JP2009245599A - Light-emitting device, and method of manufacturing light-emitting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light-emitting device with an organic layer with a comparatively uniform thickness, and to provide a method of manufacturing the light-emitting device. <P>SOLUTION: Pro-liquefied treatment such as cleaning with pure water, drying, and oxygen plasma treatment under pressure reduction conditions is applied on a substrate wherein pixel electrodes arranged at fixed intervals and partitions dividing the pixel electrodes are formed. Then, an organic compound containing liquid containing a surfactant and a high boiling point solvent as a solvent is dropped on the whole display range designated on the substrate and taking out light-emitted light at intervals of a value wherein an interval of arranged pixel electrodes is divided by a positive integer. Furthermore, the dropped organic compound containing liquid is dried under pressure reduction conditions. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a light emitting device using an organic EL (electroluminescence) element and a method for manufacturing the light emitting device.

  In recent years, as a next-generation display device following a liquid crystal light-emitting device (LCD), a light-emitting element type display panel in which self-light-emitting elements such as organic electroluminescence elements (hereinafter abbreviated as “organic EL elements”) are two-dimensionally arranged. Research and development for full-scale practical application and popularization of the light-emitting devices provided are being actively conducted.

  The organic EL element includes an anode electrode, a cathode electrode, and an organic EL layer such as an electron injection layer, a hole injection layer, and a light emitting layer formed between these electrodes. In the organic EL element, light is emitted by energy generated by recombination of holes and electrons respectively supplied from the hole injection layer and the electron injection layer in the light emitting layer.

In a light-emitting device using an organic EL element, a formation region (pixel formation region) of each display pixel arranged on a substrate is defined, and a liquid material made of an organic material is applied to an adjacent pixel formation region. In order to prevent the phenomenon of light emission color mixing (color mixing) between display pixels due to the mixing of light emitting materials of different colors, a partition wall that protrudes on the substrate and is continuously formed is provided between the pixel formation regions. One having a panel structure is known. An organic EL light-emitting device having such a partition is described in detail in, for example, Patent Document 1 and the like.
JP 2001-76881 A

  By the way, in the light emitting device using the organic EL element as described above, if the thickness of each organic EL layer is not uniform, unevenness in light emission occurs. Accordingly, there is a demand for a light-emitting device that has less unevenness in the thickness of the organic EL layer.

  The present invention has been made to solve such problems, and provides a light emitting device in which an organic layer of an organic EL element is formed with a relatively uniform thickness, and a method for manufacturing the light emitting device. With the goal.

  In order to achieve the above object, a method for manufacturing a light emitting device according to a first aspect of the present invention drops an organic compound-containing liquid onto a pixel electrode and onto a partition formed between adjacent pixel electrodes. And a dripping step of drying the solvent of the organic compound-containing liquid.

  The pixel electrodes are arranged at predetermined intervals from each other, and the dropping step drops the organic compound-containing liquid at a pitch of 1 / n (n is a positive integer) of the arrangement interval of the pixel electrodes. May be.

  In the dropping step, it is preferable that droplets are ejected by ink jetting in synchronization with a pixel electrode and a partition formed between adjacent pixel electrodes.

  The light emitting device according to the present invention is manufactured by the above manufacturing method.

  According to the present invention, the organic layer of the organic EL element can be formed relatively uniformly.

  A light emitting device and a method for manufacturing the light emitting device according to an embodiment of the present invention will be described with reference to the drawings.

  As shown in FIG. 1, the light emitting device according to the present embodiment includes a plurality of single color pixels 30 arranged in the row direction (left and right direction in FIG. 1) and monochromatic in the column direction (up and down direction in FIG. 1). A plurality of pixels 30 are arranged.

  An equivalent circuit showing a configuration example of each pixel 30 is shown in FIG. Each pixel 30 includes an organic EL element OLED and a pixel circuit DS that actively operates the organic EL element OLED. The pixel circuit DS includes a transistor (selection transistor) Tr11, a transistor (light emission drive transistor) Tr12, and a capacitor. Cs. Each of the transistor Tr11 and the transistor Tr12 illustrated in FIG. 2 is an n-channel amorphous silicon thin film transistor, but is not limited thereto, and at least one of them may be a p-channel type or a polysilicon thin film transistor.

