A solar cell and a photovoltaic module

Abstract

This invention relates to the field of photovoltaic technology, and particularly to a solar cell and a photovoltaic module. In the solar cell, a passivation layer is disposed on the side of the doped conductive layer away from the semiconductor substrate; an antireflection layer is disposed on the side of the passivation layer away from the semiconductor substrate, and the antireflection layer has an upper surface away from the semiconductor substrate; a plurality of current collectors are disposed on the antireflection layer, each current collector extending along a first direction, and the plurality of current collectors are spaced apart along a second direction; at least one current collector includes a plurality of contact portions and a transmission portion, the plurality of contact portions being spaced apart along the first direction; the transmission portion is disposed on the side of the contact portions away from the semiconductor substrate and is in contact with the plurality of contact portions, the transmission portion extending along the first direction; along a third direction, the transmission portion includes an embedded portion located below the upper surface, and at least one contact portion includes an extension portion located below the upper surface and extending to be electrically connected to the doped conductive layer, the thickness of the embedded portion being less than the thickness of the extension portion.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic technology, and in particular to a solar cell and a photovoltaic module. Background Technology

[0002] In the manufacturing process of photovoltaic modules, the metallization process is one of the core steps in solar cell production. It is mainly used to form the electrode structure to achieve current output. The metallization process requires a large amount of silver paste to form the electrode structure. Typically, the silver paste burns through the surface film layer and contacts the doped layer, thus achieving effective collection of charge carriers while simultaneously connecting with the film structure.

[0003] However, when the electrode burns through the battery surface film structure, such as the antireflection layer and passivation layer, the battery efficiency will inevitably be reduced due to the loss of passivation performance and the large amount of recombination. Summary of the Invention

[0004] In view of this, the present invention proposes a solar cell and a photovoltaic module, which aims to partially or completely solve the technical problem of photoelectric conversion efficiency loss caused by electrode burn-through of surface film structure in existing solar cells.

[0005] To achieve the above objectives, the technical solution of the present invention is implemented as follows:

[0006] In a first aspect, embodiments of the present invention provide a solar cell having opposing first and second sides. The solar cell includes a semiconductor substrate, a doped conductive layer, a passivation layer, an antireflection layer, and a plurality of current collector electrodes. The doped conductive layer is disposed on the semiconductor substrate. The passivation layer is disposed on the side of the doped conductive layer away from the semiconductor substrate. The antireflection layer is disposed on the side of the passivation layer away from the semiconductor substrate, and the antireflection layer has an upper surface away from the semiconductor substrate. The plurality of current collector electrodes are disposed on the antireflection layer, each current collector electrode extending along a first direction, and the plurality of current collector electrodes are spaced apart along a second direction. At least one current collector electrode includes a plurality of contact portions and a transmission portion, the plurality of contact portions being spaced apart along the first direction. The transmission portion is disposed on the side of the contact portion away from the semiconductor substrate and is in contact with the plurality of contact portions, the transmission portion extending along the first direction. Along a third direction, the transmission portion includes an embedded portion located below the upper surface, and at least one contact portion includes an extension portion located below the upper surface and extending to be electrically connected to the doped conductive layer, the thickness of the embedded portion being less than the thickness of the extension portion. The first direction, the second direction, and the third direction intersect each other.

[0007] In some embodiments, along the third direction, the thickness of the extended portion ranges from 20 nm to 400 nm, and the thickness of the embedded portion ranges from 10 nm to 150 nm; and / or, the difference between the thickness of the extended portion and the thickness of the embedded portion ranges from 10 nm to 300 nm; and / or, the ratio of the thickness of the antireflection layer to the thickness of the embedded portion ranges from 1 to 30; and / or, the difference between the thickness of the extended portion and the sum of the thicknesses of the antireflection layer, the passivation layer, and the doped conductive layer ranges from 20 nm to 250 nm; and / or, the ratio of the thickness of the extended portion to the sum of the thicknesses of the antireflection layer, the passivation layer, and the doped conductive layer ranges from 0.3 to 0.99; and / or, the difference between the thickness of the embedded portion and the sum of the thicknesses of the antireflection layer and the passivation layer ranges from 0 nm to 90 nm; and / or, the ratio of the thickness of the embedded portion to the sum of the thicknesses of the antireflection layer and the passivation layer ranges from 0.1 to 0.9.

[0008] In some embodiments, along the second direction, the width of the transmission part ranges from 50um to 150um, and the width of the contact part ranges from 5um to 25um; and / or, the difference between the width of the transmission part and the width of the contact part ranges from 40um to 120um; and / or, the ratio of the width of the transmission part to the width of the contact part is 2 to 20.

[0009] In some embodiments, along the first direction, the length of the transmission portion ranges from 150mm to 210mm, and the length of at least one of the contact portions ranges from 0.1mm to 5mm; and / or, the ratio of the length of the transmission portion to the sum of the lengths of the corresponding plurality of contact portions is 1 to 20.

[0010] In some embodiments, the embedded portion is located within the antireflection layer, or the embedded portion burns through the antireflection layer and enters the passivation layer.

[0011] In some embodiments, the contact portion is a honeycomb structure including multiple holes, and the transmission portion includes multiple metal particles; the interface between the transmission portion and the contact portion includes multiple interface regions, and in at least a portion of the interface regions, the metal particles fill the holes.

[0012] In some embodiments, the doped conductive layer includes a first doped conductive layer and a second doped conductive layer alternately disposed on the first side; the plurality of collector electrodes include a plurality of first collector electrodes and a plurality of second collector electrodes, wherein the plurality of first collector electrodes are disposed on the side of the first doped conductive layer away from the semiconductor substrate, and at least one first collector electrode includes a plurality of first contact portions and a first transmission portion; the plurality of second collector electrodes are disposed on the side of the second doped conductive layer away from the semiconductor substrate, and at least one second collector electrode includes a plurality of second contact portions and a second transmission portion; the extension portion includes a first extension portion disposed within the first collector electrode and a second extension portion disposed within the second collector electrode; along the third direction, the thickness of the first extension portion is less than the thickness of the second extension portion.

[0013] In some embodiments, along the third direction, the thickness of the first extension portion ranges from 3 nm to 8 nm, and the thickness of the second extension portion ranges from 3 nm to 8 nm; and / or, the ratio of the thickness of the first extension portion to the thickness of the second extension portion ranges from 0.5 to 1; and / or, the difference between the thickness of the first extension portion and the thickness of the second extension portion ranges from 0 to 5 nm.

[0014] In some embodiments, along the second direction, the width of both the first extension portion and the second extension portion ranges from 5µm to 25µm; and / or, the ratio of the width of the first extension portion to the spacing between two adjacent first collector electrodes ranges from 0.05 to 0.5; and / or, the ratio of the width of the second extension portion to the spacing between two adjacent second collector electrodes ranges from 0.05 to 0.5.

