JP2011086567A - Manufacturing method of organic el element, the organic el element, electro-optical device and electronic apparatus - Google Patents

Abstract

An organic EL element manufacturing method, an organic EL element, an electro-optical device, and an electronic apparatus that can obtain stable light emission characteristics with little luminance unevenness.
A method for manufacturing an organic EL element according to this application example includes a first step of forming a partition wall partitioning a film forming region including an anode, and a first step of including a hole injection transport layer forming material in the film forming region. Applying and drying a liquid material, applying a second step of forming a hole injecting and transporting layer on the anode, and applying and drying a second liquid material containing a light emitting layer forming material and a crosslinking agent in the film forming region; A third step of forming a light emitting layer precursor on the hole injecting and transporting layer; a fourth step of heat treating the light emitting layer precursor in an inert gas atmosphere; and exposing the heat treated light emitting layer precursor to a solvent. And removing a soluble portion of the light emitting layer precursor to form a light emitting layer that is a part of the light emitting layer precursor and insoluble in the solvent, and a sixth step of forming a cathode on the light emitting layer. And provided.
[Selection] Figure 2

Description

  The present invention relates to a method for manufacturing an organic EL (electroluminescence) element, an organic EL element, an electro-optical device, and an electronic apparatus.

  As a method for manufacturing an organic EL element in which a functional layer made of a multilayer organic film including a light emitting layer is provided between a pair of electrodes, a liquid containing a functional layer forming material is dropped in a film forming region partitioned by a partition wall. A droplet discharge method (inkjet method) is known in which a functional layer is formed by discharging and drying.

  In the case of using the droplet discharge method, a predetermined amount of the liquid material necessary for film formation is discharged and arranged on the film formation region on the substrate on which the partition wall is formed, and is discharged. The film thickness distribution of the organic film after drying varies depending on the film forming conditions such as how to dry the liquid. The three-dimensional shape of the functional layer in which several organic films are stacked also varies depending on how each organic film is formed. For example, in the film formation region, there may be a convex shape with a thick central portion or a concave shape with a thin central portion, and it is difficult to obtain a constant shape. In particular, there is a problem that light emission unevenness (luminance unevenness) occurs unless the thickness of the light emitting layer is uniform among the stacked organic films.

  In order to solve this problem, for example, Patent Document 1 discloses a liquid material that partitions a film formation region by a so-called two-layer bank in which a second partition wall portion is stacked on a first partition wall portion and is discharged to the film formation region. The method of changing the surface area of the part which protruded in the film formation area from the 2nd partition part among the 1st partition parts according to the viscosity of is described. Specifically, the surface area is reduced in a film formation region where a low-viscosity liquid material is discharged, and the surface area is increased in a film formation region where a high-viscosity liquid material is discharged.

  Further, Patent Document 2 discloses a function effective region including one or more function film forming regions that enable a function film formed on a substrate, and one or more adjustments provided around the function effective region. A method is described in which the total amount of liquid material to be arranged in the adjustment region including the film formation region is changed according to the cross-sectional shape in the thickness direction of the functional film obtained after drying under reduced pressure. Specifically, when the film thickness on the peripheral side of the functional film is thicker than the film thickness on the central side, the amount of liquid material disposed in the adjustment region is increased, and the film thickness on the peripheral side is thinner than the film thickness on the central side. Sometimes the amount of liquid material placed in the adjustment area is reduced.

  Further, for example, in Patent Document 3, according to the cross-sectional shape in the thickness direction of the functional film formed by disposing the liquid material in the first amount in the film forming region partitioned by the partition wall on the substrate, A method for changing the height of the partition wall is described. Specifically, when the film thickness on the peripheral side of the functional film is thicker than the film thickness on the central side, the height of the partition wall is made lower than the first height, and the film thickness on the peripheral side is smaller than the film thickness on the central side. When the thickness is too thin, the height of the partition wall is set to be higher than the first height.

JP 2006-12762 A JP 2007-289826 A JP 2007-310156 A

  However, even when the above conventional method is used, the drying speed of the applied liquid varies in relation to the size of the substrate to be dried and the size and arrangement of the film forming region on the substrate. There is a problem that it is difficult to form a light-emitting layer having a uniform film thickness because the wettability with respect to the partition wall differs depending on the type of the liquid material.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples. Moreover, in the following forms or application examples, “up” indicates the direction in which the component is arranged as viewed from the substrate. When “on top” is described, it touches on top of “XX”. When it is arranged or when it is arranged on XX through other components, or when it is arranged so that part of it touches on XX and part of it is arranged through other components .

  Application Example 1 An organic EL element manufacturing method according to this application example is an organic EL element manufacturing method in which a functional layer including a light emitting layer is provided between an anode and a cathode, and the film formation includes the anode. A first step of forming a partition wall partitioning the region; and a first liquid containing a hole injection transport layer forming material is applied to the film formation region and dried to form a hole injection transport layer on the anode And a third step of forming a light emitting layer precursor on the hole injecting and transporting layer by applying and drying a second liquid containing a light emitting layer forming material and a crosslinking agent on the film forming region. And a fourth step of heat-treating the light-emitting layer precursor in an inert gas atmosphere, exposing the heat-treated light-emitting layer precursor to a solvent to remove a soluble portion of the light-emitting layer precursor, A fifth step of forming a light emitting layer that is a part of the light emitting layer precursor and is insoluble in the solvent , Characterized by comprising a sixth step of forming the cathode on the light emitting layer.

  According to this method, in the fourth step, the light emitting layer precursor containing the crosslinking agent is heat-treated, so that the light emitting layer forming material is crosslinked via the crosslinking agent in the vicinity of the hole injecting and transporting layer. By exposing the light emitting layer precursor subjected to the heat treatment in the fifth step to a solvent, the non-crosslinked portion of the light emitting layer precursor is dissolved in the solvent. A portion of the light emitting layer precursor that has been crosslinked and insoluble in the solvent remains so as to trace the hole injecting and transporting layer, and this becomes the light emitting layer. The degree of crosslinking of the light emitting layer precursor can be easily managed by the content ratio of the crosslinking agent and the temperature and time in the heat treatment. As a result, compared with the case where the light emitting layer is formed by applying the second liquid material containing no cross-linking agent, the film formation region is almost constant without affecting the influence of film thickness variation due to the drying of the second liquid material. A light emitting layer having a thickness of 5 mm can be formed on the hole injecting and transporting layer. That is, an organic EL element with little light emission unevenness (luminance unevenness) can be manufactured with a high yield.

