Transfer body and method for manufacturing functional element

Abstract

To provide a transfer body capable of transferring a coating-type conductive film, and a method for manufacturing a functional element using the transfer body.SOLUTION: A transfer body includes a silicone-based substrate that has been surface-treated with a silane coupling agent, and a conductive film formed on the silicone-based substrate, the conductive film includING at least a surfactant having a functional group similar to that of the silane coupling agent and a conductive material that is dispersible in water or an alcohol-based solvent.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a transfer body and a functional element, and a method for manufacturing a photovoltaic element.

Background Art

[0002] In recent years, by popularizing a large number of electronic devices, a trillion sensor society and an Internet of Things (IoT) society have been promoted, and it is expected that human life will become more comfortable. To achieve this, mass production of functional electronic elements (hereinafter referred to as functional elements) that make up electronic devices is essential. Therefore, a method that can be easily mass-produced is required rather than the conventional manufacturing processes with a large environmental and material load such as vacuum evaporation and vacuum sputtering.

[0003] Therefore, a coating-type manufacturing process capable of constructing functional elements by solution coating has attracted attention. In this coating-type manufacturing process, functional elements can be manufactured by solution coating using an electron material (semiconductor materials such as organic semiconductors, organic-inorganic perovskite compounds, and metal oxides, and conductive materials such as metal nano / microstructures, nanocarbons, and conductive polymers) that can be dispersed in a solvent. Here, the functional element refers to an element that includes at least a first electrode, a functional layer, and a second electrode on a substrate and is formed in this order.

[0004] Specifically, transistors, rectifying elements, photovoltaic elements, sensor elements, etc. are typical examples. If these functional elements can be realized in a coating-type manufacturing process, mass production of electronic devices such as active matrix displays, Radio frequency identification (RFID) tags, and solar cells will be facilitated, and it can be expected to promote a trillion sensor society and an IoT society.

[0005] Problems to be solved for the practical application of this coating-type functional element include physical and chemical damage to the lower layer due to coating and lamination. In particular, in the formation process of the second electrode layer laminated on the outermost surface, since the coating process is carried out on a substrate including other constituent members, the influence on the entire element is particularly large. Specifically, peeling of the lower layer due to the flow of the solution and deterioration of the element performance due to penetration of a large amount of solvent during the coating process are typical examples. As a solution to this problem, a process of forming an electrode by transferring a conductive film previously formed by coating on a base material has been studied so far, and the following disclosures have been made.

[0006] In Patent Document 1, by using a highly water-repellent polyparaxylylene film as a release layer and using a liquid phase to facilitate peeling, peeling of the transfer film from the base material is made easy. As a result, it is possible to precisely laminate a circuit structure including transistors on a substrate with low heat resistance such as a plastic substrate.

[0007] In Patent Document 2, a process is disclosed in which a transfer body having a release layer and a conductive film in this order on a base material is used to bond it onto an organic semiconductor and transfer and laminate an electrode. Examples of the release layer include polymer materials, and in particular, a thermal transfer method through heat pressing is preferred. According to this disclosed technology, it is possible to manufacture an organic solar cell without causing a short-circuit path or damage to the lower layer as much as possible.

Prior Art Documents

Patent Documents

[0008]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0009] However, in the transfer process of Patent Document 1, since a water-repellent polymer material (polyparylene) is used for the release layer of the transfer body, when a conductive material dispersed in water or an alcohol-based solvent is applied, coating rejection occurs on the release layer, making it difficult to form a highly uniform film.

[0010] In addition, in Patent Document 2, there is an example of using a water-soluble polymer material for the release layer. However, when applying a conductive material dispersed in water or an alcohol-based solvent, there is a problem that the release layer dissolves and the release layer and the conductive material are mixed. As solutions to these problems, it is conceivable to cause a physical stress change to the conductive film by a transfer process using energy irradiation typified by laser ablation and perform the transfer of the conductive film. However, a process involving energy irradiation may change the film quality of the element constituent materials such as the functional layer that is the transfer destination. As a result, there is concern about a decrease in the performance of the functional element.

[0011] High-performance coating-type electrode materials are conductive polymers, metal nano / microstructures, and nanocarbons, and are mainly dispersed in water or alcohol-based solvents. Therefore, solving the above problems is important in practice.

[0012] In view of the above problems, an object of the present invention is to provide a transfer body capable of transferring a coating-type conductive film and a method for manufacturing a functional element using the transfer body.

Means for Solving the Problems

[0013] In the present invention, according to a transfer body having a silicone-based substrate surface-treated with a silane coupling agent, a surfactant having at least the same functional group as the silane coupling agent on the silicone-based substrate, and a conductive film containing a conductive material dispersible in water or an alcohol-based solvent, good transfer of the conductive film becomes possible.

[0014] Furthermore, a step of including a high-boiling solvent containing at least one selected from the group consisting of polyhydric alcohols, ethers, ketones, and sulfoxide compounds in the transfer body, and arranging the transfer body and a functional substrate having at least a first electrode and a functional layer on a substrate so as to face each other, and transferring the conductive film of the transfer body as a second electrode onto the functional layer of the functional substrate. According to the manufacturing method of the functional element having at least a first electrode, a functional layer, and a second electrode, which are laminated in this order, a high-performance coating type functional element can be realized.

Effects of the Invention

[0015] According to the transfer body of the present invention, good transfer lamination of the conductive film is possible on the body to be transferred. Furthermore, by using this transfer step, the performance of the functional element can be improved compared to the conventional coating lamination method.

Brief Description of the Drawings

[0016]

Figure 1

Figure 2

Figure 3

Figure 4

Embodiments for Carrying Out the Invention

[0017] Hereinafter, the transfer body and the manufacturing method of the functional element of the present invention will be described. Regarding the manufacturing method of the functional element, it consists of a step of including a high-boiling solvent in the transfer body and a transfer step, and the details of each will be described.

[0018] <Transfer body> The transfer body of the present invention will be described. Here, the "transfer body" in the present invention refers to a laminate including at least a conductive film to be transferred onto a target substrate and a silicone-based substrate. In the present invention, the transfer body has a silicone-based substrate surface-treated with a silane coupling agent (hereinafter referred to as a silane coupling agent-treated silicone-based substrate), and on the silicone-based substrate, there is a conductive film containing at least a surfactant having a functional group similar to that of the silane coupling agent and a conductive material dispersible in water or an alcohol-based solvent, thereby making it possible to enhance the transferability of the conductive film.

[0019] Here, the "transferability" in the present invention refers to the ability of the film to be transferred on the transfer body to be laminated on the transfer destination without remaining on the substrate. That is, "high transferability" means that there are few defects (such as cracks, wrinkles, and defects) in the film to be transferred, and "low transferability" means that there are many defects in the film to be transferred. An example of the structure of the transfer body of the present invention is shown in FIG. 1. The transfer body 01 includes a silane coupling agent-treated silicone-based substrate 10 and a conductive film 11. Hereinafter, each constituent material will be described.

[0020] 〔Silane Coupling Agent-Treated Silicone-Based Substrate〕 The role of the silane coupling agent-treated silicone-based substrate 10 will be described. The silicone-based substrate of the present invention can be any silicone as long as it has mechanical flexibility, gas permeability, and adaptability to surface treatment with a silane coupling agent (hereinafter referred to as silane coupling treatment). Due to the mechanical flexibility of the silicone-based substrate, the peeling of the substrate in the transfer process becomes easy, and mechanical damage to the transfer body can be suppressed. In addition, due to its gas permeability, the volatilization of the residual solvent in the conductive film or the transfer body is promoted. Specific examples of the silicone-based substrate include polydimethylsiloxane (PDMS) from the viewpoint of chemical durability. More preferably, it is polydimethylsiloxane having light transmissibility. If polydimethylsiloxane having light transmissibility is used, alignment with the lower layer becomes easy in the transfer process.

[0021] The silane coupling treatment will be described. By performing the silane coupling treatment, the wettability of the conductive film material can be improved on the silicone-based substrate. At this time, since the silane coupling agent has a water-repellent functional group similar to that of the surfactant contained in the conductive film material described later, it is possible to apply a conductive film material containing water or an alcohol-based solvent while having a water-repellent surface. As a result, a conductive film that can be easily peeled off can be formed on the silicone-based substrate without generating a strong hydrogen-bonding adhesion between the conductive film and the silicone-based substrate.

[0022] The silane coupling treatment of the present invention is performed, for example, using a silane coupling agent having a structure represented by the following general formula.

[0023] [Chemical formula]

[0024] R 1 is either an alkyl group, an alkoxy group, or a polyether. R 2 , R 3 , R 4 may be the same or different and is an alkyl group or an alkoxy group, and at least two are alkoxy groups. R 1 is appropriately selected to be the same as the water-repellent functional group of the surfactant in the conductive film material. From the viewpoint of facilitating the peeling of the transfer film, it is preferably an alkyl group, more preferably an alkyl group having 6 or more carbon atoms, and even more preferably an alkyl group having 8 or more carbon atoms. Also, the upper limit of the carbon number of R1 is within a range soluble in water or an alcohol-based solvent, specifically 20 or less. R 2 , R 3 , R 4 is a site where dehydration condensation occurs with the silicone-based substrate, and at least two of these may be alkoxy groups in an appropriate number suitable for the silicone-based substrate. From the viewpoint of obtaining a good bonding state, it is preferable that all of R 2 , R 3 , R 4 are alkoxy groups. More preferably, R2 , R 3 , R 4 It is preferable that all of them are ethoxy groups or all are methoxy groups.

[0025] Specific structures include dodecyltriethoxysilane, dodecyltrimethoxysilane, hexadecyltriethoxysilane, hexadecyltrimethoxysilane, octadecyltriethoxysilane, octadecyltrimethoxysilane, and the like.

[0026] The process of silane coupling treatment will be described. The silane coupling treatment in the present invention is carried out by dehydration condensation between any alkoxy group of R 2 , R 3 , R 4 of the silane coupling agent and the hydroxyl groups on the surface of the silicone-based substrate. Therefore, it is necessary to perform a hydrophilic treatment on the surface of the silicone-based substrate in advance, such as ozone irradiation. Any method may be used as long as the surface is hydrophilized. Specifically, from the viewpoint of preventing vitrification by peroxidation, UV ozone treatment is preferable, and more preferably, UV ozone treatment using vacuum ultraviolet light is mentioned. According to the UV ozone treatment using vacuum ultraviolet light, high-density ozone can be irradiated onto the silicone in a short time, so rapid production is possible. Here, the UV ozone treatment refers to a method using a UV light source in the atmosphere, and from the viewpoint of preventing peroxidation of the treatment target and deactivation of ultraviolet light, it may be carried out in an atmosphere filled with an inert gas represented by nitrogen or argon. When a silicone that has already been chemically hydrophilized on the surface is used as the substrate, it is not necessarily required to perform the above-mentioned hydrophilic treatment.

