Perovskite solar cell module

Abstract

An embodiment of the present invention provides a perovskite solar cell module comprising: a plurality of solar cells arranged in a first direction on a substrate and including a perovskite light absorption layer; and a bus bar disposed on the substrate, extending in a second direction different from the first direction, and electrically connected to the plurality of solar cells, wherein the bus bar is spaced apart from an adjacent solar cell among the solar cells by a predetermined distance in the first direction.

Description

Perovskite solar cell modules

[0001] Embodiments of the present invention relate to perovskite solar cell modules.

[0002] Solar cells are photoelectric conversion devices that convert solar energy into electrical energy using the photovoltaic effect. Various types of solar cells have been proposed, among which solar cells utilizing perovskite material—known to have the same crystal structure as calcium titanium oxide (CaTiO3)—as the light-absorbing layer are gaining attention.

[0003] Perovskite solar cells are third-generation solar cells combined with thin-film technology. They possess high photovoltaic conversion efficiency comparable to that of silicon solar cells and can absorb light in the short-wavelength range and convert it into electrical energy. Generally, a perovskite solar cell comprises a light-absorbing layer containing a perovskite compound, an electron transport layer provided on one side of the light-absorbing layer, and a hole transport layer provided on the other side of the light-absorbing layer. These perovskite solar cells have the advantage of being made of relatively inexpensive materials, can be formed in a low-temperature process of 200°C or lower, and allow for thin-film fabrication via a solution process, thereby reducing manufacturing costs.

[0004] In addition, development of tandem solar cells, which form a single solar cell by connecting single-junction solar cells containing absorption layers with different band gaps, has been actively underway recently. A tandem solar cell is a structure in which a single-junction solar cell containing an absorption layer with a relatively large band gap and a single-junction solar cell containing an absorption layer with a relatively small band gap are tunnel-junctioned via a junction layer. Among tandem solar cells, perovskite / silicon tandem solar cells, in which a perovskite solar cell is stacked on a silicon solar cell, are receiving much attention as they can achieve a high photoelectric efficiency of over 30%.

[0005] Meanwhile, solar cells are used as solar cell modules by electrically connecting multiple solar cells in series or parallel and undergoing a packaging process. In solar cell modules, busbars are used to electrically connect strings in which solar cells are connected to each other by ribbons. The current generated in each string is transmitted to a junction box through the busbars.

[0006] The spacing between the busbar and the solar cells acts as a crucial factor in determining the efficiency of a solar cell module. In typical silicon-based solar cell modules, the narrower the spacing between the busbar and the solar cells, the higher the efficiency of the solar cell module.

[0007] However, in the case of perovskite solar cells, the rigidity is relatively weak, so delamination occurs when the internal layers of the solar cell are torn off even by small external stresses during the modularization process. In particular, busbars, which expand and contract significantly with temperature, cause interfacial detachment or delamination within the solar cell due to the height difference with the solar cell, which leads to a decrease in the efficiency of the perovskite solar cell module and has a negative impact on stability and lifespan.

[0008] Accordingly, there is an urgent need for research on perovskite solar cell modules that can achieve high photoelectric efficiency while preventing the aforementioned interfacial detachment or delamination.

[0009] The embodiments of the present invention aim to solve the aforementioned problems and / or limitations and to provide a perovskite solar cell module capable of achieving high photoelectric efficiency while preventing interface detachment or delamination within the solar cell.

[0010] However, these tasks are exemplary and do not limit the scope of the invention.

[0011] One embodiment of the present invention provides a perovskite solar cell module comprising a plurality of solar cells arranged in a first direction on a substrate and including a perovskite light-absorbing layer, and a bus bar disposed on the substrate, extending in a second direction different from the first direction and electrically connected to the plurality of solar cells, wherein the bus bar is spaced apart from adjacent solar cells among the solar cells by a predetermined distance in the first direction.

[0012] A perovskite solar cell module according to one embodiment of the present invention can prevent interface detachment or delamination inside the solar cell, thereby improving stability and lifespan.

[0013] In addition, a perovskite solar cell module according to one embodiment of the present invention can prevent damage to the solar cell caused by the busbar during the modularization process or thermal cycling test for obtaining international standards, thereby providing excellent durability and enabling improved process efficiency.

[0014] Of course, the scope of the present invention is not limited by these effects.

