A composite film layer structure for edge passivation of multi-finger solar cells and a method of manufacturing the same

Abstract

This invention discloses a composite film structure for edge passivation of multi-segment solar cells and its preparation method. The composite film structure comprises the following layers sequentially stacked on the cell cutting edge: an oxygen-containing amorphous silicon layer, whose composition includes silicon, oxygen, and hydrogen; an optional first hydrogenated amorphous silicon layer, whose composition includes silicon and hydrogen; a silicon nitride layer, whose composition includes silicon, nitrogen, and hydrogen; and a second hydrogenated amorphous silicon layer, whose composition includes silicon and hydrogen. By introducing a multi-layer functionalized design, the composite film structure of this invention effectively solves the limitations caused by the single passivation film structure in the prior art, forming a complete protection system encompassing interface passivation, structural protection, and environmental protection, effectively solving the problem of composite loss at the cutting edge of segmented solar cells.

Description

Technical Field

[0001] This invention relates to the field of solar cell technology, and in particular to a composite film structure for edge passivation of multi-segment solar cells and its preparation method. Background Technology

[0002] Segmented solar cell technology, by cutting a single cell into multiple segments (such as two-segment or four-segment), effectively reduces operating current and resistive losses, and has become a mainstream approach to improve module output power. Edge passivation, as a crucial step in repairing cutting damage and reducing carrier recombination, directly determines the open-circuit voltage, fill factor, and final efficiency of the segmented cell. However, the cutting edges, as exposed bulk silicon regions, contain numerous crystallographic defects, resulting in recombination rates several orders of magnitude higher than on the passivated silicon surface. Therefore, an efficient passivation solution is urgently needed to ensure cell performance.

[0003] Currently, edge passivation technology mainly relies on two methods: atomic layer deposition (ALD) and plasma-enhanced chemical vapor deposition (PECVD). ALD technology involves depositing alumina (Al₂O₃). x While thin-film passivation can be achieved, it suffers from drawbacks such as slow deposition rates and high costs. To overcome this bottleneck, PECVD technology has attracted attention due to its fast deposition rate and low cost. For example, patent CN120435095A discloses a PECVD edge passivation method: after cutting the solar cell in half, stacking the halves to align the cut surfaces, and placing them in a reaction chamber, a passivation layer (such as amorphous silicon or silicon nitride) is deposited on the cut surfaces using PECVD. This method improves production capacity by optimizing process parameters and avoids the high-temperature annealing requirements of ALD.

[0004] Although PECVD offers improvements over ALD technology in terms of cost and process control, existing PECVD-based edge passivation technologies still face several core challenges. The proposed film structures are mostly single hydrogenated amorphous silicon layers or composite layers of hydrogenated amorphous silicon and silicon nitride. These film structures suffer from performance degradation and stability defects, specifically manifested as follows: Hydrogenated amorphous silicon layers exhibit poor passivation stability. When hydrogenated amorphous silicon operates under sunlight for extended periods, defects easily develop within its internal network, leading to a significant decrease in passivation performance. In other words, while the passivation effect is excellent immediately after deposition, it drastically reduces the passivation effect at the battery edges after prolonged exposure to outdoor sunlight, failing to achieve long-term stable edge protection.

[0005] Insufficient resistance to ultraviolet radiation. The existing film structure lacks a dedicated ultraviolet protection design, allowing some ultraviolet light to directly irradiate the inner hydrogenated amorphous silicon layer, causing silicon-hydrogen bond breakage and resulting in a sharp decline in passivation performance, severely affecting the battery's outdoor service life.

[0006] Lack of resistance to acid and alkali corrosion. Currently, the mainstream encapsulation material for photovoltaic modules is EVA film. This material is prone to decomposition to generate acetic acid under extreme environments. Silicon nitride film prepared at low temperatures does not have the ability to resist acid and alkali and is easily corroded by acetic acid. Not only is its passivation performance greatly reduced, but it also loses its protective effect on the internal passivation film, further aggravating the recombination loss at the edge of the cell.

[0007] In summary, existing passivation film structures cannot achieve long-term stable edge protection in multi-segment scenarios, leading to a decrease in cell open-circuit voltage and fill factor, which restricts the high-efficiency development of photovoltaic modules. Summary of the Invention

[0008] In view of the shortcomings of the existing technology, the present invention aims to solve the technical problems of limited passivation effect, efficiency loss and poor reliability caused by the simple passivation film structure, poor anti-ultraviolet degradation performance and insufficient environmental stability of multi-segment solar cells.

