Solar cell, preparation method thereof and photovoltaic cell module

Abstract

The invention discloses a solar cell, a preparation method thereof and a photovoltaic cell module. The solar cell comprises a substrate; the battery layer is positioned on one side of the substrate; the battery layer comprises a plurality of trunking groups, the plurality of trunking groups divide the battery layer into a plurality of sub-batteries connected in series, and trunkings in the plurality of trunking groups extend along a first direction and are arranged at intervals along a second direction; the first direction is perpendicular to the second direction; the battery layer comprises a main region and segmentation regions, the segmentation regions are located on the two opposite sides of the main region in the first direction, and the area of the segmentation regions is smaller than that of the main region; dividing a main area and a segmentation area through at least one segmentation line groove; the segmentation line groove penetrates through the battery layer; the dividing line grooves extend in the second direction and are arranged at intervals in the first direction. The reliability of the device can be improved.

Description

Technical Field

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

[0002] When a solar cell in a series circuit is shaded or experiences current limiting for other reasons, it will act as a load, consuming the energy generated by other illuminated solar cells. The shaded solar cell will then generate heat, a phenomenon known as the hotspot effect. The hotspot effect can severely damage solar cells. A portion of the energy generated by the illuminated solar cells may be consumed by the shaded cells. Hotspot durability testing measures the damage to the solar cell module caused by the hotspot effect under worst-case conditions of shading.

[0003] Thin-film battery structures differ significantly from traditional crystalline silicon battery structures. Thin-film batteries are elongated and slender cells, and while it's practically difficult to completely shield the entire elongated cell in reality, hot-spot durability tests require complete shielding. Essentially, the shielded area allows reverse current to flow through it. However, due to the inherent limitations of thin-film batteries, their localized reverse current and voltage tolerance is weak. Therefore, there is a risk of battery failure during hot-spot durability tests, impacting device reliability. Summary of the Invention

[0004] This invention provides a solar cell, its preparation method, and a photovoltaic cell module. The structure is simple and can improve the yield and reliability of packaged products.

[0005] According to one aspect of the present invention, a solar cell is provided, comprising: a substrate; A substrate; and a battery layer, the battery layer being located on one side of the substrate; The battery layer includes: Multiple slot groups divide the battery layer into multiple series-connected sub-cells. The slots in the multiple slot groups extend along a first direction and are spaced apart along a second direction. The first direction and the second direction are perpendicular to each other. At least one dividing groove is provided. The battery layer includes a main region and a dividing region. The dividing region is located on at least one side of the main region along a first direction. The area of ​​the dividing region is smaller than the area of ​​the main region. The main region and the dividing region are divided by at least one dividing groove. The dividing groove penetrates the battery layer. The dividing groove extends along a second direction.

[0006] Based on the above embodiments, optionally, the number of dividing grooves includes at least two, and the dividing areas are located on opposite sides of the main area along the first direction; At least two dividing grooves are spaced apart along the first direction.

[0007] Based on the above embodiments, optionally, the dividing groove penetrates the battery layer along the second direction, and the dividing groove penetrates the battery layer along the third direction; wherein, the third direction is perpendicular to the first direction and the second direction.

[0008] Based on the above embodiments, optionally, the area of ​​each segmented region accounts for 1% to 2.5% of the total area of ​​the battery layer; The battery layer includes a first side and a second side disposed opposite to each other along a first direction; at least two dividing grooves include at least a first sub-groove and a second sub-groove; The distance between the first sub-slot and the first side is 1% to 2.5% of the dimension of the battery layer along the first direction; the distance between the second sub-slot and the second side is 1% to 2.5% of the dimension of the battery layer along the first direction; the dimension of the dividing groove along the second direction is the same as the dimension of the battery layer along the second direction.

[0009] Based on the above embodiments, optionally, the line width of the dividing groove in the first direction is 80μm to 120μm.

[0010] Based on the above embodiments, optionally, the battery layer includes at least a first conductive layer, a functional layer and a second conductive layer stacked sequentially; the second conductive layer is located on the side of the first conductive layer away from the substrate; the functional layer includes a first buffer layer, an absorption layer and a second buffer layer stacked sequentially, the second buffer layer is located on the side of the first buffer layer away from the first conductive layer. Each group of wire slots includes a first wire slot, a second wire slot, and a third wire slot; the first wire slot penetrates the first conductive layer and a functional layer is disposed within the first wire slot; the second wire slot penetrates the functional layer and a second conductive layer is disposed within the second wire slot; the third wire slot penetrates at least the second conductive layer. The vertical projection of the third groove on the substrate is located within the vertical projection of the second groove on the substrate; the vertical projection of the second groove on the substrate does not overlap with the vertical projection of the first groove on the substrate.

[0011] In addition to the above embodiments, optionally, the following further includes: Conductive adhesive is located on both sides of the battery layer along the second direction; the conductive adhesive is in contact with the battery layer. The encapsulation layer is located on the side of the battery layer away from the substrate; the encapsulation layer covers the battery layer. The backplate is located on the side of the encapsulation layer away from the substrate and covers the encapsulation layer.

[0012] According to another aspect of the present invention, a method for preparing a solar cell is provided, comprising: Provide substrate; A battery layer is formed on one side of a substrate; the battery layer includes: multiple sets of grooves, which divide the battery layer into multiple series-connected sub-cells, the grooves in the multiple sets of grooves extending along a first direction and spaced apart along a second direction; the first direction and the second direction are perpendicular to each other; at least one dividing groove, the battery layer includes a main region and a dividing region, the dividing region is located on at least one side of the main region along the first direction, and the area of ​​the dividing region is smaller than the area of ​​the main region; the main region and the dividing region are divided by at least one dividing groove; the dividing groove penetrates the battery layer; the dividing groove extends along the second direction.

[0013] Based on the above embodiments, optionally, a battery layer is formed on one side of the substrate, including: A first conductive sublayer is formed on one side of the substrate; the first conductive sublayer covers the substrate; The first conductive layer is etched to form a first groove; the first groove penetrates the first conductive layer. A functional sublayer is formed on the side of the first conductive sublayer away from the substrate; the functional sublayer covers the first conductive sublayer and fills the first groove. The functional sublayer is etched to form a second groove; the second groove penetrates the functional sublayer, and the vertical projection of the second groove on the substrate does not overlap with the vertical projection of the first groove on the substrate. A second conductive sublayer is formed on the side of the functional sublayer away from the substrate; the second conductive sublayer covers the functional sublayer and fills the second groove. The second conductive layer is etched to form the third groove; the third groove penetrates the second conductive layer; the vertical projection of the third groove on the substrate is located within the vertical projection of the second groove on the substrate. The first conductive sublayer, the functional sublayer, and the second conductive sublayer are processed to form a first conductive layer, a functional layer, and a second conductive layer; the functional layer includes a first buffer layer, an absorption layer, and a second buffer layer stacked sequentially, and the second buffer layer is located on the side of the first buffer layer away from the first conductive layer. At least one dividing groove is formed; the dividing groove penetrates the battery layer along a second direction and also penetrates the battery layer along a third direction; wherein the third direction is perpendicular to the first direction and the second direction.

