Photovoltaic cell, photovoltaic module

Abstract

The embodiment of the present application relates to the photovoltaic field, and provides a photovoltaic cell, a photovoltaic module, the photovoltaic cell comprises: an initial cell piece; a silver nanostructure array is located on the front surface of the initial cell piece, the silver nanostructure array comprises a plurality of silver nanostructures, and at least a part of the silver nanostructures has a spacing; an oxide layer covers the surface formed by the front surface and the silver nanostructure array, and the oxide layer can at least improve the utilization rate of light of the photovoltaic cell.

Description

Technical Field

[0001] This application relates to the photovoltaic field, and in particular to a photovoltaic cell and a photovoltaic module. Background Technology

[0002] With the advancement of research and development in green energy, photovoltaic cells, which utilize sunlight as a resource, are becoming increasingly widely used. A photovoltaic cell is a device that converts solar energy into electrical energy. It uses the photovoltaic principle to generate charge carriers, which are then extracted using grid lines, thus facilitating the efficient utilization of electrical energy.

[0003] Current photovoltaic cells mainly include IBC cells (Interdigitated Back Contact cells), TOPCON (Tunnel Oxide Passivated Contact) cells, PERC cells (Passivated emitter and real cell) cells, and HIT / HJT cells (Heterojunction Technology). Further research is needed to reduce optical losses through different film layer configurations and functional limitations. Utility Model Content

[0004] This application provides a photovoltaic cell and a photovoltaic module, which can at least improve the utilization rate of light by the photovoltaic cell.

[0005] According to some embodiments of this application, one aspect of this application provides a photovoltaic cell, including: an initial cell; a silver nanostructure array located on the front side of the initial cell, the silver nanostructure array including a plurality of silver nanostructures, at least a portion of the silver nanostructures being spaced apart; and an oxide layer covering the surface formed by the front side and the silver nanostructure array together.

[0006] In some embodiments, the front side of the initial solar cell is a textured surface comprising multiple pyramidal structures, with the silver nanostructures located on the surface or apex of the pyramidal structures.

[0007] In some embodiments, the silver nanostructures are distributed at a rate of 5% to 20% on the front side.

[0008] In some embodiments, the silver nanostructure includes at least one of silver nanoparticles or silver nanowires.

[0009] In some embodiments, the diameter of the silver nanoparticles is 10 nm to 25 nm; and / or, the aspect ratio of the silver nanowires is greater than 5.

[0010] In some embodiments, the spacing between adjacent silver nanoparticles is 125 nm to 200 nm.

[0011] In some embodiments, the thickness of the oxide layer is 10 nm to 50 nm.

[0012] In some embodiments, the thickness of the oxide layer is aluminum oxide.

[0013] In some embodiments, the initial solar cell includes: a substrate having a first side corresponding to the front side and a second side corresponding to the back side of the initial solar cell, the second side including a first region and a second region alternately arranged along a second direction; a first tunneling layer located on the first region and a first doped semiconductor layer located on the side of the first tunneling layer away from the first region; a second tunneling layer located on the second region and a second doped semiconductor layer located on the side of the second tunneling layer away from the second region, one of the first doped semiconductor layer and the second doped semiconductor layer being doped with a P-type dopant and the other being doped with an N-type dopant; a first antireflection layer located on the side of the oxide layer away from the front side; a second antireflection layer located on the first region and the second region; a first gate line embedded in the second antireflection layer and in contact with the first doped semiconductor layer; and a second gate line embedded in the second antireflection layer and in contact with the second doped semiconductor layer.

[0014] According to some embodiments of this application, another aspect of this application provides a photovoltaic module, including: a battery string, formed by connecting a plurality of photovoltaic cells as described in any of the above claims; an encapsulating film for covering the surface of the battery string; a cover plate for covering the surface of the encapsulating film away from the battery string; and a frame for surrounding the outer periphery of a laminate, the laminate including the battery string, the encapsulating film, and the cover plate.