[0009] To achieve the above objectives, a first aspect of the present invention provides a composite film structure for edge passivation of multi-segment solar cells, comprising the following layers sequentially stacked on the cut edge of the cell: The oxygen-containing amorphous silicon layer is composed of silicon, oxygen, and hydrogen. An optional first hydrogenated amorphous silicon layer, the composition of which includes silicon and hydrogen; The silicon nitride layer is composed of silicon, nitrogen, and hydrogen. The second hydrogenated amorphous silicon layer comprises silicon and hydrogen.

[0010] The composite film structure of this invention effectively solves the limitations caused by the single passivation film structure in the prior art by introducing a multi-layer functional design. Specifically, the oxygen-containing amorphous silicon layer provides a stable interface passivation foundation, overcoming the shortcomings of insufficient defect passivation depth of a single film layer; the synergistic effect of the silicon nitride layer and the second hydrogenated amorphous silicon layer significantly improves the environmental stability of the film, enabling it to effectively resist the erosion of environmental factors such as water, oxygen, acids, and alkalis; the outermost second hydrogenated amorphous silicon layer enhances its resistance to ultraviolet decay through its intrinsic properties, avoiding performance degradation under long-term irradiation. Furthermore, the optional design of the first hydrogenated amorphous silicon layer allows the structure to flexibly adapt to different dicing process requirements, significantly improving the reliability and longevity of edge protection while ensuring passivation effectiveness.

[0011] Furthermore, the oxygen concentration in the oxygen-containing amorphous silicon layer is greater than 1 × 10⁻⁶. 19 cm -3 The introduction of an appropriate amount of oxygen atoms enables the amorphous silicon network to form a more stable chemical structure, improves the interfacial compatibility between the film and the crystalline silicon substrate, and provides a reliable passivation basis for subsequent multilayer structures.

[0012] Furthermore, the first hydrogenated amorphous silicon layer contains phosphorus, and the phosphorus concentration is greater than 1×10⁻⁶. 20 cm -3 By introducing a specific concentration of phosphorus into the first hydrogenated amorphous silicon layer, a synergistic enhancement of field passivation and chemical passivation was achieved.

[0013] Furthermore, the second hydrogenated amorphous silicon layer contains boron and carbon. The introduction of boron and carbon into the second hydrogenated amorphous silicon layer significantly enhances the overall protective performance of the outermost layer through synergistic effects. The incorporation of boron and carbon strengthens the chemical inertness of the amorphous silicon network and reinforces the crystal structure, giving the film excellent mechanical wear resistance and environmental tolerance, thus providing a reliable protective barrier for the inner film system.

[0014] Furthermore, the boron concentration in the second hydrogenated amorphous silicon layer is greater than 1×10⁻⁶. 19 cm -3 The appropriate boron content strengthens the amorphous silicon network while maintaining good interfacial properties, enabling the film to maintain stable protective performance over a long period of time in complex environments and effectively blocking the erosion of external environmental factors.

[0015] Furthermore, the silicon nitride layer includes carbon and / or oxygen elements. The appropriate incorporation of carbon and oxygen elements optimizes the network structure of the silicon nitride, enhances its ability to block the diffusion of water molecules and impurity atoms, provides effective environmental protection for the inner passivation film, and ensures the long-term stability of the passivation effect.

[0016] Furthermore, the thickness of the oxygen-containing amorphous silicon layer is 1–10 nm, the thickness of the first hydrogenated amorphous silicon layer is 5–20 nm, the thickness of the silicon nitride layer is 10–100 nm, and the thickness of the second hydrogenated amorphous silicon layer is 20 nm or more. By systematically optimizing the thickness configuration of each functional layer, the optimal balance between passivation effect and structural stability is achieved, ensuring that each functional film can fully exert its characteristics: the oxygen-containing amorphous silicon layer provides sufficient interface passivation, the hydrogenated amorphous silicon layer ensures sufficient hydrogen source supply, the silicon nitride layer forms an effective protective barrier, and the outermost layer provides sufficient ultraviolet absorption capacity. The multi-layer synergy achieves comprehensive edge protection.

[0017] A second aspect of the present invention provides a method for preparing the above-mentioned composite film structure, comprising the following steps: A slab solar cell is provided, the slab solar cell having cut edges; An oxygen-containing amorphous silicon layer is deposited on the cut edge; Optionally, a first hydrogenated amorphous silicon layer is deposited on the oxygen-containing amorphous silicon layer; When the first hydrogenated amorphous silicon layer is present, a silicon nitride layer is deposited on the first hydrogenated amorphous silicon layer; when the first hydrogenated amorphous silicon layer is not present, a silicon nitride layer is deposited on the oxygen-containing amorphous silicon layer. A second hydrogenated amorphous silicon layer is deposited on the silicon nitride layer to obtain a composite film structure.

