Method for manufacturing solar cell

Abstract

Provided is a method for manufacturing a solar cell in which water is prevented from entering a photoelectric conversion layer, and in which any deterioration in the characteristics of the photoelectric conversion layer is suppressed. A method for manufacturing a solar cell having a layered configuration in which a support (12), a support-side electrode (14), a perovskite-compound-containing photoelectric conversion layer (16), a sealing-layer-side electrode (18), an organic adhesive layer (19), an inorganic adhesive layer (20), and a sealing layer (22) are laminated in the stated order, wherein the method includes: a first formation step in which a first inorganic adhesive body layer is formed on a surface of the sealing layer (22) facing the sealing-layer-side electrode (18) by using a plasma CVD method, and a first laminate provided with the first inorganic adhesive body layer is formed; a second formation step in which a second inorganic adhesive body layer is formed by using a plasma CVD method, on a laminated member in which the support body (12), the support-side electrode (14), the photoelectric conversion layer (16), the sealing-layer-side electrode (18), and the organic adhesive layer (19) are laminated in the stated order, to form a second laminate provided with a second inorganic adhesive body layer; and a third formation step in which the first inorganic adhesive body layer of the first laminate and the second inorganic adhesive body layer of the second laminate are laminated to form the inorganic adhesive layer (20).

Description

Solar cell manufacturing method

[0001] The present invention relates to a method for manufacturing a solar cell in which a photoelectric conversion layer contains a perovskite compound, and in particular to a method for manufacturing a solar cell in which an inorganic adhesive layer is formed by lamination.

[0002] Currently, there are perovskite solar cells that use perovskite compounds in the photoelectric conversion layer. It is known that the performance of perovskite solar cells deteriorates when exposed to moisture. For this reason, perovskite solar cells are sealed to prevent water from penetrating into the photoelectric conversion layer.

[0003] For example, Patent Document 1 proposes a solar cell that includes a support, a solar cell element provided on the support, an adhesive layer covering the solar cell element, and a sealant layer covering the adhesive layer, the solar cell element including an electrode, a photoelectric conversion layer including a perovskite compound, and a back electrode, in that order, the sealant layer including a main body portion covering the adhesive layer and an edge region connected to the main body portion, and the average density of the edge region is 1.01 to 2 times the average density of the main body portion.

[0004] Japanese Patent Application Laid-Open No. 2023-042617

[0005] The solar cell of Patent Document 1 has an adhesive layer made of a cured acrylic resin or epoxy resin, etc. Such adhesive layers made of a cured acrylic resin or epoxy resin are prone to voids, which can allow water to penetrate through the side surfaces of the adhesive layer, resulting in an insufficient sealing effect and degradation of the photoelectric conversion layer, i.e., the solar cell's characteristics. An object of the present invention is to provide a method for manufacturing a solar cell that prevents water from penetrating the photoelectric conversion layer and suppresses degradation of the photoelectric conversion layer's characteristics.

[0006] In order to achieve the above-mentioned object, invention [1] is a method for manufacturing a solar cell having a layer structure in which a support, a support-side electrode, a photoelectric conversion layer containing a perovskite compound, a sealing layer-side electrode, an organic adhesive layer, an inorganic adhesive layer, and a sealing layer are stacked in this order, the method comprising: a first formation step of forming a first inorganic adhesive layer by a plasma CVD method on the surface of the sealing layer facing the sealing layer-side electrode to form a first laminate including the first inorganic adhesive layer; a second formation step of forming a second inorganic adhesive layer by a plasma CVD method on a laminated base material in which the support, the support-side electrode, the photoelectric conversion layer, the sealing layer-side electrode, and the organic adhesive layer are stacked in this order to form a second laminate including the second inorganic adhesive layer; and a third formation step of stacking the first inorganic adhesive layer of the first laminate and the second inorganic adhesive layer of the second laminate to form an inorganic adhesive layer.

[0007] Invention [2] is a method for manufacturing a solar cell having a layer structure in which a conductive support, a photoelectric conversion layer containing a perovskite compound, a sealing layer-side electrode, an organic adhesive layer, an inorganic adhesive layer, and a sealing layer are laminated in this order, the method comprising: a first formation step of forming a first inorganic adhesive layer by a plasma CVD method on the surface of the sealing layer facing the sealing layer-side electrode to form a first laminate including the first inorganic adhesive layer; a second formation step of forming a second inorganic adhesive layer by a plasma CVD method on a laminated base material in which the conductive support, the photoelectric conversion layer, the sealing layer-side electrode, and the organic adhesive layer are laminated in this order to form a second laminate including the second inorganic adhesive layer; and a third formation step of laminating the first inorganic adhesive layer of the first laminate and the second inorganic adhesive layer of the second laminate to form an inorganic adhesive layer.

[0008] Invention [3] is the method for manufacturing a solar cell according to Invention [1], wherein in the second forming step, a second inorganic adhesive layer is formed directly on the support in a peripheral portion of the organic adhesive layer in a direction perpendicular to the stacking direction of the laminated base material. Invention [4] is the method for manufacturing a solar cell according to Invention [2], wherein in the second forming step, a second inorganic adhesive layer is formed directly on the conductive support in a peripheral portion of the organic adhesive layer in a direction perpendicular to the stacking direction of the laminated base material. Invention [5] is the method for manufacturing a solar cell according to any one of Inventions [1] to [4], wherein the first inorganic adhesive layer and the second inorganic adhesive layer are composed of an oxide containing one of Si and Al, and when the oxide is silicon oxide, the atomic ratio of silicon to oxygen O / Si is 2.5 or more and 4.0 or less, and when the oxide is aluminum oxide, the atomic ratio of aluminum to oxygen O / Al is 2.0 or more and 3.0 or less.

[0009] Invention [6] is the method for manufacturing a solar cell according to any one of Inventions [1] to [5], wherein the total thickness of the first inorganic adhesive layer and the second inorganic adhesive layer is 0.3 to 15 nm. Invention [7] is the method for manufacturing a solar cell according to any one of Inventions [1] to [6], wherein in the third forming step, the first inorganic adhesive layer of the first laminate and the second inorganic adhesive layer of the second laminate are laminated within 30 seconds after the formation of the first laminate or the second laminate, whichever is formed first.

[0010] Invention [8] is the method for manufacturing a solar cell according to any one of Inventions [1] to [7], wherein in the second forming step, a second inorganic adhesive layer is formed while the organic adhesive layer is in an uncured state. Invention [9] is the method for manufacturing a solar cell according to any one of Inventions [1] to [6], which includes an activation treatment step of performing an activation treatment on at least one of the first inorganic adhesive layer and the second inorganic adhesive layer before the third forming step. Invention

[10] is the method for manufacturing a solar cell according to Invention [9], wherein in the third forming step, the first inorganic adhesive layer of the first laminate and the second inorganic adhesive layer of the second laminate are laminated within 60 seconds after the formation of the first laminate or the second laminate, whichever is formed first. Invention

[11] is a method for producing a solar cell according to any one of Inventions [1] to

[10] , in which the first forming step, the second forming step, and the lamination step of laminating the first inorganic adhesive layer of the first laminate and the second inorganic adhesive layer of the second laminate are carried out by roll-to-roll, and after the first forming step and the second forming step, the first laminate and the second laminate are transported in a non-contact state until the lamination step is carried out.

[0011] Invention

[12] is the method for manufacturing a solar cell according to any one of Inventions [1] to

[11] , wherein in the first forming step, a first inorganic adhesive layer is formed on the surface of the sealing layer facing the sealing layer-side electrode in a first region corresponding to the periphery of the organic adhesive layer in a direction perpendicular to the stacking direction of the laminated base material and in a second region corresponding to the organic adhesive layer, and in the second forming step, a second inorganic adhesive layer is formed on the periphery of the organic adhesive layer in a direction perpendicular to the stacking direction of the laminated base material and on the organic adhesive layer. Invention

[13] is the method for manufacturing a solar cell according to any one of Inventions [1] to

[11] , wherein in the first forming step, a first inorganic adhesive layer is formed on the surface of the sealing layer facing the sealing layer-side electrode in a first region corresponding to the periphery of the organic adhesive layer in a direction perpendicular to the stacking direction of the laminated base material and in a second region corresponding to the organic adhesive layer, and in the second forming step, a second inorganic adhesive layer is formed on the periphery of the organic adhesive layer in a direction perpendicular to the stacking direction of the laminated base material. Invention

[14] is the method for manufacturing a solar cell according to any one of Inventions [1] to

[11] , wherein in the first formation step, a first inorganic adhesive layer is formed on a surface of the sealing layer facing the sealing layer-side electrode, in a first region corresponding to a periphery of the organic adhesive layer in a direction perpendicular to the stacking direction of the laminated base material, on the surface of the sealing layer facing the sealing layer-side electrode, and in the second formation step, a second inorganic adhesive layer is formed in a periphery of the organic adhesive layer in the direction perpendicular to the stacking direction of the laminated base material.

[0012] According to the present invention, it is possible to provide a method for manufacturing a solar cell that prevents water from entering the photoelectric conversion layer and suppresses deterioration of the characteristics of the photoelectric conversion layer.

[0013] FIG. 1 is a schematic cross-sectional view showing a first example of a solar cell according to an embodiment of the present invention. FIG. 2 is a schematic cross-sectional view showing a step of a manufacturing method for the first example of a solar cell according to an embodiment of the present invention. FIG. 3 is a schematic cross-sectional view showing a step of a manufacturing method for the first example of a solar cell according to an embodiment of the present invention. FIG. 4 is a schematic cross-sectional view showing a step of a manufacturing method for the first example of a solar cell according to an embodiment of the present invention. FIG. 5 is a schematic cross-sectional view showing a step of a manufacturing method for the first example of a solar cell according to an embodiment of the present invention. FIG. 6 is a schematic cross-sectional view showing a second example of a solar cell according to an embodiment of the present invention. FIG. 7 is a schematic cross-sectional view showing a step of a manufacturing method for the second example of a solar cell according to an embodiment of the present invention. FIG. 8 is a schematic cross-sectional view showing a fourth example of a solar cell according to an embodiment of the present invention. FIG. 9 is a schematic view showing a first example of a method for forming a second inorganic adhesive layer according to an embodiment of the present invention. FIG. 10 is a schematic view showing a second example of a method for forming a second inorganic adhesive layer according to an embodiment of the present invention. FIG. 11 is a schematic view showing a first example of a roll-to-roll system apparatus used in manufacturing a solar cell according to an embodiment of the present invention. FIG. 12 is a schematic view showing a second example of a roll-to-roll system apparatus used in manufacturing a solar cell according to an embodiment of the present invention.

[0014] The method for manufacturing a solar cell of the present invention will be described in detail below based on the preferred embodiment shown in the accompanying drawings. Note that the drawings described below are merely illustrative for explaining the present invention, and the present invention is not limited to the drawings shown below. Note that in the following, the "to" symbol indicating a range of values ​​includes the values ​​written on both sides. For example, when ε is a value ε α ~Number ε β That is, the range of ε is the number ε α and the number ε β The range includes ε α ≦ε≦ε βUnless otherwise specified, angles such as "angles expressed by specific numerical values," "parallel," and "perpendicular" include a generally acceptable error range in the relevant technical field. Furthermore, temperatures include a generally acceptable error range in the relevant technical field. Note that, unless otherwise specified, "transparent" means transparent to light. More specifically, "transparent" means that the light transmittance for light in the wavelength range of 400 to 800 nm is 80% or more. In the case of transparency, the light transmittance is more preferably 85% or more, and even more preferably 90% or more. The light transmittance can be calculated by the method described in JIS (Japanese Industrial Standards)-K7105, that is, by measuring the total light transmittance and the amount of scattered light using an integrating sphere light transmittance measuring device and subtracting the diffuse transmittance from the total light transmittance.

[0015] [First Example of Solar Cell] Figure 1 is a schematic cross-sectional view showing a first example of a solar cell according to an embodiment of the present invention. The solar cell 10 shown in Figure 1 has a layer structure in which a support 12, a support-side electrode 14, an electron transport layer 15, a photoelectric conversion layer 16, a hole transport layer 17, a sealing layer-side electrode 18, an organic adhesive layer 19, an inorganic adhesive layer 20, and a sealing layer 22 are stacked in this order. The direction in which the support 12, the support-side electrode 14, the electron transport layer 15, the photoelectric conversion layer 16, the hole transport layer 17, the sealing layer-side electrode 18, the organic adhesive layer 19, the inorganic adhesive layer 20, and the sealing layer 22 are stacked is referred to as the stacking direction Ds.

[0016] The support 12 supports the support-side electrode 14, the electron transport layer 15, the photoelectric conversion layer 16, the hole transport layer 17, the sealing layer-side electrode 18, the organic adhesive layer 19, the inorganic adhesive layer 20, and the sealing layer 22. The support-side electrode 14 and the sealing layer-side electrode 18 are used to extract the electricity generated in the photoelectric conversion layer 16 to the outside. The electron transport layer 15, the photoelectric conversion layer 16, and the hole transport layer 17 constitute a photoelectric conversion section 24. Light incident on the solar cell 10 is photoelectrically converted in the photoelectric conversion layer 16. As described above, the support-side electrode 14 and the sealing layer-side electrode 18 extract the electricity generated by photoelectric conversion in the photoelectric conversion layer 16 to the outside.

