layer is formed, for example on the upper surface of a cathode.

  On the other hand, light is emitted from the light emitting layer, and this light passes through, for example, the cathode and the sealing layer and is extracted to the outside (in the case of top emission). For this reason, the sealing layer is required to have not only high gas barrier properties but also excellent light transmittance, and for example, a silicon nitride film (SiN film) or the like is used.

  In addition, in order to further improve the gas barrier property of the light emitting element, a technique for forming a sealing layer by an atomic layer epitaxy method has been proposed (for example, Patent Documents 1 and 2).

JP 2001-284042 A JP 2003-332042 A

  However, even when the sealing layer is employed, light emission unevenness and color unevenness may occur.

  For example, when some trouble occurs during the manufacturing process of the light emitting element, for example, when a foreign substance having conductivity adheres to the conductive layer in the light emitting functional layer, the electrical characteristics of the conductive layer do not change, and uneven light emission occurs.・ Causes uneven color.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a light-emitting element and a method for manufacturing the light-emitting element that can reduce unevenness in light emission even when a problem occurs.

  In order to solve the above problems, a light-emitting element according to one embodiment of the present invention includes a first electrode, a light-emitting functional layer formed over the first electrode and having a conductive layer as an uppermost layer, and one of the conductive layers. Formed on the second electrode except for the second electrode formed on the upper surface of the conductive layer with an undesired opening in a portion corresponding to the partial region and the peripheral surface constituting the opening in the second electrode And the partial region of the conductive layer is oxidized.

  In order to solve the above problems, a method for manufacturing a light-emitting element according to one embodiment of the present invention includes a first electrode, a light-emitting functional layer including a light-emitting layer and a conductive layer, a second electrode, and a sealing layer in this order. In the method of manufacturing a light emitting device provided above, a first step of forming a first electrode on a substrate, a second step of forming a light emitting functional layer on the first electrode formed in the first step, and the first A third step of forming a second electrode on the light emitting functional layer formed in two steps, a fourth step of forming a sealing layer on the second electrode formed in the third step, and the fourth step. Thereafter, the substrate is exposed to an oxygen atmosphere to perform a fifth step of promoting oxidation of the conductive layer portion exposed to the oxygen atmosphere.

  In the light-emitting element according to one embodiment of the present invention and the method for manufacturing the light-emitting element according to one embodiment of the present invention, even if some defect, for example, a foreign matter having conductivity adheres to the conductive layer during the manufacturing process of the light-emitting element, Since the foreign matter adhering portion of the conductive layer is oxidized, it is insulated from the foreign matter, the change in the electrical characteristics of the conductive layer can be suppressed, and light unevenness can be reduced.

It is a block diagram which shows typically the whole structure of a display apparatus. It is a fragmentary sectional view which shows typically the principal part of a display panel. It is a figure which shows an example of the manufacturing process of a display panel. It is a figure which shows an example of the manufacturing process of a display panel. It is a figure which shows an example of the manufacturing process of a display panel. It is a figure which shows the case where a foreign material adheres to the upper surface of an electron carrying layer. It is a figure explaining the state of the foreign material adhesion part in a manufacturing process.

<Aspect of implementation>
A light-emitting element which is one embodiment of the present invention includes a first electrode, a light-emitting functional layer formed over the first electrode and having a conductive layer as an uppermost layer, and a portion corresponding to a partial region of the conductive layer. A second electrode formed on the upper surface of the conductive layer in a state having a desired opening; and a sealing layer formed on the second electrode excluding a peripheral surface constituting the opening in the second electrode. The partial region of the conductive layer is oxidized. Thereby, even if a malfunction occurs, unevenness in light emission and the like can be reduced.

  The peripheral surface of the second electrode and the sealing layer are covered with a second sealing layer formed in units of atomic layers. Thereby, gas barrier property can be improved.

  In addition, foreign matter is attached to a partial region of the conductive layer, and the foreign matter is fixed by oxidation of the partial region. Thereby, it can prevent that a foreign material scatters and adheres to another site | part.

  Moreover, a partial region of the conductive layer is covered with the second sealing layer except for a portion where the foreign matter is attached. Thereby, the gas barrier property of a conductive layer can be improved.

  The foreign material is covered with the second sealing layer in a state where a layer of the same material as the second electrode and a layer of the same material as the sealing layer are formed on the foreign material. Thereby, it can reduce that a foreign material remove | deviates.

  The light emitting functional layer includes an organic light emitting layer, and the conductive layer is an electron transport layer that transports electrons to the light emitting layer.

