Solar cell, its manufacturing method and solar cell module including said solar cell

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 on at least one 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. Thus, a solar cell module having a series connection type 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 can be provided. In addition, the active area of ​​the solar cell having a series connection structure can be maximized, and the short circuit current can be significantly reduced to 1 / 4 of the current level.

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 having a semiconductor substrate are widely used because they have excellent photoelectric conversion efficiency. However, there are certain limitations in terms of improving the photoelectric conversion efficiency of solar cells having a semiconductor substrate, so solar cells with several types of structures are proposed.

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

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

[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 by a deposition method.

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

[0007] Various attempts have been made to reduce the inactive area as described above, but as the inactive area of ​​the cell is reduced, a problem arises in that power is reduced.

[0008] Furthermore, when using such edge regions as spaces for forming pads, pads are formed at the ends along the sides of the upper electrode, which entails the risk that electrons that separate in the perovskite layer will combine again with holes in the pads, causing a short circuit of current. [Prior art documents] [Patent documents]

[0009] Korean Patent Publication No. 10-2018-0099577 (Publication date: September 5, 2018) Summary of the Invention [Problem to be solved by the invention]

[0010] The present invention aims to provide a solar cell and a solar cell module that have a series connection type 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.

[0011] The present invention is intended to provide an optimal structure that can secure the active area of ​​a solar cell having a series-connection type structure.

[0012] The present invention is intended to provide an optimum structure that can reduce the leakage current of a solar cell having a series connection type structure.

[0013] The present invention also aims to provide a manufacturing method that can secure the active area and reduce the leakage current of a solar cell having a series connection type structure.

[0014] The present invention also aims to provide an optimal arrangement between cells in a large area solar cell module containing perovskite compounds. [Means for solving the problem]

[0015] 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 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 on at least one 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.

[0016] The first photoelectric conversion unit may have an area smaller than that of the second photoelectric conversion unit, thereby providing an end difference region in the second photoelectric conversion unit, and the end difference region may be formed on two opposing side surfaces of the first photoelectric conversion unit.

[0017] The side surface insulating layer may be formed in the end difference region that is formed on two opposing side surfaces of the first photoelectric conversion unit.

[0018] The cut region of the first electrode is not formed on the light receiving surface, and the cut region is positioned across the first photoelectric conversion unit.

[0019] The cut region may have a shape extending along a first direction in a central region of the solar cell, and the side insulating layer may have a shape extending along the first direction in the end difference region.

[0020] The solar cell may include a plurality of unit solar cell regions disposed between the cut region and the side insulating layer, and the plurality of unit solar cell regions may be separated from one another by the cut region.

[0021] The first electrode may include a plurality of first unit electrodes formed in each of the unit solar cell regions, and each of the first unit electrodes may include a pad portion formed on the side insulating layer and a plurality of bus bar electrodes spaced from each other from the pad portion and extending in a second direction perpendicular to the first direction.

[0022] The second electrode may include a plurality of second unit electrodes formed in each of the unit solar cell regions, and each of the second unit electrodes may be formed to correspond to all of the plurality of bus bar electrodes from the pad portion of the first unit electrode.

[0023] Further, in the embodiment, a solar cell is provided, the solar cell 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 includes a first long side and a second long side formed along a major axis and parallel to each other, and a first short side and a second short side formed along a minor axis intersecting the major axis and parallel to each other, the solar cell further includes 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, and the second photoelectric conversion unit is a first photoelectric conversion unit of the first photoelectric conversion unit. The first electrode is arranged below the second transport layer and has a different material or structure from the first photoelectric conversion section, the side insulating layer is formed to abut against a first long side of the first photoelectric conversion section, the first electrode is electrically connected to the first photoelectric conversion section on one side of the first photoelectric conversion section as a light receiving surface, and the second electrode is electrically connected to the second photoelectric conversion section below the second photoelectric conversion section, and the first electrode includes a pad section formed on the side insulating layer and a plurality of bus bar electrodes extending from the pad section, spaced apart from each other, and extending along the short axis.

[0024] In addition, an embodiment of the present invention provides a solar cell module, the solar cell module including a plurality of solar cells and a connection 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 first long side and a second long side formed along a major axis and parallel to each other, and a first short side and a second short side formed along a minor axis intersecting the major axis and parallel to each other, the solar cell module 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 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 abut a first long side of the first photoelectric conversion unit, the first electrode is 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 is electrically connected to the second photoelectric conversion unit below the second photoelectric conversion unit, and the first electrode includes a pad portion formed on the side insulating layer and a plurality of bus bar electrodes extending from the pad portion, spaced apart from each other, and extending along the short axis.

[0025] The present invention claims a solar cell module in which the second electrode of one solar cell and the pad portion of an adjacent solar cell are electrically connected by overlapping of the adjacent solar cells.

[0026] The solar cell may have a first overlapping portion that overlaps an adjacent upper solar cell and a second overlapping portion that overlaps an adjacent lower solar cell, and the connection member may include a conductive adhesive portion generally disposed between the second overlapping portion of the upper solar cell and the first overlapping portion of the lower solar cell.

[0027] The pad portion and the conductive adhesive portion may be in contact with each other and electrically connected.

[0028] The 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.

[0029] The connection member may contact a pad portion of the first electrode of one of the solar cells and entirely cover the second electrode of the adjacent solar cell, thereby electrically connecting the solar cells.

[0030] In addition, an embodiment of the present invention provides a method for manufacturing a solar cell, the method for manufacturing the solar cell includes the steps of forming a second photoelectric conversion unit including a conductive region on a semiconductor substrate; forming a plurality of side insulating layers on opposing side surfaces of the second photoelectric conversion unit; forming a first photoelectric conversion unit inside the plurality of side insulating layers, 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; forming a first electrode electrically connected to the first photoelectric conversion unit and having a cut region so as to open the center, and a second electrode electrically connected to the second photoelectric conversion unit below the second photoelectric conversion unit and having the cut region, on one side as a light receiving surface of the first photoelectric conversion unit; and cutting along the cut region where the first electrode and the second electrode are not formed to form a plurality of unit solar cells.

[0031] 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.

[0032] In the step of forming the first electrode, the first electrode may be formed to include a pad portion formed on the side insulating layer and a plurality of bus bar electrodes extending from the pad portion, spaced apart from one another, and extending toward the cutting area.

[0033] The step of forming the plurality of unit solar cells may include a step of primarily cutting the solar cell to a predetermined depth from the back surface of the second photoelectric conversion section by laser drawing, and a step of mechanically processing the solar cell to secondarily cut based on the cutting area to separate it into the plurality of unit solar cells.

[0034] The predetermined depth of the primary cut may be a depth that does not reach the first photoelectric conversion unit. Effect of the Invention

[0035] According to the present embodiment, a solar cell module having a series connection type 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 can be provided.

[0036] The present invention can maximize the active area of ​​a solar cell having a series-connected structure, while significantly reducing the short circuit current to 1 / 4 of the current level.

[0037] In addition, the present invention has a half cut structure, which reduces the short circuit current by up to 1 / 4, thereby reducing the output loss, thereby improving the cell to module (CTM) loss and increasing the output.

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

[0039] [Figure 1] FIG. 1 is a plan view showing a solar cell according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a rear view showing a solar cell according to an embodiment of the present invention. [Diagram 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] FIG. 5a is a process diagram for manufacturing a solar cell according to one embodiment of the present invention. [Figure 5b] FIG. 5b is a process diagram for manufacturing a solar cell according to an embodiment of the present invention. [Figure 6a] FIG. 6a is a process diagram for manufacturing a solar cell according to one embodiment of the present invention. [Figure 6b] FIG. 6b is a process diagram for manufacturing a solar cell according to an embodiment of the present invention. [Figure 6c] FIG. 6c is a process diagram for manufacturing a solar cell according to an embodiment of the present invention. [Figure 7a] FIG. 7a is a process diagram for manufacturing a solar cell according to one embodiment of the present invention. [Figure 7b] FIG. 7b is a process diagram for manufacturing a solar cell according to one embodiment of the present invention. [Figure 8a] FIG. 8a is a process diagram for manufacturing a solar cell according to one embodiment of the present invention. [Figure 8b] FIG. 8b is a process diagram for manufacturing a solar cell according to an embodiment of the present invention. [Figure 9] FIG. 9 is a process diagram for manufacturing a solar cell according to one embodiment of the present invention. [Figure 10a] FIG. 10a is a process diagram for manufacturing a solar cell according to one embodiment of the present invention. [Figure 10b] FIG. 10b is a process diagram for manufacturing a solar cell according to one embodiment of the present invention. [Figure 11] FIG. 11a is a plan view showing a solar cell according to another embodiment of the present invention, and FIG. 11b is a rear view showing a solar cell according to another embodiment of the present invention. [Figure 12] FIG. 12 is a cross-sectional view of a unit solar cell for modularization according to the present invention. [Figure 13] FIG. 13 is a plan view of a solar cell module according to an embodiment of the present invention. [Figure 14] FIG. 14 is a cross-sectional view of the solar cell module in FIG. 13 taken along line VII-VII'. [Figure 15] FIG. 15 is a plan view of part A in FIG. [Figure 16] FIG. 16 is a cross-sectional view showing a solar cell module in which the unit solar cells are those in FIG. 11a and FIG. 11b. [Figure 17] FIG. 17 is a plan view of a solar cell module according to another embodiment of the present invention. [Figure 18] FIG. 18 is an exploded perspective view of the solar cell module shown in FIG. [Figure 19] FIG. 19 is a cross-sectional view of the solar cell module shown in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0040] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the preferred embodiments and can be modified into various forms.

