Perovskite solar cell, and method for manufacturing perovskite solar cell

Abstract

A perovskite solar cell (100) comprises: a laminate (10) having a conductive layer (2) that is disposed on a substrate (1) and is electrically conductive, and a solar battery cell (3) that is disposed on the conductive layer (2), absorbs light energy, and converts the light energy into electric energy; a bus bar (B) that is disposed on the conductive layer (2) and is electrically connected to the laminate (10); and a protective layer (5) having an insulating part (51) and a conductive part (52) and protecting the solar battery cell (3), the bus bar (B) being covered with the insulating part (51) of the protective layer (5).

Description

Perovskite solar cell and method for manufacturing perovskite solar cell

[0001] The present disclosure relates to perovskite solar cells and methods for manufacturing perovskite solar cells.

[0002] Perovskite solar cells, a type of solar cell that converts solar light energy into electrical energy, have attracted attention due to their high energy conversion efficiency and light weight compared to other solar cells. However, perovskite solar cells have the problem of being easily deteriorated by oxygen, water, etc., and various techniques have been proposed to address this problem (see, for example, Patent Documents 1 and 2).

[0003] Patent Document 1 describes a method of covering solar cells (organic EL elements in Patent Document 1) arranged on a substrate with a sealing film, and arranging a protective layer (a sealing member in Patent Document 1) on the sealing film via a sealant whose main component is epoxy resin, thereby isolating the solar cells from the atmosphere.

[0004] Patent Document 2 describes a sealed body sealed with a protective layer (called a sealing sheet in Patent Document 2) having a conductive part made of metal foil (called a gas barrier film in Patent Document 2) and an insulating part having adhesiveness such as a resin (called a pressure-sensitive adhesive layer in Patent Document 2).

[0005] JP 2007-59094 A JP 2018-168304 A

[0006] In the method described in Patent Document 1, a protective layer is disposed on a sealing film using a sealant, and therefore the sealant is required to have properties such as applicability when applied to the sealing film, adhesion to the sealing film and the protective layer, and durability against external forces. Therefore, there are restrictions on the material of the sealant. Furthermore, since the sealant needs to be cured after being applied to the sealing film, the working time is long and the working efficiency is not high.

[0007] In the sealed body described in Patent Document 2, a protective layer is attached to a substrate by thermocompression bonding. The protective layer is a laminate of an insulating portion and a conductive portion, and the areas of the insulating portion and the conductive portion are approximately the same in a plan view. If such a protective layer is thermocompression bonded to a substrate so that the solar cell and the insulating portion are in contact with each other, there is a risk of a short circuit occurring due to contact between the conductive portion at the outer edge of the protective layer and the conductive layer on the substrate. Because the protective layer is cut from a sheet-like material, in order to prevent a short circuit between the conductive portion and the conductive layer, it is necessary to cut the sheet using a complex cutting method such as a gang cutting method and cure the cut surface of the protective layer, which increases manufacturing costs.

[0008] Furthermore, in perovskite solar cells, bus bars that electrically connect to solar cells and the like are arranged on a substrate at a distance from the solar cells. Because the solar cells are covered with a protective layer, it was necessary to arrange the bus bars and the protective layer at a distance from each other to prevent contact between the conductive portions at the outer edges of the protective layer and the bus bars. This increased the area of ​​the substrate relative to the solar cells, reducing the amount of power generated per area of ​​the perovskite solar cell. Furthermore, because the protective layer was attached with the solar cells and bus bars arranged on the substrate, it was necessary to position the protective layer with high precision.

[0009] The present disclosure has been made in view of the above-described problems, and has an object to provide a perovskite solar cell that can prevent a short circuit between a protective layer and a bus bar, and a method for manufacturing a perovskite solar cell that is easy to work with.

[0010] A characteristic configuration of the perovskite solar cell according to the present disclosure is that it comprises a laminate having an electrically conductive layer disposed on a substrate, and solar cells disposed on the conductive layer and absorbing light energy and converting it into electrical energy, a bus bar disposed on the conductive layer and electrically connected to the laminate, and a protective layer having an insulating portion and a conductive portion and protecting the solar cells, wherein the bus bar is covered by the insulating portion of the protective layer.

