Composite intermediate connection layer and perovskite-crystalline silicon two-end laminated solar cell

Abstract

The application provides a composite intermediate connecting layer and a perovskite-crystalline silicon two-end laminated solar cell, and relates to the technical field of solar cells. The composite intermediate connecting layer is arranged between a crystalline silicon bottom cell and a perovskite top cell of a perovskite-crystalline silicon two-end laminated solar cell. The composite intermediate connecting layer is a composite film layer containing indium tin oxide and inorganic material. The inorganic material is selected from at least one of hydroxyapatite, fluorapatite and magnesium oxide. The composite intermediate connecting layer utilizes the alkaline characteristics of the specific inorganic material, effectively blocks the downward penetration of acidic degradation products by in-situ neutralization, while maintaining the high conductivity and light transmission performance of indium tin oxide, thereby preventing the corrosion of the bottom crystalline silicon and greatly improving the device stability and the recycling rate of the silicon wafer.

Description

Technical Field

[0001] This invention relates to the field of solar cell technology, and more specifically, to a composite intermediate connecting layer and a perovskite-crystalline silicon tandem solar cell. Background Technology

[0002] As the photoelectric conversion efficiency of traditional crystalline silicon solar cells gradually approaches its theoretical limit, the difficulty of further breaking through the efficiency bottleneck of single-junction cells is increasing. In order to achieve higher photoelectric conversion efficiency, the tandem cell architecture, which integrates a wide-bandgap top cell and a narrow-bandgap crystalline silicon bottom cell in series, has become an important development direction for photovoltaic technology.

[0003] In tandem solar cell devices, an intermediate interconnect layer is typically required between the top cell and the crystalline silicon bottom cell. This intermediate interconnect layer, as a key functional structure, plays multiple roles, including carrier recombination, series conductivity, and optical matching. Currently, most traditional intermediate interconnect layers utilize a single transparent conductive oxide (TCO) thin film to achieve interlayer physical and electrical interconnection, aiming to obtain high device transmittance and conductivity.

[0004] However, existing single transparent conductive films face severe chemical stability defects in actual service environments. On the one hand, the upper light-absorbing material is highly susceptible to degradation and the generation of acidic byproducts under external conditions such as light exposure and humidity. A single transparent conductive film cannot effectively prevent the downward diffusion of such acidic substances, causing them to leak to the surface of the crystalline silicon substrate, leading to severe interfacial corrosion and structural damage. On the other hand, some light-absorbing layer materials contain heavy metal lead ions. Once the battery structure is damaged due to aging or degradation, free heavy metal ions will leak out, posing a serious environmental hazard risk.

[0005] In summary, traditional intermediate connecting layers, limited by the intrinsic physicochemical properties of a single material, struggle to maintain good photoelectric transmission performance while simultaneously effectively blocking internal acidic degradation products and protecting the silicon-crystalline interface. They also fail to provide substantial suppression of heavy metal ion ionization. These inherent defects not only lead to a rapid decline in the photoelectric conversion efficiency and shortened service life of tandem solar cells but also directly cause highly destructive device failures and potential environmental pollution hazards.

[0006] In view of this, the present invention is hereby proposed. Summary of the Invention

[0007] The purpose of this invention is to provide a composite intermediate connecting layer and a perovskite-crystalline silicon tandem solar cell. The composite intermediate connecting layer, while maintaining high conductivity and light transmittance, can effectively prevent corrosion of the underlying crystalline silicon by neutralizing acidic degradation products in situ, and significantly improve its recyclability.

[0008] In order to achieve the above-mentioned objectives of the present invention, the following technical solution is adopted: In a first aspect, the present invention provides a composite intermediate connecting layer, which is used to be disposed between the crystalline silicon bottom cell and the perovskite top cell of a perovskite-crystalline silicon stacked solar cell. The composite intermediate connecting layer is a composite film layer containing indium tin oxide and inorganic materials; The inorganic material is selected from at least one of hydroxyapatite, fluorapatite, and magnesium oxide.

[0009] In an optional embodiment, the thickness of the composite intermediate connecting layer is 20nm-100nm; and / or, The sheet resistance of the composite intermediate connecting layer is less than 150 Ω / sq; and / or, The light transmittance of the composite intermediate connecting layer is greater than 80%; and / or, In the composite film, the mass ratio of indium tin oxide to the inorganic material is 90:10 to 30:70; preferably, the mass ratio of indium tin oxide to the inorganic material is 75:25.

[0010] Secondly, the present invention provides a method for preparing a composite intermediate connecting layer as described in the foregoing embodiments, comprising: Provide a base; A composite precursor solution containing an indium tin oxide precursor and an inorganic material is spin-coated onto the substrate and then annealed to obtain the composite intermediate connecting layer; the inorganic material is selected from at least one of hydroxyapatite, fluorapatite and magnesium oxide.

[0011] Thirdly, the present invention provides a method for preparing the composite intermediate connecting layer as described in the foregoing embodiments, wherein the spin coating speed is 2000 rpm to 4000 rpm; and / or, The spin coating time is 20s~60s; and / or, The annealing process includes a first annealing stage and a second annealing stage; wherein, the first annealing stage is annealing at 100℃~200℃ for 5 minutes to 10 minutes; and / or, the second annealing stage is annealing at 120℃~200℃ in an inert gas atmosphere for 30 minutes to 1 hour.

[0012] Fourthly, the present invention provides a perovskite-crystalline silicon tandem solar cell, comprising a crystalline silicon bottom cell, a perovskite top cell, and a composite intermediate connecting layer as described in the foregoing embodiments disposed between the crystalline silicon bottom cell and the perovskite top cell.

[0013] In an optional embodiment, a first hole transport layer and a second hole transport layer are sequentially disposed between the composite intermediate connecting layer and the perovskite top cell. Preferably, the first hole transport layer is a nickel oxide layer; Preferably, the thickness of the first hole transport layer is 10nm~20nm; Preferably, the second hole transport layer is a membrane containing a phosphate group structure; Preferably, the thickness of the second hole transport layer is 2nm~10nm; Preferably, the material of the second hole transport layer is selected from at least one of (4-(7H-dibenzo[C,G]carbazole-7-yl)butyl)phosphonic acid, [2-(dimethoxy-9-9-yl)ethyl]phosphonic acid, and (2-(9H-carbazole-9-yl)ethyl)phosphonic acid.

[0014] In an optional embodiment, the perovskite top solar cell comprises, from bottom to top: a perovskite light-absorbing layer, a passivation layer, an electron transport layer, a magnetron sputtering protection layer, a transparent electrode, and a metal conductive electrode; and / or, The surface of the crystalline silicon bottom cell is provided with a transparent oxide layer; the composite intermediate connection layer is disposed on the transparent oxide layer; preferably, the surface of the crystalline silicon bottom cell is N-plane microcrystalline silicon.

[0015] In an optional embodiment, the thickness of the perovskite light-absorbing layer is 500 nm to 600 nm; and / or, The passivation layer material is a mixture of phenylethylamine iodide and ethylenediamine dihydroiodide; and / or, The passivation layer has a thickness of 2 nm to 10 nm; and / or, The electron transport layer material is fullerene C. 60 ; and / or, The thickness of the electron transport layer is 10 nm to 20 nm; and / or, The anti-magnetron sputtering damage layer is a tin oxide thin film; and / or, The thickness of the anti-magnetron sputtering damage layer is 15nm~20nm; and / or, The material of the transparent electrode is selected from at least one of indium tin oxide, indium zinc oxide, or a composite layer thereof; and / or, The thickness of the transparent electrode is 30nm~120nm; and / or, The metal conductive electrode is a silver grid line electrode; and / or... The thickness of the metal conductive electrode is 100nm~200nm.

[0016] Fifthly, the present invention provides a method for fabricating a perovskite-crystalline silicon tandem solar cell, used to fabricate a solar cell as described in any of the foregoing embodiments, comprising: The composite intermediate connection layer is fabricated on the crystalline silicon bottom cell; A first hole transport layer and a second hole transport layer are fabricated on the composite intermediate connecting layer; A perovskite solution was spin-coated onto the second hole transport layer, and vacuuming and annealing were performed sequentially to prepare a perovskite light absorption layer. A passivation layer, an electron transport layer, a magnetron sputtering protection layer, a transparent electrode, and a metal conductive electrode are sequentially fabricated on the perovskite light absorption layer.

[0017] In a sixth aspect, the present invention provides an electrical device comprising a perovskite-crystalline silicon tandem solar cell as described in any of the foregoing embodiments, or a perovskite-crystalline silicon tandem solar cell obtained by the preparation method described in the foregoing embodiments.