[0015] FIG. 1 is an exploded perspective view of a perovskite solar cell module according to one embodiment of the present invention.

[0016] FIG. 2 is a cross-sectional view showing an example of a solar cell included in the perovskite solar cell module of FIG. 1.

[0017] Figure 3 is a plan view showing an enlarged view of section A of Figure 1.

[0018] Figure 4 is a cross-sectional view taken along the line B-B' of Figure 3.

[0019] Figure 5 is a graph showing the test results of a perovskite solar cell module according to one embodiment of the present invention.

[0020] One embodiment of the present invention provides a perovskite solar cell module comprising a plurality of solar cells arranged in a first direction on a substrate and including a perovskite light-absorbing layer, and a bus bar disposed on the substrate, extending in a second direction different from the first direction and electrically connected to the plurality of solar cells, wherein the bus bar is spaced apart from adjacent solar cells among the solar cells by a predetermined distance in the first direction.

[0021] In one embodiment of the present invention, the solar cell further comprises an electron transport layer disposed on the light absorption layer, and the electron transport layer may comprise a fullerene-based organic material.

[0022] In one embodiment of the present invention, the fullerene-based organic material is C 60 , C 70 It may include one or more selected from PC60BM and PC70BM.

[0023] In one embodiment of the present invention, the spacing between the busbar and the adjacent solar cell may have a value in the range of 6 to 30 times the thickness of the busbar.

[0024] In one embodiment of the present invention, the busbar may be spaced from the adjacent solar cell by a range of 3 mm to 10 mm.

[0025] In one embodiment of the present invention, the ratio of the thickness of the solar cell to the thickness of the bus bar may have a value selected in the range of 1 / 3 to 1.

[0026] In one embodiment of the present invention, the thickness of the solar cell may be 150 μm to 250 μm, and the thickness of the bus bar may be 0.3 mm to 0.5 mm.

[0027] In one embodiment of the present invention, the angle formed by the virtual connecting line between the busbar and the adjacent solar cell may be in the range of 0 to 5 degrees.

[0028] Another embodiment of the present invention provides a perovskite solar cell module comprising a plurality of solar cells arranged in a first direction on a substrate and a bus bar disposed on the substrate, extending in a second direction different from the first direction and electrically connected to the plurality of solar cells, wherein the solar cells are tandem solar cells comprising a silicon bottom cell including a silicon layer, a perovskite top cell including an electron transport layer made of a perovskite light absorption layer and a fullerene-based organic material, and a recombination layer connecting the silicon bottom cell and the perovskite top cell, and wherein the bus bar is spaced apart from adjacent solar cells among the solar cells by a predetermined distance in the first direction.

[0029] In another embodiment of the present invention, the spacing between the busbar and the adjacent solar cell may have a value in the range of 6 to 30 times the thickness of the busbar.

[0030] In another embodiment of the present invention, the busbar may be spaced from the adjacent solar cell by a range of 3 mm to 10 mm.

[0031] In another embodiment of the present invention, the ratio of the thickness of the solar cell to the thickness of the bus bar may have a value selected in the range of 1 / 3 to 1.

[0032] In another embodiment of the present invention, the thickness of the solar cell may be 150 μm to 300 μm, and the thickness of the bus bar may be 0.3 mm to 0.5 mm.

[0033] In another embodiment of the present invention, the angle formed by the virtual connecting line between the busbar and the adjacent solar cell may be in the range of 0 to 5 degrees.

[0034] Other aspects, features, and advantages other than those described above will become clear from the following drawings, claims, and detailed description of the invention.

[0035] Hereinafter, the following embodiments will be described in detail with reference to the attached drawings. When describing with reference to the drawings, identical or corresponding components are given the same reference numerals, and redundant descriptions thereof will be omitted.

[0036] Since the embodiments are capable of various modifications, specific embodiments are illustrated in the drawings and described in detail in the detailed description. The effects and features of the embodiments and the methods for achieving them will become clear by referring to the details described below in conjunction with the drawings. However, the embodiments are not limited to those disclosed below and can be implemented in various forms.

[0037] In the drawings, parts unrelated to the explanation have been omitted to clearly explain the invention, and similar parts throughout the specification have been given similar reference numerals.

[0038] In the following embodiments, terms such as first, second, etc. are used not in a limiting sense, but for the purpose of distinguishing one component from another.

