Photovoltaic conversion element and method for manufacturing the same

Abstract

Provided are a photoelectric conversion element using an inverted porous structure with high light utilization efficiency and reliability during power generation, and a method for manufacturing the same. 【Solution means】The method for manufacturing a photoelectric conversion element according to the present disclosure includes a laminate forming step of forming a laminate A having a first conductive layer 1, a porous hole transport layer 4, a porous electron transport layer 6, and a second conductive layer 8 in this order, and a precursor solution B capable of forming a perovskite compound is dropped and infiltrated from the second conductive layer 8 side of the laminate A to obtain a laminate A filled with the precursor solution B. a solution dropping step; and a heating step of heating the laminate A that has undergone the solution dropping step. The precursor solution B does not contain an additive that enhances the affinity with the porous electron transport layer 6, and contains a solvent having a higher permeability to the porous electron transport layer 6 than γ-butyllactone.

Description

Technical Field

[0001] The present disclosure relates to a photoelectric conversion element and a method for manufacturing the same.

Background Art

[0002] Photoelectric conversion elements are used in various optical sensors, copiers, solar cells, etc. In particular, solar cells are being widely popularized as a representative of renewable energy utilization. As solar cells, silicon-based solar cells, CIGS-based solar cells, CdTe-based solar cells, etc. have become widespread.

[0003] On the other hand, research has been conducted on using organic materials as photoelectric conversion materials instead of inorganic materials used in solar cells, and the development of organic thin-film solar cells and dye-sensitized solar cells has also been promoted. Since such solar cells can be manufactured by a coating process without using a vacuum process, there is a possibility of significantly reducing the manufacturing cost, and thus they are expected as next-generation solar cells. However, organic thin-film solar cells and dye-sensitized solar cells currently have a problem that their photoelectric conversion efficiency is not sufficient and their durability is low compared to solar cells using inorganic materials.

[0004] In recent years, perovskite solar cells using a perovskite compound as a photoelectric conversion material have attracted attention because they can achieve a photoelectric conversion efficiency comparable to that of silicon-based solar cells. Among photoelectric conversion elements using a perovskite compound, a photoelectric conversion element using a porous structure is known, and as its structure, a normal structure type (n-type) is known.

[0005] In general, a normal-structure type photoelectric conversion element has a structure in which a hole blocking layer, a porous electron transport layer, a porous spacer layer (porous insulator layer), and a hole collection layer as a second electrode (counter electrode to the first electrode) are laminated in this order on a substrate provided with the first electrode. In the production of a normal-structure type photoelectric conversion element, as a method of filling a perovskite compound into a laminate of the photoelectric conversion element (the laminate before filling the perovskite compound), as disclosed in Patent Document 1, a method of dropping and infiltrating a precursor solution capable of forming a perovskite compound from the second electrode side (hole collection layer side) of the laminate is known.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] FIG. 2 is a cross-sectional view schematically showing a solution dropping step of filling a precursor solution (hereinafter also referred to as "perovskite precursor solution") capable of forming a perovskite compound by dropping onto a laminate of a normal-structure type photoelectric conversion element as a comparative example. The laminate A1 of the normal-structure type photoelectric conversion element shown in FIG. 2 has a hole blocking layer 103, a porous electron transport layer 104, a porous spacer layer (porous insulator layer) 105, and a hole collection layer 108 as the second electrode laminated in this order on a substrate 101 provided with the first electrode 102. When the perovskite precursor solution B' is dropped onto this laminate A1 from the hole collection layer 108 side, the perovskite precursor solution B' penetrates, and the perovskite precursor solution B' is filled into the pores of the porous electron transport layer 104 and the pores of the porous spacer layer 105, and a solution filling portion 107 is formed. By heating and sintering the laminate A1 after filling with the perovskite precursor solution B', a perovskite compound is formed in the solution filling portion 107, and a light absorption portion is formed.

[0008] In order to allow the perovskite precursor solution B′ to penetrate to the end of the porous electron transport layer 104 on the side of the first electrode 102, an additive such as 5-aminovaleric acid hydroiodide (5-AVAI) that enhances the affinity with the porous electron transport layer 104 may be added to the perovskite precursor solution B′. By using this additive, the perovskite precursor solution B′ can be filled up to the end of the porous electron transport layer 104 on the side of the first electrode 102 due to the interaction between the metal oxide constituting the porous electron transport layer 104 and the additive.

[0009] As structures of a photoelectric conversion device using a general (i.e., non-porous structure) perovskite compound, there are a normal structure type (normal type) and an inverted structure type (inverted type). In an inverted structure type photoelectric conversion device that does not use a porous structure and has a structure in which the directions of extracting electrons and holes are reversed, there is an advantage that there is less hysteresis and higher reliability compared to the normal structure type. However, in the case of an inverted structure type photoelectric conversion device using a perovskite compound with a porous structure, performance such as reliability cannot be achieved, which becomes a major problem.

[0010] FIG. 3 is a cross-sectional view schematically illustrating a state in which the dropping method of FIG. 2 is attempted for a laminate of a photoelectric conversion device using an inverted structure type porous structure. The laminate A2 of the photoelectric conversion device using the inverted structure type porous structure shown in FIG. 3 has a structure in which a dense hole transport layer 203, a porous hole transport layer 204, a porous spacer layer (porous insulator layer) 205, a porous electron transport layer 206, and a second electrode 208 (counter electrode of the first electrode) are laminated in this order on a substrate 201 provided with the first electrode 202. By forming a perovskite compound in the pores of the porous hole transport layer 204, the porous spacer layer 205, and the porous electron transport layer 206, a light absorption part can be formed. However, when the perovskite precursor solution B′ is dropped onto this laminate A2 to form a light absorption part, the perovskite precursor solution B′ stays in the porous electron transport layer 206, and the solution filling part 207 is unevenly distributed on the side of the porous electron transport layer 206, and the perovskite precursor solution B′ cannot be evenly filled up to the end of the porous hole transport layer 204 on the side of the first electrode 202, resulting in a problem that the light utilization efficiency and reliability during power generation deteriorate.

[0011] The content of the present disclosure has been found in view of such circumstances of an inverted-type photoelectric conversion device including a perovskite compound. The main object of the present disclosure is to provide an inverted-type photoelectric conversion device using a porous structure with high light utilization efficiency and reliability during power generation, and a method for manufacturing the same.