[0027] Next, as a method for reacting the silicone-based substrate with the silane coupling agent, any method may be used as long as the target functional group is sufficiently bonded to the surface. For example, spin coating, dip coating, spray coating, blade coating, dipping, etc. using water or an alcohol-based solvent in which the silane coupling agent is dispersed can be mentioned. As an evaluation method for whether or not the target functional group is bonded to the surface, measurement of surface energy by contact angle measurement, etc. can be mentioned. It is preferable that the surface energy after silane treatment is lower than the surface energy of the hydrophilic-treated silicone-based substrate and higher than the surface energy of PDMS having no functional group. Thereby, a weak adhesion force with weak van der Waals force acts between the conductive film and the silicone-based substrate, and it can be easily peeled off by a relatively weak force such as mechanical stress or film swelling. Thereby, a transfer body excellent in transferability can be obtained. From the viewpoint of patterning the transfer film according to the application, it is preferable to perform the above-mentioned hydrophilic treatment through a mask pattern such as a photomask or a metal mask to pattern the hydrophilic surface on the silicone-based substrate. Thereby, the silane coupling treatment can be selectively performed, and it is also possible to form a pattern of the transfer film. Further, the transfer film can also be patterned by previously making the surface shape of the silicone-based substrate uneven. As a method for making the surface shape uneven, forming the silicone-based substrate using a mold can be mentioned as an example.

[0028] 〔Conductive film material〕 The material constituting the conductive film 11 in the transfer body of the present invention (hereinafter referred to as the conductive film material) will be described. The conductive film material in the present invention contains at least a conductive material, a surfactant, and water or an alcohol-based solvent, and by using this, a conductive film is formed by coating on a silicone-based substrate. Here, the "conductive material" refers to a material that bears conductivity in the film, and the "conductive film material" refers to a material containing a solvent before coating formation.

[0029] First, the conductive material will be described. The conductive material of the present invention may be any material that can be dispersed in water or an alcohol-based solvent, and any conductive material may be used as long as it can be applied onto a substrate thereby. Examples of materials that can be dispersed in water or an alcohol-based solvent include highly conductive materials such as conductive polymers, metal nano / microstructures, and nanocarbons, and they are appropriately selected according to the configuration of the functional element, the simplicity of the manufacturing process, etc. There is no limitation on the amount of the conductive material as long as it can be stably dispersed in the solvent, but its concentration is appropriately adjusted in the coating process of the conductive film material. From the viewpoints of conductivity and dispersion stability, it is preferably contained in the range of 0.1 to 10% by mass based on the total amount of the solvent.

[0030] As an example of a specific conductive material, from the viewpoint of obtaining a uniform transfer film, a conductive material containing a conductive polymer is preferable. If it has a structure containing a conductive polymer, it is possible to form a film with fewer defects such as depletion. Further, even if a polyether-based surfactant that can inhibit conductivity is used, a conductive polymer can exhibit good conductivity. Also, from the viewpoint of improving the conductivity of the conductive film 11, it is preferably present in the transfer body in combination with a metal nano / microstructure, and more preferably contains 50% by mass or less of the conductive polymer with respect to the metal nano / microstructure. Furthermore, it is preferably contained 20% by mass or less of the conductive polymer with respect to the metal nano / microstructure. Also, for an element that does not require high conductivity, for the purpose of enhancing transferability, it is preferable to use a conductive polymer alone as the material of the conductive film. Specifically, examples of elements that do not require high conductivity include sensor elements having a functional layer with a high resistance load, light-emitting elements with a size of several tens of cm 2 or less, and photovoltaic elements. As the type of the conductive polymer, polyethylenedioxythiophene added with polystyrenesulfonic acid is preferable from the viewpoints of affinity with water or an alcohol-based solvent, air stability, and conductivity.

[0031] The surfactant used for the coating formation of the conductive film 11 will be described. The surfactant may be any surfactant as long as it contains a functional group similar to the functional group on the surface of the silicone-based substrate and is soluble in water or an alcohol-based solvent. Here, "containing a similar functional group" in the present invention means that the structure of the surfactant may include those having the same structure as R of the above silane coupling agent. That is, even if it is contained within a certain variation in the structure of the surfactant, it is considered "similar". For example, if the number of carbon atoms in the alkyl group in the surfactant varies within the range of 12 to 15, R of the silane coupling agent may be an alkyl group within that range of the number of carbon atoms. When R of the silane coupling agent is an alkyl group, an alkoxy group, or a polyether, even if the number of carbon atoms is different from that of the silane coupling agent, they are similar functional groups because there is no difference in their mutual affinity. Preferably, the difference in the number of carbon atoms is within 10, more preferably within 5, and even more preferably within 3. 1 This means that it may include those having the same structure. That is, even if it is contained within a certain variation in the structure of the surfactant, it is considered "similar". For example, if the number of carbon atoms in the alkyl group in the surfactant varies within the range of 12 to 15, R of the silane coupling agent may be an alkyl group within that range of the number of carbon atoms. 1 If the number of carbon atoms in the alkyl group in the surfactant varies within the range of 12 to 15, R of the silane coupling agent may be an alkyl group within that range of the number of carbon atoms. 1 When R of the silane coupling agent is an alkyl group, an alkoxy group, or a polyether, even if the number of carbon atoms is different from that of the silane coupling agent, they are similar functional groups because there is no difference in their mutual affinity. Preferably, the difference in the number of carbon atoms is within 10, more preferably within 5, and even more preferably within 3.

[0032] As a specific structure of the surfactant, from the viewpoint of improving the wettability on the silicone-based substrate 10 subjected to the silane coupling treatment, a polyoxyalkylene alkyl ether having a high affinity for the alkyl group, alkoxy group, or polyether-based functional group of the silane coupling agent is preferable. Also, from the viewpoint of not inhibiting the conductivity of the transfer film, regarding the concentration of the surfactant, it is preferably 1% by mass or less, more preferably 0.1% by mass or less, based on the total weight of the solvent. The lower limit of the concentration of the surfactant varies depending on the type of the coating process and the drying rate of the solvent, etc., but the range of 0.025 to 0.05% by mass based on the total amount of the solvent is the lower limit value.

[0033] The solvent used for forming the conductive film 11 will be described. The solvent in the conductive film material is water or an alcohol-based solvent with a small environmental load, and any combination may be used as long as the conductive material and the surfactant can be dispersed. Here, the water or alcohol-based solvent in the present invention refers to a solvent in which 50% by volume or more of the total volume of the solvent is water or alcohol. Regarding the specific composition of the solvent, it may be appropriately adjusted in view of the solubility of the conductive material, chemical stability in the atmosphere, wettability, viscosity, drying time, etc. in order to obtain a uniform coating film. Specifically, for the purpose of enhancing storage stability and stability during coating, a water or alcohol-based solvent (hereinafter referred to as the "main solvent") having a boiling point in the range of 60°C to 100°C is contained in an amount of 50% by volume or more based on the total volume of the solvent.

[0034] Also, as will be described in the transfer process described later, in order to improve transferability, it is preferable to contain a high-boiling solvent containing at least one selected from the group consisting of polyhydric alcohols, ethers, ketones, and sulfoxide compounds. More preferably, it contains a high-boiling solvent of polyhydric alcohol, and even more preferably, it is a divalent alcohol-based high-boiling solvent having a high affinity for water and alcohol. Here, "high-boiling point" in the present invention refers to a solvent having a boiling point higher than that of water. By containing these high-boiling solvents, a conductive film that is easily peeled off from the silicone-based substrate can be obtained.

[0035] The amount of the high-boiling solvent contained is preferably 1 to 20% by volume, more preferably 1 to 10% by volume, and even more preferably 2 to 8% by volume based on the total volume of the solvent from the viewpoint of preventing aggregation due to the residual solvent in the coating film. Also, from the viewpoint of preventing deterioration of the functional layer of the functional element, the amount of the high-boiling solvent contained is preferably 2 to 5% by volume.

[0036] Furthermore, from the perspective of preventing a large amount of the high-boiling-point solvent from drying during coating, a high-boiling-point solvent having a vapor pressure of 500 Pa or less at normal temperature (20 to 25 °C) is preferable. More preferably, it is a high-boiling-point solvent of 100 Pa or less, and even more preferably 10 Pa or less. Specific examples of the high-boiling-point solvent include dimethyl sulfoxide, ethylene glycol, propylene glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, and the like.

[0037] A method for coating and forming the conductive film 11 will be described. As the coating and forming method, it is possible to use a known method, and examples include spin coating, dip coating, spray coating, blade coating, etc., and a method suitable for the form of the target conductive film may be selected.

[0038] From the perspective of improving transferability and ease of handling, the thickness of the conductive film 11 is preferably 10 nm to 1 μm, more preferably 20 to 500 nm, and even more preferably 30 to 300 nm.

[0039] During coating and forming, if the coating film is not completely dried, only the main solvent is dried, and the high-boiling-point solvent is contained in the conductive film, the step of adding the high-boiling-point solvent described later can be omitted. From the perspective of reducing the number of steps, it is more preferable to leave the high-boiling-point solvent remaining.

[0040] In addition, the conductive film 11 may be formed as a multilayer film depending on the application. For example, by forming a conductive film 11 in which a layer containing a metal nano / micro structure excellent in conductivity and a layer containing a conductive polymer excellent in hole transportability are laminated in this order, it becomes possible to transfer and laminate the hole transport layer and the anode, which constitute a photoelectric conversion element or a light-emitting element, all at once. As a method for producing the multilayer film, examples include combining the above coating and forming methods and utilizing phase separation that occurs during coating or drying of the coating film.

[0041] <Manufacturing method of functional element> The manufacturing method of the functional element in the present invention includes a step of incorporating a high-boiling solvent containing at least one selected from the group consisting of polyhydric alcohols, ethers, ketones, and sulfoxide compounds into the transfer body, and a conductive film of the transfer body containing the high-boiling solvent. The method further includes a transfer step of arranging the transfer body such that the conductive film faces a functional substrate having at least a first electrode and a functional layer on a substrate, and transferring the conductive film of the transfer body as a second electrode onto the functional layer of the functional substrate. The manufacturing method is for a functional element having at least a first electrode, a functional layer, and a second electrode, which are laminated in this order.

