Solar cell, battery pack and photovoltaic system
By setting a discontinuous protective layer in the isolation area, the problem of vulnerability of traditional isolation tank structures in photovoltaic cell production is solved, and higher production yield and battery performance are achieved.
Patent Information
- Application Number
- CN202422294532.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-20
- Publication Date
- 2025-08-01
- Estimated Expiration
- 2034-09-20
AI Technical Summary
The traditional isolation tank structure is susceptible to chemical and mechanical damage during the production process of photovoltaic cells, affecting the production yield and long-term stability of the battery.
A discontinuous protective layer is provided in the isolation area to cover some or all of the isolation areas, and a protective layer is formed by physical vapor deposition, sol-gel method or chemical solution corrosion method to prevent damage to the film layer in subsequent processes.
It improves the production yield and battery performance of solar cells, ensures film integrity, reduces waste rate, and improves photoelectric conversion efficiency.
Smart Images
Figure CN223182568U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of photovoltaics, and particularly relates to a solar cell, a battery pack and a photovoltaic system. Background Art
[0002] In the current production process of photovoltaic cells, PN junction isolation is a key process step, which directly affects the production quality and photoelectric conversion efficiency of the cells. In most cases, the isolation of the PN junction is achieved by laser preparation of isolation grooves.
[0003] However, the traditional isolation groove structure has the following significant problems: when the isolation groove is prepared by laser, the film layer at the bottom of the groove is completely exposed to the external environment. This exposed film layer is very susceptible to the influence of subsequent processes, especially during chemical cleaning or electrode preparation. Due to the direct exposure of the bottom film layer, it is extremely easy to be etched, resulting in a decline in the film layer quality. During the stacking and handling of the cells, the film layer exposed at the bottom of the isolation groove is prone to mechanical wear. Since the laser groove structure is relatively fragile, when the cell is transported, loaded or subjected to other mechanical operations in the production line, the exposed film layer is easily damaged due to friction. This not only affects the production yield but also has a negative impact on the long-term stability of the cell. Summary of the Utility Model
[0004] The utility model provides a solar cell, a battery pack and a photovoltaic system, aiming to solve the problem that the traditional isolation groove structure has a negative impact on the production yield and the long-term stability of the cell.
[0005] The utility model is implemented as follows. A solar cell includes:
[0006] A silicon substrate having a back surface and a front surface disposed opposite to each other. A first region, a second region and an isolation region are provided on the back surface of the silicon substrate, and the isolation region is disposed between the first region and the second region;
[0007] In the first region, it includes a first passivation layer, a P-type amorphous silicon layer and a first conductive film layer, the first conductive film layer is disposed on the outermost layer, and the P-type amorphous silicon layer is disposed on the second outermost layer;
[0008] In the second region, it includes a tunneling oxide layer, an N-type polysilicon layer and a second conductive film layer, the second conductive film layer is disposed on the outermost layer, and the N-type polysilicon layer is disposed on the second outermost layer;
[0009] In the isolation region, it includes a protective layer, the protective layer is disposed on the outermost layer, and the protective layer is a discontinuous structure.
[0010] Optionally, the area of the protective layer covering the isolation region accounts for 10% to 80% of the total area of the isolation region.
[0011] Optionally, the area of the isolation region covered by the protective layer accounts for 30% to 80% of the total area of the isolation region.
[0012] Optionally, the area of the isolation region covered by the protective layer accounts for 50% to 80% of the total area of the isolation region.
[0013] Optionally, the protective layer covers a part of the first conductive film layer close to the isolation region.
[0014] Optionally, the area of the first conductive film layer covered by the protective layer accounts for 10% to 20% of the total area of the first conductive film layer.
[0015] Optionally, the protective layer covers a part of the second conductive film layer close to the isolation region.
[0016] Optionally, the area of the second conductive film layer covered by the protective layer accounts for 10% to 50% of the total area of the second conductive film layer.
[0017] Optionally, the thickness of the protective layer is less than 1 μm.
[0018] The present utility model further provides a battery pack, including the above-mentioned solar cell.
[0019] The present utility model further provides a photovoltaic system, including the above-mentioned battery pack.
