Power generation module and method for manufacturing same

Abstract

A power generation module according to the present disclosure comprises: a first substrate (71); a second substrate (72) facing the first substrate (71) in the thickness direction of the first substrate (71); a solar cell disposed between the first substrate (71) and the second substrate (72); a seal member (73) disposed between the first substrate (71) and the second substrate (72) so as to surround the solar cell in a frame-like manner in a plan view seen along the thickness direction; and a lead wire (51, 52) electrically connected to the solar cell. The seal member (73) has a penetration part (73p) to which the lead wire (51, 52) is fixed in a state of penetrating to the outside, and the penetration part (73p) includes a bent portion (51k) to which the lead wire (51, 52) is fixed in a state of being bent in a cross-sectional view in the thickness direction.

Description

Power generation module and its manufacturing method

[0001] This disclosure relates to a power generation module and a method for manufacturing the same, and more specifically to a power generation module equipped with a solar cell as a power generation device and a method for manufacturing the same.

[0002] Development is underway on perovskite solar cells that use perovskite crystals represented by the compositional formula ABX3 (where A is a monovalent cation, B is a divalent cation, and X is an anion such as a halogen anion) and similar structures (hereinafter referred to as "perovskite compounds") as photoelectric conversion materials.

[0003] Meanwhile, in order to expand the applications of solar cells, power generation modules for building-integrated photovoltaics (BIPV) are also being developed. In applications such as BIPV, where long-term use is expected, high reliability is especially required for the power generation modules.

[0004] Patent Document 1 discloses a power generation module in which a perovskite solar cell is sealed between two substrates.

[0005] International Publication No. 2021 / 251048

[0006] Patent Document 1 does not consider the arrangement of lead wires for extracting power to the outside of the power generation module. This disclosure provides a power generation module in which lead wires are arranged to contribute to improved sealing performance. This disclosure also provides a novel method for manufacturing the power generation module of this disclosure.

[0007] The power generation module of the present disclosure comprises: a first substrate; a second substrate facing the first substrate in the thickness direction of the first substrate; a solar cell disposed between the first substrate and the second substrate; a sealing member disposed between the first substrate and the second substrate so as to surround the solar cell in a frame shape in a plan view along the thickness direction; and lead wires electrically connected to the solar cell, wherein the sealing member has a through portion through which the lead wires are fixed to the outside, and the through portion includes a bent portion in a cross-sectional view in the thickness direction through which the lead wires are fixed in a bent state.

[0008] A method for manufacturing a power generation module according to the present disclosure comprises: a first substrate; a second substrate facing the first substrate in the thickness direction of the first substrate; a solar cell disposed between the first substrate and the second substrate; a sealing member disposed between the first substrate and the second substrate so as to surround the solar cell in a frame shape in a plan view along the thickness direction; and lead wires electrically connected to the solar cell, the method for manufacturing a power generation module comprising: a first step of electrically connecting the solar cell and the lead wires; and a second step of arranging the lead wires and the sealing material at the peripheral edge of the second substrate on which the solar cell is disposed, such that the lead wires penetrate the sealing material. The third step includes reducing the distance between the first substrate and the second substrate, which are arranged such that the solar cell is positioned between them, while spreading the sealing material between the first substrate and the second substrate, forming a sealing member having a penetration portion through which the lead wire penetrates to the outside of the power generation module from the spread sealing material, and bonding the first substrate and the second substrate together, wherein in the second step, the lead wire is positioned such that the lead wire includes a bent portion in a cross-sectional view in the thickness direction.

[0009] This disclosure provides a power generation module in which lead wires are arranged to contribute to improved sealing performance, and a method suitable for manufacturing the same.

[0010] Figure 1 is a schematic plan view showing a power generation module according to the first embodiment of the present disclosure. Figure 2 is a cross-sectional view taken along line A-A in Figure 1. Figure 3 is a partially enlarged view of region O in Figure 1. Figure 4 is a schematic plan view showing power generation modules according to the second and fourth embodiments of the present disclosure. Figure 5 is a schematic plan view showing a power generation module according to the third embodiment of the present disclosure. Figure 6 is a partially enlarged plan view of a power generation module according to the fourth embodiment of the present disclosure. Figure 7 is a schematic plan view showing a power generation module according to the fifth embodiment of the present disclosure. Figure 8A is a cross-sectional view showing a reference example of the B-B section of Figure 7. Figure 8B is a cross-sectional view showing another reference example of the B-B section of Figure 7. Figure 8C is a cross-sectional view showing an example of the B-B section of Figure 7. Figure 9 is a cross-sectional view showing another modified example of the B-B section of Figure 7. Figure 10 is a cross-sectional view taken along line C-C in Figure 7. Figure 11 is a schematic plan view showing a power generation module according to the sixth embodiment of the present disclosure. Figure 12 is a plan view showing an example of a lead wire along with its bent portion. Figure 13 is a cross-sectional view taken along line D-D in Figure 12. Figure 14A is a plan view showing another example of a lead wire. Figure 14B is a plan view showing yet another example of a lead wire. Figure 14C is a plan view showing a modified example of the bent portion of the lead wire shown in Figure 14B. Figure 15A is a cross-sectional view showing the first step of an example of a method for forming an integrated solar cell. Figure 15B is a cross-sectional view showing the second step. Figure 15C is a cross-sectional view showing the third step. Figure 15D is a cross-sectional view showing the fourth step. Figure 15E is a cross-sectional view showing the fifth step. Figure 15F is a cross-sectional view showing the sixth step. Figure 15G is a cross-sectional view showing the seventh step. Figure 16 is a flowchart showing one embodiment of the method for manufacturing a power generation module according to the present disclosure. Figure 17A is a cross-sectional view showing the first step in one embodiment of the method for manufacturing a power generation module according to the present disclosure. Figure 17B is a cross-sectional view showing a part of the second step. Figure 17C is a cross-sectional view showing another part of the second step. Figure 17D is a cross-sectional view showing yet another part of the second step. Figure 17E is a cross-sectional view showing part of the third step. Figure 17F is a cross-sectional view showing yet another part of the third step. Figure 18 is a partial plan view showing an example of the arrangement of sealing material in an embodiment of the manufacturing method of the power generation module of the present disclosure.Figure 19 is a partial plan view showing another example of the arrangement of sealing material in an embodiment of the manufacturing method of the power generation module of the present disclosure. Figure 20 is a partial plan view showing the shape of a sealing member that may be formed from the sealing material shown in Figure 19.

[0011] <Embodiment of the Disclosure> The power generation module of this embodiment comprises: a first substrate; a second substrate facing the first substrate in the thickness direction of the first substrate; a solar cell disposed between the first substrate and the second substrate; a sealing member disposed between the first substrate and the second substrate so as to surround the solar cell in a frame shape in a plan view along the thickness direction; and lead wires electrically connected to the solar cell, wherein the sealing member has a through portion through which the lead wires are fixed to the outside, and the through portion includes a bent portion in a cross-sectional view in the thickness direction through which the lead wires are fixed in a bent state.

[0012] The power generation module of this embodiment and its manufacturing method will be described below with reference to the drawings.

[0013] Figure 16 is a flowchart showing one embodiment of the manufacturing method of the power generation module of the present disclosure. In this embodiment, first, in step 201, the solar cell and the lead wire are electrically connected. Next, in step 202, the sealing material and the lead wire are arranged on the periphery of the second substrate on which the solar cell is arranged, such that the lead wire passes through the sealing material. Subsequently, in step 203, the sealing material is spread between the first and second substrates while reducing the distance between them, thereby forming a sealing member having a penetration portion through which the lead wire passes to the outside of the power generation module, and the first and second substrates are integrated. According to this embodiment, it is possible to form a sealing member while integrating the first and second substrates. Integration refers to a state in which the first and second substrates are bonded together by pressure, adhesive, or the like.

[0014] Steps 201 to 203 will be explained with reference to Figures 17A to 17F. Figures 17A to 17F show partial cross-sections of the peripheral edge of the second substrate 72. As shown in Figure 17A, in step 201, the lead wire 51 is electrically connected to the solar cell. In the illustrated example, the lead wire 51 is electrically connected to an integrated solar cell, which is not shown in the figure, via a connector 77. Hereafter, the integrated solar cell may be simply abbreviated as "solar cell". The lead wire 51 may be fixed to the connector 77 using a conductive material 55 such as solder or conductive adhesive. A portion of the conductive material 55 may be interposed between the lead wire 51 and the connector 77. The connector 77 may be formed by expanding the electrode layer of the solar cell.

[0015] Figures 17B to 17D show an example of step 202. In this example, in step 202, first, as shown in Figure 17B, a resin film 74p and a first layer 733 of sealing material are placed on the second substrate 72. The sealing material can be placed, for example, by attaching a tape-shaped sealing material or by applying a melted sealing material using a melter or the like. As shown in the figure, it is desirable that the resin film 74p and the first layer 733 are placed so as not to overlap each other in a plan view. The resin film 74p may be placed so as to cover at least a part of the solar cell and may also be placed so as to cover the lead wires 51 and the connection part 77. The first layer 733 is placed on the periphery of the second substrate 72. The first layer 733 may be formed to have a thickness that extends from the second substrate 72 to a position further away in the thickness direction from the fixing part where the lead wires 51 are fixed for electrical connection to the solar cell, that is, to a position relatively high from the surface of the second substrate 72.

