Perovskite solar cells

Abstract

We provide a perovskite solar cell that enables high integration. [Solution] The perovskite solar cell 100 comprises a transparent conductive film 10 provided on a light-transmitting substrate 1, a plurality of solar cell elements 20 provided on the transparent conductive film 10, and carbon electrodes 30 laminated on each of the plurality of solar cell elements 20 and connected to the transparent conductive film 10 via the side surface of the solar cell element 20. A groove 70 is provided between two adjacent solar cell elements 20 and the carbon electrode 30 provided on the side surface of the other solar cell element 20, and the average width of a single groove 70 from the opening side to the bottom side is less than 50 μm.

Description

[Technical Field]

[0001] This invention relates to perovskite solar cells. [Background technology]

[0002] Conventionally, solar cells have been used to convert solar light energy into electrical energy. One example of such solar cell technology is described in Patent Document 1, which is cited below.

[0003] Patent Document 1 describes a method for manufacturing a photoelectric conversion device. The photoelectric conversion device manufactured by this method comprises a substrate and a plurality of photoelectric conversion cells arranged on the substrate. Adjacent photoelectric conversion cells are separated by grooves. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2014-49622 [Overview of the project] [Problems that the invention aims to solve]

[0005] Perovskite solar cells are desirable for high integration in terms of power supply capacity. However, in the photoelectric conversion device manufactured by the manufacturing method described in Patent Document 1, the grooves are formed by mechanical scribing. With such mechanical scribing, the width of the groove depends on the thickness of the blade, so it is not easy to make the grooves smaller (narrower). For this reason, the technology described in Patent Document 1 has room for improvement in terms of achieving high integration.

[0006] Therefore, there is a need for perovskite solar cells that can be highly integrated. [Means for solving the problem]

[0007] The characteristic configuration of the perovskite solar cell according to the present invention is that it comprises a transparent conductive film provided on a light-transmitting substrate, a plurality of solar cell elements provided on the transparent conductive film, and carbon electrodes laminated on each of the plurality of solar cell elements and connected to the transparent conductive film via the side surface of the solar cell element, wherein a groove is provided between two adjacent solar cell elements among the plurality of solar cell elements and the carbon electrode provided on the side surface of the other solar cell element, and the average width of a single groove from the opening side to the bottom side is less than 50 μm.

[0008] With this characteristic configuration, the average width of the groove from the opening side to the bottom side is narrowed, which reduces the dead area on the substrate and increases the area of ​​the solar cell element. Therefore, it becomes possible to integrate the solar cell elements more closely and improve power generation efficiency. [Brief explanation of the drawing]

[0009] [Figure 1] This is a plan view of a perovskite solar cell. [Figure 2] This is a lateral cross-sectional view of a perovskite solar cell. [Figure 3] This is a partial perspective view of a perovskite solar cell. [Figure 4] This is a lateral cross-sectional view of a perovskite solar cell. [Figure 5] This is a lateral cross-sectional view of a perovskite solar cell. [Figure 6] This is a lateral cross-sectional view of a perovskite solar cell. [Figure 7] This is a lateral cross-sectional view of a perovskite solar cell. [Modes for carrying out the invention]

[0010] The perovskite solar cell according to the present invention is configured to be integrated on a substrate. Hereinafter, the perovskite solar cell 100 of the present embodiment will be described. However, the perovskite solar cell 100 is not limited to the following embodiments, and various modifications are possible without departing from the gist thereof.

[0011] FIG. 1 is a plan view of the perovskite solar cell 100. FIG. 2 is a cross-sectional view taken along line II-II of FIG. 1. FIG. 3 is a partial perspective view of the perovskite solar cell 100. Here, generally, the perovskite solar cell 100 is configured by connecting a plurality of cells 90 in series to increase the output voltage. However, hereinafter, in the perovskite solar cell 100 shown in FIGS. 1 to 3, for ease of understanding, one of the plurality of cells 90 included in the perovskite solar cell 100 will be described as an example.

[0012] As shown in FIGS. 1 to 3, the perovskite solar cell 100 includes a transparent conductive film 10, a solar cell element 20, and a carbon electrode 30.

[0013] The substrate 1 has light transmissivity and functions as a support for the perovskite solar cell 100. The substrate 1 has insulating properties, and for example, a transparent glass substrate, a ground glass-like translucent glass substrate, a transparent resin substrate, etc. are used. As shown in FIG. 1, the substrate 1 is rectangular when viewed along the Z direction.

