Manufacturing device and manufacturing method for perovskite solar cell

Abstract

To provide a manufacturing device and a manufacturing method for a perovskite solar cell, capable of suppressing occurrence of pinholes in a photoelectric conversion layer.SOLUTION: A manufacturing device 1 for a perovskite solar cell is a device for manufacturing a perovskite solar cell including a photoelectric conversion layer containing a perovskite compound. The manufacturing device includes: a precursor solution application unit 11 that applies a precursor solution containing the perovskite compound as a solute over an application surface; a poor solvent application unit 12 that applies a poor solvent having a lower solubility for the perovskite compound than that of a solvent of the precursor solution over the application surface with the precursor solution applied; and a ventilation unit 13 that ventilates a vicinity of the application surface.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an apparatus and method for manufacturing a perovskite solar cell. [Background technology]

[0002] BACKGROUND ART As one type of solar cell, a perovskite solar cell is known, which uses a perovskite compound as the main component of a photoelectric conversion layer.

[0003] As a method for forming a photoelectric conversion layer containing a perovskite compound, for example, Patent Document 1 describes a method in which a material film for a perovskite film is applied, and then a gaseous or mist-like poor solvent is sprayed onto the material film to dry and crystallize the material film. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2023-148126 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in such conventional methods for manufacturing perovskite solar cells, pinholes can occur in the photoelectric conversion layer, which can reduce the power generation performance of the solar cell and also pose a risk of short circuits.

[0006] The present invention has been made to solve these technical problems, and has an object to provide an apparatus and method for manufacturing a perovskite solar cell that can suppress the occurrence of pinholes in the photoelectric conversion layer. [Means for solving the problem]

[0007] The apparatus for manufacturing a perovskite solar cell according to the present invention is an apparatus for manufacturing a perovskite solar cell having a photoelectric conversion layer containing a perovskite compound, and is characterized by comprising: a precursor solution application unit that applies a precursor solution containing the perovskite compound as a solute to a coating surface; a poor solvent application unit that applies a poor solvent in which the perovskite compound has a lower solubility than the solvent of the precursor solution to the coating surface coated with the precursor solution; and a ventilation unit that ventilates the vicinity of the coating surface.

[0008] The perovskite solar cell manufacturing apparatus according to the present invention includes a ventilation section that ventilates the vicinity of the coated surface where the precursor solution is applied, thereby ventilating the vicinity of the coated surface and reducing the gas concentration of the organic compound near the coated surface. As a result, crystal nuclei of the perovskite compound can be generated uniformly within the surface, thereby suppressing the occurrence of pinholes in the photoelectric conversion layer.

[0009] Preferably, the manufacturing apparatus for perovskite solar cells according to the present invention further comprises a gas concentration detector that detects the gas concentration of the organic compound near the coating surface, and a control device that controls the ventilation volume of the ventilation unit, and the control device controls the ventilation volume of the ventilation unit based on the gas concentration of the organic compound near the coating surface detected by the gas concentration detector. This makes it possible to suppress the occurrence of pinholes in the photoelectric conversion layer and to minimize the surface roughness of the photoelectric conversion layer.

[0010] In the manufacturing apparatus for perovskite solar cells according to the present invention, it is preferable that the control device controls the ventilation volume of the ventilation section so that the gas concentration of the organic compound near the coating surface is within a predetermined range. In this way, it is possible to further suppress the occurrence of pinholes in the photoelectric conversion layer and to keep the surface roughness of the photoelectric conversion layer small.

[0011] In the perovskite solar cell manufacturing apparatus according to the present invention, the ventilation section is preferably configured to have an exhaust section that exhausts gas in the vicinity of the coating surface. This allows for a greater variety of ventilation sections, thereby improving the versatility of the manufacturing apparatus.

[0012] In the perovskite solar cell manufacturing apparatus according to the present invention, it is preferable that the ventilation section is configured to have an air blowing section that blows air to the vicinity of the coating surface. This allows for a greater variety of ventilation sections, thereby improving the versatility of the manufacturing apparatus.

