Method for manufacturing solar cells and solar cell module including solar cells

Abstract

The present invention provides a solar cell, a method for producing the same, and a solar cell module including the solar cell. [Solution] A solar cell according to an embodiment of the present invention includes a first photoelectric conversion unit, a second photoelectric conversion unit, a side insulating layer, a first electrode, and a second electrode, the first photoelectric conversion unit includes a photoelectric conversion layer containing a perovskite compound, a first transport layer located on one side of the photoelectric conversion layer, and a second transport layer located on the other side of the photoelectric conversion layer, the second photoelectric conversion unit is disposed below the second transport layer of the first photoelectric conversion unit and has a different material or structure from the first photoelectric conversion unit, the side insulating layer is formed to surround the side of the first photoelectric conversion unit, the first electrode is electrically connected to the first photoelectric conversion unit on one side as a light receiving surface of the first photoelectric conversion unit, and the second electrode is electrically connected to the second photoelectric conversion unit below the second photoelectric conversion unit. Therefore, the active area of ​​the solar cell having a series connection type structure can be maximized, and the side insulating layer structure can suppress moisture permeation to improve reliability.

Description

[Technical Field]

[0001] The present invention relates to a solar cell, a method for manufacturing the same, and a solar cell module, and more particularly to a solar cell module including a perovskite structure. [Background technology]

[0002] Solar cells including semiconductor substrates have been widely used because they can have excellent photoelectric conversion efficiency. However, since there are certain limitations in improving the photoelectric conversion efficiency of solar cells including semiconductor substrates, solar cells with several types of structures have been proposed.

[0003] As an example, we propose a solar cell containing a perovskite compound that absorbs short-wavelength light to perform photoelectric conversion at short wavelengths. However, when a photoelectric conversion layer is formed using such a perovskite compound, a single perovskite compound layer is formed by combining an organic compound and an inorganic compound.

[0004] To form the above-described perovskite compound layer, Korean Patent Publication No. 10-2018-0099577 (published on September 5, 2018) discloses that a perovskite solution is prepared by mixing an organic substance and an inorganic substance, and then the solution is applied to a substrate.

[0005] Then, a technology is developed to manufacture a series cell by forming a first photoelectric conversion region using a semiconductor substrate and then forming a perovskite compound layer on top of it using a deposition method.

[0006] In the above-described series cell, the second photoelectric conversion region is continuously formed by depositing on the first photoelectric conversion region below, but the deposition must be carried out while the first photoelectric conversion region is fixed by the fixing part of the deposition device, which results in an inactive area of ​​the deposition device in the edge region.

[0007] Various attempts have been made to reduce the inactive area, but the reduction in the active area of ​​the cell results in a reduction in power consumption.

[0008] Furthermore, when using such edge regions as spaces for forming pads, pads are formed at the edge along the side of the upper electrode, which creates the risk that electrons that separate in the perovskite layer will recombine with holes in the pad, causing a short circuit of the current.

[0009] Furthermore, when it comes to modularizing multiple solar cells to form a single solar cell module, modularization of series cells including perovskite layers has emerged as a standout technology.

[0010] US Patent No. US8013236 discloses an apparatus and technology for simultaneously welding multiple wiring to multiple solar cells, but there are concerns about whether the technology can be extended to apply to series cells containing perovskite layers. [Prior art documents] [Patent documents]

[0011] Korean Patent Publication No. 10-2018-0099577 (Publication date: September 5, 2018) U.S. Patent No. US 8013236 (Publication date: September 6, 2011) Summary of the Invention [Problem to be solved by the invention]

[0012] The present invention aims to provide a solar cell and a solar cell module that have a series connection structure in which, in addition to a photoelectric conversion unit containing a perovskite compound, another photoelectric conversion unit having a different material or structure is further installed, and that have excellent efficiency and reliability.

[0013] The present invention aims to provide an optimum structure that can secure the active area of ​​a solar cell having a series connection type structure.

[0014] The present invention aims to provide an optimum structure that can reduce the short circuit current of a solar cell having a series cell structure and suppress moisture permeability to the maximum extent.

[0015] The present invention also aims to provide an optimal arrangement of cells in a large-area solar cell module containing a perovskite compound and an optimal modularization method. [Means for solving the problem]

[0016] A solar cell according to an embodiment of the present invention includes a first photoelectric conversion unit, a second photoelectric conversion unit, a side insulating layer, a first electrode, and a second electrode, wherein the first photoelectric conversion unit includes a photoelectric conversion layer containing a perovskite compound, a first transport layer located on one side of the photoelectric conversion layer, and a second transport layer located on the other side of the photoelectric conversion layer, the second photoelectric conversion unit is arranged below the second transport layer of the first photoelectric conversion unit and has a different material or structure from the first photoelectric conversion unit, the side insulating layer is formed to surround the side of the first photoelectric conversion unit, the first electrode is electrically connected to the first photoelectric conversion unit on one side serving as the light-receiving surface of the first photoelectric conversion unit, and the second electrode is electrically connected to the second photoelectric conversion unit below the second photoelectric conversion unit.

[0017] The first photoelectric conversion unit may have a smaller area than the second photoelectric conversion unit, so that the second photoelectric conversion unit has an end difference region, and the end difference region may be formed over the entire side surface of the first photoelectric conversion unit.

[0018] The side surface insulating layer may include a side surface portion that surrounds the entire side surface of the first photoelectric conversion unit, and a covering portion that is bent from the side surface portion and covers a part of the upper surface of the first photoelectric conversion unit.

[0019] The side insulating layer may include an oxide film or a nitride film.

[0020] The side portion of the side insulating layer may be disposed on the end difference region.

[0021] The side surface insulating layer may be formed in a frame shape surrounding the first photoelectric conversion unit.

[0022] The first electrode may include a plurality of bus bar electrodes extending in one direction, and a plurality of finger electrodes connected to and crossing the plurality of bus bar electrodes.

[0023] The side surface portion of the side surface insulating layer may be formed to extend from the first photoelectric conversion section to an end of the second photoelectric conversion section so as to surround the entire side surface of the solar cell.

[0024] In another embodiment of the present invention, there is provided a solar cell module, the solar cell module including a plurality of solar cells and a connecting member connecting adjacent solar cells, each of the solar cells including a first photoelectric conversion unit, a second photoelectric conversion unit, a side insulating layer, a first electrode, and a second electrode, the first photoelectric conversion unit including a photoelectric conversion layer including a perovskite compound, a first transport layer located on one side of the photoelectric conversion layer, and a second transport layer located on the other side of the photoelectric conversion layer, the second photoelectric conversion unit being disposed below the second transport layer of the first photoelectric conversion unit and having a different material or structure from the first photoelectric conversion unit, the side insulating layer being formed to surround side surfaces of the first photoelectric conversion unit, the first electrode being electrically connected to the first photoelectric conversion unit on one side serving as a light-receiving surface of the first photoelectric conversion unit, and the second electrode being electrically connected to the second photoelectric conversion unit below the second photoelectric conversion unit, and the first electrode including a plurality of bus bar electrodes spaced apart from each other and extending in one direction.

[0025] One ends of adjacent solar cells may overlap and be physically joined, and the connection member may span the overlapping area and electrically connect the second electrode of one solar cell to the bus bar electrode of the adjacent solar cell.

[0026] The connection member may include a plurality of leads extending from the second electrode of the adjacent upper solar cell to the bus bar electrode of the first electrode of the adjacent lower solar cell.

[0027] Each of the solar cells may include a first overlapping portion that overlaps the adjacent upper solar cell and a second overlapping portion that overlaps the adjacent lower solar cell, and may further include a conductive adhesive layer disposed entirely within the overlapping region.

[0028] The plurality of leads may include a core portion extending in the longitudinal direction, and a welding layer surrounding the core portion and electrically coupled to the first electrode and the second electrode by welding.

[0029] The plurality of solar cells may be arranged to be spaced apart from one another, and the connection member may connect the first electrode of one solar cell to the second electrode of an adjacent solar cell.

[0030] The present invention also provides a method for manufacturing a solar cell, the method including the steps of: forming a second photoelectric conversion section including a conductive region on a semiconductor substrate; forming a first photoelectric conversion section in the second photoelectric conversion section, the first photoelectric conversion section including a photoelectric conversion layer including a perovskite compound, a first transport layer located on one side of the photoelectric conversion layer, and a second transport layer located on the other side of the photoelectric conversion layer; forming a side insulating layer surrounding the side of the first photoelectric conversion section; and forming, on one side serving as the light-receiving surface of the first photoelectric conversion section, a first electrode electrically connected to the first photoelectric conversion section and having a cut region so as to open the center, and a second electrode electrically connected to the second photoelectric conversion section below the second photoelectric conversion section and having the cut region.

[0031] In the forming of the first photoelectric conversion section, the second photoelectric conversion section may be formed with a first photoelectric conversion section having an area smaller than that of the second photoelectric conversion section.

[0032] The step of forming the side insulating layer may include a step of placing a mask on the second photoelectric conversion section to expose the side surface, and a step of depositing the side insulating layer to a predetermined height on the exposed side surface.

[0033] In the forming of the side surface insulating layer, a covering portion that covers a part of an edge portion of the first photoelectric conversion portion may be further formed.

[0034] The step of forming the first photoelectric conversion section may include a step of forming a bonding layer having a first area on the second photoelectric conversion section, and a step of forming the first photoelectric conversion section on the bonding layer, the first photoelectric conversion section having a second area larger than the first area, and the second area may be smaller than the area of ​​the second photoelectric conversion section.

[0035] The side surface insulating layer may be formed to surround the entire side surfaces of the first photoelectric conversion section and the second photoelectric conversion section. [Effects of the Invention]

[0036] According to this example, it is possible to provide a solar cell module having a series connection structure in which, in addition to the photoelectric conversion unit containing a perovskite compound, another photoelectric conversion unit having a different material or structure is further installed, and having excellent efficiency and reliability.

[0037] The present invention maximizes the active area of ​​a solar cell having a series connection structure, and also improves reliability by suppressing moisture permeation with the side insulating layer structure.