[0018] The above preparation method achieves the controllable construction of multifunctional composite films through a flexible step-by-step deposition process, and the multi-layer sequential deposition ensures the interface quality and synergistic effect of each functional layer.

[0019] Furthermore, the composite film structure is deposited using plasma-enhanced chemical vapor deposition. This method activates the reactive gases with plasma, ensuring good compactness and interfacial adhesion of each film layer. It is particularly suitable for the continuous deposition of multilayer composite structures, guaranteeing the consistency of film quality and process repeatability, and enabling the controllable preparation of high-quality functional thin films under low-temperature conditions.

[0020] Furthermore, the deposition temperature is below 250°C. By controlling the deposition temperature within a low range, the formation quality of each functional film layer is ensured, while avoiding damage to the existing battery structure caused by high temperatures.

[0021] Furthermore, after the composite film structure is deposited, an annealing process is included. Annealing effectively promotes the activation and release of hydrogen atoms in the hydrogen-containing film, thereby systematically passivating interface defects and enhancing the interfacial bonding strength and long-term stability of the multilayer structure.

[0022] Furthermore, the annealing temperature is 150–300°C. Within this temperature range, the annealing process can provide sufficient energy to activate the diffusion motion of hydrogen atoms, ensuring that hydrogen atoms effectively migrate to the interface to complete the passivation reaction, while avoiding excessive temperature that could damage the film structure or cause excessive loss of hydrogen atoms.

[0023] In summary, the present invention has the following beneficial effects: (1) Innovative film structure design achieves all-round edge protection: The composite film structure of this invention breaks through the limitations of existing edge passivation technology through multi-layer functional design. The oxygen-containing amorphous silicon layer serves as the basic interface layer, providing a stable passivation foundation; the first hydrogenated amorphous silicon layer serves as the functional enhancement layer, further strengthening the interface passivation effect through its rich hydrogen content and tunable doping characteristics; the silicon nitride layer plays a dual role of hydrogen injection and protection; and the outermost hydrogenated amorphous silicon layer provides UV resistance and mechanical protection. This multi-layer synergistic design forms a complete protection system of interface passivation, structural protection, and environmental protection, effectively solving the composite loss problem at the cutting edge of the segmented battery.

[0024] (2) Advanced preparation process ensures film quality and performance: The preparation scheme of plasma-enhanced chemical vapor deposition combined with optimized annealing treatment has achieved controllable preparation of high-quality functional films. The low-temperature deposition process ensures full compatibility with temperature-sensitive battery technology and avoids the risk of thermal damage; the step-by-step deposition method ensures the interface quality and structural integrity of each functional layer through precise layer sequence control; the annealing treatment process effectively activates the hydrogen passivation mechanism, promotes the directional diffusion of hydrogen atoms in the film and the passivation of interfacial dangling bonds, and significantly improves the stability and durability of the passivation effect.

[0025] (3) Improved overall performance promotes industrial application: This technical solution achieves significant breakthroughs in passivation effect, environmental stability, and process compatibility. The composite film structure exhibits excellent resistance to ultraviolet degradation, avoiding performance decline under long-term irradiation; through element doping and structural optimization, the chemical stability and mechanical wear resistance of the film are enhanced, effectively resisting the erosion of environmental factors such as water, oxygen, acids, and alkalis. At the same time, this technology is well compatible with existing production line equipment, has a fast deposition rate and a wide process window, which greatly improves production efficiency and reduces manufacturing costs, providing reliable technical support for the large-scale industrialization of sectional battery technology. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the composite film structure in a specific embodiment of the present invention.

[0027] Figure 2 This is a schematic diagram of the composite film structure in another specific embodiment of the present invention.

[0028] Explanation of reference numerals in the attached figures: 1-Segmented solar cell, 11-Cell cutting edge, 2-Composite film structure, 21-Oxygen-containing amorphous silicon layer, 22-First hydrogenated amorphous silicon layer, 23-Silicon nitride layer, 24-Second hydrogenated amorphous silicon layer. Detailed Implementation

[0029] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0030] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0031] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be readily apparent to those skilled in the art.

