A solar cell module of a multilayer film structure

Abstract

The utility model relates to a solar cell module of multilayer film structure, include: solar cell piece, solar cell piece includes the multilayer function film layer of setting and the metal electrode on the most outside function film layer, protective film layer, protective film layer completely covers the solar cell piece surface and metal electrode of metal electrode and the side area of solar cell piece, and protective film layer only has the opening in the area where metal electrode and outside circuit welds. The solar cell module of multilayer film structure provided by the utility model can play the erosion effect of isolating the moisture and ultraviolet light of external environment through the structure of protective film layer, protects all kinds of solar cell pieces in all directions, effectively reduces the irreversible attenuation of the power of battery module caused by moisture invasion and ultraviolet radiation, improves the long-term reliability and service life of battery module.

Description

Technical Field

[0001] This utility model relates to the field of solar cell manufacturing technology, and more specifically, to a multilayer film structure solar cell module. Background Technology

[0002] With the continuous development and technological iteration of the photovoltaic industry, following ToPCon (tunneling oxide passivated contact) cells, HJT (heterojunction) cells, with their unique crystalline / amorphous silicon heterojunction structure, symmetrical bifaciality, high open-circuit voltage, and low temperature coefficient, are considered a disruptive path to achieving ultra-high efficiency (>26%). Meanwhile, BC (back contact) cell technology places both positive and negative electrodes on the back of the cell, completely eliminating shading losses from the front grid lines, further improving photoelectric conversion efficiency and achieving a balance between aesthetics and efficiency. Currently, the development direction of solar cell technology has shifted from solely pursuing extreme photoelectric conversion efficiency to a deeper consideration of comprehensive performance such as weather resistance, long-term stability, lifespan, and levelized cost of electricity. The industry is increasingly focusing on the power degradation rate, resistance to potential-induced degradation, mechanical load performance, and reliable output over a lifespan of 25-30 years under various complex environments. Currently, the key factors affecting the long-term reliability and lifespan of HJT and BC cell modules are mainly moisture permeation and ultraviolet radiation.

[0003] The core of HJT cells lies in their superior amorphous silicon passivation layer and transparent conductive oxide (TCO) film. The effects of moisture permeation and ultraviolet irradiation on HJT cell modules are as follows: First, moisture permeation reacts chemically with the TCO, while ultraviolet irradiation causes redox reactions in the TCO layer, leading to corrosion, decreased conductivity and transmittance, a significant reduction in fill factor and short-circuit current, ultimately resulting in rapid and irreversible power degradation of the HJT module. Second, moisture molecules and ultraviolet irradiation disrupt the perfect passivation of the crystalline silicon (c-Si) surface by hydrogen-terminated amorphous silicon (a-Si:H), intensifying carrier recombination and significantly reducing open-circuit voltage and fill factor, also causing irreversible power loss. Third, HJT uses low-temperature silver paste; moisture intrusion accelerates electrode oxidation and corrosion, affecting the electrodes' ability to collect electrons / holes, thus leading to decreased cell module power and shortened lifespan.

[0004] The positive and negative electrodes on the back of a BC battery are arranged in an alternating pattern like "fingers," with very small spacing. The specific effects of moisture penetration and ultraviolet irradiation on BC battery modules are as follows: First, moisture penetration creates electrolyte channels between the positive and negative electrodes, causing electrochemical corrosion, leading to a decrease in parallel resistance and a significant reduction in the fill factor. In severe cases, metal ions (such as silver ions) migrate under the influence of the electric field, directly causing a short circuit between the positive and negative electrodes, resulting in cell or even module failure. Second, moisture penetration and ultraviolet irradiation damage the integrity of the passivation layers such as silicon oxide / aluminum oxide on the back of the BC battery. Passivation layer failure leads to increased carrier recombination, which also manifests as a decrease in open-circuit voltage and fill factor. Third, the infiltrated moisture turns into water vapor after the module heats up during operation, generating pressure and causing bubbles to form within the encapsulation material, especially in the structurally complex back electrode area. These bubbles further accelerate the delamination process, affecting heat dissipation and light transmission, and providing channels for more moisture penetration.

[0005] Therefore, in response to the key issues affecting the long-term reliability and lifespan of HJT and BC cell modules, it is urgent to design a solar cell structure that can overcome the above-mentioned defects. Utility Model Content

[0006] This invention provides a low-temperature deposited protective film structure for high-efficiency solar cells, including heterojunction (HJT), back contact (BC), and composite types (e.g., heterojunction back contact (HBC), tunnel oxide passivated back contact (TBC), and composite passivated back contact (HPBC)). This structure effectively blocks water vapor penetration and ultraviolet radiation, thereby significantly improving the long-term environmental reliability, stability, and service life of the solar cell module.

[0007] To solve the above-mentioned technical problems or achieve the above-mentioned objectives, the present invention adopts the following technical solution:

[0008] According to an aspect of this utility model, a multilayer film structure solar cell module is provided, comprising:

[0009] Solar cell, the solar cell includes multiple functional film layers and a metal electrode located on the outermost functional film layer;

[0010] The protective film completely covers the surface of the solar cell where the metal electrode is located, the metal electrode, and the side area of ​​the solar cell. The protective film has openings only in the area where the metal electrode is soldered to the external circuit.