[0042] That is, as the entire manufacturing process, it goes through (1) the manufacturing process of the transfer body, (2) the manufacturing process of the functional substrate, (3) the step of incorporating a high-boiling solvent into the transfer body, and (4) the transfer step. Since the process of (2) only involves preparing the functional substrate, it can be in any order as long as it is before (4). Hereinafter, the processes of (1) to (4) will be described.

[0043] 〔Manufacturing process of the transfer body〕 As described above, the manufacturing of the transfer body consists of a laminate of a silicone-based substrate 10 subjected to a silane coupling treatment and a conductive film 11. First, as described above, by appropriately selecting and applying a treatment process to the silicone-based substrate, a silicone-based substrate 10 subjected to a silane coupling treatment is obtained. Next, by appropriately selecting the above-described conductive film material and the coating formation method, the conductive film material is coated and formed on the silicone-based substrate 10. Thereby, the transfer body 11 can be obtained.

[0044] 〔Step of incorporating a high-boiling solvent into the transfer body〕 The process of including a high-boiling-point solvent in the transfer body of the present invention will be described. The high-boiling-point solvent includes at least one selected from the group consisting of polyhydric alcohols, ethers, ketones, and sulfoxide compounds. FIG. 2 is a diagram showing an example of the transfer body after the step of including the high-boiling-point solvent, and represents a transfer body 02 including a conductive film 21 containing the high-boiling-point solvent and a silicone-based substrate 20 subjected to a silane coupling treatment. By this step, for example, the conductive film 21 swollen with the solvent has a stress acting in the shear direction at the interface with the silicone-based substrate 20, making peeling easier. Alternatively, during the transfer process described later, capillary action occurs between the silicone-based substrate 20 and the conductive film 21, making it easier to form a transfer film on the substrate to be transferred.

[0045] In this step of including the high-boiling-point solvent, if the high-boiling-point solvent already remains in the conductive film 11 when forming the transfer body 01, this step can be omitted. The types of the high-boiling-point solvent are the same as the preferable ranges in the description of the transfer body above. The amount to be included is an amount that the film can hold, and is not limited as long as the conductivity of the conductive film is not inhibited. The preferable range is 1 to 50% by mass, more preferably 1 to 30% by mass, based on the mass of the conductive film 11 at a temperature of 25°C and a relative humidity of 40 to 50%.

[0046] From the viewpoint of enhancing transferability, in order to promote capillary action, it is preferable that the contained high-boiling-point solvent is significantly localized at the interface between the conductive film 21 and the silicone-based substrate 20. Therefore, the high-boiling-point solvent preferably has a functional group similar to that of the silane coupling agent or the surfactant of the conductive film, and more preferably does not contain a functional group having a strong affinity for the surface of the object to be transferred. Here, the strength of the affinity can be experimentally confirmed by measuring the contact angle using the same solvent. Also, it can be confirmed theoretically by calculating various surface free energies and the like. Specific methods for including a high-boiling-point solvent include coating processes such as spin coating, dip coating, spray coating, blade coating, and slot die coating of the high-boiling-point solvent on the transfer body. A method with a high continuous affinity with the transfer body formation process or the manufacturing process of the functional element may be used. Also, the adjustment of the solvent amount depends on the process, but it is possible by changing the amount of the solvent to be applied or introducing a drying process after film formation.

[0047] 〔Functional Substrate and Its Manufacturing Process〕 A functional substrate is a structure including at least an electrode and a functional layer on a substrate, at least a part of the functional layer being located on the surface layer, and a laminate that becomes a functional electronic element (i.e., a functional element) when a part of the functional layer and the electrode are electrically connected. Hereinafter, each material such as the substrate, electrode, and functional layer constituting the functional substrate and its forming method will be described.

[0048] The substrate is preferably selected according to the type and use of the functional element. For example, inorganic materials such as non-alkali glass, quartz glass, alloys such as aluminum, iron, copper, and stainless steel; films and plates made by any method from organic materials such as polyester, polycarbonate, polyolefin, polyamide, polyimide, polyphenylene sulfide, polyparaxylylene, polymethyl methacrylate, epoxy resin, and fluorine-based resin can be mentioned.

[0049] The electrode is generally made of a material having conductivity or semiconductor properties. For example, metals such as gold, platinum, silver, copper, iron, zinc, tin, aluminum, indium, chromium, nickel, cobalt, scandium, vanadium, yttrium, cerium, samarium, europium, terbium, ytterbium, molybdenum, tungsten, titanium, and alloys thereof; metal oxides such as indium, tin, molybdenum, nickel oxides; composite metal oxides such as indium tin oxide (ITO), indium zinc oxide (IZO), aluminum zinc oxide (AZO), gallium zinc oxide (GZO); carbon materials such as graphite, graphite intercalation compounds, carbon nanotubes, graphene; conductive polymers such as polythiophene-based polymers, poly-p-phenylene vinylene-based polymers, polyfluorene-based polymers, polypyrrole polymers, polyaniline polymers, polyfuran polymers, polypyridine polymers, polycarbazole polymers; low molecular weight organic compounds exhibiting p-type semiconductor properties such as phthalocyanine derivatives (H2Pc, CuPc, ZnPc, etc.), porphyrin derivatives, acene-based compounds (tetracene, pentacene, etc.). It includes microstructures such as nanoparticles and nanowires having the above composition.

[0050] The functional layer is a layer whose electrical, optical, electromagnetic, or mechanical properties change in response to an electrical input or a surrounding physicochemical change. For example, the semiconductor layer in a transistor or a rectifying element, the photoelectric conversion layer in a photovoltaic element, the light-emitting layer in a light-emitting element, the sensing site in a physicochemical sensor, etc. can be mentioned. For this functional layer, materials similar to those constituting the above electrode can be used, and various semiconductor materials, their combinations, and other composite materials can also be used. As the functional layer that can be made highly performant by the transfer body of the present invention, coating-type semiconductor materials such as organic semiconductors, organic-inorganic hybrid perovskite compounds, metal oxides, and nanocarbons, and the above conductive materials are suitable.

[0051] In addition to the above electrode and functional layer, for the purpose of obtaining the performance of the target functional device or in combination with other devices, materials similar to the above materials or materials such as dielectrics and magnetic materials may be appropriately included.

[0052] From the viewpoint of improving transferability, it is also possible to enhance the adhesion between the conductive film of the transfer body and the functional substrate by laminating a material with a high surface energy on the outermost layer of the functional substrate. Preferably, it has a metal oxide of 1 to 500 nm on the surface layer of the functional substrate, and more preferably, it has a metal oxide of 5 to 100 nm on the surface layer of the functional substrate.

[0053] Regarding each formation method, a technique known per se may be appropriately applied according to the application of the functional element, but from the viewpoints of low environmental impact and large-area manufacturing, coating formation using a solution containing various materials is preferred. As a specific method, the steps as described in the coating formation method of the conductive film material in the transfer body may be used.

[0054] The functional substrate is manufactured from the configuration and formation method as described above and can be used as a functional element by the following transfer process. Specific examples of the element structure will be described later for the photovoltaic element and the light-emitting element.

[0055] 〔Transfer Process〕 The transfer process of the transfer body in the present invention will be described. In this transfer process, a functional substrate having at least an electrode and a functional layer and a transfer body are arranged so as to face each other on the substrate, and the conductive film of the transfer body is transferred onto the functional layer of the functional substrate. FIG. 3 is a diagram showing an example of the transfer process, and represents a process of transferring the conductive film 21 onto a substrate 30 having a laminate 31 having at least an electrode and a functional layer using a transfer body 02 including a conductive film 21 containing a high-boiling solvent and a silicone-based substrate 20.

[0056] In this transfer process, for the process of bonding the transfer body and the functional substrate and the process of peeling them off, any method may be used as long as the constituent members of each other excluding the silicone-based substrate are not destroyed.

[0057] For the purpose of improving the transferability or the performance of the functional element, a bonding process or a heat treatment may be performed in the bonded state. In the heat treatment, it is possible to prevent the solvent contained in the transfer body from penetrating onto the functional substrate, and depending on the amount of the solvent, it can be instantaneously volatilized. Thereby, it is possible to reduce the adhesion between the functional substrate and the silicone-based substrate, and to prevent deterioration of the performance of the functional element due to changes in the film quality of the functional layer or intrusion of the solvent. Specific heating conditions are appropriately changed depending on the material of the functional substrate and the type of the high-boiling solvent contained in the transfer body, and are not particularly limited. When a conductive polymer is used for the transfer body, the temperature range is preferably between 30°C and 200°C, more preferably between 30°C and 150°C.

[0058] Also, in the heat treatment, by using an oven or a heater and appropriately adjusting the position, a temperature gradient can be generated, and improvement in transferability and performance of the functional element can be obtained. Specifically, in order to prevent the solvent from staying at the interface between the transfer body and the functional substrate, it is preferable to arrange the heater near the functional substrate.

[0059] In addition to the above heat treatment, a pressure treatment may be performed. By the pressure treatment, the transfer body and the functional substrate can be closely bonded together, and defects on the transferred conductive film can be reduced. Specific pressure conditions are appropriately changed depending on the material of the functional substrate and the mechanical properties of the conductive film of the transfer body, and are not particularly limited, and pressure by the self-weight of the transfer body may be used. Preferably, it is 0.05 to 0.5 MPa, more preferably 0.05 to 0.1 MPa. The duration of the pressure is preferably 5 to 120 seconds, more preferably 10 to 90 seconds. The above pressure treatment can be carried out by using a vacuum laminator, a roller, or the like. The pressure treatment and the heat treatment may be performed simultaneously.

[0060] 〔Other Processes〕 After the transfer process, when there is a large amount of solvent remaining in the conductive film, a drying treatment may be appropriately performed to improve the conductivity of the transfer film. For example, drying may be performed using a known heating process such as vacuum drying or the above heat treatment.

[0061] In addition, depending on the application, heat treatment, pressure treatment, additional transfer processes, etc. can be appropriately carried out as needed.

[0062] <Functional element> As described above, according to the process of including the transfer body of the present invention and its high-boiling solvent and the transfer process, physicochemical damage to the functional layer is suppressed, and a high-performance functional element can be manufactured. Hereinafter, as specific examples, a photoelectric power element and a light-emitting element will be described. In addition to the following two examples, other functional elements such as transistors, rectifying elements, and thermoelectric power elements can also be manufactured by the transfer body of the present invention and the manufacturing method of the functional element.

