Solar cell and photovoltaic module

Abstract

Solar cell, characterized in that the solar cell comprises a cell substrate (11), collector electrodes (12), bus electrode segments (13) and a first welded and / or soldered and / or brazed section (14); wherein at least one of the light-facing and one of the light-facing sides of the cell substrate (11) is a target side; wherein the collector electrodes (12) and the bus electrode segments (13) are arranged on the target side of the cell substrate (11); wherein the collector electrodes (12) extend along a first direction, and wherein different collector electrodes (12) located on the same target side are spaced apart from one another along a second direction; wherein the first direction differs from the second direction; wherein the bus electrode segments (13) are located at the edge regions of both ends of the target side along the second direction, and the bus electrode segments (13) extend along the second direction;wherein the bus electrode segments (13) are electrically coupled to some of the collector electrodes (12) of the same conductivity type as the bus electrode segments (13); wherein the first welded and / or soldered section (14) is arranged on a side of a corresponding bus electrode segment (13) facing away from an edge of the cell substrate (11) along the second direction and is electrically coupled to the corresponding bus electrode segment (13).

Description

TECHNICAL FIELD

[0001] The present application relates to the field of photovoltaic technology and in particular to a solar cell and a photovoltaic module. STATE OF THE ART

[0002] Solar cells are currently being increasingly used as a new energy alternative. Photovoltaic solar cells are devices that convert the sun's light energy into electrical energy. Specifically, solar cells use the photovoltaic principle to generate charge carriers, which are then extracted via electrodes, enabling the efficient use of electrical energy.

[0003] However, after the existing solar cells are connected in series via the welding and / or soldering connection element to form a photovoltaic module, the welding and / or soldering voltage of the welding and / or soldering connection element at the edge portions of the solar cells is relatively large, and welding and / or soldering defects are likely to occur. DISCLOSURE OF APPLICATION

[0004] An object of the present application is to provide a solar cell and a photovoltaic module which can prevent the welding and / or soldering stress of the welding and / or soldering connecting element in the edge region of the solar cell from becoming large after the photovoltaic module has been formed, thereby reducing the risk of welding and / or soldering defects.

[0005] To achieve the above object, the present application provides, in a first aspect, a solar cell, the solar cell comprising a cell substrate, collector electrodes, bus electrode segments, and a first welding and / or soldering portion. At least one of the light-facing side and the light-removing side of the cell substrate is a target side. The collector electrodes and the bus electrode segments are arranged on the target side of the cell substrate. The collector electrodes extend along the first direction, and different collector electrodes located on the same target side are distributed at intervals along the second direction. The first direction is different from the second direction. The bus electrode segments are located at the edge portions of both ends of the target side along the second direction, and the bus electrode segments extend along the second direction.The bus electrode segments are electrically coupled to some of the collector electrodes of the same conductivity type as the bus electrode segments. The first welding and / or soldering section is arranged on a side of a corresponding bus electrode segment facing away from an edge of the cell substrate along the second direction and is electrically coupled to the corresponding bus electrode segment.

[0006] When the above technical solution is adopted, the collector electrodes and the bus electrode segments included in the solar cell are arranged on the target side of the cell substrate. And, the bus electrode segments are electrically coupled to some of the collector electrodes of the same conductivity type as the bus electrode segments. At this time, when the solar cell is in the operating state, the charge carriers collected by the collector electrode located at the edge region of one end of the target side along the second direction can be converged toward the bus electrode segments. Meanwhile, the first welding and / or soldering section included in the solar cell is arranged on one side of the corresponding bus electrode segment.which faces away from an edge of the cell substrate along the second direction. Based on this, and after the solar cell provided by the present application has been connected in series by the welding and / or soldering connection element to form a photovoltaic module, the welding and / or soldering connection element only needs to be welded and / or soldered to the first welding and / or soldering section to collect the charge carriers collected by the collector electrode located at the edge region at one end of the target side along the second direction, wherein the ends of the welding and / or soldering connection element do not need to extend simultaneously to edge regions of the two ends of the cell substrate along the second direction. Therefore, the effective welding and / or soldering length between the welding and / or soldering connection element and the cell substrate can be shortened, which contributes toto reduce the welding and / or soldering stress in the edge region of the cell substrate along the second direction, thereby reducing the risk of a welding and / or soldering defect. At the same time, this can also reduce the welding and / or soldering accuracy requirements of the strand welding and / or soldering machine, which in turn reduces the manufacturing difficulties of the photovoltaic module. On the other hand, this also prevents the ends of the welding connection element connecting two adjacent solar cells in the photovoltaic module from overlapping, which could lead to a short circuit.