Application Example 2 In the method for manufacturing an organic EL element according to the application example, the light emitting layer forming material into which the crosslinking agent has been introduced in advance may be used in the third step.
According to this method, as compared with the case where the light emitting layer forming material and the crosslinking agent are mixed to form the second liquid material, the ratio of the crosslinking agent to the light emitting layer forming material is kept constant, and the light emitting layer forming material is stabilized. It can be cross-linked.

Application Example 3 In the method for manufacturing an organic EL element according to the application example, it is preferable that the third step uses the cross-linking agent having a hole transporting property.
According to this method, the difference in energy level between the hole injecting and transporting layer and the light emitting layer is reduced, and the hole transportability from the hole injecting and transporting layer to the light emitting layer can be improved. That is, the light emission efficiency can be improved.

Application Example 4 In the method for manufacturing an organic EL element according to the application example described above, it is preferable that the third step is to apply the second liquid material to the film formation region using a droplet discharge method.
According to this method, a necessary amount of the second liquid material can be stably applied as droplets to the film forming region. In addition, for example, when the second liquid material has various emission colors, it is possible to easily separate the colors for each emission color.

[Application Example 5] In the method of manufacturing an organic EL element according to the application example, in the fifth step, the solvent is applied to the substrate having the light emitting layer precursor subjected to heat treatment, and the solvent is applied. It is preferable that the light emitting layer precursor soluble in the solvent is removed by rotating the substrate about an axis perpendicular to the substrate surface.
According to this method, the light emitting layer precursor dissolved in the solvent can be quickly removed from the substrate. That is, only the crosslinked light emitting layer can be easily taken out from the light emitting layer precursor.

  [Application Example 6] An organic EL device of this application example is provided with an anode, a hole injection transport layer provided on the anode, and a hole injection transport layer provided on the hole injection transport layer. A light emitting layer obtained by crosslinking and insolubilizing in a solvent and removing a portion soluble in the solvent from the light emitting layer precursor, and a cathode provided on the light emitting layer were provided. It is characterized by.

  According to this configuration, a portion of the light emitting layer precursor that is not cross-linked or incompletely cross-linked is dissolved and removed in the solvent, so that a part of the light emitting layer precursor is cross-linked and the film thickness is substantially constant. Thus, an organic EL element with little emission unevenness (luminance unevenness) can be provided.

Application Example 7 In the organic EL device according to the application example described above, it is preferable that the light-emitting layer includes a crosslinking agent having a hole transporting property.
According to this configuration, it is possible to provide an organic EL element with improved hole transportability from the hole injection transport layer to the light emitting layer.

Application Example 8 An electro-optical device according to this application example includes an organic EL element manufactured using the method for manufacturing an organic EL element according to the application example or the organic EL element according to the application example. .
According to this configuration, it is possible to provide an electro-optical device having less light emission unevenness (brightness unevenness) and having stable light emission characteristics. Note that light emission in the organic EL element is not limited to a single color but can be applied to an organic EL element that can emit multicolor light, and thus, for example, an electro-optical device as a display device capable of full-color display with good appearance can be provided.

Application Example 9 An electronic apparatus according to this application example includes the electro-optical device according to the application example described above.
According to this configuration, light emission unevenness (brightness unevenness) is small and stable light emission characteristics can be obtained, so that an electronic device having high performance and quality can be provided.

(A) is a schematic plan view which shows the structure of a light-emitting device, (b) is a schematic sectional drawing which shows the structure of an organic EL element. The flowchart which shows the manufacturing method of an organic EL element. (A)-(e) is a schematic sectional drawing which shows the manufacturing method of an organic EL element. (F)-(i) is a schematic sectional drawing which shows the manufacturing method of an organic EL element. The schematic perspective view explaining a spin coat method. The figure which shows the formation state and light emission profile of the light emitting layer in an Example. The figure which shows the formation state and light emission profile of the light emitting layer in a comparative example. FIG. 2 is a schematic perspective view showing a configuration of an optical writing head. 1 is a schematic cross-sectional view illustrating a configuration of an image forming apparatus. The schematic front view which shows a display apparatus. The schematic sectional drawing which shows the principal part structure of a display apparatus.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, embodiments of the invention will be described with reference to the drawings. Note that the drawings to be used are appropriately enlarged or reduced so that the part to be described can be recognized.

(First embodiment)
<Electro-optical device>
First, an electro-optical device including the organic EL (electroluminescence) element of this embodiment will be described with reference to FIG.
The electro-optical device of this embodiment is an example of a light-emitting device that is preferably used as an optical writing head that irradiates a photosensitive drum with light in an image forming apparatus described later.

FIG. 1A is a schematic plan view showing the configuration of the light emitting device, and FIG. 1B is a schematic cross-sectional view showing the structure of the organic EL element.
As shown in FIG. 1A, a light-emitting device 30 as an electro-optical device according to this embodiment includes a long and thin element substrate 1 and organic elements as a plurality of light-emitting elements arranged in the longitudinal direction on the element substrate 1. The EL element 10 is provided for each organic EL element 10 and includes a driving element 6 that drives the EL element 10 and a control circuit 9 that controls driving of the driving element 6. The organic EL element 10 has a substantially circular light emitting region, and the size thereof is approximately 25 μm. Further, they are arranged in a zigzag pattern at an arrangement pitch of about 42.25 μm in the longitudinal direction, and the number thereof is, for example, 122880. That is, the arrangement density of the organic EL elements 10 is equivalent to 1200 dpi.

As shown in FIG. 1B, the organic EL element 10 includes an anode 2 provided on the element substrate 1, a hole injection / transport layer 3 sequentially stacked on the anode 2, a light emitting layer 4, and a cathode. And 5. The hole injection transport layer 3 and the light emitting layer 4 sandwiched between the anode 2 and the cathode 5 are sometimes called functional layers.
The organic EL element 10 emits light when the light emitting layer 4 is excited by passing a current between the anode 2 and the cathode 5. A common wiring 8 is connected to the cathode 5 of the organic EL element 10, and a power supply line 7 is connected to the anode 2 via a driving element 6. The drive element 6 is composed of a switching element such as a thin film transistor (TFT). The operation of the drive element 6 is controlled by the control circuit 9, and the energization to the organic EL element 10 is controlled by the drive element 6.

  As the element substrate 1, a transparent or translucent one is employed. For example, glass, quartz, resin (plastic, plastic film) and the like can be mentioned, and a glass substrate is particularly preferably used. The anode 2 formed on the element substrate 1 is made of a transparent conductive film such as ITO (Indium Tin Oxide).

