Solar cell and photovoltaic module

Abstract

The invention discloses a solar cell and a photovoltaic module, and the solar cell comprises a cell body which comprises a first surface and a second surface which are opposite to each other; the passivation layer is at least arranged on the first surface, and a plurality of holes penetrating through the thickness of the passivation layer are formed in the passivation layer; the seed layer comprises a part corresponding to the open hole and an extension part extending from the open hole to one side, far away from the battery body, of the passivation layer; the ratio of the width of the extension part along the first direction to the thickness of the extension part along the thickness direction of the battery body is 0.5-10; the first direction is parallel to the first surface. According to the present invention, the sufficient adhesion between the seed layer and the cell body can be ensured, the falling risk can be reduced, the moderate contact area between the seed layer and the electrode can be ensured, and the contact resistance between the seed layer and the electrode can be small.

Description

Technical Field

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

[0002] Solar cells are now being used more and more widely as a new energy alternative. Among them, photovoltaic solar cells are devices that convert sunlight into electrical energy. Specifically, solar cells use the photovoltaic principle to generate carriers, and then use electrodes to lead the carriers out, thereby facilitating the effective use of electrical energy.

[0003] As the photovoltaic industry's market and production capacity continue to expand, the industry's demand for silver paste has also surged, and the price of silver paste has risen accordingly. Costs continue to rise, squeezing profit margins. Summary of the invention

[0004] The purpose of the present application is to provide a solar cell and a photovoltaic module, so as to reduce the manufacturing cost of the solar cell while improving the adhesion of the electrode and preventing the electrode from falling off.

[0005] In order to achieve the above objectives, this application provides the following technical solutions:

[0006] A solar cell, comprising:

[0007] The battery body comprises a first surface and a second surface which are arranged opposite to each other;

[0008] A passivation layer is provided at least on the first surface, and the passivation layer has openings extending through the thickness thereof;

[0009] The seed layer includes a portion arranged corresponding to the opening, and an extension portion extending from the opening to a side of the passivation layer away from the battery body; wherein the ratio of the width of the extension portion along the first direction to the thickness of the extension portion along the thickness direction of the battery body is 0.5 to 10; and the first direction is parallel to the first surface.

[0010] If the width of the extended part is small, and the thickness of the extended part is much larger than the width, the adhesion of the seed layer to the battery body cannot be guaranteed, and it is easy to fall off; when the width of the extended part is much larger than the thickness, the thickness of the extended part is too small, and the width of the extended part is much larger than the thickness, which will increase the contact resistance between the seed layer and the electrode. In view of the above situation, this technical solution controls the width and thickness of the extended part within the range of 0.5 to 10, which can ensure sufficient adhesion between the seed layer and the battery body and reduce the risk of falling off, while also ensuring that the contact area between the seed layer and the electrode is moderate and the contact resistance between the seed layer and the electrode is small.

[0011] In one implementation, the width of the extension portion along the first direction is less than the thickness of the extension portion along the thickness direction of the battery body. In this way, the thickness of the extension portion along the thickness direction of the battery body is slightly greater than the width of the extension portion along the first direction, and the relatively thick seed layer at the opening can better block water, oxygen and other elements from entering the battery body, reducing the erosion or damage of other elements to the battery body. In addition, the contact area between the extension portion and the electrode in the thickness direction of the battery body can be appropriately increased, that is, the contact area between the side of the extension portion and the electrode is increased, the contact area between the seed layer and the electrode is further increased, the contact resistance between the seed layer and the electrode is reduced, and the current loss is reduced.

[0012] In one implementation, the ratio of the width of the extension portion along the first direction to the thickness of the extension portion along the thickness direction of the battery body is 0.5 to 1. In this way, the thickness of the extension portion along the thickness direction of the battery body is slightly greater than the width of the extension portion along the first direction, which can reduce the erosion or damage of the battery body by other elements.

[0013] In one implementation, the width of the extension portion along the first direction is greater than the thickness of the extension portion along the thickness direction of the battery body. In this case, the seed layer can be formed by chemical plating. This arrangement makes the width of the extension portion along the first direction larger, which can increase the area of ​​the upper surface of the seed layer, thereby increasing the contact area between the upper surface of the seed layer and the electrode, improving the adhesion between the upper surface of the seed layer and the electrode, and further reducing the risk of electrode detachment; at the same time, the contact resistance between the upper surface of the seed layer and the electrode is reduced, reducing current loss.

[0014] In one implementation, the ratio of the width of the extension portion along the first direction to the thickness of the extension portion along the thickness direction of the battery body is 1 to 10. This arrangement can increase the contact area between the upper surface of the seed layer and the electrode, improve the adhesion between the upper surface of the seed layer and the electrode, and further reduce the risk of electrode detachment; it can also reduce the contact resistance between the upper surface of the seed layer and the electrode, and reduce current loss.

[0015] In one implementation, the seed layer fills the opening, and the extension portion protrudes from the opening. In this way, the extension portion surrounds the opening, which is more conducive to processing and manufacturing.

[0016] In one implementation, along the length direction or the width direction of the battery body, the width of the extension portion located on the first side of the opening is greater than the width of the extension portion located on the second side.

[0017] In one implementation, the thickness of the extension part is 60nm to 1200nm along the thickness direction of the battery body; to prevent the thickness h of the extension part from being too thick, which will lead to a prolonged process time, ensure that the upper surface area of ​​the seed layer is moderate, and thus ensure sufficient adhesion of the seed layer to the battery body, and prevent the thickness h of the extension part from being too small, which will lead to too small contact area between the side of the extension part and the electrode, which will increase the contact resistance between the seed layer and the electrode. And / or,

[0018] Along the first direction, the width of the extension part is 60nm to 1200nm, so as to prevent the width b of the extension part from being too small, thereby ensuring sufficient adhesion of the seed layer to the battery body and reducing the contact resistance between the seed layer and the electrode; and to prevent the width b of the extension part from being too wide, resulting in material waste.

[0019] In one implementation, along the first direction, the ratio of the width of the extension portion to the maximum width of the orthographic projection of the seed layer on the first surface is 0.05-0.2. This technical solution can avoid the extension portion being too wide, resulting in material waste; at the same time, it ensures a large contact area between the seed layer and the electrode, thereby ensuring sufficient adhesion of the seed layer to the battery body.

