JP2005209356A - Organic el element and color filter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic EL element having a passivation film having water vapor barrier properties and transparency higher than those of silicon nitride (SiN<SB>x</SB>) single-layer film or usual silicon oxide nitride (SiO<SB>x</SB>N<SB>y</SB>) film, and to provide a color filter. <P>SOLUTION: The passivation film which is a film of the silicon oxide nitride (SiO<SB>x</SB>N<SB>y</SB>), in which ratio of nitrogen atoms (N) and oxygen atoms (O) is tiltingly varied in the depth direction of the film is formed between the color filter and a transparent electrode on a substrate. Preferably, the ratio of the nitrogen atoms (N) and the oxygen atoms (O) in the depth direction of the passivation film varies in a range of 0.4-0.9 in a value of the number of nitrogen atoms/(the number of oxygen atoms + the number of nitrogen atoms), and the ratio of the nitrogen atoms (N) and the oxygen atoms (O) varies in a range of 0.6-0.9 in a value of the number of nitrogen atoms/(the number of oxygen atoms + the number of nitrogen atoms). <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an organic electroluminescence element (hereinafter referred to as an organic EL element) having a passivation film for protecting it from water vapor, organic gas, etc., and in particular, the ratio of oxygen atoms and nitrogen atoms in the film is inclined in the depth direction. OLED device using a passivation film using a special silicon nitride oxide (SiOxNy) film changed to, and a film in which a silicon nitride oxide (SiOxNy) film and a silicon nitride (SiNx) film are laminated, and a color used for manufacturing the same Regarding filters.

  An organic EL element is composed of a transparent electrode, an organic light emitting layer (including a hole transport layer, etc.), a metal electrode, etc. on a transparent substrate using an organic material having a function of emitting light by voltage. The

  However, organic EL elements are susceptible to deterioration such as expansion of non-light emitting parts (dark spots) due to the influence of moisture, organic gas, etc., and how to protect the organic light emitting layer and metal electrode part from moisture etc. Is a challenge. Therefore, the organic EL element is formed on a glass substrate having a high barrier property such as water vapor, and is sealed so as to cover the entire element with a glass sealing can. In some cases, moisture is absorbed in the sealing can. Some measures have been taken, such as encapsulating the agent.

  On the other hand, when an organic EL element is used for a color display panel, it is necessary to have a technique for finely patterning and separately coating organic light-emitting materials of light emission colors such as red, green, and blue. A technique such as mask vapor deposition is used to separate the organic light-emitting material by vapor deposition, but it is difficult to produce a high-definition large-screen display. In addition, a method of painting using a polymer material by using a printing technique is also conceivable, but it has not been realized at this stage.

  In view of this, a method has been devised in which a white light emitting organic light emitting material and a color filter are combined to avoid coloration for each light emission color. In this method, how to block moisture, organic gas, and the like generated from the color filter and the overcoat resin for flattening the color filter becomes a problem.

As a device for that, it is conceivable to form a transparent barrier film having a high water vapor barrier property between the color filter or overcoat layer and the transparent electrode. As the transparent barrier film, silicon oxide (SiO ₂ ), aluminum oxide (Al ₂ O ₃ ), and the like have already been put into practical use in packaging materials and packaging containers. However, with these water vapor barrier values, a barrier for organic EL is used. The performance cannot be satisfied. Therefore, a color filter or the like using a silicon nitride film (SiNx) or a silicon nitride oxide film (SiOxNy), which is said to have a water vapor barrier property higher than that of silicon oxide (SiO ₂ ) or aluminum oxide (Al ₂ O ₃ ). There has been considered a method of blocking moisture generated from the water (see, for example, Patent Document 1 and Patent Document 2).
JP 2002-1000046 A JP 2002-134268 A

  However, as a result of repeated experiments by the authors, it was found that a silicon nitride (SiNx) single layer film or a normal silicon nitride oxide (SiOxNy) film is insufficient as a passivation film for an organic EL element. This is because it is difficult for these films to achieve both high water vapor barrier properties and transparency.