[0007] Second, the bus electrode segments are arranged at the edge regions at both ends of the target side along the second direction. In other words, the lengths of the bus electrode segments included in the solar cell provided by the present application are smaller than the length of the bus electrode included in the conventional busbar solar cell. Based on this, the collector electrodes and the bus electrode segments in the solar cell provided by the present application have a smaller total metal bonding area with the cell substrate compared to the conventional busbar solar cell, which contributes to the solar cell having a higher open-circuit voltage. Thus, the material consumption in manufacturing the bus electrode segments can also be reduced, thus contributing to controlling the manufacturing cost of the solar cell.Furthermore, among all collector electrodes on the same target side, the collector electrodes electrically coupled to the bus electrode segments are defined as first-type collector electrodes, and the remaining collector electrodes are defined as second-type collector electrodes. Based on this, when the solar cells provided by the present application are connected in series to form a photovoltaic module through the welding and / or soldering connection elements, the welding and / or soldering connection elements can be electrically coupled to the second-type collector electrodes without the aid of a bus electrode.At this time, the transmission path of the charge carriers collected by the second type collector electrodes to the welding and / or soldering connection element is shorter, which is beneficial to reducing transmission losses and improving the working efficiency of the photovoltaic module formed by the solar cells provided by the present application.

[0008] As a possible embodiment, it is provided that the side of the above first welding and / or soldering section facing away from the bus electrode segments is not connected to the collector electrodes, which side is adjacent to the first welding and / or soldering section in the second direction and has the same conductivity type.In this case, it is advantageous to reduce the number of collector electrodes that are electrically coupled to the first welding and / or soldering section so that the charge carriers collected by the collector electrodes next to the side of the first welding and / or soldering section facing away from the bus electrode segments can be transferred directly to the welding and / or soldering connection element, which contributes to reducing the transmission loss of charge carriers that are collected by the collector electrodes next to the side of the first welding and / or soldering section facing away from the bus electrode segments and transferred to the welding and / or soldering connection element.

[0009] As a possible embodiment, it is provided that different bus electrode segments are distributed at the same end of the same target side along the second direction and spaced apart from each other along the first direction, and wherein the solar cell comprises two bus electrode segments arranged opposite each other at different ends of the same target side along the second direction. The two opposite bus electrode segments are not connected to each other. In this case, the distribution of the different bus electrode segments on the target side is made more regular, which contributes to reducing the difficulty of connecting adjacent solar cells to each other.At the same time, the two opposing bus electrode segments are not connected to each other, which ensures that the total length of the two bus electrode segments opposing each other along the second direction is shorter than the length of the entire bus electrode included in the conventional solar cell, thereby ensuring that the metal bond loss between the bus electrode segments and the cell substrate is reduced and the amount of consumables used in the manufacturing of the bus electrode segments is reduced. At the same time, it also helps ensure that the charge carriers collected by the collector electrodes arranged between the two opposing bus electrode segments have lower transmission losses.

[0010] As a possible embodiment, it is provided that along the second direction the length of at least one of the bus electrode segments is less than or equal to 10 mm.

[0011] By applying the above-mentioned technical solution, the length of at least one of the bus electrode segments is within the above range, which can prevent a larger bonding area between the bus electrode segments and the cell substrate due to the long lengths of the bus electrode segments, thus ensuring a higher open-circuit voltage of the solar cell; meanwhile, it also ensures that the amount of consumables used in the manufacture of the bus electrode segments can be reduced, and the loss of charge carriers collected by the collector electrode and transferred to the welding and / or soldering connection element can be reduced.

