Solar cell and photovoltaic module

Abstract

The utility model relates to the technical field of solar cells, in particular to a solar cell and a photovoltaic module. The solar cell comprises a cell body, a conductive layer and a conductive wire. The conductive layer is arranged on the surface of the battery body and is electrically connected with the battery body; the conductive wire comprises a conductive substrate and a connecting material layer, the conductive substrate is laminated on one side, deviating from the battery body, of the conductive layer, and the connecting material layer is at least arranged on the side surface, facing the conductive layer, of the conductive substrate. The connecting material layer is in contact with the conductive layer so that the conductive wires are electrically connected with the conductive layer. The connecting material layer protrudes in a direction away from the conductive substrate. Wherein the maximum height H between one end, far away from the conductive substrate, of the connecting material layer and the conductive substrate is 3-20 [mu] m, so that the contact resistance between the conductive wire and the cell body is reduced, and the collection and export efficiency of photo-generated current is improved. And the height difference of the contact part of the conductive wire and the conductive layer is small, so that the inclination angle of the conductive wire is smaller.

Description

Technical Field

[0001] This application relates to the field of solar cell technology, and more particularly to a solar cell and photovoltaic module. Background Technology

[0002] In solar cells, conductive filaments are electrically connected to the cell body by bonding with a conductive layer. However, due to the unevenness of the surface of the conductive filament facing the conductive layer, the angular offset of the filament after contact with the conductive layer is too large. This results in a significant misalignment and tilt of the filament relative to the conductive layer, leading to a high contact resistance between the filament and the cell body, and a decrease in the efficiency of photocurrent collection and extraction. Utility Model Content

[0003] This application discloses a solar cell and photovoltaic module that enables a larger contact area between the connecting material layer and the conductive layer, making it less likely for the conductive wires to be misaligned or tilted relative to the conductive layer.

[0004] To achieve the above objectives, in a first aspect, embodiments of this application disclose a solar cell, comprising:

[0005] Battery body;

[0006] A conductive layer, wherein the conductive layer is disposed on the surface of the battery body and electrically connected to the battery body; and

[0007] A conductive wire includes a conductive substrate and a connecting material layer. The conductive substrate is stacked on the side of the conductive layer away from the battery body. The connecting material layer is disposed at least on the side of the conductive substrate facing the conductive layer. The connecting material layer contacts the conductive layer to electrically connect the conductive wire to the conductive layer. The connecting material layer protrudes in a direction away from the conductive substrate.

[0008] The maximum height H between the end of the connecting material layer away from the conductive substrate and the conductive substrate is 3μm to 20μm.

[0009] In one possible implementation of the first aspect, the width of the connecting material layer on the side closest to the conductive substrate is W; wherein H / W is 0.005 to 0.6.

[0010] In a possible implementation of the first aspect, the width W of the connecting material layer on the side closest to the conductive substrate is 0.05 mm to 0.2 mm;

[0011] And / or, the width of the connecting material layer on the side closest to the conductive substrate is the same as the width of the conductive substrate.

[0012] In a possible implementation of the first aspect, the side where the connecting material layer is connected to the conductive layer is configured as an arc shape;

[0013] On the connecting material layer, the angle of the arc-shaped side is ≤60°.

[0014] In one possible implementation of the first aspect, the maximum distance between the side of the conductive substrate facing the battery body and the surface of the battery body in the thickness direction is D; wherein, D≤0.1mm.

[0015] In a possible implementation of the first aspect, the side of the conductive substrate facing away from the battery body is inclined relative to the surface of the battery body, and this portion of the side is a reflective surface.

[0016] In one possible implementation of the first aspect, the conductive substrate has a triangular cross-section with three said sides, the cross-section being a plane formed by the height direction and the width direction of the conductive wire;

[0017] One of the sides of the conductive substrate is located on the side of the conductive substrate facing the conductive layer, and the connecting material layer is disposed at least on this side.

[0018] The other two sides are disposed opposite to the battery body and inclined to the surface of the battery body, and at least one of the two sides is the reflective surface.

