JP2006253443A - Organic el device, its manufacturing method, and electronic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic EL device which is improved in emission luminance and allows its directional emission. <P>SOLUTION: A component material of a hole injection layer 70 is dissolved into a solvent whose vapor pressure is 10 to 100 Pa and turned into a liquid material. The side face 221a of an organic partition wall 221 is subjected to a liquid repelling treatment so as to have a surface tension of 40 to 90 dyn/cm. The liquid material is applied on the inner side of the organic partition wall 221, and subjected to a reduced-pressure drying process which is carried out at an atmospheric temperature of about 60°C and where a pressure reducing time required for reducing a normal pressure to a pressure of 100 Pa is set at 5 to 20 minutes. The surface of the hole injection layer 70 is formed into a protrudent shape that extends from both the side faces 221a of the organic partition walls 221 to the center of a pixel region 26. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an organic EL device, a manufacturing method thereof, and an electronic apparatus.

  As a next-generation display device, an organic electroluminescence device (organic EL device) is expected. An organic EL device is configured by disposing an organic EL element having a light emitting layer between upper and lower electrodes on a base, and typically has a pixel electrode serving as an anode on a substrate such as glass. A structure in which an organic functional layer (a hole injection layer, a light-emitting layer, an electron transport layer, or the like) and a cathode are sequentially stacked is employed. The light emitting layer of the organic functional layer is caused to emit light by supplying current to the organic functional layer through the anode and the cathode.

Recently, a method of forming the above-described organic functional layer by a liquid phase process has been studied (see, for example, Patent Documents 1 and 2). In this method, a liquid material containing a material for forming each layer is applied by an inkjet method, a spin coating method, or the like, and the liquid material is dried to form an organic functional layer. By adopting such a liquid phase process, it is possible to reduce energy consumption compared to a gas phase process. In addition, it is possible to form a film at a relatively low temperature, and it is possible to reduce damage to an organic functional film, a substrate, or the like serving as a base.
JP 2002-231447 A JP 2002-222695 A

  In the organic EL device described above, it is a problem to achieve both sufficient light emission luminance and light emission lifetime. This is because if the current density between the electrodes is increased, the light emission luminance is improved, but the light emission lifetime is reduced.

  In addition, since the self-luminous organic EL device emits light radially, image display with a wide viewing angle is performed. However, in an image display device for a mobile phone, in order to prevent peeping from the periphery, image display with a narrow viewing angle may be desired. Thus, an organic EL device having directivity in the light emitting direction is desired.

The present invention has been made in order to solve the above-described problem, and can improve the luminance of light emission, and can provide directivity in the light emission direction, and a method for manufacturing the same. The purpose is to provide.
Another object is to provide an electronic device with excellent display quality.

In order to achieve the above object, an organic EL device according to the present invention includes a partition wall erected so as to surround a pixel electrode, a hole injection layer formed in a pixel region inside the partition wall by a liquid phase process, An organic EL device comprising at least a light emitting layer formed on a surface of a hole injection layer, wherein the surface of the hole injection layer is convex from a side surface of the partition wall to a central portion of the pixel region. It is formed as follows.
According to this configuration, since the surface of the light emitting layer is a curved surface, the effective light emitting area is larger than when the surface is a flat surface. Therefore, the light emission luminance can be improved. Further, since the surface of the light emitting layer is a curved surface, directivity can be imparted to the light emitting direction as compared with the case where the surface is flat.

The side wall of the partition wall is subjected to a liquid repellent treatment so that the surface tension of the partition wall is 40 dyn / cm or more and 90 dyn / cm or less, and the constituent material of the hole injection layer is a solvent having a vapor pressure of 10 Pa or more and 100 Pa or less. The liquid material dissolved in is applied to the inside of the partition wall, and the applied liquid material is depressurized at a temperature of about 60 ° C. so that the depressurization time from normal pressure to 100 Pa is 5 minutes or more and 20 minutes or less. It is desirable that the hole injection layer is formed by drying.
According to this configuration, the surface of the hole injection layer can be formed to be convex from the side surface of the partition wall to the central portion of the pixel region.

Another organic EL device according to the present invention includes a partition wall erected so as to surround a pixel electrode, a hole injection layer formed by a liquid phase process in a pixel region inside the partition wall, and the hole injection layer. An organic EL device comprising at least a light-emitting layer formed on the surface of the organic EL device, wherein the surface of the hole injection layer is formed to be concave from a side surface of the partition wall to a central portion of the pixel region. It is characterized by being.
According to this configuration, since the surface of the light emitting layer is a curved surface, the effective light emitting area is larger than when the surface is a flat surface. Therefore, the light emission luminance can be improved. Further, since the surface of the light emitting layer is a curved surface, directivity can be imparted to the light emitting direction as compared with the case where the surface is flat.

The side wall of the partition wall is subjected to a liquid repellent treatment so that the surface tension of the partition wall is 20 dyn / cm or more and 40 dyn / cm or less, and the constituent material of the hole injection layer is a solvent having a vapor pressure of 10 Pa or more and 100 Pa or less. The liquid material dissolved in is applied to the inside of the partition wall, and the applied liquid material is depressurized at a temperature of about 60 ° C. so that the pressure reduction time from normal pressure to 100 Pa is 20 seconds or more and 100 seconds or less. It is desirable that the hole injection layer is formed by drying.
According to this configuration, the surface of the hole injection layer can be formed to be concave from the side surface of the partition wall to the central portion of the pixel region.