[0011] According to this configuration, the busbar is covered by the insulating portion of the protective layer, so the conductive portion of the protective layer and the busbar do not come into contact with each other, preventing short circuits between them. This eliminates the need to create the protective layer using a complex cutting method, reducing the manufacturing cost of the protective layer. Furthermore, since it is not necessary to space the busbar and the protective layer apart, an increase in the substrate area relative to the solar cell is suppressed. This makes it possible to miniaturize perovskite solar cells without reducing the solar cell area in a plan view, thereby improving the amount of power generated per area.

[0012] Furthermore, a characteristic configuration of the manufacturing method for perovskite solar cells according to the present disclosure is that it includes a laminate formation step of forming a laminate by arranging, in this order on a substrate, an electrically conductive layer and a solar cell that absorbs light energy and converts it into electrical energy; a busbar bonding step of bonding, to an upper surface of a busbar electrically connected to the laminate, the insulating portion formed on the lower surface of a protective layer having an insulating portion and a conductive portion and having an area in a planar view larger than that of the substrate; a laminate bonding step, after the busbar bonding step, of bonding the insulating portion formed on the lower surface of the protective layer and the lower surface of the busbar to an upper surface of the conductive layer; and a removal step, after the laminate bonding step, of removing the protective layer that is located outside the outer peripheral edge of the substrate.

[0013] According to this configuration, the busbar bonding process bonds the insulating portion of the protective layer to the busbar, thereby covering the busbar with the insulating portion and preventing contact between the conductive portion and the busbar. Therefore, no short circuit occurs between the conductive portion and the busbar. Furthermore, the laminate bonding process covers the top surface of the laminate with the insulating portion, preventing contact between the conductive layer of the laminate and the conductive portion of the protective layer and preventing a short circuit between them. Here, since the area of ​​the protective layer is larger than the area of ​​the substrate, it is not necessary to position the protective layer with high precision relative to the substrate, thereby improving the workability of the laminate bonding process. Furthermore, even if the area of ​​the protective layer is larger than the area of ​​the substrate, removing the protective layer located outside the outer peripheral edge of the substrate in the removal process allows the size of the perovskite solar cell to be adjusted and contact between the outer edge of the protective layer and the conductive layer to be avoided. Furthermore, if the insulating portion has adhesive properties, adhesives or the like are not required to bond the protective layer to the laminate, thereby improving the manufacturing efficiency of perovskite solar cells.

[0014] In this way, it has been possible to provide a perovskite solar cell that can prevent short circuits between the protective layer and the bus bar, and a method for manufacturing a perovskite solar cell that is easy to work with.

[0015] FIG. 1 is a schematic diagram showing the configuration of a perovskite solar cell; FIG. 2 is a schematic plan view of a perovskite solar cell; FIG. 3 is an explanatory diagram of a laminate formation step in a manufacturing method for a perovskite solar cell; FIG. 4 is an explanatory diagram of a busbar bonding step in a manufacturing method for a perovskite solar cell; FIG. 5 is an explanatory diagram of a laminate bonding step in a manufacturing method for a perovskite solar cell; FIG. 6 is an explanatory diagram of a removal step in a manufacturing method for a perovskite solar cell; FIG. 7 is a schematic diagram showing the configuration of a perovskite solar cell according to another embodiment; FIG. 8 is an explanatory diagram of a manufacturing method for a perovskite solar cell module according to another embodiment; FIG. 9 is an explanatory diagram of a manufacturing method for a perovskite solar cell module according to another embodiment.

[0016] Hereinafter, embodiments of a perovskite solar cell and a method for manufacturing a perovskite solar cell according to the present disclosure will be described with reference to the drawings. However, the present disclosure is not limited to the following embodiments, and various modifications are possible without departing from the spirit of the present disclosure.

[0017] [Schematic configuration of perovskite solar cell] As shown in Figure 1, a perovskite solar cell 100 includes a laminate 10 and a protective layer 5. The laminate 10 is formed by laminating a substrate 1, a conductive layer 2, a solar cell 3, and an electrode 4 in this order. [Substrate] The substrate 1 functions as a support for the laminate 10. The substrate 1 is a transparent glass substrate, a semi-transparent glass substrate, a transparent resin substrate, or the like, and has insulating properties. As shown in Figure 2, the substrate 1 is rectangular when viewed along the Z direction.