The functional layers (the hole injecting and transporting layer 3 and the light emitting layer 4) provided on the anode 2 are formed by a droplet discharge method (inkjet method). The droplet discharge method is a method of forming a film made of a film-forming material by applying a solution (liquid composition) in which a film-forming material is dissolved or dispersed in a solvent and drying it, and removing the solvent.
The periphery of the anode 2 is covered in a frame shape with an insulating film 11 made of an inorganic material such as SiO _2, and the anode 2 is made of an organic material such as a phenol resin or a polyimide resin formed on the insulating film 11. The partition wall portion 12 is substantially partitioned. A predetermined amount of the liquid composition is ejected as droplets from the nozzles of the inkjet head onto the film forming region including the anode 2 partitioned by the partition wall 12.

  As the liquid composition (first liquid) of the hole injecting and transporting layer 3, in particular, a dispersion of 3,4-polyethylenediosithiophene / polystyrene sulfonic acid (PEDOT / PSS), that is, polystyrene sulfonic acid as a dispersion medium A material obtained by dispersing 3,4-polyethylenedioxythiophene and further adding a high-boiling solvent is preferably used. Examples of the high boiling point solvent include isopropyl alcohol, normal butanol, γ-butyrolactone, N-methylpyrrolidone (NMP), dimethylformamide (DMF), hexamethylphossolamide (HMPA), dimethyl sulfoxide (DMSO), 1, 3 -Dimethyl-2-imidazolidine (DMI) and its derivatives, and glycol ethers such as carbitol acetate and butyl carbitol acetate. The liquid composition of the hole injecting and transporting layer 3 is not limited to the above. For example, an amine skeleton derivative such as triphenylamine, a thiophene derivative, a pyrrole derivative, and a phenyl derivative are mixed with an appropriate dispersion medium such as polystyrene sulfone. What was disperse | distributed to the acid etc. can also be used.

  As the film forming material of the light emitting layer 4, a known light emitting material capable of emitting fluorescence or phosphorescence is used. For example, in the present embodiment, the light emitting layer 4 whose light emission wavelength band corresponds to red is employed. Of course, you may make it employ | adopt the light emitting layer 4 whose light emission wavelength band respond | corresponds to green and blue.

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.
Examples of the solvent for dissolving these light emitting materials include xylene. In the droplet discharge method (inkjet method), a solvent having a high boiling point is desirable to prevent the nozzle from drying, and for example, trimethylbenzene, cyclohexylbenzene, or the like is used.

  The cathode 5 is an electrode having a laminated structure in which, for example, Ca is formed to a thickness of about 10 nm and Al is formed to a thickness of about 200 nm, and Al is used as a reflective layer.

The plurality of organic EL elements 10 are covered with a sealing layer 13 so that the light emission lifetime is not hindered by the influence of moisture or oxygen. The sealing layer 13 is made of an inorganic compound having a low gas permeability, such as SiO ₂ (silicon oxide) or SiON (silicon oxynitride), or a laminate of these inorganic compounds.
The configuration of the light emitting device 30 is not limited to this, for example, an element substrate 1 provided with a plurality of organic EL elements 10 and a sealing substrate including a getter material that is made of a substrate such as glass and adsorbs moisture, oxygen, and the like. It is also possible to adopt a sealing structure in which these are joined.

The light emitting device 30 of the present embodiment is a so-called bottom emission type in which light emitted from the light emitting layer 4 is reflected by the cathode 5 and taken out from the transparent or translucent element substrate 1 side.
The light emitting device 30 is not limited to the bottom emission type, and the cathode 5 is made of a transparent conductive material, and the above-described sealing substrate is made of transparent glass or the like, so that the light emission from the light emitting layer 4 is sealed. It is also possible to adopt a top emission type that is taken out from the stop substrate side.

  In this example, a TFT element is formed on the element substrate 1 as the driving element 6 for driving the organic EL element 10, but the driving element 6 is not formed on the element substrate 1 and the driving element 6 is externally attached. May be. Specifically, a driver IC as the drive element 6 is COG mounted on the terminal region of the element substrate 1. Or the method of mounting the flexible circuit board which mounted driver IC in the element substrate 1 is mentioned.

  The light emitting device 30 is used for an optical writing head of an image forming apparatus to be described later, and irradiates the photosensitive drum with light from the organic EL element 10 to expose the photosensitive surface. As the photosensitive member of the photosensitive drum, one having sensitivity in the emission wavelength band of the light emitting layer 4 is employed.

When the light emitting device 30 is used as an optical writing head, the light emission characteristics (such as luminance characteristics) for each of the plurality of organic EL elements 10 are required to be stable at substantially the same level. Ideally, in order to realize this, it is desirable that the functional layer (particularly, the light emitting layer 4) in the organic EL element 10 is constant in a desired film thickness.
The anode 2 and the cathode 5 made of an inorganic material can secure a desired film thickness in a homogeneous state by employing a method such as vacuum deposition. In contrast, the formation of a functional layer using a droplet discharge method (inkjet method) has a problem that it is difficult to ensure a desired film thickness over a plurality of organic EL elements 10.

  The organic EL element 10 of the present embodiment is formed by using a method for manufacturing the organic EL element 10 to be described later. A light emitting layer precursor containing a crosslinking agent is formed on the hole injection transport layer 3, and a part thereof Has a light emitting layer 4 formed by cross-linking in the vicinity of the hole injecting and transporting layer 3 to make it insoluble in a solvent and removing a portion soluble in the solvent from the light emitting layer precursor. The light-emitting layer 4 insolubilized in the solvent is in a state of being completely cross-linked through a cross-linking agent and has a substantially constant film thickness. Moreover, since the film thickness variation of the light emitting layer 4 is suppressed also between the some organic EL elements 10, it has the stable light emission characteristic (luminance characteristic). A more specific method for forming the light emitting layer 4 will be described with reference to examples in the method for manufacturing the organic EL element 10 described below.

<Method for producing organic EL element>
FIG. 2 is a flowchart showing a method for manufacturing an organic EL element, FIGS. 3A to 3E and 4F to 4I are schematic cross-sectional views showing a method for manufacturing an organic EL element, and FIG. 5 is a spin coat. FIG. 6 is a diagram showing a light emitting layer formation state and a light emission profile in an example, and FIG. 7 is a diagram showing a light emitting layer formation state and a light emission profile in a comparative example.

  As shown in FIG. 2, in the method for manufacturing the organic EL element 10 of the present embodiment, a partition wall forming process for forming the partition wall 12 (Step S1) and a surface treatment process for surface treating the surface of the substrate (Step S2). A hole injection transport layer forming step (step S3) for forming the hole injection transport layer 3, and a light emitting layer precursor forming step (step S4) for forming a light emitting layer precursor on the hole injection transport layer 3. The light emitting layer forming step (step S5) for forming the light emitting layer 4 based on the light emitting layer precursor and the cathode forming step (step S6) for forming the cathode 5 are provided.