[0019] In a possible implementation of the first aspect, the side of the conductive substrate facing the conductive layer is parallel to the surface of the battery body, or the side of the conductive substrate facing the conductive layer is inclined to the surface of the battery body;

[0020] When the conductive substrate is tilted toward the side of the conductive layer on the surface of the battery body, the angle β between the side of the conductive substrate toward the conductive layer and the surface of the battery body is ≤30°.

[0021] In a possible implementation of the first aspect, the conductive wire and the conductive layer extend in the same direction;

[0022] And / or, in the extension direction of the conductive wire, at least one end of the conductive wire extends beyond the edge of the battery body;

[0023] And / or, the conductive substrate is made of copper, silver, aluminum, aluminum alloy or copper-clad aluminum;

[0024] And / or, the material of the connecting material layer includes tin or a tin alloy.

[0025] In a possible implementation of the first aspect, the conductive layer is a conductive seed layer or a conductive film layer;

[0026] And / or, the thickness of the conductive layer is 1 μm to 10 μm;

[0027] And / or, the width of the conductive layer is 5μm to 30μm;

[0028] And / or, the battery body includes a silicon substrate and a doped layer, the doped layer being disposed on the surface of the silicon substrate, and the conductive layer being disposed on the side of the doped layer opposite to the silicon substrate and in ohmic contact with the doped layer.

[0029] Secondly, embodiments of this application disclose a photovoltaic module, including a plurality of solar cells as described in the first aspect; the conductive wires of each solar cell are connected to the conductive wires of another solar cell for electrical connection.

[0030] Compared with the prior art, the beneficial effects of this application are:

[0031] The connecting material layer of the solar cell contacts the conductive layer, thereby electrically connecting the conductive wire to the conductive layer. The connecting material layer is used to enhance the bonding strength between the conductive wire and the conductive layer, so that there is a certain bonding force between the conductive wire and the battery body, and also to achieve electrical connection between the conductive wire and the battery body.

[0032] Based on this, in this application, the maximum height H between the end of the connecting material layer away from the conductive substrate and the conductive substrate is 3μm to 20μm. When the connecting material layer meets the above height range, it indicates that the connecting material layer is high enough to effectively connect the conductive substrate and the conductive layer. It also indicates that the side of the connecting material layer connected to the conductive layer is relatively flat. When the connecting material layer and the conductive layer are in contact, they are closer to surface contact. Compared with point contact, surface contact has a larger contact area. Since the contact resistance is inversely proportional to the contact area, it is beneficial to reduce the contact resistance between the conductive wire and the battery body, thereby improving the collection and extraction efficiency of photocurrent.

[0033] Furthermore, the smaller height difference at the contact point between the conductive wire and the conductive layer allows for a smaller tilt angle of the conductive wire, making it less likely for the conductive wire to misalign or tilt relative to the conductive layer. This reduces the difference in reflection caused by the tilt or offset of the conductive wire, resulting in photovoltaic modules made using this solar cell exhibiting smaller reflection differences and a more aesthetically pleasing appearance. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 This is a schematic diagram of the structure of a solar cell (the bottom surface of the conductive substrate is parallel to the surface of the cell body) disclosed in an embodiment of this application;

[0036] Figure 2 This is a cross-sectional view of the conductive wire disclosed in an embodiment of this application;

[0037] Figure 3 This is a schematic diagram of the structure of a solar cell (the bottom surface of the conductive substrate is inclined to the surface of the cell body) disclosed in an embodiment of this application;

[0038] Figure 4 This is a schematic diagram of the conductive filament of a solar cell reflecting light according to an embodiment of this application;

[0039] Figure 5 This is a cross-sectional view of a solar cell (with a conductive seed layer as the conductive layer) disclosed in an embodiment of this application;

[0040] Figure 6 This is a cross-sectional view of a solar cell (with a conductive film layer as the conductive layer) disclosed in an embodiment of this application.

[0041] Figure 7 This is a schematic diagram of the structure of a photovoltaic module disclosed in an embodiment of this application.

