Size-flexible four-terminal perovskite-crystalline silicon laminated assembly and method

Abstract

The invention discloses a four-terminal perovskite-crystalline silicon laminated assembly with a flexible size and a method, and belongs to the technical field of photovoltaic device manufacturing. According to the crystalline silicon edge passivation method, a passivation material solution is sprayed on the cutting edge and the back face of a crystalline silicon cell, and a compact and stable passivation layer is formed after drying, so that the efficiency retention rate of the cut crystalline silicon cell is improved. The solution spin coating or spraying mode is adopted, the passive film is formed at the normal pressure or the room temperature, vacuum or high-temperature equipment is not needed, and the process cost and energy consumption are greatly reduced.

Description

Technical Field

[0001] This invention belongs to the field of photovoltaic device manufacturing technology, specifically relating to a four-terminal perovskite-crystalline silicon stacked module and method with flexible dimensions. Background Technology

[0002] Four-terminal perovskite-crystalline silicon tandem solar cells represent a key pathway to improving photovoltaic conversion efficiency, combining the excellent short-wavelength absorption of perovskite materials with the high long-wavelength response and mature manufacturing system of crystalline silicon cells. Through a spectral separation mechanism, this tandem structure can achieve photon utilization over a wider wavelength range, with theoretical efficiency expected to break through the Shockley-Queisser limit (29%) of crystalline silicon single-junction cells. However, the industrialization of tandem cells faces challenges related to size compatibility and structural adaptability. Crystalline silicon cells typically use standard sizes (e.g., 182mm×182mm, 210mm×210mm), while perovskite modules require flexible customization based on the glass substrate and etching pattern, resulting in a large size range (e.g., from 300mm×300mm to 600mm×1200mm). This leads to significant mismatches in actual tandem assembly.

[0003] To achieve high-density splicing and free arrangement, large-size crystalline silicon solar cells need to be cut into smaller units (e.g., 40mm × 40mm) to adapt to different application scenarios (such as the differentiated requirements of power density and form factor in consumer electronics). However, the laser cutting process introduces a large number of lattice defects and dangling bonds at the edges of the crystalline silicon, significantly increasing the carrier recombination rate, resulting in a decrease in open-circuit voltage (Voc) and fill factor (FF), ultimately causing a significant drop in efficiency retention, only 30%~60% (e.g., a cell with an initial efficiency of 22% drops to 6.6%~13.2% after cutting). Existing research shows that the main reasons for the enhanced recombination in the edge region after cutting are: high-density dangling bonds, oxidation-induced interface defects, and accelerated charge injection and mismatch annealing phenomena in humid and hot environments. Therefore, it is urgent to develop novel edge passivation strategies suitable for crystalline silicon wafers to ensure the device performance and long-term stability of the stacked structure.

[0004] Currently, edge passivation of crystalline silicon solar cells mainly relies on hydrogenated amorphous silicon (a-Si:H) thin film deposition or atomic layer deposition (ALD) Al2O3 processes. While these passivation methods perform well on conventional crystalline silicon wafers, they expose several technical limitations in the small-sized units (<50 mm) after cutting: a-Si:H and ALD-Al2O3 processes generally rely on high vacuum and high temperature processing, requiring extremely high equipment investment and energy consumption, resulting in high barriers to industrialization and difficulty in scaling up production. a-Si:H suffers from photo-induced degradation, leading to poor passivation stability; while Al2O3 / Si has a high interface state density, making it difficult to effectively suppress deep-level recombination. In addition, these passivation layers are generally brittle, making it difficult to adapt to the complex stress and thermal expansion differences at the edges of the crystalline silicon after cutting, and are prone to cracking or delamination failure during thermal cycling and aging. After laser or mechanical cutting, a large number of dangling bonds and surface defects are introduced at the edges of small-sized crystalline silicon units, which easily induce carrier recombination, resulting in efficiency losses of 40% to 70%. Traditional passivation processes struggle to achieve uniform coverage on irregular micro-cells, resulting in a passivation quality degradation of over 20% at the edges. Because defects at the silicon dicing edges are not effectively passivated, the interface between the device and the perovskite layer is enhanced, leading to an annual efficiency degradation rate exceeding 20% ​​in humid and hot environments, far from meeting the long-term stability requirements for commercial applications. In summary, existing oxide or silicon-based passivation technologies face significant bottlenecks in terms of process adaptability, cost, dimensional uniformity, and long-term reliability. There is an urgent need to develop a novel room-temperature, flexible, chemically anchored passivation technology to achieve efficient passivation of the edges and surfaces of silicon dicing wafers. Summary of the Invention

[0005] The purpose of this invention is to overcome the deficiencies in the prior art and provide a size-flexible four-terminal perovskite-silicon multilayer assembly and method. Specifically, it includes a room-temperature, non-vacuum, flexible adaptable silicon edge passivation method suitable for four-terminal perovskite-silicon multilayer assemblies.

[0006] The specific technical solution adopted in this invention is as follows: In a first aspect, the present invention provides a method for passivating the edge of crystalline silicon in a four-terminal perovskite-crystalline silicon stacked module, wherein a passivation material solution is sprayed onto the cut edge and back side of the crystalline silicon cell, and after drying, a dense and stable passivation layer is formed to improve the efficiency retention rate of the crystalline silicon cell after cutting. The passivation material solution includes at least one of the following: perfluorosulfonic acid polymer, perfluorocyclobutyl aryl ether polymer, sulfonated polyaryl ether, polytetrafluoroethylene grafted sulfonated polystyrene, fluorinated phosphorus functionalized dendritic polymer, phosphate grafted polyethyleneimine, fluorinated phosphonate polymer, vinylidene fluoride-dimethylphosphonate copolymer, vinylidene fluoride-trichlorotrifluoroethylene copolymer, vinylidene fluoride-ortho(dimethoxyphosphoryl)methyl-2-trifluoromethyl acrylate copolymer, 3-trifluoroethoxyhexafluoropropyl phosphate, 2-trifluoroethoxytetrafluoroethyl phosphate, and trifluoroethoxy-4-trifluoromethyl-3-oxaperfluoropentyl phosphate.

[0007] Preferably, the surface roughness of the crystalline silicon cell is controlled to be <1μm before spraying. It is then ultrasonically cleaned with acetone, ethanol, and deionized water in sequence, dried with nitrogen, and then sprayed.

[0008] Preferably, the vinylidene fluoride-vinyl dimethylphosphonate copolymer is obtained by polymerizing vinylidene fluoride and vinyl dimethylphosphonate as monomers in dimethyl carbonate solvent at 60°C under the initiation of 2,5-dimethyl-2,5-di(peroxytert-butyl)hexane. The vinylidene fluoride-ortho(dimethoxyphosphoryl)methyl-2-trifluoromethacrylate copolymer is obtained by adding vinylidene fluoride and ortho(dimethoxyphosphoryl)methyl-2-trifluoromethacrylate to dimethyl carbonate solvent, using tert-amyl peroxyhexanoate as an initiator, reacting in a closed autoclave at 70-80°C for 6-10 hours, and obtaining the copolymer by precipitation and drying after polymerization. The polytetrafluoroethylene-grafted sulfonated polystyrene is obtained by grafting styrene onto a polytetrafluoroethylene film after electron beam irradiation activation, followed by sulfonation to form a –SO3H structure. The perfluorosulfonic acid polymer is obtained by emulsion polymerization of tetrafluoroethylene and perfluorosulfonic acid olefin ether monomers followed by hydrolysis. The perfluorocyclobutyl aryl ether polymer is obtained by thermally initiated [2+2] cycloaddition polymerization of aromatic ether monomers with trifluoroethylene ether; The fluorophosphorus-functionalized dendritic polymer is a fluorophosphate ester with a CF2–P(O)(OR)2 structure grafted onto a linear polyethyleneimine core, and its surface is capped with phosphonic acid or sulfonic acid groups. The 3-trifluoroethoxyhexafluoropropyl phosphate, 2-trifluoroethoxytetrafluoroethyl phosphate, and trifluoroethoxy-4-trifluoromethyl-3-oxaperfluoropentyl phosphate are all prepared from trifluorovinyl ether as the base material through fluorination, oxidation and phosphorylation reactions in sequence, and all contain the CF3–R–P(O)(OH)2 structure in their molecules. The phosphate-grafted polyethyleneimine is based on linear polyethyleneimine with a molecular weight of 5,000-10,000 g / mol. Phosphate groups are grafted onto the polyethyleneimine main chain or branches using phosphate monoester intermediates through nucleophilic substitution or amidation reactions to form a functionalized polymer with a molar content of 10%-20%. After dialysis to remove salt and freeze-drying, a light yellow solid is obtained.

