JP2016184535A - Method of manufacturing light emission device, light emission device and electronic equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light emission device manufacturing method capable of achieving a light emission device having a first pixel area and a second pixel area in which unevenness of light emission is reduced, a light emission device manufactured by using the manufacturing method and electronic equipment having the same.SOLUTION: A light emitting device 100 contains an ink applying step of applying ink 5b containing a hole transporting material or a precursor thereof to sub pixels 100B and applying ink 6a, 6b containing a light emission material or a precursor thereof to sub pixels 100R and 100G, and a dry step of drying the ink 6a, 6b in the presence of undried ink 5b to form light emission functional layers 6R, 6G, and then forming the hole transporting layer 5 by drying the ink 5b.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a method for manufacturing a light emitting device, 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.

  For example, when a display device is configured using such light emitting elements, a light emitting device in which red light emitting elements, green light emitting elements, and blue light emitting elements are combined is used (for example, see Patent Documents 1 and 2).

  For example, as disclosed in Patent Documents 1 and 2, development of a method for forming a light emitting layer of each color of such a light emitting device using a liquid phase process such as an ink jet method is in progress. This method has an advantage that, for example, each pixel can be separately applied without a mask, and the cost can be reduced as compared with the case of using a vapor phase process.

  However, conventionally, when the light emitting layer is formed by using a liquid phase process, the film thickness of the light emitting layer of a pixel of any color becomes non-uniform, and as a result, the light emission unevenness of the pixel occurs. It was.

JP 2013-171765 A JP 2008-009214 A

  An object of the present invention is to provide a manufacturing method of a light emitting device capable of obtaining a light emitting device having a first pixel region and a second pixel region with reduced unevenness of light emission, and manufactured using such a manufacturing method. A light-emitting device and an electronic apparatus including the light-emitting device are provided.

  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]
In the method for manufacturing a light emitting device of the present invention, a first ink containing a hole transport material or a precursor thereof is provided in a first pixel region, and a light emitting material or a precursor thereof is provided in a second pixel region different from the first pixel region. An ink application step of applying a second ink containing a body;
A drying step of drying the second ink in the presence of the undried first ink to form a light emitting functional layer and then drying the first ink to form a hole transport layer. Features.

  According to such a method for manufacturing a light emitting device, since the second ink is dried in the presence of the first ink, the drying speed of the second ink can be reduced. Therefore, the thickness of the light emitting functional layer obtained can be made uniform, and as a result, light emission unevenness in the second pixel region can be reduced. Further, the uniformity of the film thickness of the hole transport layer in the first pixel region has little influence on the light emission unevenness. For this reason, it is possible to obtain a light emitting device in which uneven light emission in each of the first pixel region and the second pixel region is reduced.

[Application Example 2]
In the method for manufacturing a light emitting device of the present invention, it is preferable that in the ink application step, the application amount of the first ink is larger than the application amount of the second ink.

  Thereby, the time required for the completion of the drying of the first ink in the same atmosphere can be made longer than the time required for the completion of the drying of the second ink. Therefore, the second ink can be dried in the presence of the undried first ink while simplifying the drying process.

[Application Example 3]
In the light emitting device manufacturing method of the present invention, it is preferable that in the ink application step, the vapor pressure of the first ink is lower than the vapor pressure of the second ink.

  Thereby, the time required for the completion of the drying of the first ink in the same atmosphere can be made longer than the time required for the completion of the drying of the second ink. Therefore, the second ink can be dried in the presence of the undried first ink while simplifying the drying process.

[Application Example 4]
In the method for manufacturing a light emitting device of the present invention, it is preferable that an area of the first pixel region is smaller than an area of the second pixel region.

  Thereby, the time required for the completion of the drying of the first ink in the same atmosphere can be made longer than the time required for the completion of the drying of the second ink. Therefore, the second ink can be dried in the presence of the undried first ink while simplifying the drying process.

[Application Example 5]
In the method for manufacturing a light emitting device of the present invention, a first anode provided in the first pixel region;
A second anode provided in the second pixel region;
A common cathode provided in common to the first pixel region and the second pixel region;
A first hole transport layer provided between the first anode and the common cathode;
A first light emitting functional layer provided between the second anode and the common cathode;
A first light-emitting functional layer provided between the first hole transport layer and the first light-emitting functional layer and the common cathode in common to the first pixel region and the second pixel region. A method of manufacturing a light emitting device,
In the drying step, the second ink is dried in the presence of the undried first ink to form the first light emitting functional layer, and then the first ink is dried to form the first hole transport layer. Is preferably formed.

  Thereby, the light-emitting device which reduced each light emission nonuniformity of a 1st pixel area | region and a 2nd pixel area | region can be obtained.

[Application Example 6]
In the method for manufacturing a light emitting device of the present invention, the first pixel region is a blue pixel region,
The second pixel region is preferably a red pixel region or a green pixel region.

  As a result, it is possible to obtain a light emitting device in which the uneven light emission of each of the blue pixel region and the red pixel region (or green pixel region) is reduced.

[Application Example 7]
In the method for manufacturing a light emitting device of the present invention, the common cathode is also provided in common to a third pixel region different from the first pixel region and the second pixel region,
The light emitting device
A third anode provided in the third pixel region;
A third light emitting functional layer provided between the third anode and the common cathode,
In the ink application step, a third ink is applied to the third pixel region,
In the drying step, the third ink is dried in the presence of the undried first ink to form the third light emitting functional layer, and then the first ink is dried to form the first hole transport layer. Is preferably formed.

  Thereby, it is possible to obtain a light emitting device in which uneven light emission in each of the first pixel region, the second pixel region, and the third pixel region is reduced.

[Application Example 8]
In the method for manufacturing a light emitting device of the present invention, in the ink application step, the third ink is applied to a third pixel region different from the first pixel region and the second pixel region,
In the drying step, the first ink is preferably dried after the third ink is dried in the presence of the undried first ink to form a light emitting layer.

  Thereby, it is possible to obtain a light emitting device in which uneven light emission in each of the first pixel region, the second pixel region, and the third pixel region is reduced.

[Application Example 9]
In the method for manufacturing a light emitting device of the present invention, the first pixel region is a blue pixel region,
In the second pixel region and the third pixel region, it is preferable that one pixel region is a red pixel region and the other pixel region is a green pixel region.

  As a result, it is possible to obtain a light emitting device in which the light emission unevenness of each of the blue pixel region, the red pixel region and the green pixel region is reduced.

[Application Example 10]
The light emitting device of the present invention is manufactured using the method for manufacturing a light emitting device of the present invention.

  According to such a light emitting device, it is possible to reduce light emission unevenness in each of the first pixel region and the second pixel region.

[Application Example 11]
An electronic apparatus according to the present invention includes the light emitting device according to the present invention.

  According to such an electronic apparatus, it is possible to reduce unevenness in light emission in each of the first pixel region and the second pixel region.

It is sectional drawing which shows the light-emitting device (display apparatus) which concerns on embodiment of this invention. It is a top view which shows the shape of each pixel of the light-emitting device shown in FIG. It is a figure for demonstrating the manufacturing method of the light-emitting device shown in FIG. It is a figure for demonstrating the manufacturing method of the light-emitting device shown in FIG. It is a figure for demonstrating the manufacturing method of the light-emitting device shown in FIG. It is a figure for demonstrating another form (ink vapor pressure) of the ink provision process shown in FIG.4 (b). It is a figure for demonstrating another form (pixel shape) of the ink provision process shown in FIG.4 (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, a method for manufacturing a light-emitting device, a light-emitting device, and an electronic apparatus according to the 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.

(Light emitting device)
First, a display device that is an example of the light-emitting device of the present invention will be described.

  FIG. 1 is a sectional view showing a light emitting device (display device) according to an embodiment of the present invention, and FIG. 2 is a plan view showing the shape of each pixel of the light emitting device shown in FIG. In the following description, for convenience of explanation, the upper side in FIG. 1 will be described as “upper” and the lower side as “lower”.