[0063] 〔Photoelectric power element〕 By using the manufacturing method of the functional element of the present invention, transfer lamination of a coating-type material is possible while suppressing physicochemical damage to the lower layer, so that it is possible to improve the power generation efficiency and add functionality to a coating-type photoelectric power element typified by an organic solar cell. As an example, the structure of the photoelectric power element may be formed on a substrate with the following configurations (a) to (h). However, it is not limited to the following. (a) Cathode / Electron transport layer / Photoelectric conversion layer / Hole transport layer / Anode (b) Cathode / Electron transport layer / Photoelectric conversion layer / Anode (c) Cathode / Photoelectric conversion layer / Hole transport layer / Anode (d) Cathode / Photoelectric conversion layer / Anode (e) Anode / Hole transport layer / Photoelectric conversion layer / Electron transport layer / Cathode (f) Anode / Photoelectric conversion layer / Electron transport layer / Cathode (g) Anode / Hole transport layer / Photoelectric conversion layer / Cathode (h) Anode / Photoelectric conversion layer / Cathode Here, the "hole transport layer" in the photovoltaic device is a layer formed between the photoelectric conversion layer and the anode, and has the function of extracting and transporting holes from the photoelectric conversion layer. It may also be referred to as a "hole extraction layer". Further, the "electron transport layer" in the photovoltaic device is a layer formed between the photoelectric conversion layer and the cathode, and has the function of extracting and transporting electrons from the photoelectric conversion layer. It may also be referred to as an "electron extraction layer". The "photoelectric conversion layer" is a layer that functions to generate electromotive force by photoelectric conversion. In addition, in the above configurations (a) to (h), when the hole transport layer and the electron transport layer are omitted, the anode and the cathode each perform their respective functions.

[0064] Among the above configurations of the photovoltaic device, in the case of configurations (a) to (d), either the hole transport layer and the anode or a combination thereof, and in the case of (e) to (h), the electron transport layer and the cathode or a combination thereof are transferred and laminated from the conductive film of the transfer body.

[0065] Also, among the above configurations, from the viewpoint of obtaining a higher-performance photovoltaic device, it is preferable that, as in the configurations (a) to (d), at least the cathode, the photoelectric conversion layer, and the anode are provided on the substrate and laminated in this order. For example, it has the configuration of FIG. 4, and is a photovoltaic device in which a cathode 41, an electron transport layer 42, a photoelectric conversion layer 43, a hole transport layer 44, and an anode 45 are laminated in this order on a substrate 40. With this structure, a cathode (when including the electron transport layer, also including the electron transport layer) showing a relatively shallow work function of around 4.0 eV or less is not formed on the surface of the device that is likely to come into contact with water and oxygen in the air, so a photovoltaic device with high environmental durability can be formed. The details of each component are as follows.

[0066] 〔Substrate〕 As the substrate, it is preferable to appropriately select from the materials such as those mentioned for the above functional substrates according to the type and application of the photoelectric conversion material. For example, when light is incident from the substrate side for use, the substrate preferably has a light transmittance of 80% or more.

[0067] 〔Cathode and Anode〕 As the conductive material used for the cathode, those that form an ohmic contact with adjacent layers such as an electron transport layer are preferred. As the conductive material used for the anode, those that form an ohmic contact with adjacent layers such as a hole transport layer are preferred. Specific configurations of each conductive material include the conductive materials of the above-mentioned transfer body and the electrodes used for the functional substrate.

[0068] In the photovoltaic device of the present invention, it is preferable that at least one of the cathode and the anode has light transmissivity. Furthermore, by both the cathode and the anode having light transmissivity, a semi-transparent photovoltaic device can be formed. Here, "having light transmissivity" means transmitting light to such an extent that incident light reaches the photoelectric conversion layer and an electromotive force is generated. That is, when the light transmittance has a value exceeding 0%, it is said to have light transmissivity. The electrode having light transmissivity preferably has a light transmittance of 60% or more in all wavelength regions from 400 nm to 700 nm. Also, the thickness of the electrode having light transmissivity only needs to obtain sufficient conductivity, which varies depending on the material, but is preferably 20 nm to 300 nm. Note that an electrode having no light transmissivity only needs to have conductivity, and the thickness is not particularly limited.

[0069] 〔Electron transport layer〕 The electron transport layer is used when the energy barrier between the cathode and the acceptor material of the photoelectric conversion layer is not small enough. Examples of materials for forming the electron transport layer include n-type semiconductor materials such as NTCDA, PTCDA, PTCDI-C8H, oxazole derivatives, triazole derivatives, phenanthroline derivatives, phosphine oxide derivatives, phosphine sulfide derivatives, quinoline derivatives, fullerene compounds, CNT, and CN-PPV; ionic substituted fluorene-based polymers (Advanced Materials, 2011, Vol. 23, pp. 4636-4643; Organic Electronics, 2009, Vol. 10, pp. 496-500), combinations of ionic substituted fluorene-based polymers and substituted thiophene-based polymers (Journal of American Chemical Society, 2011, Vol. 133, pp. 8416-8419), and ionic compounds such as ammonium salts, amine salts, pyridinium salts, imidazolium salts, phosphonium salts, carboxylate salts, sulfonate salts, phosphate salts, sulfate esters, phosphate esters, sulfates, nitrates, acetonato salts, oxo acid salts, and metal complexes; polyethylene oxide (Advanced Materials, 2007, Vol. 19, pp. 1835-1838); titanium oxides such as TiO x ), zinc oxides such as ZnO (ZnO x ), silicon oxides such as SiO2 (SiO x ), tin oxides such as SnO2 (SnO x ), tungsten oxides such as WO3 (WOx), tantalum oxides such as Ta2O3 (TaOx), barium titanates such as BaTiO3 (BaTi x O y ), barium zirconates such as BaZrO3 (BaZr x O y ), zirconium oxides such as ZrO2 (ZrO x ), hafnium oxides such as HfO2 (HfO x ), aluminum oxides such as Al2O3 (AlO x)、Yttrium oxides such as Y2O3 (YO x )、Zirconium silicates such as ZrSiO4 (ZrSi x O y ) and other metal oxides; nitrides such as silicon nitride (SiN x ) like Si3N4, cadmium sulfides such as cadmium sulfide (CdS x )、zinc selenides such as zinc selenide (ZnSe x )、zinc sulfides such as zinc sulfide (ZnS x )、cadmium tellurides such as cadmium telluride (CdTe x ) and other inorganic semiconductor materials. Two or more of these may be contained.

[0070] More specifically, ammonium chloride, ammonium acetate, ammonium phosphate, hexyltrimethylammonium bromide, tetrabutylammonium bromide, octadecyltrimethylammonium bromide, hexadecylpyridinium bromide, 1-butyl-3-methylimidazolium bromide, tributylhexadecylphosphonium bromide, zinc formate, zinc acetate, zinc propionate, zinc butyrate, zinc oxalate, sodium heptadecafluorononanoate, sodium myristate, sodium benzoate, sodium 1-hexadecanesulfonate, sodium dodecyl sulfate, sodium monododecyl phosphate, zinc acetylacetonate, ammonium chromate, ammonium metavanadate, ammonium molybdate, ammonium hexafluorozirconate, sodium tungstate, ammonium tetrachlorozincate, tetraisopropyl orthotitanate, lithium nickelate, potassium permanganate, silver phenanthroline complex, AgTCNQ, and compounds used in the electron transport layer described in JP-A-2013-58714, etc. are mentioned.

[0071] The electron transport layer may be a single layer or may have a laminated structure. The thickness of the electron transport layer is preferably 200 nm or less for the purpose of reducing the electrical resistance and the number of charge trap sites in the film or for the purpose of obtaining light transmittance.

[0072] 〔Photoelectric conversion layer〕 The photoelectric conversion layer is made of materials applicable to a coating manufacturing process. For example, organic semiconductors or organic-inorganic hybrid perovskite compounds are used. These photoelectric conversion layers may deteriorate in performance due to physical and chemical damage caused by solution coating. In particular, since an organic semiconductor is a film containing microcrystals composed of relatively weak van der Waals forces, the performance deterioration is significant. According to the step of including the transfer body of the present invention and its high-boiling solvent and the transfer step, it is possible to suppress the above damage. Therefore, it contributes to the high performance of a photoelectric conversion device using an organic semiconductor for the photoelectric conversion layer in particular.

[0073] From the viewpoint of obtaining high power generation efficiency, a photoelectric conversion layer using an organic-inorganic hybrid perovskite compound is preferable. For example, methylammonium lead halide (CH3NH3PbX3: MAPbX3, where X is a halogen element) can be mentioned. Further, from the viewpoint of reducing the environmental load, a lead-free perovskite compound material is more preferable.

[0074] From the viewpoint of imparting designability to the appearance, a photoelectric conversion layer using an organic semiconductor is more preferable. Hereinafter, a photoelectric conversion device using an organic semiconductor is referred to as an organic photoelectric conversion device. An organic semiconductor is easy to design optical characteristics from its molecular structure and can be easily thinned to 100 nm or less. Thereby, it becomes possible to adjust the color tone and impart light transmissibility of the photoelectric conversion device. The photoelectric conversion layer using an organic semiconductor has a structure including an electron-donating semiconductor and an electron-accepting semiconductor. Here, the "electron-donating semiconductor" refers to an organic compound exhibiting p-type semiconductor characteristics or having hole transport properties, and the "electron-accepting semiconductor" refers to an organic compound exhibiting n-type semiconductor characteristics or having electron transport properties.

[0075] For example, by using a photoelectric conversion layer that combines an electron-donating semiconductor that mainly absorbs visible light in the range of 500 to 600 nm and an electron-accepting semiconductor that absorbs near-infrared light in the vicinity of 800 to 900 nm, a highly efficient organic photovoltaic device can be obtained. For example, regarding the electron-donating organic semiconductor, an electron-donating organic semiconductor (hereinafter referred to as electron-donating organic semiconductor (2)(3)) containing a unit structure having a benzodithiophene skeleton and a benzodithiophenedione skeleton represented by the following general formulas (2) and (3) has an energy gap between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) that absorbs the above-mentioned visible light. Such an electron-donating organic semiconductor has a HOMO level of 5.0 eV or more, so a hole transport layer with a deep work function is required. Regarding the electron-accepting organic semiconductor, an electron-accepting organic semiconductor (hereinafter referred to as electron-accepting organic semiconductor (4)) centered on benzothiadiazole represented by the following general formula (4) has a HOMO-LUMO energy gap that absorbs the above-mentioned visible light.

