Solar cell and manufacturing method thereof

Abstract

The invention discloses a solar cell and a manufacturing method thereof, relates to the technical field of photovoltaics, and aims to reduce the electric leakage risk of the solar cell. The solar cell comprises a cell function layer, a first electrode layer, an insulation protection layer and a second electrode layer. The battery functional layer has a first surface and a second surface opposite to each other, and a side surface for connection. The first electrode layer is arranged on the first surface. The insulating protection layer is arranged on the side surface and extends to cover a part of the first electrode layer on the first surface. And the insulating protection layer is in direct contact with the side surface of the battery functional layer. The second electrode layer is arranged on the second surface and extends to cover the insulating protection layer. And the conduction types of carriers transmitted by the second electrode layer and the first electrode layer are opposite. The orthographic projection of the second electrode layer on the first surface is located in the orthographic projection of the insulating protection layer on the first surface. One of the first surface and the second surface is a light-facing surface, and at least one of the second electrode layer and the first electrode layer, which is arranged on the light-facing surface, is a transparent conductive layer.

Description

Technical Field

[0001] The present invention relates to the field of photovoltaic technology, and in particular to a solar cell and a manufacturing method thereof. Background Art

[0002] As a green energy source, solar cells play a positive role in energy conservation and emission reduction. With the development of the photovoltaic industry, solar cell technology has become increasingly mature. 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 out the carriers, thereby facilitating the effective use of electrical energy. As an environmentally friendly renewable energy source, solar energy has received more and more attention in recent years. Correspondingly, the application range of photovoltaic solar cells based on the photoelectric effect is also becoming wider and wider.

[0003] However, existing solar cells have a high risk of electrical leakage, which reduces the electrical reliability of the solar cells. Summary of the invention

[0004] The purpose of the present invention is to provide a solar cell and a manufacturing method thereof, which are used to reduce the risk of leakage of the solar cell and improve the electrical reliability of the solar cell. At the same time, the side of the battery functional layer can also be protected by an insulating protective layer to improve the structural reliability of the solar cell.

[0005] In order to achieve the above-mentioned object, in a first aspect, the present invention provides a solar cell, which comprises: a battery functional layer, a first electrode layer, an insulating protective layer and a second electrode layer. The battery functional layer has a first surface and a second surface opposite to each other, and a side surface for connecting the first surface and the second surface. The first electrode layer is arranged on the first surface. The insulating protective layer is arranged on the side surface and extends to cover a portion of the first electrode layer located on the first surface. The insulating protective layer is in direct contact with the side surface of the battery functional layer. The second electrode layer is arranged on the second surface and extends to cover the insulating protective layer. The conductivity type of the carriers transmitted by the second electrode layer and the first electrode layer is opposite. The orthographic projection of the second electrode layer on the first surface is located within the orthographic projection of the insulating protective layer on the first surface. One of the first surface and the second surface is a light-facing surface, and at least one of the second electrode layer and the first electrode layer arranged on the light-facing surface is a transparent conductive layer.

[0006] In the case of adopting the above technical solution, in the solar cell provided by the present invention, the first electrode layer and the second electrode layer are used to transmit carriers of opposite conductivity types, and the electrons and holes generated by the battery functional layer after absorbing photons can be respectively guided out, which is conducive to the formation of photocurrent. Among them, one of the first surface and the second surface is a light-facing surface, and at least one of the second electrode layer and the first electrode layer, which is arranged on the light-facing surface, is a transparent conductive layer to reduce shading loss and improve the conversion efficiency of the solar cell.

[0007] In addition, the above-mentioned first electrode layer is arranged on the first surface of the battery functional layer. Moreover, the solar cell provided by the present invention also includes an insulating protective layer, which is arranged on the side of the battery functional layer and extends to cover part of the first electrode layer located on the first surface. Based on this, although the second electrode layer with the opposite conductivity type of the carrier transmitted by the first electrode layer will still extend to cover the side of the battery functional layer and the top of the first surface, because the orthographic projection of the second electrode layer on the first surface is located within the orthographic projection of the insulating protective layer on the first surface, the insulating protective layer can isolate the first electrode layer and the second electrode layer with opposite conductivity types of the carriers transmitted, and the insulating protective layer can also isolate the carrier transport layer with opposite conductivity types of the carriers transmitted in the battery functional layer from the second electrode layer on the side of the battery functional layer, to prevent short circuits and reduce the risk of leakage, thereby improving the electrical reliability of the solar cell and ensuring that the second electrode layer has a larger The area ratio is large, thereby ensuring that the carriers generated at the edge of the battery functional layer can also be collected and exported by the second electrode layer in time, thereby improving the conversion efficiency of the solar cell; at the same time, the second electrode layer covers the insulating protective layer, especially when the insulating protective layer is an organic material or an organic-inorganic laminated material, the second electrode layer covers the insulating protective layer. On the one hand, it can reduce the aging of the insulating protective layer by ultraviolet light; on the other hand, it can also isolate oxygen to prevent thermal oxygen erosion and aging; it can isolate water vapor to prevent deliquescence erosion; in addition, it can also improve the temperature distribution at the edge and side of the solar cell to prevent local overheating from causing a decrease in efficiency; in addition, it can also make the light absorbed inside the solar cell reflected on the inner side surface of the battery to reduce light loss.

[0008] Furthermore, the portion of the insulating protective layer covering the side of the battery functional layer can also isolate the battery functional layer from the external environment, reducing the risk of scratches and other damage to the side of the battery functional layer due to extrusion, collision and other factors after transportation or packaging. At the same time, it can also reduce the risk of water vapor and the like entering the battery from the side of the battery and causing battery failure, thereby increasing the service life of solar cells. Secondly, the above-mentioned insulating protective layer is in direct contact with the side of the battery functional layer, and in actual application, in the photovoltaic field, the insulating material (such as silicon oxide, tin oxide, titanium oxide or silicon nitride, etc.) used to make the insulating protective layer has a passivation effect, so the insulating protective layer may also passivate the battery functional layer, reduce the carrier recombination rate, and improve the conversion efficiency of solar cells.

[0009] As a possible implementation solution, the material of the insulating protective layer is an insulating light-transmitting material.

[0010] When the above technical solution is adopted, the insulating protective layer is not only arranged on the side of the battery functional layer, but also extends to cover the part of the first electrode layer located on the first surface. At this time, the insulating protective layer covers the part of the first surface of the battery functional layer used to achieve photoelectric conversion. Based on this, when the material of the insulating protective layer is an insulating light-transmitting material, the shading loss of the insulating protective layer on the side of the battery functional layer, especially on the side of the first surface of the battery functional layer, can be reduced, ensuring that the solar cell has a higher conversion efficiency.

[0011] As a possible implementation scheme, the material of the insulating protection layer includes: at least one of tin oxide, titanium oxide, silicon oxide, silicon nitride, polytetrafluoroethylene and polyethylene terephthalate.

[0012] In the case of adopting the above technical solution, tin oxide, titanium oxide, silicon oxide, silicon nitride, polytetrafluoroethylene and polyethylene terephthalate all have good insulating properties, which is conducive to further reducing the risk of leakage between the second electrode layer and the first electrode layer and the carrier transport layer of the opposite conductivity type of the carriers transmitted by themselves. In addition, tin oxide, titanium oxide, silicon oxide, silicon nitride, polytetrafluoroethylene and polyethylene terephthalate are also insulating and light-transmitting materials, which can reduce the shading loss of the insulating protective layer and improve the conversion efficiency of solar cells. In addition, tin oxide, titanium oxide, silicon oxide, silicon nitride, polytetrafluoroethylene and polyethylene terephthalate each have a strong adhesion to the battery functional layer and the electrode layer, which is conducive to improving the structural reliability while ensuring that the insulating protective layer can prevent short circuits, reduce the risk of leakage, and ensure that the insulating protective layer and the second electrode layer have a relatively stable protective effect on the side of the battery functional layer.

[0013] As a possible implementation solution, the thickness of the insulating protection layer is greater than or equal to 10 nm and less than or equal to 50 nm.