  A light-emitting device 100 shown in FIG. 1 includes a plurality of light-emitting elements 1R, 1G, and 1B corresponding to sub-pixels 100R (R pixels), 100G (G pixels), and 100B (B pixels), and has a bottom emission display. The panel is configured. As shown in FIG. 2, each of the sub-pixels 100R, 100G, and 100B has a substantially rectangular shape in plan view, and has the same shape and area. 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 light emitting 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 taken out 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 present embodiment, the light emitting element 1R is configured to emit red (R) light, the light emitting element 1G is configured to emit green (G) light, and the light emitting element 1B is blue (B). It is comprised so that the light of this may be radiate | emitted.

  Specifically, the light emitting element 1R (second light emitting element) includes an anode 3R (second anode), a hole injection layer 4R, a hole transport layer 5R, and a light emitting functional layer 6R (first light emitting element) on the interlayer insulating film 22. A light emitting functional layer), an intermediate layer 7 (common hole transport layer), a light emitting functional layer 6B (second light emitting functional layer), an electron transport layer 8, an electron injection layer 9, and a cathode 10 (common cathode) are laminated in this order. Configured.

  Similarly, the light-emitting element 1G (third light-emitting element) includes an anode 3G (third anode), a hole injection layer 4G, a hole transport layer 5G (third hole transport layer), and a light emission on the interlayer insulating film 22. Functional layer 6G (third light emitting functional layer), intermediate layer 7 (common hole transport layer), light emitting functional layer 6B (second light emitting functional layer), electron transport layer 8, electron injection layer 9 and cathode 10 (common cathode) Are stacked in this order.

  On the other hand, the light emitting element 1B (first light emitting element) includes an anode 3B (first anode), a hole injection layer 4B, a hole transport layer 5B (first hole transport layer), an intermediate layer on the interlayer insulating film 22. 7 (common hole transport layer (intermediate layer)), light emitting functional layer 6B (second light emitting functional layer), electron transport layer 8, electron injection layer 9 and cathode 10 (common cathode) are laminated in this order.

  Here, the anodes 3R, 3G, and 3B constitute pixel electrodes individually provided for the corresponding light emitting elements 1R, 1G, and 1B, and are electrically connected to the drain electrode of the switching element 23 via the wiring 24. ing. Further, the hole injection layers 4R, 4G, and 4B, the hole transport layers 5R, 5G, and 5B, the light emitting functional layer 6R, and the light emitting functional layer 6G are also provided individually for the corresponding light emitting elements 1R, 1G, and 1B. . Hereinafter, the light emitting elements 1R, 1G, and 1B are collectively referred to as “light emitting element 1”, the anodes 3R, 3G, and 3B are collectively referred to as “anode 3”, and the hole injection layers 4R, 4G, and 4B are collectively referred to. The “hole injection layer 4” and the hole transport layers 5R, 5G, and 5B are collectively referred to as “hole transport layer 5”.

  On the other hand, the cathode 10 constitutes a common electrode provided in common to the light emitting elements 1R, 1G, and 1B. Further, the intermediate layer 7 (common hole transport layer), the light emitting functional layer 6B, the electron transport layer 8 and the electron injection layer 9 are also provided in common to the light emitting elements 1R, 1G and 1B.

  According to such a light emitting device 100, the hole transport layers 5R, 5G, and 5B, the light emitting functional layers 6R and 6G, and the like are individually formed for each element using a liquid phase process, and a gas phase process is used. The intermediate layer 7 and the light emitting functional layer 6B can be formed in common for the three elements. Therefore, the light emitting elements 1R, 1G, and 1B can be efficiently manufactured.

  A partition wall 31 (bank) made of a resin material 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.

Hereinafter, the light emitting elements 1R, 1G, and 1B will be described in detail.
In the light emitting elements 1R, 1G, 1B, electrons are supplied (injected) from the cathode 10 side to the light emitting functional layers 6R, 6G, 6B, and holes are supplied (injected) from the anodes 3R, 3G, 3B side. The In the light emitting functional layers 6R, 6G, and 6B, holes and electrons recombine, and excitons are generated by the energy released during the recombination, and the excitons return to the ground state. Emits energy (fluorescence or phosphorescence).

  Here, although the light emitting functional layers 6B are provided in the light emitting elements 1R and 1G, the light emitting functional layers 6R and 6G selectively emit light without causing the light emitting functional layer 6B to emit light. Thereby, the light emitting elements 1R, 1G, and 1B emit light in red, green, and blue, respectively.

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

Specifically, the constituent materials of the anodes 3R, 3G, and 3B are, for example, ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide), In ₃ O ₃ , SnO ₂ , Sb-containing SnO ₂ , and Al-containing, respectively. Examples thereof include oxides such as ZnO, Au, Pt, Ag, Cu, and alloys containing these, and one or more of these can be used in combination. The constituent materials of the anodes 3R, 3G, and 3B may be the same or different from each other, but by using the same materials, the anodes 3R, 3G, and 3B can be collectively formed. Productivity can be increased.

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

  The constituent material (hole injection material) of each of the hole injection layers 4R, 4G, and 4B is not particularly limited. For example, a polystyrene sulfonic acid (DPP) as a dopant is added to a polythiophene derivative such as polyethylenedioxythiophene (PEDOT). PSS) and a high-molecular hole injection material such as polystyrene, polypyrrole, polyaniline, oligoaniline, polyacetylene, and derivatives thereof are included, and one of these is used alone or 2 A combination of more than one species can be used. The constituent materials of the hole injection layers 4R, 4G, and 4B may be the same as or different from each other. However, the constituent materials of the hole injection layers 4R, 4G, and 4B are the same as each other. The hole injection layers 4R, 4G, and 4B having stable characteristics can be formed at low cost and high productivity.

  The thicknesses of the hole injection layers 4R, 4G, and 4B are not particularly limited, but are preferably in the range of 10 nm to 150 nm, and more preferably in the range of 20 nm to 100 nm. .

(Hole transport layer)
The hole transport layer 5R (first hole transport layer) has a function of transporting holes injected from the anode 3R through the hole injection layer 4R to the light emitting functional layer 6R. Similarly, the hole transport layer 5G (third hole transport layer) has a function of transporting holes injected from the anode 3G through the hole injection layer 4G to the light emitting functional layer 6G.

  In addition, the hole transport layer 5R has an electron blocking property and also has a function of preventing a functional deterioration of the hole injection layer 4R due to electrons entering the hole injection layer 4R. Similarly, the hole transport layer 5G has an electron blocking property, and also has a function of preventing a functional deterioration of the hole injection layer 4G due to electrons entering the hole injection layer 4G.

  The hole transport layer 5B (second hole transport layer) and the intermediate layer 7 have a function of transporting holes injected from the anode 3B through the hole injection layer 4B to the light emitting functional layer 6B.

  In addition, the hole transport layer 5B and the intermediate layer 7 have an electron blocking property, and also have a function of preventing a functional deterioration of the hole injection layer 4B due to electrons entering the hole injection layer 4B. Since the intermediate layer 7 is extremely thin as will be described later, the electron blocking property of the intermediate layer 7 alone is extremely low and does not hinder the movement of electrons in the light emitting elements 1R and 1G.