[0042] Explanation of reference numerals in the attached figures:

[0043] 1. Solar cell; 11. Cell body; 111. Silicon substrate; 112. Doped layer; 12. Conductive layer; 13. Conductive filament; 131. Conductive substrate; 1311. Side surface; 1312. Reflective surface; 132. Connecting material layer; 2. Busbar; X, length direction of the cell body; Z, thickness direction of the cell body. Detailed Implementation

[0044] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0045] In this application, the terms "upper," "top," "bottom," "inner," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for the purpose of better describing this application and its embodiments, and are not intended to limit the indicated device, element, or component to having a specific orientation, or to be constructed and operated in a specific orientation.

[0046] Furthermore, in addition to indicating location or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in some cases to indicate a certain dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0047] Furthermore, the terms "set up," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0048] The technical solution of this utility model will be described below with reference to the embodiments and accompanying drawings.

[0049] Firstly, such as Figures 1 to 3 As shown in the illustration, this application discloses a solar cell 1, including a cell body 11, a conductive layer 12, and conductive wires 13. The conductive layer 12 is disposed on the surface of the cell body 11 and electrically connected to the cell body 11. The conductive wires 13 include a conductive substrate 131 and a connecting material layer 132. The conductive substrate 131 is stacked on the side of the conductive layer 12 facing away from the cell body 11, and the connecting material layer 132 is disposed at least on the side 1311 of the conductive substrate 131 facing the conductive layer 12. The connecting material layer 132 contacts the conductive layer 12, thereby electrically connecting the conductive wires 13 to the conductive layer 12.

[0050] The connecting material layer 132 protrudes in a direction away from the conductive substrate 131. The maximum height H between the end of the connecting material layer 132 away from the conductive substrate 131 and the conductive substrate 131 is 3μm to 20μm.

[0051] More specifically, the connection material layer 132 is at least disposed on the side 1311 of the conductive substrate 131 facing the conductive layer 12. This means that the connection material layer 132 may be disposed only on the side 1311 of the conductive substrate 131 facing the conductive layer 12; or, the connection material layer 132 may be disposed on both the side 1311 of the conductive substrate 131 facing the conductive layer 12 and other sides 1311 of the conductive substrate 131. Taking a conductive substrate 131 with a triangular cross-section as an example, the conductive substrate 131 has three sides 1311, and the connection material layer 132 may be disposed on one or more sides 1311. This embodiment of the application does not limit this. In addition, the connection material layer 132 may cover the entire side 1311 or may be disposed on a local area of ​​a side 1311.

[0052] In this application, the connecting material layer 132 contacts the conductive layer 12 to electrically connect the conductive wire 13 to the conductive layer 12. The connecting material layer 132 is used to enhance the bonding strength between the conductive wire 13 and the conductive layer 12, so that there is a certain bonding force between the conductive wire 13 and the battery body 11, and also to achieve electrical connection between the conductive wire 13 and the battery body 11.

[0053] Due to the properties of the material used to make the connecting material layer 132, such as the surface tension of the liquid alloy, the connecting material layer 132 protrudes in the direction away from the conductive substrate 131 in the height direction of the conductive wire 13.

[0054] It should be noted that the side 1311 of the conductive substrate 131 facing the conductive layer 12 is the bottom surface of the conductive substrate 131, and the height direction of the conductive wire refers to the direction perpendicular to the bottom surface of the conductive substrate 131. More specifically, as... Figure 1 As shown, when the bottom surface of the conductive substrate 131 is parallel to the surface of the battery body 11, since the thickness direction Z of the battery body is also perpendicular to the surface of the battery body 11, the height direction of the conductive wire is in the same direction as the thickness direction Z of the battery body. Conversely, as... Figure 3 As shown, when the bottom surface of the conductive substrate 131 is inclined to the surface of the battery body 11, the height direction of the conductive wire 13 is set at an angle to the thickness direction Z of the battery body.

[0055] Considering that if the height between the end of the connecting material layer 132 furthest from the conductive substrate 131 and the conductive substrate 131 is too large, the side where the connecting material layer 132 connects to the conductive layer 12 will become uneven. This will make point contact more likely when the conductive layer 12 contacts the connecting material layer 132, resulting in a smaller contact area between the connecting material layer 132 and the conductive layer 12. Furthermore, due to the large height difference at the contact point between the conductive wire 13 and the conductive layer 12, the conductive wire 13 and the conductive layer 12 are prone to misalignment, displacement, and tilting.