[0015] In some embodiments, along the second direction, the embedded portion includes a first embedded portion disposed within the first current collector electrode and a second embedded portion disposed within the second current collector electrode, wherein along the third direction, the thickness of the first embedded portion is smaller than that of the second embedded portion.

[0016] In some embodiments, along the second direction, the embedded portion includes a first embedded portion disposed within the first current collector electrode and a second embedded portion disposed within the second current collector electrode. Along the third direction, the thickness of the first embedded portion ranges from 10 nm to 80 nm, and the thickness of the second embedded portion ranges from 20 nm to 100 nm; and / or, the ratio of the thickness of the first embedded portion to the thickness of the second embedded portion ranges from 0.5 to 1; and / or, the difference between the thickness of the first embedded portion and the thickness of the second embedded portion ranges from 0 to 30 nm.

[0017] In some embodiments, along the second direction, the width of both the first embedded portion and the second embedded portion ranges from 5µm to 25µm; and / or, the ratio of the width of the first embedded portion to the spacing between two adjacent first collector electrodes ranges from 0.05 to 0.5; and / or, the ratio of the width of the second embedded portion to the spacing between two adjacent second collector electrodes ranges from 0.05 to 0.5.

[0018] In some embodiments, the doped conductive layer includes a first doped conductive layer and a second doped conductive layer, the first doped conductive layer being disposed on the first side and the second doped conductive layer being disposed on the second side, wherein the first side is the light-facing side of the solar cell; the passivation layer includes a first passivation layer and a second passivation layer, the first passivation layer being disposed on the side of the first doped conductive layer away from the first side and the second passivation layer being disposed on the side of the second doped conductive layer away from the second side; the current collector includes a first current collector and a second current collector, the first current collector being disposed on the side of the first passivation layer away from the semiconductor substrate and the second current collector being disposed on the side of the second passivation layer away from the semiconductor substrate, wherein, along the third direction, the thickness of at least one first current collector is greater than that of at least one second current collector.

[0019] In some embodiments, the contact portion includes a first contact portion disposed within the first current collector electrode and a second contact portion disposed within the second current collector electrode. A plurality of first contact portions pass through the first passivation layer and are electrically connected to the first doped conductive layer, and a plurality of second contact portions pass through the second passivation layer and are electrically connected to the second doped conductive layer. In the third direction, the thickness of at least one first contact portion is greater than that of at least one second contact portion.

[0020] In some embodiments, the extension includes a first extension disposed within the first collector electrode and a second extension disposed within the second collector electrode, wherein, along the third direction, the thickness of the first extension is greater than the thickness of the second extension.

[0021] In some embodiments, the plurality of contact portions are made of a different material than the transmission portion; and / or, the transmission portion includes at least one of copper, nickel, chromium, antimony, lead, zinc, silver-plated copper, and silver-plated copper containing silver powder; and / or, the contact portion includes at least one of silver, silver-plated copper, and silver-plated copper containing silver powder.

[0022] In some embodiments, the plurality of contact portions include silver particles, the transmission portion includes copper particles, and the copper particles are at least partially coated with a coating layer comprising organic and inorganic portions.

[0023] Secondly, embodiments of the present invention also provide a photovoltaic module, comprising:

[0024] At least one battery string, the battery string being formed by connecting multiple solar cells as described above;

[0025] An encapsulation layer for covering the surface of the battery string; and,

[0026] A cover plate is used to cover the surface of the encapsulation layer away from the battery string.

[0027] This invention discloses a solar cell in which the extended portion of the contact is burned through to electrically connect with a doped conductive layer. Photogenerated carriers in the doped conductive layer are collected by the extended portion and then transported through a transport portion. The thickness of the embedded portion of the transport portion is smaller than that of the extended portion of the contact, reducing damage to the surface film structure and thus improving the photoelectric conversion efficiency of the cell. Furthermore, compared to base metal paste cells that do not burn through at all, the transport portion partially burns through the surface film structure, ensuring the connection strength between the current collector electrode and the semiconductor substrate. Secondly, since the transport portion can use a lower-cost paste than the contact portion, and the contacts are spaced apart, cost reduction in the metallization process is maximized. In other words, the current collector electrode in this invention, compared to traditional silver paste electrodes, achieves cost reduction and minimizes damage to the surface film, while ensuring the tensile strength performance of the solar cell after welding.

[0028] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and in order to make the above embodiments, objectives, features and advantages of the present invention more obvious and understandable, the following are specific embodiments of the present invention. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments will be briefly introduced below.

[0030] Figure 1 This is a schematic diagram of the structure of the solar cell described in an embodiment of the present invention;

[0031] Figure 2 This is a schematic diagram of the current collector electrode structure according to an embodiment of the present invention. Figure 1 ;

[0032] Figure 3 This is a schematic diagram of the current collector electrode structure according to an embodiment of the present invention. Figure 2 ;

[0033] Figure 4 This is a schematic diagram of the cross-sectional view of the solar cell described in an embodiment of the present invention. Figure 1 ;

[0034] Figure 5 This is a schematic diagram of the cross-sectional view of the solar cell described in an embodiment of the present invention. Figure 2 .

[0035] Explanation of reference numerals in the attached figures:

[0036] 10. Semiconductor substrate; 11. First side; 12. Second side; 20. Doped conductive layer; 21. First doped conductive layer; 22. Second doped conductive layer; 30. Passivation layer; 31. First passivation layer; 32. Second passivation layer; 40. Antireflection layer; 41. Upper surface; 43. First antireflection layer; 44. Second antireflection layer; 50. Collector electrode; 51. Contact portion; 511. Extension portion; 512. Surface portion; 513. First contact portion; 514. Second contact portion; 515. First extension portion; 516. Second extension portion; 52. Transport portion; 521. Embedded portion; 522. Protruding portion; 523. First transport portion; 524. Second transport portion; 525. First embedded portion; 526. Second embedded portion; 53. First collector electrode; 54. Second collector electrode; X, First direction; Y, Second direction; Z, Third direction. Detailed Implementation

[0037] Exemplary embodiments of the invention will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the invention and to fully convey the scope of the invention to those skilled in the art.

[0038] Reference Figures 1 to 3As shown, this application provides a solar cell, which includes a semiconductor substrate 10, a doped conductive layer 20, a passivation layer 30, an antireflection layer 40, and a plurality of current collectors 50. The semiconductor substrate 10 has a first side 11 and a second side 12 opposite to each other. The doped conductive layer 20 is disposed on the semiconductor substrate 10. The passivation layer 30 is disposed on the side of the doped conductive layer 20 away from the semiconductor substrate 10. The antireflection layer 40 is disposed on the side of the passivation layer 30 away from the semiconductor substrate 10, and the antireflection layer 40 has an upper surface 41 away from the semiconductor substrate 10. The plurality of current collectors 50 are disposed on the antireflection layer 40, and each current collector 50 extends along a first direction X. Multiple collector electrodes 50 are spaced apart along a second direction Y; at least one collector electrode 50 includes multiple contact portions 51 and transmission portions 52, the multiple contact portions 51 are spaced apart along a first direction X; the transmission portion 52 is disposed on the side of the contact portion 51 away from the semiconductor substrate 10 and is in contact with the multiple contact portions 51, the transmission portion 52 extends along the first direction X; along a third direction Z, the transmission portion 52 includes an embedded portion 521 located below the upper surface 41, at least one contact portion 51 includes an extension portion 511 located below the upper surface 41 and extending to be electrically connected to the doped conductive layer 20, the thickness of the embedded portion 521 is less than the thickness of the extension portion 511.