Means for Solving the Problems

[0012] In order to solve the above problems, the method for manufacturing a photoelectric conversion device of the present disclosure is a method for manufacturing a photoelectric conversion device including a perovskite compound, a laminate forming step of forming a laminate having a first conductive layer, a porous hole transport layer, a porous electron transport layer, and a second conductive layer in this order; a solution dropping step of obtaining a post-filling laminate filled with the precursor solution by dropping and infiltrating a precursor solution capable of constituting a perovskite compound from the second conductive layer side of the laminate; a heating step of heating the post-filling laminate, and the precursor solution does not contain an additive for enhancing affinity with the porous electron transport layer, the precursor solution is characterized by containing a solvent having higher permeability to the porous electron transport layer than γ-butyrolactone.

[0013] In the above method for manufacturing a photoelectric conversion device, it is preferable that the porous electron transport layer contains a metal oxide, and the additives not contained in the precursor solution are an organic onium salt containing a carboxylic acid and a silane coupling agent.

[0014] Further, in the above method for manufacturing a photoelectric conversion device, it is preferable that the solvent is at least one selected from the group consisting of N,N-dimethylformamide, dimethyl sulfoxide, N-methylformamide, and γ-valerolactone.

[0015] In order to solve the above problems, the photoelectric conversion device of the present disclosure has a first conductive layer, a porous layer, and a second conductive layer in this order, The light absorption layer provided with a light absorption part is provided in the pores of the porous layer, The porous layer has a porous hole transport layer on the first conductive layer side from the light absorption part, or has a porous electron transport layer on the second conductive layer side from the light absorption part, The light absorption part is characterized by not containing an organic onium salt containing a carboxylic acid and a silane coupling agent.

[0016] In the above photoelectric conversion element, it is preferable that the light absorption part contains a perovskite compound.

[0017] Further, in the above photoelectric conversion element, it is preferable that a porous spacer layer is provided between the porous hole transport layer and the second conductive layer, or between the porous electron transport layer and the first conductive layer.

[0018] Further, in the above photoelectric conversion element, it is preferable that a dense hole transport layer is provided between the first conductive layer and the porous hole transport layer.

Advantages of the Invention

[0019] According to the photoelectric conversion element and its manufacturing method of the present disclosure, excellent effects such as improving the light utilization efficiency and reliability during power generation can be achieved.

Brief Description of the Drawings

[0020]

Figure 1

Figure 2

Figure 3

Best Mode for Carrying Out the Invention

[0021] The method for manufacturing a photoelectric conversion element of the present disclosure includes a laminate formation step, a solution dropping step, and a heating step. The laminate formed in the laminate formation step has a first electrode, a porous layer, and a second electrode in this order. Further, the porous layer has a porous hole transport layer and a porous electron transport layer in this order from the side of the first electrode. Note that the porous layer does not necessarily have to have a porous hole transport layer and a porous electron transport layer, and it may have at least either a porous hole transport layer or a porous electron transport layer. Further, the porous layer can have a porous spacer layer at a position corresponding to the position between the porous hole transport layer and the porous electron transport layer. The "position corresponding to the position between the porous hole transport layer and the porous electron transport layer" means the position in the order of the first electrode, the porous spacer layer, and the porous electron transport layer when there is no porous hole transport layer, while when there is no porous electron transport layer, it means the position in the order of the porous hole transport layer, the porous spacer layer, and the second electrode (hereinafter, the description of "corresponding position" has the same meaning). In the solution dropping step, a precursor solution (perovskite precursor solution) capable of forming a perovskite compound is dropped onto the laminate and infiltrated to obtain a laminate filled with the perovskite precursor solution (hereinafter referred to as a filled laminate). In the heating step, the filled laminate is heated to obtain a photoelectric conversion element as a sintered product thereof.

[0022] Hereinafter, embodiments of the photoelectric conversion element and the manufacturing method thereof of the present disclosure will be described with reference to the drawings.

[0023] FIG. 1 is a cross-sectional view schematically showing a solution dropping step of filling a perovskite precursor solution by dropping onto a laminate of a photoelectric conversion element according to an embodiment of the present disclosure. As shown in FIG. 1, the laminate A includes a first conductive layer 2, a porous layer (porous hole transport layer 4 or porous electron transport layer 6), and a second conductive layer 8 in this order on a substrate 1, and a dense hole transport layer 3 may be provided between the first conductive layer 2 and the porous layer, and a porous spacer layer 5 may be provided at a position corresponding to the position between the porous hole transport layer 4 and the porous electron transport layer 6.

[0024] "Porous" can also be called "porous" or "mesoporous", etc., and can be the same as or include them. In the present disclosure, "porous" means a material that can contain a light absorption part (e.g., a perovskite compound) in the void part (which can be expressed in various ways such as gaps, pores, or holes) it has. In the present disclosure, unless there is a particular contradiction, the "void part of a certain member" means the "region where a certain member does not exist in the region where a certain member is dispersed or continuously and generally distributed". Note that the porous material is not limited to a material that can contain a perovskite compound in the void part, and may also be a material that can contain a material having a photoelectric conversion function other than the perovskite compound in the void part.

[0025] "Dense" can also be called "compact", "compact mass", etc., and can be the same as or include them. "Dense" means that in cross-sectional observation, on one side (e.g., the lower side) in the thickness direction of the dense part, a light absorption part (which is a perovskite compound in this embodiment and will be described as a perovskite compound hereinafter) can be in a state of not existing. That is, even if there is a perovskite compound on the upper side of the dense part, it is possible to prevent it from penetrating and existing on the lower side of the dense part. Preferably, "dense" refers to a material with extremely small voids. Preferably, "dense" refers to a material with a maximum void width of less than 5 nm. More preferably, "dense" means a material that cannot contain a perovskite compound in the void part or a material that does not have a part where the perovskite compound exists continuously through the thickness of the dense part. That is, for the dense part, it is sufficient if it is found by SEM and EDX observations that there is no part where the perovskite compound penetrates through the layer thickness. In the present disclosure, unless there is a particular contradiction, the SEM observation is performed on a cross-sectional SEM (or EDX) image with a width of 400 nm, and it is sufficient if it can be confirmed. For example, if in the observation of a cross-sectional SEM and EDX with a width of 400 nm, there is no part where the perovskite compound penetrates through the layer thickness, that layer can be said to be dense.

[0026] Since the porous layer has a large number of pores in the layer and the pores are connected to each other, when a liquid is dropped, it penetrates into the layer. On the other hand, since the dense layer has few pores in the layer and the existing pores are almost independent of each other and not connected, when a liquid is dropped, it hardly penetrates into the layer. That is, in the solution dropping step, the perovskite precursor solution B is filled in the pores of the porous hole transport layer 4, the porous spacer layer 5, and the porous electron transport layer 6, which is the solution filling portion 7 shown in FIG. 1.