[0013] Furthermore, a method for manufacturing a perovskite solar cell according to the present invention is a method for manufacturing a perovskite solar cell having a photoelectric conversion layer containing a perovskite compound, and is characterized by comprising: a precursor solution application step of applying a precursor solution containing the perovskite compound as a solute to a coating surface; a poor solvent application step of applying a poor solvent in which the perovskite compound has a lower solubility than the solvent of the precursor solution to the coating surface coated with the precursor solution; and a ventilation step of ventilating the vicinity of the coating surface at least between the precursor solution application step and the poor solvent application step.

[0014] The method for producing a perovskite solar cell according to the present invention includes a ventilation step of ventilating the vicinity of the coating surface between at least the precursor solution coating step and the poor solvent coating step, which ventilates the vicinity of the coating surface and reduces the gas concentration of the organic compound near the coating surface, thereby suppressing the occurrence of pinholes in the photoelectric conversion layer.

[0015] Furthermore, the control device according to the present invention controls the operation of the manufacturing apparatus for perovskite solar cells. In this way, for example, by controlling the operation of the ventilation unit, the vicinity of the coating surface can be ventilated and the gas concentration of the organic compound near the coating surface can be reduced. As a result, the occurrence of pinholes in the photoelectric conversion layer can be suppressed.

[0016] In the control device according to the present invention, it is preferable to control the ventilation volume of the ventilation section based on the gas concentration of the organic compound near the coating surface, thereby suppressing the occurrence of pinholes in the photoelectric conversion layer and minimizing the surface roughness of the photoelectric conversion layer.

[0017] In the control device according to the present invention, it is preferable to control the ventilation volume of the ventilation section so that the gas concentration of the organic compound near the coating surface is within a predetermined range. In this way, it is possible to further suppress the occurrence of pinholes in the photoelectric conversion layer and to keep the surface roughness of the photoelectric conversion layer small. [Effects of the Invention]

[0018] According to the present invention, it is possible to suppress the occurrence of pinholes in the photoelectric conversion layer. [Brief explanation of the drawings]

[0019] [Figure 1] FIG. 1 is a block diagram showing a manufacturing apparatus for a perovskite solar cell according to a first embodiment. [Figure 2] FIG. 1 is a schematic diagram showing a perovskite crystal structure. [Figure 3] FIG. 10 is a block diagram showing a manufacturing apparatus for a perovskite solar cell according to a second embodiment. [Figure 4] 10 is a graph showing a change in gas concentration over time when the gas concentration of an organic compound is changed by exhaust. [Figure 5] 10 is a graph showing a change in gas concentration over time when the gas concentration of an organic compound is changed by blowing air. DETAILED DESCRIPTION OF THE INVENTION

[0020] Hereinafter, embodiments of a manufacturing apparatus and a manufacturing method for a perovskite solar cell according to the present invention will be described in order with reference to the drawings. The perovskite solar cell described in the embodiments includes a substrate, a first electrode layer (transparent electrode), a first carrier transport layer (hole transport layer or electron transport layer), a photoelectric conversion layer, a second carrier transport layer (electron transport layer or hole transport layer), and a second electrode layer (rear electrode).

[0021] Furthermore, the manufacturing apparatus for perovskite solar cells described in the following embodiments is an apparatus for manufacturing perovskite solar cells having a photoelectric conversion layer containing a perovskite compound. Note that, although the following description will be given using a roll-to-roll method, the manufacturing apparatus for perovskite solar cells is not limited to the roll-to-roll method.

[0022] [First embodiment] Fig. 1 is a block diagram showing a manufacturing apparatus for a perovskite solar cell according to Embodiment 1. As shown in Fig. 1, the manufacturing apparatus 1 for a perovskite solar cell according to this embodiment (hereinafter simply referred to as "manufacturing apparatus 1") includes a precursor solution application section 11, a poor solvent application section 12, and a ventilation section 13.