[0011] In one embodiment of the present invention, the protective film layer includes at least one of a silicon nitride film layer, a silicon oxynitride film layer, a silicon oxide film layer, and an aluminum oxide film layer.

[0012] In one embodiment of this utility model, the protective film layer is any one of a silicon nitride film layer, a silicon oxynitride film layer, a silicon oxide film layer, and an aluminum oxide film layer.

[0013] In one embodiment of this utility model, the protective film layer is a combination of any two of the following: silicon nitride film layer, silicon oxynitride film layer, silicon oxide film layer, and aluminum oxide film layer.

[0014] In one embodiment of this utility model, any one of the following film layers—silicon nitride film layer, silicon oxynitride film layer, silicon oxide film layer, and aluminum oxide film layer—comprises multiple sublayers of the same material.

[0015] In one embodiment of this utility model, the thickness of the protective film layer is 5-200nm.

[0016] In one embodiment of this utility model, the solar cell includes any one of a heterojunction cell, a composite passivated back contact cell, a tunnel oxide passivated back contact cell, and a heterojunction back contact cell.

[0017] In one embodiment of this invention, the metal electrode is made of silver, aluminum, or copper.

[0018] In one embodiment of this utility model, the opening is formed by laser drilling.

[0019] In addition, this utility model also provides a method for preparing a multilayer film structure solar cell module as described above, comprising the following steps:

[0020] The solar cells, after screen printing and sintering, are placed on a carrier plate;

[0021] The carrier plate is fed into the process chamber of the hot filament chemical vapor deposition equipment to deposit a protective film on the entire metal electrode of the solar cell and the entire surface of the solar cell on which the metal electrode is located, and to deposit a protective film on the entire side area of ​​the solar cell.

[0022] After the protective film is deposited, openings are formed only in the area where the metal electrode is welded to the external circuit, and the external circuit is welded to the metal electrode through the openings to form a conductive path.

[0023] In one embodiment of this utility model, the deposition of the protective film includes:

[0024] H2, SiH4, O2, or H2, SiH4, N2O, or H2, hexamethyldisilazane, N2O are introduced into the process chamber of a hot-wire chemical vapor deposition (CVD) apparatus to deposit silicon oxide films; and / or

[0025] H2, SiH4, NH3 or H2, hexamethyldisilazane, NH3 are introduced into the process chamber of a hot-wire chemical vapor deposition (CVD) apparatus to deposit silicon nitride films; and / or

[0026] H2, SiH4, NH3, O2, or H2, SiH4, NH3, N2O, or H2, hexamethyldisilazane, NH3, N2O are introduced into the process chamber of a hot-wire chemical vapor deposition (CVD) apparatus to deposit silicon oxynitride films; and / or

[0027] H2, O2, and trimethylaluminum or H2, N2O, and trimethylaluminum are introduced into the process chamber of a hot-wire chemical vapor deposition equipment to deposit an alumina film.

[0028] In one embodiment of this utility model, depositing a protective film layer on the entire metal electrode of the solar cell and the entire surface of the solar cell where the metal electrode is located includes:

[0029] The metal electrodes of the solar cells placed on the carrier plate are positioned so that the side containing the metal electrodes faces the hot wire direction of the hot wire chemical vapor deposition equipment. The carrier plate is then fed into the process chamber of the hot wire chemical vapor deposition equipment to deposit a protective film.

[0030] In one embodiment of this invention, depositing a protective film over the entire side surface area of ​​a solar cell includes:

[0031] The side coating generated during the deposition of a protective film on the surface of the metal electrode and the solar cell containing the metal electrode serves as the side protective film of the solar cell; or

[0032] Solar cells with protective films deposited on the metal electrodes and the surface of the solar cells on which the metal electrodes are located are stacked, with the side edges of the solar cells facing the hot wire direction of the hot filament chemical vapor deposition equipment. Then, the carrier plate is fed into the process chamber of the hot filament chemical vapor deposition equipment, and the same deposition gas and process parameters as those used for the deposition of the protective film on the surface of the metal electrodes and the solar cells on which the metal electrodes are located are used to deposit the protective film on the side area.

[0033] The technical solution provided by this utility model has the following advantages compared with the prior art:

[0034] (1) This utility model utilizes the good weather resistance and chemical stability of protective film layers (such as silicon nitride film layer, silicon oxynitride film layer, silicon oxide film layer, aluminum oxide film layer) to cover the metal electrodes of the multilayer film structure solar cell module and the surface of the solar cell where the metal electrodes are located, as well as the side of the cell. This can isolate the water vapor and ultraviolet light from the external environment, and protect the solar cell in all directions. This effectively reduces the TCO corrosion and the decrease in the passivation effect of the amorphous silicon layer caused by water vapor intrusion and ultraviolet radiation, thereby reducing the irreversible power decay of the battery module caused by TCO corrosion and the decrease in the passivation effect of the amorphous silicon layer, and improving the long-term reliability and service life of the battery module.

[0035] (2) This utility model utilizes the good weather resistance and chemical stability of protective film layers (such as silicon nitride film layer, silicon oxynitride film layer, silicon oxide film layer, aluminum oxide film layer) to protect the electrodes of solar cells, prevent moisture intrusion that leads to electrode oxidation and corrosion, avoid the decrease in the electrode's ability to collect electrons / holes due to electrode oxidation and corrosion, and improve the service life of the battery module.