  A light-emitting element which is one embodiment of the present invention is a method for manufacturing a light-emitting element including a first electrode, a light-emitting functional layer including a light-emitting layer and a conductive layer, a second electrode, and a sealing layer in this order. A first step of forming a first electrode thereon; a second step of forming a light emitting functional layer on the first electrode formed in the first step; and a light emitting functional layer formed in the second step. A third step of forming a second electrode; a fourth step of forming a sealing layer on the second electrode formed in the third step; and after the fourth step, exposing the substrate to an oxygen atmosphere, And a fifth step of promoting oxidation of the conductive layer portion exposed to the oxygen atmosphere. As a result, it is possible to manufacture a light emitting element that can reduce unevenness in light emission even if a problem occurs.

  In the fifth step, oxygen is vented for several hundreds of milliseconds to several seconds. Thereby, oxidation can be easily formed in the conductive layer portion.

  Further, after the fifth step, a second sealing layer is formed by an atomic layer growth method or an atomic layer deposition method. Thereby, sealing performance can be improved.

  The light-emitting element which is one embodiment of the present invention includes a conductive layer as an uppermost layer as a light-emitting functional layer, and attention is paid to the conductive layer as follows.

  The light-emitting element includes a first functional layer having a first region having conductivity, a second region formed by oxidizing a part of the first region and having an insulating property, and the first function layer. A first layer including one or a plurality of layers having a first portion corresponding to the first region in the functional layer and having conductivity, and an opening corresponding to the second region in the first functional layer. 2 functional layers, a first sealing portion covering the surface of the second functional layer, a second sealing portion corresponding to the second region in the first functional layer, and the first A first seal formed between the sealing portion and the second sealing portion and having one end side having a crack portion extending to the second region of the first functional layer and having an insulating property A layer and an insulating material, covering the surfaces of the first sealing portion and the second sealing portion of the first sealing film, and A part of the second region of the first functional layer is present in a portion facing the crack portion, and a path extending to the second region of the first functional layer in the crack portion is blocked. And a second sealing layer.

  Here, the first functional layer corresponds to the conductive layer. The second region of the first functional layer corresponds to a partial region of the conductive layer. The layer having the first portion and the opening in the second functional layer corresponds to the second electrode, and the opening corresponds to the opening. The first sealing layer corresponds to the sealing layer, and the second sealing layer corresponds to the second sealing layer.

  In addition, foreign matter adheres to the surface portion of the second region of the first functional layer, the opening of the second functional layer is formed corresponding to the foreign matter, and the first sealing The second sealing portion of the film directly or indirectly covers the foreign matter.

  The first functional layer is a layer containing an alkali metal or an alkaline earth metal, and the second functional layer is a cathode.

  In other words, the light-emitting element includes a first layer in which a defect portion is partially formed, and a second layer in which the peripheral portion of the defect portion in the first layer is oxidized to form an oxidation portion. And a sealing member that covers the functional layer.

  Here, the first layer corresponds to the first functional layer, the second layer corresponds to the second functional layer, and the first layer and the second layer may be the same or different. May be.

   On the other hand, the manufacturing method according to one embodiment of the present invention includes the conductive layer as the uppermost layer as the light emitting functional layer, and attention is paid to the conductive layer as follows.

  A method for manufacturing a light-emitting element includes: a first step of forming a first functional layer having conductivity; and a second functional layer including one or more layers having conductivity on the first functional layer. A second step of forming, a third step of forming a first sealing layer having insulating properties on the second functional layer, and a second sealing having insulating properties on the first sealing film A fourth step of forming a layer, and in the second step, in the region where the foreign matter adheres to the surface of the first layer, the periphery of the surface separated from the foreign matter with a space Forming the second functional layer with respect to the portion, and the third step includes the first sealing layer, the foreign material, and the second layer formed in the peripheral portion thereof. A step of covering the surface of the second layer and the surface of the foreign matter except for a portion corresponding to a space (between), In the step, the second sealing layer is formed in an oxygen atmosphere so as to cover the surface of the first sealing layer and to enter the space not covered by the first sealing film. And when forming the second sealing film, the first sealing layer in the first functional layer is formed through oxygen in the atmosphere through the space portion. This is a step of oxidizing a surface portion that is in contact with the foreign matter including the exposed portion by acting on a nonexposed portion.

  In the fourth step, the second sealing layer is formed using an atomic layer growth method in which a constituent material is deposited in an atomic state in an oxygen atmosphere.

  In the fourth step, the intermediate of the organic light emitting device having the first sealing layer formed in the third step is exposed to an oxygen atmosphere, and after the oxygen aeration step, On the other hand, the second sealing layer includes a film forming step of forming a film using an atomic layer growth method, and the oxygen aeration step allows oxygen to be aerated from 100 msec to 20 sec through the intermediate.