[0018] As shown in FIG. 1 , a conductive conductive layer 2 is stacked on a substrate 1. The orientation of the perovskite solar cell 100 during use is not particularly limited, but it is preferable that the perovskite solar cell 100 be used so that light is incident in the direction from the substrate 1 to the conductive layer 2. Hereinafter, the direction from the substrate 1 to the conductive layer 2 will be referred to as the "Z1 direction" (an example of a stacking 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." Furthermore, one of the directions perpendicular to the Z direction will be referred to as the "X direction," and the direction perpendicular to the Z direction and the X direction will be referred to as the "Y direction" (see FIG. 2 ). Note that FIG. 2 is a view of the perovskite solar cell 100 shown in FIG. 1 as viewed along the Z direction. The Z1 direction may also be referred to as upward, and the Z2 direction as downward.

[0019] [Conductive Layer] The conductive layer 2 is formed on one surface (the surface on the Z1 side) of the substrate 1 by CVD (chemical vapor deposition), sputtering, or the like. In this embodiment, the conductive layer 2 is formed on the entire surface of one surface of the substrate 1. The conductive layer 2 contains, for example, fluorine-doped tin oxide (FTO), tin oxide (TO), or the like as a material. The solar cell 3 is arranged (stacked) on the conductive layer 2 (the surface on the Z1 side).

[0020] [Solar Cell] The solar cell 3 converts light energy into electrical energy. The solar cell 3 has an electron transport layer 31, a photoelectric conversion layer 32, and a hole transport layer 33, which are arranged in this order along the Z1 direction. When viewed along the Z direction, the electron transport layer 31, the photoelectric conversion layer 32, and the hole transport layer 33 each have a rectangular shape. In this embodiment, when viewed along the Z direction, the electron transport layer 31, the photoelectric conversion layer 32, and the hole transport layer 33 each have the same size (area).

[0021] The electron transport layer 31 is disposed on the Z1-side surface of the conductive layer 2. The electron transport layer 31 receives electrons from the photoelectric conversion layer 32 (described later) and passes through it (transports electrons). The electron transport layer 31 includes, as a material, a metal oxide such as titanium oxide, tin oxide, or zinc oxide. In this embodiment, the electron transport layer 31 includes an insulating layer 311 extending into the recess 21 formed by removing a portion of the conductive layer 2. The insulating layer 311 divides the conductive layer 2 into two sections (in the example shown in FIG. 1 , it divides the conductive layer 2 into two sections in the X direction). In the electron transport layer 31, electrons can move in the Z direction but have difficulty moving in directions perpendicular to the Z direction (the X and Y directions), restricting movement between the two sections of the conductive layer 2. The electron transport layer 31 is sometimes referred to as a "blocking layer."

[0022] Since the substrate 1, the conductive layer 2, and the electron transport layer 31 are optically transparent, light such as sunlight and indoor light is guided to the photoelectric conversion layer 32 without being substantially absorbed (or without being absorbed) by the substrate 1, the conductive layer 2, and the electron transport layer 31.

[0023] The photoelectric conversion layer 32 absorbs light energy and converts it into electrical energy. Specifically, the photoelectric conversion layer 32 absorbs light and transfers excited electrons and holes to perform photoelectric conversion. The photoelectric conversion layer 32 includes a perovskite layer made of a perovskite compound. The photoelectric conversion layer 32 also includes a porous oxide semiconductor layer (e.g., a porous titanium layer).

[0024] The hole transport layer 33 transmits holes received from the photoelectric conversion layer 32 (transports holes). The hole transport layer 33 contains an organic compound such as chlorobenzene as a material. The electrode 4 is disposed on the hole transport layer 33 (on the Z1 side).

[0025] The electrode 4 is conductive and functions as a positive electrode. The electrode 4 is electrically connected to the bus bar B via the conductive layer 2. As shown in FIG. 1 , the electrode 4 is disposed on (a part of) the Z1-side surface of the conductive layer 2, extending in the Z direction from the Z1-side surface of the hole transport layer 33, passing through each side surface of the solar cell 3 (see also FIG. 3 ). The electrode 4 contains, for example, carbon nanotubes (an example of an active material) as a material.

