JP2015191792A - Ink for forming functional layer, method of manufacturing light-emitting element, light-emitting device and electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a functional layer formation ink capable of forming a functional layer of high flatness and a method of manufacturing a light-emitting element, and to provide a light-emitting device having the light-emitting element manufactured by such a manufacturing method and an electronic apparatus.SOLUTION: A functional layer formation ink contains a solute composed of the constituent material of a functional layer or its precursor, a first solvent dissolving the solute, and having a first boiling point and first solubility parameters, and a second solvent dissolving the solute, and having a second boiling point lower than the first boiling point and second solubility parameters smaller than the first solubility parameters. The first boiling point is 250°C or more, the second boiling point is 170°C or more, the difference between the first boiling point and second boiling point is 40°C or more, and the second solubility parameters are 9.0 (cal/cm)or less.

Description

  The present invention relates to an ink for forming a functional layer, a method for manufacturing a light emitting element, a light emitting device, and an electronic apparatus.

  An organic electroluminescence element (so-called organic EL element) is a light emitting element having a structure in which at least one light emitting organic layer (light emitting layer) is interposed between an anode and a cathode. In such a light emitting device, by applying an electric field between the cathode and the anode, electrons are injected into the light emitting layer from the cathode side and holes are injected from the anode side, and electrons and holes are injected into the light emitting layer. Recombination generates excitons, and when the excitons return to the ground state, the energy is emitted as light.

  As a method for manufacturing such an organic EL element, a method of forming a light emitting layer using a liquid phase process such as an inkjet method is known (for example, see Patent Document 1). In the ink used for forming such a liquid phase process, for example, as disclosed in Patent Document 1, a mixed solvent of a good solvent and a poor solvent is used as a solvent for the purpose of improving the wettability of the coated surface. Is generally done.

  However, the conventional ink has a problem that when a poor solvent is added to the solvent, the behavior during drying becomes unstable, and it is difficult to ensure the flatness of the resulting film.

Special table 2008-503870

  An object of the present invention is to provide a functional layer forming ink capable of forming a functional layer with high flatness and a method for manufacturing a light emitting element, and a light emitting device including a light emitting element manufactured by the manufacturing method and To provide electronic equipment.

  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.

[Application Example 1]
The functional layer forming ink of the present invention includes a solute composed of a constituent material of the functional layer or a precursor thereof,
A first solvent that dissolves the solute and has a first boiling point and a first solubility parameter;
A second solvent that dissolves the solute and has a second boiling point lower than the first boiling point and a second solubility parameter smaller than the first solubility parameter;
The first boiling point is 250 ° C. or higher,
The second boiling point is 170 ° C. or higher,
The difference between the first boiling point and the second boiling point is 40 ° C. or more,
The second solubility parameter is 9.0 (cal / cm ³ ) ^1/2 or less.

  According to such a functional layer forming ink, since the first solvent that is a good solvent and the second solvent that is a poor solvent for the solute are included, the solubility to the solute is ensured, and the base material When applied on top, it can be easily spread on the substrate. In addition, the boiling point of the second solvent is lower than that of the first solvent, the solubility of the second solvent in the solute is lower than that of the first solvent, and the boiling point and solubility parameters of the one solvent and the second solvent are optimized. Therefore, when applied on the substrate, the second solvent is quickly removed before the first solvent, effectively causing pinning on the substrate and stabilizing the behavior of the ink during drying. Can be achieved. As a result, a functional layer with high flatness can be formed.

[Application Example 2]
In the functional layer forming ink of the present invention, the content of the first solvent in the total solvent is 50 wt% or more and 90 wt% or less,
The content of the second solvent in all the solvents is preferably 10 wt% or more and 50 wt% or less.

  Thereby, the pinning effect produced when the 2nd solvent is removed can be heightened, ensuring the solubility with respect to a solute.

[Application Example 3]
In the functional layer forming ink of the present invention, the second solvent is preferably an aliphatic diether or a derivative thereof.

Thereby, while making a 2nd boiling point into 170 degreeC or more, a 2nd solubility parameter can be made into 9.0 (cal / cm < ³ >) < ^1/2 > or less. In addition, aliphatic diethers or derivatives thereof have a relatively high melting point and are easy to spread on a substrate made of an inorganic material. In addition, aliphatic diethers or derivatives thereof have low aggressiveness against adhesives such as epoxy resins used in the joints of inkjet heads.

[Application Example 4]
In the functional layer forming ink of the present invention, the second solvent is preferably diethylene glycol or dipropylene glycol diether or monoether acetate.

Thereby, while making a 2nd boiling point into 170 degreeC or more, a 2nd solubility parameter can be made into 9.0 (cal / cm < ³ >) < ^1/2 > or less. In addition, aliphatic diethers or derivatives thereof have a relatively high melting point and are easy to spread on a substrate made of an inorganic material. In addition, aliphatic diethers or derivatives thereof have low aggressiveness against adhesives such as epoxy resins used in the joints of inkjet heads. These diethers and monoether acetates are easily available.

[Application Example 5]
In the functional layer forming ink of the present invention, the viscosity of the first solvent is preferably higher than the viscosity of the second solvent.
Thereby, the pinning effect produced when the 2nd solvent is removed can be heightened.

[Application Example 6]
In the functional layer forming ink of the present invention, the surface tension of the second solvent is preferably 30 mN / s or less.
Thereby, when applied on the substrate, the ink can be easily spread.

[Application Example 7]
In the functional layer forming ink of the present invention, the functional layer is preferably an organic layer included in the organic electroluminescence element.

  The flatness of the organic layer included in the organic electroluminescent element greatly affects the light emission distribution. On the other hand, when such an organic layer is formed by a liquid phase process, generally, ink is applied to the partitioned bank. However, since the wall surface of the bank exhibits liquid repellency, the behavior of the ink applied to the bank. Tends to be unstable. Therefore, it is extremely useful to apply the present invention to an ink for forming such an organic layer.

[Application Example 8]
In the functional layer forming ink of the present invention, the organic layer is preferably a hole injection layer or a hole transport layer.

  The hole injection layer or the hole transport layer is generally formed on an anode made of an inorganic material such as ITO. However, when the hole transport layer or the hole injection layer is formed by a liquid phase process, Since the wettability of the anode is relatively low, the ink behavior tends to become unstable. Therefore, it is extremely useful to apply the present invention to an ink for forming a hole transport layer or a hole injection layer.

[Application Example 9]
The method for producing a light emitting device of the present invention comprises a step of applying the functional layer forming ink of the present invention on a substrate,
And removing the first solvent and the second solvent to form a layer made of the constituent material of the functional layer or a precursor thereof.

  According to such a method for manufacturing a light-emitting element, a light-emitting element having an organic layer with high flatness can be obtained. Therefore, the obtained light-emitting element has a uniform light emission distribution over a wide range and has excellent characteristics.

[Application Example 10]
The light-emitting device of the present invention includes a light-emitting element manufactured using the method for manufacturing a light-emitting element of the present invention.
Thereby, a light-emitting device including a light-emitting element having excellent characteristics can be provided.

[Application Example 11]
An electronic apparatus according to the present invention includes a light emitting element manufactured using the method for manufacturing a light emitting element according to the present invention.
Accordingly, an electronic device including a light emitting element having excellent characteristics can be provided.

