JP2006012552A - Manufacturing method of organic photoelectric conversion element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing an organic photoelectric conversion element like an organic EL element having good photoelectric conversion characteristics while preventing lowering of dispersion stability of photocatalyst containing painting liquid caused by a photoelectric conversion property improving material. <P>SOLUTION: The manufacturing method of the organic photoelectric conversion element comprises a photocatalyst-containing layer forming process forming the photocatalyst-containing layer on a substrate in which a first electrode is formed; a doping process doping the photoelectric conversion property improving material in the photocatalyst-containing layer; and an organic photoelectric conversion layer forming process forming the organic photoelectric conversion layer on the photocatalyst-containing layer. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for producing an organic photoelectric conversion element such as an organic electroluminescent element and an organic thin film solar cell.

  Organic electroluminescent (hereinafter abbreviated as EL) elements are attracting attention as self-luminous planar display elements. Among them, an organic EL display using an organic substance as a light emitting material has high luminous efficiency such as high luminance light emission even when an applied voltage is less than 10 V, and can emit light with a simple element structure. It is expected to be applied to advertisements for displaying patterns in light emission and other simple displays for low cost.

  However, when actually manufacturing a display using an organic EL element, patterning of an electrode and an organic EL layer is necessary, and typically requires a photolithography process and a patterning process by a complicated pattern film forming apparatus, This leads to process complexity and cost increase. In addition, in the method of patterning the organic EL material by mask vapor deposition, a high-priced vacuum device is required, and yield and cost are problematic. On the other hand, the method of forming a pattern by the ink jet method has a problem in terms of yield and film thickness uniformity although the process is relatively simple. Further, when various shapes such as EL elements for advertisement and an increase in area are required, there is a problem that productivity is significantly reduced.

  As described above, in the manufacture of EL elements, particularly organic EL displays, the number of processes is very large in order to perform patterning of electrodes, organic EL layers, insulating layers and the like, which is large in terms of yield, productivity, and cost. I have a problem.

  In order to solve such problems, Patent Document 1 uses a photocatalyst-containing layer in the EL element manufacturing process, and forms a wettability change pattern with changed wettability by pattern exposure on the photocatalyst-containing layer. However, a method has been proposed in which a fine EL layer can be patterned more easily and accurately by patterning the EL layer using this wettability change pattern. However, since the photocatalyst-containing layer has a low resistivity, there is a problem that when it is included in an EL element, the light emission characteristics (current-voltage characteristics and light emission luminance-voltage characteristics) are deteriorated.

Therefore, Patent Document 2 proposes a method for improving the light emission characteristics of an EL element by adding a photoelectric conversion characteristic improving substance containing a metal salt of Fe or Cu to the photocatalyst containing layer. In this method, a photocatalyst-containing layer-forming coating liquid to which a photoelectric conversion property-improving substance is added is applied on a substrate with an ITO electrode to form a photocatalyst-containing layer containing a photoelectric conversion characteristic-improving substance, and this photocatalyst-containing layer is formed. An EL layer is formed on the layer. However, the photocatalyst-containing layer forming coating solution is a solution in which a fine photocatalyst such as TiO ₂ is highly dispersed in a solvent. When the above-described Fe or Cu metal salts are added, the photocatalyst-containing layer forming coating solution is used. In some cases, the dispersion stability of the working liquid is lost, the TiO ₂ particles are aggregated, and the photocatalyst-containing layer forming coating liquid becomes cloudy. When the photocatalyst-containing layer is formed using the coating solution for forming the photocatalyst-containing layer that has become dispersible due to such dispersion stability, and the organic EL layer is formed thereon, the photoelectric conversion property improving substance is added. Nevertheless, there is a problem that the characteristics (current-voltage characteristics, light emission luminance-voltage characteristics, lifetime, etc.) of the organic EL element are deteriorated.

JP 2001-257073 A JP 2002-15867 A

  The present invention has been made in view of the above problems, and prevents a decrease in the dispersion stability of the photocatalyst-containing layer-forming coating liquid due to the photoelectric conversion property improving substance, such as an organic EL device having good photoelectric conversion properties, etc. The main object is to provide a method for producing an organic photoelectric conversion element.

As a result of intensive studies in view of the above circumstances, the present inventor does not add a photoelectric conversion property improving substance to the photocatalyst containing layer forming coating solution, but first forms a photocatalyst containing layer to which no photoelectric conversion property improving substance is added. In the photocatalyst-containing layer forming coating liquid, a photocatalyst-containing layer is formed using a coating liquid for the photocatalyst, and the photocatalyst-containing layer is doped with a photoelectric conversion property improving substance, and then an organic photoelectric conversion layer is formed. It was found that a photocatalytic material such as TiO ₂ could be prevented from agglomerating and a high-performance organic photoelectric conversion device could be produced, and the present invention was completed.

That is, in the present invention, a base, a first electrode formed on the base, a photocatalyst containing layer formed on the first electrode and containing a photocatalyst and a photoelectric conversion property improving substance, and the photocatalyst containing layer An organic photoelectric conversion device having an organic photoelectric conversion layer formed thereon and a second electrode formed on the organic photoelectric conversion layer,
A photocatalyst-containing layer forming step for forming a photocatalyst-containing layer on the substrate on which the first electrode is formed, a doping step for doping the photocatalyst-containing layer with a photoelectric conversion property improving substance, and the photoelectric conversion property improving substance are doped An organic photoelectric conversion layer forming step of applying an organic photoelectric conversion layer forming coating solution on the photocatalyst-containing layer and forming an organic photoelectric conversion layer is provided. .

  In the present invention, after the photocatalyst containing layer forming step, a doping step of doping the photocatalyst containing layer with a photoelectric conversion property improving substance is performed, so that the photocatalyst containing layer forming coating liquid used in the photocatalyst containing layer forming step is photoelectrically converted. Since there is no need to add a property-improving substance, aggregation of the photocatalyst in the photocatalyst-containing layer forming coating liquid can be prevented, and an organic photoelectric conversion element having good photoelectric conversion characteristics can be produced.

  In the above invention, the photocatalyst-containing layer is one whose wettability is changed by the action of the photocatalyst accompanying energy irradiation, and the photocatalyst-containing layer is irradiated with energy to change the wettability of the photocatalyst-containing layer. A changing step may be performed. By irradiating the photocatalyst-containing layer with energy, the wettability can be changed and the surface of the photocatalyst-containing layer can be made lyophilic, so that it becomes easy to apply the organic photoelectric conversion layer forming coating liquid, and the organic photoelectric conversion layer This is because it can be easily formed. Moreover, since the wettability change pattern in which the wettability of the photocatalyst containing layer is changed can be formed by irradiating energy in a pattern, it is useful when the patterning of the organic photoelectric conversion layer is required.

  In the present invention, the doping step may be a step of bringing the photoelectric conversion property improving substance-containing liquid containing the photoelectric conversion property improving substance into contact with the photocatalyst containing layer, and the photoelectric conversion property improving substance. May be a step of vaporizing and doping the photocatalyst-containing layer.

  Furthermore, in the present invention, the photoelectric conversion property improving substance is preferably a metal salt of Fe or Cu, or iodine. This is because the effect of improving the photoelectric conversion characteristics is high.

  In the present invention, in the photocatalyst-containing layer forming step, it is preferable to use a photocatalyst-containing layer forming coating solution having a neutral pH and containing a photocatalyst. The photocatalyst-containing layer forming coating solution having a neutral pH has poor photocatalyst dispersibility compared to the photocatalyst-containing layer forming coating solution having an acidic pH, and such photocatalyst has a poor dispersibility. When the above-described photoelectric conversion property improving substance is added to the photocatalyst-containing layer forming coating solution having a neutral pH, the photocatalyst dispersibility is further deteriorated, and it is difficult to improve the photoelectric conversion properties. In the present invention, as described above, since the photoelectric conversion property-improving substance is doped after the formation of the photocatalyst containing layer, the above-described problems can be avoided and the effects of the present invention can be made more remarkable. Because it can. In addition, when the photocatalyst-containing layer coating solution has a neutral pH, the metal or the like of the device for applying the photocatalyst-containing layer forming coating solution is eluted into the photocatalyst-containing layer forming coating solution. It is possible to prevent metal and the like from being contained in the formed photocatalyst-containing layer, and further prevent rusting of equipment used for coating the photocatalyst-containing layer forming coating solution. This is because the photocatalyst-containing layer can be stably formed.

  In the present invention, the organic photoelectric conversion layer forming step in the organic photoelectric conversion device manufacturing method is an organic EL layer forming step in which the organic EL layer is formed using the above-described organic photoelectric conversion device manufacturing method. Provided is a method for producing a characteristic organic EL element.

  According to the present invention, as described above, after the photocatalyst containing layer forming step, the photocatalyst containing layer is doped with a photoelectric conversion property improving substance, so that the photocatalyst containing layer forming coating solution is photoelectrically converted. Since it is not necessary to add a property-improving substance, it is possible to prevent aggregation of the photocatalyst in the photocatalyst-containing layer forming coating solution, and it is possible to produce an organic EL device having good light emission characteristics.

  In the above invention, the wettability changing step in the method for producing an organic photoelectric conversion element is a step of irradiating the photocatalyst containing layer with energy in a pattern to form a wettability changing pattern in which the wettability of the photocatalyst containing layer is changed. The organic EL layer forming step is preferably a step of applying an organic EL layer forming coating solution on the wettability changing pattern to form the organic EL layer in a pattern. This is because the organic EL layer can be easily applied by using the wettability change pattern, and high-definition patterning becomes possible.

  Moreover, in the said invention, the said organic EL layer formation process is a process of forming the light emitting layer of at least 3 colors of red, green, and blue in a pattern shape, It is preferable to enable a color display. In the present invention, the light emitting layer can be easily formed into a pattern using the wettability change pattern as described above, and therefore, when the light emitting layer of three colors of red, green, and blue is formed. High-definition patterning is also possible.

  In the present invention, since the doping step is performed after the photocatalyst-containing layer forming step, the aggregation of the photocatalyst in the photocatalyst-containing layer forming coating liquid can be prevented, and an organic photoelectric conversion element having a good photoelectric conversion characteristic is obtained. It is possible to manufacture. In the present invention, since the surface of the photocatalyst containing layer can be made lyophilic in the wettability changing step, it becomes easy to apply the organic photoelectric conversion layer forming coating solution, and the organic photoelectric conversion layer is easily formed. There is an effect that can be done.

  Hereinafter, the manufacturing method of the organic photoelectric conversion element of this invention and the manufacturing method of an organic EL element are demonstrated in detail.

