Method for producing solar cell, and solar cell

Abstract

The present invention provides a method for producing a solar cell and a solar cell which each prevent infiltration of water to a photoelectric conversion layer and suppress deterioration of the properties of the photoelectric conversion layer. Provided is a method for producing a solar cell which has at least a support body, an electron transport layer provided on the support body, a photoelectric conversion layer including a perovskite compound, and a sealing resin layer, and in which the photoelectric conversion layer and the sealing resin layer are provided on the electron transport layer, said method comprising: a first step for forming droplets of a solution which is to form the photoelectric conversion layer, applying the solution which is in droplet form onto a photoelectric conversion layer formation region (Q1) on the electron transport layer, and forming a coating film (47) of the solution; and a second step for forming droplets of a sealant which is to form the sealing resin layer, applying the sealant which is in droplet form onto a sealing resin layer formation region (Q2) on an electron transport layer, and forming a coating film (48) of the sealant, wherein the photoelectric conversion layer formation region (Q1) and the sealing resin layer formation region (Q2) partially overlap.

Description

Solar cell manufacturing method and solar cell

[0001] The present invention relates to a method for manufacturing a solar cell having a photoelectric conversion layer containing a perovskite compound, and the solar cell, and in particular to a method for manufacturing a solar cell in which a photoelectric conversion layer and a sealing resin layer are formed so as to partially overlap each other, and the solar cell.

[0002] Currently, there are 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 entering the photoelectric conversion layer.

[0003] For example, Patent Document 1 proposes a solar cell including a support having a first surface and a second surface, a solar cell element provided on the first surface of the support, an adhesive layer covering the entire solar cell element, and a sealant layer covering the entire adhesive layer, wherein the solar cell element includes, in this order, an electrode, a photoelectric conversion layer containing a perovskite compound, and a back electrode, and the sealant layer includes a main body portion covering the adhesive layer portion on the solar cell element, a first edge region that is continuous with the main body portion and extends to the edge of the first surface, and a second edge region that is continuous with the first edge region and extends to the second surface.

[0004] Japanese Patent Application Laid-Open No. 2023-067523

[0005] The solar cell of Patent Document 1 has an adhesive layer made of a cured acrylic resin or epoxy resin, for example. The photoelectric conversion layer is not sealed before the adhesive layer is formed, and moisture in the environment surrounding the photoelectric conversion layer can deteriorate the characteristics of the photoelectric conversion layer. Furthermore, the adhesive layer made of a cured acrylic resin or epoxy resin used in the solar cell of Patent Document 1 is prone to voids, which can allow water to penetrate through the side portions of the adhesive layer, resulting in an insufficient sealing effect and deterioration of the characteristics of the photoelectric conversion layer, i.e., the solar cell. An object of the present invention is to provide a solar cell manufacturing method and a solar cell that prevent water from penetrating the photoelectric conversion layer and suppress deterioration of the characteristics of the photoelectric conversion layer.

[0006] In order to achieve the above-mentioned object, invention [1] is a method for manufacturing a solar cell having at least a support, an electron transport layer provided on the support, a photoelectric conversion layer containing a perovskite compound, and a sealing resin layer, wherein the photoelectric conversion layer and the sealing resin layer are provided on the electron transport layer, the method comprising: a first step of forming droplets of a solution that forms the photoelectric conversion layer and applying the droplet-state solution to a photoelectric conversion layer-forming region on the electron transport layer to form a coating film of the solution; and a second step of forming droplets of a sealant that forms the sealing resin layer and applying the droplet-state sealant to a sealing resin layer-forming region on the electron transport layer to form a coating film of the sealant, wherein the photoelectric conversion layer-forming region and the sealing resin layer-forming region partially overlap each other.

[0007] Invention [2] is the method for producing a solar cell according to Invention [1], wherein the sealant contains less than 1 mass% of an organic solvent. Invention [3] is the method for producing a solar cell according to Invention [1] or [2], wherein the first step and the second step are carried out simultaneously. Invention [4] is the method for producing a solar cell according to Invention [1] or [2], wherein the second step is carried out while the coating film of the solution is drying at a constant rate after the first step is carried out. Invention [5] is the method for producing a solar cell according to Invention [1] or [2], wherein the first step is carried out while the coating film of the sealant is drying at a constant rate after the second step is carried out.

[0008] Invention [6] is a method for manufacturing a solar cell according to any one of Inventions [1] to [5], in which, in the first step, a solution for forming a photoelectric conversion layer is formed into droplets using ultrasound, and the droplet-like solution is applied to a region for forming a photoelectric conversion layer on the electron transport layer. Invention [7] is a method for manufacturing a solar cell according to any one of Inventions [1] to [5], in which, in the second step, a sealant is formed into droplets using ultrasound, and the droplet-like sealant is applied to a region for forming a sealing resin layer on the electron transport layer. Invention [8] is a method for manufacturing a solar cell according to any one of Inventions [1] to [5], in which, in the first step, a solution for forming a photoelectric conversion layer is formed into droplets using a spray, and the droplet-like solution is applied to a region for forming a photoelectric conversion layer on the electron transport layer. Invention [9] is a method for manufacturing a solar cell according to any one of Inventions [1] to [5], in which, in the second step, a sealant is formed into droplets using a spray, and the droplet-like sealant is applied to a region for forming a sealing resin layer on the electron transport layer. Invention

[10] is the method for producing a solar cell according to any one of Inventions [1] to [9], which includes, after the first step and the second step, a third step of at least heating and drying the coating film of the solution to form a photoelectric conversion layer.

[0009] Invention

[11] is a solar cell having at least a support, an electron transport layer provided on the support, a photoelectric conversion layer containing a perovskite compound, and an encapsulating resin layer, the photoelectric conversion layer and the encapsulating resin layer being provided on the electron transport layer, wherein a mixed region of the photoelectric conversion layer and the encapsulating resin layer is present between the photoelectric conversion layer and the encapsulating resin layer. Invention

[12] is the solar cell according to Invention

[11] , wherein the mixed region has a phase-separated structure including a first phase formed of components constituting the photoelectric conversion layer and a second phase formed of components constituting the encapsulating resin layer. Invention

[13] is the solar cell according to Invention

[12] , wherein the phase-separated structure is at least one of a sea-island structure, a continuous spherical structure, a composite dispersed structure, and a co-continuous structure.

[0010] 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, and a solar cell.