  The silicon nitride (SiNx) film is usually colored brownish brown, but when the film thickness exceeds 200 nm, the total light transmittance of visible light decreases to 90% or less and decreases as the film thickness increases. Since the passivation film formed between the color filter and the transparent electrode is on the light extraction side of the organic EL display, it needs to have high transparency, and has a visible light transmittance of at least 90%, preferably 95% or more. I need. On the other hand, in order to improve the barrier property such as water vapor, it is natural that the thicker the film, the better. In the case of the silicon nitride film formed by CVD as a result of the author's experiment, the barrier property as a passivation film of the organic EL element. It was a result that 200 nm or more is desirable in order to maintain.

  Therefore, it has been found that a single layer film of silicon nitride (SiNx) is insufficient to satisfy the demand as a passivation layer of the organic EL element.

  On the other hand, the silicon nitride oxide (SiOxNy) film is more transparent than the silicon nitride (SiNx) film, and the higher the ratio of oxygen atoms (O), the higher the transparency. On the other hand, the water vapor barrier property is silicon nitride ( It is inferior to the SiNx) film, and the barrier property decreases as the proportion of oxygen atoms (O) increases. Therefore, it is difficult to achieve both the water vapor barrier property and the transparency required for the organic EL element with a normal silicon nitride oxide (SiOxNy) film.

  Therefore, we changed the ratio of oxygen atoms (O) and nitrogen atoms (N) in the depth direction in the silicon nitride oxide (SiOxNy) film so that the ratio of nitrogen atoms (N) in the film is changed. We devised a film composition that blocks water vapor permeation at the high part and maintains transparency while supplementing the water vapor barrier at the high part of the remaining oxygen atoms (O), thereby providing a passivation film for organic EL It was decided to.

  In addition, instead of the gradient film, a silicon nitride (SiNx) film having a high water vapor barrier property and a silicon nitride oxide (SiOxNy) film having a high transparency are laminated and combined to maintain transparency while maintaining high barrier properties. Therefore, a passivation film for organic EL composed of the laminated film is also provided.

  To achieve the above object, the invention according to claim 1 is a film made of silicon nitride oxide (SiOxNy), wherein the ratio of nitrogen atoms (N) to oxygen atoms (O) is inclined in the depth direction of the film. An organic EL element having a passivation film that changes to

  In the invention according to claim 2, the change in the ratio of nitrogen atoms (N) to oxygen atoms (O) in the depth direction of the passivation film is a value of N atoms / (O atoms + N atoms). The organic EL element according to claim 1, wherein the organic EL element varies in a range of 0.4 to 0.9.

  In the invention according to claim 3, the change in the ratio of nitrogen atoms (N) to oxygen atoms (O) in the depth direction of the passivation film is a value of N atoms / (O atoms + N atoms). The organic EL element according to claim 1, wherein the organic EL element varies in a range of 0.6 to 0.9.

  In the invention according to claim 4, a high nitrogen concentration layer having a value of N atom number / (O atom number + N atom number) of 0.90 to 0.99 exists in a part of the passivation film. The organic EL device according to claim 1.

  Further, in the invention according to claim 5, a nitrogen high concentration layer having a value of N atom number / (O atom number + N atom number) of 0.90 to 0.99 exists in a part of the passivation film. 2. The organic EL device according to claim 1, wherein the average value of the number of N atoms / (number of O atoms + N atoms) of the remaining layers excluding the high nitrogen concentration layer is 0.6 or less.

  Further, in the invention according to claim 6, the thickness of the nitrogen high-concentration layer in which the value of N atom number / (O atom number + N atom number) is 0.90 to 0.99 is in the range of 50 nm to 100 nm. 6. The organic EL element according to claim 4, wherein the organic EL element is characterized in that

  The invention according to claim 7 is an organic EL element characterized in that the passivation film comprises a laminated film of silicon nitride oxide (SiOxNy) and silicon nitride (SiNx).