[0018] Compared to existing technologies, the composite intermediate bonding layer provided by this invention significantly improves the internal chemical stability of the device by combining indium tin oxide with specific inorganic materials (hydroxyapatite, fluorapatite, or magnesium oxide). Because the selected inorganic materials possess intrinsic alkalinity, when the top light-absorbing material degrades under complex service conditions and releases acidic byproducts, the composite film can undergo an in-situ acid-base neutralization reaction. This core mechanism effectively cuts off the downward diffusion path of acidic substances, fundamentally preventing interface corrosion and structural damage to the underlying crystalline silicon substrate caused by acid leakage, thereby significantly improving the lifespan of the tandem solar cell and the subsequent recycling rate of the crystalline silicon substrate.

[0019] Meanwhile, the composite structure built using indium tin oxide as the matrix ensures that while providing excellent corrosion resistance, the fundamental photoelectric transmission channels required for device operation are not sacrificed. It also maintains excellent visible light transmittance and low sheet resistance, guaranteeing smooth carrier recombination and series conduction between the top and bottom cells. This structural design cleverly overcomes the inherent chemical stability limitations of a single transparent conductive film, achieving a high degree of balance between photoelectric performance and device reliability. Attached Figure Description

[0020] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific 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 from these drawings without creative effort.

[0021] Figure 1 This is a stability test diagram of the device of the present invention stored at room temperature and 85% humidity. Figure 2 This is a light transmittance test diagram of the composite film layer of the present invention; Figure 3 This is a schematic diagram of a perovskite-crystalline silicon tandem solar cell provided in an embodiment of the present invention.

[0022] Explanation of reference numerals in the attached figures: a-Top metal electrode; b-Transparent conductive electrode; c-Sputter damage protection layer; d-Electron transport layer; e-Passivation layer; f-Perovskite light absorption layer; g-Second hole transport layer; h-First hole transport layer; i-Composite intermediate connection layer; j-Crystal silicon bottom cell; k-Bottom metal electrode. Detailed Implementation

[0023] The embodiments of the present invention will be described in detail below with reference to examples. However, those skilled in the art will understand that the following examples are for illustrative purposes only and should not be considered as limiting the scope of the invention. Unless otherwise specified in the examples, conventional conditions or conditions recommended by the manufacturer are followed. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0024] This application provides a composite intermediate connection layer, which is used to be disposed between the crystalline silicon bottom cell and the perovskite top cell of a perovskite-crystalline silicon tandem solar cell, and serves as a functional medium for electrical interconnection, optical matching and interface chemical protection.

[0025] The composite intermediate connecting layer is a composite film layer containing indium tin oxide and inorganic materials; The inorganic material is selected from at least one of hydroxyapatite, fluorapatite, and magnesium oxide.

[0026] Specifically, the composite intermediate connecting layer is composed of an indium tin oxide (ITO) matrix and inorganic materials dispersed within the matrix. The indium tin oxide, acting as a continuous conductive and transparent framework, provides a smooth, low-impedance series path for non-equilibrium carrier recombination between the perovskite top cell and the crystalline silicon bottom cell in a tandem solar cell. The inorganic material is selected from at least one of hydroxyapatite, fluorapatite, and magnesium oxide. In specific fabrication conditions, the inorganic material is typically uniformly embedded or interwoven within the amorphous or polycrystalline micronetwork of indium tin oxide in the form of micro / nano-scale particles or amorphous functional phases, forming a dense inorganic hybrid composite film.

[0027] The inorganic material utilizes its intrinsic physicochemical properties to provide active interface protection for the intermediate connecting layer. When tandem solar cells are subjected to prolonged exposure to sunlight, high heat, or humidity in actual service environments, the top perovskite light-absorbing layer may undergo slow lattice degradation, generating acidic gaseous or liquid byproducts, including hydroiodic acid (HI). These acidic byproducts are highly diffusive and, once they penetrate the conventional transport layer, will directly reach the intermediate connecting layer structure.

[0028] In the composite intermediate connecting layer provided in this embodiment, the dispersed inorganic material captures and intercepts the diffused acidic substances through an in-situ chemical reaction mechanism.

[0029] Specifically, when the inorganic material is selected from hydroxyapatite (Ca... 10 When (PO4)6(OH)2 is present, the local basic sites within its structure undergo an in-situ acid-base neutralization reaction with the leaked hydroiodic acid, transforming it into a stable apatite derivative and trace amounts of water molecules. This process, through the fixation and consumption of protons (H+), allows for the formation of a stable apatite derivative and a trace amount of water molecules. + This cuts off the physical path for acidic substances to continue penetrating into the lower crystalline silicon cell substrate.

[0030] When the inorganic material is selected as fluorapatite (Ca 10 When (PO4)6F2 is used, it utilizes its high lattice energy microstructure to maintain excellent corrosion resistance and stability, while also exerting the ability to consume acidic substances through the polar attraction of the alkaline centers.

[0031] When magnesium oxide (MgO) is selected as the inorganic material, as a basic oxide, the oxygen ion centers released from its dissociation exhibit extremely high proton affinity, and can rapidly react with hydroiodic acid to generate a stable magnesium salt.

[0032] By introducing multiple or single inorganic materials, the composite intermediate connecting layer in this embodiment successfully utilizes a chemical neutralization barrier to block the interfacial corrosion and oxidative damage of acidic degradation products on the surface of the underlying crystalline silicon cell, ensuring the lattice integrity and electrical passivation characteristics of the underlying crystalline silicon substrate. This in-situ protection mechanism not only curbs the surge in overall series resistance and power conversion efficiency decay of the stacked device caused by interlayer corrosion, but also creates favorable interfacial conditions for the non-destructive peeling and high-purity recycling of the crystalline silicon bottom cell and silicon wafer after the stacked cell has been scrapped.

[0033] Furthermore, as an additional physicochemical synergy, the dispersed inorganic material also endows the composite intermediate connecting layer with an environmentally friendly function of suppressing heavy metal leakage. Currently, high-performance perovskite light-absorbing layers are typically lead-based materials. Under extreme conditions such as extreme aging, encapsulation failure, or severe physical damage to the device, water-soluble lead ions (Pb) can leak out. 2+There is a risk of lead ions escaping to the outside. The inorganic materials used in this embodiment (especially hydroxyapatite and fluorapatite) have abundant ion exchange sites in their unique crystal framework, exhibiting extremely strong specific adsorption and solidification capabilities for heavy metal ions. When free lead ions diffuse downwards and come into contact with the composite film layer, they are firmly captured by the inorganic materials through surface complexation or in-situ ion replacement. For example, hydroxyapatite can react with free lead ions, transforming them in situ into a thermodynamically insoluble lead apatite structure, thereby firmly anchoring the lead element within the intermediate connecting layer. According to relevant tests, the adsorption rate of free lead ions by the inorganic materials (such as hydroxyapatite) inside the composite intermediate connecting layer can exceed 80%. This spontaneous ion trapping mechanism, without the need for additional leakage prevention layers, constructs an invisible environmental protection barrier for the entire tandem solar cell, significantly reducing the pollution risk of heavy metals leaking into the external environment.

[0034] Meanwhile, due to the maintenance of the continuity of the indium tin oxide matrix, the composite intermediate connecting layer not only plays a strong chemical barrier protection role, but also maintains excellent lateral and longitudinal conductivity, and has no negative impact on the block resistance and light transmittance in the visible-infrared band, thus achieving a deep synergy between photoelectric transmission efficiency enhancement and device structure chemical protection.

[0035] In summary, the composite intermediate connecting layer, by combining an inorganic material with alkaline characteristics (hydroxyapatite, fluorapatite, or magnesium oxide) with indium tin oxide, significantly enhances the device's chemical corrosion resistance while maintaining its original high light transmittance and excellent conductivity. This composite structure can effectively consume acidic byproducts generated from the degradation of the upper layer through in-situ neutralization, completely blocking their downward penetration and fundamentally preventing corrosion of the bottom silicon interface. This not only ensures the long-term reliability of the battery but also significantly improves the subsequent recycling rate of the silicon substrate.

[0036] Furthermore, in order to achieve the best synergistic balance between interlayer chemical barrier, electrical interconnection and optical matching, this embodiment has optimized and limited the geometric dimensions and physicochemical properties of the composite intermediate connecting layer.

[0037] In some embodiments, the thickness of the composite intermediate connecting layer is 20nm-100nm.

