Flexible thin-film solar cell and interconnection structure and fabrication process

Abstract

The present application relates to flexible thin film solar cell and interconnection structure and preparation process, the cell includes the layout of bottom to top in turn substrate layer, first electrode layer, device layer, second electrode layer, bus layer, interconnection connection layer. The present application is based on the scheme of low internal loss, high flexible interconnection of non-conductive flexible substrate thin film solar cell on one aspect, which can effectively avoid the conduction short circuit or electric leakage between electrode layers, and the overall flexibility is strong, which reduces the risk of damage of the cell due to large curvature, and the bending curvature is smaller during bending process, and the damage to the cell is smaller; on the other hand, the interconnection connection layer is formed based on the first electrode surface as the reference, which not only eliminates the influence of the deformation degree and flatness of the flexible substrate in the epitaxial forming, but also can significantly reduce the internal resistance of the interconnection, improve the collection efficiency, significantly improve the fill factor, thereby improve the output power of the assembly, and also improve the stability and yield of mass production.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of solar cells, and particularly relates to a flexible thin-film solar cell, and also relates to a flexible thin-film solar cell interconnection structure, a preparation process of the flexible thin-film solar cell, and a preparation process of the flexible thin-film solar cell interconnection structure. BACKGROUND

[0002] At present, flexible thin-film solar cells are mostly prepared on ultra-thin flexible glass and polymer-based material substrates. Such substrates are not conductive, so it is difficult to realize interconnection through solder strip top and bottom connection in the component manufacturing process as in the traditional crystalline silicon solar cell. Therefore, for the flexible thin-film solar cell on the non-conductive substrate, three scribing interconnection processes are generally required to meet the actual use requirements. The components are divided into a plurality of sub-cell units by laser or mechanical scribing method and then interconnected. The specific interconnection process is as follows: first, the transparent conductive oxide (TCO) layer on the substrate is scribed into a plurality of small sections to form P1 scribing; then, the device layer for photoelectric conversion is deposited by depositing P / N type functional layer, intrinsic absorption layer and N / P type functional layer, and then the device layer is scribed in parallel at the same number of times on the side of the "P1 scribing" with the smallest distance to form P2 scribing; finally, the TCO / metal electrode layer is deposited, and then the device layer is scribed in parallel at the same number of times on the side of the "P2 scribing" with the smallest distance to form P3 scribing, so that the whole forms a series connection structure of a plurality of sub-cells.

[0003] However, this scribing section interconnection method has the following problems:

[0004] 1) The scribing process is complex and has high processing precision requirements. In addition to the control of the equipment itself, the substrate itself also has high requirements for the degree of deformation and flatness. However, the flexible substrate itself is difficult to meet these requirements as stable as the rigid glass substrate, so the scribing process has great challenges in the preparation of flexible thin-film solar cells;

[0005] 2) The limited contact interconnection current cross section at the P2 scribing position and the Schottky barrier of the TCO / metal half interface will inevitably cause high contact resistance (i.e. internal resistance of the sub-cell string), so it is necessary to control the area of the sub-cell to reduce the current of the cell string as much as possible to reduce the internal loss, which will limit the overall electrical output characteristics and application scenarios of the component;

[0006] 3) The scribing process will cause a certain degree of damage to the film layer, and there will be residual stress at the scribing position. When the flexible cell is bent under the influence of external strain, the stress release will cause irreversible damage to the film layer. SUMMARY

[0007] The technical problem to be solved by the present application is to overcome the shortcomings of the prior art and provide an improved flexible thin-film solar cell.

[0008] The present application also relates to a flexible thin-film solar cell interconnection structure, a preparation process of the flexible thin-film solar cell, and a preparation process of the flexible thin-film solar cell interconnection structure.

[0009] To solve the above technical problems, the technical solutions adopted by the present application are as follows:

[0010] A flexible thin-film solar cell has first and second interconnection parts formed on opposite sides, and includes, from bottom to top, a substrate layer, a first electrode layer, a device layer, a second electrode layer, and a busbar layer. In particular, the substrate layer, the first electrode layer, the device layer, the second electrode layer, and the busbar layer are aligned from the interconnection side to form the first interconnection part. The interconnection side of the second electrode layer, the device layer, the first electrode layer, and the substrate layer is formed from the top to the bottom layer by layer extension based on the interconnection side of the busbar layer, and the second interconnection part is formed between the reference side and the multiple interconnection sides. The extension width of the second electrode layer is less than or equal to the extension width of the device layer, and the extension width of the first electrode layer is less than or equal to the extension width of the substrate layer. The flexible thin-film solar cell further includes an interconnection connection layer covering the interconnection side of the first electrode layer, wherein the interconnection connection layer and the reference side of the busbar layer are offset and insulated based on the interconnection side of the device layer and the second electrode layer.

[0011] Preferably, the interconnection edges of the second electrode layer and the device layer are aligned.

[0012] Further, the interconnection edges of the first electrode layer and the substrate layer are aligned.

[0013] Here, based on the configuration of the first and second interconnection parts, not only is the interconnection assembly facilitated, but also the short circuit caused by the communication of the first and second electrode layers is avoided.

[0014] In some specific embodiments, the width of the interconnection connection layer is w1, and the width of the interconnection side of the second electrode layer is w2, wherein 50 μm≤w1≤w2. The width of the interconnection connection layer as an electrode interconnection area should be considered to obtain sufficient flux, and the width is generally ≥50 μm. The larger the area of the cell, i.e., the larger the string current, the larger the electrode connection area in theory. At the same time, the width of the interconnection side of the second electrode layer mainly determines the insulation width between the interconnection connection layer and the busbar layer, and in general cases,

[0015] The insulation width should be ≥50 μm, i.e., the risk of electrode leakage should be completely avoided, and the insulation width is determined according to the process conditions and the electrical output characteristics of the product after interconnection.