[0015] The technical solution provided in this application has at least the following advantages: Upon exposure to light, the free electrons on the surface of the silver nanostructure undergo collective oscillation, i.e., localized surface plasmon resonance. On one hand, the plasmon resonance effect of the silver nanostructure involves the interaction between the conductive electrons on the metal surface and the incident photons, producing resonant absorption and scattering effects. This is beneficial for improving the response of the initial solar cell to near-infrared light by leveraging the resonant absorption and scattering effects of the silver nanostructure, thereby enhancing the utilization rate of light in the initial solar cell. On the other hand, the uneven surface formed by the array of multiple silver nanostructures allows for multi-angle adjustment of the light propagation path, which helps to extend the effective path length of light within the photovoltaic cell, thus increasing the total amount of light received by the initial solar cell. Furthermore, designing an oxide layer to cover the surface of the silver nanostructure array offers several advantages. Firstly, the oxide layer protects the surface of the silver nanostructure array, preventing subsequent oxidation or damage and failure. Secondly, the oxide layer acts as a confinement layer, preventing the clustering of spaced silver nanostructures and subsequent failure. Thirdly, the oxide layer effectively passivates surface defects in the initial solar cell, such as dangling bonds, and provides a passivation effect on the initial cell. In summary, these multiple benefits contribute to improving the short-circuit current and photoelectric conversion efficiency of photovoltaic cells. Attached Figure Description

[0016] One or more embodiments are illustrated by way of example with corresponding pictures in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Unless otherwise stated, the pictures in the accompanying drawings do not constitute a limitation on scale. In order to more clearly illustrate the technical solutions in the embodiments of this application or in the conventional technology, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a partial cross-sectional schematic diagram of a photovoltaic cell provided in an embodiment of this application; Figure 2 This is another partial cross-sectional schematic diagram of a photovoltaic cell provided in an embodiment of this application; Figure 3 This is a partial three-dimensional schematic diagram of a cell string in a photovoltaic module provided in another embodiment of this application; Figure 4 This is a partial cross-sectional schematic diagram of a photovoltaic module provided in another embodiment of this application.

[0018] Explanation of reference numerals in the attached figures: 100. Initial solar cell; 110. Front side; 110a. Pyramid structure; 120. Back side; 101. Silver nanostructure array; 111. Silver nanostructure; 102. Oxide layer; 103. Substrate; 113. First side; 123. Second side; 133. First region; 143. Second region; 153. Trench; 104. First tunneling layer; 105. First doped semiconductor layer; 106. Second tunneling layer; 107. Second doped semiconductor layer; 118. First antireflection layer; 128. Second antireflection layer; 119. First grid line; 129. Second grid line; 40. Photovoltaic cell; 41. Encapsulating film; 42. Cover plate; 402. Solder ribbon. Detailed Implementation

[0019] As can be seen from the background technology, the utilization rate of light by photovoltaic cells needs further research.

[0020] Analysis revealed that in photovoltaic cells, whether the cell has grid lines on both sides or the electrode has grid lines on only one side, the grid lines cause certain optical losses due to their blocking of light. Although IBC cells only have grid lines on the back side and the front side is not blocked by grid lines, the light propagation effect and passivation effect of the film layer on the substrate still need further research.

[0021] This application provides a photovoltaic cell and a photovoltaic module. In the photovoltaic cell, after being exposed to light, the free electrons on the surface of the silver nanostructure undergo collective oscillation, i.e., localized surface plasmon resonance occurs. On the one hand, the plasmon resonance effect of the silver nanostructure is the interaction between the conductive electrons on the metal surface and the incident photons, producing resonance absorption and scattering effects. This is beneficial to improving the response of the initial cell to near-infrared light by utilizing the resonance absorption and scattering effect of the silver nanostructure, thereby improving the utilization rate of light in the initial cell. On the other hand, the uneven surface formed by the array of multiple silver nanostructures is beneficial to the multi-angle adjustment of the light propagation path, thereby extending the effective path length of light in the photovoltaic cell and increasing the total amount of light received by the initial cell. Furthermore, designing an oxide layer to cover the surface of the silver nanostructure array offers several advantages. Firstly, the oxide layer protects the surface of the silver nanostructure array, preventing subsequent oxidation or damage and failure. Secondly, the oxide layer acts as a confinement layer, preventing the clustering of spaced silver nanostructures and subsequent failure. Thirdly, the oxide layer effectively passivates surface defects in the initial solar cell, such as dangling bonds, and provides a passivation effect on the initial cell. In summary, these multiple benefits contribute to improving the short-circuit current and photoelectric conversion efficiency of photovoltaic cells.

[0022] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0023] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0024] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A exists, A and B exist simultaneously, and B exists. In addition, the character " / " in this document generally indicates that the related objects before and after it have an "or" relationship.

[0025] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0026] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0027] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0028] In the accompanying drawings corresponding to the embodiments of this application, the thickness and area of ​​the layers are enlarged for better understanding and ease of description. When describing a component (such as a layer, film, region, or substrate) on or on the surface of another component, the component may be "directly" located on the surface of the other component, or there may be a third component between the two components. Conversely, when describing a component on the surface of another component, or when another component is formed or disposed on the surface of a component, it indicates that there is no third component between the two components. Furthermore, when describing a component as being "generally" formed on another component, it means that the component is not formed on the entire surface (or front surface) of the other component, nor is it formed on a portion of the edge of the entire surface.