[0039] In the following embodiments, singular expressions include plural expressions unless the context clearly indicates otherwise.

[0040] In the following examples, terms such as "include" or "have" mean that the features or components described in the specification are present, and do not preclude the possibility that one or more other features or components may be added.

[0041] In the following embodiments, when a part such as a unit, area, or component is described as being on or above another part, it includes not only cases where it is directly on top of another part, but also cases where another unit, area, or component is interposed in between.

[0042] In the following embodiments, terms such as "connect" or "combine" do not necessarily imply a direct and / or fixed connection or combination of two members unless the context clearly indicates otherwise, nor do they exclude the interposition of another member between the two members.

[0043] In the drawings, the size of components may be exaggerated or reduced for convenience of explanation. For example, the size and thickness of each component shown in the drawings are depicted arbitrarily for convenience of explanation, so the following embodiments are not necessarily limited to those illustrated.

[0044] The terms "up," "upper," "lower," "lower," etc., used in this specification are used merely to facilitate the description of the relationships between the components illustrated in the drawings and do not limit the direction in which the components are arranged.

[0045] FIG. 1 is an exploded perspective view of a perovskite solar cell module (10) according to one embodiment of the present invention, and FIG. 2 is a cross-sectional view showing an example of a solar cell (100) included in the perovskite solar cell module (10) of FIG. 1. FIG. 3 is a plan view showing an enlarged view of part A of FIG. 1, and FIG. 4 is a cross-sectional view taken along the line B-B' of FIG. 3.

[0046] Referring to FIGS. 1 to 4, a perovskite solar cell module (hereinafter "solar cell module") (10) according to one embodiment of the present invention may include a solar cell (100), a first substrate (hereinafter "front substrate") (210) located on the front surface of the solar cell (100), a second substrate (hereinafter "rear substrate") (220) located on the rear surface of the solar cell (100), and a busbar (242) electrically connected to the solar cell (100). Additionally, the solar cell module (10) may include a first sealing material (231) between the solar cell (100) and the front substrate (210), and a second sealing material (232) between the solar cell (100) and the rear substrate (220).

[0047] The solar cell module (10) can convert solar energy into battery energy. That is, the solar cell module (10) can generate electricity by receiving sunlight.

[0048] The solar cell (100) may be a perovskite solar cell including a perovskite light-absorbing layer or a tandem solar cell including a perovskite solar cell.

[0049] A solar cell module (10) may include a plurality of solar cells (100). The plurality of solar cells (100) may be arranged in rows and columns on a first substrate. Specifically, the plurality of solar cells (100) may be connected in a first direction (the x-axis direction of the drawing) to form a single column (i.e., a solar cell string (S)), and the plurality of solar cell strings (S) may be arranged in parallel in a second direction (the y-axis direction of the drawing).

[0050] A plurality of solar cells (100) included in a solar cell string (S) can be electrically connected in series, parallel, or series-parallel by a ribbon (241). Specifically, the ribbon (241) can connect a front electrode formed on the light-receiving surface of a solar cell (100) and a back electrode formed on the back surface of an adjacent solar cell (100) by a tabbing process.

[0051] The front substrate (210) may be placed on the first sealing material (231) to form one side of the solar cell module (10). The front substrate (210) may be made of an insulating material having rigidity and durability to protect the solar cell (100) from external impacts, moisture, ultraviolet rays, etc.

[0052] Additionally, the front substrate (210) may be made of a transparent material capable of transmitting sunlight. For example, the front substrate (210) may be made of low-iron tempered glass containing less iron to prevent reflection of sunlight and increase the transmittance of sunlight, but is not limited thereto.

[0053] As shown in FIG. 4, the front substrate (210) may be divided into an inner region (CR) and an outer region (OR). The inner region (CR) may be an active area where a solar cell (100) is placed, and the outer region (OR) may be a non-active area where a solar cell (100) is not placed, which is an area surrounding the inner region (CR). A busbar (242), which will be described later, may be placed in the outer region (OR).

[0054] The rear substrate (220) may be placed on the second sealing material (232) to form the back side of the solar cell module (10). The rear substrate (220) may be formed in the form of a film or a sheet, but is not limited thereto.

