Composite transfer film and preparation method thereof, electrode grid line preparation method and crystalline silicon perovskite laminated cell

Abstract

The invention relates to a composite transfer film and a preparation method thereof, an electrode grid line preparation method and a crystalline silicon perovskite laminated cell, and relates to the technical field of solar cells. The composite transfer film comprises a patterned layer with a micro-groove structure, a functional layer with the surface energy lower than 25 mN / m, and an additional structure layer compounded with the patterned layer, the additional structural layer can be configured as a combination of a substrate layer and an adhesive layer on one side of the patterned layer facing away from the functional layer, or a reinforcing layer between the patterned layer and the functional layer. The preparation method of the electrode grid line uses the transfer printing film and is completed through the procedures of slurry filling, hot-pressing lamination, dry-method physical stripping and curing. Through collaborative design of a full-dry-method stripping mechanism and a multi-layer structure, the fundamental contradiction that a traditional washing or high-temperature process is incompatible with the perovskite thermo-sensitive characteristic is solved, low-temperature reliable transfer printing of a high-precision electrode is achieved, and the performance of the crystalline silicon perovskite laminated cell is remarkably improved.

Description

A composite transfer film and its preparation method, an electrode grid line preparation method, and a crystalline silicon perovskite tandem solar cell. Technical Field

[0001] This application relates to the field of solar cell technology, and in particular to a composite transfer film and its preparation method, an electrode grid line preparation method, and a crystalline silicon perovskite tandem solar cell. Background Technology

[0002] In the photovoltaic field, crystalline silicon-perovskite tandem solar cells are considered the next-generation core technology for breaking through the single-junction efficiency limit and achieving ultra-high photoelectric conversion efficiency (>30%). The successful fabrication of this structure relies on a key process: the preparation of metal grid electrodes. These electrodes not only need to form good ohmic contact with the crystalline silicon base cell (usually requiring high-temperature treatment), but also must ensure that the perovskite functional layer, which is extremely sensitive to heat, humidity, and solvents, remains undamaged throughout the entire process.

[0003] Currently, the mainstream electrode fabrication methods in the industry are derived from traditional crystalline silicon solar cell processes, generally employing transfer film technology based on water-soluble polymers (such as polyvinyl alcohol PVA) or pattern transfer technology based on thermal imprinting (such as polylactic acid PLA film). However, when these existing methods are applied to tandem solar cell scenarios, their inherent defects are significantly amplified. On the one hand, the removal steps required for water-soluble transfer films rely on water washing or high-temperature combustion. The wastewater generated by the former can corrode the perovskite layer, while the high temperature required by the latter far exceeds the thermal decomposition temperature of perovskite, leading to device failure. On the other hand, existing imprinting technologies have limitations in terms of transfer pattern accuracy and adaptability to rough or fragile surfaces, making it difficult to achieve precision grid lines with linewidths less than 10 micrometers and high aspect ratios, thus restricting further improvements in cell performance. In addition, related processes are often cumbersome, have low material utilization rates, and are accompanied by solvent residues or exhaust emissions, which are detrimental to production cost control and green manufacturing.

[0004] Therefore, there is an urgent need in this field for an electrode transfer technology that can eliminate the dependence on water washing and high-temperature combustion, achieve high-precision pattern transfer under low or medium temperature conditions, and is fully compatible with the properties of crystalline silicon and perovskite materials. Summary of the Invention

[0005] To address the problems of process incompatibility (water washing or high temperature damage to perovskite), insufficient pattern accuracy, and environmental unfriendliness of existing transfer technology when applied to the preparation of electrodes for crystalline silicon perovskite tandem solar cells, this application provides a composite transfer film and its preparation method, an electrode grid line preparation method, and a crystalline silicon perovskite tandem solar cell.

[0006] The composite transfer film and its preparation method, electrode grid line preparation method, and crystalline silicon perovskite tandem solar cell provided in this application adopt the following technical solution: A composite transfer film includes: a patterned layer having a microgroove structure; an additional structural layer composited with the patterned layer; and a functional layer having a surface energy of less than 25 mN / m; wherein the additional structural layer is a reinforcement layer, which is bonded between the patterned layer and the functional layer; and the reinforcement layer is a SiO2 layer or an Al2O3 layer.

[0007] In one specific feasible implementation, the thickness of the reinforcing layer is 0.1-10 μm.

[0008] A composite transfer film includes: a patterned layer having a microgroove structure; an additional structural layer composited with the patterned layer; and a functional layer having a surface energy below 25 mN / m. The additional structural layer is located on the side of the patterned layer opposite to the functional layer, and includes a substrate layer and an adhesive layer. The adhesive layer is connected to the surface of the patterned layer opposite to the functional layer and is located between the substrate layer and the patterned layer. The adhesive layer is a self-healing adhesive layer with a reversible adhesion interface, including an adhesive layer with a dynamic cross-linked network formed by coordination bonds between metal ions and a polymer matrix, or an organosilicon layer, an acrylic adhesive layer, or a perfluoroethylene propylene adhesive layer.

[0009] In one specific implementation, the thickness of the adhesive layer is 2-20 μm, and the thickness of the base layer is 20-80 μm.

[0010] In one specific implementation, the polymer matrix is ​​polyvinyl alcohol, and the metal ions include Al. 3+ or Fe 3+ .

[0011] In one specific implementation, the substrate layer is a high-temperature resistant polymer film with a surface modified by fluorosilane and a hydrophobic angle greater than 110°; the material of the substrate layer includes polyethylene terephthalate, polypropylene, polycarbonate, polymethyl methacrylate, polyimide, or polytetrafluoroethylene.

[0012] For the two composite transfer films mentioned above, the material of the functional layer includes at least one of fluorinated compounds, silane compounds, wax compounds, or fatty acid salts.

[0013] For the two composite transfer films mentioned above, the material of the patterned layer includes polyvinyl alcohol, polyvinylpyrrolidone, hydroxypropyl methylcellulose, polyethylene glycol, polyolefin, polyethylene terephthalate, or polylactic acid; the thickness of the patterned layer is 5-80 μm.

[0014] For the two composite transfer films mentioned above, the width of the microgroove structure is 3-20 μm, the depth is 6-30 μm, and the aspect ratio is >1.

[0015] A method for preparing a composite transfer film as described above includes the following steps: providing a mold having a raised structure on its surface; forming a patterned layer on the surface of the mold; performing a demolding and lamination step, such that a microgroove structure corresponding to the raised structure is formed on the patterned layer, and an additional structural layer is laminated onto the patterned layer; forming a functional layer.

[0016] In one specific implementation, when the additional structural layer includes a base layer and an adhesive layer, the demolding and lamination steps specifically involve: aligning and bonding the pre-formed additional structural layer, which includes the adhesive layer and the base layer, with the surface of the adhesive layer aligned with the side surface of the patterned layer facing away from the microgroove structure; and then demolding the composite including the adhesive layer, the base layer, and the patterned layer from the mold surface.

[0017] In one specific implementation, the adhesive layer material is subjected to at least one freeze cycle before forming the additional structural layer comprising the adhesive layer and the substrate layer.

[0018] In a specific implementation scheme, when the additional structural layer is a reinforcing layer, the demolding and lamination steps are as follows: first, the patterned layer is demolded from the mold surface, and then the reinforcing layer is directly deposited on the side surface of the patterned layer with the microgroove structure through a physical vapor deposition process.

[0019] In one specific implementation, the step of forming the functional layer includes: depositing the functional layer on the surface of the patterned layer and the microgroove structure, or on the surface of the reinforcement layer, by means of a physical vapor deposition process.

[0020] A method for fabricating electrode grid lines, using a composite transfer film as described above, includes the following steps: filling the microgroove structure of the composite transfer film with conductive paste; aligning and bonding the composite transfer film filled with the conductive paste to the surface of a battery substrate; performing a hot-pressing process to transfer the conductive paste to the surface of the battery substrate; physically peeling off the composite transfer film to leave the conductive paste pattern on the surface of the battery substrate; and curing the conductive paste on the surface of the battery substrate to form electrode grid lines.

[0021] In one specific implementation, when the surface of the battery substrate is a crystalline silicon battery surface, the hot pressing temperature is 80-180℃ and the pressure is 0.5-20MPa; the curing process is sintered and cured at 500-1000℃.

[0022] When the surface of the battery substrate is a perovskite top cell surface, the hot pressing temperature is 60-150℃ and the pressure is 0.05-10MPa; the curing process is carried out at a temperature not exceeding 150℃.

[0023] A crystalline silicon perovskite tandem solar cell includes: a crystalline silicon bottom cell; a perovskite top cell; and at least one electrode, fabricated by the electrode grid line fabrication method described above; wherein the at least one electrode includes a front electrode located on the surface of the crystalline silicon bottom cell and / or a top electrode located on the surface of the perovskite top cell.

[0024] In summary, the beneficial technical effects of this application are as follows: By designing a composite transfer film with a specific layered structure and function, this application fundamentally solves the process compatibility problem in the preparation of electrodes for crystalline silicon perovskite tandem solar cells. Its core lies in utilizing fluorine-containing compounds to form an ultra-low surface energy functional layer, combined with a fully dry physical exfoliation process, completely eliminating the water washing and high-temperature combustion steps relied upon by traditional technologies. This not only resolves the thermal budget conflict between the high-temperature process of crystalline silicon and the thermally sensitive characteristics of perovskite, achieving unified and gentle preparation of the upper and lower electrodes of the tandem structure, but also ensures high fidelity of the microgroove pattern from the source through in-situ mold forming technology, thereby enabling high-precision grid line transfer with a linewidth of less than 10 micrometers and an excellent aspect ratio. This solution also has significant advantages in green manufacturing and economy, with no wastewater or exhaust gas emissions, and the transfer film is reusable. Combined with precise groove filling technology, it significantly reduces material consumption and production costs.