[0029] In the description of the embodiments of this application, when a component "includes" another component, other components are not excluded unless otherwise stated, and other components may be further included. Furthermore, when a component such as a layer, film, region, or plate is referred to as being "on / located" on another component, it can be "directly" on the other component (i.e., located on the surface of the other component with no other components between them), or another component may be present therein. Moreover, when a component such as a layer, film, region, or plate is "directly located" on another component, or when a component such as a layer, film, region, or plate is located on the surface of another component, it indicates that no other components are located therein.

[0030] The terminology used in the description of the various embodiments herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used in the description of the various embodiments and the appended claims, the term "component" is also intended to include the plural form unless the context clearly indicates otherwise. Components include layers, films, regions, or plates, etc.

[0031] The embodiments of this application will now be described in detail with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details have been provided in the embodiments of this application to facilitate a better understanding of the embodiments. However, the technical solutions claimed in the embodiments of this application can be implemented even without these technical details and various variations and modifications based on the following embodiments.

[0032] refer to Figure 1 , Figure 1 This is a partial cross-sectional schematic diagram of a photovoltaic cell provided in an embodiment of this application. The photovoltaic cell includes: an initial cell 100; a silver nanostructure array 101 located on the front side 110 of the initial cell 100, the silver nanostructure array 101 including a plurality of silver nanostructures 111, at least a portion of the silver nanostructures 111 being spaced apart; and an oxide layer 102 covering the surface jointly formed by the front side 110 and the silver nanostructure array 101.

[0033] It is worth noting that when silver nanostructure 111 is photoexcited by light of a specific wavelength, such as light in the visible to near-infrared band, the free electrons on the surface of silver nanostructure 111 undergo collective oscillation, that is, localized surface plasmon resonance (LSPR). Thus, on the one hand, the plasmon resonance effect of the silver nanostructure involves the interaction between electrons conducted on the metal surface and incident photons, generating resonant absorption and scattering effects. This facilitates the concentration of photon energy around the silver nanostructure 111 for further absorption. Furthermore, the scattering effect reflects long-wavelength light, such as near-infrared light, that is not easily absorbed by the initial solar cell 100 back onto the initial solar cell 100. This enhances the response of the initial solar cell 100 to near-infrared light through the resonant absorption and scattering effects of the silver nanostructure 111, thereby improving the light utilization rate of the initial solar cell 100. On the other hand, the uneven surface of the silver nanostructure array 101, comprising multiple silver nanostructures 111, provides more reflection angles for the light incident on the array 101. Based on the adjustment of the light propagation path, this extends the effective path length of light within the photovoltaic cell, thereby increasing the total amount of light received by the initial solar cell 100. Therefore, based on these multiple gains, it is beneficial to improve the short-circuit current and photoelectric conversion efficiency of the final photovoltaic cell.

[0034] Furthermore, an oxide layer 102 is designed to cover the surface of the silver nanostructure array 101. This serves several purposes: firstly, the oxide layer 102 protects the surface of the silver nanostructure array 101 from subsequent oxidation or damage to the silver nanostructures 111, ensuring that the initial solar cell 100 can absorb and utilize more light thanks to the silver nanostructures 111; secondly, the oxide layer 102 can also limit the silver nanostructures 111 due to their nanoscale size and the resulting localized surface plasmon resonance, preventing the clustered silver nanostructures 111 from agglomerating and failing, thus ensuring that the initial solar cell 100 can absorb and utilize more light thanks to the silver nanostructures 111; and thirdly, the oxide layer 102 effectively passivates surface defects of the initial solar cell 100, such as dangling bonds, and provides a passivation effect.

[0035] It should be noted that at least a portion of the silver nanostructures 111 are spaced apart. Therefore, in the silver nanostructure array 101 composed of multiple silver nanostructures 111, the initial solar cell 100 has a region that is not blocked by the silver nanostructure array 101. Thus, the oxide layer 102 can be in the space between adjacent silver nanostructures 111.

[0036] The silver nanostructure array 101 provided in one embodiment of this application will be described in more detail below with reference to the accompanying drawings.

[0037] In some embodiments, continue to refer to Figure 1 The oxide layer 102 is located not only in the gaps between different silver nanostructures 111, but also on the surface of the silver nanostructures 111.

[0038] In some cases, with the front surface 110 as the reference plane, along the first direction X, i.e., the thickness direction of the initial solar cell 100, the top surface of the oxide layer 102 away from the initial solar cell 100 is higher than the top surface of the silver nanostructure 111 away from the initial solar cell 100. This helps to ensure that the oxide layer 102 fully covers the surfaces of the silver nanostructure 111 that are not in contact with the initial solar cell 100.

