Packaging structure and preparation method of perovskite-back contact crystalline silicon laminated solar cell module

Abstract

The invention relates to the technical field of solar cell module packaging, in particular to a packaging structure for a perovskite-back contact crystalline silicon laminated solar cell and a preparation method of the packaging structure. The packaging structure comprises a front light conversion glass layer, a perovskite top cell layer, an infrared light-transmitting adhesive film layer, a back contact crystal silicon bottom cell layer, an adhesive film layer and a packaging bottom plate which are arranged in sequence, and butyl rubber surrounding the perovskite top cell layer, the infrared light-transmitting adhesive film layer, the back contact crystal silicon bottom cell layer and the adhesive film layer is arranged between the front light conversion glass layer and the packaging bottom plate, and the near infrared transmittance of 780 nm to 1100 nm in the infrared transparent adhesive film layer is 93% to 100%. According to the packaging structure based on the front light conversion glass layer and the infrared light-transmitting adhesive film layer, regulation and control of short-wave ultraviolet and near-infrared spectrums are considered, and the photoelectric property and reliability of the perovskite-crystalline silicon four-terminal laminated device are remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of solar cell module encapsulation technology, specifically to an encapsulation structure for perovskite-back-contact crystalline silicon tandem solar cells and its fabrication method. Background Technology

[0002] Perovskite-crystalline silicon tandem solar cells are considered an important direction for next-generation high-performance photovoltaic technology due to their potential combination of high efficiency and low cost. Perovskite materials possess excellent visible light absorption capabilities, while crystalline silicon cells exhibit stable output performance in the near-infrared region. Their spectral responses are highly complementary, making them suitable for constructing high-efficiency tandem structures. Especially in the perovskite-back-contact (BC) crystalline silicon tandem architecture, the absence of metal grid lines obstructing the front of the bottom cell effectively improves light transmittance and the external quantum efficiency of the bottom cell, giving these modules the potential to achieve photoelectric conversion efficiencies exceeding 30%.

[0003] However, several key technological bottlenecks still exist in the packaging design and manufacturing process of this type of high-efficiency stacked module, which seriously restrict its large-scale production and long-term stable operation. These bottlenecks are mainly reflected in the following aspects: 1. Insufficient utilization and stability of short-wavelength spectrum: Conventional modules mostly use high-transmittance or anti-reflection cover glass. Although it has a certain transmittance, it cannot achieve active control of the incident spectrum, resulting in the energy in the ultraviolet band (300nm–400nm) not being effectively utilized, and may even cause damage to the perovskite layer material structure, reducing the stability and lifespan of the device. 2. Limited infrared transmittance: Commonly used encapsulating films such as EVA or POE have significant insufficient transmittance in the 800nm–1100nm infrared band, affecting the effective coupling of the perovskite layer's transmitted energy to the underlying crystalline silicon, thus restricting the improvement of the overall photoelectric efficiency of the stacked structure. 3. Complex structure, challenging process, and limited yield: At present, most perovskite-crystalline silicon tandem modules are constructed using a series-parallel connection method based on crystalline silicon cells. Especially in large-size modules, the length of a single cell string is large, which leads to increased series resistance and increased risk of hot spots. At the same time, multiple busbars need to be set, which increases the complexity of packaging, process difficulty and module failure rate, which is not conducive to the stable control of mass production process and the long-term outdoor reliability guarantee.

[0004] Therefore, there is an urgent need for a packaging system with a more rational structure, optimized spectral utilization, and stronger hermeticity and durability to meet the technical requirements for the industrial application of perovskite-back-contact crystalline silicon multilayer modules. Summary of the Invention

[0005] The purpose of this invention is to provide a packaging structure and preparation method for a perovskite-back-contact crystalline silicon tandem solar cell module, in order to solve the above-mentioned technical problems.