  In the invention according to claim 8, the thickness of the silicon nitride (SiNx) film layer in the laminated film of silicon nitride oxide (SiOxNy) and silicon nitride (SiNx) is in the range of 50 nm to 150 nm. 8. The organic EL device according to claim 7, wherein the organic EL device is characterized in that:

  The invention according to claim 9 is the organic EL element according to claim 1, wherein the passivation film is formed between the color filter layer on the substrate and the transparent electrode.

  The invention according to claim 10 is the organic EL element according to any one of claims 1 to 8, wherein the passivation film is formed so as to enclose at least a layer between the transparent electrode and the metal electrode. .

  The invention according to claim 11 is a color filter, wherein the passivation film according to claims 1 to 8 is formed between the color filter layer on the substrate and the transparent electrode.

  By forming a SiOxNy passivation film on the organic EL element or the color filter, expansion of dark spots (DS) due to water vapor and gas barrier properties is suppressed. Further, the passivation film has very good transparency. Therefore, it is possible to provide an organic EL element having good characteristics.

  In addition, since water vapor in the organic EL element is mostly derived from the color filter layer or the resin layer, it is effective that the passivation film is formed between the color filter layer on the substrate and the transparent electrode.

  Embodiments of the present invention will be specifically described.

  The passivation film in the present invention, that is, the passivation film for protecting the organic EL element from water vapor, organic gas, etc., has the ratio of nitrogen atoms (N) and oxygen atoms (O) changed in a gradient manner in the depth direction of the film. It consists of a silicon nitride oxide (SiOxNy) film. A silicon nitride oxide (SiOxNy) film can be formed by a sputtering method, a CVD method, or the like, and the film forming method is not particularly limited in the present invention, but in the embodiment of the present invention, the surface smoothness of the film and the uneven surface An embodiment of a CVD method that is advantageous in terms of film forming property will be described.

In the case of forming a silicon nitride oxide (SiOxNy) film by a CVD method, the film is formed using silane gas (SiH ₄ ), nitrogen oxide gas (N ₂ O), nitrogen gas (N ₂ ), ammonia (NH ₃ ), or the like as a raw material. The method is general, and the ratio of nitrogen atoms (N) and oxygen atoms (O) in the film can be adjusted by adjusting the flow ratio of these source gases.

In addition, the ratio of nitrogen atoms (N) and oxygen atoms (O) in the depth direction of the film can be changed by changing the flow rate ratio of each source gas during the film formation by the authors' experiments. Was confirmed. For example, when the flow rate ratio of nitrogen oxide gas (N ₂ O) is gradually increased during the film formation, the ratio of oxygen atoms (O) in the film becomes higher in the depth direction from the substrate side, and ammonia It was confirmed that when the flow rate ratio of the gas (NH ₃ ) is gradually increased during film formation, the ratio of nitrogen atoms (N) in the film increases in a depth direction from the substrate side.

By utilizing this, the passivation film, that is, the silicon nitride oxide (SiOxNy) gradient film in the present invention has a high nitrogen (N) ratio on the substrate side, for example, and gradually decreases the nitrogen (N) ratio to increase the oxygen (O) ratio. In the case of an inclined film, the film formation is started at a gas flow rate ratio where the flow rate ratio of ammonia gas (NH ₃ ) is high and the flow rate ratio of nitrogen oxide gas (N ₂ O) is low, and the ratio is gradually increased. The film was formed while reversing. In addition, in the case of an inclined film including a layer having an extremely high nitrogen atom ratio with a certain thickness in the middle of the inclined film, the gas flow rate ratio is gradually changed in the direction in which the nitrogen atom (N) ratio gradually increases, Gas flow rate ratio with the highest nitrogen atom (N) ratio For example, a film is formed for a certain time in a state where nitrogen oxide gas (N ₂ O) is completely shut off, and then the gas gradually decreases in the nitrogen atom (N) ratio. By changing the flow rate ratio, a gradient film including an extremely high concentration nitrogen layer with a constant thickness was formed in the middle of the gradient film. In this case, even if nitrogen oxide gas (N ₂ O) is shut off for a certain period of time, the film formed during this time is not completely silicon nitride (SiNx) due to the influence of O atoms remaining in the film formation chamber. The presence of a few oxygen atoms (O) is also observed, so that a silicon nitride oxide (SiOxNy) film with a high concentration of nitrogen is formed.