[0014] When the above technical solution is adopted, the thickness of the insulating protective layer is within the above range, which is conducive to preventing the insulating properties of the insulating protective layer from being poor due to its small thickness, ensuring that the second electrode layer can be isolated from the first electrode layer and the carrier transport layer of the opposite conductivity type of the carriers it transmits through the insulating protective layer, which is conducive to further reducing the risk of leakage between the second electrode layer and the first electrode layer and the carrier transport layer of the opposite conductivity type of the carriers it transmits. In addition, it can also prevent the use of large consumables due to the large thickness of the insulating protective layer, which is conducive to controlling the manufacturing cost of solar cells; and prevent the insulating protective layer from being easily formed through the gap between the mask covering part of the first electrode layer and the first electrode layer due to the large thickness of the insulating protective layer. Covering the middle area of ​​the first electrode layer through the gap between the mask covering part of the first electrode layer and the first electrode layer reduces the difficulty of interconnection between the first electrode layer and the external circuit.

[0015] As a possible implementation scheme, on the first surface, a distance between an edge of the second electrode layer and an edge of the insulating protection layer is greater than or equal to 0.5 mm and less than or equal to 20 mm.

[0016] When the above technical solution is adopted, the distance between the edge of the second electrode layer and the edge of the insulating protective layer is within the above range, which is conducive to preventing the distance between the second electrode layer and the first electrode layer in the direction parallel to the first surface from being small due to the small distance, thereby reducing the risk of leakage between the second electrode layer and the first electrode layer; at the same time, it can also prevent the formation range of the insulating protective layer on the first surface from being small, resulting in the need to strictly control the manufacturing parameters to prevent short circuits in order to form a second electrode layer with a smaller plating range on the first surface, thereby reducing the manufacturing difficulty of the second electrode layer. In addition, it can also prevent the formation range of the insulating protective layer on the first surface from being too large and / or the formation range of the second electrode layer on the first surface from being too small due to the large distance, thereby further reducing the manufacturing difficulty of the second electrode layer, while reducing the amount of consumables used for the insulating protective layer and the difficulty of interconnection between the first electrode layer and the external circuit.

[0017] As a possible implementation scheme, on the first surface, a distance between an edge of the insulating protection layer and an edge of the first surface is less than or equal to 30 mm.

[0018] When the above technical solution is adopted, the distance between the edge of the insulating protective layer and the edge of the first surface is within the above range, which is beneficial to prevent the insulating protective layer from being formed over a large range on the first surface due to the large distance, thereby reducing the consumption of consumables of the insulating protective layer and the difficulty of interconnection between the first electrode layer and the external circuit.

[0019] As a possible implementation scheme, on the first surface, the edge of the second electrode layer close to the center of the first surface is straight, wavy, serrated or comb-shaped. In this case, the edge morphology of the second electrode layer close to the center of the first surface has multiple examples, which is conducive to improving the applicability of the solar cell provided by the present invention in different application scenarios, and is also conducive to reducing the difficulty of manufacturing solar cells. In addition, the edge contour morphology of the second electrode layer on the first surface that is adapted thereto can be determined based on the edge contour morphology of the insulating protective layer on the first surface, ensuring that the second electrode layer and the first electrode layer can be isolated by the insulating protective layer to prevent short circuits.

[0020] As a possible implementation scheme, the distance between the edge of the first electrode layer and the edge of the first surface is less than or equal to 5 mm along the direction from the edge to the center of the first surface. In this case, it is beneficial for the first electrode layer to have a larger area share on the first surface, and it is beneficial for the corresponding conductive type carriers generated in each area of ​​the battery functional layer along the direction parallel to the first surface to be collected and exported by the first electrode layer in time, further improving the conversion efficiency of the solar cell.

[0021] As a possible implementation scheme, on the first surface and along the direction from the edge to the center of the first surface, the distance between the edge of the insulating protection layer and the edge of the first electrode layer is greater than or equal to 1 mm and less than or equal to 25 mm.

[0022] When the above technical solution is adopted, the distance between the edge of the insulating protective layer and the edge of the first electrode layer is within the above range, which helps to prevent the distance between the edge of the insulating protective layer on the first surface and the edge of the first surface from being small due to the small distance (that is, the formation range of the insulating protective layer on the first surface is small), ensuring that the second electrode layer can be isolated from the first electrode layer and the carrier transport layer of the opposite conductivity type of the carriers it transports through the insulating protective layer. In addition, it can also prevent the distance between the edge of the insulating protective layer on the first surface and the edge of the first surface from being too large due to the large distance, ensuring a low risk of leakage while reducing the amount of consumables used for the insulating protective layer.

[0023] As a possible implementation solution, the above-mentioned battery functional layer includes a perovskite light absorption layer.

[0024] When the above technical solution is adopted, the perovskite cell has the advantages of simple manufacturing process, low cost, good light absorption effect, high efficiency and stable carriers. Therefore, when the cell functional layer includes a perovskite light absorption layer, it is beneficial to further improve the conversion efficiency of the solar cell. In addition, during the large-scale manufacturing process of the perovskite cell, the surface uniformity is not high, which easily causes a gap between the cell functional layer and the mask. The insulating protective layer in the solar cell provided by the present invention can solve the short circuit problem caused by the electrode layer winding plating connection in the existing perovskite cell and / or the problem of high carrier recombination rate at the edge of the cell caused by shielding the winding plating by the mask, thereby improving the conversion efficiency and yield of the solar cell.

[0025] As a possible implementation scheme, the solar cell is a stacked solar cell. The stacked solar cell includes a bottom cell and a top cell connected in series. Along the direction from the top cell to the bottom cell, the cell functional layer includes: a first carrier transport layer, a first light absorption layer, a second carrier transport layer, a middle composite layer, a third carrier transport layer, a second light absorption layer, and a fourth carrier transport layer. The top cell includes a first carrier transport layer, a first light absorption layer, and a second carrier transport layer, and the bottom cell includes a third carrier transport layer, a second light absorption layer, and a fourth carrier transport layer.

[0026] In a second aspect, the present invention provides a method for manufacturing a solar cell, the method for manufacturing a solar cell comprising: first, forming a battery functional layer. The battery functional layer has a first surface and a second surface opposite to each other, and a side surface for connecting the first surface and the second surface. Next, a first electrode layer is formed on the first surface. Next, an insulating protective layer is formed on the side surface and extends to cover a portion of the first electrode layer on the first surface, and the insulating protective layer is in direct contact with the side surface of the battery functional layer. Next, a second electrode layer is formed on the second surface and extends to cover the insulating protective layer. The second electrode layer and the first electrode layer have opposite conductivity types for the carriers transmitted. The orthographic projection of the second electrode layer on the first surface is located within the orthographic projection of the insulating protective layer on the first surface. One of the first surface and the second surface is a light-facing surface, and at least one of the second electrode layer and the first electrode layer that is disposed on the light-facing surface is a transparent conductive layer.

[0027] As a possible implementation scheme, the above-mentioned insulating protective layer formed on the side and extending to cover the portion of the first electrode layer located on the first surface includes: placing the battery functional layer formed with the first electrode layer on the deposition equipment platform from the second surface side of the battery functional layer. Next, a mask is set on the side of the first electrode layer away from the battery functional layer. The orthographic projection of the mask on the first surface is located within the orthographic projection of the first electrode layer on the first surface. Next, under the protection of the mask, the insulating protective layer is deposited on the portion of the first electrode layer located on the first surface and on the side.

[0028] As a possible implementation solution, along the direction from the edge to the center of the first surface, the distance between the edge of the mask and the edge of the first electrode layer is less than or equal to 25 mm.

[0029] When the above technical solution is adopted, the distance between the edge of the mask and the edge of the first electrode layer is within the above range, which is conducive to preventing the insulating protection layer from covering a larger area on the first electrode layer due to the larger distance, thereby reducing the difficulty of interconnection between the first electrode layer and the external circuit. In addition, it can also prevent the distance between the edge of the insulating protection layer on the first surface and the edge of the first electrode layer from being too small due to the smaller distance, thereby further reducing the risk of leakage between the second electrode layer and the first electrode layer on the first surface.

