Photoelectric conversion module and manufacturing method for photoelectric conversion module

Abstract

Provided is a photoelectric conversion module that is capable of preventing a short circuit, and that has weld sections. A photoelectric conversion module (100) includes: a photoelectric conversion element (10a); a first weld section (210a) provided to a first surface of the photoelectric conversion element (10a); and a second weld section (220b) provided to a second surface of the photoelectric conversion element (10a), the second surface being opposite the first surface. When viewed from the thickness direction orthogonal to the first surface of the photoelectric conversion element (10a), the centre of gravity of the first weld section (210a) deviates from the centre of gravity of the second weld section (220b).

Description

Photoelectric conversion module and method for manufacturing the same

[0001] The present invention relates to a photoelectric conversion module and a method for manufacturing a photoelectric conversion module.

[0002] A photoelectric conversion module that converts light energy into electrical energy is known (see Patent Document 1). The photoelectric conversion module described in Patent Document 1 includes a plurality of photoelectric conversion elements. The ends of adjacent photoelectric conversion elements are overlapped with each other. The adjacent photoelectric conversion elements are electrically connected to each other in the overlapping region by a conductor such as solder (see Figures 5 and 6 of Patent Document 1).

[0003] JP 2016-119401 A

[0004] For example, in a photoelectric conversion module for use in space, aviation, or a moving object such as a car, a large load may be placed on the connections between the photoelectric conversion elements due to loads such as vibrations on the moving object. Electrical connections using conductors such as solder may not be reliable enough to withstand such loads.

[0005] The present inventors have considered connecting a conductor, such as a conductive interconnector, to a photoelectric conversion element by welding, but have found that in this case, the electrodes of the photoelectric conversion element may be short-circuited due to the high heat generated during welding.

[0006] Therefore, it is desirable to provide a photovoltaic conversion module having a welded portion that can suppress short circuits, and a method for manufacturing the same.

[0007] A photoelectric conversion module according to one aspect includes a photoelectric conversion element, a first weld provided on a first surface of the photoelectric conversion element, and a second weld provided on a second surface of the photoelectric conversion element opposite the first surface, wherein the center of gravity of the first weld is offset from the center of gravity of the second weld when viewed in a thickness direction perpendicular to the first surface of the photoelectric conversion element.

[0008] According to one aspect, a method for manufacturing a photoelectric conversion module includes the steps of: preparing a photoelectric conversion element; and forming a first weld on a first surface of the photoelectric conversion element while forming a second weld on a second surface of the photoelectric conversion element opposite the first surface. In the welding step, the first weld is formed such that the center of gravity of the first weld is offset from the center of gravity of the second weld when viewed from a thickness direction perpendicular to the first surface of the photoelectric conversion element.

[0009] 1 is a schematic plan view of a photovoltaic conversion module according to a first embodiment; FIG. 2 is a schematic side view of the photovoltaic conversion module according to the first embodiment as seen from the Y direction of FIG. 1; FIG. 3 is a schematic plan view of each photovoltaic conversion element constituting the photovoltaic conversion module; FIG. 4 is a schematic plan view of each interconnector; FIG. 5 is a schematic plan view illustrating the interconnector arrangement and the positions of welds; FIG. 6 is a schematic side view of a photovoltaic conversion module according to a second embodiment; FIG. 7 is a schematic plan view illustrating the interconnector arrangement and the positions of welds according to the second embodiment; FIG. 8 is a schematic side view of a photovoltaic conversion module according to a third embodiment; FIG. 9 is a schematic plan view illustrating the interconnector arrangement and the positions of welds according to the third embodiment; FIG. 10 is a schematic side view of a photovoltaic conversion module according to a fourth embodiment; FIG. 11 is a schematic plan view of each interconnector according to the fourth embodiment; FIG. 12 is a schematic plan view illustrating the interconnector arrangement and the positions of welds according to the fourth embodiment; FIG. 13 is a schematic plan view illustrating the interconnector arrangement and the positions of welds according to the fifth embodiment; FIG. 14 is a schematic plan view of a photovoltaic conversion module according to a sixth embodiment; FIG. 15 is a schematic oblique view of a satellite equipped with a photovoltaic conversion module.

[0010] Hereinafter, embodiments will be described with reference to the drawings. In the following drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic and the ratios of the dimensions may differ from those of the actual parts.

[0011] It should be noted that in this specification, the terms "first" and "second" do not represent the quantity of the items to which they are attached, but are used for convenience to distinguish the items to which they are attached.

[0012] [First Embodiment] Fig. 1 is a schematic plan view of a photovoltaic conversion module according to a first embodiment. Fig. 2 is a schematic side view of the photovoltaic conversion module according to the first embodiment as viewed from the Y direction in Fig. 1. Fig. 3 is a schematic plan view of each photovoltaic conversion element constituting the photovoltaic conversion module. It should be noted that in Fig. 3, reference numerals are assigned to each photovoltaic conversion element in order to explain the structure of each photovoltaic conversion element constituting the photovoltaic conversion module. Fig. 4 is a schematic plan view of each interconnector. It should be noted that in Fig. 4, reference numerals are assigned to each interconnector constituting the photovoltaic conversion module.

[0013] The photoelectric conversion module 100 according to the first embodiment includes a plurality of photoelectric conversion elements 10a, 10b and interconnectors 200a, 200b that electrically connect adjacent photoelectric conversion elements 10a, 10b. The photoelectric conversion elements 10a, 10b are arranged side by side in a second direction (the X direction in the figure; the same applies below). Adjacent photoelectric conversion elements 10a, 10b are arranged side by side so as to partially overlap. Specifically, one end of each photoelectric conversion element 10a, 10b overlaps the other end of the adjacent photoelectric conversion element 10a, 10b in the thickness direction. The adjacent photoelectric conversion elements 10a, 10b are electrically connected to each other at the overlapping portions by the interconnectors 200a, 200b. The number of photoelectric conversion elements 10a, 10b arranged side by side in the second direction may be at least two, and preferably three or more.

[0014] The photoelectric conversion elements 10a and 10b may be known photoelectric conversion elements, such as compound-based photoelectric conversion elements such as CZTS-based photoelectric conversion elements, CIGS-based photoelectric conversion elements, CdTe-based photoelectric conversion elements, and GaAs-based photoelectric conversion elements, silicon-based photoelectric conversion elements, and organic-based photoelectric conversion elements. Preferably, the photoelectric conversion elements 10a and 10b are solar cell elements that convert light energy into electrical energy.

[0015] Each of the photoelectric conversion elements 10a, 10b may, but is not required to, have a conductive substrate 20a, 20b that serves as a base on which layers such as the first electrode layers 22a, 22b described below are formed. The conductive substrates 20a, 20b may be formed of a substrate such as a metal substrate. Furthermore, the conductive substrates 20a, 20b may be flexible substrates. The shape and dimensions of the conductive substrates 20a, 20b are determined appropriately depending on the size, etc., of the photoelectric conversion elements 10a, 10b.

[0016] When a metal substrate is used as the conductive substrate 20a, 20b, the conductive substrate 20a, 20b may be formed of, for example, titanium (Ti), stainless steel (SUS), copper, aluminum, or an alloy thereof. Alternatively, the conductive substrate 20a, 20b may have a laminated structure in which multiple metal substrates are stacked, and for example, stainless steel foil, titanium foil, or molybdenum foil may be formed on the surface of the substrate. Furthermore, to prevent warping, a film of a metal material such as molybdenum, titanium, or chromium may be formed on the back side of the conductive substrate 20a, 20b.

[0017] When the conductive substrates 20 a, 20 b are flexible metal substrates, the photoelectric conversion elements 10 a, 10 b can be bent, and cracking of the conductive substrates 20 a, 20 b due to bending can be suppressed. Furthermore, in the above case, it is easier to achieve a reduction in weight and thickness of the photoelectric conversion module 100 compared to a case where a glass substrate is used.