[0017] The organic adhesive layer 19 and the inorganic adhesive layer 20 bond the sealing layer 22. The inorganic adhesive layer 20 and the sealing layer 22 protect the photoelectric conversion layer 16 from water. The organic adhesive layer 19 covers the periphery of the photoelectric conversion layer 16 and is also formed on the end surface 16c in the direction Dw perpendicular to the stacking direction Ds of the photoelectric conversion layer 16. The organic adhesive layer 19 is in a cured state. If the organic adhesive layer 19 is made of a thermosetting adhesive, the cured state refers to the state after the adhesive is heated to a temperature required for curing. If the organic adhesive layer 19 is made of an ultraviolet-curing adhesive, the cured state refers to the state after the adhesive is irradiated with ultraviolet light required for curing. The inorganic adhesive layer 20 is provided, for example, on the entire surface 19a of the organic adhesive layer 19 and covers the periphery of the photoelectric conversion layer 16. The support 12, the support-side electrode 14, the electron transport layer 15, the photoelectric conversion layer 16, the hole transport layer 17, the sealing layer-side electrode 18, the organic adhesive layer 19, the inorganic adhesive layer 20, and the sealing layer 22 will be described in detail later.

[0018] In the solar cell 10, as described below, the inorganic adhesive layer 20 is formed using a plasma CVD (chemical vapor deposition) method after the organic adhesive layer 19 is formed. By providing the organic adhesive layer 19, the photoelectric conversion layer 16 is protected from plasma when the inorganic adhesive layer 20 is formed using a plasma CVD method, thereby suppressing a decrease in the photoelectric conversion efficiency of the photoelectric conversion layer 16. By providing the inorganic adhesive layer 20, it is possible to prevent water from penetrating into the photoelectric conversion layer 16 from the end face of the organic adhesive layer 19, thereby suppressing deterioration of the characteristics of the photoelectric conversion layer 16. Furthermore, the inorganic adhesive layer 20 allows the sealing layer 22 to be provided with high adhesion, thereby achieving a sufficient sealing effect. As a result, the solar cell 10 has high humidity and heat resistance.

[0019] The inorganic adhesive layer 20 is preferably provided directly on the support 12, i.e., on the surface 12a of the support 12, other than on the organic adhesive layer 19. By providing the inorganic adhesive layer 20 directly on the support 12, the end 19c of the organic adhesive layer 19 is sealed with the inorganic adhesive layer 20, and the entire organic adhesive layer 19 is sealed with the inorganic adhesive layer 20. This makes it possible to prevent moisture from penetrating through the end 19c of the organic adhesive layer 19. The end 19c of the organic adhesive layer 19 is the end in the direction Dw orthogonal to the stacking direction Ds, i.e., the end of the organic adhesive layer 19 opposite the photoelectric conversion layer 16.

[0020] The inorganic adhesive layer 20 is composed of, for example, an oxide containing one of the elements Si and Al. In this case, the oxide is, for example, silicon oxide (SiO) and aluminum oxide (AlO). When the oxide is silicon oxide (SiO), the atomic ratio of silicon to oxygen, O / Si, is preferably 2.5 or more and 4.0 or less. When the oxide is aluminum oxide (AlO), the atomic ratio of aluminum to oxygen, O / Al, is preferably 2.0 or more and 3.0 or less.

[0021] The atomic ratios O / Si and O / Al of the Si or Al element contained in the oxide constituting the inorganic adhesive layer 20 to the oxygen or nitrogen contained in the oxide can be calculated from the analysis results obtained by X-ray photoelectron spectroscopy using an XPS apparatus (AXIS-ULTRA manufactured by Shimadzu Corporation). Specific elements from Si, Al, O, and N are measured at multiple locations at predetermined intervals along the thickness direction Dt of the inorganic adhesive layer 20 according to the oxide composition, and the atomic ratios O / Si and O / Al at each location are calculated from the measurement results of the measured elements among Si, Al, O, and N. The average values ​​of the multiple locations are taken as the atomic ratios O / Si and O / Al. An oxide containing one of Si and Al can increase the sunlight transmittance and the absorbance of the photoelectric conversion layer 16 compared to general-purpose adhesives used to seal solar cells. For this reason, it is preferable that the inorganic adhesive layer 20 be composed of an oxide containing one of Si and Al.

[0022] Solar cell 10 may be configured such that sunlight Ls is irradiated from, for example, the surface 22a side of sealing layer 22, photoelectric conversion occurs in photoelectric conversion layer 16, and the resulting electricity is extracted to the outside from support-side electrode 14 and sealing-layer-side electrode 18. Solar cell 10 may also be configured such that sunlight Ls is irradiated from, for example, the side opposite support 12 from support-side electrode 14, photoelectric conversion occurs in photoelectric conversion layer 16, and the resulting electricity is extracted to the outside from support-side electrode 14 and sealing-layer-side electrode 18. In this case, it is not necessary to make sealing layer 22, inorganic adhesive layer 20, organic adhesive layer 19, sealing-layer-side electrode 18, and hole transport layer 17 transparent, and support 12, support-side electrode 14, and electron transport layer 15 are transparent.

[0023] [First Example of Manufacturing Method for Solar Cell] Figures 2 to 5 are schematic cross-sectional views each showing a step of a first example of a manufacturing method for a solar cell according to an embodiment of the present invention. In Figures 2 to 5, components identical to those in the solar cell 10 shown in Figure 1 are designated by the same reference numerals, and detailed descriptions thereof will be omitted. The first example of a manufacturing method for a solar cell is a manufacturing method for the solar cell 10 shown in Figure 1. The manufacturing method for the solar cell 10 shown in Figure 1 will be described below. First, as shown in Figure 2, a first inorganic adhesive layer 26 is formed by plasma CVD on the surface 22b of the sealing layer 22 facing the sealing layer-side electrode 18 (see Figure 1). This forms a first laminate 30 having the first inorganic adhesive layer 26 on the surface 22b of the sealing layer 22 facing the sealing layer-side electrode 18 (first formation step). The first inorganic adhesive layer 26 constitutes the inorganic adhesive layer 20. In the first forming step, a first region Q corresponding to the peripheral portion 12c of the organic adhesive layer 19 in the direction Dw perpendicular to the stacking direction Ds of the laminated base material 27 is formed on the surface 22b of the sealing layer 22 facing the sealing layer side electrode 18. １ and a second region Q corresponding to the organic adhesive layer 19 ２ The first inorganic adhesive layer 26 is formed on the organic adhesive layer 19. The peripheral portion 12c of the organic adhesive layer 19 is a region on the opposite side of the end portion 19c of the organic adhesive layer 19 from the photoelectric conversion layer 16 in the direction Dw. The peripheral portion 12c of the organic adhesive layer 19 is a region on the surface 12a of the support 12.

[0024] Next, with the support 12, support-side electrode 14, electron transport layer 15, photoelectric conversion layer 16, hole transport layer 17, and sealing layer-side electrode 18 stacked in this order as shown in FIG. 3, for example, an organic resin composition that will become the organic adhesive layer 19 is applied by spin coating to the surface 18a of the sealing layer-side electrode 18 and the side surface of the photoelectric conversion section 24 to form the organic adhesive layer 19 as shown in FIG. 4. In this case, the organic adhesive layer 19 is in an uncured state, that is, in the form of a coating film. As a result, a laminated substrate 27 is prepared in which the support 12, support-side electrode 14, electron transport layer 15, photoelectric conversion layer 16, hole transport layer 17, and sealing layer-side electrode 18 are stacked in this order as shown in FIG. 4. The uncured state of the organic adhesive layer 19 refers to a state in which the adhesive has not been heated to a temperature required for curing, if the organic adhesive layer 19 is composed of a thermosetting adhesive. Furthermore, if the organic adhesive layer 19 is composed of a UV-curable adhesive, it refers to a state in which the adhesive has not been irradiated with UV light required for curing.

[0025] For example, the laminated substrate 27 can be formed as follows: For example, a support 12 is prepared, and a support-side electrode 14, an electron transport layer 15, a photoelectric conversion layer 16, a hole transport layer 17, and a sealing layer-side electrode 18 are formed in this order on the support 12 using a known method. Thereafter, an organic adhesive layer 19 is formed as described above to obtain the laminated substrate 27.

[0026] Next, a second inorganic adhesive layer 28 is formed on the laminated substrate 27 by plasma CVD to form a second laminate 32 including the second inorganic adhesive layer 28 (second formation process). As a result, as shown in FIG. 5 , a second laminate 32 is obtained in which the second inorganic adhesive layer 28 is formed on the organic adhesive layer 19 and on the surface 12a of the support 12 of the laminated substrate 27. More specifically, in the second formation process, the second inorganic adhesive layer 28 is formed on the peripheral portion 12c of the organic adhesive layer 19 and on the organic adhesive layer 19 in the direction Dw perpendicular to the stacking direction Ds of the laminated substrate 27. The second inorganic adhesive layer 28 formed in the second formation process is formed to cover the periphery of the photoelectric conversion section 24 including the photoelectric conversion layer 16, and is also formed on the end surface 16c of the photoelectric conversion layer 16 in the direction Dw perpendicular to the stacking direction Ds. The second inorganic adhesive layer 28 constitutes the inorganic adhesive layer 20.

[0027] In the second formation step, it is preferable to form the second inorganic adhesive layer 28 directly on the support 12 in the peripheral portion 12c of the organic adhesive layer 19 in the direction Dw orthogonal to the stacking direction Ds of the laminated base material 27. This allows the inorganic adhesive layer 20 to be disposed on the end portion 19c of the organic adhesive layer 19, and since the end portion 19c of the organic adhesive layer 19 is sealed with the inorganic adhesive layer 20 as described above, it is possible to prevent moisture from penetrating through the end portion 19c of the organic adhesive layer 19.

[0028] In the second forming step, the second inorganic adhesive layer 28 is formed by a plasma CVD method while the organic adhesive layer 19 is in an uncured state. In this case, the organic adhesive layer 19 is more flexible than in a cured state, and the formed second inorganic adhesive layer 28 has good conformability. Furthermore, when the first inorganic adhesive layer 26 and the second inorganic adhesive layer 28 are later laminated, the first inorganic adhesive layer 26 and the second inorganic adhesive layer 28 are well adhered to each other. For this reason, in the second forming step, it is preferable to form the second inorganic adhesive layer 28 by a plasma CVD method while the organic adhesive layer 19 is in an uncured state. Furthermore, in the second forming step, the second inorganic adhesive layer 28 is formed by a plasma CVD method while the organic adhesive layer 19 is in an uncured state. However, the present invention is not limited to this, and the second inorganic adhesive layer 28 may also be formed by a plasma CVD method while the organic adhesive layer 19 is in a cured state. In this case, the organic adhesive layer 19 is subjected to a curing treatment before forming the second inorganic adhesive layer 28. The curing treatment is a heat treatment if the adhesive of the organic adhesive layer 19 is thermosetting, or an ultraviolet irradiation treatment if the adhesive is ultraviolet-curable.

[0029] Next, the first inorganic adhesive layer 26 of the first laminate 30 and the second inorganic adhesive layer 28 of the second laminate 32 are laminated together to form the inorganic adhesive layer 20 (see FIG. 1 ) (third formation step). In the third formation step, the step of laminating the first inorganic adhesive layer 26 of the first laminate 30 and the second inorganic adhesive layer 28 of the second laminate 32 is referred to as a lamination step. The lamination step corresponds to a temporary bonding step in which temporary bonding is performed, which will be described later.

[0030] In the third forming step, for example, the surface 26 a of the first inorganic adhesive layer 26 of the first laminate 30 shown in FIG. 2 is positioned opposite the surface 28 a of the second inorganic adhesive layer 28 of the second laminate 32 shown in FIG. 5 , and the first inorganic adhesive layer 26 and the second inorganic adhesive layer 28 are laminated together. Next, the first inorganic adhesive layer 26 and the second inorganic adhesive layer 28 are heated in their laminated state to a predetermined temperature, and then, using, for example, a pressure press, the first inorganic adhesive layer 26 and the second inorganic adhesive layer 28 are pressed and bonded together to form the inorganic adhesive layer 20 (see FIG. 1 ). This results in the solar cell 10 shown in FIG. 1 . Heating is performed when forming the inorganic adhesive layer 20 (see FIG. 1 ). If the organic adhesive layer 19 is thermosetting, the heating temperature is set to a temperature equal to or higher than the temperature at which the organic adhesive layer 19 thermosets, thereby curing the organic adhesive layer 19 and entering a cured state.

[0031] In the third formation step, the first inorganic adhesive layer 26 of the first laminate 30 and the second inorganic adhesive layer 28 of the second laminate 32 are preferably laminated together within 30 seconds after the formation of the first or second laminate 32, whichever is formed first, to form an inorganic adhesive layer. By laminating the first inorganic adhesive layer 26 and the second inorganic adhesive layer 28 within 30 seconds after the formation of the first laminate, the first inorganic adhesive layer 26 and the second inorganic adhesive layer 28 are well adhered to each other. This allows the sealing layer 22 to be formed with high adhesion, preventing water penetration into the photoelectric conversion layer 16 and resulting in a solar cell in which deterioration of the properties of the photoelectric conversion layer 16 is suppressed. The resulting solar cell also has high durability.

[0032] Furthermore, it is preferable to have an activation treatment step of performing an activation treatment on at least one of the first laminate 30 and the second laminate 32 before the third formation step. By performing the activation treatment, the first inorganic adhesive layer 26 of the first laminate 30 and the second inorganic adhesive layer 28 of the second laminate 32 can be more firmly bonded. This further prevents water from penetrating the photoelectric conversion layer 16, and a solar cell can be obtained in which deterioration of the characteristics of the photoelectric conversion layer 16 is further suppressed. The obtained solar cell has even greater durability.