[0027] As a method for forming the dense hole transport layer 3, the porous hole transport layer 4, the porous spacer layer 5, the porous electron transport layer 6, and the second conductive layer 8 in the laminate A, examples thereof include a method of forming a film by coating with a known method such as a screen printing method, a spin coating method, or a bar coating method.

[0028] Hereinafter, first, the laminate A formed in the laminate forming step will be described for each member, and then the perovskite precursor solution B used in the solution dropping step will be described.

[0029] 1. Laminate Formed in Laminate Forming Step <Substrate> The substrate 1 is the substrate of the photoelectric conversion element 10 and is the same as or includes a substrate or a base material. It may be hard and highly rigid, or may be flexible or low in rigidity. Examples of the shape of the substrate 1 include a flat plate shape, a sheet shape, and a cylindrical shape. When the photoelectric conversion element irradiates light on the surface on the substrate 1 side, the substrate 1 preferably can transmit light. In this case, examples of the material of the substrate 1 include transparent materials such as glass and heat-resistant resins. Examples of the glass include soda lime glass and alkali-free glass. Examples of the heat-resistant resin include polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyphenylene sulfide (PPS), polyetherimide (PEI), polytetrafluoroethylene (PTFE), polyamideimide (PAI), and polyethylene naphthalate (PEN). When the photoelectric conversion element irradiates light from the side other than the surface on the substrate 1 side, the substrate 1 may be opaque.

[0030] <First conductive layer (first electrode)> The first conductive layer 2 as the first electrode is a conductive member. The first conductive layer 2 is disposed on or above the substrate 1 and serves as the positive electrode of the photoelectric conversion element according to the embodiment of the present disclosure. Examples of the formation method of the first conductive layer 2 include known film formation methods such as sputtering and chemical vapor deposition (CVD).

[0031] Examples of the material constituting the first conductive layer 2 include conductive transparent materials such as fluorine-doped tin oxide (FTO), CuI, indium tin oxide (ITO), SnO2, aluminum-doped zinc oxide (AZO), indium zinc oxide (IZO), gallium-doped zinc oxide (GZO), and antimony-doped tin oxide (ATO); and conductive transparent polymers.

[0032] The layer thickness of the first conductive layer 2 is not particularly limited as long as it can exhibit desired characteristics (for example, hole transportability and transparency).

[0033] <Hole transport layer> The hole transport layer is a layer that transports holes generated in the light absorption part to the first conductive layer 2 which is the positive electrode. The hole transport layer preferably also functions as an electron blocking layer that suppresses the movement of electrons generated in the light absorption part to the first conductive layer 2. As long as the photoelectric conversion element has a photoelectric conversion function, it is self-evident that a hole transport layer on the hole transport side (or the positive electrode side, the same in the present disclosure) from the light absorption part or on the hole transport side of the light absorption layer has the function of transporting holes, and it is not necessary to confirm the ability to transport holes which is actually difficult to confirm. That is, as long as the photoelectric conversion element has a photoelectric conversion function, a layer on the hole transport side from the light absorption part or on the hole transport side of the light absorption layer and having an appropriate material is referred to as a hole transport layer.

[0034] The hole transport layer is preferably composed of an inorganic material having a band gap of 2 eV or more and an absolute value of ionization potential smaller than 5.3 eV (i.e., a shallow VBM). Here, the lower end of the conduction band is referred to as CBM, and the upper end of the valence band is referred to as VBM. For CBM and VBM, "deep" means "having a large corresponding electron affinity or ionization energy or being far from the vacuum level", and "shallow" means "having a small corresponding electron affinity or ionization energy or being close to the vacuum level". Furthermore, the absolute value of the difference between the vacuum level and the lower end of the conduction band can be rephrased as the absolute value of the electron affinity, and the absolute value of the difference between the vacuum level and the upper end of the valence band can be rephrased as the absolute value of the ionization potential.

[0035] The hole transport layer is composed mainly of a hole transport material. Examples of the hole transport material include metal oxides (P-type metal oxides) such as molybdenum oxide, vanadium oxide, tungsten oxide, nickel oxide, copper oxide, tin oxide; metal sulfides (P-type metal sulfides) such as molybdenum sulfide, tungsten sulfide, copper sulfide, tin sulfide; copper compounds such as fluoro group-containing phosphonic acid, carbonyl group-containing phosphonic acid, CuSCN, CuI; and carbon-containing materials such as carbon nanotubes and graphene which may be surface-modified. Components other than the hole transport material contained in the hole transport layer include an organic binder resin and a plasticizer.

[0036] The hole transport layer preferably contains 70% by mass or more of the hole transport material, and more preferably contains 85% to 100% by mass. The hole transport layer may be composed only of the hole transport material without containing an organic binder resin, a plasticizer, or the like.

[0037] Examples of the structure of the hole transport layer include a structure in which a plurality of hole transport material particles are bonded by an organic binder resin, and a structure in which a plurality of hole transport material particles are molded or sintered.

[0038] The hole transport layer can be configured to include a dense hole transport layer 3 and a porous hole transport layer 4. The dense hole transport layer 3 is disposed on the first conductive layer 2, and the porous hole transport layer 4 is disposed on the dense hole transport layer 3. Also, the dense hole transport layer 3 can be omitted.

[0039] As shown in FIG. 1, the dense hole transport layer 3 is a hole transport layer with a relatively low porosity, and the porous hole transport layer 4 is a hole transport layer with a higher porosity than the dense hole transport layer 3. For example, the dense hole transport layer 3 has a porosity of 35% or less with respect to the area of the layer in cross-sectional observation, and the porous hole transport layer 4 has a porosity exceeding 35% with respect to the area of the layer in cross-sectional observation.

[0040] When the perovskite precursor solution B is dropped onto the laminate A in the solution dropping step, the perovskite precursor solution B penetrates into the porous hole transport layer 4, while the perovskite precursor solution B hardly penetrates into the dense hole transport layer 3. Therefore, by providing the dense hole transport layer 3, the contact between the light absorption part (solution filling part 7 in FIG. 1) and the first conductive layer 2 can be suppressed.

[0041] In the solution dropping step, the pores of the porous hole transport layer 4 are filled with the perovskite precursor solution B. Next, in the heating step, when the laminate A after filling with the perovskite precursor solution B is heated to dry the perovskite precursor solution B, a perovskite compound is formed in the pores, and a light absorption part is formed. The porous hole transport layer 4 is preferably composed of a mesoporous material, in other words, it is preferably a mesoporous hole transport layer.