[0025] Furthermore, this application ensures high process reliability and superior performance of the final device through innovative material and structural design. Two optimized structures are designed for different application scenarios: a self-healing adhesive layer with dynamic coordination bonds provides strong and reversible adhesion to rough crystalline silicon surfaces, while also endowing the transfer film with excellent self-healing capabilities and a long service life; an inorganic reinforcement layer provides necessary mechanical support for the fragile patterned layer, enabling reliable dry film removal on perovskite surfaces. This gentle dry process protects sensitive material interfaces throughout, reducing defects and recombination centers, thus ensuring that the fabricated tandem solar cells simultaneously achieve high photoelectric conversion efficiency and excellent long-term operational stability, providing a crucial process foundation for the industrialization of next-generation high-performance photovoltaic technology. Attached Figure Description

[0026] Figure 1 is a schematic diagram of the composite transfer film used to demonstrate configuration one (structure A).

[0027] Figure 2 is a schematic diagram of the composite transfer film used to demonstrate configuration two (structure B).

[0028] Figure 3 is a flowchart illustrating the preparation method of the composite transfer film of configuration one (structure A).

[0029] Figure 4 is a flowchart illustrating the preparation method of the composite transfer film of configuration two (B structure).

[0030] Figure 5 is a flowchart illustrating the method for fabricating electrode grid lines.

[0031] Figure 6 is a schematic diagram of the composite transfer film used to demonstrate the fabrication of electrode grid lines in application configuration one (structure A).

[0032] Figure 7 is a schematic diagram of the composite transfer film used to demonstrate the fabrication of electrode grid lines using configuration two (B structure).

[0033] Explanation of reference numerals in the attached figures: 1. Composite transfer film; 2. Patterned layer; 21. Microgroove structure; 3. Functional layer; 4. Additional structural layer; 41. Base layer; 42. Adhesive layer; 43. Reinforcing layer; 5. Battery substrate; 6. Conductive paste; 7. Electrode grid lines. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be described in detail and completely below with reference to Figures 1-7. It should be understood that the specific embodiments described herein are only for explaining this application and are not intended to limit this application.

[0035] In the fabrication of crystalline silicon perovskite tandem solar cells, the preparation of the electrode grid lines is a crucial step connecting high performance and manufacturability. Traditional wet processes based on water-soluble transfer films (such as PVA and PEG films), or processes based on high-temperature combustion to remove the carrier film, fundamentally conflict with the thermal and water sensitivity of perovskite materials due to their inherent water washing steps or high-temperature processes. This not only leads to complex processes, low yields, and heavy environmental burdens, but also makes it difficult to achieve reliable transfer of high-precision, high aspect ratio grid lines on rough crystalline silicon textured surfaces or fragile perovskite surfaces, forming a core process bottleneck restricting the industrialization of crystalline silicon perovskite tandem solar cells. This application aims to completely solve this series of interrelated problems.

[0036] Referring to Figures 1 and 2, this application provides a composite transfer film for the fabrication of electrodes in crystalline silicon perovskite tandem solar cells. The core design of this transfer film lies in achieving high-precision patterning of the conductive paste and full-process dry physical stripping through the synergistic and decoupled design of multi-layer functional structures, matching the vastly different thermal budgets and process requirements of the upper and lower layers of the crystalline silicon perovskite tandem solar cell.

[0037] The composite transfer film 1 is basically composed of three core functional layers: a patterning layer 2, a functional layer 3, and an additional structural layer 4. The following sections will provide a detailed explanation of each layer, incorporating design principles, material selection, and structural parameters.

[0038] The patterned layer 2 serves as the graphic carrier for the transfer film. Its surface is pre-set with microgroove structures 21 that are complementary to the target electrode pattern. The microgroove structures 21 are used to accommodate conductive paste and directly determine the width, depth, and morphology of the final electrode grid lines. The cross-sectional shape of the microgroove structure 21 can be selected according to the electrode design requirements, including but not limited to rectangles, trapezoids, triangles, semicircles, etc. In a preferred embodiment, the cross-sectional shape of the microgroove structure 21 is triangular, and the sidewalls of the triangular grooves are inclined. This facilitates the filling and demolding of the conductive paste 6 during the transfer process and reduces paste residue. Furthermore, the electrode grid lines formed by the triangular cross-section have a better conductive cross-sectional shape after sintering, which helps to reduce series resistance. In addition, the inclined sidewalls can also reduce light reflection and further improve the light absorption efficiency of the battery.

[0039] The patterned layer 2 uses a film-forming polymer material that is compatible with subsequent processes, including but not limited to polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), hydroxypropyl methylcellulose (HPMC), polyethylene glycol (PEG), and polylactic acid (PLA), polyethylene terephthalate (PET), polyethylene (PE), and other polyolefin materials. Among them, PVA is a preferred option due to its excellent water solubility (facilitating mold cleaning), good film-forming properties, and excellent chemical affinity with the PVA-based self-healing adhesive layer that may be used later.

[0040] The thickness of the patterned layer 2 is 5-80 μm, preferably controlled between 5-20 μm. This thickness range ensures that the microgroove structure 21 has sufficient depth to accommodate a sufficient amount of conductive paste (forming highly conductive electrode grid lines), while also ensuring that the film layer has good flexibility and adhesion to the substrate. The width of the microgroove structure 21 is designed to be 3-20 μm and the depth is 6-30 μm, thereby achieving a balance between ultra-fine grid lines (reducing light shading loss) and sufficient conductive cross-sectional area (reducing series resistance). Through high-precision mold forming technology, the microgroove structure 21 has extremely high contour fidelity, steep sidewalls, and a depth-to-width ratio greater than 1, thus laying the foundation for transferring high aspect ratio electrode grid lines.

[0041] Functional layer 3 is key to achieving dry stripping and selective retention of conductive paste. Functional layer 3 is constructed on the inner surface of patterned layer 2 and its microgroove structure 21. Its main function is to significantly reduce the adhesion between the surface and the conductive paste, so that separation can occur precisely at the weak interface during the subsequent physical stripping process, thereby achieving clean demolding of the paste and high-precision pattern transfer.

[0042] The functional layer 3 is made of a low surface energy material. The surface energy of the functional layer 3 should be significantly lower than that of the main material of the patterned layer 2. The surface energy of the functional layer 3 is lower than 25 mN / m, preferably lower than 20 mN / m. With this design, when peeling off after transfer, the interface between the conductive paste and the inner surface of the microgroove structure 21 becomes the weakest interface in the entire adhesion system, thereby achieving clean demolding of the conductive paste.

[0043] To achieve the aforementioned surface energy requirements, various low surface energy materials can be selected for the functional layer, and films can be formed through specific processes. The following are specific feasible implementation schemes: Fluorine-containing compounds, including polytetrafluoroethylene (PTFE) nanolayers formed by physical vapor deposition (PVD) or liquid-phase methods, and self-assembled monolayers of perfluorosilanes, etc., provide extremely low surface energy and excellent release properties. For example, magnetron sputtering can be used with a high-purity PTFE target. The process parameters are: substrate (patterned layer) temperature maintained at 80℃, working gas pressure in the sputtering chamber 0.5 Pa, argon flow rate 50 sccm, sputtering power 100 W, and deposition time 5-15 minutes. By controlling the deposition time, a dense PTFE nanofilm with a thickness of 10-30 nm can be obtained. Water droplet contact angle testing shows that its surface energy can be stabilized at 12-15 mN / m.

[0044] Silane compounds, especially silane coupling agents with long-chain alkyl or fluoroalkyl groups (such as octadecyltrichlorosilane and perfluorooctyltriethoxysilane), can also effectively reduce surface energy by self-assembling to form monolayers. For example, a 0.5 wt% perfluorooctyltriethoxysilane (FAS-17) ethanol solution can be prepared, and a patterned layer with a microgrooved structure can be immersed in the solution for 5 minutes or uniformly sprayed onto its surface under ultrasonic spraying conditions. Subsequently, heat treatment in an oven at 120°C for 30 minutes can promote the hydrolysis of silanes and their condensation on the surface to form a self-assembled monolayer. The thickness of this layer is about 1-2 nm, the contact angle is greater than 110°, and the surface energy can be reduced to about 10 mN / m.

[0045] Other low surface energy organic materials, such as certain waxes, higher fatty acid salts, or organosilicon polymers; in this embodiment, the organosilicon polymer includes, but is not limited to, dimethyl organosilicon oil, benzyl organosilicon oil, methylhydrosilicone oil, etc.; they can be coated onto the patterned layer surface using various coating processes to form a uniform coating. For example, using a microgravure coating process, methylphenyl silicone oil with a viscosity of approximately 1000 mPa·s, or addition-reaction liquid silicone rubber premixed with a crosslinking agent (such as hydrogen-containing silicone oil) and a platinum catalyst, is directly coated onto the patterned layer surface at a speed of 3-10 m / min using a microgravure coating process; by precisely controlling the cell depth and coating speed of the gravure roller, the wet film thickness can be controlled at 2-8 μm, and then heat-cured at 120-180℃ for 1-5 minutes to form a crosslinked organosilicon coating with a thickness of approximately 0.2-2 μm and a surface energy of approximately 20-22 mN / m.