[0018] The photoelectric conversion elements 10a, 10b may include at least first electrode layers 22a, 22b, second electrode layers 24a, 24b, and photoelectric conversion layers 26a, 26b provided between the first electrode layers 22a, 22b and the second electrode layers 24a, 24b. The second electrode layers 24a, 24b have a polarity different from that of the first electrode layers 22a, 22b. The photoelectric conversion layers 26a, 26b are layers that contribute to the mutual conversion of light energy and electrical energy. In solar cell elements that convert light energy into electrical energy, the photoelectric conversion layers 26a, 26b are sometimes referred to as light absorption layers.

[0019] The first electrode layers 22 a, 22 b and the second electrode layers 24 a, 24 b are adjacent to the photoelectric conversion layers 26 a, 26 b. In this specification, the term “adjacent” means not only that both layers are in direct contact with each other, but also that both layers are close to each other via another layer.

[0020] The first electrode layers 22a, 22b are provided between the photoelectric conversion layers 26a, 26b and the conductive substrates 20a, 20b. The second electrode layers 24a, 24b are located on the opposite side of the photoelectric conversion layers 26a, 26b from the conductive substrates 20a, 20b. Therefore, the photoelectric conversion layers 26a, 26b are located between the first electrode layers 22a, 22b and the second electrode layers 24a, 24b. The first electrode layers 22a, 22b are connected to the conductive substrates 20a, 20b.

[0021] In this embodiment, the second electrode layers 24 a and 24 b may be formed of transparent electrode layers. When the second electrode layers 24 a and 24 b are formed of transparent electrode layers, light incident on or emitted from the photoelectric conversion layers 26 a and 26 b passes through the second electrode layers 24 a and 24 b.

[0022] When the second electrode layers 24a and 24b are transparent electrode layers, the first electrode layers 22a and 22b may be opaque or transparent electrode layers. The first electrode layers 22a and 22b may be made of a metal such as molybdenum, titanium, or chromium.

[0023] As an example, the second electrode layers 24a and 24b may be formed of an n-type semiconductor, more specifically, a material having n-type conductivity and relatively low resistance. The second electrode layers 24a and 24b may function both as an n-type semiconductor and a transparent electrode layer. The second electrode layers 24a and 24b include, for example, a metal oxide doped with a Group III element (B, Al, Ga, or In). Examples of the metal oxide include ZnO and SnO. ２ The second electrode layer 24 is made of, for example, indium tin oxide (In ２ O ３ : Sn), indium titanium oxide (In ２ O ３:Ti), indium zinc oxide (In ２ O ３ :Zn), tin-zinc-doped indium oxide (In ２ O ３ : Sn, Zn), tungsten-doped indium oxide (In ２ O ３ :W), hydrogen-doped indium oxide (In ２ O ３ :H), indium gallium zinc oxide (InGaZnO ４ ), zinc tin oxide (ZnO:Sn), fluorine-doped tin oxide (SnO ２ :F), gallium-doped zinc oxide (ZnO:Ga), boron-doped zinc oxide (ZnO:B), aluminum-doped zinc oxide (ZnO:Al), and the like can be selected.

[0024] The photoelectric conversion layers 26a and 26b have a configuration according to the type of photoelectric conversion element. For example, in the case of a silicon-based photoelectric conversion element, the photoelectric conversion layers 26a and 26b may include an n-type semiconductor (n-type silicon) and a p-type semiconductor (p-type silicon). The photoelectric conversion layers 26a and 26b may also include i-type silicon between the n-type semiconductor and the p-type semiconductor. The photoelectric conversion layers 26a and 26b may also have a buffer layer (not shown).

[0025] In the case of a compound-based photoelectric conversion element such as a CZTS-based photoelectric conversion element, a CIGS-based photoelectric conversion element, a CdTe-based photoelectric conversion element, or a GaAs-based photoelectric conversion element, the photoelectric conversion layers 26 a, 26 b may include, for example, a p-type semiconductor. In a specific example, the photoelectric conversion layers 26 a, 26 b may function as, for example, a polycrystalline or microcrystalline p-type compound semiconductor layer.

[0026] In a specific example of the CIGS-based photoelectric conversion element, the photoelectric conversion layers 26a and 26b are made of a chalcogen semiconductor containing chalcogen elements and function as polycrystalline or microcrystalline p-type compound semiconductor layers. The photoelectric conversion layers 26a and 26b are made of, for example, a I-III-VI chalcopyrite structure containing group I elements, group III elements, and group VI elements (chalcogen elements). ２The photoelectric conversion layers 26a and 26b are composed of group I compound semiconductors. Here, the group I element can be selected from copper (Cu), silver (Ag), gold (Au), etc. The group III element can be selected from indium (In), gallium (Ga), aluminum (Al), etc. Furthermore, the photoelectric conversion layers 26a and 26b may contain tellurium (Te) as a group VI element in addition to selenium (Se) and sulfur (S). Furthermore, the photoelectric conversion layers 26a and 26b may contain alkali metals such as Li, Na, K, Rb, and Cs.

[0027] Instead, the photoelectric conversion layers 26a and 26b are made of I, a CZTS-based chalcogen semiconductor containing Cu, Zn, Sn, S, or Se. ２ -(II-IV)-VI ４ A typical example of a CZTS-based chalcogen semiconductor is Cu. ２ ZnSnSe ４ , Cu ２ ZnSn(S,Se) ４ and the like.

[0028] The photoelectric conversion layers 26a and 26b are not limited to those described above, and may be made of any material that causes photoelectric conversion.

[0029] The photoelectric conversion elements 10a and 10b may have a first buffer layer (not shown) between the photoelectric conversion layers 26a and 26b and the first electrode layers 22a and 22b, as needed. The first buffer layer may be made of a semiconductor material having the same conductivity type as the first electrode layers 22a and 22b, or a semiconductor material having a different conductivity type. The first buffer layer may be made of a material having a higher electrical resistance than the first electrode layers 22a and 22b.

[0030] The first buffer layer is not particularly limited, but may be, for example, a layer containing a chalcogenide compound of a transition metal element having a layered structure. Specifically, the first buffer layer may be composed of a compound made of a transition metal material such as M, W, Ti, V, Cr, Nb, or Ta and a chalcogen element such as O, S, or Se. The first buffer layer may be, for example, M(Se,S) ２ Layer, MоSe ２ Layer or MoS ２It may be a layer or the like.

[0031] The photoelectric conversion elements 10a, 10b may optionally include a second buffer layer (not shown) between the photoelectric conversion layers 26a, 26b and the second electrode layers 24a, 24b. In this case, the second buffer layer may be a semiconductor material having the same conductivity type as the second electrode layers 24a, 24b, or a semiconductor material having a different conductivity type. The second buffer layer may be made of a material having a higher electrical resistance than the second electrode layers 24a, 24b. The second buffer layer is formed on the photoelectric conversion layers 26a, 26b.

[0032] The second buffer layer can be selected from compounds containing zinc (Zn), cadmium (Cd), and indium (In). Examples of compounds containing zinc include ZnO, ZnS, and Zn(OH). ２ , or mixed crystals thereof such as Zn(O,S) and Zn(O,S,OH), as well as ZnMgO and ZnSnO. Compounds containing cadmium include, for example, CdS, CdO, or mixed crystals thereof such as Cd(O,S) and Cd(O,S,OH). Compounds containing indium include, for example, In ２ S ３ , In ２ O ３ or a mixed crystal thereof, In ２ (O, S) ３ , In ２ (O, S, OH) ３ There is In ２ O ３ , In ２ S ３ , In(OH) ｘ The second buffer layer may have a laminated structure of these compounds.

[0033] The second buffer layer has the effect of improving characteristics such as photoelectric conversion efficiency, but it can be omitted. When the second buffer layer is omitted, the second electrode layers 24 a, 24 b are formed directly on the photoelectric conversion layers 26 a, 26 b.