[0006] To achieve the above objectives, the present invention provides an encapsulation structure for a perovskite-back-contact crystalline silicon tandem solar cell module. The encapsulation structure includes a front light-converting glass layer, a perovskite top cell layer, an infrared-transmitting adhesive film layer, a back-contact crystalline silicon bottom cell layer, an adhesive film layer, and an encapsulation base plate arranged sequentially. A butyl rubber is disposed between the front light-converting glass layer and the encapsulation base plate, surrounding the perovskite top cell layer, the infrared-transmitting adhesive film layer, the back-contact crystalline silicon bottom cell layer, and the adhesive film layer. Among them, the near-infrared transmittance of 780nm~1100nm in the infrared translucent film layer is 93%-100%.

[0007] The present invention also provides a method for preparing a packaging structure, the method comprising: The encapsulation front panel is fabricated based on the front light-converting glass layer and the perovskite top cell layer; The encapsulation structure is obtained by laminating an infrared transparent adhesive film layer, a back contact crystalline silicon base cell layer, an adhesive film layer, butyl adhesive, and an encapsulation base plate on the front plate of the encapsulation.

[0008] The technical effects and advantages of this invention are as follows: 1. Dual-spectrum modulation packaging structure enhances device efficiency and stability. The packaging structure proposed in this invention, based on a front light-converting glass layer and an infrared-transmitting adhesive film layer, balances the modulation of short-wave ultraviolet and near-infrared spectra, significantly improving the photoelectric performance and reliability of perovskite-crystalline silicon four-terminal stacked devices. For example, the front light-converting glass layer includes a light-converting anti-reflective coating and / or the light-converting glass substrate contains light-converting materials (such as rare-earth ions, quantum dots, or inorganic phosphors), which can convert part of the 300nm–400nm ultraviolet light into visible light, enhancing the absorption of the perovskite layer while reducing damage to the device from high-energy irradiation. Furthermore, the infrared-transmitting adhesive film has a transmittance of over 93% in the 780nm–1100nm band, which facilitates the transmission of light from the perovskite layer into the back-contact crystalline silicon base cell, effectively improving the infrared response. With the synergistic effect of the two technologies, the EQE response of the perovskite-crystalline silicon tandem module is significantly enhanced in the 400nm–1100nm spectral range, with an improvement of about 5% in the visible light band. The module efficiency is about 1.0% higher than that of the conventional structure, while also exhibiting better UV resistance.

[0009] 2. High-reliability packaging design enhances airtightness and stability. A composite ion-barrier layer effectively prevents corrosion of the perovskite layer by moisture, alkali metal ions, and ultraviolet radiation. The addition of functional interface compatibility additives in the infrared-transmitting adhesive film further improves the adhesion and interface stability between the film and each functional layer, enhancing the long-term operational reliability of the component from a material perspective.

[0010] 3. Low-temperature nitrogen lamination process, adapted to perovskite encapsulation characteristics. This invention employs a 75℃–110℃ low-temperature lamination process, completing encapsulation under a pressure of 0.3MPa–0.6MPa and an inert gas (such as nitrogen) purging environment (oxygen concentration <1000ppm, humidity <1.0%). This avoids the decomposition or degradation of the perovskite layer under high temperature, oxygen, and moisture conditions, significantly improving the initial performance and stability of the encapsulated device.

[0011] 4. The modular structure and strong process adaptability facilitate large-scale mass production. The modular short-string arrangement proposed in this invention, combined with the flexible interconnect conductor design, significantly reduces the length of a single battery string and the series resistance, reduces the number of encapsulation holes and solder points, facilitates integration into automated production lines and improves product yield, and has good engineering adaptability and industrialization prospects.

[0012] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 This is a schematic diagram of the packaging structure; Figure 2 This is a modular component matrix diagram. Detailed Implementation

[0015] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0016] It should be noted that the structures, proportions, sizes, etc., illustrated in the accompanying drawings are merely for illustrative purposes to aid those skilled in the art and to facilitate understanding and reading. They are not intended to limit the scope of the invention and therefore have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness and purpose of the invention, should still fall within the scope of the technical content disclosed herein. Furthermore, the terms "upper," "lower," "left," "right," "middle," and "one" used in this specification are merely for clarity and not intended to limit the scope of the invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention.