Step S1 in FIG. 2 is a partition wall forming process. In the partition wall forming step, as shown in FIG. 3A, first, an insulating film 11 that covers the peripheral edge of the anode 2 in a frame shape is formed. As a method for forming the insulating film 11, for example, the surface of the element substrate 1 including the anode 2 is covered with a photosensitive resist, and exposure and development are performed so that the photosensitive resist is left only in a portion excluding the peripheral portion of the anode 2. Thereafter, a method of forming a SiO ₂ film on the entire surface by using a vacuum deposition method or a sputtering method and peeling off the photosensitive resist remaining on the anode 2 can be mentioned. As a result, the insulating film 11 having a substantially circular opening on the anode 2 is formed in plan view. Then, the insulating film 11 and the anode 2 are covered with a phenol-based or polyimide-based photosensitive resin, and the photosensitive resin is patterned so that the plurality of anodes 2 are partitioned to form the partition wall portion 12. Specifically, the partition wall 12 is formed so that the insulating film 11 covering the peripheral edge of the anode 2 protrudes inside the film formation region A. Then, the process proceeds to step S2.

Step S2 in FIG. 2 is a surface treatment process. In the surface treatment step, the element substrate 1 on which the partition walls 12 are formed is first plasma treated using O ₂ gas as a treatment gas. As a result, the surface of the anode 2 and the insulating film 11 and the surface of the partition wall 12 (including the wall surface) are activated to perform lyophilic treatment. Next, plasma processing is performed using a fluorine-based gas such as CF ₄ as a processing gas. As a result, the fluorine-based gas reacts only on the surface of the partition wall portion 12 made of a photosensitive resin, which is an organic material, and the liquid repellent treatment is performed. That is, surface treatment is performed to impart lyophilicity to the surfaces of the anode 2 and the insulating film 11 made of an inorganic material and to impart lyophobicity to the surface of the partition wall portion 12 made of an organic material. If the partition wall 12 itself has liquid repellency, it is possible to eliminate the subsequent plasma treatment. Then, the process proceeds to step S3.

  Step S3 in FIG. 2 is a hole injection transport layer forming step. In the hole injecting and transporting layer forming step, as shown in FIG. 3B, the first liquid 3L containing the PEDOT / PSS dispersion as the hole injecting and transporting layer forming material is dropped from the nozzle 52 of the ink jet head 50. As shown in FIG. The discharged first liquid 3L wets and spreads in the film formation region A. Further, the first liquid 3L is discharged in the film formation region A until it rises due to surface tension. As a result, a predetermined amount of the first liquid 3L is stably applied to each film formation region A. The solvent component is removed from the first liquid 3L by heating and drying at about 150 ° C., and the hole injecting and transporting layer 3 is formed on the anode 2 in the film forming region A as shown in FIG. The concentration of the hole injection transport layer forming material (PEDOT / PSS dispersion) in the first liquid 3L is set so that the thickness of the hole injection transport layer 3 after drying is 50 nm to 60 nm. Then, the process proceeds to step S4.

Step S4 in FIG. 2 is a light emitting layer precursor forming step. In the light emitting layer precursor forming step, first, a second liquid 4L containing a light emitting layer forming material is prepared. The second liquid body 4L is, for example, a poly [{2-methoxy-5- (2-ethylhexyioxy} -1,4- (1-cyanovinylenephenylene))-co- {2,5-bis (N , N′-diphenylamino) -1,4-phenylene}] at a rate of 1 wt% to 50 wt% as a crosslinking agent TFB (poly (2,7- (9,9-di-n-octylfluorenne) -alt) This is a trimethylbenzene solution containing a solute mixed with-(1,4-phenylene-((4-sec-butylphenyl) imino-1,4-phenylene)))) at a ratio of about 1.5 wt%.
In addition, the ratio of the crosslinking agent with respect to the light emitting material is appropriately adjusted depending on the crosslinked state in the light emitting layer precursor after the heat treatment described later. If the ratio is too small, it is difficult to obtain the light-emitting layer 4 having a desired film thickness. If the ratio is too large, crosslinking proceeds too much and the film thickness may vary. Therefore, it is preferable that the said ratio is the range of 10 wt%-20 wt%.

TFB as a cross-linking agent is used as a binder having a hole transporting property provided between a hole injection layer and a light emitting layer, and energy between the hole injection transport layer 3 and the light emitting layer 4 The hole transport property can be improved by lowering the barrier. That is, the light emission efficiency in the light emitting layer 4 is improved.
In addition, a crosslinking agent is not limited to this, The binder which has the following hole transportability can also be used.
PFB; poly (9,9-dioctylfluorene-co-bis-N, N '-(4-butylphenyl) -bis-N, N'-phenyl-1,4-phenylenediamine)
PFM; poly (9,9-dioctylfluorene-co-bis-N, N '-(4-methylphenyl) -bis-N, N'-phenyl-1,4-phenylenediamine)
PFMO; poly (9,9-dioctylfluorene-co-bis-N, N '-(4-methoxyphenyl) -bis-N, N'-phenyl-1,4-phenylenediamine)
BFB: poly (9,9-dioctylfluorene-co-bis-N, N '-(4-butylphenyl) -bis-N, N'-phenylbenzidine)

  Next, as shown in FIG. 3D, the second liquid 4 </ b> L is discharged as droplets from the nozzle 52 of the inkjet head 50 to the film formation region A. The discharged second liquid 4L wets and spreads in the film formation region A. Further, the second liquid 4L is discharged in the film formation region A until it rises due to surface tension. As a result, a predetermined amount of the second liquid 4L is stably applied to each film formation region A. The solvent component is removed from the second liquid 4L by heating and drying at about 130 ° C., and a light emitting layer precursor 4a is formed on the hole injection transport layer 3 in the film formation region A as shown in FIG. Is done. The concentration of the solute in the second liquid 4L is set so that the thickness of the light emitting layer precursor 4a after drying is 80 nm to 100 nm. Then, the process proceeds to step S5.

  Step S5 in FIG. 2 is a light emitting layer forming step. In the light emitting layer forming step, the element substrate 1 on which the light emitting layer precursor 4a is formed is heat-treated at about 180 ° C. for 1 hour in a nitrogen atmosphere. By performing the heat treatment, the light emitting layer precursor 4 a containing a crosslinking agent is crosslinked in the vicinity of the hole injection transport layer 3. The cross-linked portion of the light emitting layer precursor 4a is insoluble in trimethylbenzene as a solvent. In other words, the non-crosslinked portion of the light emitting layer precursor 4a is dissolved in trimethylbenzene as a solvent. As a principle that the portion in the vicinity of the hole injecting and transporting layer 3 of the light emitting layer precursor 4a is cross-linked, the S (sulfur) component contained in the hole injecting and transporting layer 3 functions as a crosslinking agent, It is considered that protons are supplied from the organic acid contained in the transport layer 3 and the crosslinking proceeds.