[0023] The precursor solution applying unit 11 applies a precursor solution containing a perovskite compound as a solute to the application surface.

[0024] A perovskite compound is a compound having a perovskite-type crystal structure. FIG. 2 is a schematic diagram showing a perovskite-type crystal structure. As shown in FIG. 2, the perovskite-type crystal structure has a cubic unit cell, with A located at each vertex of the cubic crystal, B located at the body center, and X located at each face center of the cubic crystal centered on A. The fact that a compound has a perovskite-type crystal structure can be confirmed, for example, by X-ray diffraction measurement.

[0025] The composition formula of the perovskite compound can be expressed, for example, by the following formula (1). ABX3(1) (wherein A is a monovalent cation, B is a divalent cation, and X is a monovalent anion.)

[0026] In one embodiment, in formula (1), A is preferably at least one selected from the group consisting of a monovalent organic ammonium ion, a monovalent amidinium ion, and a monovalent metal ion. Examples of the monovalent organic ammonium ion include CH3NH3 + (Methylammonium ion: MA), C2H5NH3 + , C3H7NH3 + and C4H9NH3 + Examples of monovalent amidinium ions include HC(NH2)2 + (formamidinium ion: FA). Examples of monovalent metal ions include rubidium ion (Rb + ) and cesium ions (Cs + In formula (1), A may be a combination of a monovalent organic ammonium ion, a monovalent amidinium ion, and a monovalent metal ion. In formula (1), A is preferably MA, FA, or Cs + , and combinations of two or three of these.

[0027] In one embodiment, in formula (1), B is a divalent metal ion, for example, a lead ion (Pb 2+ ), tin ions (Sn 2+ ) and their combinations. From the viewpoint of durability, B is Pb 2+ It is preferable that:

[0028] In one embodiment, in formula (1), X is a halogen ion, for example, a fluoride ion (F - ), chloride ions (Cl - ), bromide ion (Br - ) and iodide ion (I - ) and at least one selected from Cl - , Br - and I - is preferred.

[0029] Any method may be used to apply the precursor solution as long as it can uniformly apply the precursor solution to the surface to be coated. Examples of usable precursor solution application methods include spin coating, inkjet, blade coating, die coating, and spraying. The precursor solution application unit 11 has a configuration corresponding to the precursor solution application method to be used. For example, when the inkjet method is used as the precursor solution application method, the precursor solution application unit 11 is configured to have an inkjet head, and applies the precursor solution to the surface (i.e., the application surface) of the first or second carrier transport layer unwound from a roll-shaped member.

[0030] The poor solvent coating unit 12 coats the coating surface coated with the precursor solution with a poor solvent. Like the precursor solution coating unit 11, the poor solvent coating unit 12 is configured to have an inkjet head suitable for an inkjet method, but is not limited to this. That is, the poor solvent coating unit 12 may be suitable for a blade coating method, a die coating method, or a spray method.

[0031] Here, the poor solvent is a solvent in which the solubility of the perovskite compound is at least lower than that of the solvent of the precursor solution, and more preferably a solvent in which the perovskite compound cannot substantially dissolve. For example, the poor solvent is a solvent in which the solubility of the perovskite compound at 25°C (weight ratio of solute to 100 g of solvent) is usually less than 1 wt%, preferably less than 0.5 wt%.

[0032] The solvent that can be used as the poor solvent is not particularly limited, and examples thereof include organic solvents such as substituted aliphatic hydrocarbons such as dichloromethane and chloroform; aromatic compounds such as toluene, benzene, chlorobenzene, and tetralin; ethers such as diethyl ether and tetrahydrofuran (THF); alcohols having 3 or more carbon atoms; hydrocarbons having 4 to 10 carbon atoms; and acetic acid. In the present invention, aromatic compounds also include compounds containing an aromatic ring in part. These solvents may be used alone or in combination of two or more as the poor solvent. In one embodiment, the poor solvent is chlorobenzene.