[0017] To better understand the present invention, its core design concept is briefly described below: This packaging structure is synergistically optimized from three dimensions: spectral response efficiency, infrared transmittance, and structural manufacturability. It is the first to systematically propose the design concept of "dual-regulated spectral packaging materials," significantly improving the synergistic light absorption capability of the upper and lower layers of the perovskite-crystalline silicon stack by employing a material combination of "top-layer front-converting glass + bottom-layer infrared-transmitting adhesive film." In terms of structural design, this solution introduces a modular short-string cell arrangement, adapting to large-size module layouts, reducing series complexity, simplifying the process flow, and possessing good mass production adaptability. The overall packaging structure achieves synergistic integration of optical optimization and electrical performance, suitable for two-terminal or four-terminal electrical structures, enhancing the flexibility and compatibility of system integration.

[0018] An encapsulation structure for a perovskite-back-contact crystalline silicon tandem solar cell module, such as... Figure 1 As shown, it includes: a front light-converting glass layer, a perovskite top cell layer, an ion-barrier layer, an infrared-transmitting adhesive film layer, a back contact crystalline silicon bottom cell layer, an adhesive film layer (i.e., the bottom adhesive film), and an encapsulation substrate (such as a back glass or backplate).

[0019] Specifically, the front light-converting glass layer includes: a light-converting anti-reflection coating, a light-converting glass substrate layer containing light-converting materials, and a TCO / FTO front electrode. Note that this solution allows for improvements to the light-converting anti-reflection coating and the light-converting glass substrate layer containing light-converting materials; these two improvements are parallel solutions, and either one can be used, or both can be used simultaneously. This front light-converting glass is a functional glass with light-converting capabilities, capable of converting ultraviolet light with wavelengths of 300nm–400nm and some short-wavelength blue light into visible light with wavelengths of 400nm–700nm, thereby improving the external quantum efficiency (EQE) of the perovskite solar cell layer in the short-wavelength band.

[0020] The light-converting material includes, but is not limited to, the following components: (1) Rare earth ionic materials. The rare earth ionic materials include at least one of the following: yttrium aluminum garnet doped with trivalent cerium ions, yttrium oxide doped with trivalent europium ions, and phosphate glass co-doped with trivalent cerium and trivalent terbium ions. The preferred embodiment is cerium-doped yttrium aluminum garnet (Ce:YAG). This material uses yttrium aluminum garnet as a matrix and is doped with trivalent cerium ions, exhibiting 4f→5d energy level transition characteristics. Under ultraviolet or blue light excitation, it can emit a broad spectrum of yellow-green light (approximately 520nm–580nm). It has high quantum efficiency (QE>85%), strong thermal stability (temperature resistance exceeding 200°C), high irradiation stability, stable chemical properties, and good compatibility with glass substrates, making it suitable for large-area integration.

[0021] (2) Quantum dot materials. The quantum dot materials include at least one of the following: zinc sulfide quantum dots, manganese-doped zinc sulfide quantum dots, and cadmium-free indium phosphide quantum dots. Zinc sulfide (ZnS) quantum dots are preferred in this design, belonging to group II–VI semiconductor nanocrystals. Their emission wavelength is modulated by confinement effect; when the particle size is controlled within the range of 2 nm–6 nm, the emission spectrum is located in the 430 nm–520 nm blue-green region, which can efficiently match the absorption window of perovskite. These quantum dots possess high photoluminescence efficiency, a broad excitation spectrum, and excellent resistance to photobleaching. Furthermore, their dispersibility and environmental stability can be improved through surface ligand modification.