[0011] 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 plan view showing an example of a mixed region of the first example of the solar cell according to an embodiment of the present invention; FIG. 3 is a schematic cross-sectional view showing an example of a mixed region of the first example of the solar cell according to an embodiment of the present invention; FIG. 4 is a schematic view showing a first example of a phase separation structure of the mixed region of the first example of the solar cell according to an embodiment of the present invention; FIG. 5 is a schematic view showing a second example of a phase separation structure of the mixed region of the first example of the solar cell according to an embodiment of the present invention; FIG. 6 is a schematic view showing a third example of a phase separation structure of the mixed region of the first example of the solar cell according to an embodiment of the present invention; FIG. 7 is a schematic cross-sectional view showing a step of a method for manufacturing the first example of the solar cell according to an embodiment of the present invention; FIG. 8 is a schematic perspective view showing a step of a method for manufacturing the first example of the solar cell according to an embodiment of the present invention; FIG. 9 is a schematic cross-sectional view showing a step of a method for manufacturing the first example of the solar cell according to an embodiment of the present invention; FIG. 10 is a schematic perspective view showing a step of a method for manufacturing the first example of the solar cell according to an embodiment of the present invention; FIG. 11 is a schematic perspective view showing a step of a method for manufacturing the second example of the solar cell according to an embodiment of the present invention; FIG. 12 is a schematic perspective view showing a step of a method for manufacturing the second example of the solar cell according to an embodiment of the present invention; Fig. 1 is a schematic perspective view showing one step of a manufacturing method for a third example of a solar cell according to an embodiment of the present invention; Fig. 2 is a schematic cross-sectional view showing a second example of a solar cell according to an embodiment of the present invention; Fig. 3 is a schematic cross-sectional view showing one step of a manufacturing method for a solar cell according to Comparative Example 1; Fig. 4 is a schematic perspective view showing one step of a manufacturing method for a solar cell according to Comparative Example 1;

[0012] The solar cell manufacturing method and the solar cell of the present invention will be described in detail below based on the preferred embodiments 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 numerical range includes the numerical values ​​written on both sides. For example, when ε is a numerical 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 βAngles such as "specific angle" and "orthogonal" include the error range generally accepted in the relevant technical field unless otherwise specified. Furthermore, temperatures include the error range generally accepted 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.

[0013] [First Example of Solar Cell] 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 plan view showing an example of a mixed region of the first example of a solar cell according to an embodiment of the present invention. FIG. 3 is a schematic cross-sectional view showing an example of a mixed region of the first example of a solar cell according to an embodiment of the present invention. Note that FIGS. 2 and 3 show the photoelectric conversion layer 16, the mixed region 21, and the encapsulating resin layer 19, and do not show other components of the solar cell 10. FIG. 3 is a schematic cross-sectional view taken along line A-A in FIG. 2. The solar cell 10 shown in FIG. 1 has a layer structure in which, for example, a support 12, a support-side electrode 14, an electron transport layer 15, a photoelectric conversion layer 16, a hole transport layer 17, an encapsulating layer-side electrode 18, an adhesive layer 20, and an encapsulating layer 22 are stacked in this order, and the photoelectric conversion layer 16 and the encapsulating resin layer 19 are provided on the electron transport layer 15. A mixed region 21 of the photoelectric conversion layer 16 and the encapsulating resin layer 19 is present between the photoelectric conversion layer 16 and the encapsulating resin layer 19. The photoelectric conversion layer 16 contains a perovskite compound. In the solar cell 10, 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 adhesive layer 20, and the sealing layer 22 are stacked is referred to as the stacking direction Ds. The direction perpendicular to the stacking direction Ds of the photoelectric conversion layer 16 is referred to as the width direction Dw.

[0014] As described above, the solar cell 10 has a mixed region 21 between the photoelectric conversion layer 16 and the encapsulating resin layer 19. The photoelectric conversion layer 16, the mixed region 21, and the encapsulating resin layer 19 are continuously provided on the surface 15a of the electron transport layer 15 in the width direction Dw. A hole transport layer 17 is provided on the surface 16a of the photoelectric conversion layer 16. The mixed region 21 is a region where a part of the photoelectric conversion layer 16 and a part of the encapsulating resin layer 19 are mixed. In the mixed region 21, the photoelectric conversion layer 16 and the encapsulating resin layer 19 are intercalated and not clearly distinguishable. Due to the presence of the mixed region 21, there is no clear interface between the photoelectric conversion layer 16 and the encapsulating resin layer 19. The mixed region 21 has, for example, a phase-separated structure. For example, as shown in FIGS. 2 and 3 , the phase-separated structure includes a first phase 21a formed from components constituting the photoelectric conversion layer 16 and a second phase 21b formed from components constituting the encapsulating resin layer 19. The first phase 21a is a part of the photoelectric conversion layer 16, and the second phase 21b is a part of the encapsulating resin layer 19. The first phase 21a and the second phase 21b are mixed in the mixed region 21. This produces an anchor effect, firmly bonding the photoelectric conversion layer 16 and the encapsulating resin layer 19 together, and increasing adhesion.

[0015] By continuously arranging the photoelectric conversion layer 16, the mixed region 21, and the encapsulating resin layer 19 in the width direction Dw on the surface 15a of the electron transport layer 15, water is prevented from penetrating into the photoelectric conversion layer 16 from the width direction Dw. This makes it possible to suppress deterioration of the photoelectric conversion characteristics and other properties of the photoelectric conversion layer 16. The photoelectric conversion efficiency of the photoelectric conversion layer 16 is maintained. Furthermore, the presence of the mixed region 21 improves adhesion between the encapsulating resin layer 19 and the photoelectric conversion layer 16. This improves adhesion particularly at the ends of the photoelectric conversion layer 16 in the width direction Dw. Furthermore, it is preferable that the surface 16a of the photoelectric conversion layer 16, the surface 21c of the mixed region 21, and the surface 19a of the encapsulating resin layer 19 are at the same position in the stacking direction Ds, i.e., are flush with each other. If the surface 16a of the photoelectric conversion layer 16, the surface 21c of the mixed region 21, and the surface 19a of the sealing resin layer 19 are flush with each other, the organic adhesive 49 (see Figure 11) has better conformability when bonding the sealing layer 22 as described below, making bonding easier.

[0016] Next, the phase separation structure of the mixed region 21 will be described. Examples of phase separation structures include a sea-island structure, a continuous spherical structure, a composite dispersed structure, and a co-continuous structure. The phase separation structure is at least one of a sea-island structure, a continuous spherical structure, a composite dispersed structure, and a co-continuous structure. FIG. 4 is a schematic diagram showing a first example of a phase separation structure of the mixed region of the first example of a solar cell according to an embodiment of the present invention. FIG. 5 is a schematic diagram showing a second example of a phase separation structure of the mixed region of the first example of a solar cell according to an embodiment of the present invention. FIG. 6 is a schematic diagram showing a third example of a phase separation structure of the mixed region of the first example of a solar cell according to an embodiment of the present invention. FIG. 7 is a schematic diagram showing a fourth example of a phase separation structure of the mixed region of the first example of a solar cell according to an embodiment of the present invention. In FIGS. 4 to 7, components identical to those in the mixed region 21 shown in FIGS. 2 and 3 are denoted by the same reference numerals, and detailed descriptions thereof will be omitted. The sea-island structure is a structure in which a small-volume first phase 21a is dispersed in a continuous second phase 21b, as shown in FIG. 4. The continuous spherical structure is a structure in which particulate or spherical first phases 21a are dispersed in a continuous second phase 21b. As shown in FIG. 5, the continuous spherical structure is a structure in which approximately spherical first phases 21a are connected and dispersed in a second phase 21b. As shown in FIG. 6, the composite dispersed structure is a structure in which the first phase 21a is dispersed in a continuous second phase 21b, and further, continuous second phases 21b are dispersed in the first phase 21a. As shown in FIG. 7, the co-continuous structure is a structure in which the first phase 21a and the second phase 21b form a complex three-dimensional network.