[0034] It should be noted that the stacked structure of the photoelectric conversion elements 10a, 10b is not limited to the above-described embodiment and can take various forms. For example, the photoelectric conversion elements 10a, 10b may have a configuration in which both an n-type semiconductor and a p-type semiconductor are sandwiched between a first electrode layer and a second electrode layer. In this case, the second electrode layer does not need to be composed of an n-type semiconductor. Furthermore, the photoelectric conversion elements 10a, 10b are not limited to a p-n junction type structure, and may have a p-i-n junction type structure that includes an intrinsic semiconductor layer (i-type semiconductor) between an n-type semiconductor and a p-type semiconductor.

[0035] The thickness from the lower surface of the first electrode layers 22a, 22b to the upper surface of the second electrode layers 24a, 24b is not particularly limited, but may be, for example, about 1.5 μm to 10 μm.

[0036] The photoelectric conversion elements 10a, 10b include collecting electrodes 30a, 30b connected to the second electrode layers 24a, 24b. The collecting electrodes 30a, 30b collect charge carriers from the second electrode layers 24a, 24b and are formed of a conductive material. The collecting electrodes 30a, 30b may be in direct contact with the second electrode layers 24a, 24b. From the viewpoint of ensuring a photoelectric conversion region that contributes to photoelectric conversion, it is preferable that the area of ​​the collecting electrodes 30a, 30b be as small as possible.

[0037] The current collecting electrodes 30a, 30b may have a plurality of substantially linear first portions 31a, 31b and second portions 32a, 32b connected to the plurality of first portions 31a, 31b. The first portions 31a, 31b may also be referred to as "fingers." The second portions 32a, 32b may also be referred to as "bus bars."

[0038] The first portions 31 a and 31 b are arranged at an interval from each other and serve to guide electric energy (charge carriers) generated in the photoelectric conversion layers 26 a and 26 b to the second portions 32 a and 32 b.

[0039] In the illustrated embodiment, the substantially linear first portions 31 a, 31 b extend straight along the second direction (the X direction in the drawing). Alternatively, the first portions 31 a, 31 b may extend in a wavy or zigzag broken line shape. In this specification, the term "linear" is not limited to a straight line, but is defined by a concept that includes elongated, curved lines such as wavy lines and broken lines.

[0040] The first portions 31a, 31b of the current collecting electrodes 30a, 30b may be arranged in a plurality of rows in a first direction (the Y direction in the figure; the same applies below). Here, the first direction is defined by a direction intersecting the second direction. The plurality of linear first portions 31a, 31b may be connected to a single second portion 32a, 32b. The plurality of first portions 31a, 31b may be arranged on one side of the second portion 32a, 32b.

[0041] The second portions 32a, 32b of the current collecting electrodes 30a, 30b may extend along the first direction. The second portions 32a, 32b may be connected to the first portions 31a, 31b at the ends of the first portions 31a, 31b. In this case, the plurality of first portions 31a, 31b may extend from the second portions 32a, 32b along the second direction.

[0042] The second portions 32a, 32b of the collecting electrodes 30a, 30b may extend in the first direction substantially from near one end to near the other end of the photoelectric conversion elements 10a, 10b. The widths of the second portions 32a, 32b of the collecting electrodes 30a, 30b in the second direction may be greater than the widths of the first portions 31a, 31b of the collecting electrodes 30a, 30b in the first direction.

[0043] The collecting electrodes 30a, 30b (first portions 31a, 31b and second portions 32a, 32b) may be made of a material having a higher conductivity than the material constituting the second electrode layers 24a, 24b. The materials constituting the collecting electrodes 30a, 30b (first portions 31a, 31b and second portions 32a, 32b) are materials that have good conductivity and can obtain high adhesion to the second electrode layers 24a, 24b. For example, the material constituting the collecting electrodes 30a, 30b may be indium tin oxide (In ２ O ３: Sn), indium titanium oxide (In ２ O ３ :Ti), indium zinc oxide (In ２ O ３ :Zn), tin-zinc-doped indium oxide (In ２ O ３ : Sn, Zn), tungsten-doped indium oxide (In ２ O ３ :W), hydrogen-doped indium oxide (In ２ O ３ :H), indium gallium zinc oxide (InGaZnO ４ ), zinc tin oxide (ZnO:Sn), fluorine-doped tin oxide (SnO ２ The material can be selected from at least one of aluminum-doped zinc oxide (ZnO:Al), boron-doped zinc oxide (ZnO:B), gallium-doped zinc oxide (ZnO:Ga), Ni, Ti, Cr, Mo, Al, Ag, and Cu, or a compound containing one or more of these. The current collecting electrodes 30a, 30b may be formed from an alloy or a laminate formed from a combination of the above-mentioned materials.

[0044] The second portions 32a, 32b of the collecting electrodes 30a, 30b are provided near one end of the photoelectric conversion elements 10a, 10b in a plan view seen from a direction perpendicular to the surface of the photoelectric conversion elements (see FIG. 3). In this embodiment, the second portions 32a, 32b of the collecting electrodes 30a, 30b are near the end of the photoelectric conversion elements 10a, 10b in the second direction and extend along the end in the first direction.

[0045] Here, the first photoelectric conversion element 10a may include a photoelectric conversion capable region that contributes to photoelectric conversion and a non-photoelectric conversion region that does not contribute to photoelectric conversion. The photoelectric conversion capable region may be, for example, a region where the first electrode layer 22a, the photoelectric conversion layer 26a, and the second electrode layer 24a are stacked one on top of the other, and may be a region that is not covered above by an opaque structure when viewed in the thickness direction (Z direction in the figure).

[0046] The non-photoelectric conversion region may be defined, for example, as a region where the first electrode layer 22a, the photoelectric conversion layer 26a, and the second electrode layer 24a are not stacked on one another, or as a region covered by an opaque structure as viewed in the thickness direction (Z direction in the figure). For example, as viewed in the thickness direction, the region of the first photoelectric conversion element 10a covered by the second photoelectric conversion element 20a corresponds to the non-photoelectric conversion region. Also, as viewed in the thickness direction, the region covered by the second portion 32a of the collecting electrode 30a corresponds to the non-photoelectric conversion region.

[0047] The conductive substrate 20b of the second photoelectric conversion element 10b may be disposed so as to overlap a portion of the collecting electrode 30a of the first photoelectric conversion element 10a (see FIGS. 1 and 2). Specifically, the conductive substrate 20b of the second photoelectric conversion element 10b may cover at least a portion of the second portion 32a of the collecting electrode 30a of the first photoelectric conversion element 10a when viewed in the thickness direction.

[0048] It is preferable that the second photoelectric conversion element 10b does not cover the first portion 31a of the collecting electrode 30a of the first photoelectric conversion element 10a. This increases the area of ​​the first photoelectric conversion element 10a exposed from the second photoelectric conversion element 10b, thereby ensuring a wide photoelectric conversion area for the first photoelectric conversion element 10a. This improves the photoelectric conversion efficiency of the entire photoelectric conversion module 100.

[0049] The second photoelectric conversion element 10b covers at least a portion, preferably the entirety, of the second portion 32a of the collecting electrode 30a of the first photoelectric conversion element 10a. More preferably, the second photoelectric conversion element 10b is arranged so as to substantially entirely cover the second portion 32a of the collecting electrode 30a of the first photoelectric conversion element 10a, while substantially not covering the first portion 31a. This allows the first photoelectric conversion element 10a and the second photoelectric conversion element 10b to be densely arranged so that the area that does not contribute to photoelectric conversion, i.e., the area of ​​the second portion 32a, is not exposed. Therefore, the size of the entire photoelectric conversion module can be reduced without reducing the photoelectric conversion efficiency.

[0050] The interconnectors 200a and 200b mechanically and electrically connect the adjacent photoelectric conversion elements 10a and 10b to each other, and are connected to the photoelectric conversion elements 10a and 10b by welding.