[0026] Light, such as sunlight, enters the perovskite solar cell 100 in the Z1 direction. Upon reaching the photoelectric conversion layer 32 via the substrate 1, conductive layer 2, and electron transport layer 31, the light is absorbed in the photoelectric conversion layer 32, generating electrons and holes. The electrons generated in the photoelectric conversion layer 32 migrate to the conductive layer 2 (negative electrode) via the electron transport layer 31. At the same time, holes generated in the photoelectric conversion layer 32 migrate to the electrode 4 (positive electrode) electrically connected to the hole transport layer 33. When a load (not shown) is connected between the conductive layer 2 and the electrode 4, the holes combine with the electrons that have traveled through the load. As a result, electricity is generated. Note that electrons moving through the electron transport layer 31 move smoothly along the Z2 direction to reach the conductive layer 2, but as described above, the insulating layer 311 restricts their movement in a direction perpendicular to the Z direction. In other words, the perovskite solar cell 100 is configured to prevent short-circuiting.

[0027] [Busbar] As shown in FIG. 2 , when viewed along the Z direction, the busbar B is arranged (laminated) on the Z1-side surface of the conductive layer 2 outer than the solar cell 3 (outer in the X direction). More specifically, two busbars B are arranged on the Z1-side surface (partial regions) of the conductive layer 2 on both sides of the solar cell 3, spaced apart from the solar cell 3 and the electrode 4. One busbar B (the busbar B on the right side of the paper in FIG. 1 ) is electrically connected to the electrode 4 via a portion of the conductive layer 2 (a portion to the right of the recess 21 as viewed in FIG. 1 ), as described above. The other busbar B (the busbar B on the left side of the paper in FIG. 1 ) is electrically connected to a portion of the conductive layer 2 serving as the negative electrode (a portion to the left of the recess 21 as viewed in FIG. 1 ). In other words, the busbar B is arranged on the conductive layer 2 and electrically connected to the laminate 10. In this embodiment, the busbar B is arranged closer to the solar cell 3 than the outer circumferential edge of the conductive layer 2, but may be arranged along the outer circumferential edge of the conductive layer 2. The bus bar B includes, as a material, a simple metal such as gold, platinum, silver, or copper, an alloy thereof, or an oxide conductor such as FTO or ITO.

[0028] [Protective Layer] As shown in FIG. 1 , the protective layer 5 includes an insulating portion 51, a conductive portion 52, and a film portion 53. The insulating portion 51 may have adhesive properties, gas barrier properties, and waterproof properties, and may be made of, for example, an olefin-based adhesive, an epoxy-based adhesive, or an acrylic-based adhesive. The insulating portion 51 may also include a getter material that adsorbs moisture and gases. The conductive portion 52 is conductive and includes, for example, a metal oxide such as aluminum oxide or silicon oxide, or a metal such as aluminum. The film portion 53 includes, for example, a resin such as polyethylene terephthalate. The protective layer 5 is formed by laminating the insulating portion 51, the conductive portion 52, and the film portion 53 in this order. In FIG. 1 , the insulating portion 51 is formed on the Z2-side surface (an example of the lower surface) of the protective layer 5, and the film portion 53 is formed on the Z1-side surface. That is, the Z2-side surface of the conductive portion 52 is covered by the insulating portion 51, and the Z1-side surface of the conductive portion 52 is covered by the film portion 53.

[0029] Because the protective layer 5 is a sheet-like material, when the protective layer 5 is disposed on the surface of the laminate 10, the protective layer 5 is cut to fit the size of the laminate 10. The conductive portion 52 is exposed at the cut surface of the protective layer 5. Therefore, if the cut surface (outer edge) of the protective layer 5 comes into contact with the bus bar B or the laminate 10, a short circuit will occur between the conductive portion 52 and the bus bar B or the conductive layer 2. Therefore, in this embodiment, the protective layer 5 is disposed on the laminate 10 so that the cut surface of the protective layer 5 is located outside the outer peripheral edge of the substrate 1 in a plan view (when viewed in the Z direction).