[0038] Furthermore, it is possible to provide an optimal arrangement between cells in a large-area solar cell module containing a perovskite compound, thereby enabling modularization. [Brief explanation of the drawings]

[0039] [Figure 1] FIG. 1 is a plan view showing a solar cell according to an embodiment of the present invention. [Figure 2]FIG. 2 is a rear view showing a solar cell according to an embodiment of the present invention. [Figure 3] FIG. 3 is a cross-sectional view of the solar cell in FIG. 1 taken along II'. [Figure 4] FIG. 4 is a sequence diagram for manufacturing a solar cell according to one embodiment of the present invention. [Figure 5a] ~ [Figure 8b] 5a to 8b are process diagrams for manufacturing a solar cell according to one embodiment of the present invention. [Figure 9] FIG. 9 is a plan view of a solar cell module according to an embodiment of the present invention. [Figure 10] FIG. 10 is a cross-sectional view of one solar cell in the solar cell module shown in FIG. 9 in a first direction. [Figure 11] FIG. 11 is a process diagram showing the bonding of multiple solar cells in the second direction in the solar cell module shown in FIG. [Figure 12] FIG. 12 is a cross-sectional view of a solar cell module obtained by the bonding process in FIG. [Figure 13] FIG. 13 is a plan view of a solar cell module according to another embodiment of the present invention. [Figure 14] FIG. 14 is a cross-sectional view of the solar cell module shown in FIG. [Figure 15] FIG. 15 is a cross-sectional view of a solar cell according to another embodiment of the present invention. [Figure 16] FIG. 16 is a cross-sectional view of a solar cell according to a further embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0040] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the accompanying drawings, but it should be understood that the present invention is not limited to the above-described embodiments and can be modified into various forms.

[0041] In order to clearly and simply describe the present invention, parts not related to the description in the drawings are omitted, and the same or very similar parts are designated by the same drawing symbols throughout the specification. In addition, in order to clarify the description, thicknesses, widths, etc. are shown enlarged or reduced in the drawings, and the thicknesses, widths, etc. of the present invention are not limited to those shown in the drawings.

[0042] Furthermore, throughout the specification, when a part is said to "include" another part, it does not exclude the other part and may further include the other part, unless specifically stated to the contrary. Furthermore, when a part such as a layer, film, region, or plate is "on" another part, it not only includes the case where it is "directly on" the other part, but also the case where the other part is positioned in the middle of it. When a part such as a layer, film, region, or plate is said to be "directly on" the other part, it means that the other part is not positioned in the middle.

[0043] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A solar cell and a method for manufacturing the solar cell according to an embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

[0044] FIG. 1 is a plan view showing a solar cell according to one embodiment of the present invention, FIG. 2 is a back view showing a solar cell according to one embodiment of the present invention, and FIG. 3 is a cross-sectional view of the solar cell in FIG. 1 taken along II'.

[0045] A solar cell 10 according to an embodiment of the present invention may be a series-connected solar cell 10 and may include, in the vertical direction as the stacking direction, a first photoelectric conversion unit 110 including a photoelectric conversion layer 112 containing a perovskite compound, and a first electrode 42 and a second electrode 44 electrically connected thereto. Here, the photoelectric conversion layer 112 containing a perovskite compound may be formed as a thick film having a thickness equal to or greater than a predetermined thickness and may be formed to have a uniform composition in the stacking direction. Furthermore, the solar cell 10 according to this embodiment may have a series-connected structure further including a second photoelectric conversion unit 120 having a different material or structure from the first photoelectric conversion unit 110. Furthermore, the solar cell 10 according to this embodiment may be formed as a large-area solar cell, i.e., a large-area perovskite solar cell 10 having a diameter of 10 cm to 20 cm, preferably 12 cm to 17 cm.

[0046] 1 and 2, a solar cell 10 according to this embodiment has a planar surface on which conductive regions and electrodes are disposed to define at least one solar cell active area AA where photoelectric conversion actually occurs, and a non-active area NA is positioned within an edge area surrounding the solar cell active area AA. Such a solar cell 10 may have a side insulating layer formed along the non-active area NA, and has a structure that can prevent moisture from penetrating into the active area of ​​the solar cell and causing a short circuit.

[0047] First, the cross-sectional structure of the solar cell active area AA will be described with reference to FIG. 3, and then the specific planar shape of the solar cell 10 will be described in detail with reference to FIGS. 1 and 2 again.

[0048] 3, in the solar cell 10 according to this embodiment, the second photoelectric conversion unit 120 may have a pn junction structure including a semiconductor substrate 122. As an example, the second photoelectric conversion unit 120 may include the semiconductor substrate 122 and conductive regions 124, 126 formed in or on the semiconductor substrate 122. The conductive regions 124, 126 may include a first conductive region 124 having a first conductivity type and a second conductive region 126 having a second conductivity type.

[0049] The semiconductor substrate 122 may be made of a crystalline semiconductor (e.g., a single-crystal or polycrystalline semiconductor, e.g., single-crystal or polycrystalline silicon) containing a single semiconductor material (e.g., a Group 4 element). Second, since the second photoelectric conversion unit 120 is based on the semiconductor substrate 122 with high crystallinity and few defects, it may have excellent electrical properties. As an example, the second photoelectric conversion unit 120 may have a crystalline silicon solar cell structure.

[0050] The front and / or back surface of the semiconductor substrate 122 may be textured to have irregularities. As an example, the irregularities may have a pyramidal shape with irregular dimensions because the outer surface is configured as the (111) plane of the semiconductor substrate 122. This can reduce light reflectance when the surface has a relatively large surface roughness. However, the present invention is not limited thereto.

[0051] In this embodiment, the semiconductor substrate 122 may be configured as a base region having a first or second conductivity type by doping it with a dopant of the first or second conductivity type at a lower doping concentration than the first conductive region 124 or the second conductive region 126. That is, the semiconductor substrate 122 may not be provided with a doped region formed by additionally doping the base region with a dopant, and may be provided with only the base region.

[0052] A first passivation film 122a is formed on the front surface of the semiconductor substrate 122, and a second passivation film 122b is formed on the back surface of the semiconductor substrate 122.

[0053] The first passivation film 122a and the second passivation film 122b may act as a barrier to electrons and holes, preventing minority carriers from passing through. Furthermore, only majority carriers with a predetermined energy level or higher may pass through the first passivation film 122a and the second passivation film 122b after accumulating in the areas adjacent to the first passivation film 122a and the second passivation film 122b. As an example, the first passivation film 122a and the second passivation film 122b may be tunneling films. In this case, majority carriers with a predetermined energy level or higher can easily pass through the first passivation film 122a and the second passivation film 122b due to the tunneling effect.

[0054] The first passivation film 122a or the second passivation film 122b may include a variety of materials capable of tunneling carriers, such as nitrides, semiconductors, and conductive polymers. For example, the first passivation film 122a or the second passivation film 122b may include silicon oxide, silicon nitride, silicon-containing oxynitride, intrinsic amorphous semiconductors (such as intrinsic amorphous silicon), or intrinsic polycrystalline semiconductors (such as intrinsic nano-polycrystalline silicon). In this case, the first passivation film 122a and the second passivation film 122b may include intrinsic amorphous semiconductors. For example, the first passivation film 122a and the second passivation film 122b may be formed as an amorphous silicon (a-Si) layer, an amorphous silicon carbide (a-SiCx) layer, an amorphous silicon oxide (a-SiOx) layer, or the like. Secondly, since the first passivation film 122a and the second passivation film 122b have properties similar to those of the semiconductor substrate 122, the surface properties of the semiconductor substrate 122 can be improved more effectively.

[0055] In this case, the first passivation film 122a and the second passivation film 122b may be formed over the entire front and back surfaces of the semiconductor substrate 122, respectively. This allows the entire front and back surfaces of the semiconductor substrate 122 to be passivated, and can be easily formed when no additional patterning is required. The thickness of the passivation films 122a and 122b may be smaller than that of the conductive regions 124 and 126 (for example, 5 nm or less), thereby fully realizing the tunneling effect. However, the present invention is not limited thereto, and the passivation films 122a and 122b may have a variety of materials, shapes, thicknesses, etc.

[0056] However, according to an embodiment, the first passivation film 122a may be omitted.

[0057] A first conductive region 124 having a first conductivity type may be formed on (for example, in contact with) the first passivation film 122a, and a second conductive region 126 having a second conductivity type opposite the first conductivity type may be positioned on (for example, in contact with) the second passivation film 122b.

[0058] The first conductive region 124 may be a region having a first conductivity type by including a dopant of a first conductivity type, and the second conductive region 126 may be a region having a second conductivity type by including a dopant of a second conductivity type.

[0059] The first conductive region 124 and the second conductive region 126 may each include the same semiconductor material as the semiconductor substrate 122 (more specifically, a single semiconductor material, for example, silicon). For example, the first conductive region 124 and the second conductive region 126 may be configured as an amorphous silicon (a-Si) layer, an amorphous silicon carbide (a-SiCx) layer, an amorphous silicon oxide (a-SiOx) layer, etc. Second, the first conductive region 124 and the second conductive region 126 may have properties similar to those of the semiconductor substrate 122, minimizing differences in properties that may occur if the first conductive region 124 and the second conductive region 126 include different semiconductor materials. However, because the first conductive region 124 and the second conductive region 126 are formed independently of the semiconductor substrate 122, they may have a different crystal structure from the semiconductor substrate 122, making them easier to form on the semiconductor substrate 122.

[0060] For example, the first conductive region 124 and the second conductive region 126 may each be formed by doping a first or second conductive type dopant into an amorphous semiconductor, which can be easily manufactured by a variety of methods, such as deposition. The first conductive region 124 and the second conductive region 126 may then be easily formed through a simple process. In this case, if the first passivation film 122a and the second passivation film 122b are made of an intrinsic amorphous semiconductor (for example, intrinsic amorphous silicon), they may have excellent adhesion properties and excellent conductivity. Alternatively, the first conductive region 124 and the second conductive region 126 may each be formed in a nanocrystalline silicon or polycrystalline silicon layer by a variety of methods, such as deposition, and then doped with a first or second conductive type dopant. The first conductive region 124 and the second conductive region 126 may then be easily formed through a simple process. In this case, when the first passivation film 122a and the second passivation film 122b are made of an intrinsic amorphous semiconductor (for example, intrinsic amorphous silicon), they may have excellent adhesive properties and excellent conductivity.