It is a figure for demonstrating the effect | action at the time of film-forming of the ink for functional layer formation of this invention. It is sectional drawing which shows the light-emitting device (display apparatus) which concerns on embodiment of this invention. (A) is a top view of the bank with which the light-emitting device shown in FIG. 2 is provided, (b) is sectional drawing of the light emitting element with which the light-emitting device shown in FIG. 2 is provided. It is a figure for demonstrating the manufacturing method of the light emitting element shown in FIG.3 (b). It is a figure for demonstrating the manufacturing method of the light emitting element shown in FIG.3 (b). It is a figure for demonstrating the manufacturing method of the light emitting element shown in FIG.3 (b). It is a figure for demonstrating the manufacturing method of the light emitting element shown in FIG.3 (b). 1 is a perspective view illustrating a configuration of a mobile (or notebook) personal computer that is an example of an electronic apparatus of the present invention. It is a perspective view which shows the structure of the mobile telephone (PHS is also included) which is an example of the electronic device of this invention. 1 is a perspective view illustrating a configuration of a digital still camera that is an example of an electronic apparatus of the present invention.

  Hereinafter, the functional layer forming ink, the light emitting element manufacturing method, the light emitting device, and the electronic apparatus of the present invention will be described based on preferred embodiments shown in the drawings. In each drawing, the scale of each part is appropriately changed for convenience of explanation, and the illustrated configuration does not necessarily match the actual scale.

(Functional layer forming ink)
The functional layer forming ink of the present invention (hereinafter, also simply referred to as “ink”) includes a solute composed of a constituent material of the functional layer or a precursor thereof, and a solvent that dissolves the solute. In particular, the functional layer forming ink has a first solvent having a first boiling point and a first solubility parameter as a solvent, and a second solvent having a second boiling point lower than the first boiling point and smaller than the first solubility parameter. A second solvent having two solubility parameters. The first boiling point is 250 ° C. or higher, the second boiling point is 170 ° C. or higher, the difference between the first boiling point and the second boiling point is 40 ° C. or higher, and the second solubility parameter is 9. 0 (cal / cm ³ ) ^1/2 or less.

  According to such a functional layer forming ink, since the first solvent that is a good solvent and the second solvent that is a poor solvent for the solute are included, the solubility to the solute is ensured, and the base material When applied on top, it can be easily spread on the substrate. In addition, the boiling point of the second solvent is lower than that of the first solvent, the solubility of the second solvent in the solute is lower than that of the first solvent, and the boiling point and solubility parameters of the one solvent and the second solvent are optimized. Therefore, when applied on the substrate, the second solvent is quickly removed before the first solvent, effectively causing pinning on the substrate and stabilizing the behavior of the ink during drying. Can be achieved. As a result, a functional layer with high flatness can be formed.

Hereinafter, each component of the functional layer forming ink of the present invention will be described in detail.
(Solute)
The solute contained in the functional layer forming ink of the present invention comprises a constituent material of the functional layer or a precursor thereof.

  Such a solute is determined according to the type of the functional layer to be formed, and is not particularly limited, and various organic materials can be used. Examples of the solute include a constituent material of an organic layer of an organic electroluminescence (organic EL) element or a precursor thereof, a constituent material of a colored layer of a color filter, or a precursor thereof.

  The flatness of the organic layer (hole injection layer, hole transport layer, light emitting layer, intermediate layer, etc.) included in the organic electroluminescence element greatly affects the light emission distribution. On the other hand, when such an organic layer is formed by a liquid phase process, generally, ink is applied to the partitioned bank. However, since the wall surface of the bank exhibits liquid repellency, the behavior of the ink applied to the bank. Tends to be unstable. In particular, the hole injection layer or the hole transport layer is generally formed on an anode composed of an inorganic material such as ITO, but when the hole transport layer or the hole injection layer is formed by a liquid phase process, Since the anode wettability with respect to ink is relatively low, the ink behavior tends to become unstable. Therefore, it is extremely useful to apply the present invention to an ink for forming such an organic layer. In addition, the specific material and formation method of this organic layer are explained in full detail later.

  In the functional layer forming ink, the solute is dissolved in the solvent described later, but a part of the solute may be dispersed in the solvent.

  The content of the solute in the functional layer forming ink is determined according to the use of the functional layer forming ink, and is not particularly limited, but is preferably 0.01 to 10 wt%, for example. It is more preferable that it is 05-5 wt%. When the content of the solute is a value within the above range, the discharge property (discharge stability) from the droplet discharge head (inkjet head) for film formation can be made particularly excellent.

(solvent)
The solvent contained in the functional layer forming ink of the present invention contains a first solvent and a second solvent having different boiling points and solubility parameters, and dissolves the solute described above. Most of this solvent is removed in the film forming process described later.

Hereinafter, the first solvent and the second solvent will be described in detail.
[First solvent]
The first solvent dissolves the solute described above and has a first boiling point and a first solubility parameter.

  Here, the first boiling point (boiling point at normal temperature and normal pressure) is 250 ° C. or higher. Thereby, when the ink is applied on the base material, the first solvent can be prevented from volatilizing rapidly, and the ink can be spread in a desired region. From such a viewpoint, the first boiling point is preferably 270 ° C. or higher and 350 ° C. or lower, and more preferably 290 ° C. or higher and 330 ° C. or lower. On the other hand, if the first boiling point is too low, depending on the type and content of the solute and the second solvent, when the ink is applied on the base material, the first solvent volatilizes abruptly. Shows a tendency to become difficult to spread. On the other hand, if the first boiling point is too high, the first solvent tends to remain in the resulting functional layer, or a high temperature is required when removing the first solvent, and the type of the first solvent or solute Depending on the above, the characteristics of the functional layer may be deteriorated.

  In addition, the melting point of the first solvent is preferably normal temperature or lower than normal temperature. Thereby, an ink can be provided on a base material under normal temperature and normal pressure.

  Also, the first solubility parameter is larger than the second solubility parameter. Thereby, while making a 1st solvent into a good solvent with respect to a solute, the difference with a 1st solvent degree parameter 2nd solubility parameter can be enlarged, and it can make it easy to remove a 2nd solvent.

  Specific examples of such a first solvent are determined according to the type and amount of the solute and are not particularly limited as long as they have the characteristics described above. For example, dibutyl ether (DBE) ), 2-isopropylnaphthalene, and the like. Among these, one kind can be used alone or two or more kinds can be used in combination.

  In addition, the content of the first solvent in all the solvents is preferably 50 wt% or more and 90 wt% or less, more preferably 60 wt% or more and 90 wt% or less, and further preferably 60 wt% or more and 80 wt% or less. preferable. Thereby, the pinning effect produced when the 2nd solvent is removed can be heightened, ensuring the solubility with respect to a solute.

[Second solvent]
The second solvent dissolves the solute, has a second boiling point lower than the first boiling point, and has a second solubility parameter that is smaller than the first solubility parameter.

Here, the second boiling point is 170 ° C. or higher, and the difference from the first boiling point is 40 ° C. or higher. The second solubility parameter is 9.0 (cal / cm ³ ) ^1/2 or less. As a result, when the ink is applied onto the substrate, the second solvent is easily removed before the first solvent, and the pinning is effectively generated on the substrate. Thus, it is possible to stabilize the behavior of the ink during drying. From such a viewpoint, the second boiling point is preferably 200 ° C. or higher and 300 ° C. or lower, and more preferably 240 ° C. or higher and 270 ° C. or lower. On the other hand, if the second boiling point is too small, the nozzles of the inkjet head are likely to be clogged depending on the configuration of the inkjet head when the film is formed using the inkjet. On the other hand, if the second boiling point is too large, the difference from the first boiling point becomes small, the second solvent becomes difficult to volatilize, and the above-described pinning effect tends to decrease.

