Solar cell, laminated cell and photovoltaic module

Abstract

The invention relates to the photovoltaic field, and provides a solar cell, a laminated cell and a photovoltaic module. The solar cell comprises a substrate, a doped conductive layer, a first grid line and a second grid line. The doped conductive layer is located on the substrate; the first grid line is located on the substrate and is in electric contact with the doped conducting layer, the orthographic projection of the first grid line on the substrate is in a wave shape or a sawtooth shape with a plurality of inflection points, and the first grid line comprises a plurality of first sections and second sections which are alternately distributed; the distance between adjacent inflection points in the first section along the first direction is smaller than that between adjacent inflection points in the second section along the first direction; the second grid line is located on the substrate, extends in the second direction and is connected with the first section. The performance of the solar cell can be improved at least.

Description

Technical Field

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

[0002] As fossil energy is gradually depleted, solar energy is becoming more and more widely used as a new energy alternative. Solar cells are devices that convert sunlight into electrical energy. Solar cells use the photovoltaic principle to generate carriers, and then use electrodes to lead the carriers out, which is conducive to the effective use of electrical energy.

[0003] However, there are problems with the fine grid design in current solar cells, resulting in the performance of solar cells to be improved. Summary of the invention

[0004] The embodiments of the present disclosure provide a solar cell, a stacked cell and a photovoltaic module, which are at least beneficial to improving the performance of the solar cell.

[0005] According to some embodiments of the present disclosure, on one hand, an embodiment of the present disclosure provides a solar cell. The solar cell includes: a substrate; a doped conductive layer, the doped conductive layer is located on the substrate; a first grid line, the first grid line is located on the substrate and is in electrical contact with the doped conductive layer, the positive projection of the first grid line on the substrate is a wave shape or a sawtooth shape with multiple inflection points, the first grid line includes a plurality of alternatingly distributed first segments and second segments, the distance between adjacent inflection points in the first segment along the first direction is less than the distance between adjacent inflection points in the second segment along the first direction; a second grid line, the second grid line is located on the substrate, the second grid line extends along the second direction, and is connected to the first segment.

[0006] In some embodiments, in a direction approaching the first segment, the distance between adjacent inflection points in the second segment along the first direction gradually decreases.

[0007] In some embodiments, the distance between adjacent inflection points in the first section along the first direction is 0.25 mm to 0.75 mm, and the distance between adjacent inflection points in the second section along the first direction is 0.76 mm to 1.5 mm.

[0008] In some embodiments, the distance between adjacent inflection points along the second direction is 0.1 mm to 0.5 mm.

[0009] In some embodiments, the solar cell further includes: a passivation layer located on the surface of the doped conductive layer facing away from the substrate. A groove penetrating through the passivation layer is provided in the passivation layer. The first grid line and the second grid line are cross-connected, and the cross portion of the first grid line and the second grid line is located in the groove; a conductive portion located in the groove and in electrical contact with the first grid line and the second grid line located in the groove.

[0010] In some embodiments, the width of the groove in the first direction is greater than the width of the second grid line in the first direction, and the width of the groove in the second direction is greater than the width of the first grid line in the second direction.

[0011] In some embodiments, the substrate includes two relatively arranged first edges, and the width of the second grid line near the first edge in the first direction is greater than the width of the second grid line far from the first edge in the first direction.

[0012] In some embodiments, the second grid line includes a main body portion and edge portions located at both ends of the main body portion. The edge portion includes a first end close to the main body portion and a second end far from the main body portion. The width of the first end in the first direction is equal to the width of the main body portion in the first direction, the width of the second end in the first direction is less than the width of the main body portion in the first direction, and the width of the edge portion in the first direction gradually increases in the direction close to the main body portion.

[0013] According to some embodiments of the present disclosure, on the other hand, the present disclosure also provides a tandem cell. The tandem cell includes: a bottom cell, which is the solar cell described in any one of the above embodiments; a top cell located on the bottom cell.

[0014] According to some embodiments of the present disclosure, on the other hand, the present disclosure also provides a photovoltaic module. The photovoltaic module includes: a cell string formed by connecting a plurality of the solar cells described in any one of the above embodiments, or formed by connecting the tandem cells described in the above embodiments; an encapsulation adhesive film for covering the surface of the cell string; a cover plate for covering the surface of the encapsulation adhesive film facing away from the cell string.

[0015] The technical solution provided by the embodiments of the present disclosure has at least the following advantages: In the solar cell provided by the embodiment of the present disclosure, the positive projection of the first grid line on the substrate is wavy or serrated, that is, the structure of the first grid line is wavy or serrated, which is beneficial to multiple reflections of incident light on the surface of the first grid line, so that part of the incident light can be absorbed by the substrate after reflection, thereby helping the substrate absorb more incident light, improving the light absorption rate of the solar cell, and enhancing the performance of the solar cell.

