Solar cell element and solar cell module

Abstract

The solar cell element has a solar cell section (103), an electrode section (101), and a first diffusion reduction section (102). The solar cell unit (103) has a light receiving surface (F1). The first diffusion reduction section (102) is located between the solar cell section (103) and the electrode section (101). The first diffusion reduction section (102) has a first surface (F3) on the light receiving surface (F1) side and a second surface (F4) on the electrode section (101) side. The first diffusion-reducing section (102) is disposed so as to avoid at least a part of a region that does not overlap the electrode section (101) in plan view of the light-receiving surface (F1).

Description

[0001] Cross-references of related applications

[0002] This application claims priority based on Japanese application No. 2022-145444 (filed on September 13, 2022), the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present invention relates to a solar cell element and a solar cell module. Background Art

[0004] There is a solar cell element, which includes: a semiconductor that generates electricity using incident light; a transparent electrode film that is disposed on a light-receiving surface of a solar cell portion; and a collector electrode that is disposed on the transparent electrode film (for example, Patent Document 1). In such a solar cell element, it is known that a transparent electrode film is used as an interface layer for reducing degradation caused by diffusion between the collector electrode and the semiconductor (for example, Patent Document 2).

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2002-76385.

[0008] Patent document 2: Japanese Patent Application Publication No. 2015-122435. Summary of the invention

[0009] Problems to be solved by the invention

[0010] Regarding solar cell elements, there is room for improvement in achieving both improved reliability and reduced reduction in power generation efficiency.

[0011] Means for solving problems

[0012] A solar cell element has a solar cell section, an electrode section, and a first diffusion reduction section. The solar cell section has a light-receiving surface. The first diffusion reduction section is located between the solar cell section and the electrode section. The first diffusion reduction section has a first surface on the light-receiving surface side and a second surface on the electrode section side. The first diffusion reduction section is arranged to avoid at least a portion of an area that does not overlap with the electrode section when the light-receiving surface is viewed from above.

[0013] One embodiment of a solar cell element comprises a solar cell unit, an electrode unit, and a first diffusion reduction unit. The solar cell unit has a light-receiving surface. The first diffusion reduction unit is located between the solar cell unit and the electrode unit. The first diffusion reduction unit comprises: a first surface on the light-receiving surface side; a second surface on the electrode unit side; and a third surface on the side opposite to the first surface, the third surface being located at least in a portion of a region that does not overlap with the electrode unit when the light-receiving surface is viewed from above. The thickness between the first surface and the third surface is smaller than the thickness between the first surface and the second surface.

[0014] One embodiment of a solar cell module includes a solar cell unit having a light-receiving surface. The solar cell module includes a first diffusion reduction unit, the first diffusion reduction unit including: a first surface, the first surface in contact with the light-receiving surface; a second surface, the second surface being a surface on the opposite side of the first surface; and a third surface, the third surface being a surface different from the second surface, and the first diffusion reduction unit is located on the light-receiving surface. The solar cell module includes an electrode unit located on the second surface. The first diffusion reduction unit includes: a first portion, the first portion having a thickness from the first surface to the second surface; and a second portion, the second portion having a thickness from the first surface to the third surface. The thickness of the second portion is smaller than the thickness of the first portion.

[0015] Effects of the Invention

[0016] It is possible to achieve both improvement in reliability and reduction in reduction in power generation efficiency in solar cell elements and solar cell modules. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a perspective view showing a part of the solar cell element 10 according to the first embodiment.

[0018] Figure 2 It is a plan view showing a part of the solar cell element 10 according to the first embodiment.

[0019] Figure 3 The solar cell element 10 of the first embodiment, Figure 2 End view of the III-III section in FIG.

[0020] Figure 4 The solar cell element 10 of the first embodiment Figure 3 A magnified portion of the image.

[0021] Figure 5 It is a diagram showing a modification of the solar cell element 10 according to the first embodiment.

[0022] Figure 6 This is a diagram showing an example of the solar cell element 10 according to the first embodiment.

[0023] Figure 7This is a diagram showing an example of the solar cell element 10 according to the first embodiment.

[0024] Figure 8 This is a diagram showing an example of the solar cell element 10 according to the first embodiment.

[0025] Fig. 9 This is a diagram showing an example of the solar cell element 10 according to the first embodiment.

[0026] Fig.10 This is a flowchart of the method for manufacturing the solar cell element 10 according to the first embodiment.

[0027] Fig.11 It is a cross-sectional view of the solar cell module 1 according to the first embodiment.

[0028] Fig.12 It is a cross-sectional view of a solar cell module 2 according to the second embodiment.

[0029] Fig.13 It is a diagram of a solar cell element 30 according to the third embodiment.

[0030] Fig.14 It is a diagram of a solar cell element 40 according to a fourth embodiment.

[0031] Fig.15 It is a diagram of a solar cell element 50 according to the fifth embodiment.

[0032] Fig.16 It is a diagram of a solar cell element 60 according to a sixth embodiment.

[0033] Fig.17 It is a diagram of a solar cell element module 6 according to the sixth embodiment.

[0034] Fig.18 It is a diagram of a solar cell element 70 according to the seventh embodiment.

[0035] Fig.19 It is a diagram of a solar cell element module 7 according to the seventh embodiment. DETAILED DESCRIPTION

[0036] The solar cell element has a first electrode portion on a light receiving surface side of the solar cell element that receives light, and the first electrode portion collects electricity generated by the solar cell portion that generates electricity using incident light.

[0037] It is known that the power generation efficiency of such solar cell elements decreases after a predetermined period of use. One of the main causes of the decrease in power generation efficiency is that the material of the solar cell section diffuses into the first electrode section, or the material of the first electrode section diffuses into the solar cell section.

[0038] Therefore, for example, it is considered that by forming the diffusion reduction portion between the first electrode portion and the solar cell portion, the possibility of reduction in power generation efficiency due to diffusion between the first electrode portion and the solar cell portion is reduced. In other words, it is considered that by forming the diffusion reduction portion between the first electrode portion and the solar cell portion, the reliability of the solar cell element is improved.

[0039] However, if the diffusion reduction portion is formed between the first electrode portion and the solar cell portion, sunlight is absorbed in the diffusion reduction portion, and the amount of sunlight received by the solar cell portion that contributes to power generation is reduced. In other words, it is believed that the power generation efficiency of the solar cell element is reduced if the diffusion reduction portion is formed.

[0040] Therefore, there is room for improvement in solar cell elements in terms of achieving both improved reliability and reduced reduction in power generation efficiency. In addition, solar cell modules using solar cell elements also have the same problem.

[0041] Therefore, the inventors of the present invention have created a technology that can improve the power generation efficiency and reliability of solar cell elements and solar cell modules. In this regard, Embodiments 1 to 7 will be described below with reference to the drawings.

[0042] Hereinafter, the implementation mode will be described with reference to the accompanying drawings. In the accompanying drawings, the same figure marks are given to parts having the same or similar structures and functions, and repeated descriptions are omitted in the following descriptions. The accompanying drawings are shown schematically. In each figure, a right-handed XYZ coordinate system is marked respectively. In the XYZ coordinate system, the normal direction of the light-receiving surface F1 of the solar cell element 10 is the +Z direction, a direction along the light-receiving surface F1 is the +X direction, and a direction along the light-receiving surface F1 and orthogonal to the +X direction and the +Z direction is the +Y direction. In addition, below, unless otherwise specified, the upward direction refers to the +Z direction.

[0043] [Implementation Method 1]

[0044] <1-1. Solar cell element 10>

[0045] Reference Figures 1 to 3 The solar cell element 10 according to the first embodiment will be described. Figure 1 This is a perspective view of a portion of the solar cell element 10 according to the first embodiment. Figure 2 This is a plan view of a portion of the solar cell element 10 according to the first embodiment, as viewed from the light receiving surface F1 side. Figure 3 is along Figure 2 That is, Figure 3 is a cross-sectional view taken along a cross section perpendicular to the length direction of the first electrode portion 101. It should be noted that, Figure 1 and Figure 2 The figure does not show the entire solar cell element 10 but a portion of the solar cell element 10 cut out and shown.

[0046] like Figure 1 As shown, the solar cell element 10 has: a light receiving surface F1, which mainly receives light; and a back surface F2, which is located on the opposite side of the light receiving surface F1. In the first embodiment, the light receiving surface F1 faces the +Z direction. The back surface F2 faces the -Z direction. For example, the +Z direction is set to the direction toward the sun at the zenith.

[0047] like Figure 3 As shown in FIG. 1 , the solar cell element 10 includes a first electrode portion 101, a first diffusion reducing portion 102, a solar cell portion 103, a second electrode portion 104, and a substrate portion 105. Figure 3 As shown, the solar cell unit 103 has a first carrier transport unit 1031, a photoelectric conversion unit 1032, and a second carrier transport unit 1033. In the first embodiment, the second electrode unit 104, the second carrier transport unit 1033, the photoelectric conversion unit 1032, the first carrier transport unit 1031, the first diffusion reducing unit 102, and the first electrode unit 101 are stacked on the substrate unit 105 in the order described.

[0048] It should be noted that, although not shown in the figure, an anti-reflection film may be arranged on the surface of the solar cell module 1 (described later). The anti-reflection film may be, for example, an insulating film composed of silicon nitride or the like. In addition, although not shown in the figure, a passivation film may be arranged between the first electrode portion 101, the first diffusion reduction portion 102, or the solar cell portion 103 and the anti-reflection film. The passivation film may be, for example, a thin film composed of an oxide such as aluminum oxide or a nitride or the like.

[0049] By connecting a plurality of solar cell elements 10 to each other, the plurality of solar cell elements 10 can form a solar cell module 1. For example, a solar cell module 1 having a size of about 1 m square can be prepared by connecting a plurality of solar cell elements 10. In addition, by connecting a plurality of solar cell modules 1 to each other, the plurality of solar cell modules 1 can form a solar cell string. By connecting a plurality of solar cell strings to each other, the plurality of solar cell strings can form a solar cell array.

[0050] Next, the components included in the solar cell element 10 will be described. For convenience of description, the components will be described in order starting from the substrate portion 105 .

[0051] <1-1-1. Substrate part 105>

[0052] The substrate 105 is a base that forms a portion (solar cell 103, etc.) included in the solar cell element 10. The material of the substrate 105 can be, for example, glass, plastic such as acrylic or polycarbonate, or metal such as stainless steel. As the shape of the substrate 105, for example, a flat plate, a sheet, or a film can be applied. The thickness of the substrate 105 can also be, for example, about 0.01 millimeters (mm) to 5 mm.

[0053] <1-1-2. Second Electrode Section 104 >

[0054] The second electrode portion 104 is located on the substrate portion 105. The second electrode portion 104 can collect carriers generated by photoelectric conversion according to the irradiation of light to the solar cell portion 103 described later. The second electrode portion 104 can, for example, play a role as an electrode (also referred to as a negative electrode) that collects electrons as carriers. As a material for the second electrode portion 104, for example, a metal with excellent conductivity such as silver (Ag), gold (Au), copper (Cu), titanium (Ti), indium (In) or tin (Sn) can be applied.