  In addition, the melting point of the second solvent is preferably normal temperature or lower at normal pressure. Thereby, an ink can be provided on a base material under normal temperature and normal pressure.

The second solubility parameter may be smaller than the first solubility parameter and not more than 9.0 (cal / cm ³ ) ^1/2 . Thereby, while making a 2nd solvent into a poor solvent with respect to a solute, the difference with a 1st solvent degree parameter 2nd solubility parameter can be enlarged, and it can make it easy to remove a 2nd solvent.

  The viscosity of the second solvent is preferably lower than the viscosity of the first solvent. Thereby, the viscosity of the 1st solvent becomes higher than the viscosity of the 2nd solvent, and the pinning effect produced when the 2nd solvent is removed can be heightened.

  The surface tension of the second solvent is preferably 30 mN / s or less. Thereby, when applied on the substrate, the ink can be easily spread.

Such a second solvent is determined according to the type and amount of the solute, and is not particularly limited as long as it has the second boiling point and the second solubility parameter as described above. A derivative thereof is preferred, and among them, diethylene glycol or dipropylene glycol diether or monoether acetate is preferred. Thereby, while making a 2nd boiling point into 170 degreeC or more, a 2nd solubility parameter can be made into 9.0 (cal / cm < ³ >) < ^1/2 > or less. In addition, aliphatic diethers or derivatives thereof have a relatively high melting point and are easy to spread on a substrate made of an inorganic material. In addition, aliphatic diethers or derivatives thereof have low aggressiveness against adhesives such as epoxy resins used in the joints of inkjet heads. These diethers and monoether acetates are easily available.

  Specific examples of such diethers and monoether acetates include, for example, BDB (diethylene glycol dibutyl ether), BCA (diethylene glycol monobutyl ether acetate), BDPOM, DPMA (dipropylene glycol monomethyl ether acetate), BDM (diethylene glycol butyl methyl ether). , DPMNP (dipropylene glycol propyl methyl ether), DMM (dipropylene glycol dimethyl ether), and the like. Among these, one can be used alone or two or more can be used in combination.

  In addition, the content of the second solvent in all the solvents is preferably 10 wt% or more and 50 wt% or less, more preferably 10 wt% or more and 40 wt% or less, and further preferably 20 wt% or more and 40 wt% or less. preferable. Thereby, the pinning effect produced when the 2nd solvent is removed can be heightened, ensuring the solubility with respect to a solute.

  The solvent as described above may contain a solvent other than the first solvent and the second solvent described above, but the content of the other solvent in the total solvent is the first solvent as described above. In order to suitably exhibit the effect of the second solvent, it is preferably 10 wt% or less, more preferably 5 wt% or less, and even more preferably 3 wt% or less.

  The functional layer forming ink as described above is used for film formation using an ink jet method (droplet discharge method) as described later. According to the inkjet method, fine patterning can be performed relatively easily and reliably.

Hereinafter, the operation at the time of film formation of the functional layer forming ink as described above will be described.
FIG. 1 is a diagram for explaining the action of the functional layer forming ink of the present invention during film formation.

Hereinafter, the film forming process using the functional layer forming ink of the present invention will be sequentially described in detail.
[1] Ink application process 1-1
First, as shown in FIG. 1A, a base material 50 is prepared.

  The base material 50 is an object on which a film intended for film formation is formed, and is not particularly limited. For example, various substrates, various substrates processed or processed, and the like can be used. .

1-2
Next, as shown in FIG. 1B, the functional layer forming ink 60 that is the above-described functional layer forming ink is supplied onto the substrate 50. Thereby, a film 60 </ b> A made of the functional layer forming ink 60 is formed on the substrate 50.

  In the present embodiment, the functional layer forming ink 60 is supplied onto the substrate 50 by a droplet discharge method. That is, the functional layer forming ink 60 is ejected as droplets from the inkjet head 200 of the droplet ejection apparatus that ejects the functional layer forming ink, and the functional layer forming ink 60 is supplied onto the substrate 50.

  Further, the temperature and pressure of the atmosphere in the ink application step [1] are not particularly limited as long as the functional layer forming ink 60 can be applied on the substrate 50, but it is preferably normal temperature and pressure. . Thereby, the ink application process [1] can be easily performed.

[2] First drying step 2-2
Next, by removing the second solvent from the film 60A (functional layer forming ink 60) formed on the substrate 50, as shown in FIG. 1C, a film (first film) is formed as an intermediate film. ) 60B is formed.

  In the first drying step [2], since the boiling point of the second solvent is lower than the boiling point of the first solvent, the second solvent is removed from the film 60A (functional layer forming ink 60) on the substrate 50 by the first solvent. Can be preferentially volatilized and removed. And the film | membrane 60B can be formed as an intermediate film which has a solute and a 1st solvent as a main component. Thereby, the film 60B is pinned on the base material 50, and the behavior is stabilized.

  The temperature and pressure of the atmosphere in the first drying step [2] are not particularly limited as long as the second solvent can be removed from the film 60A on the substrate 50, but are preferably normal temperature and pressure. Thereby, a 1st drying process [2] can be performed easily. In this case, the second solvent can be removed from the film 60A on the substrate 50 almost simultaneously with the ink application step [1] described above.

  Further, for example, the evaporation (removal) of the second solvent is promoted by heating the substrate 50 with a rubber heater (not shown) provided on a table (not shown) on which the substrate 50 is placed. Can do. In that case, the heating temperature of the base material 50 is determined according to the boiling points and melting points of the first solvent and the second solvent.

  The time required for removing the second solvent is determined according to the composition of the functional layer forming ink 60 and the boiling points and melting points of the first solvent and the second solvent, and is not particularly limited. It is preferably 90 seconds or less.

  In this step, it is not necessary to remove all the second solvent in the film 60A, and a part of the second solvent may remain in the film 60B.

[3] Second drying step 3-1.
Next, by removing the first solvent from the film 60B, a film 60C containing a solute as a main component is obtained as shown in FIG.

  The removal of the first solvent is not particularly limited, but is preferably performed under reduced pressure. Thereby, a 1st solvent can be removed rapidly. In this case, for example, a vacuum dryer with a heater may be used.

As described above, when the pressure is reduced, the pressure is not particularly limited, but is preferably about 10 ⁰ Pa or more and 10 ⁻⁷ Pa or less.

  Moreover, the time of the said pressure reduction is although it does not specifically limit, It is preferable that it is about 1 minute or more and 30 minutes or less.

  The film 60C thus obtained is made of a constituent material of the functional layer intended for film formation or a precursor thereof.

  When a precursor is used as the solute, the film 60C is subjected to a predetermined process as necessary. For example, as shown in FIG.1 (e), heat processing is performed and the target functional layer 60D is obtained. Thereby, when a solute is a low molecular weight compound, the film | membrane comprised including the high molecular weight compound can be obtained by performing the process which causes the polymerization reaction of the low molecular weight compound. In addition, when the solute is a resin material, a film including a high molecular weight compound can be obtained by performing a treatment that causes a crosslinking reaction of the resin material.

  This heating is not particularly limited, but can be performed by a hot plate, infrared rays, or a rubber heater (not shown) provided on a table (not shown) on which the substrate 50 is placed.

  The heating temperature and heating time are determined according to the type of solute and are not particularly limited.