[0016] In addition, the first section of the first grid line is connected to the second grid line, and the distance between adjacent inflection points in the first direction in the first section is smaller than the distance between adjacent inflection points in the first direction in the second section. On the one hand, the distance between adjacent inflection points in the first direction in the first section is small, and the positive projection area of the first section on the substrate is large. That is, the contact area between the first section and the doped conductive layer can be large, and the first section can collect more current and transmit the collected more current to the second grid line. Thus, it is beneficial to improve the current collection efficiency of the solar cell, and further enhance the performance of the solar cell. On the other hand, the distance between adjacent inflection points in the first direction in the second section is large, and the positive projection area of the second section on the substrate is small, which can reduce the light shielding area of the second section, and thus is also beneficial to enhancing the performance of the solar cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] One or more embodiments are exemplarily illustrated by the pictures in the corresponding drawings. These exemplary illustrations do not constitute a limitation on the embodiments. Unless otherwise stated, the figures in the drawings do not constitute a proportional limitation; in order to more clearly illustrate the technical solutions in the embodiments of the present disclosure or in the prior art, the following will briefly introduce the drawings required to be used in the embodiments. Obviously, the following-described drawings are only some embodiments of the present disclosure. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0018] Figure 1 It is a schematic cross-sectional structure diagram of a solar cell provided by an embodiment of the present disclosure; Figure 2 It is a schematic top view structure diagram of a solar cell provided by an embodiment of the present disclosure; Figure 3 It is Figure 2 a partial enlarged schematic diagram of part A in Figure 4 It is another schematic top view structure diagram of a solar cell provided by an embodiment of the present disclosure; Figure 5 It is Figure 4 a partial enlarged schematic diagram of part B in Figure 6 It is another schematic cross-sectional structure diagram of a solar cell provided by an embodiment of the present disclosure; Figure 7A top view structural schematic diagram of a conductive part in a solar cell provided by an embodiment of the present disclosure; Figure 8 A structural schematic diagram of a second grid line in a solar cell provided by an embodiment of the present disclosure; Figure 9 A structural schematic diagram of a stacked cell provided by an embodiment of the present disclosure; Figure 10 A structural schematic diagram of a photovoltaic module provided by an embodiment of the present disclosure.

[0019] Explanation of reference numerals: 100, substrate; 110, first surface; 120, second surface; 130, first edge; 101, doped conductive layer; 102, first grid line; 112, first segment; 122, second segment; 103, second grid line; 113, main body part; 123, edge part; 133, first end; 143, second end; 104, passivation layer; 114, groove; 105, conductive part; 106, bottom cell; 107, top cell; 20, solar cell; 21, encapsulant film; 22, cover plate; 23, solder ribbon. Detailed implementation manners

[0020] In current solar cells, the fine grid is usually straight. The straight fine grid is difficult to help the substrate absorb more incident light, resulting in a low light absorption rate of the solar cell and poor performance of the solar cell.

[0021] In the solar cell provided by an embodiment of the present disclosure, the orthographic projection of the first grid line on the substrate is wavy or serrated, that is, the structure of the first grid line is wavy or serrated, which is beneficial to multiple reflections of incident light on the surface of the first grid line, so that part of the incident light can be absorbed by the substrate after reflection, thereby helping the substrate absorb more incident light, improving the light absorption rate of the solar cell, and enhancing the performance of the solar cell.

[0022] In addition, the first segment of the first grid line is connected to the second grid line, and the distance between adjacent inflection points in the first direction in the first segment is less than the distance between adjacent inflection points in the first direction in the second segment. On the one hand, the distance between adjacent inflection points in the first direction in the first segment is small, and the orthographic projection area of the first segment on the substrate is large. That is, the contact area between the first segment and the doped conductive layer can be large, and the first segment can collect more current and transmit the collected more current to the second grid line. Thus, it is beneficial to improve the current collection efficiency of the solar cell, and further enhance the performance of the solar cell. On the other hand, the distance between adjacent inflection points in the first direction in the second segment is large, and the orthographic projection area of the second segment on the substrate is small, which can reduce the light shielding area of the second segment, and thus is also beneficial to improving the performance of the solar cell.

[0023] In the description of the embodiments of the present disclosure, technical terms such as "first" and "second" are only used to distinguish different objects, and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity, specific order, or primary-secondary relationship of the indicated technical features. In the description of the embodiments of the present disclosure, the meaning of "plurality" is more than two, unless otherwise specifically and clearly defined.

[0024] Reference to "embodiment" herein means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the present disclosure. The phrase appears in various places in the specification and does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0025] In the description of the embodiments of the present disclosure, the term "and / or" is merely a description of the association relationship of associated objects, indicating that three relationships can exist. For example, A and / or B can represent three situations: the existence of A, the simultaneous existence of A and B, and the existence of B. Additionally, the character " / " in this text generally represents an "or" relationship between the associated objects before and after.