[0022] (3) Inorganic fluorescent materials. The inorganic fluorescent materials include at least one of the following: polysilicate rare earth composites, aluminosilicate polysilicate composites. This solution preferably uses polysilicate rare earth composites. , Using the same substrate as the base material, doped , , Rare earth ions can emit red (approximately 610 nm), green (approximately 540 nm), and white light, respectively. These materials can emit multicolor visible light under ultraviolet excitation through an energy transfer mechanism. They are characterized by high thermal stability, strong chemical inertness, and good glass compatibility, making them suitable for long-term embedding in functional glass.

[0023] The aforementioned light-converting materials can be introduced into the light-converting glass substrate layer through processes such as sol-gel method, melt doping method, and spray heat treatment method to form a uniformly dispersed and long-term stable light-converting composite structure, which has good outdoor weather resistance and mass production characteristics.

[0024] The three types of light-converting materials share the following characteristics: (1) They are all inorganic structures with excellent thermal stability and resistance to ultraviolet aging; (2) The excitation light band is concentrated in the range of 300nm–400nm, effectively utilizing the ultraviolet and short-wave blue light that are difficult to absorb in sunlight; (3) The emission spectrum is located between 400nm–700nm, which covers the high EQE response region of the perovskite top cell layer; (4) The light-emitting mechanism is based on non-thermal processes (such as fd transition, quantum confinement recombination, 4f-4f transition), and the conversion process has low energy consumption and low heat loss, making it an ideal material choice for constructing efficient and low-attenuation packaging structures.

[0025] Among them, the light-converting anti-reflective coating can improve light transmittance across the entire wavelength range and enhance weather resistance. Preferably, it adopts... The double-layer interference film structure enhances visible light transmittance and reduces surface reflectivity to less than 3%. This light-converting anti-reflective coating also possesses composite functions such as hydrophobicity, UV aging resistance, and uniform spectral transmittance, which helps improve the photoelectric conversion efficiency and long-term stability of the component.

[0026] Specifically, the perovskite top solar cell layer consists of, in sequence: ETL, perovskite absorber layer, HTL, and metal back electrode. Since this perovskite top solar cell layer is not the focus of this improvement, it will not be discussed in detail.

[0027] Specifically, the infrared translucent film is an optical-grade encapsulation film with high infrared transmittance. Its near-infrared transmittance at wavelengths of 780nm–1100nm is 93%–100%, which improves the effective transmission of unabsorbed infrared light from the perovskite solar cell to the underlying crystalline silicon solar cell.

[0028] The infrared-transmitting adhesive film comprises at least one of the following materials: (1) Polyolefin elastomer (POE) optical film: This material is naturally free of polar groups and has excellent infrared transmittance. By controlling the copolymer structure and adding low refractive index nanofillers (such as silicon oxide particles), its transmittance in the near-infrared region can reach 88%–94%, while also having good weather resistance and low water vapor transmittance.

[0029] (2) Modified ethylene-vinyl acetate (EVA) film: By grafting fluorine-containing monomers or acrylate groups and adding optical additives (such as UV absorbers, scavengers, and stabilizers), its optical stability and light transmittance can be improved. The light transmittance of the modified EVA film can reach more than 92% in the 950nm wavelength band.

[0030] (3) Modified polyvinyl butyral (PVB) film: After dehydration treatment and the addition of optical grade anti-reflective components, it also has good transmittance in the near-infrared region and exhibits high interfacial adhesion and mechanical flexibility, making it suitable for flexible structures.

[0031] (4) Thermoplastic polyurethane (TPU) film: It has good optical transparency and mechanical extensibility. Through modification, it can have both high light transmittance and high adhesion performance, and has a certain buffering and protective effect on perovskite materials.

[0032] In this process, interfacial compatibility agents are introduced into the infrared permeable membrane to optimize the interlayer interface quality. These interfacial compatibility agents are grafts or coupling agents.