[0033] In the activation treatment step, for example, plasma is irradiated onto the first inorganic adhesive layer 26 of the first laminate 30 and the second inorganic adhesive layer 28 of the second laminate 32. After the activation treatment, the first inorganic adhesive layer 26 and the second inorganic adhesive layer 28 are laminated together. When the activation treatment step is performed, in the third formation step, the first inorganic adhesive layer 26 of the first laminate 30 and the second inorganic adhesive layer 28 of the second laminate 32 can be laminated together within 60 seconds after the formation of the first or second laminate 32, whichever is formed first, to form an inorganic adhesive layer. The activation treatment is also preferable because it allows for a longer time until lamination compared to when the activation treatment is not performed. To enhance the effect of the activation treatment, the activation treatment step is preferably performed in a reduced pressure atmosphere. A reduced pressure atmosphere is, for example, an atmosphere with a pressure of 100 Pa or less. The pressure is measured, for example, using a pressure gauge.

[0034] As described above, after the formation of the previously formed laminate, it is preferable to laminate the first inorganic adhesive layer 26 and the second inorganic adhesive layer 28 within 30 seconds if no activation treatment has been performed, or within 60 seconds if activation treatment has been performed. However, after lamination, the first inorganic adhesive layer 26 and the second inorganic adhesive layer 28 in a laminated state may be bonded together by heating to a predetermined temperature and applying pressure as described above if no activation treatment has been performed, or may be bonded together by applying pressure if activation treatment has been performed. Laminating the first inorganic adhesive layer 26 and the second inorganic adhesive layer 28 is temporary bonding. After temporary bonding, heating and applying pressure to bond the first inorganic adhesive layer 26 and the second inorganic adhesive layer 28 in a laminated state is final bonding. The final bonding process, which follows the temporary bonding process, is the final bonding process, which corresponds to the third forming process. The formation time by the plasma CVD method is predetermined depending on the thickness of the first laminate 30 and the second laminate 32. In the third formation process, the above-mentioned period of 30 seconds or 60 seconds after the formation of the previously formed laminate means 30 seconds or 60 seconds after the elapse of the shorter of the predetermined formation times by the plasma CVD method.

[0035] The first inorganic adhesive layer 26 and the second inorganic adhesive layer 28 constitute the inorganic adhesive layer 20 (see FIG. 1 ). Therefore, the first inorganic adhesive layer 26 and the second inorganic adhesive layer 28 are composed of the compounds that constitute the inorganic adhesive layer 20 described above. Depending on the compounds that constitute the first inorganic adhesive layer 26 and the second inorganic adhesive layer 28, the first inorganic adhesive layer 26 and the second inorganic adhesive layer 28 are formed by a known method using the above-mentioned plasma CVD method.

[0036] When a plasma irradiation device (not shown) is used in a plasma film formation device that performs a plasma CVD method to form the first inorganic adhesive layer 26 and the second inorganic adhesive layer 28, the first inorganic adhesive layer 26 and the second inorganic adhesive layer 28 can be formed with the plasma irradiation device fixed. Furthermore, when forming the first inorganic adhesive layer 26, the plasma irradiation device can be reciprocated in a direction parallel to the surface 22 b of the sealing layer 22, which is the target of film formation, and the speed of the plasma irradiation device can be controlled so that each portion of the target of film formation is irradiated with plasma for the same period of time, thereby forming the first inorganic adhesive layer 26 with a uniform film thickness. Furthermore, when forming the second inorganic adhesive layer 28, the plasma irradiation device can be reciprocated in a direction parallel to the surface 18 a of the sealing layer-side electrode 18, which is the target of film formation, and the speed of the plasma irradiation device can be controlled so that each portion of the target of film formation is irradiated with plasma for the same period of time, thereby forming the second inorganic adhesive layer 28 with a uniform film thickness. As will be described later, the first inorganic adhesive layer 26 and the second inorganic adhesive layer 28 can also be formed using, for example, an atmospheric pressure plasma jet device having a double-tube bullet nozzle.

[0037] The thicknesses of the first inorganic adhesive layer 26 and the second inorganic adhesive layer 28 are appropriately determined depending on the thickness of the inorganic adhesive layer 20 to be formed. The thicknesses of the first inorganic adhesive layer 26 and the second inorganic adhesive layer 28 can each be set to a predetermined thickness by, for example, adjusting the formation time using the plasma CVD method. Furthermore, the first inorganic adhesive layer 26 and the second inorganic adhesive layer 28 have, for example, the same composition. This results in an inorganic adhesive layer 20 composed of a compound with a single composition. As described above, the inorganic adhesive layer 20 is composed of an oxide containing one of the elements Si and Al. The same composition means that the first inorganic adhesive layer 26 and the second inorganic adhesive layer 28 are each composed of silicon oxide (SiO) or aluminum oxide (AlO). Since the first inorganic adhesive layer 26 and the second inorganic adhesive layer 28 have the same composition, the surface roughness and surface film quality of the film are equivalent, so that the surface 26a of the first inorganic adhesive layer 26 and the surface 28a of the second inorganic adhesive layer 28 are easily compatible with each other, which is preferable because it increases the adhesion between the first inorganic adhesive layer 26 and the second inorganic adhesive layer 28.

[0038] [Second Example of Solar Cell] Figure 6 is a schematic cross-sectional view showing a second example of a solar cell according to an embodiment of the present invention. In Figure 6, the same components as those in the solar cell 10 shown in Figure 1 are designated by the same reference numerals, and detailed descriptions thereof will be omitted. The solar cell 10a shown in Figure 6 differs from the solar cell 10 shown in Figure 1 in the configuration of the inorganic adhesive layer 34, but the other configurations are the same as those of the solar cell 10 shown in Figure 1, and detailed descriptions thereof will be omitted. The inorganic adhesive layer 34 has a different thickness between a peripheral portion 34c adjacent to the end 19c of the organic adhesive layer 19 and a portion 34b on the surface 19a of the organic adhesive layer 19. The inorganic adhesive layer 34 has a thickness m of the peripheral portion 34c adjacent to the end 19c of the organic adhesive layer 19. ２ is larger than the thickness m of the portion 34b on the surface 19a of the organic adhesive layer 19. １The inorganic adhesive layer 34 is thicker at the peripheral portion 34c. The inorganic adhesive layer 34 has a single-layer structure at the portion 34b and a two-layer structure at the peripheral portion 34c. The portion 34b of the inorganic adhesive layer 34 is made up of the first inorganic adhesive layer 26, and the peripheral portion 34c of the inorganic adhesive layer 34 is made up of the first inorganic adhesive layer 26 and the second inorganic adhesive layer 28. The solar cell 10a can achieve the same effects as the solar cell 10 shown in FIG. 1.

[0039] [Second Example of Manufacturing Method for Solar Cell] FIG. 7 is a schematic cross-sectional view showing a step of a second example of a manufacturing method for a solar cell according to an embodiment of the present invention. In FIG. 7, components identical to those in FIG. 5 are designated by the same reference numerals, and detailed descriptions thereof will be omitted. The second example of a manufacturing method for a solar cell is a manufacturing method for a solar cell 10a shown in FIG. 6. The manufacturing method for the solar cell 10a shown in FIG. 6 will be described below. The manufacturing method for the solar cell 10a shown in FIG. 6 differs from the first example of a manufacturing method for a solar cell described above in that, in the second formation step, as shown in FIG. 7, a second inorganic adhesive layer 28 is formed only on the peripheral portion 12c of the organic adhesive layer 19 in the direction Dw perpendicular to the stacking direction Ds of the laminated base material 27. The remaining steps are the same as those in the first example of a manufacturing method for a solar cell described above. Therefore, detailed descriptions of the manufacturing method will be omitted. Note that in FIG. 7, the second inorganic adhesive layer 28 is formed in a ring shape only on the peripheral portion 12c of the organic adhesive layer 19.

[0040] In the third forming step, for example, the surface 26a of the first inorganic adhesive layer 26 of the first laminate 30 shown in Fig. 2 is arranged opposite the surface 28a of the second inorganic adhesive layer 28 formed only on the peripheral portion 12c of the organic adhesive layer 19 of the second laminate 32 shown in Fig. 7, and the first inorganic adhesive layer 26 and the second inorganic adhesive layer 28 are laminated together. While the first inorganic adhesive layer 26 and the second inorganic adhesive layer 28 are heated in a laminated state to a predetermined temperature, the first inorganic adhesive layer 26 and the second inorganic adhesive layer 28 are pressed and bonded together using, for example, a pressure press, to form the inorganic adhesive layer 20. This results in the solar cell 10a shown in Fig. 6. In the second example manufacturing method of a solar cell, heating is also performed when forming the inorganic adhesive layer 34 (see Figure 6), but if the organic adhesive layer 19 is thermosetting, the heating temperature is set to a temperature at which the organic adhesive layer 19 thermosets or higher, causing the organic adhesive layer 19 to harden and enter a hardened state.

[0041] [Third Example of Solar Cell] Figure 8 is a schematic cross-sectional view showing a third example of a solar cell according to an embodiment of the present invention. In Figure 8, components identical to those in the solar cell 10 shown in Figure 1 are designated by the same reference numerals, and detailed descriptions thereof will be omitted. The solar cell 10b shown in Figure 8 differs from the solar cell 10 shown in Figure 1 in the configuration of the inorganic adhesive layer 36. The other components are identical to those of the solar cell 10 shown in Figure 1, and detailed descriptions thereof will be omitted. The inorganic adhesive layer 36 is formed only on the peripheral portion 12c of the organic adhesive layer 19. Although the inorganic adhesive layer 36 is shown as a single layer in Figure 8, it may have, for example, a two-layer structure, including a first inorganic adhesive layer 26 and a second inorganic adhesive layer 28. The solar cell 10b can achieve the same effects as the solar cell 10 shown in Figure 1.

[0042] [Third Example of Manufacturing Method of Solar Cell] Figure 9 is a schematic cross-sectional view showing one step of a second example of a manufacturing method of a solar cell according to an embodiment of the present invention. In Figure 9, the same components as those in Figure 2 are given the same reference numerals, and detailed description thereof will be omitted. The third example of a manufacturing method of a solar cell is a manufacturing method of a solar cell 10b shown in Figure 8. The manufacturing method of the solar cell 10b shown in Figure 8 will be described below. Compared to the first example of a manufacturing method of a solar cell described above, the manufacturing method of the solar cell 10b shown in Figure 8 differs from the first example of a manufacturing method of a solar cell in that, in the first forming step, as shown in Figure 9, on the surface 22b of the encapsulating layer 22 facing the encapsulating layer-side electrode 18, a first region Q corresponding to the peripheral portion 12c of the organic adhesive layer 19 in the direction Dw perpendicular to the stacking direction Ds of the stacked base material 27 is formed. １ 9 differs in that a first inorganic adhesive layer 26 is formed on the surface 22b of the sealing layer 22. In addition, in the second forming step, as shown in FIG. 7, a second inorganic adhesive layer 28 is formed only on the peripheral portion 12c of the organic adhesive layer 19 in the direction Dw perpendicular to the stacking direction Ds of the laminated base material 27. The remaining steps are the same as those in the first example of the method for manufacturing a solar cell described above. Therefore, a detailed description of the manufacturing method will be omitted.

[0043] In the third forming step, for example, the surface 26a of the first inorganic adhesive layer 26 of the first laminate 30 shown in Fig. 9 is arranged opposite the surface 28a of the second inorganic adhesive layer 28 formed only on the peripheral portion 12c of the organic adhesive layer 19 of the second laminate 32 shown in Fig. 7, and the first inorganic adhesive layer 26 and the second inorganic adhesive layer 28 are laminated together. While the first inorganic adhesive layer 26 and the second inorganic adhesive layer 28 are heated in their laminated state to a predetermined temperature, the first inorganic adhesive layer 26 and the second inorganic adhesive layer 28 are pressed and bonded together using, for example, a pressure press, to form the inorganic adhesive layer 20. This results in the solar cell 10b shown in Fig. 8. In the third example manufacturing method of a solar cell, heating is also performed when forming the inorganic adhesive layer 36 (see Figure 8), but if the organic adhesive layer 19 is thermosetting, the heating temperature is set to a temperature at which the organic adhesive layer 19 thermosets or higher, causing the organic adhesive layer 19 to harden and enter a hardened state.

[0044] In the third example of the manufacturing method for the solar cell, the inorganic adhesive layer 36 is formed by laminating the annular first inorganic adhesive layer 26 of the first laminate 30 shown in Fig. 9 and the annular second inorganic adhesive layer 28 of the second laminate 32 shown in Fig. 7 , but the configuration of the inorganic adhesive layer is not limited to this. For example, the inorganic adhesive layer may be formed by laminating the annular first inorganic adhesive layer 26 of the first laminate 30 shown in Fig. 9 and the second inorganic adhesive layer 28 formed on the entire surface of the organic adhesive layer 19 shown in Fig. 5 . In this case, a solar cell having a thicker peripheral portion 34c of the inorganic adhesive layer 34 can be obtained, similar to the solar cell 10a shown in Fig. 6 .

[0045] [Fourth Example of Solar Cell] Figure 10 is a schematic cross-sectional view showing a fourth example of a solar cell according to an embodiment of the present invention. In Figure 10, components identical to those in the solar cell 10 shown in Figure 1 are designated by the same reference numerals, and detailed descriptions thereof will be omitted. The solar cell 11 shown in Figure 10 differs from the solar cell 10 shown in Figure 1 in that a conductive support 13 is used instead of the support 12 and the support-side electrode 14, but otherwise has the same configuration as the solar cell 10 shown in Figure 1. The solar cell 11 has a layer structure in which the conductive support 13, the electron transport layer 15, the photoelectric conversion layer 16, the hole transport layer 17, the sealing layer-side electrode 18, the inorganic adhesive layer 20, and the sealing layer 22 are stacked in this order. The support-side electrode 14 shown in Figure 1 is absent, and the electron transport layer 15 is provided on the conductive support 13.