[0076]

Chemical formula

[0077] In the above general formulas (2) to (3), R 5 ~R 6 may be the same or different and each represents a hydrogen atom, an alkyl group or an alkoxy group. Among these, from the viewpoints of the solubility of the electron-donating organic semiconductors (2)(3) in organic solvents and the packing property in the photoelectric conversion layer, an alkyl group is preferred.

[0078] X1 may be the same or different and each represents a hydrogen atom or a halogen atom. Among these, from the viewpoint of deepening the HOMO level of the electron-donating organic semiconductors (2)(3) and improving the open-circuit voltage of the photovoltaic device, a halogen atom is preferred.

[0079] In the present invention, the "alkyl group" is, for example, a monovalent saturated aliphatic hydrocarbon group such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, etc. It may be linear, branched or cyclic, and may be unsubstituted or substituted. From the viewpoint of improving the solubility of the electron-donating organic semiconductors (2) and (3) in an organic solvent, it is preferably branched. Examples of the substituent in the case of substitution include an alkoxy group, an aryl group, a heteroaryl group, a halogen atom, etc., which will be described later. R 5 ~R 6 From the viewpoint of improving the solubility of the electron-donating organic semiconductors (2) and (3) in an organic solvent, the number of carbon atoms of the alkyl group in R

[0080] ~R 5 ~R 6 is preferably 4 or more. On the other hand, from the viewpoint of further improving the carrier mobility of the electron-donating organic semiconductors (2) and (3), the number of carbon atoms of the alkyl group is preferably 12 or less.

[0081] The halogen atom is any one of fluorine, chlorine, bromine and iodine. Among these, fluorine, which has the strongest electron-withdrawing property, is more preferably used because it has a small atomic radius and can maintain the packing property.

[0082] Further, in the above general formula (4), R 7 may be the same or different and each represents a hydrogen atom, an alkyl group or an alkoxy group. Among these, from the viewpoints of the solubility of the electron-accepting organic semiconductor (4) in an organic solvent and the packing property in the photoelectric conversion layer, an alkyl group is preferable. R 7From the viewpoint of improving the solubility of the electron-accepting organic semiconductor (4) in an organic solvent, the number of carbon atoms of the alkyl group is preferably 4 or more. On the other hand, from the viewpoint of further improving the carrier mobility of the electron-accepting organic semiconductor (4), the number of carbon atoms of the alkyl group is preferably 12 or less. From the viewpoint of improving the solubility of the electron-accepting organic semiconductor (4) in an organic solvent, the alkyl group is preferably branched.

[0083] X 2 may be the same or different and represents a hydrogen atom or a halogen atom. Among these, a halogen atom is preferable.

[0084] Furthermore, the electron-donating organic semiconductors (2) and (3) represented by the following structural formulas and the electron-accepting organic semiconductor (4) are preferable examples because the above optical characteristics can be obtained, they have high charge transport characteristics, and excellent power generation efficiency can be obtained.

[0085] [Chemical formula]

[0086] The electron-donating organic semiconductor and the electron-accepting organic semiconductor may each be one type, or a plurality of them may be combined. For example, by using two types of electron-accepting organic semiconductors, the energy barrier between the electron-donating organic semiconductor and the electron-accepting organic semiconductor can be reduced, and the loss of the open-circuit voltage can be suppressed. Thereby, it is possible to improve the power generation efficiency of the organic photovoltaic element. The photoelectric conversion layer may be a single layer or have a laminated structure, and its thickness is selected according to the application.

[0087] [Hole transport layer] The hole transport layer is used when the energy barrier between the anode and the donor material of the photoelectric conversion layer is not small enough. Specific materials for forming the hole transport layer include conductive polymers such as polythiophene-based polymers, poly-p-phenylene vinylene-based polymers, polyfluorene-based polymers, polypyrrole polymers, polyaniline polymers, polyfuran polymers, polypyridine polymers, and polycarbazole polymers; low molecular weight organic compounds exhibiting p-type semiconductor properties such as phthalocyanine derivatives (H2Pc, CuPc, ZnPc, etc.), porphyrin derivatives, and acene-based compounds (tetracene, pentacene, etc.); carbon materials and carbon compounds such as carbon nanotubes, graphene, and graphene oxide; metal oxides such as molybdenum oxide (MoO x ), tungsten oxide (WO x ), nickel oxide (NiO x ), vanadium oxide (VO x ), zirconium oxide (ZrO x ), copper oxide (CuO x ), copper iodide, ruthenium oxide (RuO x ), and rhenium oxide (ReO x ). Two or more of these may be contained. Among these, polyethylenedioxythiophene (PEDOT), which is a polythiophene-based polymer, and those obtained by adding polystyrene sulfonate (PSS) to PEDOT, molybdenum oxide, vanadium oxide, and tungsten oxide are preferably used.

[0088] The thickness of the hole transport layer is preferably 200 nm or less for the purpose of reducing the electrical resistance and the number of charge trap sites in the film or for the purpose of obtaining light transmittance. However, when it functions as a transparent electrode, this is not the case, and the thickness within the range where light transmittance can be obtained may be appropriately selected. For example, in the case of PH1000 (manufactured by Heraeus Co., Ltd.), which is a high-conductivity grade product of PEDOT:PSS, when the thickness is 200 nm or less, a visible light transmittance of 80% or more can be obtained, which is preferable.

[0089] 〔Manufacturing Method of Photovoltaic Element〕 Regarding the method for manufacturing a photoelectric conversion device of the present invention, the case of an organic solar cell having a cathode, an electron transport layer, a photoelectric conversion layer, a hole transport layer, and an anode in this order on a substrate will be described as an example. In this example, the transfer body and the transfer process are used when forming the anode.

[0090] First, a transparent electrode such as ITO (corresponding to the cathode in this case) is formed on the substrate by a sputtering method or the like.

[0091] Next, a solution containing a material constituting the electron transport layer is applied onto the cathode and heated to form the electron transport layer. When forming the electron transport layer with an inorganic material, examples include a method of applying a precursor solution such as a metal salt or a metal alkoxide and then heating to form the electron transport layer, and a method of applying a nanoparticle dispersion liquid onto the photoelectric conversion layer to form the electron transport layer. At this time, depending on the heating temperature and time, the synthesis conditions of the nanoparticles, etc., the reaction may not proceed completely, and it may become a partially hydrolyzed or condensed intermediate product, or a mixture of the precursor, the intermediate product, the final product, etc.

[0092] Next, a solution in which the material constituting the photoelectric conversion layer is dissolved in an organic solvent is applied onto the electron transport layer and heated to form the photoelectric conversion layer. The organic solvent is not particularly limited as long as the electron-donating organic semiconductor and the electron-accepting organic semiconductor can be appropriately dissolved or dispersed therein. From the viewpoint of handleability, an organic solvent having a boiling point of 50°C or higher is preferred. More specifically, halogenated hydrocarbons such as dichloromethane, 1,2-dichloroethylene, trichloroethylene, tetrachloroethylene, chloroform, carbon tetrachloride, dichloroethane, trichloroethane, 1,3-dichloropropane, 1,1,1,2-tetrachloroethane, 1,1,1,3-tetrachloropropane, 1,2,2,3-tetrachloropropane, 1,1,2,3-tetrachloropropane, pentachloropropane, hexachloropropane, heptachloropropane, 1-bromopropane, 1,2-dibromopropane, 2,2-dibromopropane, 1,3-dibromopropane, 1,2,3-tribromopropane, 1,4-dibromobutane, 1,5-dibromopentane, 1,6-dibromohexane, 1,7-dibromoheptane, 1,8-dibromooctane, 1-iodopropane, 1,3-diiodopropane, 1,4-diiodobutane, 1,5-diiodopentane, 1,6-diiodohexane, 1,7-diiodoheptane, 1,8-diiodooctane are preferred.

[0093] Examples of the method for forming the photoelectric conversion layer include spin coating, blade coating, slit die coating, screen printing, bar coater coating, mold coating, printing transfer method, dip coating method, inkjet method, spray method, vacuum evaporation method, and the like. It is preferable to select the forming method according to the characteristics of the photoelectric conversion layer to be obtained, such as film thickness control and orientation control.

[0094] Next, a solution containing the material constituting the hole transport layer is applied onto the photoelectric conversion layer and heated to form the hole transport layer. Examples of the method for forming the hole transport layer include the methods exemplified as the method for forming the photoelectric conversion layer.

[0095] Next, on the hole transport layer, the conductive film is transferred using the above-described transfer body. When performing the transfer, a step of including the above-described high-boiling point solvent and a transfer step are used to laminate the conductive film as an anode on the hole transport layer. Further, if the energy barrier between the anode and the photoelectric conversion layer is sufficiently small, the anode can also serve as the hole transport layer, and the hole transport layer can be omitted, and the conductive film can be transferred onto the photoelectric conversion layer. Further, by previously forming two layers of a hole transport layer and an anode on the transfer body, the two layers of the hole transport layer and the anode can be transferred together.

[0096] The manufacturing process of the above-described photoelectric power generation element is an example of the photoelectric power generation element as described above, and does not limit the application range of the step of including the transfer body and the high-boiling point solvent of the present invention and the transfer step.

[0097] 〔Use of the photoelectric power generation element〕 The photoelectric power generation element of the present invention can be applied to various photoelectric conversion devices utilizing a photoelectric conversion function, a photo rectification function, etc. For example, in addition to a photovoltaic cell (such as a solar cell), it is useful for electronic elements (such as a photosensor, an optical switch, a phototransistor), optical recording materials (such as an optical memory), an imaging element, etc. Further, as will be described below, applications taking advantage of the designability of the appearance can be developed from the photoelectric power generation element with a transparent electrode laminated by the transfer body and the manufacturing method of the present invention.

Example

[0098] Hereinafter, the present invention will be described more specifically based on examples and comparative examples. Note that the present invention is not limited to the following examples. Among the compounds used in the examples etc., those using abbreviations are shown below. Jsc: Short-circuit current density Voc: Open-circuit voltage FF: Fill factor η: Power generation efficiency ITO: Indium tin oxide DMSO: Dimethyl sulfoxide DMF: N,N-Dimethylformamide EG: Ethylene glycol PG: Propylene glycol 1,3-BG: 1,3-Butanediol DTES: Dodecyltriethoxysilane, a silane coupling agent having the structural formula represented by the following formula (1)

[0099]

Chem.