[0020] In one implementation, along the thickness direction of the battery body, the ratio of the thickness of the extension portion to the thickness of the seed layer at the corresponding opening is 50%-96%. This arrangement can prevent the thickness h of the extension portion from being too small, resulting in too small a contact area between the side of the extension portion and the electrode, which would increase the contact resistance between the seed layer and the electrode.

[0021] In one implementation, the thickness of the passivation layer is 60 nm to 180 nm along the thickness direction of the battery body, which can ensure the passivation effect and prevent the process time from being prolonged.

[0022] In one implementation, the battery body includes a semiconductor substrate, a first doped semiconductor layer, and a second doped semiconductor layer, wherein the first doped semiconductor layer is disposed on a first surface of the semiconductor substrate, and the second doped semiconductor layer is disposed on a first surface or a second surface of the semiconductor substrate, and the first doped semiconductor layer and the second doped semiconductor layer have opposite conductivity types;

[0023] The passivation layer covers the first doped semiconductor layer and the second doped semiconductor layer on a side away from the semiconductor substrate, the passivation layer is provided with a first opening corresponding to the first doped semiconductor layer and a second opening corresponding to the second doped semiconductor, and along the first direction, the equivalent width of the first opening is different from the equivalent width of the second opening;

[0024] The number of the first openings is multiple and arranged along the second direction, the number of the second openings is multiple and arranged along the second direction, and the first direction and the second direction intersect;

[0025] Wherein, the equivalent width is the ratio of the area of ​​the first opening to the spacing between two adjacent first openings, or the ratio of the area of ​​the second opening to the spacing between two adjacent second openings. In this way, the contact resistance between the doped semiconductor layer with lower conductivity and the seed layer is equal to or closer to the contact resistance between the doped semiconductor layer with higher conductivity and the seed layer, thereby reducing the current difference between the seed layer and the second doped semiconductor layer and between the seed layer and the first doped semiconductor layer, reducing the current loss of the battery, and ensuring the performance of the battery. In addition, after the battery body is pretreated, the plating activity of the first opening and the second opening is different, so the equivalent width of the first opening is different from the equivalent width of the second opening, so that the equivalent width of the opening with lower plating activity is wider, thereby reducing the difficulty of plating.

[0026] In one implementation, the second doped semiconductor layer is a P-type doped semiconductor layer; along the first direction, the equivalent width of the first opening is smaller than the equivalent width of the second opening; in this way, when the conductivity of the first doped semiconductor layer is greater than the conductivity of the second doped semiconductor layer, it is ensured that the contact resistance between the second doped semiconductor layer with smaller conductivity and the electrode is equal to or closer to the contact resistance between the first doped semiconductor layer with larger conductivity and the electrode, thereby reducing the current difference between the electrode and the second doped semiconductor layer and between the electrode and the first doped semiconductor layer, thereby reducing the current loss of the battery.

[0027] And / or, along the first direction, the equivalent width of the first opening is 3μm to 20μm; this makes the equivalent width of the first opening more matched with the conductivity of the first doped semiconductor, reduces the contact resistance between the first doped semiconductor and the electrode, and reduces current loss; at the same time, it avoids damage to the battery during the laser opening process and reduces recombination.

[0028] And / or, along the first direction, the equivalent width of the second opening is 5 μm to 30 μm. This makes the equivalent width of the second opening more compatible with the conductivity of the second doped semiconductor, reduces the contact resistance between the second doped semiconductor and the electrode, and reduces current loss; at the same time, it avoids easy damage to the battery during the laser opening process and reduces recombination.

[0029] In one implementation, the total area of ​​the first opening is different from the total area of ​​the second opening. In order to make the contact area between the doped semiconductor layer with lower conductivity and the seed layer larger, in some examples, the equivalent width of the opening of the doped semiconductor layer with lower conductivity can be set larger, thereby making the contact resistance between the doped semiconductor layer with lower conductivity and the electrode equal to or closer to the contact resistance between the doped semiconductor layer with higher conductivity and the electrode, thereby reducing the current difference between the electrode and the second doped semiconductor layer and between the electrode and the first doped semiconductor layer, reducing the current loss of the battery, and ensuring the performance of the battery.

[0030] In one implementation, the battery body includes a semiconductor substrate, a first doped semiconductor layer and a second doped semiconductor layer, the first doped semiconductor layer is arranged on the first surface of the semiconductor substrate, the second doped semiconductor layer is arranged on the first surface or the second surface of the semiconductor substrate, and the first doped semiconductor layer and the second doped semiconductor layer have opposite conductivity types; a passivation layer covers the first doped semiconductor layer and the second doped semiconductor layer on a side away from the semiconductor substrate, and the passivation layer is provided with a first opening corresponding to the first doped semiconductor layer and a second opening corresponding to the second doped semiconductor;

[0031] The seed layer includes a first seed layer and a second seed layer, the first seed layer includes a portion arranged corresponding to the first opening, and a first extension portion extending from the first opening to a side of the passivation layer away from the battery body; the second seed layer includes a portion arranged corresponding to the second opening, and a second extension portion extending from the second opening to a side of the passivation layer away from the battery body;

[0032] Along the first direction, a width of the first extending portion and a width of the second extending portion are different.

[0033] In one implementation, the solar cell further includes an electrode disposed on a side of the seed layer facing away from the cell body, and the electrode covers at least a portion of a surface of the seed layer facing away from the cell body.

[0034] In one implementation, the electrode covers the surface and side of the seed layer facing away from the battery body, so that the contact area between the electrode and the seed layer is maximized, further reducing the contact resistance between the electrode and the seed layer, and improving the efficiency of the solar cell.

[0035] And / or, the width of the electrode is 40 μm to 200 μm. By adopting this technical solution, the electrode is set within a reasonable range of 40 μm to 200 μm, which can prevent the electrode from being too wide, causing the electrode to contact with the doped semiconductor layer of opposite polarity and leak electricity, and at the same time prevent the electrode from being too small, ensuring that the contact resistance between the electrode and the seed layer is small.

[0036] In one implementation, the edge thickness of the extended portion gradually decreases from the center of the opening to the edge, thereby making the contact between the seed layer and the electrode more secure and further reducing the risk of falling off.

[0037] A photovoltaic module comprises any one of the solar cells described above.

[0038] Compared with the prior art, the beneficial effects of the photovoltaic module provided by the present application can be analyzed with reference to the beneficial effects of solar cells, which will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0040] Figure 1 A schematic diagram of a photovoltaic module provided in an embodiment of the present application;

[0041] Figure 2 A cross-sectional view of a battery body provided in an embodiment of the present application;

[0042] Figure 3 A partial cross-sectional view of a solar cell provided in an embodiment of the present application;

[0043] Figure 4 A local enlarged view of the edge of the seed layer provided in an embodiment of the present application;

[0044] Figure 5 This is a SEM image of the extended portion of the seed layer provided in an embodiment of the present application.