[0039] In a solar cell, the semiconductor substrate 10 is the core component, which converts solar energy into electrical energy. The semiconductor substrate 10 has a first side 11 and a second side 12, one of which is a light-receiving surface facing sunlight, and the other is a backlighting surface facing away from sunlight. The doped conductive layer 20 can be disposed on the light-receiving surface, on the backlighting surface, or on both the light-receiving and backlighting surfaces respectively. This application does not impose specific limitations on this.

[0040] The semiconductor substrate 10 in this embodiment can be a rectangular structure, a square structure, or a near-rectangular structure. A near-rectangular structure refers to a rectangular solar cell with rounded or square chamfers, which are directly connected to one side of the semiconductor substrate 10. Of course, the semiconductor substrate 10 can also be other shapes. In this embodiment, no excessive restrictions are placed on the specific structure of the semiconductor substrate 10. The following description will use a rectangular semiconductor substrate 10 as an example.

[0041] It should be noted that the solar cell has three intersecting directions: a first direction X, a second direction Y, and a third direction Z. The specific angles between these three directions can be set according to usage requirements; for example, the first direction X, the second direction Y, and the third direction Z can be perpendicular to each other. When the semiconductor substrate 10 has a rectangular structure, if the first direction X is the length direction of the semiconductor substrate 10, then the second direction Y is the width direction of the semiconductor substrate 10. If the first direction X is the width direction of the semiconductor substrate 10, then the second direction Y is the length direction of the semiconductor substrate 10. The third direction Z is the thickness direction of the semiconductor substrate 10.

[0042] The passivation layer 30 is disposed on the side of the doped conductive layer 20 away from the semiconductor substrate 10; the antireflection layer 40 is disposed on the side of the passivation layer 30 away from the semiconductor substrate 10; and multiple current collectors 50 are disposed on the antireflection layer 40, which collect and gather the current generated at the corresponding position of the solar cell.

[0043] According to the solar cell of this application embodiment, the extension portion 511 of the contact portion 51 is burned through to electrically connect with the doped conductive layer 20. Photogenerated carriers in the doped conductive layer 20 are collected by the extension portion 511, and the carriers are then transported through the transport portion 52. The thickness of the embedded portion 521 of the transport portion 52 is less than the thickness of the extension portion 511 of the contact portion 51, reducing damage to the surface film structure and thus improving the photoelectric conversion efficiency of the cell. At the same time, compared with the base metal paste cell that does not burn through at all, the transport portion 52 also partially burns through the surface film structure, which can ensure the connection strength between the current collector electrode 50 and the semiconductor substrate 10. Secondly, since the transport portion 52 can use a paste with lower cost than the contact portion 51, and the contact portions 51 are spaced apart, the cost reduction of the metallization process is maximized. In other words, the current collector electrode 50 of this invention, compared with the traditional silver paste electrode, can reduce costs and reduce damage to the surface film, while ensuring the tensile strength performance of the solar cell after welding.

[0044] Reference Figure 2 As shown, the transmission part 52 also includes a protruding portion 522 located on the upper surface 41, and the contact part 51 includes a surface portion 512 located on the upper surface 41, with the protruding portion 522 located outside the surface portion 512.

[0045] Along the third direction Z, the extension portion 511, the embedded portion 521, the anti-reflection layer 40, the passivation layer 30 and the doped conductive layer 20 have corresponding thickness relationships, so as to reduce the current transmission distance and improve the transmission efficiency while reducing the amount of material used and the material cost.

[0046] The thickness of the extension portion 511 ranges from 20nm to 400nm, and the thickness of the embedded portion 521 ranges from 10nm to 150nm. The thicknesses of the extension portion 511 and the embedded portion 521 can be specifically set according to the application requirements. For example, the thickness of the extension portion 511 can be one of 20nm, 30nm, 40nm, 50nm, 60nm, 70nm, 80nm, 90nm, 100nm, 120nm, 140nm, 160nm, 180nm, 200nm, 220nm, 240nm, 260nm, 280nm, 300nm, 550nm, and 400nm, or any thickness between the above. For example, the thickness of the embedded portion 521 is one of 10nm, 20nm, 30nm, 40nm, 50nm, 60nm, 70nm, 80nm, 90nm, 100nm, 120nm, 140nm, 150mm, or any thickness between the above.

[0047] The difference between the thickness of the extension portion 511 and the thickness of the embedded portion 521 ranges from 10nm to 300nm. The smaller the difference between the thicknesses of the extension portion 511 and the embedded portion 521, the greater the contact ratio between the extension portion 511 and the embedded portion 521 along the third direction Z, and the higher the carrier transport efficiency. The specific difference between the thicknesses of the extension portion 511 and the embedded portion 521 can be set according to the application requirements. For example, the difference between the thicknesses of the extension portion 511 and the embedded portion 521 can be one of 10nm, 20nm, 30nm, 40nm, 50nm, 60nm, 70nm, 80nm, 90nm, 100nm, 120nm, 140nm, 160nm, 180nm, 200nm, 220nm, 240nm, 250nm, 280mm, 300mm, or any value between the above.

[0048] The ratio of the thickness of the anti-reflection layer 40 to the thickness of the embedded portion 521 ranges from 1 to 30. For example, the ratio can be one of 1, 2, 3, 4, 5, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, or 30, or any ratio between these values. When the ratio of the thickness of the anti-reflection layer 40 to the thickness of the embedded portion 521 is greater than 1, the embedded portion 521 is located within the anti-reflection layer 40. When the ratio of the thickness of the anti-reflection layer 40 to the thickness of the embedded portion 521 is equal to 1, the embedded portion 521 burns through the anti-reflection layer 40, or the embedded portion 521 burns through the anti-reflection layer 40 and enters the passivation layer 30.

[0049] The difference between the thickness of the extension portion 511 and the sum of the thicknesses of the antireflection layer 40, the passivation layer 30, and the doped conductive layer 20 is 20nm-250nm. This difference can be specifically set according to usage requirements. For example, the difference between the thickness of the extension portion 511 and the sum of the thicknesses of the antireflection layer 40, the passivation layer 30, and the doped conductive layer 20 can be one of 20nm, 30nm, 40nm, 50nm, 60nm, 70nm, 80nm, 90nm, 100nm, 120nm, 140nm, 160nm, 180nm, 200nm, 220nm, 240nm, or 250nm, or any value between these values. The difference is the absolute value of the minuend minus the difference of the subtrahend. In this embodiment, the absolute value of the difference between the thickness of the extension portion 511 and the sum of the thicknesses of the antireflection layer 40, the passivation layer 30, and the doped conductive layer 20 is the aforementioned difference.