[0009] Preferably, the thickness of the passivation layer is 0.01 μm-100 μm.

[0010] Preferably, the cutting method is laser cutting, and the drying method is room temperature drying.

[0011] Secondly, the present invention provides a method for fabricating a size-flexible four-terminal perovskite-crystalline silicon stacked module, as detailed below: S1: Passivate the cut and cleaned crystalline silicon cell using the crystalline silicon edge passivation method as described in any of the first aspects; S2: The passivated crystalline silicon cells are arranged in an array and interconnected in series using conductive silver paste, with the series resistance controlled to be <0.1 Ω·cm. 2 This yields passivated crystalline silicon modules; S3: The prepared perovskite top cell is laminated with the passivated crystalline silicon module obtained in S2 through a POE or EVA transparent film, and four electrode terminals are independently led out. The bottom of the passivated crystalline silicon module is laminated with the backplane glass through a POE film. After encapsulation, a four-terminal perovskite-crystalline silicon stacked module is obtained.

[0012] Thirdly, the present invention provides a dimensionally flexible four-terminal perovskite-silicon stacked assembly obtained by the preparation method described in the second aspect.

[0013] The present invention has the following advantages over the prior art: 1) Room temperature, non-vacuum, low-cost process The solution spraying method can form a film under normal pressure and room temperature conditions, eliminating the need for vacuum and high temperature equipment such as PECVD / ALD, which significantly reduces equipment investment and energy consumption. The process is production line friendly and can be directly integrated into the existing component manufacturing process of cutting-cleaning-spraying-lamination.

[0014] 2) Significantly improves electrical performance and efficiency retention after cutting. Without altering the battery's core structure, edge / backside passivation alone can increase the effective carrier lifetime (τeff) of the diced silicon wafer from approximately 0.5 ms to 9.0 ms, and reduce the surface recombination rate (SRV) from approximately 300 cm / s to 1.3 cm / s; correspondingly, at the module level, the efficiency retention rate after dicing consistently reaches ≥95%. Taking a representative system as an example: The VDF-MAF-DMP and perfluorosulfonic acid-based polymer systems showed that the cleavage efficiency increased from approximately 13.2% to 19.8%, the Voc increased from 0.62 to 0.66, and the FF increased from approximately 54% to approximately 76%, verifying that interfacial recombination was effectively suppressed.

[0015] The above data are all derived from comparative test results of embodiments of the present invention, obtained under AM1.5G and 25℃ conditions.

[0016] 3) Improved long-term stability and environmental adaptability The passivation layer molecular framework is rich in CF2 / CF3 fluorinated segments, forming a dense hydrophobic barrier and improving heat resistance, moisture resistance and photo-aging resistance. After 200 kWh of UV aging, the efficiency decay of the stacked crystalline silicon branch passivated by the present invention is about 4.83%, which is better than the 10.58% of the comparative alumina passivated sample, showing a lower failure rate and better lifetime expectation.

[0017] 4) Synergistic passivation mechanism of chemical anchoring + electrical shielding The side chains of the materials used contain polar functional groups such as phosphonic acid / phosphate ester / sulfonic acid, which can form chemical bonds or strong interactions with polar functional groups such as silanol groups on the surface of crystalline silicon, thus sealing defect states in situ. At the same time, the high dielectric constant polymer forms a charge blocking layer at the interface, further reducing minority carrier recombination. The fluorinated backbone is oriented outward to inhibit water and oxygen penetration and interface aging, thereby achieving dual passivation of "chemical + physical".

[0018] 5) Strong adaptability to size and shape The passivation layer thickness window is wide (0.01μm-100μm), and significant effects can be achieved with 0.01μm. It has good coverage and flexibility for micro-notches / steps on the edge after laser cutting, making it suitable for free assembly of small-sized units and high-density arrays. Furthermore, synchronous passivation on the back side can reduce the risk of leakage current and enhance mechanical reliability.

[0019] 6) Material versatility and substitutability A variety of optional materials (fluorophosphate monomers, phosphine / phosphorus functional polymers, perfluorosulfonic acid polymers, PFCB, sulfonated polyarylethers, PTFE-g-PS-SO3H, VDF-based copolymers, etc.) are presented in the examples, all of which show significant effects in reducing SRV, increasing τeff and improving efficiency retention, making it easy to make equivalent replacements based on cost, solvent system and production line compatibility.

[0020] 7) Systemic benefits of four-terminal stacked structures Without altering the electrical independence of the four-terminal structure, the Voc / FF and Jsc of the bottom crystalline silicon unit are improved, the overall efficiency of the stacked module is increased, and it maintains low degradation after UV aging; it is compatible with conventional lamination processes using POE / EVA, and the independent lead-out of the four terminals is unaffected.

[0021] In summary, this invention achieves efficient, stable, and scalable defect passivation of laser-cut crystalline silicon units through an edge / backside passivation strategy of "room temperature solution method + fluorine-containing polar functional groups" at low cost, significantly improving the initial performance and long-term reliability of four-terminal perovskite-crystalline silicon stacked modules. Attached Figure Description

[0022] Figure 1 Comparison of EL images of Comparative Example 1 (conventional alumina passivated crystalline silicon module, left) and Example 1 (crystalline silicon module using the passivation method of the present invention, right); Figure 2 Image comparison of conventional cutting (left) and passivated crystalline silicon module of the present invention (right); Figure 3 This is a schematic diagram of the structure of the four-terminal stacked battery assembly with a passivation layer according to the present invention. Detailed Implementation

[0023] The present invention will be further described and illustrated below with reference to the accompanying drawings and specific embodiments. The technical features of each embodiment of the present invention can be combined accordingly, provided that there is no mutual conflict.

[0024] This invention provides a method for passivating the crystalline silicon edge of a four-terminal perovskite-crystalline silicon stacked module. The method mainly involves spraying a passivation material solution onto the cut edge and back side of the crystalline silicon cell, and after drying, forming a dense and stable passivation layer to improve the efficiency retention rate of the crystalline silicon cell after cutting.

[0025] The purpose of passivating the back side in this invention is to prevent leakage and improve mechanical strength, making the crystalline silicon cell less prone to microcracks during use.

[0026] In this invention, the passivation material solution comprises one or more of the following monomers or polymers: perfluorosulfonic acid-based polymers (-[CF2-CF2]-[CF2-C) +F(Rf)-SO3H]-, where Rf is a perfluoroether side chain), perfluorocyclobutyl aryl ether polymer (PFCB), sulfonated polyaryl ether (-[Ar-O-Ar-SO3H]-), polytetrafluoroethylene grafted sulfonated polystyrene (PTFE-g-PS-SO3H), fluorophosphorus functionalized dendritic polymers (polyamine or PEI dendritic core, containing CF2-P(O)(OR)2 side chain, with sulfonic acid / phosphonic acid groups as end caps), phosphate grafted polyethyleneimine (Ph-PEI), fluorinated phosphonate polymers (including but not limited to dimethyl(trifluoroethyleneoxyhexylfluoropropyl)phosphonate, dimethylphosphonate vinyl ester (VDMP, structural formula: CH2=CH-P) (O)(OCH3)2), ortho(dimethoxyphosphoryl)methyl-2-trifluoromethacrylate (MAF-DMP, structural formula: CF3-C(CH2-P(O)(OCH3)2)=CH2), vinylidene fluoride-dimethylphosphonic acid vinyl ester copolymer (VDF-VDMP), vinylidene fluoride-trichlorotrifluoroethylene copolymer (VDF-CTFE), vinylidene fluoride-ortho(dimethoxyphosphoryl)methyl-2-trifluoromethacrylate copolymer (VDF-MAF-DMP), 3-trifluoroethoxyhexafluoropropyl phosphate, 2-trifluoroethoxytetrafluoroethyl phosphate, trifluoroethoxy-4-trifluoromethyl-3-oxaperfluoropentyl phosphate.