[0046] For silicone resins or silicone oil systems with viscosities ranging from 500 to 2000 mPa·s, spraying processes can be used for direct application using high-pressure airless spraying or rotary cup electrostatic spraying, without the need for solvent dilution. High-pressure airless spraying involves pressurizing the material to 5-20 MPa using a high-pressure pump, atomizing it through a dedicated nozzle, and then spraying it onto the substrate surface. The atomization pressure and nozzle diameter can be precisely adjusted according to the viscosity to ensure uniform atomization. Rotary cup electrostatic spraying utilizes a high-speed rotating cup (10,000-100,000 RPM). The centrifugal force generated by the spraying process (rpm) atomizes the material, while a high voltage electrostatic charge of 50-90kV is applied, causing the atomized particles to become charged and more uniformly adsorbed onto the grounded substrate surface. After spraying, the wet film thickness can be controlled by the walking speed and the amount of spraying. After curing by heat treatment at 60-160℃ for 0.5-10 minutes, a uniform organosilicon functional layer with a thickness of about 0.2-2μm and a surface energy of about 20-24mN / m is formed. The spraying process is particularly suitable for achieving rapid and uniform film coverage on complex surfaces with microgroove structures 21.

[0047] The thickness of functional layer 3 is 0.1-0.5 μm. This nanometer-scale thickness is sufficient to form a continuous and dense low-energy layer on its surface, while not changing the original geometry and size of the microgroove, thus ensuring the accuracy of pattern transfer.

[0048] The additional structural layer 4 is combined with the patterned layer 2, and its configuration is one of the following two: configuration one, located on the side of the patterned layer 2 facing away from the functional layer 3; configuration two, located between the patterned layer 2 and the functional layer 3; the main function of the additional structural layer 4 is to provide necessary mechanical support and operational rigidity for the entire transfer film, and to achieve interface adaptation and stress management with the battery substrate during the transfer process; based on the completely different substrate characteristics of the upper and lower layers of the crystalline silicon perovskite tandem battery (rough and hard crystalline silicon textured surface and flat and fragile perovskite functional layer), this application provides two optimized implementation schemes for the additional structural layer 4.

[0049] Referring to Figure 1, Configuration 1, a four-layer structure including a substrate layer 41 and an adhesive layer 42 (referred to as Structure A): This structure is used when it is applied to scenarios where a strong temporary adhesion is required to the rough textured surface of a crystalline silicon base cell, and the electrode subsequently needs to undergo high-temperature sintering (>500°C) to form an ohmic contact; the excellent high-temperature resistance of the crystalline silicon surface allows this high-temperature process step to be completed independently before the preparation of the heat-sensitive perovskite layer.

[0050] In this configuration, the additional structural layer 4 is located on the side of the patterned layer 2 facing away from the functional layer 3, specifically including a base layer 41 and an adhesive layer 42; the adhesive layer 42 is located between the base layer 41 and the patterned layer 2, and the adhesive layer 42 is in direct contact with the patterned layer 2, and the thickness of the adhesive layer 42 is preferably 2-20 μm; the adhesive layer 42 is a self-healing adhesive layer with a reversible adhesion interface.

[0051] In a preferred embodiment, the adhesive layer 42 is a glue layer with a dynamic cross-linked network formed by coordination bonds between metal ions and the polymer matrix. For example, the glue layer is a PVA-metal ion hydrogel based on dynamic coordination bonds; specifically, polyvinyl alcohol (PVA) is used as the polymer matrix, and Al is introduced. 3+ or Fe 3+ When metal ions act as crosslinking agents, they form dynamic coordination bonds of "-O-Al-O-" or "-O-Fe-O-" with the hydroxyl groups (-OH) on the PVA chain, thus forming a reversible crosslinking network.

[0052] This network exhibits reversible bond breakage under external forces (such as thermoforming or tearing stress) to dissipate energy, and can recombine after the external force is removed, giving the adhesive layer self-healing capabilities (e.g., a 50μm deep scratch heals at 25°C for 3 minutes with a healing rate >92%). This not only significantly extends the lifespan of the transfer film (reusable >50 times), but more importantly, it possesses high viscosity and rheological properties at transfer temperatures (e.g., 80-180°C), fully filling the voids in the crystalline silicon textured surface, achieving a viscosity as high as 10 N / cm. 2 The above exhibits strong temporary adhesion; however, its adhesion can be controlled to decrease during cooling or subsequent peeling, facilitating demolding.

[0053] In other embodiments, the adhesive layer 42 may also be an adhesive layer with similar reversible or thermo-adhesive properties, such as an organosilicon (silicone, silicone resin) layer, an acrylic adhesive layer, or a polyfluoroethylene propylene (FEP) layer.

[0054] The base layer 41, located on the outermost side, is the main mechanical support. Its material needs to possess high mechanical strength, a low coefficient of thermal expansion, and excellent high-temperature resistance to withstand potential subsequent high-temperature processes or repeated use. Materials for the base layer 41 include polyimide (PI), polyethylene terephthalate (PET), polypropylene (PP), polycarbonate (PC), polymethyl methacrylate (PMMA), or polytetrafluoroethylene (PTFE), etc. Among these, polyimide (PI) is a preferred embodiment due to its high strength (elastic modulus up to 3.2 GPa), high heat resistance (long-term operating temperature >300℃), and dimensional stability. The thickness of the base layer 41 is 20-80 μm, preferably 20-50 μm, to ensure sufficient stiffness and tensile strength.

[0055] The substrate 41 has two opposing surfaces: a bonding surface facing the adhesive layer 42 and an outer surface facing away from the adhesive layer 42. To further optimize performance, the bonding surface of the substrate 41 is activated by plasma, corona discharge, or ultraviolet ozone to increase its surface energy and introduce active groups, thereby forming a strong bond with the adhesive layer 42. The outer surface of the substrate 41 is modified with fluorosilane reagent to make its hydrophobic angle greater than 110°. This superhydrophobic surface helps to provide an easy-to-grip interface when the entire transfer film is finally peeled off from the battery substrate and helps to ensure a smooth peeling process.

[0056] Referring to Figure 2, configuration two, a three-layer structure including the reinforcing layer 43 (referred to as structure B): This structure is used when applied to the flat but heat-sensitive surface of the functional layer 3 of a perovskite top cell, where organic solvents or adhesive contamination are strictly prohibited; perovskite materials generally cannot withstand long-term heat loads exceeding 150°C, and their interface quality is crucial to cell performance.

[0057] In this configuration, the additional structural layer 4 is located between the patterned layer 2 and the functional layer 3, and is directly composed of a reinforcement layer 43. The reinforcement layer 43 is deposited directly on the patterned layer 2 and the microgroove structure 21 layer using processes such as physical vapor deposition (PVD) to form a dense inorganic material film, such as a silicon dioxide (SiO2) layer or an aluminum oxide (Al2O3) layer. The reinforcement layer 43 can greatly improve the mechanical strength, modulus and thermal stability of the patterned layer 2 (such as PVA) which originally has weak mechanical properties. It enables the ultrathin patterned layer 2 to withstand sufficient tensile stress without cracking or excessive plastic elongation during the subsequent dry peeling process, thereby achieving dry physical peeling.

[0058] The thickness of the reinforcing layer 43 is between 0.1-10 μm, preferably 10 nm-1 μm, which is sufficient to provide a significant reinforcing effect while maintaining the overall flexibility of the composite transfer film 1; subsequently, the functional layer 3 will be constructed on the surface of this reinforcing layer 43.

[0059] Referring to Figures 3 and 4, based on the innovative structure of the composite transfer film 1 described above, this application also provides its corresponding preparation method. The core of this method lies in direct coating with a mold and dry lamination to ensure high precision at the source of the microgroove structure 21 and a stable bond between each layer. For the two different composite transfer films 1, configuration one (structure A) and configuration two (structure B) (please refer to Figures 1 and 2 for the specific structure of the composite transfer film 1), the preparation methods differ in the order of key steps, which will be described in detail below.

[0060] Referring to Figure 3, the preparation method of the composite transfer film 1 of configuration one (structure A): This method is applicable to the preparation of a four-layer composite transfer film 1 containing a base layer 41 and an adhesive layer 42, and mainly includes the following steps: Mold preparation: Provide a mold with a raised structure on the surface; In this embodiment, the mold material is metal (such as nickel, stainless steel) or silicon, and its surface is formed with a raised structure of the target electrode grid pattern by photolithography, etching or electroforming process. The size of the raised structure directly determines the size of the microgroove structure 21 on the composite transfer film 1.

[0061] For example, for electrode grid lines with a target linewidth of 3-5 μm and a height of 6-12 μm, the width and height of the mold protrusions need to be precisely designed, taking into account material shrinkage. The mold surface must maintain extremely high smoothness (roughness Ra < 0.05 μm) and dimensional accuracy (error < ± 0.1 μm), and undergo hydrophobic treatment (such as coating with a perfluorinated release agent) before use to facilitate the subsequent demolding of the polymer film, controlling the demolding force to 0.1 N / cm. 2 The following steps should be taken to avoid damaging the delicate structure.

[0062] Patterned layer 2 forming: Patterned layer 2 is formed on the surface of the mold; the forming of patterned layer 2 is a key step that directly determines the accuracy of the electrode grid lines. There are two main forming methods for patterned layer 2: Method 1: Direct coating forming on the mold surface. The patterned layer 2 material (such as PVA solution) is applied to the mold surface and cured through spin coating, scraping coating, slot coating or melt extrusion process.