  The light emitting device 10 includes a plurality of anode lines La connected to a plurality of pixel circuits DS arranged in a predetermined row, a data line Ld connected to a plurality of pixel circuits DS arranged in a predetermined column, respectively. A plurality of scanning lines Ls for selecting the transistors Tr11 of the plurality of pixel circuits DS arranged in a predetermined row are formed.

  As shown in FIG. 2, the gate terminal of the selection transistor Tr11 is connected to the scanning line Ls, the drain terminal is connected to the data line Ld arranged in the column direction of the display panel, and the source terminal is connected to the contact N11. The gate terminal of the light emission drive transistor Tr12 is connected to the contact N11, the drain terminal is connected to the supply voltage line La, and the source terminal is connected to the contact N12. Each end of the capacitor Cs is connected to the gate terminal and the source terminal of the transistor Tr12. Note that the capacitor Cs is an auxiliary capacitance additionally provided between the gate and the source of the transistor Tr12 or a capacitance component composed of these parasitic capacitance and auxiliary capacitance. In the organic EL element OLED, the anode terminal (pixel electrode 34) is connected to the contact N12, and the reference voltage Vss is applied to the cathode terminal (counter electrode 40). Note that in the case where the transistor Tr11 and the transistor Tr12 are p-channel field effect transistors, the source terminal and the drain terminal are connected in the opposite manner to that in FIG.

  The scanning line Ls is connected to a scanning driver (not shown) disposed at the peripheral edge of the display panel, and sets a plurality of pixels 30 arranged in the row direction of the display panel to a selected state at a predetermined timing. The selection voltage signal (scanning signal) Ssel is applied. The data line Ld is connected to a data driver (not shown) arranged at the peripheral edge of the display panel, and a data voltage (grayscale signal) corresponding to display data at a timing synchronized with the selection state of the pixel 30. Vpix is applied. The scan driver and the data driver may be separate IC chips or the same IC chip.

  A plurality of transistors Tr12 arranged for each row are set to a state in which a light emission driving current according to display data flows through the pixel electrode 34 (for example, an anode electrode) of the organic EL element OLED connected to the transistor Tr12. The plurality of anode lines La (supply voltage lines) are all directly or indirectly connected to a predetermined high potential power source. That is, the anode line La is applied with a predetermined high potential (supply voltage Vdd) sufficiently higher than the reference voltage Vss applied to the counter electrode 40 of the organic EL element OLED. The counter electrode 40 is directly or indirectly connected to, for example, a predetermined low potential power source, and is formed of a single electrode layer for all the pixels 30 two-dimensionally arranged on the pixel substrate 31. A predetermined low voltage (reference voltage Vss, for example, ground potential GND) is set to be applied in common.

  That is, in each pixel, the supply voltage Vdd and the reference voltage Vss are applied to both ends (the drain terminal of the transistor Tr12 and the cathode terminal of the organic EL element OLED) of the pair of the transistor Tr12 and the organic EL element OLED connected in series. Thus, a forward bias is applied to the organic EL element OLED so that the organic EL element OLED can emit light, and the current value of the light emission drive current that flows according to the gradation signal Vpix is controlled by the pixel circuit DS.

  Next, the top view of the light-emitting device 10 of this embodiment is shown in FIG. 4 is a cross-sectional view taken along line IV-IV shown in FIG. In FIG. 3, the hole injection layer 36, the light emitting layer 37, and the counter electrode 40 are not shown. The light emitting device 10 of the present embodiment is a so-called bottom emission type in which light is extracted from the pixel substrate 31 side on which the organic EL element OLED is provided.

  The pixel substrate 31 is formed from a material having translucency, and is, for example, a glass substrate. In addition, gate electrodes 11 g and 12 g and an insulating film 32 are formed on the pixel substrate 31.

  The insulating film 32 is made of an insulating material such as a silicon oxide film or a silicon nitride film, and is formed on the pixel substrate 31 so as to cover the gate electrodes 11g and 12g. The insulating film 32 functions as a gate insulating film for the transistors Tr11 and Tr12 in the region where the gate electrodes 11g and 12g are formed.

  The transistors Tr11 and Tr12 are each an n-channel thin film transistor (TFT). The transistors Tr11 and Tr12 are formed on the pixel substrate 31, respectively. The transistor Tr11 includes a semiconductor layer 111, a protective insulating film 112, ohmic contact layers 113 and 114, a source electrode 11s, a drain electrode 11d, and a gate electrode 11g. Similar to the transistor Tr11, the transistor Tr12 includes a semiconductor layer 121, a protective insulating film 122, ohmic contact layers 123 and 124, a source electrode 12s, a drain electrode 12d, and a gate electrode 12g. The source electrode 12s of the transistor Tr12 is connected to the pixel electrode 34.