[0045] Reference numerals:

[0046] 1-battery body, 2-passivation layer, 3-opening, 4-seed layer, 41-extension part, 5-electrode. DETAILED DESCRIPTION

[0047] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0048] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0049] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, "multiple" means two or more, unless otherwise clearly and specifically defined. "Several" means one or more, unless otherwise clearly and specifically defined.

[0050] In the description of the present application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", etc., indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present application.

[0051] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0052] The present application embodiment provides a photovoltaic module, which includes a plurality of solar cells, and the plurality of solar cells are electrically connected in series and / or in parallel. For example, Figure 1 A schematic diagram of a plurality of solar cells electrically connected together is provided. Figure 1 As shown, multiple solar cells are arranged in sequence along direction A to form a battery string, and multiple solar cells in the battery string are connected in series in sequence. Two or more battery strings are arranged in sequence along direction A to form a group of battery strings, and multiple groups of battery strings are arranged in sequence along direction B.

[0053] In the process of manufacturing solar cells, high-temperature silver paste is generally used to form silver electrodes by screen printing. Compared with low-temperature silver paste, the silver paste used for high-temperature sintering is more expensive. At the same time, as the price of silver paste increases, the production cost of solar cells continues to increase. In addition, in some solar cell structures, the electrode needs to pass through the passivation layer 2 through sintering to contact the doped semiconductor layer, resulting in the contact area between the electrode and the doped semiconductor layer being limited, the contact area is small, and the contact resistance between the electrode 5 and the doped semiconductor layer is large.

[0054] In view of the above situation, in order to reduce the manufacturing cost of solar cells, the present application also provides a solar cell, which can be applied to the above photovoltaic module.

[0055] like Figure 2 and Figure 3As shown, the solar cell provided in the embodiment of the present application includes a cell body 1, a passivation layer 2 and a seed layer 4. The cell body 1 includes a first surface and a second surface that are arranged opposite to each other, that is, the two surfaces opposite to each other along the thickness direction of the cell body 1 are the first surface and the second surface respectively. The first surface may correspond to the light-facing surface of the solar cell, and the second surface may correspond to the backlight surface of the solar cell; or the first surface may correspond to the backlight surface of the solar cell, and the second surface may correspond to the light-facing surface of the solar cell.

[0056] Specifically, the battery body 1 may include a semiconductor substrate, a first doped semiconductor layer and a second doped semiconductor layer, and the opposite two side surfaces of the semiconductor substrate correspond to the first surface and the second surface respectively. The first doped semiconductor layer and the second doped semiconductor layer have opposite conductivity types, so as to collect and extract electrons and holes respectively, which is conducive to the formation of photocurrent. In the case where the solar cell is a back contact cell, the first doped semiconductor layer and the second doped semiconductor layer are both located on the first surface, and there is an electrical isolation structure between the first doped semiconductor layer and the second doped semiconductor layer. At this time, the first doped semiconductor layer and the second doped semiconductor layer may be alternately distributed along the first direction on the first surface. In the case where the solar cell is a bifacial cell, the first doped semiconductor layer is located on the first surface, and the second doped semiconductor layer is located on the second surface. At this time, the first doped semiconductor layer may be arranged as a whole layer on the first surface, or may be arranged partially, for example, the first doped semiconductor layer may be arranged in a strip shape on the first surface; the second doped semiconductor layer may be arranged as a whole layer on the second surface, or may be arranged partially, for example, the second doped semiconductor layer may be arranged in a strip shape on the second surface.

[0057] The passivation layer 2 is at least provided on the first surface. Specifically, the passivation layer 2 may be provided only on the first surface, or both on the first surface and the second surface. In addition, the passivation layer 2 is provided with an opening 3 that penetrates the thickness thereof, and the opening 3 is provided corresponding to the first doped semiconductor layer or the second doped semiconductor layer.

[0058] In some embodiments, the seed layer 4 includes a portion disposed at the opening 3 corresponding to the opening 3, and an extension portion 41 extending from the opening 3 to the side of the passivation layer 2 away from the battery body 1. Specifically, the extension portion 41 may be disposed around the opening 3, and may be continuously disposed from the portion corresponding to the opening 3 to the extension portion 41 to ensure electrical conductivity between the portion of the seed layer 4 corresponding to the opening 3 and the extension portion 41. The first direction is parallel to the first surface, and may be any direction parallel to the first surface.

[0059] By adopting the above technical solution, a seed layer 4 is first formed in the opening 3 of the passivation layer 2, and then an electrode 5 is formed on the seed layer 4. In this way, the seed layer 4 can be made of a variety of metals, for example, one or more of Al, Zn, Fe, Co, Mg, Cu, Ag, Ni and their alloys. Among them, the electrode 5 can also be made of a variety of metals, such as one or more of Cu, Ni, Cr, Ti, W, Mo, Ag, Sn and their alloys. The material of the electrode 5 can be the same as or different from that of the seed layer 4. The electrode 5 formed is as follows: Figure 4 As shown. Compared with the prior art, in which silver paste burns through the passivation layer 2 to form a silver electrode as a whole, the material forming the electrode no longer needs to pass through the opening 3, thereby reducing the amount of silver paste required for the overall electrode structure of the solar cell, and reducing the production cost of the overall electrode structure. In addition, in the process of making the seed layer 4 and the electrode 5 of the above-mentioned metal, a low-temperature process can be used. Specifically, the seed layer 4 can be formed by electroplating or chemical plating deposition, and the electrode 5 can be formed by electroplating or screen printing, which reduces the difficulty of production, saves energy consumption, and can further reduce production costs.

[0060] It should be noted that after the opening 3 is formed in the passivation layer 2, the opening 3 area can be pretreated to improve the activity of the surface of the battery body 1, and then the seed layer 4 is formed by electroplating or chemical plating deposition, so that the bottom of the seed layer 4 forms a good contact with the battery body 1.

[0061] Among them, Figure 3 As shown, the ratio of the width of the extension portion 41 along the first direction to the thickness of the extension portion 41 along the thickness direction of the battery body 1 is 0.5 to 10, that is, the width of the extension portion 41 along the first direction is b, the thickness of the extension portion 41 along the thickness direction of the battery body 1 is h, and b / h is in the range of 0.5 to 10. The thickness of the extension portion 41 refers to the average thickness of the extension portion 41, or the thickness of the extension portion 41 refers to the thickness of the thickest position of the extension portion 41.