[0017] The support 12 shown in FIG. 1 supports a support-side electrode 14, an electron transport layer 15, a photoelectric conversion layer 16, a mixed region 21, an encapsulating resin layer 19, a hole transport layer 17, a encapsulating layer-side electrode 18, an adhesive layer 20, and a encapsulating layer 22. The support-side electrode 14 is formed on a surface 12a of the support 12. The support-side electrode 14 and the encapsulating layer-side electrode 18 are used to extract power 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 form a photoelectric conversion section 24. Light such as sunlight Ls 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 encapsulating layer-side electrode 18 extract power generated by photoelectric conversion in the photoelectric conversion layer 16 to the outside.

[0018] The adhesive layer 20 is for adhering the sealing layer 22 to the sealing layer-side electrode 18 and the photoelectric conversion section 24. The adhesive layer 20 covers the periphery of the photoelectric conversion layer 16 and is also formed on the end surface 19c in the width direction Dw of the sealing resin layer 19. The sealing layer 22 is for protecting the solar cell 10, and specifically, protects the photoelectric conversion layer 16 from substances that deteriorate the photoelectric conversion layer, such as water and oxygen. The sealing layer 22 covers the surface 20a of the adhesive layer 20, and the sealing layer 22 covers the periphery of the photoelectric conversion layer 16.

[0019] The support 12, support-side electrode 14, electron transport layer 15, photoelectric conversion layer 16, hole transport layer 17, sealing layer-side electrode 18, sealing resin layer 19, adhesive layer 20, mixed region 21, and sealing layer 22 that constitute the solar cell 10 will be described in detail later.

[0020] 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 is performed 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 is performed 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, adhesive layer 20, 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. The solar cell 10 is not particularly limited in configuration as long as it has at least a support 12, an electron transport layer 15 provided on the support 12, a photoelectric conversion layer 16 containing a perovskite compound, and a sealing resin layer 19, and the photoelectric conversion layer 16 and the sealing resin layer 19 are provided on the electron transport layer 15.

[0021] [First Example of Manufacturing Method of Solar Cell] Figure 8 is a schematic cross-sectional view showing one step of a manufacturing method of a first example of a solar cell according to an embodiment of the present invention. Figure 9 is a schematic perspective view showing one step of a manufacturing method of a first example of a solar cell according to an embodiment of the present invention. Figures 10 and 11 are schematic cross-sectional views showing one step of a manufacturing method of a first example of a solar cell according to an embodiment of the present invention. In Figures 8 to 11, the same components as those in Figures 1 to 3 are designated by the same reference numerals, and detailed descriptions thereof will be omitted.

[0022] A first example of a method for manufacturing the solar cell 10 shown in Fig. 1 will be described below. As shown in Fig. 8, a support-side electrode 14 is formed on the surface 12a of the support 12, and an electron transport layer 15 is formed on the support-side electrode 14. The support-side electrode 14 and the electron transport layer 15 are formed using a known method. Next, a photoelectric conversion layer 16 and an encapsulating resin layer 19 are formed on the surface 15a of the electron transport layer 15 to form a mixed region 21.

[0023] To form the photoelectric conversion layer 16, the encapsulating resin layer 19, and the mixed region 21, for example, a coating device 40 shown in FIG. 9 is used. The coating device 40 includes, for example, a first nozzle 42 for forming the photoelectric conversion layer 16, a second nozzle 44 for forming the encapsulating resin layer 19, and a control unit 46 for controlling the operation of the first nozzle 42 and the second nozzle 44. In one example, the second nozzle 44, the first nozzle 42, the first nozzle 42, and the second nozzle 44 are arranged in this order along the width direction Dw. The second nozzle 44, the first nozzle 42, the first nozzle 42, and the second nozzle 44 are collectively referred to as a nozzle row 41. The coating device 40 includes a moving unit (not shown) that moves the nozzle row 41 in a longitudinal direction Dm that is perpendicular to the stacking direction Ds and the width direction Dw. The nozzle row 41 is moved in the longitudinal direction Dm by the moving unit. The moving unit can also separately move the first nozzle 42 and the second nozzle 44. The moving unit is controlled by a control unit 46, which controls the timing of application by the first nozzle 42 and the second nozzle 44 and the movements of the first nozzle 42 and the second nozzle 44.

[0024] The photoelectric conversion layer forming region Q is formed on the surface 15a of the electron transport layer 15. １ and the sealing resin layer forming region Q２ The photoelectric conversion layer forming region Q is set in advance. １ and sealing resin layer formation region Q ２ Each of the photoelectric conversion layer forming regions Q is a rectangular region extending in the longitudinal direction Dm. １ and the sealing resin layer forming region Q ２ are set to overlap each other in the width direction Dw, and the photoelectric conversion layer forming region Q １ and the sealing resin layer forming region Q ２ and overlapping area Q ３ There is an overlapping area Q ３ is the photoelectric conversion layer forming region Q １ and sealing resin layer formation region Q ２ The overlapping area Q is a rectangular area whose length in the width direction Dw is shorter than that of the overlapping area Q. ３ A mixed region 21 (see FIG. 1) is formed in the overlapping region Q shown in FIG. ３ The length δ in the width direction Dw of the nozzle 42 is, for example, 1 to 50 mm. For example, by adjusting the area coated by the first nozzle 42 and the area coated by the second nozzle 44, the overlapping area Q ３ The length δ in the width direction Dw of the overlapping region Q ３ If the length δ of the overlapping region Q is 1 to 50 mm, the anchoring effect of the mixed region 21 is sufficiently exhibited. ３ The length of the electron transport layer 15 is the length of the surface 15a of the electron transport layer 15 in the width direction Dw and the photoelectric conversion layer forming region Q １ the length in the width direction Dw of the sealing resin layer forming region Q ２ and the length in the width direction Dw can be determined by measuring them by known methods.