[0016] Next, as shown in Figure 17C, the lead wire 51 is raised from its fixed portion so as to pass over or on the surface of the first layer 733 and further positioned to reach the outside of the second substrate 72. As shown in Figures 17B and 17C, the lead wire 51 may be bent along the edge of the resin film 74p in a direction that moves away from the second substrate 72 in its thickness direction. This arrangement facilitates the movement of the sealing material toward the inner circumferential end in step 203.

[0017] As shown in Figure 17C, in this embodiment, the lead wire 51 is arranged such that, in a cross-sectional view in the thickness direction of the second substrate 72, the lead wire 51 includes a bent portion 51k.

[0018] Next, as shown in Figure 17D, a second layer 734 of the sealing material is arranged so as to sandwich the lead wire 51 between it and the first layer 733. The first layer 733, the lead wire 51, and the second layer 734 are arranged in this order from the second substrate 72 side. The lead wire 51 is led out to the outside by passing through the sealing material 730, which is composed of the first layer 733 and the second layer 734. The height HS from the surface of the second substrate 72 to the upper end of the sealing material 730 may be set to be higher than the height HP from the surface of the second substrate 72 to the upper end of the resin film 74p, i.e., HS > HP. The sealing material 730 may be arranged so as to substantially surround the solar cell in a frame shape when the second substrate 72 is viewed from above. Surrounding substantially in a frame shape means allowing for a frame division, which will be described later.

[0019] Next, as shown in Figure 17E, in order to carry out step 203, the first substrate 71 is positioned between it and the second substrate 72 such that the solar cell, connection part 77, part of the lead wire 51, resin film 74p, sealing material 730, etc. are located.

[0020] As shown in Figure 17F, in step 203, the sealing material is spread between the first substrate 71 and the second substrate 72 while reducing the distance between them, and a sealing member 73 is formed from the spread sealing material 730. In the illustrated example, an intermediate layer 74 containing resin supplied from the resin film 74p is formed together with the sealing member 73. The resin formed from the resin film 74p can fill the space between the first substrate 71 and the second substrate 72. As in the illustrated example, a portion of the resin may reach the space between the lead wire 51 and the second substrate 72. The first substrate 71 and the second substrate 72 are joined by the resin contained in the intermediate layer 74 and the sealing member 73. In step 203, the formation of the sealing member 73 and the integration of the two substrates 71 and 72 can proceed simultaneously. In the power generation module obtained by steps 201 to 203, the sealing member 73 has a through-hole 73p through which the lead wire 51 passes, and the lead wire 51 is led out from the power generation module via the through-hole 73p.

[0021] At the through-hole 73p of the sealing member 73, it is desirable that the lead wire 51 is not in contact with either the first substrate 71 or the second substrate 72. An upper sealing member 73U may be interposed between the lead wire 51 and the first substrate 71, and a lower sealing member 73D may be interposed between the lead wire 51 and the second substrate 72. This desirable arrangement can improve the reliability of the sealing. To realize this arrangement, in Figure 17D, the ratio of the thickness D1 of the first layer 733 of the sealing material 730 to the thickness D2 of the second layer 734 is expressed as D1 / D2 and should be, for example, 0.5 or more and 2 or less. This ratio may be reflected in the ratio of the thickness of the lower sealing member 73D to the thickness of the upper sealing member 73U.

[0022] Figure 17F shows the inner circumferential end 730i and outer circumferential end 730o of the sealing material 730 before it is expanded, and the inner circumferential end 73i and outer circumferential end 73o of the sealing member 73 formed by expanding the sealing material 730. The inner circumferential end 73i of the sealing member 73 may be in contact with the end 74o of the intermediate layer 74, which is made of resin. This indicates that the sealing member 73 and the intermediate layer 74 are formed while the inner circumferential end of the sealing material 730 being expanded is blocked by the end of the resin film 74p. This contact facilitates the positioning of the inner circumferential end 73i of the sealing member 73. As shown in Figure 17F, the distance ID between the inner circumferential end 730i and the inner circumferential end 73i may be shorter than the distance OD between the outer circumferential end 730o and the outer circumferential end 73o. The above embodiment can also reduce unintended gaps between the sealing member 73 formed by expanding the sealing material 730 and the intermediate layer 74.

[0023] In the embodiment shown in Figure 17F, similar to the embodiment shown in Figure 8C described later, the lead wire 51 includes a bent portion 51k inside the sealing member 73, in a cross-sectional view in the thickness direction of the second substrate 72. The bent portion 51k is also the bent portion at the through portion 73p. At the interface between the lead wire and the sealing member, tiny voids are likely to occur because dissimilar materials are in contact. Tiny irregularities on the surface of the lead wire and differences in the thermal expansion coefficients of the lead wire and the sealing member can be factors that cause tiny voids. These voids can become pathways for substances that can affect the characteristics of the solar cell to enter from the outside to the inside of the power generation module. By relatively increasing the distance the lead wire 51 passes through the sealing member 73, it is possible to suppress the entry of such substances. The bent portion 51k can improve the sealing performance of the power generation module 1.

[0024] As can be seen from Figures 17E and 17F, by positioning the bent portion of the lead wire 51 in the area where the sealing member 73 is formed from the expanded sealing material, a bent portion can be formed in the through portion 73p of the sealing member 73.

[0025] In the embodiment shown in Figure 17F, both bent portions 51k are located at a position where the distance from the outer peripheral end 73o of the sealing member 73 is longer than the distance from the inner peripheral end 73i of the sealing member 73.

[0026] In step 203, the sealing material and resin film may be softened by heating, and the gap between the first substrate 71 and the second substrate 72 may be reduced by applying pressure. Pressure to narrow the gap is applied, for example, by reducing the pressure in the space between the two substrates 71 and 72. In step 203, the gap between the first substrate 71 and the second substrate 72 may be reduced by heating and reducing pressure.

[0027] In step 203, the distance between the first substrate 71 and the second substrate 72 can be reduced until it becomes a predetermined distance G. The distance G may be substantially the same as the thickness of the resin film 74p. In this disclosure, "substantially the same" means that the difference between the two values ​​is 15% or less of the relatively larger value. If the distance G is substantially the same as the thickness of the resin film 74p, the deformation of the resin film 74p is limited to a very narrow range. Therefore, it becomes easy to determine the position of the end 74o of the intermediate layer 74 by the arrangement of the end of the resin film 74p. Fluctuations in the position of the end 74o of the intermediate layer 74 may be accompanied by fluctuations in the inner circumference end 73i of the sealing member 73, which can be a factor that degrades the appearance of the power generation module 10. The embodiment in which the distance G is substantially the same as the thickness of the resin film 74p is useful for improving the appearance of the power generation module 10.

[0028] Figure 18 is a partial plan view of the vicinity of the corner portion of the second substrate 72 in step 202. The sealing material 730 is formed in a frame shape surrounding the solar cell on the peripheral edge of the second substrate 72. The sealing material 730 may have a dividing portion 70 in a part of the frame that divides the frame. In the illustrated example, the dividing portion 70 divides the sealing material 730a and the sealing material 730b near the bent portion 730c of the sealing material 730. The dividing portion 70 provides a gas discharge passage in step 203.

[0029] The spaced-apart sealing materials 730a and 730b can be easily formed, for example, by attaching a tape-shaped sealing material to the illustrated position. The dividing portion 70 is formed between the side of the sealing material 730a and the longitudinal end of the sealing material 730b. With this arrangement, the dividing portion 70 can be formed efficiently and easily.

[0030] Figure 19 is a partial plan view showing another example of the vicinity of the corner of the second substrate 72 in step 202. As shown, the frame formed by the sealing material 730 has a thickness variation portion 730t in a part thereof, which has a different thickness from the rest of the frame. In the illustrated example, the thickness variation portion 730t is formed at the bent portion 730c of the frame. In the thickness variation portion 730t, the sealing material 730 is formed to be thicker than in the parts other than the bent portion 730c. The thickness variation portion 730t forms a gas discharge passage in the vicinity of the thickness variation portion 730t in step 203. The thickness variation portion 730t can be formed by locally adding a third layer 735 in addition to the first layer 733 and the second layer 734. The formation of the thickness variation portion 730t can be carried out by partially applying a tape-like sealing material or by partially applying a sealing material melted by heat.

[0031] As shown in Figure 19, it is desirable that the thickness variation portion 730t be placed in the bent portion of the frame formed by the sealing material 730, as a part in which the thickness is locally increased. In this example, a relatively large amount of sealing material is placed in the bent portion, making it easy to maintain the width of the sealing member 73 near the corner portion to a length desirable for sealing. Figure 20 illustrates a sealing member 73 that can be formed from the sealing material 730 shown in Figure 19. The sealing material 730 is expanded, and the thickness variation portion 730t is eliminated from the sealing member 73. Although not shown in the figure, the separation portion 70 can also be eliminated from the sealing member 73 by expanding the sealing material 730 in step 203.