A. Manufacturing method of organic photoelectric conversion element The manufacturing method of the organic photoelectric conversion element of the present invention includes a base, a first electrode formed on the base, and a photocatalyst and a photoelectric conversion property improving substance formed on the first electrode. A method for producing an organic photoelectric conversion element comprising: a photocatalyst containing layer containing: an organic photoelectric conversion layer formed on the photocatalyst containing layer; and a second electrode formed on the organic photoelectric conversion layer,
A photocatalyst-containing layer forming step for forming a photocatalyst-containing layer on the substrate on which the first electrode is formed, a doping step for doping the photocatalyst-containing layer with a photoelectric conversion property improving substance, and the photoelectric conversion property improving substance are doped An organic photoelectric conversion layer forming step of applying an organic photoelectric conversion layer forming coating solution on the photocatalyst-containing layer to form an organic photoelectric conversion layer;

  Further, in the present invention, the photocatalyst-containing layer changes wettability due to the action of the photocatalyst accompanying energy irradiation, and the photocatalyst-containing layer is irradiated with energy to change the wettability of the photocatalyst-containing layer. A wettability changing step may be performed.

  The manufacturing method of the organic photoelectric conversion element of this invention is demonstrated referring drawings. FIG. 1 is a process diagram showing an example of a method for producing an organic photoelectric conversion element of the present invention. First, as shown in FIG. 1 (a), a photocatalyst-containing layer 3 is formed by applying a photocatalyst-containing layer forming coating solution containing a photocatalyst to the substrate 1 on which the first electrode 2 is formed. Next, a photoelectric conversion property improving substance-containing liquid 14 containing a photoelectric conversion characteristic improving substance is applied on the photocatalyst containing layer 3 or the photocatalyst containing layer 3 is applied to the photoelectric conversion characteristic improving substance containing liquid 14. A doping step (FIG. 1B) of immersing and doping the photocatalyst containing layer 3 with the photoelectric conversion property improving substance is performed. Also, the photocatalyst-containing layer 3 is irradiated with energy 12 using a photomask 11 to change the wettability of the surface of the photocatalyst-containing layer 3, and the lyophilic region where the wettability is changed by irradiation with energy. A wettability changing step (FIGS. 1C to 1D) for forming a wettability changing pattern composed of 3a and the liquid repellent region 3b not irradiated with energy is performed. Further, as shown in FIG. 1 (e), an organic photoelectric conversion layer-forming coating solution is applied onto the photocatalyst-containing layer 3 'doped with the photoelectric conversion property improving substance and having changed wettability. The organic photoelectric conversion layer forming step of forming the organic photoelectric conversion layer 5 in a pattern shape is performed using the difference in wettability of the wettability change pattern composed of the conductive region 3a and the liquid repellent region 3b. Finally, as shown in FIG.1 (f), an organic photoelectric conversion element can be manufactured by performing the 2nd electrode formation process which forms the 2nd electrode 6 on the organic photoelectric converting layer 5. FIG.

  According to the present invention, after the photocatalyst-containing layer forming step, the doping step of doping the photocatalyst-containing layer with the photoelectric conversion property improving substance is performed, so that the photocatalyst-containing layer forming coating liquid used in the photocatalyst-containing layer forming step is charged with photoelectric. Since there is no need to add a conversion property improving substance, the photocatalyst can be prevented from aggregating in the photocatalyst-containing layer forming coating solution, and the photoelectric conversion properties (current-voltage characteristics, emission luminance-voltage characteristics, etc.) It is possible to suppress the decrease. Thereby, a high performance organic photoelectric conversion element can be manufactured.

  In addition, when the photocatalyst-containing layer changes wettability due to the action of the photocatalyst accompanying energy irradiation, the photocatalyst-containing layer is excited by irradiating the photocatalyst-containing layer with energy in the wettability changing step. Thus, the wettability of the photocatalyst-containing layer can be changed, and the surface of the photocatalyst-containing layer can be made lyophilic. Since an organic photoelectric conversion layer can be formed by apply | coating the coating liquid for organic photoelectric conversion layer formation to the photocatalyst containing layer surface used as this lyophilic property, formation of an organic photoelectric conversion layer becomes easy.

  Furthermore, when a wettability change pattern consisting of a lyophilic region and a liquid repellent region is formed by irradiating the photocatalyst-containing layer with energy in a pattern in the wettability changing step, such wettability is easily obtained. A change pattern can be formed, and the organic photoelectric conversion layer can be easily formed into a pattern using the wettability difference of the wettability change pattern. For example, when manufacturing an organic photoelectric conversion element that requires patterning of an organic photoelectric conversion layer such as an organic EL element, such patterning characteristics are useful.

  In the present invention, when the wettability changing step is performed, the photocatalyst-containing layer changes its wettability due to the action of the photocatalyst accompanying the energy irradiation, thereby enabling patterning of the organic photoelectric conversion layer. On the other hand, when the wettability changing step is not performed, the photocatalyst-containing layer may not change in wettability due to the action of the photocatalyst. Such a photocatalyst-containing layer whose wettability does not change by the action of the photocatalyst cannot be used when the patterning of the organic photoelectric conversion layer is required, but sufficiently obtains the effect of suppressing the deterioration of the photoelectric conversion characteristics described above. Is possible.

In addition, the organic photoelectric conversion element in this invention means both what converts light energy into electrical energy, or what converts electrical energy into light energy. Examples of such organic photoelectric conversion elements include organic thin film solar cells and organic EL elements.
Hereinafter, each process of the manufacturing method of such an organic photoelectric conversion element is demonstrated.

1. Photocatalyst containing layer formation process First, the photocatalyst content layer forming process in the manufacturing method of the organic photoelectric conversion element of this invention is demonstrated. The photocatalyst-containing layer forming step in the present invention is a step of forming a photocatalyst-containing layer on the substrate on which the first electrode is formed, and usually a photocatalyst containing a photocatalyst and a binder on the substrate on which the first electrode is formed. It is formed by applying a coating solution for forming a containing layer and drying it.
Hereinafter, each structure of a photocatalyst content layer formation process is explained.

(1) Photocatalyst-containing layer forming coating solution First, the photocatalyst-containing layer forming coating solution used in this step will be described. The photocatalyst-containing layer forming coating solution used in this step contains a photocatalyst and a binder. Hereinafter, the photocatalyst, binder, and other components contained in such a photocatalyst-containing layer forming coating solution will be described.

a. Photocatalyst Examples of photocatalysts used in the present invention include titanium oxide (TiO ₂ ), zinc oxide (ZnO), tin oxide (SnO ₂ ), strontium titanate (SrTiO ₃ ), and tungsten oxide (WO ₃ ), metal oxides such as bismuth oxide (Bi ₂ O ₃ ) and iron oxide (Fe ₂ O ₃ ) can be used, and one or a mixture of two or more selected from these may be used. it can. In the present invention, it is particularly preferable to use titanium oxide among these. Titanium oxide is advantageous in that it has a high band gap energy, is chemically stable, is not toxic, and is easily available.

  Titanium oxide includes an anatase type and a rutile type, and both can be used in the present invention, but anatase type titanium oxide is preferably used. Anatase type titanium oxide has an excitation wavelength of 380 nm or less.

  Examples of such anatase-type titanium oxide include hydrochloric acid peptizer-type anatase-type titania sol (STS-02 manufactured by Ishihara Sangyo Co., Ltd. (average particle size 7 nm), ST-K01 manufactured by Ishihara Sangyo Co., Ltd.), nitric acid peptizer. Type anatase titania sol (TA-15 manufactured by Nissan Chemical Industries, Ltd. (average particle size 12 nm)).

  The smaller the particle size of the photocatalyst, the more effective the photocatalytic reaction takes place. The average particle size is preferably 50 nm or less, and it is particularly preferable to use a photocatalyst of 30 nm or less.

  The content of the photocatalyst in the photocatalyst-containing layer forming coating solution used in the present invention is such that when the photocatalyst-containing layer is formed using this photocatalyst-containing layer forming coating solution, The content is preferably in the range of 1 to 90% by weight, and more preferably in the range of 40 to 80% by weight.

b. Binder In the present invention, when the wettability changing step described later is not performed, the binder may not have a function of changing the wettability of the photocatalyst-containing layer by the action of the photocatalyst. The binder is not particularly limited as long as the main skeleton has a high binding energy that is not decomposed by photoexcitation of the photocatalyst, and for example, an alkyl silicate can be used. Examples of the alkyl silicate include compounds represented by the general formula: Si _n O _n-1 (OR) _{2n + 2} (wherein Si represents silicon, O represents oxygen, and R represents an alkyl group). Here, n is preferably in the range of 1 to 6, and R is preferably an alkyl group having 1 to 4 carbon atoms from the viewpoint of a high proportion of silicon.

The average molecular weight of the alkyl silicate is preferably in the range of 500 to 2,000. If the average molecular weight is too small, cracks are likely to occur in the photocatalyst-containing layer, and when the organic EL device is produced according to the present invention, the lifetime of the organic EL device tends to be shortened. Conversely, if the average molecular weight is too large, the viscosity of the photocatalyst-containing layer forming coating solution increases, and it may be difficult to form a uniform coating film.
In the present invention, as described above, when the wettability changing step is not performed, that is, when the photocatalyst-containing layer is not used for patterning, the photocatalyst-containing layer has a function of changing the wettability by the action of the photocatalyst. May be used, or a material having a function of changing the wettability of the photocatalyst-containing layer by the action of the photocatalyst described below may be used. Thus, when using a material having a function of changing the wettability of the photocatalyst-containing layer by the action of the photocatalyst, a material having a relatively high lyophilicity on the surface without exposure, or if necessary, The entire surface may be exposed and used as a lyophilic property.

  On the other hand, in the present invention, when the wettability changing step described later is performed, the binder needs to have a function of changing the wettability of the photocatalyst containing layer by the action of the photocatalyst. As such a binder, one having a high binding energy such that the main skeleton is not decomposed by photoexcitation of the photocatalyst and having an organic substituent that is decomposed by the action of the photocatalyst is preferable. Can be exemplified by organopolysiloxanes that exhibit high strength by hydrolysis and polycondensation of chloro or alkoxysilane.

As such an organopolysiloxane, one or two or more hydrolyzed condensates or cohydrolyzed compounds of a silicon compound represented by the general formula: Y _n SiX _4-n (n is an integer of 0 to 3) It is preferable that it is organopolysiloxane which is. Here, in the above general formula, Y is an alkyl group, a fluoroalkyl group, a vinyl group, an amino group, a phenyl group or an epoxy group, or a substituent containing these, and X is, for example, an alkoxyl group, an acetyl group or a halogen. Show. Moreover, it is preferable that the carbon number of the whole substituent shown by Y exists in the range of 1-20, especially in the range of 5-10. Thus, when the photocatalyst-containing layer is formed, the surface can be made liquid-repellent by Y constituting the organopolysiloxane, and the Y is decomposed by the action of the photocatalyst accompanying energy irradiation. This is because it can be made lyophilic.

  For example, when forming a wettability change pattern in which the wettability of the photocatalyst containing layer is changed in order to pattern the organic photoelectric conversion layer with high accuracy, the photocatalyst containing layer before energy irradiation is required to have high liquid repellency. Sometimes. In such a case, among the above, organopolysiloxane in which Y constituting the organopolysiloxane is a fluoroalkyl group is preferably used. This is because when the organopolysiloxane having a fluoroalkyl group is used, the photocatalyst-containing layer before energy irradiation can be made particularly high in liquid repellency. Specific examples of such organopolysiloxanes include one or more of the following hydroalkyl silanes, co-hydrolysis condensates, and generally as fluorine-based silane coupling agents. Known ones may be used.