[0016] Another technical solution of the present application: a preparation process of a flexible thin film solar cell, which comprises the following steps:

[0017] 1) selecting a non-conductive flexible substrate;

[0018] 2) depositing a first electrode layer based on covering the entire surface of the flexible substrate;

[0019] 3) depositing a device layer of a P-N junction photoelectric device with photoelectric conversion capability on the first electrode layer;

[0020] 4) depositing a second electrode layer on the surface of the device layer;

[0021] 5) defining the opposite sides of the structure layer as interconnection sides, wherein the edge cutting is performed with one interconnection side as a reference to form the interconnection side edges of the first electrode layer and the substrate layer extending oppositely;

[0022] 6) depositing an interconnection connection layer on the interconnection side edges of the first electrode layer, and forming a busbar layer on the second electrode layer, wherein the cut side edges of the second electrode layer and the device layer extend oppositely to form the interconnection side edges of the busbar layer, the interconnection connection layer and the busbar layer are insulated and misaligned, and the uncut substrate layer, the first electrode layer, the device layer, the second electrode layer, the busbar layer are aligned from the interconnection side to form a first interconnection part, and the cut side interconnection side edges, the interconnection connection layer, and the busbar layer side form a second interconnection part.

[0023] Preferably, in step 5), the full-size cell is cut into several sub-cells, and then the edge cutting of the interconnection side of each sub-cell is performed. The full-size cell can be cut to form the required single sub-cell, and then the sub-cell is cut to form the required second interconnection part, so that the processing efficiency is increased by several times. The cutting method includes but is not limited to any one of laser, scribing knife, gate knife, scissors, etc., and the cutting needs to ensure the minimization of damage to the cell and the non-connection short circuit of the edge first electrode layer and the second electrode layer.

[0024] According to a specific embodiment and preferred aspect of the present application, in step 1), the material of the flexible substrate is any one or more of ultrathin flexible glass, polymers such as polyethylene terephthalate, polyethylene naphthalate, polyimide, parylene, polycarbonate; the surface of the substrate layer formed based on the flexible substrate is the light receiving surface of the cell, the first electrode layer is a transparent conductive oxide; the surface of the substrate layer is not the light receiving surface of the cell, the first electrode layer is a transparent conductive oxide, a metal, and a composite stack of a metal and a transparent conductive oxide.

[0025] Preferably, the transparent conductive oxide includes, but is not limited to, any one or more of fluorine-doped tin oxide, tin-doped indium oxide, zinc-doped indium oxide, aluminum-doped zinc oxide, tungsten-doped indium oxide, titanium-doped tin indium oxide, boron-doped zinc oxide, or cerium-doped indium oxide; and / or, the metal includes, but is not limited to, one or more of copper, silver, iron, aluminum, tungsten, molybdenum, chromium, nickel, tantalum, vanadium, titanium, manganese.

[0026] Briefly, the base material is a non-conductive flexible substrate, including, but not limited to, any one or a combination of at least two of ultra-thin flexible glass (UTG), polymers such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyimide (PI), parylene, polycarbonate (PC), etc. If the base material is on the light-receiving side of the battery, the first electrode layer is a transparent conductive oxide (TCO), including, but not limited to, any one or a combination of at least two of FTO (fluorine-doped tin oxide), ITO (tin-doped indium oxide), IZO (zinc-doped indium oxide), AZO (aluminum-doped zinc oxide), IWO (tungsten-doped indium oxide), ITIO (titanium-doped tin indium oxide), BZO (boron-doped zinc oxide), or ICO (cerium-doped indium oxide). If the base material is not on the light-receiving side of the battery, the first electrode layer, in addition to the above-mentioned transparent conductive oxide, can be any one or a combination of at least two of high-conductivity metals and alloys, including, but not limited to, metals such as copper, silver, iron, aluminum, tungsten, molybdenum, chromium, nickel, tantalum, vanadium, titanium, manganese, etc., or a composite laminated structure of metals and TCOs.

[0027] In some embodiments, in step 2), the deposition method of the first electrode layer includes, but is not limited to, any one of vacuum evaporation, magnetron sputtering, reactive plasma deposition, chemical vapor deposition, screen printing, electroplating, and transfer printing; and the thickness of the formed first electrode layer is 10-1000 nm.

[0028] According to still another embodiment and preferred aspect of the present application, in step 3), the material of the device layer is amorphous silicon germanium, copper indium gallium selenide, cadmium telluride, gallium arsenide, perovskite. Preferably, the deposition method of the device layer includes, but is not limited to, any one of vacuum evaporation, magnetron sputtering, reactive plasma deposition, chemical vapor deposition, screen printing, electroplating, coating, spraying, printing, near-space sublimation deposition, and vapor transport deposition.

[0029] According to another specific implementation and preferred aspect of the present application, in step 5), the cutting method is laser and / or mechanical scribing, and the upper film layers are removed based on the surface of the first electrode layer to form corresponding interconnection side edges, wherein the first electrode layer and the substrate layer are aligned, and the width of the corresponding interconnection side edges is at least 50 μm, and the interconnection connection layer fully covers the corresponding interconnection side edges. In short, all film layers above the first electrode layer are removed to obtain an electrode connection area, and the width of the electrode connection area should be minimized, but the width of the area as the electrode interconnection should be considered to obtain sufficient flux, and the width is generally ≥ 50 μm. The larger the area of the battery, i.e., the larger the string current, the larger the electrode connection area in theory should be, and the removal method includes but is not limited to any one or a combination of at least two of laser and mechanical scribing.

[0030] Preferably, the second electrode layer and the device layer interconnection side are aligned, and the width of the formed interconnection side edge is at least 50 μm. This width is the insulation width between the interconnection connection layer and the busbar layer, and in general, the insulation width should be ≥ 50 μm, i.e., the risk of leakage between electrodes should be completely avoided, and the determination is based on the process conditions and the electrical output characteristics of the product after interconnection.

[0031] In some specific implementations, in step 6), the busbar layer and the interconnection connection layer are both metallized pattern layers, wherein the metallized pattern layer includes a grid line layer and / or a cover plate layer, and the material used by the metallized pattern layer includes but is not limited to one or more of copper, silver, iron, aluminum, tungsten, molybdenum, chromium, nickel, tantalum, vanadium, titanium, and manganese. In short, the width, number, and spacing of the grid lines depend on the light receiving amount requirement of the product, and if the surface does not need to receive light, it can be a film layer that completely covers without gaps. The metal material includes but is not limited to any one or a combination of at least two of copper, silver, iron, aluminum, tungsten, molybdenum, chromium, nickel, tantalum, vanadium, titanium, and manganese, or an alloy thereof. At the same time, the grid line structure is patterned using a mask or a screen according to the component packaging design, and the deposition method of the back electrode drainage grid line includes but is not limited to any one of vacuum evaporation, magnetron sputtering, reactive plasma deposition, chemical vapor deposition, screen printing, electroplating, and transfer printing.