Another organic EL device according to the present invention includes a partition wall erected so as to surround a pixel electrode, a hole injection layer formed by a liquid phase process in a pixel region inside the partition wall, and the hole injection layer. An organic EL device comprising at least a light emitting layer formed on a surface of the pixel region, wherein the surface of the hole injection layer is convex at a peripheral portion of the pixel region and concave at a central portion of the pixel region. It is formed so that it may become.
According to this configuration, since the surface of the light emitting layer is a curved surface, the effective light emitting area is larger than when the surface is a flat surface. Therefore, the light emission luminance can be improved.

The hole injection layer is preferably composed of PEDOT / PSS.
According to this configuration, the hole injection layer can be formed using a liquid phase process, and an organic EL device excellent in luminous efficiency can be provided.

On the other hand, the method of manufacturing the organic EL device of the present invention includes a partition wall erected so as to surround the pixel electrode, a hole injection layer formed in a pixel region inside the partition wall, and a surface of the hole injection layer And a liquid repellent treatment is applied to the side surface of the partition wall so that the surface tension of the partition wall is 40 dyn / cm or more and 90 dyn / cm or less. Applying the liquid material obtained by dissolving the constituent material of the hole injection layer in a solvent having a vapor pressure of 10 Pa or more and 100 Pa or less to the inner side of the partition wall, and applying the applied liquid material to about 60 ° C. The surface of the hole injection layer is projected from the side surface of the partition wall to the center of the pixel region by drying under reduced pressure so that the pressure reduction time from normal pressure to 100 Pa is 5 minutes to 20 minutes. To be in the shape And having a step of forming the hole injection layer.
According to this configuration, light emission luminance can be improved. In addition, directivity can be imparted to the light emitting direction.

According to another method of manufacturing the organic EL device of the present invention, the partition wall is provided so as to surround the pixel electrode, the hole injection layer formed in the pixel region inside the partition wall, and the hole injection layer. A method for producing an organic EL device comprising at least a light emitting layer formed on a surface, wherein a liquid repellent treatment is applied to the side surface of the partition wall so that the surface tension of the partition wall is 20 dyn / cm or more and 40 dyn / cm or less. Applying the liquid material obtained by dissolving the constituent material of the hole injection layer in a solvent having a vapor pressure of 10 Pa or more and 100 Pa or less to the inside of the partition wall, and applying the applied liquid material to about 60 The surface of the hole injection layer extends from the side surface of the partition wall to the center of the pixel region by drying under reduced pressure at a temperature of ° C. so that the pressure reduction time from normal pressure to 100 Pa is 20 seconds to 100 seconds. Concave Sea urchin, and having a step of forming the hole injection layer.
According to this configuration, light emission luminance can be improved. In addition, directivity can be imparted to the light emitting direction.

On the other hand, an electronic apparatus according to the present invention includes the above-described organic EL device.
According to this configuration, since the organic EL device having excellent light emission luminance is provided, an electronic device having excellent display quality can be provided.

  Embodiments of the present invention will be described below with reference to the drawings. In each drawing referred to below, the dimensions and the like of each component are appropriately changed and displayed for easy understanding.

(First embodiment)
First, the organic EL device according to the first embodiment of the present invention will be described with reference to FIGS.
FIG. 1 is a side sectional view of a general organic EL device. The organic EL device includes an element substrate 2, a drive circuit unit 5 disposed on the surface of the element substrate 2, a plurality of organic EL elements 3 disposed on the surface of the drive circuit unit 5, and the organic EL element 3. The sealing substrate 30 to be sealed is mainly configured. The organic EL elements 3 are formed in a circular shape, an oval shape, or the like when viewed from a direction perpendicular to the element substrate 2, and are arranged in a matrix on the element substrate 2. In the present embodiment, a bottom emission type organic EL device that takes out light emitted from the organic EL element 3 from the element substrate 2 side will be described as an example.

(Organic EL device)
In the bottom emission type organic EL device, since the emitted light in the light emitting layer 60 is taken out from the element substrate 2 side, a transparent or translucent element substrate 2 is employed. For example, glass, quartz, resin (plastic, plastic film) or the like can be used, and a glass substrate is particularly preferably used.

  On the element substrate 2, a drive circuit unit 5 including a drive TFT 123 (drive element 4) of the organic EL element 3 is formed. It is also possible to configure an organic EL device by mounting a semiconductor element provided with a drive circuit on the element substrate 2.

As a specific configuration of the drive circuit unit 5, a base protective layer 281 made of an insulating material is formed on the surface of the element substrate 2, and a silicon layer 241 that is a semiconductor material is formed thereon. A gate insulating layer 282 mainly composed of SiO ₂ and / or SiN is formed on the surface of the silicon layer 241. A gate electrode 242 is formed on the surface of the gate insulating layer 282. The gate electrode 242 is constituted by a part of a scanning line (not shown). Of the silicon layer 241, a region facing the gate electrode 242 with the gate insulating layer 282 interposed therebetween is a channel region 241a. On the other hand, a first interlayer insulating layer 283 mainly composed of SiO ₂ is formed on the surfaces of the gate electrode 242 and the gate insulating layer 282.

  Further, in the silicon layer 241, a low concentration source region 241b and a high concentration source region 241S are provided on one side of the channel region 241a, and a low concentration drain region 241c and a high concentration drain region 241D are provided on the other side of the channel region 241a. A so-called LDD (Lightly Doped Drain) structure is provided. Among these, the high-concentration source region 241S is connected to the source electrode 243 through a contact hole 243a penetrating the gate insulating layer 282 and the first interlayer insulating layer 283. The source electrode 243 is configured by a part of a power supply line (not shown). On the other hand, the high concentration drain region 241D is connected to a drain electrode 244 disposed in the same layer as the source electrode 243 through a contact hole 244a that penetrates the gate insulating layer 282 and the first interlayer insulating layer 283.