[0055] In addition, the material of the second electrode portion 104 can be, for example, a transparent conductive oxide (TCO) that is translucent to light in a specific wavelength range. The thickness of the second electrode portion 104 can be, for example, about 10 nanometers (nm) to 1000 nm. For example, the second electrode portion 104 can be formed on the substrate portion 105 using a vacuum process such as sputtering.

[0056] TCO can be, for example, indium tin oxide (ITO), aluminum-doped zinc oxide (AZO), boron-doped zinc oxide (BZO), gallium-doped zinc oxide (GZO), fluorine-doped tin oxide (FTO), antimony-doped tin oxide (ATO), titanium-doped indium oxide (ITiO), indium zinc oxide (IZO), indium gallium zinc oxide (IGZO), tantalum-doped tin oxide (SnO2:Ta), niobium-doped tin oxide (Nb-doped tin oxide: SnO2:Nb), tungsten-doped tin oxide (W-doped tin oxide: SnO2:Nb), and tungsten-doped tin oxide (TCO). The transparent conductive oxide film may be a laminated film having a plurality of films, and in addition to the above-mentioned oxides, films such as tin oxide may also be included in the laminated film. The dopant in the film such as tin oxide may be one or more selected from the group consisting of In, silicon (Si), germanium (Ge), Ti, Cu, antimony (Sb), Nb, F, Ta, W, Mo, bromine (Br), iodine (I) or chlorine (Cl), etc., without particular limitation.

[0057] <1-1-3. Solar cell section 103>

[0058] The solar cell section 103 is located on the second electrode section 104. The solar cell section 103 converts light incident from the outside (e.g., sunlight) into electricity. For example, the solar cell section 103 can generate carriers by photoelectric conversion according to the irradiation of light. The carriers include at least one of electrons and holes. The solar cell section 103 has a first light-receiving surface F1.

[0059] In the first embodiment, the first carrier transporting section 1031 as a p-type semiconductor, the photoelectric conversion section 1032 as an i-type semiconductor, and the second carrier transporting section 1033 as an n-type semiconductor are in a state of forming a PIN junction region. With the help of the PIN junction region, power generation can be performed by photoelectric conversion corresponding to light irradiation.

[0060] In the first embodiment, the case where the solar cell section 103 is a perovskite solar cell is used as an example for explanation. However, this is only an example, and other types of solar cells may also be applied. For example, the type of solar cell may be an inorganic solar cell or an organic solar cell. The inorganic solar cell may be a silicon solar cell or a compound solar cell. The organic solar cell may be a dye-sensitized solar cell or an organic thin film solar cell. In addition, for example, the type of solar cell may be a crystalline solar cell or a thin film solar cell. The crystalline solar cell may be a silicon solar cell or a compound semiconductor solar cell such as a copper indium gallium selenide (CIGS) solar cell. The thin film solar cell may be a perovskite solar cell or a dye-sensitized solar cell or an organic thin film solar cell, etc.

[0061] like Figure 3 As shown, the solar cell portion 103 includes a first carrier transport portion 1031, a photoelectric conversion portion 1032, and a second carrier transport portion 1033. In the first embodiment, the second carrier transport portion 1033, the photoelectric conversion portion 1032, and the first carrier transport portion 1031 are stacked on the second electrode portion 104 in this order.

[0062] Next, the parts included in the solar cell portion 103 will be described. For convenience of description, the parts will be described in order starting from the second carrier transporting portion 1033.

[0063] The second carrier transporting unit 1033 is located on the second electrode unit 104. For example, the second carrier transporting unit 1033 may be an inorganic semiconductor (also referred to as an inorganic semiconductor) having a higher resistance than the second electrode unit 104. Thus, it is difficult to establish electrical contact between the second electrode unit 104 and the photoelectric conversion unit 1032.

[0064] In the first embodiment, the material of the inorganic semiconductor may be, for example, a semiconductor having an n-type conductivity (also referred to as an n-type semiconductor). In this case, the second carrier transport unit 1033 may function as, for example, a so-called hole blocking layer or an electron transport layer (ETL). The electron transport layer may, for example, collect electrons and output them.

[0065] As an n-type semiconductor, for example, [6,6]-phenyl-C-61-butyric acid methyl ester (PCBM), C60 or an oxide semiconductor layer can be used. As an oxide semiconductor layer, for example, titanium (IV) oxide (TiO2), zinc oxide (ZnO), indium (III) oxide (In2O3), tin (IV) oxide (SnO2), or magnesium oxide (MgO) can be used.

[0066] The photoelectric conversion unit 1032 is located on the second carrier transport unit 1033. The photoelectric conversion unit 1032 can absorb light that passes through the first diffusion reduction unit 102 and the first carrier transport unit 1031 described later. In embodiment 1, the photoelectric conversion unit 1032 applies, for example, an intrinsic semiconductor (also called an i-type semiconductor). The i-type semiconductor can apply, for example, a semiconductor having a perovskite structure (also called a perovskite semiconductor). The perovskite semiconductor can include, for example, a halide-based organic-inorganic perovskite semiconductor. The halide-based organic-inorganic perovskite semiconductor is a semiconductor having a perovskite structure composed of ABX3. Here, A, for example, applies one or more ions of methylammonium (CH3NH3), formamidine (CH(NH2)2), cesium (Cs), rubidium (Rb) and potassium (K). In addition, B, for example, applies one or more ions of lead (Pb) and tin (Sn). In addition, X, for example, applies one or more ions of iodine (I), bromine (Br) and chlorine (Cl). Specifically, a semiconductor having a perovskite structure composed of ABX3 can be composed of organic perovskites such as CH3NH3PbI3 or (CH(NH2)2, Cs)Pb(I, Br)3. For example, a first raw material liquid is applied to the second carrier transport unit 1033 and dried to form an organic perovskite. Here, the organic perovskite is a crystalline film. The first raw material liquid can be generated, for example, by dissolving alkyl amine halide and lead halide as raw materials in a solvent. The thickness of the photoelectric conversion unit 1032 can be, for example, about 100nm to 2000nm.

[0067] The first carrier transporting portion 1031 is located on the photoelectric conversion portion 1032. The surface of the first carrier transporting layer 1031 on the opposite side to the photoelectric conversion portion 1032 may be a light receiving surface F1. In the first embodiment, for example, the first carrier transporting portion 1031 may be a semiconductor having a p-type conductivity (also referred to as a p-type semiconductor). In this case, the first carrier transporting portion 1031 has a function as a so-called electron blocking layer or a hole transporting layer (HTL), for example. The HTL, for example, collects holes and outputs them.

[0068] The material of the HTL is, for example, [2,2',7,7'-tetrakis(N,N-di-p-methoxyphenylamino)-9,9'-spirobifluorene] (spiro-OMeTAD) which is a soluble diamine derivative. For example, the second raw material solution is applied on the perovskite semiconductor layer as the photoelectric conversion unit 1032 and dried to generate the HTL. The thickness of the carrier transport layer can be, for example, about 50 nm to 200 nm.

[0069] As a p-type semiconductor, for example, nickel (II) oxide (NiO), copper (I) thiocyanate (CuSCN) or copper (I) oxide (Cu2O) or an organic semiconductor layer, etc. As an organic semiconductor layer, for example, spiro-OMeTAD, poly [bis (4-phenyl) (2,4,6-triphenylmethyl) amine] (PTAA), poly (3-hexylthiophene-2,5-diyl) (P3HT), poly (3,4-ethylenedioxythiophene) / poly (4-styrene sulfonate) (PEDOT / PSS) can be used.

[0070] <1-1-4. First diffusion reducing portion 102>

[0071] The first diffusion reduction portion 102 is located on the solar cell portion 103. In other words, the first diffusion reduction portion 102 is located on the light receiving surface F1 of the solar cell portion 103. In other words, the first diffusion reduction portion 102 is located between the first electrode portion 101 and the solar cell portion 103. Here, the first diffusion reduction portion 102 may have a first surface F3 and a second surface F4, the first surface F3 being a surface in contact with the light receiving surface F1 of the solar cell portion 103, and the second surface F4 being a surface on the side opposite to the first surface F3. The first surface F3 is a surface on the solar cell portion 103 side of the first diffusion reduction portion 102, and the second surface F4 is a surface on the first electrode portion 101 side of the first diffusion reduction portion 102. The second surface F4 is also a surface opposite to the first surface F3 in the thickness direction of the solar cell portion 103. The first surface F3 and the second surface F4 may be, for example, flat surfaces.

[0072] exist Figure 1 In the example of FIG. 1 , the first diffusion reducing portion 102 has a third surface F5 that is consistent with the first surface F3. That is, the position of the third surface F5 in the +Z direction is consistent with the position of the first surface F3 in the +Z direction. Fig.13 As described in detail, the third face F5 may be different from the first face F3 and the second face F4. Fig.13 As shown, the third surface F5 may exist between the position of the first surface F3 in the +Z direction and the position of the second surface F4 in the +Z direction. The third surface F5 is located at least in a portion of the region that does not overlap with the first electrode portion 101 when the light receiving surface F1 is viewed from above. Fig.13In the embodiment, the third surface F5 can be composed of one surface, which can be considered as a set of surfaces of the first diffusion reduction portion 102 parallel to the first surface F3 and the second surface F4. For example, the third surface F5 can be considered as a set of surfaces of the first diffusion reduction portion 102 whose position in the +Z direction exists between the position of the first surface F3 in the +Z direction and the position of the second surface F4 in the +Z direction. Fig.13 In the example, the third surface F5 may be parallel to the first surface F3 and the second surface F4.

[0073] It can be considered Figures 1 to 3 FIG. 1 shows a solar cell element 10 when the thickness of the second portion A2 described later is 0. Figure 1 and Figure 3 As shown, the third surface F5 (here the first surface F3) may be parallel to the second surface F4.

[0074] Hereinafter, the thickness of the first diffusion reducing portion 102 refers to the thickness in the +Z direction. In other words, the thickness of the first diffusion reducing portion 102 can be considered to be the thickness in the direction from the first surface F3 toward the second surface F4. The thickness of the first portion A1 or the second portion A2 described later is also considered to be the same as the thickness of the first diffusion reducing portion 102.

[0075] As the material of the first diffusion reduction portion 102, a conductive inorganic substance can be applied. For example, a conductive oxide or a conductive nitride can be applied. For example, the first diffusion reduction portion 102 can be formed on the first carrier transport portion 1031 using a vacuum process. The vacuum process can be sputtering, chemical vapor deposition (CVD), vacuum evaporation or atomic layer deposition (ALD). The thickness of the first diffusion reduction portion 102 can be, for example, about 1 nm to 100 nm.