[0038] Within this thickness range, for example, it can be 20nm, 30nm, 40nm, 50nm, 60nm, 70nm, 80nm, 90nm, 100nm, etc. This thickness range constructs the optimal microscopic physical morphology: on the one hand, a thickness of not less than 20nm ensures that the composite precursor can form a continuous, pinhole-free, dense film on the crystalline silicon substrate, thereby ensuring sufficient capacity of the inorganic material neutralization sites and the continuity of the physical barrier layer, effectively preventing vertical leakage of acidic substances; on the other hand, a thickness of not more than 100nm strictly controls the parasitic absorption loss of the film for long-wavelength photons and keeps the bulk resistance in the vertical direction at a low level, which is conducive to the efficient tunneling and recombination of charge carriers between the top and bottom cells.

[0039] In some embodiments, the sheet resistance of the composite intermediate connecting layer is less than 150 Ω / sq.

[0040] Specifically, the sheet resistance can be, for example, 10Ω / sq, 30Ω / sq, 50Ω / sq, 70Ω / sq, 90Ω / sq, 110Ω / sq, 130Ω / sq, 140Ω / sq, 145Ω / sq, 149Ω / sq, etc. This excellent lateral conductivity is due to the good lattice continuity of the indium tin oxide (ITO) matrix. The low sheet resistance effectively suppresses ohmic losses during carrier recombination at the interface, significantly reducing the overall series resistance (R0) of the tandem solar cell. s This ensures that the device can output an ideal voltage and a high fill factor (FF).

[0041] In some embodiments, the light transmittance of the composite intermediate connecting layer is greater than 80%.

[0042] Specifically, the light transmittance can be, for example, 81%, 83%, 85%, 88%, 90%, 92%, 95%, 97%, 98%, 99%, etc. Through optimized control of the dispersion morphology of inorganic materials and the overall film thickness in the composite film, the film exhibits extremely low optical attenuation characteristics while ensuring corrosion resistance and conductivity. A high transmittance of over 80% allows visible to near-infrared photons that are not absorbed by the top cell to pass smoothly, avoiding photon retention losses in the intermediate layer. This ensures that the bottom crystalline silicon cell receives sufficient excitation light flux, maximizing the short-circuit current contribution of the bottom cell and the overall photoelectric conversion efficiency of the device.

[0043] In some embodiments, the mass ratio of indium tin oxide to the inorganic material in the composite film is 90:10 to 30:70.

[0044] Furthermore, the mass ratio of indium tin oxide to the inorganic material is 75:25.

[0045] In the composite intermediate connecting layer, the ratio of indium tin oxide (ITO) to the inorganic material has a decisive influence on the overall photoelectric performance and interface characteristics of the film. Controlling the mass ratio of ITO to the inorganic material within the range of 90:10 to 30:70 ensures that the composite film exhibits excellent conductivity (dominated by ITO) while fully leveraging the modifying effects of the inorganic material in interface passivation, energy level matching, and stress relief between layers.

[0046] Specifically, if the mass ratio of indium tin oxide (ITO) is too high (greater than 90:10), the content of inorganic materials is relatively insufficient, making it difficult to achieve significant interface modification and defect passivation effects. If the mass ratio of ITO is too low (less than 30:70), the overall sheet resistance of the composite film layer will increase sharply, deteriorating the longitudinal transport efficiency of charge carriers, thereby reducing the fill factor and overall photoelectric conversion efficiency of the tandem solar cell. More preferably, when the mass ratio of ITO to inorganic materials is controlled at 75:25, the composite film layer achieves an excellent synergistic balance between light transmittance, lateral / longitudinal conductivity, and interfacial chemical stability, maximizing the overall performance of the device.

[0047] By combining the above parameters, the composite intermediate connecting layer achieves a perfect integration of strong corrosion resistance, extremely low electrical impedance, and extremely high light transmittance without changing the conventional battery architecture.

[0048] This application also provides a method for preparing the composite intermediate connecting layer as described above. This method employs a process route combining liquid-phase film formation and heat treatment. By controlling the film growth kinetics, a high degree of integration between the indium tin oxide matrix and the functional inorganic material at the microscale is achieved. Specifically, it includes: Step S1, provide the substrate.

[0049] This substrate is used to support the liquid-phase film deposition process, and its surface condition directly affects the adhesion and uniformity of the film. In specific applications, this substrate can be the surface of a semiconductor device that has already undergone partial fabrication. To ensure film quality, the substrate surface should maintain a high degree of smoothness and appropriate wettability to ensure that subsequent droplets can achieve defect-free macroscopic spreading on its surface.

[0050] Step S2: Spin-coating a composite precursor solution containing indium tin oxide precursor and inorganic material onto the substrate, and then annealing it to obtain the composite intermediate connecting layer; the inorganic material is selected from at least one of hydroxyapatite, fluorapatite and magnesium oxide.

[0051] Subsequently, the core film-forming step is performed: a composite precursor solution containing an indium tin oxide precursor and an inorganic material is spin-coated onto the substrate. It should be noted that the "spin-coating" process referred to here is a thin film preparation technique in which a prepared fluid is dropped onto the substrate, and the substrate is driven to rotate at high speed along its central axis, utilizing centrifugal force to cause the fluid to spread radially outward on the substrate surface. In this step, the composite precursor solution is a multiphase or homogeneous mixed liquid system containing a chemical precursor capable of thermally decomposing to generate indium tin oxide (ITO), and an inorganic material serving as an anti-corrosion and adsorption functional phase. The inorganic material is selected from at least one of hydroxyapatite, fluorapatite, and magnesium oxide. During spin-coating, with the driving force of centrifugal force and rapid solvent evaporation, the viscosity of the solution increases sharply, resulting in a sol-gel transition. Because the spin-coating process occurs extremely rapidly, the uniformly dispersed form of the inorganic material in the liquid phase is instantly "frozen" and locked within the precipitated precursor network, forming a wet precursor film with an extremely uniform component distribution. This rapid film formation method based on fluid dynamics effectively overcomes the process bottleneck of traditional physical vapor deposition (such as sputtering) in achieving uniform doping of multiple components.

[0052] Finally, the substrate coated with the composite precursor solution is annealed to obtain the composite intermediate connecting layer. The "annealing" process referred to here is a series of controlled thermodynamic evolution processes. Driven by heat, the residual solvent and volatile organic ligands first desorb and vaporize within the wet film; with continuous heat input, the indium tin oxide precursor undergoes thermal decomposition and gradually crystallizes, with atoms rearranging themselves in long-range or short-range configurations to form a continuous conductive lattice network. During this densification and crystallization process, the inorganic materials (such as hydroxyapatite) are tightly embedded and anchored within the microstructure of the indium tin oxide matrix. This annealing process not only eliminates insulating organic impurities within the film, resulting in excellent carrier transport capabilities and high light transmittance in the visible-near-infrared band, but also retains and activates the alkaline neutralization and ion adsorption activities of the inorganic materials, ultimately forming a solid film structure that combines photoelectric transmission and chemical protection.

[0053] To further optimize the microstructure, density, and photoelectric transmission performance of the composite intermediate connecting layer, this embodiment precisely defines the hydrodynamic parameters of spin coating and the thermodynamic parameters of annealing.

[0054] After providing the substrate and preparing the composite precursor solution, a wet film is deposited using a spin coating process. Specifically, in some embodiments, the spin coating speed is 2000 rpm to 4000 rpm.

[0055] Within this speed range, for example, it can be 2000rpm, 2200rpm, 2500rpm, 2800rpm, 3000rpm, 3200rpm, 3500rpm, 3800rpm, 4000rpm, etc.

[0056] In the spin coating operation, the amount of the composite precursor solution added to the substrate at one time is preferably 50 μL to 100 μL (for example, it can be 50 μL, 60 μL, 80 μL or 100 μL, etc.).

[0057] The centrifugal shear force generated by this moderate rotation speed can ensure that the composite precursor solution achieves uniform radiative spreading of nanometer-thickness on the substrate surface, and effectively avoid the separation or agglomeration of the inorganic materials dispersed inside the precursor due to excessive centrifugal force, thereby ensuring the uniform distribution of the inorganic anti-corrosion phase on the two-dimensional plane.

[0058] In some embodiments, the spin coating time is 20s to 60s. Within this time range, for example, it can be 20s, 25s, 30s, 35s, 40s, 45s, 50s, 55s, 60s, etc. This time window, in conjunction with the spin speed, provides ample solvent evaporation time for the liquid phase system. During this process, the rapid evaporation of the solvent causes a surge in system viscosity, ensuring that the precursor solution just crosses the sol-gel critical point before shutdown, forming a stable wet gel network. This completely eliminates film thickness unevenness and surface undulation defects caused by liquid backflow after shutdown.

[0059] After liquid phase coating is completed, the wet film is annealed. To avoid thermal stress cracking or micropores in the film during thermal evolution, this embodiment adopts a stepped heat treatment process including a first annealing stage and a second annealing stage.