  Over the source electrode 243 and the drain electrode 244 and the first interlayer insulating layer 283 described above, a planarizing film 284 mainly composed of a heat-resistant insulating resin material such as acrylic or polyimide is formed. The planarizing film 284 is formed to eliminate surface irregularities due to the driving TFT 123 (driving element 4), the source electrode 243, the drain electrode 244, and the like.

  A plurality of pixel electrodes 23 are formed in the formation region of the organic EL element 3 on the surface of the planarizing film 284. The pixel electrodes 23 are arranged in a matrix on the surface of the planarizing film 284. The pixel electrode 23 is connected to the drain electrode 244 through a contact hole 23 a provided in the planarization film 284. That is, the pixel electrode 23 is connected to the high concentration drain region 241D of the silicon layer 241 through the drain electrode 244.

In addition, an inorganic partition wall 25 made of an inorganic insulating material such as SiO ₂ is formed so as to surround the pixel electrode 23 on the surface of the planarizing film 284. Furthermore, an organic partition 221 made of an organic insulating material such as polyimide is formed on the surface of the inorganic partition 25. A side surface 25 a of the inorganic partition wall 25 and a side surface 221 a of the organic partition wall 221 are disposed above the pixel electrode 23 disposed in the formation region of the organic EL element 3.

  A plurality of functional films are laminated on the side surface 25 a of the inorganic partition wall 25 and the side surface 221 a of the organic partition wall 221 to constitute the organic EL element 3. The organic EL element 3 includes a pixel electrode 23 that functions as an anode, a hole injection layer 70 that injects / transports holes from the pixel electrode 23, a light emitting layer 60 made of an organic EL material, and a cathode 52. Configured.

In the case of a bottom emission type organic EL device, the pixel electrode 23 that functions as an anode is formed of a transparent conductive material such as ITO (indium tin oxide).
As a material for forming the hole injection layer 70, in particular, a dispersion of 3,4-polyethylenedioxythiophene / polystyrene sulfonic acid (PEDOT / PSS), that is, 3,4-polyethylenedioxy in polystyrene sulfonic acid as a dispersion medium. A dispersion in which thiophene is dispersed and further dispersed in water is preferably used.
The material for forming the hole injection layer 70 is not limited to those described above, and various materials can be used. For example, a material obtained by dispersing polystyrene, polypyrrole, polyaniline, polyacetylene or a derivative thereof in an appropriate dispersion medium such as the aforementioned polystyrene sulfonic acid can be used.

  As a material for forming the light emitting layer 60, a known light emitting material capable of emitting fluorescence or phosphorescence is used. Specifically, (poly) fluorene derivative (PF), (poly) paraphenylene vinylene derivative (PPV), polyphenylene derivative (PP), polyparaphenylene derivative (PPP), polyvinyl carbazole (PVK), polythiophene derivative, polymethyl Polysilanes such as phenylsilane (PMPS) are preferably used. In addition, these polymer materials include polymer materials such as perylene dyes, coumarin dyes, rhodamine dyes, rubrene, perylene, 9,10-diphenylanthracene, tetraphenylbutadiene, Nile red, coumarin 6, and quinacridone. It can also be used by doping a low molecular weight material such as.

  The cathode 52 is configured by laminating a main cathode 50 and an auxiliary cathode 51. As the main cathode 50, it is desirable to employ a material such as Ca, Mg, LiF or the like having a work function of 3.0 eV or less. Thereby, since the function as an electron injection layer is provided to the main cathode 50, a light emitting layer can be light-emitted by a low voltage. The auxiliary cathode 51 has a function of enhancing the conductivity of the entire cathode 52 and protecting the main cathode 50 from oxygen, moisture, and the like. Therefore, it is desirable to employ a metal material such as Al, Au, or Ag having excellent conductivity as the auxiliary cathode 51.

On the other hand, the sealing substrate 30 is bonded to the upper side of the cathode 52 through the adhesive layer 40. A sealing cap that covers the entire cathode 52 may be fixed to the periphery of the element substrate 2, and a getter agent that absorbs moisture, oxygen, or the like may be disposed inside the sealing cap. Further, an inorganic sealing film made of SiO ₂ or the like may be laminated on the surface of the cathode 52.

  In the organic EL device described above, the image signal supplied from the source electrode 243 of the drive circuit unit 5 is applied to the pixel electrode 23 by the drive element 4 at a predetermined timing. Then, the holes injected from the pixel electrode 23 and the electrons injected from the cathode 52 are recombined in the light emitting layer 60 and light having a predetermined wavelength is emitted. The emitted light passes through the pixel electrode 23 made of a transparent material, the drive circuit unit 5 and the element substrate 2 and is extracted outside. Thereby, image display is performed on the element substrate 2 side. Since the inorganic partition wall 25 is made of an insulating material, a current flows only inside the side surface 25a of the inorganic partition wall 25 and the light emitting layer 60 emits light. Therefore, the inside of the side surface 25 a of the inorganic partition wall 25 is the pixel region 26 of the organic EL element 3.

(Hole injection layer)
FIG. 2 is an explanatory diagram of the organic EL device according to the first embodiment. In the organic EL device of this embodiment, the surface of the hole injection layer 70 on the light emitting layer 60 side is formed to be convex from the side surface of the organic partition 221 to the center of the pixel region 26. That is, the thickness of the hole injection layer 70 increases from the peripheral part to the center part of the pixel region 26. The light emitting layer 60 is formed with a substantially uniform thickness along the surface of the hole injection layer 70 formed in a convex shape. Therefore, the surface of the light emitting layer 60 on the hole injection layer 70 side is concave.