[0076] The first diffusion reduction portion 102 is an interface layer between the first electrode portion 101 and the solar cell portion 103. The interface layer between the upper portion and the lower portion described here refers to an intermediate layer having an upper surface in contact with the upper portion and a lower surface in contact with the lower portion. For example, the first diffusion reduction portion 102 has a function as a diffusion barrier film. If the first electrode portion 101 is directly formed on the light receiving surface F1, the metal constituting the first electrode portion 101 diffuses into the first carrier transport portion 1031 or the photoelectric conversion portion 1032, so that the first carrier transport portion 1031 or the photoelectric conversion portion 1032 sometimes deteriorates. Alternatively, the molecules constituting the first carrier transport portion 1031 or the photoelectric conversion portion 1032 diffuse into the first electrode portion 101, so that the first electrode portion 101 sometimes deteriorates. As a result, the conversion efficiency of the solar cell element 10 sometimes deteriorates. Therefore, by providing the first diffusion reducing portion 102 between the first carrier transporting portion 1031 and the first electrode portion 101, it is possible to reduce the degradation of the conversion efficiency of the solar cell element 10 caused by diffusion. That is, the first diffusion reducing portion 102 reduces at least one of the amount of metal moving from the first electrode portion 101 to the first carrier transporting portion 1031 and the amount of metal moving from the first carrier transporting portion 1031 to the first electrode portion 101.

[0077] The first diffusion reducing portion 102 includes a first portion A1 and a second portion A2. The first portion A1 is a portion of the first diffusion reducing portion 102 having a thickness extending from the first surface F3 to the second surface F4. Fig.13 It can be easily understood that the second portion A2 is a portion of the first diffusion reduction portion 102 having a thickness from the first surface F3 to the third surface F5. For example, when the position of the third surface F5 in the +Z direction exists between the position of the first surface F3 in the +Z direction and the position of the second surface F4 in the +Z direction, the thickness of the first portion A1 is greater than the thickness of the second portion A2. It can be considered that the first diffusion reduction portion 102 has the first portion A1 and the second portion A2 having a thickness less than the first portion A1. In other words, in this case, it can be considered that the first diffusion reduction portion 102 has the second portion A2 and the first portion A1 having a thickness greater than the second portion A2. That is, in the first diffusion reduction portion 102, the portion with a relatively large thickness can be considered to be the first portion A1, and the portion with a relatively small thickness can be considered to be the second portion A2.

[0078] The thickness of the second portion A2 may be 0 (see also Figure 1). In other words, it can be considered that the third surface F5 can be consistent with the first surface F3 instead of being parallel to the first surface F3. In this case, the second portion A2 is the portion where the first diffusion reduction portion 102 does not cover the light receiving surface F1 of the solar cell portion 103. In other words, in this case, when looking down at the solar cell element 10, the second portion A2 is the portion where the light receiving surface F1 of the solar cell portion 103 is exposed. It should be noted that the exposure mentioned here means, for example, that the light receiving surface F1 of the solar cell portion 103 has a portion exposed from the first diffusion reduction portion 102. In other words, a transparent layer different from the first diffusion reduction portion 102 can also be provided on the portion of the light receiving surface F1 of the solar cell portion 103.

[0079] From another perspective, it can be considered that the light-receiving surface F1 of the solar cell section 103 includes: a first portion A1, which is a portion covered by the first diffusion reduction portion 102; and a second portion A2, which is a portion not covered by the first diffusion reduction portion 102. In this case, when the solar cell element 10 is viewed from the light-receiving surface F1 side, the first diffusion reduction portion 102 or the first electrode portion 101 is observed at the first portion A1. On the other hand, when the solar cell element 10 is viewed from the light-receiving surface F1 side, the light-receiving surface F1 of the solar cell section 103 is observed at the second portion A2. That is, when the solar cell element 10 is viewed from the light-receiving surface F1 side, the light-receiving surface F1 of the solar cell section 103 is exposed at the second portion A2. In other words, the first diffusion reduction portion 102 is arranged to avoid at least a portion of the region that does not overlap with the first electrode portion 101 when the light-receiving surface F1 is viewed from above. As a specific example, the first electrode portion 101 may include a plurality of length portions 1011 extending along a predetermined length direction when the light receiving surface F1 is viewed from above (see FIG. Figure 2 The length portions 1011 may be arranged at intervals in a direction intersecting the length direction. The first diffusion reducing portion 102 may be arranged, for example, to avoid at least a portion of the region between the length portions 1011 .

[0080] It should be noted that if Fig.13 As shown, the thickness of the second portion A2 may be constant within the first diffusion reduction portion 102. In this case, the position of the third surface F5 in the +Z direction is constant within the first diffusion reduction portion 102. In other words, in this case, the height of the third surface F5 in the +Z direction based on the first surface F3 is constant within the first diffusion reduction portion 102. By setting the thickness of the second portion A2 to be constant within the first diffusion reduction portion 102, the manufacturing process of the solar cell element 10 can be simplified.

[0081] On the other hand, the thickness of the second portion A2 may have a plurality of thicknesses within the first diffusion reduction portion 102. For example, the second portion A2 may include a portion having a first thickness and a portion having a second thickness. In other words, the position of the third surface F5 in the +Z direction may take a plurality of positions within the first diffusion reduction portion 102. For example, the third surface F5 may have: a portion where the distance between the first surface F3 and the third surface F5 is equal to the first thickness; and a portion where the distance between the first surface F3 and the third surface F5 is equal to the second thickness. It should be noted that the first thickness or the second thickness may be 0, or may be the same thickness as the thickness between the first surface F3 and the second surface F4. The thickness of the second portion A2 has a plurality of thicknesses within the first diffusion reduction portion 102, so that the second portion A2 has a thick portion and a thin portion. As a result, the manufacturing cost of the solar cell element 10 associated with the thin portion of the second portion A2 can be reduced.

[0082] The first electrode portion 101 described later is located on the first portion A1. Specifically, the first electrode portion 101 described later is located on the second surface F4 in the first portion A1. In other words, for the first diffusion reduction portion 102, it can be considered that the thickness of the first diffusion reduction portion 102 is different at the portion (first portion A1) on which the first electrode portion 101 is arranged and the portion (second portion A2) on which the first diffusion reduction portion 102 is not arranged. For example, in the first embodiment, the thickness of the portion on which the first electrode portion 101 is arranged on the first diffusion reduction portion 102 is greater than the thickness of the portion on which the first electrode portion 101 is not arranged on the first diffusion reduction portion 102 (=0).

[0083] It should be noted that, when the thickness of the second portion A2 is 0, the first electrode portion 101 described later is also located on the first portion A1. In this case, it can be considered that the first electrode portion 101 is located on the first diffusion reducing portion 102.

[0084] When the above structure is adopted, since light does not enter the solar cell section 103 located below the first electrode section 101, even if the thickness of the first diffusion reducing section 102 is increased, the change in light incident on the photoelectric conversion section 1032 is small. On the other hand, by increasing the thickness of the first diffusion reducing section 102, the possibility of the molecules of one between the first electrode section 101 and the solar cell section 103 diffusing to the other can be reduced. That is, by positioning the first electrode section 101 only on the first portion A1 of the first diffusion reducing section 102, the diffusion reduction function of the first diffusion reducing section 102 can be improved without almost changing the amount of light received by the solar cell section 103.

[0085] In the solar cell element 10, the thickness of the second portion A2 may be made smaller than the thickness of the first portion A1. In this case, for the first diffusion reduction portion 102, the position of the third surface F5 in the +Z direction exists between the position of the first surface F3 in the +Z direction and the position of the second surface F4 in the +Z direction. When this structure is adopted, the amount of attenuation of light incident on the solar cell portion 103 when passing through the second portion A2 of the first diffusion reduction portion 102 can be reduced. That is, by making the thickness of the second portion A2 smaller than the thickness of the first portion A1, the amount of light incident on the solar cell portion 103 can be increased compared to the case where the thickness of the second portion A2 is equal to the thickness of the first portion A1. As a result, the power generation efficiency of the solar cell element 10 can be improved.

[0086] For example, the thickness of the second portion A2 may be 0. That is, the first diffusion reduction portion 102 may not be provided in at least a portion of the portion where the first electrode portion 101 is not configured. That is, the first diffusion reduction portion 102 may be formed in such a manner that the solar cell portion 103 is observed at the portion where the first electrode portion 101 is not present when the solar cell element 10 is viewed from the light-receiving surface F1 side. In other words, when the third surface F5 is aligned with the first surface F3 instead of being parallel to the first surface F3, the first diffusion reduction portion 102 may not be provided in at least a portion of the portion where the first electrode portion 101 is not configured. That is, the first diffusion reduction portion 102 may be formed in such a manner that the light-receiving surface F1 of the solar cell portion 103 is observed at the second portion A2 when the solar cell element 10 is viewed from the first electrode portion 101 side.

[0087] When the above structure is adopted, the absorption loss of light caused by the first diffusion reduction portion 102 of the second portion A2 can be reduced. That is, the light passing through the second portion A2 and incident on the photoelectric conversion portion 1032 can be increased. Therefore, since the light incident on the photoelectric conversion portion 1032 is increased, the conversion efficiency of the solar cell element 10 can be improved.

[0088] When the thickness of the second portion A2 is 0, the material of the first diffusion reducing portion 102 may include a material having an absorption wavelength overlapping the absorption wavelength of the photoelectric conversion portion 1032. That is, the material of the first diffusion reducing portion 102 may include a material that is not transparent to the absorption wavelength of the photoelectric conversion portion 1032.

[0089] When the above structure is adopted, since light does not originally enter the solar cell section 103 located below the first electrode section 101, even if the first diffusion reducing section 102 located below the first electrode section 101 has the same absorption wavelength as the absorption wavelength of the photoelectric conversion section 1032, the light entering the photoelectric conversion section 1032 is almost unchanged. On the other hand, since the requirement for the absorption wavelength is relaxed, it is possible to increase the selection of materials applicable to the first diffusion reducing section 102. Therefore, when the thickness of the second portion A2 is 0, by setting the material of the first diffusion reducing section 102 to include a material having an absorption wavelength overlapping the absorption wavelength of the photoelectric conversion section 1032, it is possible to increase the selection of materials applicable to the first diffusion reducing section 102.

[0090] When looking down at the light receiving surface F1 of the solar cell element 10, the width Wp of the first diffusion reducing portion 102 of the first portion A1 may be greater than the width We of the first electrode portion 101. In other words, in a cross section ( Figure 4 ), the width Wp of the first diffusion reducing portion 102 of the first portion A1 may be greater than the width We of the first electrode portion 101. The width Wp may also be the width of the second surface F4 of the first diffusion reducing portion 102.

[0091] When the above structure is adopted, compared with the case where the width Wp of the first diffusion reducing portion 102 of the first portion A1 is the same as the width We of the first electrode portion 101, it is possible to reduce the molecules on the side of the first electrode portion 101 from falling off and diffusing into the solar cell portion 103. Thus, the decrease in the conversion efficiency of the solar cell element 10 can be reduced.