[0046] In the solar cell 11, for example, sunlight Ls is irradiated from the surface 22a side of the encapsulating layer 22, photoelectrically converted in the photoelectric conversion layer 16, and the resulting electricity is extracted to the outside from the conductive support 13 and the encapsulating layer-side electrode 18. The solar cell 11 differs from the above-described solar cell 10 only in that the conductive support 13 is used instead of the support 12 and the support-side electrode 14, and the same effects as those of the solar cell 10 are obtained. Furthermore, in the solar cell 11, the inorganic adhesive layer 20 may have the same configuration as the inorganic adhesive layer 34 of the solar cell 10a shown in FIG. 6 or the inorganic adhesive layer 36 of the solar cell 10b shown in FIG. 8. Furthermore, in the solar cell 11, for example, sunlight Ls may be irradiated from the side opposite the electron transport layer 15 of the conductive support 13, photoelectrically converted in the photoelectric conversion layer 16, and the resulting electricity may be extracted to the outside from the support-side electrode 14 and the encapsulating layer-side electrode 18. In this case, it is not necessary to make the sealing layer 22, the inorganic adhesive layer 20, the organic adhesive layer 19, the sealing layer-side electrode 18, and the hole transport layer 17 transparent, and only the conductive support 13 is transparent. Note that the light irradiated to the solar cells 10, 10a, 10b, and 11 is not limited to sunlight Ls.

[0047] The solar cell 11 can be manufactured in the same manner as the solar cell 10, except that the conductive support 13 is used instead of the support 12 and the support-side electrode 14 as described above. In the manufacturing method of the solar cell 11, the first and third formation steps are the same as the manufacturing method of the solar cell described above, except that the second formation step is a step of forming a second inorganic adhesive layer by plasma CVD on a laminated base material in which the conductive support 13, the photoelectric conversion layer 16, the sealing layer-side electrode 18, and the organic adhesive layer 19 are stacked in this order, thereby forming a second laminate including the second inorganic adhesive layer. Similarly to the manufacturing method of the solar cell 10 described above, in the second formation step, the second inorganic adhesive layer is preferably formed directly on the conductive support 13 in the peripheral portion 12c of the organic adhesive layer 19 in the direction Dw perpendicular to the stacking direction Ds of the laminated base material.

[0048] In the second and third exemplary solar cell manufacturing methods described above, an activation treatment is preferably performed, as in the first exemplary solar cell manufacturing method. If the activation treatment is performed, the first inorganic adhesive layer 26 and the second inorganic adhesive layer 28 are preferably laminated within 60 seconds. If the activation treatment is not performed, the first inorganic adhesive layer 26 and the second inorganic adhesive layer 28 are preferably laminated within 30 seconds. In any of the solar cell manufacturing methods described above, the order of the first and second formation steps is not particularly limited; either the first formation step or the second formation step may be performed first. The first and second formation steps can also be performed in parallel, as in a roll-to-roll process. The solar cell to be manufactured needs only to have an inorganic adhesive layer disposed at least in the peripheral portion 12c of the organic adhesive layer 19.

[0049] (Method for forming second inorganic adhesive layer) The method for forming the second inorganic adhesive layer will be described in more detail. Fig. 11 is a schematic diagram showing a first example of a method for forming a second inorganic adhesive layer according to an embodiment of the present invention. Fig. 12 is a schematic diagram showing a second example of a method for forming a second inorganic adhesive layer according to an embodiment of the present invention. In Figs. 11 and 12, the same components as those in Fig. 4 are designated by the same reference numerals, and detailed descriptions thereof will be omitted.

[0050] 5 is formed on the entire surface of the organic adhesive layer 19 of the laminated substrate 27 shown in FIG. 4. As shown in FIG. 11, the organic adhesive layer 19 of the laminated substrate 27 is rectangular when viewed from a direction perpendicular to the surface 12a of the support 12. As shown in FIG. 11, when the laminated substrate 27 is conveyed in the conveying direction D ＬAfter the support 12 is transported to a predetermined position, a nozzle 40 of a plasma film formation device (not shown) is positioned at a film formation start position S set for the organic adhesive layer 19 of the laminated substrate 27, and a second inorganic adhesive layer 28 is formed. The path and scanning speed of the nozzle 40 are predetermined according to the thickness and size of the second inorganic adhesive layer 28, and the nozzle 40 is scanned along the path to form the second inorganic adhesive layer 28. At this time, the transport speed of the support 12 and the scanning speed of the nozzle 40 are synchronized to form the second inorganic adhesive layer 28.

[0051] 7, a case will be described in which a second inorganic adhesive layer 28 is formed only on the peripheral portion 12c of the organic adhesive layer 19 of the laminated substrate 27 shown in FIG. 4. As shown in FIG. 12, the organic adhesive layer 19 of the laminated substrate 27 is quadrangular when viewed from a direction perpendicular to the surface 12a of the support 12. A film formation start position S of a nozzle 40 of a plasma film formation device (not shown) is positioned on a corner of the organic adhesive layer 19 of the laminated substrate 27. １ , S ２ , S ３ is set. １ , S ２ , S ３ The path of the nozzle 40 and the scanning speed of the nozzle 40 are determined in advance according to the thickness and size of the second inorganic adhesive layer 28. In the example shown in FIG. 12, the path is set along the four sides 19d of the organic adhesive layer 19. More specifically, the film formation start position S １ The nozzle 40 deposits a film along one side 19d from the film deposition start position S ２ The nozzle 40 deposits a film along two different sides 19d from the film deposition start position S ３ In this way, the nozzles 40 are positioned at the film formation start position S １ , S ２ , S ３ 12, the laminated substrate 27 is scanned along a path relative to the conveyance direction D to form the second inorganic adhesive layer 28. At this time, the conveyance speed of the support 12 and the scanning speed of each nozzle 40 are synchronized to form the second inorganic adhesive layer 28. As shown in FIG. ＬAfter the film is transported to a predetermined position, the film is transferred to the film formation start position S １ , S ２ , S ３ The film formation is started from the position S of the nozzle 40, and the annular second inorganic adhesive layer 28 is formed. １ , S ２ , S ３ , S ４ Alternatively, the second inorganic adhesive layer 28 may be formed using four nozzles 40 .

[0052] For example, an alignment mark (not shown) is provided on the support 12, and the alignment mark is detected to determine whether the laminated base material 27 is aligned in the transport direction D. Ｌ The laminated substrate 27 is transported by a laser beam, and it is detected that the laminated substrate 27 has reached a preset position. The timing of starting the film formation is determined, for example, by setting in advance the elapsed time from the detection of the alignment mark. The second inorganic adhesive layer 28 has been described, but the first inorganic adhesive layer 26 can also be formed in the same manner as the second inorganic adhesive layer 28, as shown in Figures 11 and 12 above. The method of forming a film by scanning the nozzle 40 along a path as shown in Figures 11 and 12 above is also called the burette method.

[0053] (Plasma Film Forming Apparatus) A plasma film forming apparatus, for example, may have a double-tube structure with coaxial nozzles. In a double-tube film forming apparatus, a source gas containing a film forming source flows through the inner tube, and a plasma-generating gas flows through the outer tube. The plasma-generating gas is converted into plasma by a discharge generated by a pair of electrodes (a ground electrode and a high-voltage electrode) arranged around the outer tube, and is then guided to a downstream outlet. The source gas is then guided to a downstream outlet via the inner tube. At the outlet, the plasma and source gas merge, causing the plasma to decompose the source gas. This decomposition promotes a reaction, generating products that are then jet-likely emitted from the outlet toward the substrate. The released products are deposited in the film formation region to form a film. Plasma refers to a gas containing charged particles, such as ions or electrons, and active species, such as radicals. For example, a plasma film forming apparatus such as that described in Japanese Patent Publication No. 7293379 may be used.

[0054] Similarly to the inorganic adhesive layer, the first inorganic adhesive layer 26 and the second inorganic adhesive layer 28 are made of an oxide containing one of Si and Al. When the oxide is silicon oxide (SiO), the atomic ratio of silicon to oxygen, O / Si, is preferably 2.5 or more and 4.0 or less. When the oxide is aluminum oxide (AlO), the atomic ratio of aluminum to oxygen, O / Al, is preferably 2.0 or more and 3.0 or less.

[0055] In the solar cell manufacturing method, for example, the first laminate 30 and the second laminate 32 are individual sheets, and the third formation process can be performed after the first formation process and the second formation process. A single sheet refers to a single sheet. In this case, the sealing layer 22 and the laminated base material 27 are each configured as a single sheet. In addition to the methods shown in FIGS. 11 and 12 , the first inorganic adhesive layer 26 and the second inorganic adhesive layer 28 can be formed using, for example, a mask. When using a mask, the support 12 is stopped at the mask position, and the first inorganic adhesive layer 26 or the second inorganic adhesive layer 28 is formed. A film formation method using a mask is called a mask method. In the mask method, the support 12 is intermittently transported to form the film. Compared to the mask method, the burette method described above is suitable for continuous processing such as roll-to-roll processing in addition to batch processing. Therefore, the burette method allows the inorganic adhesive layer to be formed while the support is continuously transported, rather than intermittently transported. It is preferable to use the roll-to-roll method because it has excellent productivity.

[0056] Furthermore, for example, the first and second forming steps can be performed by roll-to-roll, and the third forming step can be performed after the first and second forming steps. When the first and second forming steps are performed by roll-to-roll, for example, methods other than those shown in Figures 11 and 12 above can be used. For example, the first and second forming steps can be performed using an apparatus 50 shown in Figure 13. Figure 13 is a schematic diagram showing a first example of a roll-to-roll type apparatus used in manufacturing solar cells according to an embodiment of the present invention.

[0057] The device 50 includes, for example, a conveying shaft 51 around which the long sealing layer 22 is wound in a roll, a conveying roller 52 that conveys the sealing layer 22 delivered from the conveying shaft 51, a pair of rollers 56 that laminate the first laminate 30 and the second laminate 32 described below, a conveying roller (not shown) that conveys the laminate 38 formed by laminating the layers with the pair of rollers 56, and a take-up shaft (not shown) that winds up the laminate 38. Furthermore, a nozzle 40 that forms a first inorganic adhesive layer 26 (see FIG. 2 ) on the surface 22 b of the sealing layer 22 is provided between the conveying roller 52 and the pair of rollers 56. Also, for example, a conveying shaft (not shown) around which the long laminated substrate 27 is wound in a roll, and the laminated substrate 27 delivered from the conveying shaft is conveyed by the pair of rollers 56. A nozzle 40 is provided between the roller pair 56 to form a second inorganic adhesive layer 28 (see FIG. 6) on the surface 18a (see FIG. 5) of the sealing layer side electrode 18 (see FIG. 5) of the laminated substrate 27. As the nozzle 40, for example, a double-tube bullet nozzle of a plasma jet device is used.

[0058] The transport shaft 51, the transport roller 52, the roller pair 56, and the nozzle 40 are disposed in a film formation chamber 57. The film formation chamber 57 is provided with an exhaust pump 58 and a gas supply unit 59. The exhaust pump 58 reduces the pressure inside the film formation chamber 57 to a preset pressure. The exhaust pump 58 is provided with a pressure gauge or pressure sensor (not shown) that measures the pressure inside the film formation chamber 57. The gas supply unit 59 supplies a gas into the film formation chamber 57 according to the atmosphere during film formation. The gas supply unit 59 is provided with a supply amount adjustment unit (not shown), such as a valve, for adjusting the amount of gas supplied. The gas supplied by the gas supply unit 59 is a gas according to the atmosphere during film formation, such as nitrogen gas, argon gas, or helium gas.

[0059] The nozzle 40 is part of a film formation apparatus using a plasma CVD method. The plasma CVD method is performed in a dry atmosphere at atmospheric pressure, a reduced pressure atmosphere, or a nitrogen gas atmosphere. As long as the first inorganic adhesive layer 26 and the second inorganic adhesive layer 28 can be formed using the plasma CVD method as described above, the configuration is not particularly limited. A dry atmosphere is an atmosphere with a moisture content of 20 ppm or less. A reduced pressure atmosphere is an atmosphere with a pressure of 100 Pa or less. A nitrogen gas atmosphere is an atmosphere containing nitrogen gas, with an oxygen concentration of 1% or less and a moisture content of 20 ppm or less. The moisture content is measured, for example, using a quartz crystal moisture meter. The pressure is measured, for example, using a pressure gauge. The oxygen concentration is measured, for example, using an oxygen concentration meter. An atmosphere such as a reduced pressure atmosphere refers to a state within a closed space such as the film formation chamber 57. The nozzle 40 forms the first inorganic adhesive layer 26 on the surface 22b of the sealing layer 22 to form the first laminate 30. The nozzle 40 forms a second inorganic adhesive layer 28 on the organic adhesive layer 19 (see FIG. 5 ) to form a second laminate 32. For example, within 30 seconds after the formation of the first laminate, the first laminate 30 and the second laminate 32 are laminated by a pair of rollers 56 to obtain a laminate 38, and the laminate 38 is taken up in a roll on a take-up shaft. In other words, temporary bonding is performed within 30 seconds after the formation of the first laminate.

[0060] The roller pair 56 has two rollers 56a and 56b and has a function of changing the pressure between the two rollers 56a and 56b. The device 50 is provided with, for example, a conveying shaft 51, a motor (not shown) that rotates the conveying shaft and the winding shaft, and a control unit (not shown) that controls the motor. The control unit also controls the film formation by the nozzle 40 and the scanning of the nozzle 40. The control unit also enables the conveying shaft 51 to feed the sealing layer 22, the conveying shaft to feed the long laminate substrate 27, and the winding shaft to wind the laminate 38, and further enables adjustment of the timing of the above-mentioned feeding and winding.