When the passivation film in the present invention is a laminated film of a silicon nitride oxide (SiOxNy) film and a silicon nitride (SiNx) film, for example, a silicon nitride oxide (SiOxNy) film is first formed, and then silicon nitride (SiNx) is formed. If the films are stacked, the film formation is stopped once the silicon nitride oxide (SiOxNy) film is formed, and the film formation chamber is evacuated for a certain period of time to completely eliminate the O component in the film formation chamber. After that, a silicon nitride film (SiNx) was formed only with silane gas (SiH ₄ ), ammonia gas (NH ₃ ), and nitrogen gas (N ₂ ).

  When the passivation film in the present invention is formed between a color filter layer or an overcoat resin optionally provided for planarization on the color filter layer and a transparent electrode (anode), a color filter and Using the substrate on which the overcoat resin is formed, a silicon nitride oxide (SiOxNy) gradient film or a laminated film of silicon nitride (SiNx) and silicon nitride oxide (SiOxNy) is formed on the overcoat resin layer by a CVD method. A transparent electrode (anode), an organic light emitting layer (hole transporting layer, light emitting layer), and a metal electrode (cathode) were sequentially formed thereon, and finally sealed with sealing glass to form an element.

  Further, in the case of protecting the entire organic EL layer from the transparent electrode (anode) to the metal electrode (cathode) with the passivation film in the present invention, the CVD method is applied on the overcoat resin layer as described above. A passivation film is formed, and a transparent electrode (anode), an organic light emitting layer (hole transport layer, light emitting layer), and a metal electrode (cathode) are sequentially formed thereon, and silicon nitride oxide (SiOxNy) is again formed thereon by a CVD method. ) A tilted film or a laminated film of silicon nitride (SiNx) and silicon nitride oxide (SiOxNy) is formed, and the passivation film covers the entire organic EL element from above the metal electrode (cathode). I tried to double up.

  Examples of the present invention will be specifically described below, but the present invention is not limited thereto.

  Each of the passivation films of each Example and Comparative Example was an organic EL element including those passivation films, and the passivation performance was evaluated by observing the non-light-emitting portion (the expansion of dark spots).

  The organic EL element was produced as follows.

  First, the color filter 2 and the overcoat resin layer 3 were formed on the glass substrate 1 by using a photolithographic method, followed by heating and drying at 230 ° C. for 1 hour after ultrasonic cleaning. A passivation film 4 based on each of the examples and comparative examples was formed thereon by CVD, and an ITO film was formed thereon by sputtering and patterned by etching to form a transparent electrode (anode) 5. . A hole transport layer and a light emitting layer as the organic light emitting layer 6 and a cathode 7 were sequentially formed thereon by vapor deposition. Α-naphthylphenyldiamine (α-NPD) was used as the hole transport material, tris (8-quinolinol) aluminum (Alq) was used as the light emitting layer material, and calcium and silver were used as the metal electrode (cathode) material. Finally, a glass sealing can 9 was placed on the cathode and sealed with UV curable adhesive resin. A desiccant 8 was sealed in the space between the sealing can and the cathode.

  However, in Example 7, a passivation film was formed on the cathode instead of the sealing can, and film sealing was performed so as to cover the entire element.