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

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

[0043] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a solar cell and a method for manufacturing the solar cell according to embodiments of the present invention will be described in detail 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] The solar cell 10 according to an embodiment of the present invention may be a series-connected solar cell 10, and may include a first photoelectric conversion section 110 including a photoelectric conversion layer 112 containing a perovskite compound, and a first electrode 42 and a second electrode 44 electrically connected thereto, in the vertical direction as the stacking direction. Here, the photoelectric conversion layer 112 containing a perovskite compound may be formed as a thick film having a thickness of a predetermined thickness or more, and may be formed to have a uniform composition in the stacking direction. In addition, the solar cell 10 according to this embodiment may have a series-connected structure further including a second photoelectric conversion section 120 having a material or structure different from the first photoelectric conversion section 110. In addition, the solar cell 10 according to this embodiment may be formed as a large-area solar cell, as a large-area perovskite solar cell 10 having a diameter of 10 cm to 20 cm, preferably a diameter of 12 cm to 17 cm.

[0046] 1 and 2, a solar cell 10 according to this embodiment has a plurality of solar cell regions AA1, AA2 defined on a plane where conductive regions and electrodes are provided and where photoelectric conversion actually occurs, and a cutting region NA is positioned across the solar cell 10 between the adjacent solar cell regions AA1, AA2. Such a solar cell 10 is cut along the cutting region NA to form a plurality of solar cells AA1, AA2 that are separated from each other. Each of the separated solar cells AA1, AA2 has a corresponding solar cell region AA1, AA2 provided thereon, and thus the solar cells are used as independent solar cells.

[0047] Hereinafter, for clearer distinction, the solar cell 10 separated by cutting the cutting region NA of the solar cell 10 will be referred to as unit solar cells AA1 and AA2. This is merely a term used for clearer explanation, and in addition to the solar cell 10, the unit solar cells AA1 and AA2 (which use the same drawing symbol as the solar cell region) that are actually used as one solar cell may also be considered as solar cells, and the present invention is not limited to such terminology.

[0048] First, the cross-sectional structure of the solar cell regions AA1 and AA2 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.

[0049] 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 conductive type and a second conductive region 126 having a second conductive type.

[0050] 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 photoelectric conversion unit 120 may have excellent electrical properties since it is based on semiconductor substrate 122 with high crystallinity and few defects. As an example, second photoelectric conversion unit 120 may have a crystalline silicon solar cell structure.

[0051] In this embodiment, the semiconductor substrate 122 may be configured as a base region having a first or second conductivity type by doping the semiconductor substrate 122 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 dopant into the base region, 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] A first conductive region 124 having a first conductivity type may be formed on (as one 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 (as one example, in contact with) the second passivation film 122b.

[0054] The first conductive region 124 may be a region having a first conductivity type that includes a dopant of a first conductivity type, and the second conductive region 126 may be a region having a second conductivity type that includes a dopant of a second conductivity type.

[0055] In this embodiment, when the semiconductor substrate 122 (or the 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. Next, since the emitting region that directly participates in photoelectric conversion is located on the back surface, the emitting region may be formed with a sufficient thickness (for example, formed thicker than the front surface field region) to further improve the 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.

[0056] 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 first transport layer 114 located in the upper part can transport electrons, and the second transport layer 116 located in the lower part can transport holes. In this situation, the first photoelectric conversion section 110 may have a superior effect compared to the opposite situation. In addition, the semiconductor substrate 122 may have n-type conductivity, thereby improving the carrier life time. However, the present invention is not limited to this, and various modifications can be made regarding which conductive type of the semiconductor substrate 122 is the first conductive type or the second conductive type, or which conductive type of the semiconductor substrate 122 is the n-type or the p-type.

[0057] The junction layer (tunneling junction layer) 110a is located in front of the second photoelectric conversion section 120, thereby connecting the second photoelectric conversion section 120 to the first photoelectric conversion section 110 located thereon. Although the drawings show a case where the junction layer 110a directly contacts the first conductive region 124 and the first photoelectric conversion section 110, respectively, the present invention is not limited thereto. Such a junction layer 110a may have a thin thickness, and as an example, may have a thickness thinner than that of the electrode layers 420 and 440, thereby allowing smooth tunneling of carriers.

[0058] The bonding layer 110a may be electrically connected to the first photoelectric conversion section 110 and the second photoelectric conversion section 120, and may include a material capable of transmitting light (for example, light having a long wavelength) used in the first photoelectric conversion section 110. As an example, the bonding layer 110a may include at least one of a plurality of materials, such as a transparent conductive material (for example, a transparent conductive oxide), a conductive carbon material, a conductive polymer, and 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, so that light (for example, light having a short wavelength) used in the second photoelectric conversion section 120 is reflected by the second photoelectric conversion section 120, and light (for example, light having a long wavelength) used in the first photoelectric conversion section 110 is transmitted through the first photoelectric conversion section 110 and supplied thereto.

[0059] The bonding layer 110a is formed to have the same area as the second photoelectric conversion section 120, and the area of ​​the first photoelectric conversion section 110 formed thereon is smaller than the area of ​​the bonding layer 110a.

[0060] Therefore, due to the difference in area between the second photoelectric conversion section 120 and the first photoelectric conversion section 110, an end difference is formed around the first photoelectric conversion section 110, thereby forming an end difference region SA that exposes the underlying bonding layer 110a.

[0061] The above-mentioned end difference area SA may be formed at two ends in a direction parallel to the cutting area NA in the central area, with the cutting area NA as the center.

[0062] Specifically, the end difference region SA may be formed on one side of the pad on which each unit solar cell AA1, AA2 may be formed when cutting the solar cell 10 into two solar cell regions AA1, AA2, and may correspond to two side surfaces of the solar cell 10 before cutting.

[0063] When the first photoelectric conversion section 110 is formed on the second photoelectric conversion section 120 by a deposition process, the two sides of the solar cell 10 as described above are limited to position the 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 in an area above the semiconductor substrate 122.

[0064] Therefore, when a cutting area NA is formed in the central region of the solar cell 10 in the longitudinal direction, the fixing portion of the deposition device is located within the end difference areas SA formed on the two side surfaces of the solar cell 10 in the longitudinal direction.

[0065] Therefore, the above-mentioned end difference region SA may be formed in the bonding layer 110a, and the first photoelectric conversion unit 110 including the photoelectric conversion layer 112 containing a perovskite compound may be positioned. The first photoelectric conversion unit 110 is also formed in a limited manner on the bonding layer 110a, thereby maintaining the end difference region SA, thereby maintaining a constant difference in area between the second photoelectric conversion unit 120 and the first photoelectric conversion unit 110.

[0066] 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 between the junction layer 110a and the photoelectric conversion layer 112 on one side of the photoelectric conversion layer 112, and a first transport layer (first carrier transport layer) 114 located between the photoelectric conversion layer 112 and the first electrode 42 on the other side of the photoelectric conversion layer 112.

[0067] The second transport layer 116 located on the junction layer 110a is a layer that extracts and transports second carriers (holes, as an example) according to the band gap relationship with the photoelectric conversion layer 112. As an 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.