[0063] The material of the patterned layer 2 can be a solution-based polymer or a thermoplastic polymer; among which, solution-based polymers include, but are not limited to, polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), hydroxypropyl methylcellulose (HPMC), polyethylene glycol (PEG), etc., which can be formulated into corresponding polymer solutions for coating and molding; thermoplastic polymers include, but are not limited to, polylactic acid (PLA), polyethylene terephthalate (PET), etc., which can be molded through melt extrusion process.

[0064] Taking PVA solution as an example: Prepare a PVA aqueous solution with a solid content of 10-20 wt%. A small amount (0.1-2%) of surfactant or leveling agent can be added to improve wettability. The solution viscosity should be controlled between 50-150 mPa·s to ensure good leveling and filling properties. Apply the prepared PVA solution to the mold surface by spin coating, blade coating, or slot coating. After hot air drying (80-100℃) to allow the solvent to evaporate, the solution will solidify and form the mold.

[0065] Taking PLA melt extrusion as an example: PLA particles are heated to 170-200℃ to melt, and then uniformly coated onto the mold surface through the extrusion die. After cooling, they are solidified and formed.

[0066] Method 2: Pre-film imprinting. This method first prepares a flat polymer film, and then imprints a pattern onto it. Specifically: materials such as PVA, PTFE, polylactic acid (PLA), thermoplastic polyurethane (TPU), or polyester, polyamide, and polyolefin films can be used; the preheated and softened film is aligned with a cooled mold, and pressed together at a certain temperature (such as above the glass transition temperature of PLA) and pressure (0.5-10MPa) to cause plastic deformation of the film, forming a microgroove structure 21. Alternatively, a UV curing process can be used, in which liquid resin is applied to the film, pressed together with a transparent mold, and UV cured. This method is highly efficient, but the precision is slightly lower than that of direct coating.

[0067] Composite of Additional Structural Layer 4 (Base Layer 41 and Adhesive Layer 42): After the patterned layer 2 on the mold is cured, the additional structural layer 4, which includes the base layer 41 and the adhesive layer 42, is laminated onto it. Specifically: a. Pretreatment of Base Layer 41: In this embodiment, the material of the base layer 41 is a 25μm thick polyimide (PI) film; in other embodiments, the material of the base layer 41 may also be polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polytetrafluoroethylene (PTFE), or polycarbonate (PC), etc.

[0068] First, the surface of the PI film facing the adhesive layer 42 is activated (e.g., oxygen plasma treatment, corona treatment, or ultraviolet ozone treatment) to increase its surface energy and introduce active groups (e.g., hydroxyl, carboxyl groups). This treatment enables stronger physical adsorption or chemical bonding (e.g., hydrogen bonds) between the substrate layer 41 and the adhesive layer 42 (e.g., PVA hydrogel), ensuring that the substrate layer 41 and the adhesive layer 42 are firmly bonded as a whole during the transfer and peeling process, without interlayer separation. For example, after oxygen plasma treatment, the surface contact angle of the PI film can be significantly reduced from about 90° to below 35°, and the surface energy is greatly improved.

[0069] The outer surface of the substrate 41 (the outer surface that does not contact any functional layer 3) is usually hydrophobically modified and has low surface energy. It can be treated with fluorosilane reagents to make its hydrophobic angle greater than 110°. The purpose of this modification is to ensure that the operator or equipment can easily grasp and apply force when the entire composite transfer film 1 is finally peeled off from the battery substrate. At the same time, its extremely low surface energy characteristics further ensure that any accidental adhesion or interference during the peeling process tends to be overcome at this superhydrophobic interface, thereby assisting in achieving a clean and neat overall peeling.

[0070] b. Preparation of adhesive layer 42: A self-healing adhesive layer precursor solution is prepared. Taking PVA-metal ion dynamic coordination hydrogel as an example: PVA1799 powder is dissolved in deionized water to prepare a 10-20 wt% PVA solution. AlCl3, FeCl3, or other polyvalent metal salts are added as crosslinking agents, controlling the molar ratio of metal ions to PVA hydroxyl groups to be between 0.1 and 0.5 (preferably 0.3); Al 3+ Fe 3+ Plasma forms dynamic coordination bonds "-O-Al-O-" or "-O-Fe-O-" with the -OH on the PVA chain. These bonds can be reversibly broken to dissipate energy when subjected to external forces (adhesion pressure, tearing force), and can be rapidly reassembled after the external force is removed, giving the adhesive layer self-healing ability.

[0071] Before coating, the above solution is subjected to freezing cycle treatment (e.g., freezing at -20℃ for 12 hours, thawing at 25℃ for 12 hours, and repeating 3 times); the growth and melting of ice crystals can physically crosslink PVA chains, significantly improving the elastic modulus of the hydrogel (from 0.8MPa to over 1.5MPa), elongation at break (>300%), and toughness.

[0072] c. Composite: The above-mentioned precursor liquid of adhesive layer 42 is applied to the base layer 41 (PI film) that has been activated by oxygen plasma and modified with fluorosilane by scraping or slit coating to form a wet film with a thickness of 2-20 μm; then, immediately or while the adhesive layer 42 still has a certain degree of tackiness, it is aligned and bonded to the surface of the patterned layer 2 (PVA layer) that has been cured on the mold, and a pressure of 0.1-0.5 MPa is applied and held for 10-60 seconds to make the two layers tightly bonded; at this point, an additional structural layer 4 (base layer 41 and adhesive layer 42) is formed on the side of the patterned layer 2 facing away from the mold.

[0073] Adhesive layer 42 Other optional adhesive layers: silicone (silicone, silicone resin), acrylic pressure-sensitive adhesive, polytetrafluoroethylene (FEP) hot melt adhesive, etc.

[0074] Demolding: The composite material, which includes the additional structural layer 4 (base layer 41 and adhesive layer 42) and the patterned layer 2, is peeled off from the mold in a whole and smoothly; at this time, a micro-groove structure 21 corresponding to the protruding structure of the mold is formed on the patterned layer 2.

[0075] Functional layer 3 construction: Functional layer 3 is formed on the inner surface of the patterned layer 2 and its microgroove structure 21 of the composite film obtained after demolding; this is mainly achieved by physical vapor deposition (PVD) or liquid phase self-assembly. Specifically: Physical vapor deposition (PVD): The composite containing the additional structural layer 4 and the patterned layer 2 after demolding is placed in a vacuum chamber, and a 0.1-0.5 μm thick fluorocarbon film is deposited on the corresponding surface of the patterned layer 2 by sputtering or evaporating fluorocarbon (such as PTFE) target material to form functional layer 3; the functional layer 3 formed by this method has good uniformity and moderate adhesion.

[0076] Liquid phase method / self-assembly method: Using a spraying or dip-coating method, for example, the corresponding surface of the composite containing the additional structural layer 4 and the patterned layer 2 is immersed in a 0.1-0.5 wt% perfluorooctyltriethoxysilane (FAS) ethanol solution, held for several seconds to several minutes, and then pulled out. After heat treatment at 100-120°C for 10-30 minutes, the silane hydrolyzes and undergoes a condensation reaction with the hydroxyl groups on the surface of materials such as PVA, forming a strong chemical bond and generating a self-assembled monolayer with a thickness of only a few nanometers to form the functional layer 3; the functional layer 3 formed by this method is ultrathin and uniform.

[0077] The addition of functional layer 3 enables interface control, significantly increasing the contact angle of the final surface of patterned layer 2 from approximately 72° before processing to >110°, and drastically reducing its surface energy from 38 mN / m to 18 mN / m; this also reduces the peel force between the subsequent conductive paste and the inner surface of the microgroove structure 21 to 0.05 N / cm. 2 This reduces costs by 82%, creating a decisive condition for clean demolding.

[0078] Thus, the composite transfer film 1 of configuration one (A structure) has been prepared.

[0079] Referring to Figure 4, the preparation method of the composite transfer film 1 of configuration two (B structure): This method is applicable to the preparation of a three-layer composite transfer film 1 containing a reinforcing layer 43, and mainly includes the following steps: Mold preparation: This step has the same mold preparation requirements as the preparation method of configuration one, and a high-precision mold with a hydrophobic surface is provided.

[0080] Patterned layer 2 forming: A patterned layer 2 is formed on the surface of the mold; this step is the same as the patterned layer 2 forming requirement in the configuration preparation method; the mold surface can be directly coated and formed by the molding method (such as the above PVA solution coating), or the mold pre-filming and imprinting method can be used.

[0081] Demolding: The patterned layer 2 is demolded from the mold; at this time, the patterned layer 2 has formed a micro-groove structure 21 corresponding to the mold protrusion structure and exists as an independent film.

[0082] Composite of Additional Structural Layer 4 (Reinforcement Layer 43): The reinforcement layer 43 is directly deposited on the surface of the patterned layer 2 with the microgroove structure 21 (i.e., the surface on which the functional layer 3 will be formed). Specifically: Using physical vapor deposition (PVD) technology, the patterned layer 2 with the microgroove structure 21 is introduced into a vacuum chamber, and silicon dioxide (SiO2) or aluminum oxide (Al2O3) is deposited by magnetron sputtering or electron beam evaporation. By controlling the sputtering power, gas pressure, and deposition time, a dense and uniform reinforcement layer 43 is formed on the inner surface of the patterned layer 2 and the microgroove structure 21, with a thickness typically between 10 nm and 1 μm, preferably 30-100 nm. This nanoscale reinforcement layer 43 can significantly improve the elastic modulus and tear resistance of the polymer patterned layer 2. Thus, the additional structural layer 4 (reinforcement layer 43) is formed on the patterned layer 2 between it and the subsequent functional layer 3.