[0026] In the description of the embodiments of the present disclosure, the term "plurality" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0027] In the description of the embodiments of the present disclosure, the orientation or positional relationship indicated by technical terms such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the embodiments of the present disclosure and simplifying the description, rather than indicating or implying that the indicated device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation on the embodiments of the present disclosure.

[0028] In the description of the embodiments of the present disclosure, unless otherwise clearly specified and limited, technical terms such as "installation", "connection", "coupling", "fixing", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present disclosure can be understood according to specific circumstances.

[0029] In the accompanying drawings corresponding to the embodiments of the present disclosure, for better understanding and description, the thickness and area of the layers are enlarged. When describing a component (such as a layer, film, region, or substrate) on or on the surface of another component, the component can be "directly" on the surface of the other component, or there can be a third component between the two components. Conversely, when describing a component on the surface of another component or when a surface of a component forms or is provided with another component, it means that there is no third component between the two components. In addition, when describing a component as being "substantially" formed on another component, it means that the component is not formed on the entire surface (or front surface) of the other component, nor on a partial edge of the entire surface.

[0030] In the description of the embodiments of the present disclosure, when a certain component "includes" another component, unless otherwise specified, other components are not excluded, and other components may further be included. In addition, when components such as layers, films, regions, or plates are referred to as being "on / located on" another component, it can be "directly on" the other component (i.e., on the surface of the other component with no other components in between), or there can be another component in between. In addition, when components such as layers, films, regions, plates, etc. are "directly located on" another component, or when components such as layers, films, regions, plates, etc. are located on the surface of another component, it means that no other components are located in between.

[0031] The embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. However, those of ordinary skill in the art can understand that in the embodiments of the present disclosure, many technical details are provided to enable readers to better understand the present disclosure. However, even without these technical details and various changes and modifications based on the following embodiments, the technical solutions claimed in the present disclosure can still be implemented.

[0032] Figure 1 It is a schematic cross-sectional structure diagram of a solar cell provided for the embodiments of the present disclosure. Figure 2 It is a schematic top view structure diagram of a solar cell provided for the embodiments of the present disclosure. Figure 3 It is Figure 2 a partial enlarged schematic diagram of part A in Figure 4 It is another schematic top view structure diagram of a solar cell provided for the embodiments of the present disclosure. Figure 5 It is Figure 4 a partial enlarged schematic diagram of part B in

[0033] With reference to Figures 1 to 5, the solar cell includes: a substrate 100, a doped conductive layer 101, a first grid line 102, and a second grid line 103. The doped conductive layer 101 is located on the substrate 100; the first grid line 102 is located on the substrate 100 and is in electrical contact with the doped conductive layer 101. The positive projection of the first grid line 102 on the substrate 100 is a wavy or zigzag shape with multiple inflection points. The first grid line 102 includes multiple alternately distributed first segments 112 and second segments 122, and the distance D1 between adjacent inflection points in the first segment 112 along the first direction X is less than the distance D2 between adjacent inflection points in the second segment 122 along the first direction X; the second grid line 103 is located on the substrate 100, extends along the second direction Y, and is connected to the first segment 112.

[0034] The solar cell is one or any combination of a PERC (Passivated Emitter Rear Cell) cell, an IBC (Interdigitated Back Contact) cell, a TOPCon (Tunnel Oxide Passivated Contact) cell, a heterojunction cell, a thin-film solar cell, and a tandem cell. Among them, the thin-film solar cell includes, but is not limited to, a perovskite thin-film solar cell, a copper indium selenide thin-film solar cell, a gallium arsenide thin-film solar cell, and a cadmium sulfide thin-film solar cell. The tandem cell includes, but is not limited to, a perovskite cell stacked with a crystalline silicon cell, a perovskite cell stacked with a perovskite cell, and a perovskite cell stacked with a thin-film cell.

[0035] The substrate 100 is used to receive incident light and generate photo-generated carriers. In some embodiments, the substrate 100 can be a semiconductor substrate.

[0036] In some embodiments, the material of the substrate 100 can be an elemental semiconductor material. Specifically, the elemental semiconductor material is composed of a single element, for example, it can be silicon or germanium. Among them, the elemental semiconductor material can be in a single crystal state, a polycrystalline state, an amorphous state, or a microcrystalline state (a state that has both a single crystal state and an amorphous state is called a microcrystalline state). For example, silicon can be at least one of single-crystalline silicon, polycrystalline silicon, amorphous silicon, or microcrystalline silicon.

[0037] In some embodiments, the material of the substrate 100 can also be a compound semiconductor material. Common compound semiconductor materials include, but are not limited to, silicon germanide, silicon carbide, gallium arsenide, indium gallium, perovskite, cadmium telluride, copper indium selenide, and other materials.

[0038] The substrate 100 can also be a sapphire substrate, a silicon-on-insulator substrate, or a germanium-on-insulator substrate.