[0051] The interconnectors 200a and 200b may include a conductive member. Specifically, the interconnector 200 may be a ribbon wire made of a conductive metal including, for example, Ag, Ni, Co, Fe, Cr, Mo, Mn, Cu, Al, Ti, or a combination thereof. The interconnector 200 may also be made of an alloy containing some of the aforementioned conductive metals, such as an alloy of Kovar or stainless steel (SUS).

[0052] In the first embodiment, each of the interconnectors 200 a, 200 b may be a conductive sheet having a substantially rectangular or square shape. Alternatively, each of the interconnectors 200 a, 200 b may be a mesh-like member having a substantially rectangular or square shape.

[0053] Each interconnector 200a, 200b may have a first weldable portion 260a, 260b capable of forming a first weld 210a, 210b and a second weldable portion 270a, 270b capable of forming a second weld 220a, 220b spaced apart from the first weld 210a, 210b in a second direction. Here, the first weldable portion 260a, 260b and the second weldable portion 270a, 270b may be separate regions. Alternatively, the first weldable portion 260a, 260b and the second weldable portion 270a, 270b may correspond to portions of a single, unseparated region. In other words, as long as the first welded portions 210a, 210b and the second welded portions 220a, 220b can be formed at positions spaced apart from each other in the second direction, the boundary between the first weldable portions 260a, 260b and the second weldable portions 270a, 270b does not need to be clearly defined.

[0054] The first welds 210a, 210b and the second welds 220a, 220b refer to the locations where the interconnectors 200a, 200b and the photoelectric conversion elements 10a, 10b are welded to each other. Therefore, the first welds 210a, 210b and the second welds 220a, 220b are formed across both the interconnectors 200a, 200b and the photoelectric conversion elements 10a, 10b. Therefore, it should be noted that hereinafter, the first welds 210a, 210b and the second welds 220a, 220b may be described as components provided in the interconnectors 200a, 200b, or as components provided in the photoelectric conversion elements 10a, 10b.

[0055] Preferably, first weldable portions 260a, 260b may be regions where a plurality of first welds 210a, 210b aligned in a first direction can be formed. Similarly, second weldable portions 270a, 270b may be regions where a plurality of second welds 220a, 220b aligned in a first direction can be formed (see FIG. 4).

[0056] The first welds 210a, 210b can preferably be formed at the end portions of the respective interconnectors 200a, 200b in the second direction. In this case, the second welds 220a, 220b can preferably be formed at the end portions of the respective interconnectors 200a, 200b on the opposite side in the second direction from the first welds 210a, 210b.

[0057] Next, a structure related to the connection between the photoelectric conversion elements 10a and 10b will be described. Hereinafter, one of the adjacent photoelectric conversion elements 10a and 10b may be referred to as a "first photoelectric conversion element," and the other of the adjacent photoelectric conversion elements 10a and 10b may be referred to as a "second photoelectric conversion element." In the illustrated embodiment, of the two adjacent photoelectric conversion elements, the photoelectric conversion element 10a on the left side of the paper as viewed in the drawing is referred to as the "first photoelectric conversion element," and the photoelectric conversion element 10b on the right side of the paper as viewed in the drawing is referred to as the "second photoelectric conversion element." It should be noted, however, that the terms "first photoelectric conversion element" and "second photoelectric conversion element" are used merely for convenience in distinguishing between elements. The first photoelectric conversion element and the second photoelectric conversion element may each have the structure of the photoelectric conversion elements 10a and 10b described above. Therefore, the first photoelectric conversion element and the second photoelectric conversion element may be elements having the same structure.

[0058] In the following, one of the plurality of interconnectors 200a, 200b may be referred to as a "first interconnector," and another of the plurality of interconnectors 200a, 200b may be referred to as a "second interconnector." In the embodiment shown in FIG. 2, the first interconnector 200a is provided below the first photoelectric conversion element 10a, and the second interconnector 200b is provided below the second photoelectric conversion element 10b. However, it should be noted that the terms "first interconnector" and "second interconnector" are used merely for convenience to distinguish between the connectors. The first interconnector 200a and the second interconnector 200b may have the same structure.

[0059] The first interconnector 200a electrically connects the first photoelectric conversion element 10a to another photoelectric conversion element. In the embodiment shown in Fig. 2, the first interconnector 200a electrically connects the first photoelectric conversion element 10a to a photoelectric conversion element that is partially depicted to the left of the first photoelectric conversion element.

[0060] The first interconnector 200a is connected to the first photoelectric conversion element 10a at a first weld 210a. The first interconnector 200a may be connected to the conductive substrate 20a of the first photoelectric conversion element 10a or to a connection pad (not shown) provided on the conductive substrate 10a of the first photoelectric conversion element 10a, for example, at the first weld 210a.

[0061] The first interconnector 200a is connected to the photoelectric conversion element adjacent to the first photoelectric conversion element 10a (the photoelectric conversion element partially shown on the left side of the first photoelectric conversion element 10a in FIG. 2) at the second weld 220a. The first interconnector 200a may be connected, for example, at the second weld 220a to the second electrode layer 24a or the collecting electrode 30a (for example, the second portion 32a of the collecting electrode) provided on the photoelectric conversion element adjacent to the first photoelectric conversion element 10a, directly or via a connection pad.

[0062] The second interconnector 200b electrically connects the first photoelectric conversion element 10a to another second photoelectric conversion element 10b. The second interconnector 200b is connected to the first photoelectric conversion element 10a at a second weld 220b. The second interconnector 200b may be connected, for example, at the second weld 220b to the second electrode layer 24a of the first photoelectric conversion element 10a or the collecting electrode 30a of the first photoelectric conversion element 10a, directly or via a connection pad. In the embodiment shown in FIG. 2, the second interconnector 200b is connected to the second portion 32b of the collecting electrode 30a of the first photoelectric conversion element 10a at the second weld 220b.

[0063] The second interconnector 200b is connected to the second photoelectric conversion element 10b at a first weld 210b. The second interconnector 200b may be connected, for example, at the first weld 210b to the conductive substrate 20b of the second photoelectric conversion element 10b or to a connection pad (not shown) provided on the conductive substrate 10b of the second photoelectric conversion element 10b.

[0064] The length of the interconnectors 200a, 200b in the second direction may be shorter than the length of the photoelectric conversion elements 10a, 10b in the second direction. As a result, the first interconnector 200a is provided in a region covered by the first photoelectric conversion element 10a when viewed from the thickness direction. Also, the second interconnector 200b is provided in a region covered by the first photoelectric conversion element 10b when viewed from the thickness direction.

[0065] The first weld 210a is provided on a first surface (the bottom surface in FIG. 2 ) of the first photoelectric conversion element 10a. In the first embodiment, the first weld 210a provided on the first photoelectric conversion element 10a connects the first interconnector 200a and the first photoelectric conversion element 10a. The second weld 220b provided on the first photoelectric conversion element 10a is provided on a second surface (the top surface in FIG. 2 ) of the first photoelectric conversion element 10a, which is opposite to the first surface. In the first embodiment, the second weld 220b provided on the first photoelectric conversion element 10a connects the second interconnector 200b and the first photoelectric conversion element 10a. Here, when viewed from the thickness direction perpendicular to the surface of the first photoelectric conversion element 10a, the center of gravity of the first welding portion 210a provided on the first photoelectric conversion element 10a is shifted from the center of gravity of the second welding portion 220b provided on the first photoelectric conversion element 10a.

[0066] In this specification, the "center of gravity" of a weld means the center of gravity of the two-dimensional shape of the welded area as viewed from the thickness direction. The "welded area" is defined by the area where the welded members (e.g., interconnectors) and the photoelectric conversion element are integrally connected by welding. Therefore, if the weld is, for example, circular or elliptical as viewed from the thickness direction, the "center of gravity" of the weld coincides with the center of the circular or elliptical welded area.