  Examples of the constituent material of the hole transport layers 5R, 5G, and 5B include triphenylamine polymers such as TFB (poly (9,9-dioctyl-fluorene-co-N- (4-butylphenyl) -diphenylamine)). Amine-based compounds, polyfluorene derivatives (PF), polyparaphenylene vinylene derivatives (PPV), polyparaphenylene derivatives (PPP), polyvinylcarbazole (PVK), polythiophene derivatives, polysilanes including polymethylphenylsilane (PMPS) High molecular hole transport materials such as m-MTDATA (4,4 ', 4 "-tris (N-3-methylphenylamino) -triphenylamine), TCTA (4,4', 4"- Low molecular hole transport materials such as tri (N-carbazole group) triphenylamine) and α-NPD (bis (N- (1-naphthyl) -N-phenyl) benzidine). 1 type or 2 types or more of these can be used in combination. The constituent materials of the hole transport layers 5R, 5G, and 5B (first hole transport layer, second hole transport layer, and third hole transport layer) may be the same as or different from each other. , The constituent materials of the hole transport layers 5R, 5G (first hole transport layer, third hole transport layer) are the same, and the constituent materials of the hole transport layer 5B (second hole transport layer) are By being different from the hole transport layers 5R and 5G, the light emission balance between the light emitting elements 1R and 1G and the light emitting element 1B can be easily adjusted.

  In addition, the hole transport layers 5R and 5G are each configured using a polymer hole transport material, and the hole transport layer 5B and the intermediate layer 7 are each configured using a low molecular hole transport material. Is preferred. Thereby, the hole transport layers 5R and 5G having high dimensional accuracy can be efficiently formed using a liquid phase process. Further, by forming both the light emitting functional layers 6R and 6G and the hole transporting layers 5R and 5G using a liquid phase process, carriers (holes) are transferred from the hole transporting layers 5R and 5G to the light emitting functional layers 6R and 6G. It can be transported smoothly.

  Further, the hole transport layer 5B and the intermediate layer 7 having high dimensional accuracy can be efficiently formed using a vapor phase process. In particular, by forming the intermediate layer 7 using a vapor phase process, the extremely thin intermediate layer 7 can be formed with high accuracy (with good controllability). Further, even if the hole transport layer 5B and the intermediate layer 7 are formed by different manufacturing methods, since the hole transporting materials constituting them are both low molecules, carriers from the hole transport layer 5B to the intermediate layer 7 are used. (Holes) can be transported smoothly.

  Here, when the hole transport layer 5B is formed using a low molecular hole transport material, the hole transport layer 5B includes a high molecular hole transport material in addition to the low molecular hole transport material. The content of the low-molecular hole transport material in the hole transport layer 5B is preferably 50 wt% or more and 100 wt% or less, and more preferably 70 wt% or more and 100 wt% or less. Preferably, it is 90 wt% or more and 100 wt% or less.

  Examples of the constituent material of the intermediate layer 7 include m-MTDATA (4,4 ′, 4 ″ -tris (N-3-methylphenylamino) -triphenylamine) and TCTA (4,4 ′, 4 ″). Low molecular hole transport materials such as -tri (N-carbazole group) triphenylamine) and α-NPD (bis (N- (1-naphthyl) -N-phenyl) benzidine). One kind or a combination of two or more kinds can be used. The constituent material of the intermediate layer 7 (common hole transport layer) may be the same as or different from the hole transport layers 5R, 5G, and 5B, but the hole transport layer 5B (second hole transport layer). By including the same or similar material as the constituent material of the layer, carriers (holes) can be smoothly transported from the hole transport layer 5B to the light emitting functional layer 6B via the intermediate layer 7.

  The thicknesses of the hole transport layers 5R, 5G, and 5B are not particularly limited, but are preferably in the range of 15 nm to 25 nm.

  Further, the thickness t of the intermediate layer 7 is preferably 2 nm or less, more preferably 0.1 nm or more and 1.5 nm or less, further preferably 0.1 nm or more and 1 nm or less, and 0.1 nm The thickness is most preferably 0.9 nm or less. Thereby, in the light emitting elements 1R and 1G, since the thickness of the intermediate layer 7 provided between the light emitting functional layers 6R and 6G and the light emitting functional layer 6B is extremely thin, the light emitting functional layers 6B to 6R, Carriers (electrons) can be delivered to 6G. Therefore, the light emitting functional layers 6R and 6G can selectively emit light without causing the light emitting functional layers 6B to emit light in the light emitting elements 1R and 1G. Since the thickness of the intermediate layer 7 is extremely thin, an increase in the driving voltage of the light emitting elements 1R, 1G, and 1B due to the provision of the intermediate layer 7 can be suppressed.

  Here, since the constituent material of the intermediate layer 7 has the electron blocking property as described above, the light emitting functional layer 6B can efficiently emit light by utilizing the electron blocking property of the intermediate layer 7 in the light emitting element 1B. On the other hand, in the light emitting elements 1R and 1G, if the electronic block property of the intermediate layer 7 is too high, light emission by the light emitting functional layers 6R and 6G does not occur or the light emission efficiency is remarkably lowered. Therefore, it is extremely useful to make the thickness of the intermediate layer 7 extremely thin so that the electron blocking property of the intermediate layer 7 in the light emitting elements 1R and 1G is lowered.

On the other hand, when the thickness t of the intermediate layer 7 is too thin, the above-described effect due to the provision of the intermediate layer 7 tends to become extremely small. On the other hand, if the thickness t of the intermediate layer 7 is too thick, the driving voltage of the light emitting elements 1R and 1G increases rapidly (the light emission efficiency decreases rapidly), or the light emitting functional layer 6B in the light emitting elements 1R and 1G As a result, light of a desired color cannot be obtained.
The intermediate layer 7 may be omitted.

(Light emitting functional layer)
The light emitting functional layer 6R is provided in contact with the hole transport layer 5R. The light emitting functional layer 6G is provided in contact with the hole transport layer 5G. The light emitting functional layer 6B is provided in contact with the intermediate layer 7.

  Each of the light emitting functional layers 6R, 6G, and 6B includes a light emitting material. The light emitting material is not particularly limited, and various fluorescent materials and phosphorescent materials can be used singly or in combination, and the light emitting functional layer 6R is made of a red fluorescent material or a red phosphorescent material as the light emitting material. The light emitting functional layer 6G uses a green fluorescent material or a green phosphorescent material as a light emitting material, and the light emitting functional layer 6B uses a blue fluorescent material or a blue phosphorescent material as a 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), ADS111RE (manufactured by American Dice Source) and the like can be mentioned.

  The red phosphorescent material is not particularly limited as long as it emits red phosphorescence. For example, Bt2Ir (acac) (Bis (2-phenylbenxothiozolato-N, C2 ′) Iridium (III) (acetylacetonate)), Btp2Ir (acac ) (Bis (2,2′-benzothienyl) -pyridinato-N, C3) Iridium (acetylacetonate)), PtOEP (2,3,7,8,12,13,17,18-Octaethyl-21H, And platinum complexes such as 23H-porphine and platinum (II)).

  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)], ADS109GE (manufactured by American Dice Source), and the like.

  The green phosphorescent material is not particularly limited as long as it emits green phosphorescence. For example, Ir (ppy) 3 (Fac-tris (2-phenypyridine) iridium), Ppy2Ir (acac) (Bis (2-phenyl-) pyridinato-N, C2) Iridium (acetylacetone)) 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)], ADS136BE (American) Die Source).

  The blue phosphorescent material is not particularly limited as long as it emits blue phosphorescence. For example, FIrpic (Iridium-bis (4,6-difluorophenyl-pyridinato-N, C2) -picolinate), Ir (pmb) 3 (Iridium-tris (1-phenyl-3-methylbenzimidazolin-2-ylidene-C, C (2) ′), FIrN4 (Iridium (III) bis (4,6-difluorophenylpyridinato) (5- (pyridin-2-yl) -Tetrazolate)), FIrtaz (Iridium (III) bis (4,6-difluorophenylpyridinato) (5- (pyridine-2-yl) -1,2,4-triazolate)) and the like.