[0014] Based on the above embodiments, optionally, at least one dividing groove is formed, including: At least one dividing groove is formed by laser etching at an etching rate of 800 mm / s to 1200 mm / s and / or a power of 1 W to 3 W.

[0015] According to one aspect of the present invention, a solar cell is provided, comprising: The first battery unit includes a plurality of first sub-cells connected in series in sequence; the first battery unit has a first length along a first direction and a first width along a second direction; the first direction and the second direction are perpendicular to each other; the first battery unit includes a first output terminal and a second output terminal. The second battery unit includes a plurality of second sub-cells connected in series; the second battery unit has a second length along a first direction and a second width along a second direction; the second battery unit includes a third output terminal and a fourth output terminal; The number of multiple first sub-cells and multiple second sub-cells is equal; the first length is less than the second length; the first width and the second width are equal; the first output terminal and the third output terminal are coupled, and the second output terminal and the fourth output terminal are coupled.

[0016] Based on the above embodiments, optionally, a third battery unit includes a plurality of third sub-batteries connected in series in sequence; the third battery unit has a third length along a first direction and a third width along a second direction; the third battery unit includes a fifth output terminal and a sixth output terminal; The number of multiple second sub-cells and multiple third sub-cells is equal; the third length is less than the second length; the second width and the third width are equal; the first output terminal, the third output terminal and the fifth output terminal are coupled in sequence, and the second output terminal, the fourth output terminal and the sixth output terminal are coupled in sequence.

[0017] Based on the above embodiments, optionally, the first battery cell has a first voltage and a first current; The second battery cell has a second voltage and a second current; The third battery cell has a third voltage and a third current; Among them, the first voltage, the second voltage, and the third voltage are equal, and the first current and the third current are both less than the second current.

[0018] Based on the above embodiments, optionally, the first battery unit, the second battery unit, and the third battery unit each include multiple wire groove groups; the wire grooves in the multiple wire groove groups extend along a first direction and are spaced apart along a second direction; Multiple wire trough groups divide the first battery unit into multiple first sub-cells, the second battery unit into multiple second sub-cells, and the third battery unit into multiple third sub-cells; The troughs in multiple trough groups are divided by at least two dividing troughs, and the solar cells are divided into first cell units, second cell units, and third cell units.

[0019] Based on the above embodiments, optionally, each first sub-cell, each second sub-cell, and each third sub-cell includes a light-emitting device and a diode; The light-emitting device and the diode are connected in parallel, with the positive terminal of the light-emitting device electrically connected to the negative terminal of the diode, and the negative terminal of the light-emitting device electrically connected to the positive terminal of the diode.

[0020] According to another aspect of the present invention, a photovoltaic cell module is provided, including the solar cell described in any embodiment of the present invention.

[0021] The solar cell provided by the embodiments of the present invention includes: a substrate; a cell layer located on one side of the substrate; the cell layer includes: multiple groove groups, which divide the cell layer into multiple series-connected sub-cells, the grooves in the multiple groove groups extending along a first direction and spaced apart along a second direction; the first direction and the second direction are perpendicular to each other; at least one dividing groove, the cell layer includes a main region and a dividing region, the dividing region is located on at least one side of the main region along the first direction, and the area of ​​the dividing region is smaller than the area of ​​the main region; the main region and the dividing region are divided by at least one dividing groove; the dividing groove penetrates the cell layer; the dividing groove extends along the second direction. The present invention provides dividing grooves in the dividing regions, which can transform multiple series-connected sub-cells into a series and parallel connection, and can divide reverse current into separate current channels, avoiding current accumulation at small short-circuit points in the cells, thereby preventing module burn-out and breakage, and improving the reliability of the solar cell.

[0022] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the structure of a solar cell provided in an embodiment of the present invention.

[0025] Figure 2 yes Figure 1 A schematic diagram of the cross section along section line AA.

[0026] Figure 3 yes Figure 1 A schematic diagram of the cross section along section line BB.

[0027] Figure 4 This is a circuit diagram of a sub-battery in the prior art.

[0028] Figure 5 This is a circuit diagram of a sub-battery provided in an embodiment of the present invention.

[0029] Figure 6 This is a partial structural diagram of a solar cell in the prior art.

[0030] Figure 7 This is a partial structural schematic diagram of a solar cell provided in an embodiment of the present invention.

[0031] Figure 8 This is a schematic diagram of a hot spot effect that occurs when a solar cell is shaded in the prior art.

[0032] Figure 9 This is a partial structural diagram of a segmented region provided in an embodiment of the present invention.

[0033] Figure 10 This is a partial structural diagram of another segmented region provided in an embodiment of the present invention.

[0034] Figure 11 This is a schematic diagram of another type of solar cell provided in an embodiment of the present invention.

[0035] Figure 12 This is a schematic diagram of another type of solar cell provided in an embodiment of the present invention.

[0036] Figure 13 This is a partial structural schematic diagram of another solar cell provided in an embodiment of the present invention.

[0037] Figure 14 This is a schematic diagram of another type of solar cell provided in an embodiment of the present invention.

[0038] Figure 15 This is a schematic diagram of another type of solar cell provided in an embodiment of the present invention.

[0039] Figure 16 This is a flowchart of a method for preparing a solar cell according to an embodiment of the present invention.

[0040] Figure 17 This is a flowchart of a method for preparing a solar cell according to an embodiment of the present invention.

[0041] Figure 18 This is a schematic diagram of a partial intermediate structure of a solar cell provided in an embodiment of the invention.

[0042] Figure 19 This is a schematic diagram of another type of solar cell provided in an embodiment of the present invention.

[0043] Figure 20 This is a schematic diagram of another type of solar cell provided in an embodiment of the present invention. Detailed Implementation

[0044] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0045] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0046] In existing technologies, due to process errors, leakage points can appear at both the edges and center of solar cells, generally appearing as pinholes. However, leakage points at the edges are more likely to occur than those in the center. For example, in the formation of solar cells, a coating process is often used. During coating, the thickness uniformity of the edge region cannot be guaranteed compared to the center region. Completely removing the edge region would waste material and increase costs; moreover, removing the entire edge region simply because of film thickness issues is time-consuming, labor-intensive, and costly. However, ignoring these film thickness areas can lead to leakage points at the edges of the solar cell during hot spot durability tests or outdoor hot spot testing, often causing the solar cell to fail due to ablation or even cracking caused by hot spot problems, thus affecting the reliability of the device.