[0033] The grafting material can be isocyanate-grafted polyolefins (such as MDI-g-POE) or graft copolymers containing maleic anhydride groups (such as POE-g-MA). This invention uses MDI-grafted POE as a representative example. MDI is uniformly dispersed in a film system, where the isocyanate groups (–NCO) can react with the hydroxyl groups (–OH) on the surface of the interface material to form urethane bonds (–NH–CO–O–); or they can react with the amine groups (–NH–CO–O–). The reaction forms urea bonds (–NH–CO–NH–). This reaction mechanism can establish stable chemical bonds between the encapsulant film and inorganic glass, electrode oxide layer, perovskite encapsulation layer, etc., effectively improving the interlayer interface quality and enhancing the overall reliability of the module encapsulation.

[0034] The coupling agent can be the nano-scale silane coupling agent GPTMS (γ-glycidyl etheroxypropyltrimethoxysilane), which is used as a low-concentration solution to pretreat or spray-modify the interface between the perovskite solar cell layer and the encapsulant film before lamination. GPTMS molecules have a bifunctional structure: the trimethoxysilyl group at one end can react with hydroxyl groups on inorganic surfaces (such as glass, electrode oxide layers, etc.) after hydrolysis to form stable Si–O–Si covalent bonds; the epoxy group at the other end can undergo ring-opening reactions with hydroxyl or amino groups in organic encapsulation films (such as EVA, POE, or TPU) to form C–O or C–N type covalent links. This molecular bridging mechanism significantly enhances the chemical coupling strength of the inorganic-organic interface, effectively suppresses abrupt changes in refractive index and microscale light scattering effects at the interface, thereby improving the light transmittance efficiency of the stacked structure in the infrared band and the stability of the encapsulation interface.

[0035] Furthermore, in actual processes, the addition ratio of interfacial compatibility aids (such as GPTMS, MDI-g-POE, POE-g-MA) is preferably controlled between 0.1wt% and 0.5wt% to enhance the interfacial coupling effect between the infrared-transmitting film and the inorganic / organic functional layers. This design helps improve the quality of interlayer bonding and prevents film embrittlement caused by excessive cross-linking or performance degradation of the perovskite layer due to residual byproducts.

[0036] Specifically, an ion-barrier layer is placed between the infrared-transmitting film and the perovskite solar cell layer to limit the diffusion of migrating ions such as iodine ions and methylamine cations at the interface. This ion-barrier layer can be a single layer of an anti-UV functional layer, an ion-coupled agent layer, or an alumina thin layer, or it can be a stacked structure formed by any two or three of these layers. The order of the two- or three-layer stacked structure is: perovskite solar cell layer + anti-UV functional layer + ion-coupled agent layer + alumina thin layer + infrared-transmitting film. The reason for this order is that the anti-UV functional layer can effectively block high-energy ultraviolet light from entering the underlying material, delaying the aging of the coupling agent and the film; the ion-coupled agent layer (such as GPTMS) enhances the organic-inorganic interface adhesion and improves structural stability; the alumina thin layer has high density and extremely low ion transmittance, and can act as a core barrier to inhibit the migration of iodine, lead, and other ions and the intrusion of moisture, ensuring the long-term encapsulation stability and electrical performance reliability of the module.

[0037] For single-layer ion-barrier layers, a thin alumina layer is preferred, such as an alumina thin layer with a thickness of 10nm–50nm prepared by atomic layer deposition (ALD). This thin layer has excellent density and high infrared light transmittance, and can significantly improve the stability of the encapsulation interface without significantly affecting the optical properties of the component. This alumina thin layer can be selectively deposited on the surface of the infrared-transmitting adhesive film or on the inner surface of the top glass. For ion-barrier layers formed by double or triple-layer stacked structures, a double-layer stacked structure formed by an anti-UV functional layer and an ion coupling agent layer, a double-layer stacked structure formed by an ion coupling agent layer and an alumina thin layer, or a triple-layer stacked structure formed by an anti-UV functional layer, an ion coupling agent layer, and an alumina thin layer are preferred.

[0038] Related studies have shown that this barrier layer can significantly reduce the migration rate of iodine ions in perovskite solar cells by 1 to 2 orders of magnitude and maintain encapsulation stability for more than 1,000 hours in high temperature and high humidity environments (85℃, 85%RH), making it one of the key technical paths to improve module lifespan.