[0032] Another technical solution of the present application is a flexible thin-film solar cell interconnection structure, which includes a flexible thin-film solar cell, an interconnection connecting piece, and an interconnection insulating piece, wherein two flexible thin-film solar cells are aligned and matched from a first interconnection part and a second interconnection part, and the formed gap between the first interconnection part and the second interconnection part, the interconnection connecting piece electrically communicates the busbar layer of the first interconnection part with the interconnection connection layer of the second interconnection part, and the interconnection insulating piece is filled into the gap and insulates and separates the interconnection connecting piece and the second electrode layer of the second interconnection part.

[0033] Preferably, the gap comprises a first groove formed between the base layer of the first interconnection part, the first electrode layer and the base layer of the second interconnection part, the first electrode layer, the interconnection connecting layer; a second groove formed between the device layer of the first interconnection part, the second electrode layer of the first interconnection part, the busbar layer of the first interconnection part and the device layer of the second interconnection part, the second electrode layer of the second interconnection part, the busbar layer of the second interconnection part, the interconnection connecting part is a drainage strip installed in the second groove and electrically connected to the busbar layer of the first interconnection part and the interconnection connecting layer of the second interconnection part, and the drainage strip separates the first groove and the second groove, and the interconnection insulating part comprises a first insulator for filling the space formed by the drainage strip and the first groove, and a second insulator for filling the space formed by the drainage strip and the second groove and covering the busbar layer of the first interconnection part.

[0034] In some embodiments, the insulating material of the first insulator can be glass powder, rubber, silicone, nylon, resin, electrical wood, insulating polymer, etc. The insulating material with high resistance is easy to fill and solidify, and the resistivity is greater than or equal to 10 15 Ω·m.

[0035] The insulating material of the second insulator can be glass powder, rubber, silicone, UV glue, polymer, etc. The insulating material with high resistance is easy to fill and solidify, and the resistivity is greater than or equal to 10 15 Ω·m.

[0036] In some embodiments, the interconnection connecting part and the interconnection insulating part are used to interconnect each adjacent two flexible thin-film solar cells to form a cell string, and the cell interconnection structure is formed based on the parallel or series connection of the cell string.

[0037] Another technical solution of the present application is a preparation process of a flexible thin-film solar cell interconnection structure, which uses the above-mentioned flexible thin-film solar cell interconnection structure and comprises the following steps:

[0038] S1, laying sub-cells

[0039] The flexible thin-film solar cell is used as a sub-cell, and the side-to-side laying of the first interconnection part and the second interconnection part of two sub-cells is opposite to each other to form a gap;

[0040] S2, series structure

[0041] The drainage strip is used to connect the busbar layer and the interconnection connecting layer between the adjacent two sub-cells;

[0042] S3, insulation protection

[0043] The insulating material is used to fill the gap between the drainage strip and the first interconnection part and the second interconnection part, so as to insulate and separate the first electrode layer of the first interconnection part, the drainage strip and the second electrode layer.

[0044] Preferably, the insulation material is a material that is easy to seal and cure and has an electrical resistivity of ≥ 10 15 Ω·m.

[0045] Specifically, the insulation material is one or more of glass powder, rubber, silicone, UV glue, and high molecular polymer.

[0046] Meanwhile, the interconnection process of the parallelly connected flexible thin-film solar cell groups is as follows:

[0047] 1) A battery string is formed using the preparation process of the flexible thin-film solar cell interconnection structure, and then a plurality of battery strings are aligned left and right and spaced apart up and down, wherein the left and right sides of the plurality of battery strings are respectively a first interconnection part and a second interconnection part;

[0048] 2) Each battery string is provided with a busbar corresponding to the first interconnection part and the second interconnection part on both sides, wherein in each adjacent three battery strings, the first interconnection part and the second interconnection part of the upper and lower battery strings are aligned left and right, the first interconnection part and the second interconnection part of the middle battery string are opposite to the layout of the first interconnection part and the second interconnection part of the upper and lower battery strings, one second interconnection part is arranged between the two first interconnection parts on the left side and the three are aligned, and one first interconnection part is arranged between the two second interconnection parts on the right side and the three are aligned, wherein each interval of two battery strings is connected from one side of the busbar, and the connected side alternates left and right along the up and down direction to form a left and right winding series of battery groups.

[0049] Due to the implementation of the above technical solutions, the present application has the following advantages compared with the prior art:

[0050] The existing flexible thin film solar cell uses a scribing section interconnection. Firstly, the scribing process is complex and has high processing precision requirements. In addition to the control of the equipment itself, the deformation degree and flatness of the substrate itself also have higher requirements. However, the characteristics of the flexible substrate itself are difficult to stabilize like the rigid glass substrate, so the scribing process has great challenges in the preparation of the flexible thin film solar cell. Secondly, the limited contact interconnection flux section at the P2 scribing position and the Schottky barrier of the TCO / metallic half interface will inevitably cause a high contact resistance (i.e., the internal resistance of the sub-cell string), so it is necessary to control the sub-cell area and reduce the current of the cell string as much as possible to reduce the internal loss, which will limit the overall electrical output characteristics and application scenarios of the module. Finally, the scribing process will cause a certain degree of damage to the film layer, and the residual stress at the scribing position will be released when the flexible cell is bent under the influence of external strain, causing irreversible damage to the film layer and other deficiencies. The present application designs the structure of the flexible thin film solar cell as a whole, and ingeniously solves the deficiencies and defects of the prior art. After using the flexible thin film solar cell, based on the design of the first interconnection part and the second interconnection part formed by the flexible thin film solar cell itself, the interconnection connection piece and the interconnection insulation piece can quickly realize the flexible interconnection between two flexible thin film solar cells. Therefore, on the one hand, the low internal loss and high flexible interconnection scheme based on the non-conductive flexible substrate thin film solar cell can effectively avoid the short circuit or leakage between the electrode layers, and the overall flexibility is strong, reducing the risk of damage to the cell due to large curvature. At the same time, the bending curvature is smaller during the bending process under the influence of external strain, and the damage to the cell is smaller. On the other hand, the interconnection connection layer is formed based on the first electrode surface, which not only eliminates the influence of the deformation degree and flatness of the flexible substrate in the epitaxial forming, but also significantly reduces the interconnection resistance, improves the collection efficiency, and significantly improves the fill factor, thereby improving the output power of the module. At the same time, the stability and yield of mass production are also improved. In addition, the size of the cell and the module can be freely customized and developed according to the demand, and the appearance is uniform and beautiful, greatly expanding the application of the interconnection structure of the flexible thin film solar cell. BRIEF DESCRIPTION OF DRAWINGS

[0051] Figure 1 It is a structure schematic diagram of the flexible thin film solar cell in Example 1.