[0068] 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 is excited by light to form carriers (electrons and holes). 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 have a perovskite structure such as CH3NH3PbI3, ... 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) Or, a compound in which A of AMX3 is partially doped with Cs may be included. However, the present invention is not limited thereto, and a plurality of kinds of materials may be used as the photoelectric conversion layer 112.

[0069] 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.

[0070] As an example, the photoelectric conversion layer 112 may be formed to have a predetermined thickness of 400 nm to 800 nm or more, but is not limited thereto.

[0071] 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 is maintained in the stacking direction, and the region from the region in contact with the second transport layer 116 to the region in contact with the first transport layer 114 can all be formed to have a perovskite structure.

[0072] 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 caused by the remaining basic material layer is eliminated, thereby ensuring photoelectric efficiency and allowing the formation of a thick film over a large area.

[0073] 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.

[0074] The first electrode 42 may be located on the first photoelectric conversion unit 110 (for example, 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, 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 type 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.

[0075] In this embodiment, the first photoelectric conversion section 110 has a larger band gap than the second photoelectric conversion section 120. That is, the first photoelectric conversion section 110 has a relatively large band gap, absorbs short wavelengths having relatively small wavelengths, and generates photoelectric conversion by utilizing the same, and the second photoelectric conversion section 120 has a lower band gap than the first photoelectric conversion section 110, and effectively absorbs long wavelengths having wavelengths larger than that of light used in the first photoelectric conversion section 110, and generates photoelectric conversion by utilizing the same.

[0076] More specifically, when light is incident through the front surface of the solar cell 10, the first photoelectric conversion section 110 absorbs the short wavelength light to generate electrons and holes by photoelectric conversion. At this time, the first carriers (electrons as an example) move to the first electrode 42 side and are collected, and the second carriers (holes as an example) move to the second electrode 44 side and are collected through the first photoelectric conversion section 110 and the second photoelectric conversion section 120. When the 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 by photoelectric conversion. At this time, the first carriers (electrons as an example) move to the first electrode 42 side and are collected through the first photoelectric conversion section 110, and the second carriers (holes as an example) move to the second electrode 44 side and are collected.

[0077] As described above, in this embodiment, since light having a plurality of wavelengths can be used for a plurality of photoelectric conversion units 110 and 120, the efficiency of the solar cell 10 can be significantly improved. In particular, in this embodiment, the first photoelectric conversion unit 110 based on a perovskite compound and the second photoelectric conversion unit 120 having a heterojunction structure are provided to improve a plurality of characteristics. As an example, the first photoelectric conversion unit 110 and the second photoelectric conversion unit 120 may both be formed in a low-temperature process, and since the process temperatures are similar, the temperature range can be easily adjusted, and therefore, there is process compatibility. In addition, since the first photoelectric conversion unit 110 and the second photoelectric conversion unit 120 each have an excellent open circuit voltage, the efficiency of the solar cell 10 having a series connection type structure can be significantly improved. A plurality of types of structures may be applied as the second photoelectric conversion unit 120, and various other modifications are also possible.

[0078] 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).

[0079] The first electrode 42 may include a first electrode layer 420 and a second electrode layer 422a, 422b sequentially stacked on the photoelectric conversion units 110, 120. As an 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). The entire formation may include a case where the first photoelectric conversion unit 110 is entirely covered when there is no blank space or blank area, and a case where a part of the first photoelectric conversion unit 110 is inevitably not formed. 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 the resistance in the horizontal direction.

[0080] As described above, the first electrode layer 420 may be formed on 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, and thus can transmit light and easily move carriers. As a result, the first electrode layer 420 is formed on the entire first photoelectric conversion unit 110 and does not block the transmission of light. As an example, the first electrode layer 420 may include a transparent conductive material (e.g., a transparent conductive oxide, for example, indium tin oxide (ITO), etc.), carbon nanotubes (CNTs), etc. However, the present invention is not limited thereto, and the first electrode layer 420 may include a plurality of other types of materials.

[0081] The second electrode layers 422a, 422b may be formed on (for example, in contact with) the first electrode layer 420. The second electrode layers 422a, 422b may be made of a material having a higher electrical conductivity than the first electrode layer 420. This can further improve characteristics such as carrier collection efficiency and resistance reduction based on the second electrode layers 422a, 422b. For example, the second electrode layers 422a, 422b 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.

[0082] As described above, the second electrode layers 422a and 422b are opaque or have low transparency, which prevents the light from entering, and therefore, by having a predetermined pattern, it is possible to minimize shading loss, thereby allowing the light to enter the areas where the second electrode layers 422a and 422b are not formed.

[0083] In this embodiment, the second electrode layers 422a, 422b 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.

[0084] The deposition process for forming the second electrode layers 422a and 422b may be performed by vacuum deposition, sputtering, or electroplating. In this case, the second electrode layers 422a and 422b formed by deposition may be formed to a thickness of 5 μm or less.

[0085] The second electrode layers 422a, 422b may have a multi-layer structure, but are not limited to this.

[0086] 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.

[0087] Since 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, the description thereof may be applied as is.

[0088] As shown in FIG. 3, side insulating layers 130a and 130b are formed in the end difference regions SA formed on both sides of the first photoelectric conversion section 110. As shown in FIG.

[0089] The side insulating layers 130a and 130b may be formed to have a thickness similar to or greater than a height h1 from the top of the bonding layer 110a to the top of the first photoelectric conversion section 110 (i.e., the thickness of the first photoelectric conversion section 110). Preferably, the height of the side insulating layers 130a and 130b may be 10 nm to 1 μm.

[0090] The side insulating layers 130a, 130b are similarly formed in the two end difference regions SA, so that the two side surfaces of one solar cell 10 are formed to have a bar-type shape extending in the longitudinal direction, and the first photoelectric conversion section 110 may be arranged in the space formed by the two side insulating layers 130a, 130b on the two side surfaces.

[0091] The side insulating layers 130a, 130b may be formed by atomic deposition, chemical deposition or physical deposition, but are not limited thereto. The width W1 of the side insulating layers 130a, 130b has a desired small characteristic, but according to the necessity, the width W1 of the side insulating layers 130a, 130b on one side can satisfy 0.1 mm to 3.0 mm, and can be adjusted according to the size of the fixing part of the deposition equipment.

[0092] The side insulating layers 130a and 130b may be made of a compound containing an oxide, and may be made of SiC, SiN, or the like, for example.

[0093] 1 and 2 again, in plan view, the solar cell 10 of this embodiment does not form the second electrode layers 422a, 422b, 442a, 442b of the first electrode 42 and the second electrode 44 in the cutting area NA located in the central region. The layer structures of the first photoelectric conversion section 110 and the second photoelectric conversion section 120 may all be maintained in the cutting area NA.

[0094] As described above, since the second electrode layers 422a, 422b, 442a, 442b are not present in the cutting region NA, the lower first electrode layers 420, 440 may be exposed in the cutting region NA, and if the second electrode layers 422a, 422b, 442a, 442b are exposed to additionally form a passivation (not shown), the passivation may be exposed.

[0095] Other than the fact that the electrodes 42 and 44 are not formed, the cut area NA has a structure similar to that of the solar cell areas AA1 and AA2, and therefore a detailed description thereof will be omitted.

[0096] As shown in FIG. 1, the cut area NA formed in the central area on the front surface of one solar cell 10 may be formed in a bar shape extending in the length direction and satisfy the second width W2.

[0097] In this case, the end difference regions SA formed on the two side surfaces may extend in the longitudinal direction parallel to the cutting region NA, and each end difference region SA may have a first width W1, and the first width W1 may be smaller than the second width W2.

[0098] The solar cell 10 according to this embodiment may be separated into a plurality of unit solar cells AA1, AA2 by cutting along a cutting region NA. As described above, when the solar cell 10 is separated into two unit solar cells AA1, AA2, it is possible to reduce the output loss (CTM loss, cell to module loss) that occurs when the plurality of unit solar cells AA1, AA2 are connected to manufacture a solar cell module.

[0099] To explain the above in more detail, the output loss has a value obtained by multiplying the resistance by the square of the current in each solar cell 10, and in a solar cell module including a plurality of solar cells 10, the output loss has a value obtained by multiplying the resistance by the square of the current in each solar cell 10, and the value multiplied by the number of solar cells 10. However, as for the current of each solar cell 10 generated by the area of ​​the solar cell 10 itself, when the area of ​​the solar cell 10 becomes larger, the current also becomes larger, and when the area of ​​the solar cell 10 becomes smaller, the current also becomes smaller.