[0047] This invention provides a solar cell. Figure 1 This is a schematic diagram of the structure of a solar cell provided in an embodiment of the present invention. Figure 2 yes Figure 1 A schematic diagram of the cross-section along section line AA. Figure 3 yes Figure 1 A cross-sectional view along section line BB, for reference. Figures 1-3The solar cell includes: a substrate 10; and a cell layer 20, located on one side of the substrate 10. The cell layer 20 includes: multiple groove groups 31, which divide the cell layer 20 into multiple series-connected sub-cells 201. The grooves in the multiple groove groups 31 extend along a first direction X and are spaced apart along a second direction Y; the first direction X and the second direction Y are perpendicular to each other; and at least one dividing groove 32. The cell layer 20 includes a main region 01 and a dividing region 02, which is located on at least one side of the main region 01 along the first direction X, and the area of ​​the dividing region 02 is smaller than the area of ​​the main region 01. The main region 01 and the dividing region 02 are divided by at least one dividing groove 32; the dividing groove 32 penetrates the cell layer 20; and the dividing groove 32 extends along the second direction Y. By converting multiple series-connected sub-cells into a series and parallel connection, reverse current can be divided and diverted, avoiding current accumulation at small short-circuit points in the cells, which could cause module burn-out and breakage.

[0048] The solar cell may include a thin-film solar cell; for example, it may be a perovskite solar cell. The photovoltaic module includes a solar cell. The substrate 10 may include a glass substrate, and the cell layer 20 may be a perovskite cell layer. The main region 01 and the segmented region 02 of the cell layer 20 may be the cell etched regions of the solar cell. The segmented region 02 may include two regions, located on opposite sides of the main region 01 in the first direction X. The segmented region 02 is the region from the segmented groove 32 to the edge of the cell layer 20 adjacent to the segmented groove 32 in the first direction X. The cell layer 20 may cover part of the substrate 10. The solar cell also includes a cleaned edge region surrounding the cell etched regions. The cleaned edge region has no cell layer 20 and exposes the substrate 10. Alternatively, the cell layer 20 may completely cover the substrate 10.

[0049] Multiple slot groups 31 divide the battery layer 20 into multiple series-connected sub-batteries 201. The multiple series-connected sub-batteries can be all connected in series or partially connected in series. For example, some sub-batteries 201 on the left side of the battery layer 20 are connected in series, some sub-batteries 201 in the middle are connected in parallel, and some sub-batteries 201 on the right side are connected in series.

[0050] Let the first direction X be the length direction of the battery layer 20, and the second direction Y be the width direction of the battery layer 20. Since the potential difference of the multiple sub-cells 201 in the battery layer 20 is equal along the first direction X, that is, the potential difference of the long side of the battery layer 20 is equal; the multiple sub-cells 201 in the battery layer 20 are connected in series along the second direction Y. Figure 4 This is a circuit diagram of a sub-battery in the prior art, exemplary. Figure 4It can include 190 sub-cells 201 connected in series. The series-connected sub-cells 201 have a potential difference, meaning that leakage points, or short circuit points, are prone to occur on the short side of the cell layer 20. Therefore, this embodiment of the invention provides a segmented region 02, which includes edge regions with a high probability of leakage points. A segmenting groove 32 divides the main region 01 and the segmented region 02 into two regions. The segmenting groove 32 can convert multiple series-connected sub-cells 201 into a series and parallel connection, which can shunt the current in the solar cell, avoid large currents that could damage the solar cell, and improve the reliability of the solar cell. Figure 5 This is a circuit diagram of a sub-battery provided in an embodiment of the present invention, for reference. Figure 5 The multiple series-connected sub-cells 201 corresponding to the main region 01 are connected in parallel with the multiple series-connected sub-cells 201 corresponding to the two segmented regions 02. This series-parallel circuit structure can improve the stability of the solar cell during outdoor operation. For example, the number of multiple series-connected sub-cells 201 corresponding to the main region 01 is the same as the number of multiple series-connected sub-cells 201 corresponding to each segmented region 02. This ensures that the voltage of the solar cell remains unchanged after etching the segmentation grooves 32. Furthermore, since the area of ​​each segmented region 02 is smaller than the area of ​​the main region 01, the current passing through the sub-cells in the segmented region 02 is relatively small. The total current after parallel connection hardly changes, thus having almost no impact on the efficiency of the solar cell.

[0051] In the process of conducting hot spot durability tests on solar cells, for example, Figure 6 This is a partial structural diagram of a solar cell in the prior art. Figure 7 This is a partial structural schematic diagram of a solar cell provided in an embodiment of the present invention, for reference. Figure 6 and Figure 7 Under the most stringent conditions, the edge-clearing area of ​​the solar cell and the adjacent cell marking area are shaded, and the solar cell is short-circuited. At an irradiance of 1000 W / m², the short-circuiting time is no less than 1 hour (refer to IEC 61215 standard for details). Figure 6 This is a routine solar cell hotspot durability test. The shaded area 03 and the first edge area 04 represent locations where the film thickness of the cell layer 20 is uneven. Figure 8 This is a schematic diagram illustrating the hot spot effect that occurs when a solar cell is shaded in existing technology. (Reference) Figure 8 Under the influence of hot spot effect and diode reverse current, the load is large, and the total current of the solar cell is twice the original short-circuit current (ISC). This causes the solar cell temperature to rise sharply, and the first edge region 04 is prone to film layer breakdown and ablation, and in severe cases, glass breakage. However, in the embodiments of this invention... Figure 7The main region 01 and the segmented region 02 are divided by the dividing groove 32. Although there are still uneven film thicknesses in the first edge region 04, the short-circuit current is extremely small due to the shielding effect of the dividing groove 32. The dividing groove 32 is determined according to the distance. Each segmented region 02 can be set to occupy only 1 / 40 of the overall area of ​​the battery layer 20, so that the length of the sub-cells 201 in the segmented region 02 is shorter and the current is smaller. This means that the short-circuit current (ISC) is only 1 / 40 of the original. The film layer in the edge region 05 of the main region 01 near the segmented region 02 is uniform. The reverse current passes evenly through the sub-cells 201 in the edge region 05, which will not cause the battery layer to burn. This can improve the reliability of the solar cell and avoid the current from accumulating at the tiny short-circuit point of the battery, thus effectively avoiding the problem of film layer burn-out and solar cell failure under the most severe hot spot effect.