[0060] In some implementations, the annealing process includes a first annealing stage and a second annealing stage.

[0061] (1) The first annealing stage is annealing at 100℃~200℃ for 5 minutes to 10 minutes.

[0062] The temperature in this stage can be, for example, 100℃, 110℃, 120℃, 140℃, 150℃, 160℃, 180℃, 190℃, 200℃, etc.; the annealing time in this stage can be, for example, 5 minutes, 6 minutes, 7 minutes, 8 minutes, 9 minutes, 10 minutes, etc. The first annealing stage mainly plays a "soft baking" role, using relatively gentle heat energy to drive the slow vaporization and desorption of residual macromolecular solvents and volatile components, effectively preventing solution boiling and pinhole defects caused by excessively rapid heating, and initially solidifying the physical framework of the film layer.

[0063] (2) The second annealing stage is annealing in an inert gas atmosphere at 120°C to 200°C for 30 minutes to 1 hour.

[0064] The temperature in this stage can be, for example, 120℃, 130℃, 140℃, 150℃, 160℃, 170℃, 180℃, 190℃, 200℃, etc.; the annealing time in this stage can be, for example, 30 minutes, 35 minutes, 40 minutes, 45 minutes, 50 minutes, 55 minutes, 60 minutes, etc. The second annealing stage is a "hard baking" and crystallization process. On the one hand, continuous heat input causes the indium tin oxide precursor to undergo thermal decomposition and gradually complete network rearrangement and densification, while firmly anchoring the inorganic material in the matrix; on the other hand, the use of an inert gas atmosphere (such as nitrogen or argon) for protection cleverly avoids excessive oxidation of indium tin oxide at high temperatures. This oxygen-deficient annealing environment effectively maintains and increases the oxygen vacancy concentration in the indium tin oxide lattice, greatly activating its carrier transport capability as an n-type semiconductor, ensuring that the final composite film has both chemical protection capabilities and excellent low resistivity performance.

[0065] This application also provides a perovskite-crystalline silicon tandem solar cell, including a crystalline silicon bottom cell, a perovskite top cell, and a composite intermediate connecting layer as described above disposed between the crystalline silicon bottom cell and the perovskite top cell.

[0066] In this tandem architecture, sub-cells with different bandgap synergistically achieve wideband, tiered, and efficient utilization of the solar spectrum. The perovskite top cell at the top is mainly responsible for absorbing high-energy, short-wavelength photons (such as those in the visible light region) in the solar spectrum to generate a higher open-circuit voltage; while the crystalline silicon bottom cell at the bottom is responsible for absorbing low-energy, long-wavelength photons (such as those in the near-infrared region) that penetrate the top structure to broaden the spectral response range of the entire device.

[0067] The composite intermediate connecting layer, positioned between the top and bottom cells, constitutes the core physical and electrical hub of this tandem solar cell. In terms of electrical transport, this composite intermediate connecting layer acts as the non-equilibrium carrier recombination center between the top and bottom cells. Photogenerated holes (or electrons) from the top cell and photogenerated electrons (or holes) from the bottom cell are driven into the composite intermediate connecting layer for efficient tunneling and recombination, thus completing a lossless electrical series closed loop within the device and ensuring the continuity and matching of the current output of the entire tandem solar cell. In terms of optical matching, the composite intermediate connecting layer, with its extremely high visible-infrared transmittance, ensures that the bottom cell receives sufficient photon flux.

[0068] More importantly, during the long-term service of this stacked device, the composite intermediate connecting layer utilizes inorganic materials with alkaline neutralization and ion adsorption properties dispersed within it to construct an active chemical protection barrier for the crystalline silicon bottom cell. When the perovskite top cell experiences lattice degradation due to light or damp heat, releasing highly corrosive byproducts such as hydroiodic acid downwards, the composite intermediate connecting layer can completely intercept and consume the acidic substances within the layer through in-situ chemical reactions, effectively blocking the penetration path of corrosive fluids to the surface of the crystalline silicon bottom cell.

[0069] In summary, by introducing the aforementioned composite intermediate connecting layer, this perovskite-crystalline silicon tandem solar cell not only maintains the excellent optoelectronic interconnect performance required for series devices, but also fundamentally eliminates the risk of chemical corrosion inside the device. This significantly improves the overall power stability and service life of the tandem cell under complex operating conditions, and lays a materials science foundation for the non-destructive separation and green recycling of high-value crystalline silicon bottom cells from scrapped devices.

[0070] To further optimize the extraction efficiency of photogenerated carriers in the perovskite top cell and reduce the non-radiative recombination loss at the interface, in some embodiments, a first hole transport layer and a second hole transport layer are sequentially disposed between the recombination intermediate connecting layer and the perovskite top cell.

[0071] Preferably, the first hole transport layer is a nickel oxide layer; Preferably, the thickness of the first hole transport layer is 10nm~20nm; The aforementioned nickel oxide material possesses excellent chemical stability and a deep valence band energy level. While providing an efficient hole transport channel, it also forms a natural barrier to electrons by utilizing its high conduction band bottom position. To balance physical barrier properties with vertical conductivity, the thickness of the first hole transport layer is precisely controlled within the range of 10nm to 20nm; for example, it can be 10nm, 11nm, 12nm, 14nm, 15nm, 16nm, 18nm, 19nm, 20nm, etc. This moderate thickness ensures that the film can completely cover the microscopic roughness of the underlying surface to prevent pinhole leakage, while also avoiding an increase in series resistance due to excessive thickness.

[0072] Preferably, the second hole transport layer is a membrane containing a phosphate group structure; Preferably, the thickness of the second hole transport layer is 2nm to 10nm.

[0073] Preferably, the material of the second hole transport layer is selected from at least one of (4-(7H-dibenzo[C,G]carbazole-7-yl)butyl)phosphonic acid, [2-(dimethoxy-9-9-yl)ethyl]phosphonic acid, and (2-(9H-carbazole-9-yl)ethyl)phosphonic acid.

[0074] A second hole transport layer is disposed above the first hole transport layer. The second hole transport layer is an ultrathin film layer containing phosphate groups, which serves as an electrical modulation layer for the interface. Specifically, at the microscopic level, one end of the structure of these molecules has a highly polar phosphate group, which can undergo dehydration condensation reaction with hydroxyl groups or dangling bonds on the surface of the underlying nickel oxide to form a strong covalent anchor, thereby effectively passivating the surface defect states of the underlying layer; the other end of its structure has a carbazole-like conjugated group with high hole mobility. These directionally self-assembled polar molecules construct a strong interfacial dipole moment at the interface, which can finely down-regulate the surface work function of the underlying layer, enabling it to achieve perfect energy level matching with the valence band of the perovskite light-absorbing layer above.

[0075] Because the material of the second hole transport layer often possesses a certain degree of bulk insulation, its thickness is strictly limited to an ultrathin scale of 2nm to 10nm; for example, it can be 2nm, 3nm, 4nm, 5nm, 6nm, 7nm, 8nm, 9nm, 10nm, etc. At this quantum scale, holes at the interface mainly rely on the quantum tunneling effect to achieve ultrafast crossing.

[0076] In order to achieve optimal photon capture efficiency, unidirectional carrier extraction, and physical protection during device manufacturing, this embodiment systematically optimizes the internal stacked structure of the perovskite top cell and the surface morphology of the crystalline silicon bottom cell.

[0077] Specifically, in some embodiments, the perovskite top solar cell comprises, from bottom to top: a perovskite light-absorbing layer, a passivation layer, an electron transport layer, a magnetron sputtering protection layer, a transparent electrode, and a metal conductive electrode.

[0078] In this sequence structure, the perovskite light-absorbing layer serves as the core photoelectric conversion medium of the top solar cell, responsible for absorbing sunlight and generating electron-hole pairs. A passivation layer is tightly covered above the perovskite light-absorbing layer. This passivation layer aims to repair or shield microscopic defect states on the perovskite crystal surface through surface modification, suppressing nonradiative recombination of charge carriers at the interface, thereby improving the open-circuit voltage of the device. The subsequently placed electron transport layer, utilizing its energy level matching characteristics, selectively extracts photogenerated electrons and effectively blocks the return flow of holes, ensuring efficient unidirectional charge transport.

[0079] Specifically, an anti-magnetron sputtering damage layer is introduced between the electron transport layer and the transparent electrode. Since transparent electrodes are typically fabricated using high-energy physical vapor deposition processes (such as magnetron sputtering) in industrial manufacturing, high-energy particle bombardment can easily penetrate the fragile underlying semiconductor structure. This anti-magnetron sputtering damage layer acts as a dense physical buffer shield, effectively absorbing the kinetic energy of sputtered particles and protecting the lattice integrity of the underlying structure from process damage. The transparent electrode, arranged sequentially at the top, works in conjunction with the metal conductive electrode to achieve low-ohmic-loss photocurrent collection and discharge while ensuring high solar transmittance.