[0061] In this embodiment, if the semiconductor substrate 122 (or base region) has a first conductivity type, the second conductive region 126 may constitute an emitting region that forms a pn junction with the semiconductor substrate 122. The first conductive region 124 may constitute a front surface field region that prevents coupling by forming a front surface field. Since the emitting region that directly participates in photoelectric conversion is located on the back surface, forming the emitting region with a sufficient thickness (for example, thicker than the front surface field region) can further improve photoelectric conversion efficiency. However, the present invention is not limited thereto. Therefore, since the semiconductor substrate 122 has a second conductivity type, the first conductive region 124 may also constitute an emitting region, and the second conductive region 126 may also constitute a back surface field region.

[0062] In this embodiment, the first conductive region 124 and the semiconductor substrate 122 may have n-type conductivity, and the second conductive region 126 may have p-type conductivity. Next, in the first photoelectric conversion section 110 located in the second photoelectric conversion section 120, the upper first transport layer 114 can transport electrons, and the lower second transport layer 116 can transport holes. This situation may provide superior performance for the first photoelectric conversion section 110 compared to the opposite situation. Furthermore, the semiconductor substrate 122 may have n-type conductivity, thereby improving carrier lifetime. However, the present invention is not limited thereto, and various modifications may be made to the conductivity type of the semiconductor substrate 122, whether it is the first conductivity type or the second conductivity type, or whether it is the n-type or the p-type.

[0063] The junction layer (tunneling junction layer) 110a is located in front of the second photoelectric conversion unit 120, thereby connecting the second photoelectric conversion unit 120 to the first photoelectric conversion unit 110 located thereover. Although the drawings show the junction layer 110a in direct contact with the first conductive region 124 and the first photoelectric conversion unit 110, respectively, the present invention is not limited thereto. The junction layer 110a may have a thin thickness, and for example, may have a thickness thinner than that of the electrode layers 420 and 440, thereby facilitating smooth tunneling of carriers.

[0064] The bonding layer 110a may electrically connect the first photoelectric conversion unit 110 and the second photoelectric conversion unit 120 and may include a material that can transmit light used in the first photoelectric conversion unit 110 (for example, long-wavelength light). For example, the bonding layer 110a may include at least one of a variety of materials, such as a transparent conductive material (for example, a transparent conductive oxide), a conductive carbon material, a conductive polymer, or n-type or p-type amorphous silicon. Alternatively, the bonding layer 110a may be formed as a structure in which silicon layers having different refractive indices are alternately stacked. As a result, light used in the second photoelectric conversion unit 120 (for example, short-wavelength light) may be reflected by the second photoelectric conversion unit 120, and light used in the first photoelectric conversion unit 110 (for example, long-wavelength light) may be transmitted through the first photoelectric conversion unit 110 and supplied to it.

[0065] The bonding layer 110a is formed to have an area smaller than the area of ​​the second photoelectric conversion section 120, and the area of ​​the first photoelectric conversion section 110 formed thereon is formed to be the same as or smaller than the area of ​​the bonding layer 110a.

[0066] Therefore, due to the difference in area between the second photoelectric conversion section 120 and the first photoelectric conversion section 110, an edge difference is formed around the first photoelectric conversion section 110, and an edge difference region NA is formed at the edge, exposing the underlying second photoelectric conversion section 120.

[0067] The above-described end difference regions NA may have a frame shape by being formed on the edges of the four sides of the active area AA in the central region as the center.

[0068] When the first photoelectric conversion section 110 is formed on the second photoelectric conversion section 120 by a deposition process, the four sides of the solar cell 10 described above are formed to include an area where two legs of the fixing part of the deposition equipment that fixes the semiconductor substrate 122 of the solar cell 10 within the deposition equipment are positioned on the semiconductor substrate 122.

[0069] Therefore, the fixing portion of the deposition device is located in at least one of the end difference regions NA formed on the four sides of the solar cell 10 in the length direction.

[0070] Therefore, the above-described edge difference region NA may be formed in the second photoelectric conversion section 120, and the first photoelectric conversion section 110 including the bonding layer 110a and the photoelectric conversion layer 112 including a perovskite compound may be positioned. The first photoelectric conversion section 110 is also formed exclusively on the bonding layer 110a, thereby maintaining the edge difference region NA, and thereby maintaining a constant difference in area between the second photoelectric conversion section 120 and the first photoelectric conversion section 110.

[0071] In this case, as shown in Figure 3, the bonding layer 110a may have an area similar to that of the first photoelectric conversion section 110 formed on top, but alternatively, the bonding layer 110a may be formed to have an area smaller than that of the first photoelectric conversion section 110, and the first photoelectric conversion section 110 may cover the above-mentioned bonding layer 110a and be formed within the end difference region NA.

[0072] As described above, when the area of ​​the first photoelectric conversion section 110 is larger than the area of ​​the bonding layer 110a, there is also a difference between the area of ​​the first photoelectric conversion section 110 and the area of ​​the second photoelectric conversion section 120, thereby forming an end difference region NA.

[0073] More specifically, the first photoelectric conversion section 110 may include a photoelectric conversion layer 112, a second transport layer (second carrier transport layer) 116 located on one side of the photoelectric conversion layer 112 between the junction layer 110a and the photoelectric conversion layer 112, and a first transport layer (first carrier transport layer) 114 located on the other side of the photoelectric conversion layer 112 between the photoelectric conversion layer 112 and the first electrode 42.

[0074] The second transport layer 116 located on the junction layer 110a is a layer that extracts and transports second carriers (for example, holes) according to the band gap relationship with the photoelectric conversion layer 112. For example, the second carriers transported by the second transport layer 116 can move to the first photoelectric conversion section 110 through the junction layer 110a.

[0075] The photoelectric conversion layer 112 located on the second transport layer 116 may be composed of a perovskite compound having a perovskite structure, and may be a photoactive layer that can generate carriers (electrons and holes) by being excited by light. As an example, the perovskite structure may have a chemical formula of AMX3 (where A is a monovalent organic ammonium cation or metal cation, M is a divalent metal cation, and X is a halogen anion). Such a photoelectric conversion layer 112 may be composed of a perovskite compound such as CH3NH3PbI3, CH3NH3PbI3, or the like as AMX3. x Cl (3-x) , CH3NH3PbI x Br (3-x) , CH3NH3PbClxBr (3-x) , HC(NH2)2PbI3, HC(NH2)2PbI x Cl (3-x) , HC(NH2)2PbI x Br (3-x) , HC(NH2)2PbCl x Br (3-x) Alternatively, a compound in which A in AMX3 is partially doped with Cs may be included. However, the present invention is not limited thereto, and multiple types of materials may be used as the photoelectric conversion layer 112.

[0076] The photoelectric conversion layer 112 made of a perovskite compound may have a thickness equal to or greater than a predetermined thickness, and may have a thickness greater than that of the first conductive region 124 .

[0077] As an example, the predetermined thickness of the photoelectric conversion layer 112 may be formed to be 400 nm to 800 nm or more, but is not limited thereto.

[0078] However, when the photoelectric conversion layer 112 is formed to have a thick film having a predetermined thickness or more, the photoelectric efficiency can be improved, and when the photoelectric conversion layer 112 is transported in the stacking direction, the composition of the perovskite compound can be maintained in the stacking direction, and the layer can be formed so that all regions from the region in contact with the second transport layer 116 to the region in contact with the first transport layer 114 have a perovskite structure.

[0079] Therefore, since no basic material layer for forming a perovskite compound remains in the boundary region, such as the region in contact with the first transport layer 114 or the region in contact with the second transport layer 116, the problem of carrier blocking due to the remaining basic material layer is eliminated, thereby ensuring photoelectric efficiency and allowing the formation of a thick film over a large area.

[0080] First transport layer 114 located on photoelectric conversion layer 112 is a layer that extracts and transports first carriers (electrons, as an example) due to the band gap relationship with photoelectric conversion layer 112.

[0081] The first electrode 42 may be located on the first photoelectric conversion unit 110 (for example, on the first transport layer 114 located on the front surface thereof), and the second electrode 44 may be located on the second photoelectric conversion unit 120 (for example, on the second conductive region 126 located on the back surface thereof). That is, the solar cell 10 according to this embodiment may have a series connection structure in which the second photoelectric conversion unit 120 based on a single semiconductor material (for example, silicon) and the first photoelectric conversion unit 110 based on a perovskite compound are joined by a joining layer 110a.

[0082] In this embodiment, the first photoelectric conversion section 110 has a larger bandgap than the second photoelectric conversion section 120. That is, the first photoelectric conversion section 110 has a relatively large bandgap and absorbs short wavelength light having a relatively small wavelength and uses it to generate photoelectric conversion, and the second photoelectric conversion section 120 has a lower bandgap than the first photoelectric conversion section 110 and effectively absorbs long wavelength light having a wavelength larger than that of light used in the first photoelectric conversion section 110 and uses it to generate photoelectric conversion.

[0083] More specifically, when light is incident through the front surface of the solar cell 10, the first photoelectric conversion section 110 absorbs short wavelength light and generates electrons and holes through photoelectric conversion. At this time, first carriers (electrons, for example) move toward the first electrode 42 and are collected, and second carriers (holes, for example) move through the first photoelectric conversion section 110 and the second photoelectric conversion section 120 toward the second electrode 420 and are collected. When light is not used by the first photoelectric conversion section 110 and reaches the second photoelectric conversion section 120 at its long wavelength, the second photoelectric conversion section 120 absorbs it and generates electrons and holes through photoelectric conversion. At this time, the first carriers (electrons, for example) move through the first photoelectric conversion section 110 toward the first electrode 42 and are collected, and the second carriers (holes, for example) move toward the second electrode 44 and are collected.