[0030] The beneficial effects of the second aspect of the present invention and its various implementations can be analyzed by referring to the beneficial effects of the first aspect and its various implementations, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0032] Figure 1 A schematic longitudinal cross-sectional view of the structure of a solar cell provided in an embodiment of the present invention Figure 1 ;

[0033] Figure 2 A schematic longitudinal cross-sectional view of the structure of a solar cell provided in an embodiment of the present invention Figure 2 ;

[0034] Figure 3 A schematic longitudinal cross-sectional view of the structure of a solar cell provided in an embodiment of the present invention Figure 3 ;

[0035] Figure 4 A schematic longitudinal cross-sectional view of the structure of a solar cell provided in an embodiment of the present invention Figure 4 ;

[0036] Figure 5 A schematic longitudinal cross-sectional view of the structure of a solar cell provided in an embodiment of the present invention Figure 5 ;

[0037] Figure 6 A schematic longitudinal cross-sectional view of the structure of a solar cell during the manufacturing process provided by an embodiment of the present invention Figure 1 ;

[0038] Figure 7 A schematic longitudinal cross-sectional view of the structure of a solar cell during the manufacturing process provided by an embodiment of the present invention Figure 2 ;

[0039] Figure 8 A schematic longitudinal cross-sectional view of the structure of a solar cell during the manufacturing process provided by an embodiment of the present invention Figure 3 ;

[0040] Fig. 9 A schematic longitudinal cross-sectional view of the structure of a solar cell during the manufacturing process provided by an embodiment of the present invention Figure 4 ;

[0041] Fig.10 A schematic longitudinal cross-sectional view of the structure of a solar cell during the manufacturing process provided by an embodiment of the present invention Figure 5 ;

[0042] Fig.11 A schematic longitudinal cross-sectional view of the structure of a solar cell during the manufacturing process provided by an embodiment of the present invention Figure 6 ;

[0043] Fig.12 A schematic longitudinal cross-sectional view of the structure of a solar cell during the manufacturing process provided by an embodiment of the present invention Figure 7 ;

[0044] Fig.13A schematic longitudinal cross-sectional view of the structure of a solar cell during the manufacturing process provided by an embodiment of the present invention Figure 8 ;

[0045] Fig.14 A schematic longitudinal cross-sectional view of the structure of a solar cell during the manufacturing process provided by an embodiment of the present invention Figure 9 ;

[0046] Fig.15 A schematic longitudinal cross-sectional view of the structure of a solar cell during the manufacturing process provided by an embodiment of the present invention Figure 10 ;

[0047] Fig.16 A schematic longitudinal cross-sectional view of the structure of a solar cell during the manufacturing process provided by an embodiment of the present invention Figure 10 one;

[0048] Fig.17 A schematic longitudinal cross-sectional view of the structure of a solar cell during the manufacturing process provided by an embodiment of the present invention Figure 10 two.

[0049] Figure numerals: 11 is a battery functional layer, 12 is a first surface, 13 is a second surface, 14 is a first electrode layer, 15 is an insulating protection layer, 16 is a second electrode layer, 17 is a bottom battery, 18 is a top battery, 19 is a first carrier transport layer, 20 is a first light absorption layer, 21 is a second carrier transport layer, 22 is a middle composite layer, 23 is a third carrier transport layer, 24 is a second light absorption layer, 25 is a fourth carrier transport layer, 26 is a mask, 27 is a light absorption layer, 28 is a first metal electrode, and 29 is a second metal electrode. DETAILED DESCRIPTION

[0050] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the present invention. In addition, in the following description, descriptions of known structures and technologies are omitted to avoid unnecessary confusion of the concept of the present invention.

[0051] Various structural schematic diagrams according to embodiments of the present invention are shown in the accompanying drawings. These figures are not drawn to scale, and some details are magnified and some details may be omitted for a clearer expression. The shapes of various regions and layers shown in the figures and the relative sizes and positional relationships therebetween are only exemplary, and may deviate in practice due to manufacturing tolerances or technical limitations, and those skilled in the art may additionally design regions / layers with different shapes, sizes, and relative positions according to actual needs.

[0052] In the context of the present invention, when a layer / element is referred to as being "on" another layer / element, the layer / element may be directly on the other layer / element, or there may be an intermediate layer / element between them. In addition, if a layer / element is "on" another layer / element in one orientation, then when the orientation is reversed, the layer / element may be "under" the other layer / element. In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention clearer, the present invention 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 invention and are not used to limit the present invention.

[0053] 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 the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined. The meaning of "several" is one or more, unless otherwise clearly and specifically defined.

[0054] In the description of the present invention, 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 the present invention can be understood according to specific circumstances.

[0055] As a green energy source, solar cells play a positive role in energy conservation and emission reduction. With the development of the photovoltaic industry, solar cell technology has become increasingly mature. 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 out the carriers, thereby facilitating the effective use of electrical energy. Secondly, as an environmentally friendly and renewable energy source, solar energy has received more and more attention in recent years. Correspondingly, the application scope of photovoltaic solar cells based on the photoelectric effect is also becoming wider and wider.

[0056] However, the existing solar cells have a high risk of leakage, which reduces the electrical reliability of the solar cells. Specifically, the existing solar cells generally include a battery functional layer, a first electrode layer and a second electrode layer. Among them, the battery functional layer generally includes a light absorption layer, and a first carrier transport layer and a second carrier transport layer arranged on both sides of the light absorption layer along the thickness direction. The first electrode layer and the second electrode layer are respectively used to guide the electrons or holes collected by the first carrier transport layer or the second carrier transport layer, which is conducive to the formation of photocurrent. However, in the actual manufacturing process, after forming the above-mentioned battery functional layer and the first electrode layer, and when forming the second electrode layer, not only will the second electrode layer be formed on the side of the battery functional layer corresponding to the light side or the backlight side of the battery, but also the side of the battery functional layer and the other side of the battery functional layer will also be plated with a second electrode layer. At this time, the second electrode layer plated on the side of the battery functional layer and on the other side of the battery functional layer transports carriers with conductivity types opposite to those of the first carrier transport layer and the first electrode layer. Therefore, the second electrode layer plated on the side of the battery functional layer and on the other side of the battery functional layer will cause a short circuit after being connected to the first carrier transport layer and the first electrode layer respectively.

[0057] In response to the above technical problems, those skilled in the art use a mask to block the edge of the corresponding surface of the battery functional layer when forming the second electrode layer, thereby preventing the second electrode layer from being plated around the side and the other side of the battery functional layer. However, the size of the mask is large, resulting in the inability of the carriers generated by the edge of the battery functional layer blocked by the mask to be collected by the second electrode layer in time. In addition, if the surface of one side of the battery functional layer forming the second electrode layer is not a flat polished surface in the strict sense, it is difficult to achieve seamless contact between the mask and the battery functional layer. At this time, even if the mask is used for blocking, the second electrode layer may still be plated around the side and the other side of the battery functional layer when the second electrode layer is formed, and the risk of leakage is still high.

[0058] In order to solve the above technical problems, in the first aspect, an embodiment of the present invention provides a solar cell. In terms of the type of battery, such as Figure 1 As shown, the solar cell provided in the embodiment of the present invention may be a single-layer solar cell; or Figure 2 As shown, the solar cell provided in the embodiment of the present invention may also be a stacked solar cell.

[0059] In terms of the cell structure, when the solar cell is a single-layer solar cell, the solar cell provided in the embodiment of the present invention may be any solar cell such as a silicon solar cell, a perovskite solar cell or a cadmium telluride solar cell. When the solar cell is a stacked solar cell, the solar cell may include a combination of at least two solar cells such as a silicon solar cell, a perovskite solar cell and a cadmium telluride solar cell.