[0025] The first nozzle 42 forms droplets of the solution for forming the photoelectric conversion layer 16 and deposits the droplet-state solution onto the photoelectric conversion layer forming region Q on the surface 15 a of the electron transport layer 15 . １ The first nozzle 42 applies droplets 43 of the solution that will form the photoelectric conversion layer 16 to the photoelectric conversion layer forming region Q. １The second nozzle 44 turns the sealant that forms the sealing resin layer 19 into droplets, and the droplets of the sealant are sprayed onto the sealing resin layer forming region Q on the surface 15 a of the electron transport layer 15. ２ The second nozzle 44 applies droplets 45 of the sealant that form the sealing resin layer 19 to the sealing resin layer forming region Q. ２ The photoelectric conversion layer forming region Q on the surface 15 a of the electron transport layer 15 is sprayed and applied. １ The area in which the droplets 43 of the solution from the first nozzle 42 spread is set in accordance with the above. ２ The range over which the droplets 45 of the sealant from the second nozzle 44 spread is set in accordance with the above. When adjusting the size and thickness of the coating film to be formed in the first nozzle 42 and the second nozzle 44, the liquid flow rate of the solution or the air flow rate is adjusted.

[0026] The above-described moving unit is not necessarily required if the support 12 is moved rather than the first nozzle 42 and the second nozzle 44 when forming the solution coating film 47 and the sealant coating film 48. The thicknesses of the solution coating film 47 and the sealant coating film 48 in the stacking direction Ds are preferably adjusted so that the surface 16 a of the photoelectric conversion layer 16 to be formed, the surface 21 c of the mixed region 21, and the surface 19 a of the sealing resin layer 19 are flush with each other.

[0027] When forming the photoelectric conversion layer 16, the sealing resin layer 19, and the mixed region 21 on the electron transport layer 15, the solution for forming the photoelectric conversion layer 16 is made into droplets, and the droplet-state solution is applied to the photoelectric conversion layer forming region Q on the electron transport layer 15. １ The solution is applied to the photoelectric conversion layer forming region Q １ a first step of forming the sealing resin layer 19 in a region Q on the electron transport layer 15; and a second step of forming the sealing resin layer 19 in a region Q on the electron transport layer 15. ２ The sealant coating film 48 is applied to the sealing resin layer forming region Q ２At this time, the nozzle row 41, i.e., the first nozzles 42 and the second nozzles 44, are moved together in the longitudinal direction Dm, and droplets 43 for forming a coating film 47 of the solution are ejected from the first nozzles 42 of the nozzle row 41 onto the photoelectric conversion layer forming region Q １ Further, droplets 45 for forming a coating film 48 of the sealant are sprayed from the second nozzle 44 of the nozzle row 41 onto the sealing resin layer forming region Q ２ In forming the photoelectric conversion layer 16, the sealing resin layer 19, and the mixed region 21, the solution for forming the photoelectric conversion layer 16 is made into droplets and sprayed onto the photoelectric conversion layer forming region Q. １ The coating film 47 is formed on the sealing resin layer forming region Q ２ By forming the coating film 48 on the substrate 41, the coating film 47 and the coating film 48 can be formed continuously. Therefore, the productivity is superior to that when the coating film 47 is formed by spin coating, for example.

[0028] Next, a third step is performed in which the solution coating 47 is at least heated and dried to form the photoelectric conversion layer 16. Note that depending on the composition of the solution that forms the photoelectric conversion layer 16, the photoelectric conversion layer 16 may not be formed by simply heating and drying. In this case, for example, the coating 47 is immersed in a predetermined solution and then annealed to form the photoelectric conversion layer 16. The annealing corresponds to the heating and drying described above. When forming the photoelectric conversion layer 16, if the sealant that forms the sealing resin layer 19 is thermosetting, the heating or annealing treatment of the solution coating 47 hardens the sealant coating 48 to form the sealing resin layer 19, and the mixed region 21 is formed.

[0029] As described above, the photoelectric conversion layer forming region Q １ and the sealing resin layer forming region Q ２ Therefore, by performing the first step and the second step, a region Q where the droplets 43 of the solution that forms the photoelectric conversion layer 16 and the droplets 45 of the sealant overlap is formed. ３ The coating film 47 of the solution and the coating film 48 of the sealant overlap each other in a region Q ３ The mixed region 21 is then formed in the above-described manner.

[0030] Next, a hole transport layer 17 is formed on the surface 16a of the photoelectric conversion layer 16, as shown in Fig. 10. The hole transport layer 17 is formed by applying a hole transport material solution to the surface 16a of the photoelectric conversion layer 16 using, for example, an ultrasonic spray, and then drying the applied hole transport material solution. Furthermore, a sealing layer-side electrode 18 is formed on the hole transport layer 17 using, for example, a vacuum deposition method. This results in a laminated substrate 27 in which the support 12, the support-side electrode 14, the electron transport layer 15, the photoelectric conversion layer 16, the sealing resin layer 19, the hole transport layer 17, and the sealing layer-side electrode 18 are laminated in this order.

[0031] Next, as shown in FIG. 11 , for example, an organic adhesive 49 is applied to the back surface 22b of the sealing layer 22 on the sealing layer-side electrode 18 side. The organic adhesive 49 is, for example, a thermosetting adhesive. The sealing layer 22 to which the organic adhesive 49 has been applied is placed so that the organic adhesive 49 faces the sealing layer-side electrode 18 of the laminated substrate 27, and the sealing layer 22 is placed on the laminated substrate 27. Next, the sealing layer 22 and the laminated substrate 27 are bonded together using a pressure press while being heated to a temperature at which the organic adhesive 49 hardens. As a result, the organic adhesive 49 hardens to form an adhesive layer 20, and the sealing layer 22 is fixed to the laminated substrate 27, thereby obtaining the solar cell 10 shown in FIG. 1 . As described above, the coating film 47 of the solution that forms the photoelectric conversion layer 16 and the coating film 48 of the sealant are bonded to the region Q ３ By forming the mixed region 21 in the encapsulating resin layer 19, the mixed region 21 is formed. After the photoelectric conversion layer 16 is formed, the mixed region 21 and the encapsulating resin layer 19 seal the ends of the photoelectric conversion layer 16. Therefore, in the subsequent processes, moisture contained in the environment surrounding the photoelectric conversion layer 16 is prevented from penetrating through the ends of the photoelectric conversion layer 16, and deterioration of the characteristics of the photoelectric conversion layer 16 is suppressed.

[0032] The first example of the manufacturing method corresponds to simultaneously carrying out the first step and the second step. Here, simultaneously carrying out the first step and the second step means that the start and end timings of the first step of forming a coating film of the solution and the second step of forming a coating film of the sealant are synchronized to form a coating film of the solution and a coating film of the sealant. Simultaneous carrying out the first step and the second step also includes starting to form the remaining coating film before the formation of the coating film of the solution or the coating film of the sealant, which started first, is completed.