[0052] The solar cell provided by the technical solution of this invention includes: a substrate 10; a cell layer 20, the cell layer 20 being located on one side of the substrate 10, the cell layer 20 including: a plurality of groove groups 31, the plurality of groove groups 31 dividing the cell layer 20 into a plurality of series-connected sub-cells 201, the grooves in the plurality of groove groups 31 extending along a first direction X and spaced apart along a second direction Y; the first direction X and the second direction Y are perpendicular to each other; at least one dividing groove 32, the cell layer 20 including a main region 01 and a dividing region 02, the dividing region 02 being located on at least one side of the main region 01 along the first direction X, the area of ​​the dividing region 02 being smaller than the area of ​​the main region 01; the main region 01 and the dividing region 02 are divided by at least one dividing groove 32; the dividing groove 32 penetrates the cell layer 20; the dividing groove 32 extends along the second direction Y. In this embodiment of the invention, the dividing groove 32 divides the main region 01 and the dividing region 02 into two regions, which can transform multiple series-connected sub-cells 201 into a series and parallel connection. This can divide the reverse current into separate regions, avoid the current from accumulating at the tiny short-circuit point of the cell, thereby preventing module burn-out and breakage, and improving the reliability of the solar cell. Furthermore, since the area of ​​the dividing region 02 is smaller than the area of ​​the main region 01, the current passing through the sub-cells in the dividing region 02 is smaller, and the total current after parallel connection hardly changes, so it has almost no impact on the efficiency of the solar cell.

[0053] Based on the above embodiments, optionally, refer to Figure 1 The number of dividing grooves 32 includes at least two, and the dividing area 02 is located on opposite sides of the main area 01 along the first direction X; at least two dividing grooves 32 are spaced apart along the first direction X.

[0054] Based on the above embodiments, optionally, refer to Figure 1 and Figure 3The dividing groove 32 penetrates the battery layer 20 along the second direction Y, and the dividing groove 32 penetrates the battery layer 20 along the third direction Z; wherein, the third direction Z is perpendicular to the first direction X and the second direction Y.

[0055] The dividing groove 32 penetrates the battery layer 20 along the second direction Y and the third direction Z, which makes the number of multiple series-connected sub-cells 201 corresponding to the main region 01 the same as the number of multiple series-connected sub-cells 201 corresponding to each dividing region 02. This ensures that the voltage of the solar cell remains unchanged after the dividing groove 32 is etched.

[0056] Based on the above embodiments, optionally, Figure 9 This is a partial structural diagram of a segmented region provided in an embodiment of the present invention. Figure 10 This is a partial structural diagram of another segmented region provided in an embodiment of the present invention, for reference. Figures 1-3 ,as well as Figure 9 and Figure 10 Each segmented region 02 accounts for 1% to 2.5% of the total area of ​​the battery layer 20. The battery layer 20 includes a first side C1 and a second side C2 disposed opposite to each other along the first direction X; the segmentation groove 32 includes at least a first sub-groove 321 and a second sub-groove 322; the distance D1 between the first sub-groove 321 and the first side C1 is 1% to 2.5% of the dimension of the battery layer 20 along the first direction X; the distance D2 between the second sub-groove 322 and the second side is 1% to 2.5% of the dimension of the battery layer 20 along the first direction X; the dimension of the segmentation groove 32 along the second direction Y is the same as the dimension of the battery layer 20 along the second direction Y.

[0057] In this design, the area of ​​each segmented region 02 accounts for 1% to 2.5% of the total area of ​​the battery layer 20, resulting in shorter lengths of the sub-cells 201 in segmented region 02 and lower currents in the series-connected sub-cells corresponding to segmented region 02. The distance D1 between the first sub-slot 321 and the first side C1 in segmented region 02 is 1% to 2.5% of the dimension of the battery layer 20 along the first direction X; the distance D2 between the second sub-slot and the second side in segmented region 02 is 1% to 2.5% of the dimension of the battery layer 20 along the first direction X; the dimension of the segmented slot 32 along the second direction Y is the same as the dimension of the battery layer 20 along the second direction Y, meaning that the length of the sub-cells in segmented region 02 is shorter than that of the sub-cells in main region 01, while the width is the same, resulting in lower currents in the sub-cells in segmented region 02. This design avoids battery layer ablation, thereby improving the reliability of the solar cell, preventing current from accumulating at tiny short-circuit points and damaging the solar cell, and effectively preventing film layer ablation and cracking failures of the solar cell under the most severe hot spot effects. Furthermore, the fact that the width of the sub-cells in different regions is the same ensures that the number of multiple sub-cells 201 connected in series in the main region 01 is the same as the number of multiple sub-cells 201 connected in series in each segmented region 02. This ensures that the voltage of the solar cell remains unchanged after the etched segmentation grooves 32 are etched.

[0058] For example, if the dimension of the first direction X of the substrate 10 is about 2 mm, and the dimension of the first direction X of the edge cleaning area is about 12 mm, then the dimension H of the edge cleaning area and the segmentation area is 20 mm to 50 mm, and the ratio of H to the corresponding dimension of the first direction of the substrate 10 is also 1 to 2.5%.

[0059] For example, based on the above embodiments, optionally, Figure 11 This is a schematic diagram of another type of solar cell provided in an embodiment of the present invention. Figure 12 This is a schematic diagram of another type of solar cell provided in an embodiment of the present invention, for reference. Figure 11 and Figure 12 The number of dividing grooves 32 along the first direction X can be multiple, and multiple dividing grooves 32 can divide a main region 01 and multiple dividing regions 02; Reference Figure 11 The adjacent dividing grooves 32 are equidistant along the first direction X, or, refer to Figure 12 The distances between adjacent dividing grooves 32 along the first direction X are different.

[0060] Among them, reference Figure 11 The adjacent dividing grooves 32 are equidistant along the first direction X, as referenced. Figure 12The distances between adjacent dividing grooves 32 along the first direction X are different. There are multiple dividing grooves 32, which can play a role in current distribution. Each pair of adjacent dividing grooves is a region of a sub-cell connected in series. Different regions are connected in parallel, which can play a role in current distribution, thus reducing the risk of solar cells failing due to ablation or even cracking caused by hot spots.

[0061] Based on the above embodiments, optionally, refer to Figure 1 The width of the dividing groove 32 in the first direction X is 80μm to 120μm.

