Photovoltaic cell and photovoltaic module

Abstract

The invention provides a photovoltaic cell and a photovoltaic module. The photovoltaic cell comprises a substrate, a doping layer, a passivation layer and an electrode layer, wherein the doping layer, the passivation layer and the electrode layer are sequentially stacked on the substrate. The electrode layer comprises a plurality of first grid lines arranged at intervals in the second direction and at least one bonding pad, each first grid line extends in the first direction, and each bonding pad is connected with at least one first grid line. Wherein the bonding pad comprises a first bottom metal layer, a first hollow area is formed on the first bottom metal layer, and the passivation layer is exposed out of the first hollow area. When the assembly is connected, the electric connecting piece can be connected with the bonding pad and the passivation layer exposed out of the first hollow area through the bonding layer, so that the contact area between the electric connecting piece and the photovoltaic cell is increased, the connecting strength between the electric connecting piece and the photovoltaic cell is improved, the pulling-out force between the electric connecting piece and the photovoltaic cell is further increased, and the reliability of the assembly is improved. Therefore, the abnormal phenomena of unsoldering, EL blackening and the like after the assembly is connected are avoided, and the reliability of the assembly in the using process is improved.

Description

Technical Field

[0001] The present application belongs to the field of photovoltaic cell manufacturing technology, and in particular, relates to a photovoltaic cell and a photovoltaic module. Background Art

[0002] At present, the mainstream metallization routes of crystalline silicon photovoltaic cells (also known as solar cells) include screen printing, electroplating, evaporation, etc. Among them, in the electroplating route, the bonding force between the electroplated grid line and the cell surface is poor, especially on the polished / quasi-polished surface, the adhesion of the electroplated grid line cannot meet the requirements of component welding. After the battery is serially soldered, desoldering, EL blackening and other abnormalities often occur due to the low connection strength between the soldering ribbon and the electroplated grid line, making it difficult for the electroplating metallization solution of photovoltaic cells to adapt to the production of photovoltaic modules. Summary of the invention

[0003] The present application provides a photovoltaic cell and a photovoltaic module to solve the technical problems of existing photovoltaic cells such as desoldering and EL blackening after battery string welding.

[0004] According to one aspect of the present application, a photovoltaic cell is provided, which includes a substrate and a doping layer, a passivation layer and an electrode layer stacked in sequence on the substrate. The electrode layer includes a plurality of first grid lines spaced apart along a second direction and at least one pad, each of the first grid lines extending along a first direction, and each of the pads connected to at least one of the first grid lines. The pad includes a first bottom metal layer at least partially passing through the passivation layer and connected to the doping layer. The first bottom metal layer is formed with a first hollow region, and the first hollow region exposes the passivation layer.

[0005] In an optional solution of the present application, the first hollow area includes a first sub-hollow area, and the first sub-hollow area extends to the edge of the pad to form an open structure.

[0006] In an optional solution of the present application, the first hollow area further includes a second sub-hollow area, and the second sub-hollow area is spaced apart from the edge of the pad to form a closed structure.

[0007] In an optional solution of the present application, each of the pads is connected to one of the first gate lines, and the first hollow area extends along the first direction to form a long strip structure.

[0008] In an optional solution of the present application, the length of the first hollow area is smaller than the width of the pad in the extension direction of the first hollow area.

[0009] In an optional solution of the present application, the electrode layer further includes a second gate line extending along the second direction, and at least one of the first gate lines is connected to the corresponding pad through the second gate line. The second gate line includes a second bottom metal layer, and the second bottom metal layer is formed with a second hollow area, and the second hollow area exposes the passivation layer.

[0010] In an optional solution of the present application, the first hollow area extends along the second direction to form a long strip structure.

[0011] In an optional solution of the present application, the second hollow area includes a third sub-hollow area, and the third sub-hollow area extends from the second gate line area to the pad area.

[0012] In an optional solution of the present application, the first bottom metal layer and the second bottom metal layer are made of the same material.

[0013] In an optional solution of the present application, the second hollow area extends along the second direction to form a long strip structure.

[0014] In an optional solution of the present application, the first hollow area and the second hollow area both extend along the second direction to form a long strip structure.

[0015] In an optional scheme of the present application, the passivation layer is provided with an opening, and at the edge of the opening, the passivation layer has a warped portion, the warped portion is connected to the inner wall of the opening and forms a gap with the doped layer, and a portion of the first bottom metal layer is located in the opening and the gap and is connected to the doped layer.

[0016] In an optional solution of the present application, the passivation layer is provided with an opening, the doping layer forms a pit at the edge of the opening, and part of the first bottom metal layer is located in the opening and the pit and is connected to the doping layer.

[0017] In an optional solution of the present application, the doping layer includes a plurality of first doping regions and a plurality of second doping regions. Along the thickness direction of the substrate, the plurality of first doping regions are respectively arranged corresponding to the plurality of first gate lines of the first polarity, and the plurality of second doping regions are respectively arranged corresponding to the plurality of first gate lines of the second polarity. The first doping region and the second doping region have different doping types, and the first polarity is opposite to the second polarity.

[0018] In an optional solution of the present application, the pad further includes a first upper metal layer located on a side of the first bottom metal layer away from the substrate, wherein the thickness of the first bottom metal layer is greater than the thickness of the passivation layer, and / or the thickness of the first bottom metal layer is less than the thickness of the first upper metal layer.

[0019] In an optional solution of the present application, the first upper metal layer covers the first bottom metal layer and exposes the passivation layer exposed in the first hollow area.

[0020] In an optional solution of the present application, the first upper metal layer covers the first bottom metal layer and covers the passivation layer exposed in the first hollow area.

[0021] According to another aspect of the present application, a photovoltaic assembly is provided, which includes an electrical connector, a bonding layer, and the photovoltaic cell described above, wherein the electrical connector is connected to the pad via the bonding layer.