[0030] As shown in FIG. 1 , the insulating portion 51 of the protective layer 5 is bonded to the Z1-side surface of the laminate 10 and the Z1-side surface (an example of the upper surface) of the bus bar B, covering the surface of the laminate 10. As shown in FIG. 2 , the area of ​​the protective layer 5 in a plan view is larger than the area of ​​the substrate 1, and therefore the cut surface of the protective layer 5 is located outside the outer circumferential edge of the substrate 1. Therefore, in the Z direction, the insulating portion 51 is present between the conductive portion 52 and the bus bar B and the laminate 10, and no short circuit occurs between the conductive portion 52 and the bus bar B and the laminate 10. Furthermore, in the X and Y directions, the cut surface of the protective layer 5 is located outside the outer circumferential edge of the substrate 1, and therefore the conductive portion 52 does not come into contact with the bus bar B or the conductive layer 2, and no short circuit occurs between them. In this manner, in this embodiment, the area of ​​the protective layer 5 is made larger than the area of ​​the substrate 1, and the laminate 10 is brought into contact with the insulating portion 51, thereby preventing not only a short circuit between the conductive portion 52 and the bus bar B, but also a short circuit between the conductive portion 52 and the laminate 10.

[0031] If the area of ​​the protective layer 5 in plan view is smaller than the area of ​​the substrate 1, it is also possible to arrange the protective layer 5 on the conductive layer 2 so that the cut surface of the protective layer 5 is spaced apart from the bus bar B in order to prevent contact between the cut surface of the protective layer 5 and the bus bar B. In this case, the area of ​​the perovskite solar cell 100 (specifically, the substrate 1 and conductive layer 2) in plan view increases by the distance between the protective layer 5 and the bus bar B, thereby reducing the amount of power generated per area of ​​the perovskite solar cell 100. According to the present embodiment, there is no need to space the protective layer 5 from the bus bar B, and therefore it is possible to increase the amount of power generated per area without increasing the area of ​​the solar cell 3.

[0032] [Method for manufacturing perovskite solar cell] Next, a method for manufacturing the perovskite solar cell 100 will be described with reference to Figures 3 to 6. The method for manufacturing the perovskite solar cell 100 in this embodiment includes a laminate formation step, a bus bar bonding step, a laminate bonding step, and a removal step.

[0033] First, as shown in FIG. 3 , a laminate formation step is performed to form a laminate 10. In the laminate formation step, a conductive layer 2 is formed on the Z1-side surface of the substrate 1. The conductive layer 2 may be formed by, for example, CVD (chemical vapor deposition) or sputtering. Next, laser scribing is performed to partially remove the conductive layer 2, forming recesses 21. Thereafter, solar cell 3 and electrode 4 are formed on the Z1-side surface of the conductive layer 2 by a known method. After the electrode 4 is formed, a coating material such as an insulating porous film may be disposed on the surface of the electrode 4 using an adhesive or the like.

[0034] Next, as shown in FIG. 4 , a busbar bonding step is performed, in which the insulating portion 51 formed on the Z2-side surface of the protective layer 5 and the Z1-side surface of the busbar B are pressure-bonded to each other. The busbar bonding step may be performed by heat and pressure bonding using a roller or the like. The protective layer 5 used in this step is a sheet-like protective layer 5 cut to a predetermined size, and the area of ​​the protective layer 5 in a plan view is larger than the area of ​​the substrate 1. The two busbars B are each positioned at a predetermined distance in the X direction from the center of the protective layer 5 in a plan view (see FIG. 2 ). The distance between the busbars B, B in the X direction is preferably larger than the X-direction dimension of the solar cell 3 and smaller than the X-direction dimension of the conductive layer 2. As a result, in the subsequent laminate bonding step, the busbar B is positioned on the conductive layer 2 while being spaced apart from the solar cell 3.

[0035] Next, as shown in FIG. 5 , a laminate bonding process is performed, in which the bonded insulating portion 51 of the bus bar B is pressure-bonded to the Z1-side surface of the laminate 10. The laminate bonding process may also be performed by heat and pressure bonding using a roller or the like. This brings the Z2-side surface of the bus bar B into contact with the Z1-side surface of the conductive layer 2, and bonds the Z2-side surface of the insulating portion 51 to the Z1-side surface of the laminate 10 (e.g., the Z1-side surfaces of the conductive layer 2 and the electrodes 4). In FIGS. 3 to 6 , for illustrative purposes, the Z-direction dimension of the solar cell 3 is illustrated as being larger than the Z-direction dimension of the substrate 1. However, because the Z-direction dimensions of the solar cell 3 and the electrodes 4 are small, approximately 20 μm, the protective layer 5 is disposed parallel to the horizontal plane of the substrate 1. Therefore, the bus bar B is covered by the insulating portion 51 and is bonded to the Z1-side surface of the conductive layer 2.