[0032] A specific embodiment of the present invention provides a composite film structure for edge passivation of multi-segment solar cells, comprising four functional films sequentially stacked on the cell cutting edge 11 of the segmented solar cell 1. Combined with... Figure 1 As shown, the structure includes an oxygen-containing amorphous silicon layer 21, a first hydrogenated amorphous silicon layer 22, a silicon nitride layer 23, and a second hydrogenated amorphous silicon layer 24 arranged sequentially from the inside to the outside.

[0033] The oxygen-containing amorphous silicon layer 21 is mainly composed of silicon, oxygen, and hydrogen. Preferably, the oxygen concentration is greater than 1×10⁻⁶. 19 cm -3 The oxygen-containing amorphous silicon layer 21 primarily serves a passivation function; the introduction of trace oxygen atoms results in oxygen-containing amorphous silicon with higher structural stability. In specific implementations, the thickness of the oxygen-containing amorphous silicon layer 21 is greater than 1 nm, with a typical thickness range of 1–10 nm, achieving an optimal balance between interface passivation and carrier transport.

[0034] The first hydrogenated amorphous silicon layer 22 is mainly composed of silicon and hydrogen, and is primarily used to enhance surface passivation. Preferably, the first hydrogenated amorphous silicon layer contains phosphorus, and the phosphorus concentration is greater than 1 × 10⁻⁶. 20 cm -3 A trace amount of phosphorus atoms is introduced to achieve a field passivation effect. In specific implementations, the thickness of the first hydrogenated amorphous silicon layer 22 is greater than 5 nm, with a common thickness range of 5~20 nm.

[0035] The silicon nitride layer 23 is mainly composed of silicon, nitrogen, and hydrogen, serving both hydrogen injection and protection functions, protecting the inner amorphous silicon layer from moisture. Preferably, the silicon nitride layer 23 includes carbon and / or oxygen elements, which enhances its ability to block the diffusion of water molecules and impurity atoms, providing effective environmental protection for the inner passivation film. In specific implementations, the thickness of the silicon nitride layer 23 is greater than 10 nm, with a typical thickness range of 10–100 nm, ensuring sufficient hydrogen supply while avoiding stress problems caused by excessive thickness.

[0036] The second hydrogenated amorphous silicon layer 24 is mainly composed of silicon and hydrogen, serving to absorb ultraviolet light and provide protection. Preferably, the second hydrogenated amorphous silicon layer 24 contains boron and carbon, wherein the boron concentration is greater than 1 × 10⁻⁶. 19 cm -3The incorporation of boron and carbon enhances the chemical inertness of the amorphous silicon network, giving the film excellent mechanical wear resistance and environmental tolerance, providing a reliable protective barrier for the inner film system. In specific implementations, the thickness of the second hydrogenated amorphous silicon layer 24 is greater than 20 nm, with a typical thickness range of 20–100 nm, ensuring sufficient ultraviolet absorption and environmental protection capabilities.

[0037] The innovative composite film structure effectively overcomes the technical bottlenecks of existing edge passivation technologies, such as limited passivation effect, efficiency loss, and poor reliability due to the single film structure, poor UV resistance, and insufficient environmental stability, thus achieving a significant performance improvement. Specifically, each functional layer exhibits a unique synergistic mechanism: the oxygen-containing amorphous silicon layer 21, as an interface layer, forms a stable amorphous network structure through the introduction of appropriate oxygen atoms, providing an excellent adhesion basis for subsequent film layers. The first hydrogenated amorphous silicon layer 22 provides ample hydrogen sources through its abundant Si-H bonds. These hydrogen atoms can diffuse to the interface and combine with the dangling bonds on the crystalline silicon surface, effectively eliminating recombination centers; when this layer is doped with phosphorus, it can also generate a field passivation effect, further enhancing the passivation effect. The silicon nitride layer 23 not only plays a protective role but also injects hydrogen into the interface during annealing, improving the passivation quality. The outermost second hydrogenated amorphous silicon layer 24, through doping with boron and carbon, significantly enhances UV resistance and corrosion resistance, providing comprehensive protection for the inner film system.

[0038] Combination Figure 2 As shown, in some other embodiments, the composite film structure can omit the first hydrogenated amorphous silicon layer 22, directly forming a three-layer structure, including an oxygen-containing amorphous silicon layer 21, a silicon nitride layer 23, and a second hydrogenated amorphous silicon layer 24 sequentially disposed on the cell cutting edge 11. This simplified design reduces process complexity and production costs while ensuring basic passivation effects, providing flexibility for different application needs.

[0039] The preparation method of the above-mentioned composite film structure includes the following steps: S1. Provide slab solar cells 1 and clean the cut edges 11 of the cells.