[0062] It can be understood that if the width of the extension part 41 is small, and the thickness of the extension part 41 is much larger than the width, the adhesion of the seed layer 4 to the battery body 1 cannot be guaranteed, and it is easy to fall off; when the width of the extension part 41 is much larger than the thickness, the thickness of the extension part 41 is too small, which increases the contact resistance between the seed layer 4 and the electrode 5. In view of the above situation, the technical solution controls the width and thickness of the extension part 41 within the range of 0.5 to 10, which can ensure sufficient adhesion between the seed layer 4 and the battery body 1 and reduce the risk of falling off, and at the same time ensure that the contact area between the seed layer 4 and the electrode 5 is moderate, and the contact resistance between the seed layer 4 and the electrode 5 is small.

[0063] Illustratively, the ratio of the width of the extension portion 41 along the first direction to the thickness of the extension portion 41 along the thickness direction of the battery body 1 is 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5 or 10, etc.

[0064] In some embodiments, the width of the extension portion 41 along the first direction is less than the thickness of the extension portion 41 along the thickness direction of the battery body 1, that is, b / h is less than 1. In this case, the seed layer 4 can be formed by electroplating and / or chemical plating. In this way, the thickness of the extension portion 41 along the thickness direction of the battery body 1 is slightly greater than the width of the extension portion 41 along the first direction. The relatively thick seed layer 4 at the opening 3 can better block water, oxygen and other elements from entering the battery body 1, thereby reducing the erosion or damage of the battery body 1 by other elements. In addition, the contact area between the extension portion 41 and the electrode 5 in the thickness direction of the battery body 1 can be appropriately increased, that is, the contact area between the side of the extension portion 41 and the electrode 5 is increased, so as to further increase the contact area between the seed layer 4 and the electrode 5, reduce the contact resistance between the seed layer 4 and the electrode 5, and reduce the current loss.

[0065] In some embodiments, the ratio of the width of the extension portion 41 along the first direction to the thickness of the extension portion 41 along the thickness direction of the battery body 1 is 0.5 to 1, that is, b / h is in the range of 0.5 to 1. In this way, the thickness of the extension portion 41 along the thickness direction of the battery body 1 is slightly greater than the width of the extension portion 41 along the first direction, which can reduce the erosion or damage of other elements to the battery body 1. In addition, the contact area between the extension portion 41 and the electrode 5 in the thickness direction of the battery body 1 can be appropriately increased, that is, the contact area between the side of the extension portion 41 and the electrode 5 is increased, the contact area between the seed layer 4 and the electrode 5 is further increased, the contact resistance between the seed layer 4 and the electrode 5 is reduced, and the current loss is reduced. However, the thickness of the extension portion 41 along the thickness direction of the battery body 1 cannot be too large, that is, b / h is less than 0.5, resulting in too small a contact area between the seed layer 4 and the passivation surface, which reduces the bonding force between the seed layer 4 and the surface of the passivation layer 2. Illustratively, the ratio of the width of the extending portion 41 along the first direction to the thickness of the extending portion 41 along the thickness direction of the battery body 1 is 0.5, 0.6, 0.7, 0.8, 0.9 or 1, etc.

[0066] In other embodiments, the width of the extension portion 41 along the first direction is greater than the thickness of the extension portion 41 along the thickness direction of the battery body 1, that is, b / h is greater than 1. In this case, the seed layer 4 can be formed by chemical plating. In this way, the width of the extension portion 41 along the first direction is larger, which can increase the area of ​​the upper surface of the seed layer 4, thereby increasing the contact area between the seed layer 4 and the passivation layer 2, improving the adhesion between the seed layer 4 and the passivation layer 2, and further reducing the risk of the seed layer 4 falling off; at the same time, the contact area between the seed layer 4 and the electrode 5 is increased, and the contact performance between the seed layer 4 and the electrode 5 is improved.

[0067] In some embodiments, the ratio of the width of the extension portion 41 along the first direction to the thickness of the extension portion 41 along the thickness direction of the battery body 1 is 1 to 10, that is, b / h is in the range of 1 to 10. Such a configuration can increase the contact area between the seed layer 4 and the passivation layer 2, improve the adhesion between the seed layer 4 and the passivation layer 2, and further reduce the risk of the seed layer 4 falling off; it can also improve the contact performance between the upper surface of the seed layer 4 and the electrode 5, and reduce current loss.

[0068] Exemplarily, the ratio of the width of the extension portion 41 along the first direction to the thickness of the extension portion 41 along the thickness direction of the battery body 1 is 1, 1.2, 1.8, 2.2, 2.8, 3.2, 3.8, 4.2, 4.8, 5.2, 5.8, 6.2, 6.8, 7.2, 7.8, 8.2, 8.8, 9.2, 9.8 or 10, etc.

[0069] In addition, when the ratio of the thickness of the extension portion 41 along the thickness direction of the battery body 1 to the width of the extension portion 41 along the first direction is greater than or equal to 0.8, the longitudinal contact area between the seed layer 4 and the electrode 5 can be increased, thereby reducing the contact resistance while ensuring good contact between the seed layer 4 and the battery body 1.

[0070] like Figure 4 As shown, the edge thickness of the extension portion 41 gradually decreases along the direction from the center to the edge of the opening 3. That is, along the first direction, there is a smooth transition from the upper surface to the side of the extension portion 41, so that the contact between the seed layer 4 and the electrode 5 is more firm, further reducing the risk of falling off.

[0071] In some embodiments, Figure 3As shown, the seed layer 4 fills the opening 3, and the seed layer 4 protrudes from the opening 3 and has an extension portion 41 extending to the passivation layer 2. Specifically, the bottom of the seed layer 4 fills the inside of the opening 3, the top of the seed layer 4 overflows the opening 3, and the portion of the seed layer 4 overflowing the opening 3 extends in the direction surrounding the opening 3 and in the thickness direction of the passivation layer 2, and finally forms the extension portion 41 on the passivation layer 2, and the upper surface height of the seed layer 4 is higher than the upper surface of the passivation layer 2. In this way, the extension portion 41 is arranged around the opening 3, which is more conducive to processing and manufacturing.