[0022] In summary, the photovoltaic cell and photovoltaic module provided by the present application have at least the following beneficial effects:

[0023] In the present application, since the first bottom metal layer of the pad is formed with a first hollow area, and the passivation layer can be exposed through the first hollow area, when connecting the components between photovoltaic cells, the electrical connector can be connected to the pad and the passivation layer exposed in the first hollow area through the bonding layer, or connected to the first upper metal layer of the pad through the bonding layer, thereby realizing the connection between the photovoltaic cells. Since the electrical connector is connected to the pad of the photovoltaic cell and the passivation layer exposed in the first hollow area through the bonding layer, or connected to the first upper metal layer of the pad through the bonding layer, the contact area between the electrical connector and the photovoltaic cell is increased, the connection strength between the electrical connector and the photovoltaic cell is improved, and the pulling force between the electrical connector and the photovoltaic cell is increased, thereby avoiding abnormal phenomena such as desoldering and EL blackening after the component connection, and improving the reliability of the component during use. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the specific implementation of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific implementation or the prior art description. Obviously, the drawings described below are some implementations of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0025] Figure 1 A schematic diagram of the internal structure of a photovoltaic module provided in an embodiment of the present application;

[0026] Figure 2 A schematic diagram of a partial structure of an electrode layer of a photovoltaic cell provided in an embodiment of the present application;

[0027] Figure 3 A schematic diagram of a partial structure of an electrode layer of another photovoltaic cell provided in an embodiment of the present application;

[0028] Figure 4 For along Figure 2 Schematic diagram of the internal structure of the E1-E2 line section;

[0029] Figure 5 For along Figure 2 Schematic diagram of the internal structure of the F1-F2 line cut;

[0030] Figure 6 is a top view of a pad formed in an electrode layer;

[0031] Figure 7 for Figure 6 A partial enlarged view of the

[0032] Figure 8 is a side view of a pad formed in an electrode layer;

[0033] Fig. 9 is a side view of a second gate line formed in the electrode layer;

[0034] Fig.10 is a side view of a first gate line formed in an electrode layer;

[0035] Fig.11 A schematic diagram of a partial structure of an electrode layer of a photovoltaic cell provided in an embodiment of the present application;

[0036] Fig.12 For along Fig.11 Schematic diagram of the internal structure of the E1-E2 line section;

[0037] Fig.13 For along Fig.11 Schematic diagram of the internal structure of the F1-F2 line segmentation;

[0038] Fig.14 A schematic diagram of the internal structure of a photovoltaic cell at an opening in an embodiment of the present application;

[0039] Fig.15 A schematic diagram of the surface structure of a photovoltaic cell provided in an embodiment of the present application;

[0040] Fig.16 A schematic diagram of the surface structure of another photovoltaic cell provided in an embodiment of the present application;

[0041] Fig.17 A schematic diagram of the surface structure of another photovoltaic cell provided in an embodiment of the present application.

[0042] The reference numerals are as follows:

[0043] 1000. Photovoltaic modules;

[0044] 100. Photovoltaic cells;

[0045] 10. Base;

[0046] 20. doping layer; 21. first doping region; 22. second doping region; E. pit;

[0047] 30, passivation layer; 31, warping portion; C1, first opening; C2, second opening; C3, third opening; D, gap;

[0048] 40, electrode layer; 41, first gate line; 411, third bottom metal layer; 412, third upper metal layer; 42, pad; 421, first bottom metal layer; 422, first upper metal layer; A, first hollow area; A1, first sub-hollow area; A2, second sub-hollow area; 43, second gate line; 431, second bottom metal layer; 432, second upper metal layer; B, second hollow area;

[0049] L1, first direction; L2, second direction; H, thickness direction. DETAILED DESCRIPTION

[0050] In order to make the above and other features and advantages of the present application more clear, the present invention is further described below in conjunction with the accompanying drawings. It should be understood that the specific embodiments given herein are for the purpose of explaining to those skilled in the art and are only exemplary and not restrictive.

[0051] In the description of this application, if there is a feature defined as "first" or "second" for descriptive purposes only, it cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Features defined as "first" or "second" may explicitly or implicitly include at least one of the defined features. If the description of "plurality" appears, the general meaning is to include at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0052] In this application, unless otherwise clearly specified and limited, the terms such as "installed", "connected", "connected", "fixed" and so on should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection, it can be a direct connection, or it can be an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0053] In the description of the present application, if the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" appear, it means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0054] Figure 1 A schematic diagram of the internal structure of a photovoltaic module provided in an embodiment of the present application.

[0055] Reference Figure 1 The photovoltaic assembly 1000 provided in the embodiment of the present application includes a plurality of photovoltaic cells 100 , an electrical connector 200 and a bonding layer 300 .

[0056] Specifically, a plurality of photovoltaic cells 100 in a photovoltaic module can be connected in series to form a plurality of cell strings, and the plurality of cell strings can be connected in series, in parallel, or in a combination of series and parallel to achieve current convergence output. The plurality of photovoltaic cells 100 in each cell string are connected in series in sequence through an electrical connector 200 and a bonding layer 300 to form a cell string. The photovoltaic cell 100 in the present application can be a back contact cell or a double-sided cell.

[0057] It can be understood that the electrical connector 200 can be a welding strip, and the multiple photovoltaic cells 100 in each cell string are sequentially welded together through the welding strip and the bonding layer 300 to form a cell string. The cross-section of the electrical connector 200 can be circular, oval, rectangular or track-shaped, and its width can be 0.15-0.3 mm.

[0058] The bonding layer 300 can be a solder paste layer formed by solder paste or a conductive adhesive formed by conductive resin, which is arranged between the photovoltaic cell 100 and the electrical connector 200. The electrical connector 200 is connected to the photovoltaic cell 100 through the bonding layer 300, which can ensure the connection reliability between the photovoltaic cells 100.

[0059] Continue to refer to Figure 1 The photovoltaic cell 100 in the embodiment of the present application includes a substrate 10 and a doping layer 20 , a passivation layer 30 and an electrode layer 40 which are sequentially stacked on the substrate 10 .

[0060] The substrate 10 has a first surface and a second surface that are oppositely disposed along its thickness direction H. The doping layer 20, the passivation layer 30, and the electrode layer 40 may be sequentially stacked on the first surface or the second surface to form a back contact battery; or the doping layer 20, the passivation layer 30, and the electrode layer 40 may be sequentially stacked on the first surface and the second surface, respectively, to form a bifacial battery, and in the bifacial battery, the polarities of the electrode layers 40 on the first surface and the second surface are opposite.