[0040] S2. Using plasma-enhanced chemical vapor deposition (PECVD), silane, nitrous oxide and hydrogen are introduced into the reaction chamber to deposit an oxygen-containing amorphous silicon layer 21 on the battery cutting edge 11.

[0041] S3. Silane and hydrogen are introduced into the reaction chamber to deposit a first hydrogenated amorphous silicon layer 22 on the oxygen-containing amorphous silicon layer 21; phosphine is introduced if necessary to achieve phosphorus doping. In some embodiments, this step may be omitted.

[0042] S4. Silane, ammonia and hydrogen are introduced into the reaction chamber. When the first hydrogenated amorphous silicon layer 22 is present, a silicon nitride layer 23 is deposited on the layer. When step S3 is omitted, the silicon nitride layer 23 is deposited directly on the oxygen-containing amorphous silicon layer 21.

[0043] S5. Silane and hydrogen are introduced into the reaction chamber to deposit a second hydrogenated amorphous silicon layer 24 on the silicon nitride layer 23. Borane and methane are introduced when necessary to achieve boron and carbon co-doping and complete the preparation of the composite film structure.

[0044] S6. Preferably, an annealing process is performed to release hydrogen from the hydrogen-containing film layer, effectively passivating the dangling bonds on the silicon wafer surface.

[0045] In a specific embodiment, the deposition temperature in steps S2 to S5 is below 250°C to avoid damage to the battery due to high temperature. The annealing temperature in step S6 is 150–300°C to ensure sufficient energy to activate the diffusion motion of hydrogen atoms, while avoiding excessive temperature leading to damage to the film structure or excessive loss of hydrogen atoms.

[0046] This invention provides a reliable technical solution for efficient, stable, and low-cost edge passivation of slab solar cells by combining an innovative multilayer functional film structure with a low-temperature PECVD process. The optimized layer thickness configuration and doping strategy significantly improve the environmental stability and UV resistance of the film while ensuring passivation effectiveness. The mild preparation temperature ensures full compatibility with existing battery processes, demonstrating excellent prospects for industrial application.

[0047] The technical solution and effects of the present invention will be illustrated below with specific embodiments.

[0048] Example 1 (1) Prepare an n-type silicon wafer with a thickness of 160 μm and a resistivity of 0.6~8.5 Ω·cm. Perform standard RCA cleaning on the silicon wafer.

[0049] (2) After cleaning, the silicon wafer is placed in the PECVD reaction chamber, and an oxygen-containing amorphous silicon layer with a thickness of about 3 nm is deposited on both sides of the silicon wafer at a deposition temperature of 170℃.

[0050] (3) Deposit hydrogenated amorphous silicon layers with a thickness of about 10 nm on both sides of the substrate at a deposition temperature of 170 °C.

[0051] (4) A silicon nitride layer with a thickness of about 15 nm is deposited on both sides of the substrate at a deposition temperature of 170°C.

[0052] (5) Deposit hydrogenated amorphous silicon layers with a thickness of about 20 nm on both sides of the substrate at a deposition temperature of 170 °C.

[0053] (6) The silicon wafer is annealed at 200°C for 30 minutes.

[0054] Example 2 (1) Prepare an n-type silicon wafer with a thickness of 160 μm and a resistivity of 0.6~8.5 Ω·cm. Perform standard RCA cleaning on the silicon wafer.

[0055] (2) After cleaning, the silicon wafer is placed in the PECVD reaction chamber, and an oxygen-containing amorphous silicon layer with a thickness of about 3 nm is deposited on both sides of the silicon wafer at a deposition temperature of 170℃.

[0056] (3) A silicon nitride layer with a thickness of about 15 nm is deposited on both sides of the substrate at a deposition temperature of 170℃.

[0057] (4) Deposit hydrogenated amorphous silicon layers with a thickness of about 20 nm on both sides of the substrate at a deposition temperature of 170 °C.

[0058] (5) Anneal the silicon wafer at 200°C for 30 minutes.

[0059] Example 3 The difference between this embodiment and embodiment 1 is that an oxygen-containing amorphous silicon layer with a thickness of about 6 nm is deposited in step (2), while the other steps and process parameters are the same as in embodiment 1.

[0060] Example 4 The difference between this embodiment and embodiment 1 is that the hydrogenated amorphous silicon layer deposited in step (5) is doped with boron and carbon elements, while the other steps and process parameters are the same as in embodiment 1.

[0061] Example 5 The difference between this embodiment and embodiment 1 is that the hydrogenated amorphous silicon layer deposited in step (3) is doped with phosphorus, while the other steps and process parameters are the same as in embodiment 1.