[0056] Based on this, in this application, in the height direction of the conductive wire 13, the maximum height H between the end of the connecting material layer 132 away from the conductive substrate 131 and the conductive substrate 131 is 3μm to 20μm, including any value within this height range, such as 3μm, 6μm, 9μm, 12μm, 15μm, 18μm, or 20μm. Specifically, the term "maximum height" refers to the height value at the point of maximum height. It can be understood that if the maximum height H is less than 3μm, the overall height of the connecting material layer 132 is too low, that is, the thickness of the connecting material in the connecting material layer 132 is too thin, making it difficult to effectively connect the conductive substrate 131 and the conductive layer 12. If the maximum height H is greater than 20μm, it indicates that the protrusion height of the connecting material layer 132 is large, and correspondingly, the side where the connecting material layer 132 connects to the conductive layer 12 is not flat enough. When the connecting material layer 132 meets the height range of 3μm to 20μm, it indicates that the connecting material layer 132 is high enough and the connecting material in the connecting material layer 132 is thick enough, so as to effectively connect the conductive substrate 131 and the conductive layer 12. On the other hand, it indicates that the side where the connecting material layer 132 is connected to the conductive layer 12 is relatively flat. When the connecting material layer 132 and the conductive layer 12 are in contact, the connecting material layer 132 and the conductive layer 12 are closer to surface contact. Compared with point contact, surface contact has a larger contact area. Since the contact resistance is inversely proportional to the contact area, it is beneficial to reduce the contact resistance between the conductive wire 13 and the battery body 11, thereby improving the collection and output efficiency of photocurrent.

[0057] Furthermore, the height difference at the contact point between the conductive wire 13 and the conductive layer 12 is small, which makes the tilt angle of the conductive wire 13 smaller. The conductive wire 13 is less likely to be misaligned or tilted relative to the conductive layer 12, thereby reducing the reflection difference caused by the tilt or offset of the conductive wire 13. The photovoltaic module made using this solar cell 1 has a smaller reflection difference and a more beautiful appearance.

[0058] Furthermore, such as Figure 2 As shown, the width of the connecting material layer 132 near the conductive substrate 131 is W. It can be understood that the width W is the chord length of the arc, and the height H is the chord height of the arc. The larger the chord length relative to the chord height, the smaller the curvature of the arc, meaning the flatter the connecting material layer 132. In this application, H / W is 0.005 to 0.6. When H / W meets the above ratio range, it indicates that the curvature of the connecting material layer 132 is small, the side of the connecting material layer 132 connected to the conductive layer 12 is flatter, and the connecting material layer 132 and the conductive layer 12 are more likely to form surface contact. This means the contact area between the conductive wire 13 and the conductive layer 12 is larger, and the contact resistance between them is lower.

[0059] Optionally, the width W of the connecting material layer 132 near the conductive substrate 131 is 0.05 mm to 0.2 mm. When the width W meets the above-mentioned width range, the width of the conductive substrate 131 is narrower, reducing the light-shielding effect on the battery body 11. Furthermore, when the connecting material layer 132 simultaneously meets both the width W range and the height H range, it indicates that the curvature of the connecting material layer 132 is smaller, the side of the connecting material layer 132 connected to the conductive layer 12 is flatter, and the connecting material layer 132 and the conductive layer 12 are more likely to form surface contact. That is, the contact area between the conductive wire 13 and the conductive layer 12 is larger, and the contact resistance between them is lower.

[0060] It should be noted that the width direction of the conductive wire 13 can refer to the direction of the short side of the bottom surface of the conductive substrate 131. When the bottom surface of the conductive substrate 131 is parallel to the surface of the battery body 11, the width direction of the conductive wire is also parallel to the surface of the battery body 11. For example, the width direction of the conductive wire 13 can be the same as the length direction X or the width direction of the battery body. When the bottom surface of the conductive substrate 131 is inclined to the surface of the battery body 11, the width direction of the conductive wire 13 is also inclined at the same angle relative to the surface of the battery body 11.