[0042] The layer thickness of the dense hole transport layer 3 is preferably 5 nm or more and 200 nm or less, and the layer thickness of the porous hole transport layer 4 is preferably 100 nm or more and 500 nm or less.

[0043] <Porous spacer layer> As shown in FIG. 1, a porous spacer layer 5 may be provided between the porous hole transport layer 4 and the porous electron transport layer 6. By providing the porous spacer layer 5, contact between the porous hole transport layer 4 and the porous electron transport layer 6 can be prevented, and the occurrence of leakage current can be suppressed. By adding the porous spacer layer, the distance between the first conductive layer side (including the hole transport layer in some cases) and the second conductive layer side (including the electron transport layer in some cases) can be increased, physical contact between the materials on both sides can be suppressed, and recombination of electrons and holes generated in the light absorption part can be suppressed. That is, by adding the porous spacer layer, the performance of the photoelectric conversion element can be improved, which contributes to having a performance at the commercialization level. That is, the porous spacer layer exists between the first conductive layer side (including the hole transport layer in some cases) and the second conductive layer side (including the electron transport layer in some cases), contributes to increasing the distance between both sides, and as a result, it is sufficient if the photoelectric conversion element has been commercialized. For example, it is not necessary to confirm physical property values such as insulation performance that are difficult to measure.

[0044] The porous spacer layer 5 is mainly composed of an insulator material or a high-resistance semiconductor material. Examples of the insulator material or the high-resistance semiconductor material include metal oxides containing titanium oxide, zirconium dioxide, aluminum oxide, and oxides containing silicon dioxide. Examples of components other than the insulator material and the high-resistance semiconductor material included in the porous spacer layer include an organic binder resin and a plasticizer.

[0045] The porous spacer layer 5 preferably contains 70% by mass or more of an insulator material or a high-resistance semiconductor material, and more preferably contains 85% to 100% by mass. The hole transport layer may be composed only of an insulator material or a high-resistance semiconductor material without containing an organic binder resin, a plasticizer, or the like.

[0046] Examples of the structure of the porous spacer layer 5 include a structure in which a plurality of insulator material particles or high-resistance semiconductor material particles are bonded by an organic binder resin, and a structure in which a plurality of insulator material particles or high-resistance semiconductor material particles are molded or sintered.

[0047] In the solution dropping step, the pores of the porous spacer layer 5 are filled with the perovskite precursor solution B. Next, in the heating step, when the laminate A after filling with the perovskite precursor solution B is heated to dry the perovskite precursor solution B, a perovskite compound is formed in the pores, and a light absorption part is formed. The porous spacer layer 5 is preferably composed of a mesoporous material, in other words, it is preferably a mesoporous spacer layer.

[0048] The layer thickness of the porous spacer layer 5 is preferably 500 nm or more and 3000 nm or less, and more preferably 1000 nm or more and 2000 nm or less.

[0049] <Electron transport layer> The electron transport layer is a layer having a function of transporting electrons generated in the light absorption part. As long as the photoelectric conversion element has a photoelectric conversion function, it is obvious that an electron transport layer on the electron transport side (or the negative electrode side, the same in the present disclosure) from the light absorption part or on the electron transport side of the light absorption layer has a function of transporting electrons, and it is not necessary to confirm the electron transport function which is actually difficult to confirm. That is, as long as the photoelectric conversion element has a photoelectric conversion function, a layer on the electron transport side from the light absorption part or on the electron transport side of the light absorption layer and made of an appropriate material is referred to as an electron transport layer.

[0050] <Porous electron transport layer> The porous electron transport layer 6 is a layer that transports electrons generated in the light absorption part to the second conductive layer 8 which is the negative electrode. The porous electron transport layer 6 preferably also functions as a hole blocking layer that suppresses the movement of holes generated in the light absorption part to the second conductive layer 8.

[0051] The porous electron transport layer 6 is composed mainly of an electron transport material. Examples of the electron transport material include metal oxides (N-type metal oxides) such as titanium oxide, zinc oxide, indium oxide, tin oxide, aluminum oxide, and gallium oxide; and metal sulfides (N-type metal sulfides) such as tin sulfide, indium sulfide, and zinc sulfide.

[0052] The porous electron transport layer 6 preferably contains a metal oxide among these. When the porous electron transport layer contains a metal oxide, since the affinity between an organic onium salt containing a carboxylic acid (for example, 5-AVAI) and the metal oxide is particularly high, even when a perovskite precursor solution containing the organic onium salt is dropped, the perovskite precursor solution is trapped in the upper porous electron transport layer and does not spread to the lower porous hole transport layer. However, according to the method for manufacturing a photoelectric conversion element of the present disclosure, it is possible to penetrate the perovskite precursor solution to the end on the first electrode side of the porous hole transport layer.

[0053] Examples of components other than the electron transport material contained in the porous electron transport layer 6 include an organic binder resin and a plasticizer.

[0054] The porous electron transport layer 6 preferably contains 70% by mass or more of the electron transport material, and more preferably contains 85% by mass to 100% by mass. The porous electron transport layer 6 may be composed only of the electron transport material without containing an organic binder resin, a plasticizer, or the like.

[0055] Examples of the structure of the porous electron transport layer 6 include a structure in which a plurality of electron transport material particles are bonded by an organic binder resin, and a structure in which a plurality of electron transport material particles are molded or sintered.

[0056] In the solution dropping step, the pores of the porous electron transport layer 6 are filled with the perovskite precursor solution B. Next, in the heating step, when the laminate A after filling with the perovskite precursor solution B is heated to dry the perovskite precursor solution B, a perovskite compound is formed in the pores and a light absorption part is formed. The porous electron transport layer 6 is preferably composed of a mesoporous material, in other words, preferably a mesoporous electron transport layer.

[0057] The layer thickness of the porous electron transport layer 6 is preferably 100 nm or more and 20000 nm or less, and more preferably 200 nm or more and 1500 nm or less.

[0058] <Light absorption part, light absorption layer> The photoelectric conversion element according to an embodiment of the present disclosure has a light absorption layer in which a light absorption part is provided in the pores of a porous layer. The light absorption part is a part that can absorb light. For example, the light absorption part contains a perovskite compound. It is a part that can absorb the light incident on the photoelectric conversion element and generate electrons and holes. These electrons move to the second conductive layer side, and the holes move to the first conductive layer side. It is a self-evident truth that the light absorption part absorbs light and generates electrons and holes as long as the photoelectric conversion element has a photoelectric conversion function, and no confirmation is required. As long as a material having a light absorption function is included, it can be assumed that the light absorption part absorbs light and generates electrons and holes, and it is not necessary to confirm the generation of electrons and holes by absorbing light, which is actually difficult to confirm.