_{CF 3 (CF 2) 3 CH} 2 CH 2 Si (OCH 3) 3;
_{CF 3 (CF 2) 5 CH} 2 CH 2 Si (OCH 3) 3;
_{CF 3 (CF 2) 7 CH} 2 CH 2 Si (OCH 3) 3;
_{CF 3 (CF 2) 9 CH} 2 CH 2 Si (OCH 3) 3;
(CF ₃ ) ₂ CF (CF ₂ ) ₄ CH ₂ CH ₂ Si (OCH ₃ ) ₃ ;
_{(CF 3) 2 CF (CF} 2) 6 CH 2 CH 2 Si (OCH 3) 3;
_{(CF 3) 2 CF (CF} 2) 8 CH 2 CH 2 Si (OCH 3) 3;
_{CF 3 (C 6 H 4)} C 2 H 4 Si (OCH 3) 3;
_{CF 3 (CF 2) 3 (} C 6 H 4) C 2 H 4 Si (OCH 3) 3;
_{CF 3 (CF 2) 5 (} C 6 H 4) C 2 H 4 Si (OCH 3) 3;
_{CF 3 (CF 2) 7 (} C 6 H 4) C 2 H 4 Si (OCH 3) 3;
_{CF 3 (CF 2) 3 CH} 2 CH 2 SiCH 3 (OCH 3) 2;
_{CF 3 (CF 2) 5 CH} 2 CH 2 SiCH 3 (OCH 3) 2;
_{CF 3 (CF 2) 7 CH} 2 CH 2 SiCH 3 (OCH 3) 2;
_{CF 3 (CF 2) 9 CH} 2 CH 2 SiCH 3 (OCH 3) 2;
_{(CF 3) 2 CF (CF} 2) 4 CH 2 CH 2 SiCH 3 (OCH 3) 2;
_{(CF 3) 2 CF (CF} 2) 6 CH 2 CH 2 Si CH 3 (OCH 3) 2;
_{(CF 3) 2 CF (CF} 2) 8 CH 2 CH 2 Si CH 3 (OCH 3) 2;
_{CF 3 (C 6 H 4)} C 2 H 4 SiCH 3 (OCH 3) 2;
_{CF 3 (CF 2) 3 (} C 6 H 4) C 2 H 4 SiCH 3 (OCH 3) 2;
_{CF 3 (CF 2) 5 (} C 6 H 4) C 2 H 4 SiCH 3 (OCH 3) 2;
_{CF 3 (CF 2) 7 (} C 6 H 4) C 2 H 4 SiCH 3 (OCH 3) 2;
_{CF 3 (CF 2) 3 CH} 2 CH 2 Si (OCH 2 CH 3) 3;
_{CF 3 (CF 2) 5 CH} 2 CH 2 Si (OCH 2 CH 3) 3;
_{CF 3 (CF 2) 7 CH} 2 CH 2 Si (OCH 2 CH 3) 3;
_{CF 3 (CF 2) 9 CH} 2 CH 2 Si (OCH 2 CH 3) 3; and _{CF 3 (CF 2) 7 SO} 2 N (C 2 H 5) C 2 H 4 CH 2 Si (OCH 3) 3.

  Furthermore, when high liquid repellency is required for the photocatalyst-containing layer before energy irradiation, for example, an organopolysiloxane obtained by crosslinking a reactive silicone excellent in water repellency and oil repellency can be used. Examples of such reactive silicones include compounds having a skeleton represented by the following general formula.

Here, n is an integer of 2 or more, R ^1, R ² is a substituted or unsubstituted 1 to 10 carbon atoms each alkyl, alkenyl, aryl or cyanoalkyl group, preferably 40% or less of the total molar ratio Vinyl, phenyl and phenyl halide. Further, those in which R ¹ and R ² are methyl groups are preferable because the surface energy is the smallest, and the methyl groups are preferably 60% or more by molar ratio. In addition, the chain end or side chain has at least one reactive group such as a hydroxyl group in the molecular chain.

In addition to the above organopolysiloxane, a stable organosilicon compound that does not cause a crosslinking reaction such as dimethylpolysiloxane may be mixed in the binder.
In the present invention, as described above, even when the wettability changing step is performed, that is, when the photocatalyst containing layer is used for patterning, the function of changing the wettability of the photocatalyst containing layer by the action of the photocatalyst is provided. You may use the material which does not have with the material which has a function which changes the wettability of a photocatalyst content layer by the effect | action of the said photocatalyst. This is because some materials that do not have a function of changing the wettability of the photocatalyst-containing layer have good film forming properties, and the film forming properties can be improved by using a mixture.

c. Decomposing Substance The photocatalyst-containing forming coating solution used in the present invention can contain a decomposing substance that can be further decomposed by the action of the photocatalyst by energy irradiation and thereby change the wettability of the photocatalyst-containing layer. .

  Examples of such a decomposing substance include a surfactant having a function of decomposing by the action of a photocatalyst and changing the wettability of the photocatalyst-containing layer surface by decomposing. Specifically, hydrocarbons such as NIKKOL BL, BC, BO, BB series manufactured by Nikko Chemicals Co., Ltd., ZONYL FSN, FSO manufactured by DuPont, Surflon S-141, 145 manufactured by Asahi Glass Co., Ltd., Dainippon Megafac F-141, 144 manufactured by Ink Chemical Industry Co., Ltd., Footgent F-200, F251 manufactured by Neos Co., Ltd., Unidyne DS-401, 402 manufactured by Daikin Industries, Ltd., Fluorard FC-170 manufactured by 3M Co., Ltd. Fluorine-based or silicone-based nonionic surfactants such as 176, and cationic surfactants, anionic surfactants, and amphoteric surfactants can also be used.

Besides surfactants, polyvinyl alcohol, unsaturated polyester, acrylic resin, polyethylene, diallyl phthalate, ethylene propylene diene monomer, epoxy resin, phenol resin, polyurethane, melamine resin, polycarbonate, polyvinyl chloride, polyamide, polyimide Styrene butadiene rubber, chloroprene rubber, polypropylene, polybutylene, polystyrene, polyvinyl acetate, nylon, polyester, polybutadiene, polybenzimidazole, polyacrylonitrile, epichlorohydrin, polysulfide, polyisoprene, oligomers, polymers, and the like.

d. Sensitizing Dye Further, the photocatalyst-containing layer forming coating solution used in the present invention may contain a sensitizing dye which is a component for sensitizing the photoactivity of the photocatalyst. By adding such a sensitizing dye, the wettability can be changed with a low exposure amount, or the wettability can be changed with exposure at a different wavelength.

e. Solvent The solvent that can be used in the photocatalyst-containing layer forming coating solution used in the present invention is a mixture with the above-mentioned photocatalyst, binder, etc., and does not affect the patterning characteristics due to white turbidity or other phenomena. If there is no particular limitation. Examples of such solvents include alcohols such as ethanol and isopropanol, acetone, acetonitrile, ethylene glycol monomethyl ether, ethylene glycol dimethyl ether, dimethylformamide, dimethyl sulfoxide, dioxane, ethylene glycol, hexamethylphosphoric triamide, pyridine, Tetrahydrofuran, N-methylpyrrolidinone and the like and mixed solvents thereof can be mentioned.

f. Others The photocatalyst-containing layer forming coating solution used in the present invention is preferably prepared by mixing a photocatalyst immediately before applying the photocatalyst-containing layer forming coating solution. Thereby, the change with time of the photocatalyst-containing layer forming coating liquid can be prevented, and a photocatalyst-containing layer capable of forming a stable and uniform wettability change pattern can be formed.

  Here, mixing the photocatalyst immediately before applying the photocatalyst-containing layer forming coating liquid means mixing in a stage of filling in an apparatus used for applying the photocatalyst-containing layer forming coating liquid. Specifically, it is preferably within 24 hours, particularly within 10 hours, particularly within 5 hours after the preparation of the photocatalyst-containing layer forming coating solution.

  The photocatalyst-containing layer forming coating solution used in the present invention is not particularly limited as long as it contains the above-mentioned photocatalyst, binder and the like, and the pH of the photocatalyst-containing layer forming coating solution is medium. It may be neutral or acidic, but in the present invention, it preferably has a neutral pH.

  The photocatalyst-containing layer forming coating solution having a neutral pH has a lower dispersibility of the photocatalyst such as titanium oxide than the photocatalyst-containing layer forming coating solution having an acidic pH. When the above-described photoelectric conversion property-improving substance is added to the photocatalyst-containing layer forming coating solution having a neutral pH with poor dispersibility, the dispersibility of the photocatalyst is further deteriorated and it is difficult to improve the photoelectric conversion property. However, in the present invention, after the formation of the photocatalyst containing layer, the photocatalyst containing layer is doped with the photoelectric conversion property improving substance, so that the above-mentioned problems can be avoided and the effect of the present invention is more remarkable. It can be.

  Usually, in order to form the photocatalyst-containing layer, the device for applying the photocatalyst-containing layer forming coating liquid uses a metal from the aspects of accuracy and ease of processing, etc. When the photocatalyst-containing layer coating liquid has a neutral pH, for example, a metal such as a nozzle for applying the photocatalyst-containing layer forming coating liquid is eluted into the photocatalyst-containing layer forming coating liquid. It is possible to prevent the metal and the like from being contained in the formed photocatalyst containing layer. In addition, it is possible to prevent rusting of equipment used for application of the photocatalyst-containing layer forming coating solution, and it is possible to stably form the photocatalyst-containing layer.

  Furthermore, when drying the photocatalyst-containing layer forming coating solution, a hot plate, an infrared heater, an oven, or the like is used. By using the photocatalyst-containing layer forming coating solution having a neutral pH, The hot plate and the infrared heater can be prevented from being rusted by the adhesion of the photocatalyst-containing layer forming coating solution, and the oven from being rusted by the acid released from the photocatalyst-containing layer forming coating solution.

  Furthermore, when the photocatalyst-containing layer is formed using the photocatalyst-containing layer forming coating liquid having a neutral pH, it is unlikely that a metal or the like is contained in the photocatalyst-containing layer as described above. Therefore, in the wettability changing step described later, the action of titanium oxide accompanying energy irradiation can be stabilized, and the wettability can be changed uniformly. Furthermore, since no acid is contained in the photocatalyst-containing layer, there is no problem that when the energy is irradiated, the acid is released by the irradiated energy and the energy source or the mask is corroded. It has the advantage of being able to.

  In addition, when the photocatalyst-containing layer is formed using a photocatalyst-containing layer-forming coating liquid having a neutral pH, the photocatalyst-containing layer whose wettability change has been changed in the organic photoelectric conversion layer forming step described later. Even when an organic photoelectric conversion layer is formed on the organic photoelectric conversion layer, there is no possibility of being affected by an acid or the like, and an organic photoelectric conversion element that is stable over time can be obtained.