[0036] (3) The design of the outer protective film layer (e.g., silicon nitride film layer, silicon oxynitride film layer, silicon oxide film layer, aluminum oxide film layer) of this utility model can appropriately reduce the TCO layer of solar cells such as HJT and HBC, so that the TCO layer only plays the role of increasing conductivity. The reduction of TCO will greatly reduce the manufacturing cost of solar cells such as HJT and HBC. At the same time, it can also enhance the light transmittance, improve the cell's ability to absorb sunlight, and improve the photoelectric conversion efficiency.

[0037] (4) The multilayer film structure solar cell module provided by this utility model can prepare a protective film layer in the range of room temperature to 200°C using HoFCVD coating equipment and technology, so as to avoid the damage of high temperature to the amorphous silicon film layer, tunneling oxide layer and other components of the solar cell.

[0038] (5) The multilayer film structure solar cell module provided by this utility model can be applied to, for example, HJT, HPBC, TBC and HBC cells. Combined with the coating principle of HoFCVD equipment and the control of key parameters of the equipment, the mass industrial production and large-scale application of this protective film layer can be realized. Attached Figure Description

[0039] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the present invention and, together with the description, serve to explain the principles of the present invention.

[0040] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0041] Figure 1 A schematic diagram of the planar structure of a multilayer film solar cell module provided in this utility model is shown.

[0042] Figure 2 A schematic diagram of the planar structure of a heterojunction (HJT) battery module provided in one embodiment of the present invention is shown.

[0043] Figure 3 A schematic diagram of the planar structure of a heterojunction back contact (HBC) battery assembly provided in another embodiment of the present invention is shown.

[0044] Figure 4 A schematic diagram of the planar structure of a tunnel oxide passivated back contact (TBC) battery module provided in another embodiment of the present invention is shown.

[0045] Figure 5 A schematic diagram of the planar structure of a composite passivated back contact (HPBC) battery assembly provided in another embodiment of the present invention is shown.

[0046] Figure 6 A schematic flowchart illustrating the fabrication method of a multilayer film structure solar cell module provided in this invention is shown.

[0047] Among them, 1. Solar cell; 2. Metal electrode; 3. Protective film layer; 4. Opening; 5. HJT cell; 6. HBC cell; 7. TBC cell; 8. HPBC cell; 9. Crystalline silicon substrate; 10. Intrinsic amorphous silicon layer; 11. P-type amorphous silicon layer; 12. N-type amorphous silicon layer; 13. TCO layer; 14. First passivation layer; 15. ITO layer; 16. N-type diffusion layer; 17. Tunneling silicon oxide layer; 18. Second passivation layer; 19. Boron-doped aluminum back field; 20. Aluminum electrode. Detailed Implementation

[0048] To better understand the above-mentioned objectives, features, and advantages of this utility model, embodiments of this utility model will be further described below. It should be noted that, unless otherwise specified, embodiments of this utility model and features thereof can be combined with each other.

[0049] Many specific details are set forth in the following description in order to provide a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein; obviously, the embodiments in the specification are only some embodiments of the present invention, and not all embodiments.

[0050] like Figure 1 As shown, this utility model provides a multilayer film structure solar cell module, comprising:

[0051] Solar cell 1, the solar cell 1 includes multiple functional film layers (not shown) and a metal electrode 2 located on the outermost functional film layer;

[0052] The protective film layer 3 completely covers the surface of the solar cell where the metal electrode 2 is located, the metal electrode 2, and the side area of ​​the solar cell 1. The protective film layer 3 has openings 4 only in the area where the metal electrode 2 is welded to the external circuit.

[0053] Through the above-mentioned technical solution of this utility model, the structure of the protective film layer 3 provided by this utility model can isolate the water vapor and ultraviolet light from the external environment, protect the solar cell in all aspects, effectively reduce the irreversible power decay of the battery module caused by water vapor intrusion and ultraviolet radiation, and improve the long-term reliability and service life of the battery module.

[0054] Specifically, the protective film layer 3 of this invention covers the metal electrode 2 of the multilayer film structure solar cell module, the surface of the solar cell containing the metal electrode 2, and the sides of the solar cell 1. It effectively isolates the solar cell 1 from external environmental moisture and ultraviolet light, providing comprehensive protection. This effectively reduces TCO corrosion and the decrease in passivation effect of the amorphous silicon layer caused by moisture intrusion and ultraviolet radiation, thereby reducing irreversible power degradation of the battery module caused by TCO corrosion and the decrease in passivation effect of the amorphous silicon layer, and improving the long-term reliability and service life of the battery module. The protective film layer 3 of this invention prevents moisture intrusion that leads to electrode oxidation and corrosion, avoiding a decrease in the electrode's electron / hole collection capacity due to electrode oxidation and corrosion, thus improving the service life of the battery module. Furthermore, the design of the outer protective film layer 3 of this invention allows for appropriate thinning of the TCO layer in solar cells such as HJT and HBC, so that the TCO layer only functions to increase conductivity. Thinning the TCO layer significantly reduces the manufacturing cost of HJT and HBC solar cells, while also enhancing light transmittance, improving the cell's ability to absorb sunlight, and increasing photoelectric conversion efficiency.