[0100] In the present embodiment, when a plurality of unit solar cells AA1 and AA2 are manufactured by cutting the solar cell 10 and then connected, the current is reduced in proportion to the area, and the number of unit solar cells AA1 and AA2 is increased inversely. For example, when one cutting region NA is installed and there are two solar cell regions AA1 and AA2, the current in each solar cell region AA1 and AA2 is reduced to half the current of the solar cell 10, and the number of unit solar cells AA1 and AA2 is twice that of the solar cell 10. As described above, since the current is reflected in the square value and the number is reflected as it is in the output loss, when the current is reduced to half and the number is doubled, the output loss value is reduced to half. As a result, when a solar cell module is manufactured by cutting the solar cell 10 into a plurality of unit solar cells AA1 and AA2 as in the present embodiment, the output loss of the solar cell module can be reduced.

[0101] In this embodiment, when manufacturing and cutting the series-connected solar cells 10 to reduce the area of ​​the unit solar cells AA1 and AA2, the series-connected solar cells 10 can be manufactured and cut by using the same design optimized by conventional equipment. This minimizes the burden on the equipment and process costs. Conversely, when manufacturing the solar cells 10 by reducing the dimensions themselves, there is a burden such as the need to replace the equipment used or change the installation.

[0102] As described above, in this embodiment, the solar cell 100 is cut to produce a plurality of unit solar cells AA1 and AA2.

[0103] At this time, by not forming the second electrode layers 422a, 422b, 442a, 442b in the cutting area NA, efficiency reduction and defects that may occur in the cutting process are prevented, and the shunt path based on the second electrode layers 422a, 422b, 442a, 442b as highly conductive materials is blocked.

[0104] This can minimize problems that may occur in the cutting process, and further ensure that the unit solar cells AA1 and AA2 have excellent efficiency, performance and reliability.

[0105] In this embodiment, the cutting region NA may be formed in one direction (length direction) across the central region of the solar cell 10. That is, on the plane, the cutting region NA may be formed so as to connect two opposing edge portions of the semiconductor substrate 122.

[0106] Next, by cutting along the cutting regions NA, the solar cell regions AA1, AA2 can be separated independently from each other, and the area of ​​the cutting regions NA can be minimized while the cutting regions NA can be stably formed.

[0107] In this case, the cut region (201) may have a shape extending along the longitudinal direction as the first direction (the up-down direction in the drawing), and each of the solar cell regions AA1, AA2 may extend along the first direction and be separated from each other by the cut region NA.

[0108] For the sake of easy description and illustration, this embodiment illustrates a case where two solar cell areas AA1 and AA2 are installed, and one cutting area NA is positioned between the two solar cell areas AA1 and AA2, because each solar cell area AA1 and AA2 has essentially the same area and thus has similar electrical properties.

[0109] However, the present invention is not limited to this. Therefore, the number of cutting areas NA may be two or more, and the number of solar cell areas AA1, AA2 may be one more than the number of cutting areas NA.

[0110] The cutting region NA may have a second width W2 that does not affect the electrodes 42, 44 formed in the region other than the cutting region NA during the cutting process. As an example, the second width W2 of the cutting region NA may be 0.3 mm to 1 mm. If the second width W2 of the cutting region NA is less than 0.3 mm, the electrodes 42, 44 located in the solar cell regions AA1, AA2 may melt or cause problems due to scattering materials during the cutting process. If the second width W2 of the cutting region NA exceeds 1 mm, the area of ​​the emission region 20 may be insufficient, and the efficiency of the solar cell 100 or the unit solar cells 110a, 120a may decrease. However, the present invention is not limited thereto, and the second width W2 of the cutting region NA may have multiple values.

[0111] The shapes of the first electrode 42 and the second electrode 44 based on the cutting area NA will be described in more detail.

[0112] Below, we will explain as an example the case where one cutting area NA is installed, and the solar cell areas AA1 and AA2 are provided with a first solar cell area AA1 located on one side of the cutting area NA and a second solar cell area AA2 located on the other side of the cutting area NA.

[0113] 1, the first photoelectric conversion unit 110 and its first electrode 42 are positioned on the front surface of the solar cell 10 according to this embodiment. At this time, the second electrode layers 422a, 422b of the first electrode 42 are not formed in the cutting area NA, and are positioned to correspond to each of the solar cell areas AA1, AA2.

[0114] The first electrode 42 and the second electrode 44 are formed throughout the entire area other than the cutting area NA, and the layer structure of the first photoelectric conversion section 110 and the second photoelectric conversion section 120 between the first electrode 42 and the second electrode 44 is formed throughout.

[0115] Next, maximizing the area of ​​the first photoelectric conversion section 110 and the second photoelectric conversion section 120 that constitute the emission region can help improve the photoelectric conversion efficiency of the solar cell 10 or unit solar cells AA1 and AA2.

[0116] The second electrode layers 422a, 422b of the first electrode 42 connected to the first photoelectric conversion unit 110 may be included in a plurality of bus bar electrodes 422a, 422b spaced apart from each other with a predetermined interval w3. The drawings show an example in which the bus bar electrodes 422a, 422b are parallel to each other and to one edge of the semiconductor substrate 122, but the present invention is not limited to this.

[0117] At this time, the bus bar electrode 422a formed in the first solar cell area AA1 and the bus bar electrode 422b formed in the second solar cell area AA2 are separated from each other at the cutting area NA.

[0118] The bus bar electrodes 422a, 422b in each of the solar cell areas AA1, AA2 may be formed in parallel to each other in the first direction, and one ends of the bus bar electrodes 422a, 422b may be connected to each other.

[0119] Specifically, as shown in FIG. 1, a plurality of busbar electrodes 422a formed in the first solar cell area AA1 may be connected to each other on a first side insulating layer 130a formed in an end difference area SA, one end of which is one end of the first solar cell area AA1.

[0120] As described above, the connection portions of the multiple bus bar electrodes 422a formed on the first side insulating layer 130a may be used as pad portions 14a, and may have a rod-like shape extending in the first direction parallel to the cutting area NA.

[0121] One second electrode layer 422a formed in the first solar cell area AA1 includes a plurality of bus bar electrodes 422a extending from a pad portion 14a formed on the first side insulating layer 130a and extending in a second direction perpendicular to the first direction.

[0122] At this time, the pad portion 14a formed on the side insulating layer 130a may be formed as a unit pad cluster separated from each other by unit pads (not shown) to which one ends of a predetermined number of bus bar electrodes 422a are connected, but is not limited thereto.

[0123] Therefore, one second electrode layer 422a formed in the first solar cell area AA1 may have a plurality of bus bar electrodes 422a extending from a pad portion 14a formed on the first side insulating layer 130a and extending in a second direction perpendicular to the first direction, and the shape of the second electrode layer 422a may be formed as a comb shape in which the plurality of bus bar electrodes 422a extend from the pad portion 14a.

[0124] In this case, the width of the pad portion 14a may be greater than the width of the bus bar electrode 422a, and may be smaller than the interval w3 between adjacent bus bar electrodes 422a.

[0125] The pad portion 14a as described above may be used as a region for electrically and physically connecting the adjacent unit solar cells AA1 and AA2.

[0126] In addition, the shape of the second electrode layer 422b formed on the second solar cell area AA2 may be formed as a comb shape in which multiple bus bar electrodes 422b extend in a second direction perpendicular to the first direction from a pad portion 14b formed on the second side insulating layer 130b.

[0127] In fact, the shape of the second electrode layer 422a on the first solar cell area AA1 and the shape of the second electrode layer 422b on the second solar cell area AA2 may be formed symmetrically to each other with respect to the cutting area NA, and both of their dimensions and shapes may be symmetrical.

[0128] Here, each second electrode layer 422a, 422b may further include a boundary electrode (not shown) that is continuously formed along the edge of each solar cell area AA1, AA2 to connect the ends of the multiple busbar electrodes 422a, 422b within each solar cell area AA1, AA2.

[0129] As described above, when the boundary electrodes are provided, carriers can be effectively collected at the portions located at the edges of the solar cell areas AA1 and AA2. However, the present invention is not limited to this, and the boundary electrodes are not essential.

[0130] Referring to FIG. 2, the second electrode 44 is located on the other surface (more specifically, the back surface) of the solar cell 10 according to this embodiment.

[0131] At this time, the second electrode 44 is also not formed in the cutting area NA, and is positioned so as to correspond to each of the solar cell areas AA1 and AA2.