  In the organic EL device of the present embodiment, since the surface 60a of the light emitting layer 60 on the hole injection layer 70 side is a curved surface, the effective light emitting area is larger than when the surface is flat. Therefore, the light emission luminance can be improved. Moreover, since the current density does not change, the light emission lifetime is not reduced. In addition, since PEDOT / PSS constituting the hole injection layer 70 has an electrical resistance that is about an order of magnitude lower than that of the constituent material of the light emitting layer 60, the thickness of the hole injection layer 70 is unevenly formed in the pixel region 26. Even if the light emitting layer 60 is formed, light emission unevenness does not occur as long as the light emitting layer 60 has a substantially uniform thickness.

  Moreover, since the surface 60a of the light emitting layer 60 on the hole injection layer 70 side is a curved surface, directivity can be imparted to the light emitting direction. In this embodiment, it is a bottom emission type organic EL device, and since the surface 60a of the light emitting layer 60 on the hole injection layer 70 side is concave, the emitted light 61 is compared to the case where the surface is flat. Can be converged. Thereby, light can be emitted in a narrow angle range.

(Method for manufacturing organic EL device)
Next, a method for manufacturing the above-described organic EL device will be described.
First, as shown in FIG. 1, the drive circuit unit 5 including the drive TFT 123 (drive element 4), the planarizing film 284, and the like is formed on the surface of the element substrate 2.

FIG. 3 is a process diagram of a method for manufacturing an organic EL device. Next, as shown in FIG. 3A, the pixel electrode 23 is patterned on the surface of the planarizing film 284.
Next, an inorganic partition wall 25 is formed so as to surround the pixel electrode 23. Specifically, first, an inorganic partition layer made of an insulating material such as SiO ₂ is formed so as to cover the entire surface of the element substrate. Subsequently, the pixel region 26 of the organic EL element is opened, and the inorganic partition wall 25 is formed.
Next, an organic partition 221 is erected on the surface of the inorganic partition 25. Specifically, first, an organic partition layer made of a resin material or the like is formed so as to cover the entire surface of the element substrate. Subsequently, the organic partition wall 221 is formed by opening the formation region of the organic EL element.

Next, a region showing lyophilicity and a region showing liquid repellency are formed on the surface of the element substrate. Specifically, first, the element substrate is preheated to about 70 to 80 ° C. Next, plasma processing (O ₂ plasma processing) using oxygen as a reaction gas under atmospheric pressure is performed, and the upper surface of the pixel electrode 23, the surface of the inorganic partition wall 25, and the side surface 221a and the upper surface of the organic partition wall 221 are lyophilic. To do. Further, plasma treatment (CF ₄ plasma treatment) using methane tetrafluoride as a reaction gas is performed under atmospheric pressure, and the side surfaces 221a and the upper surface of the organic partition wall 221 are subjected to liquid repellency treatment. In particular, in this embodiment, the plasma processing time is extended so that the surface tension of the side surface 221a of the organic partition wall 221 is 40 dyn / cm or more and 90 dyn / cm or less. Thereafter, the element substrate is cooled to room temperature.

Note that the upper surface of the pixel electrode 23 and the surface of the inorganic partition wall 25 are also affected by the CF ₄ plasma treatment. However, ITO, which is a material of the pixel electrode 23, such as SiO ₂ is a constituent material of the inorganic partition 25, since poor affinity to fluorine, the hydroxyl granted in lyophilic process is replaced with a fluorine group Absent. Therefore, the lyophilic property imparted to the upper surface of the pixel electrode 23 and the surface of the inorganic partition wall 25 is maintained. As a result, the state shown in FIG.

  Next, as shown in FIG. 3B, a hole injection layer made of PEDOT / PSS or the like is formed. This hole injection layer is formed by a liquid phase process. In the liquid phase process, a liquid material containing a functional film forming material is applied, and the liquid material is dried to form a functional film. This liquid phase process does not require a vacuum condition as compared with a vapor phase process such as a vapor deposition method, so that energy consumption can be reduced and manufacturing costs can be reduced. Further, since there is no restriction on the substrate size, it is effective for manufacturing a large screen display. Furthermore, since a vapor deposition mask is not required, it is effective for manufacturing a high-definition display. In addition, film formation at a relatively low temperature is possible, which is effective for development of a flexible display using a plastic substrate having low heat resistance.

  Specifically, it is desirable to employ an ink jet method as the liquid phase process. In the ink jet method, a liquid material containing a functional film forming material is filled in an ink chamber, a pressure change is generated in the ink chamber, and droplets are ejected from nozzles communicating with the ink chamber to form a functional film. It is landed at a predetermined position. For this reason, an ink jet head including at least an ink chamber filled with a liquid to be applied, a driving element such as a piezo element that causes a pressure change in the ink chamber, and a nozzle communicating with the ink chamber is used. By adopting this ink jet method, it becomes possible to accurately apply a predetermined amount of liquid material to a predetermined position, and it is possible to form a functional film having excellent dimensional accuracy. Further, the liquid material can be used efficiently, and the manufacturing cost can be reduced.

Specifically, first, a liquid material in which PEDOT / PSS is dissolved in a polar solvent is filled into the ink chamber of the inkjet head. Examples of the polar solvent include isopropyl alcohol (IPA), normal butanol, γ-butyrolactone, N-methylpyrrolidone (NMP), 1,3-dimethyl-2-imidazolidinone (DMI) and its derivatives, carbitol acetate, butyl Glucol ethers such as carbitol acetate can be used. In particular, in the present embodiment, a solvent having a vapor pressure of about 10 Pa to 100 Pa (at a temperature of 23 ° C.) is employed.
Next, the nozzle of the ink jet head is opposed to the pixel region 26 of the element substrate while relatively moving the ink jet head and the element substrate. Then, a pressure change is generated in the ink chamber by the driving element, and droplets are ejected from the nozzle toward the pixel region 26.