[0039] In some embodiments, continue to refer to Figure 1 The silver nanostructure 111 may include at least one of silver nanoparticles or silver nanowires. It should be noted that... Figure 1 The diagram only shows the silver nanostructure 111 as silver nanoparticles. In practical applications, the silver nanostructure array corresponding to an initial battery cell includes at least one of silver nanoparticles and silver nanowires. That is, a single silver nanostructure array can include both silver nanoparticles and silver nanowires, or it can include only silver nanoparticles or only silver nanowires.

[0040] It should be noted that silver nanowires (AgNWs) are typically one-dimensional nanostructures with nanometer-scale diameters (usually 1 nm to 100 nm) and micrometer-scale lengths, with an aspect ratio (length / diameter) much greater than 1. Notably, the surface of silver nanowires, especially at their tips or bends, generates extremely strong localized electromagnetic fields, which enhance Raman scattering on the surface of the silver nanowires. This results in more light being reflected onto the initial solar cell 100. Furthermore, silver nanowires help to lengthen the light propagation path within the photovoltaic cell, thereby improving the photovoltaic cell's light capture efficiency.

[0041] In addition, silver nanoparticles (AgNPs) also enhance Raman scattering on their surface, allowing more light to be reflected onto the initial solar cell 100. Furthermore, silver nanoparticles also facilitate the efficient scattering of more light onto the nearest initial solar cell 100 based on Mie scattering, thereby improving the total amount of light received by the photovoltaic cell in multiple ways.

[0042] In some examples, the aspect ratio of the silver nanowires is greater than 5. For example, the aspect ratio of the silver nanowires can be 5.1, 5.3, 5.5, 5.6, 5.8, 6, 6.2, 6.3, 6.5, 6.6, 6.8, or 7. This allows for maximizing the localized surface plasmon resonance effect using silver nanowires with larger aspect ratios, thereby further enhancing the absorption and utilization rate of the initial solar cell 100 for light in the visible to near-infrared bands.

[0043] In some examples, the diameter of the silver nanoparticles can be 10nm to 25nm, for example, 11nm, 12nm, 13nm, 14nm, 15nm, 16nm, 17nm, 18nm, 19nm, 20nm, 21nm, 22nm, 23nm, or 24nm. This also helps to maximize the local surface plasmon resonance effect using silver nanoparticles of suitable diameter, thereby further enhancing the absorption and utilization rate of the initial solar cell 100 for light in the visible to near-infrared bands. It avoids the poor light scattering effect due to excessively small diameter silver nanoparticles, and prevents the silver nanoparticles from being exposed to the subsequently formed oxide layer and oxidized when their diameter is too large, ensuring that the initial solar cell 100 can absorb and utilize more light using the silver nanoparticles.

[0044] In some examples, the spacing between adjacent silver nanoparticles can be 125nm to 200nm, for example, it can be 130nm, 135nm, 140nm, 145nm, 150nm, 155nm, 160nm, 165nm, 170nm, 175nm, 180nm, 185nm, 190nm or 195nm, etc.

[0045] In some embodiments, reference Figure 1 The distribution rate of silver nanostructure 111 on the front side 110 can be 5% to 20%, for example, it can be 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18% or 19%, etc.

[0046] It is worth noting that if the distribution rate of silver nanostructures 111 on the front side 110 is less than 5%, the number of silver nanostructures 111 distributed in the silver nanostructure array 101 within the limited distribution area will be small, which will weaken the concentration efficiency of photon energy and the scattering effect of light, thereby limiting the total amount of light received by the initial solar cell 100; if the distribution rate of silver nanostructures 111 on the front side 110 is greater than 20%, the area of ​​the initial solar cell 100 not covered by silver nanostructures 111 will be small, which is not conducive to the formation of a uniform and dense oxide layer 102 in the subsequent step S3 (see reference). Figure 1Therefore, designing the silver nanostructure 111 to have a distribution rate of 5%~20% on the front side 110 is beneficial to ensure that the silver nanostructure 111 has a good effect on improving the total amount of light received by the initial solar cell 100, while facilitating the formation of a uniform and dense oxide layer 102 in the subsequent step S3, so as to improve the passivation effect of the oxide layer 102 on the initial solar cell 100.