[0067] When the center of gravity of the first weld 210a provided on the first photoelectric conversion element 10a is offset from the center of gravity of the second weld 220b provided on the first photoelectric conversion element 10a, the heat generated when the first weld 210a and the second weld 220b are formed are less likely to concentrate on the same part of the first photoelectric conversion element 10a. This prevents a short circuit between the first weld 210a and the second weld 220b, i.e., a short circuit between the first electrode layer 22a and the second electrode layer 24a. Furthermore, because excessive heat concentration is prevented, peeling or disconnection of the first interconnector 200a can also be prevented.

[0068] When the thickness from the lower surface of the first electrode layer 22a to the upper surface of the second electrode layer 24a is small, if the center of gravity of the first weld 210a provided on the first photoelectric conversion element 10a coincides with the center of gravity of the second weld 220b provided on the first photoelectric conversion element 10a as viewed in the thickness direction, the first weld 210a and the second weld 220b are likely to short-circuit due to the influence of heat during welding. In such a case, it is particularly preferable that the center of gravity of the first weld 210a provided on the first photoelectric conversion element 10a is offset from the center of gravity of the second weld 220b provided on the first photoelectric conversion element 10a as viewed in the thickness direction.

[0069] Preferably, the entire first weld 210a provided on the first photoelectric conversion element 10a is offset from the center of gravity of the second weld 220b provided on the first photoelectric conversion element 10a when viewed in the thickness direction. In this case, the first weld 210a provided on the first photoelectric conversion element 10a does not overlap the center of gravity of the second weld 220b provided on the first photoelectric conversion element 10a when viewed in the thickness direction. This makes it less likely that heat from both sides of the first photoelectric conversion element 10a during welding will concentrate on the same portion, thereby further suppressing short-circuiting between the first electrode layer 22a and the second electrode layer 24a and peeling and disconnection of the first interconnector 200a.

[0070] More preferably, the entire first weld 210a provided on the first photoelectric conversion element 10a is offset from the entire second weld 220b provided on the first photoelectric conversion element 10a when viewed in the thickness direction. In this case, the first weld 210a provided on the first photoelectric conversion element 10a does not overlap the second weld 220b provided on the first photoelectric conversion element 10a when viewed in the thickness direction. This makes it even more difficult for heat from both sides of the first photoelectric conversion element 10a during welding to concentrate on the same portion, thereby further suppressing short-circuiting between the first electrode layer 22a and the second electrode layer 24a and peeling and disconnection of the first interconnector 200a.

[0071] The first welds 210a, 210b and the second welds 220a, 220b preferably overlap the non-photoelectric conversion region as viewed from the thickness direction (Z direction). This reduces thermal damage to the photoelectric conversion layer 26a and other components in the photoelectric conversion region caused by heat generated when forming the welds. In the illustrated embodiment, the first welds 210a, 210b and the second welds 220a, 220b are provided in a region where the first photoelectric conversion element 10a and the second photoelectric conversion element 10b overlap each other as viewed from the thickness direction (Z direction). More specifically, the first welds 210a, 210b and the second welds 220a, 220b are provided in a region where the first welds 210a, 210b and the second welds 220a, 220b overlap the second portion 32a of the collecting electrode 30a as viewed from the thickness direction (Z direction).

[0072] As described above, it is desirable that the non-photoelectric conversion region of the photoelectric conversion element be as small as possible. Therefore, it is desirable that the first welded portions 210a, 210b and the second welded portions 220a, 220b be provided within a small non-photoelectric conversion region as viewed in the thickness direction. Even in such a case, it should be noted that, as described above, the entirety or center of gravity of the first welded portions 210a, 210b is positioned offset from the entirety or center of gravity of the second welded portions 220b, 220b as viewed in the thickness direction.

[0073] FIG. 5 is a schematic plan view illustrating the arrangement of interconnectors and the positions of welds. In FIG. 5, only the positions of the first interconnector 200a, the second interconnector 200b, and the welds of the photovoltaic conversion module 100 shown in FIGS. 1 and 2 are shown from the thickness direction. FIG. 5 also shows the positions of the first welds 210a, 210b and the second welds 220a, 220b provided on the first interconnector 200a and / or the second interconnector 200b. Here, in FIG. 5, the first welds 210a, 210b are depicted as white circles, and the second welds 220a, 220b are depicted as black circles (similarly in FIGS. 7, 9, and 11 to 13). It should be noted that the first weld 210a is provided on the first interconnector 200a and is actually located in a position covered by the second interconnector 200b, but is clearly shown in FIG. 5 to clarify the positional relationship. The same points to note regarding FIG. 5 also apply to FIG. 7, which will be described later.

[0074] 5, the photoelectric conversion module 100 includes at least a plurality of first welds 210a and a plurality of second welds 220b. The plurality of first welds 210a provided on the first photoelectric conversion element 10a may be arranged at intervals along the first direction. The plurality of second welds 220b provided on the first photoelectric conversion element 10a may be arranged at intervals along the first direction.

[0075] The first interconnector 200a partially overlaps the second interconnector 200b when viewed in the thickness direction. The first welded portions 210a of the first interconnector 200a and the second welded portions 220b of the second interconnector 200b are arranged to overlap the area where the first interconnector 200a and the second interconnector 200b overlap when viewed in the thickness direction.

[0076] The plurality of second welds 220b of the second interconnector 200b are arranged offset in the second direction from the plurality of first welds 210a of the first interconnector 200a. This makes it possible to minimize the distance between the plurality of first welds 210a lined up along the first direction. Similarly, it is possible to minimize the distance between the plurality of second welds 220b lined up along the first direction. This makes it possible to increase the connection strength of the interconnectors 200a, 200b to the first photoelectric conversion element 10a.

[0077] The above has described the connection portion of two adjacent photoelectric conversion elements 10a, 10b and the configuration in the vicinity thereof. This connection configuration may be applied between any two adjacent photoelectric conversion elements.

[0078] The photoelectric conversion module 100 including the plurality of photoelectric conversion elements 10 a, 10 b may include a sealing material (not shown). The sealing material may be provided to seal the entire plurality of photoelectric conversion elements 10 a, 10 b having the above-described configuration or the conductive substrate 20 a, 20 b side of the plurality of photoelectric conversion elements 10 a, 10 b. The photoelectric conversion module 100 may also include a support substrate (not shown) that supports the entire plurality of photoelectric conversion elements 10 a, 10 b including the sealing material.

[0079] Next, an example of a method for manufacturing the photoelectric conversion module 100 according to the first embodiment will be described. First, a first photoelectric conversion element 10a and a second photoelectric conversion element 10b, each including a first electrode layer 22a, 22b, a second electrode layer 24a, 24b, and a photoelectric conversion layer 26a, 26b between the first electrode layer 22a, 22b and the second electrode layer 24a, 24b, and interconnectors 200a, 200b are prepared. The first photoelectric conversion element 10a, the second photoelectric conversion element 10b, and the interconnectors 200a, 200b may have the structures described above.

[0080] Next, the first interconnector 200a is connected to a first surface of the first photoelectric conversion element 10a by a first weld 210a, and the second interconnector 200b is connected to a second surface of the first photoelectric conversion element 10a opposite the first surface by a second weld 220b (welding step). In the welding step, as described above, the first weld 210a provided on the first photoelectric conversion element 10a is formed so that its center of gravity does not overlap with the center of gravity of the second weld 220b provided on the first photoelectric conversion element 10a when viewed from the thickness direction perpendicular to the first surface of the first photoelectric conversion element 10a. More preferably, the first weld 210a provided on the first photoelectric conversion element 10a does not overlap with the entirety or center of gravity of the second weld 220b provided on the first photoelectric conversion element 10a when viewed from the thickness direction perpendicular to the first surface of the first photoelectric conversion element 10a. The welding method is not particularly limited, but may be, for example, a technique such as parallel gap resistance welding.