A passivation film between the overcoat resin layer and the transparent electrode (anode) was formed using a plasma CVD apparatus under the following conditions. Under the following conditions, the NH ₃ gas flow rate is 300 SCCM at the start of film formation and gradually decreases to 0 SCCM over 3 minutes of the film formation time, and the N ₂ O gas flow rate is 30 SCCM at the start of film formation. It means that it was gradually increased to 270 SCCM over 3 minutes of film formation time.

  Thereby, the inclination of the ratio of nitrogen atom (N) to oxygen atom (O) changes in the range of 0.4 to 0.9 as a value of N atom number / (O atom number + N atom number). The total thickness of the film is 300 nm.

SiH ₄ gas flow rate 100SCCM
NH ₃ gas flow rate 300SCCM → 0SCCM
N ₂ O gas flow rate 30SCCM → 270SCCM
N ₂ gas flow rate 2000SCCM
Deposition temperature 230 ° C
Pressure 120pa
RF power 1000W
Deposition time 3 minutes

A passivation film between the overcoat resin layer and the transparent electrode (anode) was formed using a plasma CVD apparatus under the following conditions. Under the following conditions, the NH ₃ gas flow rate is 300 SCCM at the start of film formation and gradually decreased to 100 SCCM over 3 minutes of the film formation time, and the N ₂ O gas flow rate is 30 SCCM at the start of film formation. It means that it was gradually increased to 170 SCCM over 3 minutes of film formation time.

  As a result, the slope of the ratio of nitrogen atoms (N) to oxygen atoms (O) changes in the range of 0.6 to 0.9 as a value of N atoms / (O atoms + N atoms). The total thickness of the film is 300 nm.

SiH ₄ gas flow rate 100SCCM
NH ₃ gas flow rate 300SCCM → 100SCCM
N ₂ O gas flow rate 30SCCM → 170SCCM
N ₂ gas flow rate 2000SCCM
Deposition temperature 230 ° C
Pressure 120pa
RF power 1000W
Deposition time 3 minutes

A passivation film between the overcoat resin layer and the transparent electrode (anode) was formed using a plasma CVD apparatus under the following conditions. Under the following conditions, the NH ₃ gas flow rate is 0 SCCM at the start of film formation, gradually increases to 300 SCCM over 2 minutes and 30 seconds, and the last 30 seconds are held at 300 SCCM. The N ₂ O gas flow rate is It means that the film was gradually lowered to 0 SCCM over 2 minutes and 30 seconds at 270 SCCM at the start of the film, and the last 30 seconds were held at 0 SCCM.

  As a result, a high concentration nitrogen layer exists in the film with a thickness of 50 μm, and the value of the number of N atoms / (number of O atoms + N atoms) of the high concentration nitrogen layer is in the range of 0.9 to 0.99. In the remaining portion, the slope of the ratio of nitrogen atom (N) to oxygen atom (O) varies in the range of 0.4 to 0.9 in terms of N atom number / (O atom number + N atom number), The average value is 0.65. The total thickness of the film is 300 nm.

SiH ₄ gas flow rate 100SCCM
NH ₃ gas flow rate 0 SCCM → 300 SCCM (hold for 30 seconds)
N ₂ O gas flow rate 270 SCCM → 0 SCCM (hold for 30 seconds)
N ₂ gas flow rate 2000SCCM
Deposition temperature 230 ° C
Pressure 120pa
RF power 1000W
Deposition time 3 minutes

A passivation film between the overcoat resin layer and the transparent electrode (anode) was formed using a plasma CVD apparatus under the following conditions. Under the following conditions, the NH ₃ gas flow rate is 0 SCCM at the start of film formation, gradually increased to 300 SCCM over 2 minutes, and the last 1 minute is held at 300 SCCM, and the N ₂ O gas flow rate is started. Sometimes it is 270 SCCM, it is gradually lowered to 0 SCCM over 2 minutes, and the last 1 minute is held at 0 SCCM.