[0020] The beneficial effects achieved by the present utility model are as follows: Since the first region is a P-type region and the second region is an N-type region, an isolation region is provided between the first region and the second region to prevent current crosstalk between adjacent regions. The protective layer is provided on the outermost layer of the isolation region and plays a key role as a protective film layer during the manufacturing process of the solar cell, ensuring that subsequent processes do not cause physical or chemical damage to the film layer, thereby guaranteeing the film formation quality and ultimately achieving higher production yield and battery performance. Description of the Drawings
[0021] Figure 1 It is a schematic structural diagram of the solar cell provided by the present utility model.
[0022] Description of the Reference Numerals:
[0023] 100, solar cell; 110, first region; 111, first passivation layer; 112, P-type amorphous silicon layer; 113, first conductive film layer; 120, second region; 121, tunneling oxide layer; 122, N-type polysilicon layer; 123, second conductive film layer; 124, phosphosilicate glass layer; 130, isolation region; 131, protective layer; 140, second passivation layer; 150, antireflection layer. Detailed Embodiments
[0024] In order to make the objectives, technical solutions and advantages of the present utility model more clear and understandable, the present utility model will be further described in detail below in conjunction with the accompanying drawings and embodiments. The examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals denote the same or similar elements or elements with the same or similar functions from beginning to end. The embodiments described below by referring to the accompanying drawings are exemplary and are only used to explain the present utility model, and should not be construed as a limitation to the present utility model. In addition, it should be understood that the specific embodiments described herein are only used to explain the present utility model and are not used to limit the present utility model.
[0025] In the description of the present utility model, it should be understood that the orientation or positional relationship indicated by the terms "length", "width", "upper", "lower", "left", "right", "horizontal", "top", "bottom", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present utility model.
[0026] In addition, the terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of the said features. In the description of the present utility model, the meaning of "a plurality" is two or more unless otherwise specifically defined.
[0027] In the description of the present utility model, it should be noted that unless otherwise clearly specified and defined, the terms "installed", "connected" and "coupled" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection or an integral connection; it may be a mechanical connection, an electrical connection or a connection capable of mutual communication; it may be directly connected or indirectly connected through an intermediate medium, and it may be the internal communication of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.
[0028] In the present utility model, unless otherwise clearly specified and defined, the first feature being "above" or "below" the second feature may include the direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through additional features therebetween. Moreover, the first feature being "above", "over" and "on" the second feature includes that the first feature is directly above and obliquely above the second feature, or merely indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature being "below", "under" and "beneath" the second feature includes that the first feature is directly below and obliquely below the second feature, or merely indicates that the horizontal height of the first feature is lower than that of the second feature.
[0029] The following disclosure provides many different embodiments or examples for implementing different structures of the present utility model. To simplify the disclosure of the present utility model, the components and settings of specific examples are described below. Of course, they are merely examples and are not intended to limit the present utility model. In addition, the present utility model may repeat reference numerals and / or reference letters in different examples. Such repetition is for the purpose of simplification and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the present utility model provides examples of various specific processes and materials, but those of ordinary skill in the art can be aware of the application of other processes and / or the use of other materials.
[0030] The first region of the present utility model is a P-type region, the second region is an N-type region, and an isolation region is provided between the first region and the second region to prevent current crosstalk between adjacent regions. The protective layer is disposed on the outermost layer of the isolation region and plays a key role as a protective film layer during the manufacturing process of the solar cell, ensuring that subsequent processes do not cause physical or chemical damage to the film layer, thereby guaranteeing the film formation quality and ultimately achieving a higher production yield and battery performance.
[0031] Example 1
[0032] As Figure 1 shown, this embodiment provides a solar cell 100, including:
[0033] A silicon substrate, the silicon substrate having a back surface and a front surface disposed opposite to each other. A first region 110, a second region 120 and an isolation region 130 are disposed on the back surface of the silicon substrate, and the isolation region 130 is disposed between the first region 110 and the second region 120;
[0034] The first region 110 includes a first passivation layer 111, a P-type amorphous silicon layer 112 and a first conductive film layer 113. The first conductive film layer 113 is disposed on the outermost layer, and the P-type amorphous silicon layer 112 is disposed on the sub-outermost layer;
[0035] It includes a tunneling oxide layer 121, an N-type polysilicon layer 122 and a second conductive film layer 123 in the second region 120. The second conductive film layer 123 is placed on the outermost layer, and the N-type polysilicon layer 122 is placed on the second outermost layer;
[0036] It includes a protective layer 131 in the isolation region. The protective layer 131 is placed on the outermost layer and is a discontinuous structure.