[0080] In some embodiments, a transparent oxide layer is disposed on the surface of the crystalline silicon bottom cell; the composite intermediate connection layer is disposed on the transparent oxide layer.

[0081] To ensure that the composite intermediate connecting layer forms an ideal electrical interconnection and optical match with the underlying crystalline silicon cell, this embodiment specifically optimizes the surface contact structure of the crystalline silicon cell. Specifically, a transparent oxide layer is disposed on the surface of the crystalline silicon cell, and the composite intermediate connecting layer is grown and disposed on this transparent oxide layer. Optically, this transparent oxide layer acts as an anti-reflection buffer to facilitate the refractive index gradient transition, reducing interface reflection loss of transmitted light; simultaneously, electrically, it lowers the interface contact barrier, promoting tunneling recombination of charge carriers.

[0082] Furthermore, the surface of the crystalline silicon bottom cell (i.e., the interface below the transparent oxide layer) is N-plane microcrystalline silicon.

[0083] Microcrystalline silicon structures possess excellent lateral carrier mobility and doping activation characteristics, enabling the construction of extremely strong field-effect passivation on their surface. Combined with the upper transparent oxide layer, they provide a perfect growth substrate with low recombination rate and high conductivity for the composite intermediate connecting layer. The multilayer architecture of the top cell and the surface structure of the bottom cell described above can be used individually or in combination to jointly improve the overall performance of tandem solar cells.

[0084] In some embodiments, the thickness of the perovskite light-absorbing layer is 500 nm to 600 nm.

[0085] Specifically, this thickness can be, for example, 500nm, 510nm, 520nm, 530nm, 540nm, 550nm, 560nm, 580nm, 590nm, 600nm, etc. This thickness range ensures that the perovskite material has sufficient light absorption volume to fully capture incident photons, while ensuring that the film thickness does not exceed the effective diffusion length of photogenerated carriers, effectively avoiding excessive recombination of electrons and holes in the bulk phase.

[0086] In some embodiments, the passivation layer material is a mixture of phenylethylamine iodide and ethylenediamine dihydroiodide.

[0087] In some embodiments, the thickness of the passivation layer is 2 nm to 10 nm.

[0088] The passivation layer, covering the light-absorbing layer, is made of a mixture of phenylethylamine iodide and ethylenediamine dihydroiodide. The bulky phenylethylamine iodide cations construct a hydrophobic barrier and passivate surface defects, while the ethylenediamine dihydroiodide provides lattice cross-linking. Together, they significantly reduce the non-radiative recombination rate of the surface. To ensure smooth charge transport, the thickness of the passivation layer is strictly controlled within an ultrathin range of 2 nm to 10 nm; for example, it can be 2 nm, 3 nm, 4 nm, 5 nm, 6 nm, 7 nm, 8 nm, 9 nm, 10 nm, etc. At this quantum thickness, electrons can cross the insulating layer without loss through quantum tunneling.

[0089] In some embodiments, the electron transport layer material is fullerene C60.

[0090] In some embodiments, the thickness of the electron transport layer is 10 nm to 20 nm.

[0091] The electron transport layer, which performs the electron extraction function, is preferably made of fullerene C60. Fullerene C60 possesses perfect energy level matching and ultra-high electron mobility, enabling ultra-fast electron extraction and effectively blocking hole leakage. The thickness of the electron transport layer is limited to 10 nm to 20 nm; for example, it can be 10 nm, 11 nm, 12 nm, 14 nm, 15 nm, 16 nm, 17 nm, 18 nm, 19 nm, 20 nm, etc. This thickness ensures physical density while minimizing bulk resistance and parasitic light absorption.

[0092] In some embodiments, the anti-magnetron sputtering damage layer is a tin oxide thin film.

[0093] In some embodiments, the thickness of the anti-magnetron sputtering damage layer is 15nm~20nm.

[0094] To address the issue of bombardment damage during the manufacturing process, the anti-magnetron sputtering damage layer employs a dense and high-hardness tin oxide film. The thickness of the anti-magnetron sputtering damage layer is set to 15nm~20nm; for example, it can be 15nm, 16nm, 16.5nm, 17nm, 17.5nm, 18nm, 18.5nm, 19nm, 19.5nm, 20nm, etc. This thickness range allows for perfect absorption of the kinetic energy of high-energy particles in subsequent sputtering processes, providing robust physical protection without causing a significant increase in series resistance.

[0095] In some embodiments, the material of the transparent electrode is selected from at least one of indium tin oxide, indium zinc oxide, or a composite layer thereof.

[0096] In some embodiments, the thickness of the transparent electrode is 30 nm to 120 nm. For example, it can be 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, 100 nm, 110 nm, 120 nm, etc. This range precisely balances optical transmittance and lateral conductivity.

[0097] In some embodiments, the metal conductive electrode is a silver grid electrode. In some embodiments, the thickness of the metal conductive electrode is 100 nm to 200 nm. For example, it can be 100 nm, 110 nm, 120 nm, 130 nm, 150 nm, 160 nm, 170 nm, 180 nm, 190 nm, 200 nm, etc., to ensure extremely low ohmic contact resistance when the microcurrent is collected and discharged.

[0098] This application also provides a method for fabricating a perovskite-crystalline silicon tandem solar cell, used to fabricate the solar cell as described above, comprising: Step S10: Prepare the composite intermediate connection layer on the crystalline silicon bottom cell.

[0099] In this step, a pre-prepared crystalline silicon base cell (such as a silicon wafer with surface microcrystalline silicon and a transparent oxide layer) is used as the physical carrier substrate. A dense composite intermediate connection layer is deposited and solidified in situ on the substrate surface through a combination of liquid phase film deposition and thermal treatment. This layer not only forms a strong physical adhesion with the base cell, but also constructs a corrosion-resistant and conductive substrate for the subsequent growth of the top layer structure.

[0100] Step S20: Prepare a first hole transport layer and a second hole transport layer on the composite intermediate connecting layer.

[0101] By employing processes such as physical vapor deposition or liquid-phase self-assembly, a first hole transport layer with strong physical barrier properties is first deposited, followed by a second hole transport layer with energy level modulation or defect passivation functions. This two-layer fabrication process successfully constructs a stepped hole extraction channel while ensuring the physical sealing of the underlying structure.

[0102] Step S30: Spin-coat a perovskite solution onto the second hole transport layer, and perform vacuuming and annealing treatments in sequence to prepare a perovskite light absorption layer.

[0103] Specifically, a wet liquid film containing a perovskite precursor can first be uniformly spread on the substrate surface using a spin-coating process. Then, this wet liquid film is immediately subjected to vacuum treatment. This vacuum treatment utilizes the sudden drop in ambient pressure to disrupt the gas-liquid balance of the solvent on the film surface, forcibly accelerating the rapid evaporation of high-boiling-point solvents. The instantaneous removal of solvent forces the precursor system to rapidly enter an extremely supersaturated state, thereby triggering high-density and uniform in-situ nucleation throughout the substrate. After vacuum-induced nucleation, the film is annealed. The input of thermal energy drives the rapid growth of crystal nuclei and the fusion of grain boundaries, ultimately achieving complete transformation of the perovskite crystal phase, resulting in a flat, dense, and highly crystalline perovskite light-absorbing layer. This vacuum-assisted crystallization process effectively avoids pinholes and morphological defects during film formation.

[0104] Step S40: A passivation layer, an electron transport layer, a magnetron sputtering protection layer, a transparent electrode, and a metal conductive electrode are sequentially prepared on the perovskite light absorption layer.

[0105] Specifically, the process involves first coating or depositing a passivation layer in situ on the perovskite surface to modify and eliminate lattice defect states; then depositing an electron transport layer to construct a unidirectional electron extraction barrier; next, depositing a dense anti-magnetron sputtering damage layer as a buffer physical shield; based on this, using vacuum sputtering technology to fabricate a large-area transparent electrode; and finally, fabricating a metal conductive electrode through processes such as mask evaporation or screen printing. This rigorous sequential fabrication process ensures that the upper-layer high-energy deposition process does not cause physical bombardment or electrical breakdown to the underlying fragile organic and perovskite structures, ultimately completing the closed-loop construction of the entire tandem solar cell device.

[0106] This application also provides an electrical device, including a perovskite-crystalline silicon tandem solar cell as described above, or a perovskite-crystalline silicon tandem solar cell obtained by the preparation method described above.