[0036] As described above, the protective layer 5 is formed by cutting a sheet-like material to a predetermined size, and therefore the conductive portion 52 is exposed at the cut surface. In this process, the protective layer 5 and the laminate 10 are attached so that the cut surface of the protective layer 5 is located outside the outer peripheral edge of the substrate 1, and therefore the conductive portion 52 and the laminate 10 do not come into contact with each other. This prevents a short circuit between them. Furthermore, compared to a case in which the area of ​​the protective layer 5 in a plan view is smaller than the area of ​​the substrate 1 and the protective layer 5 and the laminate 10 are attached with a separation distance between the cut surface of the protective layer 5 and the bus bar B, the protective layer 5 and the laminate 10 do not need to be aligned with high precision, and therefore the bonding process is easier.

[0037] Furthermore, when cutting the protective layer 5 to a predetermined size, there is no need to use a complicated cutting method such as a gang cutting method to prevent the occurrence of sagging or burrs on the cut surface, which can improve the efficiency of the cutting operation of the protective layer 5. Furthermore, if the insulating portion 51 of the protective layer 5 has adhesive properties, an adhesive or the like is not required when bonding the protective layer 5 and the laminate 10, and the application process of the adhesive or the like and the curing time are omitted, making it possible to efficiently perform the laminate bonding process.

[0038] 6, a removal step is performed to remove the protective layer 5 located outside the outer peripheral edge of the substrate 1. The protective layer 5 may be removed so that the area of ​​the protective layer 5 in a plan view is approximately the same as the area of ​​the substrate 1, or may be removed so that the area of ​​the protective layer 5 is slightly larger than the area of ​​the substrate 1. Even in this case, insulation between the conductive portion 52 of the protective layer 5 and the laminate 10 is ensured, so there is no need to use a complicated cutting method to cut the protective layer 5.

[0039] The above-described manufacturing method prevents short circuits between the conductive portion 52 of the protective layer 5 and the laminate 10 and the bus bar B, and provides a perovskite solar cell 100 with high power generation efficiency per area.

[0040] The above-described embodiment contemplates the following configuration: (1) A perovskite solar cell 100 including a laminate 10 having an electrically conductive layer 2 disposed on a substrate 1, solar cells 3 disposed on the conductive layer 2 and absorbing light energy and converting it into electrical energy, a bus bar B disposed on the conductive layer 2 and electrically connected to the laminate 10, and a protective layer 5 having an insulating portion 51 and a conductive portion 52 and protecting the solar cells 3, wherein the bus bar B is covered by the insulating portion 51 of the protective layer 5.

[0041] According to this configuration, the bus bar B is covered by the insulating portion 51 of the protective layer 5, so the conductive portion 52 of the protective layer 5 and the bus bar B do not come into contact with each other, and no short circuit occurs between them. This eliminates the need to create the protective layer 5 using a complex cutting method, making it possible to reduce the manufacturing cost of the protective layer 5. Furthermore, since it is not necessary to arrange the bus bar B and the protective layer 5 at a distance from each other, an increase in the area of ​​the substrate 1 relative to the solar cell 3 is suppressed. This makes it possible to reduce the size of the perovskite solar cell 100 without reducing the area of ​​the solar cell 3 in a plan view, and makes it possible to improve the amount of power generation per area.

[0042] (2) In the perovskite solar cell 100 of (1), it is preferable that the area of ​​the protective layer 5 in a plan view is larger than the area of ​​the substrate 1.

[0043] According to this configuration, the area of ​​protective layer 5 is larger than the area of ​​substrate 1, so that conductive layer 2 arranged on substrate 1 and conductive portion 52 exposed at the end of protective layer 5 do not come into contact with each other, preventing a short circuit between them. Furthermore, there is no need to process protective layer 5 using a complicated cutting method so as to prevent conductive portion 52 from being exposed at the end of protective layer 5, so the manufacturing cost of perovskite solar cell 100 can be reduced.