  Next, as shown in FIG.4 (f), the light emitting layer precursor 4a heat-processed is exposed to a solvent, and the part soluble in a solvent is removed from the light emitting layer precursor 4a. That is, the non-crosslinked light emitting layer precursor 4a is dissolved in a solvent and removed. As a method for removing the soluble portion of the light emitting layer precursor 4a by exposing it to the solvent without unevenness, it is desirable to use a spin coating method as shown in FIG.

In the process of actually manufacturing the light emitting device 30, a mother substrate W on which a plurality of element substrates 1 are attached is used. The spin coater 300 includes a table 301 on which a mother substrate W is placed and which can be rotated around an axis, and a nozzle 302 which is disposed on the axis so as to face the table 301. If such a spin coater 300 is used, the solvent is discharged from the nozzle 302 toward the mother substrate W while rotating the table 301 at a predetermined speed, so that the solvent is evenly distributed over the entire surface of the mother substrate W. Can do. Since the mother substrate W rotates, the light emitting layer precursor 4a dissolved in the solvent is discharged to the outer peripheral side of the table 301 by centrifugal force. Although depending on the size of the mother substrate W, the uncrosslinked light emitting layer precursor 4a can be removed cleanly from the mother substrate W by exposing the mother substrate W to a solvent for about 30 seconds. As a result, as shown in FIG. 4G, the light emitting layer precursor 4a, that is, the light emitting layer 4 insolubilized in the solvent so as to trace the surface of the hole injection transport layer 3 in the film forming region A is formed. The film thickness is 10 nm to 30 nm.
In addition, the solvent used at this process is not limited to the trimethylbenzene mentioned above, Solvents, such as a cyclohexylbenzene and toluene, can also be used. Then, the process proceeds to step S6.

  Step S6 in FIG. 2 is a cathode forming step. In the cathode forming step, the cathode 5 is formed so as to cover the light emitting layer 4 and the partition wall portion 12 of the element substrate 1 as shown in FIG. As a material for the cathode 5, it is preferable to use a combination of metals such as Ca, Ba and Al and fluorides such as LiF. In particular, it is preferable to form a film of Ca, Ba or LiF having a small work function on the side close to the light emitting layer 4 and a film of Al or the like having a large work function on the far side. Examples of the method for forming the cathode 5 include vacuum deposition, sputtering, and CVD. In particular, vacuum vapor deposition is preferable in that the light emitting layer 4 can be prevented from being damaged by heat. In this embodiment, after forming the Ca layer so that the film thickness is about 10 nm, the Al layer is formed so that the film thickness is about 200 nm to form the cathode 5. Further, as shown in FIG. 4 (i), a SiON layer was formed to cover the cathode 5 and to have a film thickness of about 400 nm, thereby forming a sealing layer 13.

According to such a method of manufacturing the organic EL element 10, as shown in FIG. 6, the light emitting layer 4 laminated so as to trace the surface of the hole injecting and transporting layer 3 can be formed. It is almost constant. That is, the organic EL element 10 including the light emitting layer 4 having a substantially constant film thickness can be manufactured with high yield regardless of the irregularities in the cross-sectional shape of the hole injecting and transporting layer 3. Further, when the organic EL element 10 is driven, a light emission profile having a substantially flat luminance in the film formation region A is obtained.
That is, it is possible to manufacture the light emitting device 30 in which the luminance variation among the plurality of organic EL elements 10 is suppressed and stable light emission characteristics can be obtained.
The luminance (Cd / m ² ) on the vertical axis in the graph showing the light emission profile is obtained by replacing the maximum luminance with “1”.

(Comparative example)
Next, a comparative example will be described. The manufacturing method of the organic EL element of the comparative example is the same as that of the above embodiment up to step S3 in FIG. 2, and the second liquid material containing no crosslinking agent is formed as droplets on the hole injection transport layer 3. Discharge. And it heated at 130 degreeC under nitrogen atmosphere, and was dried for about 1 hour, and the light emitting layer 4 with a film thickness of 80-100 nm was formed.

  As shown in FIG. 7, the cross-sectional shape of the light emitting layer 4 of the comparative example formed on the hole injecting and transporting layer 3 is thin at the central portion of the film forming region A, and the film thickness toward the partition wall portion 12. Is getting thicker. The light emission profile of the light emitting layer 4 has a mountain shape in which the luminance is maximum near the center of the film formation region A. In the organic EL element of the comparative example, luminance unevenness occurs in the film formation region A, that is, the light emitting region, and stable luminance characteristics cannot be obtained even between a plurality of organic EL elements. In addition, since the current flows intensively in the vicinity of the center of the light emitting region, the light emission life is likely to be shortened.

  Compared with such an organic EL element of the comparative example, it can be seen how flat the light emission profile in the organic EL element 10 of the above-described embodiment. In other words, it can be seen how the light emitting layer 4 is formed with a constant film thickness.

  Next, an optical writing head to which the light emitting device as the electro-optical device according to the present embodiment is applied, and an image forming apparatus as an electronic apparatus including the optical writing head will be described. FIG. 8 is a schematic perspective view showing the configuration of the optical writing head, and FIG. 9 is a schematic cross-sectional view showing the configuration of the image forming apparatus.

<Optical writing head>
As shown in FIG. 8, the optical writing head 80 as the electro-optical device of the present embodiment includes the light-emitting device 30 of the above-described embodiment, the support 31 that supports the light-emitting device 30, and the imaging lens unit 32. ing. The X direction in the figure is an arrangement direction in which a plurality of organic EL elements 10 are arranged in a staggered pattern on the element substrate 1, and the Y direction is a direction orthogonal to the X direction. The optical writing head 80 is disposed with respect to the outer peripheral surface of the photosensitive drum 41 so that the major axis thereof coincides with the X direction and along the generatrix of the photosensitive drum 41. The support 31 has an opening on the photosensitive drum 41 side, and supports and fixes the light emitting device 30 so as to emit light toward the photosensitive drum 41.

  The imaging lens unit 32 includes a lens group (not shown) such as a SELFOC (registered trademark) lens array inside, and is attached to the support 31 so as to be positioned between the light emitting device 30 and the photosensitive drum 41. The support is fixed. The imaging lens unit 32 condenses the light emitted from the organic EL element 10 in the light emitting device 30 on one end side, emits it from the other end side, and irradiates the outer peripheral surface of the photosensitive drum 41 to form an electrostatic latent image. To do.