[0061] The laminate 38 wound around the winding shaft is cut into a predetermined size, for example, and the cut piece is heated while a pressure press is used to bond the first inorganic adhesive layer 26 and the second inorganic adhesive layer 28 to obtain the solar cell 10. That is, the first inorganic adhesive layer 26 and the second inorganic adhesive layer 28 are permanently bonded to obtain the solar cell 10. In the device 50 shown in FIG. 13 , the path of the conveying shaft 51, the conveying roller 52, and the roller pair 56 is referred to as line P, and the path of the conveying shaft and the roller pair 56 is referred to as line Q. In the device 50, for example, the conveying speed of the sealing layer on line P and the conveying speed of the laminated base material on line Q are adjusted in accordance with the plasma treatment time. In the device 50, within the film-forming chamber 57, a first forming step is performed up to the roller pair 56 of the line P, a second forming step is performed up to the roller pair 56 of the line Q, and a lamination step, i.e., a temporary bonding step, is performed by the roller pair 56 to laminate the first inorganic adhesive layer 26 of the first laminate 30 and the second inorganic adhesive layer 28 of the second laminate 32. In the lines P and Q, after the first forming step and the second forming step, no pass rollers or the like are provided on the conveyance path until the lamination step to laminate the first inorganic adhesive layer 26 of the first laminate 30 and the second inorganic adhesive layer 28 of the second laminate 32 is performed. Therefore, after the first forming step and the second forming step, the first laminate 30 and the second laminate 32 are transported in a non-contact state until the lamination step of the first inorganic adhesive layer 26 of the first laminate 30 and the second inorganic adhesive layer 28 of the second laminate 32 is performed. Note that the lamination step, i.e., the main bonding step after the temporary bonding step, may be performed outside the film formation chamber 57.

[0062] Here, when forming an inorganic film using the sputtering method, etching by ions progresses, which can deteriorate the photoelectric conversion layer and reduce the photoelectric conversion rate, but this does not occur with the plasma CVD method. Furthermore, when the above-mentioned first inorganic adhesive layer 26 and second inorganic adhesive layer 28 are formed by the sputtering method, the surface is dense and the adhesion between the first inorganic adhesive layer 26 and the second inorganic adhesive layer 28 is poor.

[0063] The first and second forming steps can also be performed using an apparatus 50a shown in FIG. 14 . FIG. 14 is a schematic diagram showing a second example of a roll-to-roll type apparatus used in manufacturing solar cells according to an embodiment of the present invention. In FIG. 14 , components identical to those in the apparatus 50 shown in FIG. 13 are designated by the same reference numerals, and detailed descriptions thereof will be omitted. The apparatus 50a shown in FIG. 14 differs from the apparatus 50 shown in FIG. 13 in that it includes activation processing units 42 and 43; otherwise, the configuration is similar to that of the apparatus 50 shown in FIG. 13 . Therefore, detailed descriptions thereof will be omitted. In the apparatus 50a, an activation processing unit 42 is disposed between the nozzle 40 of line P and the roller pair 56. An activation processing unit 43 is disposed between the nozzle 40 of line Q and the roller pair 56.

[0064] The activation processing unit 42 performs an activation processing on the first laminate 30. The activation processing unit 42, for example, irradiates the first inorganic adhesive layer 26 with plasma using, for example, an inert gas as the plasma gas. The activation processing unit 43 performs an activation processing on the second laminate 32. The activation processing unit 43, for example, irradiates the first inorganic adhesive layer 26 with plasma using, for example, an inert gas as the plasma gas. The activation processing units 42, 43 can be, for example, the plasma film forming device used to form the second inorganic adhesive layer 28 described above. When a plasma film forming device is used for the activation processing, an inert gas is used as the plasma gas, and no film formation raw material gas is used. The inert gas is, for example, nitrogen gas, argon gas, or helium gas. In the apparatus 50a shown in Fig. 14, after the first inorganic adhesive layer 26 is formed, the activation treatment is performed by irradiating the first inorganic adhesive layer 26 with plasma from the activation treatment unit 42 before being transported to the roller pair 56. After the second inorganic adhesive layer 28 is formed, the activation treatment is performed by irradiating the second inorganic adhesive layer 28 with plasma from the activation treatment unit 43 before being transported to the roller pair 56. After the formation of the previously formed laminate, the first laminate 30 and the second laminate 32 are laminated by the roller pair 56 within 60 seconds to obtain the laminate 38, and the laminate 38 is wound up in a roll on a winding shaft. In other words, temporary bonding may be performed within 60 seconds after the formation of the previously formed laminate.

[0065] Each component of the solar cell will be specifically described below. (Support) The support is not particularly limited as long as it can hold the solar cell consisting of each layer formed thereon, and can be selected appropriately depending on the purpose, for example, glass, plastic film, etc. When making a flexible solar cell, the support is preferably flexible, such as a plastic film. The flexibility described above is preferably such that the photoelectric conversion characteristics are not reduced even when the solar cell is deformed by handling, heating, cooling, etc. during or after production, and is preferably bendable to a curvature radius of 2 cm or less, and more preferably bendable to a curvature radius of 1 cm or less. Note that hereinafter, flexibility is as described above.

[0066] Examples of the material of the plastic film used for the support include thermoplastic resins such as polyester resin, methacrylic resin, resin composed of methacrylic acid-maleic acid copolymer, polystyrene resin, fluororesin, polyimide resin, fluorinated polyimide resin, polyamide resin, polyamideimide resin, polyetherimide resin, cellulose acylate resin, polyurethane resin, polyether ether ketone resin, polycarbonate resin, alicyclic polyolefin resin, polyarylate resin, polyethersulfone resin, polysulfone resin, resin composed of cycloolefin copolymer, fluorene ring-modified polycarbonate resin, alicyclic ring-modified polycarbonate resin, fluorene ring-modified polyester resin, and acryloyl compound.

[0067] The plastic film preferably has heat resistance. Specifically, the heat resistance preferably satisfies at least one of the physical properties of a glass transition temperature (Tg) of 100°C or higher and a linear thermal expansion coefficient of 40 ppm / K or lower. The Tg and linear expansion coefficient of the plastic film are measured by the method for measuring the transition temperature of plastics described in JIS-K7121 and the test method for linear expansion coefficient by thermomechanical analysis of plastics described in JIS-K7197.

[0068] The Tg or linear expansion coefficient of the plastic film can be adjusted by additives, etc. Examples of such thermoplastic resins having excellent heat resistance include polyethylene naphthalate (PEN: 120°C (Tg, the same applies hereinafter)), polycarbonate (PC: 140°C), alicyclic polyolefins (for example, Zeonor 1600 (trade name), manufactured by Zeon Corporation: 160°C), polyarylate (PAr: 210°C), polyethersulfone (PES: 220°C), polysulfone (PSF: 190°C), and cycloolefins. Examples of suitable plastic films include fluorene ring-modified polycarbonate (BCF-PC: compound disclosed in JP 2000-227603 A: 225°C), alicyclic modified polycarbonate (IP-PC: compound disclosed in JP 2000-227603 A: 205°C), acryloyl compounds (compound disclosed in JP 2002-80616 A: 300°C or higher), and polyimide. Of these, polyethylene terephthalate and polyethylene naphthalate are preferred. Furthermore, a polyethylene terephthalate (PET) film can also be used as the plastic film.

[0069] The support may be transparent to light depending on the direction of light irradiation. Transparency is as described above. The thickness of the support is not particularly limited, but is, for example, 1 to 800 μm, and preferably 10 to 300 μm.

[0070] (Conductive Support) The conductive support is not particularly limited as long as it is conductive and can support the solar cell composed of the layers formed thereon. The conductive support can be made of a conductive material, such as a metal or a conductive resin. For example, an aluminum substrate is used as the conductive support. Like the support, the conductive support can also be made transparent to light depending on the direction of light irradiation. Transparency is as described above. The thickness of the conductive support is not particularly limited, but like the support, it is, for example, 1 to 800 μm, preferably 10 to 300 μm.

[0071] (Support-side electrode) This electrode is used to extract the power generated in the photoelectric conversion layer to the outside. The material of the support-side electrode is not particularly limited as long as it is conductive, and examples thereof include metals, metal oxides, conductive polymers, and mixtures thereof. Among these, conductive polymers are preferred in terms of flexibility. Examples of metals include magnesium (Mg), aluminum (Al), calcium (Ca), titanium (Ti), chromium (Cr), manganese (Mn), iron (Fe), copper (Cu), zinc (Zn), strontium (Sr), silver (Ag), indium (In), tin (Sn), barium (Ba), bismuth (Bi), and alloys thereof. Examples of metal oxides include transparent conductive oxides (TCOs) such as tin oxide, fluorine-doped tin oxide (FTO), zinc oxide, antimony-doped zinc oxide (AZO), indium oxide, indium tin oxide (ITO), indium zinc oxide (IZO), and indium tungsten oxide (IWO).

[0072] The conductive polymer is not particularly limited as long as it is a polymer compound having conductivity, and the charge carriers to be transported may be either holes or electrons. Specific examples of conductive polymers include polythiophene, polypyrrole, polyaniline, polyphenylene vinylene, polyphenylene, polyacetylene, polyquinoxaline, polyoxadiazole, polybenzothiadiazole, etc., as well as polymer compounds having multiple conductive skeletons. Among these, polythiophene is preferred, and polyethylene dioxythiophene and polythienothiophene are particularly preferred. These polythiophenes are typically partially oxidized to achieve conductivity. The electrical conductivity of conductive polymers can be adjusted by the degree of partial oxidation (doping amount), with higher doping amounts resulting in higher electrical conductivity. Polythiophenes become cationic upon partial oxidation, requiring counter anions to neutralize the charge. An example of such a polythiophene is polyethylene dioxythiophene (PEDOT-PSS) with polystyrene sulfonic acid as the counter ion. As the conductive polymer, for example, the conductive polymer described in JP 2015-191916 A can be used. The support-side electrode is preferably transparent to light, similar to the support. Transparency is as described above. The film thickness of the support-side electrode is not particularly limited, and is preferably, for example, 0.01 to 30 μm. The layer structure of the support-side electrode is not particularly limited, and may be a single-layer structure, a laminated structure, or the like.

[0073] (Electron Transport Layer) The electron transport layer has the function of transporting electrons generated in the photoelectric conversion layer to the support-side electrode or the conductive support. The electron transport layer is formed of an electron transport material capable of transporting electrons. The electron transport material is not particularly limited, but an organic material (organic electron transport material) is preferred. Examples of organic electron transport materials include fullerene compounds such as [6,6]-phenyl-C61-butylic acid methyl ester (PC61BM), perylene compounds such as perylene tetracarboxylic diimide (PTCDI), and other low-molecular-weight compounds such as tetracyanoquinodimethane (TCNQ), or polymer compounds. The film thickness of the electron transport layer is not particularly limited, but is preferably 0.001 to 10 μm, and more preferably 0.01 to 1 μm.

[0074] (Photoelectric Conversion Layer) The photoelectric conversion layer has a photoelectric conversion function and obtains electricity from incident light. The photoelectric conversion layer contains a perovskite compound. The perovskite compound is a compound having a perovskite crystal structure. The compound having a perovskite crystal structure is not particularly limited. For example, the perovskite compounds described in International Publication No. 2019 / 053967, JP 2017-17166 A, and JP 2015-191916 A can be used in the photoelectric conversion layer. The method for forming the photoelectric conversion layer is not particularly limited, and examples include vacuum deposition, sputtering, gas phase reaction methods such as CVD, electrochemical deposition, and printing. In particular, by employing the printing method, solar cells can be easily formed over a large area. Examples of printing methods include spin coating and casting, and when using the printing method, a roll-to-roll method can be used. The thickness of the photoelectric conversion layer is not particularly limited, but is preferably, for example, 0.001 to 100 μm, more preferably 0.01 to 10 μm, and particularly preferably 0.01 to 5 μm.

[0075] (Hole Transport Layer) The hole transport layer has the function of replenishing electrons to the oxidized product of the photoelectric conversion layer and is preferably a solid layer (solid hole transport layer). The hole transport material forming the hole transport layer may be a liquid material or a solid material, and is not particularly limited. Examples include inorganic materials such as CuI and CuNCS, and organic hole transport materials described in paragraphs 0209 to 0212 of JP 2001-291534 A. Examples of organic hole transport materials include low-molecular-weight compounds such as aniline, thiophene, pyrrole, and aromatic amine compounds. Other examples of organic hole transport materials include conductive polymers such as polythiophene, polyaniline, polypyrrole, and polysilane; spiro compounds in which two rings share a central atom having a tetrahedral structure such as C or Si; aromatic amine compounds such as triarylamine; triphenylene compounds; nitrogen-containing heterocyclic compounds; and liquid crystalline cyano compounds. The hole transport material is preferably an organic hole transport material that can be applied as a solution and becomes a solid, and specific examples thereof include 2,2',7,7'-tetrakis-(N,N-di-p-methoxyphenylamino)-9,9'-spirobifluorene (also referred to as spiro-MeOTAD), poly(3-hexylthiophene-2,5-diyl), 4-(diethylamino)benzaldehyde diphenylhydrazone, polyethylenedioxythiophene (PEDOT), etc. As the hole transport material for forming the hole transport layer, for example, the materials used for the hole transport layer described in WO 2019 / 053967, JP 2017-17166 A, and JP 2015-191916 A can be used.