[0052] Figure 2 It is a front view schematic diagram of Figure 1 .

[0053] Figure 3 It is a left view schematic diagram of Figure 2 .

[0054] Figure 4 It is a top view schematic diagram of Figure 1 .

[0055] Figure 5 a front view schematic diagram of the flexible thin-film solar cell interconnection structure in Example 2;

[0056] Figure 6 a front view schematic diagram of the flexible thin-film solar cell interconnection structure in Example 2; Figure 5 a front view schematic diagram of the flexible thin-film solar cell interconnection structure in Example 2;

[0057] Figure 7 a front view schematic diagram of the flexible thin-film solar cell interconnection structure in Example 2;

[0058] Figure 8 a front view schematic diagram of the flexible thin-film solar cell interconnection structure in Example 2;

[0059] wherein: ①, flexible thin-film solar cell; H1, first interconnection part; H2, second interconnection part; 1, base layer; 2, first electrode layer; 3, device layer; 4, second electrode layer; 5, busbar layer; 6, interconnection connecting layer; ②, interconnection connecting piece; ③, interconnection insulation piece; t1, first insulation body; t2, second insulation body; m, gap; m1, first separation groove; m2, second separation groove; s1, first busbar; s2, first busbar; h, busbar. DETAILED DESCRIPTION

[0060] In order to make the above objectives, characteristics and advantages of the present application more apparent, more comprehensible, the present application will be described in detail below with the accompanying drawings and specific embodiments. In the following description, a large number of specific details are set forth in order to fully understand the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present application, therefore the present application is not limited by the specific embodiments disclosed below.

[0061] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0062] In addition, the terms "first", "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "a plurality of" is at least two, for example, two, three, etc., unless otherwise explicitly specified.

[0063] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0064] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0065] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation. Example 1

[0066] like Figures 1 to 4 As shown, the flexible thin-film solar cell involved in this embodiment has a first interconnection portion H1 and a second interconnection portion H2 formed on opposite sides, and the flexible thin-film solar cell includes a substrate layer 1, a first electrode layer 2, a device layer 3, a second electrode layer 4, and a bus layer 5 arranged sequentially from bottom to top.

[0067] Specifically, the substrate layer 1, the first electrode layer 2, the device layer 3, the second electrode layer 4, and the bus layer 5 are aligned from one side (left) to form a first interconnection H1; with the other side (right) of the bus layer 5 as a reference, the second electrode layer 4, the device layer 3, the first electrode layer 2, and the other side (right) of the substrate layer 1 are extended outward from top to bottom to form interconnection sides, and the reference side and the multiple interconnection sides constitute a second interconnection H2.

[0068] In this example, the epitaxial width of the second electrode layer 4 is equal to the epitaxial width of the device layer 3, i.e., the resulting interconnection side edges are equal in width; the epitaxial width of the first electrode layer 2 is equal to the epitaxial width of the substrate layer 1, i.e., the resulting interconnection side edges are equal in width. The flexible thin-film solar cell further comprises an interconnection connecting layer 6 covering the interconnection side edges of the first electrode layer 2, wherein the interconnection connecting layer 6 and the reference side of the busbar layer 5 are misaligned and insulated based on the interconnection side edges of the device layer 3 and the second electrode layer 4. Here, based on the configuration of the first interconnection part H1 and the second interconnection part H2, not only is the interconnection assembly facilitated, but also the short circuit caused by the communication between the first electrode layer and the second electrode layer is avoided.

[0069] In some embodiments, the width of the interconnection connecting layer 6 is w1, and the width of the interconnection side edge of the second electrode layer 4 is w2, wherein 50 μm≤w1≤w2. The interconnection connecting layer 6 is the area for electrode interconnection, and the width thereof should be considered to obtain sufficient flux, and generally the width≥50 μm. The larger the area of the cell, i.e., the larger the string current, the larger the electrode connecting area should be in theory. At the same time, the width of the interconnection side edge of the second electrode layer 4 mainly determines the insulation width between the interconnection connecting layer and the busbar layer, and generally the insulation width should be≥50 μm, i.e., the risk of electrode leakage should be completely avoided, and the determination should be made according to the process conditions and the electrical output characteristics of the product after interconnection.

[0070] Specifically, the preparation process of the flexible thin-film solar cell comprises the following steps:

[0071] 1) selecting a flexible substrate (substrate layer 1) that is not conductive;

[0072] 2) depositing a first electrode layer 2 based on covering the entire surface of the flexible substrate (substrate layer 1);

[0073] 3) depositing a device layer 3 of a P-N junction photoelectric device having photoelectric conversion capability on the first electrode layer 2;

[0074] 4) depositing a second electrode layer 4 on the surface of the device layer 3;

[0075] 5) defining the opposite sides of the structure layer as interconnection sides, wherein one interconnection side is used as a reference to perform edge cutting to form the interconnection side edges of the first electrode layer 2 and the substrate layer 1 opposite to the epitaxial direction;

[0076] 6) depositing an interconnection connection layer 6 on the interconnection side of the first electrode layer 2, while forming a busbar layer 5 on the second electrode layer 4, wherein the second electrode layer 4 and the cutting side of the device layer 3 form the interconnection side opposite to the busbar layer 5, the interconnection connection layer 6 and the busbar layer 5 are insulated and misaligned, and the uncut substrate layer 1, the first electrode layer 2, the device layer 3, the second electrode layer 4, the busbar layer 5 form a first interconnection part H1 from the interconnection side, and the interconnection side of the cutting side, the interconnection connection layer 6 and the busbar layer 5 form a second interconnection part H2.