[0032] If the outer shape of the frame formed by the sealing material 730 is polygonal in plan view, thickness variation portions 730t may be formed near the vertices of the polygon, i.e., at each of the bent portions of the frame. If the outer shape of the frame is quadrilateral, thickness variation portions may be formed at the four bent portions of the frame. In this case, the straight paths between the thickness variation portions can function as exhaust paths. However, the arrangement of the thickness variation portions is not limited to this. Furthermore, the thickness variation portions may be areas where the thickness is locally reduced. Thickness variation portions with locally reduced thickness are preferably placed in the straight paths of the frame formed by the sealing material 730.

[0033] In the configurations shown in Figures 17A to 20, a resin film 74p and a sealing material 730 are used as bonding materials for two substrates 71 and 72. The resin film 74p and the sealing material 730 may be composed of different materials, and may also be composed of different organic materials. The sealing material 730 may be selected to begin softening at a lower temperature than the resin constituting the resin film 74p. However, the sealing material 730 alone may be used as the bonding material. In other words, the intermediate layer 74 may be composed of a gas phase. The gas phase may be under reduced pressure and may be composed of a gas with a different composition than air. The intermediate layer 74 may be sealed with an inert gas.

[0034] Figure 20 shows a configuration in plan view in which the through-hole 73p of the sealing member 73 through which the lead wire 51 passes has bent portions 51b and 51c. As can be seen from Figures 18 and 19, the bent portions 51b and 51c can be introduced by forming bent portions on the lead wire 51 that is placed in step 202 at the portion that contacts the sealing material 730. However, the bent portions of the through-hole 73p are not essential in this disclosure, and their formation is optional.

[0035] <Other Embodiments of the Disclosure> Other embodiments of the Disclosure will be described below. Figure 1 is a schematic plan view showing the power generation module 1.

[0036] As shown in FIG. 1, the power generation module 1 includes a power generation region 11, two connection regions 12 arranged adjacent to the power generation region 11, and a seal region 15 surrounding the power generation region 11 and the connection regions 12.

[0037] Solar battery cells are arranged in the power generation region 11. A plurality of solar battery cells may be arranged in the power generation region 11, and the plurality of solar battery cells may be electrically connected to each other and integrated to constitute a solar battery. The power generation region 11 only needs to have a solar battery arranged in at least a part thereof, and may have a portion where no solar battery is arranged. Such a portion is appropriately set, for example, to increase the light transmittance of the module 1 or improve the visibility. Lead wires 51 and 52 for extracting electric power from the solar battery are arranged in the two connection regions 12, respectively. The two connection regions 12 are arranged so as to sandwich the power generation region 11 in the illustrated X-axis direction, and extend along the power generation region 11 in the illustrated Y-axis direction. The lead wires 51 and 52 also extend in the Y-axis direction on the connection region 12.

[0038] A seal member 73 is arranged in the seal region 15. The seal member 73 surrounds the solar battery arranged in the power generation region 11 in a frame-forming shape, that is, a frame shape. An intermediate region 13 may be interposed between the power generation region 11, the connection regions 12, and the seal region 15. The intermediate region 13 may surround the power generation region 11 and the connection regions 12 in a frame shape.

[0039] As shown in FIG. 1, the power generation module 1 may have a quadrangular outer shape in a plan view. However, the outer shape of the power generation module 1 is not limited thereto, and may be a polygon other than a quadrangle, or may be other shapes such as a circle or an ellipse. The shapes of the respective regions 11, 12, 13, and 15, and the shape of the frame formed by the seal member 73 can also have shapes corresponding to the shape of the power generation module 1.

[0040] Figure 2 is a cross-sectional view taken along line A-A in Figure 1. As shown in Figure 2, the power generation module 1 comprises a first substrate 71 and a second substrate 72. In the configuration shown in Figure 1, the first substrate 71 is translucent, but it may also be opaque. The second substrate 72 may also be translucent or opaque, but is preferably translucent. In Figure 2, the power generation module 1 comprises a sealing member 73, an intermediate layer 74, and a solar cell 75 between the first substrate 71 and the second substrate 72, and further comprises lead wires 52.

[0041] The sealing member 73 contacts both the first substrate 71 and the second substrate 72 in at least a portion of the sealing region 15, sealing the interior of the power generation module 1 from the outside at its periphery. The intermediate layer 74 is interposed between the first substrate 71 and the solar cell 75 in the power generation region 11, between the first substrate 71 and the lead wire 52 and connection portion 77 in the connection region 12, and between the first substrate 71 and the second substrate 72 in the intermediate region 13. In the intermediate region 13, the intermediate layer 74 forms an intermediate portion 74m that contacts the first substrate 71 and the second substrate 72. The intermediate layer 74 may be in solid phase or gas phase, or may contain both. Examples of solid phase and gas phase will be described later.

[0042] The solar cell 75 may be formed on the second substrate 72. The solar cell 75 may have a laminated structure in which a first electrode layer 81, a power generation layer 82 including a semiconductor layer, and a second electrode layer 83 are laminated in this order from the second substrate 72 side. In the power generation layer 82, the semiconductor layer functions as a photoelectric conversion layer. The power generation layer 82 may be a laminate including layers such as an electron transport layer and a hole transport layer together with the semiconductor layer. The semiconductor layer may contain a perovskite compound. Although illustration is omitted in FIG. 2, in the power generation region 11, the solar cell may be configured by sequentially connecting solar cells (unit cells) arranged along the illustrated X-axis direction in series in order. However, the solar cell may have a configuration other than the illustrated configuration. For example, the solar cell may be formed on the first substrate 71. Further, for example, the solar cell may be integrated by connecting a plurality of solar cells to each other with internal lead wires. In this case, a resin may be interposed between the solar cells and the internal lead wires, and between the two substrates 71 and 72, respectively.

[0043] A connection portion 77 is arranged in the connection region 12. As illustrated, the connection portion 77 may be formed by extending the first electrode layer 81 from the power generation region 11 to the connection region 12. The power generation layer 82 and the second electrode layer 83 are not formed in the connection region 12, and instead, a lead wire 52 electrically connected to the connection portion 77 is arranged there. The lead wire 52 is formed directly on the connection portion 77 or via a conductive material not illustrated in FIG. 2. On the connection portion 77, a conductive material may adhere to the surface of the lead wire 52.

[0044] It is desirable that the lead wire 52 is arranged spaced apart from the power generation layer 82, specifically spaced apart from the semiconductor layer included in the power generation layer 82. The lead wire 52 may be arranged at a position spaced apart from the semiconductor layer along the direction in which the connection region 12 extends. This arrangement mitigates the influence of heat generation of the lead wire 52. The degree of separation is represented by a distance d. Details of the distance d and a desirable range thereof will be described later.

[0045] The width W of the sealing member 73 is determined by the distance between the outer peripheral end 73o and the inner peripheral end 73i of the sealing member 73. From the viewpoint of reliably preventing the intrusion of substances from the outside to the inside of the power generation module 1, it is desirable that the width W is not too narrow. The width W is, for example, 5 mm or more, and more preferably 10 mm or more. On the other hand, from the viewpoint of securing a wide power generation area 11, a narrow width W is advantageous. The width W is, for example, 40 mm or less, and more preferably 20 mm or less. As will be described later, the presence of a bent portion can contribute to ensuring the reliability of the module 1 without increasing the width W of the sealing member 73. Note that, as shown in Figure 2, the outer peripheral end 73o of the sealing member 73 may be located in a position set back from the outer peripheral end 17 of the power generation module 1 towards the inside of the module 1.

[0046] From the viewpoint of reliably preventing the intrusion of material from the outside into the power generation module 1, it is desirable that the gap G between the first substrate 71 and the second substrate 72 not be too large. The gap G is, for example, 5 mm or less, less than 3 mm, and even 2 mm or less. On the other hand, from the viewpoint of ensuring the strength against failure of the module, it is desirable that the thickness of the intermediate layer 74, i.e., the gap G, not be too small. The gap G is, for example, 0.1 mm or more, 0.76 mm or more, and even 1.52 mm or more.

[0047] The above describes the cross-sectional structure near the left side of Figure 1 where the lead wire 52 is located, but the cross-sectional structure near the right side of Figure 1 where the lead wire 51 is located is the same as described above.

[0048] Referring again to Figure 1, the arrangement of lead wires 51 and 52 will be explained. Lead wires 51 and 52 each have first ends 51a and 52a located outside the power generation module 1, and second ends 51z and 52z located inside the power generation module 1. The first ends 51a and 52a may be led into members such as junction boxes or structural elements such as building sashes. Lead wires 51 and 52 may be led out from the same side that constitutes the outer perimeter as defined by a plan view of the power generation module 1, the upper side shown in Figure 1. In Figure 1, lead wires 51 and 52 are led out from near the center of the upper side.

[0049] The second ends 51z and 52z may each be located near the end of the connection region 12, specifically near the end opposite to the side from which the lead wires 51 and 52 are led out. From the first ends 51a and 52a to the second ends 51z and 52z, the lead wires 51 and 52 are arranged inside the power generation module 1 to pass through the seal region 15, the intermediate region 13, and the connection region 12 in that order.

[0050] In the sealing region 15, the sealing member 73 has a through-hole 73p through which the lead wires pass. The lead wires 51 and 52 each electrically connect the outside and inside of the power generation module 1 via the through-hole 73p.