[0060] Specifically, if Figure 1 As shown, the solar cell provided by the embodiment of the present invention includes: a battery function layer 11, a first electrode layer 14, an insulating protective layer 15 and a second electrode layer 16. The battery function layer 11 has a first surface 12 and a second surface 13 opposite to each other, and a side surface for connecting the first surface 12 and the second surface 13. The first electrode layer 14 is arranged on the first surface 12. The insulating protective layer 15 is arranged on the side surface and extends to cover the part of the first electrode layer 14 located on the first surface 12. The insulating protective layer 15 is in direct contact with the side surface of the battery function layer 11. The second electrode layer 16 is arranged on the second surface 13 and extends to cover the insulating protective layer 15. The conductivity type of the carriers used for transmission by the second electrode layer 16 and the first electrode layer 14 is opposite. The orthographic projection of the second electrode layer 16 on the first surface 12 is located within the orthographic projection of the insulating protective layer 15 on the first surface 12. One of the first surface 12 and the second surface 13 is a light-facing surface, and at least one of the second electrode layer 16 and the first electrode layer 14 arranged on the light-facing surface is a transparent conductive layer.

[0061] When the above technical solution is adopted, in the solar cell provided by the embodiment of the present invention, the first electrode layer and the second electrode layer are used to transmit carriers of opposite conductivity types, and the electrons and holes generated by the battery functional layer after absorbing photons can be respectively guided out, which is conducive to the formation of photocurrent. Among them, one of the first surface and the second surface is a light-facing surface, and at least one of the second electrode layer and the first electrode layer, which is arranged on the light-facing surface, is a transparent conductive layer to reduce shading loss and improve the conversion efficiency of the solar cell.

[0062] In addition, if Figure 1As shown, the first electrode layer 14 is disposed on the first surface 12 of the battery functional layer 11. In addition, the solar cell provided in the embodiment of the present invention further includes an insulating protective layer 15, which is disposed on the side of the battery functional layer 11 and extends to cover a portion of the first electrode layer 14 located on the first surface 12. Based on this, although the second electrode layer 16 of the opposite conductivity type of the carriers transmitted by the first electrode layer 14 will still extend to cover the side of the battery functional layer 11 and the top of the first surface 12, because the orthographic projection of the second electrode layer 16 on the first surface 12 is located within the orthographic projection of the insulating protection layer 15 on the first surface 12, the insulating protection layer 15 can isolate the first electrode layer 14 and the second electrode layer 16 of opposite conductivity types of the carriers transmitted, and the insulating protection layer 15 can also isolate the carrier transport layer of opposite conductivity types of the carriers transmitted in the battery functional layer 11 from the second electrode layer 16 on the side of the battery functional layer 11, to prevent short circuits and reduce the risk of leakage, improve the electrical reliability of the solar cell, and ensure that the second electrode layer 16 has a larger area occupancy on the second surface 13, thereby ensuring that the carriers generated at the edge of the battery functional layer 11 can also be collected and exported by the second electrode layer 16 in a timely manner, thereby improving the conversion efficiency of the solar cell. Furthermore, if Figure 1 As shown, the portion of the insulating protective layer 15 covering the side of the battery functional layer 11 can also isolate the battery functional layer 11 from the external environment, reducing the risk of scratches and other damage to the side of the battery functional layer 11 due to extrusion, collision and other factors after transportation or packaging. At the same time, it can also reduce the risk of water vapor entering the battery from the side of the battery and causing battery failure, thereby increasing the service life of the solar cell. Secondly, the above-mentioned insulating protection layer 15 is in direct contact with the side of the battery functional layer 11. In actual application, in the photovoltaic field, the insulating material (such as silicon oxide, tin oxide, titanium oxide or silicon nitride, etc.) used to manufacture the insulating protection layer 15 not only has insulating properties, but also has a passivation effect. Therefore, the insulating protection layer 15 may also passivate the battery functional layer 11, reduce the carrier recombination rate, and improve the conversion efficiency of the solar cell; at the same time, the second electrode layer 16 covers the insulating protection layer 15, especially when the insulating protection layer 15 is an organic material or an organic-inorganic laminated material, the second electrode layer 16 covers the insulating protection layer 15. On the one hand, it can reduce the aging of the insulating protection layer 15 by ultraviolet light; on the other hand, it can also isolate oxygen to prevent thermal oxygen erosion and aging; it can isolate water vapor to prevent deliquescence erosion; in addition, it can also improve the temperature distribution at the edge and side of the solar cell to prevent local overheating from causing a decrease in efficiency; in addition, it can also make the light absorbed inside the solar cell reflected on the internal side surface of the battery to reduce light loss.

[0063] In actual application, the embodiments of the present invention do not specifically limit the structure and materials of the battery functional layer, as long as they can be applied to the solar cell provided by the embodiments of the present invention.

[0064] For example, Figure 1 As shown, in the case where the solar cell is a single-layer solar cell, the cell functional layer 11 may include a light absorbing layer 27, a first carrier transport layer 19, and a second carrier transport layer 21. The first carrier transport layer 19 and the second carrier transport layer 21 are respectively arranged on both sides of the light absorbing layer 27 along its own thickness direction. In addition, one of the first carrier transport layer 19 and the second carrier transport layer 21 is an electron transport layer and the other is a hole transport layer. The structure, material and thickness of the light absorbing layer 27, the first carrier transport layer 19 and the second carrier transport layer 21 included in the single-layer solar cell can be determined according to the specific type of solar cell in the actual application scenario, and are not specifically limited here.

[0065] For example, when the solar cell provided in the embodiment of the present invention is a single-layer solar cell, if the solar cell is a silicon solar cell, one of the first carrier transport layer and the second carrier transport layer is an N-type doped silicon layer, and the other is a P-type doped silicon layer. The light absorption layer can be an intrinsic silicon substrate, an N-type doped silicon substrate, or a P-type doped silicon substrate.

[0066] For example, in the case where the solar cell provided in the embodiment of the present invention is a single-layer solar cell, if the solar cell is a perovskite cell, one of the first carrier transport layer and the second carrier transport layer 13 may be made of a material including [6,6]-phenyl C60 butyric acid methyl ester (abbreviated as PC 60 BM), [6,6]-phenyl C70 butyric acid methyl ester (abbreviated as PC 70 BM), [6,6]-phenyl C80 butyric acid methyl ester (abbreviated as PC 80 BM) and [6,6]-phenyl C82 butyric acid methyl ester (abbreviated as PC 82The electron transport layer of at least one of the above-mentioned materials may be a material including (2-(9H-carbazole-9-yl)ethyl)phosphonic acid) (abbreviated as 2PACz), (4-(9H-carbazole-9-yl)ethyl)phosphonic acid) (abbreviated as 4PACz), [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid (abbreviated as MeO-2PACz), [4-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid (abbreviated as MeO-2PACz), The hole transport layer is at least one of [2-(3,6-dimethyl-9H-carbazole-9-yl)ethyl]phosphonic acid (can be abbreviated as MeO-4PACz), [2-(3,6-dimethyl-9H-carbazole-9-yl)ethyl]phosphonic acid (can be abbreviated as Me-2PACz), [4-(3,6-dimethyl-9H-carbazole-9-yl)ethyl]phosphonic acid (can be abbreviated as Me-4PACz) and [4-(3,6-dibromo-9H-carbazole-9-yl)butyl] (can be abbreviated as 2Br-4PACz). The molecular formula of the material of the light absorption layer is ABX3. Among them, A and B are cations of different sizes, and X is an anion bonded to both. In addition, the cation B coordinates with the anion X to form a regular octahedral symmetrical structure, and the cation A is located at the center of the eight regular octahedra, and the cation B is located at the center of the regular octahedron. Specifically, the material contained in the perovskite absorption layer can be an inorganic perovskite material, an organic perovskite material, or an organic-inorganic hybrid perovskite material. For example, the material contained in the perovskite absorption layer can be CsPbI2Br, MAPbBr3, FAPbI3 or Cs 1-y-z FA y MA z PbI 3-x Br x (wherein, FA is methyl ether, MA is methylamine, 0≤x≤3, 0≤y≤1, 0≤z≤1, and 0≤y+z≤1), etc. In this case, the solar cell provided by the embodiment of the present invention can have the advantages of high conversion efficiency, low exciton binding energy, flexible and adjustable band gap, simple manufacturing process and low cost.