[0014] As shown in FIG. 2, a conductive and transparent transparent conductive film 10 used as a negative electrode is provided on the substrate 1. The orientation of the perovskite solar cell 100 during use is not particularly limited. Hereinafter, the direction from the substrate 1 to the transparent conductive film 10 will be referred to as the "Z1 direction", the opposite direction will be referred to as the "Z2 direction", and the Z1 direction and the Z2 direction will be collectively referred to as the "Z direction". Also, one of the directions orthogonal to the Z direction will be referred to as the "X direction", and the direction orthogonal to the Z direction and the X direction will be referred to as the "Y direction".

[0015] The transparent conductive film 10 is formed (deposited) on one surface (the surface on the Z1 direction side) of the substrate 1 by chemical vapor deposition (CVD method), sputtering, or the like. In the present embodiment, the transparent conductive film 10 is formed over the entire surface of one surface of the substrate 1. The transparent conductive film 10 is composed of, for example, fluorine-doped tin oxide (FTO), tin oxide (TO), tin-doped indium oxide (ITO), zinc oxide (ZnO), aluminum-doped zinc oxide (AZO), or the like. In the process of patterning the transparent conductive film 10, a groove portion 11 extending along the Y direction is formed in the transparent conductive film 10. Therefore, due to this groove portion 11, the transparent conductive film 10 on the substrate 1 is divided into a first transparent conductive film 10A and a second transparent conductive film 10B.

[0016] A solar cell element 20 is provided on the transparent conductive film 10 (the surface in the Z1 direction). The solar cell element 20 converts light energy into electrical energy. The solar cell element 20 includes an electron transport layer 21, a photoelectric conversion layer 22, and a hole transport layer 2, and the electron transport layer 21, the photoelectric conversion layer 22, and the hole transport layer 23 are arranged in this order along the Z1 direction. When the perovskite solar cell 100 is viewed along the Z direction, each of the electron transport layer 21, the photoelectric conversion layer 22, the hole transport layer 23, and the carbon electrode 30 has a rectangular shape. In the present embodiment, when the perovskite solar cell 100 is viewed along the Z direction, the outer shapes of the electron transport layer 21, the photoelectric conversion layer 22, and the hole transport layer 23 are configured to be equal to each other.

[0017] The electron transport layer 21 is positioned on the Z1-direction side of the transparent conductive film 10. The electron transport layer 21 is made of titanium dioxide (TiO2). This makes it possible to secure a large surface area for stacking the perovskite layer used as the photoelectric conversion layer 22. Electrons (free electrons) received from the photoelectric conversion layer 22 pass through the electron transport layer 21 (transporting electrons). In this embodiment, the electron transport layer 21 includes an insulating layer 211 that fits into the groove 11 described above. The insulating layer 211 divides the transparent conductive film 10 into two parts: the first transparent conductive film 10A and the second transparent conductive film 10B (in the example shown in Figure 2, it is divided along the X direction). In the electron transport layer 21, electrons can move along the Z direction, but it is difficult for them to move in directions perpendicular to the Z direction (X and Y directions), thus restricting movement between the two sections of the transparent conductive film 10. Furthermore, the electron transport layer 21 is sometimes referred to as a "blocking layer" because it restricts the movement of electrons.

[0018] Since the substrate 1, the transparent conductive film 10, and the electron transport layer 21 are light-transmitting, light such as sunlight and indoor light is guided to the photoelectric conversion layer 22 without being absorbed (or almost absorbed) by the substrate 1, the transparent conductive film 10, and the electron transport layer 21.

[0019] The photoelectric conversion layer 22 absorbs light energy and converts it into electrical energy. More specifically, the photoelectric conversion layer 22 absorbs light and performs photoelectric conversion by moving excited electrons and holes. The photoelectric conversion layer 22 includes a perovskite layer composed of organic and inorganic perovskite compounds. Specifically, the perovskite layer is produced by reacting a compound composed of lead and halogen element X (PbX2, where X = halogen element) with methylammonium iodide (CH3NH3I; hereinafter sometimes abbreviated as "MAI"). The photoelectric conversion layer 22 further includes a porous oxide semiconductor layer (for example, a porous titanium layer). A solution containing lead and halogen element X (for example, a PbI2 N,N-dimethylformamide solution) is permeated into the pores of this porous oxide semiconductor layer and dried. After immersion in a mixed solution of MAI, crystals of the perovskite compound (CH3NH3PbI3 when X=I) that forms the perovskite layer are produced. The halogen element X can be, for example, iodine, bromine, or chlorine, and it is particularly preferable to use iodine, which has high morphological stability.