[0083] Functional layer 3 construction: Functional layer 3 is formed on the surface of the deposited reinforcement layer 43 and its replicated microgroove structure. The method is similar to that of configuration one, and PVD deposition of a fluorinated compound film or liquid-phase self-assembly can be used; for example, a PTFE film can be deposited on the surface of reinforcement layer 43 by PVD, or a perfluorosilane self-assembled film can be formed on the surface of reinforcement layer 43 by dip-coating, thereby obtaining an interface with ultra-low surface energy.

[0084] Thus, the composite transfer film 1 of configuration two (B structure) has been prepared.

[0085] Referring to Figures 5-7, this application further provides a method for preparing electrode grid lines using the composite transfer film 1 described above, which is integrated into the manufacturing process of crystalline silicon perovskite tandem solar cells. Specifically, it includes the following steps: Slurry filling: Using a doctor blade or precision dispensing equipment, a suitable conductive slurry 6 is precisely filled into each microgroove structure 21 of the composite transfer film 1, and excess conductive slurry 6 is scraped away to ensure complete filling without overflow.

[0086] In this embodiment, for the surface of the crystalline silicon bottom cell (refer to Figures 5 and 6), it is preferable to use the composite transfer film 1 with configuration one (structure A); for the surface of the perovskite top cell (refer to Figures 5 and 7), it is preferable to use the composite transfer film 1 with configuration two (structure B).

[0087] To achieve synergy with the dry transfer process and the thermal budget of crystalline silicon perovskite tandem solar cells, conductive paste 6 is a specially developed paste. This paste is characterized by containing a specific low-temperature molten glass frit and a composite system of nano- and micro-sized silver particles. The low-temperature glass frit can soften and flow within the temperature window (80-150℃) of the transfer and curing process in this application, playing a key role in promoting interfacial contact and reducing the sintering temperature. The nano-silver particles can undergo surface sintering under these relatively mild conditions, forming a dense and highly conductive network together with the micro-silver particles. The combination of this special paste and the dry transfer film is an important foundation for forming a low-contact-resistance ohmic contact on the crystalline silicon surface under conditions far lower than the traditional crystalline silicon sintering temperature, while achieving good conductivity of the top electrode within the perovskite's tolerance temperature.

[0088] Alignment and Hot-press Transfer: With the assistance of a vision alignment system, the transfer film filled with conductive paste 6 is precisely aligned with the surface of the battery substrate 5 and then hot-pressed. Specifically: For the surface of the crystalline silicon battery substrate (refer to Figures 5 and 6): it is preferable to use a configuration one (A structure) composite transfer film 1. After aligning the configuration one (A structure) composite transfer film 1 with the crystalline silicon textured surface, hot-pressing is performed; the hot-pressing parameters are: temperature 80-180℃ (this temperature can effectively activate the rheological and adhesive properties of the adhesive layer 42), pressure 0.5-20MPa (this pressure is sufficient to ensure that the conductive paste 6 and the rough textured surface achieve tight mechanical contact and filling), and time 5-120 seconds.

[0089] Under these conditions, the heat causes the adhesive layer 42 (such as PVA-Al) to... 3+ The hydrogel self-healing adhesive layer softens and flows, fully wetting and filling the rough textured surface to form a strong temporary adhesion, while pressure forces the conductive paste 6 into close contact with the silicon wafer surface.

[0090] For the surface of the perovskite top cell (refer to Figures 5 and 7): it is preferred to use the configuration two (B structure) composite transfer film 1. After aligning the configuration two (B structure) composite transfer film 1 with the surface of the perovskite cell, hot pressing is performed. The hot pressing parameters are: the hot pressing conditions are a temperature of 60-150°C, which must be strictly lower than the thermal decomposition temperature of the perovskite functional layer used (usually preferably 80-115°C), a pressure of 0.05-10 MPa (using a lower pressure to absolutely avoid damaging the fragile perovskite multilayer film structure underneath), and a time of 1-180 seconds. The gentle hot pressing mainly promotes the wetting and initial bonding of the conductive paste 6 with the surface of the perovskite top cell, and the reinforcing layer 43 provides the necessary pressure stiffness.

[0091] Dry physical peeling: After hot pressing, the component is cooled to room temperature or below the glass transition temperature of the adhesive layer; then, the entire composite transfer film 1 is peeled off vertically or nearly vertically from the surface of the battery substrate 5 at a constant low speed (e.g., 5-20 mm / s); due to the ultra-low surface energy of the functional layer 3, the peeling interface is precisely controlled between the conductive paste 6 and the inner surface of the microgroove structure 21, and almost all (>98%) of the conductive paste 6 is retained on the surface of the battery substrate 5, forming a clear and complete electrode pre-formed pattern; the composite transfer film 1 is intact and can be cleaned and reused.

[0092] Electrode curing: The conductive paste 6 pattern retained on the battery substrate 5 is cured to form the final metal electrode grid lines 7. Specifically: For electrodes on the surface of crystalline silicon bottom cells: Silicon wafers with pre-formed electrode patterns are fed into a rapid thermal annealing (RTP) furnace or a chain sintering furnace and instantaneously sintered at 500-1000°C (e.g., 850°C peak). This high-temperature process melts the glass frit in the conductive paste 6, promoting the formation of ohmic contacts between the conductive paste 6 and the silicon wafer, and sintering and curing to form the electrode grid lines 7. This high-temperature step is completed before the fabrication of the perovskite top cell, so it does not conflict with the thermal sensitivity of the perovskite material.

[0093] For the electrodes on the surface of the perovskite top cell: the crystalline silicon perovskite tandem cell with the top electrode transferred is placed in a hot plate or oven and cured at ≤150℃ for 1-60 minutes to form the electrode grid line 7; this low-temperature process is sufficient to volatilize the organic carrier in the low-temperature conductive paste 6 and sinter the silver particles into a conductive network without damaging the heat-sensitive perovskite absorption layer and each functional layer below.

[0094] In this embodiment, the cross-sectional shape of the final electrode grid line 7 is determined by the cross-sectional shape of the microgroove structure 21 in the transfer film. That is, through the transfer process, the geometric shape of the microgroove structure 21 is accurately copied into the pattern of the conductive paste 6, and after curing, a grid line shape complementary to the microgroove structure 21 is formed. Therefore, the cross-sectional shape of the electrode grid line 7 includes, but is not limited to, rectangle, trapezoid, triangle, semicircle, etc., preferably triangle. The electrode grid line 7 with a triangular cross-section can maintain the inclined profile of the sidewall after curing, which is beneficial to improving the interface bonding strength between the grid line and the battery substrate 5. At the same time, its larger conductive cross-sectional area helps to reduce the line resistance and further improve the fill factor and photoelectric conversion efficiency of the battery.

[0095] This application also provides a crystalline silicon perovskite tandem solar cell, including a crystalline silicon bottom cell, a perovskite top cell, and at least one electrode, which is fabricated by the above-described electrode grid line fabrication method (including the electrode grid line fabrication method using a composite transfer film 1 of configuration one and configuration two); wherein, at least one electrode includes a front electrode located on the surface of the crystalline silicon bottom cell, and / or a top electrode located on the surface of the perovskite top cell.

[0096] To fully disclose the application scenarios and technical advantages of this application, the following will describe in detail the complete process fabrication method of crystalline silicon perovskite tandem solar cells based on the composite transfer film 1 of this application. This method fully demonstrates how to seamlessly integrate the aforementioned dry transfer process of electrode grid lines into the manufacturing sequence of crystalline silicon perovskite tandem solar cells, thereby systematically solving the process compatibility problem from the crystalline silicon bottom cell to the perovskite top cell.

[0097] A typical full-process fabrication method for crystalline silicon perovskite tandem solar cells includes the following steps: 1. Fabrication of the front electrode of the crystalline silicon bottom cell. First, prepare the completed crystalline silicon bottom cell, whose surface is texturized, cleaned and passivated, as the cell substrate 5.

[0098] In view of its rough textured surface and the need for high-temperature sintering to form ohmic contacts, the composite transfer film 1 of configuration one (structure A, i.e., the additional structural layer 4 includes a base layer 41 and an adhesive layer 42) of this application is selected. The adhesive layer 42 of the composite transfer film 1 is preferably a PVA-based dynamic cross-linked hydrogel, which can adapt well to and fill the textured surface morphology under hot pressing to form a strong temporary adhesion.

[0099] Subsequently, following the electrode grid line preparation method of the composite transfer film 1 with configuration one (A structure), conductive paste 6 is filled on the composite transfer film 1 with configuration one (A structure), and it is aligned with the textured surface of the silicon wafer and hot-pressed for 5-120 seconds under the conditions of 80-180℃ and 0.5-20MPa.

[0100] Subsequently, dry physical stripping was performed to remove the composite transfer film 1 of configuration one (A structure), and the conductive paste 6 was precisely left on the textured surface of the silicon wafer.

[0101] Finally, the silicon wafer with conductive paste 6 is rapidly thermally sintered at 500-1000°C to form a front electrode (i.e., electrode grid line 7) with excellent ohmic contact.

[0102] 2. Fabrication of intermediate interconnect layers and perovskite top cells in tandem solar cells: On the crystalline silicon bottom cell with the front electrode already completed, intermediate functional layers required for tandem solar cells are continuously deposited: a. Transparent conductive interconnect layer: A transparent conductive oxide layer is deposited on the surface of the crystalline silicon front electrode grid line as an interconnect layer, serving as an electrical connection and optical window between the upper and lower cells; the interconnect layer material includes, but is not limited to, deposition by magnetron sputtering, and the material can be indium tin oxide (ITO), indium zinc oxide (IZO), or metals (such as gold).