[0107] The aforementioned perovskite-crystalline silicon tandem solar cells can serve as independent power supply units or auxiliary power sources, providing the electrical energy required for the operation of the electrical equipment. Specifically, the type of electrical equipment is not limited; any device capable of using photovoltaic power for driving or energy storage is included. The electrical equipment may include, but is not limited to: various portable consumer electronics (such as smartphones, tablets, smartwatches, portable power banks), smart home terminals, outdoor independent power supply equipment (such as solar streetlights, field environmental meteorological monitoring stations, security surveillance cameras, communication base stations), transportation vehicles and aerospace vehicles (such as new energy vehicles, solar roof systems, solar-powered drones, artificial satellites), and various large-scale energy infrastructure systems (such as centralized photovoltaic power plants, distributed rooftop photovoltaic modules, building-integrated photovoltaic (BIPV) components, etc.). By incorporating the aforementioned tandem solar cells with high photoelectric conversion efficiency, excellent chemical protection, and long-term reliability, the electrical equipment can obtain a stable, efficient, and environmentally friendly clean energy supply in complex external service environments, significantly improving the overall endurance and lifespan of the equipment.

[0108] The present invention will be further illustrated below with specific embodiments. However, it should be understood that these embodiments are merely for the purpose of more detailed illustration and should not be construed as limiting the present invention in any way.

[0109] Example 1 This embodiment provides a complete fabrication process for a perovskite-crystalline silicon tandem solar cell including a hydroxyapatite-indium tin oxide (HA-ITO) composite intermediate connecting layer. The specific device layer structure corresponds to [reference needed]. Figure 1 [Schematic diagram of perovskite-crystalline silicon stacked solar cell, a-top metal electrode, b-transparent conductive electrode, c-sputter damage protection layer, d-electron transport layer, e-passivation layer, f-perovskite light absorption layer, g-second hole transport layer, h-first hole transport layer, i-composite intermediate connection layer, j-bottom silicon cell (crystalline silicon bottom cell), k-bottom metal electrode].

[0110] The preparation method is as follows: (1) Preparation of composite intermediate connecting layer: A composite intermediate connecting layer was prepared on the N-side microcrystalline silicon of a crystalline silicon solar cell substrate by spin coating. The spin coater was set to a speed of 3500 rpm and a spin coating time of 45 s. The mass ratio of ITO nanosolution and hydroxyapatite nanosolution was set to 90:10, and the composite precursor solution was dropped onto the N-side microcrystalline silicon at a volume of 60 μL. After spin coating, the sample was immediately placed on a hot stage at 180 °C for annealing for 8 minutes. Subsequently, the sample was transferred to a tube annealing furnace, inert gas was introduced, the temperature was set to 150 °C, and annealing was performed for 40 minutes. After annealing, a HA-ITO composite film with a thickness of 30 nm was obtained.

[0111] (2) Preparation of the first hole transport layer: A nickel oxide hole transport layer with a thickness of 15 nm was sputtered on the intermediate connecting layer by magnetron sputtering.

[0112] (3) Preparation of the second hole transport layer: The second hole transport layer was prepared on the first hole transport layer by spin coating. The material used for the second hole transport layer was (4-(7H-dibenzo[C,G]carbazole-7-yl)butyl)phosphonic acid (4PADCB), and the solvent was isopropanol, with a solution concentration of 0.6 mg / mL. The spin coater speed was set to 4000 rpm and the spin coating time was 30 s, resulting in a second hole transport layer with a thickness of 5 nm.

[0113] (4) Preparation of perovskite light-absorbing layer: Precursor preparation: Cesium iodide (CsI), formamidine iodide (FAI), lead bromide (PbBr2), and lead iodide (PbI2) were prepared in a molar ratio of 30:170:69:131. A mixed solvent of N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) in a volume ratio of 4:1 was added. The mixture was then stirred on a magnetic stirrer for 5 hours to ensure complete dissolution.

[0114] Spin-coating crystallization: A perovskite light-absorbing layer was prepared on the hole transport layer by spin coating. The spin coater speed was set to 3500 rpm, and the spin coating time was 38 s. The completely dissolved perovskite solution was spin-coated onto the hole transport layer. After spin coating, it was placed in a vacuum flash chamber, and a vacuum of 6 Pa was drawn within 3 s and maintained for 15 s. Then, it was placed on a hot stage at 100℃ and heated for 20 min for annealing and crystallization to obtain a light-absorbing layer with a thickness of 545 nm.

[0115] (5) Passivation layer preparation: A passivation layer was prepared on the perovskite light-absorbing layer by spin coating. The passivation layer material was a mixture of phenylethylamine iodide (PEAI) and ethylenediamine dihydroiodide (EDAI2), and the solvent was isopropanol with a solution concentration of 2 mg / mL. The spin coater speed was set to 4000 rpm and the spin coating time was 30 s, resulting in a passivation layer with a thickness of 5 nm.

[0116] (6) Electron transport layer preparation: An electron transport layer with a thickness of 18 nm was prepared on the passivation layer by organic vapor deposition. The material was fullerene C. 60 .

[0117] (7) Preparation of anti-sputtering damage layer: A 16nm thick tin oxide film was deposited on the electron transport layer using atomic deposition technology as an anti-magnetron sputtering damage layer.

[0118] (8) Preparation of transparent electrode: A transparent electrode layer is sputtered on the surface of the tin oxide thin film by magnetron sputtering. The transparent electrode is ITO with a thickness of 50 nm.

[0119] (9) Preparation of metal conductive electrode: A layer of 180 nm thick metal silver grid line electrode is deposited on the surface of the transparent electrode by vapor deposition, and finally the perovskite crystalline silicon tandem cell is obtained.

[0120] Example 2 The difference between this embodiment and Example 1 is that the mass ratio of ITO nanosolution and hydroxyapatite nanosolution is set to 80:20, while the rest of the preparation process is the same as in Example 1.

[0121] Example 3 The difference between this embodiment and Example 1 is that the mass ratio of ITO nanosolution and hydroxyapatite nanosolution is set to 75:25, while the rest of the preparation process is the same as in Example 1.

[0122] Example 4 The difference between this embodiment and Example 1 is that the mass ratio of ITO nanosolution and hydroxyapatite nanosolution is set to 60:40, while the rest of the preparation process is the same as in Example 1.

[0123] Example 5 The difference between this embodiment and Example 1 is that the mass ratio of ITO nanosolution and hydroxyapatite nanosolution is set to 30:70, while the rest of the preparation process is the same as in Example 1.

[0124] Example 6 In this embodiment, to examine the application effects of different anti-corrosion and adsorption inorganic phase materials, a tandem solar cell fabrication process using fluorapatite (FA) instead of hydroxyapatite is provided. The only difference between this embodiment and Embodiment 1 is that, in the preparation process of the composite intermediate connecting layer, hydroxyapatite is replaced with fluorapatite; the materials and preparation process steps of the remaining layers are exactly the same as in Embodiment 1.

[0125] Example 7 The only difference between this embodiment and Embodiment 1 is that hydroxyapatite is replaced with magnesium oxide in the preparation of the composite intermediate connecting layer, while the materials and preparation process steps of the other layers are exactly the same as in Embodiment 1.

[0126] Example 8 (1) Preparation of composite intermediate connecting layer: A composite intermediate connecting layer was prepared on the N-side microcrystalline silicon of a crystalline silicon solar cell substrate by spin coating. The spin coater speed was set to 2000 rpm and the spin coating time was 20 s. The mass ratio of ITO nanosolution and hydroxyapatite nanosolution was set to 90:10, and the composite precursor solution was dropped onto the N-side microcrystalline silicon at a volume of 100 μL. After spin coating, the sample was immediately placed on a hot stage at 100 °C for annealing for 5 minutes. Then the sample was transferred to a tube annealing furnace, inert gas was introduced, the temperature was set to 120 °C, and annealing was performed for 30 minutes. After annealing, a HA-ITO composite film with a thickness of 100 nm was obtained.

[0127] (2) Preparation of the first hole transport layer: A nickel oxide hole transport layer with a thickness of 10 nm was sputtered on the intermediate connecting layer by magnetron sputtering.

[0128] (3) Preparation of the second hole transport layer: The second hole transport layer was prepared on the first hole transport layer by spin coating. The material used for the second hole transport layer was (4-(7H-dibenzo[C,G]carbazole-7-yl)butyl)phosphonic acid (4PADCB), and the solvent was isopropanol, with a solution concentration of 0.5 mg / mL. The spin coater speed was set to 4000 rpm and the spin coating time was 30 s, resulting in a second hole transport layer with a thickness of 2 nm.