[0077] In some embodiments, in step 1), the flexible substrate is any one or more of ultra-thin flexible glass, polymers such as polyethylene terephthalate, polyethylene naphthalate, polyimide, parylene, polycarbonate; the surface of the substrate layer formed based on the flexible substrate is the light-receiving surface of the battery, and the first electrode layer is a transparent conductive oxide; the surface of the substrate layer is not the light-receiving surface of the battery, and the first electrode layer is a transparent conductive oxide, a metal, and a composite stack of a metal and a transparent conductive oxide. The transparent conductive oxide includes but is not limited to any one or more of fluorine-doped tin oxide, tin-doped indium oxide, zinc-doped indium oxide, aluminum-doped zinc oxide, tungsten-doped indium oxide, titanium-doped tin indium oxide, boron-doped zinc oxide, or cerium-doped indium oxide; and / or, the metal includes but is not limited to one or more of copper, silver, iron, aluminum, tungsten, molybdenum, chromium, nickel, tantalum, vanadium, titanium, manganese. In short, the substrate material is a non-conductive flexible substrate, including but not limited to any one or a combination of at least two of ultra-thin flexible glass (UTG), polymers such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyimide (PI), parylene, polycarbonate (PC), etc. If one side of the substrate material is the light-receiving surface of the battery, the first electrode layer is a transparent conductive oxide (TCO), including but not limited to any one or a combination of at least two of FTO (fluorine-doped tin oxide), ITO (tin-doped indium oxide), IZO (zinc-doped indium oxide), AZO (aluminum-doped zinc oxide), IWO (tungsten-doped indium oxide), ITIO (titanium-doped tin indium oxide), BZO (boron-doped zinc oxide), or ICO (cerium-doped indium oxide). If one side of the substrate material is not the light-receiving surface of the battery, the first electrode layer can be any one or a combination of at least two of high-conductivity metals such as copper, silver, iron, aluminum, tungsten, molybdenum, chromium, nickel, tantalum, vanadium, titanium, manganese, or alloys thereof, or a composite stack of a metal and a TCO.

[0078] In step 2), the deposition method of the first electrode layer includes but is not limited to any one of vacuum evaporation, magnetron sputtering, reactive plasma deposition, chemical vapor deposition, screen printing, electroplating, and transfer printing; and the thickness of the formed first electrode layer is 10-1000 nm.

[0079] In step 3), the material of the device layer is amorphous silicon germanium, copper indium gallium selenide, cadmium telluride, gallium arsenide, perovskite. Preferably, the deposition method of the device layer includes but is not limited to any one of vacuum evaporation, magnetron sputtering, reactive plasma deposition, chemical vapor deposition, screen printing, electroplating, coating, spraying, printing, near-space sublimation deposition, and vapor transport deposition.

[0080] In step 5), based on the full-size battery cutting into several sub-batteries, the edge cutting of each sub-battery interconnection side is carried out. Based on the full-size battery cutting, the required single sub-battery can be formed, and the second interconnection part is cut and processed from each sub-battery to form the required second interconnection part, therefore, the processing efficiency is multiplied, and the cutting method includes but is not limited to any one of laser, scribing knife, gate knife, scissors, etc., and the cutting needs to ensure the minimization of damage to the battery and not cause the short circuit of the connection of the first electrode layer and the second electrode layer on the edge. At the same time, in step 5), the cutting method is laser and / or mechanical scribing, and the upper film layer is removed based on the first electrode layer surface to form the corresponding interconnection side edge, wherein the first electrode layer and the substrate layer are aligned, and the width of the corresponding interconnection side edge is at least 50 μm, and the interconnection connection layer fully covers the corresponding interconnection side edge. In short, all film layers above the first electrode layer are removed to obtain the electrode connection area, and the width of the removal should be minimized, but the width of the area as the electrode interconnection should consider that sufficient flux can be obtained, generally the width is ≥ 50 μm, the larger the area of the battery, that is, the larger the string current, the larger the electrode connection area in theory, and the removal method includes but is not limited to any one of laser, mechanical scribing or a combination of at least two.

[0081] In step 6), the busbar layer is a grid line structure, and the material used includes but is not limited to one or more of copper, silver, iron, aluminum, tungsten, molybdenum, chromium, nickel, tantalum, vanadium, titanium, manganese. In short, the width, number, and spacing of the grid lines depend on the light demand of the product, and if the surface does not need to be lighted, it can be a film layer with no gap and full coverage. The metal material includes but is not limited to any one of copper, silver, iron, aluminum, tungsten, molybdenum, chromium, nickel, tantalum, vanadium, titanium, manganese, and other high-conductivity metals and alloys or a combination or alloy of at least two. At the same time, the grid line structure is patterned by using a mask or a screen according to the component packaging design, and the deposition method of the back electrode drainage grid line includes but is not limited to any one of vacuum evaporation, magnetron sputtering, reactive plasma deposition, chemical vapor deposition, screen printing, electroplating, and transfer printing. Embodiment 2

[0082] In combination Figure 5 and Figure 6As shown, the embodiment relates to a flexible thin-film solar cell interconnection structure, which comprises a flexible thin-film solar cell ① (which is the same as the structure of embodiment 1), an interconnection connector ②, and an interconnection insulating member ③, wherein two flexible thin-film solar cells ① are aligned and matched with each other at a first interconnection part H1 and a second interconnection part H2, and a gap m is formed between the first interconnection part H1 and the second interconnection part H2, the interconnection connector ② electrically connects the busbar layer 5 of the first interconnection part H1 and the interconnection connecting layer 6 of the second interconnection part H2, and the interconnection insulating member ③ is filled into the gap m and insulates and separates the interconnection connector ② and the second electrode layer 4 of the second interconnection part H2.

[0083] Specifically, the gap m comprises a first slot m1 formed by the base layer 1, the first electrode layer 2 of the first interconnection part H1, and the base layer 1, the first electrode layer 2, and the interconnection connecting layer 6 of the second interconnection part H2; and a second slot m2 formed by the device layer 3, the second electrode layer 4, and the busbar layer 5 of the first interconnection part H1, and the device layer 3, the second electrode layer 4, and the busbar layer 5 of the second interconnection part H2, the interconnection connector ② is a current guide strip installed in the second slot m2 and electrically connecting the busbar layer 5 of the first interconnection part H1 and the interconnection connecting layer 6 of the second interconnection part H2, and the current guide strip separates the first slot m1 and the second slot m2, and the interconnection insulating member ③ comprises a first insulator t1 for filling the space formed by the current guide strip and the first slot m1, and a second insulator t2 for filling the space formed by the current guide strip and the second slot m2 and covering the busbar layer 5 of the first interconnection part H1.