[0100] PM6: An electron-donating organic semiconductor having the structural formula represented by the following formula (2)(3) Y6: An electron-accepting organic semiconductor having the structural formula represented by the following formula (4)

[0101]

Chem.

[0102] The evaluation methods for each example and comparative example are shown below.

[0103] 〔Evaluation Method for Transfer Film〕 The evaluation methods for the transfer films in each example and comparative example are shown below.

[0104] Regarding the transferability of the transfer film, it was evaluated from the transfer state and appearance. Regarding the transfer state, an optical microscope or a digital microscope was used to observe the conductive film on the transfer body and the conductive film on the functional substrate before and after the transfer process, and the evaluation was carried out according to the following evaluation criteria. S: A state in which 90% or more of the total area of the conductive film on the transfer body was transferred onto the functional substrate A: A state in which 80 - 90% of the total area of the conductive film on the transfer body was transferred onto the functional substrate B: A state in which 50 - 80% or more of the total area of the conductive film on the transfer body was transferred onto the functional substrate C: A state in which less than 50% of the total area of the conductive film on the transfer body was transferred onto the functional substrate Regarding the evaluation of the appearance, an optical microscope or a digital microscope was used to observe the conductive film on the transfer body and the conductive film on the functional substrate before and after the transfer process, and the evaluation was carried out according to the following evaluation criteria. S: Wrinkles and creases do not occur in an area of 90% or more of the total area of the transfer film after the transfer process. A: Wrinkles and creases do not occur in an area of 80% to 90% of the total area of the transfer film after the transfer process. B: Wrinkles and creases do not occur in an area of 50% to 80% of the total area of the transfer film after the transfer process. C: Wrinkles and creases do not occur in an area of less than 50% of the total area of the transfer film on the functional substrate after the transfer process. Regarding the electrical characteristics of the transfer film, the sheet resistance was measured using a Loresta-AX series simple low resistivity meter manufactured by Nitto Seiko Analytic Co., Ltd. Regarding the optical characteristics of the transfer film, the visible light transmittance was measured using a U-3010 series visible spectrophotometer manufactured by Hitachi High-Tech Corporation. The visible light transmittance was calculated by averaging the total light transmittance at wavelengths of 400 to 700 nm.

[0105] 〔Evaluation method of photovoltaic device〕 In this example, as an example of a functional device, an organic photovoltaic device will be described. Here, the evaluation methods of the photovoltaic devices in each example and comparative example are shown below.

[0106] The anode and cathode of the photovoltaic device obtained in each example and comparative example were connected to a 2400 series source meter manufactured by Keithley Instruments, Inc., and in the atmosphere, simulated sunlight (OTENTO-SUNIII manufactured by Spectral Instruments Co., Ltd., spectral shape: AM1.5, intensity: 100 mW / cm 2 ) was irradiated from the ITO layer side, and the current value was measured when the applied voltage was changed from -1 V to +2 V.

[0107] From the obtained current value, the power generation efficiency (η) was obtained by the following formula. η(%) = Isc (mA / cm 2 ) × Voc (V) × FF / irradiation light intensity (mW / cm 2 ) × 100 FF = JVmax / (Isc (mA / cm 2 ) × Voc (V)) JVmax (mW / cm 2) is the value of the product of the current density and the applied voltage at the point where the product of the current density and the applied voltage is maximized between an applied voltage of 0 V and the open-circuit voltage.

[0108] The visible light transmittance of the photovoltaic element was calculated by averaging the total light transmittance at wavelengths of 400 to 700 nm, similar to the evaluation of the transparent electrode. [Examples 1 to 5] In Examples 1 to 5, since a transfer body was produced, evaluation regarding transferability on a functional substrate, and a photovoltaic element was formed as an example of a functional element, the evaluation of the element performance will be described. (Example 1) [Production of transfer body] To 1 mL of an ethanol solvent (manufactured by Wako Pure Chemical Industries, Ltd.), 1 volume % of pure water (manufactured by Wako Pure Chemical Industries, Ltd.) and 0.5 volume % of DTES (manufactured by Tokyo Chemical Industry Co., Ltd.) were added, and the mixture was stirred to obtain a silane coupling treatment agent A-1. As a conductive material, a high-boiling solvent, and a surfactant for forming a conductive film material, 3.7 mL of PEDOT:PSS dispersion PH1000 (manufactured by Heraeus), 0.3 mL of ethylene glycol (manufactured by Wako Pure Chemical Industries, Ltd.), and 4 mg of surfactant Emulgen 108 (manufactured by Kao Corporation) were mixed. The main component of Emulgen 108 is polyoxyethylene (6) lauryl ether containing an alkyl group having 12 to 15 carbon atoms. Since DTES in the silane coupling treatment agent has an alkyl group containing 12 carbon atoms as a functional group, Emulgen 108 has a similar functional group. By mixing the above conductive material, solvent, and surfactant, a conductive film material B-1 was obtained.

[0109] After a 1 mm-thick PDMS sheet was formed with a silicone potting agent (manufactured by Dow Chemical Company, Sylgard (registered trademark) 184), it was cut into 30 mm × 30 mm. The cut PDMS sheet was irradiated with atmospheric plasma for 1 minute for hydrophilic treatment to obtain a hydrophilic-treated silicone-based substrate.

[0110] On the above-mentioned hydrophilized silicone-based substrate, several drops of silane coupling treatment agent A were applied, coated at 500 rpm by the spin coating method, and then heat-treated on a hot plate at 100 °C for 1 minute to obtain a silane coupling-treated silicone-based substrate C-1.

[0111] Several drops of conductive film material B-1 were dropped onto the silicone-based substrate C-1, coated at 1000 rpm by the spin coating method under the atmosphere, and heat-treated on a hot plate at 100 °C for 1 minute to form a conductive film with a thickness of 100 to 150 nm. Thereby, a transfer body D-1 was obtained.

[0112] [Preparation of Functional Substrate] 1 mL of chloroform (manufactured by Nacalai Tesque, Inc.) was added to a sample bottle containing 4.5 mg of PM6 (manufactured by One Materials) and 5.5 mg of L8-BO (manufactured by One Materials), and further subjected to ultrasonic irradiation for 30 minutes in an ultrasonic cleaner (US-2 manufactured by Sei-Ei-Dou Co., Ltd., output 120 W) to obtain a solution E-1.

[0113] 0.5 mL of ethanol solvent (manufactured by Wako Pure Chemical Industries, Ltd.) was added to a sample bottle containing 10 mg of zinc acetate dihydrate (manufactured by Wako Pure Chemical Industries, Ltd.), heat-dissolved, and 3-aminopropyltriethoxysilane (manufactured by Wako Pure Chemical Industries, Ltd.) was added at a ratio of 1% by volume to obtain a precursor solution F-1 for forming an electron transport layer.

[0114] After cutting a glass substrate on which an ITO transparent conductive layer serving as a cathode (i.e., the first electrode) was deposited by sputtering to a size of 38 mm × 46 mm, the ITO was patterned into a rectangular shape of 38 mm × 13 mm by photolithography. As a result of measuring the light transmittance of the obtained substrate with a Hitachi spectrophotometer U-3010, it was 85% or more in all wavelength regions from 400 nm to 700 nm. This substrate was ultrasonically cleaned with an alkaline cleaning solution (manufactured by Furuchi Chemical Co., Ltd., "Semiclean" (registered trademark) EL56) for 10 minutes and then cleaned with ultrapure water.

[0115] After subjecting this substrate to UV / ozone treatment for 30 minutes, in the atmosphere, the above solution F-1 was dropped onto the ITO layer, coated at 3,000 prm by the spin coating method, and heat-treated on a hot plate at 150 °C for 30 minutes to form an electron transport layer with a thickness of approximately 30 nm.

[0116] Next, the substrate was transferred to a glove box under a nitrogen atmosphere, the above solution E-1 was dropped onto the electron transport layer, coated by the spin coating method, and heat-treated on a hot plate at 80 °C for 1 minute to form a photoelectric conversion layer (i.e., functional layer) with a thickness of 60 nm. Thus, a functional substrate G-1 was obtained. In Tables 2 to 3, this topmost material is referred to as PM6:Y6 (60 nm).

[0117] 〔Manufacture of Functional Element〕 The surface of the transfer body D-1 and the surface of the functional substrate G-1 were bonded to each other and placed on a table so that the functional substrate G-1 was on the bottom surface, and pressure was applied only by the self-weight of the transfer body D-1. After standing for 30 seconds, while the functional substrate G-1 was fixed on the table, the silicone-based substrate C-1 was peeled off from the edge of the substrate, and the conductive film (i.e., the second electrode) on the substrate was transferred onto the functional substrate G-1. The laminated structure of this photoelectric conversion layer and the conductive film was patterned by the laser ablation method so that the area of the intersection of the striped ITO layer and the anode was 2.5 mm × 2.5 mm, and an organic photovoltaic element was fabricated. In Example 1, the transferred conductive film also serves as the hole transport layer and the anode of the photovoltaic element. Also, at this time, a conductive film was also transferred and laminated on a 5 cm × 5 cm non-alkali glass substrate EAGLE XG (manufactured by Corning) under the same conditions to obtain a conductive film for electrical property evaluation. The transfer state and appearance of the transferred film on the functional substrate evaluated by the above method were A and A, respectively. The Jsc, Voc, FF, and η of the organic photovoltaic element evaluated by the above method were 12.3 mA / cm 2 , 0.77 V, 0.65, and 6.20%, respectively. Also, the visible light transmittance of the organic photovoltaic element was 51%. (Example 2) 〔Fabrication of Transfer Body〕 In exactly the same manner as in Example 1, a transfer body D-1 was obtained. [Fabrication of Functional Substrate] A functional substrate G-2 was obtained in exactly the same manner as in Example 1, except that the photoelectric conversion layer was formed to a thickness of 100 nm. The outermost material is designated as PM6:Y6 (100 nm). [Fabrication of Functional Element] The surface of the transfer body D-1 and the surface of the photoelectric conversion layer of the functional substrate G-2 were bonded to each other and placed on a table so that the functional substrate G-2 was on the bottom surface, and pressure was applied only by the self-weight of the transfer body D-1. After standing for 30 seconds, while the functional substrate G-2 was fixed on the table, the silicone-based substrate C-1 was peeled off from the edge of the substrate, and the conductive film on the substrate was transferred onto the functional substrate G-2. The laminated structure of this photoelectric conversion layer and the conductive film was patterned by the laser ablation method so that the area of the intersecting portion of the striped ITO layer and the anode was 2.5 mm × 2.5 mm, and an organic photovoltaic element was fabricated. The transfer state and appearance of the transfer film on the functional substrate evaluated by the above method were A and A, respectively. The Jsc, Voc, FF, and η of the organic photovoltaic element evaluated by the above method were 17.9 mA / cm 2 , 0.78 V, 0.64, and 8.90%, respectively. Also, the visible light transmittance of the organic photovoltaic element was 37%.