  Here, the pH in the neutral range refers to a region that does not adversely affect the coating equipment to be used, such as corrosion. Specifically, the pH is in the range of 5 to 9, particularly in the range of 6 to 8. In particular, it is preferably in the range of 6.5 to 7.5. When the pH is within this range, when the photocatalyst-containing layer forming coating solution is used as the photocatalyst-containing layer, the metal of the device used for coating is eluted into the photocatalyst-containing layer forming coating solution. This can be prevented. As a result, the wettability of the layer formed by applying the photocatalyst-containing layer forming coating liquid can be changed stably by the action of the photocatalyst accompanying energy irradiation, and a high-definition wettability change pattern is formed. Can do.

  Examples of the photocatalyst-containing layer-forming coating solution having such a neutral pH include those containing titanium oxide and organopolysiloxane, or methyl silicate, ethyl silicate or butyl silicate. it can. In addition, about titanium oxide and organopolysiloxane, what was described in the term of the photocatalyst and binder mentioned above can be used, respectively.

  The photocatalyst-containing layer forming coating solution having a neutral pH used in the present invention preferably contains an alkyl silicate. This is because it becomes possible to maintain a finely dispersed state of titanium oxide even in a neutral pH range.

Such an alkyl silicate is used as a dispersion stabilizer for the above titanium oxide, and is used for the purpose of stabilizing the photocatalyst-containing layer forming coating solution in a neutral range. Examples of the alkyl silicate used in the present invention include compounds represented by the general formula: Si _n O _n-1 (OR) _{2n + 2} (wherein Si represents silicon, O represents oxygen, and R represents an alkyl group). Here, n is in the range of 1 to 6, and R is more preferably an alkyl group having 1 to 4 carbon atoms in terms of a high silicon ratio.

  The average molecular weight of the alkyl silicate is preferably in the range of 500 to 2,000. If the average molecular weight is too small, cracks are likely to occur in the photocatalyst-containing layer, and when the organic EL device is produced according to the present invention, the lifetime of the organic EL device tends to be shortened. Conversely, if the average molecular weight is too large, the viscosity of the photocatalyst-containing layer forming coating solution increases, and it may be difficult to form a uniform coating film.

The amount of alkyl silicate, the weight ratio of the titanium oxide in the titanium to silicon in the alkyl silicate described above to the amount in terms of SiO ₂ to the amount in terms of _{TiO 2 (SiO 2 / TiO 2} ) 0.7 -10, especially 0.9-4. This is because if the amount of the alkyl silicate is less than the above range, the dispersion stability tends to be lowered, and if it is more than the above range, the photocatalytic function of titanium oxide is likely to be lowered.

  The photocatalyst-containing layer forming coating solution having a pH in the neutral range includes a neutral titanium oxide sol solution containing titanium oxide and an alkyl silicate, and a hydrolyzed solution of fluoroalkylsilane having a pH within a predetermined range. Can be prepared by mixing.

  Usually, many fluoroalkylsilanes have the property of being hydrolyzed by acidity and hardly hydrolyzed by neutrality, and are hardly hydrolyzed even when heat is applied. In the present invention, a neutral titanium oxide sol solution containing titanium oxide and an alkyl silicate and a hydrolyzed liquid of the fluoroalkylsilane are separately prepared and mixed, whereby the titanium oxide is finely dispersed. It is possible to produce a coating solution for forming a photocatalyst-containing layer that is stable in a neutral region without breaking the surface.

  The fluoroalkylsilane hydrolyzate used in the present invention can be obtained by hydrolyzing the above-described fluoroalkylsilane into water or alcohol in which an inorganic acid or an organic acid is dissolved. Here, the alcohol preferably has 4 or less carbon atoms.

  Under the present circumstances, the quantity of the fluoroalkylsilane used for the hydrolyzed liquid of fluoroalkylsilane and the alkoxysilane used as needed is in the range of 10% by weight to 90% by weight, especially in the range of 50% to 80%. It is preferable.

  At this time, when the hydrolyzed liquid of fluoroalkylsilane was a strong acid, the dispersion state of the neutral titanium oxide sol was changed when mixing with the neutral titanium oxide sol liquid, so that the titanium oxide was finely dispersed. There is a possibility of breaking the state. Therefore, the pH of the hydrolyzed solution when finally added to the neutral titanium oxide sol is in the range of 2 to 7, preferably in the range of 5 to 7.

  On the other hand, a neutral titanium oxide sol solution having titanium oxide and an alkyl silicate can be obtained by mixing an alkyl silicate and a titanium oxide sol and then neutralizing. Here, the pH of the neutral titanium oxide sol solution refers to a region in which the dispersion of titanium oxide or the like is stable in the neutral titanium oxide sol solution. Specifically, the pH is in the range of 5 to 9, In particular, it is preferably in the range of 6 to 8, particularly in the range of 6.5 to 7.5.

  As the titanium oxide sol, a titanium oxide sol obtained by a conventional method can be used. For example, titanium oxide such as hydrous titanium oxide can be peptized with a monobasic acid or a salt thereof, or titanium tetrachloride can be treated with low-temperature water. And then dialyzed, or titanium alkoxide is added to an aqueous hydrochloric acid solution.

  Next, these titanium oxide sol and alkyl silicate are mixed by a conventional method. When both are mixed, the aqueous titanium oxide sol may be diluted with a hydrophilic organic solvent, or the alkyl silicate may be diluted with a hydrophilic organic solvent. The hydrophilic organic solvent is not particularly limited as long as it is hydrophilic, such as alcohols such as methanol, ethanol, 2-propanol, and ethylene glycol, ketones, and carboxylic acid esters. Alcohol is preferred in terms of good solubility. The dilution ratio of the titanium oxide sol with the hydrophilic organic solvent is more preferably 1.2 to 5 times by weight, while the dilution ratio of the alkyl silicate with the hydrophilic organic solvent is more preferably 1.5 to 5 times by weight. preferable. It is more preferable to mix both the titanium oxide sol and the alkyl silicate after diluting with a hydrophilic organic solvent because they can be mixed without causing aggregation of titanium oxide. The hydrophilic organic solvent for diluting the titanium oxide sol and the hydrophilic organic solvent for diluting the alkyl silicate need not necessarily use the same compound.

  Furthermore, neutral titanium oxide sol can be obtained by neutralizing the obtained mixture. The neutralization of the titanium oxide sol can be performed by a conventional method, but is preferably performed by at least one method selected from a method by ion exchange, a method of adding a neutralizing agent, and a method by dialysis. In particular, it is more preferable to neutralize by adding a neutralizing agent after ion exchange because the content of impurities can be reduced.

  In the ion exchange method, an ion exchange resin is used. For example, a cation exchange resin or an anion exchange resin is added to the above mixture to remove cations and anions, and then the ion exchange resin is separated. As an ion exchange resin, there is no distinction between strong acidity and weak acidity, and as an anion exchange resin, there is no distinction between strong basicity and weak basicity, for example, commercially available Urbanlite (manufactured by Organo), Dia Ion (manufactured by Mitsubishi Chemical Corporation) can be used.

  In addition, as the neutralizing agent, alkali such as sodium hydroxide, potassium hydroxide, aqueous ammonia, monobasic acid such as hydrochloric acid, nitric acid, acetic acid, chloric acid, chloric acid or its salt, sulfuric acid, hydrofluoric acid, etc. An acid or a salt thereof can be used.

  The neutral titanium oxide sol thus obtained may be adjusted to a desired solid content concentration or to a desired pH depending on its use.

  Next, a photocatalyst-containing layer-forming coating solution having a neutral pH can be obtained by mixing the neutral titanium oxide sol solution and the hydrolyzed solution of the fluoroalkylsilane. At this time, the mixing ratio of the neutral titanium oxide sol solution and the hydrolyzed fluoroalkylsilane solution was such that the weight of the hydrolyzed fluoroalkylsilane solution was 0 when the weight of the neutral titanium oxide sol solution was 1. It is preferable that it is in the range of 0.1 to 1, especially 0.1 to 0.5. Thereby, the pH can be adjusted to a neutral range, and a stable coating solution for forming a photocatalyst-containing layer can be obtained.

(2) Application and Drying of Photocatalyst-Containing Layer Forming Coating Liquid In this step, the photocatalyst-containing layer forming coating liquid is applied onto a substrate described later and dried to form a photocatalyst-containing layer. be able to.

  The method for applying the photocatalyst-containing layer forming coating solution is not particularly limited as long as it is a method capable of applying the photocatalyst-containing layer forming coating solution. For example, spray coating, dip coating, roll Examples thereof include a coating method such as coating, bead coating, spin coating, and slit coating, or a method of coating by combining slit coating and spin coating.

  The drying method for the photocatalyst-containing layer forming coating solution is not particularly limited as long as it is a method capable of forming a uniform photocatalyst-containing layer. For example, a hot plate, an infrared heater, an oven The method using is mentioned.

  The film thickness of the photocatalyst-containing layer formed as described above is preferably in the range of 5 to 200 nm, and more preferably in the range of 30 to 100 nm. This is because if the thickness of the photocatalyst-containing layer is too thin, the difference in wettability does not clearly appear and it becomes difficult to form a wettability change pattern. Conversely, if the photocatalyst-containing layer is too thick, it may hinder the transport of holes or electrons and adversely affect the photoelectric conversion of the organic photoelectric conversion element.

  Further, the photocatalyst-containing layer may be formed not only in one layer but also in a plurality of layers. In this case, a plurality of layers can be formed in a pattern on the photocatalyst-containing layer, and such patterning can be realized easily and with high quality.

(4) Substrate Next, the substrate used in this step will be described. The material of the substrate used in this step is not particularly limited, and is appropriately selected depending on the purpose of the organic photoelectric conversion element and the energy irradiation method in the wettability changing step described later. For example, when energy irradiation described later is performed from the substrate side, the substrate needs to be transparent.

  The substrate used in the present invention may be a flexible substrate such as a resin film, or may be a non-flexible substrate such as a glass substrate. Further, the substrate may be the first electrode itself, which will be described later, but usually the first electrode is formed on the substrate that maintains strength.

  In the present invention, a light shielding part may be provided on the substrate. When the light shielding part is formed, when the wettability change pattern is formed in the wettability changing process described later, the light shielding part is formed without using a mask or a laser by irradiating energy from the substrate side. It becomes possible to change the wettability of the surface of the photocatalyst-containing layer in a portion not provided. Therefore, since alignment between the photocatalyst-containing layer and the mask is unnecessary, a simple process can be achieved, and an expensive apparatus necessary for drawing irradiation is unnecessary, which is advantageous in terms of cost. It has the advantage of becoming.

  Such a light-shielding portion is formed at a position where a light-shielding portion is formed on a substrate and a photocatalyst-containing layer is formed thereon, that is, when the photocatalyst-containing layer is formed between the substrate and the photocatalyst-containing layer. In some cases, a pattern is formed on the surface on which the layer is not formed.