[0072] In some embodiments, along the length direction or width direction of the battery body 1, the width of the extension portion 41 located on the first side of the opening 3 is greater than the width of the extension portion 41 located on the second side. Figure 3 As shown, Figure 3 The left side of the middle opening 3 is the first side, the right side of the opening 3 is the second side, and the first direction is along the length direction of the battery body 1 .

[0073] In some embodiments, Figure 4 and Figure 5 As shown, along the thickness direction of the battery body 1, the thickness h of the extension part 41 is 60nm to 1200nm, so as to prevent the thickness h of the extension part 41 from being too thick, which will lead to a prolonged process time, ensure that the upper surface area of ​​the seed layer 4 is moderate, and then ensure that the seed layer 4 has sufficient adhesion to the battery body 1, and prevent the thickness h of the extension part 41 from being too small, resulting in too small contact area between the side of the extension part 41 and the electrode 5, which will increase the contact resistance between the seed layer 4 and the electrode 5. Exemplarily, the thickness h of the extension part 41 can be 60nm, 100nm, 150nm, 200nm, 300nm, 400nm, 500nm, 600nm, 700nm, 800nm, 900nm, 1000nm, 1100nm or 1200nm, etc.

[0074] In addition, if Figure 4 and Figure 5 As shown, along the first direction, the width b of the extension portion 41 is 60nm to 1200nm, so as to prevent the width b of the extension portion 41 from being too small, thereby ensuring sufficient adhesion of the seed layer 4 to the battery body 1, and reducing the contact resistance between the seed layer 4 and the electrode 5; at the same time, the width b of the extension portion 41 is prevented from being too wide, resulting in waste of materials. Exemplarily, the width b of the extension portion 41 can be 60nm, 100nm, 150nm, 200nm, 300nm, 400nm, 500nm, 600nm, 700nm, 800nm, 900nm, 1000nm, 1100nm or 1200nm, etc.

[0075] In other embodiments, Figure 3As shown, along the first direction, the ratio of the width of the extension portion 41 to the maximum width of the orthographic projection of the seed layer 4 on the first surface is 0.05-0.2. That is, along the first direction, the ratio of the width b of the extension portion 41 to the total width of the upper surface of the seed layer 4 is 0.05-0.2. With this technical solution, the width of the extension portion 41 can be prevented from being too wide, resulting in material waste; at the same time, the contact area between the seed layer 4 and the electrode 5 is ensured to be large, thereby ensuring sufficient adhesion of the seed layer 4 to the battery body 1. Exemplarily, the ratio of the width of the extension portion 41 to the width of the surface of the seed layer 4 away from the battery body 1 is 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19 or 0.2, etc.

[0076] In other embodiments, along the first direction, the ratio of the sum of the widths of the extended portions 41 on both sides of the seed layer 4 to the maximum width of the orthographic projection of the seed layer 4 on the first surface is 0.1-0.4. For example, the ratio of the sum of the widths of the extended portions 41 on both sides of the seed layer 4 to the maximum width of the orthographic projection of the seed layer 4 on the first surface can be 0.1, 0.15, 0.2, 0.25, 0.3, 0.35 or 0.4, etc.

[0077] In other embodiments, along the thickness direction of the battery body 1, the ratio of the thickness of the extension portion 41 to the thickness of the portion of the seed layer 4 corresponding to the opening 3 is 50%-96%. Such a configuration can prevent the thickness h of the extension portion 41 from being too small, resulting in too small a contact area between the side of the extension portion 41 and the electrode 5, which will increase the contact resistance between the seed layer 4 and the electrode 5. For example, the ratio of the thickness of the extension portion 41 to the thickness of the portion of the seed layer 4 located in the opening 3 is 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95% or 96%, etc.

[0078] In addition, if the thickness of the passivation layer 2 is too small, the passivation effect will be affected; if the thickness of the passivation layer 2 is too thick, the process time will be extended; in view of the above situation, in this solution, along the thickness direction of the battery body 1, the thickness of the passivation layer 2 is 60nm to 180nm. In this way, the passivation effect can be guaranteed while preventing the process time from being extended. For example, the thickness of the passivation layer 2 is 60nm, 70nm, 80nm, 90nm, 100nm, 110nm, 120nm, 130nm, 140nm, 150nm, 160nm, 170nm or 180nm, etc.

[0079] In some embodiments, the passivation layer 2 includes one or more stacked layers of a silicon nitride layer, a silicon oxynitride layer, and a silicon oxide layer. Specifically, in the case where the passivation layer 2 is a double-layer structure, the passivation layer 2 may include a stacked silicon nitride layer and a silicon oxynitride layer, or may include a stacked silicon nitride layer and a silicon oxide layer, and of course may also include a stacked silicon oxynitride layer and a silicon oxide layer, wherein the stacking order of each layer may be set according to actual conditions. In the case where the passivation layer 2 is a three-layer structure, the passivation layer 2 may include a stacked silicon nitride layer, a silicon oxynitride layer, and a silicon oxide layer, wherein the stacking order of the silicon nitride layer, the silicon oxynitride layer, and the silicon oxide layer may be set according to actual conditions.

[0080] In the case where the solar cell includes a first doped semiconductor layer and a second doped semiconductor layer, the passivation layer 2 covers the first doped semiconductor layer and the second doped semiconductor layer on the side away from the semiconductor substrate, that is, the passivation layer 2 covers both the first doped semiconductor layer and the second doped semiconductor layer. The passivation layer 2 is provided with a first opening corresponding to the first doped semiconductor layer and a second opening corresponding to the second semiconductor. Along the first direction, the equivalent width of the first opening is different from the equivalent width of the second opening. Among them, the equivalent width of the first opening is the ratio of the area of ​​the first opening to the spacing between two adjacent first openings, and the equivalent width of the second opening is the ratio of the area of ​​the second opening to the spacing between two adjacent second openings. In this way, the equivalent width of the first opening and the equivalent width of the second opening can be adjusted as needed, so that the contact resistance between the doped semiconductor layer with a smaller conductivity and the electrode 5 is equal to or closer to the contact resistance between the doped semiconductor layer with a larger conductivity and the electrode 5, thereby reducing the current difference between the electrode 5 and the second doped semiconductor layer and between the electrode 5 and the first doped semiconductor layer, reducing the current loss of the battery, and ensuring the performance of the battery. In addition, after the battery body 1 is pre-treated, since the doping types of the doping layers corresponding to the first opening and the second opening are different, the plating activities of the first opening and the second opening are different. Therefore, the equivalent width of the first opening is different from the equivalent width of the second opening, so that the equivalent width of the opening with lower plating activity is wider, thereby reducing the difficulty of plating.