[0051] The lead wires 51 and 52 may each be bent at the bent portions within the sealing region 15. In the illustrated embodiment, the first lead wire 51 is bent at two bent portions 51b and 51c within the sealing region 15, and the second lead wire 52 is bent at two bent portions 52b and 52c within the sealing region 15. Bending typically means being folded, folded, twisted, or curved, and the bent portions may have a bending angle within the range described later. As shown in Figure 1, adjacent bent portions 51b (52b) and 51c (52c) may be bent in opposite directions, giving the through portion 73p passing through them a crank-shaped or stepped shape. Note that the bent portions 51b, 51c, 52b, and 52c are also bent portions of the through portion 73p of the sealing member. In this disclosure, all bent portions of the lead wires can be read as bent portions of the through portion. The reverse is also possible.

[0052] The number of bends may be two, three or more, or one. In the sealing region 15, the lead wires 51 and 52 enter from the outside and inside of the power generation module 1, respectively, along the illustrated Y-axis that defines the width of the sealing member 73, and reach the bends. Between the two bends, they may extend parallel to the illustrated X-axis, along which the frame formed by the sealing member 73 extends.

[0053] The bending at the bent portion allows the through portion 73p to be made relatively longer. As the distance through the inside of the sealing member 73 increases, the area over which the lead wires 51 and 52 are fixed by contact with the sealing member 73 also becomes relatively larger. The increase in the fixed area improves the resistance of the lead wires with the bent portion to external forces, and the reliability of the power generation module 1 can be improved.

[0054] The bending at the bends allows the lead wires 51 and 52 to be held by more sealing members 73 against pulling or pushing forces. For example, when the lead wire 51 is pulled from the outer first end 51a along the Y-axis direction shown in the figure, the sealing members 73 located on the outer peripheral end 73o side of the two bends 51b and 51c provide resistance to that force. The relative number of sealing members 73 providing holding force also improves the resistance of the lead wires with bends to externally applied forces, and the reliability of the power generation module 1 can be improved.

[0055] At the interface between the lead wires 51 and 52 and the sealing member 73, tiny voids are likely to occur because dissimilar materials are in contact. Tiny irregularities on the surfaces of the lead wires 51 and 52, as well as differences in the coefficient of thermal expansion between the lead wires 51 and 52 and the sealing member 73, can be factors that cause these tiny voids to form. These voids can become pathways for substances that may affect the characteristics of the solar cell to enter the power generation module from the outside. By relatively increasing the distance that the lead wires 51 and 52 travel through the sealing region 15, it is possible to suppress the entry of such substances, and in this respect as well, the presence of the bent portion can improve the sealing performance of the power generation module 1.

[0056] The ratio D / W of the length D of the through portion 73p to the width W of the sealing member 73 is, for example, greater than 1, and may be 2 or more, 5 or more, or even 10 or more. The length D is determined by the entire through portion 73p, or the entire path of the through portion 73p within the crank-shaped sealing member 73 in Figure 1.

[0057] As shown in Figure 1, the lead wires 51 and 52 may be arranged in the intermediate region 13 between the sealing region 15 and the connection region 12, along the Y-axis shown in the figure, which is the direction in which the connection region 12 extends. That is, the lead wires 51 and 52 may be arranged in the intermediate region 13 so as to be the shortest in a plan view. However, this is not limited to this, and they may be arranged in the intermediate region 13 to allow for some slack or play.

[0058] Figure 3 is a partially enlarged view of region O in Figure 1. For illustrative purposes, the first substrate 71 is omitted in Figure 3. As shown in Figure 3, the sealing member 73 may have a recess 73h at its outer peripheral end 73o. In the recess 73h, the outer peripheral end 73o is partially recessed toward the inner peripheral end of the sealing member 73. The first end 73f on the outer side of the through-hole 73p is located in the recess 73h. The recess 73h expands the limit to which deformation of the lead wire 51 is permissible in the exposed portion, thereby mitigating the effects of force applied to the lead wire 51. The recess 73h can further improve the reliability of the power generation module 1.

[0059] In Figure 3, the depth of the recess indicated by h is, for example, 0.5 mm or more, and more specifically, 2 mm or more. There is no particular upper limit to the depth h of the recess, but for example, it is 5 mm. Although not directly visible in Figure 3, the first end portion 73f may be positioned so as not to be in contact with either the first substrate 71 or the second substrate 72 in the Z-axis direction shown in the figure. Although not shown, a similar recess may also be formed in the through-hole through which the second lead wire 52 passes.

[0060] The power generation module 1 can be a translucent module having a region through which light is transmitted in the thickness direction. At least a portion of the power generation region 11, connection region 12, and intermediate region 13 of the power generation module 1 may be translucent. Perovskite solar cells can themselves be translucent, making them suitable for ensuring and improving the translucency of the power generation region 11.

[0061] Figure 4 is a plan view showing the power generation module 2. In the power generation module 2, lead wires 51 and 52 are led out to the outside from a position closer to the corner 18 of the power generation module 2 than in the power generation module 1. Except for this, the power generation module 2 is configured in the same way as the power generation module 1.

[0062] Figure 5 is a plan view showing the power generation module 3. In the power generation module 3, lead wires 51 and 52 are led out to the outside from a position near the opposite corner 19 of the module 3. In the power generation module 3, the lead wire 52 does not have a bend at the through-hole 73q of the sealing member. Except for this point and the position of the lead wires leading out to the outside, the power generation module 3 is configured in the same way as the power generation module 1. In the power generation module 3 as well, the bends 51b and 51c of the through-hole 73p can improve the reliability of the power generation module 3 compared to when these bends are not present. In the power generation module of this disclosure, the sealing member 73 may have at least one through-hole 73p having a bend.

[0063] The plan view of the power generation module 4 is the same as in Figure 4. The power generation module 4 has the configuration described above. Figure 6 is a partial plan view of the area near the corner 18 of the power generation module 4. The frame formed along the periphery of the power generation module 4 by the sealing member 73 has a bent portion 73c near the corner 18.

[0064] At the bent portion 73c, the outer peripheral end 73o of the sealing member 73 includes a curved portion 73r that protrudes outward. The curved portion 73r is a curve that protrudes outward, specifically toward the corner 18 side of the power generation module 4. The curved portion 73r connects the first outer peripheral line 731o of the outer peripheral end 73o that extends toward the bent portion 73c along the upper edge of the power generation module 4, and the second outer peripheral line 732o of the outer peripheral end 73o that extends toward the bent portion 73c along the side edge of the power generation module 4.

[0065] On the other hand, at the bent portion 73c, the inner circumferential end 73i of the sealing member 73 has a bending point 73b at the position where a first inner circumferential line 731i extending toward the bent portion 73c along the upper edge of the module intersects with a second inner circumferential line 732i extending toward the bent portion 73c along the side edge of the module. At the bending point 73b, the first inner circumferential line 731i and the second inner circumferential line 732i are connected to form an angle α. The angle α may be substantially right angle, or it may be a right angle, i.e., 90 degrees. In this disclosure, “substantially right angle” means an angle in the range of 90 degrees ± 10 degrees, and moreover, 90 degrees ± 5 degrees.

[0066] The inner circumference end 73i, which is bent at a substantially right angle, can be a desirable feature of the power generation module 4, especially in applications where aesthetics are important, such as windows of buildings or vehicles. On the other hand, the vicinity of the outer circumference end 73o is located inside a window frame, such as a sash, or a structure such as a building, and is often not visible from the outside. Also, as shown by the dashed line near the corner 18 in Figure 6, if the outer circumference end 73o is set to pass through a virtual bending point 73d where the first outer circumference line 731o and the second outer circumference line 732o intersect, similar to the inner circumference end 73i, the width of the sealing member 73 will be unnecessarily increased at the bent portion 73c. ​​It is reasonable to form the outer circumference end 73o near the bent portion 73c with a curved portion 73r that passes on the inner circumference end 73i side of the virtual bending point 73d.

[0067] The width Wc of the sealing member 73 at the bent portion 73c may be 85% or more, and even 90% or more, of the width W at other parts. The width Wc may also be, for example, 125% or less, 120% or less, and even 110% or less of the width W. The width Wc can be determined by the length from the bending point 73b toward the virtual bending point 73d to the curved portion 73r. In order to appropriately control the width Wc, it is desirable to appropriately adjust the amount of sealing material forming the sealing member 73 near the bent portion 73c. ​​For example, at the bent portion 73c, the amount of sealing material supplied per unit area may be relatively larger than at other parts.

[0068] In the power generation module 4, it is desirable that the intermediate portion 74m is composed of a solid phase at least in the portion that contacts the sealing member 73. This configuration makes it easy to form a bending point 73b by blocking the sealing material with the solid phase. The intermediate portion 74m or intermediate layer 74 may contain resin and may be substantially filled with resin. In this disclosure, "substantially filled" means accounting for 80% or more, and more specifically, 90% or more, by volume.

[0069] As shown in Figure 6, the two bent portions 51b and 51c of the through portion 73p may both be positioned at a distance from the outer peripheral end 73o of the sealing member 73 that is greater than the distance from the inner peripheral end 73i. The entirety of the bent portions 51b and 51c may be located on the inner peripheral end 73i side of a virtual center line C that equally divides the sealing member 73 along the circumferential direction in which the frame formed by the sealing member 73 extends. Thus, at least one of the bent portions may be located closer to the inner peripheral end 73i than to the outer peripheral end 73o, and further, may be located on the inner peripheral end 73i side of the virtual center line C.