[0067] For example, Figure 2As shown, in the case where the solar cell is a stacked solar cell, the stacked solar cell includes a bottom cell 17 and a top cell 18 connected in series. Along the direction from the top cell 18 to the bottom cell 17, the cell functional layer 11 may include: a first carrier transport layer 19, a first light absorption layer 20, a second carrier transport layer 21, a middle composite layer 22, a third carrier transport layer 23, a second light absorption layer 24, and a fourth carrier transport layer 25. The top cell 18 includes the first carrier transport layer 19, the first light absorption layer 20, and the second carrier transport layer 21, and the bottom cell 17 includes the third carrier transport layer 23, the second light absorption layer 24, and the fourth carrier transport layer 25. In this case, when the stacked solar cell is in working condition, sunlight with shorter wavelength can be utilized by the top cell 18 located above, and sunlight with longer wavelength can be transmitted through the top cell 18 to the bottom cell 17 and utilized by the bottom cell 17. Therefore, the stacked solar cell can utilize sunlight with a relatively wide wavelength range, so that the solar cell provided by the embodiment of the present invention can have a higher light energy utilization rate.

[0068] Specifically, the materials and thicknesses of the first carrier transport layer, the first light absorption layer, and the second carrier transport layer included in the above-mentioned top battery can be determined according to the specific type of the top battery in the actual application scenario. The materials and thicknesses of the third carrier transport layer, the second light absorption layer, and the fourth carrier transport layer included in the bottom battery can be determined according to the specific type of the bottom battery in the actual application scenario. In addition, the conductivity types of the third carrier transport layer and the fourth carrier transport layer can be determined according to the conductivity types of the first carrier transport layer and the second carrier transport layer in the top battery, as long as the top battery and the bottom battery in the stacked solar cell can be connected in series. Specifically, the first carrier transport layer included in the top battery is of opposite conductivity type to the fourth carrier transport layer included in the bottom battery, and the second carrier transport layer included in the top battery is of opposite conductivity type to the third carrier transport layer included in the bottom battery.

[0069] For example, when the top cell is a perovskite cell, if the perovskite cell is a formal structure, the first carrier transport layer is an electron transport layer, the second carrier transport layer is a hole transport layer, and the first light absorption layer is a perovskite light absorption layer. If the perovskite cell is a trans structure, the first carrier transport layer is a hole transport layer, the second carrier transport layer is an electron transport layer, and the first light absorption layer is a perovskite light absorption layer. The materials of the electron transport layer, the hole transport layer, and the perovskite light absorption layer can be referred to in the previous text and will not be repeated here.

[0070] For example: when the bottom cell is a silicon heterojunction cell, the second light absorption layer can be an intrinsic silicon substrate, an N-type doped silicon substrate or a P-type doped silicon substrate. In addition, when the conductivity type of the first carrier transport layer included in the top cell is N-type, the material of the fourth carrier transport layer included in the bottom cell is a P-type doped silicon layer, and the material of the third carrier transport layer included in the bottom cell is an N-type doped silicon layer. When the conductivity type of the first carrier transport layer included in the top cell is P-type, the material of the fourth carrier transport layer included in the bottom cell is an N-type doped silicon layer, and the material of the third carrier transport layer included in the bottom cell is a P-type doped silicon layer. Among them, at least one of the above-mentioned P-type doped silicon layer and N-type doped silicon layer is a doped amorphous silicon layer, and the bottom cell also includes an intrinsic amorphous silicon layer located between the doped amorphous silicon layer and the second light absorption layer.

[0071] Of course, in addition to silicon heterojunction cells, the bottom cell can also be an emitter back passivation cell, a tunneling oxide layer passivation contact solar cell or a back contact cell, etc.

[0072] As for the middle composite layer included in the above-mentioned stacked solar cell, the material of the middle composite layer can be set according to actual needs, as long as it can be applied to the solar cell provided in the embodiment of the present invention. For example, the middle composite layer can be at least one of a tunnel junction composite layer, an indium zinc oxide layer, an indium tin oxide layer, and a zinc aluminum oxide layer.

[0073] Optionally, the above-mentioned battery functional layer may include a perovskite light absorption layer. In this case, the perovskite battery has the advantages of simple manufacturing process, low cost, good light absorption effect, high efficiency and stable carriers. Therefore, when the battery functional layer includes a perovskite light absorption layer, it is beneficial to further improve the conversion efficiency of the solar cell. In addition, during the large-scale manufacturing process of the perovskite battery, the surface uniformity is not high, which easily causes a gap between the battery functional layer and the mask. The insulating protective layer in the solar cell provided by the embodiment of the present invention can solve the short circuit problem caused by the electrode layer winding plating connection in the existing perovskite battery and / or the problem of high carrier recombination rate at the edge of the battery caused by shielding the winding plating by the mask, thereby improving the conversion efficiency and yield of the solar cell.

[0074] Regarding the first electrode layer and the second electrode layer, in terms of the formation position, as shown in FIG. Figure 3 As shown, the first surface 12 of the battery functional layer 11 may correspond to the light-facing surface of the solar cell, and the second surface 13 of the battery functional layer 11 may correspond to the backlight surface of the solar cell. The first electrode layer 14 is a transparent conductive layer. In this case, the second electrode layer 16 may be a transparent conductive layer or may not be a transparent conductive layer. Alternatively, Figure 1As shown, the first surface 12 of the battery functional layer 11 may also correspond to the backlight surface of the solar cell. In this case, the second surface 13 of the battery functional layer 11 corresponds to the light-facing surface of the solar cell. In this case, the second electrode layer 16 is a transparent conductive layer; the first electrode layer 14 may be a transparent conductive layer or may not be a transparent conductive layer.

[0075] The material of the transparent conductive layer may include any light-transmitting conductive material such as fluorine-doped tin oxide, aluminum-doped zinc oxide, tin-doped indium oxide, tungsten-doped indium oxide, molybdenum-doped indium oxide, cerium-doped indium oxide, and indium hydroxide, as long as it can be applied to the solar cell provided in the embodiment of the present invention. When at least one of the second electrode layer and the first electrode layer disposed on the backlight surface is not a transparent conductive layer, the material of at least one of the second electrode layer and the first electrode layer disposed on the backlight surface may include any light-impermeable conductive material such as copper, silver, aluminum, titanium, or nickel.

[0076] In terms of the scope of formation, Figure 4 As shown, the first electrode layer 14 may cover various regions of the first surface 12. Alternatively, as shown in FIG. Figure 1 As shown, along the direction from the edge to the center of the first surface 12, the edge of the first electrode layer 14 and the edge of the first surface 12 may also have a spacing greater than 0. The size of the spacing can be determined according to the specific structure of the battery functional layer 11 in the actual application scenario, the manufacturing process for forming the first electrode layer 14, and the requirements for the carrier collection efficiency of the first electrode layer 14, and is not specifically limited here.

[0077] Exemplarily, along the direction from the edge to the center of the first surface, the distance between the edge of the first electrode layer and the edge of the first surface may be less than or equal to 5 mm. For example, the distance between the edge of the first electrode layer and the edge of the first surface may be 0.5 mm, 1 mm, 2 mm, 3 mm, 4 mm or 5 mm, etc. In this case, it is beneficial for the first electrode layer to have a larger area on the first surface, and it is beneficial for the corresponding conductive type carriers generated in each region of the battery functional layer 11 along the direction parallel to the first surface to be collected and exported by the first electrode layer in a timely manner, thereby further improving the conversion efficiency of the solar cell.

[0078] As for the second electrode layer, the formation range of the second electrode layer on the first surface can be determined according to the formation range of the insulating protective layer on the first surface and the manufacturing process of the second electrode layer, as long as the orthographic projection of the second electrode layer on the first surface is within the orthographic projection of the insulating protective layer on the first surface. Figure 1 As shown, the orthographic projection of the second electrode layer 16 on the first surface 12 is located within the orthographic projection of the insulating protection layer 15 on the first surface 12, which may mean that: on the first surface 12, the edge of the second electrode layer 16 is flush with the edge of the insulating protection layer 15; or Figure 4As shown, it may also mean that on the first surface 12 and along the direction from the edge to the center of the first surface 12, the edge of the second electrode layer 16 is located on the inner side of the edge of the insulating protection layer 15 to further reduce the risk of leakage and improve the electrical reliability of the solar cell.