[0103] b. Hole transport layer: A hole transport layer for the perovskite solar cell is formed on the interconnect layer. This layer can be a single-layer or multi-layer structure, and its materials and methods include, but are not limited to, deposition of nickel oxide (NiO) by magnetron sputtering. xThin films or nickel oxide nanoparticle dispersions can be coated; or solution methods such as spin coating, blade coating or slot coating can be used to prepare organic hole transport layers, such as PEDOT:PSS solutions; self-assembly technology can also be used to form single-molecule self-assembled materials (SAM) or polymer self-assembled materials (Poly-SAM) layers.

[0104] c. Perovskite Absorbing Layer: A perovskite light-absorbing layer is prepared on the hole transport layer; a solution containing a perovskite precursor is prepared, the precursor material including but not limited to SnI2, formamidinium iodide (FAI), methylamine bromide (MABr), and cesium iodide (C). S I), lead iodide (PbI2), methylamine chloride (MACl), etc., are used to form films through processes such as spin coating, blade coating, or slot coating, and are then annealed at a temperature not exceeding 150°C to crystallize and form a high-quality perovskite layer.

[0105] d. Interface passivation layer: To further optimize the surface properties of the perovskite layer, a passivation layer can be deposited on its surface. The passivation layer material can be phenylethylammonium iodide (PEAI), malonic acid diammonium iodide (PDAI2), ethylenediammonium iodide (EDAI2), or lithium fluoride (LiF), etc. The corresponding preparation methods include spin coating, blade coating, thermal evaporation or slot coating.

[0106] e. Electron transport layer: An electron transport layer is prepared on the perovskite layer (or passivation layer). The electron transport layer material can be fullerene (C10 ... 60 (e.g., PCBM) or its derivatives are deposited by methods such as spin coating, blade coating or thermal evaporation.

[0107] f. Buffer layer: Finally, a buffer layer is deposited on the electron transport layer to improve contact with the subsequent top electrode and enhance device stability. The buffer layer material can be tin oxide (SnO2) or copper bath (BCP), and the corresponding preparation methods include spin coating, blade coating, atomic layer deposition (ALD), thermal evaporation or slot coating.

[0108] 3. Fabrication of the top electrode of the perovskite top cell: The top electrode is fabricated on the surface of the perovskite top cell after all the above functional layers are completed, and the surface of the perovskite top cell is used as the cell substrate 5.

[0109] In view of the characteristics of perovskite layers being heat-sensitive, having a fragile surface, and requiring low-temperature processing, the composite transfer film 1 of configuration two (B structure, i.e., the additional structural layer 4 is the reinforcing layer 43) described in this application is selected. It does not contain an organic adhesive layer, thus avoiding adverse reactions with the fragile perovskite surface, and its reinforcing layer 43 provides the necessary mechanical strength to support dry peeling.

[0110] Subsequently, following the electrode grid line preparation method of the composite transfer film 1 with configuration two (B structure), a low-temperature curing conductive paste 6 was filled on the composite transfer film 1 with configuration two (B structure), and it was aligned with the surface of the perovskite cell and hot-pressed together under mild conditions of 60-150℃ and 0.05-10MPa.

[0111] After dry physical stripping, the composite transfer film 1 of configuration two (B structure) is removed, and the conductive paste 6 is completely transferred.

[0112] Finally, the conductive paste 6 is cured at a temperature not exceeding 150°C to form the top electrode (i.e., electrode grid line 7) of the perovskite top cell.

[0113] Thus, a complete crystalline silicon perovskite tandem solar cell is fabricated, with both the upper and lower electrodes prepared using the dry transfer printing process of this invention.

[0114] The above-described process creatively and precisely matches the two composite transfer film structures (Structure A and Structure B) with the requirements for the fabrication of the upper and lower electrodes of crystalline silicon perovskite tandem solar cells: the A-structure composite transfer film solves the high-temperature compatibility and textured surface adhesion problems of the crystalline silicon end; the B-structure composite transfer film solves the low-temperature limitations and interface sensitivity problems of the perovskite end. Through this strategy, the high-temperature sintering and water washing steps in the traditional electrode process, which are fundamentally incompatible with perovskite, are successfully transformed into a fully dry physical transfer process compatible with the temperature window of the perovskite process chain, eliminating the risks of moisture erosion and thermal degradation at the source. This integrated solution not only ensures the integrity of each functional interface, but also ensures the geometric and electrical performance of the electrodes through high-precision pattern transfer, thus providing a crucial process foundation for crystalline silicon perovskite tandem solar cells to achieve a certified photoelectric conversion efficiency of over 31% and excellent long-term operational stability (such as T80 > 2500 hours).

[0115] To more fully and completely illustrate the technical solution and effects of this application, the following detailed description is provided through specific embodiments and comparative examples.

[0116] Example 1: Preparation of configuration one (A structure) composite transfer film and its application on the surface electrode of crystalline silicon bottom cell.

[0117] This embodiment demonstrates the complete preparation process of a four-layer composite transfer film (Structure A) and its application in scenarios requiring strong adhesion to rough surfaces.

[0118] 1. Preparation of composite transfer film of configuration one (A structure): a. Mold: a rectangular raised array silicon mold with a line width of 5μm and a height of 11μm, the surface of the mold is treated with perfluorosilane.

[0119] b. Patterned layer: A PVA1799 aqueous solution with a solid content of 18wt% (containing 0.2% wetting agent) is applied to the surface of the mold through a slit (slit width 80μm, speed 1.5 m / min), and then dried with hot air at 85℃ for 2 minutes to form a PVA patterned layer with a thickness of about 15μm, on which the depth of the microgroove structure is 11.8±0.2μm.

[0120] c. Adhesive layer and base layer: Prepare a solution containing 15wt% PVA and 0.45wt% AlCl3·6H2O (Al 3+ The PVA hydroxyl molar ratio was approximately 0.3. The solution was frozen at -25°C for 12 hours, then thawed at 25°C for 12 hours, and this cycle was repeated three times. The treated solution was then coated onto a 25 μm thick PI film that had been activated by oxygen plasma and modified with fluorosilane. The wet film thickness was controlled at 50 μm. After drying at room temperature, a PVA-Al film with a thickness of approximately 12 μm was formed. 3+ Hydrogel adhesive layer.

[0121] d. Composite and demolding: The composite of the PI base layer and hydrogel adhesive layer prepared above is aligned with the surface of the PVA patterned layer on the mold with its hydrogel surface, and a pressure of 0.3 MPa is applied and held for 20 seconds. Then, the three-layer composite of the PI base layer, hydrogel adhesive layer and PVA patterned layer is smoothly peeled off from the mold; thus, an additional structural layer of configuration one is formed under the patterned layer.

[0122] e. Functional layer construction: An electron beam evaporation process was used to deposit a 100 nm thick PTFE film on the PVA patterned layer surface of the exfoliated composite as a functional layer; process parameters: deposition rate 0.2 nm / s, substrate temperature 80 °C; the surface energy of the functional layer was measured to be 14.5 mN / m.

[0123] 2. Electrode preparation on the surface of crystalline silicon substrate cells: a. A silicon wafer with an n-type heterojunction (HJT) that has been texturized, cleaned and deposited with an amorphous silicon passivation layer is used as the cell substrate.

[0124] b. Apply a special low-temperature curing silver paste suitable for HJT batteries into the microgroove structure of the composite transfer film.

[0125] c. Under visual alignment, align the composite transfer film with the textured surface of the HJT silicon wafer and place it in a hot press; set the hot pressing conditions as follows: temperature 125℃, pressure 10MPa, time 70 seconds.

[0126] d. After the component has cooled naturally to about 40°C, peel the composite transfer film vertically off the silicon wafer surface at a speed of 10 mm / s.

[0127] e. The silicon wafer with silver paste lines is cured in a chain sintering furnace at 210°C (HJT process compatible temperature) for 15 minutes to form electrode grid lines.

[0128] Example 2: Preparation of configuration two (B structure) composite transfer film and its application on the surface electrode of perovskite top cell.

[0129] 1. Preparation of the composite transfer film of configuration two (B structure): a. Preparation of patterned layer and reinforcing layer in one step: A flexible transparent polyurethane (TPU) film with a thickness of 50μm is selected as a temporary carrier.

[0130] The roll-to-roll continuous production process is adopted: First, a layer of UV-curable adhesive is coated on the TPU film; then it is passed through an imprinting unit equipped with a quartz imprinting roller. The surface of the imprinting roller has an electrode protrusion pattern. Under UV light, the adhesive layer is instantly cured, forming a micro-groove structure with a width of 5μm and a depth of 15μm on the TPU film, which constitutes the patterned layer; the patterned layer is demolded from the mold, and a silicon dioxide (SiO2) film with a thickness of 80nm is continuously deposited on the surface of the imprinted patterned layer as a reinforcement layer through magnetron sputtering process; process parameters: sputtering power 500W, argon atmosphere; thus, an additional structural layer of configuration two, namely the reinforcement layer, is formed on the patterned layer.

[0131] b. Carrier stripping and functional layer construction: The composite of the patterned layer and the SiO2 reinforcement layer was immersed in a 0.3 wt% perfluorooctyltriethoxysilane (FAS-17) ethanol solution for 10 minutes, and then pulled out of the liquid surface at a constant speed and heat-treated in an oven at 120°C for 30 minutes. This process formed a perfluorosilane self-assembled monomolecular functional layer on the surface of the reinforcement layer, and the water contact angle was measured to be 115°.