In the second step, the second functional layer is formed over the entire surface where no foreign matter is attached in a region where no foreign matter is attached to the surface of the first functional layer.
<Embodiment>
Here, a display panel will be described as an example of the light emitting panel.
1. Display Device FIG. 1 is a block diagram schematically showing the overall configuration of a display device.

  As shown in the figure, the display device 1 includes a display panel 10 and a drive control unit 20 connected thereto.

  The display panel 10 is, for example, a top emission type organic EL display panel using an electroluminescence phenomenon of an organic material. The drive control unit 20 includes four drive circuits 21 to 24 and a control circuit 25 that controls the drive circuits 21 to 24.

  The display panel is not limited to the organic EL type using an organic material, but may be an inorganic EL type using an inorganic material, a bottom emission type organic EL type, or a bottom emission type inorganic. An EL type may be used.

The arrangement of the drive control unit 20 is not limited to this, and the number of drive circuits is not limited to four. For example, a circuit in which a control circuit and a drive circuit are integrated may be used.
2. Display Panel FIG. 2 is a partial cross-sectional view schematically showing a main part of the display panel 10.

  As shown in the figure, the display panel 10 has a plurality of pixels (pixels) formed in a matrix on a substrate 101.

  Here, one pixel is composed of a plurality (specifically, three) of sub-pixels, and is composed of three sub-pixels arranged in the X direction. The sub-pixel corresponds to the light-emitting element of the present invention. Here, the three sub-pixels are, for example, sub-pixels whose emission colors are red (R), green (G), and blue (B).

  In the substrate 101, an interlayer insulating film 105 is formed on the TFT substrate 103. An anode 107 (corresponding to the “first electrode” in the present invention) 107 is formed on the substrate 101 in units of subpixels. Note that in this specification, the direction in which various functional layers are stacked on the substrate 101 is referred to as the upward direction, with the substrate 101 as a reference. This upward direction is the Z direction in FIG. 2, and the upper side is also referred to as the front side.

  A hole injection layer 109 is formed on a region of the substrate 101 where the anode 107 is not formed and on the anode 107. Note that the hole injection layer 109 is formed on substantially the entire surface of the substrate 101 in the state where the anode 107 corresponding to the subpixel exists, and therefore, the adjacent anode 107 107 with reference to the hole injection layer 109 on the upper surface of the anode 107. Recess between.

  Banks (partitions) 111 are formed in each of the regions on the hole injection layer 109 corresponding to the area between the adjacent anodes 107.

  As shown in FIG. 2, the bank 111 fills the gap between the adjacent anodes 107 and is above the hole injection layer 109 existing on the upper surface of the end portion of the anode 107 (in the thickness direction and away from the substrate 101). (It is the Z direction in the middle.) Here, the protruding shape has a trapezoidal shape, for example. Note that the banks 111 are formed in a cross-beam shape in plan view.

  A predetermined light color (here, the above-described red, green, etc.) is formed on the hole injection layer 109 in each region defined by the bank 111 (in FIG. 2, the region corresponding to between the adjacent banks 111). , Blue).).

  An electron transport layer 115, a cathode 117, and a sealing portion 119 are formed in this order on the surface region of the bank 111 above the light emitting layer 113 and on the light emitting layer 113. The electron transport layer 115, the cathode 117, and the sealing portion 119 are formed so as to be continuous with those of other adjacent subpixels beyond the region defined by the bank 111.

  The electron transport layer 115 corresponds to the “conductive layer” of the present invention, and the three layers including the hole injection layer 109, the light emitting layer 113, and the electron transport layer 115 correspond to the “light emitting functional layer” of the present invention, and the cathode Corresponds to the “second electrode” of the present invention.