<Image forming apparatus>
As shown in FIG. 9, an image forming apparatus 100 as an electronic apparatus according to the present embodiment has four photosensitive drums (image carriers) corresponding to the optical writing heads 80 (K, C, M, Y) as exposure apparatuses. Body) 41K, 41C, 41M, and 41Y are each configured as a tandem system.

  The image forming apparatus 100 includes a driving roller 91, a driven roller 92, and a tension roller 93, and the intermediate transfer belt 90 is stretched around these rollers so as to circulate in the direction indicated by the arrow (counterclockwise) in FIG. 9. Is. Photosensitive drums 41K, 41C, 41M, and 41Y are arranged at predetermined intervals with respect to the intermediate transfer belt 90. These photoreceptor drums 41K, 41C, 41M, and 41Y have a photosensitive layer as an image carrier on the outer peripheral surface thereof.

Here, K, C, M, and Y in the above symbols mean black, cyan, magenta, and yellow, respectively, and indicate that the photoconductors are for black, cyan, magenta, and yellow, respectively.
The meanings of these symbols (K, C, M, Y) are the same for the other members. The photosensitive drums 41K, 41C, 41M, and 41Y are driven to rotate in the arrow direction (clockwise direction) in FIG. 9 in synchronization with the driving of the intermediate transfer belt 90.

  Around each photosensitive drum 41 (K, C, M, Y), charging means (corona charger) 42 for uniformly charging the outer peripheral surface of the photosensitive drum 41 (K, C, M, Y), respectively. (K, C, M, Y) and rotation of the photosensitive drum 41 (K, C, M, Y) on the outer peripheral surface uniformly charged by the charging means 42 (K, C, M, Y) And an optical writing head 80 (K, C, M, Y) that sequentially scans the line in synchronization with each other.

  Further, a developing device 44 (K, C, and C) that forms a visible image (toner image) by adding toner as a developer to the electrostatic latent image formed by the optical writing head 80 (K, C, M, Y). M, Y) and a primary transfer roller 45 (K, C) as transfer means for sequentially transferring the toner image developed by the developing device 44 (K, C, M, Y) to the intermediate transfer belt 90 as a primary transfer target. , M, Y). In addition, a cleaning device 46 (K, C, M, Y) is provided as a cleaning unit for removing toner remaining on the surface of the photosensitive drum 41 (K, C, M, Y) after being transferred. Yes.

  Each optical writing head 80 (K, C, M, Y) is arranged so that the arrangement direction (X direction) of the organic EL elements 10 is parallel to the rotation axis of the photosensitive drum 41 (K, C, M, Y). is set up. Then, the emission energy peak wavelength of each optical writing head 80 (K, C, M, Y) and the sensitivity peak wavelength of the photosensitive drum 41 (K, C, M, Y) are set so as to substantially match. Yes.

  The developing device 44 (K, C, M, Y) uses, for example, nonmagnetic one-component toner as a developer. Then, the one-component developer is conveyed to the developing roller by, for example, a supply roller, the film thickness of the developer adhered to the surface of the developing roller is regulated by a regulating blade, and the developing roller is moved to the photosensitive drum 41 (K, C, M , Y) is brought into contact with or pressed against the photosensitive drum 41 (K, C, M, Y) to cause the developer to adhere and develop as a toner image.

  The black, cyan, magenta, and yellow toner images formed by the four-color single-color toner image forming station are intermediated by the primary transfer bias applied to the primary transfer roller 45 (K, C, M, Y). Primary transfer is sequentially performed on the transfer belt 90. The toner images that are sequentially superimposed on the intermediate transfer belt 90 to become a full color are secondarily transferred to the recording medium P such as paper by the secondary transfer roller 66 and further pass through the fixing roller pair 61 that is a fixing unit. Is fixed on the recording medium P. Thereafter, the paper is discharged onto a paper discharge tray 68 formed in the upper part of the apparatus by the paper discharge roller pair 62.

  In FIG. 9, reference numeral 63 is a paper feed cassette in which a large number of recording media P are stacked and held, reference numeral 64 is a pickup roller for feeding the recording media P from the paper feed cassette 63 one by one, and reference numeral 65 is two. A gate roller pair 67, which regulates the supply timing of the recording medium P to the secondary transfer portion of the next transfer roller 66, is a cleaning means for removing toner remaining on the surface of the intermediate transfer belt 90 after the secondary transfer. It is a cleaning blade.

  As described above, the image forming apparatus 100 includes the optical writing head 80 having the light emitting device 30 shown in FIG. 8 as an exposure apparatus. Therefore, since the light emission characteristics (such as luminance characteristics) of the organic EL element 10 arranged at a density of 1200 dpi are stable, a high-definition and clear image can be obtained after exposure. In addition, since the light emitting device 30 has a longer light emission life than conventional ones, maintenance such as replacement work accompanying the life of the optical writing head 80 is reduced. The image forming apparatus 100 including the optical writing head 80 is not limited to the above-described embodiment, and various modifications can be made.

(Second Embodiment)
Next, another embodiment of the electro-optical device to which the present invention is applied will be described using a display device as an example. FIG. 10 is a schematic front view showing the display device, and FIG. 11 is a schematic cross-sectional view showing the main structure of the display device.

  As shown in FIGS. 10 and 11, the display device 200 of this embodiment includes an element substrate 201 provided with an organic EL element 212 (see FIG. 11) corresponding to each pixel 207, and a plurality of organic EL elements. And a sealing substrate 202 for sealing the element substrate 201 through a sealing layer 235 (see FIG. 11) for sealing 212.

  The element substrate 201 includes a circuit unit 211 (see FIG. 11) including a driving element that drives the organic EL element 212. In the display area 206, the display pixels 207 that can obtain the same emission color among red (R), green (G), and blue (B) are arranged in a so-called stripe system. . Note that the pixel 207 is actually very fine and is enlarged for the sake of illustration.

  The element substrate 201 is slightly larger than the sealing substrate 202, and two scanning line driving circuits for driving a TFT (Thin Film Transistor) element 208 (see FIG. 11) as a driving element are provided in a frame-like protruding portion. A unit 203 and one data line driver circuit unit 204 are provided. A flexible relay substrate 205 for connecting the drive circuit portions 203 and 204 and the external drive circuit is mounted on the terminal portion 201 a of the element substrate 201.

  As shown in FIG. 11, in the display device 200, the organic EL element 212 includes an anode 231, a partition wall 233 that partitions the anode 231, and a functional layer including a light-emitting layer made of an organic film stacked on the anode 231. 232. Further, the cathode 234 is formed so as to face the anode 231 with the functional layer 232 interposed therebetween.