[0092] The width Wp of the first diffusion reduction portion 102 of the first portion A1 may be a width obtained by adding a predetermined width to the width We of the first electrode portion 101. The predetermined width may be determined based on the position accuracy of forming the first electrode portion 101. For example, the predetermined width may be determined to be a value greater than an error when forming the first electrode portion 101. In this case, the error when forming the first electrode portion 101 may occur in either the left or right direction, and therefore, the predetermined width may be more than twice the error when forming the first electrode portion 101.

[0093] The width Wp of the first diffusion reduction portion 102 of the first portion A1 may be determined according to the width We of the first electrode portion 101. For example, the width Wp of the first diffusion reduction portion 102 of the first portion A1 may be smaller than the width We of the first electrode portion 101 by about 100 nm or more and about 100 micrometers (μm) or less. For example, when the width We of the first electrode portion 101 is greater than 10 μm and less than 100 μm, the width Wp of the first diffusion reduction portion 102 of the first portion A1 may be greater than 10 μm and less than 100 μm than the width We of the first electrode portion 101. For example, relative to the width We of the first electrode portion 101, the width Wp of the first diffusion reduction portion 102 of the first portion A1 may be greater than 100% and less than 200%.

[0094] It should be noted that the first electrode portion 101 may be formed at a position on either the left or right side of the first diffusion reducing portion 102 that is biased toward the first portion A1. Figure 4 In the embodiment, the left-right center line of the first electrode portion 101 and the left-right center line of the first diffusion reducing portion 102 of the first portion A1 can be separated. Figure 4 In the embodiment, the distance from the left end of the first electrode unit 101 to the left end of the first diffusion reducing portion 102 of the first portion A1 may be different from the distance from the right end of the first electrode unit 101 to the right end of the first diffusion reducing portion 102 of the first portion A1.

[0095] It should be noted that in the first embodiment, the cross-sectional shape of the first diffusion reducing portion 102 of the first portion A1 is a rectangle, but the cross-sectional shape of the first diffusion reducing portion 102 of the first portion A1 is not limited thereto. Figures 5 to 9 The types of cross-sectional shapes of the first diffusion reducing portion 102 of the first portion A1 will be described.

[0096] For example, in the cross-sectional shape of the first diffusion reducing portion 102 of the first portion A1, as Figures 5 to 7 As shown in FIG. 1 , the width Wd of the surface in contact with the solar cell portion 103 may be greater than the width Wu of the surface in contact with the first electrode portion 101. That is, the width Wd of the surface on the first surface F3 side of the first portion A1 may be greater than the width Wu of the surface on the second surface F4 side of the first portion A1. In other words, in the cross-sectional shape of the first diffusion reducing portion 102 of the first portion A1, as shown in FIG. Figures 5 to 7 As shown in FIG. 1 , the area of ​​the surface in contact with the solar cell section 103 may be larger than the area of ​​the surface in contact with the first electrode section 101. By adopting this structure, the center of gravity of the first diffusion reducing section 102 is located on the solar cell section 103 side, so the structural stability of the first diffusion reducing section 102 can be improved. In this case, Figure 5As shown in FIG. 1 , the cross-sectional shape of the first diffusion reducing portion 102 of the first portion A1 may be a trapezoid. Figure 6 As shown in FIG. 1 , the cross-sectional shape of the first diffusion reducing portion 102 of the first portion A1 may be a dome shape. In other words, the fourth surface F6 as the side surface of the first portion A1 may be an arc-shaped curved surface having a center in the first diffusion reducing portion 102. Figure 7 As shown, the cross-sectional shape of the first diffusion reducing portion 102 of the first portion A1 may be a shape with an expanded hem. In other words, the fourth surface F6 of the first portion A1 may be an arc-shaped curved surface having a center outside the first diffusion reducing portion 102 in the X direction.

[0097] For example, in the cross-sectional shape of the first diffusion reducing portion 102 of the first portion A1, as Figure 8 As shown, the width Wd on the solar cell portion 103 side may be smaller than the width Wu on the first electrode portion 101 side. By adopting this structure, the area of ​​the solar cell portion 103 that can receive light can be increased, so the conversion efficiency of the solar cell element 10 can be improved.

[0098] In addition, if Fig. 9 As shown, when looking down at the light receiving surface F1 of the solar cell element 10, even if the width Wp of the first diffusion reduction portion 102 of the first part A1 is greater than the width We of the first electrode portion 101, the material of the first diffusion reduction portion 102 may also include a material whose absorption wavelength overlaps with the absorption wavelength of the photoelectric conversion portion 1032.

[0099] It should be noted that in Figures 5 to 8 In the embodiment of the present invention, the surface connecting the first surface F3 of the first part A1 and the second surface F4 is called the fourth surface F6. The fourth surface F6 is a surface different from the third surface F5. The fourth surface F6 can be a plane or a curved surface. In addition, the fourth surface F6 can be considered to be a set of surfaces connecting the first surface F3 of the first part A1 and the second surface F4.

[0100] The resistivity of the first electrode portion 101 may be lower than the resistivity of the solar cell portion 103. The resistivity value of the first diffusion reduction portion 102 may be lower than the resistivity value of the solar cell portion 103 and higher than the resistivity value of the first electrode portion 101. In this case, the resistivity value of the first diffusion reduction portion 102 may be lower than the resistivity value of the first carrier transport portion 1031 and higher than the resistivity value of the first electrode portion 101. According to the setting of the resistivity value, the resistivity value changes in stages from the solar cell portion 103 to the first electrode portion 101, so that the increase in resistance can be reduced. In this case, the resistivity value of the first diffusion reduction portion 102 can be achieved by selecting the material of the first diffusion reduction portion 102 or adjusting the film forming conditions of the first diffusion reduction portion 102. It should be noted that the resistivity may be resistivity (specific electric resistance), resistivity (electrical resistivity) or resistivity (resistivity), and its unit uses units such as ohm-meter (Ω·m).

[0101] <1-1-5. First Electrode Section 101 >

[0102] The first electrode unit 101 is located on the first diffusion reducing unit 102. Specifically, the first electrode unit 101 is arranged on the second surface F4 of the first diffusion reducing unit 102.

[0103] The first electrode unit 101 can collect carriers generated by photoelectric conversion when light is irradiated to the photoelectric conversion unit 1032. The first electrode unit 101 can, for example, function as an electrode (also referred to as a positive electrode) that collects holes that are carriers. In addition, the first electrode unit 101 can, for example, function as a collector electrode.

[0104] As a material of the first electrode portion 101, for example, a metal with excellent conductivity such as Ag, Au, Cu, Ti, In or Sn can be applied. For example, the first electrode portion 101 can be formed on the first diffusion reduction portion 102 by a vacuum process such as sputtering. The average thickness of the first electrode portion 101 is not particularly limited, and for example, a range of 1 μm or more and 50 μm or less can be adopted.

[0105] In addition, for example, after applying a metal paste as a coating liquid by screen printing or the like, the metal paste is dried to solidify the metal paste, thereby forming the first electrode portion 101. The metal paste can be prepared, for example, by adding particles having high light reflectivity and conductivity to an adhesive such as a light-transmitting resin. Here, as a light-transmitting resin, for example, an epoxy resin or the like can be used. In addition, as particles contained in the metal paste, for example, metal particles such as Cu, Al, Ni, and an alloy of Zn and Ag can be used. In this case, a large number of particles having conductivity are contained in the first electrode portion 101, and the conductivity of the first electrode portion 101 can be ensured by using the large number of particles. The first electrode portion 101 can be, for example, in a layered form.

[0106] The shape of the first electrode portion 101 is not limited to that of the first embodiment. Figures 1 to 3 The shape of the first electrode portion 101 and the shape of the first diffusion reduction portion 102 can be appropriately changed to improve the carrier recovery efficiency. The shape of the first electrode portion 101 and the shape of the first diffusion reduction portion 102 can be a so-called comb-type electrode structure, or a structure combining a so-called busbar electrode and a so-called finger electrode.

[0107] The first electrode portion 101 and the second electrode portion 104 are, for example, in a state of being electrically connected to the wires, respectively. Specifically, for example, the first electrode portion 101 is electrically connected to the first wire and the second electrode portion 104 is electrically connected to the second wire. Each wire can be respectively joined to the first electrode portion 101 and the second electrode portion 104 by, for example, soldering. Here, for example, the output obtained by photoelectric conversion in the solar cell element 10 can be extracted using the first wire and the second wire.

[0108] <1-1-6. Method for manufacturing solar cell element 10>

[0109] For example, Fig.10 As shown, by performing the processes from step S1 to step S5 in the order described, the solar cell element 10 of the first embodiment can be manufactured.

[0110] In step S1, the second electrode portion 104 is formed on the substrate portion 105. Here, for example, the material of the second electrode portion 104 is deposited on the substrate portion 105 by a vacuum process such as sputtering, so that the second electrode portion 104 can be formed on the substrate portion 105. The material of the second electrode portion 104 is, for example, a metal with excellent conductivity such as Au or a TCO such as ITO, FTO, or ZnO.

[0111] In step S2, a second carrier transporting portion 1033 is formed on the second electrode portion 104. The material of the second carrier transporting portion 1033 is, for example, a metal oxide such as TiO2, SnO2, ZnO or In2O3. Here, for example, a raw material solution prepared by dissolving a raw material such as a metal chloride or a metal isopropoxide in a polar solution is applied to the second electrode portion 104, and the raw material is hydrolyzed to generate a metal oxide, so that the second carrier transporting portion 1033 can be formed on the second electrode portion 104. Metal chlorides include, for example, titanium chloride, tin chloride, zinc chloride or indium chloride. Metal isopropoxides include, for example, titanium isopropoxide, tin isopropoxide, zinc isopropoxide or indium isopropoxide. Specifically, for example, a titanium tetrachloride aqueous solution is applied to the second electrode portion 104 by spin coating and dried. Then, for example, titanium tetrachloride is hydrolyzed by heating at about 150° C. on a hot plate, so that the second carrier transporting portion 1033 of TiO 2 can be formed on the second electrode portion 104 .

[0112] In addition, here, for example, an organic material can be applied to the material of the second carrier transport portion 1033. The organic material can be applied to fullerene derivatives such as PCBM, for example. In this case, for example, a raw material solution prepared by dissolving a fullerene derivative in a chlorobenzene solvent in a manner such that one milliliter (1 mL) of the raw material solution contains about 5 milligrams (mg) to 20 mg of the fullerene derivative is used. In other words, for example, a raw material solution in which the solvent is chlorobenzene and the concentration of the fullerene derivative is about 5 mg / mL to 20 mg / mL is used. Then, the raw material solution applied to the second electrode portion 104 is dried and annealed, so that the second carrier transport portion 1033 of PCBM can be formed on the second electrode portion 104. In addition, for the organic material used for the material of the second carrier transport portion 1033, for example, the functional group can be changed to change the solubility and physical properties in the organic solvent.