[0132] In this embodiment, a case where a single cutting area NA is provided and two solar cell areas, a first solar cell area AA1 and a second solar cell area AA2, are provided is illustrated.

[0133] In this embodiment, the second electrode 44 connected to the second photoelectric conversion unit 110 on the back surface may be formed in a single surface shape (planar type) that covers the entire back surface.

[0134] That is, the second electrode layers 442a, 442b of the second electrode 44 may be formed entirely in the area other than the cutting area NA, and have a back surface area corresponding to the end difference area SA.

[0135] Therefore, the rear surface may be separated into two second electrode layers 422a, 422b to form an end covering the front pad portions 14a, 14b to the bus bar electrodes 422a, 422b. As described above, the two separated second electrode layers 422a, 422b may have shapes that are symmetrical to each other with respect to the cutting area NA, like the second electrode layers 422a, 422b of the first electrode 42. The materials of the second electrode layers 442a, 442b have been described above, so a detailed description will be omitted here.

[0136] 1 and 2, for each solar cell region AA1, AA2, the second electrode layers 422a, 422b of the first electrode 42 formed on the front side are formed to have a comb shape, and the second electrode layers 442a, 442b of the second electrode 44 formed on the back side are formed to have a single surface shape in each solar cell region AA1, AA2. However, the present invention is not limited to this, and the planar shapes of the first electrode 42 and the second electrode 44 may be the same, and various other modifications may also be made.

[0137] The solar cell 10 formed as described above has solar cell regions AA1 and AA2 constituting two unit solar cells AA1 and AA2 arranged on either side of the cutting region NA in the central region within one solar cell 10, and further the outermost electrode layers 422a, 422b, 442a, 442b of the first electrode 42 and the second electrode 44 are formed symmetrically.

[0138] The present invention is directed to cutting the series-connected solar cells shown in FIGS. 1 to 3, and the manufacturing method thereof will be described in detail below.

[0139] Hereinafter, a method for manufacturing a unit solar cell according to the first embodiment of the present invention will be described with reference to Figs. 4 to 10b.

[0140] Fig. 4 is a sequence diagram for manufacturing a solar cell according to one embodiment of the present invention, and Fig. 5a to Fig. 10b are process diagrams for manufacturing a solar cell according to one embodiment of the present invention, where in each figure, a is mostly a plan view of the solar cell at each step, and b is mostly a cross-sectional view of the solar cell at each step.

[0141] 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 side insulating layer (S20), a step of forming a first photoelectric conversion unit (S30), a step of forming a first electrode and a second electrode (S40), a two-stage cutting step (S50), and a modularization step (S60), which will be described in more detail.

[0142] 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, a first conductive region 124, and a second conductive region 126 is formed from a semiconductor substrate 122.

[0143] First, a semiconductor substrate 122 is manufactured, which is configured as a base region having a first or second conductive type dopant. At this time, at least one of the front and back surfaces of the semiconductor substrate 122 may be patterned to have unevenness so as to have an anti-reflection structure. Wet or dry patterning may be used to pattern the surface of the semiconductor substrate 122. 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 cuts the surface of the semiconductor substrate 122 using a diamond grid or a laser, etc., and can uniformly form unevenness, but the process time is long and there is a risk of damaging the semiconductor substrate 122. In addition, the semiconductor substrate 122 may be patterned using reactive ion etching (RIE) or the like. As described above, the semiconductor substrate 122 may be patterned using a number of methods in the present invention.

[0144] Next, conductive regions 124, 126 are formed on the surface of the semiconductor substrate 122. More specifically, a first passivation film and a first conductive region 124 are formed on the front surface of the semiconductor substrate 122, and a second passivation film and a second conductive region 126 are formed on the back surface of the semiconductor substrate 122.

[0145] The conductive regions 124, 126 may be formed by thermal growth techniques, deposition techniques (e.g., chemical vapor deposition (CVD), atomic layer deposition (ALD)), low pressure chemical vapor deposition (LPCVD), etc., although the invention is not limited thereto.

[0146] The dopants of the first or second conductivity type may be simultaneously included in 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.

[0147] Next, as shown in FIG. 5b, a protective layer is formed on the second conductive region 126. At this time, in this embodiment, the first electrode layer 440 of the second electrode 44 may be formed on the second conductive region 126 as a protective layer. Such a first electrode layer 440 may function as a protective layer that performs a protective function of the second conductive region 126 on the second conductive region 126 in the manufacturing process, and may remain as it 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 unit 110 is formed, and is used as a protective layer, thereby simplifying the process. However, the present invention is not limited to this, and the first electrode layer 440 may be formed in a state where different protective layers of the first electrode layer 440 are formed separately and removed or not removed.

[0148] 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 on one side or the other side. However, the present invention is not limited thereto, and multiple methods such as a coating method may be applied.

[0149] Next, the bonding layer 110a is formed on the second photoelectric conversion section 120. More specifically, the bonding layer 110a may be formed on the entire 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 the bonding layer 110a may be formed only on the second conductive region 124 as a one-sided process. However, the present invention is not limited thereto, and multiple methods such as a coating method may be applied.

[0150] Next, as shown in FIGS. 6a and 6b, side insulating layers 130a and 130b (S20) are formed on two side surfaces of the adhesive layer 110a.

[0151] First, as shown in Fig. 6a, the solar cell 10 is mounted in a deposition apparatus, and then a mask 200 is attached to the front of the solar cell, exposing two side surfaces and covering a central region of the solar cell 10. The mask 200 may be, but is not limited to, a mask 200 made of carbide, nitride, etc.

[0152] After aligning the solar cell 10 so as to cover the central region thereof, side insulating layers 130a and 130b are deposited on the exposed side surfaces.

[0153] In this case, the deposition device may apply a number of methods such as atomic deposition, physical deposition, and chemical deposition, and further, an oxide such as SiO2, or a carbide or nitride such as SiC or SiN may be applied to the side surface.

[0154] At this time, the thickness H1 of the formed side insulating layers 130a, 130b can satisfy 10 nm to 1 μm, and may be formed to be similar to or thicker than the subsequently formed first photoelectric conversion section 110. Furthermore, the width W1 of each side insulating layer 130a, 130b can satisfy 0.1 to 0.3 mm, and may correspond to the contact area for fixing the solar cell 10 in a fixing section of a deposition apparatus.

[0155] Therefore, the width W1 of the side insulating layers 130a and 130b may be adjusted according to desired conditions, but essentially not to exceed 0.3 mm.

[0156] As described above, by minimizing the area occupied by the side insulating layers 130a, 130b, the area for photoelectric conversion can be maximized, and by ensuring the junction between the fixing part of the deposition device and the solar cell 10 in the insulating layer, it is possible to prevent damage to the active region that comes into physical contact during fixing.

[0157] As described above, when the side insulating layers 130a, 130b are respectively formed on the two side surfaces of the adhesive layer 110a of the solar cell 10, the mask 200 is removed as shown in FIG. 6b, and a groove 131 as a space between the side insulating layers 130a, 130b on the two side surfaces is exposed as shown in FIG. 6c.

[0158] Next, as shown in FIGS. 7a and 7b, the first photoelectric conversion section 110 is formed (S30).

[0159] 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 only in the groove 131 between the side insulating layers 130a and 130b.

[0160] More specifically, in a deposition apparatus, the second transport layer 116, the photoelectric conversion layer 112, and the first transport layer 114 may be formed sequentially on the bonding layer 110a in the groove 131 with the legs of the fixing part of the deposition apparatus fixed to the upper parts of the side insulating layers 130a, 130b.

[0161] The second transport layer 116, the photovoltaic layer 112, and the first transport layer 114 may be formed by deposition (eg, physical deposition, chemical deposition, etc.).

[0162] 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.

[0163] 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 only on the front surface as one side. However, the present invention is not limited thereto, and multiple methods such as a coating method may be applied.

[0164] In addition, this embodiment illustrates a case where 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, or may be formed before or after the first electrode layer 420 of the first electrode 42 is formed. Various other modifications are possible.

[0165] 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 layers 422a and 422b of the first electrode 42 will be described as being formed as a single layer, but they may be formed as a multi-layer structure instead.

[0166] 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.

[0167] First, a deposition process is carried out to form the second electrode layers 422a, 422b, 442a, and 442b of the first electrode 42 and the second electrode 44, as shown in FIG. 8a.

[0168] At this time, as a deposition process, sputtering, vacuum deposition or plating (electroplating) can be applied in a number of ways.