[0118] (Example 3) [Fabrication of Transfer Body] In exactly the same manner as in Example 1, a transfer body D-1 was obtained. [Fabrication of Functional Substrate] After forming the photoelectric conversion layer in the same manner as in Example 1, molybdenum trioxide was deposited to a thickness of 15 nm by vacuum thermal evaporation to form a hole transport layer. Thereby, a functional substrate G-3 was obtained. The outermost material is designated as MoO3 (15 nm). [Fabrication of Functional Element] The surface of the transfer body D-1 and the surface of the functional substrate G-3 were bonded to each other, and the assembly was placed on a table so that the functional substrate G-3 was on the bottom surface, and pressure was applied only by the self-weight of the transfer body D-1. After standing for 30 seconds, while keeping the functional substrate G-3 fixed on the table, the silicone-based substrate C-1 was peeled off from the edge of the substrate, and the conductive film on the substrate was transferred onto the functional substrate G-3. The laminated structure of this photoelectric conversion layer, hole transport layer, and conductive film was patterned by the laser ablation method so that the area of the intersection of the striped ITO layer and the anode was 2.5 mm × 2.5 mm, and an organic photovoltaic device was fabricated. The transfer state and appearance of the transfer film on the functional substrate evaluated by the above method were S and S, respectively. The Jsc, Voc, FF, and η of the organic photovoltaic device evaluated by the above method were 11.7 mA / cm 2 , 0.76 V, 0.63, and 5.57%, respectively. Also, the visible light transmittance of the organic photovoltaic device was 50%.

[0119] (Example 4) 〔Fabrication of transfer body〕 A transfer body D-1 was obtained in exactly the same manner as in Example 1. 〔Fabrication of functional substrate〕 A functional substrate G-4 was obtained in the same manner as in Example 3, except that the photoelectric conversion layer was formed to a thickness of 100 nm. In Tables 2 to 3, this topmost material is referred to as MoO3 (15 nm). 〔Fabrication of functional device〕 The surface of the transfer body D-1 and the surface of the functional substrate G-4 were bonded to each other, and the assembly was placed on a table so that the functional substrate G-4 was on the bottom surface, and pressure was applied only by the self-weight of the transfer body D-1. After standing for 30 seconds, while keeping the functional substrate G-4 fixed on the table, the silicone-based substrate C-1 was peeled off from the edge of the substrate, and the conductive film on the substrate was transferred onto the functional substrate G-4. The laminated structure of this photoelectric conversion layer, hole transport layer, and conductive film was patterned by the laser ablation method so that the area of the intersection of the striped ITO layer and the anode was 2.5 mm × 2.5 mm, and an organic photovoltaic device was fabricated. The transfer state and appearance of the transfer film on the functional substrate evaluated by the above method were S and S, respectively. The Jsc, Voc, FF, and η of the organic optoelectronic device evaluated by the above method were 17.5 mA / cm 2 , 0.78 V, 0.66, and 9.0%, respectively. The visible light transmittance of the organic optoelectronic device was 37%.

[0120] (Example 5) [Production of Transfer Body] In the same manner as in Example 1, a transfer body D-1 was obtained. [Production of Functional Substrate] In the same manner as in Example 2, a functional substrate G-1 was obtained. [Manufacture of Functional Element] In Example 5, as follows, a heating process was carried out as an additional process during transfer. The surface of the transfer body D-1 and the surface of the photoelectric conversion layer of the functional substrate G-1 were bonded to each other, and with the functional substrate G-1 on the bottom, it was placed on a hot plate with the surface temperature set to 80 °C and pressed only with the weight of the transfer body D-1. After standing on the hot plate for 1 minute, the transfer body D-1 and the functional substrate G-1 were cooled to 25 °C while still in the bonded state. Then, the functional substrate G-1 was fixed on a table, and the silicone-based substrate C-1 was peeled off from the edge of the substrate, so that the conductive film on the substrate was transferred onto the functional substrate G-1. The laminated structure of this photoelectric conversion layer and the conductive film was patterned by the laser ablation method so that the area of the intersecting portion of the stripe-shaped ITO layer and the anode was 2.5 mm × 2.5 mm, and an organic optoelectronic device was manufactured. The Jsc, Voc, FF, and η of the organic optoelectronic device evaluated by the above method were 14.1 mA / cm 2 , 0.79 V, 0.59, and 6.6%, respectively. The visible light transmittance of the organic optoelectronic device was 51%.

[0121] [Examples 6 to 8] In Examples 6 to 8, a transfer body was formed using a high-boiling solvent different from ethylene glycol, and only the transferability was evaluated.

[0122] (Example 6) [Preparation of Transcript] A transcript D-2 was obtained in the same manner as in Example 1, except that ethylene glycol was changed to DMSO (manufactured by Wako Pure Chemical Industries, Ltd.). [Preparation of Functional Substrate] A functional substrate G-4 was obtained in the same manner as in Example 4. [Manufacture of Functional Element] An organic photovoltaic element was fabricated in the same manner as in Example 4, except that the transcript D-1 was changed to the transcript D-2. The transfer state and appearance of the transfer film on the functional substrate evaluated by the above method were B and B, respectively.

[0123] (Example 7) [Preparation of Transcript] A transcript D-3 was obtained in the same manner as in Example 1, except that ethylene glycol was changed to PG (manufactured by Wako Pure Chemical Industries, Ltd.). [Preparation of Functional Substrate] A functional substrate G-4 was obtained in the same manner as in Example 4. [Manufacture of Functional Element] An organic photovoltaic element was fabricated in the same manner as in Example 4, except that the transcript D-1 was changed to the transcript D-3. The transfer state and appearance of the transfer film on the functional substrate evaluated by the above method were A and A, respectively.

[0124] (Example 8) [Preparation of Transcript] A transcript D-4 was obtained in the same manner as in Example 1, except that ethylene glycol was changed to 1,3-BG (manufactured by Wako Pure Chemical Industries, Ltd.). [Preparation of Functional Substrate] A functional substrate G-4 was obtained in the same manner as in Example 4. [Manufacture of Functional Element] An organic photovoltaic element was fabricated in the same manner as in Example 4, except that the transcript D-1 was changed to the transcript D-4. The transfer state and appearance of the transfer film on the functional substrate evaluated by the above method were A and A, respectively. [Examples 9 to 11] In Examples 9 to 11, ethylene glycol was used as the high-boiling solvent, and the amount of the high-boiling solvent added was changed to form a transfer body. Since a photoelectric power device was formed as an example of a functional device after evaluating the transferability, the evaluation of the device performance will be described.

[0125] (Example 9) [Production of Transfer Body] As the conductive material, high-boiling solvent, and surfactant for forming the conductive film material, 3.84 mL of PEDOT:PSS dispersion PH1000 (manufactured by Heraeus Co., Ltd.), 0.16 mL of ethylene glycol (manufactured by Wako Pure Chemical Industries, Ltd.), and 4 mg of surfactant Emulgen 108 (manufactured by Kao Corporation) were mixed. In the same manner as in Example 1 except that the ethylene glycol concentration was set to 4%, a transfer body D-8 was obtained. In Table 1, it is referred to as EG(4%) as the type of high-boiling solvent. [Production of Functional Substrate] In the same manner as in Example 1, a functional substrate G-1 was obtained. [Manufacture of Functional Device] An organic optoelectronic device was fabricated in the same manner as in Example 5 except that the transfer body D-1 was changed to the transfer body D-8. The transfer state and appearance of the transfer film on the functional substrate evaluated by the above method were A and A, respectively. The Jsc, Voc, FF, and η of the organic optoelectronic device evaluated by the above method were 12.7 mA / cm 2 , 0.8 V, 0.66, and 6.67%, respectively. The visible light transmittance of the organic optoelectronic device was 51%.

[0126] (Example 10) [Production of Transfer Body] As the conductive material, high-boiling solvent, and surfactant for forming the conductive film material, 3.88 mL of PEDOT:PSS dispersion PH1000 (manufactured by Heraeus Co., Ltd.), 0.12 mL of ethylene glycol (manufactured by Wako Pure Chemical Industries, Ltd.), and 4 mg of surfactant Emulgen 108 (manufactured by Kao Corporation) were mixed. In the same manner as in Example 1 except that the ethylene glycol concentration was set to 3%, a transfer body D-9 was obtained. In Table 1, it is referred to as EG(3%) as the type of high-boiling solvent. [Fabrication of Functional Substrate] A functional substrate G-1 was obtained in exactly the same manner as in Example 1. [Manufacture of Functional Element] An organic photovoltaic element was fabricated in exactly the same manner as in Example 5, except that the transfer body D-1 was changed to the transfer body D-9. The transfer state and appearance of the transfer film on the functional substrate evaluated by the above method were A and A, respectively. The Jsc, Voc, FF, and η of the organic photovoltaic element evaluated by the above method were 12.7 mA / cm 2 , 0.79 V, 0.65, and 6.51%, respectively. Also, the visible light transmittance of the organic photovoltaic element was 52%.

[0127] (Example 11) [Fabrication of Transfer Body] As the conductive material, high-boiling solvent, and surfactant for forming the conductive film material, 3.82 mL of PEDOT:PSS dispersion PH1000 (manufactured by Heraeus Co., Ltd.), 0.18 mL of ethylene glycol (manufactured by Wako Pure Chemical Industries, Ltd.), and 4 mg of surfactant Emulgen 108 (manufactured by Kao Corporation) were mixed. A transfer body D-10 was obtained in exactly the same manner as in Example 1, except that the ethylene glycol concentration was 2%. In Table 1, it is referred to as EG(2%) as the type of high-boiling solvent. [Fabrication of Functional Substrate] A functional substrate G-1 was obtained in exactly the same manner as in Example 1. [Manufacture of Functional Element] An organic photovoltaic element was fabricated in exactly the same manner as in Example 5, except that the transfer body D-1 was changed to the transfer body D-10. The transfer state and appearance of the transfer film on the functional substrate evaluated by the above method were B and A, respectively. The Jsc, Voc, FF, and η of the organic photovoltaic element evaluated by the above method were 12.9 mA / cm 2 , 0.80 V, 0.64, and 6.56%, respectively. Also, the visible light transmittance of the organic photovoltaic element was 51%.