[0084] In some specific embodiments, the insulating material of the first insulator t1 can be glass powder, rubber, silicone, nylon, resin, electrical wood, insulating polymer, and other insulating materials with high resistance that are easy to fill and cure, and the resistivity is ≥10 15 Ω·m. The insulating material of the second insulator t2 can be glass powder, rubber, silicone, UV glue, polymer, and other insulating materials with high resistance that are easy to fill and cure, and the resistivity is ≥10 15 Ω·m.

[0085] The preparation process of the flexible thin-film solar cell interconnection structure of the embodiment adopts the above-mentioned flexible thin-film solar cell interconnection structure, and comprises the following steps:

[0086] S1, laying sub-cells

[0087] The flexible thin-film solar cell is used as a sub-cell, and the first interconnection part and the second interconnection part of the two sub-cells are laid side by side with the interconnection sides opposite to each other to form a gap;

[0088] S2, series connection structure

[0089] The current guide strip is used to connect the busbar layer and the interconnection connecting layer between the adjacent two sub-cells;

[0090] S3, insulation protection

[0091] The gap between the drainage strip and the first and second interconnection parts is filled with insulation material to insulate the first electrode layer of the first and second interconnection parts and the second electrode layer of the drainage strip.

[0092] Preferably, the insulation material is a material that is easy to seal and cure and has a resistivity ≥ 10 15 Ω·m. The insulation material of the first insulation t1 can be glass powder, rubber, silicone, nylon, resin, electrical wood, insulating polymer, etc. which is easy to seal and cure and has high resistance with resistivity ≥ 10 15 Ω·m. The insulation material of the second insulation t2 can be glass powder, rubber, silicone, UV glue, polymer, etc. which is easy to seal and cure and has high resistance with resistivity ≥ 10 15 Ω·m. Example 3

[0093] As Figure 7 shown, it is connected in parallel to form a parallel group string by the battery string in Example 2, specifically, the preparation process of the flexible thin-film solar cell interconnection structure in Example 2 is used to form a battery string, and then two battery strings are aligned left and right and separated up and down, wherein each battery string has a first interconnection part H1 and a second interconnection part H2 on the left and right sides; then the first interconnection parts H1 on the same side are connected in series based on the first bus bar s1, and the second interconnection parts H2 on the same side are connected in series based on the second bus bar s2, to form a parallel battery string of flexible thin-film solar cells.

[0094] In this example, a specific implementation is taken as an example, the interconnection structure of the parallel battery string used, the size of the sub-cell: 190*96mm, the number of sub-cells: 36, the size of the module: 1200*600, the preparation steps are as follows:

[0095] 1) Use 300*400mm full-size flexible battery device film, a total of 6 pieces;

[0096] 2) Each full-size flexible battery device is cut into 6 sub-cells using a cutting and marking knife, a total of 36 sub-cells are prepared;

[0097] 3) Use a picosecond green laser to remove the electrode connection area on the film surface, with a width of 200μm;

[0098] 4) Divide each 12 cells into a group string, lay out 3 group strings with a cell spacing of 100μm;

[0099] 5) using copper conductive bus bar to connect the interconnection layer of the previous sub-cell with the bus layer of the next sub-cell in turn, the metal contact part adopts ultrasonic welding, and 12 sub-cells form a series structure;

[0100] 6) using insulating rubber to fill and cover the drainage bar and the gap between the battery drainage side and the sub-cell;

[0101] 7) using copper drainage bar to completely connect the bus layer of the corresponding three sub-cells on one side of the three battery group strings, and using copper drainage bar to connect the interconnection layer of the corresponding three sub-cells on the other side of the three battery group strings by ultrasonic welding, forming a parallel structure of three series battery group strings;

[0102] 8) laying POE adhesive film;

[0103] 9) laying butyl rubber strip on the edge;

[0104] 10) laminating the flexible PET barrier front plate and back plate after splicing to obtain a flexible perovskite assembly. Example 4

[0105] As shown in Figure 8 , it is formed by series connection of the battery string in Example 2 to form a series group string interconnection structure. Specifically, the battery string is formed by using the preparation process of the flexible thin film solar cell interconnection structure in Example 2, then the three battery strings are aligned left and right and separated up and down, then the first interconnection part H1 and the second interconnection part H2 on both sides of each battery string are respectively provided with a bus bar h, among the three battery strings, the first interconnection part H1 and the second interconnection part H2 of the upper and lower two battery strings are aligned left and right, the first interconnection part H1 and the second interconnection part H2 of the middle battery string are opposite to the first interconnection part H1 and the second interconnection part H2 of the upper and lower two battery strings, one second interconnection part H2 is arranged between the two first interconnection parts H1 on the left side and the three are aligned, one first interconnection part H1 is arranged between the two second interconnection parts H2 on the right side and the three are aligned, wherein every two battery strings are connected from one side of the bus bar, and the connected sides are alternated left and right along the up and down direction to form a left and right circuitous series battery group string.

[0106] Taking one specific implementation as an example, the series battery group string interconnection structure is adopted, at the same time, the battery string structure formed is exactly the same as that of Example 3, and the difference lies in the circuit connection between the battery strings.

[0107] In this example, three 12-cell series strings are arranged side by side, the head and tail of the middle string are arranged in reverse with the adjacent strings, and the bus bar h is used to connect the interconnection connection layer 6 of one series string and the bus connection layer 5 of another series string, (in short, the left side of the battery string in the middle is the second interconnection part, and the right side is the first interconnection part, and the direction of the upper and lower battery strings (defined as: top battery string and bottom battery string) is the same, the left side is the first interconnection part, and the right side is the second interconnection part, so during the series connection, the second interconnection part of the top battery string is connected with the first interconnection part of the middle battery string through the bus bar h (the interconnection connection layer of the second interconnection part and the bus connection layer of the first interconnection part are connected), at the same time, the second interconnection part of the middle battery string is connected with the first interconnection part of the bottom battery string through the bus bar h (the interconnection connection layer of the second interconnection part and the bus connection layer of the first interconnection part are connected), at the same time, the metal contact part adopts ultrasonic welding, and the three series strings are connected in series with each other.