[0070] The sealing member 73 is formed, for example, by pushing the sealing material between the first substrate 71 and the second substrate 72 with the end of the lead wire 51, which has been previously fixed to the connection portion 77, pulled out to the outside of the power generation module 4. At this time, as the sealing material is pushed out and moves toward the outer peripheral end 73o, the lead wire 51 is subjected to stress toward the outer peripheral end 73o, particularly between the two bent portions 51b and 51c. In order to prevent this tensile stress from becoming excessive and damaging the lead wire 51, it is desirable to position the bent portions 51b and 51c so that they are relatively closer to the inner peripheral end 73i than to the outer peripheral end 73o.

[0071] The width W of the sealing member 73 and the length L between the first end 73f and the second end 73s of the through-port 73p, measured along the direction perpendicular to the width W, i.e., the circumferential direction in which the sealing member 73 extends in a frame shape, may satisfy the following relationships, assuming 0 < L: W < L, 4W < L, and further 9W < L. This relationship is suitable for improving the reliability of the power generation module while ensuring the area of ​​the power generation region 11. In the illustrated configuration, the total length D of the through-port 73p corresponds to (W + L).

[0072] For reference, Figure 6 shows a typical external lead wire exit position H in a conventional power generation module. If the lead wire 51 is pulled out from a through hole provided in the first substrate 71 at exit position H, it is not necessary to provide a through portion in the sealing member 73. However, at exit position H, a sealing member is required separately to seal the through hole, and a wider area than the illustrated intermediate area 13 is required for routing the lead wire from the connection area 12 to exit position H. In the power generation module 4, it is possible to narrow the width m of the intermediate area 13 between the power generation area 11 or connection area 12 and the sealing area 15 along the Y-axis direction in which the connection area 12 extends to 20 mm or less, and further to 5 mm or less. The lower limit of the width m is not particularly limited and may be, for example, 0.5 mm or even 0 mm. By reducing the area for routing the lead wire and making the sealing member 73 adjacent to or overlapping the power generation area 11 or connection area 12, the power generation area can be maximized.

[0073] Figure 6 also shows a line segment I connecting the first outer end 73f and the second inner end 73s of the power generation module 4 at the penetration 73p. The line segment I is not parallel to the illustrated Y-axis to which the connection region 12 extends. As can be seen from Figure 4, this relationship can hold not only for the penetration 73p of the lead wire 51 but also for the penetration 73p of the lead wire 52.

[0074] For lead wires 51 and 52, it is desirable that the distance OL (see Figure 6) between the first ends 73f of the two through-holes 73p is shorter than the distance IL (not shown) between the second ends 73s of the two through-holes 73p. This configuration facilitates the connection of lead wires 51 and 52 to the outside.

[0075] The above-described features of the power generation module 4, as explained with reference to Figure 6, can also be present in any of the other power generation modules described above. In addition, even in the power generation module 4, the lead wires 51 and the semiconductor layer formed in the power generation region 11 are spaced apart, and a distance d may be maintained between them.

[0076] Figure 7 is a plan view showing the power generation module 5. The power generation module 5 may be configured in the same way as the power generation module 1, except for the parts described below. Figure 8A is a reference example of the B-B cross section of Figure 7. In the connection region 12, the lead wire 51 is fixed on the connection portion 77 by a conductive material 55 and is electrically connected to the first electrode layer 81 that constitutes the connection portion 77. As shown in the figure, the conductive material 55 may cover the periphery of the lead wire 51 when its cross section is observed. The conductive material is, for example, solder or conductive adhesive.

[0077] In the intermediate region 13 between the connection region 12 and the sealing region 15, the lead wire 51 is positioned within the intermediate portion 74m between the first substrate 71 and the second substrate 72. In the intermediate portion 74m, the lead wire 51 is positioned between a first position 51f at the end of the connection portion 77 on the intermediate portion 74m side and a second position 51s at the end of the penetration portion 73p of the sealing member 73 on the intermediate portion 74m side. The first position 51f and the second position 51s differ in their positions with respect to the Z-axis shown in the figure. With respect to the Z-axis direction, which is the thickness direction, the second position 51s is located further above the surface of the connection portion 77 than the first position 51f. More specifically, in the intermediate portion 74m, the height of the lead wire 51 is gradually increased when viewed from the connection portion 77 side, and it enters the sealing member 73 at a relatively higher position.

[0078] Since the lead wires 51 are positioned so that they are higher on the sealing member 73 side, an expanded lower intermediate portion 74u is created below the lead wires 51 in the intermediate region 13. If the intermediate layer 74 contains resin, the resin is usually supplied from above in the form of a film and then heated and flows to fill the intermediate portion 74m. The expansion of the lower intermediate portion 74u facilitates the flow of resin into this portion. The lower intermediate portion 74u may contain resin, or may be substantially filled with resin. The resin located below the lead wires 51, together with the resin located above it, contributes to fixing the lead wires 51, mitigating impacts to the lead wires 51, and can improve the reliability of the power generation module 5. Thus, in the intermediate region 13, it is desirable that a portion of the resin constituting the intermediate layer 74 is interposed between the lead wires 51 and the second substrate 72. The inner surface of the second substrate 72 in the intermediate region 13 may be covered with resin. The resin coating can be a desirable feature as it can at least physically fill in some of the fine processing marks that may occur on the surface of the substrate 72. Fine processing marks may be caused, for example, by laser scribing.

[0079] Due to the high position 51s of the lead wire 51 on the sealing member 73 side, an extended lower sealing member 73u is formed below the lead wire 51 in the sealing member 73 as well. In the sealing member 73, the extension of the lower sealing member 73u facilitates the leakage of sealing material, contributing to the prevention of sealing defects and potentially improving the reliability of the power generation module.

[0080] Figure 8B shows another reference example of the B-B cross section of Figure 7. As shown in Figure 8B, the lead wire 51 is bent upward in the intermediate portion 74m near the inner circumference end of the sealing member 73. Thus, the lead wire 51 may have a bent portion within the intermediate region 13. The bend at the bent portion may be a bend in the Z-axis direction shown. In the example shown in Figure 8B, as in the example shown in Figure 8A, a part of the resin constituting the intermediate layer 74 is interposed between the lead wire 51 and the second substrate 72. Also as in the example shown in Figure 8A, in the intermediate region 13, the lead wire 51 is not in contact with the surface of the second substrate 72.

[0081] Figure 8C shows an example of a cross-section along line B-B in Figure 7. In the embodiment shown in Figure 8C, unlike the embodiments shown in Figures 8A and 8B, the lead wire 51 includes a bent portion 51k that is bent in cross-sectional view inside the sealing member 73. The bent portion 51k is also the bent portion at the through-hole 73p. According to this embodiment, the sealing performance of the power generation module 5 is improved. The number of bent portions observed in cross-sectional view may be one, two as shown in Figure 8C, or three or more.

[0082] The bent portion 51k within the sealing member 73 contributes significantly more to sealing performance than the bent portion 51k within the intermediate portion 74m.

[0083] Figure 9 shows yet another example of the B-B cross-section of Figure 7. In this example, the second position 51s of the lead wire 51 is lower than the first position 51f. As a result, the lower intermediate portion 74u and the lower sealing member 73u below the lead wire 51 are narrowed, making it difficult for resin to flow into these areas and leaving gaps. Also, in the intermediate region 13, the lead wire 51 is in contact with the second substrate 72. However, even in the embodiment of Figure 9, the reliability of the power generation module 5 is improved by the lead wire 51 and the bent portion 51c present in the through-hole 73p. Specifically, the reliability of the power generation module 5 is improved because the position of the bent portion 51c in the through-hole 73p is located on the inner circumference side of the sealing member 73 in a cross-sectional view. Also, in the embodiment of Figure 9, a bent portion 51k can be formed in the through-hole 73p in a cross-sectional view. The bent portion 51k can contribute to improving the sealing performance of the power generation module 5.

[0084] Figure 10 is a cross-sectional view taken along line C-C in Figure 7. The lead wire 51 is fixed to the connection portion 77 by a conductive material 55 and is electrically connected to the first electrode layer 81 via the conductive material 55 and the connection portion 77. The conductive portion 56, including the lead wire 51 and the conductive material 55, extends along the Y-axis shown in the figure on the connection portion 77. Examples of the conductive material 55 include solder and conductive adhesive, as described above.

[0085] Distance d is defined by the distance between the conductive portion 56, which is composed of the lead wire 51 and the conductive material 55, and the semiconductor layer included in the power generation layer 82, when the conductive material 55 is attached to the surface of the lead wire 51, particularly its side surface. If the conductive material 55 is not attached to the surface of the lead wire 51, distance d can be defined by the distance between the lead wire 51 and the semiconductor layer. In either case, distance d is precisely the length along the X-axis in the figure. Distance d is, for example, 0.5 mm or more, and more specifically, 1 mm or more. Ensuring a distance d of this magnitude reduces the effect of thermal expansion of the conductive portion due to heat generation associated with current flow. The upper limit of distance d is not particularly limited, but for example, 5 mm, and more specifically, 3 mm. A distance d of this magnitude is particularly suitable when the lead wire 51 is positioned long enough to extend 0.5 m or more on the connection region 12 in the direction in which the connection region 12 extends (distance y in Figure 7), and the risk of short circuit due to partial deformation of the lead wire 51 is relatively high. The upper limit of distance y is, for example, 3 m.