[0084] As described above, in this embodiment, light having multiple wavelengths can be used for multiple photoelectric conversion sections 110, 120, thereby significantly improving the efficiency of the solar cell 10. In particular, this embodiment includes a first photoelectric conversion section 110 based on a perovskite compound and a second photoelectric conversion section 120 having a heterojunction structure, thereby improving multiple characteristics. As an example, both the first photoelectric conversion section 110 and the second photoelectric conversion section 120 may be formed using a low-temperature process. Because the process temperatures are similar, the temperature range can be easily adjusted, thereby ensuring process compatibility. Furthermore, because the first photoelectric conversion section 110 and the second photoelectric conversion section 120 each have excellent open-circuit voltages, the efficiency of the solar cell 10 with a series-connected structure can be significantly improved. Multiple types of structures may be applied to the second photoelectric conversion section 120, and various other modifications are also possible.

[0085] In this embodiment, the first photoelectric conversion section 110 may be formed by a low-temperature process (for example, a low-temperature process below 200°C), for example, at a temperature below room temperature of 150°C, more specifically, at room temperature (for example, a temperature higher than 20°C and below 150°C).

[0086] The first electrode 42 may include a first electrode layer 420 and a second electrode layer 422 sequentially stacked on the photoelectric conversion units 110 and 120. For example, the first electrode layer 420 may be formed entirely on (for example, in contact with) the first photoelectric conversion unit 110 (more specifically, the first transport layer 114). Forming the first electrode layer entirely may include covering the entire first photoelectric conversion unit 110 without any blank spaces or blank areas, as well as unavoidably forming only a portion of the first photoelectric conversion unit 110. As described above, when the first electrode layer 420 is formed entirely on the first conductive region 124, carriers can easily pass through the first electrode layer 420 to reach the second electrode layer 422, thereby reducing resistance in the horizontal direction.

[0087] As described above, the first electrode layer 420 is formed over the entire first photoelectric conversion unit 110 and may be made of a material that can transmit light (light-transmitting material). That is, the first electrode layer 420 is made of a transparent conductive material, which allows light to pass through and facilitates carrier movement. As a result, the first electrode layer 420 is formed over the entire first photoelectric conversion unit 110 and does not block the transmission of light. For example, the first electrode layer 420 may include a transparent conductive material (e.g., a transparent conductive oxide, such as indium tin oxide (ITO)) or carbon nanotubes (CNTs). However, the present invention is not limited thereto, and the first electrode layer 420 may include a variety of other materials.

[0088] The second electrode layer 422 may be formed on (for example, in contact with) the first electrode layer 420. The second electrode layers 422a and 422b may be made of a material having a higher electrical conductivity than the first electrode layer 420. This may further improve properties such as carrier collection efficiency and reduced resistance based on the second electrode layer 422. For example, the second electrode layer 422 may be made of an opaque material having a higher electrical conductivity, or a metal having a lower transparency than the first electrode layer 420.

[0089] As described above, the second electrode layer 422 is opaque or has low transparency, which blocks the incidence of light, and therefore, by having a predetermined pattern, shading loss can be minimized, allowing light to be incident on areas where the second electrode layer 422 is not formed.

[0090] In this embodiment, the second electrode layer 422 may be formed of an alloy containing at least one of Ag, Cu, Al, Mo, Ti, Pd, W, and Pt, and may be formed by a deposition process.

[0091] The deposition process for forming the second electrode layer 422 may be vacuum deposition, sputtering, or electroplating. In this case, the second electrode layer 422 formed by deposition may be formed to a thickness of 5 μm or less. The second electrode layer 422 may have a multi-layer structure, but is not limited thereto.

[0092] Alternatively, the second electrode layer 422 may be formed as a paste electrode, and the electrode material may be formed by sintering metal powder containing Ag, Cu, Al, Sn, or the like.

[0093] The second electrode layer 422 may have a variety of planar shapes.

[0094] As an example, as shown in FIG. 1, the second electrode layer 422 may include a plurality of finger electrodes 422a spaced apart from one another at a predetermined interval. While the drawing illustrates a case in which the finger electrodes 422 are parallel to one another and parallel to the edges of the photoelectric conversion units 110 and 120 (for example, the semiconductor substrate 122), the present invention is not limited thereto and may also be formed in an oblique line. Furthermore, the second electrode layer 422 may include busbar electrodes 422 (which are used with the same reference symbol as the second electrode layer because they occupy the main electrode structure) formed in a direction intersecting the finger electrodes 422a and connected to the finger electrodes 422a. Only one busbar electrode 422 may be provided, or, as shown in FIG. 2, multiple busbar electrodes 422 may be provided with a spacing greater than the spacing between the finger electrodes 422a. In this case, the width of the busbar electrode 422 may be greater than the width of the finger electrodes 422a, but the present invention is not limited thereto. Therefore, the width of the busbar electrode 422 may be the same as or smaller than the width of the finger electrodes 422a.

[0095] The bus bar electrodes 422 may be formed parallel to one another in the first direction, and adjacent bus bar electrodes 422 may be formed to have a spacing w3 greater than the spacing between finger electrodes 422a.

[0096] Furthermore, the plurality of bus bar electrodes 422 as described above may be used as pad portions that contact the leads 20 corresponding to the implementation of electrical and physical bonding with the adjacent solar cells 10 .

[0097] In addition, the second electrode 44 may be located in the second photoelectric conversion section 120, and may have a two-layer structure of a first electrode layer 440 and a second electrode layer 442 as shown in FIG.

[0098] The first electrode layer 440 of the second electrode 44 has the same or similar function, material, shape, etc. as the first electrode layer 420 of the first electrode 42, and therefore the same description may be applied as is.

[0099] The second electrode layer 442 of the second electrode 44 may have the same or different planar shape as the second electrode 42. For example, it may be patterned into finger electrodes and bus bar electrodes like the finger electrodes 422a and bus bar electrodes 422 of the first electrode 42, or, unlike that, it may be formed entirely over the entire second photoelectric conversion section 120 like the first electrode layer 442. Various modifications are possible.

[0100] Alternatively, the anti-reflective coating 430 may be formed on the first electrode layers 420, 440 of the first electrode 42 and the second electrode 44, exposing only a portion of the first electrode layers 420, 440, thereby allowing the second electrode layers 422, 442 to contact the first electrode layers 420, 440.

[0101] As shown in FIG. 3, side insulating layers 130, 131, and 132 are formed in the end difference regions NA formed on the four edges of the first photoelectric conversion section 110.

[0102] The side insulating layer 130 may be formed to have a thickness similar to or greater than a height h1 from the top of the second photoelectric conversion section 120 to the top of the first photoelectric conversion section 110 (i.e., the thickness of the first photoelectric conversion section 110). Preferably, the height h1 of the side insulating layers 130a, 130b may be 10 nm to 1 μm.

[0103] The side insulating layer 130 is similarly formed within the four end difference regions NA, so that the four sides of one solar cell 10 may be formed to have a frame type shape that surrounds the internal first photoelectric conversion section 110.

[0104] The side insulating layer 130 may be formed by atomic deposition, chemical deposition, or physical deposition, and may be formed by applying an insulating paste, but is not limited thereto. The width W1 of the side insulating layer 130 has a desired small characteristic, and according to the need, the width W1 of the side insulating layer 130 on one side can satisfy 0.1 mm to 3.0 mm, and can be adjusted according to the dimensions of the fixing part of the deposition equipment.

[0105] The side insulating layer 130 may be formed of a compound containing oxide or nitride, and examples thereof include Al2O3, SiC, and SiN.

[0106] The side insulating layer 130 as described above may include a side portion 131 that fills the end difference region NA and forms a frame, and a covering portion 132 that is bent from the side portion 132 toward the light receiving surface of the central first photoelectric conversion portion 110 and is partially covered by the first photoelectric conversion portion 110.

[0107] The above-mentioned covering portion 132 may be formed with a width narrower than the width of the side portion 131, and may cover the edge of the anti-reflection film 430 of the first photoelectric conversion portion 110, thereby preventing moisture from penetrating into the first photoelectric conversion portion 110 from the outside.

[0108] The solar cell 10 according to this embodiment can be separated and used as multiple solar cells, but is not limited to this. As described above, when the solar cell 10 is separated into two solar cells, it is possible to reduce the output loss (CTM loss, cell to module loss) that occurs when connecting multiple solar cells to manufacture a solar cell module.

[0109] A method for manufacturing the series-connected solar cell shown in FIGS. 1 to 3 will be described in detail below with reference to FIGS. 4 to 8b.

[0110] FIG. 4 is a sequence diagram for manufacturing a solar cell according to one embodiment of the present invention, and FIGS. 5a to 8b are process diagrams for manufacturing a solar cell according to one embodiment of the present invention.

[0111] 4, the method for manufacturing a solar cell according to an embodiment of the present invention includes a step of forming a second photoelectric conversion unit (S10), a step of forming a first photoelectric conversion unit (S20), a step of forming a side insulating layer (S30), a step of forming a first electrode and a second electrode (S40), and a step of modularization (S50), which will be described in more detail below.

[0112] As shown in Figures 5a and 5b, in the step (S10) of forming the second photoelectric conversion section 120, the second photoelectric conversion section 120 including the semiconductor substrate 122, the first conductive region 124, and the second conductive region 126 is formed from the semiconductor substrate 122.

[0113] First, a semiconductor substrate 122 configured as a base region containing a first or second conductivity type dopant is manufactured. At least one of the front and back surfaces of the semiconductor substrate 122 may be patterned to have projections and recesses to form an anti-reflection structure. The surface of the semiconductor substrate 122 may be patterned using wet or dry patterning. Wet patterning may be performed by immersing the semiconductor substrate 122 in a patterning solution and has the advantage of a short process time. Dry patterning involves cutting the surface of the semiconductor substrate 122 using a diamond grid or laser, etc., to form uniform projections and recesses, but requires a long process time and may damage the semiconductor substrate 122. Alternatively, the semiconductor substrate 122 may be patterned using reactive ion etching (RIE), etc. As described above, the semiconductor substrate 122 may be patterned using multiple methods in the present invention.

[0114] Next, conductive regions 124, 126 are formed on the surface of the semiconductor substrate 122. More specifically, a first passivation film 122a and a first conductive region 124 are formed on the front surface of the semiconductor substrate 122, and a second passivation film 122b and a second conductive region 126 are formed on the back surface of the semiconductor substrate 122.

[0115] The conductive regions 124, 126 may be formed by thermal growth, deposition (e.g., chemical vapor deposition (PECVD), atomic layer deposition (ALD)), low pressure chemical vapor deposition (LPCVD), etc., although the invention is not limited thereto.