  As a result, a high concentration nitrogen layer exists in the film with a thickness of 100 μm, and the value of the number of N atoms / (number of O atoms + N atoms) of the high concentration nitrogen layer is in the range of 0.9 to 0.99. In the remaining portion, the slope of the ratio of nitrogen atom (N) to oxygen atom (O) varies in the range of 0.4 to 0.9 in terms of N atom number / (O atom number + N atom number), The average value is 0.65. The total thickness of the film is 300 nm.

SiH ₄ gas flow rate 100SCCM
NH ₃ gas flow rate 0 SCCM → 300 SCCM (1 minute hold)
N ₂ O gas flow rate 270 SCCM → 0 SCCM (1 minute hold)
N ₂ gas flow rate 2000SCCM
Deposition temperature 230 ° C
Pressure 120pa
RF power 1000W
Deposition time 3 minutes

A passivation film between the overcoat resin layer and the transparent electrode (anode) was formed using a plasma CVD apparatus under the following conditions. Under the following conditions, the NH ₃ gas flow rate is 0 SCCM at the start of film formation, gradually increased to 300 SCCM over 2 minutes, and the last 1 minute is held at 300 SCCM, and the N ₂ O gas flow rate is started. Sometimes it means holding at 270 SCCM for 1 minute, gradually lowering to 0 SCCM over 1 minute, and holding the last 1 minute at 0 SCCM.

  Thereby, a high concentration nitrogen layer exists in the film with a thickness of 100 nm, and the value of the number of N atoms / (number of O atoms + N atoms) of the high concentration nitrogen layer is in the range of 0.9 to 0.99. In the remaining portion, the slope of the ratio of nitrogen atom (N) to oxygen atom (O) varies in the range of 0.4 to 0.9 in terms of N atom number / (O atom number + N atom number), The average value is 0.5. The total thickness of the film is 300 nm.

SiH ₄ gas flow rate 100SCCM
NH ₃ gas flow rate 0 SCCM → 300 SCCM (1 minute hold)
N ₂ O gas flow rate 270 SCCM (1 minute hold) → 0 SCCM (1 minute hold)
N ₂ gas flow rate 2000SCCM
Deposition temperature 230 ° C
Pressure 120pa
RF power 1000W
Deposition time 3 minutes

  A passivation film between the overcoat resin layer and the transparent electrode (anode) was formed twice using the plasma CVD apparatus under the following conditions.

As a result, a laminated film of a silicon nitride oxide (SiOxNy) film having a thickness of 200 nm and a silicon nitride (SiNx) film having a thickness of 100 nm was formed.
(First time)
SiH ₄ gas flow rate 100SCCM
NH ₃ gas flow rate 0SCCM
N ₂ O gas flow rate 270 SCCM
N ₂ gas flow rate 2000SCCM
Deposition temperature 230 ° C
Pressure 120pa
RF power 1000W
Deposition time 2 minutes (second time)
SiH ₄ gas flow rate 100SCCM
NH ₃ gas flow rate 300SCCM
N ₂ O gas flow rate 0 SCCM
N ₂ gas flow rate 2000SCCM
Deposition temperature 230 ° C
Pressure 120pa
RF power 1000W
Deposition time 2 minutes

  A passivation film between the overcoat resin layer and the transparent electrode (anode) was formed under the same conditions as in Example 1 using a plasma CVD apparatus, and only on the metal electrode (cathode) under the same conditions as the film formation time. The film was formed in 30 minutes.

As a result, the entire device from the transparent electrode (anode) to the metal electrode (cathode) was covered with the passivation film, and the film could be sealed without using a sealing can. The thickness of the passivation film on the metal electrode was 3 μm.
<Comparative Example 1>
A passivation film between the overcoat resin layer and the transparent electrode (anode) was formed using a plasma CVD apparatus under the following conditions.