[0169] As an example, when forming a sputtering layer by sputtering, the process temperature for forming the second electrode layers 422a, 422b, 442a, 442b may be 150° C. or less (100° C. to 145° C. as an example), and the second electrode layers 422a, 422b, 442a, 442b can have a desired pattern by forming the second electrode layers 422a, 422b, 442a, 442b by sputtering in a state where a mask or mask layer is placed. Also, the second electrode layers 422a, 422b, 442a, 442b may further include an additional conductive layer formed by sputtering or electroplating (electrolytic plating as an example) on the sputtering layer formed by sputtering. Moreover, the second electrode layers 422a, 422b, 442a, 442b of the first electrode 42 or the second electrode 44 according to this embodiment may be formed by a plurality of processes carried out at 150° C. or less.

[0170] At this time, as shown in FIG. 8b, the second electrode layers 422a, 422b of the first electrode 42 formed have two comb shapes formed symmetrically with respect to the cutting area NA, and the second electrode layers 442a, 442b of the second electrode 44 have two surface shapes that open the cutting area NA and are separated from each other.

[0171] Therefore, on the front surface of the solar cell 10, pad portions 14a, 14b are formed on side insulating layers 130a, 130b, and a plurality of bus bar electrodes 422a, 422b are formed extending from the pad portions 14a, 14b toward the cutting area NA, and on the underside of the solar cell 10, second electrode layers 442a, 442b of a second electrode 44 having a single surface shape are formed so as to correspond to the entire area from the pad portions 14a, 14b to where the bus bar electrodes 422a, 422b are formed.

[0172] In this embodiment, in a solar cell 100 in which a first photoelectric conversion unit 110 containing a perovskite compound is installed, after forming the second electrode layers 422a, 422b, 442a, 442b by a deposition process, a coating layer may be further formed thereon to ensure a filling rate as well as 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).

[0173] When the first electrode 42 and the second electrode 44 are formed as described above, the solar cell shown in Fig. 9 is formed. The solar cell 10 in Fig. 9 is formed to have the front and back shapes shown in Figs.

[0174] Next, cutting of the solar cell 10 into a plurality of unit solar cells AA1, AA2 is carried out along cutting region NA.

[0175] As shown in Figure 10a, by cutting the solar cell 10 along cutting lines CL within cutting area NA of the solar cell 10 having the above structure, multiple unit solar cells AA1, AA2 corresponding to multiple solar cell areas AA1, AA2, respectively, can be formed, as shown in Figure 10b.

[0176] As an example, a two-step cutting method such as laser processing and mechanical processing may be applied as a method for cutting the cutting area NA.

[0177] In a basic manner, in the laser processing, a laser is irradiated onto the cutting area NA to melt that portion, thereby cutting the solar cell 10 to a predetermined depth.

[0178] Cutting is performed on the rear surface of solar cell 10 based on cutting depth d1 of the laser processing described above, and is performed up to the central region of semiconductor substrate 122 of second photoelectric conversion section 120 on the rear surface of solar cell 10.

[0179] Therefore, since laser irradiation by laser processing is not performed on the first photoelectric conversion section 110, it is possible to prevent the perovskite compound from being damaged by the laser.

[0180] Secondly, after the laser cutting, a physical impact is applied to the substrate that has been mechanically cut down to the central region of the semiconductor substrate 122 to cut it all the way through.

[0181] At this time, a clean machined surface can be obtained even within the narrow cutting area NA, and secondary processing of laser drawing and machining can be performed if the perovskite layer is not damaged.

[0182] Thus, in the unit solar cells AA1 and AA2 formed, the semiconductor substrate 122 has a major axis and a minor axis. In general, the solar cell 10 is manufactured from an ingot of the semiconductor substrate 122 having a substantially circular shape, and the lengths of the sides of two mutually perpendicular axes are similar or substantially similar to each other, such as a circle, a square, or a shape similar thereto. As an example, in this embodiment, the semiconductor substrate 122 of the solar cell 10 may have a square shape, an octagonal shape having inclined sides at the four corners, or a plate shape having a rounded and chamfered curved surface. When it has such a shape, the semiconductor substrate 122 with the widest area can be obtained from the ingot. Thus, the solar cell 10 has horizontal and vertical axes with the same distance.

[0183] In this embodiment, such solar cell 10 is cut along cutting area NA to form unit solar cells AA1 and AA2, so that semiconductor substrates 122 of unit solar cells AA1 and AA2 have a shape including a major axis and a minor axis.

[0184] 10a, each of the unit solar cells AA1 and AA2 includes a first long side and a second long side that are parallel to each other and a first short side and a second short side that are parallel to each other and that are parallel to each other and a short axis that intersects with the long axis, where one of the long sides is an edge portion formed by cutting along a cutting line CL.

[0185] The other of the long sides is an edge where the side insulating layers 130a, 130b are formed, and where the pads 14a, 14b are formed.

[0186] In order to form the unit solar cells AA1 and AA2 by cutting the cutting region NA, an edge portion having a width W3 that is approximately half the width W2 of the cutting region NA is formed on one edge of the unit solar cells AA1 and AA2 as shown in Fig. 11. Such an edge portion is positioned along one of the long sides. As a result, the electrodes 42 and 44 are not formed on the edge portion formed by cutting the cutting region NA.

[0187] As described above, in the unit solar cells AA1 and AA2, the two long sides may be formed asymmetrically to each other, but the two short sides may be formed symmetrically to each other, and the two unit solar cells AA1 and AA2 formed by cutting have the same shape.

[0188] As described above, a plurality of unit solar cells AA1, AA2 formed by cutting one solar cell 10 have the cross section shown in FIG. 11, and can be modularized into a plurality of forms on glass.

[0189] Also, in the first electrode 42 and the second electrode 44, the second electrode layers 422, 442 on the first electrode layer 440 may have the shapes shown in Figures 12a and 12b.

[0190] FIG. 12a is a plan view showing a solar cell according to another embodiment of the present invention, and FIG. 12b is a rear view showing a solar cell according to another embodiment of the present invention.

[0191] Referring to FIG. 12a, the first electrode 42 may be connected to bus bar electrodes 422a, 422b, and may be formed into a plurality of finger electrodes 423a, 423b arranged in a crossing direction.

[0192] In this case, the width of the busbar electrodes 422a, 422b may be greater than the width of the finger electrodes 423a, 423b, but the present invention is not limited to this. Therefore, the width of the busbar electrodes 422b, 422b may be the same as or smaller than the width of the finger electrodes 423a, 423b.

[0193] Since the cutting area NA is positioned in the first direction across the semiconductor substrate 122 in a direction intersecting with the bus bar electrodes 422a, 422b, the finger electrodes 423a, 423b are arranged parallel to the cutting area NA, thereby allowing sufficient current to flow.

[0194] As described above, when the cutting region NA is arranged so as to intersect with the busbar electrodes 422a, 422b and is arranged so as to be parallel to the finger electrodes 423a, 423b, the area of ​​the busbar electrodes 422a, 422b can be reduced while ensuring the amount of current.

[0195] At this time, boundary electrodes may be formed that are connected to the finger electrodes 423a and 423b and define the solar cell areas AA1 and AA2, but are not limited thereto.

[0196] As described above, when the boundary electrodes are provided, carriers can be effectively collected at the portions located at the edges of the solar cell areas AA1 and AA2. However, the present invention is not limited to this, and the boundary electrodes are not essential.

[0197] Furthermore, as shown in FIG. 12b, the second electrode layers 443a, 443b formed on the back surface of the solar cell 10 may include pad portions 15a, 15b formed in the end difference region SA, and a plurality of bus bar electrodes 443a, 443b extending from the pad portions 15a, 15b toward the cutting region NA.

[0198] That is, the second electrode layers 422a and 422b of the first electrode 42 in Fig. 1 may have the same shape as the second electrode layers 422a and 422b, and may further include a plurality of finger electrodes (not shown) spaced apart from each other at a predetermined interval. That is, although the finger electrodes are not shown in the drawings, the case where the finger electrodes can be formed is not excluded.

[0199] As described above, in this embodiment, since 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 sides of the semiconductor substrate 122. This can help to 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 thereto.

[0200] Hereinafter, a solar cell module 100 provided by arranging unit solar cells AA1 and AA2 (hereinafter, unit solar cells are denoted by reference symbol 10') in FIG. 11 in a number of ways will be described.