[0037] For the solar cell 100 provided by this application, the "front" and "back" of the silicon substrate are relative. That is, the "front" refers to the side facing the sunlight along the vertical direction, and the "back" refers to the side facing away from the sunlight along the vertical direction.
[0038] The first region 110 and the second region 120 on the back of the silicon substrate are arranged alternately, and an isolation region 130 is arranged between the adjacent first region 110 and the second region 120. The first region 110 is provided with layers related to P-type materials, including: a first passivation layer 111, a P-type amorphous silicon layer 112 and a first conductive film layer 113. The first passivation layer 111 is used to reduce surface recombination and improve the battery efficiency. The P-type amorphous silicon layer 112 is used to provide P-type electrical properties and help charge separation. The first conductive film layer 113, as the outermost layer, is used for current collection and transmission.
[0039] The second region 120 is provided with layers related to N-type materials, including: a tunneling oxide layer 121, an N-type polysilicon layer 122 and a second conductive film layer 123. The tunneling oxide layer 121 is an oxide layer with a very thin thickness, usually used to enhance the tunneling effect of carriers. The N-type polysilicon layer 122 is used to provide N-type electrical properties. The second conductive film layer 123, as the outermost layer, is used for current collection and transmission. The P-type amorphous silicon layer 112, the silicon substrate and the N-type polysilicon layer 122 form a PN junction structure to realize the separation and collection process of photo-generated carriers of the solar cell 100.
[0040] It can be understood that the first conductive film layer 113 and the second conductive film layer 123 are light-transmitting film layers to avoid blocking the P-type amorphous silicon layer 112 and the N-type polysilicon layer 122 and affecting the absorption of sunlight.
[0041] The isolation region 130 is disposed between the first region 110 and the second region 120 to prevent current crosstalk between adjacent regions. A protective layer 131 is provided within the isolation region 130. The protective layer 131 is placed on the outermost layer and has a discontinuous structure. During the manufacturing process of the solar cell 100, especially when it comes to subsequent processing and treatment (such as photolithography, etching, or electrode deposition processes), the film layers on the silicon substrate are prone to being affected by mechanical stress. The protective layer 131 can act as a barrier to prevent the underlying film layers from being damaged or thinned due to friction or other mechanical contacts during these processes, maintaining the integrity and thickness consistency of the film layers, reducing the rejection rate caused by film layer failure or quality issues, greatly improving the production yield of the solar cell 100, and thus enhancing the overall production efficiency.
[0042] The protective layer 131 can be formed in the following ways: Physical Vapor Deposition (PVD), where the material is deposited on the substrate surface by evaporation or sputtering to form the protective layer 131; Sol-Gel method, where the protective layer 131 is formed by converting a liquid sol into a solid gel; Chemical Solution Etching method, where the original coating agent is chemically etched, and the remaining material after etching forms the protective layer 131.
[0043] Specifically, in the Chemical Solution Etching method, a third conductive film layer can be provided in the isolation region and connected to the first conductive film layer 113 and the second conductive film layer 123. The first conductive film layer 113, the second conductive film layer 123, and the third conductive film layer are formed simultaneously. A protective ink is printed to cover the first conductive film layer 113 and the second conductive film layer 123, and then chemically etched with a chemical solution. The chemical solution etches the third conductive film layer. At the same time, the protective ink on the first conductive film layer 113 and the second conductive film layer 123 diffuses towards the edge and combines with the remaining conductive film layer in the isolation region to form a discontinuous protective film.
[0044] In this embodiment, the first region 110 is a P-type region, the second region 120 is an N-type region. An isolation region is provided between the first region 110 and the second region 120 to prevent current crosstalk between adjacent regions. The protective layer 131 is provided on the outermost layer of the isolation region 130 and plays a key role as a protective film during the manufacturing process of the solar cell 100, ensuring that subsequent processes do not cause physical or chemical damage to the film layers, thus guaranteeing the film formation quality and ultimately achieving a higher production yield and battery performance.