  The method for forming the light-shielding part is not particularly limited, and is appropriately selected and used depending on the characteristics of the surface on which the light-shielding part is formed, the shielding property against required energy, and the like.

  For example, it may be formed by forming a metal thin film of chromium or the like having a thickness of about 1000 to 2000 mm by a sputtering method, a vacuum deposition method, or the like, and patterning the thin film. As this patterning method, a normal patterning method such as sputtering can be used.

  Alternatively, a method may be used in which a layer containing light-shielding particles such as carbon fine particles, metal oxides, inorganic pigments, and organic pigments in a resin binder is formed in a pattern. As the resin binder to be used, polyimide resin, acrylic resin, epoxy resin, polyacrylamide, polyvinyl alcohol, gelatin, casein, cellulose, or a mixture of one or more kinds, photosensitive resin, or O / A W emulsion type resin composition, for example, an emulsion of a reactive silicone can be used. The thickness of such a resin light-shielding portion can be set within a range of 0.5 to 10 μm. As a method for patterning such a resin light shielding portion, a generally used method such as a photolithography method or a printing method can be used.

(5) 1st electrode Next, the 1st electrode used for this process is demonstrated. The 1st electrode used for this process is formed on the above-mentioned base, and is formed as an electrode which counters the 2nd electrode mentioned below. The first electrode may be either an anode or a cathode, but is usually an anode. The first electrode may be transparent or translucent, and may not be transparent or translucent. However, depending on the energy irradiation method, the light extraction surface, or the light reception surface, which will be described later, It is selected appropriately.

  When the first electrode is an anode, a conductive material having a high work function is preferably used so that holes can be easily injected, and a conductive material having a resistance as low as possible is preferably used. As a conductive material used for such an anode, a metal material is generally used, but an organic substance or an inorganic compound may be used. Specific examples include ITO, indium oxide, gold, and polyaniline.

  Further, the first electrode may be formed on the entire surface of the substrate or may be formed in a pattern. As a method for forming the first electrode, a general electrode forming method can be used, and examples thereof include a PVD method such as a vacuum deposition method, a sputtering method, and an ion plating method, a CVD method, and the like. The patterning method for forming the first electrode in a pattern is not particularly limited as long as the first electrode can be accurately formed in a desired pattern. Specifically, a photolithography method or the like is used. Can be mentioned.

2. Doping Step Next, doping in the method for producing the organic photoelectric conversion element of the present invention will be described. The doping step in the present invention is a step of doping the photocatalyst containing layer with a photoelectric conversion property improving substance.

In the present invention, by performing this doping step after the above-described photocatalyst-containing layer forming step, it is not necessary to add a photoelectric conversion property improving substance in the photocatalyst-containing layer forming coating solution. Aggregation of the photocatalyst in the coating liquid can be prevented, and an organic photoelectric conversion element having good photoelectric conversion characteristics can be produced.
Hereinafter, each configuration of the doping process will be described.

(1) Substance for improving photoelectric conversion characteristics First, the substance for improving photoelectric conversion characteristics used in this step will be described. The photoelectric conversion property improving substance used in this step is a substance that enhances the photoelectric conversion characteristics of the organic photoelectric conversion layer, for example, a substance that promotes injection of holes or electrons from the first electrode and the second electrode to the organic photoelectric conversion layer. Alternatively, the substance is not particularly limited as long as it is a substance that promotes transport of holes or electrons from the organic photoelectric conversion layer to the first electrode and the second electrode.

  Examples of such a photoelectric conversion property improving substance include metal salts, halogens, Lewis acids and the like.

Examples of the metal salt include FeCl ₂ , FeCl ₃ , Cr (NO ₃ ) ₃ , CrCl ₃ , NaNO ₃ , Ca (NO ₃ ) ₂ , Sr (NO ₃ ) ₂ , Co (NO ₃ ) ₂ , CoCl ₂ , Cd (NO ₃ ) ₂ , Mg (NO ₃ ) ₂ , Cu (CH ₃ COO) ₂ , Cu (NO ₃ ) ₂ , Ni (NO ₃ ) ₂ , Mn (NO ₃ ) ₂ , MnCl ₂ , PbNO ₃ , RuCl ₃ , IrCl ₄ , Ir (NO ₃ ) ₃ , ScCl ₃ , Sc (NO ₃ ) ₃ , H ₂ PtCl ₆ , RhCl ₃ , Tb (NO ₃ ) ₃ , Pr (NO ₃ ) ₃ , Dy (NO ₃ ) ₃ , _{sm (NO 3) 3, Ga} (NO 3) 3, Gb (NO 3) 3, Yb (NO 3) 3, NbCl 5, ZrCl 4, Zr (NO 3) 2, KNO 3, LiNO 3, hAsC _{4, Pd (NO 3) 2} , Eu (NO 3) 2, Nd (NO 3) 2, NiCl 3, Ce (NO 3) 3, CsNO 3, Er (NO 3) 3, Ba (NO 3) 2, La (NO ₃ ) ₃ , AgCl, CH ₃ CH (OH) COOAg, AgNO ₃ , TlNO ₃ , Y (NO ₃ ) ₃ , Pb (NO ₃ ) ₂ , Ho (NO ₃ ) ₃ , Bi (NO ₃ ) ₃ Etc. In the present invention, among these, it is preferable to use a metal salt of Fe or Cu, and FeCl ₂ , FeCl ₃ , Cu (NO ₃ ) ₂ , and Cu (CH ₃ COO) ₂ are particularly preferable for improving the photoelectric conversion characteristics.

Examples of the halogen include I ₂ (iodine), Cl ₂ , Br ₂ , ICl, ICl ₃ , IBr, IF _{3 and the} like.

Furthermore, examples of the Lewis acid include PF ₅ , AsF ₅ , SbF _{5 and the} like.

Among the above, the photoelectric conversion property improving substance used in the present invention is preferably a metal salt of Fe or Cu, or I ₂ (iodine). This is because these substances have a high effect of improving photoelectric conversion characteristics as described later.

2 and 3 show the current-voltage characteristics and the light emission luminance-voltage characteristics, respectively, of an organic EL element having a photocatalyst containing layer doped with FeCl ₃ . By doping the photocatalyst containing layer with FeCl ₃ , the current at the same applied voltage is increased as shown in FIG. 2, and the emission start voltage is lowered as shown in FIG. 3, and the emission luminance at the same applied voltage is also increased. I understand.
The current-voltage characteristic in FIG. 2 is obtained by measuring the value of current flowing in a 2 mm × 2 mm square range.

FIG. 4 shows the light emission efficiency-voltage characteristics of an organic EL device having a photocatalyst containing layer doped with FeCl ₃ or iodine. As shown in FIG. 4, it can be seen that the luminous efficiency is improved by doping the photocatalyst-containing layer with FeCl ₃ or iodine. In particular, when iodine is doped, the light emission efficiency on the low voltage side is improved.

  Moreover, the photoelectric conversion property improving substance doped in the photocatalyst containing layer may exist as a molecule in the photocatalyst containing layer or may exist as an ion, but in the present invention, it exists as an ion. Preferably it is.

(2) Doping of photoelectric conversion property improving substance Next, a method of doping a photoelectric conversion property improving substance used in this step will be described. The method for doping the photoelectric conversion property-improving substance is not particularly limited as long as it is a method capable of doping the photoelectric conversion property-improving substance into the photocatalyst-containing layer. For example, (i) photoelectric conversion property Examples include a method of bringing a photoelectric conversion property improving substance-containing liquid containing an improving substance into contact with the photocatalyst containing layer, or (ii) a method of vaporizing the photoelectric conversion property improving substance and doping the photocatalyst containing layer. These methods are appropriately selected depending on the type of the photoelectric conversion property improving substance.

  In the case of (i), the photoelectric conversion property-improving substance-containing liquid used is not particularly limited as long as the photoelectric conversion property-improving substance is dissolved or dispersed in a solvent. It is preferable that it is dissolved in. This is because the photoelectric conversion property improving substance doped in the photocatalyst containing layer is preferably present as ions in the photocatalyst containing layer as described above.

  The solvent used in the photoelectric conversion property-improving substance-containing liquid is one that dissolves or disperses the photoelectric conversion property-improving substance and does not adversely affect the photocatalyst-containing layer when applied on the photocatalyst-containing layer. Although it will not specifically limit if it exists, it is preferable to use what melt | dissolves the photoelectric conversion characteristic improvement substance as mentioned above.

  In addition, the method for contacting the photoelectric conversion property-improving substance-containing liquid with the photocatalyst-containing layer is not particularly limited as long as the method can dope the photoelectric conversion property-improving substance into the photocatalyst-containing layer. A method of immersing the containing layer in a photoelectric conversion property improving substance-containing liquid, a method of applying a photoelectric conversion property improving substance-containing liquid on the photocatalyst containing layer, a method of dropping a photoelectric conversion characteristic improving substance-containing liquid on the photocatalyst containing layer, etc. Is mentioned.

  When using the above coating method, a general method can be used as the coating method, for example, spray coating, dip coating, roll coating, blade coating, spin coating, etc., or a method using an inkjet, an electric field jet, or a dispenser. Nozzle discharge methods including the like.

  As the photoelectric conversion property improving substance used in the case of (i), any of the above-described substances may be used.

  On the other hand, in the case of (ii) above, since the photoelectric conversion property improving substance is vaporized, the photoelectric conversion property improving substance used is preferably iodine among the above-described substances. This is because the photocatalyst-containing layer can be doped by sublimating iodine.

  In this case, for example, iodine can be doped into the photocatalyst-containing layer by placing iodine and a substrate on which the first electrode and the photocatalyst-containing layer are formed and sublimating iodine.

  The temperature at which the photoelectric conversion characteristic improving substance is vaporized varies depending on the type of the photoelectric conversion characteristic improving substance, but when iodine is used, it may be at room temperature or higher.

  In the present invention, the amount of doping of the photoelectric conversion property improving substance varies depending on the photocatalyst and binder, which are constituent materials of the photocatalyst containing layer, or the kind of the photoelectric conversion property improving substance. It is preferably in the range of 0.0001 to 100 parts by weight, more preferably in the range of 0.01 to 10 parts by weight, with respect to 1 part by weight of the sum of the titanium oxide and the binder. This is because if the doping amount is too small, the effect of improving the photoelectric conversion characteristics may not be sufficiently obtained, and conversely, if the doping amount is too large, the light emission luminance characteristics deteriorate.

  The doping amount can be controlled, for example, by changing the time for contacting the photoelectric conversion property improving substance-containing liquid, the time for vaporizing the photoelectric conversion property improving substance, and the like. In the present invention, such conditions such as time are determined in advance through experiments or the like.