[0055] In the above embodiments, such as Figure 1 As shown, the protective film layer 3 includes at least one of a silicon nitride film layer, a silicon oxynitride film layer, a silicon oxide film layer, and an aluminum oxide film layer.

[0056] In the above embodiments, such as Figure 1 As shown, the protective film layer 3 can refer to any one of the following: silicon nitride film layer, silicon oxynitride film layer, silicon oxide film layer, and aluminum oxide film layer.

[0057] In the above embodiments, such as Figure 1 As shown, the protective film layer 3 can refer to any two combinations of silicon nitride film layer, silicon oxynitride film layer, silicon oxide film layer, and aluminum oxide film layer.

[0058] Of course, alternatively, the protective membrane 3 can be other protective membranes of the same kind.

[0059] This invention utilizes the excellent weather resistance and chemical stability of silicon nitride film, silicon oxynitride film, silicon oxide film, and aluminum oxide film to cover the metal electrode and the surface and sides of the solar cell where the metal electrode is located, thereby isolating the solar cell from moisture and ultraviolet light from the external environment and providing all-round protection for the solar cell.

[0060] In the above embodiments, any one of the following film materials—silicon nitride film, silicon oxynitride film, silicon oxide film, and aluminum oxide film—comprises multiple sub-layers of the same material.

[0061] In this embodiment, the protective film layer 3 is not limited to a single layer, but can be composed of multiple sub-layers of the same material. For example, the silicon nitride film layer can be multi-layered, composed of multiple silicon nitride sub-layers; the silicon oxynitride film layer can be multi-layered, composed of multiple silicon oxynitride sub-layers; the silicon oxide film layer can be multi-layered, composed of multiple silicon oxide sub-layers; and the aluminum oxide film layer can be multi-layered, composed of multiple aluminum oxide sub-layers.

[0062] In the above embodiments, such as Figure 1 As shown, the thickness of the protective film layer 3 is 5-200nm.

[0063] In the above embodiments, such as Figure 1 As shown, the solar cell 1 includes any one of the following: heterojunction cell, composite passivated back contact cell, tunnel oxide passivated back contact cell, and heterojunction back contact cell.

[0064] In the above embodiments, such as Figure 1 As shown, the metal electrode 2 is made of silver, aluminum, or copper. Preferably, the metal electrode 2 is a silver electrode.

[0065] In the above embodiments, such as Figure 1 As shown, the opening 4 is formed by laser drilling.

[0066] In this embodiment, the method of drilling holes in the protective film layer 3 at the part of the metal electrode 2 that needs to be welded to the external circuit includes, but is not limited to, laser drilling.

[0067] In addition, such as Figure 6 As shown, this utility model also provides a method for preparing a multilayer film structure solar cell module as described above, comprising the following steps:

[0068] S1: Place the completed screen-printed and sintered solar cell onto the carrier plate;

[0069] S2: The carrier plate is fed into the process chamber of the hot filament chemical vapor deposition equipment to deposit a protective film on the entire metal electrode of the solar cell and the entire surface of the solar cell where the metal electrode is located, and to deposit a protective film on the entire side area of ​​the solar cell.

[0070] S3: After the protective film is deposited, an opening is formed only in the area where the metal electrode is welded to the external circuit, and the external circuit is welded to the metal electrode through the opening to form a conductive path.

[0071] The multilayer film structure solar cell module provided by this invention utilizes HoFCVD coating technology to prepare a protective film layer within a temperature range of room temperature to 200°C, preventing high temperatures from damaging the amorphous silicon film layer and tunneling oxide layer of the solar cell. This multilayer film structure solar cell module can be applied to cells such as HJT, HPBC, TBC, and HBC. By combining the HoFCVD equipment coating principle and controlling key equipment parameters, large-scale industrial production and application of this protective film layer can be achieved.

[0072] In the above embodiments, step S2, which involves depositing a protective film, includes:

[0073] H2, SiH4, O2, or H2, SiH4, N2O, or H2, hexamethyldisilazane, N2O are introduced into the process chamber of a hot-wire chemical vapor deposition (CVD) apparatus to deposit silicon oxide films; and / or

[0074] H2, SiH4, NH3 or H2, hexamethyldisilazane, NH3 are introduced into the process chamber of a hot-wire chemical vapor deposition (CVD) apparatus to deposit silicon nitride films; and / or

[0075] H2, SiH4, NH3, O2, or H2, SiH4, NH3, N2O, or H2, hexamethyldisilazane, NH3, N2O are introduced into the process chamber of a hot-wire chemical vapor deposition (CVD) apparatus to deposit silicon oxynitride films; and / or

[0076] H2, O2, and trimethylaluminum or H2, N2O, and trimethylaluminum are introduced into the process chamber of a hot-wire chemical vapor deposition equipment to deposit an alumina film.

[0077] The hot filament chemical vapor deposition (HoFCVD) equipment used in this invention generally includes automated loading, a feed chamber (a transition chamber connecting the atmosphere and the high vacuum chamber), a heating chamber (for heating the sample cell), a process chamber (for depositing the protective film), an discharge chamber (a transition chamber connecting the atmosphere and the high vacuum chamber), and automated unloading. However, except for the process chamber, the above four chambers are not essential; the structure of the protective film in this invention can be achieved as long as there is a process chamber.