[0055] The rear substrate (220) may be made of a material capable of being waterproof, insulating, and blocking ultraviolet rays. Additionally, the rear substrate (220) may be made of a light-transmitting material, or may include a non-transparent material or a reflective material. For example, the rear substrate (220) may be composed of a fluorine-based film, a weather-resistant polyethylene terephthalate (PET) film, or a weather-resistant polyolefin film, and is not particularly limited as long as it is in a form capable of protecting the solar cell (100).

[0056] The first sealant (231) may be placed on the light-receiving surface of the solar cell (100), and the second sealant (232) may be placed on the back surface of the solar cell (100). In one embodiment, the first sealant (231) and the second sealant (232) may be bonded by a lamination process.

[0057] The first sealing material (231) and the second sealing material (232) may include polymeric materials. More specifically, the first sealing material (231) and the second sealing material (232) may include thermosetting resins. For example, the first sealing material (131) and the second sealing material (132) may include ethylene vinyl acetate copolymer resin (EVA), polyvinyl butyral, silicon resin, ester resin, olefin resin, etc.

[0058] By forming the first sealing material (231) and the second sealing material (232) with materials having excellent thermal and adhesive properties, good stability and light transmittance at high temperatures, and excellent moisture resistance, the inside of the solar cell module (10) can be filled to prevent leakage of current and protect the solar cell (100) from electric shock.

[0059] Additionally, the first sealing material (231) and the second sealing material (232) can serve to protect the solar cell (100) from temperature changes, excessive light and ultraviolet rays, wind or external physical impact, external moisture and foreign substances. Additionally, the first sealing material (231) and the second sealing material (232) can be placed between the front substrate (210), the rear substrate (220), and the solar cell (100) to serve to combine each element of the solar cell module (10).

[0060] The busbar (242) can be positioned adjacent to both ends of a row of solar cells (100), i.e., a solar cell string (S), connected by a ribbon (241). The busbar (242) can be positioned at the ends of the solar cell string (S) in a direction that intersects with it. That is, the busbar (242) can be positioned in a second direction (y-axis direction) that intersects with the first direction (x-axis direction) in which the solar cell string (S) extends.

[0061] A ribbon (241) extending from both ends of a solar cell string (S) in a first direction (x-axis direction in the drawing) can be electrically connected to a bus bar (242). Accordingly, the current produced by each solar cell (100) is collected by the ribbon (241) and transmitted to the bus bar (242), and can be transmitted to an external circuit (e.g., a junction box) (not shown) through the bus bar (242).

[0062] The busbar (242) may include a conductive material. For example, the busbar (242) may include gold (Au), silver (Ag), copper (Cu), tin (Sn), aluminum (Al), or an alloy thereof.

[0063] The busbar (242) may be positioned at a predetermined distance from the adjacent first solar cell (100a) and may be formed with a predetermined thickness. The separation distance (d) and step (t3) between the busbar (242) and the adjacent first solar cell (100a) will be described later with reference to FIGS. 3 and 4.

[0064] Hereinafter, a tandem solar cell included in a solar cell module (10) according to one embodiment of the present invention will be described in detail with reference to FIG. 2.

[0065] As shown in FIG. 2, in one embodiment, the solar cell (100) may include a silicon bottom cell (110), a perovskite top cell (120), and a recombination layer (130) connecting the silicon bottom cell (110) and the perovskite top cell (120).

[0066] The silicon lower cell (110) may include a silicon layer (111), an emitter layer (112) disposed on the upper surface of the silicon layer (111), and a first grid electrode (113) disposed on the lower surface of the silicon layer (111).

[0067] The silicon layer (111) may have one of the structures of a known silicon solar cell and is not limited to a specific structure. For example, the silicon layer (111) may include a crystalline silicon substrate (not shown), a p-type amorphous or crystalline silicon layer (not shown), an n-type amorphous or crystalline silicon layer (not shown), and an amorphous intrinsic silicon layer (not shown), and may include additional layers as needed, although not shown in the drawings. According to a more preferred embodiment, considering industrial advantages such as ease of internal gettering or process simplification that help improve cell efficiency of p-type silicon compared to n-type silicon, the silicon layer (111) may be a p-type silicon layer and the emitter layer (112) may be an n-type emitter layer.

[0068] The silicon lower cell (110) includes a first grid electrode (113) disposed on the lower surface of the silicon layer (111), thereby increasing light absorption for light reflected from the rear surface and enabling an increase in current value and high photoelectric conversion efficiency.