[0108] Comparative Example

[0109] The comparative example uses a laser scribing interconnection process to make a flexible perovskite thin film solar cell module, which has a size of 1200*600mm, and the number of sub-cells is 93, and the preparation steps are as follows:

[0110] 1) Deposition of ITO layer on full-size flexible PET substrate to form first electrode layer;

[0111] 2) Using infrared laser P1 process to divide the first electrode layer into 93 regions along the long side direction;

[0112] 3) Using a reverse structure process to complete the preparation of the interlayer;

[0113] 4) Using picosecond green laser P2 process, scribing to ITO electrode along P1 parallel side;

[0114] 5) Using magnetron sputtering to deposit ITO / Cu composite back electrode;

[0115] 6) Using picosecond green laser P3 process, scribing to perovskite layer along P2 parallel side, and completely cutting off the back electrode;

[0116] 7) Using infrared laser edge cleaning process to remove the full-size edge by 10mm width for edge sealing;

[0117] 8) Laying bus bars and drainage bars;

[0118] 9) Laying POE adhesive film;

[0119] 10) Laying butyl rubber strip on the edge;

[0120] 11) Laminating the flexible PET barrier front plate and back plate to obtain a flexible perovskite module.

[0121] Based on the above, the interconnection structure of the solar cell module of examples 3, 4 and comparative examples is tested for the light power conversion efficiency of the cell under standard light and related electrical performance parameters under simulated solar light source using an IV tester. The specific test results are shown in Table 1.

[0122]

[0123] Based on the results in Table 1, using the interconnection structure of the present application, the module output characteristics can be flexibly adjusted, and compared with the process product of laser scribing interconnection, the following technical advantages are mainly obtained:

[0124] 1) The full metallization interconnection structure can significantly reduce the interconnection resistance, improve the collection efficiency, significantly improve the fill factor, and thus significantly improve the output power of the module.

[0125] 2) The sub-cell current can be significantly improved, while good output power can also be obtained, and the output characteristics of the current mainstream crystalline silicon module can be completely matched, and the system cost of thin film photovoltaic module installation can be significantly reduced.

[0126] 3) In the case of large sub-cell curvature radius, the module curvature radius can be realized at the same level as laser interconnection, reducing the risk of damage to the cell due to large curvature, and reducing the process difficulty of thin film device preparation, thereby improving the stability and yield of mass production.

[0127] 4) Under the same curvature and bending times, the module power loss is significantly reduced, which is mainly due to the smaller actual bending curvature of the sub-cell in the process of bending the module under the same curvature, and the damage to the cell is smaller.

[0128] The above has described the present application in detail, the purpose of which is to enable persons skilled in the art to understand the content of the present application and implement it, and it cannot limit the protection scope of the present application, any equivalent changes or modifications made according to the spirit and principle of the present application should be covered within the protection scope of the present application.

Claims

1. A flexible thin-film solar cell interconnection structure, comprising a flexible thin-film solar cell, interconnection connectors, and interconnection insulating components, wherein the flexible thin-film solar cell forms a first interconnection portion and a second interconnection portion on opposite sides, and the flexible thin-film solar cell includes a substrate layer, a first electrode layer, a device layer, a second electrode layer, and a current bus layer arranged sequentially from bottom to top, characterized in that, The substrate layer, the first electrode layer, the device layer, the second electrode layer, and the bus layer are aligned from the interconnect side to form the first interconnect portion; Taking the other side of the busbar layer as a reference, the other side of the interconnection of the second electrode layer, the device layer, the first electrode layer, and the substrate layer extends outward layer by layer from top to bottom to form interconnection sides, and the reference side and the multiple interconnection sides constitute a second interconnection portion. The extension width of the second electrode layer is less than or equal to the extension width of the device layer, and the extension width of the first electrode layer is less than or equal to the extension width of the substrate layer. The flexible thin-film solar cell also includes an interconnection layer covering the interconnection side of the first electrode layer. The interconnection layer and the reference side of the busbar layer are misaligned and insulated from each other based on the interconnection sides of the device layer and the second electrode layer. The width of the interconnection layer is w1, and the width of the interconnection side of the second electrode layer is w2, where 50μm≤w1≤w2. Two flexible thin-film solar cells are aligned and matched from the first interconnection section and the second interconnection section, and a gap is formed between the first interconnection section and the second interconnection section. An interconnect connector electrically connects the bus layer of the first interconnection section and the interconnection layer of the second interconnection section. An interconnect insulating member fills the gap and insulatingly separates the interconnect connector and the second electrode layer of the second interconnection section. The gap includes a first slot formed by the base layer of the first interconnection section, the base layer of the first electrode layer and the base layer of the second interconnection section, the first electrode layer and the interconnection layer; and a second slot formed by the device layer of the first interconnection section, the second electrode layer of the first interconnection section, the bus layer of the first interconnection section and the device layer of the second interconnection section, the second electrode layer of the second interconnection section and the bus layer of the second interconnection section. The interconnect connector is a current guide strip installed in the second slot and electrically connects the bus layer of the first interconnection section and the interconnection layer of the second interconnection section, and the current guide strip separates the first slot and the second slot. The interconnect insulating member includes a first insulator that fills the space formed by the current guide strip and the first slot, and a second insulator that fills the space formed by the current guide strip and the second slot and covers the bus layer of the first interconnection section.

2. The flexible thin-film solar cell interconnection structure according to claim 1, characterized in that, Interconnectors and insulators are used to interconnect each pair of flexible thin-film solar cells to form a cell string, and the cell interconnection structure is formed based on the parallel or series connection of the cell strings.

3. The flexible thin-film solar cell interconnection structure according to claim 1, characterized in that, The interconnect edges of the second electrode layer and the device layer are aligned.

4. The flexible thin-film solar cell interconnection structure according to claim 1, characterized in that, The interconnection edges of the first electrode layer and the substrate layer are aligned.

5. The flexible thin-film solar cell interconnection structure according to any one of claims 1 to 4, characterized in that, The fabrication of flexible thin-film solar cells includes the following steps: 1) Select a non-conductive flexible substrate; 2) Based on covering the entire surface of the flexible substrate, a first electrode layer is deposited and formed; 3) Deposit a device layer for a PN junction optoelectronic device with photoelectric conversion capability on the first electrode layer; 4) Deposited on the surface of the device layer to form a second electrode layer; 5) Define the opposite sides of the structural layer as interconnect sides, and perform edge cutting based on one interconnect side to form the interconnect side of the first electrode layer and the substrate layer that are relatively extended. 6) An interconnection layer is deposited on the interconnection side of the first electrode layer, and a bus layer is formed on the second electrode layer. The cut sides of the second electrode layer and the device layer extend outward relative to the bus layer to form interconnection sides. The interconnection layer and the bus layer are insulated from each other and staggered. The uncut substrate layer, the first electrode layer, the device layer, the second electrode layer, and the bus layer are aligned from the interconnection side to form a first interconnection portion. A second interconnection portion is formed between the interconnection side on the cut side, the interconnection layer, and the side of the bus layer.