[0061] Specifically, the substrate 10 in the present application can be a p-type silicon substrate, an n-type silicon substrate, or a silicon substrate close to the intrinsic conductivity type. The crystal type can be a single crystal or a polycrystalline, etc. The portion where the doped layer 20 is provided on the first surface or the second surface can select a polished surface structure composed of a plurality of pyramid bases (short prisms) or a velvet structure composed of a plurality of pyramids. It is more preferred to select a polished surface structure for opening, because the surface of the polished surface structure is flat, and the damage during laser opening is small, while if it is an uneven pyramid velvet structure, the damage is random and the damage is large.

[0062] Wherein, when the doping layer 20 is disposed on the first surface and the second surface of the substrate 10, the doping type of the doping layer 20 located on the first surface of the substrate 10 and the doping type of the doping layer 20 located on the second surface of the substrate 10 may be different, one of which is n-type doping and the other is p-type doping. When the doping layer 20 is disposed only on the first surface or the second surface of the substrate 10, the doping type of the portion of the doping layer 20 corresponding to the electrode layer 40 of different polarities may be different, one of which is n-type doping and the other is p-type doping.

[0063] Specifically, the doping layer 20 may be composed of one or more of monocrystalline silicon, polycrystalline silicon, amorphous silicon, and microcrystalline silicon. Specifically, the p-type doping layer is generally doped with group III elements, and the n-type doping layer is generally doped with group V elements or group VI elements.

[0064] The passivation layer 30 is disposed on the doping layer 20, and may be a single layer or a multi-layer structure, or may be composed of different materials in different regions. The material of the passivation layer 30 may include: one or more of silicon nitride, silicon oxide, silicon oxynitride, aluminum oxide, and silicon carbide.

[0065] Specifically, the passivation layer 30 is provided with an opening (or a hole), and the opening is used to receive at least a portion of the electrode layer 40 so that the electrode layer 40 can be in electrical contact with the doping layer 20 .

[0066] The electrode layer 40 is disposed on the passivation layer 30, and at least a portion of the electrode layer 40 passes through the passivation layer 30 and is connected to the doping layer 20 to collect and conduct current from the doping layer 20. The electrode layer 40 includes an electrode layer of a first polarity and an electrode layer of a second polarity, and the first polarity is opposite to the second polarity.

[0067] Figure 2 A schematic diagram of a partial structure of an electrode layer of a photovoltaic cell provided in an embodiment of the present application, Figure 3 A schematic diagram of the partial structure of an electrode layer of another photovoltaic cell provided in an embodiment of the present application.

[0068] Reference Figure 2 and Figure 3 For the electrode layer 40 of any polarity, the electrode layer 40 includes a plurality of first gate lines 41 spaced apart along the second direction L2 and at least one pad 42 . The first gate lines 41 extend along the first direction L1 , and the pad 42 is connected to at least one first gate line 41 .

[0069] The pad 42 includes a first bottom metal layer 421 that at least partially passes through the passivation layer 30 and is connected to the doping layer 20, and the first bottom metal layer 421 is formed with a first hollow area A, and the first hollow area A exposes the passivation layer 30. The connection between the pad 42 and the first gate line 41 can be a direct physical connection or an indirect electrical connection. For example, in some embodiments, the pad 42 may not be directly connected to the first gate line 41, and may be connected to the first gate line 41 through, for example, other gate lines or electrical connections.

[0070] At least a portion of the bonding layer 300 is disposed on the pad 42 , and the electrical connector 200 is connected to the pad 42 through the bonding layer 300 to achieve connection between the photovoltaic cells 100 .

[0071] In this embodiment, since the pad 42 includes a first bottom metal layer 421 that at least partially passes through the passivation layer 30 and is connected to the doping layer 20, and the first bottom metal layer 421 is formed with a first hollow area A that can expose the passivation layer 30, when the components between the photovoltaic cells 100 are connected, the electrical connector 200 can be connected to the first bottom metal layer 421 of the pad 42 and the passivation layer 30 exposed in the first hollow area A through the bonding layer 300, thereby realizing the connection between the photovoltaic cells 100. Since the electrical connector 200 is connected to the first bottom metal layer 421 of the pad 42 of the photovoltaic cell 100 and the passivation layer 30 exposed in the first hollow area A through the bonding layer 300, the contact area between the electrical connector 200 and the photovoltaic cell 100 is increased, and the connection strength between the electrical connector 200 and the photovoltaic cell 100 is improved, thereby increasing the pulling force between the electrical connector 200 and the photovoltaic cell 100, thereby avoiding abnormal phenomena such as desoldering and EL blackening after the components are connected, and improving the reliability of the components during use.

[0072] Specifically, the first hollow area A on the first bottom metal layer 421 of the pad 42 may include a first sub-hollow area A1 and / or a second sub-hollow area A2. The first sub-hollow area A1 and the second sub-hollow area A2 are two different forms of hollow structures. Based on different manufacturing process requirements and / or usage requirements of the photovoltaic cell 100, only the first sub-hollow area A1 or only the second sub-hollow area A2 may be provided on the pad 42, or the first sub-hollow area A1 and the second sub-hollow area A2 may be provided on the pad 42 at the same time, and the first sub-hollow area A1 and the second sub-hollow area A2 are provided at intervals.

[0073] The first sub-hollow region A1 extends to the edge of the first bottom metal layer 421 of the pad 42 to form an open structure, and the second sub-hollow region A2 is spaced from the edge of the first bottom metal layer 421 of the pad 42 to form a closed structure. In other words, the first sub-hollow region A1 has a notch at one end in its extension direction, while the second sub-hollow region A2 does not have an end notch.

[0074] In this embodiment, no matter what structural form the first hollow area A is, the contact area between the electrical connector 200 and the photovoltaic cell 100 can be increased, thereby improving the connection strength between the electrical connector 200 and the photovoltaic cell 100, and further increasing the pull-off force between the electrical connector 200 and the photovoltaic cell 100. In particular, when the two structural forms of the hollow areas are used in combination, the pull-off force between the electrical connector 200 and the photovoltaic cell 100 can be significantly increased.

[0075] In addition, the number of the first sub-hollow area A1 and / or the second sub-hollow area A2 can be set according to demand. The first sub-hollow area A1 or the second sub-hollow area A2 can be set to one or more, and this application does not make specific limitations.

[0076] In order to further increase the contact area between the electrical connector 200 and the photovoltaic cell 100 , the first hollow area A may extend along the first direction L1 or along the second direction L2 to form a long strip structure.