[0033] [Second Example of Method for Manufacturing Solar Cell] A second example of a method for manufacturing the solar cell 10 shown in FIG. 1 will be described below. FIGS. 12 and 13 are schematic perspective views showing a step in a second example of a method for manufacturing a solar cell according to an embodiment of the present invention. In FIGS. 12 and 13, the same components as those in FIG. 9 are designated by the same reference numerals, and detailed descriptions thereof will be omitted. In the coating device 40 shown in FIGS. 12 and 13, the control unit 46 shown in FIG. 9 is not shown. A second example of a method for manufacturing the solar cell 10 shown in FIG. 1 will be described below. The second example of the manufacturing method is the same as the first example of the manufacturing method described above, except for the methods for forming the photoelectric conversion layer 16, the encapsulating resin layer 19, and the mixed region 21, and therefore detailed descriptions thereof will be omitted. In the second example of the manufacturing method, the first step is performed first, and the second step is performed after the first step.

[0034] In the second example of the manufacturing method, as shown in FIG. 12, droplets 43 of a solution for forming the photoelectric conversion layer 16 are ejected from a first nozzle 42 onto a photoelectric conversion layer forming region Q on the surface 15 a of the electron transport layer 15. １ The solution is sprayed onto the photoelectric conversion layer forming region Q to form a coating film 47. １ After the first step is performed, while the coating film 47 of the solution is drying at a constant rate, droplets 45 of the sealant that will form the sealing resin layer 19 are sprayed from a second nozzle 44 onto the sealing resin layer forming region Q on the electron transport layer 15 as shown in FIG. ２ The sealant coating film 48 is sprayed onto the sealing resin layer forming region Q ２(second step). That is, after the first step is performed, the second step is performed while the solution coating film 47 is drying at a constant rate. In this case, in the first step, only the first nozzle 42 of the nozzle row 41 is used, and the solution coating film 47 is formed while the first nozzle 42 is moved in the longitudinal direction Dm. In the second step, only the second nozzle 44 of the nozzle row 41 is used, and the sealant coating film 48 is formed while the second nozzle 44 is moved in the longitudinal direction Dm.

[0035] Constant-rate drying refers to a constant drying rate, also known as fixed-rate drying. In the case of the coating film 47 of the solution that forms the photoelectric conversion layer 16, during constant-rate drying, the film is in a state before it dries and solidifies and crystal nuclei precipitate, before it becomes the photoelectric conversion layer 16. During constant-rate drying, the solvent is generally abundant, and the surface of the coating film is liquid rather than solid. Therefore, due to surface tension, the surface of the coating film is smooth and glossy. Therefore, whether the coating film is undergoing constant-rate drying can be determined visually or by shining light on the surface of the coating film and measuring the specular reflection intensity and scattered light intensity. During constant-rate drying, the specular reflection intensity of the coating film surface is higher than the scattered light intensity. Alternatively, whether the coating film is undergoing constant-rate drying can be determined by, for example, directly touching the surface of the coating film to prevent the solvent from transferring to anything it touches. By maintaining constant drying conditions such as temperature, solvent humidity, and drying air speed, the time from the start of drying to the end of constant-rate drying can be made constant. Therefore, by managing the time from the start of drying, it is possible to identify whether or not constant rate drying is in progress.

[0036] If the second step is performed while the coating film 47 of the solution is drying at a constant rate after the first step, the area Q where the droplets 45 of the sealant overlap the coating film 47 of the solution will be ３ The coating film 47 of the solution and the coating film 48 of the sealant are mixed in the overlapping region Q ３The mixed region 21 is then formed later. As a result, the photoelectric conversion layer 16, the mixed region 21, and the sealing resin layer 19 are continuously formed in the width direction Dw on the surface 15a of the electron transport layer 15. As a result, after the photoelectric conversion layer 16 is formed, the ends of the photoelectric conversion layer 16 are sealed with the mixed region 21 and the sealing resin layer 19. This prevents moisture from penetrating from the ends of the photoelectric conversion layer 16 in the subsequent processes, and suppresses deterioration of the characteristics of the photoelectric conversion layer 16.

[0037] [Third Example of Manufacturing Method for Solar Cell] A third example of a manufacturing method for the solar cell 10 shown in FIG. 1 will be described below. FIGS. 14 and 15 are schematic perspective views showing a step in a manufacturing method for the third example of a solar cell according to an embodiment of the present invention. In FIGS. 14 and 15, the same components as those in FIG. 9 are designated by the same reference numerals, and detailed descriptions thereof will be omitted. In the coating device 40 shown in FIGS. 14 and 15, the control unit 46 shown in FIG. 9 is not shown. A third example of a manufacturing method for the solar cell 10 shown in FIG. 1 will be described below. The third example of the manufacturing method is the same as the first example of the manufacturing method described above, except for the methods of forming the photoelectric conversion layer 16, the encapsulating resin layer 19, and the mixed region 21, and therefore detailed descriptions thereof will be omitted. In the third example of the manufacturing method, the second step is performed first, and the first step is performed after the second step.

[0038] In the third example of the manufacturing method, as shown in FIG. 14 , droplets 45 of a sealant that forms the sealing resin layer 19 are sprayed from a second nozzle 44 onto a sealing resin layer forming region Q on the surface 15 a of the electron transport layer 15. ２ The sealant coating film 48 is sprayed onto the sealing resin layer forming region Q ２ After the second step is performed, while the sealant coating film 48 is drying at a constant rate, droplets 43 of a solution for forming the photoelectric conversion layer 16 are sprayed from a first nozzle 42 onto the photoelectric conversion layer forming region Q on the surface 15 a of the electron transport layer 15 as shown in FIG. １ The solution is sprayed onto the photoelectric conversion layer forming region Q to form a coating film 47. １(first step). After the second step is performed, the first step is performed while the sealant coating film 48 is drying at a constant rate. In the second step, only the second nozzle 44 of the nozzle row 41 is used, and the sealant coating film 48 is formed while the second nozzle 44 is moved in the longitudinal direction Dm. In the first step, only the first nozzle 42 of the nozzle row 41 is used, and the solution coating film 47 is formed while the first nozzle 42 is moved in the longitudinal direction Dm.

[0039] If the first step is carried out while the sealant coating film 48 is drying at a constant rate after the second step, the droplets 43 of the solution that forms the photoelectric conversion layer 16 overlap the sealant coating film 48 in the region Q ３ The coating film 47 of the solution and the coating film 48 of the sealant are mixed in the overlapping region Q ３ The mixed region 21 is then formed later. As a result, the photoelectric conversion layer 16, the mixed region 21, and the sealing resin layer 19 are continuously formed in the width direction Dw on the surface 15a of the electron transport layer 15. As a result, after the photoelectric conversion layer 16 is formed, the ends of the photoelectric conversion layer 16 are sealed. This prevents moisture from penetrating from the ends of the photoelectric conversion layer 16 in the subsequent processes, and suppresses deterioration of the characteristics of the photoelectric conversion layer 16.