  In addition, the light emitting functional layers 6R, 6G, and 6B may contain a host material to which the light emitting material is added as a guest material in addition to the light emitting material described above. 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 the functions described above for the light emitting material to be used. For example, TDAPB (1,3,5-tris- (N, N-bis -(4-methoxy-phenyl) -aminophenyl) -benzene), CBP (4,4'-bis (9-dicarbazolyl) -2,2'-biphenyl), BAlq (Bis- (2-methyl-8-quinolinolate) ) -4- (phenylphenolate) aluminium), mCP (N, N-dicarbazolyl-3,5-benzene: CBP derivative), CDBP (4,4′-bis (9-carbazolyl) -2,2′-dimethyl-biphenyl) ), DCB (N, N′-Dicarbazolyl-1,4-dimethene-benzene), P06 (2,7-bis (diphenylphosphineoxide) 9,9-dimethylfluorene), SimCP (3,5-bis (9-carbazolyl) tetraphenylsilane) ), UGH3 (W-bis (triphenylsilyl benzene) host material of low molecular weight can be mentioned, such as may be used singly or in combination of two or more of them.

  The constituent materials of the light emitting functional layers 6R and 6G are preferably soluble in a solvent capable of dissolving the constituent materials of the hole transport layers 5R and 5G described above. Thereby, the light emitting functional layers 6R and 6G and the hole transport layers 5R and 5G can be formed by a liquid phase process using the same solvent. That is, when the light emitting functional layers 6R and 6G are formed by a liquid phase process, the same solvent as that used when the hole transport layers 5R and 5G are formed by a liquid phase process can be used. As a result, the adhesion or affinity of the interface between the light emitting functional layers 6R, 6G and the hole transport layers 5R, 5G is increased, and carriers (positive) from the hole transport layers 5R, 5G to the light emitting functional layers 6R, 6G are increased. Hole) can be improved.

  The constituent materials of the light emitting functional layers 6R and 6G are preferably composed of a low molecular material as a main material, and more preferably composed of a low molecular guest material and a low molecular host material as a main material. preferable. Thereby, the luminous efficiency of the light emitting functional layers 6R and 6G can be increased, and the decrease in the luminous efficiency of the light emitting elements 1R and 1G due to the provision of the intermediate layer 7 can be compensated. As a result, the light emission balance between the light emitting elements 1R and 1G and the light emitting element 1B can be made excellent. From such a viewpoint, the content of the low molecular material in the light emitting functional layers 6R and 6G is preferably 60 wt% or more, more preferably 80 wt% or more, and further preferably 90 wt% or more. .

  The thicknesses of such light emitting functional layers 6R, 6G, and 6B are not particularly limited, but are preferably in the range of 5 nm to 100 nm, and more preferably in the range of 10 nm to 50 nm.

(Electron transport layer)
The electron transport layer 8 has a function of transporting electrons injected from the cathode 10 through the electron injection layer 9 to the light emitting functional layer 6B.

As a constituent material (electron transport material) of the electron transport layer 8, for example, BALq, OXD-1 (1,3,5-tri (5- (4-tert-butylphenyl) -1,3,4-oxadi) Azole)), BCP (Bathocuproine), PBD (2- (4-biphenyl) -5- (4-tert-butylphenyl) -1,2,4-oxadiazole), TAZ (3- (4-biphenyl) -5- (4-tert-butylphenyl) -1,2,4-triazole), DPVBi (4,4'-bis (1,1-bis-diphenylethenyl) biphenyl), BND (2,5-bis ( 1-naphthyl) -1,3,4-oxadiazole), DTVBi (4,4′-bis (1,1-bis (4-methylphenyl) ethenyl) biphenyl), BBD (2,5-bis (4 -Biphenylyl) -1,3 4- oxadiazole), also, tris (8-quinolinolato) aluminum _(Alq 3), oxadiazole derivatives, oxazole derivatives, Fenansororin derivatives, anthraquinodimethane derivatives, benzoquinone derivatives, naphthoquinone derivatives, anthraquinone derivatives, tetracyanoethylene anthracite A quinodimethane derivative, a fluorene derivative, a diphenyldicyanoethylene derivative, a diphenoquinone derivative, a hydroxyquinoline derivative, and the like can be given, and one or more of these can be used in combination.

  Although the thickness of the electron carrying layer 8 is not specifically limited, It is preferable to exist in the range of 1 nm or more and 100 nm or less, and it is more preferable to exist in the range of 5 nm or more and 50 nm or less.

  The electron transport layer 8 can be omitted depending on the constituent material and thickness of other layers.

(Electron injection layer)
The electron injection layer 9 has a function of improving the efficiency of electron injection from the cathode 10.

  Examples of the constituent material (electron injection material) of the electron injection layer 9 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 obtain high luminance by forming the electron injection layer 9 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 thickness of the electron injection layer 9 is not particularly limited, but is preferably in the range of 0.01 nm to 10 nm, and more preferably in the range of 0.1 nm to 10 nm.

  The electron injection layer 9 can be omitted depending on the constituent material and thickness of other layers.

(cathode)
The cathode 10 is an electrode that injects electrons into the electron transport layer 8 through the electron injection layer 9. As a constituent material of the cathode 10, it is preferable to use a material having a small work function.

  Examples of the constituent material of the cathode 10 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 10, 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 a constituent material of the cathode 10, the electron injection efficiency and stability of the cathode 10 can be improved.

  Moreover, since the light emitting element 1 of this embodiment is a bottom emission type, the cathode 10 does not need to have a light transmittance. In the case of the bottom emission type, as the constituent material of the cathode 10, for example, a metal or an alloy such as Al, Ag, AlAg, and AlNd is preferably used. By using such a metal or alloy as a constituent material of the cathode 10, the electron injection efficiency and stability of the cathode 10 can be improved.

  The thickness of the cathode 10 in the case of the bottom emission type is not particularly limited, but is preferably in the range of 50 nm to 1000 nm, and more preferably in the range of 100 nm to 500 nm.

  In addition, when the light emitting element 1 is a top emission type, it is preferable to use a metal or an alloy such as MgAg, MgAl, MgAu, and AlAg as a constituent material of the cathode 10. By using such a metal or alloy as the constituent material of the cathode 10, it is possible to improve the electron injection efficiency and stability of the cathode 10 while ensuring the light transmittance of the cathode 10.

  The thickness of the cathode 10 in the case of the top emission type is not particularly limited, but is preferably in the range of 1 nm to 50 nm, and more preferably in the range of 5 nm to 20 nm.

  According to the light emitting device 100 configured as described above, the hole transport layers 5R, 5G, and 5B and the light emitting functional layers 6R and 6G are individually provided for each element using a liquid phase process, as will be described in detail later. In addition, the intermediate layer 7 and the light emitting functional layer 6B can be formed in common to the light emitting elements 1R, 1G, and 1B by using a vapor phase process. Therefore, the light emitting elements 1R, 1G, and 1B can be efficiently manufactured.

  In particular, the light emitting device 100 is manufactured using a manufacturing method as described in detail below, so that the thickness of the light emitting functional layers 6R and 6G is made uniform. Thereby, each light emission nonuniformity of sub pixel 100R, 100G, 100B can be reduced.

(Method for manufacturing light emitting device)
Hereinafter, the manufacturing method of the light emitting device of the present invention will be described by taking the case of manufacturing the above-described light emitting device 100 as an example.

  3-5 is a figure for demonstrating the manufacturing method of the light-emitting device shown in FIG. FIG. 6 is a view for explaining another form (ink vapor pressure) of the ink application process shown in FIG. FIG. 7 is a diagram for explaining another form (pixel shape) of the ink application process shown in FIG.

  The manufacturing method of the light emitting device 100 includes: [1] a step of forming the anodes 3R, 3G, 3B, the partition walls 31, the hole injection layers 4R, 4G, 4B and the hole transport layers 5R, 5G; A step of forming 6R, 6G and a hole transport layer 5B; [3] a step of forming the intermediate layer 7, the light emitting functional layer 6B, the electron transport layer 8, the electron injection layer 9 and the cathode 10, and [4] the cathode 10 And a step of adhering the sealing substrate 40 with the resin layer 32 interposed therebetween. Hereinafter, each process is demonstrated one by one.