[0047] In some embodiments, reference Figure 1 The front surface 110 of the initial solar cell 100 can be a textured surface comprising multiple pyramid structures 110a, with silver nanostructures 111 located on the surface or apex of the pyramid structures 110a. Notably, the arrangement of the silver nanostructures 111 can vary with the textured surface. This not only facilitates the localized surface plasmon resonance effect of the silver nanostructures 111, enhancing the light absorption and utilization rate of the initial solar cell 100, but also further improves the light-trapping effect through the textured surface structure, thereby further enhancing the light absorption and utilization rate of the initial solar cell 100. It should be noted that the pyramid structure 110a generally has four circumferentially connected surfaces, with the silver nanostructures 111 located on these surfaces. The silver nanostructures 111 are generally not located at the bottom of adjacent pyramid structures 110a.

[0048] In some embodiments, reference Figure 1 The thickness of the oxide layer 102 can be 10nm~50nm, for example, it can be 12nm, 15nm, 17nm, 20nm, 23nm, 25nm, 28nm, 30nm, 33nm, 35nm, 37nm, 40nm, 42nm, 45nm or 48nm, etc.

[0049] In some embodiments, the oxide layer 102 may be made of aluminum oxide.

[0050] In some embodiments, reference Figure 2 , Figure 2This is a partial cross-sectional schematic diagram of a photovoltaic cell provided in an embodiment of this application. The initial cell 100 may include: a substrate 103, the substrate 103 having a first surface 113 corresponding to the front surface 110 and a second surface 123 corresponding to the back surface 120 of the initial cell 100, the second surface 123 including a first region 133 and a second region 143 alternately arranged along a second direction Y; a first tunneling layer 104 located on the first region 133, and a first doped semiconductor layer 105 located on the side of the first tunneling layer 104 away from the first region 133; a second tunneling layer 106 located on the second region 143, and a first doped semiconductor layer 105 located on the side of the first tunneling layer 104 away from the first region 133; and a second tunneling layer 106 located on the second region 143. The second doped semiconductor layer 107 is located on the side of the tunneling layer 106 away from the second region 143. One of the first doped semiconductor layer 105 and the second doped semiconductor layer 107 is doped with a P-type dopant element, and the other is doped with an N-type dopant element. The first anti-reflection layer 118 is located on the side of the oxide layer 102 away from the front side 110. The second anti-reflection layer 128 is located on the first region 133 and the second region 143. The first gate line 119 is embedded in the second anti-reflection layer 128 and is in contact with the first doped semiconductor layer 105. The second gate line 129 is embedded in the second anti-reflection layer 128 and is in contact with the second doped semiconductor layer 107.

[0051] In this way, the photovoltaic cell can be an IBC cell. The front side 110 of the initial cell 100 is unblocked by grid lines. A silver nanostructure array 101 covering the entire front side 110 can be designed, which is beneficial to further improve the light absorption and utilization rate of the front side 110, thereby improving the photoelectric conversion efficiency of the IBC cell.

[0052] In some cases, substrate 103 is used to receive incident light and generate photogenerated carriers. In some examples, the material of substrate 103 can be an elemental semiconductor material. Optionally, the elemental semiconductor material is composed of a single element, such as silicon or germanium. The elemental semiconductor material can be monocrystalline, polycrystalline, amorphous, or microcrystalline (a state simultaneously possessing monocrystalline and amorphous states is called microcrystalline). For example, silicon can be at least one of monocrystalline silicon, polycrystalline silicon, amorphous silicon, or microcrystalline silicon. In other examples, the material of substrate 103 can be a compound semiconductor material. Optionally, common compound semiconductor materials include, but are not limited to, silicon germanide, silicon carbide, gallium arsenide, indium gallium dichromate, perovskite, cadmium telluride, or copper indium selenide. In still other examples, substrate 103 can also be a sapphire substrate, a silicon-on-insulator substrate, or a germanium-on-insulator substrate.

[0053] It is worth noting that when the material of the substrate 103 includes silicon or germanium, in step S3, for the oxide layer 102 formed by oxidizing the surface of the front side 110 of the initial cell 100 that is not covered by the silver nanostructure 111, the material of the oxide layer 102 may include silicon oxide or germanium oxide.

[0054] In some cases, the substrate 103 can be an N-type semiconductor substrate or a P-type semiconductor substrate. The N-type semiconductor substrate is doped with N-type dopant elements, and the P-type semiconductor substrate is doped with P-type dopant elements.

[0055] In some examples, the N-type dopant can be at least one of group V elements such as phosphorus (P), bismuth (Bi), antimony (Sb), or arsenic (As); the P-type semiconductor substrate is doped with a P-type element, which can be at least one of group III elements such as boron (B), aluminum (Al), gallium (Ga), or gallium (In).

[0056] In some cases, the second surface 123 of the substrate 103 can be a polished surface. It should be noted that the following explanation will use the second surface 123 as a polished surface as an example.