[0012] As a possible embodiment, it is provided that along the second direction, the ratio between the length of at least one of the bus electrode segments and the width of the cell substrate is less than or equal to 12%. The advantageous effects in this case can be analyzed with reference to the above-described advantageous effects of at least one of the bus electrode segments having a length of less than or equal to 10 mm and are not described in detail here.

[0013] As a possible embodiment, it is provided that along the first direction a width of at least one of the bus electrode segments is greater than or equal to 10µm and less than or equal to 500µm.

[0014] By applying the above-mentioned technical solution, the width of at least one of the bus electrode segments along the first direction is within the above range, which can prevent the narrower width of the bus electrode segments from resulting in increased transmission resistance of the bus electrode segments, thus contributing to reducing transmission losses of the bus electrode segments. Furthermore, the bus electrode segments can also be prevented from having a larger width, resulting in a larger metal bonding area between the bus electrode segments and the cell substrate, thus ensuring a higher open-circuit voltage of the solar cell. At the same time, the amount of consumables used in the manufacturing of the bus electrode segments can also be reduced.Secondly, when the solar cell provided by the present application is a back contact cell, the width of at least one of the bus electrode segments is within the above-mentioned range, which can also prevent the amount of consumables of insulating material arranged at the interface of the collector electrodes and the bus electrode segments having a conductivity type opposite to their own at the edge portions of both ends of the target side along the second direction from being relatively large due to the large widths of the bus electrode segments.Or it will prevent the collector electrodes at the edge regions of both ends of the target side along the second direction from being separated by a large distance at the interfaces with the bus electrode segments having a conductivity type opposite to their own, and ensure that the collection efficiency of the charge carriers at the edge regions at both ends of the target side along the second direction is high.

[0015] As a possible embodiment, the width of the above bus electrode segments gradually increases along the direction of the first welding and / or soldering section. In this case, it is advantageous to increase the contact area between the bus electrode segments and the first welding and / or soldering section, thereby reducing transmission loss. At the same time, the connection stability between the bus electrode segments and the first welding and / or soldering section can be improved, thereby increasing the reliability of the solar cell structure.

[0016] As a possible embodiment, it is provided that the number of bus electrode segments located at the same end of the same target side along the second direction is greater than or equal to 6 and less than or equal to 30.

[0017] When applying the above-mentioned technical solution, the number of bus electrode segments at the same end of the same target side along the second direction is within the above-mentioned range, which can prevent the charge carriers from having to travel a longer distance on the collector electrodes before they can be collected at the bus electrode segments due to the above-mentioned small number, which contributes to reducing the transmission losses of the collector electrodes and also contributes to reducing the risk that corresponding charge carriers cannot be transported to the bus electrode segments after the collector electrodes break.In addition, the above-mentioned large number can also be prevented from causing a large metal bonding area between all the bus electrode segments located at the edge portions at both ends of the target side along the second direction and the cell substrate and a large amount of consumables of at least all the bus electrode segments.

[0018] As a possible embodiment, the ratio of the number of collector electrodes arranged at the edge region of one end of the target side along the second direction to the total number of all collector electrodes arranged on the target side is less than or equal to 12%. The advantageous effects in this case can be analyzed by reference to the advantageous effects of the number of bus electrode segments at the same end on the same target side along the second direction being less than or equal to 30, as described above, which will not be discussed in detail here.

[0019] As a possible embodiment, it is provided that the first welding and / or soldering section and the bus electrode segments electrically connected to the first welding and / or soldering section form a one-piece structure.

[0020] When applying the above-mentioned technical solution, the first welding and / or soldering section and the bus electrode segments electrically coupled to it are an integrated structure, which means that the first welding and / or soldering section and the bus electrode segments electrically coupled to it are made of the same material and manufactured at the same time. Based on this, when the first welding and / or soldering section and the bus electrode segments electrically coupled to the first welding and / or soldering section are an integral structure, there are no pores at the junction between the first welding and / or soldering section and the bus electrode segments electrically coupled to the first welding and / or soldering section, which contributes to improving the contact performance between the first welding and / or soldering section and the bus electrode segments electrically coupled to itself and reducing transmission losses.