[1]
1-1
First, the circuit board 20 is prepared. As shown in FIG. 3A, after the anodes 3R, 3G, and 3B are formed on the circuit board 20, the partition walls 31 are formed.

  The anodes 3R, 3G, and 3B are formed by, for example, forming an electrode material on the circuit board 20 by using a vapor deposition method such as an evaporation method or a CVD method, and then patterning the electrode material by etching or the like. can get.

  The partition wall 31 can be formed by patterning using a photolithography method or the like so that the anodes 3R, 3G, and 3B are 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 circuit board 20 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 . Moreover, liquid repellency can be provided to the partition wall 31 by the material to be used.

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

  Here, as conditions for the oxygen plasma treatment, for example, the plasma power is about 100 to 800 W, the oxygen gas flow rate is about 50 to 100 mL / min, and the conveyance speed of the member to be treated (anode 3R, 3G, 3B) is 0.5 to 10 mm / min. It is preferable that the temperature of the circuit board 20 is about 70 to 90 ° C. for about sec.

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. Note that when the partition wall 31 having liquid repellency is used depending on the constituent material, the above plasma treatment can be omitted.

1-2
Next, as shown in FIG. 3B, the ink 4 a for forming a hole injection layer is applied from the inkjet head 200 onto the anodes 3 </ b> R, 3 </ b> G, and 3 </ b> B in the partition wall 31.

  The ink 4a is obtained by dissolving the constituent material of the hole injection layers 4R, 4G, and 4B or a precursor thereof in a solvent or dispersing in a dispersion medium. Examples of the solvent or dispersion medium include various inorganic solvents, various organic solvents, or mixed solvents containing these.

  Thereafter, the ink 4a on the anode 3 is dried (desolvent or dedispersing medium), and heat-treated as necessary, so that the hole injection layers 4R, 4G, and 4B are formed as shown in FIG. Form.

  Drying can be performed, for example, by standing in an atmospheric pressure or reduced pressure atmosphere, heat treatment, spraying of an inert gas, etc., but after drying under reduced pressure for about 10 minutes to 1 hour in a vacuum state of 5 Pa or less. It is preferable to heat dry at 100 ° C. to 250 ° C. for about 5 minutes to 30 minutes in an atmospheric pressure oven or in a hot plate. Thereby, it is possible to form the hole injection layers 4R, 4G, and 4B that are flat and have excellent characteristics.

  As described above, the hole injection layers 4R, 4G, and 4B are formed by the liquid phase process using the ink 4a.

1-3
Next, as shown in FIG. 3 (d), the ink 5 a for forming a hole transport layer is applied from the inkjet head 200 onto the hole injection layers 4 </ b> R and 4 </ b> G in the partition wall 31.

  The ink 5a is obtained by dissolving the constituent material of the hole transport layers 5R and 5G or a precursor thereof in a solvent or dispersing in a dispersion medium. Examples of the solvent or dispersion medium include various inorganic solvents, various organic solvents, or mixed solvents containing these.

  Thereafter, the ink 5a on the hole injection layers 4R and 4G is dried (desolvent or dedispersion medium) and subjected to heat treatment as necessary, so that the hole transport layer 5R as shown in FIG. 5G is formed.

  Drying can be performed, for example, by standing in an atmospheric pressure or reduced pressure atmosphere, heat treatment, spraying of an inert gas, etc., but after drying under reduced pressure for about 10 minutes to 1 hour in a vacuum state of 5 Pa or less. It is preferable to heat and dry at 100 ° C. to 250 ° C. for about 5 minutes to 30 minutes in an oven in a nitrogen atmosphere or on a hot plate. Thereby, the flat and excellent hole transport layers 5R and 5G having excellent characteristics can be formed.

  As described above, the hole transport layers 5R and 5G are formed by the liquid phase process using the ink 5a.

[2]
2-1
Next, as shown in FIG. 4B, the ink 6a and 6b for forming the light emitting functional layer are applied from the inkjet head 200 onto the hole transport layers 5R and 5G in the partition wall 31, respectively. An ink 5b for forming a hole transport layer is applied onto the hole injection layer 4B in the partition wall 31.

  That is, the ink 5b containing a hole transport material or a precursor thereof is applied to the subpixel 100B, the red light emitting material or the ink 6a containing the precursor thereof is applied to the subpixel 100R, and the green light emitting material or the subpixel 100G. An ink application process for applying the ink 6b containing the precursor is performed. Here, the region in the partition wall 31 of the sub-pixel 100B is the “first pixel region”, the region in the partition wall 31 of one of the sub-pixels 100R and 100G is the “second pixel region”, and the other partition walls 31. The area inside is the “third pixel area”. Further, the ink 5b is “first ink”, and one of the inks 6a and 6b (ink applied to the second pixel area) is “second ink”, and the other ink (ink is applied to the third pixel area). Ink) is “third ink”.

  The ink 6a is obtained by dissolving the constituent material of the light emitting functional layer 6R or its precursor in a solvent or dispersing it in a dispersion medium. The ink 6b is obtained by dissolving the constituent material of the light emitting functional layer 6G or its precursor in a solvent or dispersing it in a dispersion medium. Examples of the solvent or dispersion medium include various inorganic solvents, various organic solvents, or mixed solvents containing these.

  The ink 5b is obtained by dissolving the constituent material of the hole transport layer 5B or its precursor in a solvent or dispersing it in a dispersion medium. Examples of the solvent or dispersion medium include various inorganic solvents, various organic solvents, or mixed solvents containing these.

  In this ink application process, as shown in FIG. 4B, the application amount of the ink 5b is larger than the application amounts of the inks 6a and 6b. Thereby, the time required to complete the drying of the ink 5b in the same atmosphere can be made longer than the time required to complete the drying of the inks 6a and 6b. Therefore, in the drying process described later, the inks 6a and 6b can be dried in the presence of the undried ink 5b while simplifying the drying process. Here, the concentrations of the inks 5b, 6a, and 6b are adjusted so that the hole transport layer 5B and the light emitting functional layers 6R and 6G have a desired film thickness after the drying process described later, respectively.

  Also, when the amount of ink 5b applied is larger than the amount of ink 6a, 6b applied, the amount of ink applied to ink 5b should be 1.1 to 3 times the amount of ink 6a or 6b applied. Is preferable, and it is more preferable to set it to 1.3 times or more and 2 times or less. Thereby, ink 5b, 6a, 6b can be dried suitably. On the other hand, if the applied amount of the ink 5b is too large, the drying time of the ink 5b may become longer than necessary, or the structure may be complicated by increasing the partition wall 31 of the sub-pixel 100B. On the other hand, if the applied amount of the ink 5b is too small, there may be a pixel region in which the inks 6a and 6b cannot be dried in the presence of the undried ink 5b due to variations in the area of each pixel region.

Further, the specific ink application amount (application amount per unit area) of the inks 5b, 6a, and 6b is preferably 6.6 × 10 ⁻³ pl / μm ² or more. Thereby, the film thickness of the light emitting functional layers 6R and 6G can be effectively made uniform.

  In addition, in the drying process described later, if the inks 6a and 6b can be dried in the presence of the undried ink 5b, the applied amount of the ink 5b may be the same as the applied amount of the inks 6a and 6b. The amount of ink 6a, 6b may be less than the applied amount.

  As a method for drying the inks 6a and 6b in the presence of the undried ink 5b in the drying step described later, in addition to the above, a method for changing the drying conditions of each pixel in the drying step, as shown in FIG. These methods include a method of making the vapor pressure of 5b lower than the vapor pressure of the inks 6a and 6b, a method of making the area of the sub-pixel 100B smaller than the areas of the sub-pixels 100R and 100G, as shown in FIG. Can be used alone or in combination of two or more.