[0045] In one embodiment, the second region 120 includes a first subregion and second subregions disposed on both sides of the first subregion. In the first subregion, a tunneling oxide layer 121, an N-type polysilicon layer 122, and a second conductive film layer 123 are sequentially stacked. In the second subregion, a tunneling oxide layer 121, an N-type polysilicon layer 122, a phosphosilicate glass layer 124, a first passivation layer 111, a P-type amorphous silicon layer 112, and a second conductive film layer 123 are sequentially stacked. A second passivation layer 140 and an anti-reflection layer 150 may also be sequentially stacked on the front side of the silicon substrate. The stacking arrangement in this embodiment refers to the positional relationship between the aforementioned layers, and does not exclude the possibility that other functional layers are disposed between the aforementioned layers.
[0046] Example 2
[0047] Based on the first embodiment, the area of the isolation region covered by the protection layer 131 accounts for 10% to 80% of the total area of the isolation region.
[0048] Partial coverage of the protective layer 131 can be used to address material deformation caused by thermal expansion or mechanical stress. Complete coverage may lead to the accumulation of thermal stress, while partial coverage allows the material to have a certain amount of free expansion space in a local area to avoid cracking or delamination. Partial coverage of the protective layer 131 can reduce the generation of parasitic capacitance effects or parasitic resistance. Complete coverage may increase additional capacitance effects, while by limiting the coverage area, the accumulation of capacitance can be reduced.
[0049] The protective layer 131 covers the isolation region 130 at a rate of 10% to 80%. By only partially covering the isolation region, sufficient protection can be provided while maintaining the region's other functionality. For example, the protective layer 131 coverage can be reduced in certain areas where electrical or optical conduction is required, without affecting the material's conductivity or light transmittance. This partially covered protective layer 131 design provides greater design flexibility for solar cells 100 and other advanced manufacturing processes, enabling fine-tuning based on the needs of different regions, achieving dual optimization of functionality and cost.
[0050] Example 3
[0051] Based on the second embodiment, the area of the isolation region covered by the protection layer 131 accounts for 30% to 80% of the total area of the isolation region.
[0052] An increase in the coverage ratio indicates a more significant need for protection in isolated areas. Compared to smaller coverage ratios, 30% to 80% coverage provides stronger protection while taking into account other functional needs.
[0053] Example 4
[0054] Based on Embodiment 3, the area of the protective layer 131 covering the isolation region accounts for 50% to 80% of the total area of the isolation region.
[0055] The coverage ratio of the protective layer 131 in the isolation region is further increased, which means that the protection strength for this region is enhanced. Large-area coverage can effectively prevent corrosion, mechanical damage, and chemical reactions in the external environment. While providing strong protection, the functionality of the remaining region is ensured. Compared with a lower coverage ratio, this coverage range is more suitable for application scenarios that require enhanced protection capabilities, resistance to environmental aggression, and extended service life.
[0056] Example 5
[0057] Based on Embodiment 1, the protective layer 131 covers a part of the first conductive film layer 113 close to the isolation region.
[0058] Covering the protective layer 131 on a part of the first conductive film layer 113 close to the isolation region realizes the protection of a partial area of the first conductive film layer 113. The conductive film layer is generally very thin and is prone to failure due to mechanical stress or frictional damage. By covering the protective layer 131 on the part close to the isolation region, the mechanical strength of these thin film layers can be significantly improved, reducing the damage caused by external physical impacts to them, and at the same time not overly affecting the performance of the entire device.
[0059] Example 6
[0060] Based on Embodiment 5, the area of the protective layer 131 covering the first conductive film layer 113 accounts for 10% to 20% of the total area of the first conductive film layer 113.
[0061] In a solar cell, the P-type amorphous silicon layer 112 is one of the core parts of the photovoltaic cell, responsible for absorbing photons and generating current. The P-type amorphous silicon layer 112 needs to be exposed to sunlight for efficient photoelectric conversion. If the coverage layer is too large, it will block the light from entering the P-type amorphous silicon layer 112, thereby reducing the photoelectric conversion efficiency. Therefore, controlling the coverage area of the protective layer 131 within the range of 10% to 20% can ensure that most of the light can penetrate to the silicon layer, minimizing the light blockage to the greatest extent and ensuring the conversion efficiency of the battery.
[0062] Example 7
[0063] Based on Embodiment 1, the protective layer 131 covers a part of the second conductive film layer 123 close to the isolation region.
[0064] In part of the second conductive film layer 123 near the isolation region, the protective layer 131 is covered to protect part of the region of the second conductive film layer 123. The conductive film layer is generally very thin and is prone to failure due to mechanical stress or frictional damage. By covering the protective layer 131 in part near the isolation region, the mechanical strength of these thin film layers can be significantly improved, reducing damage caused by external physical impacts to it, and at the same time not overly affecting the performance of the entire device.