[0033] The ventilation unit 13 ventilates the vicinity of the coating surface. More specifically, the ventilation unit 13 ventilates the vicinity of the coating surface, thereby suppressing an increase in the organic compound gas concentration near the coating surface. In other words, the ventilation unit 13 suppresses an increase in the organic compound gas concentration near the coating surface by replacing gas near the coating surface having a high organic compound gas concentration with gas having a low organic compound gas concentration. The ventilation unit 13 may have any configuration as long as it can appropriately ventilate the vicinity of the coating surface. For example, the ventilation unit 13 may exhaust the vicinity of the coating surface by exhausting gas near the coating surface, or may ventilate the vicinity of the coating surface by blowing gas toward the coating surface.

[0034] The ventilation section 13 is configured to have, for example, an exhaust fan (exhaust section) that exhausts gas near the coating surface. The number of exhaust fans may be one or more. When there are multiple exhaust fans, the number of exhaust fans is determined based on the size of the coating surface, the coating speed of the precursor solution coating section 11, the gas concentration of the organic compound near the coating surface, room temperature, humidity, etc.

[0035] The location of the ventilation unit 13 is not particularly limited as long as it can ventilate the vicinity of the coating surface. For example, the ventilation unit 13 may be an exhaust fan installed above the coating surface as long as it does not interfere with the operating ranges of the precursor solution coating unit 11 and the poor solvent coating unit 12. Alternatively, the ventilation unit 13 may have multiple exhaust pipes arranged above and / or around the coating surface, and an exhaust fan connected to the exhaust pipes and installed away from the coating surface. Note that the vicinity of the coating surface here includes the projected area directly above the coating surface and the surrounding area of ​​the projected area.

[0036] The ventilation by the ventilation unit 13 may be performed at least between the application of the precursor solution and the application of the poor solvent. Therefore, the ventilation may be performed between the end of application of the precursor solution by the precursor solution application unit 11 and the start of application of the poor solvent by the poor solvent application unit 12, between the start of application of the precursor solution by the precursor solution application unit 11 and the start of application of the poor solvent by the poor solvent application unit 12, between the end of application of the precursor solution by the precursor solution application unit 11 and the end of application of the poor solvent by the poor solvent application unit 12, or between the start of application of the precursor solution by the precursor solution application unit 11 and the end of application of the poor solvent by the poor solvent application unit 12.

[0037] The organic compound referred to here includes at least the solvent of the precursor solution, and may also include a poor solvent or an organic compound that has been unintentionally mixed in. Here, it is considered that the solvent contained in the precursor solution has volatilized near the coating surface and exists in a gaseous state. Therefore, the gas concentration of the organic compound referred to here may be understood to be essentially the gas concentration of the solvent of the precursor solution.

[0038] The vicinity of the coating surface may be defined as a region where the gas concentration of the organic compound measured in the region correlates with the evaporation rate of the solvent contained in the liquid film of the precursor solution located on the coating surface. In one embodiment, the vicinity of the coating surface refers to, for example, a region within 25 mm in the vertical direction from the coating surface.

[0039] By controlling the gas concentration of the organic compound through ventilation by the ventilation unit 13, the solvent volatilizes at an appropriate volatilization rate from the coating film of the precursor solution formed on the surface of the coating surface. As a result, a sufficient number of crystal nuclei of the perovskite compound are uniformly generated within the coating film of the precursor solution. The generated crystal nuclei of the perovskite compound undergo crystal growth by performing at least one of a drying process and an annealing process, thereby forming a photoelectric conversion layer. Therefore, by uniformly generating a sufficient number of crystal nuclei within the coating film of the precursor solution, pinholes are suppressed, and a photoelectric conversion layer containing a uniform amount of the perovskite compound can be formed.

[0040] The perovskite solar cell manufacturing apparatus 1 of this embodiment is equipped with a ventilation section 13 that ventilates the vicinity of the coated surface where the precursor solution is applied, thereby ventilating the vicinity of the coated surface and reducing the gas concentration of the organic compound near the coated surface. As a result, crystal nuclei of the perovskite compound can be generated uniformly within the surface, thereby suppressing the occurrence of pinholes in the photoelectric conversion layer.