[0050] The ratio of the thickness of the extension portion 511 to the sum of the thicknesses of the antireflection layer 40, the passivation layer 30, and the doped conductive layer 20 is in the range of 0.3 to 0.99. For example, the ratio is one of 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, and 0.99, as well as any ratio between the above.

[0051] The difference between the thickness of the embedded portion 521 and the sum of the thicknesses of the antireflection layer 40 and the passivation layer 30 is 0nm-90nm. For example, the difference between the thickness of the embedded portion 521 and the sum of the thicknesses of the antireflection layer 40 and the passivation layer 30 is one of 0nm, 5nm, 10nm, 15nm, 20nm, 30nm, 40nm, 50nm, 60nm, 70nm, 80nm, and 90nm, as well as any difference between the above values.

[0052] The ratio of the thickness of the embedded portion 521 to the sum of the thicknesses of the antireflection layer 40 and the passivation layer 30 ranges from 0.1 to 0.9. For example, the ratio of the thickness of the embedded portion 521 to the sum of the thicknesses of the antireflection layer 40 and the passivation layer 30 is one of 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, or any ratio between the above values.

[0053] Along the second direction Y, the transmission part 52 and the contact part 51 have a corresponding width relationship, so as to reduce the current transmission distance, improve the transmission efficiency, and reduce the amount of material used and the material cost.

[0054] The width of the transmission part 52 ranges from 50µm to 150µm, and the width of the contact part 51 ranges from 5µm to 25µm. The specific widths of the transmission part 52 and the contact part 51 can be set according to usage requirements. For example, the width of the transmission part 52 can be one of 50µm, 60µm, 70µm, 80µm, 90µm, 100µm, 110µm, 120µm, 130µm, 140µm, or 150µm, or any width between these values. Similarly, the width of the contact part 51 can be one of 5µm, 6µm, 8µm, 10µm, 12µm, 14µm, 16µm, 18µm, 20µm, 22µm, or 24µm, or any width between these values.

[0055] The difference between the width of the transmission section 52 and the width of the contact section 51 is in the range of 40um to 120um. For example, the difference between the width of the transmission section 52 and the width of the contact section 51 is one of 40um, 50um, 60um, 70um, 80um, 90um, 100um, 110um, and 120um, or any difference between the above-mentioned differences.

[0056] The ratio of the width of the transmission section 52 to the width of the contact section 51 is 2 to 20. For example, the ratio of the width of the transmission section 52 to the width of the contact section 51 is one of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, or any ratio between the above ratios.

[0057] Along the first direction X, the transmission part 52 and the contact part 51 have a corresponding length relationship to reduce the current transmission distance, improve the transmission efficiency, and reduce the amount of material used and the material cost.

[0058] The length of the transmission part 52 ranges from 150mm to 210mm, and the length of at least one contact part 51 ranges from 0.1mm to 5mm. The lengths of the transmission part 52 and the contact part 51 can be specifically set according to usage requirements. For example, the length of the transmission part 52 can be one of 150mm, 160mm, 170mm, 180mm, 190mm, 200mm, or 210mm, or any length between these values. Similarly, the length of the contact part 51 can be one of 0.1mm, 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, or 5mm, or any length between these values.

[0059] The ratio of the length of the transmission section 52 to the sum of the lengths of the corresponding plurality of contact sections 51 is 1 to 20. For example, the ratio of the length of the transmission section 52 to the sum of the lengths of the corresponding plurality of contact sections 51 is one of 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, or any ratio between the above ratios.

[0060] To further reduce material costs, the material of the transmission section 52 differs from that of the plurality of contact sections 51. Contact sections 51 can use relatively expensive silver-containing pastes, silver paste and glass-based mixed pastes, while the transmission section 52 can use relatively inexpensive pastes composed of resin and conductive metals. In some embodiments, the conductive metal of the transmission section 52 includes at least one of copper, nickel, chromium, antimony, lead, zinc, silver-plated copper, and silver-plated copper containing silver powder. Contact sections 51 include at least one of silver, silver-plated copper, and silver-plated copper containing silver powder to provide better conductivity and collection capabilities.

[0061] In other embodiments, the plurality of contact portions 51 include silver particles, and the transport portion 52 includes copper particles, with the copper particles at least partially coated by a coating layer comprising an organic portion and an inorganic portion. The organic portion includes resin, etc., and the inorganic portion includes metal, etc. The inclusion of silver particles in the contact portions 51 provides the advantage of strong carrier collection capability. The inclusion of copper particles in the transport portion 52 provides the advantage of lower cost compared to silver particles while maintaining good conductivity. Furthermore, the fact that the copper particles are at least partially coated by the coating layer also prevents the copper particles from being oxidized and from penetrating into the semiconductor substrate 10, thus avoiding recombination effects and damage to the semiconductor substrate 10.

[0062] In some embodiments, the contact portion 51 is a honeycomb structure including multiple holes, and the transmission portion 52 includes multiple metal particles; the interface between the transmission portion 52 and the contact portion 51 includes multiple interface regions, and in at least a portion of the interface regions, the metal particles fill the holes. This increases the contact area between the transmission portion 52 and the contact portion 51, thereby increasing the conductivity of the transmission portion 52 and the contact portion 51, and also increases the reliability of the connection between the transmission portion 52 and the contact portion 51.

[0063] The contact portion has various configuration structures to meet different requirements such as length and width, as well as the requirements for carrier transport. In some embodiments, the projection of the contact portion onto the semiconductor substrate 10 is one or more combinations of point-like and line-segment-like shapes.

[0064] When the doped conductive layer 20 is disposed on either the first side 11 or the second side 12, the solar cell is a single-sided cell. When the doped conductive layer 20 is disposed on the backside, it is a back-contact solar cell. Since disposing the doped conductive layer 20 on the backside can reduce shading of sunlight and improve the photoelectric conversion efficiency of the solar cell, the following explanation uses the example of the doped conductive layer 20 being disposed on the backside for further illustration.