[0116] The dopants of the first or second conductivity type may be simultaneously added to the process of growing the semiconductor layers that form the conductive regions 124, 126, or may be doped after the semiconductor layers are formed by ion implantation, thermal diffusion, laser doping, etc. However, the present invention is not limited thereto, and the conductive regions 124, 126 may be formed by a variety of methods.

[0117] Next, as shown in FIG. 5b, a protective layer is formed on the second conductive region 126. In this embodiment, a first electrode layer 440 of the second electrode 44 may be formed on the second conductive region 126 as a protective layer. This first electrode layer 440 functions as a protective layer on the second conductive region 126 to protect the second conductive region 126 during the manufacturing process, and may also remain as is to function as the first electrode layer 440. That is, in this embodiment, the first electrode layer 440 of the second electrode 44 is formed before the first photoelectric conversion section 110 is formed, and is used as a protective layer, thereby simplifying the process. However, the present invention is not limited thereto, and the first electrode layer 440 may be formed with different protective layers of the first electrode layer 440 separately formed and removed or not removed.

[0118] As an example, the first electrode layer 440 of the second electrode 44 may be formed by sputtering. The sputtering process may be performed at a low temperature, and the first electrode layer 440 of the second electrode 44 may be formed only on the rear surface as one side. However, the present invention is not limited to this, and multiple methods, such as a coating method, may also be applied.

[0119] Next, the bonding layer 110a is formed on the second photoelectric conversion section 120. More specifically, the bonding layer 110a may be formed on a portion of the first conductive region 124 of the second photoelectric conversion section 120. As an example, the bonding layer 110a may be formed by sputtering. The sputtering process may be performed at a low temperature, and may be a one-sided process in which the bonding layer 110a is formed only on the second conductive region 124. However, the present invention is not limited to this, and multiple methods such as a coating method may also be applied.

[0120] The area of ​​the bonding layer 110a may be smaller than that of the second photoelectric conversion section 120 and smaller than that of the first photoelectric conversion section 110, or alternatively, may be formed to have the same area as that of the first photoelectric conversion section 110.

[0121] This may be formed only in the central region between placing a mask (not shown) and sputtering to expose the edge region of the second photoelectric conversion section 110, but is not limited to this and may be formed in multiple ways.

[0122] Next, as shown in FIGS. 6a, 6b, and 6c, the first photoelectric conversion section 110 is formed on the bonding layer 110a (S20).

[0123] In the step of forming the first photoelectric conversion section 110, the first photoelectric conversion section 110 is formed on the bonding layer 110a. At this time, the first photoelectric conversion section 110 is selectively formed so as to expose four edge regions and to have an area larger than the bonding layer 110a and smaller than the second photoelectric conversion section 120.

[0124] More specifically, the second transport layer 116, the photoelectric conversion layer 112, and the first transport layer 114 may be sequentially formed on the bonding layer 110a in a deposition apparatus by coating the bonding layer 110a.

[0125] Second transport layer 116, photovoltaic layer 112, and first transport layer 114 may be formed by deposition (eg, physical deposition, chemical deposition, etc.).

[0126] Next, the first electrode layer 420 of the first electrode 42 may be formed on the first photoelectric conversion section 110. More specifically, the first electrode layer 420 of the first electrode 42 may be formed on the first transport layer 114.

[0127] As an example, the first electrode layer 420 of the first electrode 42 may be formed by sputtering. The sputtering process may be performed at a low temperature, and the first electrode layer 420 of the first electrode 42 may be formed on only one surface, i.e., the front surface. However, the present invention is not limited to this, and multiple methods, such as a coating method, may also be applied.

[0128] Furthermore, this embodiment illustrates a case in which the first electrode layer 440 of the second electrode 44 is formed before the first photoelectric conversion section 110 is formed, and the first electrode layer 420 of the first electrode 42 is formed after the first photoelectric conversion section 110 is formed. However, the present invention is not limited to this, and the first electrode layer 440 of the second electrode 44 may be formed after the first photoelectric conversion section 110 is formed. In this case, the first electrode layer 440 of the second electrode 44 may be formed together with the first electrode layer 420 of the first electrode 42, and may be formed before or after the first electrode layer 440 of the first electrode 42 is formed. Various other variations are possible.

[0129] 6b, an anti-reflective coating 430 is formed on the first electrode layer 420. The anti-reflective coating 430 may be formed by a deposition process and may be partially patterned to expose an area for forming the second electrode layer 422, as shown in FIG.

[0130] As described above, when the opening 431 for bonding the second electrode layer 422 and the first electrode layer 420 is formed in the anti-reflection film 430, the side insulating layer 130 is formed as shown in FIGS. 7a and 7b (S30).

[0131] First, as shown in Fig. 7a, the solar cell 10 is mounted in a deposition apparatus, and then a mask 200 is attached to the front of the solar cell 10, exposing two side surfaces and covering the central region of the solar cell 10. The mask 200 may be, but is not limited to, a mask made of carbide, nitride, etc.

[0132] After aligning the solar cell 10 so as to cover the central region thereof, a side insulating layer 130 is deposited on the exposed side surfaces.

[0133] At this time, the mask is formed smaller than the anti-reflection film 430 to partially expose the edge of the anti-reflection film 430, thereby allowing the covering portion 132 of the side insulating layer 130 to be formed at the same time.

[0134] In this case, the deposition device may be used in a variety of ways, such as atomic deposition, physical deposition, and chemical deposition, and may also be used to apply oxides such as SiO2, or carbides or nitrides such as SiC or SiN to the side surfaces.

[0135] In this case, the thickness H1 of the side surface portion 131 of the formed side surface insulating layer 130 can satisfy 10 nm to 1 μm, and may be formed to be the same as or higher than the first photoelectric conversion layer 110. In addition, the width W1 of each of the side surface insulating layers 130a, 130b can satisfy 0.1 to 0.3 mm.

[0136] Therefore, the width W1 of the side insulating layer 130 may be adjusted to comply with desired requirements, but not to exceed essentially 0.3 mm.

[0137] As described above, the side insulating layer 130 includes a covering portion 132 that covers the edge of the anti-reflection film 430, thereby protecting the first photoelectric conversion section 110 from being affected by moisture that has penetrated from the outside.

[0138] Furthermore, by minimizing the area of ​​the covering portion 132, the area for photoelectric conversion can be maximized.

[0139] As described above, when forming a frame by forming side insulating layers 130 on the four side surfaces of the junction layer 110a of the solar cell 10, the mask 200 is removed as shown in Figure 7b, and the internal first photoelectric conversion section 110 is exposed as shown in Figure 7c.

[0140] At this time, the area of ​​the exposed first photoelectric conversion section 110 may be reduced due to the covering section 132 compared to before the side-surface insulating layer 130 is formed.

[0141] At this time, when the side insulating layer is formed, a passivation layer (not shown) may be simultaneously formed on the lower surface of the semiconductor substrate. If the passivation layer is formed on the backside, a patterning process may be further included to form a backside opening to expose the lower first electrode layer 440.

[0142] 8a and 8b, in the step of forming the second electrode layer 422, the second electrode layer 422 of the first electrode 42 and the second electrode layer 442 of the second electrode 44 are formed (S40). Hereinafter, the second electrode layer 422 of the first electrode 42 will be described as being formed as a single layer, but it may alternatively be formed as a multi-layer structure.

[0143] At this time, the second electrode layers 422a, 422b, 442a, and 442b of the first electrode 42 and the second electrode 44 are formed simultaneously.

[0144] First, as shown in FIG. 8a, a deposition process is carried out to form the second electrode layers 422, 442 of the first electrode 42 and the second electrode 44.

[0145] At this time, the deposition process can be applied in a number of ways, such as sputtering, vacuum deposition or plating (electroplating).

[0146] As an example, when forming a sputtering layer by sputtering, the process temperature for forming the second electrode layers 422, 442 may be 150°C or lower (e.g., 100°C to 145°C). By forming the second electrode layers 422, 442 by sputtering while a mask or mask layer is in place, the second electrode layers 422, 442 can have a desired pattern. The second electrodes 422, 442 may further include an additional conductive layer formed by sputtering or electroplating (e.g., electrolytic plating) on ​​the sputtering layer formed by sputtering. The second electrode layers 422, 442 of the first electrode 42 or second electrode 44 according to this embodiment may be formed by multiple processes performed at 150°C or lower.

[0147] In this case, the second electrode layer 422 of the formed first electrode 42 includes a plurality of bus bar electrodes 422 arranged in parallel in one direction as shown in FIG. 8b, and finger electrodes 422a formed to cross the bus bar electrodes 422.

[0148] The second electrode layer 442 of the second electrode 44 has a planar shape.

[0149] In this embodiment, in a solar cell 100 in which a first photoelectric conversion section 110 containing a perovskite compound is installed, after forming the second electrode layers 422, 442 by a deposition process, a coating layer may be further formed thereon to ensure a filling rate and excellent efficiency and reliability, thereby allowing the first electrode 42 and the second electrode 44 to be formed at a low temperature (i.e., 150°C or less).

[0150] When the first electrode 42 and the second electrode 44 are formed as described above, the solar cell shown in Fig. 8a is formed. The solar cell 10 according to one embodiment of the present invention is formed to have the front and back shapes shown in Figs. 1 and 2.

[0151] Thereafter, when the solar cell 10 is cut into a plurality of units for use, cutting may be performed, but is not limited to this.

[0152] A plurality of solar cells 10 formed as described above may be modularized into a plurality of forms on a glass substrate (S50).

[0153] In addition, the second electrode layer 442 of the second electrode 44 in FIG. 2 may have a shape similar to the second electrode layer 422 of the first electrode 42, and may be formed to include a plurality of finger electrodes (not shown) and bus bar electrodes spaced apart from one another at a predetermined interval.

[0154] Because the electrodes 42, 44 of the solar cell 10 have a predetermined pattern, the solar cell 10 may have a bi-facial structure in which light can be incident on both the front and back surfaces of the semiconductor substrate 122. This can help increase the brightness available to the solar cell 10 and improve the efficiency of the solar cell 10. However, the present invention is not limited to this.