  Thereby, a silicon nitride oxide (SiOxNy) single layer film having a thickness of 300 nm was formed.

SiH ₄ gas flow rate 100SCCM
NH ₃ gas flow rate 0SCCM
N ₂ O gas flow rate 270 SCCM
N ₂ gas flow rate 2000SCCM
Deposition temperature 230 ° C
Pressure 120pa
RF power 1000W
Deposition time 3 minutes <Comparative Example 2>
A passivation film between the overcoat resin layer and the transparent electrode (anode) was formed using a plasma CVD apparatus under the following conditions.

  As a result, a silicon nitride (SiNx) single layer film having a thickness of 300 nm was formed.

SiH ₄ gas flow rate 100SCCM
NH ₃ gas flow rate 300SCCM
N ₂ O gas flow rate 0 SCCM
N ₂ gas flow rate 2000SCCM
Deposition temperature 230 ° C
Pressure 120pa
RF power 1000W
Film formation time: 3 minutes An organic EL device having the passivation film of each of the above examples and comparative examples was subjected to a storage test under an accelerated condition of 60 ° C. and humidity of 90%, and the enlargement of the non-light emitting portion (dark spot) was observed. Evaluation was made in comparison with an organic EL device directly formed on a glass substrate. The results are shown in Table 1.

  In addition, measurement results of light transmittance (400 nm to 700 nm) in the visible region of each passivation layer are also shown.

ＤＳ：ダークスポット ＰＶ：パッシベーション層
ＣＦ：カラーフィルター ＯＣ：オーバーコート層
参考例２はオーバーコート（以下ＯＣと表記する）層と透明電極（陽極）の間にパッシベーション層を形成せずに素子化したサンプルであるが、表１に示すように６０℃、９０％環境下でのダークスポット（以下ＤＳと表記する）の状況を観察すると、当初発光していた素子も１００時間経過後にはＤＳの拡大が進んで発光しなくなった。参考例３のように、カラーフィルター（以下ＣＦと表記する）とＯＣがない場合には、パッシベーション層がなくてもＤＳの拡大がほとんどみられないことから、ＣＦやＯＣからの水分や有機ガスがＥＬ素子のＤＳ拡大に強く影響することが示唆される。

DS: Dark spot PV: Passivation layer CF: Color filter OC: Overcoat layer In Reference Example 2, an element was formed without forming a passivation layer between the overcoat (hereinafter referred to as OC) layer and the transparent electrode (anode). Although it is a sample, as shown in Table 1, when the state of a dark spot (hereinafter referred to as DS) in an environment of 60 ° C. and 90% is observed, the element that originally emitted light also expanded DS after 100 hours. Ceased to emit light. As in Reference Example 3, when there is no color filter (hereinafter referred to as CF) and OC, there is almost no DS expansion even without a passivation layer, so moisture and organic gas from CF and OC It is suggested that strongly affects the DS expansion of the EL element.

  And from the results of Examples 1 to 7, Comparative Examples 1 and 2, and Reference Example 1, there is no passivation layer by forming a passivation film such as SiOx, SiOxNy, or SiNx between the OC layer and the transparent electrode. It can also be seen that the expansion of the DS is suppressed compared to. However, there is a large difference in the DS expansion suppression effect depending on the type of passivation film, and the DS expansion suppression effect is higher in the order of SiNx> SiOxNy> SiOx. That is, it is largely due to the water vapor and gas barrier properties of the passivation film.

  As in Reference Example 2, the progress of DS expansion was faster in the SiOx film than in the other films, and no light was emitted after 500 hours. As in Comparative Example 1, in the case of the SiOxNy film, the DS expansion is suppressed as compared with the SiOx film, but after about 500 hours, the DS expansion is considerably about 30 times the initial value, and the passivation film of the organic EL element is observed. Is insufficient.