[0078] In the above embodiments, step S2, depositing a protective film layer on the entire metal electrode of the solar cell and the entire surface of the solar cell where the metal electrode is located, includes:

[0079] The metal electrodes of the solar cells placed on the carrier plate are positioned so that the side containing the metal electrodes faces the hot wire direction of the hot wire chemical vapor deposition equipment. The carrier plate is then fed into the process chamber of the hot wire chemical vapor deposition equipment to deposit a protective film.

[0080] In this embodiment, the deposition step of the metal electrode and the protective film layer on the surface of the solar cell on which the metal electrode is located is as follows:

[0081] After the solar cell has been screen-printed and sintered, it is placed on a carrier plate with the metal electrode and the side containing the metal electrode facing the hot wire.

[0082] The aforementioned carrier plate was sent to a hot filament chemical vapor deposition (HoFCVD) apparatus for the deposition of a protective film.

[0083] The process chamber is vented with H2, SiH4, O2, or H2, SiH4, N2O, or H2, hexamethyldisilazane, N2O to deposit silicon oxide film; and / or the process chamber is vented with H2, SiH4, NH3, or H2, hexamethyldisilazane, NH3 to deposit silicon nitride film; and / or the process chamber is vented with H2, SiH4, NH3, O2, or H2, SiH4, NH3, N2O, or H2, hexamethyldisilazane, NH3, N2O to deposit silicon oxynitride film; and / or the process chamber is vented with H2, O2, trimethylaluminum, or H2, N2O, trimethylaluminum to deposit alumina film. The hot wire in the process chamber is a tungsten wire, and the temperature is 1800-2100℃. The pressure is controlled at 1-2 Pa during film deposition in the process chamber.

[0084] In the above embodiments, step S2, depositing a protective film layer on the entire side surface of the solar cell, includes:

[0085] The side coating generated during the deposition of a protective film on the surface of the metal electrode and the solar cell containing the metal electrode serves as the side protective film of the solar cell; or

[0086] Solar cells with protective films deposited on the metal electrodes and the surface of the solar cells on which the metal electrodes are located are stacked, with the side edges of the solar cells facing the hot wire direction of the hot filament chemical vapor deposition equipment. Then, the carrier plate is fed into the process chamber of the hot filament chemical vapor deposition equipment, and the same deposition gas and process parameters as those used for the deposition of the protective film on the surface of the metal electrodes and the solar cells on which the metal electrodes are located are used to deposit the protective film on the side area.

[0087] When depositing a protective film on the side: (1) During the deposition of a protective film on the surface of the metal electrode and the solar cell on which the metal electrode is located, there will be a winding plating, which will be deposited on the side of the solar cell. Since the solar cell is very thin, the protective film deposited on the side can protect the side. In order to further protect the battery in all directions, it is possible to deposit a protective film on the side of the solar cell; (2) The method of depositing a protective film on the side is the same as the above-mentioned protective film deposition on the metal electrode. The only difference is that a certain number of solar cells that have already deposited a protective film on the metal electrode are stacked up, and the side edge of the solar cell is faced with the hot wire for side protective film deposition.

[0088] The technical solution of this utility model will be described in detail below through specific embodiments.

[0089] Example 1

[0090] The solar cells use heterojunction (HJT) cells.

[0091] like Figure 2 As shown in the figure, the structural schematic diagram of the HJT battery 5 is shown. The HJT battery 5 has multiple functional film layers stacked together (intrinsic amorphous silicon layer 10, P-type amorphous silicon layer 11, N-type amorphous silicon layer 12, and TCO layer 13). In the structure of this HJT cell 5, the core light absorption region is a crystalline silicon substrate 9. On the upper and lower sides of the crystalline silicon substrate 9, an intrinsic amorphous silicon layer 10 (used for interface passivation to reduce carrier recombination) and a doped amorphous silicon layer (a P-type amorphous silicon layer 11 on the upper side and an N-type amorphous silicon layer 12 on the lower side, forming a heterojunction structure to regulate carrier separation) are sequentially disposed. A TCO layer 13 (TCO: transparent conductive oxide) is covered on the outer side of both the upper P-type amorphous silicon layer 11 and the lower N-type amorphous silicon layer 12 for efficient carrier collection and current transport. Four uniformly distributed metal electrodes 2 (silver electrodes, used to extract current) are disposed on the outer side of both the upper and lower TCO layers 13. The HJT cell 5 has a symmetrical bifacial structure.