[0081] For example, if the opening 3 is a circular hole with a diameter of 14um and a spacing between two adjacent circular holes of 20um, the equivalent film opening width is (π*7*7) / 20=7.7um; if the opening 3 is a square hole, the width of the square hole along the first direction is 20um and a spacing between two adjacent square holes is 100um, the equivalent film opening width is (20*20) / 100=4um.

[0082] In some embodiments, the number of first openings is multiple and arranged along the second direction, the number of second openings is multiple and arranged along the second direction, and the second direction is parallel to the first surface. Specifically, the multiple first openings can be distributed in multiple columns or one column, and each column of first openings is arranged along the second direction; similarly, the multiple second openings can be distributed in multiple columns or one column, and each column of second openings is arranged along the second direction. The first openings can be distributed in one column, two columns, three columns or more columns; the second openings can be distributed in one column, two columns, three columns or more columns. The second direction can be the length direction of the semiconductor substrate or the width direction of the semiconductor substrate.

[0083] In some embodiments, the second doped semiconductor layer is a P-type doped semiconductor layer, and along the second direction, the equivalent width of the first opening is smaller than the equivalent width of the second opening. In this way, when the conductivity of the first doped semiconductor layer is greater than the conductivity of the second doped semiconductor layer, the contact resistance between the second doped semiconductor layer with smaller conductivity and the electrode 5 is ensured to be equal to or closer to the contact resistance between the first doped semiconductor layer with larger conductivity and the electrode 5, thereby reducing the current difference between the electrode 5 and the second doped semiconductor layer and between the electrode 5 and the first doped semiconductor layer, thereby reducing the current loss of the battery.

[0084] In some embodiments, if the equivalent width of the first opening is too small, the contact resistance between the first doped semiconductor and the electrode 5 increases, increasing the current loss; if the equivalent width of the first opening is too large, the battery is easily damaged during the laser opening process, and the more the first doped semiconductor layer is exposed, the easier it is to recombine. In view of the above situation, along the first direction, the equivalent width of the first opening is 3μm to 20μm, which makes the equivalent width of the first opening more matched with the conductivity of the first doped semiconductor, reduces the contact resistance between the first doped semiconductor and the electrode 5, and reduces the current loss; at the same time, it avoids easy damage to the battery during the laser opening process and reduces recombination. Exemplarily, the equivalent width of the first opening can be 3μm, 5μm, 8μm, 10μm, 12μm, 15μm, 18μm or 20μm, etc.

[0085] In other embodiments, along the first direction, the equivalent width of the second opening is 5 μm to 30 μm, and the technical effect is the same as that of the first opening, which will not be described in detail here. For example, the equivalent width of the second opening can be 5 μm, 8 μm, 10 μm, 12 μm, 15 μm, 18 μm or 20 μm, etc.

[0086] In other embodiments, the total area of ​​the first openings is different from the total area of ​​the second openings. The total area of ​​the first openings is the total area of ​​all the first openings on the first doped semiconductor layer; the total area of ​​the second openings is the total area of ​​all the second openings on the second doped semiconductor layer. In order to make the contact area between the doped semiconductor layer with lower conductivity and the seed layer 4 larger, in some examples, the total area of ​​the openings of the doped semiconductor layer with lower conductivity can be set larger, so that the contact resistance between the doped semiconductor layer with lower conductivity and the seed layer 4 is equal to or closer to the contact resistance between the doped semiconductor layer with higher conductivity and the seed layer 4, thereby reducing the current difference between the seed layer 4 and the second doped semiconductor layer and between the seed layer 4 and the first doped semiconductor layer, reducing the current loss of the battery, and ensuring the performance of the battery.

[0087] In some embodiments, the battery body includes a semiconductor substrate, a first doped semiconductor layer and a second doped semiconductor layer, and the first doped semiconductor layer and the second doped semiconductor layer have opposite conductivity types; the passivation layer 2 covers the first doped semiconductor layer and the second doped semiconductor layer on the side away from the semiconductor substrate, that is, the passivation layer 2 covers both the first doped semiconductor layer and the second doped semiconductor layer. The passivation layer 2 is provided with a first opening corresponding to the first doped semiconductor layer and a second opening corresponding to the second doped semiconductor; the seed layer 4 includes a first seed layer and a second seed layer, the first seed layer includes a portion arranged corresponding to the first opening, and a first extension portion extending from the first opening to the side of the passivation layer 2 away from the battery body 1; the second seed layer includes a portion arranged corresponding to the second opening, and a second extension portion extending from the second opening to the side of the passivation layer 2 away from the battery body 1. In this technical solution, the width b1 of the first extension portion is different from the width b2 of the second extension portion.

[0088] At the opening, the doped conductive layer forms electrical contact with the electrode through the seed layer. The conductivity types of the doped layers corresponding to the first opening and the second opening are different. Therefore, the different widths of the extended parts of the first seed layer and the second seed layer can adjust the contact performance between doped conductive layers of different doping types and the electrodes, reduce the current difference between the seed layer 4 and the second doped semiconductor layer and between the seed layer 4 and the first doped semiconductor layer, reduce the current loss of the battery, and ensure the performance of the battery.

[0089] In some embodiments, the first seed layer is disposed on the N-type doped semiconductor layer, and the second seed layer is disposed on the P-type doped semiconductor layer. The width of the first extension portion is smaller than the width of the second extension portion. Since the P region has poor contact performance, the width of the second extension portion corresponding to the P region increases, which can increase the contact area between the electrode of the P region and the second seed layer, thereby reducing contact resistance, improving contact performance, and improving the photoelectric conversion efficiency of the solar cell.

[0090] The contact resistance between the first seed layer and the electrode 5 may be less than or equal to 0.3 mΩ*cm 2 The contact resistance between the second seed layer and the electrode 5 can be less than or equal to 0.8 mΩ*cm 2 .

[0091] In other embodiments, the first seed layer is disposed on the N-type doped semiconductor layer, and the second seed layer is disposed on the P-type doped semiconductor layer. The width of the first extension portion is greater than the width of the second extension portion. By increasing the width of the first extension portion, the contact performance between the N-region electrode and the first seed layer can be improved, thereby reducing the number of N-region openings. When the number of openings is reduced, the damage to the N-region caused by laser mold opening is reduced, and the passivation effect of the N-region can be effectively guaranteed.