  In particular, by using a method in which the vapor pressure of the ink 5b is lower than the vapor pressure of the inks 6a and 6b or a method in which the area of the subpixel 100B is smaller than the areas of the subpixels 100R and 100G in the ink application step, Under the same atmosphere, the time required to complete the drying of the ink 5b can be made longer than the time required to complete the drying of the inks 6a and 6b. Therefore, the inks 6a and 6b can be dried in the presence of the undried ink 5b while simplifying the drying process. Further, according to these methods, even when the application amount of the ink 5b is equal to the application amount of the inks 6a and 6b, the time required to complete the drying of the ink 5b is more than the time required to complete the drying of the inks 6a and 6b. Can also be long.

  In the ink application step, when using a method in which the vapor pressure of the ink 5b is lower than the vapor pressure of the inks 6a and 6b, the type of the solvent or dispersion medium of the inks 5b, 6a, and 6b may be adjusted as appropriate. Specifically, the vapor pressure of the solvent or dispersion medium of the ink 5b may be made lower than the vapor pressure of the inks 6a and 6b. As a result, the ink 5b is less likely to dry than the inks 6a and 6b, and the time required to complete the drying of the ink 5b can be made longer than the time required to complete the drying of the inks 6a and 6b.

  Further, in the case of using a method in which the area of the sub-pixel 100B is made smaller than the areas of the sub-pixels 100R and 100G, the opening area of each pixel may be appropriately adjusted as shown in FIG. Specifically, the opening area of the subpixel 100B may be smaller than the opening areas of the subpixels 100R and 100G. As a result, the solvent or dispersion medium of the ink 5b applied to the sub-pixel 100B becomes less volatile than the solvent or dispersion medium of the inks 6a and 6b applied to the sub-pixels 100R and 100G, and the drying of the ink 5b is completed. Can be made longer than the time required to complete drying of the inks 6a and 6b. In the light emitting device 100A shown in FIG. 7, the lengths of the sub-pixels 100B in the longitudinal direction are made shorter than the lengths of the sub-pixels 100R and 100G in the longitudinal direction while making the widths equal to each other.

2-2
Thereafter, the inks 6a and 6b on the hole transport layers 5R and 5G and the ink 5b on the hole injection layer 4B are dried (desolvent or dedispersion medium), and heat-treated as necessary, whereby the light emitting functional layer 6R, 6G and hole transport layer 5B are formed.

  At this time, as shown in FIG. 5B, after the inks 6a and 6b are dried in the presence of the undried ink 5b to form the light emitting functional layers 6R and 6G, as shown in FIG. Then, the ink 5b is dried to form a hole transport layer 5B. As a result, the inks 6a and 6b can be dried in the solvent or dispersion medium atmosphere of the ink 5b from the start of drying to the completion of drying, and the drying speed of the inks 6a and 6b can be reduced. Therefore, it is possible to make the film thickness of the light emitting functional layers 6R and 6G obtained uniform.

  On the other hand, when the drying of the inks 6a and 6b is completed at the same time as the drying of the ink 5b or after the drying of the ink 5b is completed, the solvent or dispersion medium of the ink 5b is not present or is in an atmosphere with a small amount. As a result, the inks 6a and 6b are dried. During this time, the inks 6a and 6b are dried at a rapid speed. As a result, the inks 6a and 6b are solidified while the flatness of the liquid surfaces of the inks 6a and 6b is lost, and the film thickness uniformity of the resulting light emitting functional layers 6R and 6G is lowered.

  Drying can be performed, for example, by standing in an atmospheric pressure or reduced pressure atmosphere, heat treatment, spraying of an inert gas, etc., but after drying under reduced pressure for about 10 minutes to 1 hour in a vacuum state of 5 Pa or less. It is preferable to heat and dry at 100 ° C. to 250 ° C. for about 5 minutes to 30 minutes in an oven in a nitrogen atmosphere or on a hot plate. Thereby, the light emitting functional layers 6R and 6G and the hole transport layer 5B having flat and excellent characteristics can be formed.

  As described above, the light emitting functional layers 6R and 6G and the hole transport layer 5B are formed by the liquid phase process using the inks 6a, 6b, and 5b.

[3]
Next, as shown in FIG. 5B, the intermediate layer 7, the light emitting functional layer 6 </ b> B, the electrons are formed on the light emitting functional layers 6 </ b> R and 6 </ b> G and the hole transport layer 5 </ b> B so as to cover the barrier ribs 31. The transport layer 8, the electron injection layer 9, and the cathode 10 are formed in this order.

  The intermediate layer 7, the light emitting functional layer 6 </ b> B, the electron transport layer 8, the electron injection layer 9, and the cathode 10 can be formed by, for example, a vapor phase process using a dry plating method such as vacuum deposition.

[4]
Finally, as shown in FIG. 5C, the sealing substrate 40 is bonded to the cathode 10 through the resin layer 32 (sealing layer). Thereby, the light emitting device 100 is obtained.

  As described above, the hole transport layers 5R, 5G, and 5B and the light emitting functional layers 6R and 6G are individually formed for each element by using a liquid phase process, and the intermediate layer 7 and light emission are formed by using a gas phase process. The functional layer 6B is formed in common to the light emitting elements 1R, 1G, and 1B, respectively, and the light emitting elements 1R, 1G, and 1B can be efficiently manufactured.

  According to the method for manufacturing the light emitting device 100 as described above, since the inks 6a and 6b are dried in the presence of the ink 5b, the drying speed of the inks 6a and 6b can be reduced. Therefore, the thickness of the light emitting functional layers 6R and 6G obtained can be made uniform, and as a result, the light emission unevenness of the subpixels 100R and 100G can be reduced. Further, the uniformity of the film thickness of the hole transport layer 5B in the sub-pixel 100B has little influence on the light emission unevenness. For this reason, it is possible to obtain the light emitting device 100 in which the uneven light emission of each of the subpixels 100R, 100G, and 100B is reduced.

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

  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 light emitting device 100 described above.

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

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 cellular phone 1200, the display unit is configured by the light emitting device 100 described above.

  FIG. 10 is a perspective view showing a configuration of a digital still camera which is an example of the electronic apparatus of the present invention. 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 light emitting 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 input / output terminal 1314 for data communication 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.

  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. 10, the electronic apparatus of the present invention includes, for example, a smartphone, a tablet terminal, a clock, a television, Video camera, viewfinder type, monitor direct-view type video tape recorder, laptop personal computer, car navigation device, pager, electronic notebook (including communication function), electronic dictionary, calculator, electronic game device, word processor, workstation , Videophones, crime prevention TV monitors, electronic binoculars, POS terminals, devices equipped with touch panels (for example, cash dispensers and ticket vending machines for financial institutions), medical devices (for example, electronic thermometers, blood pressure monitors, blood glucose meters, electrocardiographs) , Ultrasonic diagnostic equipment, endoscope Display device), fish finders, various measurement devices, gauges (e.g., gages for vehicles, aircraft, and ships), a flight simulator, various monitors, and a projection display such as a projector.

  As mentioned above, although the manufacturing method of the light-emitting device of this invention, the light-emitting device, and the electronic device were demonstrated based on embodiment of illustration, this invention is not limited to these.

Next, specific examples of the present invention will be described.
1. Production of light emitting device (Example 1)
<1> First, a transparent glass substrate having a thickness of 0.5 mm was prepared. Next, an ITO electrode (first anode, second anode, and third anode) having a thickness of 100 nm was formed as a pixel electrode of each of the RGB pixels on the substrate by sputtering. Then, after forming an insulating layer composed of an acrylic resin, the insulating layer was patterned using a photolithography method to expose each ITO electrode, thereby forming a partition (a bank having liquid repellency). . Here, the partition walls were formed so that the pixel region had a shape as shown in FIG. The area of each pixel region was 30000 μm ² .
And the board | substrate was immersed in order of acetone and 2-propanol, and ultrasonically cleaned.