3. Next, the wettability change process in the manufacturing method of the organic photoelectric conversion element of this invention is demonstrated. The wettability changing step in the present invention is a step of changing the wettability of the photocatalyst containing layer by irradiating the photocatalyst containing layer with energy. In the present invention, such a wettability changing step is not an essential step, but since a wettability changing pattern in which the wettability of the photocatalyst-containing layer is changed can be formed, patterning of the organic photoelectric conversion layer is required. Is particularly useful.

  The mechanism of action of the photocatalyst typified by the above-described titanium oxide in the photocatalyst-containing layer is not necessarily clear, but carriers generated in the photocatalyst by irradiation of energy react directly with nearby compounds, or oxygen, The reactive oxygen species generated in the presence of water is thought to change the chemical structure of organic matter. In the present invention, it is considered that this carrier acts on the binder in the photocatalyst-containing layer and changes the wettability of the surface.

  The energy irradiation method in this step is not particularly limited as long as it is a method capable of changing the wettability of the photocatalyst-containing layer.

  The energy irradiation (exposure) in the present invention is a concept including irradiation of any energy ray capable of changing the wettability of the surface of the photocatalyst containing layer, and is not limited to visible light irradiation. Absent.

  In addition, when a wettability change pattern is formed on the surface of the photocatalyst-containing layer, energy irradiation may be performed using a mask such as a photomask on which a target pattern is formed. This is because it is possible to irradiate the target pattern with energy, and the wettability of the photocatalyst-containing layer can be changed to the pattern. In this case, the type of mask used is not particularly limited as long as the target pattern can be irradiated with energy, and is a photomask in which a light-shielding portion is formed on a material that transmits energy. Alternatively, a shadow mask or the like in which holes are formed in a desired pattern may be used. Specific examples of materials for these masks include metals, inorganic materials such as glass and ceramics, and organic materials such as plastics.

  Furthermore, as described above, when the wettability change pattern is formed on the surface of the photocatalyst-containing layer and the light shielding portion is formed on the substrate, energy irradiation is performed using this light shielding portion. Alternatively, the entire surface may be exposed from the substrate side. Thereby, energy can be irradiated only to the photocatalyst containing layer at a position where the light shielding portion is not formed, and the wettability of the photocatalyst containing layer can be changed. In this case, since there is no need to perform drawing with the mask, laser, or the like, there is an advantage that alignment or an expensive drawing apparatus is not required.

  The wavelength of the light used for the energy irradiation is usually set in the range of 400 nm or less, preferably in the range of 150 nm to 380 nm. This is because the preferable photocatalyst used in the photocatalyst-containing layer is titanium oxide as described above, and light having the above-described wavelength is preferable as energy for activating the photocatalytic action by the titanium oxide.

  Examples of light sources that can be used for such energy irradiation include mercury lamps, metal halide lamps, xenon lamps, excimer lamps, and various other light sources.

  Moreover, when forming a wettability change pattern in the photocatalyst containing layer surface as mentioned above, you may irradiate energy using lasers, such as an excimer and YAG. By performing energy irradiation using a laser, it is possible to change the wettability of the photocatalyst-containing layer with high definition without the need for alignment of the above-described photomask or the like and without forming a light-shielding portion on the substrate. It can be done.

  The energy irradiation amount at the time of the energy irradiation is an irradiation amount necessary for changing the wettability of the surface of the photocatalyst containing layer by the action of the photocatalyst in the photocatalyst containing layer.

  At this time, it is preferable in that the sensitivity can be increased by irradiating the photocatalyst-containing layer with energy while heating, and the wettability can be changed efficiently. Specifically, it is preferable to heat within a range of 30 ° C to 80 ° C.

  In the present invention, the photocatalyst-containing layer changes wettability due to the action of the photocatalyst accompanying energy irradiation, and changes in a direction in which the contact angle with the liquid decreases. Thereby, the lyophilic area | region of the part irradiated with energy can be formed in the photocatalyst content layer surface. In addition, when energy is irradiated in a pattern, it is possible to form a wettability change pattern including a lyophilic region of the irradiated portion and a lyophobic region of the non-irradiated portion.

  Here, the lyophilic region is a region having a small contact angle with the liquid, and refers to a region having good wettability with respect to the coating liquid for forming an organic photoelectric conversion layer. Further, the liquid repellent region is a region having a large contact angle with the liquid, and refers to a region having poor wettability with respect to the organic photoelectric conversion layer forming coating solution.

  In the present invention, when the contact angle with the liquid in the adjacent region is 1 ° or more lower than the contact angle with the liquid in the adjacent region, the contact with the liquid is determined from the contact angle with the liquid in the lyophilic region or the adjacent region. When the contact angle is higher than 1 °, the liquid repellent region is used.

  The contact angle between the lyophilic region formed by energy irradiation and the liquid repellent region not irradiated with energy with respect to the coating solution for forming an organic photoelectric conversion layer is at least 1 ° or more, preferably 5 ° or more, particularly 10 It is preferable that they differ by more than °.

  In the photocatalyst-containing layer, in the energy irradiated portion, that is, in the hydrophilic region, the contact angle with the liquid is reduced by the energy irradiation, and the contact angle with the liquid having a surface tension of 40 mN / m is preferably 9 ° or less. It is preferable that the contact angle with a liquid having a surface tension of 50 mN / m is 10 ° or less, and in particular, the contact angle with a liquid having a surface tension of 60 mN / m is 10 ° or less. If the contact angle with the energy irradiated part, that is, the liquid in the lyophilic region is high, when the organic photoelectric conversion layer is formed, the spread of the coating liquid for forming the organic photoelectric conversion layer in this part may be inferior. This is because problems such as chipping of the organic photoelectric conversion layer may occur.

  On the other hand, the photocatalyst-containing layer has a contact angle with a liquid with a surface tension of 40 mN / m in a portion not irradiated with energy, that is, a water-repellent region, preferably with a liquid with a surface tension of 30 mN / m. It is preferable that the contact angle with a liquid having an angle of 10 ° or more, particularly a surface tension of 20 mN / m, is 10 ° or more. Since the part not irradiated with energy is a part that requires liquid repellency, when the contact angle with the liquid is small, the liquid repellency is not sufficient, and when forming the organic photoelectric conversion layer, organic This is because the photoelectric conversion layer forming coating solution may remain.

  In addition, the contact angle with the liquid here is measured using a contact angle measuring instrument (Kyowa Interface Science Co., Ltd. CA-Z type) with a liquid having various surface tensions (from the microsyringe to the liquid. 30 seconds after dropping), and the result was obtained or the result was graphed. In this measurement, as a liquid having various surface tensions, a wetting index standard solution manufactured by Pure Chemical Co., Ltd. was used.

4). Organic photoelectric conversion layer formation process Next, the organic photoelectric conversion layer formation process in the manufacturing method of the organic photoelectric conversion element of this invention is demonstrated. In the organic photoelectric conversion layer forming step in the present invention, the organic photoelectric conversion layer-forming coating liquid is applied onto the photocatalyst-containing layer doped with the photoelectric conversion property improving substance and having changed wettability. Is a step of forming.

  In this step, the wettability of the surface of the photocatalyst containing layer is changed in the direction in which the contact angle with the liquid decreases due to the energy irradiation in the wettability changing step, so that the organic photoelectric conversion layer on the photocatalyst containing layer Application of the forming coating solution is facilitated.

  In addition, when a wettability change pattern is formed on the surface of the photocatalyst-containing layer, an organic photoelectric conversion layer is easily formed in a pattern with high definition by using the wettability difference of the wettability change pattern. It becomes possible.

  The coating liquid for forming an organic photoelectric conversion layer used in the present invention varies greatly depending on the function of the organic photoelectric conversion element, the method of forming the organic photoelectric conversion element, etc. Those that are not diluted with a solvent or liquid that is diluted or dissolved with a solvent can be used.

  The organic photoelectric conversion layer forming coating solution used in the present invention may be an organic photoelectric conversion layer by being attached to the lyophilic region, or may be attached to the lyophilic region. Then, it may be an organic photoelectric conversion layer after being treated with a chemical agent or treated with ultraviolet rays, heat or the like.

  The method for applying the organic photoelectric conversion layer-forming coating solution is not particularly limited as long as it is a method that can be applied onto the photocatalyst-containing layer with changed wettability, but organic photoelectric conversion is not limited. It is preferable that the method be capable of forming the layer uniformly and with high definition. Examples of such a coating method include a coating method such as dip coating, roll coating, blade coating, and spin coating, and a nozzle discharge method including a method using an inkjet, an electric field jet, and a dispenser.

  Moreover, in this invention, when patterning an organic photoelectric converting layer, this patterning solidified the organic photoelectric converting layer forming coating liquid other than the method of patterning in the state of the organic photoelectric converting layer forming coating liquid. Thereafter, only the portion of the organic photoelectric conversion layer on the liquid repellent region may be peeled off in a state where the organic photoelectric conversion layer is formed. As such a patterning method, for example, a method of inclining the substrate before the organic photoelectric conversion layer forming coating liquid is solidified, a method of spraying air, or an adhesive tape after the organic photoelectric conversion layer forming coating liquid is solidified The method of sticking and peeling off is mentioned.

5. Second electrode formation step In the present invention, after the organic photoelectric conversion layer formation step, a second electrode formation step of forming a second electrode on the organic photoelectric conversion layer is performed.

  The 2nd electrode used for the present invention is formed as an electrode which counters the 1st electrode mentioned above. The second electrode may be either an anode or a cathode, but is usually a cathode. The second electrode may be transparent or translucent, and may not be transparent or translucent, but is appropriately selected depending on the light extraction surface or the light reception surface.

  When the second electrode is a cathode, a conductive material having a low work function is preferably used so that electrons can be easily injected, and a conductive material having a resistance as low as possible is preferably used. As a conductive material used for such a cathode, a metal material is generally used, but an organic substance or an inorganic compound may be used. Specific examples include magnesium alloys (MgAg, etc.), aluminum alloys (AlLi, AlCa, AlMg, etc.), alkaline earth metals (metal calcium, etc.), alkali metals (potassium, lithium, etc.), and the like.

  The method for forming the second electrode is the same as that described in the section of the first electrode in “1. Photocatalyst-containing layer forming step” described above, and a description thereof is omitted here.

6). Others Examples of the organic photoelectric conversion element produced according to the present invention include an organic EL element and an organic thin film solar cell.

  In the present invention, the doping step and the wettability changing step may be performed first, and are appropriately selected depending on the type of the photoelectric conversion property improving substance to be used. For example, by doping the photocatalyst-containing material with the photocatalyst-containing material, the photocatalytic performance is reduced or the wettability change rate is slowed. When adversely affecting the sex change, the wettability changing process is performed first.

  In the present invention, before or after the photocatalyst-containing layer forming step, there is an insulating layer forming step of forming an insulating layer in a pattern on the substrate on which the first electrode is formed or on the photocatalyst-containing layer. It may be done. This insulating layer is formed in a pattern as a non-light emitting portion.

  The insulating layer can be formed using a photocurable resin composition such as an ultraviolet curable resin composition or a resin composition containing a thermosetting resin composition. As a patterning method, a general method such as a photolithography method or a printing method can be used.