[0044] (3) A method for manufacturing a perovskite solar cell 100, comprising: a laminate formation step of forming a laminate 10 by arranging, in this order, an electrically conductive layer 2 and solar cells 3 that absorb light energy and convert it into electrical energy on a substrate 1; a busbar bonding step of bonding the insulating portion 51, which has an insulating portion 51 and a conductive portion 52 and is formed on the lower surface of a protective layer 5 whose area in a planar view is larger than the area of ​​the substrate 1, to the upper surface of a busbar B that is electrically connected to the laminate 10; a laminate bonding step, after the busbar bonding step, of bonding the insulating portion 51 formed on the lower surface of the protective layer 5 and the lower surface of the busbar B to the upper surface of the conductive layer 2; and a removal step, after the laminate bonding step, of removing the protective layer 5 that is located outside the outer peripheral edge of the substrate 1.

[0045] According to this configuration, the busbar bonding step bonds the insulating portion 51 of the protective layer 5 to the busbar B, so that the busbar B is covered with the insulating portion 51, preventing contact between the conductive portion 52 and the busbar B. As a result, no short circuit occurs between the conductive portion 52 and the busbar B. Furthermore, the stack bonding step covers the Z1-side surface of the stack 10 with the insulating portion 51, preventing contact between the conductive layer 2 of the stack 10 and the conductive portion 52 of the protective layer 5 and preventing a short circuit therebetween. Here, because the area of ​​the protective layer 5 is larger than the area of ​​the substrate 1, there is no need to position the protective layer 5 with high precision relative to the substrate 1, thereby improving the workability of the stack bonding step. Furthermore, even if the area of ​​the protective layer 5 is larger than the area of ​​the substrate 1, removing the protective layer 5 located outside the outer peripheral edge of the substrate 1 in the removal step allows the size of the perovskite solar cell 100 to be adjusted, and contact between the outer edge of the protective layer 5 and the conductive layer 2 to be avoided. Furthermore, if the insulating portion 51 has adhesive properties, there is no need for an adhesive or the like to bond the protective layer 5 and the laminate 10 together, which makes it possible to improve the manufacturing efficiency of the perovskite solar cell 100.

[0046] (4) In the method for manufacturing the perovskite solar cell 100 of (3), it is preferable that the protective layer 5 and the bus bar B are bonded together using an insulating adhesive sheet 6 in the bus bar bonding step.

[0047] When the perovskite solar cell 100 includes a plurality of adjacent laminates 10, a large current is likely to flow through the bus bar B, which is used to extract the power generated by the plurality of laminates 10 to the outside. According to this configuration, the adhesive sheet 6 is sandwiched between the protective layer 5 and the bus bar B, making it possible to reliably insulate the protective layer 5 from the bus bar B. Furthermore, the protective layer 5 and the bus bar B can be bonded together even if the insulating portion 51 does not have adhesive properties.

[0048] Other embodiments (a) As shown in Figure 7, an insulating adhesive sheet 6 may be disposed between the protective layer 5 and the bus bar B. This ensures reliable insulation between the bus bar B, through which a large current tends to flow, and the protective layer 5, thereby improving the safety of the perovskite solar cell 100. The dimension of the adhesive sheet 6 in the X direction may be approximately the same as or larger than the dimension of the bus bar B in the X direction.

[0049] When the adhesive sheet 6 is disposed between the protective layer 5 and the bus bar B as in (a), in the bus bar bonding step, the adhesive sheet 6 may be bonded to the Z2-side surface of the insulating portion 51 of the protective layer 5, and the bus bar B may be bonded to the Z2-side surface of the adhesive sheet 6. The adhesive sheet 6 may have adhesiveness on both the Z1-side surface and the Z2-side surface, or only on the Z2-side surface.

[0050] (b) A plurality of perovskite solar cells 100 according to this embodiment may be connected to manufacture a perovskite solar cell module 200. The perovskite solar cell module 200 is formed by electrically connecting the bus bars B of adjacent perovskite solar cells 100. A method for manufacturing the perovskite solar cell module 200 according to this embodiment will be described with reference to Figs. 8 and 9 .