[0077] It can be understood that when the first hollow area A includes the first sub-hollow area A1, the first sub-hollow area A1 can extend along the first direction L1 or along the second direction L2 to form a long strip structure. When the first hollow area A includes the second sub-hollow area A2, the top view of the second sub-hollow area A2 can be a water drop shape, an arc shape, a cloud shape, a circle or a long strip, etc., and its size (including diameter, length, and width) is smaller than the length of the first sub-hollow area A1.

[0078] In the case where the first hollow area A includes both the first sub-hollow area A1 and the second sub-hollow area A2, the first sub-hollow area A1 and the second sub-hollow area A2 can both be formed into a long strip structure, and the two extend in the same direction. Of course, the first sub-hollow area A1 of the first sub-hollow area A1 and the second sub-hollow area A2 can also be formed into a long strip structure, while the second sub-hollow area A2 can be formed into other shapes, such as a water drop shape, an arc shape, a cloud shape, a circle, etc., which is not specifically limited in this application.

[0079] However, no matter in which direction the first hollow area A (i.e., the first sub-hollow area A1 and / or the second sub-hollow area A2) extends, the length of the first hollow area A in the extension direction is less than the width of the first bottom metal layer 421 of the pad 42 in the extension direction of the first hollow area A. In this way, the point transmission failure caused by the open circuit of the first bottom metal layer 421 of the pad 42 can be prevented. This is because, if the length of the first hollow area A is equal to the width of the first bottom metal layer 421 of the pad 42 in the extension direction, the first bottom metal layer 421 of the pad 42 may be isolated to form an independent area (i.e., a disconnected area), which is not conducive to the uniform transmission of current and may cause a open circuit, thereby causing a point transmission failure.

[0080] Preferably, the length of the first hollow area A in the extension direction thereof is 4 / 5-1 / 10 of the width of the first bottom metal layer 421 of the pad 42 in the extension direction of the first hollow area A. For example, the length of the first hollow area A may be 1 / 10, 1 / 5, 3 / 10, 2 / 5, 1 / 2, 3 / 5, 7 / 10, 4 / 5, etc. of the width of the first bottom metal layer 421 of the pad 42.

[0081] By setting the length of the first hollow area A within the above range, the contact area between the electrical connector 200 and the photovoltaic cell 100 can be increased while ensuring the stability of current transmission, thereby further increasing the pulling force between the electrical connector 200 and the photovoltaic cell 100.

[0082] In some embodiments, the size of the pad 42 in the first direction L1 is any value between 20um-3000um, the size of the pad 42 in the second direction L2 is any value between 20um-3000um, and the size of the first gate line 41 in the second direction L2 is any value between 1um-50um, which can be determined according to specific needs.

[0083] In some embodiments, the first hollow area A is formed into a long strip structure, and the length of the first hollow area A is 0.1um-3000um and the width is 10μm-50μm.

[0084] Continue to refer to Figure 2The electrode layer 40 may further include a second gate line 43 extending along the second direction L2, at least one first gate line 41 is connected to the corresponding pad 42 through the second gate line 43, each second gate line 43 is used to connect the corresponding other first gate lines 41 that are not directly connected to the pad 42 to the pad 42, and the electrical connection member 200 is connected to multiple first gate lines 41 of the same polarity via the pad 42 and the second gate line 43 to collect and conduct the current on the doping layer 20. The second gate line 43 includes a second bottom metal layer 431, and the second bottom metal layer 431 is formed with a second hollow area B, and the second hollow area B exposes the passivation layer 30.

[0085] Among them, part of the bonding layer 300 is arranged on the pad 42 and part of it is arranged on the second gate line 43. The electrical connector 200 is connected to the pad 42, the passivation layer 30 exposed in the first hollow area A and the passivation layer 30 exposed in the second hollow area B through the bonding layer 300 at different positions to achieve connection between the photovoltaic cells 100.

[0086] In this embodiment, since the first bottom metal layer 421 of the pad 42 forms a first hollow area A, the second bottom metal layer 431 of the second gate line 43 forms a second hollow area B, and the passivation layer 30 can be exposed through the first hollow area A and the second hollow area B, when the components between the photovoltaic cells 100 are connected, the electrical connector 200 can be connected to the pad 42, the passivation layer 30 exposed in the first hollow area A, and the passivation layer 30 exposed in the second hollow area B through the bonding layer 300, thereby realizing the connection between the photovoltaic cells 100. Since the electrical connector 200 is connected to the solder pad 42 of the photovoltaic cell 100, the passivation layer 30 exposed in the first hollow area A, and the passivation layer 30 exposed in the second hollow area B through the bonding layer 300, the contact area between the electrical connector 200 and the photovoltaic cell 100 is further increased, and the connection strength between the electrical connector 200 and the photovoltaic cell 100 is improved, thereby increasing the pulling force between the electrical connector 200 and the photovoltaic cell 100, thereby avoiding abnormal phenomena such as desoldering and EL blackening after the components are connected, and improving the reliability of the components during use.

[0087] Continue to refer to Figure 2 , the second hollow area B on the second bottom metal layer 431 of the second grid line 43 includes a third sub-hollow area B1 and / or a fourth sub-hollow area B2. The third sub-hollow area B1 and the fourth sub-hollow area B2 are two different forms of hollow structures. Based on different manufacturing process requirements and / or usage requirements of the photovoltaic cell 100, only the third sub-hollow area B1 or only the fourth sub-hollow area B2 may be provided on the second bottom metal layer 431 of the second grid line 43, or the third sub-hollow area B1 and the fourth sub-hollow area B2 may be provided on the second grid line 43 at the same time, and the third sub-hollow area B1 and the fourth sub-hollow area B2 are provided at intervals.

[0088] The third sub-hollow region B1 extends from the second bottom metal layer 431 of the second gate line 43 to the pad 42, and is interconnected with the first sub-hollow region A1 to form a closed structure. The fourth sub-hollow region B2 is spaced from the edge of the second gate line 43 to form a closed structure.

[0089] In this embodiment, no matter what structural form the second hollow area B on the second grid line 43 is, the contact area between the electrical connector 200 and the photovoltaic cell 100 can be increased, thereby improving the connection strength between the electrical connector 200 and the photovoltaic cell 100, and further increasing the pull-off force between the electrical connector 200 and the photovoltaic cell 100. In particular, when the second grid line 43 has both of the above two structural forms of hollow areas, it can significantly increase the pull-off force between the electrical connector 200 and the photovoltaic cell 100.