[0062] Example 6 The difference between this embodiment and embodiment 1 is that carbon elements are doped in the silicon nitride layer deposited in step (4), while the other steps and process parameters are the same as in embodiment 1.

[0063] Example 7 The difference between this embodiment and embodiment 1 is that step (6) is omitted, while the other steps and process parameters are the same as in embodiment 1.

[0064] Comparative Example 1 (1) Prepare an n-type silicon wafer with a thickness of 160 μm and a resistivity of 0.6~8.5 Ω·cm. Perform standard RCA cleaning on the silicon wafer.

[0065] (2) After cleaning, the silicon wafer is placed in the ALD reaction chamber and an aluminum oxide layer with a thickness of about 30 nm is deposited on both sides at a deposition temperature of 170°C.

[0066] Comparative Example 2 The difference between this comparative example and comparative example 1 is that the deposition temperature in step (2) is 250℃, while the other steps and process parameters are the same as those in comparative example 1.

[0067] Comparative Example 3 (1) Prepare an n-type silicon wafer with a thickness of 160 μm and a resistivity of 0.6~8.5 Ω·cm. Perform standard RCA cleaning on the silicon wafer.

[0068] (2) After cleaning, the silicon wafer is placed in the PECVD reaction chamber and a hydrogenated amorphous silicon layer with a thickness of about 10 nm is deposited on both sides of the silicon wafer at a deposition temperature of 170℃.

[0069] Comparative Example 4 (1) Prepare an n-type silicon wafer with a thickness of 160 μm and a resistivity of 0.6~8.5 Ω·cm. Perform standard RCA cleaning on the silicon wafer.

[0070] (2) After cleaning, the silicon wafer is placed in the PECVD reaction chamber and a hydrogenated amorphous silicon layer with a thickness of about 10 nm is deposited on the front and back sides of the substrate at a deposition temperature of 170℃.

[0071] (3) A silicon nitride layer with a thickness of about 15 nm is deposited on both sides of the substrate at a deposition temperature of 170℃.

[0072] (4) The silicon wafer is annealed at 200°C for 30 minutes.

[0073] Comparative Example 5 (1) Prepare an n-type silicon wafer with a thickness of 160 μm and a resistivity of 0.6~8.5 Ω·cm. Perform standard RCA cleaning on the silicon wafer.

[0074] (2) After cleaning, the silicon wafer is placed in the PECVD reaction chamber, and an oxygen-containing amorphous silicon layer with a thickness of about 3 nm is deposited on both sides of the silicon wafer at a deposition temperature of 170℃.

[0075] (3) Deposit hydrogenated amorphous silicon layers with a thickness of about 10 nm on both sides of the substrate at a deposition temperature of 170 °C.

[0076] (4) A silicon nitride layer with a thickness of about 15 nm is deposited on both sides of the substrate at a deposition temperature of 170°C.

[0077] (5) Anneal the silicon wafer at 200°C for 30 minutes.

[0078] Comparative Example 6 (1) Prepare an n-type silicon wafer with a thickness of 160 μm and a resistivity of 0.6~8.5 Ω·cm. Perform standard RCA cleaning on the silicon wafer.

[0079] (2) After cleaning, the silicon wafer is placed in the PECVD reaction chamber, and a silicon nitride layer with a thickness of about 15 nm is deposited on both sides of the silicon wafer at a deposition temperature of 170℃.

[0080] Comparative Example 7 (1) Prepare an n-type silicon wafer with a thickness of 160 μm and a resistivity of 0.6~8.5 Ω·cm. Perform standard RCA cleaning on the silicon wafer.

[0081] (2) After cleaning, the silicon wafer is placed in the PECVD reaction chamber. A hydrogenated amorphous silicon layer with boron and carbon elements with a thickness of about 20 nm is deposited on both sides of the silicon wafer at a deposition temperature of 170℃.

[0082] The UV resistance of the film structures prepared in the test examples and comparative examples was assessed by irradiating the samples prepared in the above examples and comparative examples under a UV lamp, and testing the open-circuit voltage before irradiation and after irradiation at different intensities. iV oc ) and current density ( J 0,s The results are shown in Table 1 below.

[0083] Table 1. UV resistance test results of the film structures prepared in the examples and comparative examples.

[0084] The resistance of the film structures prepared in the test examples and comparative examples to weak acid corrosion and water vapor barrier were tested by immersing the samples prepared in the above examples and comparative examples in a 5 vol% acetic acid solution for 120 min. The changes in passivation performance before and after immersion were tested, and the results are shown in Table 2 below.