  In the transistors Tr11 and Tr12, the gate electrodes 11g and 12g are made of, for example, aluminum-titanium (AlTi), aluminum-titanium-neodymium (AlTiNd), or chromium (Cr). The drain electrodes 11d and 12d and the source electrodes 11s and 12s are made of, for example, AlTi / Cr, AlTiNd / Cr, or AlTiNd. In addition, ohmic contact layers 113, 114, 123, and 124 are formed between the drain electrodes 11d and 12d and the source electrodes 11s and 12s and the semiconductor layers 111 and 121 for low resistance contact.

  If the light emitting device 10 is a bottom emission type, the pixel electrode (anode electrode) 34 formed on the insulating film 32 is made of a conductive material having translucency, such as ITO (Indium Tin Oxide), ZnO, or the like. . In this embodiment, it is made of ITO having a thickness of 50 nm. Note that the top emission type light emitting device 10 may have a two-layer structure of a light reflective metal layer such as Al and a transparent conductive layer such as the above-described ITO laminated thereon. In addition, each pixel electrode 34 is insulated from the pixel electrode 34 of another adjacent pixel 30 by an interlayer insulating film 35.

  The interlayer insulating film 35 is made of an insulating material, and is made of, for example, SiN having a thickness of 20 nm in the present embodiment. The interlayer insulating film 35 is a protective insulating film that protects the transistors Tr11 and Tr12, and is formed so as to cover the transistors Tr11 and Tr12 disposed between the pixel electrodes 34, and insulates between adjacent pixel electrodes 34. The interlayer insulating film 35 includes an opening 35 a that opens the pixel electrode 34, and the light emitting region of the pixel 30 is defined by the opening 35 a.

  The hole injection layer 36 is made of an organic polymer material that can inject and transport holes. For example, in the present embodiment, a high-boiling solvent (for example, ethylene glycol, N-methylpyrrolidone (NMP), 1, 3) is added to polyethylenedioxythiophene (PEDOT), which is a conductive polymer, and polystyrenesulfonic acid (PSS), which is a dopant. -Dimethyl-2-imidazolidinone (DMI) and the like) and a surfactant are appropriately mixed. The hole injection layer 36 is formed on the pixel electrode 34, the interlayer insulating film 35, and the partition wall 38. In particular, in this embodiment, as will be described in detail later, the hole injection layer 36 drops a solution on the pixel electrode 34, the interlayer insulating film 35, and the partition wall 38, and applies the solution to the entire display region. For this reason, the hole injection layer 36 is formed not only on the pixel electrode 34 but also on the interlayer insulating film 35 and the partition wall 38. In this way, by applying the solution to the entire display region and leveling, the unevenness generated in the film thickness of the hole injection layer 36 can be suppressed, and the hole injection layer 36 has a relatively uniform thickness. Have. The display area indicates an area where the pixels 30 on the pixel substrate 31 are formed.

  The light emitting layer 37 is formed on the hole injection layer 36. The light emitting layer 37 has a function of generating light by applying a predetermined voltage between the anode electrode and the cathode electrode. The light emitting layer 37 is made of a known polymer light emitting material capable of emitting fluorescence or phosphorescence, for example, a light emitting material containing a conjugated double bond polymer such as polyparaphenylene vinylene or polyfluorene. These light-emitting materials are formed by applying a solution dissolved in a high-boiling aromatic solvent (such as tetralin or tetramethylbenzene) as appropriate by the ink jet method or the like and volatilizing the solvent. In the present embodiment, since the light emitting device 10 emits monochromatic light from all the pixels 30, the hole injection layer 36 and the light emitting layer 37 of all the pixels 30 are formed of the same material. Become. Therefore, like the hole injection layer 36, it is formed not only on the pixel electrode 34 but also on the interlayer insulating film 35 and the partition wall 38. As described above, when the light emitting layer 37 is formed, the solution is applied to the entire display region and is leveled, whereby occurrence of unevenness in the film thickness of the light emitting layer 37 can be suppressed. It has a uniform thickness.

  The partition wall 38 is made of a resin, for example, photosensitive polyimide, and is formed on the interlayer insulating film 35. As shown in FIGS. 3 and 4, the partition wall 38 is formed in a stripe shape so as to have a square cross-sectional shape and extend in the column direction (vertical direction shown in FIG. 3). The thickness of the partition wall 38 is preferably about 1 to 5 μm.