(Light emitting device)
Next, prior to the description of the method for manufacturing a light-emitting element of the present invention, a display device that is an example of a light-emitting device (that is, the light-emitting device of the present invention) including a light-emitting element manufactured using such a manufacturing method will be described.

  FIG. 2 is a cross-sectional view showing a light emitting device (display device) according to an embodiment of the present invention. In the following description, for convenience of explanation, the upper side in FIG. 2 will be described as “upper” and the lower side as “lower”.

  A display device 100 shown in FIG. 2 includes a plurality of light emitting elements 1R, 1G, and 1B corresponding to the sub-pixels 100R, 100G, and 100B, and forms a bottom emission display panel. In the present embodiment, an example in which an active matrix method is employed as a display device driving method will be described. However, a passive matrix method may be employed.

  The display device 100 includes a circuit board 20, a plurality of light emitting elements 1 R, 1 G, and 1 B provided on the circuit board 20, and a sealing substrate 40.

  The circuit board 20 includes a substrate 21, an interlayer insulating film 22 provided on the substrate 21, a plurality of switching elements 23, and wirings 24.

  The substrate 21 is substantially transparent (colorless transparent, colored transparent or translucent). Thereby, the light from each light emitting element 1R, 1G, 1B can be extracted from the substrate 21 side. Examples of the constituent material of the substrate 21 include resin materials such as polyethylene terephthalate, polyethylene naphthalate, polypropylene, cycloolefin polymer, polyamide, polyethersulfone, polymethyl methacrylate, polycarbonate, and polyarylate, quartz glass, and soda glass. Such glass materials can be used, and one or more of these can be used in combination.

  In the case of a top emission structure in which light from the light emitting elements 1R, 1G, and 1B is extracted from the side opposite to the substrate 21, the substrate 21 may be an opaque substrate. And a substrate made of an oxide film (insulating film) on the surface of a metal substrate such as stainless steel, a substrate made of a resin material, and the like.

  On such a substrate 21, a plurality of switching elements 23 are arranged in a matrix. Each switching element 23 is provided corresponding to each light emitting element 1R, 1G, 1B, and is a driving transistor for driving each light emitting element 1R, 1G, 1B.

  Each switching element 23 includes a semiconductor layer 231 made of silicon, a gate insulating layer 232 formed on the semiconductor layer 231, a gate electrode 233 formed on the gate insulating layer 232, a source electrode 234, A drain electrode 235.

  An interlayer insulating film 22 made of an insulating material is formed so as to cover the plurality of switching elements 23. A wiring 24 is provided in the interlayer insulating film 22.

  On the interlayer insulating film 22, light emitting elements 1R, 1G, and 1B are provided corresponding to the switching elements 23, respectively. In the light emitting element 1R, the anode 3 (first electrode), the stacked bodies 10 (10R) and 11, and the cathode 9 (second electrode) are stacked on the interlayer insulating film 22 in this order. In the present embodiment, the anode 3 of each light emitting element 1R, 1G, 1B constitutes a pixel electrode, and is electrically connected to the drain electrode 235 of each switching element 23 via the wiring 24. The cathode 9 of the light emitting element 1R is a common electrode with the cathode 9 of the light emitting elements 1G and 1B. The stacked body 11 of the light emitting element 1R is common to the light emitting elements 1G and 1B.

  The configurations of the light emitting elements 1G and 1B can be configured in the same manner as the light emitting element 1R, respectively. Here, different colors can be emitted by making the stacked bodies 10R, 10G, and 10B (particularly, the light emitting layers) of the light emitting elements 1R, 1G, and 1B different from each other. For example, the light emitting element 1R emits red light, the light emitting element 1G emits green light, and the light emitting element 1B emits blue light.

  A partition wall 31 (bank) is provided between the adjacent light emitting elements 1R, 1G, and 1B. Moreover, the sealing substrate 40 is joined to such light emitting elements 1R, 1G, and 1B through a resin layer 32 made of a thermosetting resin such as an epoxy resin.

  As described above, since each of the light emitting elements 1R, 1G, and 1B of the present embodiment is a bottom emission type, the sealing substrate 40 may be a transparent substrate or an opaque substrate. As a constituent material, the same material as the substrate 21 described above can be used.

(Light emitting element)
Next, the light emitting elements 1R, 1G, and 1B will be described in detail.

  3A is a plan view of a bank included in the light-emitting device shown in FIG. 2, and FIG. 3B is a cross-sectional view of a light-emitting element included in the light-emitting device shown in FIG.

  A light-emitting element (electroluminescence element) 1 shown in FIG. 3 constitutes the light-emitting elements 1R, 1G, and 1B described above. As described above, the anode 3 (first electrode) and the cathode 9 (second electrode). The laminated bodies 10 and 11 are inserted between the two. As shown in FIG. 3, the laminate 10 includes a hole injection layer 4, a hole transport layer 5 (first layer), and a light emitting layer 6 (second layer) from the anode 3 side to the cathode 9 side. They are stacked in order. In the laminate 11, the electron transport layer 7 and the electron injection layer 8 are laminated in this order from the anode 3 side to the cathode 9 side.

  That is, the light emitting device 1 includes a positive hole injection layer 4, a positive hole transport layer 5, a light emitting layer 6, an electron transport layer 7, and an electron injection layer between the anode 3 and the cathode 9 from the anode 3 side to the cathode 9 side. 8 are stacked in this order.

  In such a light emitting element 1, electrons are supplied (injected) from the cathode 9 side to the light emitting layer 6, and holes are supplied (injected) from the anode 3 side. In the light emitting layer 6, holes and electrons are recombined, and excitons (excitons) are generated by the energy released upon the recombination, and energy (fluorescence or phosphorescence) is generated when the excitons return to the ground state. Is emitted (emitted).

Hereinafter, the configuration of each part of the light emitting element 1 will be briefly described.
(anode)
The anode 3 is an electrode that injects holes into the hole transport layer 5 through the hole injection layer 4. As a constituent material of the anode 3, it is preferable to use a material having a large work function and excellent conductivity.

Examples of the constituent material of the anode 3 include oxides such as ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide), In ₃ O ₃ , SnO ₂ , Sb-containing SnO ₂ , and Al-containing ZnO, Au, Pt, and Ag. Cu, alloys containing these, and the like can be used, and one or more of these can be used in combination.

(cathode)
On the other hand, the cathode 9 is an electrode that injects electrons into the electron transport layer 7 via the electron injection layer 8. As a constituent material of the cathode 9, it is preferable to use a material having a small work function.

  Examples of the constituent material of the cathode 9 include Li, Mg, Ca, Sr, La, Ce, Er, Eu, Sc, Y, Yb, Ag, Cu, Al, Cs, Rb, and alloys containing these. These can be used alone or in combination of two or more thereof (for example, a multi-layer laminate).

  In particular, when an alloy is used as the constituent material of the cathode 9, it is preferable to use an alloy containing a stable metal element such as Ag, Al, or Cu, specifically, an alloy such as MgAg, AlLi, or CuLi. By using such an alloy as the constituent material of the cathode 9, the electron injection efficiency and stability of the cathode 9 can be improved.

  Moreover, since the light emitting element 1 of this embodiment is a bottom emission type, the cathode 9 does not need to have light transmittance.

(Hole injection layer)
The hole injection layer 4 has a function of improving the hole injection efficiency from the anode 3.