[0061] Optionally, such as Figure 2 As shown, the width W of the connecting material layer 132 near the conductive substrate 131 is the same as the width of the conductive substrate 131. Therefore, the connecting material layer 132 can be fabricated by making full use of the width of the conductive substrate 131, so that the width W is as large as possible, and the side of the connecting material layer 132 that is connected to the conductive layer 12 is as flat as possible.

[0062] Optionally, such as Figure 2 As shown, the side where the connecting material layer 132 connects to the conductive layer 12 is constructed as an arc. It should be noted that the arc-shaped side of the connecting material layer 132 can be a continuous arc or a discontinuous arc. For example, after the conductive layer 12 is embedded in the connecting material layer 132, the connecting material layer 132 is equivalent to a discontinuous arc structure. Furthermore, the angle θ on the arc-shaped side of the connecting material layer 132 is ≤ 60°. When the connecting material layer 132 meets the above-mentioned height H range, and the arc-shaped side of the connecting material layer 132 meets the above-mentioned angle range, it indicates that the side where the connecting material layer 132 connects to the conductive layer 12 is relatively flat, and the connecting material layer 132 and the conductive layer 12 are closer to surface contact. Compared to point contact, the contact area when the connecting material layer 132 and the conductive layer 12 are in surface contact is larger, thereby reducing the contact resistance between the conductive wire 13 and the conductive layer 12, and thus improving the collection and extraction efficiency of the photocurrent.

[0063] Optionally, such as Figure 1 and Figure 3As shown, in the thickness direction Z of the battery body, the maximum distance between the side 1311 of the conductive substrate 131 facing the battery body 11 and the surface of the battery body 11 is D; where D ≤ 0.1 mm. When the conductive substrate 131 meets the above-mentioned distance range, it indicates that the height difference of the side portion in contact with the conductive wire 13 and the conductive layer 12 is small, which makes the tilt angle of the conductive wire smaller. The conductive wire is less likely to be misaligned or tilted relative to the conductive layer, thereby reducing the reflection difference caused by the tilt or offset of the conductive wire. The photovoltaic module made using this solar cell has less reflection difference and a more beautiful appearance.

[0064] In some embodiments, such as Figure 4 As shown, the side 1311 of the conductive substrate 131 facing away from the battery body 11 is inclined relative to the surface of the battery body 11, and this part of the side 1311 is a reflective surface 1312. Specifically, part of the light incident on the battery body 11 is reflected back to the battery body 11 by the reflective surface 1312, and this part of the light is absorbed by the battery body 11 and converted into electrical energy to improve the conversion efficiency of the solar cell 1.

[0065] It should be noted that the conductive substrate 131 may have one or more side surfaces 1311. When the conductive substrate 131 has only one side surface 1311, part of the side surface 1311 is located on the side of the conductive substrate 131 facing the conductive layer 12, and part of the side surface 1311 is away from the battery body 11 and inclined relative to the surface of the battery body 11, and this part of the side surface 1311 is a reflective surface 1312. When the conductive substrate 131 has multiple side surfaces 1311, one or more of the side surfaces 1311 are located on the side of the conductive substrate 131 facing the conductive layer 12, and the remaining one or more side surfaces 1311 are located on the side of the conductive substrate 131 away from the battery body 11.

[0066] Optionally, the conductive substrate 131 has a triangular cross-section with three sides 1311, and the cross-section is a plane formed by the height direction of the conductive wire and the width direction of the conductive wire.

[0067] One side 1311 of the conductive substrate 131 is located on the side of the conductive substrate 131 facing the conductive layer 12, and the connecting material layer 132 is disposed on at least this side 1311.

[0068] The other two sides 1311 are disposed opposite to the battery body 11 and inclined to the surface of the battery body 11, and at least one of these two sides 1311 is a reflective surface 1312.