The sealing part 119 has a two-layer structure of a first sealing layer 121 and a second sealing layer 123 formed on the surface of the first sealing layer. The first sealing layer 121 corresponds to the “sealing layer” of the present invention.
3. Example of display panel (1) Substrate (1-1) TFT substrate The TFT substrate 103 is, for example, alkali-free glass, soda glass, non-fluorescent glass, phosphate glass, borate glass, quartz, acrylic resin, styrene series TFT, wiring member, and passivation film for covering the TFT on the substrate body of an insulating material such as resin, polycarbonate resin, epoxy resin, polyethylene, polyester, silicone resin, or alumina (not shown) It is the structure which formed. The substrate body may be an organic resin film.
(1-2) Interlayer Insulating Film The interlayer insulating film 105 is provided to adjust the surface level difference of the TFT substrate 103 to be flat and is made of an insulating material such as polyimide resin or acrylic resin.
(2) Anode The anode 107 is made of aluminum (Al) or an aluminum alloy. The anode 107 may be formed of, for example, silver (Ag), an alloy of silver, palladium (Pd), and copper (Cu), an alloy of silver, rubidium (Rb), and gold (Au), molybdenum (Mo), and chromium ( It may be formed of an alloy of Cr), an alloy of nickel (Ni) and chromium, or the like.
(3) Hole Injection Layer The hole injection layer 109 has a function of injecting holes into the light emitting layer 113. The hole injection layer 109 is formed of a metal oxide including a transition metal oxide such as tungsten oxide (WOx), molybdenum oxide (MoOx), molybdenum tungsten oxide (MoxWyOz), or the like.
(4) Bank The bank 111 has a function of partitioning adjacent subpixels. The bank 111 is made of, for example, an organic material such as resin and has an insulating property. Examples of the organic material include an acrylic resin, a polyimide resin, and a novolac type phenol resin. The bank 111 preferably has organic solvent resistance. Furthermore, since the bank 111 may be subjected to an etching process, a baking process, or the like, it is preferable that the bank 111 be formed of a highly resistant material that does not excessively deform or alter the process.
(5) Light emitting layer When the light emitting layer 113 is an organic light emitting layer, for example, polymers such as polyfluorene, polyphenylene vinylene, polyacetylene, polyphenylene, polyparaphenylene ethylene, poly-3-hexylthiophene, and derivatives thereof are used. Oxinoid compounds, perylene compounds, coumarin compounds, azacoumarin compounds, oxazole compounds, oxadiazole compounds, perinone compounds, pyrrolopyrrole compounds, naphthalene compounds, anthracene compounds, fluorene compounds, fluoranthenes described in JP-A-5-163488 Compound, tetracene compound, pyrene compound, coronene compound, quinolone compound and azaquinolone compound, pyrazoline derivative and pyrazolone derivative, rhodamine compound, chrysene compound, phenant Len compound, cyclopentadiene compound, stilbene compound, diphenylquinone compound, styryl compound, butadiene compound, dicyanomethylenepyran compound, dicyanomethylenethiopyran compound, fluorescein compound, pyrylium compound, thiapyrylium compound, serenapyrylium compound, telluropyrylium compound, aromatic Ardadiene compound, oligophenylene compound, thioxanthene compound, cyanine compound, acridine compound, metal complex of 8-hydroxyquinoline compound, metal complex of 2-bipyridine compound, complex of Schiff salt and group III metal, oxine metal complex, rare earth complex It is preferable to form with fluorescent materials, such as.
(6) Electron transport layer The electron transport layer 115 is, for example, a nitro-substituted fluorenone derivative, a thiopyrandioxide derivative, a diphequinone derivative, a perylenetetracarboxyl derivative, an anthraquinodimethane derivative, fluorenylidene described in JP-A-5-163488. It is formed of a methane derivative, anthrone derivative, oxadiazole derivative, perinone derivative, or quinoline complex derivative.

In order to further improve the electron injection property, the material constituting the electron transport layer 115 is doped with an alkali metal or alkaline earth metal such as sodium (Na), barium (Ba), or potassium (K). In this embodiment, barium is doped (in this case, the electron transport layer also has an electron injection function).
(7) Cathode The cathode 117 is an electrode for injecting electrons into the light emitting layer 113. In this embodiment, since it is a top emission type, the cathode 117 needs to transmit light emitted from the light emitting layer 113 and is formed of a transparent electrode such as ITO or IZO.
(8) Sealing portion The sealing portion 119 has a function of suppressing the light emitting layer 113 and the like from being exposed to moisture or being exposed to air.

The first sealing layer 121 includes, for example, silicon oxide (SiO), silicon nitride (SiN), silicon oxynitride (SiON), silicon carbide (SiC), carbon-containing silicon oxide (SiOC), aluminum nitride (AlN), oxide It is made of a material such as aluminum (Al ₂ O ₃ ).

The second sealing layer 123 is formed of a material such as aluminum oxide (Al ₂ O ₃ ), silicon oxide (SiO ₂ ), aluminum nitride (AlN), or aluminum oxynitride (Al _X O _Y N _Z ). .
4). Manufacturing Method The manufacturing process of the display panel 10 is illustrated.

  3 to 5 are diagrams showing an example of the manufacturing process of the display panel 10. FIG. 3 to 5, a part of the display panel 10 is extracted and schematically shown.