[0090] Moreover, based on the closed hollow structure formed by the third sub-hollow area B1 and the first sub-hollow area A1, the overall length of the hollow area is significantly extended, which helps to further increase the contact area between the electrical connector 200 and the photovoltaic cell 100, thereby improving the connection strength between the electrical connector 200 and the photovoltaic cell 100, and further increasing the pulling force between the electrical connector 200 and the photovoltaic cell 100.

[0091] In addition, the number of the third sub-hollow area B1 and / or the fourth sub-hollow area B2 can be set according to demand. The third sub-hollow area B1 or the fourth sub-hollow area B2 can be set to one or more, which is not specifically limited in this application.

[0092] In order to further increase the contact area between the electrical connector 200 and the photovoltaic cell 100 , the second hollow area B may extend along the first direction L1 or along the second direction L2 to form a long strip structure.

[0093] It can be understood that when the second hollow area B includes the third sub-hollow area B1, the third sub-hollow area B1 can extend along the first direction L1 or along the second direction L2 to form a long strip structure. When the second hollow area B includes the fourth sub-hollow area B2, the fourth sub-hollow area B2 can extend along the first direction L1 or along the second direction L2 to form a long strip structure.

[0094] In the case where the second hollow area B includes both the third sub-hollow area B1 and the fourth sub-hollow area B2, both the third sub-hollow area B1 and the fourth sub-hollow area B2 can be formed into a strip-shaped structure, and the extension directions of the two can be the same or different. Of course, one of the third sub-hollow area B1 and the fourth sub-hollow area B2 can be formed into a strip-shaped structure, and the other can be formed into a structure of other shapes, such as a water drop shape, an arc shape, a cloud shape, a circle, etc., which is not specifically limited in this application.

[0095] However, no matter in which direction the second hollow area B (i.e., the third sub-hollow area B1 and / or the fourth sub-hollow area B2) extends, the length of the second hollow area B in the extension direction thereof is less than the width of the second bottom metal layer 431 of the second grid line 43 in the extension direction of the second hollow area B. In this way, the point transmission failure caused by the disconnection of the second bottom metal layer 431 of the second grid line 43 can be prevented. This is because, if the length of the second hollow area B is equal to the width of the second bottom metal layer 431 of the second grid line 43 in the extension direction of the second hollow area B, the second bottom metal layer 431 of the second grid line 43 may be isolated to form an independent area (i.e., a disconnected area), which is not conducive to the uniform transmission of current and may cause disconnection, thereby causing point transmission failure.

[0096] Preferably, the length of the second hollow area B in the extension direction thereof is 4 / 5-1 / 10 of the width of the second bottom metal layer 431 of the second gate line 43 in the extension direction of the second hollow area B. For example, the length of the second hollow area B may be 1 / 10, 1 / 5, 3 / 10, 2 / 5, 1 / 2, 3 / 5, 7 / 10, 4 / 5, etc. of the width of the second bottom metal layer 431 of the second gate line 43.

[0097] By setting the length of the second hollow area B within the above range, the contact area between the electrical connector 200 and the photovoltaic cell 100 can be increased while ensuring the stability of current transmission, thereby further increasing the pull-off force between the electrical connector 200 and the photovoltaic cell 100.

[0098] In some embodiments, the second hollow area B is formed into a long strip structure, and the length of the second hollow area B in its extension direction is 0.1-3000 um and the width is 10-50 μm.

[0099] In a specific embodiment, if Figure 2 As shown, the photovoltaic cell 100 in the embodiment of the present application includes a first gate line 41, a pad 42 and a second gate line 43. The first hollow area A on the first underlying metal layer 421 of the pad 42 can extend along the first direction L1 or along the second direction L2 to form a long strip structure, and the second hollow area B on the second underlying metal layer 431 of the second gate line 43 can also extend along the first direction L1 or the second direction L2 to form a long strip structure.

[0100] In this embodiment, in order to adapt to the forming process (i.e., metallization process) of the electrode layer 40, preferably, the second hollow area B extends along the second direction L2, and the first hollow area A on the first bottom metal layer 421 of the pad 42 also extends along the second direction L2. In this way, during the forming process of the electrode layer 40, it is convenient to form the pad 42 along the direction of the second gate line 43, which helps to improve the forming efficiency of the electrode layer 40.

[0101] In another specific embodiment, referring to Figure 3 The photovoltaic cell 100 in the embodiment of the present application includes a first grid line 41 and a pad 42, but a second grid line 43 is not provided. At this time, each first grid line 41 in the electrode layer 40 is directly connected to a corresponding pad 42, and the electrical connector 200 is connected to multiple first grid lines 41 of the same polarity via the pad 42 to realize the collection and conduction of the current on the doping layer 20.

[0102] In this embodiment, in order to adapt to the forming process (i.e., metallization process) of the electrode layer 40, preferably, the first hollow area A on the first bottom metal layer 421 of the pad 42 extends along the first direction L1 (i.e., extends along the extending direction of the first gate line 41) to form a long strip structure. In this way, during the forming process of the electrode layer 40, it is convenient to form the pad 42 along the direction of the first gate line 41, which helps to improve the forming efficiency of the electrode layer 40.

[0103] In some embodiments, in order to adapt to the forming process of the electrode layer 40 , the first gate line 41 includes a third bottom metal layer 411 , and the third bottom metal layer 411 is connected to the first bottom metal layer 421 and the second bottom metal layer 431 as a whole.

[0104] Figure 4 For along Figure 2 Schematic diagram of the internal structure of the E1-E2 line segmentation, Figure 5 For along Figure 2 Schematic diagram of the internal structure divided by the F1-F2 line.

[0105] Reference Figure 4 and Figure 5, the passivation layer 30 in the embodiment of the present application is provided with an opening. Wherein, corresponding openings are formed in different areas of the passivation layer 30, respectively. Specifically, the passivation layer 30 has an area corresponding to the pad 42 (referred to as the pad area), an area corresponding to the first gate line 41 (referred to as the fine gate area), and an area corresponding to the second gate line 43 (referred to as the main gate area), that is, the pad area, the fine gate area, and the main gate area of ​​the passivation layer 30 are all provided with corresponding openings. Wherein, the opening on the pad area is referred to as the first opening C1, and a portion of the first bottom metal layer 421 of the pad 42 is located in the first opening C1 and connected to the doped layer 20; the opening on the main gate area is referred to as the second opening C2, and a portion of the second bottom metal layer 431 of the second gate line 43 is located in the second opening C2 and connected to the doped layer 20; the opening on the fine gate area is referred to as the third opening C3, and a portion of the third bottom metal layer 411 of the first gate line 41 is located in the third opening C3 and connected to the doped layer 20.