[0076] The thickness of the hole transport layer is not particularly limited, and is preferably 50 μm or less, more preferably 1 nm to 10 μm, even more preferably 5 nm to 5 μm, and particularly preferably 10 nm to 1 μm. The thickness of the hole transport layer corresponds to the average distance between the sealing layer side electrode 18 and the photoelectric conversion layer 16 in the stacking direction Ds shown in FIG. 1 . Regarding the thickness of the hole transport layer, a cross-sectional image of the solar cell is obtained using a scanning electron microscope (SEM) or the like, and 10 locations corresponding to the distance between the sealing layer side electrode 18 and the photoelectric conversion layer 16 in the stacking direction Ds are selected from the cross-sectional image. The length of each of the selected 10 locations on the cross-sectional image is measured to obtain length values ​​at the 10 locations. The average of the length values ​​at the 10 locations is calculated, and this average value is used as the thickness of the hole transport layer.

[0077] (Sealing layer-side electrode) The sealing layer-side electrode functions as a positive electrode in the solar cell. The sealing layer-side electrode is not particularly limited as long as it is conductive. The structure of the sealing layer-side electrode is preferably a structure with a high current collection effect. In order for light to reach the photoelectric conversion layer, at least one of the support or conductive support and the sealing layer-side electrode needs to be transparent to light. Transparency is as described above. In a solar cell, when the support or conductive support is transparent to light and sunlight or the like is incident from the support or conductive support side, it is preferable that the sealing layer-side electrode has a property of reflecting light.

[0078] Examples of materials for forming the sealing layer side electrode include metals such as platinum (Pt), gold (Au), nickel (Ni), copper (Cu), silver (Ag), indium (In), ruthenium (Ru), palladium (Pd), rhodium (Rh), iridium (Ir), osnium (Os), and aluminum (Al), the above-mentioned conductive metal oxides, carbon materials, and conductive polymers. Carbon materials may be any conductive material formed by bonding carbon atoms, such as fullerenes, carbon nanotubes, graphite, and graphene. The sealing layer side electrode may be a thin film (including a thin film formed by vapor deposition) of a metal or a conductive metal oxide, or a glass or plastic substrate having such a thin film. The glass or plastic substrate is preferably glass having a thin film of gold or platinum, or glass having platinum vapor-deposited thereon. The thickness of the sealing layer side electrode is not particularly limited, but is preferably 0.01 to 100 μm, more preferably 0.01 to 10 μm, and particularly preferably 0.01 to 1 μm.

[0079] (Organic Adhesive Layer) The organic adhesive layer is provided between the sealing layer and the sealing layer-side electrode, and adheres the sealing layer to the sealing layer-side electrode and the photoelectric conversion section, thereby fixing the sealing layer to the sealing layer-side electrode and the photoelectric conversion section. The organic adhesive layer is composed of, for example, a cured product of an acrylic resin, a cured product of an epoxy resin, or a cured product of a urethane resin. Any known material can be used as the cured product of the acrylic resin, as long as it is a cured product of a monomer or oligomer having an acrylic group in the molecule, and any known material can be used as the cured product of the epoxy resin, as long as it is a cured product of a monomer or oligomer having an epoxy group in the molecule.

[0080] Examples of epoxy resins include water-dispersed, solvent-free, solid, heat-curable, curing agent-mixed, and ultraviolet-curable resins. Of these, heat-curable and ultraviolet-curable resins are preferred, with ultraviolet-curable resins being more preferred. Even with ultraviolet-curable resins, heating is possible, and it is preferable to heat the resins even after UV curing. Specific examples of epoxy resins include bisphenol A, bisphenol F, novolac, cyclic aliphatic, long-chain aliphatic, glycidyl amine, glycidyl ether, and glycidyl ester resins. These may be used alone or in combination of two or more. It is also preferable to mix a curing agent or various additives into the epoxy resin as needed. As the epoxy resin, commercially available epoxy resin compositions can be used.

[0081] The curing agent is not particularly limited and can be appropriately selected depending on the purpose. Examples include amine-based, acid anhydride-based, polyamide-based, and other curing agents. Examples of amine-based curing agents include aliphatic polyamines such as diethylenetriamine and triethylenetetramine, and aromatic polyamines such as metaphenylenediamine, diaminodiphenylmethane, and diaminodiphenylsulfone. Examples of acid anhydride-based curing agents include phthalic anhydride, tetrahydrophthalic anhydride and hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylnadic anhydride, pyromellitic anhydride, PEG-4 anhydride, and dodecenyl succinic anhydride. Other curing agents include imidazoles and polymercaptan. These may be used alone or in combination of two or more. It is also preferable to mix a curing agent or various additives with the epoxy resin as needed. Commercially available epoxy resin compositions can be used.

[0082] The additives are not particularly limited and can be selected appropriately depending on the purpose. Examples include fillers, gap agents, polymerization initiators, desiccants (moisture absorbers), curing accelerators, coupling agents, flexibilizers, colorants, flame retardant aids, antioxidants, and organic solvents. Among these, fillers, gap agents, curing accelerators, polymerization initiators, and desiccants (moisture absorbers) are preferred, and fillers and polymerization initiators are more preferred. The inclusion of a filler as an additive can suppress the penetration of moisture and oxygen, and can also provide effects such as reduced volumetric shrinkage during curing, reduced outgassing during curing or heating, improved mechanical strength, and control of thermal conductivity and fluidity. Therefore, including a filler as an additive is very effective in maintaining stable output in various environments. The organic adhesive layer is formed using, for example, a thermosetting epoxy resin or an ultraviolet-curing epoxy resin. A solventless epoxy resin can also be used for the organic adhesive layer.

[0083] (Inorganic adhesive layer) This is provided between the sealing layer and the organic adhesive layer, and serves to adhere the sealing layer and fix it to the organic adhesive layer. The compound constituting the inorganic adhesive layer is as described above. The inorganic adhesive layer preferably has a thickness of 0.3 to 15 nm, since this provides excellent moisture resistance, moist heat resistance, and adhesion of the inorganic adhesive layer. Therefore, the total thickness of the first inorganic adhesive layer and the second inorganic adhesive layer is preferably 0.3 to 15 nm. In addition, the thickness D of the first inorganic adhesive layer 26 is preferably 0.3 to 15 nm. １ (see FIG. 2) and the thickness D of the second inorganic adhesive layer 28 ２ (see FIG. 7 ) is the same, the adhesive strength of the inorganic adhesive layer is high. １ (see FIG. 2) and the thickness D of the second inorganic adhesive layer 28 ２ (see FIG. 7) are preferably the same.

[0084] The thickness D of the first inorganic adhesive layer 26 １ and the thickness D of the second inorganic adhesive layer 28 ２ The thickness direction Dt of the first inorganic adhesive layer 26 and the second inorganic adhesive layer 28 is measured by using a scanning electron microscope.１ and the thickness D of the second inorganic adhesive layer 28 ２ The average value of each of the 10 points is determined as the thickness D of the first inorganic adhesive layer 26. １ and the thickness D of the second inorganic adhesive layer 28 ２ Let's say.

[0085] The inorganic adhesive layer, i.e., the first inorganic adhesive layer and the second inorganic adhesive layer, are formed by the plasma CVD method as described above. For example, when the compound constituting the inorganic adhesive layer is silicon oxide (SiO), it is formed by the plasma CVD method using tetraethoxysilane (TEOS). When the compound constituting the inorganic adhesive layer is aluminum oxide (AlO), it is formed by the plasma CVD method using trimethylaluminum. The inorganic adhesive layer is composed of the first inorganic adhesive layer and the second inorganic adhesive layer. Therefore, the thickness of the inorganic adhesive layer is, for example, the thickness D of the first inorganic adhesive layer 26. １ (see FIG. 2) and the thickness D of the second inorganic adhesive layer 28 ２ (See FIG. 7) The thickness D of the first inorganic adhesive layer 26 can be changed by adjusting the thickness D of the first inorganic adhesive layer 26. １ (see FIG. 2) and the thickness D of the second inorganic adhesive layer 28 ２ (See FIG. 7) is adjusted by the formation time by the plasma CVD method.

[0086] (Sealing Layer) The sealing layer is intended to protect the solar cell. The sealing layer is provided to prevent substances that deteriorate the photoelectric conversion layer, such as water and oxygen, from penetrating into the photoelectric conversion layer. Examples of the sealing layer include a film of silicon or aluminum oxide, nitride, or nitride oxide formed on a PET (polyethylene terephthalate) film or a PEN film. The sealing layer may have a surface functional layer on the side opposite the photoelectric conversion layer, as needed. Examples of the surface functional layer include a matting agent layer, an anti-reflection layer, a hard coat layer, an anti-fogging layer, an anti-fouling layer, and an easy-adhesion layer. In addition, the surface functional layer is described in detail in JP 2006-289627 A.

[0087] (Other Configurations) The solar cell is not limited to the configuration described above, and may have, for example, a configuration having a blocking layer (not shown) and a porous layer (not shown) between the support-side electrode or the conductive support and the photoelectric conversion layer. In this case, the support-side electrode or the conductive support, the blocking layer, the porous layer, and the photoelectric conversion layer are stacked in this order.

[0088] (Blocking Layer) In a solar cell, for example, a reverse current occurs when the photoelectric conversion layer or the hole transport layer is electrically connected to the support-side electrode or the like. The blocking layer functions to prevent this reverse current. The blocking layer is also called a short-circuit prevention layer. The blocking layer can also function as a scaffold for supporting the photoelectric conversion layer.

[0089] The material forming the blocking layer is not particularly limited as long as it can fulfill the above-mentioned function. It is preferable that the material transmits light in the wavelength range of 400 to 800 nm and is insulating against the support-side electrode, the conductive support, and the like. Specifically, the "insulating material against the support-side electrode and the conductive support" refers to a compound (n-type semiconductor compound) whose conduction band energy level is equal to or higher than the conduction band energy level of the material forming the support-side electrode and the conductive support, and lower than the conduction band energy level of the material forming the porous layer and the ground state energy level of the material forming the photoelectric conversion layer. Examples of materials forming the blocking layer include silicon oxide, magnesium oxide, aluminum oxide, calcium carbonate, cesium carbonate, polyvinyl alcohol, and polyurethane. Materials commonly used in photoelectric conversion materials may also be used, such as titanium oxide, tin oxide, zinc oxide, niobium oxide, and tungsten oxide. Among these, titanium oxide, tin oxide, magnesium oxide, and aluminum oxide are preferred. The thickness of the blocking layer is not particularly limited, but is preferably 0.001 to 10 μm, more preferably 0.005 to 1 μm, and particularly preferably 0.01 to 0.1 μm.

[0090] (Porous Layer) The porous layer is provided between the blocking layer and the photoelectric conversion layer. The porous layer functions as a scaffold supporting the photoelectric conversion layer. In order to increase the light absorption efficiency of a solar cell, it is preferable to increase the surface area of ​​at least the portion that receives light such as sunlight, and it is also preferable to increase the overall surface area of ​​the porous layer.

[0091] The porous layer is preferably a microparticle layer having pores, in which microparticles of the material forming the porous layer are deposited or adhered to each other. The porous layer may also be a microparticle layer formed by depositing two or more types of microparticles. When the porous layer is a microparticle layer having pores, the amount of light absorber carried (adsorbed) can be increased. To increase the surface area of ​​the porous layer, it is preferable to increase the surface area of ​​each microparticle constituting the porous layer. When the microparticles forming the porous layer are coated on a support-side electrode, a conductive support, or the like, the surface area of ​​the microparticles is preferably 10 times or more, more preferably 100 times or more, the projected area. There is no particular upper limit, but it is usually about 5,000 times. The particle size of the microparticles forming the porous layer is preferably 0.001 to 1 μm as primary particles, in terms of the average particle size calculated by converting the projected area into the diameter of a circle. When the porous layer is formed using a dispersion of microparticles, the average particle size of the microparticles is preferably 0.01 to 100 μm as the average particle size of the dispersion.

[0092] The material constituting the porous layer is not particularly limited in terms of conductivity, and may be an insulator (insulating material), a conductive material, or a semiconductor (semiconductive material). Examples of materials that can be used to constitute the porous layer include metal chalcogenides (e.g., oxides, sulfides, selenides, etc.), compounds having a perovskite crystal structure (excluding perovskite compounds used as light absorbers), silicon oxides (e.g., silicon dioxide, zeolite), and carbon nanotubes (including carbon nanowires and carbon nanorods, etc.).

[0093] The metal chalcogenide is not particularly limited, and preferred examples include oxides of titanium, tin, zinc, tungsten, zirconium, hafnium, strontium, indium, cerium, yttrium, lanthanum, vanadium, niobium, aluminum, or tantalum, cadmium sulfide, cadmium selenide, etc. The crystal structure of the metal chalcogenide may be anatase, brookite, or rutile, with anatase and brookite being preferred.

[0094] The compound having a perovskite crystal structure is not particularly limited, and examples thereof include transition metal oxides. Examples include strontium titanate, calcium titanate, barium titanate, lead titanate, barium zirconate, barium stannate, lead zirconate, strontium zirconate, strontium tantalate, potassium niobate, bismuth ferrate, strontium barium titanate, barium lanthanum titanate, calcium titanate, sodium titanate, and bismuth titanate. Among these, strontium titanate and calcium titanate are preferred.

[0095] The material forming the porous layer is preferably an oxide of titanium, tin, zinc, zirconium, aluminum, or silicon, or carbon nanotubes, with titanium oxide or aluminum oxide being more preferred. The porous layer may be formed of at least one of the above-mentioned metal chalcogenides, compounds having a perovskite crystal structure, silicon oxides, and carbon nanotubes, or may be formed of a plurality of materials. The thickness of the porous layer is not particularly limited and is typically in the range of 0.05 to 100 μm, preferably 0.1 to 100 μm. When used as a solar cell, the thickness is preferably 0.1 to 50 μm, more preferably 0.2 to 30 μm. Regarding the thickness of the layers constituting the solar cell, unless otherwise specified, a scanning electron microscope is used to obtain a cross-sectional image of the solar cell in the stacking direction Ds, and 10 points corresponding to the thickness of each layer are measured. The average value of each of the 10 points is taken as the thickness of each layer constituting the solar cell.