[0065] In some embodiments, the doped conductive layer 20 includes a first doped conductive layer 21 and a second doped conductive layer 22 alternately disposed on the first side 11; the plurality of collector electrodes 50 includes a plurality of first collector electrodes 53 and a plurality of second collector electrodes 54, wherein the plurality of first collector electrodes 53 are disposed on the side of the first doped conductive layer 21 away from the semiconductor substrate 10, the plurality of first collector electrodes 53 extend along a first direction and are spaced apart along a second direction; at least one first collector electrode 53 includes at least one section of collector electrode, the at least one section of collector electrode of the first collector electrode 53 includes a plurality of first contact portions 513 and a first transmission portion 523, the plurality of first contact portions 513 are electrically connected to the first doped conductive layer 21, the plurality of first contact portions 513 are spaced apart along the first direction; the first transmission portion 523 is disposed on the side of the first contact portion 513 away from the semiconductor substrate 10 and is in contact with the plurality of first contact portions 513, the first transmission portion 523 extends along the first direction; A plurality of second collector electrodes 54 are disposed on the side of the second doped conductive layer 22 away from the semiconductor substrate 10. The plurality of second collector electrodes 54 extend along a first direction and are spaced apart along a second direction. Each second collector electrode 54 includes at least one collector electrode segment, which includes a plurality of second contact portions 514 and a second transmission portion 524. The plurality of second contact portions 514 are electrically connected to the second doped conductive layer 22 and are spaced apart along the first direction. The second transmission portion 524 is disposed on the side of the second contact portion 514 away from the semiconductor substrate 10 and is in contact with the plurality of second contact portions 514. The second transmission portion 524 extends along the first direction. The extension portion 511 includes a first extension portion 515 disposed within the first collector electrode 53 and a second extension portion 516 disposed within the second collector electrode 54. Along the third direction Z, the thickness of the first extension portion 515 is less than the thickness of the second extension portion 516.

[0066] In this embodiment, one of the first doped conductive layer 21 and the second doped conductive layer 22 is a P-type doped conductive layer, and the other is an N-type doped conductive layer. The P-type doped conductive layer is formed by doping silicon crystal with a trivalent element (such as boron), creating holes (positive charges) as the majority carriers. The N-type doped conductive layer is formed by doping with a pentavalent element (such as phosphorus or arsenic), providing free electrons (negative charges) as the majority carriers. The difficulty of doping trivalent and pentavalent elements differs, as does the difficulty of collecting charge carriers (including holes and negative charges). In this embodiment of the solar cell, by making the thickness of the first extension portion 515 along the third direction Z smaller than the thickness of the second extension portion 516 along the third direction Z, the thickness of the first current collector electrode 53 and the second current collector electrode 54 can be set according to the difficulty of collecting charge carriers, thus ensuring the efficiency of charge carrier collection while reducing material usage and cost.

[0067] It is understandable that it is more difficult to incorporate trivalent elements into silicon crystals than to incorporate pentavalent elements into silicon crystals, and it is more difficult to collect holes than to collect electrons. Thus, in one specific embodiment, the first doped conductive layer 21 is an N-type doped conductive layer, and the first collector electrode 53 collects electrons; the second doped conductive layer 22 is a P-type doped conductive layer, and the second collector electrode 54 collects holes.

[0068] Along the third direction Z, the thicknesses of the first extension portion 515 and the second extension portion 516 have a corresponding relationship, so as to reduce the amount of material used and the material cost while satisfying the collection efficiency of charge carriers.

[0069] The thickness of the first extension portion 515 ranges from 3nm to 8nm, and the thickness of the second extension portion 516 also ranges from 3nm to 8nm. The specific thicknesses of the first extension portion 515 and the second extension portion 516 can be set according to application requirements. For example, the thickness of the first extension portion 515 can be one of 3nm, 4nm, 5nm, 6nm, 7nm, or 8nm, or any thickness between these values. Similarly, the thickness of the second extension portion 516 can be one of 3nm, 4nm, 5nm, 6nm, 7nm, or 8nm, or any thickness between these values.

[0070] The ratio of the thickness of the first extension portion 515 to the thickness of the second extension portion 516 is in the range of 0.5 to 1. For example, the ratio of the thickness of the first extension portion 515 to the thickness of the second extension portion 516 is one of 0.5, 0.6, 0.7, 0.8, 0.9, 1, or any ratio between the above ratios.

[0071] The difference between the thickness of the first extension portion 515 and the thickness of the second extension portion 516 is in the range of 0-5nm; for example, the difference between the thickness of the first extension portion 515 and the thickness of the second extension portion 516 is one of 0, 0.5nm, 1nm, 1.5nm, 2nm, 2.5nm, 3nm, 3.5nm, 4nm, 4.5nm, 5nm, and any difference between the above-mentioned differences.

[0072] Along the second direction Y, the widths of the first extension portion 515 and the second extension portion 516 have a corresponding relationship, so as to reduce the amount of material used and the material cost while satisfying the collection efficiency of charge carriers.

[0073] The width of both the first extension portion 515 and the second extension portion 516 is in the range of 5um to 25um; for example, the width of both the first extension portion 515 and the second extension portion 516 is one of 5um, 6um, 7um, 8um, 9um, 10um, 11um, 12um, 13um, 14um, 15um, 16um, 17um, 18um, 19um, 20um, 21um, 22um, 23um, 24um, 25um, or any width between the above widths.

[0074] The ratio of the width of the first extension portion 515 to the distance between two adjacent first collector electrodes 53 is in the range of 0.05 to 0.5; for example, the ratio of the width of the first extension portion 515 to the distance between two adjacent first collector electrodes 53 is one of 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, and any ratio between the above ratios.

[0075] The ratio of the width of the second extension portion 516 to the distance between two adjacent second collector electrodes 54 is in the range of 0.05 to 0.5; for example, the ratio of the width of the second extension portion 516 to the distance between two adjacent second collector electrodes 54 is one of 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, and any ratio between the above values.

[0076] The embedded portion 521 includes a first embedded portion 525 disposed within the first current collector 53 and a second embedded portion 526 disposed within the second current collector 54. Along the third direction Z, the thickness of the first embedded portion 525 is smaller than that of the second embedded portion 526. Thus, the thickness of the first embedded portion 525 and the thickness of the second embedded portion 526 can be adapted to the relationship between the thickness of the first extension portion 515 and the thickness of the second extension portion 516. Furthermore, setting the thickness of the first embedded portion 525 according to the thickness of the first extension portion 515 can also ensure the connection strength between the first embedded portion 525 and the first extension portion 515. Setting the thickness of the second embedded portion 526 according to the thickness of the second extension portion 516 can also ensure the connection strength between the second embedded portion 526 and the second extension portion 516. Moreover, by setting the thickness of the first embedded portion 525 to be relatively small, the amount of raw materials used and the cost of raw materials can be reduced.

[0077] Along the third direction Z, there is also a corresponding relationship between the thickness of the first embedded portion 525 and the thickness of the second embedded portion 526, so as to satisfy the connection strength of the first embedded portion 525 and the second extension portion 516, as well as the connection strength of the second embedded portion 526 and the second extension portion 516, and reduce the amount of raw materials used and the cost of raw materials for the first embedded portion 525.

[0078] The thickness of the first embedded portion 525 ranges from 10nm to 80nm, and the thickness of the second embedded portion 526 ranges from 20nm to 100nm. The specific thicknesses of the first embedded portion 525 and the second embedded portion 526 can be set according to usage requirements. For example, the thickness of the first embedded portion 525 can be one of 10nm, 20nm, 30nm, 40nm, 50nm, 60nm, 70nm, or 80nm, or any thickness between these values. Similarly, the thickness of the second embedded portion 526 can be one of 20nm, 30nm, 40nm, 50nm, 60nm, 70nm, 80nm, 90nm, or 100nm, or any thickness between these values.