[0041] [Manufacturing method of perovskite solar cells] The method for manufacturing a perovskite solar cell according to this embodiment (hereinafter simply referred to as the "manufacturing method") is a method for manufacturing a perovskite solar cell having a photoelectric conversion layer containing a perovskite compound, using the above-described manufacturing apparatus 1. This manufacturing method includes a precursor solution application step, a poor solvent application step, a ventilation step, a drying step, and an annealing step.

[0042] The precursor solution coating step is a step of coating a precursor solution containing a perovskite compound as a solute. In this precursor solution coating step, the precursor solution is coated onto the surface (i.e., the coating surface) of the first or second carrier transport layer using precursor solution coating unit 11, for example, in a dry air atmosphere or an inert gas atmosphere.

[0043] The poor solvent application step is a step of applying a poor solvent to the application surface on which the precursor solution has been applied. In this poor solvent application step, the poor solvent is applied to the application surface using the poor solvent application unit 12.

[0044] The ventilation step is a step of ventilating the vicinity of the coating surface using the ventilation unit 13, and is performed at least between the precursor solution coating step and the poor solvent coating step. Therefore, the ventilation step may be performed between the end of the precursor solution coating step and the start of the poor solvent coating step, between the start of the precursor solution coating step and the start of the poor solvent coating step, between the end of the precursor solution coating step and the end of the poor solvent coating step, or between the start of the precursor solution coating step and the end of the poor solvent coating step.

[0045] The drying step is a step of removing the solvent in the coating film and growing perovskite crystals, and in this drying step, the solvent in the coating film is removed using a known drying method such as a heating method, a dry gas blowing method, or a vacuum drawing method.

[0046] In the annealing step, the coating film is usually heated at a temperature of 70° C. to 200° C. This annealing step can also be performed in one step with the drying step.

[0047] The photoelectric conversion layer containing the perovskite compound is formed by the above steps. Note that the layers other than the photoelectric conversion layer can be formed by known methods, and therefore their respective descriptions will be omitted.

[0048] The manufacturing method according to this embodiment includes a ventilation step of ventilating the vicinity of the coating surface between at least the precursor solution coating step and the poor solvent coating step, which ventilates the vicinity of the coating surface and reduces the gas concentration of the organic compound near the coating surface, thereby suppressing the occurrence of pinholes in the photoelectric conversion layer.

[0049] [Second embodiment] A second embodiment of a manufacturing apparatus for a perovskite solar cell will now be described with reference to Figure 3. The manufacturing apparatus 1A of this embodiment differs from the first embodiment described above in that it further includes a gas concentration detector 14 and a control device 15. The other structures are the same as those of the first embodiment, so repeated explanations will be omitted.

[0050] The gas concentration detection unit 14 detects the gas concentration near the application surface. The gas concentration detection unit 14 is configured, for example, with a volatile organic compound (VOC) concentration meter, and is preferably a VOC concentration meter using a photoionization detector (PID). The gas concentration detection unit 14 is electrically connected to the control device 15 and outputs the detection result to the control device 15.

[0051] The control device 15 is configured, for example, by a microcomputer that combines a CPU (Central Processing Unit) that executes calculations, a ROM (Read Only Memory) as a secondary storage device that stores programs for the calculations, and a RAM (Random Access Memory) as a temporary storage device that saves the calculation progress and temporary control variables, and controls each component that makes up the manufacturing apparatus 1 by executing the stored program. Note that the control device 15 may be a device configured independently from the manufacturing apparatus 1. In other words, the control device 15 may be a control device that controls the operation of the manufacturing apparatus 1. For example, the control device 15 may be a computer that controls the operation of each component of the manufacturing apparatus 1A from outside the manufacturing apparatus 1.