  The constituent material (hole injection material) of the hole injection layer 4 is not particularly limited. For example, TAPC ((1,1-bis [4- (di-p-tolyl) ami.nophenyl] cyclohexane)) : 4,4'-Cyclohexylidenebis [N, N-bis (4-methylphenyl) aniline]), TPD (N, N'-diphenyl-N, N'-bis- (3-methylphenyl) -1,1'biphenyl -4,4'-diamine), α-NPD (N, N'-diphenyl-N, N'-bis- (1-naphthyl) -1,1'biphenyl-4,4'-diamine), m-MTDATA (4,4 ′, 4 ″ -tris (N-3-methylphenylamino) -triphenylamine: 4,4 ′, 4 ″ -Tris (N-3-methylphenyl-N-phenylamino) -triphenylamine), 2- TNATA (4,4 ′, 4 ″ -tris (N, N- (2-naphthyl) phenylamino) triphenylamine), TCTA (4,4 ′, 4 ″ -tri (N-carbazole group) triphenylamine: Tris- (4-carbazoyl-9- yl-phenyl) -amine), TDAPB (1,3,5-tris- (N, N-bis- (4-methoxy-phenyl) -aminophenyl) -benzene: 1,3,5-tris [4- ( diphenylamino) phenyl] benzene), spiro TAD, HTM1 (Tri-p-tolylamineHTM2,1,1-bis [(di-4-tolylamino) phenyl] cyclohexane), HTM2 (1,1-bis [(di-4-tolylamino) ) phenyl] cyclohexane), TPT1 (1,3,5-tris (4-pyridyl) -2,4,6-triazin), TPTE (Triphenylamine-tetramer), etc., one or two of these A combination of the above can be used.

  The average thickness of the hole injection layer 4 is not particularly limited, but is preferably about 5 to 150 nm, and more preferably about 10 to 100 nm.

(Hole transport layer)
The hole transport layer 5 has a function of transporting holes injected from the anode 3 through the hole injection layer 4 to the light emitting layer 6.

  The constituent material of the hole transport layer 5 is not particularly limited. For example, a triphenylamine system such as TFB (poly (9,9-dioctyl-fluorene-co-N- (4-butylphenyl) -diphenylamine)) is used. Includes amine compounds such as polymers, polyfluorene derivatives (PF), polyparaphenylene vinylene derivatives (PPV), polyparaphenylene derivatives (PPP), polyvinylcarbazole (PVK), polythiophene derivatives, polymethylphenylsilane (PMPS) Examples include high molecular organic materials such as polysilanes, and one or more of these can be used in combination. Further, the constituent material of the hole injection layer 4 described above can also be used as the constituent material of the hole transport layer 5.

  The average thickness of the hole transport layer 5 is not particularly limited, but is preferably about 10 to 150 nm, and more preferably about 10 to 100 nm.

  The hole transport layer 5 can be omitted. In this case, the hole injection layer 4 also functions as the hole transport layer 5.

(Light emitting layer)
The light emitting layer 6 is provided in contact with the hole transport layer 5. The light emitting layer 6 includes a light emitting material.

  The light emitting material is not particularly limited, and various fluorescent materials and phosphorescent materials can be used alone or in combination. When the light emitting element 1 is used for the light emitting element 1R described above, a red fluorescent material or a red phosphorescent material is used as the light emitting material. When the light emitting element 1 is used for the light emitting element 1G described above, a green fluorescent material is used as the light emitting material. Alternatively, when a green phosphorescent material is used and the light emitting element 1 is used as the light emitting element 1B, a blue fluorescent material or a blue phosphorescent material is used as the light emitting material.

  The red fluorescent material is not particularly limited as long as it emits red fluorescence. For example, perylene derivatives such as diindenoperylene derivatives, europium complexes, benzopyran derivatives, rhodamine derivatives, benzothioxanthene derivatives, porphyrin derivatives, Nile Red, 2- (1,1-dimethylethyl) -6- (2- (2,3,6,7-tetrahydro-1,1,7,7-tetramethyl-1H, 5H-benzo (ij) quinolidine- 9-yl) ethenyl) -4H-pyran-4H-ylidene) propanedinitrile (DCJTB), 4- (dicyanomethylene) -2-methyl-6- (p-dimethylaminostyryl) -4H-pyran (DCM), etc. Can be mentioned.

The red phosphorescent material is not particularly limited as long as it emits red phosphorescence, and examples thereof include metal complexes such as iridium, ruthenium, platinum, osmium, rhenium, and palladium. Among the ligands of these metal complexes, And those having at least one of phenylpyridine skeleton, bipyridyl skeleton, porphyrin skeleton and the like. More specifically, tris (1-phenylisoquinoline) iridium, bis [2- (2′-benzo [4,5-α] thienyl) pyridinate-N, C ³ ′] iridium (acetylacetonate) (btp2Ir ( acac)), 2,3,7,8,12,13,17,18-octaethyl-12H, 23H-porphyrin-platinum (II), bis [2- (2′-benzo [4,5-α] thienyl ) Pyridinate-N, C ³ '] iridium, bis (2-phenylpyridine) iridium (acetylacetonate).

  The green fluorescent material is not particularly limited as long as it emits green fluorescence. For example, quinacridone such as coumarin derivatives and quinacridone derivatives and derivatives thereof, 9,10-bis [(9-ethyl-3-carbazole)- Vinylenyl] -anthracene, poly (9,9-dihexyl-2,7-vinylenefluorenylene), poly [(9,9-dioctylfluorene-2,7-diyl) -co- (1,4-diphenylene-vinylene) -2-methoxy-5- {2-ethylhexyloxy} benzene)], poly [(9,9-dioctyl-2,7-divinylenefluorenylene) -ortho-co- (2-methoxy-5- (2 -Ethoxylhexyloxy) -1,4-phenylene)] and the like.

The green phosphorescent material is not particularly limited as long as it emits green phosphorescence, and examples thereof include metal complexes such as iridium, ruthenium, platinum, osmium, rhenium, and palladium. 2-phenylpyridine) iridium (Ir (ppy) 3), bis (2-phenyl-pyridinium sulfonate -N, ^{C 2} ') iridium (acetylacetonate), fac - tris [5-fluoro-2- (5-tri Fluoromethyl-2-pyridine) phenyl-C, N] iridium and the like.

  The blue fluorescent material is not particularly limited as long as it emits blue fluorescence. For example, distyrylamine derivatives such as distyryldiamine compounds, fluoranthene derivatives, pyrene derivatives, perylene and perylene derivatives, anthracene derivatives, benzo Oxazole derivatives, benzothiazole derivatives, benzimidazole derivatives, chrysene derivatives, phenanthrene derivatives, distyrylbenzene derivatives, tetraphenylbutadiene, 4,4′-bis (9-ethyl-3-carbazovinylene) -1,1′-biphenyl (BCzVBi) ), Poly [(9.9-dioctylfluorene-2,7-diyl) -co- (2,5-dimethoxybenzene-1,4-diyl)], poly [(9,9-dihexyloxyfluorene-2, 7-diyl) -ortho-co- (2-me Xyl-5- {2-ethoxyhexyloxy} phenylene-1,4-diyl)], poly [(9,9-dioctylfluorene-2,7-diyl) -co- (ethylnylbenzene)] and the like. .

The blue phosphorescent material is not particularly limited as long as it emits blue phosphorescence. Examples thereof include metal complexes such as iridium, ruthenium, platinum, osmium, rhenium, and palladium. Specifically, bis [4 , 6-difluorophenyl pyridinium sulfonate -N, ^{C 2} '] - picolinate - iridium, tris [2- (2,4-difluorophenyl) pyridinate -N, ^{C 2']} iridium, bis [2- (3,5 - trifluoromethyl) pyridinate -N, ^{C 2} '] - picolinate - iridium, bis (4,6-difluorophenyl pyridinium sulfonate -N, ^{C 2')} iridium (acetylacetonate) and the like.