[0081] In the welding step, the first welded portion 210a and the second welded portion 220b are preferably formed simultaneously on both sides of the first photoelectric conversion element 10a. In this case, heat is applied simultaneously from both sides of the first photoelectric conversion element 10a during welding. Even in this case, the first welded portion 210a or its center of gravity does not overlap the entire second welded portion 220b or its center of gravity when viewed from the thickness direction, thereby preventing excessive heat from being applied to the same location. As a result, short-circuiting between the first electrode layer 22a and the second electrode layer 24a caused by excessive heat can be prevented.

[0082] Next, the first photoelectric conversion element 10 a and the second photoelectric conversion element 10 b are arranged side by side so as to partially overlap each other, and an interconnector is connected to the second photoelectric conversion element 10 b by welding in the same manner as described above. By repeating the above connection steps, a large number of photoelectric conversion elements can be connected side by side.

[0083] Second Embodiment Next, a photovoltaic conversion module according to a second embodiment will be described with reference to FIGS. 6 and 7. FIG. 6 is a schematic side view of the photovoltaic conversion module according to the second embodiment. FIG. 7 is a schematic plan view illustrating the interconnector arrangement and the positions of welded portions according to the second embodiment. The same reference numerals are used for components similar to those in the first embodiment. Please note that the description of components similar to those in the first embodiment may be omitted.

[0084] 7 , the photoelectric conversion module 100 includes at least a plurality of first welds 210 a and a plurality of second welds 220 b. The plurality of first welds 210 a provided on the first photoelectric conversion element 10 a may be arranged at intervals along the first direction. The plurality of second welds 220 b provided on the first photoelectric conversion element 10 a may be arranged at intervals along the first direction.

[0085] The first interconnector 200a partially overlaps the second interconnector 200b when viewed in the thickness direction. The first welds 210a and the second welds 220b provided on the first photoelectric conversion element 10a are arranged to overlap the area where the first interconnector 200a and the second interconnector 200b overlap when viewed in the thickness direction.

[0086] In the second embodiment, the plurality of second welds 220b provided on the first photoelectric conversion element 10a are not positioned offset from the plurality of first welds 210a in the second direction. Instead, the plurality of second welds 220b provided on the first photoelectric conversion element 10a are positioned between the first welds 210a provided on the first photoelectric conversion element 10a in the first direction. That is, the plurality of second welds 220b provided on the first photoelectric conversion element 10a are positioned offset from the plurality of first welds 210a provided on the first photoelectric conversion element 10a in the first direction. Even in this case, it is possible to mitigate the concentration of heat caused by the heat during welding of both the first welds 210a and the first welds 220b, and to suppress short-circuiting between the first electrode layer and the second electrode layer.

[0087] In the second embodiment, the plurality of second welds 220b provided on the first photoelectric conversion element 10a are not arranged offset in the second direction from the plurality of first welds 210a provided on the first photoelectric conversion element 10a. Therefore, the width of the region where the first interconnector 200a and the second interconnector 200b overlap as viewed in the thickness direction (width in the second direction) can be made as small as possible. In other words, the width of the non-photoelectric conversion region of the first photoelectric conversion element 10a can be made small.

[0088] The other configurations and the method of manufacturing the photoelectric conversion module are the same as those in the first embodiment, and therefore the description thereof will be omitted.

[0089] [Third Embodiment] Next, a photovoltaic conversion module according to a third embodiment will be described with reference to Figs. 8 and 9. Fig. 8 is a schematic side view of the photovoltaic conversion module according to the third embodiment. Fig. 9 is a schematic plan view illustrating the interconnector arrangement and the positions of welded portions according to the third embodiment. The same reference numerals are used for components similar to those in the first embodiment. Please note that the description of components similar to those in the first embodiment may be omitted.

[0090] 9 , the photovoltaic conversion module 100 has at least a plurality of first welds 210 a and a plurality of second welds 220 b. The plurality of first welds 210 a provided on the first photovoltaic conversion element 10 a may be arranged at intervals along the first direction. The plurality of second welds 220 b provided on the first photovoltaic conversion element 10 a may be arranged at intervals along the first direction.

[0091] In the third embodiment, the first interconnector 200a is disposed at a distance G from the second interconnector 200b in the second direction. Therefore, the first interconnector 200a does not overlap with the second interconnector 200b when viewed in the thickness direction. As a result, the plurality of second welds 220b formed on the second interconnector 200b are naturally disposed offset from the plurality of first welds 210a formed on the first interconnector 200a.

[0092] Even in this case, it is desirable that the first welded portion 210a and the second welded portion 220b be formed in the non-photoelectric conversion region.

[0093] [Fourth Embodiment] Next, a photovoltaic conversion module according to a fourth embodiment will be described with reference to Figs. 10, 11, and 12. Fig. 10 is a schematic side view of the photovoltaic conversion module according to the fourth embodiment. Fig. 11 is a schematic plan view of each interconnector according to the fourth embodiment. Fig. 12 is a schematic plan view illustrating the arrangement of interconnectors and the positions of welded portions according to the fourth embodiment. The same reference numerals are used for components similar to those in the first embodiment. Please note that the description of components similar to those in the first embodiment may be omitted.

[0094] In the fourth embodiment, the shapes of the interconnectors 200a and 200b are different from those in the first embodiment.

[0095] Each interconnector 200 a, 200 b may have at least one first notch 240 a, 240 b adjacent to a first weldable portion 260 a, 260 b and at least one second notch 250 a, 250 b adjacent to a second weldable portion 270 a, 270 b. The second notch 250 a, 250 b may be spaced apart from the first notch 240 a, 240 b in the second direction.

[0096] The first notches 240a, 240b and / or the second notches 250a, 250b may be notches formed in the ends of the interconnectors 200a, 200b, or holes formed in the interconnectors 200a, 200b. In the fourth embodiment, the first notches 240a, 240b and the second notches 250a, 250b are notches formed in the ends of the interconnectors 200a, 200b. In this case, it is preferable that the second notches 250a, 250b are provided at the ends opposite to the ends of the interconnectors 200a, 200b having the first notches 240a, 240b.

[0097] The interconnectors 200a, 200b may have a shape obtained by removing the first notched portions 240a, 240b and the second notched portions 250a, 250b from a substantially rectangular or substantially square shape. In other words, when the shapes of the first notched portions 240a, 240b and the second notched portions 250a, 250b are added to the shape of the interconnectors 200a, 200b, the shape becomes a substantially rectangular or substantially square shape.

[0098] In the fourth embodiment, the first notches 240a, 240b and the second notches 250a, 250b are substantially rectangular or square cutouts provided at the ends of the interconnectors 200a, 200b. A plurality of the first notches 240a, 240b and the second notches 250a, 250b are provided at intervals along the first direction. That is, a plurality of notches are formed at intervals along the first direction at the ends of the interconnectors 200a, 200b in the second direction. As a result, both ends of the interconnectors 200a, 200b in the second direction have a rectangular wave shape.

[0099] The interconnectors 200a, 200b may have first regions R1a, R1b including the first weldable portions 260a, 260b and the first missing portions 240a, 240b, and second regions R2a, R2b including at least the second weldable portions 270a, 270b. In the example shown in Figure 11, the interconnectors 200a, 200b have first regions R1a, R1b including the first weldable portions 260a, 260b and the first missing portions 240a, 240b, and second regions R2a, R2b including the second weldable portions 270a, 270b and the second missing portions 250a, 250b.

[0100] In the fourth embodiment, the first regions R1a, R1b are regions corresponding to the ends of the interconnectors 200a, 200b in the second direction. The second regions R2a, R2b are regions corresponding to the ends of the interconnectors 200a, 200b opposite to the first regions R1a, R1b. The first regions R1a, R1b may be regions extending from one end to the other end of the interconnectors 200a, 200b in the first direction. Similarly, the second regions R2a, R2b may be regions extending from one end to the other end of the interconnectors 200a, 200b in the first direction.