[0040] In the first to third examples of the manufacturing method described above, the solution forming the photoelectric conversion layer is formed into droplets in the first step. However, the method is not particularly limited as long as it can form the solution into droplets as described above. For example, the solution forming the photoelectric conversion layer can be formed into droplets using ultrasound or a spray. Forming droplets using ultrasound is preferred because it can produce small, uniform droplets. For this reason, the first nozzle 42 can be, for example, an ultrasonic or spray method, with the ultrasonic method being preferred. Furthermore, the sealant is formed into droplets in the second step. However, the method is not particularly limited as long as it can form the sealant into droplets as described above. For example, the sealant can be formed into droplets using ultrasound or a spray. Forming droplets using ultrasound is also preferred because it can produce small, uniform droplets. For this reason, the second nozzle 44 can be, for example, an ultrasonic or spray method, with the ultrasonic method being preferred. The spray method may be, for example, a one-fluid spray or a two-fluid spray, or may be a spray using centrifugal force or electrostatic electricity. A two-fluid spray corresponds to an air spray. In addition to the above-mentioned methods, the first nozzle 42 and the second nozzle 44 may also use an inkjet method. Furthermore, the first nozzle 42 and the second nozzle 44 may have the same configuration or different configurations. For example, the first nozzle 42 may be an ultrasonic type, and the second nozzle 44 may be a spray type.

[0041] In the first to third examples of the manufacturing method described above, the first to third forming steps can be performed on the electron transport layer 15 formed on the support 12 in the form of a single sheet. A single sheet refers to a single sheet. In the first to third examples of the manufacturing method described above, the first to third forming steps can also be performed by roll-to-roll processing.

[0042] [Second Example of Solar Cell] Figure 16 is a schematic cross-sectional view showing a second example of a solar cell according to an embodiment of the present invention. In Figure 16, 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 16 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. The remaining configuration is similar to that of the solar cell 10 shown in Figure 1, and detailed descriptions thereof will be omitted. 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 adhesive layer 20, and the sealing layer 22 are stacked in this order. The solar cell 11 does not have the support-side electrode 14 shown in Figure 1, and the electron transport layer 15 is provided on the conductive support 13. In the solar cell 11, the photoelectric conversion layer 16, the mixed region 21, and the sealing resin layer 19 are also provided continuously on the surface 15a of the electron transport layer 15 in the width direction Dw.

[0043] In the solar cell 11, sunlight Ls is irradiated from the surface 22a of the encapsulating layer 22, photoelectrically converted in the photoelectric conversion layer 16, and the resulting electricity is extracted from the conductive support 13 and the encapsulating layer-side electrode 18. The solar cell 11 differs from the solar cell 10 described above 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 the solar cell 10 can be obtained. The solar cell 11 may also be configured such that sunlight Ls is 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 is extracted from the support-side electrode 14 and the encapsulating layer-side electrode 18. In this case, the conductive support 13 must be transparent. Note that the light irradiated in the solar cells 10 and 11 is not limited to sunlight Ls. The solar cell 11 shown in FIG. 16 uses a conductive support 13 (see FIG. 16) instead of the support 12 and the support-side electrode 14, but can be manufactured using the solar cell manufacturing method described above.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] (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.

[0050] (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).

[0051] 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, like 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 or a laminated structure. The support-side electrode may be formed using a vapor phase method or a wet method such as electrolytic plating.

[0052] (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.

[0053] (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 (Chemical Vapor Deposition), 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.

[0054] (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.

[0055] The thickness of the hole transport layer is not particularly limited, and is preferably 50 μm or less, more preferably 100 nm to 10 μm, even more preferably 100 nm to 5 μm, and particularly preferably 100 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.

[0056] (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 more preferable that the sealing layer-side electrode has a property of reflecting light.

[0057] 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), as well as 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 is preferably a thin film (including a thin film formed by vapor deposition) of a metal or a conductive metal oxide, or a glass substrate or plastic substrate having such a thin film. The glass substrate 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.

[0058] (Encapsulating Resin Layer) The encapsulating resin layer may be the same as the adhesive layer described below. The encapsulating agent forming the encapsulating resin layer preferably contains less than 1% by mass of organic solvent. Having an organic solvent content of less than 1% by mass in the encapsulating agent prevents the organic solvent from diffusing from the encapsulating agent into the coating film 47 of the solution forming the photoelectric conversion layer 16. This prevents deterioration of the photoelectric conversion characteristics and other properties of the photoelectric conversion layer 16. While the encapsulating agent preferably contains less than 1% by mass of organic solvent, a lower limit of the organic solvent content is more preferably 0% by mass. In other words, it is more preferable that the encapsulating agent does not contain an organic solvent. An example of an encapsulating agent containing less than 1% by mass of organic solvent is a solventless epoxy resin composition. More specifically, an example of an encapsulating agent containing less than 1% by mass of organic solvent is a two-component resin composition containing an epoxy resin not diluted with an organic solvent as a main component and a polyamine or polyamide as a curing agent. The organic solvent content can be quantified using a known method such as gas chromatography analysis.

[0059] (Mixed Region) The mixed region continuously connects the photoelectric conversion layer and the encapsulating resin layer, preventing moisture from penetrating from the edge of the photoelectric conversion layer. The mixed region also improves adhesion between the photoelectric conversion layer and the encapsulating resin layer, improving adhesion at the edge of the photoelectric conversion layer. As described above, the photoelectric conversion layer 16, the mixed region, and the encapsulating resin layer are continuously provided on the surface of the electron transport layer in the width direction Dw (see FIG. 3). As described above, the mixed region is a region in which part of the photoelectric conversion layer 16 and part of the encapsulating resin layer 19 are mixed, and has, for example, a phase-separated structure. The phase-separated structure is as described above.

[0060] (Adhesive Layer) The 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 adhesive layer is composed of, for example, a cured acrylic resin or a cured epoxy resin. Any known material can be used as the cured acrylic resin, as long as it is a cured monomer or oligomer having an acrylic group in the molecule, and any known material can be used as the cured epoxy resin, as long as it is a cured monomer or oligomer having an epoxy group in the molecule.

[0061] 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.

[0062] 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.

[0063] 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 highly effective in maintaining stable output in various environments. The adhesive layer can be formed using, for example, a thermosetting epoxy resin or an ultraviolet-curing epoxy resin. A solventless epoxy resin composition can be used for the adhesive layer.