  The above light emitting materials can be used individually by 1 type or in combination of 2 or more types.

  In addition to the light emitting material described above, the light emitting layer 6 may contain a host material to which the light emitting material is added as a guest material. This host material recombines holes and electrons to generate excitons and to transfer the exciton energy to the luminescent material (Felster movement or Dexter movement) to excite the luminescent material. Have. In the case of using such a host material, for example, the host material can be used by doping a light emitting material that is a guest material as a dopant.

Such a host material is not particularly limited as long as it exhibits a function as described above with respect to a light emitting material to be used. For example, an acene derivative such as a naphthacene derivative, a naphthalene derivative, or an anthracene derivative (acene type) Materials), distyrylarylene derivatives, perylene derivatives, distyrylbenzene derivatives, distyrylamine derivatives, quinolinolato metal complexes such as tris (8-quinolinolato) aluminum complex (Alq ₃ ), and triphenylamine tetramers Reelamine derivatives, oxadiazole derivatives, silole derivatives, dicarbazole derivatives, oligothiophene derivatives, benzopyran derivatives, triazole derivatives, benzoxazole derivatives, benzothiazole derivatives, quinoline derivatives, 4,4'-bis (2,2'-diph Enylvinyl) biphenyl (DPVBi) and the like, and one or more of them can be used in combination.

  When the light emitting material (guest material) and the host material as described above are used, the content (doping amount) of the light emitting material in the light emitting layer 6 is preferably 0.01 to 10 wt%, and preferably 0.1 to 5 wt%. % Is more preferred. Luminous efficiency can be optimized by setting the content of the light emitting material within such a range.

  Although the average thickness of such a light emitting layer 6 is not specifically limited, It is preferable that it is about 10-150 nm, and it is more preferable that it is about 10-100 nm. Moreover, the light emitting layer 6 may be comprised by the laminated | stacked several light emitting layer, In that case, the intermediate | middle layer which does not light-emit may be interposed between arbitrary light emitting layers.

(Electron transport layer)
The electron transport layer 7 has a function of transporting electrons injected from the cathode 9 through the electron injection layer 8 to the light emitting layer 6.

As a constituent material (electron transport material) of the electron transport layer 7, for example, a quinoline derivative such as an organometallic complex having an 8-quinolinol or its derivative such as tris (8-quinolinolato) aluminum (Alq ₃ ) as a ligand. Oxadiazole derivatives, perylene derivatives, pyridine derivatives, pyrimidine derivatives, quinoxaline derivatives, diphenylquinone derivatives, nitro-substituted fluorene derivatives, and the like, and one or more of these can be used in combination.

Although the average thickness of the electron carrying layer 7 is not specifically limited, It is preferable that it is about 0.5-100 nm, and it is more preferable that it is about 1-50 nm.
The electron transport layer 7 can be omitted.

(Electron injection layer)
The electron injection layer 8 has a function of improving the electron injection efficiency from the cathode 9.

  Examples of the constituent material (electron injection material) of the electron injection layer 8 include various inorganic insulating materials and various inorganic semiconductor materials.

  Examples of such inorganic insulating materials include alkali metal chalcogenides (oxides, sulfides, selenides, tellurides), alkaline earth metal chalcogenides, alkali metal halides, and alkaline earth metal halides. Of these, one or two or more of these can be used in combination. By forming the electron injection layer using these as main materials, the electron injection property can be further improved. In particular, alkali metal compounds (alkali metal chalcogenides, alkali metal halides, and the like) have a very low work function, and the light-emitting element 1 can be obtained with high luminance by forming the electron injection layer 8 using the work function. Become.

Examples of the alkali metal chalcogenide include Li ₂ O, LiO, Na ₂ S, Na ₂ Se, and NaO. Examples of the alkaline earth metal chalcogenide include CaO, BaO, SrO, BeO, BaS, MgO, and CaSe. Examples of the alkali metal halide include CsF, LiF, NaF, KF, LiCl, KCl, and NaCl. Examples of the alkaline earth metal halide include CaF ₂ , BaF ₂ , SrF ₂ , MgF ₂ , and BeF ₂ .

  In addition, as the inorganic semiconductor material, for example, an oxide including at least one element of Li, Na, Ba, Ca, Sr, Yb, Al, Ga, In, Cd, Mg, Si, Ta, Sb, and Zn , Nitrides, oxynitrides, and the like, and one or more of these can be used in combination.

The average thickness of the electron injection layer 8 is not particularly limited, but is preferably about 0.1 to 1000 nm, more preferably about 0.2 to 100 nm, and about 0.2 to 50 nm. Further preferred.
The electron injection layer 8 can be omitted.

  In the light emitting device 1 configured as described above, each layer of the laminate 10 (the hole injection layer 4, the hole transport layer 5, and the light emitting layer 6) is liquid in the partition wall 31 as shown in FIG. Formed using a phase process. Here, the ink used for forming at least one of the hole injection layer 4, the hole transport layer 5, and the light emitting layer 6 is the aforementioned functional layer forming ink. That is, the constituent material of the hole injection layer 4, the hole transport layer 5 or the light emitting layer 6 or a precursor thereof is used as the solute of the functional layer forming ink described above.

(Manufacturing method of light emitting element)
Next, the manufacturing method of the light emitting device of the present invention will be described by taking the case of manufacturing the light emitting device 1 as an example.

  4-7 is a figure for demonstrating the manufacturing method of the light emitting element shown to Fig.2 (a), respectively.

  The manufacturing method of the light emitting element 1 includes [1] a step of forming the anode 3 and [2] a step of forming the hole injection layer 4. [3] a step of forming the hole transport layer 5, [4] a step of forming the light emitting layer 6, and [5] a step of forming the electron transport layer 7, the electron injection layer 8, and the cathode 9. Hereinafter, each process is demonstrated one by one.

[1]
First, the substrate 21 is prepared. As shown in FIG. 4A, the anode 3 is formed on the substrate 21, and then the partition wall 31 is formed.

  The anode 3 can be obtained, for example, by depositing an electrode material on the substrate 21 using a vapor deposition method such as vapor deposition or CVD, and then patterning the electrode material using etching or the like.

  The partition wall 31 can be formed by patterning using a photolithography method or the like so that the anode 3 is exposed.

Here, the constituent material of the partition wall 31 is selected in consideration of heat resistance, liquid repellency, ink solvent resistance, adhesion to the substrate 21 and the like. Specifically, examples of the constituent material of the partition wall 31 include an organic material such as an acrylic resin, a polyimide resin, and an epoxy resin, and an inorganic material such as SiO ₂ .

  In addition, after the formation of the anode 3 and the partition wall 31, the surface of the anode 3 and the partition wall 31 may be subjected to oxygen plasma treatment as necessary. Thereby, lyophilicity is imparted to the surface of the anode 3, organic substances adhering to the surfaces of the anode 3 and the partition wall 31 are removed (washed), and the work function near the surface of the anode 3 is adjusted. be able to.

  Here, the oxygen plasma treatment conditions include, for example, a plasma power of about 100 to 800 W, an oxygen gas flow rate of about 50 to 100 mL / min, a conveyance speed of the member to be treated (anode 3) of about 0.5 to 10 mm / sec, and a substrate. The temperature of 21 is preferably about 70 to 90 ° C.