[0086] The surface 77s of the connecting portion 77 on which the lead wire 51 or the conductive portion 56 including the lead wire 51 is formed may have irregularities. It is desirable that the recesses 96 and / or protrusions 95 included in the irregularities extend along the direction in which the connecting region 12 or the connecting portion 77 extends, i.e., along the Y-axis direction shown in the figure. Such recesses 96 and / or protrusions 95 are suitable for increasing the contact area between the conductive material 55 and the surface 77s and ensuring the adhesion of the conductive material 55. On the other hand, if the recesses and protrusions extend along the X-axis direction shown in the figure, when the conductive material 55, which is also an adhesive, is applied or attached along the Y-axis direction shown, the conductive material 55 may not be able to follow the surface 77s sufficiently, and the degree of adhesion may decrease. It is desirable that the surface 77s of the connecting portion 77 has at least one selected from the group consisting of recesses 96 and protrusions 95 that extends along the direction in which it extends. The surface 77s of the connecting portion 77 may have a striped pattern due to the periodic formation of irregularities. Such striped patterns can be confirmed by backscattered electron images obtained by observing the surface 77s with a scanning electron microscope. The depth of the recesses and the height of the protrusions are not particularly limited, but are, for example, 0.1 μm or more, and more specifically, 0.2 μm to 0.5 μm.

[0087] The above-mentioned features of the power generation module 5, as described with reference to Figures 7 to 10, can be possessed by any of the power generation modules 1, 2, 3, and 4.

[0088] Figure 11 is a plan view showing the power generation module 6. The power generation module 6 is configured similarly to the power generation module 1 of the first embodiment, except that the ends 51a and 52a of the lead wires 51 and 52 are connected to the external wiring 91 inside the junction box 90. The junction box 90 may include a bypass diode 92. The bypass diode 92 may be arranged to connect the two ends 51a and 52a introduced into the junction box 90. The junction box 90 is not limited to the single type shown, but may be a split type divided into two. From the viewpoint of avoiding interference with members such as sashes, the location of the junction box 90 is suitable to be near the center of the frame of the sealing member 73, which is determined in a plan view as shown in the figure.

[0089] The above-mentioned features of the power generation module 6, as explained with reference to Figure 11, can be possessed by any of the power generation modules 1, 2, 3, 4, and 5.

[0090] <Components and Materials> The components and materials for constructing the power generation module are described below.

[0091] (Lead wire and its bent portion) The lead wire may be a metal wire containing copper, aluminum, or other metallic materials. The lead wire may be a copper wire. The lead wire may have a plating layer on its surface. The lead wire may be constructed by joining multiple wires together with solder or the like. The joint portion of the lead wire made by solder or the like may be located, for example, in the intermediate portion 74m, or it may be located within the through portion 73p.

[0092] Figure 12 is a plan view showing an example of the shape and bend of a lead wire. Figure 13 is a cross-sectional view taken along line D-D in Figure 12. The lead wire 50 may be a flat wire with a width WL greater than its thickness WT. The lead wire 50 is commercially available as a rectangular wire, flat wire, etc. The ratio of width WL to thickness WT in a flat lead wire, WL / WT, may be, for example, 2 or more, 10 or more, 50 or more, or in some cases 100 or more. A small width WL is advantageous from the viewpoint of facilitating the flow of resin downwards of the lead wire 50, while a large width WL is advantageous for ensuring the conductivity of the lead wire 50. The width WL may be 1 mm or more and 10 mm or less, and further 2 mm or more and 7 mm or less.

[0093] As shown in Figure 12, the lead wire 50 is folded back at the bend. The front surface 50s and back surface 50r of the lead wire 50 are swapped at the fold line 50m, and the end forming the inner circumference 50i is also swapped. A flat lead wire is more likely to form a bend where the inner circumference 50i bends at a single point than a non-flat wire with a circular or other cross-section. The lead wire may also be a flat wire that is folded back so that the front and back surfaces are reversed at the bend. A flat lead wire is suitable for forming a bend in a thin sealing member 73 in which two substrates are arranged in a narrow width.

[0094] Figures 14A and 14B are plan views showing other examples of lead wire bending. The lead wire 53 shown in Figure 14A is a metal wire that has been pre-formed to have a bend. The lead wire 54 shown in Figures 14B and 14C is a single-wire lead wire with a round cross-section.

[0095] The bending angle at the bent portion can be determined by the angle θ formed by the inner ends of the lead wires. In configurations where the inner end 54i is not bent at a single point (see Figures 14B and 14C), the bending angle can be defined by the angle θ at a virtual bending point 54b, which is determined by extending the two inner ends 541i and 542i toward the bent portion.

[0096] In this disclosure, the bending angle θ of the penetration portion of the lead wire and sealing member is preferably within the range of 90°±30°, more preferably 90±20°, and particularly 90±10°. The bent portion may have a bending angle θ that is substantially right-angle. The bending angle θ can be determined by the overall bend at adjacent bending points in the same direction. For example, the bending angle θ at two adjacent bending points bending in the same direction at 135° is 90°. In this example, the bending angle θ coincides with the angle θ at a hypothetical bending point, as in Figures 14B and 14C.

[0097] (Substrates) The first substrate 71 and the second substrate 72 play the role of holding components such as solar cells inside. The first substrate 71 and the second substrate 72 have an insulating surface on at least the inside, and may be entirely insulating. The first substrate 71 may be translucent, and the second substrate 72 is translucent. Examples of translucent substrates include glass substrates and plastic substrates. The material of the glass substrate is not particularly limited, and various types of glass such as soda-lime silicate can be used. The first substrate 71 and the second substrate 72 may be films, particularly plastic films. Examples of materials for the plastic substrate and plastic film include polyimide, polyethylene terephthalate, polyethylene naphthalate, and cycloolefin polymers.

[0098] (Sealing Member) The sealing member 73 includes a sealing material. The sealing material may be a resin or rubber. Preferably, the sealing member 73 is made of a material with lower oxygen permeability and / or water vapor permeability than the resin that may constitute the intermediate layer 74 described later. The sealing material may be, for example, a butyl rubber-based, acrylic-based, polyurethane-based, acrylic urethane-based, polysulfide-based, silicone-based, or modified silicone-based rubber material. The sealing member 73 may contain two or more materials and may have two or more layers made of different materials. The sealing member 73 may contain butyl rubber, which has high airtightness, and may have multiple layers including a butyl rubber layer.

[0099] (Intermediate layer) The intermediate layer 74 may be in solid or gas phase, or it may be a mixture of solid and gas phases. The solid phase may contain a resin. Examples of resins include ethylene vinyl acetate (EVA), polyvinyl butyral (PVB), polyurethane (PU), and polyolefin (PO). These resins have excellent bonding properties between the first substrate 71 and the second substrate 72 and are also suitable for ensuring light transmission. Resins with low softening points, such as PO, are suitable for mitigating the extent to which heating affects the solar cell. The resin can be supplied as a resin film. The gas constituting the gas phase is not particularly limited and may be air, but it may also contain inert gases such as helium, neon, and argon at a higher partial pressure than in air. The gas phase may be under reduced pressure. The intermediate layer may contain a desiccant, oxygen absorber, etc., in part.

[0100] (Electrode Layers) The first electrode layer 81 and the second electrode layer 83 are responsible for guiding electrons or holes from the solar cell. The first electrode layer 81 and the second electrode layer 83 may be translucent or opaque. The first electrode layer 81 and the second electrode layer 83 contain a conductive material. The opaque conductive material may be a metallic material such as copper, aluminum, silver, or molybdenum, or an alloy containing these metals.

[0101] The translucent conductive material may be a metal oxide or metal nitride. Examples of such materials include: (i) titanium oxide doped with at least one selected from the group consisting of lithium, magnesium, niobium, and fluorine; (ii) gallium oxide doped with at least one selected from the group consisting of tin and silicon; (iii) gallium nitride doped with at least one selected from the group consisting of silicon and oxygen; (iv) tin oxide doped with at least one selected from the group consisting of antimony and fluorine; (v) zinc oxide doped with at least one selected from the group consisting of boron, aluminum, gallium, and indium; (vi) indium-tin composite oxide (i.e., indium tin oxide); or (vii) composites thereof.

[0102] The translucent conductive material may include at least one selected from the group consisting of indium tin oxide (ITO), fluorine-doped tin oxide (FTO), indium zinc oxide (IZO), and aluminum zinc oxide (AZO).

[0103] At least the first electrode layer 81 is preferably translucent. If the first substrate 71 and the second substrate 72 are translucent, both the first electrode layer 81 and the second electrode layer 83 may also be translucent.

[0104] Furthermore, the first electrode layer 81 and the second electrode layer 83 can be formed as light-transmitting electrode layers even when using non-transmitting materials, provided that they are given a light-transmitting pattern. The pattern can be, for example, linear, wavy, grid-like, or a perforated metal-like pattern in which a large number of fine through-holes are arranged regularly or irregularly.

[0105] The light transmittance of the light-transmitting first electrode layer 81 and second electrode layer 83 is, for example, 50% or more, and more specifically, 80% or more. The wavelength of light that determines this transmittance depends on the absorption wavelength range of the semiconductor layer contained in the power generation layer 82.