[0129] (4) Preparation of perovskite light-absorbing layer: Precursor preparation: Perovskite raw material (cesium iodide CsI, formamidine iodide FAI, lead bromide PbBr2, and lead iodide PbI2 were prepared in a molar ratio of 30:170:69:131, and a mixed solvent of N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) in a volume ratio of 4:1 was added. Then, the mixture was stirred on a magnetic stirrer for 3-5 hours until completely dissolved.

[0130] Spin-coating crystallization: A perovskite light-absorbing layer was prepared on the hole transport layer by spin coating. The spin coater speed was set to 3500 rpm, and the spin coating time was 38 s. The completely dissolved perovskite solution was spin-coated onto the hole transport layer. After spin coating, it was placed in a vacuum flash evaporation chamber, and a vacuum of 6 Pa was drawn within 3 s and maintained for 15 s. Then, it was placed on a hot stage at 100 °C and heated for 15 min for annealing and crystallization to obtain a light-absorbing layer with a thickness of 500 nm.

[0131] (5) Passivation layer preparation: A passivation layer was prepared on the perovskite light-absorbing layer by spin coating. The passivation layer material was a mixture of phenylethylamine iodide (PEAI) and ethylenediamine dihydroiodide (EDAI2), and the solvent was isopropanol with a solution concentration of 0.5 mg / mL. The spin coater speed was set to 4000 rpm and the spin coating time was 30 s, resulting in a passivation layer with a thickness of 2 nm.

[0132] (6) Electron transport layer preparation: An electron transport layer with a thickness of 10 nm was prepared on the passivation layer by organic vapor deposition. The material was fullerene C. 60 .

[0133] (7) Preparation of anti-sputtering damage layer: A 15nm thick tin oxide film is deposited on the electron transport layer using atomic deposition technology as an anti-magnetron sputtering damage layer.

[0134] (8) Preparation of transparent electrode: A transparent electrode layer is sputtered on the surface of the tin oxide thin film by magnetron sputtering. The transparent electrode is ITO with a thickness of 30 nm.

[0135] (9) Preparation of metal conductive electrode: A layer of 100nm thick metal silver grid line electrode is deposited on the surface of the transparent electrode by vapor deposition, and finally the perovskite crystalline silicon tandem cell is obtained.

[0136] Example 9 (1) Preparation of composite intermediate connecting layer: A composite intermediate connecting layer was prepared on the N-side microcrystalline silicon of a crystalline silicon solar cell substrate by spin coating. The spin coater was set to a speed of 4000 rpm and the spin coating time was 60 s. The mass ratio of ITO nanosolution and hydroxyapatite nanosolution was set to 90:10, and 50 μL of the composite precursor solution was dropped onto the N-side microcrystalline silicon. After spin coating, the sample was immediately placed on a 200℃ hot stage for annealing for 10 minutes. Then the sample was transferred to a tube annealing furnace, inert gas was introduced, the temperature was set to 200℃, and annealing was performed for 1 hour. After annealing, a HA-ITO composite film with a thickness of 20 nm was obtained.

[0137] (2) Preparation of the first hole transport layer: A nickel oxide hole transport layer with a thickness of 20 nm was sputtered on the intermediate connecting layer by magnetron sputtering.

[0138] (3) Preparation of the second hole transport layer: The second hole transport layer was prepared on the first hole transport layer by spin coating. The material used for the second hole transport layer was (4-(7H-dibenzo[C,G]carbazole-7-yl)butyl)phosphonic acid (4PADCB), and the solvent was isopropanol. The concentration of the solution was 2 mg / mL. The spin coater speed was set to 4000 rpm and the spin coating time was 30 s. A second hole transport layer with a thickness of 10 nm was obtained by spin coating.

[0139] (4) Preparation of perovskite light-absorbing layer: Precursor preparation: The perovskite raw material was prepared by mixing cesium iodide (CsI), formamidine iodide (FAI), lead bromide (PbBr2), and lead iodide (PbI2) in a molar ratio of 30:170:69:131, and then adding a mixed solvent of N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) in a volume ratio of 4:1. The mixture was then stirred on a magnetic stirrer for 5 hours to ensure complete dissolution.

[0140] Spin-coating crystallization: A perovskite light-absorbing layer was prepared on the hole transport layer by spin coating. The spin coater speed was set to 3500 rpm, and the spin coating time was 38 s. The completely dissolved perovskite solution was spin-coated onto the hole transport layer. After spin coating, it was placed in a vacuum flash evaporation chamber, and a vacuum of 6 Pa was drawn within 3 s and maintained for 15 s. Then, it was placed on a hot stage at 100 °C and heated for 25 min for annealing and crystallization to obtain a light-absorbing layer with a thickness of 600 nm.

[0141] (5) Passivation layer preparation: A passivation layer was prepared on the perovskite light-absorbing layer by spin coating. The passivation layer material was a mixture of phenylethylamine iodide (PEAI) and ethylenediamine dihydroiodide (EDAI2), and the solvent was isopropanol with a solution concentration of 2.5 mg / mL. The spin coater speed was set to 4000 rpm and the spin coating time was 30 s, resulting in a passivation layer with a thickness of 10 nm.

[0142] (6) Electron transport layer preparation: An electron transport layer with a thickness of 20 nm was prepared on the passivation layer by organic vapor deposition. The material was fullerene C. 60 .

[0143] (7) Preparation of anti-sputtering damage layer: A tin oxide film with a thickness of 20 nm was deposited on the electron transport layer using atomic deposition technology as an anti-magnetron sputtering damage layer.

[0144] (8) Preparation of transparent electrode: A transparent electrode layer is sputtered on the surface of the tin oxide thin film by magnetron sputtering. The transparent electrode is ITO with a thickness of 120 nm.

[0145] (9) Preparation of metal conductive electrode: A layer of 200 nm thick metal silver grid line electrode is deposited on the surface of the transparent electrode by vapor deposition, and finally the perovskite crystalline silicon tandem cell is obtained.

[0146] Comparative Example 1 In this comparative example, a tandem solar cell using a conventional transparent conductive film as a connecting layer is provided as a reference device to evaluate the performance improvement effect of the HA-ITO composite film layer in the aforementioned embodiments in terms of corrosion resistance, lead leakage resistance, and photoelectric synergy.

[0147] The preparation method is as follows: The difference between this comparative example and Example 1 lies in the preparation process of the composite intermediate interconnect layer: This comparative example adopts a conventional method, directly depositing a transparent oxide layer with a thickness of 10 nm on the N-plane microcrystalline silicon by magnetron sputtering, wherein the transparent oxide layer is a single indium tin oxide (ITO). The materials and preparation process steps of the remaining layers of the device are exactly the same as those in Example 1.

[0148] Performance characterization and testing 1. Testing method: The following test methods were used for qualitative and quantitative analysis when evaluating the performance of the examples and comparative examples: (1) Qualitative analysis of composition: The elements and composition of the HA-ITO composite film were qualitatively analyzed by energy dispersive X-ray spectroscopy (EDS).

[0149] (2) Thickness characterization: The thickness of the film layer is characterized by ellipsometer.

[0150] (3) Electrical and optical performance testing: The sheet resistance of the composite film was tested using a four-probe tester. The light transmittance of the film was characterized by ultraviolet-visible-near-infrared transmission spectroscopy. The photoelectric conversion efficiency of the tandem solar cell was characterized by JV curve testing.

[0151] (4) pH value test method for composite intermediate connecting layer: The product is physically peeled off from the battery metal electrode, semi-transparent electrode, tin oxide layer and electron transport layer using 3M tape. Then, the perovskite layer and hole transport layer are dissolved using the organic solvent N,N-dimethylformamide. The remaining material is then prepared into fragments with an area of ​​2cm×2cm. The surface dust is rinsed with deionized water and dried with inert gas. The above fragments are placed in a beaker containing 20mL-100mL of water and soaked in a water bath for 3h-8h. The supernatant is then taken and the pH value is measured using a pH meter.

[0152] (5) Test method for the proportion of hydroxyapatite in the composite intermediate connecting layer: Energy dispersive X-ray spectroscopy (EDS) was performed on the cross section of the battery intermediate connecting layer. Five regions were randomly tested on the cross section to count the proportion of calcium (Ca) / phosphorus (P) and indium (In) elements in hydroxyapatite.