  At this time, the droplet discharged from the nozzle wets and spreads on the upper surface of the pixel electrode 23 to which lyophilicity is imparted, and is filled inside the side surface 25 a of the inorganic partition wall 25. On the other hand, the liquid droplets scattered toward the upper surface and the side surface 221a of the organic partition wall 221 do not adhere to the above-described portion imparted with liquid repellency, and flow toward the bottom of the side surface 221a of the organic partition wall 221. Thereby, as shown in FIG. 3B, the liquid 72 can be applied only to the inside of the side surface 25 a of the inorganic partition wall 25 and the bottom of the side surface 221 a of the organic partition wall 221.

  In the present embodiment, a liquid repellent treatment is performed so that the surface tension of the side wall 221a of the organic partition wall 221 is 40 dyn / cm or more and 90 dyn / cm or less, and the solvent of the liquid 72 has a vapor pressure of 10 Pa or more and 100 Pa or less. Adopted. Therefore, the contact angle between the side surface 221a of the organic partition 221 and the liquid material is increased. Thereby, the surface of the applied liquid 72 is raised in a convex shape from the side surface 221 a of the organic partition 221 to the center of the pixel region 26.

  Next, as shown in FIG. 3C, the applied liquid material is dried. The liquid material is dried by so-called reduced-pressure drying, in which the element substrate coated with the liquid material is placed in an airtight container, and the inside of the container is gradually depressurized while maintaining the liquid material at a predetermined temperature. In this embodiment, the element substrate is heated by a hot plate or the like, and the applied liquid material is maintained at about 60 ° C. In this state, the inside of the container is evacuated so that the decompression time from atmospheric pressure to 100 Pa is 5 minutes or more and 20 minutes or less. Thereafter, drying is performed for several minutes to about 10 minutes until the pressure inside the container becomes about 1/10 (about 1 to 10 Pa) of the vapor pressure of the solvent. Thereby, the solvent contained in the liquid is evaporated, PEDOT / PSS is deposited, and the hole injection layer 70 is formed.

  The surface of the hole injection layer 70 is formed to be convex from the side surface 221 a of the organic partition 221 to the center of the pixel region 26. That is, the surface of the hole injection layer 70 can be formed in a convex shape by performing drying under reduced pressure under the above conditions from a state in which the surface of the liquid material is raised in a convex shape. Note that the higher the surface tension of the side surface 221a of the organic partition wall 221, the easier the hole injection layer 70 is formed in a convex shape. In addition, the longer the pressure reduction time from atmospheric pressure to 100 Pa, the easier the hole injection layer is formed in a convex shape.

  As a result, the state shown in FIG. In addition, it is preferable to perform the process after the formation process of the positive hole injection layer 70 in inert gas atmospheres, such as nitrogen atmosphere and argon atmosphere, in order to prevent oxidation and moisture absorption of various formation materials, the formed element, etc.

  Next, as shown in FIG. 3D, the light emitting layer 60 is formed on the surface of the hole injection layer 70. In the step of forming the light emitting layer 60, it is desirable to employ an ink jet method that is a liquid phase process, as in the step of forming the hole injection layer 70. That is, the liquid material containing the material for forming the light emitting layer 60 is discharged and dried under reduced pressure, thereby forming the light emitting layer 60 having a uniform thickness above the pixel region 26 inside the side surface 221a of the organic partition 221. .

Next, as shown in FIG. 1, a cathode 52 is formed. The cathode 52 is formed on almost the entire surface of the element substrate 2 by vapor deposition or sputtering.
Next, the sealing substrate 30 is bonded. In this sealing step, a transparent adhesive layer 40 is applied to the surface of the element substrate 2 and the sealing substrate 30 is bonded to prevent bubbles from entering.
Thus, the organic EL device according to this embodiment is formed.

  In the embodiment described in detail above, the liquid repellent treatment is performed so that the surface tension of the side surface of the organic partition wall is 40 dyn / cm or more and 90 dyn / cm or less, and the constituent material of the hole injection layer is vapor pressure of 10 Pa or more and 100 Pa. A liquid material dissolved in the following solvent is applied to the inner side of the organic partition wall, and the pressure reduction time from normal pressure to 100 Pa is 5 minutes or more and 20 minutes or less with the applied liquid material maintained at about 60 ° C. By drying under reduced pressure as described above, the surface of the hole injection layer was formed to be convex from the side surface of the organic partition wall to the center of the pixel region.

According to this configuration, since the surface of the light emitting layer on the hole injection layer side is a curved surface, the effective light emitting area is larger than that when the surface is a flat surface. Therefore, the light emission luminance can be improved. Moreover, since the current density does not change, the light emission lifetime is not reduced. Further, since the surface of the light emitting layer on the hole injection layer side is concave, directivity is imparted in the light emitting direction as compared with the case where the surface is flat, and the emitted light can be converged. Thereby, light can be emitted in a narrow angle range.
In this embodiment, the bottom emission type organic EL device is described as an example. However, the present invention can be applied to a top emission type organic EL device. In that case, contrary to the above, light can be emitted in a wide angle range.