[0101] As shown in Figures 10 and 12, when photoelectric conversion elements 10a, 10b are connected to each other by multiple interconnectors 200a, 200b, the first regions R1a, R1b and second regions R2a, R2b of the interconnectors 200a, 200b may be regions that overlap with the first regions R1a, R1b and second regions R2a, R2b of another interconnector 200a, 200b when viewed from the thickness direction.

[0102] In the first regions R1a, R1b and the second regions R2a, R2b, the first missing portions 240a, 240b and the second missing portions 250a, 250b are provided adjacent to the first weldable portions 260a, 260b and the second weldable portions 270a, 270b, respectively. In the fourth embodiment, the first missing portions 240a, 240b and the second missing portions 250a, 250b are adjacent to the first weldable portions 260a, 260b and the second weldable portions 270a, 270b, respectively, in a first direction intersecting the second direction. Therefore, when the interconnectors 200a, 200b are welded, the first welded portions 210a, 210b and the second welded portions 220a, 220b are positioned adjacent to the first missing portions 240a, 240b and the second missing portions 250a, 250b, respectively. Therefore, heat generated during welding can be easily dissipated, and the load on the vicinity of the welded portions of interconnectors 200a, 200b can be alleviated.

[0103] Preferably, the first notches 240a, 240b and / or the second notches 250a, 250b are provided to divide the first weldable portions 260a, 260b and / or the second weldable portions 270a, 270b into a plurality of sections in the first direction. Specifically, the first notches 240a, 240b may be located between the first weldable portions 260a, 260b aligned in the first direction, and the second notches 250a, 250b may be located between the second weldable portions 270a, 270b aligned in the first direction. More preferably, in the first regions R1a, R1b, the first notches 240a, 240b and the first weldable portions 260a, 260b may be aligned alternately in the first direction. Similarly, in the second regions R2a, R2b, the second missing portions 250a, 250b and the second weldable portions 270a, 270b may be arranged alternately in the first direction. As a result, when the interconnectors 200a, 200b are welded, the multiple first welded portions 210a, 210b and the multiple second welded portions 220a, 220b are separated by the first missing portions 240a, 240b and the second missing portions 250a, 250b, respectively. That is, the first welded portions 210a, 210b and the first missing portions 240a, 240b are arranged alternately in the first direction. Similarly, the second welded portions 220a, 220b and the second missing portions 250a, 250b are arranged alternately in the first direction. Therefore, heat generated in the first welded portions 210a, 210b and the second welded portions 220a, 220b during welding can be easily dissipated.

[0104] In the fourth embodiment, when the first regions R1a, R1b and the second regions R2a, R2b are overlapped with each other in the thickness direction by shifting the same shaped interconnectors 200a, 200b in the second direction, the first missing portions 240a, 240b are formed to overlap the second weldable portions 270a, 270b, and the second missing portions 250a, 250b are formed to overlap the first weldable portions 260a, 260b.

[0105] In the aspect shown in Figure 11, when the first regions R1a, R1b and the second regions R2a, R2b of the interconnectors 200a, 200b are overlapped with each other in the thickness direction, the rectangular wave-shaped edge on the right side of the figure in the second direction of the interconnectors 200a, 200b interlocks with the rectangular wave-shaped edge on the left side of the figure in the second direction of the interconnectors 200a, 200b when viewed in a plan view from the thickness direction (see also Figure 12).

[0106] In the fourth embodiment, when viewed from the thickness direction perpendicular to the surfaces of the photoelectric conversion elements 10a and 10b, the first region R1a of the first interconnector 200a overlaps with the second region R2b of the second interconnector 200b. Here, as described above, when the first regions R1a and R1b and the second regions R2a and R2a of the interconnectors 200a and 200b having the same shape are overlapped with each other in the thickness direction, the first notched portions 240a and 240b are formed to overlap with the second weldable portions 270a and 270b. Therefore, as shown in FIG. 12 , the second weldable portion 270b of the second interconnector 200b is positioned to overlap with the first notched portion 240a of the first interconnector 200a. That is, the rectangular wave shape on the right side of the figure in the second direction of the first interconnector 200a meshes with the rectangular wave shape on the left side of the figure in the second direction of the second interconnector 200b in a plan view seen from the thickness direction.

[0107] Therefore, if the second welded portion 220b is formed at a position of the second weldable portion 270b of the second interconnector 200b that overlaps with the first missing portion 240a of the first interconnector 200a, the second welded portion 220b will naturally be positioned at a position shifted from the first welded portion 210a formed in the first interconnector 200a. In this way, the shapes of the interconnectors 200a, 200b make it possible to more reliably shift the positions of the first welded portion 210a and the second welded portion 220b.

[0108] Furthermore, in the photovoltaic conversion module 100, as shown in Fig. 10 , an insulating tape 300 covering the first welded portions 210a, 210b and the second welded portions 220a, 220b may be attached to the first interconnector 200a and / or the second interconnector 200b. The area where the insulating tape 300 is attached is indicated by a dashed line in Fig. 12 . That is, the insulating tape 300 extends in the first direction from the welded portions 210a, 210b, 220a, 220b of the interconnectors 200a, 200b to the missing portions 240a, 240b, 250a, 250b. Since the cutouts 240a, 240b, 250a, and 250b are regions where the interconnectors 200a and 200b are not present, the insulating tape 300 adheres to both the portions of the photoelectric conversion elements 10a and 10b that are not covered with the interconnectors 200a and 200b, and the interconnectors 220a and 220b. This allows the interconnectors 200a and 200b to be attached to the photoelectric conversion elements 10a and 10b also by the insulating tape 300, thereby further improving the connection strength to the photoelectric conversion elements 10a and 10b.

[0109] Fifth Embodiment Next, a photovoltaic conversion module according to a fifth embodiment will be described with reference to Fig. 13. Fig. 13 is a schematic plan view illustrating the arrangement of interconnectors and the positions of welded portions according to the fifth embodiment. The same reference numerals are used for components similar to those in the first embodiment. It should be noted that the description of components similar to those in the first embodiment may be omitted.

[0110] In the fifth embodiment, as shown in FIG. 13 , the shapes of the interconnectors 200a, 200b and the positions of the welds 210a, 220a, 210b, 220b are substantially the same as those described in the fourth embodiment. However, the interconnectors 200a, 200b according to the fifth embodiment have a plurality of holes 290a, 290b. The plurality of holes 290a, 290b are provided in an area covered by the insulating tape 300. Therefore, the insulating tape 300 covering the plurality of holes 290a, 290b also adheres to the portions of the photoelectric conversion elements 10a, 10b exposed through the holes 290a, 290b. This can further improve the connection strength of the interconnectors 200a, 200b to the photoelectric conversion elements 10a, 10b.

[0111] Sixth Embodiment Next, a photovoltaic conversion module according to a sixth embodiment will be described with reference to Fig. 14. Fig. 14 is a schematic plan view of the photovoltaic conversion module according to the sixth embodiment. Note that the same reference numerals are used for components similar to those in the first embodiment. It should be noted that the description of components similar to those in the first embodiment may be omitted.

[0112] The photoelectric conversion module 100 may include one or more photoelectric conversion elements 10a, 10b. Note that Fig. 14 shows the photoelectric conversion module 100 including a plurality of photoelectric conversion elements 10a, 10b. The one or more photoelectric conversion elements 10a, 10b may be sealed with, for example, a sealing material.

[0113] When the photoelectric conversion module 100 includes a plurality of photoelectric conversion elements 10 a, 10 b, the plurality of photoelectric conversion elements 10 a, 10 b may be arranged in at least one direction, preferably in a lattice pattern, and may be electrically connected to each other in series and / or parallel.