[0027] The aforementioned monomers or polymers generally share the following structural commonalities and functional synergies: the main chain consists of carbon-fluorine bonds or carbon-carbon bonds, exhibiting high thermal stability and chemical inertness; the side chains contain phosphonic acids (-P(O)(OH)). It has a fluorine or sulfonic acid (-SO3H) functional group, which has strong polarity and good interfacial activity; the material is "amphiphilic": that is, it has a hydrophobic fluorine skeleton + hydrophilic polar head group, which is conducive to self-assembly and directional bonding with silicon surface.

[0028] The passivation mechanism achieved by the above-mentioned materials in this invention is as follows: The edges of the cut silicon crystals expose a large number of ≡Si• dangling bonds, forming a highly reactive interface. The passivation material solution used in this invention achieves passivation through the following mechanisms: 1) Chemical bonding passivation: Phosphonic acid groups react with ≡Si–OH / ≡Si• to generate stable phosphorus-silicon bridge bonds: ≡Si-OH+R–P(O)(OH)2→≡Si-OP(O)(OH)R. Sulfonic acid groups form hydrogen bonds or electrostatic adsorption with SiO2 or ≡Si•, sealing surface defects. CF2 / CF3 segments construct a dense hydrophobic layer, inhibiting oxidation, water vapor penetration, and interface aging; 2) The polymer has a high dielectric constant, which can form a charge-blocking layer at the interface, reducing minority carrier recombination; 3) The outward-facing arrangement of fluorine atoms provides long-term protection against thermal, humidity, and photo-aging. This invention uses a solution spraying method to form a passivation film at normal pressure or room temperature, eliminating the need for vacuum or high-temperature equipment, significantly reducing process costs and energy consumption. Compared with traditional PECVD or ALD / Al2O3 processes, the method of this invention has the following advantages: As a preferred embodiment of the present invention, before spraying, the surface roughness of the crystalline silicon cell is controlled to be <1μm. It is then ultrasonically cleaned with acetone, ethanol, and deionized water in sequence, dried with nitrogen, and then sprayed.

[0029] As a preferred embodiment of the present invention, the vinylidene fluoride-vinyl dimethylphosphonate copolymer (VDF-VDMP) is obtained by polymerizing vinylidene fluoride (VDF) and vinyl dimethylphosphonate (VDMP) as monomers in dimethyl carbonate (DMC) solvent at 60°C under the initiation of 2,5-dimethyl-2,5-di(peroxytert-butyl)hexane.

[0030] Vinylidene fluoride-ortho(dimethoxyphosphoryl)methyl-2-trifluoromethyl acrylate copolymer (VDF-MAF-DMP) is produced by adding vinylidene fluoride (VDF) and ortho(dimethoxyphosphoryl)methyl-2-trifluoromethyl acrylate (MAF-DMP) in a suitable molar ratio (preferably 9:1) to dimethyl carbonate solvent, using tert-amyl peroxyhexanoate (TAPE) as an initiator, and reacting in a closed autoclave at 70-80°C for 6-10 hours. After polymerization, the target copolymer is obtained by precipitation and drying. If necessary, the phosphate ester groups can be further hydrolyzed to obtain a phosphonic acid polymer.

[0031] Polytetrafluoroethylene-grafted sulfonated polystyrene (PTFE-g-PS-SO3H) is obtained by grafting styrene onto a polytetrafluoroethylene (PTFE) film after electron beam irradiation activation, followed by sulfonation to form the -SO3H structure.

[0032] Perfluorosulfonic acid polymers (such as Nafion type) are obtained by emulsion polymerization of tetrafluoroethylene and perfluorosulfonic acid ether monomers followed by hydrolysis.

[0033] Perfluorocyclobutyl aryl ether (PFCB) polymers are obtained by thermally initiated [2+2] cycloaddition polymerization of aromatic ether monomers with trifluoroethylene ether (TFVE).

[0034] Fluorophosphate-functionalized dendritic polymers are obtained by grafting fluorinated phosphates with a CF2-P(O)(OR)2 structure onto a linear polyethyleneimine (PEI) core, and end-capping the surface with phosphonic acid or sulfonic acid groups.

[0035] 3-Trifluoroethoxyhexafluoropropyl phosphate, 2-trifluoroethoxytetrafluoroethyl phosphate, and trifluoroethoxy-4-trifluoromethyl-3-oxaperfluoropentyl phosphate are all monomers prepared from trifluorovinyl ether as a base material through sequential fluorination, oxidation, and phosphorylation reactions. They all contain the CF3-RP(O)(OH)2 structure in their molecules and possess excellent silicophilicity and polar bonding ability.

[0036] Phosphate-grafted polyethyleneimine (Ph-PEI) is a functionalized polymer with a molecular weight of 5,000-10,000 g / mol (which can improve grafting efficiency) as the main body. Phosphate groups (-P(O)(OH)2) are grafted onto the main chain or side chain of polyethyleneimine (PEI) using phosphate monoester intermediates (such as phosphate acrylate, phosphate chloroacetate, etc.) through nucleophilic substitution or amidation reactions, forming a molar ratio of 10%-20%. After dialysis to remove salt and freeze-drying, a light yellow solid is obtained.

[0037] In a preferred embodiment of the present invention, one or more of the prepared polymers or monomers are sprayed onto the diced edge and back side of the silicon wafer using a pneumatic / electric spray gun, and dried at room temperature to form a passivation layer. The thickness of the passivation layer is preferably 0.01 μm-100 μm.

[0038] This invention also provides a method for fabricating a size-flexible four-terminal perovskite-crystalline silicon stacked module, the specific fabrication method of which is as follows: S1, Crystalline silicon cell cutting and passivation treatment S11: Silicon Cutting and Cleaning The crystalline silicon solar cell (e.g., 210mm × 210mm) is laser-cut to the target size (e.g., 50mm × 50mm), with the surface roughness controlled to <1μm. It is then ultrasonically cleaned sequentially with acetone, ethanol, and deionized water for 15 minutes each, and dried with nitrogen.

[0039] S12: Edge passivation to form a passivation film The cut and cleaned crystalline silicon cells are passivated using the aforementioned crystalline silicon edge passivation method.

[0040] S2, Crystalline silicon string splicing: The passivated crystalline silicon solar cells are assembled in an array (e.g., a 4×4 array) and interconnected in series using conductive silver paste, with the series resistance controlled to be <0.1 Ω·cm. 2 This yields passivated crystalline silicon modules.

[0041] Performance can be verified by testing the effective carrier lifetime τeff and iVoc using QSSPC.

[0042] S3, Fabrication of four-terminal stacked assembly and mechanical stacking and packaging of devices: S31: The fabrication process of perovskite top solar cells mainly includes key steps such as patterning, bottom electrode cleaning, functional layer deposition, tandem structure scribing, electrode encapsulation, and stacking. The process route is as follows: 1) Patterning and bottom electrode preparation (P1): Perform P1 pattern laser etching on transparent conductive glass (such as FTO, ITO, AZO, IZO, silver nanowires, copper, silver, graphene, carbon nanotubes, etc.) to completely cut off the conductive layer to form an insulating area; use cleaning agent, pure water, isopropanol (IPA) and acetone in sequence to ultrasonically clean the etched area to remove organic impurities and particulate contamination.

[0043] 2) Functional Layer Structure Deposition: Deposit the first carrier transport layer (ETL), with materials including but not limited to: tin oxide (SnO2), zinc oxide (ZnO), TiO2, MZO, ZnSnO, Nb2O5, LiF, MgO, CaF2, Al2O3, SrTiO3, CaTiO3, NiO x Materials such as CuSCN and CuI are used, with the thickness controlled between 10-100 nm.

[0044] 3) Deposition of the perovskite absorber layer: ABX3 type organic-inorganic hybrid perovskite material is used, wherein: A-site cation: methylamine (MA) + ), formamidin (FA) + ), Cesium (Cs) + B-site metal: Pb 2+ Sn 2+ Bi 3+ Sb 3+ 、Ge 2+ Cu + ; X-position halogen: I - ,Br - Cl - F - The film thickness is 80-500 nm, and it is usually synthesized by solution spin coating or vapor deposition.