[0059] The light absorption part can indicate a part of an arbitrary region that absorbs light. If there are other light-absorbing parts in addition to the indicated light absorption part, they can be collectively described as a light absorption layer. That is, the light absorption part can mean a part of an arbitrary region in the light absorption layer. Further, the light absorption layer can mean a collection of light absorption parts that have a thickness (similar to the definition of "layer", for example, it does not have to be constant) and exist discretely or continuously in a region mainly in a certain direction.

[0060] Also, the light absorption layer may be a member that occupies a certain region, but is not limited thereto. Also, it may have a certain thickness and be a member that occupies a certain area, but is not limited thereto. The light absorption layer may be one in which a light absorption layer or a light absorption portion is provided in a layer of a porous material. In other words, the light absorption layer may be one in which a light absorption layer or a light absorption portion is provided in the pores of the porous material. Although it is expressed as a light absorption layer, it may be more appropriately expressed as a light absorption portion that can be composed of the same material as the light absorption layer. That is, more appropriately expressed, the light absorption layer may be one in which a light absorption portion is provided in the layer of the porous material or in the pores of the porous material. In this case, the electron transport layer or the hole transport layer, or both the electron transport layer and the hole transport layer may also be porous materials. In other words, the light absorption layer may have a portion where a light absorption portion is provided in the pores of the porous layer. The light absorption layer may have a portion where a light absorption portion is provided in the pores of an insulator or a porous spacer layer made of a porous material. Also, the light absorption layer may be provided between the electron transport layer and the hole transport layer. Or it may be provided between the electron transport layer and the porous electrode. In this case, a light absorption portion may also be provided in the pores of the porous electrode.

[0061] In the pores of the porous layer, a light absorption part may be provided. The light absorption part means the same member as the light absorption layer, but in order to avoid misunderstanding of the shape of the member, a more specific name of "part" is used. A "layer" preferably indicates a member having a certain film thickness, but is not limited thereto, and may have portions with different thicknesses, or may be in a pattern or island shape. However, generally, a "layer" mainly means a portion arranged in a certain direction, while a "part" only means a portion arranged in a certain region. That is, a "layer" is preferably (1) a member having a certain film thickness continuous in a certain direction, (2) a member having portions with different film thicknesses continuous in a certain direction, or (3) a member in which each discrete pattern or island-like part is mainly arranged in a certain direction. A "part" can mean a part of a certain region in a "layer". Each pattern or island part in a discrete pattern or island-shaped "layer" can be referred to as a "part". That is, in the pores of the porous spacer layer, a light absorption layer is provided in which each discrete light absorption part is arranged in the same direction as the direction mainly arranged in the main direction of the porous spacer layer. In addition, the pattern or island-shaped part does not necessarily have to have a plurality of discrete parts when three-dimensional observation is possible, and may have one continuous pattern for all patterns. Since the observation that is usually possible is the observation on a plane obtained by observing an arbitrary cross-section, in that case, the pattern or island-shaped part is often divided into a plurality of discrete parts. That is, when observing the porous spacer layer in cross-section, a light absorption part, that is, the perovskite compound in this embodiment, is provided in the pore part of the porous spacer layer, and light absorption parts are arranged discretely in the same direction as the direction in which the porous spacer layer generally extends, and a certain part of these light absorption parts can be collectively referred to as a light absorption layer.

[0062] The light absorption layer preferably contains a perovskite compound or an organic-inorganic hybrid compound. This compound can generate electrons and holes in the light absorption layer. The film thickness of the light absorption layer 6 is desirably in the range of about 500 nm to 1000 nm.

[0063] <Second conductive layer 8> The second conductive layer 8 as the second electrode is disposed on the porous electron transport layer 6 or on the porous layer, and serves as the negative electrode of the photoelectric conversion element according to the embodiment of the present disclosure.

[0064] As the material constituting the second conductive layer 8, for example, fluorine-doped tin oxide (FTO), gold, silver, titanium, sodium, sodium-potassium alloy, lithium, magnesium, aluminum, magnesium-silver mixture, magnesium-indium mixture, aluminum-lithium alloy, Al / Al2O3 mixture, Al / LiF mixture, etc. can be used as metal electrode materials; conductive carbon materials such as graphite, graphene, carbon nanowires, carbon nanofibers, carbon nanotubes, and carbon black can be used. Organic electrode materials may also be used.

[0065] As the second conductive layer 8, for example, a material having a work function of 4.3 eV or less is more preferable. When the second conductive layer 8 is composed of a material with a shallow work function (4.3 eV or less), it is easier to generate a bend in the band structure that smooths the flow of electrons at the interface between the electron transport layer and the second conductive layer 8.

[0066] In the embodiment of the present disclosure, since the perovskite precursor solution B is dropped from the side of the second conductive layer 8 in the solution dropping step, the second conductive layer 8 is preferably porous, and more preferably composed of a mesoporous material. Mesoporous carbon is suitable as the mesoporous material. When the second conductive layer is porous, it can be included in the porous layer. Similar to the porous electron transport layer, the porous hole transport layer, and the porous spacer layer, it can be considered in the same way that the perovskite precursor is filled and the perovskite compound is formed in the void portion of the porous second conductive layer by the heating step. The void portion of the porous second conductive layer may have a portion where the perovskite compound is formed and a portion where it is not formed. The second conductive layer 8 can include a porous conductive carbon material.

[0067] The layer thickness of the second conductive layer 8 is not particularly limited as long as it can exhibit desired characteristics (for example, electron transport property).

[0068] 2. Perovskite precursor solution used in the solution dropping step In the solution dropping step, a perovskite precursor solution B is dropped and infiltrated from the side of the second conductive layer 8 of the laminate A to obtain a laminate A filled with the perovskite precursor solution B (laminate after filling). By this step, the perovskite precursor solution B is filled in the porous hole transport layer 4, the porous spacer layer 5, and the porous electron transport layer 6.

[0069] <Perovskite precursor solution B> The perovskite precursor solution B used in the solution dropping step is a solution containing at least a precursor capable of forming a perovskite compound and a solvent.