[0113] In step S3, the photoelectric conversion unit 1032 is formed on the second carrier transport unit 1033. Here, for example, a raw material solution is applied on the second carrier transport unit 1033, and the applied raw material solution is annealed to form the photoelectric conversion unit 1032. For example, the raw material solution can be generated by dissolving alkylamine halide and lead halide, which are raw materials of the photoelectric conversion unit 1032, in a solvent, or by dissolving alkylamine halide and tin halide, which are raw materials of the photoelectric conversion unit 1032, in a solvent. In this case, the photoelectric conversion unit 1032 can be composed of a thin film of a halide perovskite semiconductor having crystallinity.

[0114] In step S4, a first carrier transport unit 1031 is formed on the photoelectric conversion unit 1032. Here, for example, a raw material solution is applied to the photoelectric conversion unit 1032, and the raw material solution is dried and annealed, so that the first carrier transport unit 1031 can be formed on the photoelectric conversion unit 1032. The material of the first carrier transport unit 1031 can be, for example, an organic semiconductor material such as spiro-OMeTAD, P3HT, PTAA or poly(4-butyltriphenylamine) (poly-TPD). Here, for example, spiro-OMeTAD is dissolved in chlorobenzene in such a manner that about 10 mg to 85 mg of spiro-OMeTAD is contained in 1 mL of the raw material solution, so that the raw material solution can be prepared. In other words, for example, a raw material solution in which the solvent is chlorobenzene and the concentration of spiro-OMeTAD is about 10 mg / mL to 85 mg / mL is used. In addition, for example, the raw material solution can be prepared by dissolving P3HT in dichlorobenzene in such a manner that 5 mg to 20 mg of P3HT is included in 1 mL of the raw material solution. In other words, for example, a raw material solution in which the solvent is dichlorobenzene and the concentration of P3HT is about 5 mg / mL to 20 mg / mL can be used. In addition, for example, the raw material solution can be prepared by dissolving PTAA in toluene in such a manner that 5 mg to 20 mg of PTAA is included in 1 mL of the raw material solution. In other words, for example, a raw material solution in which the solvent is toluene and the concentration of PTAA is 5 mg / mL to 20 mg / mL can be used. In addition, for example, the raw material solution can be prepared by dissolving poly-TPD in chlorobenzene in such a manner that 5 mg to 20 mg of poly-TPD is included in 1 mL of the raw material solution. In other words, for example, a raw material solution in which the solvent is chlorobenzene and the concentration of poly-TPD is 5 mg / mL to 20 mg / mL can be used.

[0115] In step S5, the first diffusion reducing portion 102 is formed on the first carrier transporting portion 1031. Here, for example, the material of the first diffusion reducing portion 102 is deposited on the first carrier transporting portion 1031 by a vacuum process such as sputtering, so that the first electrode portion 101 can be formed on the first carrier transporting portion 1031. The material of the first diffusion reducing portion 102 is, for example, TCO such as ITO, FTO or ZnO.

[0116] In step S5, the first portion A1 and the second portion A2 of the first diffusion reducing portion 102 may be formed by combining a vacuum process with mask patterning. For example, in a state where a mask is formed on a portion forming the second portion A2, the material of the first diffusion reducing portion 102 is deposited on the first carrier transporting portion 1031, thereby forming the first portion A1 of the first diffusion reducing portion 102. In addition, for example, in a state where the material of the first diffusion reducing portion 102 is deposited on the entire surface of the first carrier transporting portion 1031, the portion to be the second portion A2 is etched, thereby forming the second portion A2 of the first diffusion reducing portion 102. Etching may be performed by etching using plasma gas, etching using laser, or etching using a chemical solution.

[0117] In step S6, the first electrode portion 101 is formed on the first diffusion reduction portion 102. For example, the first electrode portion 101 is formed in a manner that contacts the surface of the first diffusion reduction portion 102 on the side opposite to the first carrier transport portion 1031. Here, for example, the material of the first electrode portion 101 is deposited on the first diffusion reduction portion 102 by a vacuum process such as sputtering, so that the first electrode portion 101 can be formed on the first diffusion reduction portion 102. The material of the first electrode portion 101 is, for example, a metal with excellent conductivity such as Au or a TCO such as ITO, FTO or ZnO. In addition, for example, after applying a metal paste as a coating liquid by screen printing or the like, the metal paste is dried to solidify the metal paste, thereby forming the first electrode portion 101.

[0118] <1-2. Solar cell module 1>

[0119] In the solar cell module 1, for example, Fig.11 As shown, a plurality of solar cell elements 10 are formed on one substrate portion 105. In other words, the plurality of solar cell elements 10 share the substrate portion 105. In this case, the substrate portion 105 can play a role of supporting the plurality of solar cell elements 10 and a role of protecting the plurality of solar cell elements 10. As the substrate portion 105, for example, a flat plate having a rectangular disk surface is used. As the material of the substrate portion 105, for example, glass or a resin such as acrylic acid or polycarbonate is used. As the glass, for example, a material with high light transmittance such as white plate glass, tempered glass, or heat-reflecting glass can be used.

[0120] The plurality of solar cell elements 10 are arranged on a plane along the +X direction as the first direction. Here, the arrangement on a plane means that each solar cell element 10 is arranged along an imaginary plane or an actual plane and the plurality of solar cell elements 10 are arranged. In the first embodiment, the plurality of solar cell elements 10 are arranged on the substrate 105 along the surface of the substrate 105.

[0121] More specifically, for example, the plurality of solar cell elements 10 may include five solar cell elements 10 arranged along the first direction (+X direction) on the substrate portion 105. The five solar cell elements 10 include, for example, a first solar cell element 111, a second solar cell element 112, a third solar cell element 113, a fourth solar cell element 114, and a fifth solar cell element 115 arranged in sequence in the +X direction. That is, the plurality of solar cell elements 10 include an nth solar cell element 11n (n is a natural number from 1 to 5).

[0122] In the first embodiment, each solar cell element 10 has a strip shape with the +Y direction as the longitudinal direction. Each solar cell element 10 has a first electrode portion 101 , a first diffusion reducing portion 102 , a solar cell portion 103 , and a second electrode portion 104 .

[0123] In the first embodiment, on the substrate portion 105, five second electrode portions 104 are arranged in sequence on a plane along the +X direction. Here, the second electrode portion 104 of the mth solar cell element 11m (m is a natural number from 1 to 4) and the second electrode portion 104 of the (m+1)th solar cell element 11(m+1) are arranged with a gap (also referred to as the first gap) G1 sandwiched therebetween. For example, the second electrode portion 104 of the first solar cell element 111 and the second electrode portion 104 of the second solar cell element 112 are arranged with a gap (also referred to as the first gap) G1 sandwiched therebetween. Each first gap G1 has a length direction along the +Y direction. In addition, there is a first groove portion P1 having the substrate portion 105 as a bottom surface and having two end surfaces of the two second electrode portions 104 sandwiching the first gap G1 as side surfaces.

[0124] In the first embodiment, five first electrode portions 101 are arranged in sequence on a plane along the +X direction. Here, the first electrode portion 101 of the mth solar cell element 11m and the first electrode portion 101 of the (m+1)th solar cell element 11(m+1) are arranged with a gap (also referred to as a second gap) G2 sandwiched therebetween. For example, the first electrode portion 101 of the first solar cell element 111 and the first electrode portion 101 of the second solar cell element 112 are arranged with a gap (second gap) G2 sandwiched therebetween. Each second gap G2 has, for example, a length direction along the +Y direction. In addition, a third groove portion P3 having the second electrode portion 104 as the bottom surface is formed. In each solar cell element 10, the second electrode portion 104 protrudes in the +X direction compared to the first electrode portion 101. From another point of view, the first gap G1 exists at a position offset in the first direction (+X direction) compared to the second gap G2.

[0125] The connection portion 12 electrically connects two adjacent solar cell elements 10 in series among the plurality of solar cell elements 10. In the first embodiment, the mth connection portion 12m electrically connects the mth solar cell element 11m with the (m+1)th solar cell element 11(m+1). For example, the first connection portion 121 electrically connects the first solar cell element 111 with the second solar cell element 112. More specifically, the mth connection portion 12m electrically connects the second electrode portion 104 of the mth solar cell element 11m with the first electrode portion 101 of the (m+1)th solar cell element 11(m+1). For example, the first connection portion 121 electrically connects the second electrode portion 104 of the first solar cell element 111 with the first electrode portion 101 of the second solar cell element 112. Thus, the plurality of solar cell elements 10 can be electrically connected in series.

[0126] In addition, the connection portion 12 is located between the solar cell portions 103 in the +X direction. From another point of view, there is a second groove portion P2, which has the solar cell portions 103 as two side surfaces and the surface of the second electrode portion 104 in the -Z direction as the bottom surface. The second groove portion P2 has a length direction along the +Y direction. And, for example, the connection portion 12 is arranged in the second groove portion P2. In this case, the connection portion 12 can be a structure in which the first electrode portion 101 is filled into the second groove portion P2.

[0127] It should be noted that, in the first solar cell element 111, the first electrode portion 101 includes a portion protruding in the -X direction compared with the first diffusion reduction portion 102, the solar cell portion 103, and the second electrode portion 104, namely, a first protruding portion 101e. In addition, in the fifth solar cell element 115, the second electrode portion 104 includes a portion protruding in the +X direction compared with the first electrode portion 101, the first diffusion reduction portion 102, and the solar cell portion 103, namely, a second protruding portion 104e. A first conductor W1 for outputting a first polarity is electrically connected to the first protruding portion 101e. A second conductor W2 for outputting a second polarity is electrically connected to the second protruding portion 104e. Here, for example, if the first polarity is a negative pole, the second polarity is a positive pole. It should be noted that, for example, if the first polarity is a positive pole, the second polarity is a negative pole.

[0128] <2. Other embodiments>

[0129] The present invention is not limited to the above-described first embodiment, and various changes and improvements can be made without departing from the gist of the present invention.

[0130] [Implementation Method 2]

[0131] The second embodiment will be described below. The differences from the first embodiment will be mainly described below.

[0132] Fig.12 The solar cell module 2 and the solar cell element 20 of the second embodiment further include a first diffusion reducing portion 102 between the connecting portion 12 (first electrode portion 101 ) and the second electrode portion 104 in the second groove portion P2 .

[0133] This structure can reduce the contact area between the side surface of the connection portion 12 (first electrode portion 101) and the side surface of the solar cell portion 103. This can reduce the possibility that the first electrode portion 101 or the solar cell portion 103 may be degraded due to the contact between the first electrode portion 101 and the solar cell portion 103.

[0134] [Implementation Method 3]

[0135] The third embodiment will be described below. The differences from the first embodiment will be mainly described below.