[0096] The present invention is basically configured as described above. Although the method for manufacturing a solar cell of the present invention has been described in detail above, the present invention is not limited to the above-described embodiment, and various improvements and modifications may be made without departing from the spirit and scope of the present invention.

[0097] The features of the present invention will be described in more detail below with reference to examples. The materials, reagents, amounts of substances and their ratios, and procedures shown in the following examples can be modified as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the following examples. In these examples, solar cells of Examples 1 to 14 and Comparative Examples 1 and 2 were fabricated and evaluated for moisture resistance, moist heat resistance, and adhesion. The structures of the solar cells of Examples 1 to 14 and Comparative Examples 1 and 2 are shown in Table 1 below. The evaluation results of moisture resistance, moist heat resistance, and adhesion are shown in Table 2 below. The solar cells of Examples 1 to 14 and Comparative Examples 1 and 2 will now be described.

[0098] Example 1 Example 1 is a solar cell having the configuration shown in FIG. 1. <Preparation of Support Side Electrode / Support> A glass substrate having a thickness of 2 mm was used as the support. Fluorine-doped SnO was formed on the glass substrate as the support side electrode. ２ A conductive film (thickness: 300 nm) was formed. Fluorine-doped SnO ２ The conductive film, that is, the fluorine-doped tin oxide (FTO) conductive film, is a transparent conductive film. A support-side electrode formed on a support is called a support-side electrode / support.

[0099] <Preparation of Blocking Layer Solution> A 15% by mass isopropanol solution of titanium diisopropoxide bis(acetylacetonate) (manufactured by Aldrich) was diluted with 1-butanol to prepare a 0.02 M blocking layer solution. <Formation of Blocking Layer> Using the prepared 0.02 M blocking layer solution, a SnO film of the support side electrode / support was formed by spray pyrolysis at 450°C. ２ A blocking layer (thickness: 50 nm) made of titanium oxide was formed on the conductive film.

[0100] <Preparation of titanium oxide paste> Ethyl cellulose, lauric acid, and terpineol were added to an ethanol dispersion of titanium oxide (anatase, average particle size 20 nm) to prepare a titanium oxide paste. <Formation of porous layer> The prepared titanium oxide paste was applied onto the blocking layer by screen printing and fired in air at 500°C for 3 hours. Thereafter, the obtained fired titanium oxide body was heated in a 40 mM TiCl ４ After immersion in the aqueous solution, the sample was heated at 60°C for 1 hour and then at 500°C for 30 minutes to form TiO ２ A porous layer (thickness: 250 nm) made of TiO was formed. The porous layer corresponds to an electron transport layer. <Formation of photoelectric conversion layer> Lead iodide was dissolved in N,N-dimethylformamide to prepare a 1 M solution. ２ A film was formed on a porous layer made of lead iodide by spin coating. Furthermore, methylammonium iodide was dissolved in 2-propanol to prepare a 1M solution. The sample on which the lead iodide film was formed was immersed in this solution, and CH ３ NH ３ PbI ３ A photoelectric conversion layer made of the organic-inorganic perovskite compound was obtained. After that, an annealing treatment was carried out at 120° C. for 30 minutes.

[0101] <Preparation of Hole Transport Material Solution> Spiro-OMeTAD (180 mg) was dissolved in chlorobenzene (1 mL) as a hole transport material. To this chlorobenzene solution, 37.5 μL of an acetonitrile solution prepared by dissolving 170 mg of lithium bis(trifluoromethanesulfonyl)imide (1 mL) in acetonitrile was added, and 17.5 μL of t-butylpyridine (TBP) was added and mixed to prepare a hole transport material solution. <Formation of Hole Transport Layer> The hole transport material solution was applied to the photoelectric conversion layer by spin coating, and the applied hole transport material solution was dried to form a hole transport layer (film thickness 0.1 μm).

[0102] <Preparation of sealing layer side electrode> Gold was deposited on the hole transport layer by vacuum deposition to prepare a sealing layer side electrode (film thickness 100 nm). <Formation of organic adhesive layer> As an adhesive, 1.0 g of hydrotalcite and Epoch Corporation's epoxy resin (E-01-001 base: 4.0 g, curing agent: 2.0 g) were mixed and applied to the surface of the sealing layer side electrode and the side of the photoelectric conversion unit using a spin coating method. In this way, a laminated substrate having a layer structure of organic adhesive layer / sealing layer side electrode / hole transport layer / photoelectric conversion layer / electron transport layer / support side electrode / support was obtained.

[0103] <Preparation of First Laminate> A PET (polyethylene terephthalate) film (Barrierox manufactured by Toray Industries, Inc.) with aluminum oxide vapor-deposited on the sealing layer was used. Plasma was irradiated onto the surface of the sealing layer from a plasma irradiation device described below under the following conditions, and a silicon oxide (SiO) layer with a film thickness of 7 nm was formed as a first inorganic adhesive layer on the surface of the sealing layer in 14 seconds by plasma CVD, thereby obtaining a first laminate. When forming the first inorganic adhesive layer, the plasma irradiation device was scanned along a predetermined path relative to the surface of the sealing layer. The speed of the plasma irradiation device was controlled to form a first inorganic adhesive layer with a film thickness of 7 nm on each portion of the surface of the sealing layer.

[0104] <Preparation of Second Laminate> The surface of the laminated substrate was irradiated with plasma from a plasma irradiation device described below under the following conditions, and a silicon oxide (SiO ) layer with a film thickness of 7 nm was formed as a second inorganic adhesive layer on the surface of the second laminate by plasma CVD in 14 seconds to obtain a second laminate. When forming the second inorganic adhesive layer, the plasma irradiation device was scanned along a predetermined path relative to the surface of the laminated substrate. At this time, the speed of the plasma irradiation device was controlled to form a second inorganic adhesive layer with a film thickness of 7 nm on each portion of the surface of the laminated substrate. In Example 1, the first inorganic adhesive layer and the second inorganic adhesive layer were formed on the entire surface, so the column for "Form of inorganic adhesion" in Table 1 below states "over the entire surface."

[0105] (Plasma irradiation device) Atmospheric pressure plasma jet device (burette nozzle double tube type) Double tube structure: outer diameter of outer tube 15 mm, outer diameter of inner tube 8 mm Copper electrode placed on the outside of the outer tube Peak voltage: 11 kV Pulse width: 5 microseconds Bipolar pulse: 30 kHz Gas flowing through outer tube: helium gas (plasma generating gas, flow rate: 10 L / min) Gas flowing through inner tube: tetraethoxysilane (also known as TEOS, flow rate: 2 mg / min), oxygen gas (flow rate: 25 mL / min), nitrogen gas (flow rate: 500 mL / min) Treatment time: 14 seconds

[0106] <Activation Treatment> After forming the first inorganic adhesive layer and the second inorganic adhesive layer, activation treatment was performed on the surface of the first inorganic adhesive layer of the first laminate and the surface of the second inorganic adhesive layer of the second laminate. The activation treatment was performed by irradiating plasma for 10 seconds from an activation treatment device described below under the following conditions.

[0107] (Activation treatment device) Atmospheric pressure plasma jet device (burette nozzle double tube type) Double tube structure: outer diameter of outer tube 15 mm, outer diameter of inner tube 8 mm Copper electrode placed on the outside of the outer tube Peak voltage: 11 kV Pulse width: 5 microseconds Bipolar pulse: 30 kHz Gas flowing through outer tube: helium gas (plasma generating gas, flow rate: 10 L / min) Gas flowing through inner tube: oxygen gas (flow rate: 25 mL / min), nitrogen gas (flow rate: 500 mL / min) Treatment time: 10 seconds

[0108] <Lamination of the first laminate and the second laminate> 60 seconds after the activation treatment of the first laminate and the second laminate, the first inorganic adhesive layer of the first laminate and the second inorganic adhesive layer of the second laminate were laminated. Next, they were laminated using a pressure press while heated to 100 ° C. to form a silicon oxide (SiO ) layer with a thickness of 14 nm as an inorganic adhesive layer, thereby obtaining a solar cell. The pressure applied to the laminate of the first laminate and the second laminate by the pressure press was 20 MPa. The thickness of the inorganic adhesive layer in the solar cell was 14 nm. By laminating using the pressure press while heating to 100 ° C., the epoxy resin changed from an uncured state to a cured state.

[0109] (Example 2) In Example 2, the first inorganic adhesive layer is formed in a first region Q corresponding to the periphery of the organic adhesive layer. １ (See FIG. 2 ) and formed in a ring shape with a thickness of 7 nm and a width of 10 mm. Furthermore, the second inorganic adhesive layer was formed in a ring shape with a thickness of 7 nm and a width of 10 mm on the peripheral portion 12c of the organic adhesive layer 19, except that the same was true for Example 1. In Example 2, the first inorganic adhesive layer was formed in a ring shape, and the second inorganic adhesive layer was formed in a ring shape, so the column for "Form of inorganic adhesion" in Table 1 below states "ring-shaped." (Example 3) Example 3 was the same as Example 1, except that the activation treatment was not performed, and the first inorganic adhesive layer of the first laminate and the second inorganic adhesive layer of the second laminate were laminated 60 seconds after the first laminate or the second laminate was produced.

[0110] (Example 4) Example 4 was the same as Example 2, except that no activation treatment was performed, and the first inorganic adhesive layer of the first laminate and the second inorganic adhesive layer of the second laminate were laminated 60 seconds after the first laminate or the second laminate was prepared first.

[0111] Example 5 was the same as Example 1, except that the second inorganic adhesive layer was formed after the epoxy resin constituting the organic adhesive layer was cured. In Example 5, the epoxy resin was heated to 100°C and cured.

[0112] Example 6 Example 6 was the same as Example 1, except that the second inorganic adhesive layer was formed in a ring shape with a thickness of 7 nm and a width of 10 mm on the peripheral portion 12c of the organic adhesive layer 19. In Example 6, the first inorganic adhesive layer was formed on the entire surface, and the second inorganic adhesive layer was formed in a ring shape, so the column for "Form of inorganic adhesion" in Table 1 below states "Full surface + ring-shaped."

[0113] (Example 7) Example 7 was the same as Example 1, except that the first inorganic adhesive layer was formed to a thickness of 10 nm, and further, the second inorganic adhesive layer was formed to a thickness of 10 nm. In Example 7, a silicon oxide (SiO) layer with a thickness of 20 nm was formed as the inorganic adhesive layer to obtain a solar cell. (Example 8) Example 8 was the same as Example 1, except that the first inorganic adhesive layer was formed to a thickness of 5 nm, and further, the second inorganic adhesive layer was formed to a thickness of 9 nm. In Example 8, the thickness of the first inorganic adhesive layer and the thickness of the second inorganic adhesive layer were different.

[0114] Example 9 Example 9 was the same as Example 1, except that tetraethoxysilane (TEOS) was changed to trimethylaluminum and the inorganic adhesive layer was an AlO (aluminum oxide) layer. Example 10 Example 10 was the same as Example 2, except that tetraethoxysilane (TEOS) was changed to trimethylaluminum and the inorganic adhesive layer was an AlO (aluminum oxide) layer.

[0115] (Example 11) Example 11 was the same as Example 1, except that, among the first laminate and the second laminate that had been subjected to activation treatment, the first inorganic adhesive layer of the first laminate and the second inorganic adhesive layer of the second laminate were laminated 70 seconds after the first laminate had been subjected to activation treatment.

[0116] (Example 12) Example 12 was the same as Example 3, except that, among the first laminate and the second laminate that had been subjected to activation treatment, the first inorganic adhesive layer of the first laminate and the second inorganic adhesive layer of the second laminate were laminated 30 seconds after the first laminate was formed. (Example 13) Example 13 was the same as Example 3, except that the first laminate was laminated in the first region Q corresponding to the periphery of the organic adhesive layer. １ (See FIG. 2 ) in a ring shape with a thickness of 7 nm and a width of 10 mm. In Example 13, the first inorganic adhesive layer was formed in a ring shape, and the second inorganic adhesive layer was formed over the entire surface, so the column for “Form of inorganic adhesion” in Table 1 below states “ring shape + entire surface.”

[0117] Example 14 Example 14 is a solar cell having the configuration shown in Fig. 10. Example 14 was the same as Example 1 except that an aluminum substrate (thickness 0.5 mm) was used as the conductive support instead of the support-side electrode / support of Example 1.

[0118] (Comparative Example 1) Comparative Example 1 was the same as Example 1 except that the first inorganic adhesive layer and the second inorganic adhesive layer were not formed. In Comparative Example 1, a sealing layer was attached directly to the organic adhesive layer, and heated at 80°C for 1 hour to harden the epoxy resin that constitutes the organic adhesive layer, thereby forming a solar cell. (Comparative Example 2) Comparative Example 2 was the same as Example 1 except that the first inorganic adhesive layer and the second inorganic adhesive layer were formed using a sputtering method.