[0155] The above describes the case where the anti-reflection film 430 in the first photoelectric conversion section 110 is patterned and then the side insulating layer 130 is formed, but alternatively, the anti-reflection film 430 may be patterned after the side insulating layer 130 is formed.

[0156] The solar cell module 100 provided by arranging the solar cells 10 in FIG. 3 in a number of ways will be described below.

[0157] FIG. 9 is a plan view of a solar cell module according to one embodiment of the present invention, FIG. 10 is a cross-sectional view of one solar cell in a first direction in the solar cell module shown in FIG. 9, FIG. 11 is a process diagram showing bonding of multiple solar cells in a second direction in the solar cell module shown in FIG. 9, and FIG. 12 is a cross-sectional view of a solar cell module obtained by the bonding process in FIG. 11.

[0158] 9 to 12, a solar cell module 100 according to an embodiment of the present invention has a plurality of series-connected solar cells 10 stacked in a stepped pattern. For example, in the case of a reference series-connected solar cell 10, an adjacent upper series-connected solar cell 10 and an adjacent lower series-connected solar cell 10 partially overlap the reference series-connected solar cell 10, and the upper series-connected solar cell 10 partially overlaps the top of the reference series-connected solar cell 10, and the lower series-connected solar cell 10 partially overlaps the bottom of the reference series-connected solar cell 10.

[0159] In this specification, the upper series-connected solar cell 10 and the lower series-connected solar cell 10 may respectively refer to a series-connected solar cell 10 that is relatively lower and a series-connected solar cell 10 that is relatively upper, based on any one of the multiple series-connected solar cells 10 that are arranged in a stepped and partially overlapping manner as described above, and based on the reference series-connected solar cell 10, the same series-connected solar cell 10 may be an upper series-connected solar cell 10 or a lower series-connected solar cell 10.

[0160] The series-connected solar cell 10 according to this embodiment includes an overlapping portion OP, and when adjacent series-connected solar cells 10 are overlapped by forming a series-connected solar cell module 100, which will be described later, in the overlapping portion OP, each of the series-connected solar cells 10 may include a first overlapping portion OP1 that overlaps with the adjacent upper series-connected solar cell 10 and a second overlapping portion OP2 that overlaps with the adjacent lower series-connected solar cell 10, as the region of the series-connected solar cell 10 corresponding to the overlapping section.

[0161] For example, if multiple series-connected solar cells 10 are stacked in a stepped structure in the arrangement direction, a specific series-connected solar cell 10 will overlap an adjacent upper series-connected solar cell 10 and an adjacent lower series-connected solar cell 10 to include a first overlapping portion OP1 and a second overlapping portion OP2, and the first overlapping portion OP1 and the second overlapping portion OP2 will be arranged on both sides of the series-connected solar cell 10 so as to face each other in the arrangement direction.

[0162] The overlapping portion OP according to this embodiment may be referred to as a rectangle, a geometric polygon, or the like, depending on the shape of the series-connected solar cell 10. However, the shape of the overlapping portion OP is not limited to that described above or shown in the drawings, and should be within the scope of any change that can be easily made by a person skilled in the art.

[0163] In this embodiment, by ensuring that the width of the overlapping portion is within the width W1 of the side insulating layer 130, stable modularization and a large light-receiving area can be ensured when forming the series-connected solar cell module 100, thereby producing excellent solar cells and outputting power. If the width of the overlapping portion OP is less than 1 mm, the bonding stability of adjacent series-connected solar cells 10 during the modularization process may be reduced. If the width of the overlapping portion OP is more than 3 mm, the light-receiving area of ​​the series-connected solar cells 10 may be excessively reduced, which may actually reduce the output power of the solar cells.

[0164] The widths of the first overlapping portion OP1 and the second overlapping portion OP2 may be the same as or different from each other, and if the widths are different from each other, the difference in width between the first overlapping portion OP1 and the second overlapping portion OP2 may be within a range of approximately 1 mm to approximately 3 mm.

[0165] That is, as shown in FIG. 11 , the series-connected solar cell module 100 according to the embodiment of the present invention includes a plurality of series-connected solar cells 10 stacked in a stepped manner, and a plurality of leads 20 that span and connect the second electrode layer 442 of the second electrode 44 of the adjacent upper series-connected solar cell 10 to the second electrode layer 422 of the first electrode 42 of the lower series-connected solar cell 10.

[0166] In this case, the number of leads 20 may be the same as the number of bus bar electrodes 422 when connecting two series-connected solar cells 10, but may be less than that.

[0167] To form a plurality of leads 20 that overlap and span portions of two adjacent series-connected solar cells 10 as described above, the process shown in FIG. 11 can be carried out.

[0168] Referring to FIG. 11, in the modularization process according to one embodiment of the present invention, a lead film 300 for bonding multiple leads 20 may be applied.

[0169] When multiple leads 20 are arranged at equal intervals, the lead film 300 in Figure 11 has a first support layer 23a positioned below the leads 20 to support the multiple leads 20 in half the longitudinal area of ​​the leads 20, and a second support layer 23b positioned above the leads to support the multiple leads 20 in the remaining half of the longitudinal area of ​​the leads 20.

[0170] The lead film 300 described above has a structure in which support layers 23a and 23b for simultaneously supporting multiple leads 20 are placed below the leads 20 in half the length of the region, and above the leads 20 in the remaining half of the region.

[0171] In this case, in the case of two overlapping solar cells 10, the lead film 300 is arranged at the bottom of the upper solar cell 10' so as to expose the lead 20 toward the second electrode 44 of the upper solar cell 10', and the remaining half of the lead film 300 is arranged at the top of the lower solar cell 10 so as to expose the lead 20 toward the first electrode 42 of the lower solar cell 10.

[0172] Therefore, the upper solar cell 10' and the lower solar cell 10 may face each other in a state where they are bonded to the lead 20 when not obstructed by the support layers 23a and 23b.

[0173] By aligning the multiple leads 20 exposed to the bus bar electrode 422 of the first electrode 42 of the lower solar cell 10 and then welding, electrical and physical adhesion between the bus bar electrode 422 and the leads 20 can be achieved.

[0174] As described above, when bonding the lower solar cell 10 and the lead film 300, welding is performed between the second electrode layer 442 of the second electrode 44 of the upper solar cell 10' and the lead 20 on the opposite side where the lead film 300 is exposed.

[0175] At this time, as shown in FIG. 2, the second electrode 44 can be easily aligned if it is not additionally patterned.

[0176] When attaching the above-described lead 20, it may be disposed on a bus bar electrode 422 of the first electrode 42 as shown in FIG. 10, and the cross section of the lead 20 may be circular or rectangular.

[0177] The corresponding lead 20 has a cross-section of a predetermined shape and extends in the longitudinal direction, and when viewed in cross section, may be realized by a core layer 25 corresponding to the center and a solder layer 26 formed to surround the core layer 25.

[0178] The solder layer 26 surrounding the core layer 25 is partially melted in the welding process and electrically and physically joined to the lower bus bar electrode 422 or the second electrode layer 442 of the second electrode 44 .

[0179] When the upper solar cell 10 overlaps the lower solar cell 10', the corresponding support layers 23a, 23b of the lead film 300 are peeled off, leaving only the lead 20 remaining.

[0180] In this case, the connection portion 60 is positioned within the overlapping area of ​​the two solar cells 10, 10' to physically connect the two solar cells 10, 10', thereby enabling a stronger electrical and physical connection between adjacent series-connected solar cells 10.

[0181] The connection portion 60 may include a conductive adhesive layer, and the conductive adhesive layer may be disposed entirely between the second overlapping portion OP2 of the upper series-connected solar cell 10 and the first overlapping portion OP1 of the lower series-connected solar cell 10, based on two adjacent series-connected solar cells 10. In this specification, the term "overall arrangement" not only includes completely uniform physical arrangement within the region or space, but also includes the unavoidable presence of partially excluded portions. The conductive adhesive layer has adhesive properties, including a polymer blend such as epoxy acrylic fluoride, silicone, and polyamide, and thus is physically and electrically bonded to adjacent series-connected solar cells 10 stably and is conductive, thereby electrically connecting the adjacent series-connected solar cells 10. The conductive adhesive portion 60 may be composed of multiple types of materials, and one example is an electrically conductive adhesive (ECA). However, the type of conductive adhesive layer is not limited to those described above, and any type that can physically and electrically connect adjacent series-connected solar cells 10 may be easily selected by those skilled in the art.

[0182] As described above, the second electrode layer 442 formed on the second overlapping portion OP2 of the upper series-connected solar cell 10' and the first overlapping portion OP1 of the lower series-connected solar cell 10 are in contact with each other through the conductive adhesive layer, forming a physical connection between two adjacent unit solar cells 10 and also contacting and electrically connecting a plurality of leads 20 at the same time.

[0183] Therefore, as described above, the series-connected solar cell module 100 according to the embodiment of the present invention has a plurality of series-connected solar cells 10 stacked in a stepped manner, and the series connection is performed by a plurality of leads 20 spanning them, thereby improving the productivity rate and reducing the defect rate.

[0184] A series-connected solar cell module 100 according to another embodiment of the present invention will be described below with reference to FIGS.

[0185] FIG. 13 is a plan view of a solar cell module according to another embodiment of the present invention, and FIG. 14 is a cross-sectional view of the solar cell module shown in FIG.

[0186] 13 and 14, in a solar cell module 100 according to one embodiment of the present invention, a plurality of series-connected solar cells 10 are arranged in rows and columns and are electrically connected to one another by a plurality of leads.

[0187] A plurality of series-connected solar cells 10 are connected in a row direction by a plurality of leads 20 to form a string, and a plurality of strings are connected to each other to form a solar cell module 100.

[0188] Taking into consideration the adhesion between the electrodes and the leads 20 and the charge collection efficiency, 5 to 40 leads 20 may be used between two adjacent solar cells to connect adjacent series-connected solar cells 10 to each other, so as to optimize the power generation efficiency of the solar cells.

[0189] In the above string connection, the lead film 300 in FIG. 11 may be similarly applied.