B. Next, a method for manufacturing the organic EL element of the present invention will be described. The organic EL device manufacturing method of the present invention uses the above-described organic photoelectric conversion device manufacturing method, and the organic photoelectric conversion layer forming step in the organic photoelectric conversion device manufacturing method forms an organic EL layer. It is a process.

  That is, in the present invention, the organic EL device includes a photocatalyst-containing layer forming step for forming a photocatalyst-containing layer on the substrate on which the first electrode is formed, a doping step for doping the photocatalyst-containing layer with a photoelectric conversion property improving substance, Irradiating energy to the photocatalyst-containing layer to change the wettability of the photocatalyst-containing layer, and organic EL on the photocatalyst-containing layer doped with the photoelectric conversion property improving substance and having changed wettability It can manufacture by performing the organic EL layer formation process which forms the organic EL layer by apply | coating the coating liquid for layer formation, and the 2nd electrode formation process which forms a 2nd electrode on the said organic EL layer. .

  According to the present invention, as described in “A. Method for producing an organic photoelectric conversion element” described above, after the photocatalyst containing layer forming step, a doping step of doping the photocatalyst containing layer with a photoelectric conversion property improving substance is performed. Therefore, it is not necessary to add a photoelectric conversion property-improving substance to the photocatalyst-containing layer forming coating liquid, so that aggregation of the photocatalyst in the photocatalyst-containing layer forming coating liquid can be prevented, and the emission characteristics are good. It becomes possible to manufacture a simple organic EL element.

  Moreover, in this invention, the wettability change process in the manufacturing method of the said organic photoelectric conversion element irradiates energy to a photocatalyst containing layer in pattern shape, and forms the wettability change pattern in which the wettability of the said photocatalyst containing layer changed. Preferably, the organic EL layer forming step is a step of applying an organic EL layer forming coating solution on the wettability changing pattern to form the organic EL layer in a pattern. This is because the organic EL layer can be easily applied by using the wettability change pattern, and high-definition patterning becomes possible.

  The photocatalyst-containing layer forming step, the doping step, the wettability changing step, and the second electrode forming step in the present invention are the same as those described in the above-mentioned section “A. Method for producing organic photoelectric conversion element”. Therefore, explanation here is omitted. Hereinafter, the organic EL layer forming step and other configurations will be described.

(1) Organic EL layer formation process The organic EL layer formation process in this invention apply | coats the coating liquid for organic EL layer formation on the photocatalyst containing layer by which the photoelectric conversion characteristic improvement substance was doped and the wettability changed, This is a step of forming an organic EL layer.

The organic EL layer formed by this step is composed of one or a plurality of organic layers including at least a light emitting layer. That is, the organic EL layer is a layer including at least a light emitting layer, and the layer configuration is a layer having one or more organic layers. Usually, when an organic EL layer is formed by a wet method by coating, it is often difficult to stack a large number of layers in relation to a solvent, so that it is often formed of one or two organic layers. However, it is possible to further increase the number of layers by devising an organic material so that the solubility in a solvent is different or by combining a vacuum deposition method.
Hereinafter, the formation method of the light emitting layer which is an essential structure of the organic EL layer will be described.

a. Method for Forming Light-Emitting Layer The light-emitting layer in the present invention has a function of emitting light by providing a field for recombination of electrons and holes. The light emitting layer can be generally formed by applying a light emitting layer forming coating solution containing a light emitting material such as a dye-based light-emitting material, a metal complex-based light-emitting material, and a polymer-based light-emitting material.

  In the present invention, when manufacturing an organic EL element capable of color display, it is preferable to form at least three light emitting layers of red, green, and blue in a pattern. In the present invention, as described above, by utilizing the wettability difference of the wettability change pattern, the light emitting layer can be easily formed into a pattern, and the red, green, and blue light emitting layers are formed. Even if it is formed, high-definition patterning is possible. Thus, when forming the light emitting layer of multiple colors in a pattern, usually, a plurality of types of light emitting layer forming coating solutions are used.

  Examples of dye-based light emitting materials include cyclopentadiene derivatives, tetraphenylbutadiene derivatives, triphenylamine derivatives, oxadiazole derivatives, pyrazoloquinoline derivatives, distyrylbenzene derivatives, distyrylarylene derivatives, silole derivatives, thiophene ring compounds, pyridine rings Examples thereof include compounds, perinone derivatives, perylene derivatives, oligothiophene derivatives, trifumanylamine derivatives, coumarin derivatives, oxadiazole dimers, pyrazoline dimers, and the like.

Metal complex light emitting materials include aluminum quinolinol complex, benzoquinolinol beryllium complex, benzoxazole zinc complex, benzothiazole zinc complex, azomethyl zinc complex, porphyrin zinc complex, europium complex, iridium metal complex, platinum metal complex, etc. The metal has Al, Zn, Be, Ir, Pt, etc., or a rare earth metal such as Tb, Eu, Dy, etc., and the ligand has an oxadiazole, thiadiazole, phenylpyridine, phenylbenzimidazole, quinoline structure, etc. A metal complex etc. can be mentioned. Specifically, tris (8-quinolinolato) aluminum complex (Alq ₃ ) can be used.

  Furthermore, as the polymer light emitting material, polyparaphenylene vinylene derivatives, polythiophene derivatives, polyparaphenylene derivatives, polysilane derivatives, polyacetylene derivatives, polyvinylcarbazole, polyfluorenone derivatives, polyfluorene derivatives, polyquinoxaline derivatives, polydialkylfluorene derivatives, And copolymers thereof. Moreover, what polymerized the said pigment-type luminescent material and metal complex type | system | group luminescent material is also mentioned.

  In addition, an additive that emits fluorescent light or phosphorescent light may be added to the light emitting layer forming coating solution for the purpose of improving the light emission efficiency and changing the light emission wavelength. Examples of such additives include perylene derivatives, coumarin derivatives, rubrene derivatives, quinacridone derivatives, squalium derivatives, porphyrin derivatives, styryl dyes, tetracene derivatives, pyrazoline derivatives, decacyclene, phenoxazone, quinoxaline derivatives, carbazole derivatives, fluorene derivatives, etc. Can be mentioned.

  Furthermore, the solvent used in the light emitting layer forming coating solution is not particularly limited as long as it is a solvent capable of dissolving or dispersing the light emitting material described above. Specific examples include chloroform, methylene chloride, dichloroethane, tetrahydrofuran, toluene, xylene, tetralin, mesitylene and the like.

  The method for applying the light emitting layer forming coating solution is not particularly limited as long as it is a method that can be applied onto the wettability change pattern, but the light emitting layer is uniformly and highly finely formed. A method that can be formed is preferable. Examples of such a coating method include a dip coating method, a roll coating method, a blade coating method, a spin coating method, a micro gravure coating method, and an ink jet method.

  The thickness of the light emitting layer is not particularly limited as long as it can provide a function of emitting light by providing a recombination field between electrons and holes, and is, for example, about 1 nm to 500 nm. Can do.

  In the present invention, a partition wall can be formed between the light emitting layers. This partition wall is particularly useful when a light emitting layer having a plurality of colors is formed. Examples of the material used for forming the partition include photosensitive polyimide resin, acrylic resin, photocurable resin, thermosetting resin, and water repellent resin.

(2) Charge Injection / Transport Layer Formation Step In the present invention, a charge injection / transport layer formation step of forming a charge injection / transport layer between the organic EL layer and the first electrode or the second electrode may be performed. The charge injecting and transporting layer here has a function of stably transporting the charge from the first electrode or the second electrode to the organic EL layer. By providing between one electrode or between the organic EL layer and the second electrode, the injection of charges into the organic EL layer is stabilized, and the luminous efficiency can be increased.

  As such a charge injection transport layer, a hole injection transport layer that transports holes injected from the anode into the organic EL layer, and an electron that transports electrons injected from the cathode into the organic EL layer as well. There is an injection transport layer.

  In the present invention, as described in the section of the first electrode in “A. Production method of organic photoelectric conversion element 1. Photocatalyst-containing layer forming step” described above, the first electrode is usually formed as an anode, and the second Since the electrode is formed as a cathode, the hole injection / transport layer is formed between the first electrode and the organic EL layer, and the electron injection / transport layer is formed between the second electrode and the organic EL layer. Is done. Hereinafter, the hole injection transport layer forming step for forming the hole injection transport layer and the electron injection transport layer forming step for forming the electron injection transport layer will be described.

a. Hole injection transport layer forming step In the present invention, a hole injection transport layer forming step of forming a hole injection transport layer between the first electrode and the organic EL layer may be performed. This is because holes injected from the first electrode (anode) can be stably transported into the organic EL layer.

  The hole injecting and transporting layer forming step in the present invention may be performed before the photocatalyst-containing layer forming step, and may be a step of forming a hole injecting and transporting layer on the substrate on which the first electrode is formed. It may be a step of forming a hole injecting and transporting layer on the photocatalyst containing layer which is performed before the organic EL layer forming step and is doped with the photoelectric conversion property improving substance and whose wettability is changed. As described above, in the present invention, the hole injecting and transporting layer forming step may be performed before the photocatalyst-containing layer forming step or may be performed before the organic EL layer forming step. Which of the layer formation step and the photocatalyst-containing layer formation step is performed first may be appropriately selected depending on the constituent materials of the hole injection transport layer and the photocatalyst-containing layer. For example, the energy level of the constituent material of the hole injection transport layer and the photocatalyst of the photocatalyst containing layer may be considered.

  Moreover, in this invention, the mixed layer of a positive hole injection transport layer and a photocatalyst content layer can also be formed. In this case, the above mixed layer can be formed by using a mixed coating solution obtained by mixing a photocatalyst-containing layer forming coating solution and a hole injection transport layer forming coating solution.

  In this step, either a hole injection layer for injecting holes into the organic EL layer or a hole transport layer for transporting holes may be formed as the hole injection / transport layer. The layer and the hole transport layer may be laminated to form a single layer having both a hole injection function and a hole transport function.

  Such a hole injecting and transporting layer is formed by applying or depositing a coating liquid for forming a hole injecting and transporting layer containing a material capable of stably transporting holes injected from the anode into the organic EL layer. Can be formed.

  Such a material is not particularly limited as long as holes injected from the anode can be stably transported into the light emitting layer. For example, the compounds exemplified in the light emitting material of the above light emitting layer In addition, oxides such as phenylamine, starburst amine, phthalocyanine, vanadium oxide, molybdenum oxide, ruthenium oxide, and aluminum oxide, derivatives such as amorphous carbon, polyaniline, polythiophene, and polyphenylene vinylene can be used. . Specifically, bis (N- (1-naphthyl-N-phenyl) benzidine (α-NPD), 4,4,4-tris (3-methylphenylphenylamino) triphenylamine (MTDATA), poly 3, 4-ethylenedioxythiophene-polystyrene sulfonic acid (PEDOT-PSS), polyvinyl carbazole (PVCz), or the like can be used.