[0057] In some examples, the material of the first tunneling layer 104 may be silicon oxide; the material of the first doped semiconductor layer 105 may be amorphous silicon.

[0058] In some examples, the thickness of the first tunneling layer 104 along the first direction X can be 1nm to 3nm, for example, it can be 1.1nm, 1.2nm, 1.3nm, 1.4nm, 1.5nm, 1.6nm, 1.7nm, 1.8nm, 1.9nm, 2nm, 2.1nm, 2.2nm, 2.3nm, 2.4nm, 2.5nm, 2.6nm, 2.7nm, 2.8nm or 2.9nm, etc.

[0059] In some examples, the thickness of the first doped semiconductor layer 105 along the first direction X can be 200nm to 300nm, for example, it can be 210nm, 220nm, 230nm, 240nm, 250nm, 260nm, 270nm, 280nm, 290nm, 300nm, 310nm, 320nm, 330nm, 340nm, 350nm, 360nm, 370nm, 380nm or 390nm, etc.

[0060] In some cases, the element doped in the first doped semiconductor layer 105 is a p-type dopant, which can be boron.

[0061] In some examples, the boron doping concentration in the first doped semiconductor layer 105 can be 2 × 10⁻⁶. 18 atom / cm 3 ~5×10 19 atom / cm 3 For example, it can be 3×10 18 atom / cm 3 4×1018 atom / cm 3 5×10 18 atom / cm 3 6×10 18 atom / cm 3 7×10 18 atom / cm 3 8×10 18 atom / cm 3 9×10 18 atom / cm 3 1×10 19 atom / cm 3 2×10 19 atom / cm 3 3×10 19 atom / cm 3 Or 4×10 19 atom / cm 3 wait.

[0062] In some examples, the material of the second tunneling layer 106 may be silicon oxide; the material of the second doped semiconductor layer 107 may be amorphous silicon.

[0063] In some examples, the thickness of the second tunneling layer 106 along the first direction X can be 1nm to 3nm, for example, it can be 1.1nm, 1.2nm, 1.3nm, 1.4nm, 1.5nm, 1.6nm, 1.7nm, 1.8nm, 1.9nm, 2nm, 2.1nm, 2.2nm, 2.3nm, 2.4nm, 2.5nm, 2.6nm, 2.7nm, 2.8nm or 2.9nm, etc.

[0064] In some examples, the thickness of the second doped semiconductor layer 107 along the first direction X can be 200nm to 300nm, for example, it can be 210nm, 220nm, 230nm, 240nm, 250nm, 260nm, 270nm, 280nm, 290nm, 300nm, 310nm, 320nm, 330nm, 340nm, 350nm, 360nm, 370nm, 380nm or 390nm, etc.

[0065] In some cases, the element doped in the second doped semiconductor layer 107 is an N-type dopant, which can be phosphorus.

[0066] In some examples, the phosphorus doping concentration in the second doped semiconductor layer 107 can be 5 × 10⁻⁶. 19 atom / cm 3 ~5×10 20atom / cm 3 For example, it can be 6×10 19 atom / cm 3 7×10 19 atom / cm 3 8×10 19 atom / cm 3 9×10 19 atom / cm 3 1×10 20 atom / cm 3 2×10 20 atom / cm 3 3×10 20 atom / cm 3 Or 4×10 20 atom / cm 3 wait.

[0067] In some cases, there is also a groove 153 between the first region 133 and the second region 143, and the second antireflective layer 128 can fill the groove 153.

[0068] In some examples, at least one of the first antireflection layer 118 and the second antireflection layer 128 may be a single-layer structure or a stacked structure, and the material of at least one of the first antireflection layer 118 and the second antireflection layer 128 may include one or more of the following materials: silicon oxide, silicon nitride, silicon oxynitride, silicon carbonitride, titanium oxide, hafnium oxide, or aluminum oxide.

[0069] It is worth noting that the first grid line 119 and the second grid line 129 are both fine grids (sub-grids) of photovoltaic cells, used to collect and summarize the current of photovoltaic cells; the first grid line 119 and the second grid line 129 can be sintered from burn-through slurry; the material of the first grid line 119 and the second grid line 129 can be one or more of aluminum, silver, gold, nickel, molybdenum or copper.