[0190] That is, the multiple leads 20 are joined to the entire second electrode 44 formed on the back surface of the first unit solar cell in two adjacent series-connected solar cells 10, and are joined to the bus bar electrode 422 of the first electrode 42 formed on the front surface of the second solar cell adjacent to the first solar cell. Similarly, the other lead 20 is joined to the entire second electrode 44 of the second solar cell, and is joined to the bus bar electrode 422 of the first electrode 42 of the third solar cell adjacent to the second solar cell. In this case, the joint between the lead 20 and the bus bar electrode 422 may be configured only within the extended surface (pad area) of the bus bar electrode 422, or alternatively, the entire bus bar electrode 422 may be welded.

[0191] Since the first photoelectric conversion unit 110 is not covered with the lead 20, the area of ​​the active region of the solar cell is not reduced and the unit solar cells arranged in one string are connected in series.

[0192] In addition, the bus bar 21 can connect the lead 20 connected to one end of the string in the first row with the lead 20 connected to one end of the string in the second row. Similarly, the other bus bar 21 connects the lead 20 connected to the other end of the string in the second row with the connection pad 20 connected to one end of the string in the third row. As a result, all of the series-connected unit solar cells 10 constituting the solar cell module 100 are connected in series with each other. The solar cell module 100 connected in this manner is protected by being sealed by the front package 30 and the back package 40, and is stacked and integrated while being disposed between the front substrate 50 and the back substrate 70.

[0193] The front substrate 50 is positioned on the front (light receiving surface) of the solar cell 10 and is made of a rigid material that is not flexible to protect it from impact. As an example, the front substrate 50 may be made of tempered glass with high transmittance and excellent breakage resistance, or low-iron glass with a thickness of 3 mm or less (preferably 2 mm).

[0194] The rear substrate 70 is positioned on the rear surface of the solar cell (the non-light-receiving surface where light does not enter) and may be made of a flexible material different from the front substrate 50. The rear substrate 60 protects the solar cell from the external environment by preventing moisture penetration from the rear surface. The rear substrate 40 may have a multi-layer structure including a layer that prevents moisture and oxygen gas penetration and a layer that prevents chemical corrosion, and may be made of a thin film made of an insulating material such as fluoropolymer (FP), polyester (PE), or fluoropolymer (FP).

[0195] The rear substrate 70 may have an uneven surface, and may be printed with white or black enamel paste.

[0196] The front package 30 is manufactured to have a thickness that allows the leads 20 to be completely embedded, so that the rigid front substrate 50 is not subjected to physical shock due to the leads 20 .

[0197] The rear package 40 is located between the rear substrate 70 and the rear surface of the solar cell 10 and is made of a transparent material that transmits light. To prevent moisture penetration and protect the solar cell 10 from impacts, the rear package 40 also uses a resin product such as ethylene vinyl acetate (EVA) that can absorb shock. The rear package 40 is also configured to contain a material that absorbs ultraviolet light to prevent deterioration, while the front package 30 does not contain a UV absorber so that all light can pass through, thereby improving the power generation efficiency of the series-connected solar cell 10.

[0198] The stacking of the solar cell modules 100 as described above is carried out by first preheating to 70 to 100 degrees Celsius, preferably to a temperature of about 85 degrees Celsius, and then stacking at a temperature of 120 to 160 degrees Celsius, preferably 155 degrees Celsius or less.

[0199] As described above, the solar cell module 100 may be manufactured by arranging the solar cells 10 in FIGS.

[0200] Alternatively, a quantum dot solar cell 100 may be formed in which a first photoelectric conversion section 110 having a perovskite structure shown in Figures 1 to 3 is formed in the upper part, and a second photoelectric conversion section 140 as described below is formed in the lower part.

[0201] Hereinafter, a quantum dot solar cell according to another application example of the present invention will be described with reference to FIG.

[0202] Referring to Figure 15, a quantum dot solar cell according to another application example of the present invention may have a series-connected structure further including a first photoelectric conversion section 110 including a photoelectric conversion layer 112 containing a perovskite compound, and a second photoelectric conversion section 140 having a material or structure different from that of the first photoelectric conversion section 110.

[0203] In the solar cell 100 according to this application example, the second photoelectric conversion section 120 may have a pn junction structure including a semiconductor substrate 122. As an example, the second photoelectric conversion section 120 may include the semiconductor substrate 122 and conductive regions 124, 126 formed in or on the semiconductor substrate 122. The conductive regions 124, 126 may include a first conductive region 124 having a first conductivity type and a second conductive region 126 having a second conductivity type.

[0204] The semiconductor substrate 122 may be made of a crystalline semiconductor (e.g., a single-crystal or polycrystalline semiconductor, e.g., single-crystal or polycrystalline silicon) containing a single semiconductor material (e.g., a Group 4 element). Second, since the second photoelectric conversion unit 120 is based on the semiconductor substrate 122 with high crystallinity and few defects, it may have excellent electrical properties. As an example, the second photoelectric conversion unit 120 may have a crystalline silicon solar cell structure.

[0205] The arrangement of the semiconductor substrate 122 is the same as that of the semiconductor substrate 122 in FIG. 3, and therefore a detailed description thereof will be omitted.

[0206] A first conductive region 124 having a first conductivity type may be formed on a front surface of the semiconductor substrate 122. Also positioned on (and, in one example, contacting) the semiconductor substrate 122 may be a second conductive region 126 having a second conductivity type opposite the first conductivity type.

[0207] The first conductive region 124 may be a region having a first conductivity type by including a dopant of a first conductivity type, and the second conductive region 126 may be a region having a second conductivity type by including a dopant of a second conductivity type.

[0208] The first conductive region 124 and the second conductive region 126 may each include the same semiconductor material (more specifically, a single semiconductor material, for example, silicon) as the semiconductor substrate 122. For example, the first conductive region 124 and the second conductive region 126 may be configured as an amorphous silicon (a-Si) layer, an amorphous silicon carbide (a-SiCx) layer, an amorphous silicon oxide (a-SiOx) layer, etc. Secondly, the first conductive region 124 and the second conductive region 126 may have similar properties to the semiconductor substrate 122, minimizing differences in properties that may occur when the first conductive region 124 and the second conductive region 126 include different semiconductor materials.

[0209] For example, each of the first conductive region 124 and the second conductive region 126 may be formed by doping an amorphous semiconductor, which can be easily manufactured by a variety of methods, such as deposition, with a dopant of the first conductivity type or a dopant of the second conductivity type. Then, the first conductive region 124 and the second conductive region 126 may be easily formed by a simple process. Alternatively, each of the first conductive region 124 and the second conductive region 126 may be manufactured in a nanocrystalline silicon or polycrystalline silicon layer by a variety of methods, such as deposition, and then formed by doping the first conductive type or a dopant of the second conductivity type. Then, the first conductive region 124 and the second conductive region 126 may be easily formed by a simple process.

[0210] In this embodiment, if the semiconductor substrate 122 (or base region) has a first conductivity type, the second conductive region 126 may constitute an emitting region that forms a pn junction with the semiconductor substrate 122. The first conductive region 124 may constitute a front surface field region that prevents coupling by forming a front surface field. Since the emitting region that directly participates in photoelectric conversion is located on the back surface, forming the emitting region with a sufficient thickness (for example, thicker than the front surface field region) can further improve photoelectric conversion efficiency. However, the present invention is not limited thereto. Therefore, since the semiconductor substrate 122 has a second conductivity type, the first conductive region 124 may also constitute an emitting region, and the second conductive region 126 may also constitute a back surface field region.

[0211] In this embodiment, the first conductive region 124 and the semiconductor substrate 122 may have n-type conductivity, and the second conductive region 126 may have p-type conductivity. Next, in the first photoelectric conversion section 110 located in the second photoelectric conversion section 120, the upper first transport layer 114 can transport electrons, and the lower second transport layer 116 can transport holes. This situation may provide superior performance for the first photoelectric conversion section 110 compared to the opposite situation. Furthermore, the semiconductor substrate 122 may have n-type conductivity, thereby improving carrier lifetime. However, the present invention is not limited thereto, and various modifications may be made to the conductivity type of the semiconductor substrate 122, whether it is the first conductivity type or the second conductivity type, or whether it is the n-type or the p-type.

[0212] The junction layer (tunneling junction layer) 110a is located in front of the second photoelectric conversion unit 140, thereby connecting the second photoelectric conversion unit 120 to the first photoelectric conversion unit 110 located thereover. Although the drawings show the case where the junction layer 110a directly contacts the first conductive region 124 and the first photoelectric conversion unit 110, respectively, the present invention is not limited thereto. The junction layer 110a may have a thin thickness, and for example, may have a thickness thinner than that of the electrode layers 420 and 440, thereby facilitating smooth tunneling of carriers.

[0213] The bonding layer 110a may electrically connect the first photoelectric conversion unit 110 and the second photoelectric conversion unit 140 and may include a material that can transmit light used in the first photoelectric conversion unit 110 (for example, long-wavelength light). For example, the bonding layer 110a may include at least one of a variety of materials, such as a transparent conductive material (for example, a transparent conductive oxide), a conductive carbon material, a conductive polymer, or n-type or p-type amorphous silicon. Alternatively, the bonding layer 110a may be formed as a structure in which silicon layers having different refractive indices are alternately stacked. As a result, light used in the second photoelectric conversion unit 120 (for example, short-wavelength light) may be reflected by the second photoelectric conversion unit 120, and light used in the first photoelectric conversion unit 110 (for example, long-wavelength light) may be transmitted through the first photoelectric conversion unit 110 and supplied to it.

[0214] The detailed arrangement of the bonding layer 110a is the same as that shown in FIG. 3, and therefore will not be described.

[0215] Due to the difference in area between the second photoelectric conversion section 120 and the first photoelectric conversion section 110, an edge difference is formed around the first photoelectric conversion section 110, thereby forming an edge difference region NA at the edge that exposes the underlying second photoelectric conversion section 120.

[0216] The above-described end difference regions NA may have a frame shape by being formed on the edges of the four sides of the active area AA in the central region as the center.

[0217] When the first photoelectric conversion section 110 is formed on the second photoelectric conversion section 120 by a deposition process, the four sides of the solar cell 10 described above are formed to include an area where two legs of the fixing part of the deposition equipment that fixes the semiconductor substrate 122 of the solar cell 10 within the deposition equipment are positioned on the semiconductor substrate 122.