  The display panel 10 includes (1) a step of forming an anode (anode formation step), (2) a step of forming a hole injection layer (hole injection layer formation step), and (3) a step of forming a bank (bank formation). Step), (4) Step of forming the light emitting layer (light emitting layer forming step), (5) Step of forming the electron transport layer (electron transport layer forming step), (6) Step of forming the cathode (cathode forming step) (7) Step of forming the first sealing layer (first sealing layer forming step), (8) Oxygen exposure step, (9) Step of forming the second sealing layer (second sealing layer forming step) ) And manufactured. In addition, there exists a process of preparing the board | substrate 101 which should form an anode before said (1) anode formation process.

  Here, since the light emitting functional layer is formed by the steps from the hole injection layer forming step to the electron transport layer forming step, the steps from the hole injection layer forming step to the electron transport layer forming step are referred to as “light emitting functional layer forming step. "

  The anode forming step is the “first step” of the present invention, the hole injection layer forming step to the electron transport layer forming step (light emitting functional layer forming step) is the “second step” of the present invention, and the cathode forming step. Corresponds to the “third step” of the present invention, the first sealing layer forming step corresponds to the “fourth step” of the present invention, and the oxygen exposure step corresponds to the “fifth step” of the present invention.

Each step will be described.
(1) Anode formation step A metal film, for example, an aluminum (Al) film, which is a material of the anode 107, is formed on the substrate 101 on which the interlayer insulating film 105 is formed on the TFT substrate 103. For forming the aluminum film, for example, a vacuum film forming method such as a sputtering method or a vacuum vapor deposition method can be used.

After the aluminum film is formed, patterning is performed by, for example, photolithography to obtain the anodes 107 formed in a matrix (see FIG. 3A). The film thickness of the anode 107 is, for example, 100 [nm] to 200 [nm].
(2) Hole injection layer forming step A tungsten oxide film, which is a metal oxide film, is formed on the upper surface of the TFT substrate 101 on which the anodes 107 are formed in a matrix using a composition containing, for example, tungsten oxide (WOx). A film is formed (see FIG. 3B).

The film thickness of the hole injection layer 109 is, for example, 1 [nm] to 10 [nm], and the hole injection layer 109 is formed by using a vacuum film formation method such as a sputtering method or a vacuum evaporation method. it can.
(3) Bank Formation Step First, a bank material layer made of an insulating organic material is formed on the hole injection layer 109 formed on the substrate 101. The bank material layer can be formed, for example, by coating. Thereafter, a mask having an opening having a predetermined shape is overlaid on the bank material layer, and after exposing the mask from above, the excess bank material layer is washed out with a developer. Thereby, the patterning of the bank material layer is completed, and the bank 111 is completed (see FIG. 3C).

The height of the bank 111 from the upper surface of the hole injection layer 109 is, for example, 1 [μm] to 2 [μm].
(4) Light-Emitting Layer Formation Step A composition ink containing a light-emitting material is dropped into each region partitioned by the bank 111 by, for example, an inkjet method, and the composition ink is dried to form the light-emitting layer 113 (FIG. 4 (a)). The film thickness of the light emitting layer 113 is, for example, 10 [nm] to 100 [nm].
(5) Electron Transport Layer Formation Step After the formation of the light emitting layer 113, a derivative layer made of, for example, a nitro-substituted fluorenone derivative is formed on the substrate 101 on which the light emitting layer 113 is formed. For film formation, a vacuum film formation method such as a sputtering method or a vacuum evaporation method can be used (see FIG. 4B).

Thereafter, in order to improve the electron injection property, barium (Ba) is doped by about 2 [wt%] to 30 [wt%]. The film thickness of the electron transport layer is, for example, 0.5 [nm] to 50 [nm].
(6) Cathode formation step After the formation of the electron transport layer 115, a transparent metal film, for example, an ITO film is formed to form the cathode 117. For forming the ITO film, a vacuum film forming method such as a sputtering method or a vacuum vapor deposition method can be used (see FIG. 4C). The film thickness of the cathode 117 is, for example, 10 [nm] to 200 [nm].
(7) First Sealing Layer Formation Step After forming the cathode 117, a metal oxide film, for example, a silicon oxide (SiO) film is formed to form the first sealing layer 121. For the formation of the silicon oxide film, a vacuum film formation method such as a sputtering method or a vacuum vapor deposition film method can be used (see FIG. 5A). The film thickness of the first sealing layer 121 is, for example, 5 [nm] to 200 [nm].
(8) Oxygen exposure step The TFT substrate 103 on which the first sealing layer 121 is formed is exposed in an oxygen atmosphere. At this time, as will be described later, when the electron transport layer 115 is exposed to an oxygen atmosphere, the exposed portion (the “partial region of the conductive layer” of the present invention and the conductive layer portion exposed to the oxygen atmosphere). Is equivalent to "."), An oxide film is formed. The exposure time is several [sec] to several tens [sec].
(9) Second sealing layer formation step After the oxygen exposure step, an aluminum oxide (Al ₂ O ₃ ) film is formed to form the second sealing layer 123. The aluminum oxide film uses an atomic layer deposition (ALD) method in which constituent materials constituting the film are deposited in an atomic state.