[0045] 4) Deposition of the second carrier transport layer (HTL): Optional materials include: Spiro-MeOTAD, PTAA, TAPC, PEDOT:PSS, P3HT, TPD, NPB, CuSCN, CuO, NiO, MoO x Materials such as Fe2O3, OMeTPA-FA, CzPAF-SBF, EDOT-OMeTPA, and TPBi are used, with film thicknesses typically ranging from 20 to 300 nm.

[0046] 5) Series scribing and top electrode deposition (P2-P3): P2 scribing: The second transport layer, perovskite layer and first transport layer are cut using laser or mechanical methods, leaving a series area. The bottom transparent conductive layer can be cut as needed; Transparent top electrode deposition: AZO, ITO, IZO, silver nanowires, metal thin layers (Ag, Cu) or transparent conductors such as graphene and carbon nanotubes are deposited to form a composite electrode with a thickness controlled between 80-200nm; P3 scribing: The top electrode is cut off, but the bottom electrode is not cut; The carrier layer and perovskite layer can be cut or not; P4 edge cleaning: All functional layers (including perovskite) are completely removed around the device to leave a blank area for the encapsulation sealing material.

[0047] S32: Edge Packaging: A butyl rubber sealing ring is laid in the P4 edge clearing area; the perovskite top cell and the passivated crystalline silicon module are laminated with POE / EVA film, and four electrode terminals are independently led out to avoid current mismatch. The lamination temperature is 130℃, the pressure is 100kPa, and the time is 10 minutes. The laminated structure is as follows: perovskite top cell / POE or EVA transparent film / crystalline silicon bottom cell string / POE film / backplane glass; four-terminal electrodes are independently led out: two electrodes are led out from the top cell and two from the bottom cell to ensure no series current mismatch.

[0048] One structural form of the obtained four-terminal perovskite-crystalline silicon tandem module is as follows: Figure 3 As shown.

[0049] The following examples and comparative examples will further illustrate the method of the present invention and the effects of the resulting stacked components.

[0050] Example 1 In this embodiment, vinylidene fluoride-vinyl dimethylphosphonate copolymer (VDF-VDMP) is used to passivate crystalline silicon solar cells. The specific method is as follows: 1) Take a 210mm×210mm crystalline silicon cell, test its efficiency, and cut it into 50mm×50mm crystalline silicon cells. The surface roughness after cutting is <1μm. Then, ultrasonically clean it with acetone, ethanol, and deionized water for 15 minutes each, and blow it dry with nitrogen. Test the efficiency again. The efficiency retention rate of the crystalline silicon after cutting is low, τeff is only 0.5ms, and SRV is as high as 300 cm / s.

[0051] 2) Preparation of vinylidene fluoride-vinyl dimethylphosphonate copolymer (VDF-VDMP): Using VDF:VDMP in a molar ratio of 2:1 as raw material, the reaction was initiated by 2,5-dimethyl-2,5-di(peroxytert-butyl)hexane and carried out in dimethyl carbonate (DMC) solvent at 60°C for 4 hours to obtain VDF-VDMP copolymer.

[0052] 3) The prepared VDF-VDMP copolymer was loaded into an electric spray gun, and the solution was sprayed onto the diced edge and back of the crystalline silicon. It was then dried at room temperature to form a passivation layer (passivation film thickness 150 nm), and the efficiency of the crystalline silicon cell was tested again. The results showed that τeff increased to 9.6 ms, SRV decreased to 1.46 cm / s, and the efficiency retention rate was 95%.

[0053] Comparative Example 1 This comparative example demonstrates passivation of crystalline silicon solar cells using conventional alumina. The specific method is as follows: 1) Take a 210mm × 210mm crystalline silicon cell, test its efficiency, and cut it into 50mm × 50mm crystalline silicon cells. The surface roughness after cutting should be <1μm. Then, ultrasonically clean it with acetone, ethanol, and deionized water for 15 minutes each, and dry it with nitrogen. Test the efficiency again.

[0054] 2) Alumina passivation was used for the crystalline silicon cell, that is, a 5nm thick layer of alumina was deposited as a passivation layer at the edge of the crystalline silicon cell using PECVD. The deposition process parameters were: pressure of 1500mTorr; RF power of 6000watt; time of 100s; temperature of 350℃; N2O flow rate of 5.5slm; TMA flow rate of 0.05sccm; and the efficiency of the crystalline silicon cell was tested again.

[0055] The test results before and after passivation in Comparative Example 1 and Example 1 are shown in Table 1: Table 1 As can be seen from Table 1, after passivation by Example 1 (i.e., the method of the present invention), the effective carrier lifetime τeff of the crystalline silicon cell after cutting increased from 0.5 ms to 9.6 ms compared with the traditional alumina passivated crystalline silicon cell. The efficiency after passivation increased from 13.20% to 20.9% (retention rate 95%). This shows that the material used in Example 1 effectively bonds with the dangling bonds on the crystalline silicon surface, passivates the defects on the surface of the crystalline silicon cell after cutting, reduces the recombination rate, greatly extends the carrier lifetime, and thus improves the efficiency of the crystalline silicon cell.

[0056] As can be seen from Figure 1, in the EL image of Comparative Example 1 (traditional alumina passivation, left figure), there are obvious dark areas and uneven electroluminescence in the edge region, indicating that the cutting edge recombination is severe and the local defects are dense; while Example 1 (passivation method of the present invention, right figure) shows uniform EL brightness and good edge continuity, indicating that the interface recombination is effectively suppressed.

[0057] As can be seen from Figure 2, the surface and edges of the traditional passivated crystalline silicon wafer have obvious rough fractures and defect bands; while the surface of the passivated crystalline silicon solar cell of the present invention is smooth and the edges are densely covered, with no obvious cracks or holes, indicating that the passivation film formed has good coverage and stability.

[0058] As can be seen from the results in Figures 1 and 2, the passivation method of the present invention can effectively reduce the cutting edges and surface defects of crystalline silicon cells, significantly reduce carrier recombination, and thus improve the efficiency retention rate of the cells.

[0059] Example 2 In this embodiment, vinylidene fluoride-ortho(dimethoxyphosphoryl)methyl-2-trifluoromethacrylate copolymer (VDF-MAF-DMP) is used to passivate crystalline silicon solar cells. The specific method is as follows: Step 1: Crystalline silicon cell cutting and surface passivation treatment 1) Crystalline Silicon Cutting and Cleaning: Standard 210mm × 210mm crystalline silicon solar cells were laser-cut into 100mm × 100mm smaller units, with a surface roughness controlled to <1μm. These units were then ultrasonically cleaned sequentially with acetone, ethanol, and deionized water for 15 minutes each, and dried with nitrogen gas. The cleaned unit wafers were then assembled in a 6×12 array and interconnected using conductive silver paste to form a crystalline silicon bottom cell module, with a series resistance controlled to <0.1 Ω•cm. 2 .

[0060] 2) Synthesis of vinylidene fluoride-ortho(dimethoxyphosphoryl)methyl-2-trifluoromethyl acrylate copolymer (VDF-MAF-DMP): Vinylidene fluoride (VDF) and ortho(dimethoxyphosphoryl)methyl-2-trifluoromethyl acrylate (MAF-DMP) were dissolved in dimethyl carbonate (DMC) at a molar ratio of 8:1, with tert-amyl peroxyhexanoate (TAPE) added as a free radical initiator. The copolymerization reaction was carried out in a closed autoclave at 70°C for 10 hours. After completion of the copolymerization reaction, the VDF-co-MAF-DMP copolymer was obtained by precipitation, filtration, and vacuum drying. Subsequently, the copolymer was subjected to phosphate hydrolysis to convert it into a phosphonic acid structure to enhance its interfacial bonding with the crystalline silicon surface.

[0061] 3) Crystalline silicon edge passivation: The synthesized copolymer is dissolved to prepare a spraying solution, which is then uniformly sprayed onto the edges and back surfaces of the crystalline silicon cell units at room temperature using an electric spray gun to form a passivation film layer with a thickness of approximately 200 nm. After drying, the cells are reassembled into 6×12 array strings, and interconnected using conductive silver paste to obtain the passivated crystalline silicon cell module.