[0069] Meanwhile, the silicon bottom cell (110) may further include a passivation layer on the lower surface of the silicon layer (111), and the first grid electrode (113) may be disposed on the passivation layer. However, the present invention is not limited thereto.

[0070] At least a portion of the lower surface of the silicon lower cell (110) may be textured to improve light efficiency. That is, as shown in FIG. 2, an uneven surface is formed in the direction in which light is incident, and the light path of light incident on the silicon layer (111) is increased through the light scattering effect of the light incident through the uneven surface, thereby improving light collection and increasing the absorption rate of sunlight. At this time, the pyramid angle of the surface of the texturing may exceed 5°, and preferably the pyramid angle of the surface may exceed 30°, which may be more advantageous for achieving the purpose of the present invention.

[0071] The emitter layer (112) can perform charge recombination with the recombination layer (130) described later on the upper part of the silicon layer (111).

[0072] The perovskite upper cell (120) is a cell connected to the silicon lower cell (110) and includes a perovskite light absorption layer (121), and may have one of the structures of a perovskite solar cell. In one embodiment, the perovskite upper cell (120) may include a hole transport layer (122), a perovskite light absorption layer (121), an electron transport layer (123), a transparent electrode layer (124), an anti-reflection film (125), and a second grid electrode (126) that are sequentially stacked on a recombination layer (130) described later. The hole transport layer (122) and the electron transport layer (123) may be interchangeable.

[0073] The perovskite light-absorbing layer (121) may include various perovskite-based materials and may allow hole-electron pairs generated by receiving light energy from the sun to be separated into electrons or holes. For example, the perovskite light-absorbing layer (121) may include organic halide perovskites such as methyl ammonium iodide (MAI) and formamidinium iodide (FAI), or metal halide perovskites such as lead iodide (PbI2), bromine iodide (PbBr), and lead chloride (PbCl2).

[0074] More specifically, the perovskite light-absorbing layer (121) may be represented as AMX3 (where A means a monovalent organic ammonium cation or metal cation; M means a divalent metal cation; and X means a halogen anion). Non-limiting examples thereof include CH3NH3PbI3 and CH3NH3PbI x Cl 3-x , CH3NH3PbI x Br 3-x , CH3NH3PbCl x Br 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 , (CH3NH3)(HC(NH2)2) 1-y PbI3, (CH3NH3)(HC(NH2)2) 1-y PbI x Cl 3-x , (CH3NH3)(HC(NH2)2) 1-y PbI x Br 3-x , or (CH3NH3)(HC(NH2)2) 1-y PbCl x Br 3-x etc. can be used (0=x, y=1).

[0075] As an optional embodiment, the perovskite layer may be a single layer composed of the same perovskite material or a multilayer structure in which multiple layers composed of different perovskite materials are stacked, and may include a different type of perovskite material different from the one type of perovskite material having a pillar shape such as a column shape, plate shape, needle shape, wire shape, or rod shape inside a light absorption layer composed of one type of perovskite material.

[0076] Holes formed in the perovskite light absorption layer (121) are transferred to the hole transport layer (122), and electrons formed in the perovskite light absorption layer (121) can be transferred to the electron transport layer (123).

[0077] The hole transport layer (122) serves to separate and transport holes formed in the perovskite light absorption layer (121) and can be formed from known conventional materials as long as it aligns with the purpose of the present invention. Non-limiting examples thereof may include Mo oxide, Ni oxide, W oxide, Cu oxide, V oxide, CusCN, and CuI.

[0078] The electron transport layer (123) can serve to separate and transport electrons formed in the perovskite light absorption layer (121). In one embodiment, the electron transport layer (123) may include a fullerene-based organic material. In this case, the fullerene-based organic material is C 60 , C 70 It may include one or more selected from , PC60BM and PC70BM, and preferably C 60 It may include.

[0079] The transparent electrode layer (124) can transfer charge to a metal electrode (second grid electrode (126)). For example, the transparent electrode layer (124) may be implemented by including one or more materials from the group consisting of a transparent conductive oxide, a carbonaceous conductive material, a metallic material, and a conductive polymer, and preferably by including a transparent conductive oxide.

[0080] As the anti-reflective film (125) and the second grid electrode (126) can be used without limitation as long as they are commonly used in the industry, the present invention does not specifically limit them.