[0079] The ratio of the thickness of the first embedded portion 525 to the thickness of the second embedded portion 526 is in the range of 0.5-1; for example, the ratio of the thickness of the first embedded portion 525 to the thickness of the second embedded portion 526 is one of 0.5, 0.6, 0.7, 0.8, 0.9, 1, or any ratio between the above ratios.

[0080] The difference between the thickness of the first embedded portion 525 and the thickness of the second embedded portion 526 is in the range of 0-30nm; for example, the difference between the thickness of the first embedded portion 525 and the thickness of the second embedded portion 526 is one of 0, 1nm; 2nm; 3nm; 4nm; 5nm; 10nm; 15nm; 20nm; 25nm; 30nm, and any value between the above values.

[0081] Along the second direction Y, there is also a corresponding relationship between the widths of the first embedded portion 525 and the second embedded portion 526, so as to satisfy the connection strength of the first embedded portion 525 and the second extension portion 516, and the connection strength of the second embedded portion 526 and the second extension portion 516.

[0082] The widths of both the first embedded portion 525 and the second embedded portion 526 range from 5µm to 25µm. The specific widths of the first embedded portion 525 and the second embedded portion 526 can be set according to usage requirements. For example, the width of the first embedded portion 525 can be one of 5µm, 6µm, 7µm, 8µm, 9µm, 10µm, 15µm, 20µm, or 25µm, or any width between these values. Similarly, the width of the second embedded portion 526 can be one of 5µm, 6µm, 7µm, 8µm, 9µm, 10µm, 15µm, 20µm, or 25µm, or any width between these values.

[0083] The ratio of the width of the first embedded portion 525 to the distance between two adjacent first collector electrodes 53 is in the range of 0.05 to 0.5; for example, the ratio of the width of the first embedded portion 525 to the distance between two adjacent first collector electrodes 53 is one of 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, and any ratio between the above ratios.

[0084] The ratio of the width of the second embedded portion 526 to the distance between two adjacent second collector electrodes 54 is in the range of 0.05 to 0.5; for example, the ratio of the width of the second embedded portion 526 to the distance between two adjacent second collector electrodes 54 is one of 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, and any ratio between the above ratios.

[0085] In some embodiments, along the first direction X, the ratio of the length of at least one first contact portion 513 in at least one first collector electrode 53 to the distance between adjacent first contact portions 513 is greater than the ratio of the length of at least one second contact portion 514 in at least one second collector electrode 54 to the distance between adjacent second contact portions 514. This allows the first collector electrode 53 and the second collector electrode 54 to be set with appropriate ratios according to the difficulty of collecting charge carriers, thereby reducing material usage and material costs while ensuring the efficiency of charge carrier collection.

[0086] In at least one first current collector electrode 53, the ratio of the length of the first contact portion 513 to the distance between adjacent first contact portions 513 is in the range of 0.1-5; for example, the ratio of the length of the first contact portion 513 to the distance between adjacent first contact portions 513 is one of 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, and any ratio between the above ratios.

[0087] In at least one second current collector electrode 54, the ratio of the length of the second contact portion 514 to the distance between adjacent second contact portions 514 is in the range of 0.1-5; for example, the ratio of the length of the second contact portion 514 to the distance between adjacent second contact portions 514 is one of 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, and any ratio between the above ratios.

[0088] Along the first direction X, the sum of the lengths of the plurality of first contact portions 513 in at least one first collector electrode 53 along the first direction X is greater than the sum of the lengths of the plurality of second contact portions 514 in at least one second collector electrode 54 along the first direction X. Thus, the plurality of first contact portions 513 in the first collector electrode 53 are longer than the plurality of second contact portions 514 in the second collector electrode 54. This allows the first collector electrode 53 and the second collector electrode 54 to be set with appropriate thicknesses according to the difficulty of collecting charge carriers, thereby reducing material usage and material costs while ensuring the efficiency of collecting charge carriers.

[0089] In at least one first collector electrode 53, the length of at least one first contact portion 513 along the first direction X is greater than the length of at least one second contact portion 514 along the first direction X in at least one second collector electrode 54; thus, the first contact portion 513 can be adapted to the difficulty of collecting carriers in the first doped conductive layer 21, and the second contact portion 514 can be adapted to the difficulty of collecting carriers in the second doped conductive layer 22, thereby reducing material usage and material cost while ensuring the efficiency of carrier collection.

[0090] In at least one first collector electrode 53, the length of the first contact portion 513 along the first direction X is 5um to 100um. For example, the length of the first contact portion 513 along the first direction X is one of 5um, 6um, 7um, 8um, 9um, 10um, 20um, 30um, 40um, 50um, 60um, 70um, 80um, 90um, 100um, or any length between the above lengths.

[0091] In at least one second collector electrode 54, the length of the second contact portion 514 along the first direction X is 5um to 100um. For example, the length of the second contact portion 514 along the first direction X is one of 5um, 6um, 7um, 8um, 9um, 10um, 20um, 30um, 40um, 50um, 60um, 70um, 80um, 90um, 100um, or any length between the above lengths.

[0092] Along the second direction Y, the width of the first contact portion 513 along the second direction is greater than the width of the second contact portion 514. In this way, the width of the first contact portion 513 can be adapted to the difficulty of collecting charge carriers in the first doped conductive layer 21, and the width of the second contact portion 514 can be adapted to the difficulty of collecting charge carriers in the second doped conductive layer 22. While ensuring the efficiency of charge carrier collection, the amount of material used and the material cost are reduced.

[0093] Along the second direction Y, the width of the first contact portion 513 along the second direction is 2μm-50μm. For example, the width of the first contact portion 513 along the second direction is one of 2μm, 5μm, 10μm, 15μm, 20μm, 25μm, 30μm, 35μm, 40μm, 45μm, 50μm, or any width between the above widths.

[0094] Along the second direction Y, the width of the second contact portion 514 is 2μm-50μm; for example, the width of the first contact portion 513 along the second direction is one of 2μm, 5μm, 10μm, 15μm, 20μm, 25μm, 30μm, 35μm, 40μm, 45μm, 50μm, or any width between the above widths.

[0095] Along the second direction Y, the width of the first transmission section 523 is in the range of 10μm to 100μm; for example, the width of the first transmission section 523 is one of 10μm, 20μm, 30μm, 40μm, 50μm, 60μm, 70μm, 80μm, 90μm, 100μm, or any width between the above widths.

[0096] Along the second direction Y, the width of the second transmission section 524 is in the range of 10μm to 100μm; for example, the width of the second transmission section 524 is one of 10μm, 20μm, 30μm, 40μm, 50μm, 60μm, 70μm, 80μm, 90μm, 100μm, or any width between the above widths.

[0097] When the doped conductive layer 20 is disposed on the first side 11 and the second side 12, the solar cell is a bifacial cell, for example, the solar cell is a Topcon cell. The following explanation will further illustrate the solar cell as a Topcon cell.