[0132] 2. Electrode fabrication on the surface of the perovskite top cell: a. Operations are performed on the surface of the perovskite cell that has been fully fabricated (including the SnO2 electron transport layer, the perovskite absorber layer, and the Spiro-OMeTAD hole transport layer).

[0133] b. To demonstrate versatility and take cost into consideration, this example uses a low-temperature curing carbon slurry.

[0134] c. Under visual alignment, align the composite transfer film with the surface of the perovskite top cell and perform hot-press transfer; the conditions are: temperature 110℃, pressure 0.8MPa, time 100 seconds.

[0135] d. After hot pressing, the composite transfer film is peeled off entirely at room temperature.

[0136] e. Place the sample on a hot plate at 120°C and cure for 25 minutes to form electrode grid lines.

[0137] To objectively evaluate the technological progress and effects of this application, the following two comparative examples are established: Comparative Example 1 (Traditional wet process): Commercially available water-soluble polyvinyl alcohol (PVA) transfer film is used; a PVA film with a thickness of about 50 μm is hot-pressed onto a mold to form an electrode pattern groove, filled with the same silver paste, and then transferred to a silicon wafer; after transfer, the sample must be immersed in warm water at 50°C and stirred for 5-10 minutes to completely dissolve and remove the PVA carrier film, and then dried and sintered at high temperature to form electrode grid lines.

[0138] Comparative Example 2 (Traditional thermal release adhesive film process): Commercially available thermal release adhesive film (approximately 50 μm thick) is bonded to a regular PET substrate, and electrode pattern grooves are etched by laser. After filling and transferring the paste, the entire component needs to be heated to 120°C to make the thermal release adhesive layer lose its adhesiveness, thereby peeling off the PET substrate along with the adhesive film to obtain the electrode grid lines.

[0139] Test method: Environmental impact test: The environmental impact is assessed by recording and analyzing the wastewater discharge, volatile organic compounds (VOCs) and the types and concentrations of high-temperature decomposition gases generated throughout the entire preparation process.

[0140] Process thermal compatibility test: The matching of process temperature windows is verified by comparing the transfer / curing process temperature with the thermal decomposition temperature of perovskite material (TGA / DSC measurement), and combining the phase (XRD) and morphology (SEM) analysis of the perovskite layer after transfer.

[0141] Demolding effect test: Using a universal testing machine and the 180° peel method, the adhesion force (peel force, unit N / cm) between the dried standard conductive paste and the functional layer on the inner surface of the microgroove of the transfer film was measured. 2 ).

[0142] Linear accuracy test: The cross-section of the metal linear after transfer and curing is imaged using a scanning electron microscope (SEM) or a high-precision optical profilometer. The line width and height are statistically analyzed using image analysis software, and the average value and standard deviation of the aspect ratio are calculated.

[0143] Transfer success rate / yield test: In batch production, an automated optical inspection (AOI) system is used to perform full inspection on the transferred substrate, count the number of cells with complete, unbroken, and undamaged gate lines, and calculate their percentage of the total number of cells.

[0144] Material utilization and cost testing: The mass of paste consumed before and after filling was weighed using a precision balance, and the actual mass ratio of paste transferred to the substrate (utilization rate) was calculated; combined with the number of times the transfer film was reused, the comprehensive material cost of a single electrode preparation was calculated.

[0145] Testing on the impact on the substrate interface: X-ray photoelectron spectroscopy (XPS) or Fourier transform infrared spectroscopy (FTIR) is used to analyze the transferred substrate (especially the perovskite surface) to detect the presence of organic solvents, adhesive residues or new chemical bonds, in order to assess the interface contamination or modification.

[0146] Final performance testing of tandem solar cells: Under standard test conditions (AM 1.5G, 100 mW / cm², 25℃), the photoelectric conversion efficiency (PCE), open-circuit voltage (Voc), short-circuit current density (Jsc), and fill factor (FF) of fully crystalline silicon-perovskite tandem solar cells were measured using a calibrated solar simulator and IV test system.

[0147] Reliability (85℃ / 85%RH, T80) test: The packaged complete battery device is placed in a constant temperature and humidity test chamber and accelerated aging is carried out in a harsh environment of 85℃ temperature and 85% relative humidity. The device is periodically removed and its efficiency is tested under standard conditions. The cumulative time (T80) when the efficiency decays to 80% of the initial value is recorded.

[0148] Examples 1 and 2 were systematically compared with Comparative Examples 1 and 2, focusing on key performance indicators. The results are summarized in Table 1 below: Table 1 Through the detailed description of the specific embodiments, the actual operation demonstration of the examples, and the systematic data comparison with the comparative examples, it can be clearly seen that the composite transfer film and its dry transfer method provided in this application have shown comprehensive and groundbreaking advantages in solving the manufacturing problem of electrodes for crystalline silicon perovskite tandem solar cells.

[0149] The advantages of this application are specifically reflected in the following aspects: 1. It completely abandons the traditional water washing and high-temperature combustion steps and pioneers a whole-process dry physical stripping process chain; this not only eliminates the destructive impact of process wastewater on perovskite materials, but also avoids the damage of high-temperature decomposition to the heat-sensitive functional layer, fundamentally solving the core process compatibility conflict that has long restricted the industrialization of crystalline silicon perovskite tandem solar cells.

[0150] 2. By using direct coating technology on the mold surface, high-fidelity replication of the microgroove structure pattern is ensured from the source. Combined with precise interface control of the ultra-low energy functional layer on the inner surface of the microgroove structure, ultra-precision transfer of electrode grid lines with ultra-fine linewidth (<5μm) and high aspect ratio (>2) is achieved. This significantly reduces the light-shielding loss of the electrode grid lines to below 3%. At the same time, due to the increase in conductive cross-sectional area, the series resistance is significantly reduced, laying the foundation for high current density and high fill factor of the battery.

[0151] 3. The composite transfer film (especially the A structure) can be reused more than 50 times. Combined with the micro-groove structure precision filling technology, the silver paste utilization rate is increased to more than 85%, and the cost per use is reduced by more than 80%. The entire production process has no wastewater or exhaust gas emissions, which meets the requirements of green manufacturing and sustainable development.

[0152] 4. Two composite transfer film structures, Configuration 1 (Structure A) and Configuration 2 (Structure B), are creatively provided, which can be optimized to meet the high-temperature and strong adhesion requirements of the crystalline silicon end and the low-temperature and pollution-free requirements of the perovskite end, respectively. This differentiated design, combined with special pastes and curing processes for different battery substrates, constitutes a complete electrode preparation platform that can be seamlessly integrated into the existing crystalline silicon perovskite tandem battery manufacturing process.

[0153] The implementation principle of this application includes the following aspects: 1. By constructing a fluorine-containing functional layer with ultra-low surface energy (<18mN / m) on the inner surface of the microgroove structure rather than the overall surface, a weak interface is artificially created; during peeling, the fracture is precisely guided to the preset weak interface (slurry-functional layer), while the strong bonding interface between the slurry and the battery substrate is preserved, thereby achieving precise retention of the slurry; at the same time, the mold direct coating molding technology ensures that the microgroove structure is a perfect negative image of the mold protrusion, locking the limit accuracy of the pattern from the physical source.

[0154] 2. The developed conductive paste contains a composite system of a specific low-temperature melting glass frit and nano / micron-sized silver particles. Within the transfer and curing temperature window of 80-150℃, the glass frit softens and flows, promoting close contact between the paste and the battery substrate (such as crystalline silicon) while also acting as a flux and connector at the interface. Simultaneously, the nano-silver particles undergo surface sintering at relatively low temperatures, forming a continuous conductive network. The synergy of these two factors enables a conductivity below 0.5 Ω·cm at temperatures far below traditional sintering standards. 2 Low contact resistance.

[0155] 3. For the first configuration (Structure A) composite transfer film, the high-modulus, high-strength PI substrate layer acts as the main load-bearing component, bearing most of the tensile stress during the tearing process, while the fragile PVA patterned layer only bears a small peeling stress perpendicular to the interface, thus being protected. For the second configuration (Structure B) composite transfer film, the nano-scale SiO2 or Al2O3 reinforcement layer deposited on the back of the patterned layer by PVD forms strong interactions (such as hydrogen bonds) with the polymer molecular chains, which can improve its tensile strength and tear resistance by more than 200%, which is sufficient to withstand the test of direct tearing.

[0156] 4. Benefiting from the unique properties of the PVA-based self-healing dynamic hydrogel adhesive layer in the configuration one (A structure) composite transfer film; at the transfer temperature, this adhesive layer has excellent viscoelasticity and rheology, and can penetrate and fill the complex three-dimensional pyramid voids of the crystalline silicon textured surface like a liquid, transforming the traditional surface contact into a more mechanically interlocked volume contact, greatly increasing the effective adhesion area; its inherent dynamic coordination bond (-O-Al-O-) network can be reversibly broken and recombined under external force, which not only endows the adhesive layer with self-healing ability to extend its lifespan, but also dissipates energy through bond breaking when local stress is concentrated, thereby ensuring that the overall adhesion on rough surfaces has high reliability and tolerance.