  On the other hand, in the organic EL panel display, since light is taken out through the passivation film, the passivation film is also required to have transparency, and preferably has a light transmittance of 95% or more, preferably at least 90% or more in the visible light region. . As in Comparative Example 2, the SiNx film is sufficient as an effect of suppressing the DS expansion, but the light transmittance is insufficient at 89%.

  However, as in Example 1 to Example 7, by using a SiOxNy N / O ratio gradient film, it is very useful as a passivation film of an organic EL element from the viewpoint of DS expansion suppression and transparency. It becomes a good film. The reason is that by changing the N / O ratio in the depth direction of the film, a layer with a high N ratio exists in the film, and the barrier property is secured in that part, and other parts Then, since O ratio becomes high gradually, it can be considered that transparency can be secured.

  The range in which the N / O ratio is changed is better in terms of DS suppression when the N ratio is as high as possible. The value of N atom number / (O atom number + N atom number) is 0.4. Example 2 varied in the range of 0.6 to 0.9 was better than Example 1 varied in the range of -0.9.

  In addition, from the results of Examples 3 to 5, the inclined film includes a high nitrogen atom layer having a value of N atom number / (O atom number + N atom number) of 0.90 to 0.99. Water vapor and the like are highly blocked by the layers, and the remaining layers can ensure transparency by increasing the ratio of O atoms as much as possible. As the thickness of the high nitrogen atom layer increases, the transparency decreases, but the DS suppression effect increases, and the thickness is preferably about 100 nm.

It is explanatory drawing of an Example.

Explanation of symbols

1 Glass substrate 2 Color filter layer 3 Overcoat resin layer 4 Passivation film 5 Transparent electrode (anode)
6 Organic light emitting layer 7 Cathode 8 Desiccant 9 Sealing can

Claims (11)

  An organic film comprising a silicon nitride oxide (SiOxNy) film having a passivation film in which the ratio of nitrogen atoms (N) to oxygen atoms (O) changes in an inclined manner in the depth direction of the film EL element.   The change in the ratio of nitrogen atoms (N) and oxygen atoms (O) in the depth direction of the passivation film is in the range of 0.4 to 0.9 in terms of N atoms / (O atoms + N atoms). The organic EL element according to claim 1, wherein   The change in the ratio of nitrogen atoms (N) to oxygen atoms (O) in the depth direction of the passivation film is in the range of 0.6 to 0.9 in terms of N atoms / (O atoms + N atoms). The organic EL element according to claim 1, wherein   2. The organic layer according to claim 1, wherein a part of the passivation film includes a high nitrogen concentration layer having a value of N atom number / (O atom number + N atom number) of 0.90 to 0.99. EL element.   A part of the passivation film includes a nitrogen high-concentration layer in which the value of the number of N atoms / (the number of O atoms + N atoms) is 0.90 to 0.99, and the remaining layers excluding the nitrogen high-concentration layer 2. The organic EL device according to claim 1, wherein the average number of N atoms / (number of O atoms + N atoms) is 0.6 or less on average.   The thickness of the high-concentration nitrogen layer having a value of N atom number / (O atom number + N atom number) of 0.90 to 0.99 is in the range of 50 nm to 100 nm. Item 6. An organic EL device according to Item 5.   An organic EL element, wherein the passivation film is a laminated film of silicon nitride oxide (SiOxNy) and silicon nitride (SiNx).   8. The organic EL according to claim 7, wherein the thickness of the silicon nitride (SiNx) film layer in the laminated film of silicon nitride oxide (SiOxNy) and silicon nitride (SiNx) is in the range of 50 nm to 150 nm. element.   9. The organic EL device according to claim 1, wherein a passivation film is formed between the color filter layer on the substrate and the transparent electrode.   9. The organic EL element according to claim 1, wherein the passivation film is formed so as to enclose at least a layer between the transparent electrode and the metal electrode.   9. A color filter, wherein the passivation film according to claim 1 is formed between a color filter layer on a substrate and a transparent electrode.

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