[0062] Step 2: Construction of a four-terminal perovskite stacked assembly 1) Fabrication of the perovskite top cell structure: On an FTO conductive glass substrate, an electron transport layer SnO2 (approximately 40 nm) is first deposited; then, a MAPbI3 perovskite absorber layer is deposited using a two-step spin coating process, with a thickness controlled at approximately 400 nm; subsequently, a hole transport layer Spiro-OMeTAD (approximately 150 nm thick) is deposited; finally, ITO (approximately 100 nm thick) is deposited as a transparent top electrode by magnetron sputtering or vacuum evaporation.

[0063] 2) Module Lamination and Encapsulation: The perovskite top cell, POE transparent encapsulation film, passivated crystalline silicon bottom module, back POE film, and backsheet glass are sequentially stacked, and butyl sealing tape is pre-applied to the edge cleaning area. Encapsulation is completed by laminating at 120℃ and 60kPa for 10 minutes using a laminator. The electrodes of the top and bottom cells are independently led out, forming a standard four-terminal structure to avoid current mismatch issues.

[0064] The structure of the four-terminal stacked battery prepared in this embodiment is as follows: Figure 3 As shown, its performance data is as follows: Stacked structure: perovskite top cell (PCE=16.1%) + passivated crystalline silicon string (PCE=7.8%).

[0065] Photothermal aging performance: The stacked module prepared in Example 2 was subjected to a UV aging test. After 200kWh, the average degradation was about 5%, and the results are shown in Table 2 below.

[0066] Table 2 Attenuation data of stacked components As can be seen from the data in Table 2, the crystalline silicon solar cell module with VDF-MAF-DMP passivation in Example 2 has an initial efficiency of 7.87%, and its efficiency remains at 7.49% after 200 kWh of UV aging, with a degradation rate of only 4.83%. In contrast, the crystalline silicon solar cell module with alumina passivation in Comparative Example 2, under the same conditions, has an efficiency that decreases from 5.01% to 4.48%, with a degradation rate of 10.58%. Therefore, the passivation material used in this invention can significantly suppress performance degradation caused by UV aging, exhibiting superior long-term stability compared to traditional alumina passivation.

[0067] Comparative Example 2 This comparative example demonstrates passivation of crystalline silicon solar cells using conventional alumina. The specific method is as follows: Step 1: Crystalline silicon cell cutting and surface passivation treatment 1) Crystalline Silicon Cutting and Cleaning: Standard 210mm × 210mm crystalline silicon solar cells were laser-cut into 100mm × 100mm smaller units, with a surface roughness controlled to <1μm. These units were then ultrasonically cleaned sequentially with acetone, ethanol, and deionized water for 15 minutes each, and dried with nitrogen gas. The cleaned unit wafers were then assembled in a 6×12 array and interconnected using conductive silver paste to form a crystalline silicon bottom cell module, with a series resistance controlled to <0.1 Ω•cm. 2 .

[0068] 2) Alumina passivation was used for crystalline silicon solar cells. A 5nm alumina layer was deposited as a passivation layer at the edge of the crystalline silicon solar cell using PECVD. The deposition process parameters were: pressure 1500mTorr; RF power 6000watt; time 100s; temperature 350℃; N2O flow rate 5.5slm; TMA flow rate 0.05sccm.

[0069] Step 2: Construction of a four-terminal perovskite stacked assembly 1) Fabrication of the perovskite top cell structure: On an FTO conductive glass substrate, an electron transport layer SnO2 (approximately 40 nm) is first deposited; then, a MAPbI3 perovskite absorber layer is deposited using a two-step or integrated spin-coating process, with a thickness controlled at approximately 400 nm; subsequently, a hole transport layer Spiro-OMeTAD (approximately 150 nm thick) is deposited; finally, ITO (approximately 100 nm thick) is deposited as a transparent top electrode by magnetron sputtering or vacuum evaporation.

[0070] 2) Module Lamination and Encapsulation: The perovskite top cell, POE transparent encapsulation film, passivated crystalline silicon bottom module, back POE film, and backsheet glass are sequentially stacked, and butyl sealing tape is pre-applied to the edge cleaning area. Encapsulation is completed by laminating at 120℃ and 60kPa for 10 minutes using a laminator. The electrodes of the top and bottom cells are independently led out, forming a standard four-terminal structure to avoid current mismatch issues.

[0071] The battery modules prepared in Comparative Example 2 and Example 2 were subjected to a UV aging test of 200 kWh, and then the module efficiency was tested. The results are shown in Table 3 below.

[0072] Table 3 As can be seen from the table above, after the same 200kWh UV aging test, the efficiency of the passivated multilayer silicon in Example 2 decreased by 4.83%, which is better than that of the multilayer silicon passivated with alumina in Comparative Example 2. This further illustrates that the CF2 / CF3 segments in the passivation layer material selected in this invention form a dense hydrophobic layer, which inhibits oxidation, water vapor penetration and interface aging. The outward arrangement of fluorine atoms can provide long-term thermal, humidity and light aging protection.

[0073] Example 3 In this embodiment, fluorinated phosphate monomers with different structures (3-trifluoroethoxyhexafluoropropyl phosphate, 2-trifluoroethoxytetrafluoroethyl phosphate, and trifluoroethoxy-4-trifluoromethyl-3-oxaperfluoropentyl phosphate) were used to passivate the edges and surfaces of crystalline silicon solar cells after cutting, verifying their adhesion to the crystalline silicon surface and the passivation effect. Except for the different passivation solutions, the rest of the process flow was consistent with Example 1.

[0074] All three monomers mentioned above are prepared from trifluorovinyl ether as a base material through sequential fluorination, oxidation, and phosphorylation reactions. They simultaneously contain the CF2-RP(O)(OH)2 structure, exhibiting excellent silica affinity and polar bonding ability. Passivation treatment and testing methods: 3-trifluoroethoxyhexafluoropropyl phosphate, 2-trifluoroethoxytetrafluoroethyl phosphate, or trifluoroethoxy-4-trifluoromethyl-3-oxaperfluoropentyl phosphate monomers were dissolved in low-polarity mixed solvents and uniformly coated onto the edge and back surface of a 50mm × 50mm diced crystalline silicon cell using pneumatic spraying, forming a film thickness of approximately 10nm. After drying at room temperature, the passivation layer was completed. Subsequently, the crystalline silicon module was assembled, and performance tests were conducted, comparing it with the crystalline silicon module in Comparative Example 1 which used conventional alumina passivation. The test results are shown in Table 4 below.

[0075] Table 4 The data comparison in the table above shows that all fluorinated phosphate monomers significantly improved the passivation effect of crystalline silicon wafers, reducing the SRV from 300 cm / s without passivation to 2.1-2.8 cm / s; the efficiency after dicing increased from 13.2% to about 20%, with an efficiency retention rate of over 90%. This indicates that these phosphine-containing functional group molecules can form stable covalent or hydrogen bond complexes with ≡Si-OH or ≡Si• dangling bonds on the crystalline silicon surface, effectively sealing defect states, suppressing recombination processes, and significantly improving the photoelectric performance of the diced crystalline silicon solar cells.

[0076] Example 4 To verify the application effect of fluorinated phosphorus functional group dendritic macromolecules in passivation after crystalline silicon solar cell cutting, this embodiment selects a fluorinated phosphorus functional polymer with a CF2-P(O)(OR)2 structure. Through initiation polymerization and structural design, a functional macromolecular film with a flexible framework and strong polar side chains is constructed and sprayed onto the crystalline silicon cutting edge and back side to achieve molecular-level passivation, as detailed below: 1) Preparation of crystalline silicon solar cells: Take 210mm 210mm crystalline silicon solar cells are processed into 50mm diameters using laser cutting. 50mm in size, surface roughness <1μm, ultrasonically cleaned in three steps with acetone, IPA, and deionized water, then dried with nitrogen, and assembled into 6 12-array crystalline silicon strings, interconnected with silver paste, series resistance <0.1 Ω·cm 2 .

[0077] 2) Synthesis of dendritic functional polymers: Poly(TFE-co-Mo) polymers were synthesized by free radical copolymerization of dimethyl (trifluoroethyleneoxyhexafluoropropyl) phosphonate and tetrafluoroethylene in the presence of AIBN in R-113 solvent. After precipitation purification and drying, the polymers were dissolved in moderately polar solvents such as DMC or methyl ethyl ketone to prepare a 3 wt% spraying solution.