[0020] The hole transport layer 23 is through which holes received from the photoelectric conversion layer 22 pass (transports holes). The hole transport layer 23 contains, for example, an organic compound such as chlorobenzene as a material. A carbon electrode 30, which is used as a positive electrode, is placed on the hole transport layer 23 (on the Z1 direction side).

[0021] The carbon electrode 30 is stacked on the solar cell element 20. That is, the carbon electrode 30 is placed on the Z1 side surface of the solar cell element 20. In this embodiment, the carbon electrode 30 is composed of carbon particles. The carbon electrode 30 is constructed by coating (forming a film) a paste containing carbon particles onto the solar cell element 20, and then drying or firing it. The carbon electrode 30 should have a thickness of about 15 μm to 25 μm. Preferably, it should have a thickness of about 20 μm.

[0022] As shown in Figures 2 and 3, the carbon electrode 30 is electrically connected to the transparent conductive film 10 (in this embodiment, the second transparent conductive film 10B) via each side of the solar cell element 20 along the Z direction from the Z1-direction side of the hole transport layer 23. For this reason, the carbon electrode 30 includes a connection portion 31 that is positioned on the Z1-direction side (a portion of the area) of the transparent conductive film 10 (second transparent conductive film 10B). That is, the carbon electrode 30 is electrically insulated from the first transparent conductive film 10A, which is used as one terminal (negative terminal) in a single cell 90, and is electrically connected to the second transparent conductive film 10B, which is used as the other terminal (positive terminal) in a single cell 90, via the connection portion 31.

[0023] A pair of busbars B are provided on the Z1-direction side of the transparent conductive film 10. Each pair of busbars B is arranged (stacked) on the Z1-direction side of the transparent conductive film 10 outside the solar cell element 20 in the X direction, as shown in Figure 1. Each pair of busbars B is positioned on a portion of the Z1-direction side of the transparent conductive film 10, spaced apart from the solar cell element 20. One of the pair of busbars B is positioned on the first transparent conductive film 10A, and the other of the pair of busbars B is positioned on the second transparent conductive film 10B. The pair of busbars B are made from materials such as elemental metals like gold, platinum, silver, and copper, their alloys, and oxide conductors such as FTO and ITO.

[0024] The coating layer 40 is insulating and is positioned on the Z1 direction side of the solar cell element 20 and the transparent conductive film 10 so as to cover the solar cell element 20. Specifically, the coating layer 40 is in contact with the Z1 direction side surface (a surface perpendicular to the Z direction), the X direction side (a surface perpendicular to the X direction), and the Y direction side (a surface perpendicular to the Y direction) of the carbon electrode 30 of the solar cell element 20. In addition, a part of the coating layer 40 is also positioned on a part of the Z1 direction side surface of the transparent conductive film 10. The coating layer 40 may be a film-like (sheet-like) member. The coating layer 40 may be, for example, a porous film, a mesh sheet, an embossed sheet, etc., and may contain materials such as resin (PPS: polyphenylene sulfide resin) or glass.

[0025] As shown in Figure 2, the perovskite solar cell 100 consists of a laminate 60 comprising a substrate 1, a transparent conductive film 10, a solar cell element 20, a carbon electrode 30, and a coating layer 40, which is sealed by a first sheet 51 and a second sheet 52 via a sealing layer 50.

[0026] The first sheet 51 is provided on one side of the laminate 60 in the lamination direction in which the transparent conductive film 10 and the solar cell element 20 are laminated. In this embodiment, the one side in the lamination direction corresponds to the Z2 direction. Therefore, the first sheet 51 is provided on the Z2 direction side of the substrate 1. Here, since light is incident on the perovskite solar cell 100 from the Z2 direction side as described above, it is preferable that the first sheet 51 be transparent.

[0027] The second sheet 52 is provided on the other side of the laminate 60 in the lamination direction. In this embodiment, the other side of the lamination direction corresponds to the Z1 direction. Therefore, the second sheet 52 is provided on the Z1 direction side of the laminate 60.