[0062] The preferred linewidth of the dividing groove in the first direction X is 100 μm. If the linewidth of the dividing groove 32 in the first direction X is less than 80 μm, the parallel connection effect cannot be achieved, affecting the reliability of the device. If the linewidth of the dividing groove 32 in the first direction X is greater than 120 μm, the efficiency of the solar cell will be reduced. Therefore, setting the linewidth of the dividing groove 32 in the first direction X to 80 μm to 120 μm ensures the etching effect, allows for current shunting of the solar cell, avoids large currents that could damage the solar cell, improves the reliability of the solar cell, and indirectly reduces costs while improving yield and efficiency.

[0063] Based on the above embodiments, optionally, refer to Figures 1-3 The battery layer 20 includes at least a first conductive layer 21, a functional layer 22, and a second conductive layer 23 stacked sequentially; the second conductive layer 23 is located on the side of the first conductive layer 21 away from the substrate 10; the functional layer 22 includes a first buffer layer, an absorption layer, and a second buffer layer stacked sequentially, and the second buffer layer is located on the side of the first buffer layer away from the first conductive layer.

[0064] Each slot group 31 includes a first slot P1, a second slot P2, and a third slot P3; the first slot P1 penetrates the first conductive layer 21, and a functional layer 22 is disposed within the first slot P1; the second slot P2 penetrates the functional layer 22, and a second conductive layer 23 is disposed within the second slot P2; the third slot P3 penetrates at least the second conductive layer 23; the vertical projection of the third slot P3 on the substrate 10 is located within the vertical projection of the second slot P2 on the substrate 10; the vertical projection of the second slot P2 on the substrate 10 does not overlap with the vertical projection of the first slot P1 on the substrate 10.

[0065] The first buffer layer can be either a hole transport layer or an electron transport layer, and the second buffer layer can also be either a hole transport layer or an electron transport layer. The first and second buffer layers differ; depending on the transport method, the electron transport layer can be positioned between the first conductive layer 21 and the absorption layer, and the hole transport layer can be positioned between the absorption layer and the second conductive layer 23. If the battery layer 20 is a perovskite battery layer, the material of the first conductive layer 21 can include fluorine-doped tin oxide (FTO); the material of the second conductive layer 23 can include indium tin oxide (ITO); and the material of the absorption layer can include perovskite material (PVSK).

[0066] Specifically, the first groove P1, the second groove P2, and the third groove P3 can be formed through laser grooving, mechanical scribing, or a material isolation layer. The third groove P3 can penetrate the second conductive layer 23, or it can penetrate both the second conductive layer 23 and the functional layer 22. The formed first groove P1, second groove P2, and third groove P3 allow the cell layer 20 to form series-connected sub-cells. The vertical projection of the third groove P3 onto the substrate 10 lies within the vertical projection of the second groove P2 onto the substrate 10; the vertical projection of the second groove P2 onto the substrate 10 does not overlap with the vertical projection of the first groove P1 onto the substrate 10. This reduces the scribing area, and the overlap of the second groove P2 and the third groove P3 further reduces the area of ​​the scribing region, thereby increasing the effective power generation area of ​​the solar cell.

[0067] Based on the above embodiments, optionally, Figure 13 This is a partial structural schematic diagram of another solar cell provided in an embodiment of the present invention. Figure 14 This is a schematic diagram of another type of solar cell provided in an embodiment of the present invention. Figure 15 This is a schematic diagram of another type of solar cell provided in an embodiment of the present invention, for reference. Figures 13-15 The solar cell also includes: conductive adhesive 40, which is located on opposite sides of the cell layer 20 along the second direction Y; the conductive adhesive 40 is in contact with the cell layer 20; encapsulation layer 50, which is located on the side of the cell layer 20 away from the substrate 10; the encapsulation layer 50 covers the cell layer 20; and backplate 60, which is located on the side of the encapsulation layer 50 away from the substrate 10 and covers the encapsulation layer 50.

[0068] The conductive adhesive 40 includes a conductive tape. The conductive adhesive 40 is located on opposite sides of the battery layer 20 along the second direction Y. For example, referring to… Figure 1The battery layer 20 includes a third side C3 and a fourth side C4 opposite each other along the second direction Y. The first side C1, the third side C3, the second side C2, and the fourth side C4 are connected sequentially. The conductive adhesive 40 extends along the first direction X and is applied to the third side C3 and the fourth side C4 of the battery layer 20. The sub-cells on the long side between the segmented region 02 and the main region 01 are at the same potential. The conductive adhesive 40 is in contact with the battery layer 20, specifically with the second conductive layer 23 of the battery layer 20. During the application of the conductive adhesive 40, it can be completely applied to the second conductive layer 23. The conductive adhesive 40 is applied to the third side C3 and the fourth side C4 of the battery layer, extending from the edge of the first side C1 to the edge of the second side C2. The encapsulation layer 50 is made of polyolefin elastomer (POE), and busbars can be welded to it. It is then laminated through a backplate 60. The backplate 60 is made of glass. Because the number of sub-cells in each region is equal, the voltage of the solar cell remains unchanged after the conductive adhesive is applied to the scribe line. The small currents in the segmented region 02 are connected in parallel and then converged, so the current hardly changes and has a negligible impact on the efficiency of the solar cell.

[0069] This invention provides a method for preparing a solar cell based on the above embodiments, used to prepare the solar cell described in any embodiment of this invention. Figure 16 This is a flowchart of a method for fabricating a solar cell according to an embodiment of the present invention, see reference. Figure 16 The methods for preparing solar cells include: S110, Provides a substrate.

[0070] S120. A battery layer is formed on one side of the substrate; the battery layer includes: multiple sets of grooves, which divide the battery layer into multiple series-connected sub-cells, the grooves in the multiple sets of grooves extending along a first direction and spaced apart along a second direction; the first direction and the second direction are perpendicular to each other; at least one dividing groove, the battery layer includes a main region and a dividing region, the dividing region is located on at least one side of the main region along the first direction, and the area of ​​the dividing region is smaller than the area of ​​the main region; the main region and the dividing region are divided by at least one dividing groove; the dividing groove penetrates the battery layer; the dividing groove extends along the second direction.

[0071] The battery layer can be formed by coating process, and the first groove and the dividing groove can be formed by laser scribing process, mechanical scribing and grooving process or material isolation process.

[0072] The segmented groove of this invention divides the main area and the segmented area into two regions, which can transform multiple series-connected sub-cells into series and parallel connections. It can separate the reverse current and prevent the current from accumulating at the tiny short-circuit point of the cell, thereby avoiding module burn-out and breakage, and improving the reliability of the solar cell. Furthermore, since the area of ​​the segmented area is smaller than the area of ​​the main area, the current passing through the sub-cells in the segmented area is smaller, and the total current after parallel connection hardly changes, so it has almost no impact on the efficiency of the solar cell.