[0039] Specifically, the back-contact battery adopts a modular arrangement structure, where each sub-matrix consists of 7 rows × 7 columns of half-cell battery units, each measuring 166mm × 83mm. Every four sub-matrixes are connected in series to form a complete module, adapting to a module size of 2400mm × 1200mm. Adjacent sub-matrixes are electrically connected via flexible interconnecting conductors. The interconnection method can be either stacked interconnection (negative pitch of -0.1mm to -1mm) or gap interconnection (pitch of 0mm–5mm). When using gap interconnection, a high-reflectivity film can be optionally placed in the gap area to improve the light recovery efficiency of the module's back side; alternatively, this film structure can be omitted according to optical design requirements, such as... Figure 2 As shown.

[0040] The film can be made of polymer materials with infrared light transmission properties and good structural stability, such as black or white EP (co-extruded EVA and POE), PE (co-extruded POE and EVA), EPE (co-extruded EVA-POE-EVA), POE, PVB, TPO or equivalent alternatives.

[0041] Each submatrix can be optionally equipped with or without a bypass diode. This can either leverage the diode-like characteristics of the BC battery itself to improve its anti-shading capability, or improve system stability and simplify the layout of external terminals of the components by setting the built-in bypass diodes at the matrix level.

[0042] It should also be noted that the thickness of each layer in the packaging structure includes: the light-converting anti-reflective coating is 90nm–160nm, preferably 110nm–140nm; the light-converting glass substrate layer is 2mm–5mm, preferably 3mm–4mm; the TCO / FTO front electrode layer is 200nm–400nm, preferably 250nm–350nm; the ETL layer is 20nm–80nm, preferably 40nm–60nm; the perovskite absorber layer is 300nm–600nm, preferably 400nm–500nm; the HTL layer is 50nm–200nm, preferably 90nm–150nm; the metal back electrode layer is 50nm–150nm, preferably 90nm–120nm; and the ion barrier layer... The thickness is 10nm–50nm, preferably 20nm–40nm; the infrared transparent adhesive film layer is 0.35mm–0.7mm, preferably 0.5mm–0.6mm; the back contact crystalline silicon bottom cell layer is 110um–150um, preferably 120um–140um; the adhesive film layer is 0.35mm–0.7mm, preferably 0.5mm–0.6mm; the encapsulation substrate is 2mm–5mm, preferably 3mm–4mm (glass) or 0.2mm–0.5mm, preferably 0.3-0.4mm (backplate); the butyl rubber width of the four sides of the encapsulation structure is 5mm–15mm, preferably 8mm–11mm, and the thickness is 1.0mm–2.5mm, preferably 1.2mm–1.8mm.

[0043] The present invention also provides a method for preparing a packaging structure, comprising: fabricating a packaging front plate based on a front light-converting glass layer and a perovskite top cell layer; and obtaining a packaging structure by laminating an infrared light-transmitting adhesive film layer, a back contact crystalline silicon bottom cell layer, an adhesive film layer, butyl adhesive, and a packaging base plate onto the packaging front plate.

[0044] The encapsulation process employs a low-temperature lamination process, with the lamination temperature controlled within the range of 75℃–110℃, preferably 80℃–100℃; the lamination pressure set at 0.3MPa–0.6MPa, preferably 0.4MPa–0.5MPa; and the lamination time at 10–18 minutes, preferably 12–15 minutes. Before lamination, a vacuum extraction combined with an inert gas (such as nitrogen) circulation replacement process is used to reduce the oxygen concentration in the encapsulation environment to below 1000ppm, preferably below 700ppm; and the relative humidity is controlled to be no higher than 1.0%, preferably no higher than 0.4%.

[0045] The above process conditions can effectively suppress the erosion of perovskite materials by oxygen and moisture during the encapsulation process, and improve the chemical stability and light transmittance of the encapsulation interface.