[0201] Figure 13 is a plan view of a solar cell module according to one embodiment of the present invention, Figure 14 is a cross-sectional view of the solar cell module in Figure 13 cut along VII-VII', Figure 15 is a plan view of part A in Figure 14, and Figure 16 shows a cross-sectional view of the solar cell module when the unit solar cell is the one in Figures 12a and 12b.

[0202] 13 to 15, in a solar cell module 100 according to one embodiment of the present invention, a plurality of series-connected unit solar cells 10' are arranged in rows and columns by connection pads 20 and are electrically connected to each other.

[0203] A plurality of series-connected unit solar cells 10 ′ are connected in a row direction by connection pads 20 to form a string, and a plurality of strings are connected to each other to form a solar cell module 100 .

[0204] Taking into consideration the adhesion between the electrodes and the connection pads 20 and the charge collection efficiency, etc., one connection pad 20 is used to connect adjacent series-connected unit solar cells 10' to each other so that the power generation efficiency of the solar cell can be optimized.

[0205] That is, the connection pad 20 contacts the entire second electrode 44 formed on the back surface of the first unit solar cell of two adjacent series-connected unit solar cells 10', and contacts the pad portion 14a of the first electrode 42 formed on the front surface of the second unit solar cell adjacent to the first unit solar cell. Similarly, the other connection pad 20 contacts the entire second electrode 44 of the second unit solar cell, and contacts the pad portion 14a of the first electrode 42 of the third unit solar cell adjacent to the second unit solar cell. At this time, the connection pad 20 and the pad portion 14a are joined in a manner that overlaps with more than 1 / 2 and less than 1 of the pad portion 14a, so that the connection pad 20 does not extend through the pad portion 14a and away from the end difference region SA. Therefore, the first photoelectric conversion portion 110 is not covered with the connection pad 20, and thus 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.

[0206] Also, the sleeve rod 21 connects the connection pad 20 connected to one end of the string in the first row to the connection pad 20 connected to one end of the string in the second row. Similarly, the other sleeve rod 21 connects the wiring connected to the other end of the string in the second row to the connection pad 20 connected to the other end of the string in the third row. Meanwhile, all the series-connected unit solar cells 10' constituting the solar cell module 100 are connected in series to 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 with the front substrate 50 and the back substrate 60 in a state where it is disposed between them to realize integration.

[0207] The front substrate 50 is positioned on the front side (the light receiving surface into which light enters) of the solar cell 10 and is made of a hard material that does not have flexibility in order to protect it from impact. As an example, the front substrate 50 may be made of tempered glass having high transmittance and excellent breakage prevention function.

[0208] The rear substrate 60 is positioned on the rear surface (non-light receiving surface) of the solar cell, and is 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 from penetrating from the rear surface. The rear substrate 60 may have a multi-layer structure including a layer for preventing the penetration of moisture and oxygen gas, and a layer for preventing chemical corrosion, and may be configured as a thin piece made of insulating material such as fluoropolymer (FP) or polyester (PE).

[0209] The front package 30 is manufactured to have a thickness that completely embeds the connection pads 20 so that the rigid front substrate 50 is not subjected to physical shock due to the connection pads 20 .

[0210] The back package 40 is located between the back substrate 60 and the back surface of the unit solar cell 10' and is made of a transparent material that transmits light. The back package 40 also uses a resin product such as ethylene vinyl acetate (EVA) that can absorb shock, thereby preventing the penetration of moisture and protecting the solar cell 10' from the effects of shock. The back package 40 is also configured to include a material that absorbs ultraviolet rays to prevent deterioration, whereas the front package 30 does not include an ultraviolet absorbing agent so that all light can be transmitted, thereby improving the development efficiency of the series-connected unit solar cell 10'.

[0211] Also, when the unit solar cells 10' are as in FIGS. 12a and 12b, the solar cell module 100 may have the arrangement shown in FIG.

[0212] In a solar cell module 100 according to another embodiment of the present invention, a plurality of series-connected unit solar cells 10' are arranged in a matrix and electrically connected to each other by a plurality of wirings 22.

[0213] A plurality of series-connected unit solar cells 10 ′ are connected in the row direction by a plurality of wirings 22 to form a string, and the plurality of strings are connected to each other to form a solar cell module 100 .

[0214] Taking into consideration the adhesion between the electrodes and the wiring 22 and the charge collection efficiency, etc., multiple wirings 22 can be used to connect adjacent series-connected unit solar cells 10' to each other so that the power generation efficiency of the solar cell 10' can be optimized, and the number of wirings 22 is the same as the number of bus bar electrodes 422a, 422b.

[0215] That is, the wiring 22 is joined across pad portion 15a and bus bar electrode 443a of second electrode 44 formed on the back surface of the first unit solar cell in two adjacent series-connected unit solar cells 10', and is also joined across pad portion 14a and bus bar electrode 422a of first electrode 42 formed on the front surface of the second unit solar cell adjacent to the first unit solar cell. In addition, the wiring 21 is joined across pad portion 15a and bus bar electrode 443a of second electrode 44 of the second unit solar cell, and is also joined across pad portion 14a and bus bar electrode 422a of first electrode 42 of the third unit solar cell adjacent to the second unit solar cell. Thus, the unit solar cells arranged in one string are connected in series by multiple wirings 21.

[0216] Furthermore, the series-connected solar cell module formed by unit solar cells 10' may have the same shape as that shown in FIGS.

[0217] Hereinafter, a series-connected solar cell module 100 according to another embodiment of the present invention will be described with reference to FIGS.

[0218] FIG. 17 is a plan view of a solar cell module according to another embodiment of the present invention, FIG. 18 is an exploded perspective view of the solar cell module shown in FIG. 17, and FIG. 19 is a cross-sectional view of the solar cell module shown in FIG. 17.

[0219] A series-connected solar cell module 100' according to another embodiment of the present invention realizes a solar cell module by using the above-mentioned series-connected unit solar cell 10', and the series-connected solar cell module 100' will be described in detail below with reference to Figures 17 to 19.

[0220] In a solar cell module 100' according to another embodiment of the present invention, a plurality of series-connected unit solar cells 10' are stacked to overlap in a stepped manner. For example, in the case of a standard series-connected unit solar cell 10', the adjacent upper series-connected unit solar cell 10' and the adjacent lower series-connected unit solar cell 10' partially overlap the standard series-connected unit solar cell 10', while the upper series-connected unit solar cell 10' partially overlaps the upper part of the standard series-connected unit solar cell 10', and the lower series-connected unit solar cell 10' partially overlaps the lower part of the standard series-connected unit solar cell 10'.

[0221] In this specification, the terms "upper series-connected type unit solar cell 10'" and "lower series-connected type unit solar cell 10'" may refer to the series-connected type unit solar cell 10' arranged relatively lower and upper, respectively, based on any one of the plurality of series-connected type unit solar cells 10' arranged to partially overlap in a stepped manner as described above, and based on the reference series-connected type unit solar cell 10', the same series-connected type unit solar cell 10' may be an upper series-connected type unit solar cell 10' or a lower series-connected type unit solar cell 10'.

[0222] The series-connected unit solar cell 10' in this embodiment has an overlapping portion OP, and when adjacent series-connected solar cells 10 are overlapped by forming a series-connected solar cell module 100 described below in the overlapping portion OP, the region of the series-connected unit solar cell 10' corresponding to the overlapped section may be a first overlapping portion OP1 that overlaps with the adjacent upper series-connected unit solar cell 10', and a second overlapping portion OP2 that overlaps with the adjacent lower series-connected unit solar cell 10'.

[0223] For example, if a plurality of series-connected type unit solar cells 10' are stacked in a stepped overlapping structure in the arrangement direction, a specific series-connected type unit solar cell 10' will overlap an adjacent upper series-connected type solar cell 10' and an adjacent lower series-connected type solar cell 10' to provide a first overlapping portion OP1 and a second overlapping portion OP2, and the first overlapping portion OP1 and the second overlapping portion OP2 are respectively arranged on both sides of the series-connected solar cell 10 so as to face each other in the arrangement direction.

[0224] 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 unit 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 the shape of the overlapping portion that can be easily designed by a person skilled in the art.

[0225] In this embodiment, the width of the overlapping portion is satisfactorily maintained within the width of the side insulating layer, so that the series-connected solar cell module 100 can be stably modularized and a large light receiving area can be secured, thereby producing an excellent solar cell and outputting power. If the width of the overlapping portion OP is less than 1 mm, the bonding stability of adjacent series-connected unit solar cells 10' can be reduced during the modularization process. If the width of the overlapping portion OP is more than 3 mm, the light receiving area of ​​the series-connected unit solar cell 10' can be excessively reduced, which can reduce the output power of the solar cell.