[0119] The evaluation items of moisture resistance, moist heat resistance, and adhesion are explained below. <Moisture Resistance> Three solar cells were fabricated for each of the above-mentioned Examples 1 to 14 and Comparative Examples 1 and 2. A cell characteristics test was performed on each of the three solar cells to measure the current. The average value of the three was then taken as the initial current for each of Examples 1 to 14 and Comparative Examples 1 and 2. The cell characteristics test was performed using a solar simulator "WXS-85H" (manufactured by WACOM Corporation) and a 1000 W / m ray irradiated from a xenon lamp passed through an AM (Air Mass) 1.5 filter. ２The test was performed by irradiating the solar cell with simulated sunlight from the sealing layer side. In the cell characteristic test, the current-voltage characteristics were measured using an I-V tester, and the initial photoelectric conversion efficiency (η (%)) was determined. Three solar cells from each of Examples 1 to 14 and Comparative Examples 1 and 2 were each stored in a constant temperature and humidity chamber at a temperature of 25°C and a humidity of 60% RH (Relative Humidity) for 24 hours, and then the above-mentioned cell characteristic test was performed to measure the photoelectric conversion efficiency (η (%)). The average value of the three solar cells was taken as the photoelectric conversion efficiency (η (%)) after storage for each of Examples 1 to 14 and Comparative Examples 1 and 2. The moisture resistance of the solar cell was evaluated according to the following evaluation criteria from the rate of decrease in photoelectric conversion efficiency calculated by the following formula: Decrease rate (%) = 100 - {100 x (photoelectric conversion efficiency after storage) / (initial photoelectric conversion efficiency)} - Moisture resistance evaluation criteria - A: Decrease rate is less than 10% B: Decrease rate is 10% or more and less than 20% C: Decrease rate is 20% or more and less than 30% D: Decrease rate is 30% or more

[0120] <Moisture and Heat Resistance> Three solar cells were fabricated for each of the above-mentioned Examples 1 to 14 and Comparative Examples 1 and 2. A cell characteristic test was performed on each of the three solar cells, and the current was measured. The average value of the three was then taken as the initial current for each of Examples 1 to 14 and Comparative Examples 1 and 2. The cell characteristic test was performed using a solar simulator "WXS-85H" (manufactured by WACOM Corporation), with a 1000 W / m irradiance from a xenon lamp passed through an AM1.5 filter. ２ The test was carried out by irradiating the sealing layer side with simulated sunlight. The current-voltage characteristics were measured using an I-V tester. Three solar cells from each of Examples 1 to 14 and Comparative Examples 1 and 2 were each left to stand in a constant temperature and humidity chamber at 60% RH and 45°C for 80 hours, and then the above-mentioned battery characteristic test was carried out to measure the current. The average value of the three was taken as the current after standing for each of Examples 1 to 14 and Comparative Examples 1 and 2. The moist heat resistance of the solar cells was evaluated according to the following evaluation criteria using the rate of decrease in current calculated by the following formula: Rate of decrease (%) = [(initial current - current after standing) / (initial current)] × 100 - Moisture and heat resistance evaluation criteria - A: Rate of decrease less than 10% B: Rate of decrease 10% or more but less than 20% C: Rate of decrease 20% or more but less than 30% D: Rate of decrease 30% or more

[0121] (Adhesion) In the solar cells of Examples 1 to 14 and Comparative Examples 1 and 2 described above, when the second inorganic adhesive layer was formed on the surface of the laminated substrate, a PET film 50 mm wide x 10 mm long was sandwiched between the ends of the laminated substrate, providing a portion where the laminated substrate and the sealing layer were not in close contact, i.e., a non-adhesion portion. Other than this, the solar cells were produced in the same manner as the solar cells of Examples 1 to 14 and Comparative Examples 1 and 2 described above. Each of the solar cells of Examples 1 to 14 and Comparative Examples 1 and 2 described above was cut into a size of 50 mm x 25 mm to prepare a test specimen. In the test specimen, the glass substrate side of the laminated substrate was facing the base, and the glass substrate and the base were attached and fixed using double-sided tape. Next, the non-adhesion portion of the sealing layer in contact with the laminated substrate in the test specimen was folded back. The folded portion of the non-adhesion portion was pulled in a 180° direction (peel speed: 5 mm / sec) and the maximum load (N / 25 mm) was measured using a peel tester (Shimadzu Corporation, Universal Testing Machine AGS-100NX). The obtained maximum load (N / 25 mm) was evaluated according to the following evaluation criteria. -Adhesion evaluation criteria- A: Adhesion strength of 20 N / 25 mm or more B: Adhesion strength of 10 N / 25 mm or more and less than 20 N / 25 mm C: Adhesion strength of 1 N / 25 mm or more and less than 10 N / 25 mm D: Adhesion strength of less than 1 N / 25 mm

[0122] <Measurement of atomic ratio of inorganic adhesive layer> A PET film (Lumirror (registered trademark) #125-T60, manufactured by Toray Industries, Inc.) and a release film (JOL, manufactured by Nippa Corporation) were prepared. A second inorganic adhesive layer was formed on the PET film using the methods described above in Examples 1 to 14 and Comparative Examples 1 and 2. A first inorganic adhesive layer was formed on a release film using the methods described above in Examples 1 to 14 and Comparative Examples 1 and 2. Using the methods described above in Examples 1 to 14 and Comparative Examples 1 and 2, the PET film and the release film were laminated and heated to 100°C while being bonded using a pressure press to obtain an inorganic adhesive layer. Next, the release film was peeled off. Next, the inorganic adhesive layer on the surface of the PET film was subjected to X-ray photoelectron spectroscopy analysis using an XPS device (AXIS-ULTRA, manufactured by Shimadzu Corporation), and specific elements were measured from Si, Al, O, and N according to the oxide composition at multiple locations at predetermined intervals along the thickness direction of the inorganic adhesive layer. The atomic ratio O / Si or O / Al at each location was calculated according to the oxide composition from the measurement results of the measured elements among Si, Al, O, and N. The average values ​​of the values ​​at multiple locations were taken as the atomic ratio O / Si and the atomic ratio O / Al.

[0123]

[0124]

[0125] As shown in Table 2, Examples 1 to 14 were superior in moisture resistance, moist heat resistance, and adhesion compared to Comparative Examples 1 and 2. Furthermore, all of Examples 1 to 14 had a photoelectric conversion efficiency sufficient for normal operation as a solar cell. Comparative Example 1 did not use an inorganic adhesive layer. The sealing layer was adhered using an epoxy resin, resulting in poor moisture resistance and moist heat resistance. Comparative Example 2 used a sputtering method. When the sputtering method was used, adhesion between the first inorganic adhesive layer and the second inorganic adhesive layer was poor, making it difficult to adhere the sealing layer, resulting in poor moisture resistance, moist heat resistance, and adhesion.

[0126] From Examples 1 to 4, performing an activation treatment is preferable because moisture resistance, moist heat resistance, and adhesion are even better. From Examples 1 and 5, forming an inorganic adhesive layer on an uncured organic adhesive layer is preferable because moisture resistance, moist heat resistance, and adhesion are even better. From Examples 1 and 7, a thinner inorganic adhesive layer is preferable because moisture resistance, moist heat resistance, and adhesion are even better. When the thickness of the first inorganic adhesive layer and the thickness of the second inorganic adhesive layer are the same, the adhesion strength between the first inorganic adhesive layer and the second inorganic adhesive layer is higher. Therefore, from Examples 1 and 8, which have the same compound constituting the inorganic adhesive layer, Example 1 had better adhesion and moisture resistance and moist heat resistance than Example 8. From Examples 3 and 12, even without performing an activation treatment, by laminating the first laminate and the second laminate within 30 seconds of the one prepared earlier, moisture resistance, moist heat resistance, and adhesion were even better.

[0127] 10, 10a, 10b, 11 Solar cell 12 Support 12c Peripheral portion 13 Conductive support 14 Support-side electrode 15 Electron transport layer 16 Photoelectric conversion layer 16c End surface 17 Hole transport layer 18 Sealing layer-side electrode 19 Organic adhesive layer 19c End portion 18a, 19a, 22a, 26a, 28a Surface 20 Inorganic adhesive layer 22 Sealing layer 22b Surface 24 Photoelectric conversion portion 26 First inorganic adhesive layer 27 Laminated base material 28 Second inorganic adhesive layer 30 First laminate 32 Second laminate 34, 36 Inorganic adhesive layer 34b Portion 34c Peripheral portion 38 Laminate 40 Nozzle 42, 43 Activation processing portion 50, 50a Device 51 Conveying shaft 52 Conveying roller 56 Roller pair 56a, 56b Roller 57 Film forming chamber 58 Exhaust pump 59 Gas supply unit D Ｌ Conveying direction Ds Stacking direction Dt Thickness direction Dw Direction Ls Sunlight P, Q Line Q １ First region Q ２ Second region S, S １ , S ２ , S ３ , S ４Film formation starting position

Claims

1. A method for manufacturing a solar cell having a layer structure in which a support, a support-side electrode, a photoelectric conversion layer containing a perovskite compound, a sealing layer-side electrode, an organic adhesive layer, an inorganic adhesive layer, and a sealing layer are laminated in this order, the method comprising: a first formation step of forming a first inorganic adhesive layer on a surface of the sealing layer facing the sealing layer-side electrode by a plasma CVD method to form a first laminate including the first inorganic adhesive layer; a second formation step of forming a second inorganic adhesive layer by the plasma CVD method on a laminated base material in which the support, the support-side electrode, the photoelectric conversion layer, the sealing layer-side electrode, and the organic adhesive layer are laminated in this order, to form a second laminate including the second inorganic adhesive layer; and a third formation step of laminating the first inorganic adhesive layer of the first laminate and the second inorganic adhesive layer of the second laminate to form the inorganic adhesive layer.

2. A method for manufacturing a solar cell having a layer structure in which a conductive support, a photoelectric conversion layer containing a perovskite compound, a sealing layer side electrode, an organic adhesive layer, an inorganic adhesive layer, and a sealing layer are laminated in this order, comprising: a first formation step of forming a first inorganic adhesive layer on a surface of the sealing layer facing the sealing layer side electrode by a plasma CVD method to form a first laminate including the first inorganic adhesive layer; a second formation step of forming a second inorganic adhesive layer by the plasma CVD method on a laminated base material in which the conductive support, the photoelectric conversion layer, the sealing layer side electrode, and the organic adhesive layer are laminated in this order, to form a second laminate including the second inorganic adhesive layer; and a third formation step of laminating the first inorganic adhesive layer of the first laminate and the second inorganic adhesive layer of the second laminate to form the inorganic adhesive layer.

3. A method for manufacturing a solar cell as described in claim 1, wherein in the second formation step, the second inorganic adhesive layer is formed directly on the support in the peripheral portion of the organic adhesive layer in a direction perpendicular to the stacking direction of the laminated base material.

4. A method for manufacturing a solar cell as described in claim 2, wherein in the second formation step, the second inorganic adhesive layer is formed directly on the conductive support in the peripheral portion of the organic adhesive layer in a direction perpendicular to the stacking direction of the laminated base material.

5. A method for manufacturing a solar cell as described in claim 1 or 2, wherein the first inorganic adhesive layer and the second inorganic adhesive layer are composed of an oxide containing one of the elements Si and Al, and when the oxide is silicon oxide, the atomic ratio O / Si of silicon to oxygen is 2.5 or more and 4.0 or less, and when the oxide is aluminum oxide, the atomic ratio O / Al of aluminum to oxygen is 2.0 or more and 3.0 or less.

6. The method for manufacturing a solar cell according to claim 1 or 2, wherein the total thickness of the first inorganic adhesive layer and the second inorganic adhesive layer is 0.3 to 15 nm.

7. A method for manufacturing a solar cell as described in claim 1 or 2, wherein in the third formation step, the first inorganic adhesive layer of the first laminate and the second inorganic adhesive layer of the second laminate are laminated within 30 seconds after formation of the first laminate or the second laminate, whichever is formed first.

8. The method for manufacturing a solar cell according to claim 1 or 2, wherein in the second formation step, the second inorganic adhesive layer is formed while the organic adhesive layer is in an uncured state.

9. A method for manufacturing a solar cell as described in claim 1 or 2, comprising an activation treatment step of performing an activation treatment on at least one of the first inorganic adhesive layer and the second inorganic adhesive layer prior to the third formation step.

10. A method for manufacturing a solar cell as described in claim 9, wherein in the third formation step, the first inorganic adhesive layer of the first laminate and the second inorganic adhesive layer of the second laminate are laminated within 60 seconds after formation of the first laminate or the second laminate, whichever is formed first.

11. A method for manufacturing a solar cell as described in claim 1 or 2, wherein the first forming step, the second forming step, and a lamination step of laminating the first inorganic adhesive layer of the first laminate and the second inorganic adhesive layer of the second laminate are performed by roll-to-roll, and after the first forming step and the second forming step, the first laminate and the second laminate are transported in a non-contact state until the lamination step is performed.

12. A method for manufacturing a solar cell as described in claim 1 or 2, wherein in the first formation step, the first inorganic adhesive layer is formed on the surface of the sealing layer facing the sealing layer side electrode in a first region corresponding to the peripheral portion of the organic adhesive layer in a direction perpendicular to the stacking direction of the laminated base material and in a second region corresponding to the organic adhesive layer, and in the second formation step, the second inorganic adhesive layer is formed on the peripheral portion of the organic adhesive layer and on the organic adhesive layer in the direction perpendicular to the stacking direction of the laminated base material.

13. A method for manufacturing a solar cell as described in claim 1 or 2, wherein in the first formation step, the first inorganic adhesive layer is formed on the surface of the sealing layer facing the sealing layer side electrode in a first region corresponding to the peripheral portion of the organic adhesive layer in a direction perpendicular to the stacking direction of the laminated base material and a second region corresponding to the organic adhesive layer, and in the second formation step, the second inorganic adhesive layer is formed in the peripheral portion of the organic adhesive layer in the direction perpendicular to the stacking direction of the laminated base material.

14. A method for manufacturing a solar cell as described in claim 1 or 2, wherein in the first formation step, the first inorganic adhesive layer is formed in a first region corresponding to the peripheral portion of the organic adhesive layer in a direction perpendicular to the stacking direction of the laminated base material on the surface of the sealing layer facing the sealing layer side electrode, and in the second formation step, the second inorganic adhesive layer is formed in the peripheral portion of the organic adhesive layer in the direction perpendicular to the stacking direction of the laminated base material.

Images