[0079] As for the edge morphology of the second electrode layer near the center of the first surface on the first surface, it can be determined according to the actual manufacturing process of the second electrode layer, and is not specifically limited here. Exemplarily, the edge of the second electrode layer near the center of the first surface is straight, wavy, serrated or comb-shaped. In this case, there are many examples of the edge morphology of the second electrode layer near the center of the first surface, which is beneficial to improve the applicability of the solar cell provided by the embodiment of the present invention in different application scenarios, and is also beneficial to reduce the difficulty of manufacturing solar cells.

[0080] As for the above-mentioned insulating protective layer, from the material aspect, the material of the insulating protective layer can be an insulating light-transmitting material. In this case, if Figure 1 As shown, the insulating protective layer 15 is not only arranged on the side of the battery functional layer 11, but also extends to cover the part of the first electrode layer 14 located on the first surface 12. At this time, the insulating protective layer 15 covers the part of the first surface 12 of the battery functional layer 11 used to achieve photoelectric conversion. Based on this, when the material of the insulating protective layer 15 is an insulating and light-transmitting material, the shading loss of the insulating protective layer 15 on the side of the battery functional layer 11, especially on the side of the first surface 12 of the battery functional layer 11, can be reduced to ensure that the solar cell has a higher conversion efficiency. Of course, the material of the insulating protective layer 15 can also be an opaque insulating material to increase the range of material options for the insulating protective layer 15 and improve applicability.

[0081] As for the specific type of material of the insulating protective layer, it can be set according to actual needs. For example, the material of the above-mentioned insulating protective layer may include at least one of tin oxide, titanium oxide, silicon oxide, silicon nitride, polytetrafluoroethylene and polyethylene terephthalate. In this case, tin oxide, titanium oxide, silicon oxide, silicon nitride, polytetrafluoroethylene and polyethylene terephthalate all have good insulating properties, which is conducive to further reducing the leakage risk between the second electrode layer and the first electrode layer and the carrier transport layer of the opposite conductivity type of the carrier transported by itself. In addition, tin oxide, titanium oxide, silicon oxide, silicon nitride, polytetrafluoroethylene and polyethylene terephthalate are also insulating and light-transmitting materials, which can reduce the shading loss of the insulating protective layer and improve the conversion efficiency of solar cells. Among them, it should be noted that when the material of the insulating protective layer includes at least two types, the distribution between the regions of different materials in the insulating protective layer can be set according to actual needs, and no specific limitation is made here. For example, when the material of the insulating protective layer includes at least two types, the regions of different materials in the insulating protective layer can be distributed layer by layer in the direction close to the battery functional layer.

[0082] As for the thickness of the insulating protective layer, it can be understood that within a certain range, the thickness of the insulating protective layer is proportional to its own insulation properties. Therefore, it can be determined based on the anti-leakage requirements between the first electrode layer and the carrier transport layer of the second electrode layer having opposite conductivity types to the carriers transported by itself in actual application scenarios. No specific limitation is made here.

[0083] Exemplarily, the thickness of the insulating protective layer may be greater than or equal to 10nm and less than or equal to 50nm. For example, the thickness of the insulating protective layer may be 10nm, 15nm, 20nm, 25nm, 30nm, 35nm, 40nm, 45nm or 50nm. In this case, the thickness of the insulating protective layer is within the above range, which is conducive to preventing the insulating properties of the insulating protective layer from being poor due to its small thickness, ensuring that the second electrode layer can be isolated from the first electrode layer and the carrier transport layer of the opposite conductivity type of the carriers transmitted by itself through the insulating protective layer, which is conducive to further reducing the leakage risk between the second electrode layer and the first electrode layer and the carrier transport layer of the opposite conductivity type of the carriers transmitted by itself. In addition, it can also prevent the large amount of consumables used due to the large thickness of the insulating protective layer, which is conducive to controlling the manufacturing cost of solar cells; and prevent the insulating protective layer from being easily formed due to the large thickness of the insulating protective layer, which makes the deposition time of the insulating protective layer long, and the formation of the insulating protective layer is easy to cover the middle area of ​​the first electrode layer through the gap between the mask covering part of the first electrode layer and the first electrode layer, reducing the difficulty of interconnection between the first electrode layer and the external circuit.

[0084] In addition, if Figure 1 As shown, the thickness of each part of the insulating protective layer 15 can be the same. Figure 5 As shown, the thickness of the portion of the insulating protective layer 15 located on the first surface 12 can be greater than the thickness of the portion of the insulating protective layer 15 located on the side surface; in this case, because the insulating protective layer 15 is used to isolate the second electrode layer 16 from the first electrode layer 14 and the carrier transport layer of opposite conductivity type of the carriers transmitted by itself, and the first electrode layer 14 and the carrier transport layer of opposite conductivity type of the carriers transmitted by the second electrode layer 16 are arranged on the side of the first surface 12 of the battery functional layer 11, when the thickness of the portion of the insulating protective layer 15 located on the first surface 12 is greater than the thickness of the portion of the insulating protective layer 15 located on the side surface, it can be ensured that the portion of the insulating protective layer 15 located on the first surface 12 has higher insulation properties, further reducing the risk of leakage.

[0085] Secondly, if Figure 5As shown, on the side of the battery functional layer 11, the thickness of the insulating protective layer 15 can gradually increase from the second surface 13 to the first surface 12. The application principle of the beneficial effect in this case is similar to the application principle of the beneficial effect of the thickness of the portion of the insulating protective layer 15 located on the first surface 12 being greater than the thickness of the portion of the insulating protective layer 15 located on the side, and will not be repeated here.

[0086] In addition, in terms of the formation range, the formation range of the insulating protective layer on the first surface will affect the formable range of the second electrode layer on the first surface, as well as the leakage risk between the second electrode layer and the first electrode layer and the carrier transport layer, which are respectively opposite to the conductivity type of the carriers transported by the second electrode layer itself. Therefore, the formation range of the insulating protective layer on the first surface and the distance between the edges of the insulating protective layer on the first surface and the edges of the first electrode layer and the second electrode layer can be determined according to the manufacturing process of the second electrode layer in the actual application scenario and the requirements for the above-mentioned leakage risk. No specific limitation is made here.

[0087] Exemplarily, on the first surface, the distance between the edge of the insulating protective layer and the edge of the first surface can be less than or equal to 30 mm. For example: on the first surface, the distance between the edge of the insulating protective layer and the edge of the first surface can be 1 mm, 2 mm, 5 mm, 10 mm, 15 mm, 20 mm, 25 mm or 30 mm, etc. In this case, the distance between the edge of the insulating protective layer and the edge of the first surface is within the above range, which helps to prevent the insulating protective layer from being formed too large on the first surface due to the large distance, and reduces the amount of consumables used for the insulating protective layer and the difficulty of interconnection between the first electrode layer and the external circuit.

[0088] Exemplarily, on the first surface, the distance between the edge of the second electrode layer and the edge of the insulating protective layer can be greater than or equal to 0.5 mm and less than or equal to 20 mm. For example: on the first surface, the distance between the edge of the second electrode layer and the edge of the insulating protective layer can be 0.5 mm, 0.8 mm, 1 mm, 5 mm, 8 mm, 10 mm, 12 mm, 15 mm, 18 mm or 20 mm, etc. In this case, the distance between the edge of the second electrode layer and the edge of the insulating protective layer is within the above range, which is conducive to preventing the distance between the second electrode layer and the first electrode layer in the direction parallel to the first surface from being small due to the small distance, thereby reducing the risk of leakage between the second electrode layer and the first electrode layer; at the same time, it can also prevent the formation range of the insulating protective layer on the first surface from being small, resulting in the need to strictly control the manufacturing parameters to prevent short circuits in order to form a second electrode layer with a smaller plating range on the first surface, thereby reducing the difficulty of manufacturing the second electrode layer. In addition, it can also prevent the insulating protection layer from being formed too widely on the first surface and / or the second electrode layer from being formed too narrowly on the first surface due to the large spacing, thereby further reducing the manufacturing difficulty of the second electrode layer, while reducing the amount of consumables used for the insulating protection layer and the difficulty of interconnection between the first electrode layer and the external circuit.