[0218] Therefore, the fixing portion of the deposition device may be located in at least one of the end difference regions NA formed on the four sides of the solar cell 10 in the length direction.

[0219] Therefore, the above-described edge difference region NA may be formed in the second photoelectric conversion section 140, and the first photoelectric conversion section 110 including the bonding layer 110a and the photoelectric conversion layer 112 including a perovskite compound may be positioned. The first photoelectric conversion section 110 is also formed confinedly on the bonding layer 110a, thereby maintaining the edge difference region NA, and thereby maintaining a constant difference in area between the second photoelectric conversion section 140 and the first photoelectric conversion section 110.

[0220] The first photoelectric conversion section 110 may also include a photoelectric conversion layer 112, a second transport layer (second carrier transport layer) 116 located on one side of the photoelectric conversion layer 112 between the junction layer 110a and the photoelectric conversion layer 112, and a first transport layer (first carrier transport layer) 114 located on the other side of the photoelectric conversion layer 112 between the photoelectric conversion layer 112 and the first electrode 42.

[0221] The structure and materials of each layer of the first photoelectric conversion section 110 are the same as those in FIG. 3, and therefore detailed description thereof will be omitted.

[0222] Furthermore, the first electrode 42 may be located on the first photoelectric conversion unit 110 (for example, on the first transport layer 114 located on the front surface thereof), and the second electrode 44 may be located on the second photoelectric conversion unit 140 (for example, on the second conductive region 126 located on the back surface thereof). That is, the solar cell 10 according to this embodiment may have a series connection structure in which the second photoelectric conversion unit 140 based on a single semiconductor material (for example, silicon) and the first photoelectric conversion unit 110 based on a perovskite compound are joined by the joining layer 110a.

[0223] Furthermore, the side insulating layer 130 of the solar cell 10 in FIG. 3 according to one embodiment of the present invention and the solar cell 10 in FIG. 15 according to another embodiment may have the following structure.

[0224] FIG. 16 shows a cross section of a solar cell according to a further embodiment of the present invention.

[0225] Referring to Figure 16, a solar cell according to a further embodiment of the present invention has an end difference region NA between the first photoelectric conversion section 110 and the second photoelectric conversion section 120, and is electrically and physically joined by a bonding layer 110a, and includes a side insulating layer 130a that fills the end difference region NA and surrounds all four sides of the solar cell 10.

[0226] In the further embodiment of Figure 16, the arrangement of the first photoelectric conversion section 110, the bonding layer 110a, the second photoelectric conversion section 120, the first electrode 42 and the second electrode 44 is the same as in Figure 3, so a detailed description thereof will be omitted.

[0227] The side insulating layer 130a of the solar cell according to the further embodiment of FIG. 16 is formed from the end of the second photoelectric conversion part 120 to the top of the first photoelectric conversion part 110, that is, formed to a height that reaches the entire thickness of the solar cell.

[0228] In this case, the side surface insulating layer 130a may include a side surface portion 133 arranged on the side surface and a covering portion 132 covering part of the upper surface.

[0229] The side portion 133 may have a height reaching the entire thickness of the solar cell 10, and the side area covering the second photoelectric conversion section 120 may have a third thickness w4, and the side area covering the first photoelectric conversion section 110 may be formed to have a second thickness w3, and the second thickness w3 may be greater than the third thickness w4, but is not limited to this, and may also be formed in a case where the side has an end difference.

[0230] When the side insulating layer 130a is filled in the end difference region NA, it may be similarly formed on the four sides, thereby forming a frame-type shape that completely surrounds the four sides of one solar cell 10.

[0231] The side insulating layer 130a may be formed by, but is not limited to, atomic deposition, chemical deposition, or physical deposition.

[0232] The side insulating layer 130a may be made of a compound containing an oxide, and may be made of SiC, SiN, or the like.

[0233] In this case, the covering portion 132 may be formed with a width narrower than the width of the side portion 133, and may cover the edge of the anti-reflection film 430 of the first photoelectric conversion portion 110, thereby preventing moisture from penetrating into the first photoelectric conversion portion 110 from the outside.

[0234] In addition, the side insulating layer 130a may further include a lower covering portion (not shown) that covers a portion of the second electrode 44 of the second photoelectric conversion portion 120, but is not limited thereto.

[0235] The above features, structures, effects, etc. are included in at least one embodiment of the present invention and are not necessarily limited to one embodiment. Furthermore, the features, structures, effects, etc. exemplified in each embodiment may be implemented by a person skilled in the art by combining or modifying other embodiments. Therefore, the contents relating to such combinations and modifications should be interpreted as being included within the scope of the present invention. [Explanation of symbols]

[0236] 100, 100' solar cell module 10, 10' solar cell 20 Lead 300 Lead Film 110 First photoelectric conversion unit 120, 130 Second photoelectric conversion unit 110a Bonding layer 130, 130a Side insulating layer 42 1st electrode 44 2nd electrode

Claims

1. A solar cell module including: a plurality of solar cells; and a plurality of connecting members that connect adjacent solar cells to each other; Each of the solar cells includes a first photoelectric conversion unit, a second photoelectric conversion unit, a side insulating layer, a first electrode, and a second electrode; the first photoelectric conversion unit includes a photoelectric conversion layer containing a perovskite compound, a first transport layer located on one side of the photoelectric conversion layer, and a second transport layer located on the other side of the photoelectric conversion layer; the second photoelectric conversion unit is disposed below the second transport layer of the first photoelectric conversion unit and has a different material or structure from the first photoelectric conversion unit; the side surface insulating layer is formed to surround a side surface of the first photoelectric conversion unit, the first electrode is electrically connected to the first photoelectric conversion unit on one surface serving as a light-receiving surface of the first photoelectric conversion unit; the second electrode is electrically connected to the second photoelectric conversion unit below the second photoelectric conversion unit; the first electrode includes a plurality of bus bar electrodes spaced apart from one another and extending in one direction; one ends of adjacent solar cells overlap, and the adjacent solar cells are physically coupled by a connection portion disposed in the overlapping region of the adjacent solar cells, and the connection member spans the overlapping region and electrically connects the second electrode of one solar cell to the bus bar electrode of the other overlapping solar cell; The connection member includes a plurality of leads extending in parallel from the second electrode of a solar cell constituting an upper part of the adjacent solar cells to the bus bar electrode of the first electrode of a solar cell constituting a lower part of the adjacent solar cells, and the connection portion. Solar cell module.

2. Each of the solar cells includes a first overlapping portion that overlaps with an upper solar cell among the adjacent solar cells, and a second overlapping portion that overlaps with a lower solar cell among the adjacent solar cells, The connection portion includes a conductive adhesive layer disposed between the first overlapping portion and the second overlapping portion. The solar cell module according to claim 1 .

3. The plurality of leads each include a core portion extending in a longitudinal direction, and a welding layer surrounding the core portion and electrically coupled to the first electrode and the second electrode by welding. The solar cell module according to claim 2 .

4. The first photoelectric conversion unit has an area smaller than that of the second photoelectric conversion unit, so that the second photoelectric conversion unit has an end difference region, and the end difference region is formed over the entire side surface of the first photoelectric conversion unit. The solar cell module according to claim 1 .

5. the side surface insulating layer includes a side surface portion and a covering portion, the side surface portion surrounds the entire side surface of the first photoelectric conversion unit, The covering portion is bent from the side surface portion and covers a part of an upper surface of the first photoelectric conversion portion. The solar cell module according to claim 4 .

6. The side insulating layer includes an oxide film or a nitride film. The solar cell module according to claim 5 .

7. The side portion of the side insulating layer is disposed on the end difference region. The solar cell module according to claim 6 .

8. The side insulating layer is formed in a frame shape surrounding the first photoelectric conversion unit. The solar cell module according to claim 7 .

9. The first electrode further includes a plurality of finger electrodes connected to the plurality of bus bar electrodes in a crossing relationship. The solar cell module according to claim 8 .

10. The side surface portion of the side surface insulating layer is formed to extend from the first photoelectric conversion section to an end of the second photoelectric conversion section so as to surround the entire side surface of the solar cell. The solar cell module according to claim 8 .

11. A method for manufacturing a solar cell, wherein the solar cell is a solar cell included in the solar cell module according to any one of claims 1 to 10, The manufacturing method includes: forming a second photoelectric conversion unit including a conductive region on the semiconductor substrate; forming a first photoelectric conversion unit in the second photoelectric conversion unit, the first photoelectric conversion unit including a photoelectric conversion layer containing a perovskite compound, a first transport layer located on one side of the photoelectric conversion layer, and a second transport layer located on the other side of the photoelectric conversion layer; forming a side insulating layer surrounding a side surface of the first photoelectric conversion unit; and forming a first electrode electrically connected to the first photoelectric conversion unit and having a cutting region used to cut the solar cell into a plurality of units so as to open the center on one surface serving as a light-receiving surface of the first photoelectric conversion unit, and a second electrode electrically connected to the second photoelectric conversion unit and having the cutting region below the second photoelectric conversion unit. How solar cells are manufactured.

12. In the step of forming the first photoelectric conversion unit, the second photoelectric conversion unit is formed with a first photoelectric conversion unit having an area smaller than that of the second photoelectric conversion unit. The method for producing a solar cell according to claim 11 .

13. The step of forming the side insulating layer includes: The method includes a step of placing a mask on the second photoelectric conversion unit to expose the side surface, and a step of depositing the side surface insulating layer to a predetermined height on the exposed side surface. The method for producing a solar cell according to claim 12 .

14. In the step of forming the side insulating layer, a covering portion that covers a part of an edge portion of the first photoelectric conversion portion is further formed. The method for producing a solar cell according to claim 13 .

15. The step of forming the first photoelectric conversion unit includes: forming a bonding layer having a first area on the second photoelectric conversion portion; forming the first photoelectric conversion unit having a second area larger than the first area on the bonding layer, The second area is smaller than the area of ​​the second photoelectric conversion portion. The method for producing a solar cell according to claim 13 .

16. The side surface insulating layer is formed to surround the entire side surfaces of the first photoelectric conversion section and the second photoelectric conversion section. The method for producing a solar cell according to claim 15 .

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