  <2> Next, the hole injection layer forming ink is filled in the respective partition walls of the RGB pixels by the ink jet method and applied onto the ITO electrode, and then dried under reduced pressure and then heat-treated (baked). A hole injection layer having a thickness of 50 nm was formed.

  Here, a 0.5 wt% aqueous dispersion of PEDOT: PSS was used as the hole injection layer forming ink. The applied amount of the hole injection layer forming ink was 40 shots (10 pl / 1 shot) for all the R, G, and B pixels. The firing was performed under atmospheric pressure, the firing temperature was 200 ° C., and the firing time was 10 minutes.

  <3> Next, the hole transport layer forming ink is filled in each partition wall of the RG pixel by an ink jet method and applied onto the hole injection layer, and then dried under reduced pressure, and then heat-treated (baked). As a result, a hole transport layer (first and third hole transport layers) having a thickness of 20 nm was formed.

  Here, as a hole transport layer forming ink, a 3-phenoxytoluene solution containing 1.5 wt% of TFB (poly (9,9-dioctyl-fluorene-co-N- (4-butylphenyl) -diphenylamine)) is used. Using. The applied amount of the hole transport layer forming ink was 36 shots (10 pl / 1 shot) for both the R and G pixels. The firing was performed in a glove box filled with nitrogen, the firing temperature was 200 ° C., and the firing time was 30 minutes.

  <4> Next, the light emitting functional layer forming ink is filled in each partition wall of the RG pixel by an ink jet method and applied onto the hole transport layer, and the hole transport layer forming ink is applied to the B pixel. After filling the partition wall by an ink jet method and applying it onto the hole injection layer, this was dried under reduced pressure and then subjected to heat treatment (firing) to obtain a light emitting functional layer (first and third light emitting functional layers) having a thickness of 20 nm. ) And a 20 nm thick hole transport layer (first hole transport layer).

  Here, CBP (4,4′-bis (9-dicarbazoyl) -2,2′-biphenyl), Ir (ppy) 3 (Fac-Tris (2-phenylpyridine) is used as an ink for forming a light emitting functional layer of a G pixel. A 3-phenoxytoluene solution (concentration: 1.2 wt%) in which iridium) was mixed at a weight ratio of 90:10 was used. Further, CBP (4,4′-bis (9-dicarbazoyl) -2,2′-biphenyl) and btp2Ir (acac) were mixed at a weight ratio of 90:10 as the light emitting functional layer forming ink for the R pixel. A phenoxytoluene solution (concentration 1.2 wt%) was used.

  Further, the application amount of the light emitting functional layer forming ink was 20 shots (10 pl / 1 shot) for the R pixel and 30 shots (10 pl / 1 shot) for the G pixel. The vapor pressure at 25 ° C. of the light emitting functional layer forming ink was 3 Pa.

  As the hole transport layer forming ink, a 3-phenoxytoluene solution containing α-NPD, which is a low molecular hole transport material, at a concentration of 0.3 wt% was used. The applied amount of the hole transport layer forming ink was 40 shots (10 pl / 1 shot) for the B pixel. The vapor pressure of the hole transport layer forming ink at 25 ° C. was 3 Pa. Moreover, drying was performed by drying under reduced pressure for 10 minutes at a vacuum degree of 5 Pa or less. The firing was performed in a glove box filled with nitrogen, the firing temperature was 220 ° C., and the firing time was 10 minutes.

  <5> Next, a light emitting functional layer forming material (second light emitting functional layer) having a thickness of 20 nm was formed by depositing a material for forming a light emitting functional layer across the RGB pixels by vapor deposition.

  Here, the material for forming the light emitting functional layer is obtained by doping 90 parts by mass of CBP (4,4′-bis (9-dicarbazoyl) -2,2′-biphenyl) with 10 parts by mass of FIrpic.

<6> Next, Alq ₃ was deposited on the second light emitting functional layer by a vacuum deposition method to form an electron transport layer having a thickness of 20 nm.

  <7> Next, on the electron transport layer, lithium fluoride (LiF) was formed by a vacuum deposition method to form an electron injection layer having a thickness of 1 nm.

<8> Next, Al was formed into a film by the vacuum evaporation method on the electron injection layer. Thereby, a cathode having a thickness of 200 nm made of Al was formed.
Through the above steps, a light emitting device having RGB pixels (first to third light emitting elements) was manufactured.

(Example 2)
A light emitting device was manufactured in the same manner as in Example 1 except that the application amount of the light emitting functional layer forming ink for the R pixel was changed to 30 shots. In addition, the density | concentration of the light emission functional layer formation ink for R pixels was adjusted so that the thickness of the light emission functional layer of R pixel obtained might be set to 20 nm.

Example 3
A light emitting device was manufactured in the same manner as in Example 1 except that the application amount of the ink for forming the light emitting functional layer of the R pixel was 19 shots. In addition, the density | concentration of the light emission functional layer formation ink for R pixels was adjusted so that the thickness of the light emission functional layer of R pixel obtained might be set to 20 nm.

Example 4
A light emitting device was manufactured in the same manner as in Example 1 except that the application amount of the ink for forming the light emitting functional layer of the R pixel was 39 shots. In addition, the density | concentration of the light emission functional layer formation ink for R pixels was adjusted so that the thickness of the light emission functional layer of R pixel obtained might be set to 20 nm.

(Example 5)
A light emitting device was manufactured in the same manner as in Example 1 except that the amount of the light emitting functional layer forming ink applied to the RG pixels was 19 shots for each RG pixel. In addition, the density | concentration of the light emission functional layer formation ink for RG pixels was adjusted so that the thickness of the light emission functional layer of each pixel of RG obtained might be 20 nm.

(Example 6)
A light emitting device was manufactured in the same manner as in Example 1 except that the amount of light emitting functional layer forming ink applied to the RG pixels was 39 shots for each RG pixel. In addition, the density | concentration of the light emission functional layer formation ink for RG pixels was adjusted so that the thickness of the light emission functional layer of each pixel of RG obtained might be 20 nm.

(Example 7)
The amount of each of the light emitting functional layer forming ink for the R pixel and the hole transporting layer forming ink for the B pixel is set to 30 shots, and the vapor pressure of the ink for forming the hole transporting layer for the B pixel at 25 ° C. A light emitting device was manufactured in the same manner as in Example 1 except that the pressure was adjusted to 1 Pa. In addition, the density | concentration of the light emission functional layer formation ink for RG pixels was adjusted so that the thickness of the light emission functional layer of each pixel of RG obtained might be 20 nm. Moreover, the density | concentration of the positive hole transport layer forming ink for B pixels was adjusted so that the thickness of the positive hole transport layer of B pixel obtained might be set to 20 nm.

(Example 8)
The implementation described above, except that the amount of each of the light emitting functional layer forming ink for the R pixel and the hole transport layer forming ink for the B pixel was set to 30 shots, and the area of the pixel region of the B pixel was 20000 μm ^2. A light emitting device was manufactured in the same manner as in Example 1. In addition, the density | concentration of the light emission functional layer formation ink for RG pixels was adjusted so that the thickness of the light emission functional layer of R pixel obtained might be 20 nm. Moreover, the density | concentration of the positive hole transport layer forming ink for B pixels was adjusted so that the thickness of the positive hole transport layer of B pixel obtained might be set to 20 nm. Each pixel region was formed to have the shape shown in FIG.

(Comparative Example 1)
The light emitting device was manufactured in the same manner as in Example 1 except that the application amount of the R pixel light emitting functional layer forming ink was 40 shots and the B pixel hole transport layer forming ink application amount was 20 shots. Manufactured. In addition, the density | concentration of the light emission functional layer formation ink for R pixels was adjusted so that the thickness of the light emission functional layer of R pixel obtained might be set to 20 nm. Moreover, the density | concentration of the positive hole transport layer forming ink for B pixels was adjusted so that the thickness of the positive hole transport layer of B pixel obtained might be set to 20 nm.