[0089] Exemplarily, on the first surface, and in the direction from the edge to the center of the first surface, the distance between the edge of the insulating protective layer and the edge of the first electrode layer is greater than or equal to 1 mm and less than or equal to 25 mm. For example, the distance between the edge of the insulating protective layer and the edge of the first electrode layer is 1 mm, 2 mm, 5 mm, 8 mm, 10 mm, 12 mm, 15 mm, 18 mm, 20 mm, 22 mm or 25 mm, etc. In this case, the distance between the edge of the insulating protective layer and the edge of the first electrode layer is within the above range, which is conducive to preventing the distance between the edge of the insulating protective layer on the first surface and the edge of the first surface from being smaller due to the smaller distance (that is, the formation range of the insulating protective layer on the first surface is smaller), ensuring that the second electrode layer can be isolated from the first electrode layer and the carrier transport layer of the opposite conductivity type of the carriers transmitted by itself through the insulating protective layer. In addition, it can also prevent the distance between the edge of the insulating protective layer on the first surface and the edge of the first surface from being too large due to the larger distance, ensuring a lower risk of leakage, and reducing the amount of consumables used in the insulating protective layer.

[0090] In some cases, such as Figure 1As shown, in the case where the first electrode layer 14 and the second electrode layer 16 are light-transmitting conductive layers, the solar cell may further include a first metal electrode 28 and a second metal electrode 29. The first metal electrode 28 is disposed on the side of the first electrode layer 14 away from the battery functional layer 11, and is in electrical contact with the first electrode layer 14. The second metal electrode 29 is disposed on the side of the second electrode layer 16 away from the battery functional layer 11, and is in electrical contact with the second electrode layer 16, so as to facilitate the extraction of carriers. The materials of the first metal electrode 28 and the second metal electrode 29 may include any metal conductive material of silver, aluminum, copper, titanium or nickel.

[0091] In a second aspect, an embodiment of the present invention provides a method for manufacturing a solar cell. Figures 6 to 17 The manufacturing process is described by referring to the cross-sectional view of the operation shown in FIG. 1 . Specifically, the manufacturing method of the solar cell includes the following steps:

[0092] First, if Figure 6 and Figure 7 As shown, a battery function layer 11 is formed. The battery function layer 11 has a first surface 12 and a second surface 13 opposite to each other, and a side surface for connecting the first surface 12 and the second surface 13.

[0093] Specifically, the structure and materials of the above-mentioned battery functional layer, as well as the correspondence between the first surface and the second surface of the battery functional layer and the light-facing surface and the backlight surface of the solar cell, can be referred to in the previous text and will not be repeated here. In addition, it can be understood that when the type of solar cell is different, the process of manufacturing the battery functional layer may also be different. The manufacturing process of the battery functional layer will be divided into at least the following two types according to the different types of solar cells:

[0094] The first type is that when the manufactured solar cell is a single-layer solar cell, a first carrier transport layer, a light absorption layer, and a second carrier transport layer that are stacked can be formed in sequence by using a thermal evaporation process, a spin coating process, or a deposition process, depending on the specific type of the solar cell. For example, when the solar cell is a silicon solar cell, after providing the light absorption layer, at least a deposition process can be used to form the first carrier transport layer and the second carrier transport layer on both sides of the light absorption layer along its own thickness direction. Another example is that when the solar cell is a perovskite solar cell, one of the first carrier transport layer and the second carrier transport layer can be formed by using a process such as thermal evaporation or spin coating; next, a light absorption layer can be formed by using a process such as spin coating; then, the other of the first carrier transport layer and the second carrier transport layer can be formed by using a process such as thermal evaporation or spin coating.

[0095] Second, in the case where the manufactured solar cell is a stacked solar cell, when the stacked solar cell includes a top cell and a bottom cell connected in series, and a middle composite layer located between the top cell and the bottom cell, a fourth carrier transport layer can be formed by a thermal evaporation process, a spin coating process or a deposition process, depending on the specific type of the solar cell, and then a second light absorption layer and a third carrier transport layer are sequentially formed in a stacked manner on the fourth carrier transport layer along the direction from the bottom cell to the top cell; or, deposition or other processes can be used to respectively form a third carrier transport layer and a fourth carrier transport layer on both sides of the provided second light absorption layer along the thickness direction.

[0096] Next, along the direction from the bottom battery to the top battery, a conductive composite layer, a second carrier transport layer, a first light absorption layer and a first carrier transport layer are sequentially formed on the third carrier transport layer by using a thermal evaporation process, a spin coating process or a deposition process.

[0097] Specifically, the specific formation process of the above-mentioned battery functional layers including the first carrier transport layer, the first light absorption layer, the second carrier transport layer, the middle composite layer, the third carrier transport layer, the second light absorption layer and the fourth carrier transport layer can be determined according to the type of solar cell and the material of each film layer, and is not specifically limited here.

[0098] Next, if Figure 8 and Fig. 9 As shown, a first electrode layer 14 is formed on the first surface 12 .

[0099] Exemplarily, a process such as magnetron sputtering or reactive plasma deposition can be used, and the first electrode layer can be formed on the first surface under the protection of the corresponding mask. When the size of the mask pattern in the mask is equal to the size of the battery functional layer, the first electrode layer can be formed on various regions of the first surface. When the size of the mask pattern in the mask is smaller than the size of the battery functional layer, the edge of the first electrode layer has a spacing greater than 0 from the edge of the first surface.

[0100] In the actual manufacturing process, if the first electrode layer is a transparent conductive layer, after forming the first electrode layer and before forming the insulating protective layer, a first metal electrode may be formed on the first electrode layer by screen printing or electroplating.

[0101] Next, if Fig.14 and Fig.15 As shown, an insulating protection layer 15 is formed on the side surface and extends to cover a portion of the first electrode layer 14 located on the first surface 12 . The insulating protection layer 15 is in direct contact with the side surface of the battery functional layer 11 .

[0102] For example, Fig.10 and Fig.11As shown, the battery functional layer 11 with the first electrode layer 14 formed thereon can be placed on a deposition equipment platform from the second surface 13 of the battery functional layer 11; at this time, the first surface 12 of the battery functional layer 11 faces upward, and the first electrode layer 14 is exposed to the outside. Fig.12 and Fig.13 As shown, a mask 26 is arranged on the side of the first electrode layer 14 facing away from the battery functional layer 11. The orthographic projection of the mask 26 on the first surface 12 is located within the orthographic projection of the first electrode layer 14 on the first surface 12. Next, as shown in FIG. Fig.14 and Fig.15 As shown, under the protection of the mask 26 , an insulating protection layer 15 is deposited on a portion of the first electrode layer 14 located on the first surface 12 and on the side surfaces.

[0103] It can be understood that on one side of the first surface, an insulating protective layer will be formed on at least the area exposed outside the mask plate. Therefore, the distance between the edge of the mask plate and the edge of the first electrode layer can be determined according to the formation range of the insulating protective layer on the first surface in the actual application scenario, which will not be repeated here.

[0104] Exemplarily, along the direction from the edge to the center of the first surface, the distance between the edge of the mask and the edge of the first electrode layer may be less than or equal to 25 mm. For example, the distance between the edge of the mask and the edge of the first electrode layer may be 1 mm, 5 mm, 8 mm, 10 mm, 12 mm, 15 mm, 18 mm, 20 mm or 25 mm, etc. In this case, the distance between the edge of the mask and the edge of the first electrode layer is within the above range, which helps to prevent the insulating protection layer from covering a larger area on the first electrode layer due to the larger distance, thereby reducing the difficulty of interconnection between the first electrode layer and the external circuit. In addition, it can also prevent the distance between the edge of the insulating protection layer on the first surface and the edge of the first electrode layer from being too small due to the smaller distance, thereby further reducing the risk of leakage between the second electrode layer and the first electrode layer on the first surface.