[0070] In summary, upon exposure to light, the free electrons on the surface of the silver nanostructure 111 undergo collective oscillation, i.e., localized surface plasmon resonance (LSPR). On one hand, the plasmon resonance effect of the silver nanostructure involves the interaction between the conductive electrons on the metal surface and the incident photons, resulting in resonant absorption and scattering effects. This is beneficial for enhancing the response of the initial solar cell 100 to near-infrared light by leveraging the resonant absorption and scattering effects of the silver nanostructure 111, thereby improving the utilization rate of light by the initial solar cell 100. On the other hand, the uneven surface of the silver nanostructure array 101, which includes multiple silver nanostructures 111, facilitates multi-angle adjustment of the light propagation path, thereby extending the effective path length of light within the photovoltaic cell and increasing the total amount of light received by the initial solar cell 100. Furthermore, the oxide layer 102 is designed to cover the surface of the silver nanostructure array 101. On the one hand, the oxide layer 102 helps protect the surface of the silver nanostructure array 101, preventing the silver nanostructures 111 from being oxidized or damaged and thus failing. On the other hand, the oxide layer 102 can also limit the silver nanostructures 111, preventing the spaced silver nanostructures 111 from agglomerating and failing. Additionally, the oxide layer 102 helps passivate surface defects of the initial solar cell 100, such as dangling bonds, and it also has a passivating effect on the initial solar cell 100. In summary, based on these multiple benefits, it is beneficial to improve the short-circuit current and photoelectric conversion efficiency of the photovoltaic cell.

[0071] Another embodiment of this application provides a photovoltaic module for converting received light energy into electrical energy. The photovoltaic module provided in yet another embodiment of this application will be described in detail below with reference to the accompanying drawings. It should be noted that parts that are the same as or corresponding to those in the foregoing embodiments will not be repeated here.

[0072] Reference Figures 1 to 4 The photovoltaic module includes: a cell string, formed by connecting multiple photovoltaic cells 40 as provided in the previous embodiments; an encapsulating film 41 for covering the surface of the cell string; a cover plate 42 for covering the surface of the encapsulating film 41 facing away from the cell string; and a frame (not shown) for surrounding the outer periphery of the laminate, the laminate including the cell string, the encapsulating film 41, and the cover plate 42. The photovoltaic cells 40 are electrically connected in a single piece or in multiple segments to form multiple cell strings, and the multiple cell strings are electrically connected in series and / or parallel. In other words, the photovoltaic cell 40 can be a single cell or a sliced ​​cell; a sliced ​​cell refers to a cell formed by cutting a single, complete cell.

[0073] in, Figure 3 This is a partial three-dimensional schematic diagram of a cell string in a photovoltaic module provided in another embodiment of this application; Figure 4This is a partial cross-sectional schematic diagram of a photovoltaic module provided in another embodiment of this application.

[0074] In some embodiments, the photovoltaic cell 40 includes, but is not limited to, one or any combination of cell cells with passivated contact structures such as IBC cells, PERC cells, TOPCON cells, HIT / HJT cells, thin-film solar cells, and tandem cells. Thin-film solar cells include, but are not limited to, perovskite thin-film solar cells, copper indium selenide (CIGS) thin-film solar cells, gallium arsenide (GaAs) thin-film solar cells, and cadmium sulfide (CdS) thin-film solar cells. Tandem cells include, but are not limited to, perovskite cells stacked with crystalline silicon cells, perovskite cells stacked with perovskite cells, and perovskite cells stacked with thin-film cells.

[0075] In some embodiments, reference Figure 3 and Figure 4 Multiple battery strings can be electrically connected by soldering ribbon 402. Figure 3 and Figure 4 This illustration only shows one positional relationship between the photovoltaic cells 40, where the side of each photovoltaic cell 40 with electrodes faces the same side, so that the solder ribbon 402 connects the same side of two adjacent photovoltaic cells 40 respectively. In other embodiments, the photovoltaic cells may also be arranged such that the electrodes of two adjacent photovoltaic cells are located on different sides, in which case the solder ribbon connects two adjacent photovoltaic cells on different sides.

[0076] In some embodiments, there is no spacing between photovoltaic cells, meaning that the photovoltaic cells overlap each other.

[0077] In some embodiments, the encapsulating film 41 includes a first encapsulating layer and a second encapsulating layer. The first encapsulating layer covers one of the front or back sides of the photovoltaic cell 40, and the second encapsulating layer covers the other of the front or back sides of the photovoltaic cell 40. Specifically, at least one of the first or second encapsulating layer can be an organic encapsulating film such as polyvinyl butyral (PVB) film, ethylene-vinyl acetate copolymer (EVA) film, polyvinyl octene elastomer (POE) film, or polyethylene terephthalate (PET) film. Alternatively, at least one of the first or second encapsulating layer can also be an EP film, an EPE film, or a PVP film. Here, EP film refers to a co-extruded film composed of stacked EVA film and POE film; EPE film refers to a co-extruded film formed by sequentially stacking EVA film + POE film + EVA film; and PVP film refers to a co-extruded film formed by stacking POE film + EVA film + POE film. Co-extruded films can be prepared by sequentially extruding one or more raw materials onto another pre-made film during the film processing, or by bonding different types of pre-made films together.