[0069] The conductive substrate 131 with a triangular cross-section has a non-planar surface structure, which can reflect most of the incident light, thereby reducing the equivalent light-shielding area of ​​the battery body 11 and allowing more light to reach the surface of the battery body 11 for absorption and utilization, thus improving the photoelectric conversion efficiency. Furthermore, the side surface 1311 of the conductive substrate 131 with a triangular cross-section is planar, which allows the connecting material layer 132 formed on the side surface 1311 to also be as flat as possible, thereby enabling the conductive wire 13 to better bond and contact with the conductive layer 12.

[0070] Of course, the cross-section of the conductive substrate 131 can also be rectangular, circular, semi-circular, trapezoidal or serrated.

[0071] Optionally, the side 1311 of the conductive substrate 131 facing the conductive layer 12 is parallel to the surface of the battery body 11, or the side 1311 of the conductive substrate 131 facing the conductive layer 12 is inclined to the surface of the battery body 11.

[0072] When the conductive substrate 131 is tilted toward the side 1311 of the conductive layer 12 on the surface of the battery body 11, the angle β between the side 1311 of the conductive substrate 131 toward the conductive layer 12 and the surface of the battery body 11 is ≤30°.

[0073] It is understood that the side 1311 of the conductive substrate 131 facing the conductive layer 12 is also the bottom surface of the conductive substrate 131. When the bottom surface of the conductive substrate 131 is parallel to the surface of the battery body 11, or when the angle β between the bottom surface of the conductive substrate 131 and the surface of the battery body 11 is ≤30°, at least one side 1311 of the conductive substrate 131 can serve as a reflective surface 1312, and light can be reflected to the surface of the battery body 11 through the reflective surface 1312.

[0074] In this application, the conductive wire 13 and the conductive layer 12 extend in the same direction, that is, the continuous area of ​​the conductive layer 12 in the length direction is stacked and connected with the conductive wire 13, thereby improving the connection and contact effect between the conductive wire 13 and the conductive layer 12.

[0075] In order to be electrically connected to other solar cells 1, at least one end of the conductive wire 13 extends beyond the edge of the cell body 11 in the extension direction of the conductive wire 13, so that the end of the conductive wire 13 extending beyond the edge of the cell body 11 can be interconnected with the conductive wire 13 of other solar cells 1.

[0076] Optionally, the conductive substrate 131 may be made of copper, silver, aluminum, aluminum alloy, or copper-clad aluminum. These materials provide the conductive substrate 131 with good electrical conductivity and mechanical strength to reduce current transmission losses and prevent breakage or damage during the production, installation, and use of photovoltaic modules.

[0077] Optionally, the material of the connecting material layer 132 includes tin or a tin alloy, such as a lead-tin alloy, a silver-tin alloy, or a silver-copper-tin alloy. Connecting material layers 132 made of these materials have good solderability, allowing the conductive wire 13 to bond better to the conductive layer 12 with higher bonding strength. Furthermore, these connecting material layers 132 have low resistance, which helps reduce power transmission losses between the conductive layer 12 and the conductive wire 13.

[0078] Optionally, the conductive layer is a conductive seed layer or a conductive film layer. Specifically, the conductive film layer can be a transparent metal oxide layer, such as indium tin oxide (ITO), fluorine-doped tin oxide (FTO), or aluminum-doped zinc oxide (AZO). The conductive film layer can cover the entire surface or a portion of the surface of the battery body 11, such as a transparent metal oxide layer on a heterojunction solar cell.

[0079] The conductive seed layer can be a metal seed layer, and further, the metal seed layer can be a patterned seed layer. The conductive seed layer can be disposed on a local area of ​​the surface of the battery body 11, for example, a metal seed layer on a passivated contact solar cell.

[0080] It should be noted that the connection methods between different types of conductive layers 12 and connecting material layers 132 can also be different. For conductive seed layers, when the width of the conductive seed layer is narrow, the conductive seed layer can be wrapped or partially wrapped by the connecting material layer 132. For conductive film layers, the connecting material layer 132 can be attached to the surface of the conductive film layer.