[0105] In addition, it should be noted that if a first metal electrode is formed on the first electrode layer before the insulating protective layer is formed, although there is a gap between the mask and the first electrode layer at this time, because the first metal electrode is in electrical contact with the first electrode layer, even if the insulating protective layer is deposited through the gap on the area of ​​the first electrode layer that is partially blocked by the mask, it will not affect the collection and extraction of carriers by the first metal electrode. At the same time, the formation range of the insulating protective layer on the first surface can be increased, ensuring that the second electrode layer and the first electrode layer can be isolated by the insulating protective layer, further reducing the risk of leakage. Of course, in the case where the manufactured solar cell also includes a first metal electrode, the first metal electrode can also be formed on the first electrode layer after the insulating protective layer is formed.

[0106] Next, if Fig.16 and Fig.17 As shown, a second electrode layer 16 is formed on the second surface 13 and extends to cover the insulating protective layer 15. The conductivity type of the carriers transmitted by the second electrode layer 16 and the first electrode layer 14 is opposite. The orthographic projection of the second electrode layer 16 on the first surface 12 is located within the orthographic projection of the insulating protective layer 15 on the first surface 12. One of the first surface 12 and the second surface 13 is a light-facing surface, and at least one of the second electrode layer 16 and the first electrode layer 14 disposed on the light-facing surface is a transparent conductive layer.

[0107] Specifically, the second electrode layer can be formed by processes such as magnetron sputtering or reactive plasma deposition. When forming the second electrode layer, a corresponding mask plate can be used for shielding, or a mask plate may not be used. Specifically, it can be determined according to the formation range of the insulating protective layer on the first surface. When the formation parameters of the second electrode layer remain unchanged, if the formation range of the insulating protective layer on the first surface is smaller than the plating range of the second electrode layer on the first surface, a corresponding mask plate can be used for shielding when forming the second electrode layer to prevent short circuit. If the formation range of the insulating protective layer on the first surface is greater than or equal to the plating range of the second electrode layer on the first surface, a mask plate may not be used for shielding when forming the second electrode layer, or a mask plate may be used.

[0108] In addition, in addition to adjusting the plating range of the second electrode layer on the first surface by using a mask, the plating range of the second electrode layer on the first surface can also be adjusted by controlling formation parameters.

[0109] In addition, when the second electrode layer is a transparent conductive layer, after the second electrode layer is formed, a second metal electrode may be formed on a side of the second electrode layer away from the battery functional layer by using processes such as screen printing or electroplating.

[0110] The beneficial effects of the second aspect and its various implementations in the embodiments of the present invention can be analyzed with reference to the beneficial effects of the first aspect and its various implementations, and will not be repeated here.

[0111] In the above description, the technical details of the patterning and etching of each layer are not described in detail. However, those skilled in the art should understand that various technical means can be used to form layers, regions, etc. of desired shapes. In addition, in order to form the same structure, those skilled in the art can also design methods that are not completely the same as the methods described above. In addition, although the various embodiments are described above separately, this does not mean that the measures in the various embodiments cannot be used in combination to advantage.

[0112] The embodiments of the present invention are described above. However, these embodiments are only for a clearer description and are not intended to limit the scope of the present invention. The scope of the present invention is defined by the appended claims and their equivalents. Without departing from the scope of the present invention, a person skilled in the art may make various substitutions and modifications, which should all fall within the scope of the present invention.

Claims

1. A solar cell, characterized in that: include: A battery function layer, the battery function layer having a first surface and a second surface opposite to each other, and a side surface for connecting the first surface and the second surface; A first electrode layer, disposed on the first surface; an insulating protective layer, disposed on the side surface and extending to cover a portion of the first electrode layer located on the first surface; the insulating protective layer is in direct contact with the side surface of the battery functional layer; A second electrode layer is arranged on the second surface and extends to cover the insulating protective layer; the conductivity type of the carriers transmitted by the second electrode layer and the first electrode layer is opposite; the orthographic projection of the second electrode layer on the first surface is located within the orthographic projection of the insulating protective layer on the first surface; one of the first surface and the second surface is a light-facing surface, and among the second electrode layer and the first electrode layer, at least one of the light-facing surfaces is a transparent conductive layer.

2. The solar cell according to claim 1, characterized in that The material of the insulating protective layer is an insulating light-transmitting material; And / or, the material of the insulating protective layer includes: at least one of tin oxide, titanium oxide, silicon oxide, silicon nitride, polytetrafluoroethylene and polyethylene terephthalate; And / or, the thickness of the insulating protection layer is greater than or equal to 10 nm and less than or equal to 50 nm.

3. The solar cell according to claim 1, characterized in that On the first surface, a distance between an edge of the second electrode layer and an edge of the insulating protection layer is greater than or equal to 0.5 mm and less than or equal to 20 mm; And / or, on the first surface, a distance between an edge of the insulating protection layer and an edge of the first surface is less than or equal to 30 mm.

4. The solar cell according to claim 1, characterized in that On the first surface, an edge of the second electrode layer close to the center of the first surface is in a straight line, a wave shape, a sawtooth shape or a comb tooth shape.

5. The solar cell according to claim 1, characterized in that: Along the direction from the edge to the center of the first surface, the distance between the edge of the first electrode layer and the edge of the first surface is less than or equal to 5 mm; And / or, on the first surface, and in the direction from the edge to the center of the first surface, the distance between the edge of the insulating protection layer and the edge of the first electrode layer is greater than or equal to 1 mm and less than or equal to 25 mm.

6. The solar cell according to claim 1, characterized in that The battery functional layer includes a perovskite light absorption layer.

7. The solar cell according to any one of claims 1 to 6, characterized in that: The solar cell is a stacked solar cell; The stacked solar cell comprises a bottom cell and a top cell connected in series; Along the direction from the top battery to the bottom battery, the battery functional layers include: a first carrier transport layer, a first light absorption layer, a second carrier transport layer, a middle recombination layer, a third carrier transport layer, a second light absorption layer and a fourth carrier transport layer; the top battery includes the first carrier transport layer, the first light absorption layer and the second carrier transport layer, and the bottom battery includes the third carrier transport layer, the second light absorption layer and the fourth carrier transport layer.

8. A method for manufacturing a solar cell, characterized in that: include: forming a battery functional layer; The battery functional layer has a first surface and a second surface opposite to each other, and a side surface for connecting the first surface and the second surface; forming a first electrode layer disposed on the first surface; forming an insulating protective layer disposed on the side surface and extending to cover a portion of the first electrode layer located on the first surface, wherein the insulating protective layer is in direct contact with the side surface of the battery functional layer; A second electrode layer is formed on the second surface and extends to cover the insulating protective layer; the second electrode layer and the first electrode layer have opposite conductivity types for transmitting carriers; the orthographic projection of the second electrode layer on the first surface is located within the orthographic projection of the insulating protective layer on the first surface; one of the first surface and the second surface is a light-facing surface, and at least one of the second electrode layer and the first electrode layer that is arranged on the light-facing surface is a transparent conductive layer.

9. The method for manufacturing a solar cell according to claim 8, characterized in that: The insulating protection layer formed on the side surface and extending to cover a portion of the first electrode layer located on the first surface includes: Placing the battery functional layer with the first electrode layer formed thereon on a deposition equipment platform from the second surface side of the battery functional layer; A mask is arranged on a side of the first electrode layer facing away from the battery functional layer; an orthographic projection of the mask on the first surface is located within an orthographic projection of the first electrode layer on the first surface; Under the protection of the mask, the insulating protection layer is deposited on a portion of the first electrode layer located on the first surface and on the side surfaces.

10. The method for manufacturing a solar cell according to claim 9, characterized in that: Along the direction from the edge to the center of the first surface, the distance between the edge of the mask and the edge of the first electrode layer is less than or equal to 25 mm.

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