[0106] Further references Figure 2 , Figure 4 and Figure 5 The pad 42 further includes a first upper metal layer 422 (not shown) located on the side of the first bottom metal layer 421 away from the substrate 10. The first upper metal layer 422 covers the first bottom metal layer 421 and exposes the passivation layer 30 exposed in the first hollow area A. Specifically, the first bottom metal layer 421 and the first upper metal layer 422 of the pad 42 can be formed by a plating process such as electroplating or chemical plating.

[0107] With such an arrangement, when the components between the photovoltaic cells 100 are connected, part of the bonding layer 300 is located on the first upper metal layer 422 of the pad 42, and part of it is located in the hollow area where the passivation layer 30 can be exposed. The electrical connector 200 is connected to the first upper metal layer 422 of the pad 42 and the exposed passivation layer 30 through the bonding layer 300, which increases the contact area between the electrical connector 200 and the photovoltaic cell 100, improves the connection strength between the electrical connector 200 and the photovoltaic cell 100, and further increases the pulling force between the electrical connector 200 and the photovoltaic cell 100, thereby avoiding abnormal phenomena such as desoldering and EL blackening after the components are connected, and improving the reliability of the components during use.

[0108] In addition, in order to adapt the forming process (ie, metallization process) of the electrode layer 40, refer to Figure 4 The second gate line 43 further includes a second upper metal layer 432 located on the side of the second bottom metal layer 431 away from the substrate 10, and the second upper metal layer 432 covers the second bottom metal layer 431 and exposes the passivation layer 30 exposed in the second hollow area B. Figure 5 The first gate line 41 further includes a third upper metal layer 412 located on a side of the third bottom metal layer 411 facing away from the substrate 10 .

[0109] Figure 6 is a top view of the pad formed in the electrode layer, Figure 7 for Figure 6 A partial enlarged view of Figure 8 is a side view of a pad formed in an electrode layer; Fig. 9 is a side view of a second gate line formed in the electrode layer; Fig.10 FIG. 4 is a side view of a first gate line formed in an electrode layer.

[0110] A first opening C1 can be formed in the pad area of ​​the passivation layer 30 by opening the film, and a pad 42 is formed at the first opening C1 by a plating (electroplating or chemical plating) process or a printing process. The metal material forming the pad 42 does not completely occupy the entire pad area, but forms a first hollow area A (i.e., a first sub-hollow area A1 and / or a second sub-hollow area A2), and the first hollow area A exposes the passivation layer 30, such as Figure 2 , Figures 6 to 8 shown.

[0111] A second opening C2 can be formed in the main gate region of the passivation layer 30 by opening the film, and a continuous second gate line 43 is formed at the second opening C2 by a plating (electroplating or chemical plating) process or a printing process, and the metal material forming the second gate line 43 does not completely occupy the entire main gate region to form a second hollow area B (i.e., the third sub-hollow area B1 and / or the fourth sub-hollow area B2), and the second hollow area B exposes the passivation layer 30, such as Figure 2 and Fig. 9 shown.

[0112] A third opening C3 may be formed in the fine gate region of the passivation layer 30 by opening the film, and a first gate line 41 may be formed at the third opening C3 by a plating (electroplating or chemical plating) process or a printing process. The metal material forming the first gate line 41 completely fills the entire fine gate region and forms a continuous first gate line 41, and no hollow region is formed thereon. Figure 2 and Fig.10 shown.

[0113] In addition, it can be foreseen that the first gate line 41 in the present application is a fine gate structure, and the first gate line 41 is responsible for charge collection and conductive transmission. The first gate line 41 can be formed using the same formation process as the pad 42 and the second gate line 43, or different formation processes can be used. Preferably, the second bottom metal layer 431 of the second gate line 43, the third bottom metal layer 411 of the first gate line 41, and the first bottom metal layer 421 of the pad 42 are formed using the same formation process and at the same time, such as using any one or a combination of metallization methods such as electroplating, chemical plating or screen printing to form.

[0114] Fig.11A schematic diagram of a partial structure of an electrode layer of a photovoltaic cell provided in an embodiment of the present application, Fig.12 For along Fig.11 Schematic diagram of the internal structure of the E1-E2 line segmentation, Fig.13 For along Fig.11 Schematic diagram of the internal structure divided by the F1-F2 line.

[0115] Reference Figures 11 to 13 The pad 42 further includes a first upper metal layer 422 located on the side of the first bottom metal layer 421 away from the substrate 10. The first upper metal layer 422 covers the first bottom metal layer 421 and covers the passivation layer 30 exposed in the first hollow area A. Specifically, the first bottom metal layer 421 of the pad 42 can be formed by an electroplating process, and the first upper metal layer 422 can be formed by a screen printing process.

[0116] With such arrangement, when the components between the photovoltaic cells 100 are connected, the bonding layer 300 is located on the first upper metal layer 422 of the pad 42, and the electrical connector 200 is connected to the first upper metal layer 422 of the pad 42 through the bonding layer 300, a portion of the first upper metal layer 422 is connected to the first bottom metal layer 421, and a portion is connected to the exposed passivation layer 30 through the first hollow area A, which increases the contact area between the electrical connector 200 and the photovoltaic cell 100, improves the connection strength between the electrical connector 200 and the photovoltaic cell 100, and further increases the pull-off force between the electrical connector 200 and the photovoltaic cell 100, thereby avoiding abnormal phenomena such as desoldering and EL blackening after the components are connected, and improving the reliability of the components during use.

[0117] In addition, in order to adapt the forming process (ie, metallization process) of the electrode layer 40, refer to Fig.12 The second gate line 43 further includes a second upper metal layer 432 located on the side of the second bottom metal layer 431 away from the substrate 10. The second upper metal layer 432 covers the second bottom metal layer 431 and covers the passivation layer 30 exposed in the second hollow area B. Fig.13 The first gate line 41 further includes a third upper metal layer 412 located on a side of the third bottom metal layer 411 facing away from the substrate 10 .