[0064] (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. As described above, the sealing layer 22 covers the surface of the adhesive layer 20 and surrounds the photoelectric conversion layer 16. Examples of the sealing layer include a PET (polyethylene terephthalate) film or a PEN film on which a silicon or aluminum oxide, nitride, or nitride oxide is formed. The sealing layer may optionally have a surface functional layer on the side opposite the photoelectric conversion layer. 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. Further details regarding the surface functional layer are provided in JP 2006-289627 A.

[0065] (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.

[0066] (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.

[0067] 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.

[0068] (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.

[0069] 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.

[0070] 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.).

[0071] 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.

[0072] 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.

[0073] Among the materials forming the porous layer, oxides of titanium, tin, zinc, zirconium, aluminum, or silicon, or carbon nanotubes are preferred, 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 types. The thickness of the porous layer is not particularly limited, but is usually in the range of 0.05 to 100 μm, preferably in the range of 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.

[0074] Unless otherwise specified, a scanning electron microscope is used to obtain a cross-sectional image of the cross section of the solar cell in the stacking direction Ds of the solar cell. Ten locations corresponding to the thickness of each layer are selected in the cross-sectional image. For each layer, the length of each of the ten selected locations on the cross-sectional image is measured to obtain the length values ​​for the ten locations. For each layer, the average value of the ten locations is calculated, and this average value is used as the thickness of each layer that constitutes the solar cell.

[0075] The present invention is basically configured as described above. While the solar cell manufacturing method and the solar cell of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various improvements and modifications may be made without departing from the spirit and scope of the present invention.

[0076] The features of the present invention will be explained 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 changed 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 7 and Comparative Example 1 were fabricated and evaluated for moisture resistance, moist heat resistance, and adhesion. The results are shown in Table 1 below. The solar cells of Examples 1 to 7 and Comparative Example 1 will now be described.

[0077] 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.

[0078] <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.

[0079] <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 electron transport layer> The prepared titanium oxide paste was applied onto the blocking layer using an ultrasonic spray and fired in air at 500°C for 3 hours. Thereafter, the obtained fired titanium oxide was dissolved in 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 ２A porous layer (thickness: 250 nm) made of the above was formed as an electron transport layer.

[0080] <Formation of Photoelectric Conversion Layer and Encapsulating Resin Layer> Lead iodide was dissolved in N,N-dimethylformamide to prepare a 1 M solution. This solution was used to form the photoelectric conversion layer. Furthermore, a mixture of 1 equivalent of hydrotalcite and 6 equivalents of epoxy resin manufactured by Epoch Corporation (E-01-001 (product number) with a base:curing agent ratio of 2:1) was used as the sealant. Ultrasonic spraying was used to form the photoelectric conversion layer and the sealing resin layer. An ultrasonic sprayer manufactured by Sonotek was used for the ultrasonic spraying. An imapct nozzle was used to form a coating of the solution that forms the photoelectric conversion layer. An Accumist nozzle was used to form a coating of the sealant that forms the sealing resin layer. When forming the photoelectric conversion layer, the liquid flow rate or air flow rate of the solution was controlled. When forming the sealing resin layer, the liquid flow rate or air flow rate of the sealant was controlled. The first nozzle 42 and the second nozzle 44 shown in FIG. 9 were used as ultrasonic sprayers, and the photoelectric conversion layer and the sealing resin layer were simultaneously formed as shown in FIG. 9. Using an ultrasonic spray, droplets of a solution for forming a photoelectric conversion layer were applied to the photoelectric conversion layer formation region on the electron transport layer to form a coating of the solution. This coating of the solution was a coating of lead iodide. Also, using an ultrasonic spray, droplets of a sealant were applied to the sealing resin layer formation region on the electron transport layer to form a coating of the sealant. Furthermore, methylammonium iodide was dissolved in 2-propanol to prepare a 1 M solution. A support having the above-mentioned coating of the solution and the coating of the sealant formed on the electron transport layer was immersed in this solution, whereby 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 performed at 120° C. for 30 minutes. １ (See FIG. 9) and the sealing resin layer forming region Q ２ (See FIG. 9) and the overlapping area Q ３ The length δ (see FIG. 9) in the width direction Dw (see FIG. 9) of the sheet (see FIG. 9) was set to 5 mm.

[0081] <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, an acetonitrile solution (37.5 μL) prepared by dissolving lithium-bis(trifluoromethanesulfonyl)imide (170 mg) in acetonitrile (1 mL) and t-butylpyridine (TBP, 17.5 μL) were 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 using an ultrasonic spray, and the applied hole transport material solution was dried to form a hole transport layer (film thickness 0.1 μm).

[0082] <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). This resulted in a laminated base material in which the support, the support-side electrode, the electron transport layer, the photoelectric conversion layer, the sealing resin layer, the hole transport layer, and the sealing layer-side electrode were laminated in this order.

[0083] <Formation of Sealing Layer> An organic adhesive was prepared by mixing 6 equivalents of epoxy resin (E-01-001 (product number), main agent:curing agent ratio 2:1) manufactured by Epoch Corporation with 1 equivalent of hydrotalcite. The organic adhesive was the same as the sealant described above. The organic adhesive described above was applied to the surface of the sealing layer side electrode of a PET film (Barrierox manufactured by Toray Industries, Inc.) on which aluminum oxide had been vapor-deposited, which was prepared as a sealing layer. Next, the sealing layer coated with the organic adhesive was placed so that the organic adhesive faced the sealing layer side electrode of the laminated substrate, and the sealing layer was placed on the laminated substrate. While heating to 100°C, the sealing layer and the laminated substrate were bonded together using a pressure press. As a result, the organic adhesive cured to form an adhesive layer, and the sealing layer was fixed to the laminated substrate, thereby obtaining solar cell 10 shown in FIG. 1 .

[0084] (Example 2) Example 2 was the same as Example 1 except that, compared to Example 1, a coating film of a solution that forms a photoelectric conversion layer was formed first, and while the coating film of the solution was drying at a constant rate, a coating film of a sealant that forms a sealing resin layer was formed. (Example 3) Example 3 was the same as Example 1 except that, compared to Example 1, a coating film of a sealant that forms a sealing resin layer was formed first, and while the coating film of the sealant was drying at a constant rate, a coating film of a solution that forms a photoelectric conversion layer was formed.

[0085] (Example 4) Example 4 was the same as Example 1, except that the coating film of the solution that forms the photoelectric conversion layer and the coating film of the sealant were formed using air spray instead of ultrasonic spray, as compared to Example 1. (Example 5) Example 5 was the same as Example 1, except that the coating film of the solution that forms the photoelectric conversion layer was formed using air spray instead of ultrasonic spray, as compared to Example 1. (Example 6) Example 6 was the same as Example 1, except that the coating film of the sealant was formed using air spray instead of ultrasonic spray, as compared to Example 1.