Further, after this oxygen plasma treatment, it is preferable to perform a plasma treatment using a fluorine-based gas such as CF ₄ as a treatment gas. As a result, the fluorine-based gas reacts only on the surface of the partition wall 31 made of a photosensitive resin, which is an organic material, to make the liquid repellent. Thereby, it is possible to reduce the unintentional wetting and spreading of the liquid applied in the partition wall 31.

[2]
Next, as shown in FIG. 4B, the ink 4 a for forming a hole injection layer is applied from the inkjet head 200 onto the anode 3 (base material) in the partition wall 31.

  The ink 4a is obtained by dissolving the constituent material of the hole injection layer 4 or its precursor as a solute in a solvent. Here, the ink 4a can be the functional layer forming ink described above. In that case, the 1st solvent and 2nd solvent which satisfy | fill the conditions of a boiling point and solubility parameter as mentioned above are used as a solvent.

  Thereafter, the ink 4a on the anode 3 is dried (desolvent or dedispersing medium), and heat-treated as necessary, thereby forming the hole injection layer 4 as shown in FIG.

  Drying can be performed, for example, by standing in an atmospheric pressure or reduced-pressure atmosphere, heat treatment, spraying an inert gas, or the like.

  As described above, the hole injection layer 4 is formed by the liquid phase process using the ink 4a. The hole injection layer 4 may be formed by a vapor phase process such as a vapor deposition method or a CVD method.

[3]
Next, as shown in FIG. 5B, the ink 5 a for forming a hole transport layer is applied from the inkjet head 200 </ b> A onto the hole injection layer 4 in the partition wall 31.

  The ink 5a is obtained by dissolving the constituent material of the hole transport layer 5 or its precursor as a solute in a solvent. Here, the ink 5a can be the functional layer forming ink described above. In that case, the 1st solvent and 2nd solvent which satisfy | fill the conditions of a boiling point and solubility parameter as mentioned above are used as a solvent.

  Thereafter, the ink 5a on the hole injection layer 4 is dried (desolvent or dedispersion medium), and heat-treated as necessary to form the hole transport layer 5 as shown in FIG. 6 (a). To do.

Drying can be performed, for example, by standing in an atmospheric pressure or reduced-pressure atmosphere, heat treatment, spraying an inert gas, or the like.
As described above, the hole transport layer 5 is formed by the liquid phase process using the ink 5a.

[4]
Next, as shown in FIG. 6B, the ink 6 a (liquid) for forming the light emitting layer is applied from the inkjet head 200 </ b> B onto the hole transport layer 5 in the partition wall 31.

  The ink 6a is obtained by dissolving the constituent material of the light emitting layer 6 or its precursor as a solute in a solvent. Here, the ink 6a can be the functional layer forming ink described above. In that case, the 1st solvent and 2nd solvent which satisfy | fill the conditions of a boiling point and solubility parameter as mentioned above are used as a solvent.

  Thereafter, the ink 6a on the hole transport layer 5 is dried (desolvent or dedispersion medium), and heat-treated as necessary, thereby forming the light emitting layer 6 as shown in FIG. 7A.

Drying can be performed, for example, by standing in an atmospheric pressure or reduced-pressure atmosphere, heat treatment, spraying an inert gas, or the like.
As described above, the light emitting layer 6 is formed by the liquid phase process using the ink 6a.

[5]
Next, an electron transport layer 7, an electron injection layer 8, and a cathode 9 are formed in this order on the light emitting layer 6. Thereby, the light emitting element 1 is obtained.

The electron transport layer 7, the electron injection layer 8, and the cathode 9 can each be formed by a vapor phase process using a dry plating method such as vacuum deposition, for example. The electron transport layer 7, the electron injection layer 8, and the cathode 9 may each be formed using a liquid phase process.
The light emitting element 1 is obtained through the steps as described above.

(Electronics)
FIG. 8 is a perspective view showing a configuration of a mobile (or notebook) personal computer to which the electronic apparatus of the present invention is applied.

  In this figure, a personal computer 1100 includes a main body 1104 provided with a keyboard 1102 and a display unit 1106 provided with a display. The display unit 1106 is rotatable with respect to the main body 1104 via a hinge structure. It is supported by.

  In the personal computer 1100, the display unit included in the display unit 1106 is configured by the display device 100 described above.

  FIG. 9 is a perspective view showing a configuration of a mobile phone (including PHS) to which the electronic apparatus of the present invention is applied.

In this figure, a cellular phone 1200 includes a plurality of operation buttons 1202, an earpiece 1204 and a mouthpiece 1206, and a display unit.
In the mobile phone 1200, the display unit is configured by the display device 100 described above.

  FIG. 10 is a perspective view showing the configuration of a digital still camera to which the electronic apparatus of the present invention is applied. In this figure, connection with an external device is also simply shown.

  Here, an ordinary camera sensitizes a silver halide photographic film with a light image of a subject, whereas a digital still camera 1300 photoelectrically converts a light image of a subject with an imaging device such as a CCD (Charge Coupled Device). An imaging signal (image signal) is generated.

  A display unit is provided on the back of a case (body) 1302 in the digital still camera 1300, and is configured to display based on an imaging signal from the CCD, and functions as a finder that displays an object as an electronic image.

  In the digital still camera 1300, the display unit is configured by the display device 100 described above.

  A circuit board 1308 is installed inside the case. The circuit board 1308 is provided with a memory that can store (store) an imaging signal.

  A light receiving unit 1304 including an optical lens (imaging optical system), a CCD, and the like is provided on the front side of the case 1302 (on the back side in the illustrated configuration).

  When the photographer confirms the subject image displayed on the display unit and presses the shutter button 1306, the CCD image pickup signal at that time is transferred and stored in the memory of the circuit board 1308.

In the digital still camera 1300, a video signal output terminal 1312 and an input / output terminal 1314 for data communication are provided on the side surface of the case 1302. As shown in the figure, a television monitor 1430 is connected to the video signal output terminal 1312 and a personal computer 1440 is connected to the data communication input / output terminal 1314 as necessary. Further, the imaging signal stored in the memory of the circuit board 1308 is output to the television monitor 1430 or the personal computer 1440 by a predetermined operation.
Such an electronic apparatus of the present invention has excellent reliability.

  The electronic apparatus of the present invention includes, for example, a television, a video camera, a viewfinder type, in addition to the personal computer (mobile personal computer) in FIG. 8, the mobile phone in FIG. 9, and the digital still camera in FIG. Monitor direct-view video tape recorder, laptop personal computer, car navigation system, pager, electronic notebook (including communication function), electronic dictionary, calculator, electronic game device, word processor, workstation, video phone, security TV Monitors, electronic binoculars, POS terminals, devices equipped with touch panels (for example, cash dispensers and automatic ticket vending machines for financial institutions), medical devices (for example, electronic thermometers, blood pressure monitors, blood glucose meters, electrocardiographs, ultrasound diagnostic devices Endoscopic display device), fish finder, various measuring instruments Instruments (e.g., gages for vehicles, aircraft, and ships), a flight simulator, various monitors, and a projection display such as a projector.

  The functional layer forming ink, the light emitting element manufacturing method, the light emitting device, and the electronic apparatus of the present invention have been described based on the illustrated embodiments, but the present invention is not limited to these.

  For example, in the above-described embodiments, the light emitting element has been described as having one light emitting layer, but the light emitting layer may be two or more layers. Further, the emission color of the light emitting layer is not limited to R, G, and B in the above-described embodiment.