[0118] exist Figure 2 and Fig.11In the illustrated embodiment, the thickness of the first bottom metal layer 421 of the pad 42 is greater than the thickness of the passivation layer 30, so that the blocking effect of the first bottom metal layer 421 can be ensured. The first bottom metal layer 421 is often formed by processes such as electroplating, and can be a thin layer or a multi-layer structure. The material selected is a metal material such as nickel and titanium. The thickness of the first bottom metal layer 421 of the pad 42 is less than the thickness of the first upper metal layer 422. Among them, the material of the first upper metal layer 422 can be selected from metal materials such as copper, silver, and aluminum, which is mainly used for the purpose of transmitting current. In addition, in order to increase the protective effect, a metal layer can be covered on the first upper metal layer as the outermost protective layer.

[0119] Further, similar to the pad 42, the thickness of the second bottom metal layer 431 of the second gate line 43 is greater than the thickness of the passivation layer 30, the thickness of the third bottom metal layer 411 is greater than the thickness of the passivation layer 30, the thickness of the second bottom metal layer 431 of the second gate line 43 is less than the thickness of the second upper metal layer 432, and the thickness of the third bottom metal layer 411 is less than the thickness of the third upper metal layer 412.

[0120] Preferably, the third bottom metal layer 411 is integrally formed with the first bottom metal layer 421 and the second bottom metal layer 431 using the same material and having the same thickness, and the third upper metal layer 412 is integrally formed with the second upper metal layer 432 and the first upper metal layer 422 using the same material and having the same thickness.

[0121] Fig.14 Schematic diagram of the internal structure of the photovoltaic cell at the opening in the embodiment of the present application.

[0122] Reference Fig.11 At the edge of the opening (any one of the first opening C1, the second opening C2 and the third opening C3 mentioned above), the passivation layer 30 has a warping portion 31, the warping portion 31 is connected to the inner wall of the opening and forms a gap D with the doping layer 20, and a portion of the electrode layer 40 is located in the opening and the gap D and is connected to the doping layer 20. Since a portion of the electrode layer 40 can be embedded in the gap D between the warping portion 31 and the doping layer 20 and the opening on the passivation layer 30, it is helpful to increase the pull-off force between the electrode layer 40 and the passivation layer 30 and the doping layer 20.

[0123] Continue to refer to Fig.14, at the edge of the opening (any one of the first opening C1, the second opening C2 and the third opening C3 mentioned above), the surface of the doping layer 20 facing the passivation layer 30 may be concave to form a pit E, and part of the electrode layer 40 is located in the opening and the pit E, and is connected to the doping layer 20. Since part of the electrode layer 40 may be embedded in the pit E on the doping layer 20 and the opening on the passivation layer 30, it is helpful to increase the pull-off force between the electrode layer 40 and the passivation layer 30 and the doping layer 20. Furthermore, the pit E on the doping layer 20 may also be set at a position corresponding to the warping portion 31 of the doping layer 20 and the passivation layer 30. At this time, based on the gap D formed by the warping portion 31 and the doping layer 20 and the pit E on the doping layer 20, the pull-off force between the electrode layer 40 and the passivation layer 30 and the doping layer 20 is further increased.

[0124] Specifically, at the edge of the first opening C1, part of the first underlying metal layer 421 of the pad 42 is embedded in the gap D between the warping portion 31 and the doping layer 20, the pit E, and the first opening C1 on the passivation layer 30. At the edge of the second opening C2, part of the second underlying metal layer 431 of the second gate line 43 is embedded in the gap D between the warping portion 31 and the doping layer 20, the pit E, and the second opening C2 on the passivation layer 30. At the edge of the third opening C3, part of the third underlying metal layer 411 of the first gate line 41 is embedded in the gap D between the warping portion 31 and the doping layer 20, the pit E, and the third opening C3 on the passivation layer 30.

[0125] Fig.15 A schematic diagram of the surface structure of a photovoltaic cell provided in an embodiment of the present application, Fig.16 A schematic diagram of the surface structure of another photovoltaic cell provided in an embodiment of the present application, Fig.17 A schematic diagram of the surface structure of another photovoltaic cell provided in an embodiment of the present application.

[0126] Reference Figures 15 to 17 , the doping layer 20 of the photovoltaic cell 100 includes a plurality of first doping regions 21 and a plurality of second doping regions 22. Wherein, along the thickness direction H of the substrate 10, the plurality of first doping regions 21 are respectively arranged corresponding to the plurality of first grid lines 41 of the first polarity, and the plurality of second doping regions 22 are respectively arranged corresponding to the plurality of first grid lines 41 of the second polarity. That is to say, each first doping region 21 is arranged between the substrate 10 and a corresponding first grid line 41 of the first polarity, and each second doping region 22 is arranged between the substrate 10 and a corresponding first grid line 41 of the second polarity. Wherein, the doping types of the first doping region 21 and the second doping region 22 are different, one of which is n-type doping and the other is p-type doping. The polarity of the first polarity is opposite to that of the second polarity.

[0127] Reference Fig.15The photovoltaic cell 100 in the embodiment of the present application is a back contact cell, a plurality of first doping regions 21 and a plurality of second doping regions 22 are arranged alternately and spaced in sequence along the second direction L2, and a first grid line 41 of a first polarity (which may be referred to as a fine grid) and a first grid line 41 of a second polarity are arranged alternately and spaced in sequence along the second direction L2. The photovoltaic cell 100 is not provided with a second grid line 43 (which may be referred to as a main grid).

[0128] Since the photovoltaic cell 100 does not have the second grid line 43, the photovoltaic cell 100 can also be called a busbar-less cell. That is, in the busbar-less cell, the first hollow area A is provided on the pad 42 to increase the pulling force between the electrical connector 200 and the photovoltaic cell 100, while the first grid line 41 is not provided with a hollow area.

[0129] Reference Fig.16 The photovoltaic cell 100 in the embodiment of the present application is a back contact cell, a plurality of first doping regions 21 and a plurality of second doping regions 22 are arranged alternately and spaced in sequence along the second direction L2, and a first grid line 41 (which may be referred to as a fine grid) of a first polarity and a first grid line 41 of a second polarity are arranged alternately and spaced in sequence along the second direction L2. The photovoltaic cell 100 is provided with a second grid line 43 (which may be referred to as a main grid), a plurality of first grid lines 41 of a first polarity and a second grid line 43 of a first polarity connected thereto form an interdigitated structure together, and a plurality of first grid lines 41 of a second polarity and a second grid line 43 of a second polarity connected thereto form an interdigitated structure together.