  In addition, although the case where the temperature at the time of reduced pressure drying was about 60 degreeC was demonstrated above, when the temperature at the time of reduced pressure drying is as low as normal temperature (about 15 degreeC or more and 30 degrees C or less), it is from atmospheric pressure to 100Pa. It is desirable to perform vacuum drying so that the decompression time is 20 seconds or more and 100 seconds or less. In this case, the shorter the depressurization time from atmospheric pressure to 100 Pa, the easier the surface of the hole injection layer is formed to be convex. As described above, the reason why the reduced-pressure drying conditions greatly change depending on the temperature conditions is mainly because the viscosity of the solvent changes depending on the temperature conditions.

(Second Embodiment)
First, an organic EL device according to a second embodiment of the present invention will be described with reference to FIG.
FIG. 4 is an explanatory diagram of an organic EL device according to the second embodiment. In the organic EL device according to the second embodiment, the surface of the hole injection layer 70 on the light emitting layer 60 side is formed to be concave from the side surface 221a of the organic partition 221 to the center of the pixel region 26. This is different from the first embodiment formed to be convex. Note that detailed description of portions having the same configuration as in the first embodiment is omitted.

  In the organic EL device of the second embodiment, the surface of the hole injection layer 70 on the light emitting layer 60 side is formed to be concave from the side surface of the organic partition 221 to the center of the pixel region 26. That is, the thickness of the hole injection layer 70 is reduced from the peripheral part to the central part of the pixel region 26. The light emitting layer 60 is formed with a substantially uniform thickness along the surface of the hole injection layer 70 formed in a concave shape. Therefore, the surface of the light emitting layer 60 on the hole injection layer 70 side is a convex surface.

  Even in the organic EL device of the second embodiment, the surface 60a of the light emitting layer 60 on the hole injection layer 70 side is a curved surface, so that the light emission luminance can be improved and directivity is imparted to the light emitting direction. Can do. In particular, the second embodiment is a bottom emission type organic EL device, and the surface 60a of the light emitting layer 60 on the hole injection layer 70 side is a convex surface. 61 can be diverged. Thereby, light can be emitted in a wide angle range.

Next, a method for manufacturing an organic EL device according to the second embodiment will be described.
Also in the second embodiment, the hole injection layer is formed by a liquid phase process. Therefore, PEDOT / PSS, which is a constituent material of the hole injection layer 70, is dissolved in a solvent having a vapor pressure of about 10 Pa or more and 100 Pa or less (at a temperature of 23 ° C.) to create a liquid.
Further, the side wall 221a and the upper surface of the organic partition wall 221 are subjected to a liquid repellent treatment. Here, in the second embodiment, the plasma processing time is shortened so that the surface tension of the side surface 221a of the organic partition wall 221 is 20 dyn / cm or more and 40 dyn / cm or less.

  Next, the above-described liquid material is applied to the pixel region 26 by an inkjet method or the like. In the present embodiment, a liquid solvent having a vapor pressure of 10 Pa or more and 100 Pa or less is adopted, and the liquid repellent treatment is performed so that the surface tension of the side surface 221a of the organic partition wall 221 is 20 dyn / cm or more and 40 dyn / cm or less. Therefore, the contact angle between the side surface 221a of the organic partition wall 221 and the liquid material is reduced. As a result, the surface of the applied liquid material is recessed in a concave shape from the side surface 221 a of the organic partition wall 221 to the center of the pixel region 26.

  Next, the applied liquid is dried under reduced pressure. In the second embodiment, the applied liquid material is dried under reduced pressure so that the reduced pressure time from atmospheric pressure to 100 Pa is 20 seconds or more and 100 seconds or less while maintaining the applied liquid material at about 60 ° C. Thereafter, drying is performed for several minutes to about 10 minutes until the pressure inside the container becomes about 1/10 (about 1 to 10 Pa) of the vapor pressure of the solvent. Thereby, the solvent contained in the liquid is evaporated, PEDOT / PSS is deposited, and the hole injection layer 70 is formed.

The surface of the hole injection layer 70 is formed to be concave from the side surface 221 a of the organic partition 221 to the center of the pixel region 26. That is, the surface of the hole injection layer 70 can be formed in a concave shape by performing drying under reduced pressure under the above conditions from a state in which the surface of the liquid material is recessed in a concave shape. Note that the smaller the surface tension of the side surface 221a of the organic partition wall 221, the easier the hole injection layer 70 is formed in a concave shape. Further, the shorter the pressure reduction time from atmospheric pressure to 100 Pa, the easier the hole injection layer is formed in a concave shape.
Thus, the organic EL device according to the second embodiment is formed.

According to the organic EL device according to the second embodiment described in detail above, since the surface of the light emitting layer on the hole injection layer side is a curved surface, the effective light emitting area is larger than when the surface is a flat surface. Therefore, the light emission luminance can be improved. Moreover, since the current density does not change, the light emission lifetime is not reduced. Further, since the surface of the light emitting layer on the hole injection layer side is a convex surface, it becomes possible to diverge the emitted light as compared with the case where the surface is a flat surface. Thereby, light can be emitted in a wide angle range.
In this embodiment, the bottom emission type organic EL device is described as an example. However, the present invention can be applied to a top emission type organic EL device. In that case, contrary to the above, light can be emitted in a narrow angle range.

  In addition, although the case where the temperature at the time of reduced pressure drying is about 60 degreeC was demonstrated above, when the temperature at the time of reduced pressure drying is as low as normal temperature (about 15 degreeC or more and 30 degrees C or less), it is from atmospheric pressure to 100Pa. It is desirable to perform vacuum drying so that the pressure reduction time is 5 minutes or more and 20 minutes or less. In this case, the longer the decompression time from atmospheric pressure to 100 Pa, the easier the surface of the hole injection layer is formed to be convex.