(Comparative Example 2)
A light emitting device was manufactured in the same manner as in Example 1 except that the application amount of the R pixel light emitting functional layer forming ink was 40 shots. In addition, the density | concentration of the light emission functional layer formation ink for R pixels was adjusted so that the thickness of the light emission functional layer of R pixel obtained might be set to 20 nm.

(Comparative Example 3)
A light emitting device is manufactured in the same manner as in Example 1 except that the application amount of the R pixel light emitting functional layer forming ink is 30 shots and the G pixel light emitting functional layer forming ink application amount is 40 shots. did. The concentration of the light emitting functional layer forming ink for each pixel of RG was adjusted so that the thickness of the light emitting functional layer of each pixel of RG obtained was 20 nm.

(Comparative Example 4)
The light emitting device was prepared in the same manner as in Example 1 except that the application amount of the R pixel light emitting functional layer forming ink was 30 shots and the B pixel hole transport layer forming ink application amount was 30 shots. Manufactured. In addition, the density | concentration of the light emission functional layer formation ink for R pixels was adjusted so that the thickness of the light emission functional layer of R pixel obtained might be set to 20 nm. Moreover, the density | concentration of the positive hole transport layer forming ink for B pixels was adjusted so that the thickness of the positive hole transport layer of B pixel obtained might be set to 20 nm.

(Comparative Example 5)
The light emitting device was manufactured in the same manner as in Example 1 except that the amount of the light emitting functional layer forming ink for the R pixel was 40 shots and the amount of the light emitting functional layer forming ink for the G pixel was 40 shots. did. The concentration of the light emitting functional layer forming ink for each pixel of RG was adjusted so that the thickness of the light emitting functional layer of each pixel of RG obtained was 20 nm.

(Comparative Example 6)
The light emission was performed in the same manner as in Example 7 except that the vapor pressure at 25 ° C. of each of the ink for forming the light emitting functional layer for the G pixel and the ink for forming the hole transport layer for the B pixel was adjusted to 10 Pa. The device was manufactured.

(Comparative Example 7)
Except for adjusting the vapor pressure at 25 ° C. of the light emitting functional layer forming ink for the R pixel to 10 Pa and adjusting the vapor pressure at 25 ° C. of the ink for forming the hole transport layer of the B pixel to 3 Pa. A light emitting device was manufactured in the same manner as in Example 7.

(Comparative Example 8)
A light emitting device was manufactured in the same manner as in Example 7 except that the vapor pressure at 25 ° C. of the ink for forming the hole transport layer of the B pixel was adjusted to 3 Pa.

(Comparative Example 9)
A light emitting device was manufactured in the same manner as in Example 8 except that the area of the pixel region of the G pixel was 20000 μm ² and the area of the pixel region of the B pixel was 30000 μm ³ .

(Comparative Example 10)
A light emitting device was manufactured in the same manner as in Example 8 except that the area of the pixel region of each pixel of RG was 20000 μm ² and the area of the pixel region of B pixel was 30000 μm ³ .

2. Evaluation Regarding the light emitting devices of the respective examples and comparative examples manufactured as described above, the light emission state of each pixel of RGB was measured and evaluated according to the following criteria.

(Double-circle): The light emission nonuniformity is not recognized and the light emission state is uniform.
○: Although some unevenness in light emission is observed, the uniformity of the light emission state is high.
X: Uneven light emission is noticeable and the light emission state is irregular.
The evaluation results are shown in Table 1.

  As can be seen from Table 1, the light emitting device of each example has higher uniformity of the light emission state of each RGB pixel than the light emitting device of each comparative example.

DESCRIPTION OF SYMBOLS 1 ... Light emitting element 1B ... Light emitting element 1G ... Light emitting element 1R ... Light emitting element 3 ... Anode 3B ... Anode 3G ... Anode 3R ... Anode 4 ... Hole injection layer 4B ... Hole injection layer 4G ... hole injection layer 4R ... hole injection layer 4a ... ink 5 ... hole transport layer 5B ... hole transport layer 5G ... hole transport layer 5R ... hole transport layer 5a ... ink 5b ... Ink 6B ... Light emitting functional layer 6G ... Light emitting functional layer 6R ... Light emitting functional layer 6a ... Ink 6b ... Ink 7 ... Intermediate layer 8 ... Electron transport layer 9 ... Electron injection layer 10 ... Cathode 20 ... Circuit board 21 ... Substrate 22 ... Interlayer insulating film 23 ... Switching element 24 ... Wiring 31 ... Partition 32 ... Resin layer 40 ... Sealing substrate 100 ... Light emitting device 100A ... Light emitting device 100R ... sub pixel 100G ... sub pixel 100B ... sub pixel 200 ... ink Jet head 231 ... Semiconductor layer 232 ... Gate insulating layer 233 ... Gate electrode 234 ... Source electrode 235 ... Drain electrode 1100 ... Personal computer 1102 ... Keyboard 1104 ... Body 1106 ... Display unit 1200 ... Portable Telephone 1202 ... Operation button 1204 ... Earpiece 1206 ... Mouthpiece 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 Television monitor 1440 Personal computer

Claims (11)

A first ink containing a hole transport material or a precursor thereof is applied to the first pixel region, and a second ink containing a light emitting material or a precursor thereof is applied to a second pixel region different from the first pixel region. An ink application process;
A drying step of drying the second ink in the presence of the undried first ink to form a light emitting functional layer and then drying the first ink to form a hole transport layer. A method for manufacturing a light emitting device.   The method for manufacturing a light emitting device according to claim 1, wherein, in the ink application step, the application amount of the first ink is larger than the application amount of the second ink.   3. The method for manufacturing a light emitting device according to claim 1, wherein in the ink application step, the vapor pressure of the first ink is lower than the vapor pressure of the second ink.   4. The method for manufacturing a light emitting device according to claim 1, wherein an area of the first pixel region is smaller than an area of the second pixel region. 5. A first anode provided in the first pixel region;
A second anode provided in the second pixel region;
A common cathode provided in common to the first pixel region and the second pixel region;
A first hole transport layer provided between the first anode and the common cathode;
A first light emitting functional layer provided between the second anode and the common cathode;
A first light-emitting functional layer provided between the first hole transport layer and the first light-emitting functional layer and the common cathode in common to the first pixel region and the second pixel region. A method of manufacturing a light emitting device,
In the drying step, the second ink is dried in the presence of the undried first ink to form the first light emitting functional layer, and then the first ink is dried to form the first hole transport layer. The method for manufacturing a light emitting device according to claim 1, wherein the light emitting device is formed. The first pixel region is a blue pixel region;
The light emitting device manufacturing method according to claim 5, wherein the second pixel region is a red pixel region or a green pixel region. The common cathode is also provided in common in a third pixel region different from the first pixel region and the second pixel region,
The light emitting device
A third anode provided in the third pixel region;
A third light emitting functional layer provided between the third anode and the common cathode,
In the ink application step, a third ink is applied to the third pixel region,
In the drying step, the third ink is dried in the presence of the undried first ink to form the third light emitting functional layer, and then the first ink is dried to form the first hole transport layer. The manufacturing method of the light-emitting device of Claim 5 or 6 formed. In the ink application step, a third ink is applied to a third pixel region different from the first pixel region and the second pixel region;
8. The drying process according to claim 1, wherein in the drying step, the third ink is dried in the presence of the undried first ink to form a light emitting layer, and then the first ink is dried. Method for manufacturing the light emitting device. The first pixel region is a blue pixel region;
9. The method of manufacturing a light emitting device according to claim 7, wherein one of the second pixel region and the third pixel region is a red pixel region, and the other pixel region is a green pixel region.   A light-emitting device manufactured using the method for manufacturing a light-emitting device according to claim 1.   An electronic apparatus comprising the light emitting device according to claim 10.

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