[0098] The doped conductive layer 20 includes a first doped conductive layer 21 and a second doped conductive layer 22. The first doped conductive layer 21 is disposed on a first side 11, and the second doped conductive layer 22 is disposed on a second side 12. The first side 11 is the light-facing surface. The passivation layer 30 includes a first passivation layer 31 and a second passivation layer 32. The first passivation layer 31 is disposed on the side of the first doped conductive layer 21 away from the first side 11, and the second passivation layer 32 is disposed on the side of the second doped conductive layer 22 away from the second side 12. The antireflection layer 40 includes a first antireflection layer 43 and a second antireflection layer 44. The first antireflection layer 43 is disposed on the side of the first passivation layer 31 away from the first side 11, and the second antireflection layer 44 is disposed on the side of the second passivation layer 32 away from the second side 12. The collector electrode 50 includes a first collector electrode 53 and a second collector electrode 54. The first collector electrode 53 is disposed on the side of the first passivation layer 31 away from the semiconductor substrate 10, and the second collector electrode 54 is disposed on the side of the second passivation layer 32 away from the semiconductor substrate 10. Along the third direction Z, the thickness of at least one first collector electrode 53 is greater than the thickness of at least one second collector electrode 54.

[0099] According to the solar cell of the present application embodiment, the first current collector electrode 53 located on the light-facing side is relatively high. During the manufacturing of the solar cell, under the same sintering conditions, the first current collector electrode 53 penetrates deeper into the first doped conductive layer 21, which makes the first current collector electrode 53 have a stronger collection capability. The thickness of the current collector electrode is set according to the difference in the difficulty of collecting carriers in the first doped conductive layer 21 and the second doped conductive layer 22, so as to reduce the amount of material used and the material cost while ensuring the collection efficiency of carriers.

[0100] The contact portion 51 includes a first contact portion 513 disposed within the first collector electrode 53 and a second contact portion 514 disposed within the second collector electrode 54. A plurality of first contact portions 513 pass through the first passivation layer 31 and are electrically connected to the first doped conductive layer 21, and a plurality of second contact portions 514 pass through the second passivation layer 32 and are electrically connected to the second doped conductive layer 22. In the third direction Z, the thickness of at least one first contact portion 513 is greater than that of at least one second contact portion 514. Thus, the first contact portion 513 has a larger connection area with the doped conductive layer than the second contact portion 514, and has a stronger carrier collection capability. This is to adapt to the difference in carrier collection difficulty between the first doped conductive layer 21 and the second doped conductive layer 22, and to reduce the amount of material used and the material cost.

[0101] The extension portion 511 includes a first extension portion 515 disposed within the first collector electrode 53 and a second extension portion 516 disposed within the second collector electrode 54. Along the third direction Z, the thickness of the first extension portion 515 is greater than the thickness of the second extension portion 516. That is, the first extension portion 515 has a greater thickness in the doped conductive layer than the second extension portion 516. The first extension portion 515 has a stronger carrier collection capability than the second extension portion 516, in order to adapt to the difference in carrier collection difficulty between the first doped conductive layer 21 and the second doped conductive layer 22, and reduce the amount of material used and the material cost.

[0102] This application also provides a photovoltaic module, which includes at least one battery string, an encapsulation layer, and a cover plate; the battery string is formed by connecting multiple solar cells as described above; the encapsulation layer is used to cover the surface of the battery string; and the cover plate is used to cover the surface of the encapsulation layer away from the battery string.

[0103] Because photovoltaic modules use the aforementioned solar cells, they have low material costs, and the high tensile strength after welding the solar cells can also improve the stability of the photovoltaic modules.

[0104] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0105] The various embodiments in this specification are described in a related manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. For embodiments of devices, electronic devices, computer-readable storage media, and computer program products containing instructions, the descriptions are relatively simple because they are basically similar to the method embodiments; relevant parts can be referred to the descriptions of the method embodiments.

[0106] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of protection of the present invention.

Claims

1. A solar cell having opposing first side (11) and second side (12), characterized in that, include: Semiconductor substrate (10); A doped conductive layer (20) is disposed on the semiconductor substrate (10); A passivation layer (30) is disposed on the side of the doped conductive layer (20) away from the semiconductor substrate (10); An antireflection layer (40) is disposed on the side of the passivation layer (30) away from the semiconductor substrate (10), and the antireflection layer (40) has an upper surface (41) away from the semiconductor substrate (10); Multiple collector electrodes (50) are disposed on the antireflection layer (40), each collector electrode (50) extends along a first direction (X), and the multiple collector electrodes (50) are spaced apart along a second direction (Y); at least one collector electrode (50) includes multiple contact portions (51) and transmission portions (52), the multiple contact portions (51) are spaced apart along the first direction (X); the transmission portion (52) is disposed on the side of the contact portion (51) away from the semiconductor substrate (10) and is in contact with the multiple contact portions (51), the transmission portion (52) extends along the first direction (X); Along the third direction (Z), the transmission portion (52) includes an embedded portion (521) located below the upper surface (41), and at least one of the contact portions (51) includes an extension portion (511) located below the upper surface (41) and extending to be electrically connected to the doped conductive layer (20), wherein the thickness of the embedded portion (521) is less than the thickness of the extension portion (511); wherein the first direction (X), the second direction (Y), and the third direction (Z) intersect each other.

2. The solar cell according to claim 1, characterized in that, Along the third direction (Z), The thickness of the extension portion (511) ranges from 20 nm to 400 nm, and the thickness of the embedded portion (521) ranges from 10 nm to 150 nm; and / or, The difference between the thickness of the extension portion (511) and the thickness of the embedded portion (521) ranges from 10 nm to 300 nm; and / or, The ratio of the thickness of the antireflective layer (40) to the thickness of the embedded portion (521) ranges from 1 to 30; and / or, The difference between the thickness of the extension portion (511) and the sum of the thicknesses of the antireflection layer (40), the passivation layer (30), and the doped conductive layer (20) ranges from 20 nm to 250 nm; and / or, The ratio of the thickness of the extension portion (511) to the sum of the thicknesses of the antireflection layer (40), the passivation layer (30), and the doped conductive layer (20) ranges from 0.3 to 0.99; and / or, The difference between the thickness of the embedded portion (521) and the sum of the thicknesses of the antireflection layer (40) and the passivation layer (30) ranges from 0 nm to 90 nm; and / or, The ratio of the thickness of the embedded portion (521) to the sum of the thicknesses of the antireflection layer (40) and the passivation layer (30) is in the range of 0.1 to 0.

9.

3. The solar cell according to claim 1, characterized in that, Along the second direction (Y), The width of the transmission part (52) ranges from 50µm to 150µm, and the width of the contact part (51) ranges from 5µm to 25µm; and / or, The difference between the width of the transmission section (52) and the width of the contact section (51) ranges from 40µm to 120µm; and / or, The ratio of the width of the transmission part (52) to the width of the contact part (51) is 2-20.