[0073] Based on the above embodiments, optionally, Figure 17 This is a flowchart of a method for fabricating a solar cell according to an embodiment of the present invention, see reference. Figure 17 The preparation methods include: S110, Provides a substrate.

[0074] S121. A first conductive layer is formed on one side of the substrate; the first conductive layer covers the substrate.

[0075] The first conductive electron layer can be formed by coating or film deposition processes.

[0076] S122. Etch the first conductive layer to form a first groove; the first groove penetrates the first conductive layer.

[0077] One method is laser etching.

[0078] S123. A functional sublayer is formed on the side of the first conductive sublayer away from the substrate; the functional sublayer covers the first conductive sublayer and fills the first groove.

[0079] Functional sublayers can be formed using coating or film deposition processes.

[0080] S124. Etch the functional sublayer to form a second groove; the second groove penetrates the functional sublayer, and the vertical projection of the second groove on the substrate does not overlap with the vertical projection of the first groove on the substrate.

[0081] One method is laser etching.

[0082] S125. A second conductive sublayer is formed on the side of the functional sublayer away from the substrate; the second conductive sublayer covers the functional sublayer and fills the second groove.

[0083] The second conductive electron layer can be formed by coating or plating processes.

[0084] S126. Etch the second conductive layer to form the third groove; the third groove penetrates the second conductive layer; the vertical projection of the third groove on the substrate is located within the vertical projection of the second groove on the substrate.

[0085] One method is laser etching.

[0086] S127. The first conductive sublayer, the functional sublayer, and the second conductive sublayer are processed to form a first conductive layer, a functional layer, and a second conductive layer; the functional layer includes a first buffer layer, an absorption layer, and a second buffer layer stacked sequentially, and the second buffer layer is located on the side of the first buffer layer away from the first conductive layer.

[0087] Among them, the first conductive sublayer, the functional sublayer and the second conductive sublayer can be cleaned by laser etching process to form a cleaned area.

[0088] S128. Form at least one dividing groove; the dividing groove penetrates the battery layer along the second direction and also penetrates the battery layer along the third direction; wherein the third direction is perpendicular to the first direction and the second direction.

[0089] Based on the above embodiments, optionally, at least one dividing groove is formed, including: At least one dividing groove is formed by laser etching at an etching rate of 800 mm / s to 1200 mm / s and / or a power of 1 W to 3 W.

[0090] in, Figure 18 This is a schematic diagram of a partial intermediate structure of a solar cell provided in an embodiment of the invention, for reference. Figure 18 , Figure 18 The area within the black dashed box indicates the region where leakage points are more likely to occur. Figure 18 The intermediate structure was repositioned onto the laser stage, along... Figure 18 The black horizontal line 06 in the middle is engraved to form a dividing groove. Perovskite laser partitioning is performed. The laser engraving process is as follows: speed 1000mm / s, line width 100 micrometers, power 2w, resistance greater than 20MΩ. This ensures that there is no residue on both sides of the engraved dividing groove, so that the conductive adhesive can be completely applied in the subsequent process. After that, the encapsulation layer is applied, the busbar is soldered, and then lamination is performed.

[0091] Based on the above embodiments, optionally, the number of dividing grooves includes at least two, the dividing areas are located on opposite sides of the main area along the first direction; at least two dividing grooves are spaced apart along the first direction.

[0092] Based on the above embodiments, optionally, the dividing groove penetrates the battery layer along the second direction, and the dividing groove penetrates the battery layer along the third direction; wherein, the third direction is perpendicular to the first direction and the second direction.

[0093] Based on the above embodiments, optionally, the area of ​​each segmented region accounts for 1% to 2.5% of the total area of ​​the battery layer; the battery layer includes a first side and a second side disposed opposite to each other along the first direction; the segmentation groove includes at least a first sub-groove and a second sub-groove; the distance between the first sub-groove and the first side is 1% to 2.5% of the dimension of the battery layer along the first direction; the distance between the second sub-groove and the second side is 1% to 2.5% of the dimension of the battery layer along the first direction; the dimension of the segmentation groove along the second direction is the same as the dimension of the battery layer along the second direction.

[0094] Based on the above embodiments, optionally, the line width of the dividing groove in the first direction is 80μm to 120μm.

[0095] Optionally, based on the above embodiments, the solar cell further includes: Conductive adhesive is located on both sides of the battery layer along the second direction; the conductive adhesive is in contact with the battery layer; encapsulation layer is located on the side of the battery layer away from the substrate; the encapsulation layer covers the battery layer; backplate is located on the side of the encapsulation layer away from the substrate, and the backplate covers the encapsulation layer.

[0096] The method for preparing solar cells provided by the technical solutions of this invention has the same beneficial effects as the solar cells described in any embodiment of this invention.

[0097] This invention provides a solar cell based on the above embodiments. Figure 19 This is a schematic diagram of another type of solar cell provided in an embodiment of the present invention, for reference. Figure 19 The solar cells include: A first battery unit 71 includes a plurality of first sub-cells 711 connected in series. The first battery unit 71 has a first length along a first direction X and a first width along a second direction Y. The first direction X and the second direction Y are perpendicular to each other. The first battery unit 71 includes a first output terminal and a second output terminal. A second battery unit 72 includes a plurality of second sub-cells 721 connected in series. The second battery unit 72 has a second length along the first direction X and a second width along the second direction Y. The second battery unit 72 includes a third output terminal and a fourth output terminal. The number of the plurality of first sub-cells and the plurality of second sub-cells are equal. The first length is less than the second length. The first width and the second width are equal. The first output terminal and the third output terminal are coupled together, and the second output terminal and the fourth output terminal are coupled together.

[0098] Based on the above embodiments, the solar cell further includes: a third battery unit 73, the third battery unit 73 including a plurality of third sub-cells 731 connected in series in sequence; the third battery unit 73 has a third length along the first direction X and a third width along the second direction Y; the third battery unit 73 includes a fifth output terminal and a sixth output terminal.

[0099] The number of multiple second sub-cells 721 and multiple third sub-cells 731 is equal; the third length is less than the second length; the second width and the third width are equal; the first output terminal, the third output terminal and the fifth output terminal are coupled in sequence, and the second output terminal, the fourth output terminal and the sixth output terminal are coupled in sequence.