[0078] 3) Use a pneumatic spray gun to uniformly spray passivation liquid onto the edge and back of the cut silicon cell, with the film thickness controlled at 100μm; after drying at room temperature, assemble into a complete string and perform electrical interconnection; after the string is completed, stack it with the perovskite top cell in a four-terminal manner, with the structure and steps the same as in Example 2.

[0079] 4) Performance testing and effect comparison: The test results of the device in Comparative Example 1 and the device in Example 4 are compared as shown in Table 5 below.

[0080] Table 5 As can be seen from the data in the table above, fluorinated phosphorus functional dendritic polymers significantly improve the passivation quality of crystalline silicon dicing edges; the efficiency retention rate after dicing is higher than 90%, and the surface recombination rate (SRV) decreases to the order of 2-3 cm / s; the phosphonic acid or phosphate groups in the polymer form stable covalent / hydrogen bonds with the crystalline silicon surface, while the fluorocarbon backbone of the main chain provides excellent hydrophobicity and thermal and humid stability, making it an ideal passivation material system suitable for the manufacture of high-efficiency stacked modules.

[0081] Example 5 This embodiment uses a polymer with phosphate groups—phosphate-grafted polyethyleneimine (Ph-PEI)—as a passivation material for the edges and surfaces of cleaved crystalline silicon solar cells. This material possesses both strong polar chelating ability and a flexible branched structure, enabling effective passivation of crystalline silicon edge defects and adaptive interface coverage. The specific method is as follows: 1) Ph-PEI Synthesis: Using linear polyethyleneimine (PEI) with a molecular weight of 5,000-10,000 g / mol as the main component, phosphate groups (-P(O)(OH)2) are grafted onto the PEI main chain or branches via nucleophilic substitution or amidation reactions using phosphate monoester intermediates (such as acrylate phosphate, chloroacetic acid phosphate, etc.) to form a functionalized polymer with a content of 10%-20% (molar ratio). The product is desalted by dialysis and freeze-dried to obtain a light yellow solid.

[0082] 2) Solution preparation: Dissolve Ph-PEI in an ethanol-water (volume ratio 1:1) mixed solvent to prepare a passivation solution with a concentration of 2 wt.%, and adjust the pH to 6–7 to promote the complexation and adsorption of phosphate groups on the silicon surface.

[0083] 3) Crystalline silicon cell processing and passivation: 210mm 210mm crystalline silicon solar cells are cut into 50mm diameters. 50mm small pieces with roughness controlled to <1μm were sequentially ultrasonically cleaned with acetone, IPA, and water for 15 minutes and then dried. Spraying passivation layer: Using a pneumatic spray gun, Ph-PEI solution is uniformly sprayed onto the edge and back surface of the crystalline silicon unit wafer, and dried to form a phosphate functional film layer with a thickness of about 50 μm; 4) Component splicing: The passivated crystalline silicon cell units are assembled into a 6×12 array and interconnected with silver paste.

[0084] The test results of the device in Comparative Example 1 and the device in Example 5 are compared as shown in Table 6 below.

[0085] Table 6 The data in the table above demonstrates that the phosphate groups abundant in Ph-PEI can form stable covalent or hydrogen bond complexes with dangling bonds such as ≡Si-OH / ≡Si• on the crystalline silicon surface, effectively reducing the interfacial state density and surface recombination rate. The flexible polyethyleneimine framework can form a continuous passivation film on irregular edge structures, enhancing the uniformity of the passivation film. After passivation, the efficiency of the crystalline silicon wafer increased from 13.20% to 19.85%, and the SRV decreased to 2.6 cm / s, verifying its excellent passivation performance and practicality.

[0086] Example 6 This embodiment uses a perfluorosulfonic acid-based polymer (-[CF2-CF2]-[CF2-C)). + F(Rf)-SO3H]-, where Rf is a perfluoroether side chain (such as Nafion type), is used as a passivation material for the edges and surfaces of cleaved crystalline silicon solar cells. This material possesses a highly fluorinated main chain and sulfonic acid side chains, providing excellent chemical inertness and interfacial activity. The specific method is as follows: 1) Take a 210mm×210mm crystalline silicon cell, test its efficiency, and cut it into 50mm×50mm crystalline silicon cells. The surface roughness after cutting is <1μm. Then, ultrasonically clean it with acetone, ethanol, and deionized water for 15 minutes respectively, and blow it dry with nitrogen. Test the efficiency again. The efficiency retention rate of the crystalline silicon after cutting is low, τeff is only 0.5ms, and SRV is as high as 300 cm / s.

[0087] 2) Preparation of perfluorosulfonic acid-based polymer: It is obtained by emulsion polymerization of tetrafluoroethylene and perfluorosulfonic acid ether monomers followed by hydrolysis. The polymer is dissolved in isopropanol-water mixed solvent to prepare a 2 wt.% passivation solution.

[0088] 3) The prepared perfluorosulfonic acid polymer solution was loaded into an electric spray gun and sprayed onto the diced edge and back of the silicon wafer. It was then dried at room temperature to form a passivation layer (passivation film thickness 200 nm). The efficiency of the silicon wafer was then tested again. The results showed that τeff increased to 9.8 ms, SRV decreased to 1.32 cm / s, and the efficiency retention rate was 96%.

[0089] The test results of the device in Comparative Example 1 and the device in Example 6 are compared as shown in Table 7 below.

[0090] Table 7 As can be seen from the table, after passivation and cutting using the method of this invention, the effective carrier lifetime τeff of the crystalline silicon cell surface is increased from 0.5 ms to 9.8 ms compared to the traditional alumina passivated crystalline silicon cell, and the efficiency after passivation is increased from 13.20% to 21.20% (retention rate 96%).

[0091] Mechanism of Action: The main chain of the perfluorosulfonic acid polymer is composed of carbon-fluorine bonds, exhibiting high thermal stability and chemical inertness. The side chains contain sulfonic acid (-SO3H) functional groups, displaying strong polarity and interfacial activity, forming an amphiphilic structure (hydrophobic fluorine backbone + hydrophilic polar head group), which facilitates self-assembly and directional bonding with the silicon surface. The passivation mechanism includes: sulfonic acid groups forming hydrogen bonds or electrostatic adsorption with SiO2 or ≡Si•, sealing surface defects; CF2 / CF3 segments constructing a dense hydrophobic layer, inhibiting oxidation, moisture penetration, and interfacial aging; the polymer's high dielectric constant forming a charge-blocking layer, reducing minority carrier recombination; and outward-facing fluorine atom ends providing long-term protection against thermal, humidity, and photo-aging. This material forms a passivation film at room temperature through solution spraying, significantly reducing the recombination rate.

[0092] Example 7 In this embodiment, perfluorocyclobutyl aryl ether (PFCB) is used as a passivation material for the edges and surfaces of the crystalline silicon solar cell after dicing. This material is obtained through [2+2] cycloaddition polymerization and possesses excellent fluorinated structure and thermal stability. The specific method is as follows: 1) Take a 210mm×210mm crystalline silicon cell, test its efficiency, and cut it into 50mm×50mm crystalline silicon cells. The surface roughness after cutting is <1μm. Then, ultrasonically clean it with acetone, ethanol, and deionized water for 15 minutes in sequence, and blow it dry with nitrogen. Test the efficiency again. The efficiency retention rate of the crystalline silicon after cutting is low, τeff is only 0.5ms, and SRV is as high as 300 cm / s.

[0093] 2) Preparation of PFCB polymer: The polymer was prepared by thermally initiated [2+2] cycloaddition polymerization of aromatic ether monomers with trifluoroethylene ether (TFVE). The polymer was dissolved in a fluorinated solvent to prepare a passivation solution with a concentration of 3 wt.%.

[0094] 3) The prepared PFCB solution was loaded into an electric spray gun and sprayed onto the diced edge and back of the silicon wafer. It was then dried at room temperature to form a passivation layer (passivation film thickness 180 nm). The efficiency of the silicon cell was then tested again. τeff increased to 9.2 ms, SRV decreased to 1.58 cm / s, and the efficiency retention was 94%.

[0095] The test results of the device in Comparative Example 1 and the device in Example 7 are compared as shown in Table 8 below.

[0096] Table 8 As can be seen from the table, after passivation and cutting using the method of this invention, the effective carrier lifetime τeff of the crystalline silicon cell surface is increased from 0.5 ms to 9.2 ms compared to the traditional alumina passivated crystalline silicon cell, and the efficiency after passivation is increased from 13.20% to 20.60% (retention rate 94%).