  The partition wall 233 is made of a photosensitive resin having an insulating property such as phenol or polyimide, and is provided so as to partially cover the periphery of the anode 231 constituting the pixel 207 and partition the plurality of anodes 231.

  The anode 231 is connected to one of the three terminals of the TFT element 208 formed on the element substrate 201. For example, ITO (Indium Tin Oxide), which is a transparent electrode material, is formed to a thickness of about 100 nm. Electrode. Although not shown, a reflective layer made of Al is provided below the anode 231 (on the planarization layer 228 side) via an insulating layer. The reflective layer reflects light emitted from the functional layer 232 to the sealing substrate 202 side. Moreover, the said reflective layer is not limited to Al, What is necessary is just to have the function (reflection surface) which reflects light emission. For example, a method of forming a reflective surface having irregularities using an insulating organic material or an inorganic material, a method of forming the anode 231 itself with a conductive material having a reflective function, and forming an ITO film on the surface layer, etc. .

  Similarly, the cathode 234 is formed of a transparent electrode material such as ITO.

  As the sealing substrate 202, a substrate made of transparent glass or the like is used. On the side facing the organic EL element 212, red (R), green (G), blue (B), three-color filter elements 236R, 236G, and 236B corresponding to the arrangement of the pixels 207 and a light-shielding portion that partitions the filter elements 236R, 236G, and 236B 237 is provided.

  The display device 200 has a so-called top emission type structure, and a drive current is passed between the anode 231 and the cathode 234 so that light emitted from the functional layer 232 is reflected by the reflection layer, and the filter elements 236R, 236G, It is configured to be taken out from the sealing substrate 202 side through 236B. Since the element substrate 201 has a top emission type structure, both a transparent substrate and an opaque substrate can be used. Examples of the opaque substrate include a thermosetting resin and a thermoplastic resin in addition to a ceramic sheet such as alumina and a metal sheet such as stainless steel that has been subjected to an insulation treatment such as surface oxidation.

The element substrate 201 is provided with a circuit unit 211 that drives the organic EL element 212. That is, a base protective layer 221 mainly composed of SiO ₂ is formed on the surface of the element substrate 201 as a base, and a silicon layer 222 is formed thereon. A gate insulating layer 223 mainly composed of SiO ₂ and / or SiN is formed on the surface of the silicon layer 222.

In the silicon layer 222, a region overlapping with the gate electrode 226 with the gate insulating layer 223 interposed therebetween is a channel region 222a. Note that the gate electrode 226 is a part of a scanning line (not shown). On the other hand, a first interlayer insulating layer 227 mainly composed of SiO ₂ is formed on the surface of the gate insulating layer 223 that covers the silicon layer 222 and on which the gate electrode 226 is formed.

  In the silicon layer 222, a low concentration source region and a high concentration source region 222c are provided on the source side of the channel region 222a, while a low concentration drain region and a high concentration drain region 222b are provided on the drain side of the channel region 222a. Is provided to form a so-called LDD (Light Doped Drain) structure. Among these, the high-concentration source region 222c is connected to the source electrode 225 through a contact hole 225a that opens between the gate insulating layer 223 and the first interlayer insulating layer 227. The source electrode 225 is configured as a part of a power supply line (not shown). On the other hand, the high-concentration drain region 222b is connected to the drain electrode 224 formed of the same layer as the source electrode 225 through a contact hole 224a that opens through the gate insulating layer 223 and the first interlayer insulating layer 227.

  On the first interlayer insulating layer 227 on which the source electrode 225 and the drain electrode 224 are formed, for example, a planarizing layer 228 mainly composed of an acrylic resin component is formed. The planarizing layer 228 is formed of a heat-resistant insulating resin such as acrylic or polyimide, and is formed to eliminate surface irregularities due to the TFT element 208, the source electrode 225, the drain electrode 224, and the like. Are known.

  An anode 231 is formed on the surface of the planarization layer 228 and connected to the drain electrode 224 via a contact hole 228a provided in the planarization layer 228. That is, the anode 231 is connected to the high concentration drain region 222 b of the silicon layer 222 via the drain electrode 224. The cathode 234 is connected to GND. Accordingly, the TFT element 208 as a switching element controls the drive current supplied from the power supply line to the anode 231 and flowing between the cathode 234. The organic EL element 212 emits light with a luminance corresponding to the amount of current flowing through the functional layer 232 between the anode 231 and the cathode 234. This enables color display.

  The organic EL element 212 provided to face the filter element 236R has a functional layer 232R that can emit red light. In addition, the organic EL element 212 provided to face the filter element 236G has a functional layer 232G from which green light emission can be obtained. Similarly, the organic EL element 212 provided to face the filter element 236B has a functional layer 232B from which blue light emission can be obtained.

  Each of the functional layers 232R, 232G, and 232B is formed by laminating a hole injecting and transporting layer mainly composed of PEDOT / PSS and a light emitting layer formed in accordance with the emission color. The light-emitting layer is formed by heat-treating a light-emitting layer precursor containing a cross-linking agent to remove a non-crosslinked portion soluble in a solvent, and is composed of a cross-linked portion insoluble in a solvent. Have a thickness.

  The element substrate 201 having the organic EL element 212 is solid-sealed with a transparent sealing substrate 202 with no gap through a sealing layer 235 using a transparent thermosetting epoxy resin or the like as a sealing member.

  The display device 200 is not limited to the top emission type, and the cathode 234 is formed using a conductive material such as opaque Al having a reflection function, and light emitted from the organic EL element 212 is reflected by the cathode 234. A bottom emission type structure that is taken out from the element substrate 201 side may be employed.

In the method of manufacturing the organic EL element 212, the functional layers 232R, 232G, and 232B are formed using a droplet discharge method (inkjet method).
First, a first liquid material containing a hole injecting and transporting layer forming material is discharged as droplets from a nozzle of an ink jet head into a film forming region including an anode 231 partitioned by a partition wall portion 233. Then, the discharged first liquid material is dried to form a hole injecting and transporting layer on the anode 231.

  Subsequently, the second liquid material containing the light emitting layer forming material and the crosslinking agent in the film forming region is ejected as droplets from the nozzles of the inkjet head. And the light emitting layer precursor is formed on a positive hole injection transport layer by drying the discharged 2nd liquid. The formed light emitting layer precursor is heat-treated in a nitrogen atmosphere to crosslink the light emitting layer precursor in the vicinity of the hole injecting and transporting layer. The light-emitting layer precursor that is not cross-linked is removed by dissolving in a solvent, and the light-emitting layer precursor that has become insoluble in the solvent is left to form a light-emitting layer. As the manufacturing conditions in these manufacturing steps, the manufacturing method of the organic EL element 10 in the first embodiment can be applied.