In this example, an aluminum oxide film is used as the second sealing layer 123, trimethylaluminum (TMA, hereinafter simply referred to as “TMA”) is used as a constituent material, and O ₂ plasma is used as an oxidizing agent. Used.

The film formation is performed by introducing TMA and removing excess molecules by purging (hereinafter, simply referred to as “purge”), O ₂ plasma irradiation, and purging processing as one cycle and repeating several hundred times. The introduction of TMA, the O ₂ plasma irradiation and the purge are performed for several hundreds [msec] to 200 [sec]. The film thickness of the second sealing layer 123 is, for example, 5 [nm] to 200 [nm].
5. When a foreign substance adheres on the electron carrying layer 109 The display panel 10 is manufactured in a clean atmosphere. However, it is difficult to make foreign matter into the display panel 10 zero during the manufacturing process.

  FIG. 6 is a diagram illustrating a state in which foreign matter has adhered after the formation of the electron transport layer.

  The foreign material 130 adheres as shown in the figure, and if the sealing layer (the sealing layer here is the first sealing layer 121) is only the layer formed by the CVD method, the shadow of the foreign material 130 is affected. Thus, the cathode 117 and the sealing layer (first sealing layer 121) are not deposited around the foreign material 130, and the groove 132 is formed. That is, the electron transport layer 115 and the cathode 117 are exposed without being sealed by the sealing layer (first sealing layer 121), and an undesired opening is provided in the cathode 117.

  When the layer below the sealing layer (first sealing layer 121) is exposed, a gas intrusion path of moisture or the like is formed along the groove 132 as described above. For example, it is bonded to a glass substrate. When a resin material is applied, the gas may enter the electron transport layer 115 and the cathode 117 from the groove 132 and cause display defects of the panel.

  Furthermore, when the foreign material 130 has conductivity, the electrical characteristics of the electron transport layer 115 are greatly changed, and, for example, uneven light emission occurs.

  However, the manufacturing method described in this embodiment can suppress the occurrence of the above problems. Hereinafter, the reason for this will be described with reference to the state of the foreign matter adhering portion when the display panel 10 is manufactured in the above manufacturing process.

  In the display panel 10, even after the foreign material 130 shown in FIG. 6 is attached to the electron transport layer 115, the steps after the electron transport layer formation step are sequentially performed as they are.

FIG. 7 is a diagram for explaining a state of a foreign matter adhesion portion during the manufacturing process.
(1) Up to the first sealing layer forming step Each forming step is performed on the display panel 10 with the foreign matter 130 attached. (A) of the figure has shown the state which the 1st sealing layer formation process was complete | finished.

  As shown in FIG. 5A, when the foreign material 130 adheres to the electron transport layer 115, the cathode 117 and the first sealing layer 121 that should be originally formed on the electron transport layer 115 are formed on the electron transport layer 115. It is formed on the upper surface of the foreign material 130 without being formed.

  Note that each layer formed on the foreign material, that is, each layer formed of the same material as the electron transport layer 115, the cathode 117, and the first sealing layer 121 has a function related to light emission and a function of protecting a light emitting part. Therefore, these layers are an electron transport layer film 115b, a cathode film 117b, and a first sealing layer film 121b.

Thus, around the foreign material 130, the foreign material 130 (including the cathode film 117 b and the first sealing layer film 121 b formed on the foreign material 130), the cathode 117 formed around the foreign material, and the first. A groove 132 exists between the sealing layer 121 and the sealing layer 121.
(2) Oxygen exposure process After a 1st sealing layer formation process, as above-mentioned, an oxygen exposure process is performed. As a result, the electron transport layer 115 exposed in the oxygen atmosphere is oxidized (illustrated as an oxide film 134). In particular, when Ba is doped in the electron transport layer 115, the electron transport layer 115 is easily oxidized, and the adhesion surface with the foreign material 130 is also oxidized. Note that the foreign matter 130 is fixed to the electron transport layer 115 when the attached surface is also oxidized. This state is shown in FIG.