[0078] In some cases, the first encapsulation layer and the second encapsulation layer still have a boundary line before lamination. After lamination, the photovoltaic module will no longer have the concept of a first encapsulation layer and a second encapsulation layer. That is, the first encapsulation layer and the second encapsulation layer have formed an integral encapsulation film 41.

[0079] In some embodiments, the cover plate 42 can be a glass cover plate, a plastic cover plate, or other cover plate with light-transmitting function. Specifically, the surface of the cover plate 42 facing the encapsulating film 41 can be an uneven surface or a textured surface containing multiple raised structures, thereby increasing the utilization rate of incident light. The cover plate 42 includes a first cover plate and a second cover plate, the first cover plate being opposite to the first encapsulation layer, and the second cover plate being opposite to the second encapsulation layer.

[0080] In some embodiments, the surface of the photovoltaic cell 40 has a plurality of main grids spaced apart along a third direction and a plurality of sub-grids spaced apart along a fourth direction. During the construction of a cell string using the photovoltaic cells 40, the solder ribbon 402 is electrically connected to at least one main grid on each of two adjacent photovoltaic cells 40. The solder ribbon 402 can be electrically connected to the main grid by soldering to a pad, or it can be pre-fixed to the main grid using adhesive dots, with the electrical connection achieved through the fusion of the adhesive dots and the deformation of the solder ribbon 402 during lamination.

[0081] Those skilled in the art will understand that the above-described embodiments are specific examples of implementing this application, and in practical applications, various changes can be made in form and detail without departing from the spirit and scope of the embodiments of this application. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the embodiments of this application; therefore, the scope of protection of the embodiments of this application should be determined by the scope defined in the claims.

Claims

1. A photovoltaic cell, characterized in that, include: Initial solar cells; A silver nanostructure array is located on the front side of the initial solar cell. The silver nanostructure array includes a plurality of silver nanostructures, and at least a portion of the silver nanostructures are spaced apart. An oxide layer covers the surface formed by the front side and the silver nanostructure array.

2. The photovoltaic cell according to claim 1, characterized in that, The front of the initial battery cell has a textured surface comprising multiple pyramidal structures, with the silver nanostructures located on the surface or apex of the pyramidal structures.

3. The photovoltaic cell according to claim 1, characterized in that, The silver nanostructures are distributed in a rate of 5% to 20% on the front side.

4. The photovoltaic cell according to claim 1 or 3, characterized in that, The silver nanostructure includes at least one of silver nanoparticles or silver nanowires.

5. The photovoltaic cell according to claim 4, characterized in that, The diameter of the silver nanoparticles is 10 nm to 25 nm; and / or the aspect ratio of the silver nanowires is greater than 5.

6. The photovoltaic cell according to claim 4, characterized in that, The spacing between adjacent silver nanoparticles is 125nm~200nm.

7. The photovoltaic cell according to claim 1, characterized in that, The thickness of the oxide layer is 10 nm to 50 nm.

8. The photovoltaic cell according to claim 1, characterized in that, The oxide layer is made of aluminum oxide.

9. The photovoltaic cell according to claim 1, characterized in that, The initial battery cell includes: The substrate has a first surface corresponding to the front side and a second surface corresponding to the back side of the initial battery cell, the second surface including a first region and a second region alternately arranged along a second direction; A first tunneling layer located on the first region, and a first doped semiconductor layer located on the side of the first tunneling layer away from the first region; The second tunneling layer is located on the second region, and the second doped semiconductor layer is located on the side of the second tunneling layer away from the second region. One of the first doped semiconductor layer and the second doped semiconductor layer is doped with a P-type doping element, and the other is doped with an N-type doping element. The first antireflective layer is located on the side of the oxide layer away from the front side; The second anti-reflection layer is located on the first region and the second region; The first gate line is embedded in the second anti-reflection layer and is in contact with the first doped semiconductor layer; The second gate line is embedded in the second anti-reflection layer and is in contact with the second doped semiconductor layer.

10. A photovoltaic module, characterized in that, include: A battery string is formed by connecting multiple photovoltaic cells as described in any one of claims 1 to 9; An encapsulating film is used to cover the surface of the battery string; A cover plate is used to cover the surface of the encapsulating film that faces away from the battery string; A frame is used to surround the outer periphery of the laminate, which includes the battery string, the encapsulating film, and the cover plate.

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