[0100] Specifically, the first direction X is set as the length direction, and the second direction Y is set as the width direction. The first, third, and fifth output terminals are coupled sequentially, and the second, fourth, and sixth output terminals are coupled. The number of multiple first sub-cells 711, multiple second sub-cells 721, and multiple third sub-cells 731 is equal, which ensures that the voltage corresponding to each cell unit remains constant. The first and third lengths are both smaller than the second length. The first, second, and third widths are equal, which makes the current of the sub-cells in the first cell unit 71 and the third cell unit 73 small, and the total current after parallel connection hardly changes, so it has almost no impact on the efficiency of the solar cell. Solar cells are prone to hot spot effects in the first cell unit 71 and the third cell unit 73, but because the current of the sub-cells in the first cell unit 71 and the third cell unit 73 is small, it will not cause cell layer ablation, thereby improving the reliability of the solar cell. It can avoid the current from accumulating at the tiny short circuit point of the cell and damaging the solar cell, effectively avoiding the problem of cell layer ablation and cracking failure under the most severe hot spot effect.

[0101] Based on the above embodiments, optionally, refer to Figure 19 The first battery unit 71 has a first voltage and a first current; the second battery unit 72 has a second voltage and a second current; and the third battery unit 73 has a third voltage and a third current. The first voltage, the second voltage, and the third voltage are equal, and the first current and the third current are less than the second current.

[0102] Among them, the solar cell is prone to hot spot effect in the first cell unit 71 and the third cell unit 73. The first voltage, the second voltage, and the third voltage are equal, and the first current and the third current are less than the second current. The first current and the third current are small, which will not cause cell layer ablation. This can improve the reliability of the solar cell, avoid the current from accumulating at the tiny short circuit point of the cell and damaging the solar cell, and effectively avoid the problem of cell layer ablation and cracking failure under the most severe hot spot effect.

[0103] Based on the above embodiments, optionally, refer to Figure 19 The first battery unit 71, the second battery unit 72, and the third battery unit 73 each include multiple sets of wire grooves; the wire grooves in the multiple sets of wire grooves extend along the first direction X and are spaced apart along the second direction Y; the multiple sets of wire grooves divide the first battery unit 71 into multiple first sub-cells 711, the second battery unit 72 into multiple second sub-cells 721, and the third battery unit 73 into multiple third sub-cells 731; the wire grooves in the multiple sets of wire grooves are divided by at least two dividing wire grooves, and the solar cells are divided into the first battery unit 71, the second battery unit 72, and the third battery unit 73.

[0104] The solar cell includes a substrate and a cell layer. The cell layer includes at least a first conductive layer, a functional layer, and a second conductive layer stacked sequentially. The second conductive layer is located on the side of the first conductive layer away from the substrate. The functional layer includes a first buffer layer, an absorber layer, and a second buffer layer stacked sequentially. The second buffer layer is located on the side of the first buffer layer away from the first conductive layer. Each groove group includes a first groove, a second groove, and a third groove. The first groove penetrates the first conductive layer and a functional layer is disposed within the first groove. The second groove penetrates the functional layer and a second conductive layer is disposed within the second groove. The third groove at least penetrates the second conductive layer. The vertical projection of the third groove on the substrate is located within the vertical projection of the second groove on the substrate. The vertical projection of the second groove on the substrate does not overlap with the vertical projection of the first groove on the substrate.

[0105] Multiple slot groups divide each cell unit into multiple sub-cells connected in series. The slots in multiple slot groups are divided by at least two dividing slots, and the solar cells are divided into first cell unit 71, second cell unit 72 and third cell unit 73. This can avoid cell layer ablation, thereby improving the reliability of the solar cells. It can also prevent current from accumulating at tiny short circuit points in the cells and damaging the solar cells, effectively avoiding the problem of film layer ablation and cracking failure of solar cell devices under the most severe hot spot effect.

[0106] Based on the above embodiments, optionally, Figure 20 This is a schematic diagram of another type of solar cell provided in an embodiment of the present invention, for reference. Figure 20 Each of the first sub-cells 711, each of the second sub-cells 721 and each of the third sub-cells 731 includes a light-emitting device 81 and a diode 82; the light-emitting device 81 and the diode 82 are arranged in parallel, the positive terminal of the light-emitting device 81 is electrically connected to the negative terminal of the diode 82, and the negative terminal of the light-emitting device 81 is electrically connected to the positive terminal of the diode 82.

[0107] in, Figure 8 This is a schematic diagram illustrating the hot spot effect that occurs when a solar cell is shaded in existing technology. (Reference) Figure 8Under the influence of hot spot effect and reverse current of diodes, the load is large, and the total current of the solar cell is twice the original short-circuit current (ISC). This causes a sharp rise in the temperature of the solar cell, making it prone to film breakdown and ablation, and in severe cases, glass breakage. However, in this invention... Figure 20 The shaded sub-cell 07 is the third sub-cell 731 in the third battery unit 73. The current direction is in the direction of the green arrow. In the shaded sub-cell 07, the current direction is in the direction of the red arrow. The diode 82 is reverse biased and consumes power, causing the battery to heat up. However, the current in the third battery unit 73 is small, so the temperature rise is small and will not cause film ablation and cracking failure under the most severe hot spot effect.

[0108] The solar cells in the embodiments of this invention belong to the same inventive concept as the solar cells described in any of the above embodiments of this invention, and have the same beneficial effects.

[0109] Based on the above embodiments, this invention provides a photovoltaic cell module, including the solar cell described in any embodiment of this invention.

[0110] The photovoltaic cell modules in the embodiments of the present invention belong to the same inventive concept as the solar cells described in any of the above embodiments of the present invention, and have the same beneficial effects.

[0111] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0112] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A solar cell, characterized in that, include: substrate; A battery layer, wherein the battery layer is located on one side of the substrate; The battery layer includes: Multiple slot groups divide the battery layer into multiple series-connected sub-cells. The slots in the multiple slot groups extend along a first direction and are spaced apart along a second direction. The first direction and the second direction are perpendicular to each other. At least one dividing groove is provided. The battery layer includes a main region and a dividing region. The dividing region is located on at least one side of the main region along a first direction, and the area of ​​the dividing region is smaller than the area of ​​the main region. The main region and the dividing region are divided by the at least one dividing groove. The dividing groove penetrates the battery layer. The dividing groove extends along a second direction.

2. The solar cell according to claim 1, characterized in that, The number of the dividing grooves includes at least two, and the dividing areas are located on opposite sides of the main area along the first direction; At least two of the dividing grooves are spaced apart along the first direction.

3. The solar cell according to claim 1, characterized in that, The dividing groove penetrates the battery layer along the second direction, and the dividing groove also penetrates the battery layer along a third direction; wherein the third direction is perpendicular to both the first and second directions.