[0070] As described above, an "additive for enhancing the affinity with the porous electron transport layer" is added to the perovskite precursor solution used in the prior art. In contrast, the perovskite precursor solution B used in the solution dropping step according to the embodiment of the present disclosure does not add an "additive for enhancing the affinity with the porous electron transport layer". By not adding the additive, the problem that the perovskite precursor solution stays in the porous electron transport layer and cannot uniformly fill the end portion on the first electrode side (dense hole transport layer side) of the porous hole transport layer can be reduced.

[0071] However, simply not adding an additive for enhancing the affinity with the porous electron transport layer cannot uniformly fill the perovskite precursor solution to the end portion on the first electrode side of the porous hole transport layer. The inventors of the present invention have found that, without adding an additive for enhancing the affinity with the porous electron transport layer to the perovskite precursor solution, by changing the solvent used in the perovskite precursor solution, the perovskite precursor solution can be filled to the end portion on the first electrode side of the porous hole transport layer, and thus, a reverse structure type photoelectric conversion element capable of enhancing the light utilization efficiency and reliability during power generation can be realized.

[0072] That is, in the embodiments of the present disclosure, without adding an "additive for enhancing the affinity with the porous electron transport layer" to the perovskite precursor solution B, a solvent having higher permeability to the porous electron transport layer than γ-butyrolactone is used as the solvent of the perovskite precursor solution B.

[0073] Therefore, the light absorption part of the photoelectric conversion element according to the embodiments of the present disclosure does not contain an "additive for enhancing the affinity with the porous electron transport layer". Note that "not containing an additive" in the present disclosure means that no peak derived from the additive is seen in the diffraction chart in the X-ray diffraction method for observing the diffraction generated when irradiating the sample to be measured with X-rays. In other words, as long as no peak derived from the additive can be detected, even if a trace amount of the additive is contained, it is included in the concept of "not containing an additive" in the present disclosure.

[0074] Specific examples of the conventionally used "additive for enhancing the affinity with the porous electron transport layer" include organic onium salts containing carboxylic acid and silane coupling agents. Examples of the organic onium salts containing carboxylic acid include 5-aminovaleric acid hydroiodide, 5-aminovaleric acid hydrobromide, 5-aminovaleric acid hydrochloride, and β-alanine hydroiodide.

[0075] When the perovskite precursor solution contains an "organic onium salt containing a carboxylic acid", an interaction occurs between the metal oxide of the porous electron transport layer and the organic onium salt, which is advantageously effective for the permeability of the perovskite precursor solution in a normal structure type photoelectric conversion element. However, in an inverted structure type photoelectric conversion element, the dropped perovskite precursor solution tends to stay in the porous electron transport layer, which becomes a factor that the perovskite precursor solution cannot be uniformly filled. Further, when the perovskite precursor solution contains a silane coupling agent, it is considered that the perovskite compound and the porous electron transport layer are bonded, and it is presumed that it is advantageously effective for the permeability of the perovskite precursor solution in a normal structure type photoelectric conversion element. However, in an inverted structure type photoelectric conversion element, the dropped perovskite precursor solution tends to stay in the porous electron transport layer, which becomes a factor that the perovskite precursor solution cannot be uniformly filled.

[0076] Regarding the solvent of the perovskite precursor solution B, examples of solvents having higher permeability to the porous electron transport layer 6 than γ-butyllactone include N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), N-methylformamide (NMF), and γ-valerolactone (GVL). These solvents may be used alone or in combination of two or more.

[0077] In the heating step, the laminate A after filling with the perovskite precursor solution B is heated to obtain a photoelectric conversion element as a sintered product thereof. By the heating step, the perovskite precursor solution B is dried, a perovskite compound is formed in the region filled with the perovskite precursor solution B, and a light absorption part is formed. In the light absorption part, the perovskite compound generates electrons and holes by photoexcitation. The light absorption part may contain substances other than the perovskite compound. Further, the light absorption part may contain the solvent of the perovskite precursor solution B, but it is preferably not contained (the solvent does not remain).

[0078] The perovskite compound is composed of a compound represented by the general formula: ABX3···(1). However, although the respective composition ratios are preferably 1:1:3, they do not necessarily have to be 1:1:3, and the content rates of the respective elements may be appropriately increased or decreased. It is not necessary for each constituent element to be of one type. As long as the light absorption part has a photoelectric conversion function, the perovskite compound contained in the light absorption part is considered to exhibit a photoelectric conversion function. Therefore, even if it has the degree of freedom in configuration as described in terms of the composition ratio and the type of constituent elements, it is reasonable to consider that it is exhibiting its function. In the general formula (1), A is an organic molecule (including an organic group or an organic cation, the same applies in the present disclosure) or an inorganic atom or molecule (including an inorganic group or an inorganic cation, the same applies in the present disclosure) or a combination thereof, B is a metal atom or molecule (including a metal cation, the same applies in the present disclosure), and X is a halogen atom or molecule or a chalcogen atom or molecule (including a halogen anion or a chalcogen anion, the same applies in the present disclosure). In the general formula (1), the three Xs may be the same as or different from each other. As long as the photoelectric conversion element has a photoelectric conversion function, the perovskite compound contained in the light absorption part is considered to exhibit a photoelectric conversion function, and this fact should be considered together. That is, if it can be confirmed that a perovskite compound has A, B, and X, it is reasonable to consider it as a perovskite compound that exhibits a photoelectric conversion function. For example, it is sufficient if it is found to have an organic molecule, a metal atom, and a halogen atom. Furthermore, if a perovskite compound has elements corresponding to A, B, and X detected as long as the photoelectric conversion element has a photoelectric conversion function, it can be confirmed that it is a perovskite compound. For example, as the organic molecule, a molecule containing carbon, nitrogen, and hydrogen is suitable. Therefore, it is sufficient if carbon, nitrogen, hydrogen, a metal element, and a halogen or chalcogen are detected. Or, for a perovskite compound, it is sufficient to have A, B, and X. For example, it is sufficient if it is found to have an inorganic atom, a metal atom, and a halogen atom. Furthermore, if a perovskite compound has elements corresponding to A, B, and X detected as long as the photoelectric conversion element has a photoelectric conversion function, it can be confirmed that it is a perovskite compound.For example, cesium or rubidium is suitable as the inorganic atom. Therefore, it is sufficient to detect cesium or rubidium, a metal element, and a halogen or chalcogen. Further, since it is natural that a perovskite compound has a crystal structure as long as the photoelectric conversion element has a photoelectric conversion function, it is not necessary to confirm the presence of a crystal structure. The light absorption part is not excluded from containing substances other than the perovskite compound.