[0092] The solar cell further includes an electrode 5 disposed on the side of the seed layer 4 away from the battery body 1, and the electrode 5 covers at least a portion of the surface of the seed layer 4 away from the battery body 1. Specifically, the electrode 5 may cover only the upper surface of the seed layer 4, or may cover the upper surface and side surfaces of the seed layer 4. Specifically, the electrode 5 may be formed on the exposed seed layer 4 by screen printing, electroplating, sputtering or evaporation.

[0093] The electrode 5 can cover the surface and side of the seed layer 4 away from the battery body 1, so that the contact area between the electrode 5 and the seed layer 4 is maximized, further reducing the contact resistance between the electrode 5 and the seed layer 4, and improving the efficiency of the solar cell. The electrode 5 can include a main grid and / or a fine grid.

[0094] In addition, the width of the electrode 5 is 40 μm to 200 μm. By adopting this technical solution, the electrode 5 is set within a reasonable range of 40 μm to 200 μm, which can prevent the width of the electrode 5 from being too wide, causing the electrode 5 to contact the doped semiconductor layer of opposite polarity and leak electricity, and at the same time prevent the width of the electrode 5 from being too small, ensuring that the contact resistance between the electrode 5 and the seed layer 4 is small. Exemplarily, the width of the electrode 5 is 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 110 μm, 120 μm, 130 μm, 140 μm, 150 μm, 160 μm, 170 μm, 180 μm, 190 μm or 200 μm. It should be noted that, in view of the extension direction of the electrode 5, the width of the electrode 5 at different positions may be different. Therefore, in this application, the width of the electrode 5 may refer to the average width of the electrode 5 or the maximum width of the electrode 5.

[0095] Among them, the material of the semiconductor substrate can be selected from materials such as silicon (Si) or germanium (Ge) or materials such as gallium arsenide (GaAs). Obviously, in terms of conductivity type, the semiconductor substrate can be an intrinsic conductive substrate, an n-type conductive substrate or a p-type conductive substrate. Optionally, the semiconductor substrate is a p-type conductive substrate or an n-type conductive substrate. Compared with the intrinsic conductive substrate, the p-type conductive substrate or the n-type conductive substrate has better conductivity, so that the final solar cell has a lower body resistivity, thereby improving the efficiency of the solar cell.

[0096] In addition, the materials of the first doped semiconductor layer and the second doped semiconductor layer may be silicon (Si), germanium (Ge), silicon carbide (SiCx) or gallium arsenide (GaAs), etc. The first doped semiconductor layer may be additionally formed on the semiconductor substrate by a deposition technique, or may be formed in the semiconductor substrate by diffusion, ion implantation, etc.

[0097] In terms of conductivity type, the first doped semiconductor layer may be an n-type doped semiconductor layer, and the second doped semiconductor layer may be a p-type doped semiconductor layer; or, the first doped semiconductor layer may be a p-type doped semiconductor layer, and the second doped semiconductor layer may be an n-type doped semiconductor layer.

[0098] In addition, the materials of the first doped semiconductor layer and the second doped semiconductor layer may be silicon (Si), germanium (Ge), silicon carbide (SiCx) or gallium arsenide (GaAs), etc. Taking the case where the materials of the first doped semiconductor layer and the second doped semiconductor layer are both silicon (Si) as an example, the first doped semiconductor layer may be one or more of doped single crystal silicon, doped polycrystalline silicon, doped amorphous silicon, doped microcrystalline silicon, and doped nanocrystalline silicon. The second doped semiconductor layer may also be one or more of doped single crystal silicon, doped polycrystalline silicon, doped amorphous silicon, doped microcrystalline silicon, and doped nanocrystalline silicon.

[0099] In some embodiments, the solar cell may further include a first interface layer, which is located at least between the first doped semiconductor layer and the semiconductor substrate. In this case, the passivation contact structure composed of the first interface layer and the first doped semiconductor layer has an excellent interface passivation effect, and can achieve selective collection of carriers, reduce the carrier recombination rate in the region of the first surface of the semiconductor substrate where the first doped semiconductor layer is formed, and further improve the photoelectric conversion efficiency of the solar cell. The material and thickness of the first interface layer can be set according to the material of the first doped semiconductor layer and actual needs, and are not specifically limited here.

[0100] Among them, the material of the above-mentioned first interface layer can be determined according to the material of the first doped semiconductor layer. For example: when the first doped semiconductor layer includes a doped polysilicon layer, the first interface layer is a tunneling oxide layer; in this way, the first doped semiconductor layer and the first interface layer form a tunneling oxide passivation contact, and the tunneling oxide passivation technology can form a tunneling film between the first electrode and the semiconductor substrate, isolating the electrode from the semiconductor substrate, reducing contact recombination losses, and the electrons can tunnel through the film without affecting current transfer. At the same time, passivation can bend the surface energy band and reduce the surface recombination losses of the silicon wafer. For another example: when the first doped semiconductor layer includes a doped amorphous silicon layer, the first interface layer includes an intrinsic amorphous silicon layer. Secondly, the embodiment of the present invention does not specifically limit the material of the first interface layer.

[0101] In some embodiments, the solar cell may further include a second interface layer, which is located at least between the second doped semiconductor layer and the semiconductor substrate. The projection of the second interface layer on the semiconductor substrate may overlap with the projection of the second doped semiconductor layer on the semiconductor substrate. In this case, the passivation contact structure composed of the second interface layer and the second doped semiconductor layer can realize the selective collection of carriers and reduce the carrier recombination rate in the region where the second doped semiconductor layer is formed on the first surface of the semiconductor substrate. The material and thickness of the second interface layer can be set according to the material of the second doped semiconductor layer and actual needs, and are not specifically limited here. For example: when the material of the second doped semiconductor layer includes one or more of doped amorphous silicon, doped microcrystalline silicon, and doped nanocrystalline silicon, the second interface layer includes one or more of an intrinsic amorphous silicon layer, an intrinsic microcrystalline silicon layer, and an intrinsic nanocrystalline silicon. For another example, when the material of the second doped semiconductor layer includes doped polycrystalline silicon, the second interface layer includes a tunneling oxide layer.

[0102] For example, the first surface of the solar cell is the light-facing surface, and the second surface is the backlight surface, wherein the first surface is sequentially provided with an emitter, a passivation layer 2, a first seed layer, and a first electrode, the passivation layer 2 is provided with a first opening corresponding to the emitter, and the first seed layer is conductively connected to the first electrode through the first opening. The second surface is sequentially provided with a tunneling oxide layer, a doped polysilicon layer, a passivation layer 2, a second seed layer, and a second electrode, the passivation layer 2 is provided with a second opening corresponding to the doped polysilicon layer, and the second seed layer is conductively connected to the second electrode through the second opening.