[0097] Mechanism of Action: The main chain of PFCB consists of carbon-fluorine bonds and cyclobutyl structures, exhibiting high thermal stability and chemical inertness. The material possesses a hydrophobic fluorine framework, facilitating directional adsorption onto silicon surfaces. The passivation mechanism includes: fluorinated segments forming weak bonds or van der Waals adsorption with ≡Si•, sealing surface defects; CF2 / CF3 segments constructing a dense hydrophobic layer, inhibiting oxidation, moisture penetration, and interfacial aging; the high dielectric constant of the polymer forming a charge-blocking layer, reducing minority carrier recombination; and outward-facing fluorine atom ends providing long-term protection against thermal, humidity, and photo-aging. This material forms a passivation film at room temperature through solution spraying, enhancing interfacial stability.

[0098] Example 8 This embodiment uses sulfonated polyaryl ether (-[Ar-O-Ar-SO3H]-) as a passivation material for the edges and surfaces of the crystalline silicon solar cell after cleavage. This material has an aryl ether backbone and sulfonic acid side chains, providing mechanical strength and polarity. The specific method is as follows: 1) Take a 210mm×210mm crystalline silicon cell, test its efficiency, and cut it into 50mm×50mm crystalline silicon cells. The surface roughness after cutting is <1μm. Then, ultrasonically clean it with acetone, ethanol, and deionized water for 15 minutes in sequence, and blow it dry with nitrogen. Test the efficiency again. The efficiency retention rate of the crystalline silicon after cutting is low, τeff is only 0.5ms, and SRV is as high as 300 cm / s.

[0099] 2) Preparation of sulfonated polyaryl ethers: These are obtained through the sulfonation reaction of polyaryl ethers. The polymer is dissolved in dimethylformamide to prepare a passivation solution with a concentration of 2.5 wt.%.

[0100] 3) The prepared sulfonated polyarylene ether solution was loaded into an electric spray gun and sprayed onto the diced edge and back of the silicon wafer. It was then dried at room temperature to form a passivation layer (passivation film thickness 160 nm). The efficiency of the silicon wafer was then tested again. τeff increased to 9.4 ms, SRV decreased to 1.50 cm / s, and the efficiency retention rate was 95%.

[0101] The test results of the device in Comparative Example 1 and the device in Example 8 are compared as shown in Table 9 below.

[0102] Table 9 As can be seen from the table, after passivation and cutting using the method of this invention, the effective carrier lifetime τeff of the crystalline silicon cell surface is increased from 0.5 ms to 9.4 ms compared to the traditional alumina passivated crystalline silicon cell, and the efficiency after passivation is increased from 13.20% to 20.80% (retention rate 95%).

[0103] Mechanism of Action: The main chain of sulfonated polyaryl ether consists of carbon-carbon bonds and aryl ethers, exhibiting high thermal stability and chemical inertness. The side chains contain sulfonic acid (-SO3H) functional groups, displaying strong polarity and interfacial activity, forming an amphiphilic structure that facilitates self-assembly with silicon surfaces. The passivation mechanism includes: sulfonic acid groups forming hydrogen bonds or electrostatic adsorption with ≡Si-OH / ≡Si•, generating stable bridges to close defects; aryl segments providing mechanical flexibility and inhibiting interfacial aging; and the high dielectric constant of the polymer forming a charge-blocking layer, reducing minority carrier recombination. This material forms a passivation film at room temperature through solution spraying, reducing the recombination rate.

[0104] Example 9 In this embodiment, polytetrafluoroethylene-grafted sulfonated polystyrene (PTFE-g-PS-SO3H) is used as a passivation material for the edges and surfaces of the crystalline silicon solar cell after cutting. This material combines the fluorination of PTFE with the polarity of PS-SO3H. The specific method is as follows: 1) Take a 210mm×210mm crystalline silicon cell, test its efficiency, and cut it into 50mm×50mm crystalline silicon cells. The surface roughness after cutting is <1μm. Then, ultrasonically clean it with acetone, ethanol, and deionized water for 15 minutes in sequence, and blow it dry with nitrogen. Test the efficiency again. The efficiency retention rate of the crystalline silicon after cutting is low, τeff is only 0.5ms, and SRV is as high as 300 cm / s.

[0105] 2) Preparation of PTFE-g-PS-SO3H: PTFE film was activated by electron beam irradiation and then grafted with styrene, followed by sulfonation to form a -SO3H structure. The polymer was dissolved in dichloromethane to prepare a 3 wt.% passivation solution.

[0106] 3) The prepared PTFE-g-PS-SO3H solution was loaded into an electric spray gun and sprayed onto the diced edge and back of the silicon wafer. It was then dried at room temperature to form a passivation layer (passivation film thickness 170 nm). The efficiency of the silicon wafer was then tested again. τeff increased to 9.5 ms, SRV decreased to 1.45 cm / s, and the efficiency retention was 95%.

[0107] The test results of the device in Comparative Example 1 and the device in Example 9 are compared as shown in Table 10 below.

[0108] Table 10 As can be seen from the table, after passivation and cutting using the method of this invention, the effective carrier lifetime τeff of the crystalline silicon cell surface is increased from 0.5 ms to 9.5 ms compared to the traditional alumina passivated crystalline silicon cell, and the efficiency after passivation is increased from 13.20% to 20.85% (retention rate 95%).

[0109] Mechanism of action: The main chain of PTFE-g-PS-SO3H is composed of carbon-fluorine bonds (PTFE portion), exhibiting high thermal stability and chemical inertness. The side chains contain sulfonic acid (-SO3H) functional groups (PS portion), displaying strong polarity and interfacial activity, forming an amphiphilic structure that facilitates self-assembly with the silicon surface. The passivation mechanism includes: sulfonic acid groups forming hydrogen bonds or electrostatic adsorption with ≡Si-OH / ≡Si• to seal defects; CF2 segments constructing a dense hydrophobic layer to inhibit oxidation and permeation; the high dielectric constant of the polymer forming a charge-blocking layer to reduce recombination; and fluorine atoms providing aging protection. This material forms a passivation film at room temperature through solution spraying, enhancing stability.

[0110] Example 10 In this embodiment, a copolymer of vinylidene fluoride and trichlorotrifluoroethylene (VDF-CTFE) is used as a passivation material for the edges and surfaces of the crystalline silicon solar cell after cutting. This material is a highly fluorinated copolymer with excellent dielectric properties. The specific method is as follows: 1) Take a 210mm×210mm crystalline silicon cell, test its efficiency, and cut it into 50mm×50mm crystalline silicon cells. The surface roughness after cutting is <1μm. Then, ultrasonically clean it with acetone, ethanol, and deionized water for 15 minutes in sequence, and blow it dry with nitrogen. Test the efficiency again. The efficiency retention rate of the crystalline silicon after cutting is low, τeff is only 0.5ms, and SRV is as high as 300 cm / s.

[0111] 2) Preparation of VDF-CTFE copolymer: VDF and CTFE were polymerized in a solvent under the initiator of peroxide. The copolymer was dissolved in acetone to prepare a passivation solution with a concentration of 2 wt.%.

[0112] 3) The prepared VDF-CTFE solution was loaded into an electric spray gun and sprayed onto the diced edge and back of the silicon wafer. It was then dried at room temperature to form a passivation layer (passivation film thickness 190 nm). The efficiency of the silicon cell was then tested again. τeff increased to 9.0 ms, SRV decreased to 1.65 cm / s, and the efficiency retention was 93%.

[0113] The test results of the device in Comparative Example 1 and the device in Example 10 are compared as shown in Table 11 below.

[0114] Table 11 As can be seen from the table, after passivation and cutting using the method of this invention, the effective carrier lifetime τeff of the crystalline silicon cell surface is increased from 0.5 ms to 9.0 ms compared to the traditional alumina passivated crystalline silicon cell, and the efficiency after passivation is increased from 13.20% to 20.40% (retention rate 93%).