[0130] Since the photovoltaic cell 100 has the second grid line 43, the photovoltaic cell 100 can also be called a busbar cell. That is, in the busbar cell, the pad 42 is provided with a first hollow area A, and the second grid line 43 may be provided with a second hollow area B or may not be provided with the second hollow area B. Preferably, the second grid line 43 is provided with the second hollow area B to increase the pulling force between the electrical connector 200 and the photovoltaic cell 100.

[0131] Reference Fig.17 The photovoltaic cell 100 in the embodiment of the present application is a bifacial cell, a plurality of first doping regions 21 and a plurality of second doping regions 22 are respectively arranged on the first surface and the second surface of the substrate 10, a first grid line 41 of the first polarity (which may be referred to as a fine grid) and a first grid line 41 of the second polarity are respectively arranged on the first surface and the second surface of the substrate 10. The photovoltaic cell 100 is provided with a second grid line 43 (which may be referred to as a main grid), a plurality of first grid lines 41 of the first polarity are connected together by a second grid line 43 of the first polarity, and a plurality of first grid lines 41 of the second polarity are connected together by a second grid line 43 of the second polarity.

[0132] In the bifacial cell, the pad 42 is provided with a first hollow region A, and the second grid line 43 may or may not be provided with a second hollow region B. Preferably, the second grid line 43 is provided with a second hollow region B to increase the pulling force between the electrical connector 200 and the photovoltaic cell 100.

[0133] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Those skilled in the art can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A photovoltaic cell (100), characterized in that: It comprises a substrate (10), and a doping layer (20), a passivation layer (30), and an electrode layer (40) which are sequentially stacked on the substrate (10); The electrode layer (40) comprises a plurality of first gate lines (41) arranged at intervals along a second direction (L2) and at least one pad (42), wherein the first gate lines (41) extend along a first direction (L1), and the pad (42) is connected to at least one of the first gate lines (41); the pad (42) comprises a first bottom metal layer (421) that at least partially passes through the passivation layer (30) and is connected to the doping layer (20); The first bottom metal layer (421) is formed with a first hollow area (A), and the first hollow area (A) exposes the passivation layer (30).

2. The photovoltaic cell (100) according to claim 1, characterized in that: The first hollow area (A) includes a first sub-hollow area (A1), and the first sub-hollow area (A1) extends to the edge of the pad (42) to form an open structure.

3. The photovoltaic cell (100) according to claim 2, characterized in that: The first hollow area (A) further includes a second sub-hollow area (A2), and the second sub-hollow area (A2) is spaced apart from the edge of the pad (42) to form a closed structure.

4. The photovoltaic cell (100) according to any one of claims 1 to 3, characterized in that: Each of the pads (42) is connected to one of the first gate lines (41), and the first hollow area (A) extends along the first direction (L1) to form a long strip structure.

5. The photovoltaic cell (100) according to any one of claims 1 to 3, characterized in that: The length of the first hollow area (A) is smaller than the width of the pad (42) in the extension direction of the first hollow area (A).

6. The photovoltaic cell (100) according to any one of claims 1 to 3, characterized in that: The electrode layer (40) further comprises a second gate line (43) extending along the second direction (L2), and at least one of the first gate lines (41) is connected to the corresponding pad (42) via the second gate line (43); The second gate line (43) comprises a second bottom metal layer (431), the second bottom metal layer (431) is formed with a second hollow area (B), and the second hollow area (B) exposes the passivation layer (30).

7. The photovoltaic cell (100) according to claim 6, characterized in that: The first hollow area (A) extends along the second direction (L2) to form a long strip structure.

8. The photovoltaic cell (100) according to claim 6, characterized in that: The second hollow area (B) includes a third sub-hollow area (B1), and the third sub-hollow area (B1) extends from the second gate line (43) area to the pad (42) area.

9. The photovoltaic cell (100) according to claim 6, characterized in that: The first bottom metal layer (421) and the second bottom metal layer (431) are made of the same material; and / or, The second hollow area (B) extends along the second direction (L2) to form a long strip structure; and / or, The first hollow area (A) and the second hollow area (B) both extend along the second direction (L2).

10. The photovoltaic cell (100) according to claim 1, characterized in that: The passivation layer (30) is provided with an opening (C); At the edge of the opening (C), the passivation layer (30) has a warping portion (31), the warping portion (31) is connected to the inner wall of the opening (C) and forms a gap (D) with the doping layer (20), and a portion of the first bottom metal layer (421) is located in the opening (C) and the gap (D) and is connected to the doping layer (20); and / or, At the edge of the opening (C), the doping layer (20) forms a pit (E), and a portion of the first bottom metal layer (421) is located in the opening (C) and the pit (E) and is connected to the doping layer (20).

11. The photovoltaic cell (100) according to claim 1, characterized in that: The doping layer (20) comprises a plurality of first doping regions (21) and a plurality of second doping regions (22), Along the thickness direction (H) of the substrate (10), a plurality of the first doping regions (21) are respectively arranged corresponding to a plurality of the first gate lines (41) of a first polarity, and a plurality of the second doping regions (22) are respectively arranged corresponding to a plurality of the first gate lines (41) of a second polarity; The first doping region (21) and the second doping region (22) have different doping types, and the first polarity is opposite to the second polarity.

12. The photovoltaic cell (100) according to claim 1, characterized in that: The pad (42) further comprises a first upper metal layer (422) located on a side of the first bottom metal layer (421) away from the substrate; Wherein, the thickness of the first bottom metal layer (421) is greater than the thickness of the passivation layer (30), and / or the thickness of the first bottom metal layer (421) is less than the thickness of the first upper metal layer (422).

13. The photovoltaic cell (100) according to claim 12, characterized in that: The first upper metal layer (422) covers the first lower metal layer (421) and exposes the passivation layer (30) exposed in the first hollow area (A).

14. The photovoltaic cell (100) according to claim 12, characterized in that: The first upper metal layer (422) covers the first lower metal layer (421) and covers the passivation layer (30) exposed in the first hollow area (A).

15. A photovoltaic module, characterized in that: It comprises an electrical connector (200), a bonding layer (300), and a photovoltaic cell (100) according to any one of claims 1 to 14, wherein the electrical connector (200) is connected to the pad (42) through the bonding layer (300).

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