[0065] Example 8
[0066] On the basis of Embodiment Five, the area of the second conductive film layer 123 covered by the protective layer 131 accounts for 10% to 50% of the total area of the second conductive film layer 123.
[0067] In a solar cell, the N-type polysilicon 122 layer is one of the core parts of the photovoltaic cell, responsible for absorbing photons and generating current. The N-type polysilicon 122 layer needs to be exposed to sunlight for efficient photoelectric conversion. If the covering layer is too large, it will block light from entering the N-type polysilicon 122 layer, thereby reducing the photoelectric conversion efficiency. Therefore, controlling the covering area of the protective layer 131 within the range of 10% to 50% can ensure that most of the light can penetrate to the silicon layer, minimizing the light blockage to the greatest extent and ensuring the conversion efficiency of the battery.
[0068] Example 9
[0069] On the basis of Embodiment One, the thickness of the protective layer 131 is less than 1 μm.
[0070] On the one hand, the relatively thin protective layer 131 can minimize the light blockage and ensure that light can effectively penetrate the protective layer 131 to the lower photosensitive layer (such as the P-type amorphous silicon layer 112), thereby improving the photoelectric conversion efficiency. The protective layer 131 with a thickness less than 1 μm ensures a high light transmittance and is suitable for devices such as photovoltaic cells that require light to pass through. On the other hand, the relatively thin protective layer 131 helps to reduce the generation of parasitic capacitance or parasitic resistance. Especially in high-frequency circuits and optoelectronic devices, this parasitic effect will affect the efficiency of current transmission. The thickness of the protective layer 131 less than 1 μm can avoid these problems and ensure the integrity of the electrical performance.
[0071] Example 10
[0072] This embodiment provides a battery pack, including the solar cell 100 of the above embodiment.
[0073] The beneficial effects of the battery pack in this embodiment are equivalent to those of the above solar cell 100 and will not be elaborated here.
[0074] Example 11
[0075] This embodiment provides a photovoltaic system, including the battery pack of the above embodiment.
[0076] The beneficial effects of the photovoltaic system in this embodiment are equivalent to those of the above solar battery pack, and will not be elaborated here.
[0077] The above are only the preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.
Claims
1. A solar cell, characterized in that, Comprising: A silicon substrate having a back surface and a front surface disposed opposite to each other. A first region, a second region, and an isolation region are provided on the back surface of the silicon substrate, and the isolation region is disposed between the first region and the second region; In the first region, a first passivation layer, a P-type amorphous silicon layer, and a first conductive film layer are included. The first conductive film layer is disposed on the outermost layer, and the P-type amorphous silicon layer is disposed on the second outermost layer; In the second region, a tunneling oxide layer, an N-type polysilicon layer, and a second conductive film layer are included. The second conductive film layer is disposed on the outermost layer, and the N-type polysilicon layer is disposed on the second outermost layer; In the isolation region, a protective layer is included. The protective layer is disposed on the outermost layer, and the protective layer is a discontinuous structure.
2. A solar cell according to claim 1, wherein The area of the isolation region covered by the protective layer accounts for 10% to 80% of the total area of the isolation region.
3. A solar cell according to claim 2, characterized in that, The area of the isolation region covered by the protective layer accounts for 30% to 80% of the total area of the isolation region.
4. A solar cell according to claim 3, characterized in that, The area of the isolation region covered by the protective layer accounts for 50% to 80% of the total area of the isolation region.
5. A solar cell according to claim 1, characterized in that, The protective layer covers a part of the first conductive film layer close to the isolation region.
6. A solar cell according to claim 5, characterized in that, The area of the first conductive film layer covered by the protective layer accounts for 10% to 20% of the total area of the first conductive film layer.
7. A solar cell according to claim 1 or 5, characterized in that, The protective layer covers a part of the second conductive film layer close to the isolation region.
8. A solar cell according to claim 7, characterized in that, The area of the second conductive film layer covered by the protective layer accounts for 10% to 50% of the total area of the second conductive film layer.
9. A solar cell according to claim 1, characterized in that, The thickness of the protective layer is less than 1 μm.
10. A battery pack, characterized in that, Including the solar cell according to any one of claims 1 to 9.
11. A photovoltaic system, characterized in that, Including the battery pack according to claim 10.