[0046] In summary, through the above-mentioned multiple interface control and process optimization measures, the light transmittance efficiency and long-term encapsulation stability of perovskite-crystalline silicon four-terminal stacked modules in the infrared band can be significantly improved.

[0047] To better understand this solution, specific embodiments and comparative examples are provided below: Example 1: A method for fabricating a perovskite-back-contact crystalline silicon four-terminal tandem solar cell module encapsulated with Ce:YAG rare-earth light-converting glass and a high-transmittance infrared POE film, specifically including: Front encapsulation glass: Yttrium aluminum garnet (Ce:YAG) particles (2.5% by mass) doped with trivalent cerium ions are uniformly dispersed in a 3.2mm high borosilicate glass substrate and prepared by melt doping, combined with a surface sputtered double-layer light-converting and anti-reflective coating. The overall transmittance (300nm–700nm) is increased to over 90%. This glass can convert some of the 300nm–400nm ultraviolet light into 500nm–580nm visible light, achieving spectral compensation for the top perovskite solar cell, while significantly reducing the ultraviolet aging effect.

[0048] Encapsulation Intermediate Film Layer: A 0.45mm thick double-sided infrared-transmitting POE film is selected, with a transmittance exceeding 93% in the 780nm–1100nm wavelength band, effectively enhancing the near-infrared response of the underlying crystalline silicon solar cell. The infrared-transmitting POE film is compounded with a thermally stable interface compatibility aid, GPTMS-modified polyolefin copolymer, to strengthen the interfacial bonding strength between the perovskite and crystalline silicon solar cells, reducing the risk of interlayer delamination.

[0049] Module structure: A four-terminal lead-out method is adopted, with independent outputs for the perovskite and back-contact crystalline silicon cells, eliminating the need for an intermediate layer electrical connection structure and reducing resistance loss. The lower-layer crystalline silicon cell adopts an IBC structure, with a single cell size of 166mm × 83mm and an arrangement of 7×7 short strings, optimizing module current matching and uniformity.

[0050] Lamination process: 75°C, 0.5MPa, nitrogen gas ( Low-temperature thermal lamination is performed in an environment of <800ppm, RH<0.5% to form a tight-sealed packaging structure, which effectively inhibits water and oxygen erosion of the perovskite layer and interface reaction.

[0051] After connecting the obtained encapsulation structure to the junction box and the lead wire, you can choose to assemble a frame to protect the four sides of the encapsulation structure or not assemble a frame, and finally form a photovoltaic cell module with power output under sunlight.

[0052] Comparative Example 1 The fabrication method of this comparative battery module is referenced from Toniolo, F., et al. “Performance comparison of perovskite–silicon tandem modules encapsulated with TPU and TPO polymers.” Nanoscale, 2023, 15(12), 5432–5442. The performance of the battery modules in Example 1 and Comparative Example 1 was tested. The test method was as follows: the PCE of the perovskite-crystalline silicon tandem cells / modules was tested under standard AM1.5G illumination conditions. The test data are shown in Table 1.

[0053] Table 1 Battery Module Performance Test Data

[0054] As can be seen from the data in the table, this embodiment integrates Ce:YAG light-converting glass and a high infrared-transmitting film, which significantly enhances spectral utilization efficiency while maintaining long-term reliability.

[0055] Example 2 The component structure in this embodiment is the same as in Embodiment 1, except that the interface compatibility agent is replaced with MDI-grafted POE at a dosage of 0.2 wt%, the lamination temperature is controlled at 78°C, and the pressure is 0.4 MPa. Its encapsulation stability and interface adhesion are further improved, and the water vapor permeability is reduced by more than 20%, making it suitable for outdoor high-humidity areas.

[0056] Example 3 Thermal stress adaptability was tested using different interconnection methods: negative pitch interconnection (-0.2 mm) and gap interconnection (3 mm) were used respectively, paired with black EPE film, and the lamination process was the same as in Example 1. The results showed that the stacked interconnection method combined with ion barrier layer encapsulation can effectively alleviate module warpage stress and avoid interface delamination. After 500 cycles each of damp heat and thermal cycling (-40~85℃), good encapsulation integrity was maintained.