As a result, when the foreign matter 130 has conductivity, the peripheral portion including the attached portion of the foreign matter 130 in the electron transport layer 115 is oxidized, so that insulation against the conductive foreign matter 130 is ensured.
(3) Second sealing layer forming step In the second sealing layer forming step, as described above, the aluminum oxide film (123) is formed by the ALD method after the oxygen exposure step. This state is shown in FIG.

  In the ALD method, deposition can be performed for each atomic layer. Therefore, as shown in FIG. 7A, even if the groove 132 exists around the foreign material 130, atoms enter and accumulate inside the groove 132.

  As a result, on the exposed portion where the cathode 117 and the first sealing layer 121 are not formed around the portion on the upper surface of the electron transport layer 115 where the foreign matter 130 is attached (the portion in contact with the foreign matter). The second sealing layer 123 is formed, and the exposed portion is sealed with the second sealing layer 123.

  Thus, in the manufacturing method according to the present embodiment, even if the foreign matter 130 adheres to the upper surface of the electron transport layer 115, the second sealing layer 123 is deposited up to the groove 132 due to the adhesion, In the process, gas such as moisture can be prevented from entering the electron transport layer 115, the cathode 117, and the first sealing layer 121.

  In particular, the second sealing layer 123 is formed thinner than the first sealing layer 121, but is deposited in units of atoms, so that a dense film can be obtained (so-called pinhole-free). ) As a result, high sealing performance can be obtained.

  Furthermore, even when the foreign matter 130 has conductivity, the oxide film 134 is formed on the surface of the electron transport layer 115 exposed on the surface, and as a result, insulation is secured against these. As a result, changes in electrical characteristics can be suppressed.

  Further, the second sealing layer 123 is formed on the oxide film 134, the first sealing layer 121, the foreign material 130, the cathode film 117b deposited on the foreign material 130, and the first sealing layer film 121b. Therefore, the second sealing layer 123 can be filled into the groove 132 and the foreign matter 130 can be completely insulated. By this. Intrusion of gas such as moisture into the oxide film 134 can be prevented.

In addition, when the foreign matter 130 has conductivity, the foreign matter 130 is fixed to the electron transport layer 115 due to oxidation of the electron transport layer 115, and the foreign matter 130 is scattered and attached to other parts in another process. It is possible to prevent the occurrence of defects and the like.
<Modification>
Although the light emitting device and the manufacturing method thereof according to the present invention have been described above, the present invention is not limited to the above embodiment. For example, the following modifications can be considered.
1. Display Panel (1) Pixel In the embodiment, one pixel is composed of three (three types) sub-pixels having different emission colors, but it is not necessary to limit the number to three (three types). One pixel may be composed of one color (monochrome) subpixel, or one pixel may be composed of, for example, four or more subpixels having different emission colors. In addition, although the material etc. which comprise a light emitting layer differ if light emission colors differ, the basic composition that a light emitting layer is pinched | interposed into an anode and a cathode is the same.
(2) Anode In the embodiment, the hole injection layer 109 is formed on the surface of the anode 107. For example, a conductive layer is formed on the surface of the anode 107, and the upper surface of the conductive layer and the conductive layer are formed. The hole injection layer 109 may be formed on the upper surface of the substrate 101 that is not formed. The conductive layer here functions as a protective layer that prevents the anode 107 from being naturally oxidized during the manufacturing process.
(3) Light-Emitting Layer Although the light-emitting layer 113 is formed on the upper surface of the hole injection layer 109, for example, a hole transport layer may be provided between the light-emitting layer 113 and the hole injection layer 109. The hole transport layer has a function of transporting holes injected from the hole injection layer 109 to the light emitting layer 113.

The hole transporting layer includes, for example, triazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives and pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcones described in JP-A-5-163488. Derivatives, oxazole derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, stilbene derivatives, porphyrin compounds, aromatic tertiary amine compounds and styrylamine compounds, butadiene compounds, polystyrene derivatives, hydrazone derivatives, triphenylmethane derivatives, tetraphenylbenzines Derivatives and the like. Particularly preferably, it is formed of a porphyrin compound, an aromatic tertiary amine compound and a styrylamine compound.
(4) Sealing portion In the embodiment, the second sealing layer 123 is formed on the top surface of the first sealing layer 121. For example, a third sealing layer is formed on the top surface of the second sealing layer 123. It may be formed. In this case, the third sealing layer may be formed by the same material and molding method as the first sealing layer 121, or may be formed by another method, for example, a chemical vapor deposition (CVD) method. You may do it.