[0136] Fig.13 : is a cross-sectional view perpendicular to the length direction of the electrode when looking down at the light receiving surface F1 of the solar cell element 30 of the third embodiment. In the solar cell element 30 of the third embodiment, the thickness of the second part A2 of the first diffusion reduction part 102 is not 0. It should be noted that in the solar cell element 10 of the first embodiment, the thickness of the second part A2 of the first diffusion reduction part 102 is 0. In the third embodiment, the first diffusion reduction part 102 has: a first part A1, which has a third thickness; and a second part A2, which has a fourth thickness less than the third thickness. From another point of view, it can be considered that the first diffusion reduction part 102 has a convex shape obtained as follows: a first layer with a fourth thickness is formed on the solar cell part 103, and a second layer with a thickness of the difference between the third thickness and the fourth thickness is formed on the first layer in the first part A1. In this case, as a material of the first diffusion reduction part 102, TCO such as ITO, FTO or ZnO is applied. In this case, the thickness of the first diffusion reduction part 102 can be, for example, about 10nm to 1000nm. The third thickness may be, for example, about 1 nm to 100 nm greater than the fourth thickness.

[0137] In this case, the conductive first diffusion reducing portion 102 is formed on the first carrier transporting portion 1031 of the solar cell portion 103, thereby improving the efficiency of the first electrode portion 101 in collecting carriers from the first carrier transporting portion 1031. Thus, the conversion efficiency of the solar cell element 10 can be improved.

[0138] In the third embodiment, in step S5 of the first embodiment, the first portion A1 and the second portion A2 of the first diffusion reducing portion 102 may be formed by combining a vacuum process and mask patterning. For example, in a state where the material of the first diffusion reducing portion 102 is deposited on the entire surface of the first carrier transporting portion 1031, the portion to be the second portion A2 is etched, thereby forming the second portion A2 of the first diffusion reducing portion 102. Etching may be performed by etching using plasma gas, etching using laser, or etching using a chemical solution.

[0139] [Implementation method 4]

[0140] Hereinafter, the fourth embodiment will be described. Hereinafter, the differences from the third embodiment will be mainly described.

[0141] Fig.14 It is a cross-sectional view perpendicular to the length direction of the electrode when looking down at the light receiving surface F1 of the solar cell element 40 of the fourth embodiment. The solar cell element 40 of the fourth embodiment further includes a second diffusion reduction portion 106 between the first diffusion reduction portion 102 and the solar cell portion 103 (first carrier transport portion 1031). That is, the second diffusion reduction portion 106 is located between the first diffusion reduction portion 102 and the solar cell portion 103. From another perspective, it can be considered that the solar cell element 40 of the fourth embodiment has a structure obtained by inserting the second diffusion reduction portion 106 between the first diffusion reduction portion 102 and the solar cell portion 103 (first carrier transport portion 1031) in the solar cell element 10 of the first embodiment. In addition, from another perspective, it can be considered that the solar cell element 40 of the fourth embodiment has a structure obtained by making the first diffusion reduction portion 102 between the second surface F4 and the third surface F5 different from the first diffusion reduction portion 102 between the third surface F5 and the first surface F3 in the solar cell element 30 of the third embodiment.

[0142] The structure of the solar cell element 40 of the fourth embodiment is described in detail. The second diffusion reduction portion 106 is located on the light receiving surface F1 of the solar cell portion 103. Here, the second diffusion reduction portion 106 has: a fifth surface F7, which is a surface in contact with the light receiving surface F1 of the solar cell portion 103; and a sixth surface F8, which is a surface on the side opposite to the fifth surface F7. The first diffusion reduction portion 102 is arranged on the sixth surface F8 of the second diffusion reduction portion 106. Here, the first surface F3 of the first diffusion reduction portion 102 is in contact with the sixth surface F8 of the second diffusion reduction portion 106.

[0143] The second diffusion reduction portion 106 may cover the entire light receiving surface F1 of the solar cell portion 103. In this case, when the solar cell element 40 is viewed from the light receiving surface F1 side, the first diffusion reduction portion 102 or the first electrode portion 101 is observed at the first portion A1 of the first diffusion reduction portion 102. On the other hand, when the solar cell element 10 is viewed from the light receiving surface F1 side, the sixth surface F8 of the second diffusion reduction portion 106 is observed at the second portion A2 of the first diffusion reduction portion 102. That is, when the solar cell element 40 is viewed from the light receiving surface F1 side, the sixth surface F8 of the second diffusion reduction portion 106 is exposed at the second portion A2 of the first diffusion reduction portion 102.

[0144] In the solar cell element 40 of the fourth embodiment, the resistivity value of the first diffusion reduction portion 102 and the resistivity value of the second diffusion reduction portion 106 may be different. For example, the resistivity value of the second diffusion reduction portion 106 may be greater than the resistivity value of the first diffusion reduction portion 102. The resistivity value of the second diffusion reduction portion 106 may be greater than the resistivity value of the first diffusion reduction portion 102. By adopting this structure, the carrier density changes in stages from the second diffusion reduction portion 106 to the first diffusion reduction portion 102, thereby reducing the increase in resistance caused by band mismatch. In this case, the resistivity value of the first diffusion reduction portion 102 and the resistivity value of the second diffusion reduction portion 106 can be achieved by selecting the materials of the first diffusion reduction portion 102 and the second diffusion reduction portion 106 or adjusting the film forming conditions of the first diffusion reduction portion 102 and the second diffusion reduction portion 106.

[0145] The first diffusion reduction portion 102 and the second diffusion reduction portion 106 may be composed of the same material. In this case, the first diffusion reduction portion 102 and the second diffusion reduction portion 106 may be composed of the same element or a combination thereof. That is, the constituent elements of the first diffusion reduction portion 102 and the constituent elements of the second diffusion reduction portion 106 may be the same. As the material of the first diffusion reduction portion 102 and the material of the second diffusion reduction portion 106, for example, TCO such as ITO, FTO or ZnO is applied. In this case, the first diffusion reduction portion 102 and the second diffusion reduction portion 106 may be formed to have different carrier densities. Specifically, the carrier density of the first diffusion reduction portion 102 may be greater than the carrier density of the second diffusion reduction portion 106. Generally, in TCO, conductivity (carrier density) and transmittance are mostly in a compromise relationship. Since light does not enter the first diffusion reduction portion 102 present below the first electrode portion 101, even if the transmittance is reduced, the impact on the conversion efficiency of the solar cell element 40 is small. On the other hand, by improving the conductivity of the first diffusion reducing portion 102 to reduce the resistance loss at the first diffusion reducing portion 102, the conversion efficiency of the solar cell element 40 can be improved. In this case, the carrier density of the first diffusion reducing portion 102 and the carrier density of the second diffusion reducing portion 106 can be achieved by adjusting the film forming conditions of the first diffusion reducing portion 102 and the second diffusion reducing portion 106.

[0146] The first diffusion reduction portion 102 and the second diffusion reduction portion 106 may be composed of different types of materials. That is, the constituent elements of the first diffusion reduction portion 102 and the constituent elements of the second diffusion reduction portion 106 may be different. For example, as the material of the second diffusion reduction portion 106, TCO such as ITO, FTO or ZnO can be applied, and as the material of the first diffusion reduction portion 102, in addition to TCO, a conductive inorganic material such as a conductive oxide can be applied. Since light does not enter the first diffusion reduction portion 102 existing below the first electrode portion 101, even if the transmittance is reduced, the influence on the conversion efficiency of the solar cell element 40 is small. Therefore, the material of the second diffusion reduction portion 106 is required to have transmittance to the absorption wavelength of the solar cell portion 103, but the material of the first diffusion reduction portion 102 is not required to have transmittance to the absorption wavelength of the solar cell portion 103. That is, by making the first diffusion reduction portion 102 and the second diffusion reduction portion 106 composed of different types of materials, the selection of materials that can be used for the first diffusion reduction portion 102 can be expanded.

[0147] In the fourth embodiment, between step S4 and step S5 of the first embodiment, a step of forming the second diffusion reducing portion 106 is performed.

[0148] In this step, the second diffusion reducing portion 106 is formed on the first carrier transporting portion 1031 of the solar cell portion 103. Here, for example, the material of the second diffusion reducing portion 106 is deposited on the first carrier transporting portion 1031 by a vacuum process such as sputtering, so that the second diffusion reducing portion 106 can be formed on the first carrier transporting portion 1031.

[0149] [Implementation method five]

[0150] The fifth embodiment is described below. The differences from the first embodiment are mainly described below. The solar cell element 50 of the fifth embodiment is a multi-junction solar cell, a tandem solar cell, a cascade solar cell or a stacked solar cell, etc. More specifically, the solar cell element of the multi-junction solar cell of the fifth embodiment is a solar cell element in which thin-film solar cells are bonded to each other. The combination of thin-film solar cells can be a combination of perovskite solar cells, or a combination of perovskite solar cells and other thin-film solar cells such as silicon thin-film solar cells.

[0151] Fig.15 The figure is a cross-sectional view perpendicular to the length direction of the first electrode portion 101 when looking down at the light receiving surface F1 of the solar cell element 50 of the fifth embodiment. The solar cell element 50 of the fifth embodiment has a second solar cell portion 108 in addition to the first solar cell portion 107. In the fifth embodiment, the second electrode portion 104, the second solar cell portion 108, the first solar cell portion 107, the first diffusion reduction portion 102 and the first electrode portion 101 are stacked on the substrate portion 105 in the order described. It should be noted that in the fifth embodiment, the first diffusion reduction portion 102 may also adopt the structure described in the third or fourth embodiment.

[0152] The first solar cell section 107 converts light incident from the outside (such as sunlight) into electricity. For example, the solar cell section 103 can generate carriers by photoelectric conversion according to the irradiation of light. Carriers include at least one of electrons and holes. The first solar cell section 107 can be a perovskite solar cell, or other types of solar cells can be applied. For example, the solar cell can be an inorganic solar cell or an organic solar cell. The inorganic solar cell can be a silicon solar cell or a compound solar cell. The organic solar cell can be a dye-sensitized solar cell or an organic thin-film solar cell. The first solar cell section 107 has a first carrier transport section 1031, a photoelectric conversion section 1032, and a second carrier transport section 1033, similarly to the first embodiment.

[0153] Here, the material constituting the first solar cell section 107 has a light-transmitting property with respect to the light of the absorption wavelength of the second solar cell section 108. With this structure, the light of the absorption wavelength of the second solar cell section 108 can be incident on the second solar cell section 108.

[0154] The second solar cell section 108 converts light incident from the outside (e.g., sunlight) into electricity. The second solar cell section 108 has an absorption wavelength different from the absorption wavelength of the first solar cell section 107. The absorption wavelength of the second solar cell section 108 may be greater than the absorption wavelength of the first solar cell section 107. It should be noted that the absorption wavelength includes not only one wavelength but also a prescribed wavelength band. For example, the absorption wavelength may be a wavelength band such as the visible light region, or a wavelength band from the first wavelength to the second wavelength.

[0155] The second solar cell section 108 may be a perovskite solar cell, or other types of solar cells may be used. For example, the type of solar cell may be an inorganic solar cell or an organic solar cell. The inorganic solar cell may be a silicon solar cell or a compound solar cell. The organic solar cell may be a dye-sensitized solar cell or an organic thin film solar cell. The second solar cell section 108 has a first carrier transport section 1031, a photoelectric conversion section 1032, and a second carrier transport section 1033, similarly to the first embodiment.