(Third embodiment)
Next, an organic EL device according to a third embodiment of the invention will be described with reference to FIG.
FIG. 5 is an explanatory diagram of an organic EL device according to the third embodiment, FIG. 5A is a plan view of a pixel region, and FIG. 5B is a side view taken along line AA of FIG. It is sectional drawing. In the organic EL device of the third embodiment shown in FIG. 5B, the surface of the hole injection layer 70 on the light emitting layer 60 side is convex at the peripheral edge of the pixel region 26 and concave at the center of the pixel region 26. It is different from each said embodiment by the point formed so that it may become. Note that detailed description of portions having the same configurations as those of the above embodiments is omitted.

  As shown in FIG. 5B, in the organic EL device of the third embodiment, the surface of the hole injection layer 70 on the light emitting layer 60 side is convex at the peripheral edge of the pixel region 26, and the center of the pixel region 26. It is formed to be concave in the part. That is, the thickness of the hole injection layer 70 is once thick from the peripheral edge of the pixel region 26, and conversely, is thinned toward the center of the pixel region 26. The convex portion 70a of the hole injection layer 70 is formed in a circular shape along the peripheral edge portion of the circular pixel region 26 shown in FIG. In the case where the pixel region 26 has an oval shape, the convex portion of the hole injection layer is also formed in an oval shape along the periphery. As shown in FIG. 5B, the light emitting layer 60 is formed with a substantially uniform thickness along the surface of the hole injection layer 70 described above. Therefore, the surface 60a of the light emitting layer 60 on the hole injection layer 70 side is a curved surface.

Next, a method for manufacturing an organic EL device according to the third embodiment will be described.
Also in the third embodiment, the hole injection layer is formed by a liquid phase process. Therefore, PEDOT / PSS, which is a constituent material of the hole injection layer 70, is dissolved in a solvent having a vapor pressure of about 10 Pa or more and 100 Pa or less (at a temperature of 23 ° C.) to create a liquid.
Further, the side wall 221a and the upper surface of the organic partition wall 221 are subjected to a liquid repellent treatment. Here, in the third embodiment, the plasma processing time is extended so that the surface tension of the side surface 221a of the organic partition wall 221 is 40 dyn / cm or more and 90 dyn / cm or less.

  Next, the above-described liquid material is applied to the pixel region 26 by an inkjet method or the like. In the present embodiment, a liquid solvent having a vapor pressure of 10 Pa or more and 100 Pa or less is adopted, and the liquid repellent treatment is performed so that the surface tension of the side surface 221a of the organic partition wall 221 is 40 dyn / cm or more and 90 dyn / cm or less. Therefore, the contact angle between the side surface 221a of the organic partition 221 and the liquid material is increased. As a result, the surface of the applied liquid material is raised in a convex shape from the side surface 221 a of the organic partition 221 to the center of the pixel region 26.

Next, the applied liquid is dried under reduced pressure. In the third embodiment, the applied liquid is kept at about 60 ° C. Then, vacuum drying is performed so that the pressure reduction rate from atmospheric pressure to 100 Pa is slow in the first half and fast in the second half. For example, in the first half, the pressure reduction time from atmospheric pressure to 100 Pa is such that the pressure reduction time is from 5 minutes to 20 minutes, and in the second half, the pressure reduction time from atmospheric pressure to 100 Pa is from 20 seconds to 100 seconds. The vacuum drying may be performed at a low pressure reduction rate. Thereafter, drying is performed for several minutes to about 10 minutes until the pressure inside the container becomes about 1/10 (about 1 to 10 Pa) of the vapor pressure of the solvent. Thereby, the solvent contained in the liquid is evaporated, PEDOT / PSS is deposited, and the hole injection layer 70 is formed. The surface of the hole injection layer 70 on the light emitting layer 60 side is formed to be convex at the peripheral edge of the pixel region 26 and concave at the center of the pixel region 26.
Thus, the organic EL device according to the third embodiment is formed.

  According to the organic EL device according to the third embodiment described in detail above, since the surface of the light emitting layer on the hole injection layer side is a curved surface, the effective light emitting area is larger than when the surface is flat. Therefore, the light emission luminance can be improved. Moreover, since the current density does not change, the light emission lifetime is not reduced.

  In the above, the case where the temperature at the time of vacuum drying is about 60 ° C. has been described, but when the temperature at the time of vacuum drying is as low as room temperature (about 15 ° C. to 30 ° C.), the pressure reduction speed in the first half is high. It is desirable to perform vacuum drying so that the pressure reduction rate in the latter half is slow. For example, in the first half, the pressure reduction time from atmospheric pressure to 100 Pa is 20 seconds to 100 seconds, and in the second half, the pressure reduction time from atmospheric pressure to 100 Pa is from 5 minutes to 20 minutes. The vacuum drying may be performed at a low pressure reduction rate.

(Electronics)
Next, an electronic apparatus including the organic EL device according to each of the above embodiments will be described with reference to FIG.
FIG. 6 is a perspective configuration diagram of a mobile phone which is an example of an electronic apparatus. A cellular phone 1300 shown in the figure includes a plurality of operation buttons 1302, an earpiece 1303, a mouthpiece 1304, and a display unit 1301 including the organic EL device of the previous embodiment. The display unit employs the organic EL device of each of the above embodiments. In the organic EL device of each of the embodiments described above, since the light emission luminance can be improved, the mobile phone shown in FIG. 6 has excellent display quality.