[0103] For another example, the first surface of the solar cell is a light-facing surface, and the second surface is a backlight surface, wherein a first tunneling oxide layer, a first doped polysilicon layer, a passivation layer 2, a first seed layer and a first electrode are sequentially arranged on the first surface, the passivation layer 2 is provided with a first opening corresponding to the first doped polysilicon layer, and the first seed layer is conductively connected to the first electrode through the first opening; a second tunneling oxide layer, a second doped polysilicon layer, a passivation layer 2, a second seed layer and a second electrode are sequentially arranged on the second surface, the passivation layer 2 is provided with a second opening corresponding to the second doped polysilicon layer, and the second seed layer is conductively connected to the second electrode through the second opening.

[0104] In the description of the above embodiments, specific features, structures, materials or characteristics may be combined in a suitable manner in any one or more embodiments or examples.

[0105] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A solar cell, characterized in that: include: The battery body comprises a first surface and a second surface which are arranged opposite to each other; A passivation layer, at least disposed on the first surface, and the passivation layer is provided with a plurality of openings penetrating the thickness thereof; A seed layer, the seed layer comprising a portion disposed corresponding to the opening, and an extending portion extending from the opening to a side of the passivation layer away from the battery body; Wherein, the ratio of the width of the extending portion along the first direction to the thickness of the extending portion along the thickness direction of the battery body is 0.5-10; and the first direction is parallel to the first surface.

2. The solar cell according to claim 1, characterized in that: The ratio of the width of the extending portion along the first direction to the thickness of the extending portion along the thickness direction of the battery body is 0.5-1.

3. The solar cell according to claim 1, characterized in that The ratio of the width of the extending portion along the first direction to the thickness of the extending portion along the thickness direction of the battery body is 1-10.

4. The solar cell according to any one of claims 1, characterized in that Along the direction from the center to the edge of the opening, the edge thickness of the extending portion gradually decreases.

5. The solar cell according to claim 1, characterized in that: The seed layer fills the opening and protrudes from the opening.

6. The solar cell according to claim 1, characterized in that Along the length direction or the width direction of the battery body, the width of the extension portion located on the first side of the opening is greater than the width of the extension portion located on the second side.

7. The solar cell according to claim 1, characterized in that Along the thickness direction of the battery body, the thickness of the extension portion is 60nm to 1200nm; and / or, Along the first direction, the width of the extension portion is 60 nm to 1200 nm.

8. The solar cell according to claim 1, characterized in that Along the first direction, a ratio of a width of the extending portion to a maximum width of an orthographic projection of the seed layer on the first surface is 0.05-0.

2.

9. The solar cell according to claim 1, characterized in that: Along the thickness direction of the battery body, the ratio of the thickness of the extension portion to the thickness of the seed layer corresponding to the opening is 50%-96%.

10. The solar cell according to any one of claims 1 to 9, characterized in that: The battery body comprises a semiconductor substrate, a first doped semiconductor layer and a second doped semiconductor layer, wherein the first doped semiconductor layer is disposed on a first surface of the semiconductor substrate, and the second doped semiconductor layer is disposed on a first surface or a second surface of the semiconductor substrate, and the first doped semiconductor layer and the second doped semiconductor layer have opposite conductivity types; The passivation layer covers the first doped semiconductor layer and the second doped semiconductor layer on one side away from the semiconductor substrate, the passivation layer is provided with a first opening corresponding to the first doped semiconductor layer and a second opening corresponding to the second doped semiconductor, and along the first direction, an equivalent width of the first opening is different from an equivalent width of the second opening; The number of the first openings is multiple and arranged along the second direction, and the number of the second openings is multiple and arranged along the second direction; The equivalent width is the ratio of the area of ​​the first opening to the distance between two adjacent first openings, or the ratio of the area of ​​the second opening to the distance between two adjacent second openings.

11. The solar cell according to claim 10, characterized in that The second doped semiconductor layer is a P-type doped semiconductor layer; Along the first direction, an equivalent width of the first opening is smaller than an equivalent width of the second opening.

12. The solar cell according to any one of claims 1 to 9, characterized in that: The battery body comprises a semiconductor substrate, a first doped semiconductor layer and a second doped semiconductor layer, wherein the first doped semiconductor layer is disposed on a first surface of the semiconductor substrate, and the second doped semiconductor layer is disposed on a first surface or a second surface of the semiconductor substrate, and the first doped semiconductor layer and the second doped semiconductor layer have opposite conductivity types; The passivation layer covers the first doped semiconductor layer and the second doped semiconductor layer on one side away from the semiconductor substrate, and the passivation layer is provided with a first opening corresponding to the first doped semiconductor layer and a second opening corresponding to the second doped semiconductor layer; The total area of ​​the first openings is different from the total area of ​​the second openings.

13. The solar cell according to claim 1, characterized in that The battery body comprises a semiconductor substrate, a first doped semiconductor layer and a second doped semiconductor layer, wherein the first doped semiconductor layer is disposed on a first surface of the semiconductor substrate, and the second doped semiconductor layer is disposed on a first surface or a second surface of the semiconductor substrate, and the first doped semiconductor layer and the second doped semiconductor layer have opposite conductivity types; The passivation layer covers the first doped semiconductor layer and the second doped semiconductor layer on one side away from the semiconductor substrate, and the passivation layer is provided with a first opening corresponding to the first doped semiconductor layer and a second opening corresponding to the second doped semiconductor layer; The seed layer includes a first seed layer and a second seed layer, the first seed layer includes a portion arranged corresponding to the first opening, and a first extending portion extending from the first opening to a side of the passivation layer away from the battery body; The second seed layer includes a portion disposed corresponding to the second opening, and a second extending portion extending from the second opening to a side of the passivation layer away from the battery body; Along the first direction, a width of the first extending portion and a width of the second extending portion are different.

14. The solar cell according to any one of claims 1 to 9, characterized in that: The solar cell further comprises an electrode disposed on a side of the seed layer away from the cell body, and the electrode covers at least a portion of a surface of the seed layer away from the cell body.

15. The solar cell according to claim 14, characterized in that: The electrode covers the surface and side of the seed layer away from the battery body; and / or the width of the electrode is 40 μm to 200 μm.

16. A photovoltaic module, characterized in that: The invention comprises a solar cell according to any one of claims 1 to 15.

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