  The counter electrode (cathode electrode) 40 covers a layer made of a conductive material, for example, a material having a low work function such as Ca or Ba, and a layer made of a material having a low work function in order to suppress oxidation of the material having a low work function. A two-layer structure composed of a light-reflective conductive layer such as Al for lowering the overall sheet resistance. In the present embodiment, the counter electrode 40 is composed of a single electrode layer formed across a plurality of pixels 30 and is applied with a voltage Vss.

  Next, a method for manufacturing a light emitting device according to an embodiment of the present invention will be described with reference to FIGS.

  First, a pixel substrate 31 made of a glass substrate or the like is prepared. Next, a metal film such as AlTiNd is formed on the pixel substrate 31 by a sputtering method, a vacuum deposition method, or the like, and is patterned to form the gate electrodes 11g and 12g as shown in FIG. .

  Subsequently, as shown in FIG. 5B, an insulating film 32 such as a silicon nitride film is formed on the gate electrodes 11g and 12g by a CVD (Chemical Vapor Deposition) method or the like.

Next, as shown in FIG. 5C, an amorphous silicon film to be the semiconductor layers 111 and 121 and a silicon nitride film to be the protective insulating films 112 and 122 are successively deposited on the insulating film 32, and photolithography is performed. The protective insulating films 112 and 122 are formed by patterning the silicon nitride film. Next, a semiconductor layer containing n-type impurities in amorphous silicon is formed by a CVD method, and the semiconductor layer containing amorphous silicon in n-type impurities and the amorphous silicon film are patterned by photolithography to form an ohmic contact layer. 113, 114, 123, and 124 and semiconductor layers 111 and 121 are formed.
Next, a conductive film such as ITO is deposited by sputtering, vapor deposition, or the like, and a pixel electrode 34 is formed by patterning on the insulating film 32 by photolithography.
Thereafter, a source-drain metal layer is continuously formed by sputtering, vacuum deposition, or the like. Then, the source-drain metal layer is patterned by etching using a photolithography resist mask to form the drain electrodes 11d and 12d and the source electrodes 11s and 12s.

  Subsequently, as shown in FIG. 6A, an interlayer insulating film 35 made of a silicon nitride film is formed by CVD or the like so as to cover the transistors Tr11, Tr12 and the like. Next, an opening 35a is formed in a region corresponding to the light emitting region of the pixel 30 by photolithography or the like, and the pixel electrode 34 is exposed.

  Next, as shown in FIG. 6B, a photomask is formed on the pixel substrate 31 with an insulating material, for example, a photosensitive polyimide layer, and formed in a shape corresponding to the partition wall on the polyimide layer. A partition wall 38 having an opening 38a wider than the opening 35a is formed so that the upper surface of the pixel electrode 34 is exposed and the interlayer insulating film 35 in the vicinity of the opening 35a is exposed. As shown in FIG. 3, the openings 38a of the partition walls 38 extend in a stripe shape in the column direction. The partition wall 38 is formed so as to cover the transistors Tr11 and Tr12 and the data line Ld, and has a thickness sufficient to prevent these from being interfered with the electric field of the counter electrode 40.

  Subsequently, the top of the pixel substrate 31 is washed with pure water, dried, and then subjected to an oxygen plasma treatment under a reduced pressure condition, so that a lyophilic treatment is performed so that the liquid can easily become familiar with the surface of the pixel electrode 34 and the partition wall 38. . Here, the lyophilic liquid is, for example, an organic compound-containing liquid containing a hole injection material to be a hole injection layer, or an organic solvent used in these solutions is dropped on an insulating substrate and the contact angle is measured. In this case, it is defined that the contact angle is less than 30 °.