[0039] The substrate 100 can be an N-type semiconductor substrate or a P-type semiconductor substrate. The N-type semiconductor substrate is doped with an N-type doping element, and the N-type doping element can be any 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, and the P-type doping element can be any one of Group III elements such as boron (B), aluminum (Al), gallium (Ga), or indium (In).

[0040] The substrate 100 has opposite first and second surfaces 110 and 120. In some embodiments, the solar cell is a single-sided cell, and the first surface 110 of the substrate 100 can be used as the light-receiving surface for receiving incident light, and the second surface 120 is used as the backlight surface. In some embodiments, the solar cell is a double-sided cell, and both the first surface 110 and the second surface 120 of the substrate 100 can be used as light-receiving surfaces and can be used to receive incident light. It can be understood that the backlight surface referred to in the embodiments of the present application can also receive incident light, but the degree of receiving incident light is weaker than that of the light-receiving surface, so it is defined as the backlight surface.

[0041] In some embodiments, a texturing process can be performed on at least one of the first and second surfaces of the substrate to form a textured surface on at least one of the first and second surfaces of the substrate. In this way, the absorption utilization rate of the first and second surfaces of the substrate for incident light can be enhanced. In some embodiments, the textured surface can be a pyramid textured surface. As a common textured surface, the pyramid textured surface not only reduces the reflectivity of the substrate surface, but also forms a light trap, enhances the absorption effect of the substrate on incident light, and improves the photoelectric conversion efficiency of the solar cell.

[0042] The doped conductive layer 101 is doped with an N-type doping element or a P-type doping element.

[0043] The material of the doped conductive layer 101 can include at least one of amorphous silicon, polycrystalline silicon, or silicon carbide.

[0044] The first grid line 102 is a fine grid for contacting the doped conductive layer 101 and collecting current.

[0045] The first grid line 102 includes a plurality of alternately distributed first segments 112 and second segments 122. The first segments 112 and the second segments 122 are artificially defined. The first segment 112 is the part between two adjacent inflection points corresponding to the main grid (the second grid line 103) in the first grid line 102, and the second segment 122 is the remaining part of the first grid line 102 excluding the first segment 112. The first segment 112 is used to connect to the second grid line 103.

[0046] In some embodiments, the first segment 112 is the portion of the first gate line 102 where the distance between two adjacent inflection points along the first direction X is the smallest. Two adjacent inflection points of the first segment 112 can be considered as the two endpoints of the first segment 112.

[0047] Referring to Figure 2 , when the orthographic projection of the first gate line 102 on the substrate 100 is zigzag, the inflection point is the tooth tip. Referring to Figure 4 , when the orthographic projection of the first gate line 102 on the substrate 100 is wavy, the inflection point is the wave crest or the wave trough.

[0048] In some embodiments, the material of the first gate line 102 is a copper-silver composite paste. Using the copper-silver composite paste can reduce the preparation cost of the first gate line 102.

[0049] The second gate line 103 is the main gate. The second gate line 103 is connected to the first gate line 102 and is used to collect the current collected by the first gate line 102.

[0050] In some embodiments, the material of the second gate line 103 is pure silver paste. In this way, the second gate line 103 has good conductivity, which can improve the efficiency of the second gate line 103 in collecting current, thereby improving the performance of the solar cell.

[0051] The first direction X is the arrangement direction of multiple second gate lines 103, and the second direction Y is the extension direction of the second gate line 103. The first direction X can be perpendicular to the second direction Y.

[0052] It can be understood that Figure 1 illustrates the case where the doped conductive layer, the first gate line, and the second gate line are located on the first surface of the substrate. In fact, the doped conductive layer, the first gate line, and the second gate line can also be located on the second surface of the substrate, or the doped conductive layer, the first gate line, and the second gate line are provided on both the first surface and the second surface of the substrate. In addition, for the convenience of illustration, Figure 2 and Figure 4 only illustrate the case where the solar cell includes three second gate lines. In fact, the number of second gate lines can also be other positive integers such as 4, 5, 6, etc.

[0053] Referring to Figures 2 to 5 , in some embodiments, in the direction close to the first segment 112, the distance D2 between adjacent inflection points in the second segment 122 along the first direction X gradually decreases. That is, in the direction where the second segment 122 is close to the second gate line 103, the orthographic projection area of the second segment 122 on the substrate 100 gradually increases, so that the portion of the second segment 122 close to the second gate line 103 can collect more current, improving the efficiency of the solar cell in collecting current. And the portion of the second segment 122 far from the second gate line 103 can reduce its own light shielding area, which is beneficial to improving the performance of the solar cell.