  In the present embodiment, since the organic EL element 212 capable of obtaining red (R), green (G), and blue (B) emission colors is formed, three types of second liquid materials are prepared corresponding to the emission colors. . As the second liquid material containing the red light emitting layer forming material and the crosslinking agent, the second liquid material 4L of the first embodiment can be used.

Examples of the green light emitting material include Poly [(9,9-dioctylfluorenyl-2,7-diyl) -co- (1,4-benzo- {2,1 ′, 3} -thiadiazole)].
Examples of the blue light emitting material include Poly [(9,9-dihexylfluorenyl-2,7-diyl) -co- (9,10-anthrecene)].
Using the second liquid material containing these light emitting materials and TFB as a crosslinking agent, a light emitting layer capable of obtaining different light emission colors is separately formed by a droplet discharge method.

  The above manufacturing process may be repeated for each luminescent color to sequentially form a luminescent layer, or after forming a luminescent layer precursor for each luminescent color, the luminescent layer precursors of each color are collectively exposed to a solvent to form a solvent. The light emitting layer of each color may be formed by removing the soluble part and leaving the part that is crosslinked and insoluble in the solvent. As a method for removing the light emitting layer precursor soluble in the solvent, it is desirable to apply the solvent by using the spin coating method as in the first embodiment. Since the light emitting layer precursor soluble in the solvent can be removed in a short time, it is possible to suppress the light emitting layer precursor having a different light emission color from remaining as a residue.

  The organic EL element 212 formed in this way has a light emitting layer having a substantially constant film thickness for each emission color. Therefore, stable emission characteristics (luminance characteristics) can be obtained for each emission color. In the display device 200, light emitted from the organic EL element 212 is transmitted through filter elements 236R, 236G, and 236B provided for each light emission color. Therefore, light emission having a desired peak wavelength for each color can be obtained in a state where luminance unevenness is small, and thus a color display with good appearance can be achieved.

  Examples of electronic devices on which the display device 200 is mounted include portable information terminals such as portable telephones, monitors such as personal computers, digital cameras, video cameras, and navigators, and thin televisions.

  Various modifications other than the above embodiment are conceivable. Hereinafter, a modification will be described.

  (Modification 1) In the manufacturing method of the organic EL element 10, the configuration of the second liquid body 4L is not limited to this. For example, a material obtained by previously introducing a crosslinking agent such as TFB into the light-emitting material may be used as a solute dissolved in a solvent. Specifically, TFB as a cross-linking agent is bonded in advance to the main chain or side chain of the luminescent material. According to this, compared to the case where the second liquid 4L is configured by mixing the light emitting material, the crosslinking agent, and the solvent, the influence of the variation in the blending amount is eliminated, and the ratio of the crosslinking agent to the light emitting material is made constant. The light emitting layer precursor can be stably crosslinked at a certain ratio.

  (Modification 2) In the organic EL element 10, the configuration of the functional layer is not limited to this. For example, if the structure contains S (sulfur) or an organic acid that can promote crosslinking of the light emitting layer precursor, the hole injection transport layer 3 may be divided into a hole injection layer and a hole transport layer and laminated. Good. By further improving the transportability of holes to the light emitting layer 4, it is possible to obtain the organic EL element 10 that can obtain high light emission luminance.

  (Modification 3) In the display device 200, the organic EL element 212 is not limited to the configuration having the functional layers 232R, 232G, and 232B that can emit red (R), green (G), and blue (B) light. For example, a functional layer 232 that can emit white light may be used. Since it is not necessary to paint each luminescent color separately, the manufacturing process can be further simplified.

  (Modification 4) The electro-optical device including the organic EL element 10 is not limited to the optical writing head 80. For example, the illuminating device provided with the organic EL element 10 as a light source is mentioned.

  DESCRIPTION OF SYMBOLS 2 ... Anode, 3 ... Hole injection transport layer, 3L ... 1st liquid body, 4 ... Light emitting layer, 4a ... Light emitting layer precursor, 4L ... 2nd liquid body, 5 ... Cathode, 10 ... Organic EL element, 12 ... Partition unit, 30... Light emitting device, 80... Optical writing head as electro-optical device, 100... Image forming device, 200... Display device as electro-optical device, 212 ... Organic EL element, 231 ... Anode, 232, 232 R, 232 G , 232B ... functional layer, 233 ... partition wall part, 234 ... cathode, A ... film formation region.

Claims (9)

A method for producing an organic EL device in which a functional layer including a light emitting layer is provided between an anode and a cathode,
A first step of forming a partition wall partitioning a film forming region including the anode;
Applying a first liquid containing a hole injecting and transporting layer forming material to the film forming region and drying to form a hole injecting and transporting layer on the anode;
A third step of forming a light emitting layer precursor on the hole injecting and transporting layer by applying and drying a second liquid containing a light emitting layer forming material and a crosslinking agent on the film forming region;
A fourth step of heat-treating the light emitting layer precursor in an inert gas atmosphere;
The light emitting layer precursor subjected to heat treatment is exposed to a solvent to remove a soluble portion of the light emitting layer precursor, and a light emitting layer that is a part of the light emitting layer precursor and is insoluble in the solvent is formed. And a fifth step to
And a sixth step of forming the cathode on the light-emitting layer.   2. The method of manufacturing an organic EL element according to claim 1, wherein the light emitting layer forming material into which the crosslinking agent has been introduced is used in the third step.   3. The method of manufacturing an organic EL element according to claim 1, wherein the third step uses the cross-linking agent having a hole transporting property.   4. The method of manufacturing an organic EL element according to claim 1, wherein in the third step, the second liquid material is applied to the film formation region using a droplet discharge method. 5. .   In the fifth step, the solvent is applied to the substrate having the light emitting layer precursor subjected to heat treatment, and the substrate coated with the solvent is rotated around an axis perpendicular to the substrate surface. The method for producing an organic EL device according to any one of claims 1 to 4, wherein the light emitting layer precursor soluble in the solvent is removed. The anode,
A hole injecting and transporting layer provided on the anode;
Provided on the hole injecting and transporting layer, a part of the light emitting layer precursor was cross-linked and insolubilized in a solvent, and a part soluble in the solvent was removed from the light emitting layer precursor. A light emitting layer;
An organic EL device comprising: a cathode provided on the light emitting layer.   The organic EL device according to claim 6, wherein the light emitting layer contains a crosslinking agent having a hole transporting property.   An electric EL device comprising the organic EL device manufactured using the method for manufacturing an organic EL device according to any one of claims 1 to 5, or the organic EL device according to claim 6 or 7. Optical device.   An electronic apparatus comprising the electro-optical device according to claim 8.

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