[0051] First, as shown in Fig. 8 , in the busbar bonding step, the insulating portion 51 on the Z2 side of the protective layer 5 is bonded to the Z1 side surface of the busbar B. According to this embodiment, the X-direction dimension of the protective layer 5 is larger than the X-direction dimension of the substrate 1, and the Y-direction dimension of the protective layer 5 is at least three times the Y-direction dimension of the substrate 1. A busbar B having substantially the same dimension as the Y-direction dimension of the protective layer 5 is bonded to the insulating portion 51 of the protective layer 5. The two busbars B are each positioned at a predetermined distance apart from each other outward from the center of the protective layer 5 in the X direction. The distance between the busbars B, B in the X direction is preferably larger than the X-direction dimension of the solar cell 3 and smaller than the X-direction dimension of the conductive layer 2.

[0052] 9 , in a stack bonding step, the protective layer 5 is bonded to the stack 10 formed in the stack forming step described above. In this embodiment, the Z1 side surface of each stack 10 of the three perovskite solar cells 100 is pressure-bonded to the insulating part 51 on the Z2 side of the protective layer 5, thereby bonding them together. At this time, the stack 10 is positioned so that the bus bars B, B are bonded to the Z1 side surface of the conductive layer 2. Note that after the stack bonding step, the protective layer 5 located outside the outer circumferential edge of the substrate 1 may be removed.

[0053] The perovskite solar cell module 200 of this embodiment has one protective layer 5 disposed on the Z1-side surface of each stack 10 of three perovskite solar cells 100 arranged in parallel along the Y direction. The area of ​​the protective layer 5 in a plan view is larger than the total area of ​​the three substrates 1 arranged in parallel along the Y direction, and the outer edge of the protective layer 5 is located outside the outer peripheral edges of the three substrates 1. In addition, the bus bar B is covered by the insulating portion 51 of the protective layer 5. This prevents short-circuiting between the conductive portion 52 of the protective layer 5 and the stack 10 and the bus bar B. Furthermore, the bus bar B disposed on the Z1-side surface of the conductive layer 2 has substantially the same dimension in the Y direction as the protective layer 5, so there is no need to provide a bus bar B for each perovskite solar cell 100, and there is also no need to connect the bus bar B disposed for each perovskite solar cell 100.

[0054] According to the above manufacturing method, it is possible to omit the step of electrically connecting a plurality of perovskite solar cells 100, and therefore it is possible to efficiently manufacture the perovskite solar cell module 200. Note that, although in this embodiment the stack 10 of three perovskite solar cells 100 is bonded to one protective layer 5, it is also possible to bond stacks 10 of two or four or more perovskite solar cells 100 to one protective layer 5 having a predetermined size.

[0055] The present disclosure is applicable to a perovskite solar cell having a solar cell that absorbs light energy and converts it into electrical energy, and to a method for manufacturing a perovskite solar cell.

[0056] 1: Substrate, 2: Conductive layer, 3: Solar cell, 5: Protective layer, 6: Adhesive sheet, 10: Laminate, 51: Insulating portion, 52: Conductive portion, 100: Perovskite solar cell, B: Bus bar

Claims

1. A perovskite solar cell comprising: a laminate having an electrically conductive layer disposed on a substrate; and solar cells disposed on the conductive layer, which absorb light energy and convert it into electrical energy; a bus bar disposed on the conductive layer and electrically connected to the laminate; and a protective layer having an insulating portion and a conductive portion and protecting the solar cells, wherein the bus bar is covered by the insulating portion of the protective layer.

2. The perovskite solar cell according to claim 1, wherein the area of ​​the protective layer in a plan view is larger than the area of ​​the substrate.

3. A method for manufacturing a perovskite solar cell, comprising: a laminate formation step of forming a laminate by arranging, in this order, an electrically conductive layer and a solar cell that absorbs light energy and converts it into electrical energy on a substrate; a busbar bonding step of bonding an insulating portion formed on the underside of a protective layer having an insulating portion and a conductive portion and having an area in a planar view larger than the area of ​​the substrate, to the upper surface of a busbar electrically connected to the laminate; a laminate bonding step, after the busbar bonding step, of bonding the insulating portion formed on the underside of the protective layer and the lower surface of the busbar to the upper surface of the conductive layer; and a removal step, after the laminate bonding step, of removing the protective layer located outside the outer peripheral edge of the substrate.

4. A method for manufacturing a perovskite solar cell according to claim 3, wherein in the bus bar bonding step, the protective layer and the bus bar are bonded together using an insulating adhesive sheet.

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