[0028] The sealing layer 50 is placed between one of the first sheet 51 and the second sheet 52 and the laminate 60. In this embodiment, as shown in Figure 2, the sealing layer 50 is placed between the second sheet 52 and the laminate 60, and the surface of the substrate 1 on the Z2 direction and the first sheet 51 are facing each other (in contact).

[0029] The sealing layer 50 is positioned to cover the laminate 60. As shown in Figure 2, the area of ​​the sealing layer 50 in a plan view is larger than the area of ​​the laminate 60. The sealing layer 50 adheres closely to the laminate 60 and protects the laminate 60 from external forces acting on the perovskite solar cell 100.

[0030] In the example shown in Figure 2, the sealing layer 50 is provided only between the second sheet 52 and the laminate 60, but the sealing layer 50 may also be provided between the first sheet 51 and the laminate 60.

[0031] Here, Figures 1-3 show an example where one cell 90 is provided on the substrate 1, but in reality, multiple cells 90 are provided on the substrate 1.

[0032] Figure 4 shows a perovskite solar cell 100 having multiple cells 90 (three in the example in Figure 4). For ease of understanding, the three cells 90 will be referred to as cell 91, cell 92, and cell 93 below.

[0033] As shown in Figure 4, grooves 11 are formed in a transparent conductive film 10 provided on a substrate 1. Multiple (three in the example of Figure 4) solar cell elements 20 are provided on this transparent conductive film 10. Furthermore, carbon electrodes 30 are laminated on each of the multiple solar cell elements 20. Carbon electrodes 30 are laminated on these multiple solar cell elements 20. In the following, for ease of understanding, when distinguishing between the three solar cell elements 20, they will be described as solar cell element 20A, solar cell element 20B, and solar cell element 20C.

[0034] A groove 70 is provided between two adjacent solar cell elements 20 among the multiple solar cell elements 20, between one solar cell element 20 and the carbon electrode 30 provided on the side surface of the other solar cell element 20. The multiple solar cell elements 20 are solar cell elements 20A, 20B, and 20C. Two adjacent solar cell elements 20 correspond to solar cell elements 20A and 20B, and solar cell elements 20B and 20C. The carbon electrode 30 provided on the side surface of the solar cell element 20 corresponds to the connection portion 31.

[0035] Therefore, among the solar cell elements 20A, 20B, and 20C, a groove 70 is provided between the solar cell element 20B and the connecting portion 31 provided on the side surface of solar cell element 20A in solar cell elements 20A and solar cell element 20B, and a groove 70 is provided between the solar cell element 20C and the connecting portion 31 provided on the side surface of solar cell element 20B in solar cell elements 20B and 20C.

[0036] Each groove 70 has an average width of less than 50 μm from the front of the opening to the bottom (see Figure 5). A single groove 70 refers to the groove 70 between the solar cell element 20B and the connecting portion 31 provided on the side of solar cell element 20A, and the groove 70 between the solar cell element 20C and the connecting portion 31 provided on the side of solar cell element 20B. The front of the opening is the Z1 side of the groove 70, and the bottom is the Z2 side of the groove 70. The width from the front of the opening to the bottom corresponds to the width from the Z1 side to the Z2 side of the groove 70, i.e., the length along the X direction. Each groove 70 has an average width of less than 50 μm. For example, if the length (width) of the groove 70 along the X-direction on the near side of the opening is 50 μm, and the length (width) along the X-direction on the bottom side is 30 μm, and the groove has a tapered shape where the width gradually decreases from the near side of the opening to the bottom side, then the average width of the groove 70 is 40 μm.

[0037] This groove 70 is formed by laser processing under the following conditions. (1) Laser used: picosecond green laser (2) Processing speed: 5000mm / sec (3) Output: 20W (4) Frequency: 1500kHz

[0038] At this time, the carbon electrode 30 has a density of 1.0 mg / cm³. 3 More than 1.5mg / cm 3 It is formed as follows. Furthermore, the carbon electrode 30 is constructed with an arithmetic mean roughness of 1.0 μm or less. As a result, the groove portion 70 can be constructed with an average width of less than 50 μm.