4. The solar cell according to claim 1, characterized in that, Along the first direction (X), The length of the transmission part (52) ranges from 150 mm to 210 mm, and the length of at least one of the contact parts (51) ranges from 0.1 mm to 5 mm; and / or, The ratio of the length of the transmission section (52) to the sum of the lengths of the corresponding plurality of contact sections (51) is 1-20.

5. The solar cell according to claim 1, characterized in that, The embedded portion (521) is located within the antireflection layer (40), or the embedded portion (521) burns through the antireflection layer (40) and enters the passivation layer (30).

6. The solar cell according to claim 1, characterized in that, The contact portion (51) is a honeycomb structure including multiple holes, and the transmission portion (52) includes multiple metal particles; the interface between the transmission portion (52) and the contact portion (51) includes multiple interface regions, and in at least a portion of the interface regions, the metal particles are filled in the holes.

7. The solar cell according to claim 1, characterized in that, The doped conductive layer (20) includes a first doped conductive layer (21) and a second doped conductive layer (22) alternately disposed on the first side (11); The plurality of collector electrodes (50) include a plurality of first collector electrodes (53) and a plurality of second collector electrodes (54), wherein the plurality of first collector electrodes (53) are disposed on the side of the first doped conductive layer (21) away from the semiconductor substrate (10), and at least one first collector electrode (53) includes a plurality of first contact portions (513) and first transmission portions (523); A plurality of second collector electrodes (54) are disposed on the side of the second doped conductive layer (22) away from the semiconductor substrate (10), and at least one second collector electrode (54) includes a plurality of second contact portions (514) and a second transmission portion (524); The extension portion (511) includes a first extension portion (515) disposed within the first collector electrode (53) and a second extension portion (516) disposed within the second collector electrode (54); Along the third direction (Z), the thickness of the first extension portion (515) is less than the thickness of the second extension portion (516).

8. The solar cell according to claim 7, characterized in that, Along the third direction (Z), The thickness of the first extension portion (515) ranges from 3 nm to 8 nm, and the thickness of the second extension portion (516) ranges from 3 nm to 8 nm; and / or, The ratio of the thickness of the first extension portion (515) to the thickness of the second extension portion (516) is in the range of 0.5–1; and / or, The difference between the thickness of the first extension portion (515) and the thickness of the second extension portion (516) is in the range of 0-5 nm.

9. The solar cell according to claim 7, characterized in that, Along the second direction (Y), The widths of both the first extension portion (515) and the second extension portion (516) range from 5µm to 25µm; and / or, The ratio of the width of the first extension portion (515) to the distance between two adjacent first collector electrodes (53) is in the range of 0.05–0.5; and / or, The ratio of the width of the second extension portion (516) to the distance between two adjacent second collector electrodes (54) is in the range of 0.05-0.

5.

10. The solar cell according to claim 7, characterized in that, Along the second direction (Y), the embedded portion (521) includes a first embedded portion (525) disposed in the first collector electrode (53) and a second embedded portion (526) disposed in the second collector electrode (54), and along the third direction (Z), the thickness of the first embedded portion (525) is smaller than that of the second embedded portion (526).

11. The solar cell according to claim 7, characterized in that, Along the second direction (Y), the embedded portion (521) includes a first embedded portion (525) disposed within the first collector electrode (53) and a second embedded portion (526) disposed within the second collector electrode (54), and along the third direction (Z), The thickness of the first embedded portion (525) ranges from 10 nm to 80 nm, and the thickness of the second embedded portion (526) ranges from 20 nm to 100 nm; and / or, The ratio of the thickness of the first embedded portion (525) to the thickness of the second embedded portion (526) is in the range of 0.5–1; and / or, The difference between the thickness of the first embedded portion (525) and the thickness of the second embedded portion (526) is in the range of 0-30 nm.

12. The solar cell according to claim 10, characterized in that, Along the second direction (Y), The widths of both the first embedded portion (525) and the second embedded portion (526) range from 5µm to 25µm; and / or, The ratio of the width of the first embedded portion (525) to the spacing between the two adjacent first collector electrodes (53) is in the range of 0.05–0.5; and / or, The ratio of the width of the second embedded portion (526) to the distance between the two adjacent second collector electrodes (54) is in the range of 0.05-0.

5.

13. The solar cell according to claim 1, characterized in that, The doped conductive layer (20) includes a first doped conductive layer (21) and a second doped conductive layer (22). The first doped conductive layer (21) is disposed on the first side (11), and the second doped conductive layer (22) is disposed on the second side (12). The first side (11) is the light-facing side of the solar cell. The passivation layer (30) includes a first passivation layer (31) and a second passivation layer (32). The first passivation layer (31) is disposed on the side of the first doped conductive layer (21) away from the first side (11), and the second passivation layer (32) is disposed on the side of the second doped conductive layer (22) away from the second side (12). The current collector (50) includes a first current collector (53) and a second current collector (54). The first current collector (53) is disposed on the side of the first passivation layer (31) away from the semiconductor substrate (10), and the second current collector (54) is disposed on the side of the second passivation layer (32) away from the semiconductor substrate (10). Along the third direction (Z), the thickness of at least one of the first collector electrodes (53) is greater than the thickness of at least one of the second collector electrodes (54).

14. The solar cell according to claim 13, characterized in that, The contact portion (51) includes a first contact portion (513) disposed within the first current collector electrode (53) and a second contact portion (514) disposed within the second current collector electrode (54). A plurality of first contact portions (513) pass through the first passivation layer (31) and are electrically connected to the first doped conductive layer (21). A plurality of second contact portions (514) pass through the second passivation layer (32) and are electrically connected to the second doped conductive layer (22). Along the third direction (Z), the thickness of at least one of the first contact portions (513) is greater than that of at least one of the second contact portions (514).

15. The solar cell according to claim 13, characterized in that, The extension portion (511) includes a first extension portion (515) disposed within the first collector electrode (53) and a second extension portion (516) disposed within the second collector electrode (54). Along the third direction (Z), the thickness of the first extension portion (515) is greater than the thickness of the second extension portion (516).

16. The solar cell according to any one of claims 1-15, characterized in that, The materials of the plurality of contact portions (51) and the transmission portion (52) are different; and / or, The transmission unit (52) includes at least one of copper, nickel, chromium, antimony, lead, zinc, silver-plated copper, and silver-plated copper containing silver powder, and / or... The contact portion (51) includes at least one of silver, silver-plated copper, and silver-plated copper containing silver powder.

17. The solar cell according to any one of claims 1-15, characterized in that, The plurality of contact portions (51) include silver particles, the transmission portion (52) includes copper particles, and the copper particles are at least partially covered by a coating layer, the coating layer including an organic portion and an inorganic portion.

18. A photovoltaic module, characterized in that, include: At least one battery string, said battery string being formed by connecting a plurality of solar cells as described in any one of claims 1 to 17; An encapsulation layer for covering the surface of the battery string; and, A cover plate is used to cover the surface of the encapsulation layer away from the battery string.

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