[0081] Optionally, the thickness of the conductive layer 12 is 1 μm to 10 μm, including any value within this thickness range, such as 1 μm, 5 μm, or 10 μm. When the conductive layer 12 meets the above thickness range, since the current of the battery body 11 is transmitted along the thickness direction of the conductive layer 12, the transmission path in the conductive layer 12 with this thickness is shorter, and the problem of uneven thickness caused by the conductive layer 12 being too thin can be avoided, that is, the thickness uniformity of the conductive layer 12 is better. Specifically, the thickness direction of the conductive layer 12 and the thickness direction Z of the battery body can be the same direction.

[0082] Optionally, the width of the conductive layer 12 is 5 μm to 30 μm, including any value within this width range, such as 5 μm, 15 μm, or 30 μm. When the conductive layer 12 meets the above width range, the contact area between the conductive layer 12 and the conductive wire 13 is large, the contact resistance between the two is small, and the conductive layer 12 is also narrow enough to reduce recombination problems caused by the conductive layer 12.

[0083] Reference Figure 5 and Figure 6 Specifically, when the conductive wire 13 extends along the width direction of the battery body, Figure 5 and Figure 6 The cross-sectional view is a cross-section formed by the thickness direction Z and the length direction X of the battery body. In some embodiments, the battery body 11 includes a silicon substrate 111 and a doped layer 112. The doped layer 112 is disposed on the surface of the silicon substrate 111, and the conductive layer 12 is disposed on the side of the doped layer 112 away from the silicon substrate 111 and is in ohmic contact with the doped layer 112.

[0084] It is understood that the conductive layer 12 is configured to collect the current within the doped layer 112. Since the conductive wire 13 is stacked on the side of the conductive layer 12 away from the battery body 11 and is electrically connected to the conductive layer 12, the current in the conductive layer 12 is longitudinally transmitted to the conductive wire 13, and the conductive wire 13 then outputs the collected current. Specifically, the aforementioned longitudinal direction refers to the stacking direction of the conductive wire 13 and the conductive layer 12, which is also the thickness direction Z of the battery body.

[0085] Because the longitudinal dimension of the conductive layer 12 is smaller than its transverse dimension (for example, the thickness of the conductive layer 12 is smaller than its length), the current transmission path is shorter when the conductive layer 12 is used for longitudinal current transmission. Furthermore, because the longitudinal cross-sectional area of ​​the conductive layer 12 is larger, and the resistance of a conductor is inversely proportional to its cross-sectional area, the resistance of the conductive layer 12 is also lower when used for longitudinal current transmission. Specifically, the longitudinal cross-sectional area of ​​the conductive layer 12 can be a plane composed of the width and length directions of the conductive layer 12.

[0086] Optionally, the silicon substrate 111 can be an N-type silicon substrate or a P-type silicon substrate. The doped layer 112 can be a diffusion layer, such as a boron-doped layer or a phosphorus-doped layer. The doped layer 112 can also be a polycrystalline silicon layer, such as a P-type doped polycrystalline silicon layer or an N-type doped polycrystalline silicon layer. The doped layer 112 can also be an amorphous silicon layer, such as a P-type doped amorphous silicon layer or an N-type doped amorphous silicon layer.

[0087] More specifically, the cell type of the cell body 11 can be a passivated contact solar cell (TOPCon solar cell), a back contact solar cell (BC solar cell), a heterojunction solar cell (HJT solar cell), or an emitter and back passivated solar cell (PERC solar cell).

[0088] Secondly, such as Figure 7 As shown in the figure, this application discloses a photovoltaic module including a plurality of solar cells 1 as described in the first aspect. The conductive wire 13 of each solar cell 1 is connected to the conductive wire 13 of another solar cell 1 for electrical connection.

[0089] It should be noted that the term "electrical connection" can refer to series and / or parallel connections. For example, the positive conductive wire 13 of one solar cell 1 is connected in series with the negative conductive wire 13 of another solar cell 1 via a busbar 2, and the connection method may be welding, etc. As another example, the conductive wire 13 of one solar cell 1 is connected in parallel with the same polarity conductive wire 13 of another solar cell 1.