[0052] For example, the control device 15 controls the operation and stop timing, application amount, application range, etc. of the precursor solution coating unit 11 and the poor solvent coating unit 12. The control device 15 also controls the operation and stop timing, etc. of the ventilation unit 13. Furthermore, the control device 15 controls the ventilation volume of the ventilation unit 13 based on the gas concentration of the organic compound near the coating surface detected by the gas concentration detection unit 14.

[0053] The control of the ventilation volume by the control device 15 is performed based on, for example, a table or graph showing the correlation between the organic compound gas concentration and the ventilation volume of the ventilation unit 13 (more specifically, the correlation between the organic compound gas concentration and the rotation speed of the exhaust fan), which is stored in advance in the control device 15. The table or graph showing the correlation is obtained, for example, from empirical values ​​or actual measurement values.

[0054] In this embodiment, the control device 15 preferably controls the ventilation volume of the ventilation unit 13 so that the gas concentration of the organic compound near the coating surface is within a preset range. The preset range is preferably, for example, such that the gas concentration of the organic compound near the coating surface is 1000 ppm to 4000 ppm at the timing when coating of the poor solvent begins. In this way, it is possible to suppress the occurrence of pinholes in the photoelectric conversion layer and to minimize the surface roughness of the photoelectric conversion layer.

[0055] The manufacturing apparatus 1A of this embodiment not only provides the same effects as those of the first embodiment described above, but also provides the following additional effects by further including a gas concentration detector 14 and a control device 15. That is, the control device 15 controls the ventilation volume of the ventilation unit 13 based on the gas concentration of the organic compound near the coating surface detected by the gas concentration detector 14, thereby controlling the evaporation rate of the solvent in the coating film within an appropriate range. Therefore, it is possible to suppress the occurrence of pinholes in the photoelectric conversion layer and minimize the surface roughness of the photoelectric conversion layer. As a result, it is possible to improve the quality of the perovskite crystal.

[0056] The manufacturing method using the manufacturing apparatus 1A differs from the above-described manufacturing method in that during the ventilation process, the control device controls the ventilation volume of the ventilation section 13 based on the detection results of the gas concentration detection section 14, but otherwise is the same, so redundant explanations will be omitted.

[0057] [Third embodiment] The manufacturing apparatus 1B of the third embodiment differs from the second embodiment in that it uses a blower for ventilation. Since the other structures are the same as those of the second embodiment, a duplicated description will be omitted.

[0058] That is, in this embodiment, the ventilation section 13 is configured to have a blower (blower) that blows air to the vicinity of the coating surface. The blower is electrically connected to and controlled by the control device 15. The control device 15 then controls the amount of air blown by the blower based on the gas concentration of the organic compound in the vicinity of the coating surface detected by the gas concentration detection section 14.

[0059] According to the manufacturing apparatus 1B of this embodiment, in addition to being able to obtain the same effects as those of the second embodiment described above, the ventilation section 13 is configured to have a blower, which increases the variety of the ventilation section 13. As a result, the versatility of the manufacturing apparatus 1B can be improved.

[0060] The present invention will be described below with reference to examples, but the present invention is not limited to the scope of the examples. Comparative examples for comparison with the examples will also be described.

[0061] First, a laminate consisting of a glass plate, a fluorine-doped tin oxide (FTO) film (transparent conductive film), and a titanium oxide (TiO2) layer (electron transport layer) was used as a substrate. A precursor solution was prepared by dissolving the ternary system CsFAMAPbI3 in a solvent consisting of DMF and DMSO.

[0062] Next, the prepared precursor solution was applied to the surface (coating surface) of the electron transport layer of the substrate under a nitrogen gas atmosphere at room temperature (25°C), varying the gas concentration of the organic compound during application. Furthermore, a poor solvent was added dropwise to the applied precursor solution, followed by annealing, to form a perovskite film containing the perovskite compound on the substrate, thereby forming a photoelectric conversion layer. The gas concentration of the organic compound during application was varied by exhaust or airflow. The gas concentration of the organic compound was detected using a PID-type VOC concentration meter (gas concentration meter) placed directly above the coated surface.