[0092] In the multilayer film structure solar cell module prepared with the above-mentioned HJT cell 5, as described again... Figure 2 As shown, a protective film layer 3 covers the metal electrodes 2 (silver electrodes) on the top and bottom sides of the HJT battery 5, the surface of the solar cell containing the metal electrodes 2, and the sides of the HJT battery 5. This protective film layer 3 is deposited using a hot-wire chemical vapor deposition (HoFCVD) apparatus. The protective film layer 3 can be at least one of silicon nitride, silicon oxynitride, silicon oxide, and aluminum oxide films, preferably any one or a combination of any two of these films. This protective film layer 3 completely covers the entire area above the top and bottom metal electrodes 2 of the HJT battery 5 (covering both the main and sub-grid lines), and completely covers the entire side of the HJT battery 5. The thickness of this protective film layer 3 can be 5-200 nm, providing protection, reducing the battery's susceptibility to external environmental influences, and improving the battery's stability and performance. Of course, in cases where… Figure 2 In the structure of the solar cell module shown, after the protective film layer 3 is deposited, openings 4 can be formed in the areas where the uppermost and lowermost metal electrodes 2 are welded to the external circuit by laser drilling. Figure 2 (not shown in the image), and the external circuit is welded to the metal electrode 2 through the opening 4 to form a conductive path.

[0093] Example 2

[0094] The solar cells use heterojunction back contact (HBC) cells.

[0095] like Figure 3 As shown in the figure, the structural schematic of the HBC cell 6 is illustrated. The HBC cell 6 has multiple functional layers (intrinsic amorphous silicon layer 10, first passivation layer 14, P-type amorphous silicon layer 11, N-type amorphous silicon layer 12, and ITO layer 15). In the structure of the HBC cell 6, from the light incident side to the back contact side (from top to bottom), the structure is as follows: the top layer is the first passivation layer 14 (in this embodiment, it can be a silicon nitride layer), which serves both anti-reflection and surface passivation functions; below it is an intrinsic amorphous silicon layer 10, used to passivate the surface of the crystalline silicon substrate 9 and reduce carrier recombination at the interface; the central core part is the crystalline silicon substrate 9, which serves as the main light absorption region, absorbing photons and generating photogenerated carriers. On the back side of the crystalline silicon substrate 9 (… Figure 3On the lower middle side, firstly, another intrinsic amorphous silicon layer 10 is formed to further passivate the interface. Then, a P-type amorphous silicon layer 11 and an N-type amorphous silicon layer 12 are fabricated to form a back-contact PN junction structure, providing a barrier for carrier separation. Next is an ITO layer 15 (ITO: indium tin oxide), used for efficient carrier collection and ensuring current transport. At the bottom is a metal electrode 2, containing both positive and negative electrodes. The HBC cell 6 collects current through a back-contact method, avoiding the front electrode's obstruction of incident light and maximizing the light absorption area. The overall structure of the HBC cell 6 combines the advantages of a heterojunction (amorphous silicon and crystalline silicon form a heterojunction with excellent interface passivation) and a back-contact method (electrodes concentrated on the back side, without front-contact obstruction), achieving efficient carrier generation and collection through its multilayer structure.

[0096] In the multilayer film structure solar cell module prepared with the above-mentioned HBC cell 6, as described again... Figure 3 As shown, a protective film layer 3 covers the bottommost metal electrode 2 of the HBC battery 6, the surface of the solar cell containing the metal electrode 2, and the side surface of the HBC battery 6. This protective film layer 3 is deposited using a hot-wire chemical vapor deposition (HoFCVD) apparatus. The protective film layer 3 can be at least one of silicon nitride, silicon oxynitride, silicon oxide, and aluminum oxide films, preferably any one or a combination of two of these films. This protective film layer 3 completely covers the entire area above the bottommost metal electrode 2 of the HBC battery 6 (covering both the main and sub-grid lines) and the entire side surface of the HBC battery 6. The thickness of the protective film layer 3 can be 5-200 nm, providing protection, reducing the battery's susceptibility to external environmental influences, and improving the battery's stability and performance. Of course, in cases where… Figure 3 In the structure of the solar cell module shown, after the protective film layer 3 is deposited, an opening 4 can be formed in the area where the bottommost metal electrode 2 is welded to the external circuit by laser drilling. Figure 3 (not shown in the image), and the external circuit is welded to the metal electrode 2 through the opening 4 to form a conductive path.

[0097] Example 3

[0098] The solar cell uses a combination of TOPCon (tunneling oxide passivated contact) and IBC (cross-back contact) technologies to form a tunneling oxide passivated back contact (TBC) cell.

[0099] like Figure 4As shown in the figure, the structural schematic of the TBC battery 7 is illustrated. The TBC battery 7 has multiple functional layers (N-type diffusion layer 16, first passivation layer 14, tunneling silicon oxide layer 17, P-type amorphous silicon layer 11, N-type amorphous silicon layer 12, and second passivation layer 18). In the structure of the TBC battery 7, from the light incident side to the back contact side (from top to bottom), the structure is as follows: the top layer is the first passivation layer 14 (in this embodiment, it can be an aluminum oxide + silicon nitride composite layer), which serves both anti-reflection (reducing light reflection to improve light utilization) and surface passivation (reducing carrier interface recombination); below it is the N-type diffusion layer 16, which forms an N-type region on the surface of the crystalline silicon substrate by doping, forming part of the PN junction with the crystalline silicon substrate 9, providing a barrier for carrier separation; the core in the middle is the crystalline silicon substrate 9, which serves as the main light absorption region, absorbing photons and generating photogenerated carriers (electron-hole pairs); on the back side of the crystalline silicon substrate 9 (… Figure 4 On the lower middle side, firstly, there is a tunneling silicon oxide layer 17 (an extremely thin SiO2 layer that allows carrier tunneling while passivating the interface, significantly reducing recombination). On the tunneling silicon oxide layer 17, a P-type amorphous silicon layer 11 and an N-type amorphous silicon layer 12 are fabricated to form the doped region of the back contact, together with the tunneling silicon oxide layer 17, constituting a "tunneling oxide passivation contact" structure. Below the amorphous silicon region formed by the P-type and N-type amorphous silicon layers 11 is a second passivation layer 18 (in this embodiment, it can be a silicon nitride layer), which further passivates the back interface and provides insulating support for the electrode. The bottom layer is a metal electrode 2 (silver electrode), containing both a positive and negative electrode, which collects current through a back contact (no electrode obstruction on the front side, maximizing the light absorption area). The overall structure of this TBC battery 7 is centered on the "tunneling oxide passivation contact," combined with the back contact design and an amorphous silicon / crystalline silicon heterojunction, achieving efficient generation and collection of carriers.