  In addition, the thickness of the hole injecting and transporting layer is not particularly limited as long as it is a thickness that sufficiently injects holes from the anode and transports the holes to the organic EL layer, but specifically, It is preferably in the range of 0.5 nm to 10 μm, particularly in the range of 50 nm to 500 nm.

b. Electron Injection / Transport Layer Formation Step In the present invention, an electron injection / transport layer formation step of forming an electron injection / transport layer on the organic EL layer may be performed after the organic EL layer formation step. This is because electrons injected from the second electrode (cathode) can be stably transported into the organic EL layer.

  In this step, either an electron injection layer for injecting electrons into the organic EL layer or an electron transport layer for transporting electrons may be formed as the electron injection / transport layer. A single layer having both an electron injection function and an electron transport function may be formed.

  In the present invention, the electron injecting and transporting layer is formed by applying a coating liquid for forming an electron injecting and transporting layer containing a material capable of stably transporting electrons injected from the cathode into the organic EL layer, or on the organic EL layer. It can be formed by vapor deposition.

  Such a material is not particularly limited as long as it can stabilize injection of electrons into the light emitting layer. For example, as a material used for forming the electron injection layer, in addition to the compounds exemplified as the light emitting material of the light emitting layer, aluminum lithium, aluminum, strontium, calcium, lithium, cesium, magnesium oxide, aluminum oxide, strontium oxide, Examples include lithium oxide, lithium fluoride, magnesium fluoride, strontium fluoride, calcium fluoride, barium fluoride, cesium fluoride, polymethyl methacrylate, and sodium polystyrene sulfonate.

  The thickness of the electron injection layer is not particularly limited as long as the electron injection function is sufficiently exerted. Specifically, the thickness is preferably about 0.5 nm to 50 nm.

The material used for forming the electron transport layer is not particularly limited as long as it is a material that can transport electrons injected from the cathode or the electron injection layer into the organic EL layer. For example, bathocuproin (BCP), bathophenanthroline (Bpehn), phenanthroline derivative, or tris (8-quinolinolato) aluminum complex (Alq ₃ ), Bis (2-methyl-8-quinolinolato-N1,08)-(1,1 '-Biphenyl-4-olato) aluminum (BAlq) and the like.

  Furthermore, in the case of forming an electron injecting and transporting layer comprising a single layer having both an electron injecting function and an electron transporting function, a metal doped layer in which an alkali metal or an alkaline earth metal is doped into an electron transporting organic material And can be used as an electron injecting and transporting layer. Examples of the electron transporting organic material include bathocuproin (BCP) and bathophenanthroline (Bphen). Examples of the metal to be doped include Li, Cs, Ba, and Sr. The molar ratio of the electron transporting organic material to the metal in the metal doped layer is preferably in the range of 1: 1 to 3, and more preferably in the range of 1: 1 to 2. The thickness of the metal doped layer is preferably in the range of 5 nm to 500 nm, and more preferably in the range of 10 nm to 100 nm. Since the metal doped layer has a high electron mobility and a high light transmittance as compared with a single metal, the metal doped layer can be made thicker than the electron injection layer.

(3) Others In the present invention, holes or electrons such as a carrier block layer and an exciton block layer are prevented from penetrating between the organic EL layer and the first electrode or the second electrode. By preventing diffusion and confining excitons in the organic EL layer, a layer for increasing the recombination efficiency can be formed.

  The present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, and the present invention has substantially the same configuration as the technical idea described in the claims of the present invention, and any device that exhibits the same function and effect is the present invention. It is included in the technical scope of the invention.

Hereinafter, the present invention will be specifically described with reference to examples.
[Example 1]
(Formation of photocatalyst containing layer)
Neutral detergent, ultrasonic cleaning, and UV ozone cleaning are each performed on a glass substrate with an ITO electrode patterned in a strip shape having a width of 12 mm in the center for 15 minutes, and the following photocatalyst-containing layer is formed on the ITO electrode of the glass substrate with an ITO electrode. The forming coating solution was spin coated at 3500 rpm for 10 seconds. Thereafter, it was dried on a hot plate set at 130 ° C. for 15 minutes. As a result, a photocatalyst-containing layer having a thickness of about 80 nm was formed.

<Photocatalyst-containing layer forming coating solution>
Acidic titanium oxide sol STS-01 (trade name, manufactured by Ishihara Sangyo Co., Ltd.) and dispersion stabilizer methyl silicate 51 (general formula: Si _n O _n-1 (OCH ₃ ) _{2n + 2} (where n is 3 to 5), Colcoat (Trade name) manufactured by Co., Ltd., and a wet anion exchange resin Amberlite IRA-910 (trade name, manufactured by Organo Corporation) was added with stirring, and neutralized by ion exchange. . Next, after filtering the ion exchange resin, methanol was added to prepare a neutral titanium oxide sol solution having a pH of 6.4 and a solid content of 1%. The sample, the weight ratio of the converted amount of titanium in the amount as titanium oxide in terms of silicon in methyl silicate the SiO ₂ to _{TiO 2 (SiO 2 / TiO 2} ) is 1 (JP 2000- No. 53421).
1 part by weight of the neutral titanium oxide sol solution and 0.2 part by weight of isopropyl alcohol were mixed to prepare a photocatalyst-containing layer forming coating solution.

(Doping of photoelectric conversion property improving substance)
The glass substrate with an ITO electrode on which the photocatalyst-containing layer was formed was immersed in the following photoelectric conversion property improving substance-containing liquid for 5 minutes.

<Photoelectric conversion property improving substance-containing liquid>
・ Ferric chloride 0.06489 parts by weight ・ Isopropyl alcohol 10 parts by weight

(Formation of organic EL layer)
On the photocatalyst-containing layer, the following organic EL layer forming coating solution is spin-coated at 1500 rpm for 10 seconds in a glove box substituted with high-purity nitrogen, and dried on a hot plate set at 130 ° C. for about 1 hour. Thus, an organic EL layer was formed.

<Coating liquid for organic EL layer formation>
・ Polyfluorene derivative (ADS228GE manufactured by ADS) 1 part by weight ・ Xylene (EL grade manufactured by Kanto Chemical Co., Inc.) 99 parts by weight

(Formation of electron injection transport layer and second electrode)
On the organic EL layer, an electron injecting and transporting layer and a second electrode were formed by vacuum deposition so that the LiF film was 3 nm, the Ca film was 10 nm, and the Al film was 150 nm thick. This obtained the organic EL element.

[Example 2]
An organic EL device was produced in the same manner as in Example 1 except that the following photoelectric conversion property improving substance-containing liquid was used.

<Photoelectric conversion property improving substance-containing liquid>
・ Iodine 0.0648 parts by weight ・ Isopropyl alcohol 10 parts by weight

[Comparative Example 1]
An organic EL device was produced in the same manner as in Example 1 except that the photoelectric conversion property improving substance was not doped.

[Evaluation]
The current-voltage characteristics and the light emission luminance-voltage characteristics of the organic EL elements of Examples 1 and 2 and Comparative Example 1 are shown in FIGS. In addition, the current-voltage characteristic in FIG. 5 is a value obtained by measuring a current value flowing in a range of 2 mm × 2 mm square.

It is process drawing which shows an example of the manufacturing method of the organic photoelectric conversion element of this invention. Current of the organic EL device of FeCl ₃ doped - is a graph showing the voltage characteristic. It is a graph which shows the light emission luminance-voltage characteristic of the organic EL element doped with FeCl ₃ . FeCl ₃ or luminous efficiency of the organic EL elements doped with iodine - is a graph showing the voltage characteristic. It is a graph which shows the current-voltage characteristic of the organic EL element of Examples 1, 2 and Comparative Example 1. It is a graph which shows the light emission luminance-voltage characteristic of the organic EL element of Examples 1, 2 and Comparative Example 1.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Base | substrate 2 ... 1st electrode 3 ... Photocatalyst containing layer 3a ... Lipophilic area | region 3b ... Liquid repellency area | region 3 '... Photocatalyst containing layer which the photoelectric conversion characteristic improvement substance was doped and wettability changed 5 ... Organic photoelectric Conversion layer 6 ... 2nd electrode 14 ... Photoelectric conversion characteristic improving substance-containing liquid

Claims (9)

A base, a first electrode formed on the base, a photocatalyst-containing layer formed on the first electrode and containing a photocatalyst and a substance for improving photoelectric conversion characteristics, and an organic photoelectric film formed on the photocatalyst-containing layer A method for producing an organic photoelectric conversion element having a conversion layer and a second electrode formed on the organic photoelectric conversion layer,
A photocatalyst-containing layer forming step for forming a photocatalyst-containing layer on the substrate on which the first electrode is formed, a doping step for doping the photocatalyst-containing layer with a photoelectric conversion property improving substance, and the photoelectric conversion property improving substance are doped An organic photoelectric conversion layer forming step of applying an organic photoelectric conversion layer forming coating solution on the photocatalyst-containing layer to form an organic photoelectric conversion layer.   The wettability of the photocatalyst-containing layer is changed by the action of the photocatalyst associated with energy irradiation, and the wettability changing step is performed in which the photocatalyst-containing layer is irradiated with energy to change the wettability of the photocatalyst-containing layer. The manufacturing method of the organic photoelectric conversion element of Claim 1 characterized by the above-mentioned.   The organic photoelectric conversion according to claim 1, wherein the doping step is a step of bringing the photoelectric conversion property improving substance-containing liquid containing the photoelectric conversion property improving substance into contact with the photocatalyst containing layer. Device manufacturing method.   The method for producing an organic photoelectric conversion element according to claim 1, wherein the doping step is a step of vaporizing the photoelectric conversion property improving substance and doping the photocatalyst-containing layer.   The method for producing an organic photoelectric conversion element according to any one of claims 1 to 4, wherein the photoelectric conversion property improving substance is a metal salt of Fe or Cu, or iodine.   The claim according to any one of claims 1 to 5, wherein in the photocatalyst-containing layer forming step, a coating solution for forming a photocatalyst containing layer having a neutral pH and containing a photocatalyst is used. The manufacturing method of the organic photoelectric conversion element as described in a term.   The method for producing an organic photoelectric conversion element according to any one of claims 1 to 6, wherein the organic photoelectric conversion layer forming step in the method for producing an organic photoelectric conversion element is an organic electroluminescent layer. A method for producing an organic electroluminescent element, characterized by being an organic electroluminescent layer forming step for forming a film.   The wettability changing step in the manufacturing method of the organic photoelectric conversion element is a step of irradiating the photocatalyst containing layer with energy in a pattern to form a wettability changing pattern in which the wettability of the photocatalyst containing layer is changed, and the organic The electroluminescent layer forming step is a step of applying an organic electroluminescent layer forming coating solution on the wettability change pattern to form an organic electroluminescent layer in a pattern. The manufacturing method of the organic electroluminescent element of Claim 7.   The organic electroluminescent layer forming step is a step of forming a light emitting layer of at least three colors of red, green, and blue in a pattern, and enables color display. Manufacturing method of organic electroluminescent element.

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