[0156] With this structure, the plurality of solar cell sections 103 are connected in series by stacking the first solar cell section 107 and the second solar cell section 108. Therefore, the output power of the solar cell element 50 can be increased, and the conversion efficiency of the solar cell element 50 can be improved.

[0157] Although in Fig.15 Although not shown, the solar cell element 50 of the fifth embodiment further includes a buffer portion (not shown) between the first solar cell portion 107 and the second solar cell portion 108. The buffer portion is used to connect the first solar cell portion 107 and the second solar cell portion 108. The buffer portion is transparent to the absorption wavelength of the second solar cell portion 108.

[0158] It should be noted that in Fig.15 In the embodiment, a two-layer multi-junction solar cell element is exemplified, but the solar cell element 50 is not limited thereto. For example, the solar cell element 50 may be a two-layer or more multi-junction solar cell element.

[0159] [Implementation method six]

[0160] The sixth embodiment is described below. The differences from the first embodiment are mainly described below. In the solar cell element 60 of the sixth embodiment, the solar cell section 103 is a crystalline solar cell. In other words, the solar cell element 60 of the sixth embodiment can be considered to be an element in which the solar cell section 103 of the solar cell element 10 of the first embodiment is a crystalline solar cell.

[0161] <6-1. Solar cell element 60>

[0162] Fig.16 The figure is a cross-sectional view perpendicular to the length direction of the first electrode portion 101 when looking down at the light receiving surface F1 of the solar cell element 60 of the sixth embodiment. The solar cell element 60 of the sixth embodiment has a third solar cell portion 110. In the sixth embodiment, the second electrode portion 104, the third solar cell portion 110, the first diffusion reduction portion 102 and the first electrode portion 101 are stacked in the order described. It should be noted that in the sixth embodiment, the first diffusion reduction portion 102 may also adopt the structure described in the second or third embodiment.

[0163] The third solar cell section 110 is a solar cell including silicon crystals. The third solar cell section 110 can generate electricity by performing photoelectric conversion using light incident on the silicon crystals. The silicon crystals can be silicon single crystals or silicon polycrystalline. The third solar cell section 110 can be a PN junction type solar cell or a PIN junction type solar cell.

[0164] It should be noted that the third solar cell section 110 is made of silicon crystal and has rigidity, and therefore can function as the substrate section 105. Therefore, the solar cell element 60 does not need to include the substrate section 105.

[0165] like Fig.17 As shown, the plurality of solar cell elements 60 are located between the first protective member 61 and the second protective member 63. In addition, the plurality of solar cell elements 60 are arranged on a plane along the module surface F9 of the first protective member 61. Fig.17 In the example of FIG. 1 , a plurality of solar cell elements 60 are arranged two-dimensionally along a virtual XY plane.

[0166] <6-2. Solar cell module 6>

[0167] like Fig.17As shown, the solar cell module 6 has, for example, a module surface F9 for mainly incident sunlight and a module back surface F10 located on the opposite side of the module surface F9. The module surface F9 is the surface of the solar cell module 6 on the side toward which the light receiving surface F1 of the solar cell element 60 faces. The module back surface F10 is the surface of the solar cell module 6 on the side toward which the back surface F2 of the solar cell element 60 faces.

[0168] For example, the module surface F9 is oriented in the +Z direction. For example, the module back surface F10 is oriented in the -Z direction. When the solar cell module 6 is used outdoors to generate electricity, the +Z direction is set to, for example, the direction toward the sun at midday.

[0169] like Fig.17 As shown, for example, the solar cell module 6 includes a plurality of solar cell elements 60 , a first protective member 61 , and a sealing material 62 . The solar cell module 6 also includes a second protective member 63 .

[0170] The solar cell module 6 may further include, for example, a terminal box 65 for taking out the generated electric power to the outside. The terminal box 65 is located, for example, on the module back surface F10.

[0171] The solar cell module 6 may further include, for example, a frame 66 for protecting the outer periphery of the solar cell module 6. The frame 66 is, for example, disposed along the outer periphery of the solar cell module 6. In this case, for example, a sealing material 62 having low moisture permeability, such as a butyl resin, may be further filled between the outer periphery of the solar cell module 6 and the frame 66.

[0172] <6-2-1. First protection member 61>

[0173] The first protective component 61 is, for example, a component for protecting the solar cell element 60 from the module surface F9 side. The first protective component 61 is, for example, in a state of constituting the module surface F9. The first protective component 61 is, for example, light-transmitting. Specifically, the first protective component 61 is, for example, light-transmitting to light of a specific range of wavelengths. The specific range of wavelengths includes, for example, wavelengths of light that can be photoelectrically converted by the solar cell element 60. If the specific range of wavelengths includes wavelengths of light with high irradiation intensity in sunlight, the conversion efficiency of the solar cell module 6 can be improved. The first protective component 61 is, for example, a sheet-like or film-like component. The material of the first protective component 61 is, for example, a resin such as a fluorine-based resin having weather resistance. Fluorine-based resins having weather resistance include, for example, fluorinated ethylene propylene copolymer (Fluorinated Ethylene Propylene: FEP), ethylene-tetrafluoroethylene copolymer (Ethylene Tetrafluoroethylene: ETFE), and ethylene-chlorotrifluoroethylene copolymer (Ethylene Chlorotrifluoroethylene: ECTFE).

[0174] <6-2-2. Sealing material 62>

[0175] The sealing material 62 is, for example, in a state of covering the solar cell element 60. For example, the sealing material 62 is in a state of filling the area between the first protective member 61 and the second protective member 63, and covering the solar cell element 60 between the first protective member 61 and the second protective member 63. The sealing material 62 includes, for example, the sealing material 62 (also referred to as the first sealing material 621) located on the module surface F9 side and the sealing material 62 (also referred to as the second sealing material 622) located on the module back surface F10 side. The first sealing material 621 is, for example, in a state of covering the entire surface of the solar cell element 60 on the first protective member 61 side. In other words, the first sealing material 621 is, for example, in a state of covering the solar cell element 60 between the first protective member 61 and the solar cell element 60. The second sealing material 622 is, for example, in a state of covering the entire surface of the solar cell portion 103 on the second protective member 63 side. In other words, the second sealing material 622 is, for example, in a state of covering the solar cell element 60 between the second protective member 63 and the solar cell element 60. Therefore, the solar cell element 60 is, for example, in a state of being sandwiched and surrounded by the first sealing material 621 and the second sealing material 622. Thereby, for example, the posture of the solar cell element 60 can be maintained by the sealing material 62 .

[0176] In addition, the sealing material 62 is, for example, light-transmitting. Here, the sealing material 62 is, for example, light-transmitting to the light of the wavelength in the above-mentioned specific range. For example, if at least the first sealing material 621 of the first sealing material 621 and the second sealing material 622 constituting the sealing material 62 is light-transmitting, the incident light from the module surface F9 side can reach the solar cell element 60. For example, resin is applied to each material of the first sealing material 621 and the second sealing material 622. More specifically, the material of the first sealing material 621 is, for example, polyvinyl acetal such as ethylene-vinyl acetate copolymer (EVA: Ethylene-VinylAcetate), polyvinyl butyral (PVB: Poly-Vinyl Butyral) or acid-modified resin. Here, for example, if the material of the first sealing material 621 is relatively cheap EVA, the performance of protecting a plurality of solar cell elements 60 can be easily achieved. The acid-modified resin is, for example, a modified polyolefin resin formed by grafting and modifying a resin such as polyolefin with an acid. The second sealing material 622 may be made of, for example, polyvinyl acetal such as EVA or PVB or an acid-modified resin, similarly to the first sealing material 621. The first sealing material 621 and the second sealing material 622 may each be made of, for example, two or more materials.

[0177] In addition, the solar panel may further include a sealing portion (not shown) which is arranged along the annular portion opened to the external space in the region between the first protective member 61 and the second protective member 63. In this case, the sealing portion, for example, surrounds the peripheral portion of the region including the solar cell element 60 and the sealing material 62 in the region between the first protective member 61 and the second protective member 63. Here, the sealing portion is arranged, for example, to be embedded in the region from the first protective member 61 to the second protective member 63. Here, for example, if the sealing portion has a lower moisture permeability than the sealing material 62, the sealing portion can seal the portion along the peripheral portion in the region between the first protective member 61 and the second protective member 63. Thus, the sealing portion can, for example, reduce the intrusion of moisture or the like from the outside of the solar cell module 6 into the solar cell element 60. The material of the sealing portion, for example, butyl resin, polyisocyanate resin, or acrylic resin is applied. The material of the sealing portion, for example, can be any material with low moisture permeability, and can include metals such as copper or solder or non-metals such as glass.

[0178] <6-2-3. Second protection member 63>

[0179] The second protective component 63 is, for example, a component for protecting the solar cell element 60 from the module back side F10. The second protective component 63 is, for example, in a state of constituting the module back side F10. The second protective component 63 may be, for example, light-transmitting or light-non-transmitting. The second protective component 63 may be, for example, a sheet-like or flat-plate-like component. The sheet-like component may be, for example, a back plate constituting the module back side F10. The material of the back plate may be, for example, a resin.

[0180] <6-2-4. Current Collecting Section 64>

[0181] The power collecting portion 64 functions as an extraction electrode. The power collecting portion 64 is, for example, aluminum or copper wiring. The power collecting portion 64 is connected to a terminal for extracting electricity generated by the solar cell module 6 .

[0182] [Implementation method seven]

[0183] The seventh embodiment is described below. The differences from the sixth embodiment are mainly described below. The solar cell element 70 of the seventh embodiment is a multi-junction solar cell, a tandem solar cell, a cascade solar cell or a stacked solar cell, etc. For example, the solar cell element 70 of the seventh embodiment can be a solar cell element formed by stacking a crystalline solar cell and a thin film solar cell. More specifically, the solar cell element 70 of the seventh embodiment is a solar cell element formed by joining a silicon crystalline solar cell and a perovskite solar cell. For example, the solar cell element 70 of the multi-junction solar cell of the seventh embodiment can be a solar cell element 70 formed by joining a perovskite solar cell to a silicon crystalline solar cell.

[0184] From another perspective, the solar cell element 70 of the seventh embodiment can be considered to have a structure in which the third solar cell section 110 is inserted between the solar cell section 103 and the second electrode section 104 in the solar cell element 10 of the first embodiment. In addition, the solar cell element 70 of the seventh embodiment can be considered to have a structure in which the second solar cell section 108 is replaced with the third solar cell section 110 in the solar cell element 50 of the fifth embodiment. In addition, the solar cell element 70 of the seventh embodiment can be considered to have a structure in which the first solar cell section 107 is inserted between the first diffusion reduction section 102 and the third solar cell section 110 in the solar cell element 60 of the sixth embodiment.