[0100] In the multilayer film structure solar cell module prepared with the aforementioned TBC cell 7, as described above, again... Figure 4 As shown, a protective film layer 3 covers the bottommost metal electrode 2 (silver electrode) of the TBC battery 7, the surface of the solar cell containing the metal electrode 2, and the side surface of the TBC battery 7. This protective film layer 3 is deposited using a hot-wire chemical vapor deposition (HoFCVD) apparatus. The protective film layer 3 can be at least one of silicon nitride, silicon oxynitride, silicon oxide, and aluminum oxide films, preferably any one or a combination of any two of these films. This protective film layer 3 completely covers the entire area above the bottommost metal electrode 2 of the TBC battery 7 (covering both the main and sub-grid lines) and the entire side surface of the TBC battery 7. The thickness of the protective film layer 3 can be 5-200 nm, providing protection, reducing the battery's susceptibility to external environmental influences, and improving the battery's stability and performance. Of course, in cases where… Figure 4 In the structure of the solar cell module shown, after the protective film layer 3 is deposited, an opening 4 can be formed in the area where the bottommost metal electrode 2 is welded to the external circuit by laser drilling. Figure 4 (not shown in the image), and the external circuit is welded to the metal electrode 2 through the opening 4 to form a conductive path.

[0101] Example 4

[0102] The solar cells use composite passivated back contact (HPBC) cells.

[0103] like Figure 5 As shown in the figure, the structure of the HPBC cell 8 is as follows. The HPBC cell 8 has multiple functional layers (first passivation layer 14, tunneling silicon oxide layer 17, and N-type amorphous silicon layer 12). In the structure of the HPBC cell 8, from the light incident side to the back contact side (from top to bottom), the structure is as follows: the top layer is the first passivation layer 14 (in this embodiment, it is an aluminum oxide + silicon nitride composite layer), which has both surface passivation and anti-reflection effects, reducing light reflection and carrier interface recombination; below it is the crystalline silicon substrate 9, which serves as the core light absorption region, absorbing photons and generating photogenerated carriers; on the back side of the crystalline silicon substrate 9 (… Figure 5 On the lower middle side, firstly, there is a tunneling silicon oxide layer 17. This extremely thin oxide layer not only allows carriers to tunnel efficiently but also effectively passivates the silicon surface and significantly suppresses carrier recombination. An N-type amorphous silicon layer 12 covers the tunneling silicon oxide layer 17, forming a related structure with the crystalline silicon to aid in carrier separation and transport. A boron-doped aluminum back field 19 and an aluminum electrode 20 are also provided on the back side. The boron-doped aluminum back field enhances carrier collection capability, and the aluminum electrode is used to extract current. This HPBC cell 8 integrates the advantages of tunneling passivation contacts, heterojunctions, and back contact electrodes to achieve efficient carrier generation and collection.

[0104] In the multilayer film structure solar cell module prepared with the above-mentioned HPBC cell 8, as described again... Figure 5As shown, a protective film layer 3 covers the bottommost metal electrode 2 (silver electrode) of the HPBC battery 8, the surface of the solar cell containing the metal electrode 2, and the side surface of the HPBC battery. This protective film layer 3 is deposited using a hot-wire chemical vapor deposition (HoFCVD) apparatus. The protective film layer 3 can be at least one of silicon nitride, silicon oxynitride, silicon oxide, and aluminum oxide films, preferably any one or a combination of two of these films. This protective film layer 3 completely covers the entire area above the bottommost metal electrode 2 of the HPBC battery 8 (covering both the main and sub-grid lines) and the entire side surface of the HPBC battery 8. The thickness of the protective film layer 3 can be 5-200 nm, providing protection, reducing the battery's susceptibility to external environmental influences, and improving the battery's stability and performance. Of course, in cases where… Figure 5 In the structure of the solar cell module shown, after the protective film layer 3 is deposited, an opening 4 can be formed in the area where the bottommost metal electrode 2 is welded to the external circuit by laser drilling. Figure 5 (not shown in the image), and the external circuit is welded to the metal electrode 2 through the opening 4 to form a conductive path.

[0105] The overall process for fabricating the multilayer film structure solar cell modules in Examples 1-4 above is as follows: Figure 6 As shown.

[0106] Step S1: Place the completed screen-printed and sintered solar cell onto the carrier plate.