[0090] As analyzed above, due to the larger contact area between the conductive filament 13 and the conductive layer 12 in the solar cell 1 described in the first aspect, the current transmission and conduction efficiency of the solar cell 1 is higher, thereby resulting in higher efficiency of the photovoltaic module. Furthermore, because the height difference at the contact point between the conductive filament 13 and the conductive layer 12 in the solar cell 1 is smaller, the tilt angle of the conductive filament 13 is smaller. The conductive filament 13 is less likely to misalign or tilt relative to the conductive layer 12, thus reducing the reflection differences caused by the tilt or offset of the conductive filament 13, resulting in smaller reflection differences and a more aesthetically pleasing appearance for the photovoltaic module.

[0091] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A solar cell, characterized by, The battery comprises: a battery body; a conductive layer arranged on a surface of the battery body and electrically connected with the battery body; and a conductive wire comprising a conductive base and a connecting material layer, the conductive base is laminated on a side of the conductive layer facing away from the battery body, the connecting material layer is arranged on at least one side of the conductive base facing the conductive layer, the connecting material layer is in contact with the conductive layer to electrically connect the conductive wire with the conductive layer, and the connecting material layer protrudes in a direction away from the conductive base; wherein the maximum height H between the end of the connecting material layer away from the conductive base and the conductive base is 3-20 μm. The width of the side of the connecting material layer close to the conductive base is W; wherein H / W is 0.005-0.

6.

2. The solar cell according to claim 1, characterized in that, The width W of the side of the connecting material layer close to the conductive base is 0.05-0.2 mm.

3. The solar cell according to claim 2, characterized in that, The width of the side of the connecting material layer close to the conductive base is consistent with the width of the conductive base. The side of the connecting material layer connected with the conductive layer is configured as an arc shape.

4. The solar cell according to claim 1, characterized in that, The angle of the side of the arc shape on the connecting material layer is ≤60°. In the thickness direction of the battery body, the maximum distance D between the side of the conductive base facing the battery body and the surface of the battery body is ≤0.1 mm.

5. The solar cell according to claim 1, characterized in that, The side of the conductive base facing away from the battery body is inclined relative to the surface of the battery body, and this part of the side is a reflecting surface.

6. The solar cell according to claim 1, characterized in that, The cross section of the conductive base is triangular and has three sides, and the cross section is a plane composed of the height direction and the width direction of the conductive wire.

7. The solar cell according to claim 6, characterized in that One of the sides of the conductive base is on the side of the conductive base facing the conductive layer, and the connecting material layer is arranged on at least this side. The other two sides of the conductive base are arranged away from the battery body and are inclined to the surface of the battery body, and at least one of the two sides is the reflecting surface. The side of the conductive base facing the conductive layer is parallel to the surface of the battery body, or the side of the conductive base facing the conductive layer is inclined to the surface of the battery body.

8. The solar cell according to any one of claims 1 to 7, characterized in that, When the side of the conductive base facing the conductive layer is inclined to the surface of the battery body, the included angle β between the side of the conductive base facing the conductive layer and the surface of the battery body is ≤30°. The conductive wire and the conductive layer extend in the same direction.

9. The solar cell according to any one of claims 1 to 7, characterized in that, And / or, in the extension direction of the conductive wire, at least one end of the conductive wire exceeds the edge of the battery body. And / or, the material of the conductive base comprises copper, silver, aluminum, aluminum alloy or copper-clad aluminum. And / or, the material of the connecting material layer comprises tin or tin alloy. The conductive layer is a conductive seed layer or a conductive film layer.

10. The solar cell according to any one of claims 1 to 7, characterized in that, And / or, the thickness of the conductive layer is 1-10 μm. And / or, the width of the conductive layer is 5-30 μm. ​ And / or, the battery body comprises a silicon substrate and a doped layer, the doped layer is arranged on the surface of the silicon substrate, the conductive layer is arranged on the side of the doped layer away from the silicon substrate and is in ohmic contact with the doped layer.

11. A photovoltaic module, characterized by, The solar cell comprises a plurality of solar cells according to any one of claims 1 to 10; the conductive wire of each solar cell is connected with the conductive wire of another solar cell to be electrically connected.

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