[0063] [Change in gas concentration by exhaust (Examples 1 to 6 and Comparative Examples 1 and 2)] Next, multiple slit-shaped openings were made in the lid of the spin coater so that they were parallel to the coating surface. The openings were connected to an exhaust valve with piping, and a ventilation mechanism was added to the spin coater to ventilate the inside of the spin coater by operating the exhaust valve. Using this ventilation mechanism, the exhaust volume of the exhaust valve was set to three levels: "small," "medium," and "large," and the gas inside the spin coater was exhausted. Experiments were conducted twice for each exhaust condition.

[0064] The procedure for forming the perovskite film was as follows. 1.Start exhaust 2. Place the substrate on the spin coater stage 3. Dropping the precursor solution onto the substrate 4. Start spin coater rotation 5. While rotating, add chlorobenzene (poor solvent) with a pipette. 6. Spin coater rotation ends 7. Remove the substrate and place it on a hot plate for annealing (120°C).

[0065] [Change in gas concentration by blowing air (Examples 7 and 8)] The circulator was placed about 15 cm horizontally from the substrate, and the airflow was directed to the substrate. The airflow rate of the circulator was set to two levels: "large" and "small."

[0066] The procedure for forming the perovskite film was as follows. 1. Start blowing air 2. Place the substrate on the spin coater stage 3. Dropping the precursor solution onto the substrate 4. Start spin coater rotation 5. While rotating, add chlorobenzene (poor solvent) with a pipette. 6. Spin coater rotation ends 7. Remove the substrate and place it on a hot plate for annealing (120°C).

[0067] Next, the perovskite film formed on the substrate was analyzed as follows.

[0068] [Pinhole measurement] Images of the perovskite film were taken using a transmitted light digital microscope. The images were observed while shining light from the opposite side of the lens, and the pinholes that were visualized were analyzed to measure the area (total area) and number of pinholes.

[0069] [Calculation of surface roughness Sa] The surface of the perovskite film was observed using a white light interference microscope, and the surface roughness Sa was calculated.

[0070] Table 1 shows the analysis results of the perovskite film when the organic compound gas concentration was changed by evacuation. Figure 4 shows a graph showing the change in gas concentration over time when the organic compound gas concentration was changed by evacuation.

[0071] [Table 1]

[0072] As shown in FIG. 4, in the case of no exhaust (Comparative Examples 1 and 2), the upper measurement limit of the gas concentration meter (i.e., the upper detection limit, 15,000 ppm) was reached before the poor solvent was added. Therefore, in Comparative Examples 1 and 2, the gas concentration before the poor solvent was added exceeded 15,000 ppm. On the other hand, in Examples 1 to 6, the organic compound gas concentration increased significantly after the poor solvent was added. This shows that the organic compound gas concentration before the poor solvent was added corresponds to the concentration of the gas resulting from the evaporation of the solvent in the precursor solution, and that the organic compound gas concentration after the poor solvent was added corresponds to the total concentration of the gas resulting from the evaporation of the solvent in the precursor solution and the poor solvent gas resulting from the evaporation of the poor solvent.

[0073] Furthermore, as shown in Table 1, numerous pinholes were observed in the perovskite films in Comparative Examples 1 and 2. This is presumably because the high gas concentration in the environment caused the solvent in the coating to evaporate slowly and unevenly, resulting in uneven crystal nucleation within the surface, resulting in partial failure of perovskite crystal formation.

[0074] Furthermore, as shown in Figure 4, when the exhaust volume was "small" and "medium" (Examples 1 and 2 and Examples 3 and 4, respectively), the generated solvent gas was exhausted, and the gas concentration in the environment was reduced compared to when no exhaust was used. As shown in Table 1, in Examples 1 to 4, the solvent in the coating film was appropriately evaporated, thereby suppressing the formation of pinholes.