Next, specific examples of the present invention will be described.
1. Manufacturing of light-emitting elements

(Example 1)
<1> First, a transparent glass substrate having an average thickness of 0.5 mm was prepared. Next, an ITO electrode (anode) having an average thickness of 100 nm was formed on the substrate by sputtering. Thereafter, an insulating layer made of an acrylic resin was formed, and then this insulating layer was patterned using a photolithography method so as to expose the ITO electrode, thereby forming a partition (bank). The shape of the partition in plan view was a rectangle having a length of 300 μm and a width of 100 μm, and the height of the partition was 2 μm.

  And after immersing a board | substrate in order of acetone and 2-propanol and ultrasonically cleaning, oxygen plasma treatment and argon plasma treatment were performed. Each of these plasma treatments was performed at a plasma power of 100 W, a gas flow rate of 20 sccm, and a treatment time of 5 seconds with the substrate heated to 70 to 90 ° C.

  <2> Next, the hole transport layer forming ink (functional layer forming ink) is filled in the partition wall by the ink jet method and applied onto the ITO electrode, and then dried under reduced pressure, followed by heat treatment (firing). As a result, a hole transport layer having an average thickness of 50 nm was formed.

  Here, TFB (poly (9,9-dioctyl-fluorene-co-N- (4-butylphenyl) -diphenylamine)), which is a solute (hole transport material), is used as the hole transport layer forming ink: 0.45 g Was dissolved in a mixed solvent (mass ratio 70:30) of 2-isopropylnaphthalene (2-iPrNaph): 70 g and BDPOM: 30 g as the first solvent. The firing was performed in a glove box filled with nitrogen, the firing temperature was 180 ° C., and the firing time was 30 minutes.

  <3> Next, after the ink for forming the light emitting layer is filled in the partition wall by an ink jet method and applied onto the hole transport layer, this is dried under reduced pressure and then heat-treated (baked) to obtain an average thickness. A 20 nm light emitting layer was formed.

  Here, CBP (4,4′-bis (9-dicarbazoyl) -2,2′-biphenyl), Ir (ppy) 3 (Fac-tris (2-phenylpyridine) iridium) is used as the light emitting layer forming ink. A tetralone solution (concentration 1 wt%) mixed at a weight ratio of 90:10 was used. Further, the drying was performed under a reduced pressure from normal pressure to 5 Pa for 5 minutes immediately after application of the light emitting layer forming ink. The firing was performed in a glove box filled with nitrogen, the firing temperature was 180 ° C., and the firing time was 30 minutes.

<4> Next, on the light emitting layer, an Alq ₃ was deposited by vacuum evaporation to form an electron transport layer having an average thickness of 20 nm.

  <5> Next, on the electron transport layer, lithium fluoride (LiF) was formed by a vacuum deposition method to form an electron injection layer having an average thickness of 0.5 nm.

<6> Next, Al was formed into a film by the vacuum evaporation method on the electron injection layer. Thereby, a cathode having an average thickness of 150 nm made of Al was formed.
The light emitting device was manufactured through the above steps.

(Examples 2 to 24, Comparative Examples 1 to 20)
A light emitting device was prepared in the same manner as in Example 1 except that the types and contents of the first solvent and the second solvent in the hole transport layer forming ink (functional layer forming ink) were as shown in Table 1. Manufactured.

2. Evaluation Each light emitting device manufactured as described above was caused to emit light, the luminance distribution was measured, and evaluation was performed according to the following criteria.

A: The width of the region where the variation in the emission intensity is 5% or less is 90% or more with respect to the entire width of the pixel. ○: The width of the region where the variation in the emission intensity is 5% or less is 85% or more with respect to the entire width of the pixel. Less than 90% ×: The width of the region where the variation in the emission intensity is 5% or less is less than 85% with respect to the entire width of the pixel.

  As can be seen from Table 1, the light emitting device according to each example has a smaller variation in light emission intensity and a wider light emitting region than the light emitting device according to each comparative example. This is presumably because carriers are transported uniformly to the light emitting layer because the hole transport layer of each example is flat and has a uniform thickness.

DESCRIPTION OF SYMBOLS 1 ... Light emitting element 1B ... Light emitting element 1G ... Light emitting element 1R ... Light emitting element 3 ... Anode 4 ... Hole injection layer 4a ... Ink 5 ... Hole transport layer 5a ... Ink 6 ... Light emission Layer 6a ... Ink 7 ... Electron transport layer 8 ... Electron injection layer 9 ... Cathode 10 ... Laminated body 10R ... Laminated body 10G ... Laminated body 10B ... Laminated body 11 ... Laminated body 20 ... Circuit Substrate 21 ... Substrate 22 ... Interlayer insulating film 23 ... Switching element 24 ... Wiring 31 ... Partition 32 ... Resin layer 40 ... Sealing substrate 50 ... Base material 60 ... Functional layer forming ink 60A ... Film 60B Film 60C Film 60D Functional layer 100 Display device 100R Subpixel 100G Subpixel 100B Subpixel 200 Inkjet head 200A Inkjet head 200B Inkjet head 23 ... Semiconductor layer 232 ... Gate insulating layer 233 ... Gate electrode 234 ... Source electrode 235 ... Drain electrode 1100 ... Personal computer 1102 ... Keyboard 1104 ... Main unit 1106 ... Display unit 1200 ... Mobile phone 1202 Operation button 1204 ... Earpiece 1206 ... Earpiece 1300 ... Digital still camera 1302 ... Case 1304 ... Light receiving unit 1306 ... Shutter button 1308 ... Circuit board 1312 ... Video signal output terminal 1314 ... Input / output terminal 1430 ... TV monitor 1440 ... Personal computer

Claims (11)

A solute composed of a constituent material of the functional layer or a precursor thereof, and
A first solvent that dissolves the solute and has a first boiling point and a first solubility parameter;
A second solvent that dissolves the solute and has a second boiling point lower than the first boiling point and a second solubility parameter smaller than the first solubility parameter;
The first boiling point is 250 ° C. or higher,
The second boiling point is 170 ° C. or higher,
The difference between the first boiling point and the second boiling point is 40 ° C. or more,
The functional layer forming ink, wherein the second solubility parameter is 9.0 (cal / cm ³ ) ^1/2 or less. The content of the first solvent in all the solvents is 50 wt% or more and 90 wt% or less,
2. The functional layer forming ink according to claim 1, wherein the content of the second solvent in all the solvents is 10 wt% or more and 50 wt% or less.   The functional layer forming ink according to claim 1, wherein the second solvent is an aliphatic diether or a derivative thereof.   The functional layer forming ink according to claim 3, wherein the second solvent is diethylene glycol or dipropylene glycol diether or monoether acetate.   5. The functional layer forming ink according to claim 1, wherein the viscosity of the first solvent is higher than the viscosity of the second solvent.   6. The functional layer forming ink according to claim 1, wherein a surface tension of the second solvent is 30 mN / s or less.   The ink for forming a functional layer according to claim 1, wherein the functional layer is an organic layer included in the organic electroluminescence element.   The functional layer forming ink according to claim 7, wherein the organic layer is a hole injection layer or a hole transport layer. Applying the functional layer forming ink according to any one of claims 1 to 8 on a substrate;
And a step of removing the first solvent and the second solvent to form a layer made of the constituent material of the functional layer or a precursor thereof.   A light emitting device comprising a light emitting element manufactured using the manufacturing method according to claim 9.   An electronic apparatus comprising a light emitting element manufactured using the manufacturing method according to claim 9.

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