[0021] As a possible embodiment, it is contemplated that the solar cell further comprises a first conductive material disposed on the first welding and / or soldering portion. In this case, during the process of connecting the solar cells provided by the present application in series to form a photovoltaic module, the welding and / or soldering connection element can be welded and / or soldered together with the first welding and / or soldering portion through the first conductive material to ensure that the welding and / or soldering connection element and the first welding and / or soldering portion have good welding and / or soldering quality.

[0022] As a possible embodiment, it is provided that along the first direction a length of the first welding and / or soldering section is greater than or equal to 100µm and less than or equal to 10000µm.

[0023] When applying the above-mentioned technical solution, the length of the first welding and / or soldering section along the first direction is within the above range, which can prevent the need to strictly control the position of the welding and / or soldering connecting element on the solar cell during the welding and / or soldering process due to the short length of the first welding and / or soldering section, thereby preventing the welding and / or soldering connecting element from being displaced and thereby not being welded and / or soldered to the first welding and / or soldering section as required, thereby improving the welding and / or soldering yield.In addition, due to the increased length of the first welding and / or soldering portion, the first welding and / or soldering portion can also be prevented from having a larger metal bonding area with the cell substrate and a larger amount of consumables being used in the manufacture of the first welding and / or soldering portion, thereby ensuring that the solar cell has a higher working efficiency and reducing the manufacturing cost of the solar cell.

[0024] As a possible embodiment, it is provided that along the second direction a width of the first welding and / or soldering section is greater than or equal to 100µm and less than or equal to 10000µm.

[0025] By applying the above-mentioned technical solution, the width of the first welding and / or soldering portion along the second direction is within the above range, whereby the contact area between the first welding and / or soldering portion and the welding and / or soldering joining member can be prevented from being limited due to the narrow width of the first welding and / or soldering portion, which contributes to reducing the welding and / or soldering resistance between the first welding and / or soldering portion and the welding and / or soldering joining member and contributes to improving the welding and / or soldering adhesion force between the first welding and / or soldering portion and the welding and / or soldering joining member, thereby reducing transmission losses and meanwhile improving the structural reliability of the photovoltaic module formed from the solar cells provided by the present application.In addition, due to the larger width of the first welding and / or soldering portion, the first welding and / or soldering portion can also be prevented from having a larger bonding area with the cell substrate and a larger amount of consumables being used in the manufacture of the first welding and / or soldering portion, thereby ensuring that the solar cell has a higher working efficiency and reducing the manufacturing cost of the solar cell.

[0026] As a possible embodiment, among all collector electrodes on the same target side, the collector electrodes electrically coupled to the bus electrode segments are defined as collector electrodes of the first type, and the remaining collector electrodes are defined as collector electrodes of the second type. Furthermore, the solar cell has a second welding and / or soldering section. The second welding and / or soldering section is electrically connected to at least one collector electrode of the second type.

[0027] When applying the above-mentioned technical solution, the second welding and / or soldering section included in the solar cell is electrically coupled to the corresponding collector electrodes of the second type, and the second welding and / or soldering section is associated with at least one collector electrode of the second type. At this time, when the solar cells provided by the present application are connected in series via the welding and / or soldering connection elements to form a photovoltaic module, the welding and / or soldering connection elements can be welded and / or soldered together with the collector electrodes of the second type via the second welding and / or soldering section.Compared with the method in which the part of the second-type collector electrodes located in the extension direction of the first welding and / or soldering portion of the same conductivity type as the collector electrodes themselves along the second direction is arranged as a widened micro-electrode segment and realizes an electrical connection with the welding and / or soldering connection element, the contact area between the second welding and / or soldering portion and the welding and / or soldering connection element is larger, which contributes to reducing the welding and / or soldering resistance between the welding and / or soldering connection element and the second-type collector electrodes and improving the welding and / or soldering adhesion force between the welding and / or soldering connection element and the second-type collector electrodes.