[0079] The light absorption part may contain an organic-inorganic hybrid compound. An organic-inorganic hybrid compound means a compound containing an inorganic material and an organic material. The organic-inorganic hybrid compound includes a perovskite compound, and a solar cell using a perovskite compound is also called an organic-inorganic hybrid solar cell. "Organic" typically means something composed of multiple carbons as constituent elements. Note that carbon materials such as graphite, graphene, carbon nanowires, carbon nanofibers, carbon nanotubes, and carbon or carbon black that function as electrodes are not particularly considered organic materials. That is, "organic" refers to something that includes multiple carbons as one of the constituent elements, excluding the above-mentioned carbon materials such as graphite. "Inorganic" means something that is not organic.

[0080] The light absorption part may contain quantum dots. A quantum dot means a dot with a maximum width of 100 nm or less. The shape of the quantum dot only needs to satisfy the above maximum width and is not particularly restricted, and is not limited to a spherical three-dimensional shape (circular cross-sectional shape). For example, it may have a polygonal cross-sectional shape, a rod-shaped three-dimensional shape, a branched three-dimensional shape, a three-dimensional shape with unevenness on the surface, or a combination thereof. The quantum dot typically preferably consists of a semiconductor. The semiconductor only needs to be a material that can absorb light and may also contain at least the materials described below. The semiconductor contains, for example, at least one selected from the group consisting of II-VI group compounds, III-V group compounds, chalcogenides, and perovskite compounds. Here, the group number notation of elements using Roman numerals is based on the old IUPAC method or the old CAS method, and the group number notation of elements using Arabic numerals is based on the current IUPAC method. The semiconductor contains, for example, at least one selected from the group consisting of MgS, MgSe, MgTe, CaS, CaSe, CaTe, SrS, SrSe, SrTe, BaS, BaSe, BaTe, ZnS, ZnSe, ZnTe, CdS, CdSe, CdTe, HgS, HgSe, HgTe, GaAs, GaP, InN, InAs, InP, and InSb.

[0081] In the general formula (1), examples of the organic molecule represented by A include alkylamine, alkylammonium, and nitrogen-containing heterocyclic compounds. In the perovskite compound, the organic molecule represented by A may be only one kind of organic molecule or two or more kinds of organic molecules.

[0082] Examples of the alkylamine include methylamine, ethylamine, propylamine, butylamine, pentylamine, hexylamine, dimethylamine, diethylamine, dipropylamine, dibutylamine, dipentylamine, dihexylamine, trimethylamine, triethylamine, tripropylamine, tributylamine, tripentylamine, trihexylamine, ethylmethylamine, methylpropylamine, butylmethylamine, methylpentylamine, hexylmethylamine, ethylpropylamine, and ethylbutylamine.

[0083] The alkylammonium is an ionized product of the above-mentioned alkylamine. Examples of the alkylammonium include methylammonium, ethylammonium, propylammonium, butylammonium, pentylammonium, hexylammonium, dimethylammonium, diethylammonium, dipropylammonium, dibutylammonium, dipentylammonium, dihexylammonium, trimethylammonium, triethylammonium, tripropylammonium, tributylammonium, tripentylammonium, trihexylammonium, ethylmethylammonium, methylpropylammonium, butylmethylammonium, methylpentylammonium, hexylmethylammonium, ethylpropylammonium, and ethylbutylammonium.

[0084] Examples of the nitrogen-containing heterocyclic compound include imidazole, azole, pyrrole, aziridine, azirine, azetidine, azeto, azole, imidazoline, and carbazole. The nitrogen-containing heterocyclic compound may be an ionized product. As the ionized nitrogen-containing heterocyclic compound, phenethylammonium is preferable.

[0085] In general formula (1), as the organic molecule represented by A, methylamine, ethylamine, propylamine, butylamine, pentylamine, hexylamine, methylammonium, ethylammonium, propylammonium, butylammonium, pentylammonium, hexylammonium, or phenethylammonium is preferable, methylamine, ethylamine, propylamine, methylammonium, ethylammonium, or propylammonium is more preferable, and methylammonium is even more preferable.

[0086] In general formula (1), examples of the metal atom represented by B include lead, tin, zinc, titanium, antimony, bismuth, nickel, iron, cobalt, silver, copper, gallium, germanium, magnesium, calcium, indium, aluminum, manganese, chromium, molybdenum, and europium, etc. In the perovskite compound, the metal atom represented by B may be only one kind of metal atom or two or more kinds of metal atoms. From the viewpoint of improving the light absorption characteristics and charge generation characteristics of the perovskite compound, as the metal atom represented by B, a lead atom or a tin atom is preferable. From the viewpoint of reducing lead, a tin atom is preferable.

[0087] In general formula (1), examples of the halogen atom represented by X include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, etc., and examples of the chalcogen atom include an oxygen atom, a sulfur atom, a selenium atom, and a tellurium atom. In the perovskite compound, the halogen atom or chalcogen atom represented by X may be one kind or two or more kinds. As the halogen atom represented by X, from the viewpoint of enabling the perovskite compound to utilize light in a wide wavelength band, an iodine atom is preferable. Specifically, among the three Xs, it is preferable that at least one X represents an iodine atom, and it is more preferable that the three Xs represent iodine atoms.

[0088] As the perovskite compound, a compound represented by the general formula "CH3NH3PbX3 (where X represents a halogen atom)" is preferable, and CH3NH3PbI3 is more preferable. By using a compound represented by the general formula "CH3NH3PbX3" (particularly, CH3NH3PbI3) as the perovskite compound, electrons and holes can be generated more efficiently in the perovskite compound, and as a result, the photoelectric conversion efficiency of the photoelectric conversion device can be further improved.

[0089] The photoelectric conversion layer is a layer that converts light into electricity. It can include a porous layer and a light absorption part, and means a layer between the first conductive layer and the second conductive layer. It is a natural conclusion that the photoelectric conversion layer exists between the first conductive layer and the second conductive layer as long as the photoelectric conversion device has a photoelectric conversion function. Therefore, as long as the photoelectric conversion device has a photoelectric conversion function, the layer existing between the first conductive layer and the second conductive layer is the photoelectric conversion layer, and it is not necessary to confirm the photoelectric conversion function of the layer itself to confirm the existence of the photoelectric conversion layer. The light absorption part often exists between the first conductive layer and the second conductive layer. In that case, the photoelectric conversion layer also exists only between the first conductive layer and the second conductive layer. However, when the first conductive layer and the second conductive layer have a special shape such as porous, the light absorption part may exist in a region including the first conductive layer and the second conductive layer themselves. In such cases, the photoelectric conversion layer can include the first conductive layer and the second conductive layer themselves, which are the parts where the light absorption part exists. Even in that case, at least the photoelectric conversion layer is arranged between the first conductive layer and the second conductive layer. That is, in any case, the photoelectric conversion device is provided with a first conductive layer, a photoelectric conversion layer, and a second conductive layer in this order, and it does not exclude that the first conductive layer and the second conductive layer themselves are also included, nor does it exclude the existence of the photoelectric conversion layer in a part other than the region between the first conductive layer and the second conductive layer including them.