[0057] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A packaging structure for a perovskite-back-contact crystalline silicon tandem solar cell module, characterized in that, The encapsulation structure includes a front light-converting glass layer, a perovskite top cell layer, an infrared-transmitting adhesive film layer, a back-contact crystalline silicon bottom cell layer, an adhesive film layer, and an encapsulation base plate arranged sequentially. A butyl rubber is disposed between the front light-converting glass layer and the encapsulation base plate, surrounding the perovskite top cell layer, the infrared-transmitting adhesive film layer, the back-contact crystalline silicon bottom cell layer, and the adhesive film layer. Among them, the near-infrared transmittance of 780nm~1100nm in the infrared translucent film layer is 93%-100%.

2. The packaging structure according to claim 1, characterized in that, The front light-converting glass layer includes a light-converting anti-reflection coating, a light-converting glass substrate layer, and a TCO / FTO front electrode adjacent to the perovskite top cell layer, arranged sequentially.

3. The packaging structure according to claim 2, characterized in that, The light-converting glass matrix contains at least one of the following light-converting materials: rare earth ion materials, quantum dot materials, and inorganic fluorescent materials.

4. The packaging structure according to claim 3, characterized in that, The rare earth ionic material includes at least one of the following: yttrium aluminum garnet doped with trivalent cerium ions, yttrium oxide doped with trivalent europium ions, and phosphate glass co-doped with trivalent cerium and trivalent terbium ions; the quantum dot material includes at least one of the following: zinc sulfide quantum dots, manganese-doped zinc sulfide quantum dots, and cadmium-free indium phosphide quantum dots; the inorganic fluorescent material includes at least one of the following: polysilicate rare earth complexes and aluminosilicate polysilicate complexes.

5. The packaging structure according to claim 1, characterized in that, An ion-barrier layer is set between the perovskite top cell layer and the infrared-transmitting adhesive film layer.

6. The packaging structure according to claim 5, characterized in that, The ion barrier layer comprises a stacked structure consisting of one or more of the following single layers: an anti-ultraviolet functional layer, an ion coupling agent layer, and an alumina thin layer.

7. The packaging structure according to claim 1, characterized in that, Infrared translucent films include the following: polyolefin elastomer optical films, modified polyvinyl butyral films, modified ethylene-vinyl acetate films, and thermoplastic polyurethane films.

8. The packaging structure according to claim 7, characterized in that, The infrared translucent adhesive film contains interfacial compatibility additives; Among them, the interface compatibility aid is a graft or coupling agent.

9. The packaging structure according to claim 8, characterized in that, The grafted material includes at least one of the following: isocyanate-grafted polyolefins, graft copolymers containing maleic anhydride groups; the coupling agent is γ-glycidoxypropyltrimethoxysilane.

10. The packaging structure according to claim 1, characterized in that, The back-contact crystalline silicon solar cells are arranged in a matrix, and each sub-matrix in the matrix is ​​connected by a flexible conductor.

11. A method for preparing a packaging structure based on any one of claims 1-10, characterized in that, The method includes: The encapsulation front panel is fabricated based on the front light-converting glass layer and the perovskite top cell layer; The encapsulation structure is obtained by laminating an infrared transparent adhesive film layer, a back contact crystalline silicon base cell layer, an adhesive film layer, butyl adhesive, and an encapsulation base plate on the front plate of the encapsulation.

12. The method according to claim 11, characterized in that, The lamination conditions are: inert atmosphere with an oxygen concentration of less than 1000 ppm and a relative humidity of no more than 1.0%; lamination temperature of 75℃–110℃, lamination pressure of 0.3MPa–0.6MPa, and lamination time of 10–18 minutes.

13. The method according to claim 11, characterized in that, The method further includes: depositing an ion-barrier material on the surface of a perovskite solar cell layer adjacent to an infrared-transmitting adhesive film layer to form an ion-barrier layer.

Images