[0075] Furthermore, when the exhaust volume was "large" (Examples 5 and 6), the gas concentration in the environment was significantly reduced. As shown in Table 1, in Examples 5 and 6, pinhole formation was significantly suppressed, and no pinholes were observed under a microscope, but the surface roughness Sa value was large. This is presumably because the low gas concentration in the environment caused the solvent in the coating to evaporate quickly, resulting in uneven crystal nucleation and crystal growth within the surface, and partial crystal swelling, which increased the surface unevenness.

[0076] From the above results, it was found that in forming a perovskite film, the quality of the perovskite crystal can be improved by maintaining an appropriate gas concentration of the organic compound at the timing of applying the poor solvent.

[0077] Table 2 shows the analysis results of the perovskite film when the organic compound gas concentration was changed by blowing air. Figure 5 shows a graph showing the change in gas concentration over time when the organic compound gas concentration was changed by blowing air.

[0078] [Table 2]

[0079] As shown in Table 2 and FIG. 5, by maintaining an appropriate gas concentration of the organic compound at the timing of applying the poor solvent, the formation of pinholes was suppressed, and furthermore, the value of the surface roughness Sa was also sufficiently small.

[0080] Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various design modifications can be made without departing from the spirit of the present invention as set forth in the claims.

[0081] For example, the ventilation section 13 may be configured to have both an exhaust fan and a blower. [Explanation of symbols]

[0082] 1, 1A, 1B: Perovskite solar cell manufacturing apparatus, 11: Precursor solution application section, 12: Poor solvent application section, 13: Ventilation section, 14: Gas concentration detection section, 15: Control device

Claims

1. An apparatus for manufacturing a perovskite solar cell having a photoelectric conversion layer containing a perovskite compound, a precursor solution application unit that applies a precursor solution containing the perovskite compound as a solute to a surface to be applied; a poor solvent application unit that applies a poor solvent, in which the solubility of the perovskite compound is lower than that of the solvent of the precursor solution, to the application surface on which the precursor solution has been applied; a ventilation section for ventilating the vicinity of the application surface; A manufacturing apparatus for a perovskite solar cell, comprising:

2. The apparatus further includes a gas concentration detection unit that detects the gas concentration of an organic compound near the coating surface, and a control device that controls the ventilation volume of the ventilation unit, 2. The apparatus for manufacturing a perovskite solar cell according to claim 1, wherein the control device controls the ventilation volume of the ventilation unit based on the gas concentration of the organic compound near the coating surface detected by the gas concentration detection unit.

3. 3. The apparatus for manufacturing a perovskite solar cell according to claim 2, wherein the control device controls the ventilation volume of the ventilation section so that the gas concentration of the organic compound near the coating surface is within a predetermined range.

4. 4. The apparatus for manufacturing a perovskite solar cell according to claim 1, wherein the ventilation section is configured to have an exhaust section that exhausts gas in the vicinity of the coating surface.

5. 4. The apparatus for manufacturing a perovskite solar cell according to claim 1, wherein the ventilation section is configured to have an air blowing section that blows air to the vicinity of the coating surface.

6. A method for producing a perovskite solar cell having a photoelectric conversion layer containing a perovskite compound, comprising: a precursor solution application step of applying a precursor solution containing the perovskite compound as a solute to a surface to be coated; a poor solvent application step of applying a poor solvent, in which the solubility of the perovskite compound is lower than that of the solvent of the precursor solution, to the surface on which the precursor solution has been applied; a ventilation step of ventilating the vicinity of the coating surface at least between the precursor solution coating step and the poor solvent coating step; A method for producing a perovskite solar cell, comprising:

7. A control device that controls the operation of the perovskite solar cell manufacturing apparatus according to claim 1.

8. The control device according to claim 7 , wherein the ventilation volume of the ventilation unit is controlled based on a gas concentration of an organic compound in the vicinity of the coating surface.

9. The control device according to claim 8 , wherein the ventilation volume of the ventilation unit is controlled so that the gas concentration of the organic compound in the vicinity of the coating surface is within a preset range.

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