[0185] Fig.18The figure is a cross-sectional view perpendicular to the length direction of the first electrode portion 101 when looking down at the light receiving surface F1 of the solar cell element 70 of the seventh embodiment. The solar cell element 70 of the seventh embodiment has a third solar cell portion 110 in addition to the first solar cell portion 107. In other words, in the solar cell element 70 of the seventh embodiment, the second electrode portion 104, the third solar cell portion 110, the first solar cell portion 107, the first diffusion reduction portion 102, and the first electrode portion 101 are stacked in the order described. It should be noted that in the seventh embodiment, the first diffusion reduction portion 102 can also adopt the structure described in the second or third embodiment.

[0186] In the seventh embodiment, a buffer portion (not shown) may be provided between the first solar cell portion 107 and the third solar cell portion 110 .

[0187] like Fig.19 As shown, the solar cell module 7 of the seventh embodiment may have a structure in which the solar cell element 60 in the solar cell module 6 of the sixth embodiment is replaced with a solar cell element 70 of the seventh embodiment.

[0188] [Other embodiments]

[0189] Although the present invention has been described based on various drawings and various embodiments, those skilled in the art can make various deformations and modifications based on the present invention. Therefore, it should be noted that these deformations and modifications are included in the scope of the present invention. For example, the functions included in each functional unit and each step can be reconfigured in a logically non-contradictory manner, and multiple functional units and steps can be combined into one, or divided. In addition, the aforementioned embodiments of the present invention are not limited to the faithful implementation of the respective embodiments described, and the various features can be appropriately combined, or a part can be omitted for implementation.

[0190] [Summary of the Invention]

[0191] The present invention includes the following contents.

[0192] In one embodiment, (1) the solar cell element may have a solar cell portion, an electrode portion and a first diffusion reduction portion, wherein the solar cell portion has a light receiving surface, the first diffusion reduction portion is located between the solar cell portion and the electrode portion, the first diffusion reduction portion may have a first surface on the light receiving surface side and a second surface on the electrode portion side, and the first diffusion reduction portion may be configured to avoid at least a portion of an area that does not overlap with the electrode portion when looking down on the light receiving surface.

[0193] In one embodiment, (2) the solar cell element may have a solar cell portion, an electrode portion and a first diffusion reduction portion, the solar cell portion having a light receiving surface, the first diffusion reduction portion being located between the solar cell portion and the electrode portion, the first diffusion reduction portion having: a first surface on the light receiving surface side; a second surface on the electrode portion side; and a third surface on the side opposite to the first surface, the third surface being located at least in a portion of an area that does not overlap with the electrode portion when looking down at the light receiving surface, and the thickness between the first surface and the third surface may be smaller than the thickness between the first surface and the second surface.

[0194] (3) In the solar cell element of any one of (1) to (2) above, the width of the second surface in a direction perpendicular to the longitudinal direction of the electrode portion when the light-receiving surface is viewed from above may be larger than the width of the electrode portion.

[0195] (4) In the solar cell element of any one of (1) to (3) above, when viewed from a cross section orthogonal to the length direction of the electrode portion when looking down at the light-receiving surface, the width on the first surface side of the first portion of the first diffusion reduction portion having a thickness from the first surface to the second surface may be greater than the width on the second surface side of the first portion.

[0196] (5) In the solar cell element of any one of (1) to (4) above, the first diffusion reducing portion may further include the first diffusion reducing portion and a second diffusion reducing portion located between the solar cell portions.

[0197] (6) In the solar cell element according to any one of (1) to (5) above, the resistivity value of the second diffusion reducing portion may be equal to or higher than the resistivity value of the first diffusion reducing portion.

[0198] (7) In the solar cell element of any one of (1) to (6) above, when the constituent elements of the second diffusion reducing portion are the same as the constituent elements of the first diffusion reducing portion, the carrier density of the second diffusion reducing portion may be smaller than the carrier density of the first diffusion reducing portion.

[0199] (8) In the solar cell element of any one of (1) to (7) above, the solar cell section can include a semiconductor having a perovskite structure.

[0200] In one embodiment, (9) the solar cell module may have a solar cell portion, a first diffusion reduction portion and an electrode portion, wherein the solar cell portion has a light receiving surface, and the first diffusion reduction portion may have: a first surface, which is in contact with the light receiving surface; a second surface, which is a surface on the opposite side of the first surface; and a third surface, which is a surface different from the second surface, and the first diffusion reduction portion is located on the light receiving surface, and the electrode portion is located on the second surface. The first diffusion reduction portion may have a first part and a second part, wherein the first part has a thickness from the first surface to the second surface, and the second part has a thickness from the first surface to the third surface, and the thickness of the second part may be smaller than the thickness of the first part.

[0201] (10) In the solar cell module of (9) above, the third surface may be aligned with the first surface instead of being parallel to the first surface.

[0202] (11) In the solar cell module of any one of (9) to (10) above, the width of the first portion in a direction perpendicular to the length direction of the electrode portion when looking down at the light-receiving surface may be greater than the width of the electrode portion.

[0203] (12) In the solar cell module of any one of (9) to (11) above, when viewed from a cross section orthogonal to the length direction of the electrode portion when looking down at the light-receiving surface, the width of the first portion on the first surface side may be greater than the width of the first portion on the second surface side.

[0204] (13) In the solar cell module of any one of (9) to (12) above, the first diffusion reducing portion may further include a second diffusion reducing portion disposed between the first diffusion reducing portion and the solar cell portion.

[0205] (14) In the solar cell module of any one of (9) to (13) above, the resistivity value of the second diffusion reducing portion may be equal to or higher than the resistivity value of the first diffusion reducing portion.

[0206] (15) In the solar cell module of any one of (9) to (14) above, when the constituent elements of the second diffusion reducing portion are the same as the constituent elements of the first diffusion reducing portion, the carrier density of the second diffusion reducing portion may be smaller than the carrier density of the first diffusion reducing portion.

[0207] (16) In the solar cell module of any one of (9) to (15) above, the solar cell section can include a semiconductor having a perovskite structure.

[0208] Description of Reference Numerals

[0209] 1: Solar cell module

[0210] 10: Solar cell components

[0211] 101: First electrode part

[0212] 102: First diffusion reduction unit

[0213] 103: Solar cell department

[0214] 1031: First carrier transport unit

[0215] 1032: Photoelectric conversion unit

[0216] 1033: Second carrier transport unit

[0217] 104: Second electrode part

[0218] 105: Substrate part

[0219] 106: Second diffusion reduction unit

[0220] 107: First solar cell unit

[0221] 108: Second solar cell unit

[0222] 109: Buffer

[0223] 110: Third solar cell unit

[0224] 111: First solar cell element

[0225] 112: Second solar cell element

[0226] 113: Third solar cell element

[0227] 114: Fourth solar cell element

[0228] 115: Fifth solar cell element

[0229] 12: Connection

[0230] 121: First connection part

[0231] 122: Second connection part

[0232] 123: Third connection

[0233] 124: Fourth connection

[0234] 2: Solar cell module

[0235] 20: Solar cell components

[0236] 3: Solar cell module

[0237] 30: Solar cell components

[0238] 4: Solar cell module

[0239] 40: Solar cell components

[0240] 5: Solar cell module

[0241] 50: Solar cell components

[0242] 6: Solar cell modules

[0243] 60: Solar cell components

[0244] 61: First protection component

[0245] 62: Sealing material

[0246] 621: First sealing material

[0247] 622: Second sealing material

[0248] 63: Second protection component

[0249] 64: Current collection

[0250] 65: Terminal box

[0251] 66: Framework

[0252] 7: Solar cell module

[0253] 70: Solar cell components

[0254] F1: light receiving surface

[0255] F2: Back

[0256] F3: First side

[0257] F4: Second side

[0258] F5: Third side

[0259] F6: The fourth side

[0260] F7: Fifth side

[0261] F8: Sixth side

[0262] F9: Module surface

[0263] F10: Back of the module

[0264] A1: Part 1

[0265] A2: Part 2

[0266] G1: First gap

[0267] G2: Second gap

[0268] P1: First groove

[0269] P2: Second groove

[0270] P3: The third slot

[0271] T1: First thickness

[0272] T2: Second thickness

[0273] T3: The third thickness

[0274] T4: Fourth thickness

Claims

1. A solar cell element, wherein: The solar cell element has: a solar cell section having a light receiving surface; Electrode part; as well as a first diffusion reduction portion, the first diffusion reduction portion being located between the solar cell portion and the electrode portion, The first diffusion reducing portion has a first surface on the light receiving surface side and a second surface on the electrode portion side. The first diffusion reducing portion is arranged so as to avoid at least a portion of a region that does not overlap with the electrode portion when the light receiving surface is viewed in plan.

2. A solar cell element, wherein: The solar cell element has: a solar cell section having a light receiving surface; an electrode portion; and a first diffusion reduction portion, the first diffusion reduction portion being located between the solar cell portion and the electrode portion, The first diffusion reducing portion comprises: a first surface on the light-receiving side; a second surface on the electrode portion side; and a third surface on the side opposite to the first surface, the third surface being located in at least a part of a region that does not overlap with the electrode portion when the light receiving surface is viewed from above, The thickness between the first surface and the third surface is smaller than the thickness between the first surface and the second surface.

3. The solar cell element according to claim 1 or 2, wherein: In a direction perpendicular to the longitudinal direction of the electrode portion when the light receiving surface is viewed in plan, the width of the second surface is larger than the width of the electrode portion.

4. The solar cell element according to any one of claims 1 to 3, wherein When viewed from a cross section perpendicular to the longitudinal direction of the electrode portion when the light receiving surface is viewed from above, A first portion of the first diffusion reducing portion having a thickness from the first surface to the second surface has a width on the first surface side that is greater than a width on the second surface side of the first portion.

5. The solar cell element according to any one of claims 1 to 4, wherein The solar cell element further includes a second diffusion reducing portion located between the first diffusion reducing portion and the solar cell portion.

6. The solar cell element according to claim 5, wherein The resistivity value of the second diffusion reducing portion is equal to or greater than the resistivity value of the first diffusion reducing portion.

7. The solar cell element according to claim 5 or 6, wherein: When the constituent elements of the second diffusion reducing portion are the same as the constituent elements of the first diffusion reducing portion, The carrier density of the second diffusion lowering portion is smaller than the carrier density of the first diffusion lowering portion.

8. The solar cell element according to any one of claims 1 to 7, wherein The solar cell section includes a semiconductor having a perovskite structure.

9. A solar cell module, wherein: The solar cell module comprises: a solar cell section, the solar cell section including a light receiving surface; A first diffusion reduction portion, the first diffusion reduction portion having a first surface, a second surface and a third surface, and the first diffusion reduction portion is located on the light receiving surface; as well as an electrode portion, the electrode portion being located on the second surface, The first surface is in contact with the light receiving surface, the second surface is a surface on the opposite side of the first surface, and the third surface is different from the second surface. The first diffusion reducing portion includes: a first portion having a thickness from the first surface to the second surface; and a second portion having a thickness from the first surface to the third surface. The thickness of the second portion is smaller than the thickness of the first portion.

Images