6. The flexible thin-film solar cell interconnection structure according to claim 5, characterized in that, In step 5), the full-size battery is cut into several sub-cells, and then the edges of the interconnecting side of each sub-cell are cut.

7. The flexible thin-film solar cell interconnection structure according to claim 5, characterized in that, In step 1), the flexible substrate is made of ultra-thin flexible glass or a polymer, wherein the polymer is any one or more of polyethylene terephthalate, polyethylene naphthalate, polyimide, poly(p-xylylene), and polycarbonate; if the surface of the flexible substrate is the light-receiving surface of the battery, the first electrode layer is a transparent conductive oxide; if the surface of the flexible substrate is not the light-receiving surface of the battery, the first electrode layer is a transparent conductive oxide, a metal, or a composite layer of a metal and a transparent conductive oxide.

8. The flexible thin-film solar cell interconnection structure according to claim 7, characterized in that, The transparent conductive oxide includes fluorine-doped tin oxide, tin-doped indium oxide, zinc-doped indium oxide, aluminum-doped zinc oxide, indium oxide with tungsten doping, titanium-doped tin indium oxide, boron-doped zinc oxide, and cerium-doped indium oxide, and the transparent conductive oxide is any one or more of the included substances; and / or, the metal includes copper, silver, iron, aluminum, tungsten, molybdenum, chromium, nickel, tantalum, vanadium, titanium, and manganese, and the metal is one or more of the included substances.

9. The flexible thin-film solar cell interconnection structure according to claim 5, characterized in that, In step 2), the deposition method of the first electrode layer includes vacuum evaporation, magnetron sputtering, reactive plasma deposition, chemical vapor deposition, screen printing, electroplating and transfer printing, and the deposition method is any one of the methods included; and the thickness of the first electrode layer formed is 10-1000 nm.

10. The flexible thin-film solar cell interconnection structure according to claim 5, characterized in that, In step 3), the material of the device layer is amorphous silicon germanium, copper indium gallium selenide, cadmium telluride, gallium arsenide, or perovskite.

11. The flexible thin-film solar cell interconnection structure according to claim 5, characterized in that, The deposition methods for the device layer include vacuum evaporation, magnetron sputtering, reactive plasma deposition, chemical vapor deposition, screen printing, electroplating, coating, spraying, printing, near-space sublimation deposition, and vapor transport deposition, and the deposition method is any one of the methods included.

12. The flexible thin-film solar cell interconnection structure according to claim 5, characterized in that, In step 5), the cutting method is laser and / or mechanical scribing, and the upper film layer is removed with the surface of the first electrode layer as a reference to form the corresponding interconnect side. The first electrode layer and the substrate layer are aligned, and the width of the corresponding interconnect side is at least 50 μm. The interconnect connection layer fully covers the corresponding interconnect side.

13. The flexible thin-film solar cell interconnection structure according to claim 5, characterized in that, The second electrode layer and the device layer are aligned on the interconnect side, and the width of the interconnect side is at least 50 μm.

14. The flexible thin-film solar cell interconnection structure according to claim 5, characterized in that, In step 6), both the bus layer and the interconnect layer are metallized patterned layers, wherein the metallized patterned layer includes a gate layer and / or a cover plate layer, and the materials used in the metallized patterned layer include copper, silver, iron, aluminum, tungsten, molybdenum, chromium, nickel, tantalum, vanadium, titanium and manganese, and the materials used in the metallized patterned layer are one or more of the included materials.

15. A fabrication process for a flexible thin-film solar cell interconnect structure, characterized in that, It employs the flexible thin-film solar cell interconnection structure as described in any one of claims 1 to 14, and includes the following steps: S1, Laying out sub-batteries Flexible thin-film solar cells are used as sub-cells, and they are laid side by side with the first interconnection part and the second interconnection part of the two sub-cells separated from each other to form a gap. S2, series structure Use a current-guiding strip to connect the current-carrying layer and the interconnection layer between two adjacent sub-cells; S3, Insulation Protection The gap formed between the drain strip and the first interconnection part and the second interconnection part is filled with insulating material to relatively insulate and separate the first electrode layer of the first interconnection part and the drain strip and the second electrode layer of the second interconnection part.

16. The fabrication process of the flexible thin-film solar cell interconnection structure according to claim 15, characterized in that, A flexible thin-film solar cell interconnection structure is fabricated to form a cell string. Then, multiple cell strings are aligned left and right and separated vertically. The left and right sides of the multiple cell strings are respectively the first interconnection part and the second interconnection part. Then, the first interconnection parts on the same side are connected in series based on the first bus bar, and the second interconnection parts on the same side are connected in series based on the second bus bar to form a flexible thin-film solar cell parallel cell string.

17. The fabrication process of the flexible thin-film solar cell interconnection structure according to claim 15, characterized in that, A flexible thin-film solar cell interconnection structure is used to form a battery string. Multiple battery strings are then aligned horizontally and separated vertically. The left and right sides of each battery string are respectively the first interconnection section and the second interconnection section. Next, busbars are provided on both sides of each battery string corresponding to the first interconnection section and the second interconnection section. In every three adjacent battery strings, the first interconnection section and the second interconnection section of the upper and lower battery strings are aligned horizontally. The first interconnection section and the second interconnection section of the middle battery string are arranged in the opposite way to the first interconnection section and the second interconnection section of the upper and lower battery strings. A second interconnection section is arranged between the two first interconnection sections on the left and the three are aligned. A first interconnection section is arranged between the two second interconnection sections on the right and the three are aligned. Each two battery strings are connected by a busbar on one side, and the connected side alternates horizontally along the vertical direction to form a left-right meandering series battery string.

18. The fabrication process of the flexible thin-film solar cell interconnection structure according to claim 15, 16, or 17, characterized in that, The insulating material is a material that is easy to fill and cure and has a resistivity of ≥10¹⁵ Ω·m.

19. The fabrication process of the flexible thin-film solar cell interconnection structure according to claim 15, 16, or 17, characterized in that, The insulating material is glass powder or a polymer.

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