[0106] (Power Generation Layer) The power generation layer 82 includes a semiconductor layer having a photoelectric conversion function, in other words, a photoelectric conversion layer. Examples of semiconductor materials included in the photoelectric conversion layer include silicon, compound semiconductors, and perovskite compounds. Examples of silicon include single-crystal silicon, polycrystalline silicon, microcrystalline silicon, and amorphous silicon. Examples of compound semiconductors include CdTe, GaAs, and CuInGaSe.

[0107] The perovskite compound may have a composition represented by the formula ABX3, where A is a monovalent cation. Examples of monovalent cations are alkali metal cations and organic cations. An example of an alkali metal cation is K + , Cs + , and Rb + An example of an organic cation is the methylammonium cation (CH3NH3). + ), formamidinium cation (HC(NH2)2 +), ethylammonium cation (CH3CH2NH3 + ), and guanidinium cation (CH6N3 + ). B is a divalent cation. Examples of divalent cations include Sn 2+ , Ge 2+ , and Pb 2+ . X is a monovalent anion. Examples of monovalent anions are halogen anions. Each site of A, B, and X may be occupied by a plurality of types of ions.

[0108] The photoelectric conversion layer may contain a perovskite compound. Since perovskite compounds are easily degraded by moisture, oxygen, etc., it is desirable to seal them inside a highly reliable module.

[0109] The power generation layer 82 may include layers other than the photoelectric conversion layer. The power generation layer 82 may further contain at least one selected from the group consisting of a hole transport layer and an electron transport layer.

[0110] Hereinafter, the hole transport layer and the electron transport layer will be described by taking a perovskite solar cell in which the photoelectric conversion layer contains a perovskite compound as an example.

[0111] The hole transport layer contains a hole transport material. A hole transport material is a material that transports holes. The hole transport material is, for example, an organic semiconductor or an inorganic semiconductor.

[0112] Examples of organic semiconductors are triphenylamine, triarylamine, phenylbenzidine, phenylene vinylene, tetrathiafulvalene, vinylnaphthalene, vinylcarbazole, thiophene, aniline, pyrrole, carbazole, triptycene, fluorene, azulene, pyrene, pentacene, perylene, acridine, or phthalocyanine.

[0113] Typical examples of organic semiconductors used as hole transport materials include 2,2′,7,7′-tetrakis[N,N-di-P-methoxyphenylamino]-9,9′-spirobifluorene (spiro-OMeTAD), poly[bis(4-phenyl)(2,4,6-triphenylmethyl)amine] (PTAA), poly(3-hexylthiophene-2,5-diyl) (P3HT), poly(3,4-ethylenedioxythiophene) (PEDOT), or copper phthalocyanine (CuPC).

[0114] Inorganic semiconductors used as hole transport materials are p-type semiconductors. Examples of inorganic semiconductors include Cu₂O, CuGaO₂, CuSCN, CuI, and NiO. x MoO x This is a carbon material such as V2O5 or graphene oxide, where x satisfies x > 0.

[0115] The thickness of the hole transport layer may be 1 nm or more and 1000 nm or less, or 10 nm or more and 50 nm or less. This allows for sufficient hole transport characteristics to be achieved. Therefore, the low resistance of the photoelectric conversion element 100 can be maintained, and high photoelectric conversion efficiency can be realized.

[0116] The hole transport layer may contain additives in addition to the hole transport material to enhance conductivity. Examples of additives include supporting electrolytes, solvents, or dopants. Supporting electrolytes and solvents have the effect of stabilizing holes in the hole transport layer. Dopants have the effect of increasing the number of holes in the hole transport layer.

[0117] Examples of supporting electrolytes are ammonium salts, alkaline earth metal salts, or transition metal salts. Examples of ammonium salts are tetrabutylammonium perchlorate, tetraethylammonium hexafluoride phosphate, imidazolium salts, or pyridinium salts. Examples of alkali metal salts are lithium perchlorate or potassium borotetrafluoride. Examples of alkaline earth metal salts are lithium bis(trifluoromethanesulfonyl)imide or bis(trifluoromethanesulfonyl)imide calcium(II). Examples of transition metal salts are bis(trifluoromethanesulfonyl)imide zinc(II) or tris[4-tert-butyl-2-(1H-pyrazole-1-yl)pyridine]cobalt(III)tris(trifluoromethanesulfonyl)imide.

[0118] An example of a dopant is a fluorine-containing aromatic boron compound. An example of a fluorine-containing aromatic boron compound is tris(pentafluorophenyl)borane.

[0119] The solvent contained in the hole transport layer may have excellent ionic conductivity. This solvent may be an aqueous solvent or an organic solvent. To further stabilize the solute, the solvent contained in the hole transport layer may be an organic solvent. Examples of organic solvents are heterocyclic compound solvents such as tert-butylpyridine, pyridine, and n-methylpyrrolidone.

[0120] Ionic liquids may be used as solvents. Ionic liquids may be used alone or in mixtures with other solvents. Ionic liquids are desirable because they have low volatility and high flame retardancy. Examples of ionic liquids include imidazolium-based, pyridine-based, alicyclic amine-based, aliphatic amine-based, or azonium amine-based liquids such as 1-ethyl-3-methylimidazolium tetracyanoborate.

[0121] The electron transport layer contains an electron transport material. The electron transport material may be a semiconductor. The electron transport layer may be formed from a semiconductor with a band gap of 3.0 eV or more. This facilitates the transmission of visible light and infrared light to the photoelectric conversion layer.

[0122] Examples of electron transport materials are organic or inorganic n-type semiconductors.

[0123] Examples of organic n-type semiconductors include imide compounds, quinone compounds, and fullerenes and their derivatives. Examples of inorganic n-type semiconductors include metal oxides, metal nitrides, or perovskite oxides. Examples of metal oxides are oxides of Cd, Zn, In, Pb, Mo, W, Sb, Bi, Cu, Hg, Ti, Ag, Mn, Fe, V, Sn, Zr, Sr, Ga, Si, or Cr. Examples of metal oxides include TiO2 or SnO2. Examples of metal nitrides include GaN. Examples of perovskite oxides include SrTiO3 or CaTiO3.

[0124] The electron transport layer may use a semiconductor with a band gap of 6.0 eV or greater. Examples of such semiconductors include alkali metal or alkaline earth metal halides such as lithium fluoride and calcium fluoride, alkali metal oxides such as magnesium oxide, or silicon dioxide. In this case, in order to ensure the electron transport properties of the electron transport layer, the electron transport layer may have a thickness of, for example, 10 nm or less.

[0125] <Solar Cells> Referring to Figures 15A to 15G, an example of a manufacturing method for a solar cell, i.e., an integrated solar cell 75, will be described.

[0126] First, as shown in Figure 15A, a precursor layer 81p of the first electrode layer 81 is deposited on the second substrate 72. In the illustrated example, the precursor layer 81p is an FTO film. The FTO film is deposited by known deposition methods such as chemical vapor deposition or sputtering.

[0127] Next, as shown in Figure 15B, the precursor layer 81p is scribed and divided to form the first electrode layer 81 (P1 processing). Scribing can be carried out by laser scribing, which involves focusing and irradiating with laser light, or by mechanical scribing, which involves scraping with a hardened metal blade.

[0128] Next, as shown in Figure 15C, the precursor layer 84p of the electron transport layer, the precursor layer 85p of the photoelectric conversion layer, and the precursor layer 86p of the hole transport layer are stacked on the first electrode layer 81 in this order. In the illustrated example, the precursor layer 84p of the electron transport layer is a SnO2 film, the precursor layer 85p of the photoelectric conversion layer is a perovskite compound film, and the precursor layer 86p of the hole transport layer is PTAA. These layers are also formed by known film formation methods such as coating, printing, and vapor deposition.

[0129] Next, as shown in Figure 15D, the laminate of precursor layers 84p, 85p, and 86p is scribed and divided into a laminate of electron transport layer 84, photoelectric conversion layer 85, and hole transport layer 86, i.e., power generation layer 82 (P2 processing). P2 processing is carried out in the vicinity of P1 processing so as not to overlap with the location of P1 processing and so as not to divide the first electrode layer 81.

[0130] Next, as shown in Figure 15E, a precursor layer 83p of the second electrode layer 83 is deposited on the power generation layer 82. In the illustrated example, the precursor layer 83p is an ITO film. The ITO film is also deposited by a known deposition method such as sputtering. The conductive material constituting the precursor layer 83p fills the grooves formed by the P2 processing to form internal connection parts.

[0131] Next, as shown in Figure 15F, the precursor layer 83p is scribed and divided to form the second electrode layer 83 (P3 processing). Through P3 processing, parts of each layer 84, 85, and 86 constituting the power generation layer 82 are divided, and the power generation layer 82 is formed into its final shape. P3 processing is carried out in the same way as P2 processing, without dividing the first electrode layer 81. P3 processing can be carried out in the vicinity of P2 processing, without overlapping with the positions of P1 processing and P2 processing, and on the opposite side from the position of P1 processing when viewed from P2 processing. In this way, a solar cell 75 is formed by sequentially connecting multiple solar cells U1, U2, U3... in series.