[0054] In some embodiments, the distance D1 between adjacent inflection points in the first segment 112 along the first direction X is 0.25 mm to 0.75 mm, such as 0.25 mm to 0.4 mm, 0.4 mm to 0.6 mm, or 0.6 mm to 0.75 mm. Exemplarily, the distance D1 between adjacent inflection points in the first segment 112 along the first direction X can be 0.25 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, or 0.75 mm. When the distance D1 between adjacent inflection points in the first segment 112 is within the above range, the distance D1 between adjacent inflection points along the first direction X is relatively small, and the orthographic projection area of the first segment 112 on the substrate 100 is relatively large. The first segment 112 can collect more current and transmit the collected more current to the second gate line 103, thereby facilitating the improvement of the current collection efficiency of the solar cell and further improving the performance of the solar cell.

[0055] The distance D2 between adjacent inflection points in the second segment 122 along the first direction X is 0.76 mm to 1.5 mm, such as 0.76 mm to 1 mm, 1 mm to 1.25 mm, or 1.25 mm to 1.5 mm. Exemplarily, the distance D2 between adjacent inflection points in the second segment 122 along the first direction X can be 0.76 mm, 0.8 mm, 1 mm, 1.2 mm, 1.25 mm, 1.3 mm, or 1.5 mm. When the distance D2 between adjacent inflection points in the second segment 122 is within the above range, the distance D2 between adjacent inflection points along the first direction X is relatively large, and the orthographic projection area of the second segment 122 on the substrate 100 is relatively small, which can reduce the light-shielding area of the second segment 122 and is also beneficial to improving the performance of the solar cell.

[0056] In some embodiments, the distance between adjacent inflection points in the first segment along the second direction Y is equal to the distance between adjacent inflection points in the second segment along the second direction Y.

[0057] In some embodiments, the distance D3 between adjacent inflection points along the second direction Y is 0.1 mm to 0.5 mm, such as 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, or 0.5 mm. The distance D3 between adjacent inflection points along the second direction Y is positively correlated with the orthographic projection area of the first gate line 102 on the substrate 100. When the distance D3 between adjacent inflection points along the second direction Y is within the above range, the orthographic projection area of the first gate line 102 on the substrate 100 can be ensured to be moderate, avoiding the situation that the orthographic projection area of the first gate line 102 on the substrate 100 is too large and affecting the absorption of sunlight by the substrate 100. It can also avoid the situation that the orthographic projection area of the first gate line 102 on the substrate 100 is too small and affecting the current collection of the first gate line 102.

[0058] Figure 6 Another schematic cross-sectional structure diagram of the solar cell provided by the embodiments of the present disclosureFigure 7 FIG. 1 is a top view structural schematic diagram of a conductive portion 105 in a solar cell provided by an embodiment of the present disclosure. Among them, Figure 6 in order to better illustrate the groove, the first grid line and the second grid line are not shown. The conductive portion is filled in the groove, so Figure 7 in the width of the conductive portion in the first direction can reflect the width of the groove in the first direction, and the width of the conductive portion in the second direction can reflect the width of the groove in the second direction, that is, it can be considered that the width of the conductive portion in the first direction is equal to the width of the groove in the first direction, and the width of the conductive portion in the second direction is equal to the width of the groove in the second direction.

[0059] Refer to Figure 6 and Figure 7 , in some embodiments, the solar cell further includes a passivation layer 104 and a conductive portion 105. The passivation layer 104 is located on the surface of the doped conductive layer 101 facing away from the substrate 100. A groove 114 penetrating the passivation layer 104 is provided in the passivation layer 104. The first grid line 102 and the second grid line 103 are cross-connected, and the cross portion of the first grid line 102 and the second grid line 103 is located in the groove 114; the conductive portion 105 is located in the groove 114 and is in electrical contact with the first grid line 102 and the second grid line 103 located in the groove 114.

[0060] The passivation layer 104 can passivate the substrate 100, reduce the density of defect states on the first surface 110 of the substrate 100, and preferably suppress the carrier recombination on the first surface 110 of the substrate 100.

[0061] The material of the passivation layer 104 can be at least one of silicon oxide, aluminum oxide, silicon nitride or silicon oxynitride.

[0062] In some embodiments, the passivation layer 104 can be a single-layer structure. In some embodiments, the passivation layer 104 can also be a multi-layer structure. The materials of the layers in the multi-layer structure can be different from each other, or the materials of some of the layers can be different from each other, and the materials of the remaining layers can be the same. For example, the passivation layer 104 can be a multi-layer structure including a silicon nitride layer and an aluminum oxide layer.

[0063] The groove 114 is used to accommodate the cross portion of the first grid line 102 and the second grid line 103, and is also used to accommodate the conductive portion 105, so that the conductive portion 105 can be in electrical contact with the cross portion of the first grid line 102 and the second grid line 103, which can reduce the contact resistance of the cross portion of the first grid line 102 and the second grid line 103, and is beneficial to the efficiency of the second grid line 103 in collecting the current on the first grid line 102, thereby being beneficial to improving the performance of the solar cell.