[0226] The widths of the first overlapping portion OP1 and the second overlapping portion OP2 may be the same as each other or may be different from each other, and if the widths are different from each other, the widths of the first overlapping portion OP1 and the second overlapping portion OP2 may differ within a range of approximately 1 mm to approximately 3 mm.

[0227] That is, as shown in FIG. 17, a series-connected solar cell module 100' according to another embodiment of the present invention has a plurality of series-connected unit solar cells 10' stacked in a stepped manner, and the lower electrode of the adjacent upper series-connected solar cell 10 is electrically connected to the upper electrode of the lower series-connected solar cell 10 by a conductive adhesive part 14a and an electrode part 14b, which is not only advantageous in productivity and production costs, but can also reduce the process defect rate and maximize the efficiency of the solar cell by minimizing optical loss.

[0228] Specifically, the first overlapping portion OP1 of the reference series-connected type unit solar cell 10' and the second overlapping portion OP2 of the upper series-connected type unit solar cell 10' overlap each other, and the second overlapping portion OP2 of the reference series-connected type unit solar cell 10' and the first overlapping portion OP1 of the lower series-connected type unit solar cell 10' overlap each other, thereby forming a stepped stack.

[0229] Furthermore, in another embodiment of the present invention, the pad 14a can be formed on the overlapping first overlapping portion OP1 during the modularization process, which can contribute to the output of the solar cell. That is, since the first overlapping portion OP1 overlaps with the upper series-connected unit solar cell 10' during the modularization process and is not exposed as a light-receiving surface, the output of the solar cell formed based on the pad does not need to be reduced, and the light-receiving area within a solar cell module of a given area can be maximized.

[0230] In a series-connected solar cell module 100' according to another embodiment of the present invention, adjacent series-connected unit solar cells 10' may be electrically and physically coupled by disposing a connection portion between the second overlapping portion OP2 of the adjacent upper series-connected solar cell 10 and the first overlapping portion OP1 of the adjacent lower series-connected solar cell 10.

[0231] Specifically, referring to FIG. 18 and FIG. 19, the connection portion may have a contact portion 60 and a pad portion 14a, and the conductive adhesive portion 60 may be disposed entirely between the second overlap portion OP2 of the upper series-connected unit solar cell 10' and the first overlap portion OP1 of the lower series-connected unit solar cell 10' based on two adjacent series-connected unit solar cells 10'. In this specification, the term "overall arrangement" includes not only the case where the solar cells are physically perfectly and uniformly disposed in the region or space, but also the case where an excluded portion inevitably exists. The conductive adhesive portion 60 has adhesive properties including a polymer blend such as epoxy acrylic fluoride, silicone, and polyamide, and therefore can be physically and stably bonded to the adjacent series-connected unit solar cells 10' and has conductive properties, thereby electrically connecting the adjacent series-connected unit solar cells 10'. The conductive adhesive portion 60 may be made of a plurality of materials, and may be made of an electrical conductive adhesive (ECA) or the like, for example. However, the type of conductive adhesive 60 is not limited to those described, and may be within the range that a person skilled in the art can easily select as long as it can physically and electrically connect adjacent series-connected unit solar cells 10'.

[0232] In this case, the pad portion 14a may be arranged as the pad 14a connected to the first electrode 42 over the entire surface of the first overlapping portion OP1 serving as the end difference region SA.

[0233] As described above, the second electrode layer 442b of the second electrode 44 formed in the second overlapping portion OP2 of the upper series-connected type unit solar cell 10' and the pad portion 14a formed in the first overlapping portion OP1 of the lower series-connected type unit solar cell 10' are in electrical contact by the conductive adhesive portion 60, thereby forming an electrical connection between two adjacent unit solar cells 10'.

[0234] In other words, the upper series-connected type unit solar cell 10' and the lower series-connected type unit solar cell 10' may be electrically and physically connected by contacting the conductive adhesive portion 60 electrically connected to the second electrode 44 of the upper series-connected type unit solar cell 10' and the pad portion 14a electrically connected to the first electrode 42 of the lower series-connected type unit solar cell 10.

[0235] Therefore, the series-connected solar cell module 100' according to another embodiment of the present invention can be formed by stacking a plurality of series-connected unit solar cells 10' in a stepped manner using the above-mentioned connection parts, thereby improving productivity and reducing defect rates.

[0236] 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. In addition, the features, structures, effects, etc. exemplified in each embodiment may be implemented by a person skilled in the art to which the embodiment belongs by combining or modifying other embodiments. Therefore, the contents related to such combinations and modifications should be interpreted as being included within the scope of the present invention. [Explanation of symbols]

[0237] 100, 100′ Solar Module 10. Solar Cells 10' unit solar cell 20 Connection member 22 Wiring 110 First photoelectric conversion unit 120 Second photoelectric conversion unit 110a Bonding layer 130 Side insulation layer 42 1st electrode 44 2nd electrode

Claims

1. A solar cell 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 includes 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 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 on at least one 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 at a lower portion of the second photoelectric conversion unit, the first photoelectric conversion unit has an area smaller than that of the second photoelectric conversion unit, such that the second photoelectric conversion unit has an end difference region, and the end difference region is formed on two side surfaces of the first photoelectric conversion unit that face each other; the side surface insulating layer is formed in the end difference region formed on two opposing side surfaces of the first photoelectric conversion unit, the first electrode includes a first electrode layer and a second electrode layer sequentially stacked on the first photoelectric conversion unit, a region in which the second electrode layer is not formed is present on the light receiving surface, and the region is positioned across the first photoelectric conversion unit; The region has a shape extending along a first direction in a central region of the solar cell, and the side insulating layer has a shape extending along the first direction in the end difference region, the solar cell is configured to be separable into a plurality of unit solar cell regions disposed between the region and the side insulating layer by cutting along the region; the first electrode includes a plurality of first unit electrodes formed in each of the unit solar cell regions, Each of the first unit electrodes includes a pad portion formed on the side insulating layer, and a plurality of bus bar electrodes spaced apart from the pad portion and extending in a second direction perpendicular to the first direction. Solar cell.

2. the second electrode includes a plurality of second unit electrodes formed in each of the unit solar cell regions, Each of the second unit electrodes overlaps with all of the plurality of bus bar electrodes, and the plurality of bus bar electrodes are connected to the pad portion of the first unit electrode. The solar cell according to claim 1 .

3. A method for manufacturing a solar cell, comprising the steps of: forming a second photoelectric conversion unit including a conductive region on the semiconductor substrate; forming a plurality of side insulating layers on edges of side surfaces of the second photoelectric conversion unit facing each other; forming a 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, inside the plurality of side insulating layers; forming a first electrode having a first electrode layer and a second electrode layer sequentially stacked on the first photoelectric conversion unit on one surface serving as a light receiving surface of the first photoelectric conversion unit; forming a second electrode that is electrically connected to the second photoelectric conversion unit below the second photoelectric conversion unit and has a first electrode layer and a second electrode layer that are sequentially stacked on the second photoelectric conversion unit; The step of forming the first electrode includes forming a region in the center of the first electrode where the second electrode layer is not formed, The step of forming the second electrode includes forming a region in the center of the second electrode where the second electrode layer is not formed, and cutting along the area where the second electrode layer of the first electrode and the second electrode layer of the second electrode are not formed to form a plurality of unit solar cells. How solar cells are manufactured.

4. The step of forming the side insulating layer includes: placing a mask on the second photoelectric conversion unit to expose the side surface; and depositing the side insulating layer to a predetermined height on the exposed side edges. The method for producing a solar cell according to claim 3 .

5. In the step of forming the first electrode, the first electrode is formed to include a pad portion formed on the side insulating layer, and a plurality of bus bar electrodes extending from the pad portion, spaced apart from each other, and extending toward the region. The method for producing a solar cell according to claim 4 .

6. The step of forming a plurality of unit solar cells includes: a step of primarily cutting the solar cell from a back surface of the second photoelectric conversion unit to a predetermined depth by laser drawing; and a mechanical step of secondarily cutting the solar cell into a plurality of solar cells based on the region. The method for producing a solar cell according to claim 5 .

7. The predetermined depth of the primary cut is a depth that does not reach the first photoelectric conversion unit. The method for producing a solar cell according to claim 6 .

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