[0081] The recombination layer (130) connects the silicon lower cell (110) and the perovskite upper cell (120), serves to physically bond and electrically connect the silicon lower cell (110) and the perovskite upper cell (120), and can perform charge recombination between the upper cell and the lower cell.

[0082] The recombination layer (130) may be used without limitation as long as it is a recombination layer material that is commonly used in the industry, but for the purpose of the present invention, it may preferably include one or more selected from the group consisting of transparent conductive oxides, carbonaceous conductive materials, metallic materials and conductive polymers, and more preferably, it may be one or more TCO-based materials and / or nc-Si:H material layers selected from the group consisting of ITO (Indium Tin Oxide), ICO (Indium Cerium Oxide), IWO (Indium Tungsten Oxide), ZITO (Zinc Indium Tin Oxide), ZIO (Zinc Indium Oxide), ZTO (Zinc Tin Oxide), GITO (Gallium Indium Tin Oxide), GIO (Gallium Indium Oxide), GZO (Gallium Zinc Oxide), AZO (Aluminum doped Zinc Oxide), FTO (Fluorine Tin Oxide), and ZnO.

[0083] When the solar cell (100) is a tandem solar cell in which a silicon bottom cell (110), a recombination layer (130), and a perovskite top cell (120) are stacked, the silicon bottom cell (110) and the perovskite top cell (120) can absorb sunlight of different wavelengths and improve the efficiency of the solar cell module (10).

[0084] Although an example of a solar cell (100) included in a solar cell module (10) according to one embodiment of the present invention has been described above, this is merely an example, and the solar cell (100) may be a perovskite solar cell with a single junction structure including a perovskite light-absorbing layer (121), and may further include an additional stacked structure capable of improving the efficiency of the solar cell module (10).

[0085] Meanwhile, a perovskite solar cell or a tandem solar cell including a perovskite solar cell has a multilayer structure, and interfacial detachment or delamination may occur due to differences in the physical properties (e.g., coefficient of thermal expansion, etc.) of each layer. In particular, C, which is mainly used as an electron transport layer (123). 60 It exhibits very low adhesion. Furthermore, in a solar cell module (10) containing such perovskite solar cells, delamination within the solar cell (100) can occur more easily due to the step difference between the solar cell (100) and the bus bar (242) placed adjacent to it.

[0086] A solar cell module (10) according to one embodiment of the present invention can prevent delamination of the first solar cell (100a) by the bus bar (242) by arranging the bus bar (242) so that it has a predetermined separation distance (d) from the first solar cell (100a) adjacent thereto, as shown in FIG. 3. At this time, the separation distance (d) between the bus bar (242) and the first solar cell (100a) can be determined by the thickness (t1) of the bus bar (242) or the step difference (t3) between the bus bar (242) and the first solar cell (100a).

[0087] Here, the thickness (t1) of the bus bar (242) refers to the height from the upper surface of the electrode layer (211) to the upper surface of the bus bar (242) when the electrode layer (211) is formed on the front substrate (210) as shown in FIG. 4 and the solar cell (100) and the bus bar (242) are formed on the electrode layer (211), and the step difference (t3) between the bus bar (242) and the first solar cell (100a) refers to the difference between the height of the bus bar (242) and the height of the first solar cell (100a).

[0088] In one embodiment, the distance (d) between the busbar (242) and the first solar cell (100a) may be 3 mm or more.

[0089] Specifically, the distance (d) between the busbar (242) and the first solar cell (100a) may have a value ranging from 6 to 30 times the thickness (t1) of the busbar (242). At this time, the thickness (t1) of the busbar (242) may be about 0.3 mm to about 0.5 mm, and preferably about 0.35 mm to about 0.45 mm, and thus the distance (d) between the busbar (242) and the first solar cell (100a) may have a value ranging from about 3 mm to about 10 mm.

[0090] If the distance (d) between the busbar (242) and the first solar cell (100a) is formed to be less than six times the thickness (t1) of the busbar (242), the busbar (242) may apply physical force to the first solar cell (100a) during the process of manufacturing the solar cell module (10) or testing the solar cell module (10), and may cause interfacial detachment or peeling of the first solar cell (100a).

[0091] Meanwhile, if the distance (d) between the busbar (242) and the first solar cell (100a) is formed to be greater than 30 times the thickness (t1) of the busbar (242), a problem arises in which the light efficiency relative to the area of ​​the solar cell module (10) drops excessively.