In the embodiment, the second sealing layer using the ALD method is formed on the first sealing layer. In this case, the oxidation exposure step is performed after the light emitting functional layer forming step.
2. Manufacturing Method (1) Second Sealing Layer In the embodiment, the second sealing layer 123 is formed by an electronic layer deposition method (ADL method). When the second sealing layer 123 is composed of aluminum oxide, trimethylaluminum (TMA, hereinafter simply referred to as “TMA”) is used as a constituent material, but other constituent materials may be used. it can.

  As other materials, for example, alkyl-based metals such as TEA (triethylaluminum) and DMAH (dimethylaluminum hydride) can be used.

Moreover, you may comprise a 2nd sealing layer with another material. Other materials include silicon oxide (SiO ₂ ), aluminum nitride (AlN), oxynitrogen compound (Al _X O _Y N _Z ), and the like. For example, when configuring an acid nitrogen compound _{(Al X O Y N Z)} , as a material, for example, it is carried out by reacting TMA, TEA, a DMAH and nitrogen compounds.

Furthermore, you may form per electronic layer by another method. As another method, there is an atomic layer growth method (ALE method).
(2) Oxygen exposure step In the oxygen exposure step, the substrate 101 on which the first sealing layer 121 is formed is exposed to an oxygen atmosphere, but the electrons exposed on the surface after the first sealing layer 121 is formed. Other methods may be used as long as the transport layer 115 and the cathode 117 can be oxidized.

  The oxygen atmosphere only needs to be oxidized and may contain other gases (nitrogen, argon, etc.).

  Moreover, the oxidation exposure process should just be performed after the light emitting functional layer formation process, for example, if the layer which consists of a conductive material exposed on the surface after forming a light emitting functional layer can be oxidized. Specifically, it may be performed before the first sealing layer 121 is formed.

When ITO, which is a transparent conductive film, is used as the cathode, an oxide film is difficult to be formed on the cathode in the oxygen exposure step. However, when the cathode is made of an oxidizable material such as a metal, it is oxidized in the oxidation exposure step. A film is formed.
3. Opening In the embodiment, the undesired opening of the second electrode is caused by the adhesion of foreign matter to the conductive layer of the light emitting functional layer, but may be caused by other factors. Other factors include a distorted bank shape.

  The present invention is applicable to a display device.

DESCRIPTION OF SYMBOLS 10 Display panel 101 Substrate 107 Anode 113 Light emitting layer 117 Cathode 121 1st sealing layer 123 2nd sealing layer

Claims (9)

A first electrode;
A light emitting functional layer formed on the first electrode and having a conductive layer as an uppermost layer;
A second electrode formed on the upper surface of the conductive layer with an undesired opening in a portion corresponding to a partial region of the conductive layer;
A sealing layer formed on the second electrode except for a peripheral surface constituting the opening in the second electrode;
A light emitting element in which the partial region of the conductive layer is oxidized.
The light emitting device according to claim 1, wherein the peripheral surface of the second electrode and the sealing layer are covered with a second sealing layer formed in atomic layer units.
Foreign matter is attached to a part of the conductive layer,
The light emitting device according to claim 1, wherein the foreign matter is fixed by oxidation of the partial region.
The light emitting element according to claim 3, wherein a part of the conductive layer is covered with the second sealing layer except for a portion where the foreign matter is attached.
The said foreign material is coat | covered with the said 2nd sealing layer in the state in which the layer of the same material as the 2nd electrode and the layer of the same material as the sealing layer were formed on the said foreign material. Light emitting element.
The light emitting device according to claim 1, wherein the light emitting functional layer includes an organic light emitting layer, and the conductive layer is an electron transport layer that transports electrons to the light emitting layer.
In the method for manufacturing a light-emitting element including the first electrode, the light-emitting functional layer including the light-emitting layer and the conductive layer, the second electrode, and the sealing layer in this order on the substrate,
A first step of forming a first electrode on a substrate;
A second step of forming a light emitting functional layer on the first electrode formed in the first step;
A third step of forming a second electrode on the light emitting functional layer formed in the second step;
A fourth step of forming a sealing layer on the second electrode formed in the third step;
A method of manufacturing a light-emitting element, comprising: after the fourth step, performing a fifth step of exposing the substrate to an oxygen atmosphere to promote oxidation of the conductive layer portion exposed to the oxygen atmosphere.
The method of manufacturing a light emitting element according to claim 7, wherein in the fifth step, oxygen is ventilated for several hundred milliseconds to several seconds.
The method for manufacturing a light emitting element according to claim 7, wherein the second sealing layer is formed by an atomic layer growth method or an atomic layer deposition method after the fifth step.

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