[0107] Step S2: The carrier plate is fed into the process chamber of the hot filament chemical vapor deposition equipment to deposit a protective film on the entire metal electrode of the solar cell and the entire surface of the solar cell on which the metal electrode is located, and to deposit a protective film on the entire side area of ​​the solar cell.

[0108] In step S2:

[0109] Depositing a protective film on the entire metal electrode and the entire surface of the solar cell containing the metal electrode involves placing the metal electrode of the solar cell on a carrier plate with the side containing the metal electrode facing the hot wire direction of the hot wire chemical vapor deposition equipment, and then feeding the carrier plate into the process chamber of the hot wire chemical vapor deposition equipment to deposit the protective film.

[0110] Depositing a protective film over the entire side surface of a solar cell includes:

[0111] The side coating generated during the deposition of the protective film on the surface of the metal electrode and the solar cell on which the metal electrode is located is used as the side protective film of the solar cell; or, solar cells on which the protective film has already been deposited on the surface of the metal electrode and the solar cell on which the metal electrode is located are stacked so that the side edges of the solar cells face the hot wire direction of the hot wire chemical vapor deposition equipment, and then the carrier is fed into the process chamber of the hot wire chemical vapor deposition equipment, and the side protective film is deposited using the same deposition gas and process parameters as the deposition of the protective film on the surface of the metal electrode and the solar cell on which the metal electrode is located.

[0112] In step S2, H2, SiH4, and O2, or H2, SiH4, and N2O, or H2, hexamethyldisilazane, and N2O are introduced into the process chamber to deposit a silicon oxide film; and / or H2, SiH4, and NH3, or H2, hexamethyldisilazane, and NH3 are introduced into the process chamber to deposit a silicon nitride film; and / or H2, SiH4, NH3, and O2, or H2, SiH4, NH3, and N2O, or H2, hexamethyldisilazane, NH3, and N2O are introduced into the process chamber to deposit a silicon oxynitride film; and / or H2, O2, and trimethylaluminum, or H2, N2O, and trimethylaluminum are introduced into the process chamber to deposit an alumina film. The hot wire in the process chamber is a tungsten wire, and the temperature is 1800-2100℃. The pressure is controlled at 1-2 Pa during film deposition in the process chamber, thus completing the selection and coating of the corresponding protective film.

[0113] Step S3: After the protective film layer is deposited, an opening is formed only in the area where the metal electrode is welded to the external circuit, and the external circuit is welded to the metal electrode through the opening to form a conductive path.

[0114] Therefore, as can be seen from the above embodiments 1-4 and the preparation method, the multilayer film structure solar cell module provided by this utility model can effectively isolate the external environment's moisture and ultraviolet light through the structure of the protective film layer, providing comprehensive protection for various types of solar cells. This effectively reduces irreversible power degradation of the battery module caused by moisture intrusion and ultraviolet radiation, improving the long-term reliability and service life of the battery module. In the embodiments of this utility model, the HoFCVD coating equipment is used for coating, which can achieve the preparation of the protective film layer within the range of room temperature to 200℃, avoiding damage to the amorphous silicon film layer and tunneling oxide layer of the solar cell caused by high temperatures. The multilayer film structure solar cell module of this utility model can be applied to HJT, HPBC, TBC, and HBC cells. Combining the HoFCVD equipment coating principle and the control of key equipment parameters, the mass industrial production and large-scale application of this protective film layer can be realized.

[0115] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to the process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0116] The above description is merely an embodiment of the present invention, which enables those skilled in the art to understand and implement the present invention. Various modifications to the embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments described herein, but is to be accorded the widest scope consistent with the principles and features disclosed herein.

Claims

1. A solar cell module of a multilayer film structure, characterized by, include: A solar cell, the solar cell comprising multiple functional film layers and a metal electrode located on the outermost functional film layer; A protective film layer completely covers the surface of the solar cell where the metal electrode is located, the metal electrode, and the side area of ​​the solar cell, and the protective film layer has openings only in the area where the metal electrode is soldered to the external circuit.

2. The solar cell module of claim 1, wherein, The protective film layer includes at least one of silicon nitride film layer, silicon oxynitride film layer, silicon oxide film layer and aluminum oxide film layer.

3. The solar cell module of claim 2, wherein, The protective film is any one of silicon nitride film, silicon oxynitride film, silicon oxide film, and aluminum oxide film.

4. The solar cell module of claim 2, wherein, The protective film is a combination of any two of the following: silicon nitride film, silicon oxynitride film, silicon oxide film, and aluminum oxide film.

5. The solar cell module of claim 2, wherein, A film layer made of any one of the following materials—silicon nitride, silicon oxynitride, silicon oxide, and aluminum oxide—comprising multiple sublayers of the same material.

6. The solar cell module of claim 1, wherein, The thickness of the protective film is 5-200 nm.

7. The solar cell module with a multilayer film structure according to claim 1, characterized in that, The solar cell includes any one of heterojunction cells, composite passivated back contact cells, tunnel oxide passivated back contact cells, and heterojunction back contact cells.

8. The solar cell module of the multilayer film structure according to claim 1, characterized in that, The metal electrode is made of silver, aluminum or copper.

9. The solar cell module of the multilayer film structure according to claim 1, characterized in that, The opening is formed by laser drilling.

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