[0132] When performing the P3 processing, or before or after performing the P3 processing, scribing may also be performed at both ends shown in Figure 15G to expose the surface of the first electrode layer 81 and form the connection portion 77. In the scribing process that forms the connection portion 77, it is also possible to form irregularities on the surface 77s of the connection portion 77 by appropriately adjusting the laser output, the pressing force of the metal blade, etc.

[0133] By using laser light for scribing, along with laser scribing for forming solar cells 75, such as P3 processing, it becomes possible to efficiently form irregularities on the surface 77s of the connection portion 77. The irregularities thus formed have recesses and / or protrusions that extend substantially parallel to the grooves for integration that the solar cells 75 have. Here, "substantially parallel" indicates that the allowable error range during irregularity formation may include partial deviations or angles within ±10 degrees. However, even if there are such deviations or angles, it is desirable that the irregularities do not intersect each other.

[0134] The order in which each layer of the solar cell 75 is formed is not limited to the above, and a reverse configuration in which some or all of the layers are arranged in the opposite order from the perspective of the photoelectric conversion layer 85 is also possible.

[0135] (Note) The above description of embodiments discloses the following technologies. (Technology 1) A power generation module comprising: a first substrate; a second substrate facing the first substrate in the thickness direction of the first substrate; a solar cell disposed between the first substrate and the second substrate; a sealing member disposed between the first substrate and the second substrate so as to surround the solar cell in a frame shape in a plan view along the thickness direction; and lead wires electrically connected to the solar cell, wherein the sealing member has a through portion through which the lead wires are fixed to the outside, and the through portion includes a bent portion in a cross-sectional view in the thickness direction through which the lead wires are fixed in a bent state.

[0136] (Technology 2) The power generation module of Technology 1, wherein the bent portion includes a first bent portion and a second bent portion, and both the first bent portion and the second bent portion are located at a position where the distance from the outer peripheral end of the sealing member is longer than the distance from the inner peripheral end of the sealing member.

[0137] (Technical 3) A method for manufacturing a power generation module comprising: a first substrate; a second substrate facing the first substrate in the thickness direction of the first substrate; a solar cell disposed between the first substrate and the second substrate; a sealing member disposed between the first substrate and the second substrate so as to surround the solar cell in a frame shape in a plan view along the thickness direction; and lead wires electrically connected to the solar cell, comprising: a first step of electrically connecting the solar cell and the lead wires; a second step of arranging the lead wires and the sealing material at the peripheral edge of the second substrate surrounding the solar cell on the second substrate on which the solar cell is disposed, such that the lead wires penetrate the sealing material; and a third step of reducing the distance between the first substrate and the second substrate so that the solar cell is located between the first substrate and the second substrate, spreading the sealing material between the first substrate and the second substrate, forming the sealing member having a penetration portion through which the lead wires penetrate to the outside of the power generation module from the spread sealing material, and bonding the first substrate and the second substrate together. A method for manufacturing a power generation module, comprising the second step, arranging the lead wires such that, in a cross-sectional view in the thickness direction, the lead wires include a bent portion.

[0138] (Technical 4) The method for manufacturing a power generation module according to Technical 3, wherein in the second step, the lead wire is positioned such that the bent portion is located at a position spaced apart from the sealing material.

[0139] (Technical 5) A method for manufacturing a power generation module according to Technical 3 or 4, wherein the power generation module further comprises an intermediate layer disposed between the first substrate and the second substrate so as to cover at least a portion of the solar cells, the intermediate layer comprises a resin, and in the second step, a resin film supplying the resin is disposed together with the lead wires and the sealing material so as to cover at least a portion of the solar cells.

[0140] (Technical 6) The method for manufacturing a power generation module according to Technical 5, wherein the resin film is arranged to cover a portion of the lead wire after the first step.

[0141] (Technical 7) A method for manufacturing a power generation module according to Technical 5 or 6, wherein the resin film is arranged spaced apart from the sealing material.

[0142] (Technical 8) A method for manufacturing a power generation module according to any one of Technical 5 to 7, wherein in the second step, the lead wire is arranged in a bent state between the resin film and the sealing material in the cross-sectional view.

[0143] (Technical 9) The method for manufacturing a power generation module according to Technical 8, wherein the lead wires are arranged to bend along the edge of the resin film in a direction away from the second substrate in the thickness direction, from a fixed portion fixed for electrical connection to the solar cell.

[0144] (Technology 10) A method for manufacturing a power generation module according to any one of Technologies 5 to 9, wherein the distance between the first substrate and the second substrate is reduced while the inner circumferential end of the sealing material, which is spread out between the first substrate and the second substrate, is blocked by the end of the resin film.

[0145] (Technical 11) A method for manufacturing a power generation module according to any one of Technical 3 to 10, wherein the sealing material comprises a first layer and a second layer, and in the second step, the lead wire and the sealing material are arranged such that the first layer, the lead wire and the second layer are located in that order from the second substrate side at the periphery.

[0146] (Technical 12) A method for manufacturing a power generation module according to Technical 11, wherein, at the peripheral edge, the lead wire is arranged in contact with the first layer at a position in the thickness direction away from the second substrate from the fixing portion fixed for electrical connection to the solar cell.

[0147] (Technical 13) A method for manufacturing a power generation module according to Technical 11 or 12, wherein the ratio of the thickness of the first layer to the thickness of the second layer is adjusted so that the lead wire does not come into contact with either the first substrate or the second substrate at the through-hole of the sealing member.

[0148] This disclosure is useful for manufacturing power generation modules equipped with solar cells as power generation devices, particularly power generation modules for buildings and vehicles.

Claims

1. A power generation module comprising: a first substrate; a second substrate facing the first substrate in the thickness direction of the first substrate; a solar cell disposed between the first substrate and the second substrate; a sealing member disposed between the first substrate and the second substrate so as to surround the solar cell in a frame shape in a plan view along the thickness direction; and lead wires electrically connected to the solar cell, wherein the sealing member has a through portion through which the lead wires are fixed to the outside, and the through portion includes a bent portion in a cross-sectional view in the thickness direction through which the lead wires are fixed in a bent state.

2. The power generation module according to claim 1, wherein the bent portion includes a first bent portion and a second bent portion, and both the first bent portion and the second bent portion are located at a position where the distance from the outer peripheral end of the sealing member is longer than the distance from the inner peripheral end of the sealing member.

3. A method for manufacturing a power generation module comprising: a first substrate; a second substrate facing the first substrate in the thickness direction of the first substrate; a solar cell disposed between the first substrate and the second substrate; a sealing member disposed between the first substrate and the second substrate so as to surround the solar cell in a frame shape in a plan view along the thickness direction; and lead wires electrically connected to the solar cell, comprising: a first step of electrically connecting the solar cell and the lead wires; a second step of arranging the lead wires and the sealing material at the peripheral edge of the second substrate surrounding the solar cell on the second substrate on which the solar cell is disposed, such that the lead wires penetrate the sealing material; and a third step of reducing the distance between the first substrate and the second substrate so that the solar cell is located between the first substrate and the second substrate, spreading the sealing material between the first substrate and the second substrate, forming the sealing member having a penetration portion through which the lead wires penetrate to the outside of the power generation module from the spread sealing material, and bonding the first substrate and the second substrate together. A method for manufacturing a power generation module, comprising the second step, arranging the lead wires such that, in a cross-sectional view in the thickness direction, the lead wires include a bent portion.

4. The method for manufacturing a power generation module according to claim 3, wherein in the second step, the lead wire is positioned such that the bent portion is located at a position spaced apart from the sealing material.

5. The method for manufacturing a power generation module according to claim 3, wherein the power generation module further comprises an intermediate layer disposed between the first substrate and the second substrate so as to cover at least a portion of the solar cells, the intermediate layer comprises a resin, and in the second step, a resin film supplying the resin is disposed together with the lead wires and the sealing material so as to cover at least a portion of the solar cells.

6. The method for manufacturing a power generation module according to claim 5, wherein the resin film is arranged to cover a portion of the lead wire after the first step.

7. The method for manufacturing a power generation module according to claim 5, wherein the resin film is arranged at a distance from the sealing material.

8. The method for manufacturing a power generation module according to claim 5, wherein in the second step, the lead wire is arranged in a bent state between the resin film and the sealing material in the cross-sectional view.

9. The method for manufacturing a power generation module according to claim 8, wherein the lead wires are arranged to bend along the edge of the resin film in a direction away from the second substrate in the thickness direction, from a fixed portion fixed for electrical connection to the solar cell.

10. A method for manufacturing a power generation module according to claim 5, wherein the distance between the first substrate and the second substrate is reduced while the inner circumferential end of the sealing material, which is spread out between the first substrate and the second substrate, is blocked by the end of the resin film.

11. The method for manufacturing a power generation module according to claim 3, wherein the sealing material comprises a first layer and a second layer, and in the second step, the lead wire and the sealing material are arranged such that, at the periphery, the first layer, the lead wire and the second layer are positioned in this order from the second substrate side.

12. The method for manufacturing a power generation module according to claim 11, wherein, at the peripheral edge, the lead wire is arranged in contact with the first layer at a position in the thickness direction away from the second substrate from a fixing portion fixed for electrical connection to the solar cell.

13. The method for manufacturing a power generation module according to claim 11, wherein the ratio of the thickness of the first layer to the thickness of the second layer is adjusted so that the lead wire does not come into contact with either the first substrate or the second substrate at the through-hole of the sealing member.

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