[0064] The material of the conductive portion 105 can be a metal (e.g., tungsten (W), titanium (Ti), molybdenum (Mo), niobium (Nb), vanadium (V), hafnium (Hf), tantalum (Ta), chromium (Cr), zirconium (Zr), iron (Fe), ruthenium (Ru), osmium (Os), cobalt (Co), rhodium (Rh), iridium (Ir), nickel (Ni), palladium (Pd), platinum (Pt), copper (Cu), silver (Ag), gold (Au), aluminum (Al)), an alloy (e.g., a Co-based alloy, an Fe-based alloy, an Ni-based alloy, an Fe- and Ni-based alloy, a Co- and Ni-based alloy, an Fe- and Co-based alloy, a Co- and Ni- and Fe-based alloy, an Al-based alloy, a Cu-based alloy, a magnesium (Mg)-based alloy, a Ti-based alloy, steel, low-carbon steel, stainless steel), a conductive metal-containing material (e.g., a conductive metal nitride, a conductive metal silicide, a conductive metal carbide, a conductive metal oxide), and a conductive doped semiconductor material (e.g., conductive doped polysilicon, conductive doped germanium (Ge), conductive doped silicon-germanium (SiGe)).

[0065] It can be understood that Figure 6 and Figure 7 schematically shows a case where the conductive portion 105 is located at the bottom of the groove 114 and the crossing portion of the first gate line 102 and the second gate line 103 is located on the surface of the conductive portion 105 facing away from the substrate 100. In fact, it can also be the case where the crossing portion of the first gate line 102 and the second gate line 103 is located at the bottom of the groove 114 and the conductive portion 105 is located on the surface of the crossing portion of the first gate line 102 and the second gate line 103 facing away from the substrate 100. Among them, if the conductive portion 105 is first filled in the groove 114 and then the first gate line 102 and the second gate line 103 are printed, the conductive portion 105 is located at the bottom of the groove 114 and the crossing portion of the first gate line 102 and the second gate line 103 is located on the surface of the conductive portion 105 facing away from the substrate 100; if the first gate line 102 and the second gate line 103 are first printed and then the conductive portion 105 is filled in the groove 114, the crossing portion of the first gate line 102 and the second gate line 103 is located at the bottom of the groove 114 and the conductive portion 105 is located on the surface of the crossing portion of the first gate line 102 and the second gate line 103 facing away from the substrate 100.

[0066] In some embodiments, the width W1 of the groove 114 in the first direction X is greater than the width of the second gate line 103 in the first direction X, and the width W2 of the groove 114 in the second direction Y is greater than the width of the first gate line 102 in the second direction Y. Thus, the width W1 of the groove 114 in the first direction X is larger, and the width W2 of the groove 114 in the second direction Y is larger. The groove 114 can accommodate more conductive portions 105, which can further reduce the contact resistance between the first gate line 102 and the second gate line 103 and improve the performance of the solar cell.

[0067] In some embodiments, the width W1 of the groove 114 in the first direction X is 0.5 mm to 1 mm, such as 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, or 1 mm. When the width W1 of the groove 114 in the first direction X is within the above range, an appropriate amount of the conductive portion 105 can be accommodated, effectively reducing the contact resistance of the intersecting portion of the first gate line 102 and the second gate line 103. Moreover, it can also prevent the width of the groove 114 in the first direction X from being too large, which may affect the passivation effect of the passivation layer 104.

[0068] The width W2 of the groove 114 in the second direction Y is 10 μm to 30 μm, such as 10 μm, 15 μm, 20 μm, 25 μm, or 30 μm. When the width W2 of the groove 114 in the second direction Y is within the above range, an appropriate amount of the conductive portion 105 can be accommodated, effectively reducing the contact resistance of the intersecting portion of the first gate line 102 and the second gate line 103. Moreover, it can also prevent the width of the groove 114 in the second direction Y from being too large, which may affect the passivation effect of the passivation layer 104.

[0069] Reference Figure 1 、 Figure 2 and Figure 4 and, in some embodiments, the substrate 100 includes two oppositely arranged first edges 130, and the width of the second gate line 103 along the first direction X near the first edge 130 is greater than the width of the second gate line 103 along the first direction X away from the first edge 130. The larger width of the second gate line 103 along the first direction X near the first edge 130 can improve the ability of the second gate line 103 near the first edge 130 to collect current and enhance the performance of the solar cell; the smaller width of the second gate line 103 along the first direction X away from the first edge 130 can reduce the light-shielding area of the second gate line 103 away from the first edge 130 on the substrate 100, which is beneficial to enhancing the performance of the solar cell.

[0070] In some embodiments, the width of the second gate line 103 along the first direction X near the first edge 130 is 1.2 mm to 2 mm, such as 1.2 mm, 1.4 mm, 1.6 mm, 1.8 mm, or 2 mm. In this way, the larger width of the second gate line 103 along the first direction X near the first edge 130 can improve the ability of the second gate line 103 near the first edge 130 to collect current and enhance the performance of the solar cell.