  Next, as shown in FIGS. 7 and 8, the stage on which the inkjet head 20 or the pixel substrate 31 is placed is moved so that the inkjet head 20 having a plurality of ejection openings 20a moves relatively in the direction of the arrow. In addition, a surfactant (PEDOT: PSS shows strong acidity to the hole injection material (eg PEDOT), so that it is a cationic surfactant, such as an alkylamine salt, a quaternary ammonium salt, or an amphoteric surfactant. For example, alkyl petines and nonionic surfactants such as polyoxyethylene alkyl ethers) and high-boiling solvents (for example, ethylene glycol, NMP, DMI, etc.) are suitably mixed into PEDOT solution droplets. 36c is discharged synchronously from the plurality of discharge ports 20a of the inkjet head 20, and applied to the entire display area. The interval between the discharge ports 20a is set to the same size as the interval between the droplet landing positions 25 shown in FIG. The interval between the droplet landing positions 25 ejected from the adjacent ejection ports 20a is the interval t between the adjacent ejection ports 20a, and the arrangement direction of the plurality of ejection ports 20a with respect to the relative traveling direction (arrow direction) of the inkjet head 20 By tilting the inkjet head 20 so as to be the angle θ, it can be controlled so as to be t · sin θ. The droplets 36c of the PEDOT solution are dropped onto the flying droplet landing positions 25 set at a uniform pitch shown in FIG. The flying droplet landing position 25 is a droplet landing position, not the diameter of the droplet, and is not a region where the droplet spreads when landing. The dropped liquid droplet 36c is combined with the liquid droplet 36c dropped in the vicinity thereof, and eventually, as shown in FIG. 7, the PEDOT solution 36a can be uniformly spread over the entire display area. Since it is uniformly spread in this way, the vapor pressure of the solvent in the entire area is uniform and the temperature change due to the heat of evaporation (heat of absorption) is also uniform in the entire area. It is possible to prevent the undried hole injection material solution from being sucked statically and becoming thick. Due to such a leveling effect, the thickness of the PEDOT solution 36a becomes relatively uniform in the display region. In the present embodiment, in particular, the droplet landing position 25 is set not only on the pixel electrode 34 and the interlayer insulating film 35 but also on the partition wall 38. By landing on the partition wall 38 in this manner, the droplets 36c of the dropped PEDOT solution can be easily coupled to each other and can be more uniformly developed. As a result, a better leveling effect can be obtained.

  In particular, in this embodiment, the interval between the droplet landing positions 25 is set based on the arrangement of the pixel electrodes 34, that is, based on the size of one pixel area. For example, assume that the size of one pixel region A shown in FIG. 8 is y μm × y μm. At this time, the interval between the droplet landing positions 25 is set to a value obtained by dividing one side y μm of one pixel region A by a positive integer, for example, y / 3 μm. Thus, the interval between the droplet landing positions 25 is 1 / n (n is a positive integer) of the interval between one side of one pixel region A. Then, approximately 20 to 30 pl of the PEDOT solution 36a is dropped as droplets onto the droplet landing position 25. Thus, the PEDOT solution 36a can be spread uniformly in the display area by setting the interval and the dropping amount of the PEDOT solution flying droplet landing positions 25.

  Next, before the PEDOT solution 36a is naturally dried, the pixel substrate 31 is transferred to the decompression chamber and dried. Accordingly, the PEDOT solution 36a can be dried in a short time in a state where the PEDOT solution 36a is uniformly spread over the entire display region.

  When the drying of the pixel substrate 31 is completed in the decompression chamber, the residual solvent is subsequently removed by, for example, heat drying at 200 ° C. for 15 minutes in an air atmosphere. As a result, as shown in FIG. 9, a uniform hole injection layer 36 can be formed over the entire display region.

  Next, as shown in FIG. 10, a droplet 37c of a light emitting polymer solution containing a light emitting material (for example, a monochromatic light emitting material containing a conjugated double bond polymer such as polyparaphenylene vinylene or polyfluorene) is inkjet-printed. The ink is discharged from the discharge port 20a of the head 20 and applied to the entire display area.

  The droplet landing position of the light emitting polymer solution droplet 37c is also set to the same position as the droplet landing position 25 shown in FIG. 8 similarly to the droplet 36c of the PEDOT solution, and is approximately 20 to 30 pl at the droplet landing position 25. A droplet 37c of the light emitting polymer solution is dropped. The dropped droplet 37c is combined with the dropped droplet 37c in the vicinity thereof, and eventually the light emitting polymer solution 37a spreads over the entire display area as shown in FIG. Therefore, the light emitting polymer solution 37a can have a relatively uniform thickness due to the leveling effect.

  Next, before the light emitting polymer solution 37a applied on the pixel substrate 31 is naturally dried, the pixel substrate 31 is transferred to a decompression chamber and dried. Accordingly, the light emitting polymer solution 37a can be dried in a short time in a state where the light emitting polymer solution 37a is uniformly spread over the entire display region.