[0157] 1cm prepared using the technology described in this application 2 A tandem solar cell with two ends made of crystalline silicon perovskite achieved an institutionally certified power conversion efficiency of 31.5% (Voc=1.93V, Jsc=20.5mA / cm). 2 (FF=80.5%) This efficiency breakthrough is a direct result of the combined effect of the above advantages: The improvement in Jsc is mainly due to the fact that the ultra-fine grid lines of <5μm reduce the light-shielding loss of the front metal electrode from >8% in the traditional process to <2.5%, allowing more photons to be absorbed by the battery; The improvement in Voc is due to the dry and low-temperature top electrode preparation process, which perfectly protects the perovskite material and its interface with the transport layer, greatly suppressing non-radiative recombination; The improvement in FF is due to the low series resistance brought by the high aspect ratio grid lines, and the excellent ohmic contact formed by the paste and transfer process optimized for the crystalline silicon and perovskite ends respectively.

[0158] Furthermore, in the stringent accelerated aging test at 85°C and 85% relative humidity, the battery performance degraded to 80% of its initial value in more than 2,800 hours (T80), which far exceeds the lifespan of batteries using traditional processes, strongly demonstrating the intrinsic high quality and long-term stability of the interface guaranteed by the dry process.

[0159] In this embodiment, to demonstrate the necessity and advantages of the technical requirement that the surface energy of the functional layer is less than 25 mN / m, the following comparative experiment was designed: Example and comparative example settings: Example 3: Using the above-mentioned PTFE magnetron sputtering process, a functional layer with a surface energy of approximately 12 mN / m was prepared.

[0160] Example 4: A functional layer with a surface energy of approximately 22 mN / m was prepared using the above-described fluorosilane self-assembly process.

[0161] Comparative Example 3: A similar process was used to coat an unoptimized ordinary polymer coating with a surface energy of 28 mN / m.

[0162] Comparative Example 4: The patterned layer was not treated with any functional layers, and its PVA surface energy was approximately 38 mN / m.

[0163] Test method: Surface energy test: A contact angle meter is used to measure the contact angle of water droplets on the coating surface, and the surface energy is calculated using the Owens-Wendt method.

[0164] Peel strength test: Using a universal testing machine, the adhesion strength between the dried standard silver paste and different coating surfaces was measured by the 180° peel method (unit: N / cm). 2 ).

[0165] Evaluation of transfer effect: Conduct a complete dry transfer experiment under the same conditions, calculate the success rate of complete grid line transfer, and observe the residue of the paste.

[0166] Examples 3 and 4 were compared with Comparative Examples 3 and 4 in terms of key performance indicators. The results are summarized in Table 2 below: Table 2 Table 2 clearly shows that when the surface energy of the functional layer is below 25 mN / m (Examples 3 and 4), its peel force with the silver paste is significantly reduced, and the transfer yield remains above 98%, with excellent demolding effect. In contrast, when the surface energy increases to 28 mN / m (Comparative Example 3), the peel force increases sharply, and the transfer yield and paste residue deteriorate significantly. If there is no functional layer at all (Comparative Example 4), it is almost impossible to achieve reliable dry peeling. This fully demonstrates that controlling the surface energy of the functional layer below 25 mN / m is a necessary condition for achieving high yield and high quality dry transfer, and also verifies the technical rationality and significant progress of the parameter range set in this application.

[0167] In summary, the data comparison and principle analysis in the table above clearly demonstrate that this application is not a simple improvement on existing technologies, but rather a systematic and original breakthrough from material systems and structural design to process principles. It successfully integrates high-precision patterning, extreme process compatibility, excellent electrical performance, superior environmental reliability, and low-cost manufacturing, providing a crucial and feasible electrode preparation solution for the industrialization of high-performance, high-reliability crystalline silicon perovskite tandem solar cells, representing an important development direction for manufacturing technology in this field.

[0168] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A composite transfer film, characterized in that: include: A patterned layer having a microgroove structure; an additional structural layer, composite with the patterned layer; The functional layer has a surface energy of less than 25 mN / m; wherein the additional structural layer is a reinforcement layer, which is bonded between the patterned layer and the functional layer; the reinforcement layer is a SiO2 layer or an Al2O3 layer.

2. The composite transfer film according to claim 1, characterized in that: The thickness of the reinforcing layer is 0.1-10 μm.

3. The composite transfer film according to claim 1, characterized in that: The material of the functional layer includes at least one of fluorine-containing compounds, silane compounds, wax compounds, or fatty acid salts.

4. The composite transfer film according to claim 1, characterized in that: The patterned layer is made of materials including polyvinyl alcohol, polyvinylpyrrolidone, hydroxypropyl methylcellulose, polyethylene glycol, polyolefin, polyethylene terephthalate, or polylactic acid; the thickness of the patterned layer is 5-80 μm.

5. The composite transfer film according to claim 1, characterized in that: The width of the microgroove structure is 3-20 μm, the depth is 6-30 μm, and the aspect ratio is >1.

6. A composite transfer film, characterized in that: include: A patterned layer having a microgroove structure; an additional structural layer, composite with the patterned layer; The functional layer has a surface energy of less than 25 mN / m; wherein, the additional structural layer is located on the side of the patterned layer opposite to the functional layer, the additional structural layer includes a base layer and an adhesive layer, the adhesive layer is connected to the surface of the patterned layer opposite to the functional layer and is located between the base layer and the patterned layer; the adhesive layer is a self-healing adhesive layer with a reversible adhesion interface, including an adhesive layer with a dynamic cross-linked network formed by coordination bonds between metal ions and the polymer matrix, or an organosilicon layer, an acrylic adhesive layer, or a polytetrafluoroethylene propylene adhesive layer.

7. The composite transfer film according to claim 6, characterized in that: The polymer matrix is ​​polyvinyl alcohol, and the metal ions include Al. 3+ or Fe 3+ .

8. The composite transfer film according to claim 6, characterized in that: The substrate layer is a high-temperature resistant polymer film with a surface modified by fluorosilane and a hydrophobic angle greater than 110°; the material of the substrate layer includes polyethylene terephthalate, polypropylene, polycarbonate, polymethyl methacrylate, polyimide or polytetrafluoroethylene.

9. The composite transfer film according to claim 6, characterized in that: The thickness of the adhesive layer is 2-20 μm, and the thickness of the base layer is 20-80 μm.

10. The composite transfer film according to claim 6, characterized in that: The material of the functional layer includes at least one of fluorine-containing compounds, silane compounds, wax compounds, or fatty acid salts.

11. The composite transfer film according to claim 6, characterized in that: The patterned layer is made of materials including polyvinyl alcohol, polyvinylpyrrolidone, hydroxypropyl methylcellulose, polyethylene glycol, polyolefin, polyethylene terephthalate, or polylactic acid; the thickness of the patterned layer is 5-80 μm.

12. The composite transfer film according to claim 6, characterized in that: The width of the microgroove structure is 3-20 μm, the depth is 6-30 μm, and the aspect ratio is >1.

13. A method for preparing a composite transfer film, characterized in that: Includes the following steps: A mold is provided, the surface of which has a raised structure; a patterned layer is formed on the surface of the mold; a demolding and lamination step is performed, such that a micro-groove structure corresponding to the raised structure is formed on the patterned layer, and an additional structural layer is laminated onto the patterned layer; a functional layer is formed.

14. The method for preparing a composite transfer film according to claim 13, characterized in that: When the additional structural layer includes a base layer and an adhesive layer, the demolding and bonding steps are specifically as follows: the pre-formed additional structural layer, which includes the adhesive layer and the base layer, is aligned and bonded with the adhesive layer surface and the side surface of the patterned layer opposite to the microgroove structure; then the composite including the adhesive layer, the base layer and the patterned layer is demolded from the mold surface.

15. The method for preparing a composite transfer film according to claim 14, characterized in that: Before forming the additional structural layer comprising the adhesive layer and the base layer, the adhesive layer material is subjected to at least one freeze cycle.

16. The method for preparing a composite transfer film according to claim 13, characterized in that: When the additional structural layer is a reinforcing layer, the demolding and composite steps are as follows: first, the patterned layer is demolded from the mold surface, and then the reinforcing layer is directly deposited on the side surface of the patterned layer with the microgroove structure through a physical vapor deposition process.

17. The method for preparing a composite transfer film according to claim 13, characterized in that: The steps for forming the functional layer include: depositing the functional layer on the surface of the patterned layer and the microgroove structure, or on the surface of the reinforcement layer, using a physical vapor deposition process.

18. A method for fabricating electrode grid lines, characterized in that: Using the composite transfer film as described in any one of claims 1-12, the method includes the following steps: filling the microgroove structure of the composite transfer film with conductive paste; aligning and bonding the composite transfer film filled with the conductive paste to the surface of a battery substrate; performing a hot-pressing process to transfer the conductive paste to the surface of the battery substrate; removing the composite transfer film by physical peeling to leave the conductive paste pattern on the surface of the battery substrate; and curing the conductive paste on the surface of the battery substrate to form electrode grid lines.

19. The method for fabricating electrode grid lines according to claim 18, characterized in that: When the surface of the battery substrate is a crystalline silicon bottom cell surface, the hot pressing temperature is 80-180℃ and the pressure is 0.5-20MPa; the curing process is carried out at 500-1000℃ for sintering and curing. When the surface of the battery substrate is a perovskite top cell surface, the hot pressing temperature is 60-150℃ and the pressure is 0.05-10MPa; the curing process is carried out at a temperature not exceeding 150℃.

20. A crystalline silicon perovskite tandem solar cell, characterized in that: include: Crystalline silicon bottom cells; perovskite top cells; At least one electrode is prepared by the electrode grid line preparation method according to any one of claims 18-19; wherein the at least one electrode includes a front electrode located on the surface of the crystalline silicon bottom cell and / or a top electrode located on the surface of the perovskite top cell.

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