[0071] In some embodiments, the width of the second gate line 103 away from the first edge 130 in the first direction X is 0.8 mm to 1.9 mm, such as 0.8 mm, 1 mm, 1.2 mm, 1.4 mm, 1.6 mm, 1.8 mm or 1.9 mm. Thus, the width of the second gate line 103 away from the first edge 130 in the first direction X is small, which can reduce the light-shielding area of the second gate line 103 away from the first edge 130 on the substrate 100, and is beneficial to improving the performance of the solar cell.

[0072] Figure 8 FIG. 4 is a schematic structural diagram of the second gate line 103 in the solar cell provided by the embodiment of the present disclosure.

[0073] Reference Figure 8 , in some embodiments, the second gate line 103 includes a main body portion 113 and edge portions 123 located at both ends of the main body portion 113. The edge portion 123 includes a first end 133 close to the main body portion 113 and a second end 143 away from the main body portion 113. The width of the first end 133 in the first direction X is equal to the width of the main body portion 113 in the first direction X. The width of the second end 143 in the first direction X is smaller than the width of the main body portion 113 in the first direction X, and the width of the edge portion 123 in the first direction X gradually increases in the direction close to the main body portion 113. With such a setting, the average width of the edge portion 123 in the first direction X is small, which is beneficial to reducing the welding stress between the edge portion 123 and the solder strip when the second gate line 103 is welded to the solder strip, and avoiding the occurrence of battery hidden cracks or breakage due to excessive welding stress between the edge portion 123 and the solder strip.

[0074] In some embodiments, the ratio of the width of the second end 143 in the first direction X to the width of the first end 133 in the first direction X is 0.4 to 0.9, such as 0.4, 0.5, 0.6, 0.7, 0.8 or 0.9. When the ratio of the width of the second end 143 in the first direction X to the width of the first end 133 in the first direction X is within the above range, the width of the second end 143 is small, and the average width of the edge portion 123 in the first direction X is small. This is beneficial to reducing the welding stress between the edge portion 123 and the solder strip when the second gate line 103 is welded to the solder strip, and avoiding the occurrence of battery hidden cracks or breakage due to excessive welding stress between the edge portion 123 and the solder strip.

[0075] In some embodiments, the solar cell further includes an anti-reflection coating (not shown), and the anti-reflection coating is located on the surface of the first gate line 102 facing away from the substrate 100.

[0076] The anti-reflection coating can reduce the reflectivity of the surface of the first gate line 102 facing away from the substrate 100, and can improve the performance of the solar cell.

[0077] The material of the antireflection coating is at least one of silicon oxide and titanium oxide.

[0078] Figure 9 FIG. is a schematic structural diagram of a tandem cell provided by an embodiment of the present disclosure.

[0079] With reference to Figure 1 and Figure 9 , the tandem cell includes: a bottom cell 106 and a top cell 107. The bottom cell 106 is the solar cell provided in the foregoing embodiment; the top cell 107 is located on the bottom cell 106. Among them, the top cell 107 may be located on the first surface 110 of the bottom cell 106.

[0080] In some embodiments, the top cell 107 may include: a stacked first transport layer, a perovskite substrate 100, a second transport layer, a transparent conductive layer, and an antireflection layer. Among them, the first transport layer is located between the bottom cell 106 and the perovskite substrate 100.

[0081] In some embodiments, the first transport layer may be one of an electron transport layer or a hole transport layer, and the second transport layer may be the other of the electron transport layer or the hole transport layer.

[0082] Some embodiments of the present disclosure further provide a photovoltaic module, which may include the solar cell in any of the foregoing embodiments, or include the tandem cell in the above embodiments. It should be noted that the same or corresponding parts as those in the above embodiments may refer to the above embodiments and will not be described in detail below.

[0083] Figure 10 FIG. is a schematic structural diagram of a photovoltaic module provided by an embodiment of the present disclosure.

[0084] Refer to Figure 10 , the photovoltaic module includes: a battery string, which is formed by connecting a plurality of solar cells 20 as in any of the above embodiments, or is formed by connecting a plurality of tandem cells as in the above embodiments. The photovoltaic module further includes an encapsulant film 21 and a cover plate 22. The encapsulant film 21 is used to cover the surface of the battery string, and the cover plate 22 is used to cover the surface of the encapsulant film 21 away from the battery string.

[0085] In some embodiments, the battery string further includes a welding tape 23, which is used to electrically connect adjacent solar cells 20, or is used to electrically connect adjacent tandem cells.