[0128] [Comparative Examples 1-2] In Comparative Examples 1 and 2, examples of photovoltaic devices are shown when a conductive film is directly coated and formed on a functional substrate without using a transfer body.

[0129] (Comparative Example 1) [Fabrication of Functional Substrate] A functional substrate G-1 was obtained in exactly the same manner as in Example 1.

[0130] [Manufacture of Functional Element] Several drops of the same conductive film material B-1 as in Example 1 were dropped onto the functional substrate G-1 under the atmosphere, coated at 1000 rpm by the spin coating method, and heat-treated at 100 °C for 1 minute to laminate a conductive film of 100 to 150 nm. The laminated structure of this photoelectric conversion layer and the conductive film was patterned by the laser ablation method so that the area of the intersection of the striped ITO layer and the anode was 2.5 mm × 2.5 mm, and an organic photovoltaic device was fabricated. In Comparative Example 1, the conductive film also serves as the hole transport layer and the anode of the photovoltaic device. The Jsc, Voc, FF, and η of the organic photovoltaic device evaluated by the above method were 12.4 mA / cm 2 , 0.75 V, 0.59, and 5.46%, respectively. The visible light transmittance of the organic photovoltaic device was 51%.

[0131] (Comparative Example 2) [Fabrication of Functional Substrate] A functional substrate G-2 was obtained in exactly the same manner as in Example 2.

[0132] [Manufacture of Functional Element] In exactly the same manner as in Comparative Example 1, the conductive film material B-1 was laminated on the functional substrate G-2. The laminated structure of this photoelectric conversion layer, hole transport layer, and conductive film was patterned by the laser ablation method so that the area of the intersection of the striped ITO layer and the anode was 2.5 mm × 2.5 mm, and an organic photovoltaic device was fabricated. The Jsc, Voc, FF, and η of the organic photovoltaic device evaluated by the above method were 17.3 mA / cm 2 , 0.75 V, 0.63, and 8.1%, respectively. The visible light transmittance of the organic photovoltaic device was 37%.

[0133] [Comparative Examples 3 to 5] In Comparative Examples 3 to 5, examples regarding the transferability are given for the case where the surface treatment on the silicone-based substrate of the transfer body is omitted, or for the case where the high-boiling solvent in the process of manufacturing the functional element does not contain at least one selected from the group consisting of polyhydric alcohols, ethers, ketones, and sulfoxide compounds.

[0134] (Comparative Example 3) [Production of Transfer Body] A transfer body D-5 was produced in the same manner as in Example 1, except that a conductive film was formed on the hydrophilic-treated silicone-based substrate without performing a silane coupling treatment. [Production of Functional Substrate] A functional substrate G-1 was obtained in the same manner as in Example 1. [Manufacture of Functional Element] An organic photovoltaic element was produced in the same manner as in Example 1, except that the transfer body D-1 was changed to the transfer body D-5. The transfer state and appearance of the transfer film on the functional substrate evaluated by the above method were C and C, respectively. Also, since the transferability was extremely low, the photovoltaic element could not be evaluated.

[0135] (Comparative Example 4) [Production of Transfer Body] A transfer body D-6 was obtained in the same manner as in Example 1, except that ethylene glycol was changed to 1-butanol (manufactured by Wako Pure Chemical Industries, Ltd.). [Production of Functional Substrate] A functional substrate G-1 was obtained in the same manner as in Example 1. [Manufacture of Functional Element] An organic photovoltaic element was produced in the same manner as in Example 1, except that the transfer body D-1 was changed to the transfer body D-6. The transfer state and appearance of the transfer film on the functional substrate evaluated by the above method were C and C, respectively. Also, since the transferability was extremely low, the photovoltaic element could not be evaluated.

[0136] (Comparative Example 5) [Production of Transfer Body] A transfer body D-7 was obtained in exactly the same manner as in Example 1, except that ethylene glycol was changed to DMF (manufactured by Wako Pure Chemical Industries, Ltd.). [Production of Functional Substrate] A functional substrate G-1 was obtained in exactly the same manner as in Example 1. [Manufacture of Functional Element] An organic photovoltaic element was produced in exactly the same manner as in Example 1, except that the transfer body D-1 was changed to the transfer body D-7. The transfer state and appearance of the transfer film on the functional substrate evaluated by the above method were C and C, respectively. Also, since the transferability was extremely low, the photovoltaic element could not be evaluated. The main configurations of the transfer bodies in the examples and each comparative example are shown in Table 1, the evaluation results regarding the transfer film are shown in Table 2, and the evaluation results regarding the photovoltaic element are shown in Table 3. Also, the electrode characteristics of the conductive films obtained from the transfer bodies D-1 to D-4 and the transfer bodies D-8 to D-10 were the same before and after transfer, with a sheet resistance of 90 to 100 Ω / sq and a visible light transmittance of 88 to 95%. Regarding the transfer bodies D-5 to D-7, the electrode characteristics before transfer were equivalent to those of the transfer bodies D-1 to D-4 described above.

[0137] [Table 1]

[0138] [Table 2]

[0139] [Table 3]

[0140] According to Table 2 above, on a silicone-based substrate surface-treated with a silane coupling agent, by including a surfactant having a functional group similar to that of the silane coupling agent and a conductive material dispersible in water or an alcohol-based solvent, the transfer film was formed in a relatively good state in terms of transfer state and appearance. Furthermore, in the case of Comparative Example 3, since the silicone-based substrate was not subjected to a silane coupling treatment, the transfer film was not formed well on the functional substrate as compared with Examples 1 to 8. Also, when a high-boiling solvent other than the group of polyhydric alcohols, ethers, ketones, and sulfoxide compounds was included in the transfer body as in Comparative Examples 4 to 5, a conductive film could not be transferred and formed well on the functional substrate. Next, according to Table 3 above, in the manufacturing method of a functional element having at least a first electrode, a functional layer, and a second electrode, which has a step of including a high-boiling solvent containing at least one selected from the group of polyhydric alcohols, ethers, ketones, and sulfoxide compounds in the transfer body, and a transfer step of arranging the transfer body and a functional substrate having at least a first electrode and a functional layer on the substrate so as to face each other and transferring the conductive film of the transfer body as a second electrode onto the functional layer of the functional substrate, in Examples 1, 3, and 5 regarding a photovoltaic element in which a power generation layer was formed with a thickness of 60 nm, higher power generation efficiency was obtained as compared with Comparative Example 1 in which the second electrode was formed by the spin coating method. Focusing on the transferability of transfer bodies with different high-boiling solvents in Examples 1 to 8, a better transfer film was obtained with a dihydric alcohol as compared with DMSO. From this result, it was found that a dihydric alcohol high-boiling solvent is a more preferable form for transferring a conductive film with better transferability. Also, in Examples 2 and 4 regarding a photovoltaic element in which a power generation layer was formed with a thickness of 100 nm by the manufacturing method of the functional element, higher power generation efficiency was obtained as compared with Comparative Example 2 in which the second electrode was formed by the spin coating method. In addition, in Examples 5 and 9 to 11 in which a heating step was added to the manufacturing method, higher power generation efficiency was obtained because the penetration of the solvent in the photoelectric conversion layer was less as compared with Example 1. Furthermore, the functional elements of Examples 9 to 11 were photovoltaic elements with a higher transmittance (51 to 52%) compared to Example 1, and a high open-circuit voltage (0.79 to 0.80 V) was obtained. This is because the addition amount of the high-boiling-point solvent is in a more preferable range (2 to 5%) compared to Example 1 in terms of the performance of the functional element. From this, when the thickness of the power generation layer is increased so that the transmittance of the photovoltaic element becomes equivalent, higher short-circuit current values can be obtained for Examples 9 to 11, and high power generation efficiency can be expected, which is a practically preferable performance.

Explanation of Symbols

[0141] 01 Transfer body 10 Silicone-based substrate treated with silane coupling 11 Conductive film 02 Transfer body containing a high-boiling-point solvent 20 Silicone-based substrate treated with silane coupling 21 Conductive film 03 Functional substrate 30 Substrate 31 Laminate containing a functional layer and an electrode 04 Photovoltaic element 40 Substrate 41 Cathode 42 Electron transport layer 43 Photoelectric conversion layer 44 Hole transport layer 45 Anode

Claims

1. A transfer body having a silicone-based substrate that has been surface-treated with a silane coupling agent, and a conductive film formed on the silicone-based substrate, the conductive film including at least a surfactant having a functional group similar to that of the silane coupling agent and a conductive material that is dispersible in water or an alcohol-based solvent.

2. 2. The transfer material according to claim 1, wherein the functional group of the silane coupling agent used to treat the silicone-based substrate contains an alkyl chain or a polyether chain.

3. 2. The transfer material according to claim 1, wherein the functional group of the silane coupling agent used to treat the silicone-based substrate is an alkyl group.

4. 3. The transfer member according to claim 1, wherein the conductive film contains at least one high-boiling point solvent selected from the group consisting of polyhydric alcohols, ethers, ketones and sulfoxide compounds.

5. 3. The transfer member according to claim 1, wherein the conductive material is polyethylenedioxythiophene to which polystyrenesulfonic acid has been added.

6. A method for manufacturing a functional element in which at least a first electrode, a functional layer, and a second electrode are laminated in this order, the method comprising the steps of: impregnating the transfer body described in claim 1 with a high-boiling point solvent containing at least one selected from the group consisting of polyhydric alcohols, ethers, ketones, and sulfoxide compounds; and arranging the transfer body so as to face a functional substrate having at least a first electrode and a functional layer on a substrate, and transferring the conductive film of the transfer body onto the functional substrate as a second electrode.

7. 7. The method for producing a functional element according to claim 6, wherein the high boiling point solvent is a dihydric alcohol.

8. The method for producing a functional element according to claim 6 , wherein the transfer step includes a step of heating the transfer body and the functional substrate in a state of being laminated together.

9. 7. The method for producing a functional element according to claim 6, wherein a metal oxide is contained on an outermost surface of a functional layer of the functional substrate.

10. 10. The method for producing a functional element according to claim 6, wherein the photovoltaic element has a photoelectric conversion layer containing an organic semiconductor.

11. 11. The method for producing a photovoltaic element according to claim 10, wherein the cathode and the anode are transparent electrodes having a transmittance of 60% or more in a wavelength region of 400 nm or more and 700 nm or less.

Images