[0115] Working principle: The main chain of VDF-CTFE is composed of carbon-fluorine bonds, exhibiting high thermal stability and chemical inertness; chlorine atoms enhance polarity, forming a hydrophobic fluorine framework. The passivation mechanism includes: fluorine / chlorine segments adsorbing onto ≡Si• to seal defects; CF2 / CF3 segments constructing a dense hydrophobic layer to inhibit oxidation and permeation; the copolymer's high dielectric constant forming a charge-blocking layer to reduce recombination; and outward-facing fluorine atom ends providing protection against aging. This material forms a passivation film at room temperature through solution spraying, making it suitable for photovoltaic applications.

[0116] Example 11 This embodiment uses fluorinated phosphonate monomers with different structures (dimethyl(trifluoroethyleneoxyhexylfluoropropyl)phosphonate, vinyl dimethylphosphonate (VDMP), and ortho(dimethoxyphosphono)methyl 2-trifluoromethylacrylate (MAF-DMP)) to passivate the edges and surfaces of crystalline silicon solar cells after cutting, verifying their adhesion to the crystalline silicon surface and the passivation effect. Except for the different passivation solutions, the rest of the process flow is consistent with Example 1. These monomers are all prepared from fluorinated vinyl groups as the base material through sequential fluorination, oxidation, and phosphorylation reactions. The molecules simultaneously contain the CF3–R–P(O)(OR)2 structure, exhibiting excellent silica affinity and polar bonding ability.

[0117] Passivation treatment and testing methods: Dimethyl (trifluoroethyleneoxyhexylfluoropropyl) phosphonate, VDMP, or MAF-DMP monomers were dissolved in low-polarity mixed solvents and uniformly coated onto the edge and back areas of a 50mm × 50mm diced crystalline silicon cell using pneumatic spraying, with a film thickness of approximately 15nm. After drying at room temperature, the passivation layer was completed. Subsequently, the crystalline silicon module was assembled, and performance tests were conducted, with a comparison made with the crystalline silicon module using conventional alumina passivation in Comparative Example 1.

[0118] The test results of the device in Comparative Example 1 and the device in Example 11 are compared as shown in Table 12 below.

[0119] Table 12 The data comparison in the table above shows that all fluorophosphonate monomers significantly improved the passivation effect of crystalline silicon wafers, reducing the SRV from 300 cm / s without passivation to 2.4-2.9 cm / s; the efficiency after cutting increased from 13.2% to approximately 19.75%-19.95%, with an efficiency retention rate of over 90%.

[0120] Mechanism of Action: The main chain of these fluorinated phosphonate monomers contains carbon-fluorine bonds, exhibiting thermal stability and inertness; the side chains contain phosphonate (-P(O)(OR)2) functional groups, which can be hydrolyzed to phosphonic acid (-P(O)(OH)2), exhibiting strong polarity and interfacial activity, forming an amphiphilic structure. The passivation mechanism includes: the phosphonic acid group reacts with ≡Si–OH / ≡Si• to form a stable phosphorus-silicon bridge bond (≡Si-OH + RP(O)(OH)2 → ≡Si-OP(O)(OH)R); the CF2 / CF3 segments construct a hydrophobic layer, inhibiting oxidation and permeation; the high dielectric constant forms a charge-blocking layer, reducing recombination; and fluorine atoms provide aging protection. This material forms a passivation film at room temperature through solution spraying and is suitable for phosphorus-containing polymer systems.

[0121] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the invention. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the invention. Therefore, all technical solutions obtained through equivalent substitution or transformation fall within the protection scope of the present invention.

Claims

1. A method for passivating the silicon edge of a four-terminal perovskite-silicon multilayer module, characterized in that, A passivation material solution is sprayed onto the cut edges and back of the crystalline silicon cell. After drying, a dense and stable passivation layer is formed to improve the efficiency retention rate of the crystalline silicon cell after cutting. The passivation material solution includes at least one of the following: perfluorosulfonic acid polymer, perfluorocyclobutyl aryl ether polymer, sulfonated polyaryl ether, polytetrafluoroethylene grafted sulfonated polystyrene, fluorinated phosphorus functionalized dendritic polymer, phosphate grafted polyethyleneimine, fluorinated phosphonate polymer, vinylidene fluoride-dimethylphosphonate copolymer, vinylidene fluoride-trichlorotrifluoroethylene copolymer, vinylidene fluoride-ortho(dimethoxyphosphoryl)methyl-2-trifluoromethyl acrylate copolymer, 3-trifluoroethoxyhexafluoropropyl phosphate, 2-trifluoroethoxytetrafluoroethyl phosphate, and trifluoroethoxy-4-trifluoromethyl-3-oxaperfluoropentyl phosphate.

2. The silicon edge passivation method according to claim 1, characterized in that, Before spraying, the surface roughness of the crystalline silicon solar cell is controlled to be <1μm. It is then ultrasonically cleaned with acetone, ethanol, and deionized water in sequence, dried with nitrogen, and then sprayed.

3. The silicon edge passivation method according to claim 1, characterized in that, The vinylidene fluoride-dimethylphosphonate copolymer is obtained by polymerizing vinylidene fluoride and dimethylphosphonate as monomers in dimethyl carbonate solvent at 60°C under the initiation of 2,5-dimethyl-2,5-di(peroxytert-butyl)hexane. The vinylidene fluoride-ortho(dimethoxyphosphoryl)methyl-2-trifluoromethacrylate copolymer is obtained by adding vinylidene fluoride and ortho(dimethoxyphosphoryl)methyl-2-trifluoromethacrylate to dimethyl carbonate solvent, using tert-amyl peroxyhexanoate as an initiator, reacting in a closed autoclave at 70-80°C for 6-10 hours, and obtaining the copolymer by precipitation and drying after polymerization. The polytetrafluoroethylene-grafted sulfonated polystyrene is obtained by grafting styrene onto a polytetrafluoroethylene film after electron beam irradiation activation, followed by sulfonation to form a –SO3H structure. The perfluorosulfonic acid polymer is obtained by emulsion polymerization of tetrafluoroethylene and perfluorosulfonic acid olefin ether monomers followed by hydrolysis. The perfluorocyclobutyl aryl ether polymer is obtained by thermally initiated [2+2] cycloaddition polymerization of aromatic ether monomers with trifluoroethylene ether; The fluorophosphorus-functionalized dendritic polymer is a fluorophosphate ester with a CF2–P(O)(OR)2 structure grafted onto a linear polyethyleneimine core, and its surface is capped with phosphonic acid or sulfonic acid groups. The 3-trifluoroethoxyhexafluoropropyl phosphate, 2-trifluoroethoxytetrafluoroethyl phosphate, and trifluoroethoxy-4-trifluoromethyl-3-oxaperfluoropentyl phosphate are all prepared from trifluorovinyl ether as the base material through fluorination, oxidation and phosphorylation reactions in sequence, and all contain the CF3–R–P(O)(OH)2 structure in their molecules. The phosphate-grafted polyethyleneimine is based on linear polyethyleneimine with a molecular weight of 5,000-10,000 g / mol. Phosphate groups are grafted onto the polyethyleneimine main chain or branches using phosphate monoester intermediates through nucleophilic substitution or amidation reactions to form a functionalized polymer with a molar content of 10%-20%. After dialysis to remove salt and freeze-drying, a light yellow solid is obtained.

4. The silicon edge passivation method according to claim 1, characterized in that, The thickness of the passivation layer is 0.01μm-100μm.

5. The method for passivating the edge of crystalline silicon according to claim 1, characterized in that, The cutting method is laser cutting, and the drying method is room temperature drying.

6. A method for fabricating a size-flexible four-terminal perovskite-crystalline silicon multilayer module, characterized in that, Specifically as follows: S1: Passivate the cut and cleaned crystalline silicon cell using the crystalline silicon edge passivation method as described in any one of claims 1 to 5; S2: The passivated crystalline silicon cells are arranged in an array and interconnected in series using conductive silver paste, with the series resistance controlled to be <0.1 Ω·cm. 2 This yields passivated crystalline silicon modules; S3: The prepared perovskite top cell is laminated with the passivated crystalline silicon module obtained in S2 through a POE or EVA transparent film, and four electrode terminals are independently led out. The bottom of the passivated crystalline silicon module is laminated with the backplane glass through a POE film. After encapsulation, a four-terminal perovskite-crystalline silicon stacked module is obtained.

7. A dimensionally flexible four-terminal perovskite-silicon stacked module obtained using the preparation method of claim 6.

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