[0090] The method for preparing the perovskite precursor solution B that can constitute the perovskite compound (ABX3) is not particularly limited. For example, it can be prepared by mixing an AX solution and a BX2 solution.

[0091] In the photoelectric conversion element according to the embodiment of the present disclosure, the abundance ratio of the perovskite compound at the end of the porous hole transport layer 4 on the side of the first conductive layer 2 is preferably 1% or more, and more preferably 5% or more. According to the manufacturing method of the photoelectric conversion element of the present disclosure, the perovskite precursor solution B penetrates without staying in the porous electron transport layer 6 and spreads to the porous hole transport layer 4, so that a photoelectric conversion element having such an abundance ratio can be realized.

[0092] Note that the "abundance ratio of the perovskite compound" in the present disclosure is measured by observing the cross section of the measurement target with an energy dispersive X-ray spectroscopy (SEM-EDX) in a width of 200 nm, and means the ratio of the area of the perovskite presence region (the region where a substance having the characteristics of the perovskite compound is detected) to the observed area.

[0093] In the photoelectric conversion element according to the embodiment of the present disclosure, the abundance ratio of the perovskite compound at the end of the porous hole transport layer 4 on the side of the first conductive layer 2 may be higher than the abundance ratio of the perovskite compound at the end of the porous electron transport layer 6 on the side of the second conductive layer 8.

[0094] 3. Examples On a transparent conductive substrate (corresponding to the base material 1 and the first conductive layer 2) having fluorine-doped tin oxide (FTO) on a glass substrate, a dense NiO layer as the dense hole transport layer 3, a mesoporous NiO layer as the porous hole transport layer 4, a mesoporous ZrO2 layer as the porous spacer layer 5, a mesoporous TiO2 layer as the porous electron transport layer 6, and a mesoporous carbon layer as the second conductive layer 8 were laminated in this order by a screen printing method and then fired to obtain a laminate.

[0095] To the obtained laminate, 12 μL of a perovskite precursor solution (a CH3NH3PbI3 solution with a concentration of 1.2 M) using N-methylformamide (NMF) as a solvent was dropped and infiltrated from the side of the mesoporous carbon layer to obtain a post-filled laminate filled with the perovskite precursor solution.

[0096] By heating the obtained laminate after filling at 100 °C, the filled perovskite precursor solution was dried to obtain a photoelectric conversion device containing a perovskite compound. In the obtained photoelectric conversion device, the perovskite compound was uniformly present up to the end on the FTO side of the mesoporous NiO layer, and the light utilization efficiency during power generation was high.

[0097] Note that all the embodiments disclosed this time are illustrative in all respects and are not a basis for restrictive interpretation. Therefore, the technical scope of the present disclosure is not interpreted only by the above-described embodiments, but is defined based on the description of the claims. Also, all changes within the meaning and scope equivalent to the claims are included.

Explanation of Reference Numerals

[0098] 1 Substrate 2 First conductive layer (first electrode) 3 Dense hole transport layer 4 Porous hole transport layer 5 Porous spacer layer 6 Porous electron transport layer 7 Solution filling part (region that becomes a light absorption part after sintering) 8 Second conductive layer (second electrode) A Laminate of photoelectric conversion device B Precursor solution capable of forming a perovskite compound

Claims

1. A method for manufacturing a photoelectric conversion device including a perovskite compound, comprising: a laminate forming step of forming a laminate having a first conductive layer, a porous hole transport layer, a porous electron transport layer, and a second conductive layer in this order; a solution dropping step of obtaining a post-filling laminate filled with the precursor solution by dropping and infiltrating a precursor solution capable of forming a perovskite compound from the second conductive layer side of the laminate; a heating step of heating the post-filling laminate, and the precursor solution does not contain an additive for enhancing affinity with the porous electron transport layer, the precursor solution contains a solvent having higher permeability to the porous electron transport layer than γ-butyrolactone, a method for manufacturing a photoelectric conversion device.

2. The method for manufacturing a photoelectric conversion device according to claim 1, wherein the porous electron transport layer contains a metal oxide, the additives not contained in the precursor solution are an organic onium salt containing a carboxylic acid and a silane coupling agent, a method for manufacturing a photoelectric conversion device.

3. The method for manufacturing a photoelectric conversion device according to claim 1 or claim 2, wherein the solvent is at least one selected from the group consisting of N,N-dimethylformamide, dimethyl sulfoxide, N-methylformamide, and γ-valerolactone, a method for manufacturing a photoelectric conversion device.

4. A substrate, a first conductive layer, a porous layer, and a second conductive layer in this order, having a light absorption layer provided with a light absorption portion in pores of the porous layer, the porous layer has a porous hole transport layer and a porous spacer layer, and the porous hole transport layer is located closer to the first conductive layer side than the porous spacer layer, or has a porous electron transport layer and a porous spacer layer, and the porous spacer layer is located closer to the first conductive layer side than the porous electron transport layer, the porous spacer layer is composed mainly of an insulator material or a high-resistance semiconductor material, the photoelectric conversion device, wherein the light absorption portion does not contain an organic onium salt containing a carboxylic acid and a silane coupling agent.

5. A substrate, a first conductive layer, a porous layer, and a second conductive layer in this order, having a light absorption layer provided with a light absorption portion in pores of the porous layer, the porous layer has a porous hole transport layer and a porous electron transport layer, and the porous hole transport layer is located closer to the first conductive layer side than the porous electron transport layer, A photoelectric conversion device, wherein the light absorption part does not contain an organic onium salt containing a carboxylic acid and a silane coupling agent. **Claim 6** The photoelectric conversion device according to claim 4 or claim 5, wherein the light absorption part contains a perovskite compound. **Claim 7** The photoelectric conversion device according to claim 4 or claim 5, wherein a dense hole transport layer is provided between the first conductive layer and the porous hole transport layer. **Claim 8** The photoelectric conversion device according to claim 4 or claim 5, wherein the second conductive layer contains a porous carbon material having conductivity. **Claim 9** The photoelectric conversion device according to claim 4 or claim 5, wherein the porous electron transport layer contains a metal oxide.

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