[0039] For example, under the above conditions, the density of the carbon electrode 30 is 1.2 mg / cm³. 3In this case, the average width (length along the X direction) of the groove 70 can be set to 40 μm or less. Furthermore, as shown in Figure 5, the width (length along the X direction) of the groove 70 on the side before the opening (Z1 side) can be set to 50 μm or less, and the width (length along the X direction) of the groove 70 on the bottom side (Z2 side) can be set to 30 μm or less. In this case, the arithmetic mean roughness Ra can be set to 0.386 μm. It is desirable that the arithmetic mean roughness Ra be 0.5 μm or less, so this example is suitable.

[0040] Furthermore, under the above conditions, the density of the carbon electrode 30 is 1.0 mg / cm³. 3 In this case, the average width of the groove 70 can be set to 45 μm or less. Furthermore, as shown in Figure 6, the width of the groove 70 on the side just before the opening can be set to 70 μm or less, and the width of the groove 70 on the bottom side can be set to 20 μm or less. In addition, in this case, the arithmetic mean roughness Ra can be set to 0.766 μm or less.

[0041] On the other hand, the density of the carbon electrode 30 is 0.7 mg / cm³. 3 If the above conditions are met, the average width of the groove 70 will be 50 μm or more. In this case, as shown in Figure 7, the width of the groove 70 on the side before the opening will be 90 μm or more, and the width of the groove 70 on the bottom side will be 10 μm or less. In this case, the arithmetic mean roughness Ra will be 1.572 μm. That is, as shown in Figure 7, the density of the carbon electrode 30 described above will be 1.2 mg / cm³. 3 Examples of cases like those shown in Figure 5, or when the density of the carbon electrode 30 is 1.0 mg / cm³, are shown. 3 In the case described above, the wall of the groove 70 becomes tapered, with a slope in the Z direction, compared to the example shown in Figure 6. Furthermore, there is a possibility that some carbon (carbon electrode 30) may remain at the bottom of the groove 70, which should be removed. In the example shown in Figure 7, the processing speed is set to 3000 mm / second under the above conditions to ensure proper processing.

[0042] By configuring as described above, the difference between the width on the front side of the opening in the single groove portion 70 and the width on the bottom side of the groove portion 70 can be made 60 μm or less. Thereby, it is possible to appropriately configure the groove portion 70 without any part of carbon (carbon electrode 30) remaining on the bottom of the groove portion 70 that should be originally removed or on the surface of the carbon electrode 30 (including the surface of the connection portion 31). Therefore, the perovskite solar cell 100 can be highly integrated.

[0043] The perovskite solar cell 100 configured as described above generates electricity as follows. When light such as sunlight or indoor light is incident from the side of the substrate 1 (the side in the Z2 direction), it passes through the substrate 1 and the electron transport layer 21, and most of the light reaches the photoelectric conversion layer 22. When the photoelectric conversion layer 22 absorbs light energy, a part of the electrons in the valence band of the photoelectric conversion layer 22 is excited to the conduction band, and holes are generated at the places where the electrons excited from the valence band were present. So that the generated holes do not recombine with electrons and the charges are not eliminated, the electrons are attracted to the electron transport layer 21 and further move to the transparent conductive film 10, and the holes are attracted to the hole transport layer 23 and further move to the carbon electrode 30. Thereby, a potential difference is generated between the transparent conductive film 10 and the carbon electrode 30, and the perovskite solar cell 100 can generate electricity. Although the electrons moving through the electron transport layer 21 smoothly move along the Z2 direction and reach the transparent conductive film 10, as described above, the movement in the direction (X direction) perpendicular to the Z direction is restricted by the insulating layer 211. That is, the perovskite solar cell 100 is configured so that the transparent conductive film 10 and the carbon electrode 30 do not short-circuit with each other.

[0044] 〔Other Embodiments〕 Next, other embodiments of the perovskite solar cell 100 will be described.

[0045] In the above embodiment, the carbon electrode 30 was described assuming that the density is 1.0 mg / cm 3 or more and 1.5 mg / cm 3 or less. However, the carbon electrode 30 has a density of 1.0 mg / cm 3It may be less than 1.5 mg / cm³. 3 The above is also acceptable. In this case as well, by adjusting the processing speed and output during laser processing, the processing time can be extended to form grooves 70 with an average width of less than 50 μm.

[0046] In the above embodiment, the carbon electrode 30 was described as having an arithmetic mean roughness of 1.0 μm or less. However, the carbon electrode 30 may have an arithmetic mean roughness greater than 1.0 μm. Even in this case, by adjusting the laser processing conditions, it is possible to form grooves 70 with an average width of less than 50 μm.