[0086] In some embodiments, the encapsulation film 21 includes a first encapsulation layer and a second encapsulation layer. The first encapsulation layer covers one of the front and back surfaces of the solar cell, and the second encapsulation layer covers the other of the front and back surfaces of the solar cell. Specifically, at least one of the first encapsulation layer and the second encapsulation layer can be an organic encapsulation film such as a polyvinyl butyral (PVB) film, an ethylene-vinyl acetate copolymer (EVA) film, a polyethylene octene elastomer (POE) film, or a polyethylene terephthalate (PET) film. Alternatively, at least one of the first encapsulation layer and the second encapsulation layer can also be a film such as an EP film, an EPE film, or a PVP film. Among them, the EP film refers to a co-extruded film composed of an EVA film and a POE film stacked, the EPE film refers to a co-extruded film formed by sequentially stacking an EVA film, a POE film, and an EVA film, and the PVP film refers to a co-extruded film formed by stacking a POE film, an EVA film, and a POE film. The co-extruded film can be prepared by extruding one or more raw materials onto another film that has already been made in sequence during the film processing, or by bonding different types of films that have already been made together.

[0087] In some cases, there is a demarcation line between the first encapsulation layer and the second encapsulation layer before lamination. In the photovoltaic module formed after the lamination process, there will no longer be the concept of the first encapsulation layer and the second encapsulation layer, that is, the first encapsulation layer and the second encapsulation layer have formed an integral encapsulation film 21.

[0088] In some embodiments, the cover plate 22 can be a cover plate with a light-transmitting function such as a glass cover plate or a plastic cover plate. Specifically, the surface of the cover plate 22 facing the encapsulation film 21 can be a concave-convex surface or a suede surface including a plurality of protruding structures, so as to increase the utilization rate of incident light. The cover plate 22 includes a first cover plate and a second cover plate. The first cover plate faces the first encapsulation layer, and the second cover plate faces the second encapsulation layer.

[0089] Those of ordinary skill in the art can understand that the above embodiments are specific embodiments for implementing the present disclosure. In actual applications, various changes can be made to it in form and details without departing from the spirit and scope of the present disclosure. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present disclosure. Therefore, the protection scope of the present disclosure should be subject to the scope defined by the claims.

Claims

1. A solar cell, characterized in that, Comprising: Substrate; Doped conductive layer, which is located on the substrate; First gate line, which is located on the substrate and is in electrical contact with the doped conductive layer. The orthographic projection of the first gate line on the substrate is wavy or serrated with multiple inflection points. The first gate line includes multiple alternating first segments and second segments. The distance between adjacent inflection points in the first direction in the first segment is less than the distance between adjacent inflection points in the first direction in the second segment; Second gate line, which is located on the substrate, extends along a second direction, and is connected to the first segment.

2. The solar cell according to claim 1, characterized in that, In the direction close to the first segment, the distance between adjacent inflection points in the first direction in the second segment gradually decreases.

3. The solar cell according to claim 1, wherein The distance between adjacent inflection points in the first direction in the first segment is 0.25 mm to 0.75 mm, and the distance between adjacent inflection points in the first direction in the second segment is 0.76 mm to 1.5 mm.

4. The solar cell according to claim 1, characterized in that, The distance between adjacent inflection points in the second direction is 0.1 mm to 0.5 mm.

5. The solar cell according to claim 1, characterized in that, The solar cell further comprises: Passivation layer, which is located on the surface of the doped conductive layer facing away from the substrate. A groove penetrating through the passivation layer is provided in the passivation layer. The first gate line and the second gate line are cross-connected, and the cross part of the first gate line and the second gate line is located in the groove; Conductive part, which is located in the groove and is in electrical contact with the first gate line and the second gate line located in the groove.

6. The solar cell according to claim 5, characterized in that, The width of the groove in the first direction is greater than the width of the second gate line in the first direction, and the width of the groove in the second direction is greater than the width of the first gate line in the second direction.

7. The solar cell according to claim 1, characterized in that, The substrate includes two oppositely arranged first edges. The width of the second gate line in the first direction near the first edge is greater than the width of the second gate line in the first direction far from the first edge.

8. The solar cell according to claim 1, characterized in that The second gate line includes a main body part and edge parts located at both ends of the main body part. The edge part includes a first end close to the main body part and a second end far from the main body part. The width of the first end in the first direction is equal to the width of the main body part in the first direction. The width of the second end in the first direction is less than the width of the main body part in the first direction, and the width of the edge part in the first direction gradually increases in the direction close to the main body part.

9. A stacked battery, characterized in that, Comprising: Bottom cell, which is the solar cell according to any one of claims 1 to 8; Top cell, which is located on the bottom cell.

10. A photovoltaic module, characterized in that, Comprising: Cell string, which is formed by connecting multiple solar cells according to any one of claims 1 to 8, or is formed by connecting multiple stacked cells according to claim 9; Encapsulation adhesive film, which is used to cover the surface of the cell string; Cover plate, which is used to cover the surface of the encapsulation adhesive film facing away from the cell string.

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