[0086] Example 7 Example 7 is a solar cell having the configuration shown in Fig. 16. Example 7 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.

[0087] Comparative Example 1 Comparative Example 1 was identical to Example 1 except that a sealing resin layer was not formed. Comparative Example 1 had a configuration in which only a photoelectric conversion layer 16 was formed on the surface 15a of the electron transport layer 15, as shown in FIG. 17 . The photoelectric conversion layer 16 of Comparative Example 1 was formed by forming droplets of the solution for forming the photoelectric conversion layer 16 using only the first nozzle 42 of the coating device 40, as shown in FIG. 18 , and applying the droplets to the entire surface 15a of the electron transport layer 15 to form a coating film 47 of the solution. The first nozzle 42 used to form the photoelectric conversion layer was an ultrasonic spray. Note that in FIGS. 17 and 18 , components identical to those in FIGS. 8 and 9 are designated by the same reference numerals, and detailed descriptions thereof will be omitted. The control unit 46 shown in FIG. 9 is not shown in FIG. 18 .

[0088] 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 7 and Comparative Example 1. 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 7 and Comparative Example 1. 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. ２ The 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 7 and Comparative Example 1 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 7 and Comparative Example 1. 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

[0089] <Moisture and Heat Resistance> Three solar cells were fabricated for each of the above-described Examples 1 to 7 and Comparative Example 1. 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 7 and Comparative Example 1. 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. ２The 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 7 and Comparative Example 1 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 7 and Comparative Example 1. 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

[0090] (Adhesion) In the solar cells of Examples 1 to 7 and Comparative Example 1 described above, the portion of the sealing layer in contact with the laminated substrate that was in contact with the surface of the support was peeled off and folded back. The folded portion was pulled in a 180° direction (peel speed: 5 mm / sec) using a peel tester (Shimadzu Corporation, universal testing machine AGS-100NX) and the maximum load (N / 25 mm) was measured. 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 but less than 20 N / 25 mm C: Adhesion strength of 1 N / 25 mm or more but less than 10 N / 25 mm D: Adhesion strength less than 1 N / 25 mm

[0091]

[0092] Since Comparative Example 1 was configured with only a photoelectric conversion layer, a "-" is entered in the "Order of formation of photoelectric conversion layer and encapsulating resin layer" column in Table 1. As shown in Table 1, Examples 1 to 7 were superior to Comparative Example 1 in all of moisture resistance, moist heat resistance, and adhesion. From Examples 1 and 4 to 6, it was found that forming the photoelectric conversion layer and encapsulating resin layer using ultrasonic spraying improved adhesion between the photoelectric conversion layer and the encapsulating resin layer, prevented water from penetrating into the photoelectric conversion layer, and provided excellent moisture resistance and moist heat resistance.

[0093] DESCRIPTION OF SYMBOLS 10, 11 Solar cell 12 Support 12a, 15a, 16a, 19a, 20a, 21c, 22a Surface 13 Conductive support 14 Support-side electrode 15 Electron transport layer 16 Photoelectric conversion layer 17 Hole transport layer 18 Sealing layer-side electrode 19 Sealing resin layer 19c End surface 20 Adhesive layer 21 Mixed region 21a First phase 21b Second phase 22 Sealing layer 22b Back surface 24 Photoelectric conversion section 27 Laminated substrate 40 Coating device 41 Nozzle array 42 First nozzle 43, 45 Droplet 44 Second nozzle 46 Control unit 47, 48 Coating film 49 Organic adhesive Dm Longitudinal direction Ds Stacking direction Dw Width direction Ls Sunlight Q １ Photoelectric conversion layer forming region Q ２ Sealing resin layer forming area Q ３ area δ length

Claims

1. A method for manufacturing a solar cell comprising at least a support, an electron transport layer provided on the support, a photoelectric conversion layer containing a perovskite compound, and a sealing resin layer, the photoelectric conversion layer and the sealing resin layer being provided on the electron transport layer, the method comprising: a first step of forming droplets of a solution that forms the photoelectric conversion layer, and applying the solution in the droplet state to a photoelectric conversion layer formation region on the electron transport layer to form a coating film of the solution; and a second step of forming droplets of a sealant that forms the sealing resin layer, and applying the sealant in the droplet state to a sealing resin layer formation region on the electron transport layer to form a coating film of the sealant, the photoelectric conversion layer formation region and the sealing resin layer formation region being partially overlapped.

2. The method for manufacturing a solar cell according to claim 1, wherein the sealant contains less than 1% by mass of an organic solvent.

3. The method for producing a solar cell according to claim 1 or 2, wherein the first step and the second step are carried out simultaneously.

4. A method for producing a solar cell as described in claim 1 or 2, wherein after the first step is carried out, the second step is carried out while the coating film of the solution is being dried at a constant rate.

5. A method for producing a solar cell according to claim 1 or 2, wherein after the second step is carried out, the first step is carried out while the coating film of the sealant is undergoing the constant rate drying.

6. A method for manufacturing a solar cell as described in claim 1 or 2, wherein in the first step, the solution forming the photoelectric conversion layer is turned into droplets using ultrasound, and the solution in the droplet state is applied to the photoelectric conversion layer formation region on the electron transport layer.

7. A method for manufacturing a solar cell as described in claim 1 or 2, wherein in the second step, the sealant is turned into droplets using ultrasound, and the sealant in the droplet state is applied to the sealing resin layer formation area on the electron transport layer.

8. A method for manufacturing a solar cell as described in claim 1 or 2, wherein in the first step, the solution forming the photoelectric conversion layer is turned into droplets using a spray, and the solution in the droplet state is applied to the photoelectric conversion layer formation region on the electron transport layer.

9. A method for manufacturing a solar cell as described in claim 1 or 2, wherein in the second step, the sealant is turned into droplets using a spray, and the sealant in the droplet state is applied to the sealing resin layer formation area on the electron transport layer.

10. A method for producing a solar cell as described in claim 1 or 2, comprising a third step, after the first step and the second step, of at least heating and drying the coating of the solution to form the photoelectric conversion layer.

11. A solar cell comprising at least a support, an electron transport layer provided on the support, a photoelectric conversion layer containing a perovskite compound, and a sealing resin layer, the photoelectric conversion layer and the sealing resin layer being provided on the electron transport layer, wherein a mixed region of the photoelectric conversion layer and the sealing resin layer is present between the photoelectric conversion layer and the sealing resin layer.

12. The solar cell described in claim 11, wherein the mixed region has a phase-separated structure having a first phase formed of a component constituting the photoelectric conversion layer and a second phase formed of a component constituting the encapsulating resin layer.

13. The solar cell according to claim 12, wherein the phase-separated structure is at least one of a sea-island structure, a continuous spherical structure, a composite dispersed structure, and a co-continuous structure.

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