[0047] In the above embodiment, it was explained that the difference between the width of the front side of the opening in a single groove 70 and the width of the bottom side of the groove 70 is 60 μm or less. However, the difference between the width of the front side of the opening in a single groove 70 and the width of the bottom side of the groove 70 may be greater than 60 μm.

[0048] [Summary of the above embodiment] The following is an overview of the perovskite solar cell 100 described above.

[0049] (1) The perovskite solar cell 100 comprises a transparent conductive film 10 provided on a light-transmitting substrate, a plurality of solar cell elements 20 provided on the transparent conductive film 10, and carbon electrodes 30 laminated on each of the plurality of solar cell elements 20 and connected to the transparent conductive film 10 via the side surface of the solar cell element 20, wherein a groove 70 is provided between two adjacent solar cell elements 20 and the carbon electrode 30 provided on the side surface of the other solar cell element 20, and the average width of a single groove 70 from the front of the opening to the bottom is less than 50 μm.

[0050] According to this configuration, by narrowing the average width of the groove 70 from the front to the bottom of the opening, the dead area on the substrate 1 is reduced, and the area of ​​the solar cell element 20 can be increased. Therefore, it becomes possible to integrate the solar cell element 20 more efficiently and improve power generation efficiency.

[0051] (2) In the perovskite solar cell 100 described in (1), the carbon electrode 30 has a density of 1.0 mg / cm³. 3 More than 1.5mg / cm 3 The following is preferable.

[0052] With this configuration, by increasing the electrode density of the carbon electrode 30, the sublimation distribution of carbon by the laser used to form the groove 70 can be brought closer to the laser spot diameter. This reduces the difference between the width of the groove 70 on the near side of the opening and the width on the bottom side, thereby reducing the average width of the groove 70 from the near side of the opening to the bottom side.

[0053] (3) In the perovskite solar cell 100 described in (1) or (2), the carbon electrode 30 is preferably arithmetic mean roughness of 1.0 μm or less.

[0054] According to this configuration, for example, when forming the groove 70 using a laser, it is possible to prevent the laser spot diameter from widening due to the surface roughness (surface irregularities) of the carbon electrode 30. Therefore, it becomes possible to properly form the groove 70.

[0055] In the perovskite solar cell 100 described in (4)(3), it is preferable that the difference between the width of the front side of the opening in a single groove 70 and the width of the bottom side of the groove 70 is 60 μm or less.

[0056] With this configuration, the difference between the width of the groove 70 on the near side of the opening and the width of the groove 70 on the bottom side becomes smaller. In other words, the width of the groove 70 on the near side of the opening becomes narrower than when the difference in width exceeds 60 μm, so the bulk resistance of the carbon electrode 30 can be reduced. Therefore, it becomes possible to improve the power generation efficiency. In addition, since the width of the bottom of the groove 70 becomes wider, the occurrence of short-circuit failures can be suppressed. [Industrial applicability]

[0057] The technology described herein can be used in perovskite solar cells. [Explanation of Symbols]

[0058] 1: Substrate, 10: Transparent conductive film, 20: Solar cell element, 30: Carbon electrode, 70: Groove, 100: Perovskite solar cell

Claims

1. A transparent conductive film provided on a light-transmitting substrate, A plurality of solar cell elements provided on the transparent conductive film, The device comprises carbon electrodes stacked on each of the multiple solar cell elements and connected to the transparent conductive film via the side surface of the solar cell element, In a plurality of solar cell elements, a groove is provided between two adjacent solar cell elements and the carbon electrode provided on the side surface of one solar cell element and the other solar cell element. A perovskite solar cell in which a single groove has an average width of less than 50 μm from the front of the opening to the bottom.

2. The carbon electrode has a density of 1.0 mg / cm³. ３ 1.5mg / cm or more ３ The perovskite solar cell according to claim 1, wherein the perovskite solar cell is as follows:

3. The perovskite solar cell according to claim 1 or 2, wherein the carbon electrode has an arithmetic mean roughness of 1.0 μm or less.

4. The perovskite solar cell according to claim 1 or 2, wherein the difference between the width of the groove portion on the side in front of the opening and the width of the groove portion on the bottom side is 60 μm or less.

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