[0092] In addition, in one embodiment, the thickness (t2) of the solar cell (100) may be smaller than the thickness (t1) of the bus bar (242). Here, the thickness (t2) of the solar cell (100) may refer to the average thickness of all solar cells (100) included in the solar cell module (10). For example, the thickness (t2) of the solar cell (100) may be about 150 μm to about 300 μm, and preferably about 160 μm to about 180 μm. The thickness (t1) of the bus bar (242) may be about 0.3 mm to about 0.5 mm, and preferably about 0.35 mm to about 0.45 mm.

[0093] At this time, the ratio of the thickness (t2) of the solar cell (100) to the thickness (t1) of the bus bar (242) may have a value selected in the range of 1 / 3 to 1. That is, the thickness (t1) of the bus bar (242) may be 1 to 3 times the thickness (t2) of the first solar cell (100).

[0094] If the thickness (t1) of the busbar (242) is formed to be thinner than the thickness (t2) of the solar cell (100), it is difficult to handle the excessively thin busbar (242) during the manufacturing process of the solar cell module (10), which may lead to a decrease in productivity or an increase in the defect rate.

[0095] Meanwhile, if the thickness (t1) of the busbar (242) is formed to be thicker than three times the thickness (t2) of the solar cell (100), the busbar (242) may apply physical force to the solar cell (100) due to the step difference (t3) between the busbar (242) and the solar cell (100) during the manufacturing process or testing process of the solar cell module (10), and cause interfacial detachment or peeling of the solar cell (100).

[0096] In addition, in one embodiment, the angle (θ) formed by a virtual line connecting the upper edge positioned from the first solar cell (100a) toward the busbar (242) and the upper edge positioned from the busbar (242) toward the first solar cell (100a) may have a value in the range of about 0 degrees to about 5 degrees. That is, the busbar (242) may have an angle (θ) range determined by the distance (d) and step (t3) from the first solar cell (100a). By ensuring that the angle (θ) formed by the busbar (242) and the first solar cell (100a) is in the range of 0 degrees to 5 degrees, the solar cell module (10) can secure high light efficiency while simultaneously preventing interfacial detachment or peeling phenomena from occurring on the solar cell (100).

[0097] FIG. 5 is a graph showing the test results of a solar cell module (10) according to one embodiment of the present invention.

[0098] Referring to Table 1 below in conjunction with FIG. 5, after performing a thermal cycling test using a solar cell module (10) according to one embodiment of the present invention and examining the interfacial detachment or peeling phenomenon occurring in the solar cell (100), it was found that when the separation distance (d) between the busbar (242) and the first solar cell (100a) is 7 mm or more, the interfacial detachment or peeling phenomenon does not occur in the solar cell (100). In addition, when the separation distance (d) between the busbar (242) and the first solar cell (100a) is less than 3 mm, it was found that the peeling phenomenon occurs in an area of ​​3.92% or more, or about 4% or more, of the total area of ​​the solar cell (100).

[0099] Separation distance (d1) Presence or absence of interface detachment after thermal cycling Ratio of delamination area to total area Sample 1 Sample 2 1O 5.06% 5.51% 2O 5.30% 3.92% 3O 2.67% 2.99% 4O 2.57% 3.33% 5O 2.66% 1.45% 6O 0.44% 0.37% 7X 0.00% 0.00% 8X 0.00% 0.00%

[0100] In addition, as a result of observing the area where interfacial detachment or peeling occurs in the solar cell (100) while varying the angle (θ) formed by the imaginary line connecting the busbar (242) and the first solar cell (100a), it was found that when the angle (θ) is 2 degrees or less, interfacial detachment or peeling does not occur in the solar cell (100). In addition, it was found that when the angle (θ) formed by the imaginary line connecting the busbar (242) and the first solar cell (100a) is 4.6 degrees or less, interfacial detachment or peeling occurs only in an area of ​​about 3.33% or less of the total solar cell (100) area.