4. The solar cell according to claim 2, characterized in that, The area of ​​each of the aforementioned segmented regions accounts for 1% to 2.5% of the total area of ​​the battery layer; The battery layer includes a first side and a second side disposed opposite to each other along a first direction; at least two dividing grooves include at least a first sub-groove and a second sub-groove; The distance between the first sub-slot and the first side is 1% to 2.5% of the dimension of the battery layer along the first direction; The distance between the second sub-slot and the second side is 1% to 2.5% of the dimension of the battery layer along the first direction; the dimension of the dividing line slot along the second direction is the same as the dimension of the battery layer along the second direction.

5. The solar cell according to claim 1, characterized in that, The width of the dividing groove in the first direction is 80μm to 120μm.

6. The solar cell according to claim 1, characterized in that, The battery layer includes at least a first conductive layer, a functional layer, and a second conductive layer stacked sequentially; the second conductive layer is located on the side of the first conductive layer away from the substrate; the functional layer includes a first buffer layer, an absorption layer, and a second buffer layer stacked sequentially, the second buffer layer being located on the side of the first buffer layer away from the first conductive layer. Each of the aforementioned slot groups includes a first slot, a second slot, and a third slot; the first slot penetrates the first conductive layer and a functional layer is disposed within the first slot; the second slot penetrates the functional layer and a second conductive layer is disposed within the second slot; the third slot at least penetrates the second conductive layer. The vertical projection of the third groove on the substrate is located within the vertical projection of the second groove on the substrate; the vertical projection of the second groove on the substrate does not overlap with the vertical projection of the first groove on the substrate.

7. The solar cell according to claim 1, characterized in that, Also includes: A conductive adhesive is located on two opposite sides of the battery layer along a second direction; the conductive adhesive is in contact with the battery layer. An encapsulation layer is located on the side of the battery layer away from the substrate; the encapsulation layer covers the battery layer. A backplate is located on the side of the encapsulation layer away from the substrate and covers the encapsulation layer.

8. A method for preparing a solar cell, characterized in that, include: Provide substrate; A battery layer is formed on one side of the substrate; The battery layer includes: multiple sets of grooves that divide the battery layer into multiple series-connected sub-cells; the grooves in the multiple sets of grooves extend along a first direction and are spaced apart along a second direction; the first direction and the second direction are perpendicular to each other; at least one dividing groove; the battery layer includes a main region and a dividing region; the dividing region is located on at least one side of the main region along the first direction, and the area of ​​the dividing region is smaller than the area of ​​the main region; the main region and the dividing region are divided by the at least one dividing groove; the dividing groove penetrates the battery layer; the dividing groove extends along the second direction.

9. The method for preparing a solar cell according to claim 8, characterized in that, A battery layer is formed on one side of the substrate, including: A first conductive sublayer is formed on one side of the substrate; the first conductive sublayer covers the substrate; The first conductive sublayer is etched to form a first groove; the first groove penetrates the first conductive sublayer. A functional sublayer is formed on the side of the first conductive sublayer away from the substrate; the functional sublayer covers the first conductive sublayer and fills the first groove. The functional sublayer is etched to form a second groove; the second groove penetrates the functional sublayer, and the vertical projection of the second groove on the substrate does not overlap with the vertical projection of the first groove on the substrate; A second conductive sublayer is formed on the side of the functional sublayer away from the substrate; the second conductive sublayer covers the functional sublayer and fills the second groove. The second conductive sublayer is etched to form a third groove; the third groove penetrates the second conductive sublayer; the vertical projection of the third groove on the substrate is located within the vertical projection of the second groove on the substrate. The first conductive sublayer, the functional sublayer, and the second conductive sublayer are processed to form a first conductive layer, a functional layer, and a second conductive layer; the functional layer includes a first buffer layer, an absorption layer, and a second buffer layer stacked sequentially, and the second buffer layer is located on the side of the first buffer layer away from the first conductive layer. At least one dividing groove is formed; the dividing groove penetrates the battery layer along the second direction, and the dividing groove penetrates the battery layer along a third direction; wherein the third direction is perpendicular to the first direction and the second direction.

10. The method for preparing a solar cell according to claim 9, characterized in that, Forming at least one dividing groove includes: At least one dividing groove is formed by laser etching at an etching rate of 800 mm / s to 1200 mm / s and / or a power of 1 W to 3 W.

11. A solar cell, characterized in that, include: The first battery unit includes a plurality of first sub-cells connected in series. The first battery cell has a first length along a first direction and a first width along a second direction; the first direction and the second direction are perpendicular to each other; the first battery cell includes a first output terminal and a second output terminal; The second battery unit includes a plurality of second sub-cells connected in series; the second battery unit has a second length along a first direction and a second width along a second direction; the second battery unit includes a third output terminal and a fourth output terminal; The number of the plurality of first sub-cells and the plurality of second sub-cells are equal; the first length is less than the second length; the first width and the second width are equal; the first output terminal and the third output terminal are coupled, and the second output terminal and the fourth output terminal are coupled.

12. The solar cell according to claim 11, characterized in that, Also includes: The third battery unit includes a plurality of third sub-cells connected in series in sequence; the third battery unit has a third length along a first direction and a third width along a second direction; the third battery unit includes a fifth output terminal and a sixth output terminal. The number of the plurality of second sub-cells and the plurality of third sub-cells are equal; the third length is less than the second length; the second width and the third width are equal; the first output terminal, the third output terminal and the fifth output terminal are coupled in sequence, and the second output terminal, the fourth output terminal and the sixth output terminal are coupled in sequence.

13. The solar cell according to claim 12, characterized in that, The first battery cell has a first voltage and a first current; The second battery cell has a second voltage and a second current; The third battery cell has a third voltage and a third current; Wherein, the first voltage, the second voltage, and the third voltage are equal, and the first current and the third current are both less than the second current.

14. The solar cell according to claim 12, characterized in that, The first battery unit, the second battery unit, and the third battery unit each include multiple slot groups; the slots in the multiple slot groups extend along a first direction and are spaced apart along a second direction. Multiple wire trough groups divide the first battery unit into multiple first sub-cells, the second battery unit into multiple second sub-cells, and the third battery unit into multiple third sub-cells; The grooves in the plurality of groove groups are divided by at least two dividing grooves, and the solar cells are divided into the first battery unit, the second battery unit and the third battery unit.

15. The solar cell according to claim 12, characterized in that, Each of the first sub-cell, each of the second sub-cell, and each of the third sub-cells includes a light-emitting device and a diode; The light-emitting device and the diode are connected in parallel, with the positive terminal of the light-emitting device electrically connected to the negative terminal of the diode, and the negative terminal of the light-emitting device electrically connected to the positive terminal of the diode.

16. A photovoltaic cell module, characterized in that, It includes the solar cell according to any one of claims 1-7 or the solar cell according to any one of claims 11-15.

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