  When the drying of the pixel substrate 31 is completed in the decompression chamber, the residual solvent is subsequently removed by heating and drying in a nitrogen atmosphere at 120 ° C. for 30 minutes. Thereby, as shown in FIG. 11A, the light emitting layer 37 having a relatively uniform thickness can be formed over the entire display region on the hole injection layer 36.

  Subsequently, as shown in FIG. 11B, a low work function film such as Li, Mg, Ba, or Ca is formed on the pixel substrate 31 formed up to the light emitting layer 37 by, for example, sputtering or vacuum deposition. A counter electrode 40 is formed by depositing 4 nm of an Al alloy film to 500 nm.

  Finally, the pixel substrate 31 is transferred from a vacuum to a nitrogen atmosphere, and a sealing substrate (not shown) such as a metal cap or glass is coated with UV curing or thermosetting adhesive; Then, the light emitting device 10 is completed.

  According to the method of manufacturing the light emitting device according to the embodiment of the present invention, the PEDOT solution droplet 36c and the light emitting polymer solution droplet 37c are formed at the landing positions set on the pixel electrode 34, the interlayer insulating film 35, and the partition wall 38. The liquid droplets in the vicinity are bonded to each other, and the liquid droplets in the vicinity are combined to apply these solutions to the entire display area on the pixel substrate 31. Thereby, the thickness of these solutions can be made comparatively uniform by the leveling effect. Therefore, the hole injection layer 36 and the light emitting layer 37 can be formed with a relatively uniform thickness, and a light emitting device with less unevenness in thickness can be manufactured.

  In particular, in the present embodiment, the droplet landing positions are set at a uniform pitch, and the interval between the droplet landing positions 25 is a value obtained by dividing the size (y μm) of one pixel region A by a positive integer (for example, y / 3 μm). Therefore, the PEDOT solution 36a and the light emitting polymer solution 37a can be regularly dropped in accordance with the shape of the pixel electrode 34, the partition wall 38, and the like. Thereby, the PEDOT solution 36a and the light emitting polymer solution 37a can be spread uniformly over the entire display region, and the hole injection layer 36 and the light emitting layer 37 with relatively uniform and less unevenness can be formed.

  In this embodiment, since a high boiling point solvent is used as the solvent for the PEDOT solution 36a and the light emitting polymer solution 37a, these solutions are not dried immediately after being applied on the pixel substrate 31. . Therefore, the dropped PEDOT solution 36a and the light emitting polymer solution 37a are combined with the droplets dropped in the vicinity, and can be developed relatively uniformly over the entire display area. Further, for example, oxygen plasma treatment is performed on the surfaces of the pixel electrode 34, the interlayer insulating film 35, and the partition wall 38 to make the surfaces hydrophilic, thereby improving the wettability to the solution to be applied. Further, by adding a surfactant to the PEDOT solution 36a and the light emitting polymer solution 37a, the cohesive force of the solution can be reduced, and the PEDOT solution 36a and the light emitting polymer solution 37a are developed relatively uniformly over the entire display region. be able to.

  In the above-described embodiment, the PEDOT solution 36a and the light emitting polymer solution 37a are dried under reduced pressure in a state where the PEDOT solution 36a and the light emitting polymer solution 37a are applied to the entire display region, so that the solution can be dried in a short time. Thereby, generation | occurrence | production of the thickness nonuniformity at the time of drying can be suppressed.

  Further, in the method for manufacturing the light emitting device according to the embodiment of the present invention, the PEDOT solution 36a and the light emitting polymer solution 37a are applied onto the pixel substrate 31 by the ink jet method. In the ink jet method, the dropping position of the solution can be selected as appropriate, so that only the display region of the pixel substrate 31 can be selected and applied. This makes it possible to apply the solution evenly on the substrate with a finer and more uniform control of the application position and application amount than the spin coat method and slit coat method, which are difficult to apply to a uniform thickness due to irregularities such as partition walls. It is possible to perform film formation without thickness unevenness. In addition, since the coating is performed by the ink jet method, it is possible to apply the solution to a substrate having a size that is difficult to apply by the spin coating method or the slit coating method.

The present invention is not limited to the above-described embodiments, and various modifications and applications are possible.
In the embodiment described above, the light emitting device that emits a single color and the method for manufacturing the light emitting device have been described. However, for example, a full color in which red (R), green (G), and blue (B) light emitting materials are separately applied. It can be used in a light emitting device and a method for manufacturing the light emitting device. In this case, the method of the above-described embodiment can be used when forming the hole injection layer, which is a layer common to pixels of different colors.