[0085] Table 2. Test results of acid corrosion resistance and water vapor barrier capacity of the membrane structures prepared in the examples and comparative examples.

[0086] The test results above show that the present invention achieves a comprehensive performance breakthrough in terms of resistance to ultraviolet decay, acid corrosion, and high passivation stability through the synergistic design of a multi-layer composite film structure.

[0087] Example 8 (1) Prepare a TOPCon two-piece battery with a battery cutting edge on one side. Perform standard RCA cleaning on the battery cutting edge.

[0088] (2) The battery is placed in the PECVD reaction chamber and an oxygen-containing amorphous silicon layer with a thickness of about 3 nm is deposited on the cut edge of the battery.

[0089] (3) A silicon nitride layer with a thickness of about 15 nm is deposited on an oxygen-containing amorphous silicon layer.

[0090] (4) Deposit a hydrogenated amorphous silicon layer with a thickness of about 20 nm on the silicon nitride layer.

[0091] (5) The battery is annealed at 200°C for 30 minutes.

[0092] Example 9 (1) Prepare a TOPCon two-piece battery with a battery cutting edge on one side. Perform standard RCA cleaning on the battery cutting edge.

[0093] (2) The battery is placed in the PECVD reaction chamber and an oxygen-containing amorphous silicon layer with a thickness of about 3 nm is deposited on the cut edge of the battery.

[0094] (3) Deposit a hydrogenated amorphous silicon layer with a thickness of about 10 nm on the oxygen-containing amorphous silicon layer.

[0095] (4) Deposit a silicon nitride layer with a thickness of about 15 nm on the hydrogenated amorphous silicon layer.

[0096] (5) Deposit a hydrogenated amorphous silicon layer doped with boron and carbon elements with a thickness of about 20 nm on the silicon nitride layer.

[0097] (6) The battery is annealed at 200°C for 30 minutes.

[0098] Example 10 (1) Prepare a TOPCon four-piece battery with battery cutting edges on both sides and perform standard RCA cleaning on the battery cutting edges.

[0099] (2) The battery is placed in the PECVD reaction chamber, and an oxygen-containing amorphous silicon layer with a thickness of about 3 nm is deposited on the cut edges of the battery on both sides.

[0100] (3) Deposit hydrogenated amorphous silicon layers with a thickness of about 10 nm on both sides of oxygen-containing amorphous silicon layers.

[0101] (4) A silicon nitride layer with a thickness of about 15 nm is deposited on the hydrogenated amorphous silicon layers on both sides.

[0102] (5) Deposit a hydrogenated amorphous silicon layer with a thickness of about 20 nm on both sides of the silicon nitride layer.

[0103] (6) The battery is annealed at 200°C for 30 minutes.

[0104] Example 11 (1) Prepare a TOPCon four-piece battery with battery cutting edges on both sides and perform standard RCA cleaning on the battery cutting edges.

[0105] (2) The battery is placed in the PECVD reaction chamber, and an oxygen-containing amorphous silicon layer with a thickness of about 3 nm is deposited on the cut edges of the battery on both sides.

[0106] (3) Deposit hydrogenated amorphous silicon layers with a thickness of about 10 nm on both sides of oxygen-containing amorphous silicon layers.

[0107] (4) A silicon nitride layer with a thickness of about 15 nm is deposited on the hydrogenated amorphous silicon layers on both sides.

[0108] (5) Deposit a hydrogenated amorphous silicon layer with boron and carbon elements with a thickness of about 20 nm on both sides of the silicon nitride layer.

[0109] (6) The battery is annealed at 200°C for 30 minutes.

[0110] Comparative Example 8 (1) Prepare a TOPCon two-piece battery with a battery cutting edge on one side. Perform standard RCA cleaning on the battery cutting edge.

[0111] (2) The battery is placed in the ALD reaction chamber and an aluminum oxide layer with a thickness of about 30 nm is deposited on the cut edge of the battery.

[0112] Comparative Example 9 (1) Prepare a TOPCon two-piece battery with a battery cutting edge on one side. Perform standard RCA cleaning on the battery cutting edge.

[0113] (2) The battery is placed in the PECVD reaction chamber and an oxygen-containing amorphous silicon layer with a thickness of about 3 nm is deposited on the cut edge of the battery.

[0114] (3) Deposit a hydrogenated amorphous silicon layer with a thickness of about 10 nm on the oxygen-containing amorphous silicon layer.

[0115] (4) Deposit a silicon nitride layer with a thickness of about 15 nm on the hydrogenated amorphous silicon layer.