[0153] 2. Test Results: The present invention conducted elemental distribution, pH value, sheet resistance, thickness, light transmittance, and multilayer device performance tests on Examples 1-5 and Comparative Example 1. Specific data are shown in Tables 1-7. Figure 1 and Figure 2 As shown: Table 1. Distribution of main elements in the intermediate composite connecting layer under a mass ratio of TCO:HA=90:10 (Example 1)

[0154] Table 2. Distribution of main elements in the intermediate composite connecting layer under a mass ratio of TCO:HA=80:20 (Example 2)

[0155] Table 3. Distribution of main elements in the intermediate composite connecting layer under a mass ratio of TCO:HA=75:25 (Example 3)

[0156] Table 4. Distribution of main elements in the intermediate composite connecting layer under a mass ratio of TCO:HA=60:40 (Example 4)

[0157] Table 5. Distribution of main elements in the intermediate composite connecting layer under a mass ratio of TCO:HA=30:70 (Example 5)

[0158] Table 6. pH value and sheet resistance of the intermediate composite bonding layer

[0159] Table 7. Electrical Performance of Laminated Batteries

[0160] 3. Analysis: By comparing the elemental ratios of hydroxyapatite and TCO in different microregions of different embodiments, the mass fractions of Ca and P in hydroxyapatite in different microregions of the same composite membrane showed small fluctuations, and the Ca / P ratio in each microregion remained stable near the theoretical stoichiometric ratio of hydroxyapatite. Simultaneously, the In content corresponding to TCO showed no significant difference in each microregion. This indicates that in the hydroxyapatite / TCO composite membrane prepared by the sol-gel method of this invention, hydroxyapatite particles do not exhibit local enrichment or significant agglomeration within the TCO matrix, and can achieve uniform distribution throughout the entire composite membrane system. This allows for uniform and rapid neutralization of HI generated from perovskite degradation, effectively mitigating the corrosive effect of HI on the underlying silicon layer.

[0161] By comparing the examples and comparative examples, the TCO membrane in the comparative example exhibits weak acidity or neutrality and lacks the ability to neutralize acidic substances. It also has low sheet resistance and optimal conductivity. In the examples, as the proportion of hydroxyapatite in the composite membrane gradually increases, the pH of the composite film gradually transitions from weakly neutral to stable weakly alkaline. The increase in alkalinity can neutralize the HI produced by perovskite degradation. However, with increasing proportions, the sheet resistance of the composite membrane gradually increases because hydroxyapatite is an insulating inorganic material and has no conductivity.

[0162] By comparing the examples and comparative examples, the average light transmittance of the TCO film in the visible light band in the comparative example exceeded 90%. In the examples, as the proportion of hydroxyapatite in the composite film gradually increased, the light transmittance of the composite film in the visible light band gradually decreased, and the short-circuit current density of the stacked device gradually decreased. This is because hydroxyapatite has a weak light absorption capacity in the visible light band. As the proportion of hydroxyapatite increases, the light transmittance of the composite film decreases, the spectral utilization of the device decreases, and the short-circuit current density decreases.

[0163] By comparing the examples and the comparative examples, the efficiency of the comparative example device decreased by about 9% after being stored in a high humidity environment for 186 hours, while the efficiency of the example device decreased by about 4%. The device stability was improved because the alkaline properties of hydroxyapatite in the composite film neutralized the HI generated by the degradation of perovskite in situ, reducing the damage to the bottom silicon substrate and thus improving the overall stability of the stacked device.

[0164] In summary, when the ratio of hydroxyapatite to TCO is 25:75 (i.e., a mass ratio of 75:25), the composite film achieves an optimal balance of protective, optical, and electrical properties. This ratio results in a uniform elemental distribution, high light transmittance, and suitable weak alkalinity, effectively neutralizing HI and inhibiting silicon layer corrosion. Simultaneously, the increase in sheet resistance is not significant, maintaining good conductivity and device performance. This provides stable interfacial buffer protection for perovskite-crystalline silicon tandem solar cells, effectively improving device lifespan and silicon substrate recovery rate.

[0165] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A composite intermediate connecting layer, characterized in that, The composite intermediate connecting layer is used to be disposed between the crystalline silicon bottom cell and the perovskite top cell of the perovskite-crystalline silicon stacked solar cell. The composite intermediate connecting layer is a composite film layer containing indium tin oxide and inorganic materials; The inorganic material is selected from at least one of hydroxyapatite, fluorapatite, and magnesium oxide.

2. The composite intermediate connecting layer as described in claim 1, characterized in that, The thickness of the composite intermediate connecting layer is 20nm-100nm; and / or, The sheet resistance of the composite intermediate connecting layer is less than 150 Ω / sq; and / or, The light transmittance of the composite intermediate connecting layer is greater than 80%; and / or, In the composite film, the mass ratio of indium tin oxide to the inorganic material is 90:10 to 30:70; preferably, the mass ratio of indium tin oxide to the inorganic material is 75:

25.

3. A method for preparing a composite intermediate connecting layer as described in claim 1 or 2, characterized in that, include: Provide a base; A composite precursor solution containing indium tin oxide precursor and inorganic material is spin-coated onto the substrate and then annealed to obtain the composite intermediate connecting layer. The inorganic material is selected from at least one of hydroxyapatite, fluorapatite, and magnesium oxide.

4. The method for preparing the composite intermediate connecting layer as described in claim 3, characterized in that, The spin coating speed is 2000 rpm to 4000 rpm; and / or, The spin coating time is 20s~60s; and / or, The annealing process includes a first annealing stage and a second annealing stage; wherein, the first annealing stage is annealing at 100℃~200℃ for 5 minutes to 10 minutes; and / or, the second annealing stage is annealing at 120℃~200℃ in an inert gas atmosphere for 30 minutes to 1 hour.

5. A perovskite-crystalline silicon tandem solar cell, characterized in that, It includes a crystalline silicon bottom cell, a perovskite top cell, and a composite intermediate connecting layer as described in claim 1 or 2 disposed between the crystalline silicon bottom cell and the perovskite top cell.

6. The perovskite-crystalline silicon tandem solar cell as described in claim 5, characterized in that, A first hole transport layer and a second hole transport layer are sequentially disposed between the composite intermediate connecting layer and the perovskite top cell. Preferably, the first hole transport layer is a nickel oxide layer; Preferably, the thickness of the first hole transport layer is 10nm~20nm; Preferably, the second hole transport layer is a membrane containing a phosphate group structure; Preferably, the thickness of the second hole transport layer is 2nm~10nm; Preferably, the material of the second hole transport layer is selected from at least one of (4-(7H-dibenzo[C,G]carbazole-7-yl)butyl)phosphonic acid, [2-(dimethoxy-9-9-yl)ethyl]phosphonic acid, and (2-(9H-carbazole-9-yl)ethyl)phosphonic acid.

7. The perovskite-crystalline silicon tandem solar cell as described in claim 5, characterized in that, The perovskite top solar cell, from bottom to top, comprises: a perovskite light-absorbing layer, a passivation layer, an electron transport layer, a magnetron sputtering protection layer, a transparent electrode, and a metal conductive electrode; and / or, The surface of the crystalline silicon bottom cell is provided with a transparent oxide layer; the composite intermediate connection layer is disposed on the transparent oxide layer; preferably, the surface of the crystalline silicon bottom cell is N-plane microcrystalline silicon.

8. The perovskite-crystalline silicon tandem solar cell as described in claim 7, characterized in that, The thickness of the perovskite light-absorbing layer is 500 nm to 600 nm; and / or, The passivation layer material is a mixture of phenylethylamine iodide and ethylenediamine dihydroiodide; and / or, The passivation layer has a thickness of 2 nm to 10 nm; and / or, The electron transport layer material is fullerene C60; and / or, The thickness of the electron transport layer is 10 nm to 20 nm; and / or, The anti-magnetron sputtering damage layer is a tin oxide thin film; and / or, The thickness of the anti-magnetron sputtering damage layer is 15nm~20nm; and / or, The material of the transparent electrode is selected from at least one of indium tin oxide, indium zinc oxide, or a composite layer thereof; and / or, The thickness of the transparent electrode is 30nm~120nm; and / or, The metal conductive electrode is a silver grid line electrode; and / or... The thickness of the metal conductive electrode is 100nm~200nm.

9. A method for fabricating a perovskite-crystalline silicon tandem solar cell, characterized in that, For preparing the solar cell as described in any one of claims 5-8, comprising: The composite intermediate connection layer is fabricated on the crystalline silicon bottom cell; A first hole transport layer and a second hole transport layer are fabricated on the composite intermediate connecting layer; A perovskite solution was spin-coated onto the second hole transport layer, and vacuuming and annealing were performed sequentially to prepare a perovskite light absorption layer. A passivation layer, an electron transport layer, a magnetron sputtering protection layer, a transparent electrode, and a metal conductive electrode are sequentially fabricated on the perovskite light absorption layer.

10. An electrical appliance, characterized in that, This includes the perovskite-crystalline silicon tandem solar cell as described in any one of claims 5-8, or the perovskite-crystalline silicon tandem solar cell obtained by the preparation method described in claim 9.

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