  In the above-described embodiment, the configuration in which the partition walls are formed in a stripe shape has been described as an example. However, the present invention is not limited to this, and the partition walls may be formed in a lattice shape similarly to the interlayer insulating film 35. In this case, as shown in FIG. 12, the partition wall 38 is formed in a lattice shape so as to surround the periphery of the pixel electrode 34, and the droplet landing positions 26 of the PEDOT solution and the light emitting polymer solution are set at the pixel electrode 34 and the partition wall 38. Set above. The pitch of the droplet landing positions 26 is set based on the dimensions of the pixel area A. In FIG. 12, the hole injection layer, the light emitting layer, and the counter electrode are not shown, as in FIG. By dropping the solution onto the droplet landing positions 26 having such a pitch, the dropped droplets are combined with nearby droplets, and the solution has a relatively uniform thickness due to the leveling effect. Thereby, it is possible to form a hole injection layer and a light emitting layer having a relatively uniform thickness and little unevenness in thickness.

  In addition, controlling the interval between the droplet landing positions 25 of the PEDOT solution 36a and the light emitting polymer solution 37a by inclining the arrangement direction of the discharge ports 20a of the inkjet head 20 with respect to the traveling direction of the inkjet head 20 will be described below. This will be described in detail. For example, as shown in FIG. 12B, the inkjet head 20 having the ejection ports 20 a at 50 μm intervals shown in FIG. 13A is used as the ejection port 20 a of the inkjet head 20 with respect to the traveling direction of the inkjet head 20. For example, by rotating the inkjet head 20 by 30 ° from the original state, the droplet landing position interval can be set to 43 μm and the solution can be discharged. In addition, the arrow in a figure has shown the moving direction of the inkjet head 20. FIG.

It is a top view of the light-emitting device concerning the embodiment of the present invention. It is an equivalent circuit diagram of a pixel of the light emitting device. It is a top view of a pixel. It is the IV-IV sectional view taken on the line shown in FIG. (A)-(c) is sectional drawing for demonstrating the manufacturing method of the light-emitting device which concerns on embodiment of this invention. (A), (b) is sectional drawing for demonstrating the manufacturing method of the light-emitting device which concerns on embodiment of this invention. It is sectional drawing for demonstrating the manufacturing method of the light-emitting device which concerns on embodiment of this invention. It is a top view for demonstrating the droplet landing position of a solution. It is sectional drawing for demonstrating the manufacturing method of the light-emitting device which concerns on embodiment of this invention. It is sectional drawing for demonstrating the manufacturing method of the light-emitting device which concerns on embodiment of this invention. (A), (b) is sectional drawing for demonstrating the manufacturing method of the light-emitting device which concerns on embodiment of this invention. It is a top view which shows the principal part of the pixel of the light-emitting device which concerns on other embodiment. FIG. 2A is a plan view when the inkjet head is installed at a right angle to the moving direction, and FIG. 2B is a plan view when the head is inclined by 30 ° from the state of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Light-emitting device, 20 ... Inkjet head, 25, 26 ... Droplet landing position, 30 ... Pixel, 31 ... Pixel substrate, 32 ... Insulating film, 34 ... Pixel Electrode 35 ... Interlayer insulating film 36 ... Hole injection layer 37 ... Light emitting layer 38 ... Partition wall 40 ... Counter electrode Cs ... Capacitor La ... Anode Line, Ld ... Data line, Ls ... Select line, Tr11, Tr12 ... Transistor

Claims (4)

A dropping step of dropping an organic compound-containing liquid on each of the pixel electrodes and on the partition formed between the adjacent pixel electrodes;
A drying step of drying the solvent of the organic compound-containing liquid;
A method for manufacturing a light-emitting device. The pixel electrodes are arranged at a predetermined interval from each other,
2. The light emitting device according to claim 1, wherein in the dropping step, the organic compound-containing liquid is dropped at a pitch of 1 / n (n is a positive integer) of an interval at which the pixel electrodes are arranged. Production method.   3. The light emission according to claim 1, wherein in the dropping step, the liquid droplets are ejected in synchronization with a pixel electrode and a partition formed between the adjacent pixel electrodes by inkjet. Device manufacturing method.   A light-emitting device manufactured by the manufacturing method according to claim 1.

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