  The electronic apparatus provided with the organic EL device according to the present invention is not limited to the above-mentioned ones. For example, digital cameras, personal computers, televisions, portable televisions, viewfinder type / monitor direct view type video tape recorders. PDAs, portable game machines, pagers, electronic notebooks, calculators, clocks, word processors, workstations, videophones, POS terminals, devices with touch panels, and the like. In addition, examples of the electronic device including the organic EL device according to the present invention include an in-vehicle audio device, an in-vehicle instrument, an in-vehicle display such as a car navigation device, an optical writing head for a printer, and the like.

  The technical scope of the present invention is not limited to the above-described embodiments, and includes various modifications made to the above-described embodiments without departing from the spirit of the present invention. That is, the specific materials and configurations described in the embodiments are merely examples, and can be changed as appropriate. For example, in order to form the hole injection layer of each embodiment, it is possible to adopt a method other than the manufacturing method described above, and a liquid containing the shape and surface tension of the organic partition wall and the constituent material of the hole injection layer. By appropriately managing the surface tension of the body, the drying temperature / pressure / time of the liquid, etc., hole injection layers of various shapes can be formed.

It is side surface sectional drawing of a common organic electroluminescent apparatus. It is explanatory drawing of the organic electroluminescent apparatus which concerns on 1st Embodiment. It is process drawing of the manufacturing method of an organic electroluminescent apparatus. It is explanatory drawing of the organic electroluminescent apparatus which concerns on 2nd Embodiment. It is explanatory drawing of the organic EL apparatus which concerns on 3rd Embodiment. It is a perspective view of a mobile phone.

Explanation of symbols

  70. Hole injection layer 221 Organic barrier 221 a Side

Claims (9)

At least a partition wall erected so as to surround the pixel electrode, a hole injection layer formed in a pixel region inside the partition wall by a liquid phase process, and a light emitting layer formed on the surface of the hole injection layer An organic EL device comprising:
The organic EL device, wherein the surface of the hole injection layer is formed to be convex from a side surface of the partition wall to a central portion of the pixel region. A liquid repellent treatment is performed on the side surface of the partition wall so that the surface tension of the partition wall is 40 dyn / cm or more and 90 dyn / cm or less,
A liquid material obtained by dissolving the constituent material of the hole injection layer in a solvent having a vapor pressure of 10 Pa or more and 100 Pa or less is applied to the inside of the partition wall,
The applied liquid material is dried under reduced pressure at a temperature of about 60 ° C. so that the reduced pressure time from normal pressure to 100 Pa is 5 minutes to 20 minutes,
The organic EL device according to claim 1, wherein the hole injection layer is formed. At least a partition wall erected so as to surround the pixel electrode, a hole injection layer formed in a pixel region inside the partition wall by a liquid phase process, and a light emitting layer formed on the surface of the hole injection layer An organic EL device comprising:
The organic EL device, wherein the surface of the hole injection layer is formed to be concave from a side surface of the partition wall to a central portion of the pixel region. A liquid repellent treatment is performed on the side surface of the partition wall so that the surface tension of the partition wall is 20 dyn / cm or more and 40 dyn / cm or less,
A liquid material obtained by dissolving the constituent material of the hole injection layer in a solvent having a vapor pressure of 10 Pa or more and 100 Pa or less is applied to the inside of the partition wall,
The applied liquid material is dried under reduced pressure at a temperature of about 60 ° C. so that the reduced pressure time from normal pressure to 100 Pa is 20 seconds to 100 seconds,
The organic EL device according to claim 3, wherein the hole injection layer is formed. At least a partition wall erected so as to surround the pixel electrode, a hole injection layer formed in a pixel region inside the partition wall by a liquid phase process, and a light emitting layer formed on the surface of the hole injection layer An organic EL device comprising:
The organic EL device, wherein the surface of the hole injection layer is formed to have a convex shape at a peripheral portion of the pixel region and to have a concave shape at a central portion of the pixel region.   The organic EL device according to claim 1, wherein the hole injection layer is made of PEDOT / PSS. At least a partition wall erected so as to surround the pixel electrode, a hole injection layer and a light emitting layer formed in a pixel region inside the partition wall, and a light emitting layer formed on a surface of the hole injection layer An organic EL device manufacturing method comprising:
Performing a liquid repellent treatment on the side surface of the partition wall so that the surface tension of the partition wall is 40 dyn / cm or more and 90 dyn / cm or less;
Applying a liquid material obtained by dissolving the constituent material of the hole injection layer in a solvent having a vapor pressure of 10 Pa or more and 100 Pa or less to the inside of the partition;
The applied liquid material is dried under reduced pressure at a temperature of about 60 ° C. so that the pressure reduction time from normal pressure to 100 Pa is 5 minutes or more and 20 minutes or less, whereby the surface of the hole injection layer becomes the partition wall. Forming the hole injection layer so as to be convex from the side surface to the center of the pixel region;
A method for producing an organic EL device, comprising: An organic device comprising at least a partition wall erected so as to surround the pixel electrode, a hole injection layer formed in a pixel region inside the partition wall, and a light emitting layer formed on a surface of the hole injection layer A method of manufacturing an EL device,
Performing a liquid repellent treatment on the side surface of the partition wall so that the surface tension of the partition wall is 20 dyn / cm or more and 40 dyn / cm or less;
Applying a liquid material obtained by dissolving the constituent material of the hole injection layer in a solvent having a vapor pressure of 10 Pa or more and 100 Pa or less to the inside of the partition;
The applied liquid material is dried under reduced pressure at a temperature of about 60 ° C. so that the pressure reduction time from normal pressure to 100 Pa is 20 seconds or more and 100 seconds or less, whereby the surface of the hole injection layer becomes the partition wall. Forming the hole injection layer so as to be concave from the side surface to the center of the pixel region;
A method for producing an organic EL device, comprising:   An electronic apparatus comprising the organic EL device according to claim 1.

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