[0101] Separation distance (d1) Step difference (t3) Tan (rad) Atan (rad) Angle (θ) degree Presence or absence of interface detachment Ratio of delamination area to total area [A][B][B / A]arctan[B / A]rad to degree Sample 1 Sample 210.240.2400.23613.5O5.06%5.51%20.240.1200.1196.8O5.30%3.9 2%30.240.0800.0804.6O2.67%2.99%40.240.0600.0603.4O2.57%3.33 %50.240.0480.0482.7O2.66%1.45%60.240.0400.0402.3O0.44%0.37 %70.240.0340.0342.0X0.00%0.00%80.240.0300.0301.7X0.00%0.00%

[0102] Therefore, in the case of a solar cell module (10) according to one embodiment of the present invention, since the delamination phenomenon occurs in an area of ​​less than 3.33% of the total area of ​​the solar cell (100), it can be seen that the interfacial detachment or delamination phenomenon of the solar cell (100) caused by the bus bar (242) can be effectively prevented.

[0103] As described above, a solar cell module (10) according to one embodiment of the present invention can prevent defects caused by interfacial detachment or peeling occurring in the solar cell (100) and can improve process efficiency. In addition, a solar cell module (10) according to one embodiment of the present invention does not experience a decrease in efficiency caused by interfacial detachment or peeling occurring in the solar cell (100), and can improve stability and lifespan.

[0104] As such, the present invention has been described with reference to an embodiment illustrated in the drawings, but this is merely illustrative, and those skilled in the art will understand that various modifications and variations of the embodiments are possible therefrom. Accordingly, the true technical scope of protection of the present invention should be determined by the technical spirit of the appended claims.

Claims

1. A plurality of solar cells arranged in a first direction on a substrate and comprising a perovskite light-absorbing layer; and A bus bar disposed on the substrate, extending in a second direction different from the first direction, and electrically connected to the plurality of solar cells; The above busbar is a perovskite solar cell module spaced apart from adjacent solar cells among the above solar cells by a predetermined distance in the first direction.

2. In Paragraph 1, The above solar cell further includes an electron transport layer disposed on the light absorption layer, and A perovskite solar cell module in which the electron transport layer comprises a fullerene-based organic material.

3. In Paragraph 2, The above fullerene series organic material is C 60 , C 70 A perovskite solar cell module comprising one or more types selected from PC60BM and PC70BM.

4. In Paragraph 1, A perovskite solar cell module having a spacing distance between the busbar and the adjacent solar cell ranging from 6 to 30 times the thickness of the busbar.

5. In Paragraph 1, The above busbar is a perovskite solar cell module spaced from the adjacent solar cell by a range of 3 mm to 10 mm.

6. In Paragraph 1, A perovskite solar cell module having a ratio of the thickness of the solar cell to the thickness of the busbar selected in the range of 1 / 3 to 1.

7. In Paragraph 6, The thickness of the above solar cell is 150 μm to 250 μm, and A perovskite solar cell module having a busbar thickness of 0.3 mm to 0.5 mm.

8. In Paragraph 6, A perovskite solar cell module in which the angle formed by the imaginary connecting line between the busbar and the adjacent solar cell is in the range of 0 to 5 degrees.

9. A plurality of solar cells arranged in a first direction on a substrate; and A bus bar disposed on the substrate, extending in a second direction different from the first direction, and electrically connected to the plurality of solar cells; The above solar cell is, Silicon bottom cell including a silicon layer; A perovskite upper cell comprising a perovskite light absorption layer and an electron transport layer composed of a fullerene-based organic material; and A tandem solar cell comprising a recombination layer connecting the silicon bottom cell and the perovskite top cell; The above busbar is a perovskite solar cell module spaced apart from adjacent solar cells among the above solar cells by a predetermined distance in the first direction.

10. In Paragraph 9, A perovskite solar cell module having a spacing distance between the busbar and the adjacent solar cell ranging from 6 to 30 times the thickness of the busbar.

11. In Paragraph 9, The above busbar is a perovskite solar cell module spaced from the adjacent solar cell by a range of 3 mm to 10 mm.

12. In Paragraph 9, A perovskite solar cell module having a ratio of the thickness of the solar cell to the thickness of the busbar selected in the range of 1 / 3 to 1.

13. In Paragraph 12, The thickness of the above solar cell is 150 μm to 300 μm, and A perovskite solar cell module having a busbar thickness of 0.3 mm to 0.5 mm.

14. In Paragraph 9, A perovskite solar cell module in which the angle formed by the imaginary connecting line between the busbar and the adjacent solar cell is in the range of 0 to 5 degrees.

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