[0114] In the example shown in Fig. 14, adjacent photoelectric conversion elements 10a, 10b arranged in one direction partially overlap each other. Specifically, as shown in Fig. 14, a second photoelectric conversion element 10b may be arranged so as to cover the second portion 32a of the collecting electrode 30a of the first photoelectric conversion element 10a adjacent thereto. In this case, the second photoelectric conversion element 10b is electrically connected to the second portion 32a of the collecting electrode 30a of the first photoelectric conversion element 10a adjacent thereto.

[0115] The adjacent photoelectric conversion elements 10a, 10b may be electrically connected to each other by the above-described interconnectors 200a, 200b. In this case, the interconnectors 200a, 200b may extend across the adjacent photoelectric conversion elements 10a, 10b.

[0116] 14, the adjacent photoelectric conversion elements 10a, 10b may be arranged with a gap between them. Even in this case, the adjacent photoelectric conversion elements 10a, 10b can be electrically connected to each other by the interconnectors 200a, 200b.

[0117] [Satellite and Paddle for Satellite] Next, a satellite equipped with a photoelectric conversion module and a paddle for the satellite will be described. Fig. 15 is a schematic perspective view of a satellite equipped with a photoelectric conversion module. The satellite 900 may have a base 910 and a paddle 920. The base 910 may include equipment (not shown) necessary for controlling the satellite 900. An antenna 940 may be attached to the base 910.

[0118] The paddle 920 may include the photoelectric conversion module 100 described above. The paddle 920 including the photoelectric conversion module 100 can be used as a power source for operating various devices provided on the base 910. In this way, the photoelectric conversion module 100 can be applied to paddles for artificial satellites. In particular, since the paddle 920 for an artificial satellite is exposed to a high-temperature environment and an environment with drastic temperature changes during launch and operation of the artificial satellite, it is desirable to use the photoelectric conversion module 100 including the photoelectric conversion elements 10a, 10b having high heat resistance described above.

[0119] The paddle 920 may have a connecting portion 922 and a hinge portion 924. The connecting portion 922 corresponds to the portion that connects the paddle 920 to the base portion 910.

[0120] The hinge portion 924 extends in one direction, allowing the paddle 920 to be folded around the hinge portion 924 as a rotation axis. Each paddle 920 may have at least one, and preferably a plurality of, hinge portions 924. This allows the paddle 920 equipped with the photovoltaic conversion module 100 to be foldable into a small size. When the satellite 900 is launched, the paddle 920 may be in a folded state. The paddle 920 may be unfolded when receiving sunlight to generate power.

[0121] 15 , the paddle 920 may have a cylindrical shape formed by being wound. This allows the paddle 920 to assume a generally flat, deployed state by rotating the wound portion. When the satellite 900 is launched, the paddle 920 may maintain a generally cylindrical shape. The paddle 920 may be deployed to a generally flat state when receiving sunlight and generating power.

[0122] As described above, the contents of the present invention have been disclosed through the embodiments, but the descriptions and drawings that form part of this disclosure should not be understood to limit the present invention. Various alternative embodiments, examples, and operating techniques will become apparent to those skilled in the art from this disclosure. Therefore, the technical scope of the present invention is defined only by the inventive features of the claims that can be reasonably understood from the above description.

[0123] The features described in each of the above-described embodiments can be applied to or exchanged with other embodiments as much as possible. Furthermore, while the above-described embodiments have been described using thin-film photoelectric conversion elements as examples, the present invention is not limited to this, and can also be applied to crystalline photoelectric conversion elements as much as possible.

[0124] In the above-described embodiment, the first weld 210a and the second weld 220b provided on the first photoelectric conversion element 10a are used to connect the interconnectors 200a and 200b. Alternatively, the first weld 210a and the second weld 220b may be used to connect any other member. In this case, the welding step in the method for manufacturing a photoelectric conversion module may include forming a first weld on a first surface of the photoelectric conversion element and forming a second weld on a second surface of the photoelectric conversion element opposite the first surface. However, as described above, the center of gravity of the first weld is formed so as to be offset from the center of gravity of the second weld. Preferably, the first weld does not overlap the center of gravity of the second weld or the entire second weld when viewed in the thickness direction of the photoelectric conversion element.

[0125] This application claims priority based on Japanese Patent Application No. 2022-163018, filed on October 11, 2022, the entire contents of which are incorporated herein by reference.

Claims

1. A first photoelectric conversion element; a first welded portion provided on a first surface of the first photoelectric conversion element; a second welded portion provided on a second surface of the first photoelectric conversion element opposite to the first surface; a second photoelectric conversion element that partially overlaps the first photoelectric conversion element on a first surface side of the first photoelectric conversion element, When viewed from a thickness direction perpendicular to the first surface of the first photoelectric conversion element, a center of gravity of the first welded portion is shifted from a center of gravity of the second welded portion, A photoelectric conversion module, wherein the first welded portion and the second welded portion overlap an area covered by the second photoelectric conversion element when viewed from the thickness direction.

2. The photovoltaic conversion module according to claim 1 , wherein the first welded portion does not overlap a center of gravity of the second welded portion when viewed in the thickness direction.

3. The photovoltaic conversion module according to claim 1 , wherein the first welded portion does not overlap the second welded portion when viewed in the thickness direction.

4. The photoelectric conversion module has a plurality of the first welded portions and a plurality of the second welded portions, The first welds are arranged at intervals along a first direction, The photovoltaic conversion module according to claim 1 , wherein the second welded portions are arranged offset from the first welded portions in a second direction intersecting the first direction.

5. The photoelectric conversion module has a plurality of the first welded portions and a plurality of the second welded portions, The first welds are arranged at intervals along a first direction, The photoelectric conversion module according to claim 1 , wherein the second welded portions are provided between the first welded portions in the first direction.

6. the first photoelectric conversion element includes a non-photoelectric conversion region that does not contribute to photoelectric conversion, The photoelectric conversion module according to claim 1 , wherein the first welded portion and the second welded portion overlap the non-photoelectric conversion region when viewed in the thickness direction.

7. a first interconnector connected to the first photoelectric conversion element at the first welded portion and electrically connecting the first photoelectric conversion element to a third photoelectric conversion element; The photovoltaic conversion module of claim 1 , further comprising: a second interconnector connected to the first photovoltaic conversion element at the second welded portion and electrically connecting the first photovoltaic conversion element to the second photovoltaic conversion element.

8. The photovoltaic conversion module according to claim 7 , wherein the second welded portion is provided in a region that does not overlap with the first interconnector when viewed in the thickness direction.

9. The first interconnector and the second interconnector partially overlap each other when viewed from the thickness direction, The photovoltaic conversion module according to claim 7 , wherein the first welded portion and the second welded portion overlap a region where the first interconnector and the second interconnector overlap when viewed in the thickness direction.

10. The first photoelectric conversion element and the second photoelectric conversion element are arranged with a shift in a second direction, The first photoelectric conversion element includes a collecting electrode, the collecting electrode has a second portion extending along a first direction intersecting the second direction, The photovoltaic conversion module according to claim 1 , wherein the first welded portion and the second welded portion overlap the second portion of the current collecting electrode when viewed in the thickness direction.

11. A paddle comprising the photoelectric conversion module according to claim 1.

12. A step of preparing a first photoelectric conversion element and a second photoelectric conversion element; and forming a first weld on a first surface of the first photoelectric conversion element and a second weld on a second surface of the first photoelectric conversion element opposite to the first surface, In the welding step, the first welded portion is formed such that a center of gravity of the first welded portion is shifted from a center of gravity of the second welded portion when viewed in a thickness direction perpendicular to the first surface of the first photoelectric conversion element, A method for manufacturing a photoelectric conversion module, wherein the second photoelectric conversion element partially overlaps the first photoelectric conversion element on the first surface side of the first photoelectric conversion element, and is positioned so as to cover the first welded portion and the second welded portion when viewed from the thickness direction.

13. The method for manufacturing a photovoltaic conversion module according to claim 12 , wherein in the welding step, the first welded portion and the second welded portion are formed simultaneously.