[0116] (5) The battery is annealed at 200°C for 30 minutes.

[0117] Comparative Example 10 (1) Prepare a TOPCon four-piece battery with battery cutting edges on both sides and perform standard RCA cleaning on the battery cutting edges.

[0118] (2) The battery is placed in the ALD reaction chamber and an aluminum oxide layer with a thickness of about 30 nm is deposited on the cut edges of the battery on both sides.

[0119] Comparative Example 11 (1) Prepare a TOPCon four-piece battery with battery cutting edges on both sides and perform standard RCA cleaning on the battery cutting edges.

[0120] (2) The battery is placed in the PECVD reaction chamber, and an oxygen-containing amorphous silicon layer with a thickness of about 3 nm is deposited on the cut edges of the battery on both sides.

[0121] (3) Deposit hydrogenated amorphous silicon layers with a thickness of about 10 nm on both sides of oxygen-containing amorphous silicon layers.

[0122] (4) A silicon nitride layer with a thickness of about 15 nm is deposited on the hydrogenated amorphous silicon layers on both sides.

[0123] (5) The battery is annealed at 200°C for 30 minutes.

[0124] The performance of the segmented cells before and after edge passivation in the above embodiments and comparative examples was tested, and the results are shown in Table 3 below.

[0125] Table 3 Performance test results of edge-passivated cell segments in the examples and comparative examples

[0126] The above test results show that the multilayer composite film structure of the present invention exhibits an efficiency gain superior to existing single-layer or simplified structures in the edge passivation of segmented batteries, providing core support for the high efficiency and reliability of segmented technology.

[0127] While the present invention has been disclosed above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of this disclosure, and all such changes and modifications will fall within the scope of protection of this invention.

Claims

1. A composite film layer structure for edge passivation of a multi-faceted solar cell, characterized by, This includes the following layers stacked sequentially on the cut edge of the battery: The oxygen-containing amorphous silicon layer is composed of silicon, oxygen, and hydrogen. An optional first hydrogenated amorphous silicon layer, the composition of which includes silicon and hydrogen; The silicon nitride layer is composed of silicon, nitrogen, and hydrogen. The second hydrogenated amorphous silicon layer comprises silicon and hydrogen.

2. The composite film layer structure according to claim 1, wherein The oxygen concentration in the oxygen-containing amorphous silicon layer is greater than 1 x 1018cm-2. 19 cm -3 .

3. The composite film layer structure of claim 1, wherein The first hydrogenated amorphous silicon layer contains phosphorus element, and the phosphorus concentration is greater than 1 x 10 20 cm -3 .

4. The composite film layer structure of claim 1, wherein The second hydrogenated amorphous silicon layer contains boron and carbon elements.

5. The composite film layer structure of claim 4, wherein The boron concentration in the second hydrogenated amorphous silicon layer is greater than 1 x 1016cm-3. 19 cm -3 .

6. The composite film layer structure of claim 1, wherein The silicon nitride layer includes carbon and / or oxygen elements.

7. The composite film layer structure according to any one of claims 1 to 6, wherein The thickness of the oxygen-containing amorphous silicon layer is 1~10nm, the thickness of the first hydrogenated amorphous silicon layer is 5~20nm, the thickness of the silicon nitride layer is 10~100nm, and the thickness of the second hydrogenated amorphous silicon layer is 20nm or more.

8. A method of producing a composite film layer structure as claimed in any one of claims 1-7, characterized in that Includes the following steps: A slab solar cell is provided, the slab solar cell having cut edges; An oxygen-containing amorphous silicon layer is deposited on the cut edge; Optionally, a first hydrogenated amorphous silicon layer is deposited on the oxygen-containing amorphous silicon layer; When the first hydrogenated amorphous silicon layer is present, a silicon nitride layer is deposited on the first hydrogenated amorphous silicon layer; when the first hydrogenated amorphous silicon layer is not present, a silicon nitride layer is deposited on the oxygen-containing amorphous silicon layer. A second hydrogenated amorphous silicon layer is deposited on the silicon nitride layer to obtain a composite film structure.

9. The production method according to claim 8, characterized by, The composite film structure was deposited using plasma-enhanced chemical vapor deposition.

10. The method of claim 9, wherein, The deposition temperature is below 250℃.

11. The preparation method according to claim 8, characterized in that, After the composite film structure is deposited, the process also includes annealing or a combination of intense light irradiation and low-temperature annealing.

12. The method of claim 11, wherein, The annealing temperature is 150~300℃.

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