[0028] As a possible embodiment, it is provided that at least some of the second welding and / or soldering sections are arranged in parallel along the second direction. In this case, it is advantageous to arrange the second welding and / or soldering sections evenly distributed in the second direction, which prevents the high requirement for the adjustment accuracy of the welding and / or soldering connection element that contacts various second welding and / or soldering sections by the automatic string welding and / or soldering machine from arising due to the disordered distribution of the various second welding and / or soldering sections, and thus contributes to reducing the difficulties in connecting adjacent solar cells by the welding and / or soldering connection element.

[0029] As a possible embodiment, it is provided that a center line of at least some of the second welding and / or soldering sections along the second direction is collinear with a center line of at least one bus electrode segment along the second direction.In this case, along the second direction, the center line of at least some of the second welding and / or soldering portions is located on the same extension line as the center line of at least one bus electrode segment, thereby preventing the center lines of the two from being offset along the second direction, and thereby the adjustment accuracy of the welding and / or soldering connection element that contacts the second welding and / or soldering portion and the first welding and / or soldering portion electrically coupled to the bus electrode segments by the automatic strand welding and / or soldering machine is high, thereby reducing the difficulty of connecting adjacent solar cells to each other by the welding and / or soldering connection element.

[0030] As a possible embodiment, at least some of the second welding and / or soldering sections are arranged parallel along the second direction. Along the second direction, a gap exists between a second welding and / or soldering section and another adjacent second welding and / or soldering section; wherein at least one of the collector electrodes is interrupted at the gap or at least one of the collector electrodes extends continuously through the gap.In this case, after the adjacent solar cells are connected to each other by the welding and / or soldering connection member, the welding and / or soldering connection member can be electrically insulated by the distance of the collector electrodes by which they are interrupted at the gap, and the collector electrodes having a conductivity type opposite to their own, which contributes to reducing the cost of connecting solar cells and also reducing the labor for attaching insulating material to the gap.

[0031] As a possible embodiment, it is provided that a length of the second welding and / or soldering section along the first direction is greater than or equal to 100 µm and less than or equal to 10,000 µm. The advantageous effects in this case are similar to the advantageous effects described above for a length of the first welding and / or soldering section along the first direction being greater than or equal to 100 µm and less than or equal to 10,000 µm, which will not be discussed in detail here.

[0032] As a possible embodiment, it is provided that a width of the above second welding and / or soldering section along the second direction is greater than or equal to 100 µm and less than 500 µm. The advantageous effects in this case are similar to the advantageous effects described above for the case where a width of the first welding and / or soldering section along the second direction is greater than or equal to 500 µm and less than or equal to 10,000 µm.Furthermore, when the solar cell provided by the present application is a back contact cell, the width of the second welding and / or soldering portion along the second direction is within the above range, which can also prevent the width of the second welding and / or soldering portion from being so large that the end of the second welding and / or soldering portion overlaps with the adjacent collector electrodes of the opposite conductivity type, resulting in a short circuit, thereby ensuring high electrical reliability of the solar cell.

[0033] As a possible embodiment, it is provided that the width of the above-described first welding and / or soldering section is greater than or equal to the width of the second welding and / or soldering section. In this case, it can be ensured that the first welding and / or soldering section has a larger contact area with the welding and / or soldering connection element, which contributes to reducing the welding and / or soldering resistance between the first welding and / or soldering section and the welding and / or soldering connection element and contributes to improving the welding and / or soldering adhesion force between the first welding and / or soldering section and the welding and / or soldering connection element.In addition, this can also prevent the width of the second welding and / or soldering section from becoming too large, which would result in a larger metal bonding area between the second welding and / or soldering section and the cell substrate, thereby ensuring that the solar cell has higher operational reliability.

[0034] As a possible embodiment, it is provided that the length of the first welding and / or soldering section described above is equal to the length of the second welding and / or soldering section.

[0035] When applying the above-mentioned technical solution, the length of the first welding and / or soldering section and the length of the second welding and / or soldering section affect the effective contact size between them and the welding and / or soldering connection element along the first direction. Furthermore, during the actual manufacturing process, deviations in the placement position of the welding and / or soldering connection element on the solar cell may occur due to equipment accuracy issues.Thus, when the length of the first welding and / or soldering section is equal to the length of the second welding and / or soldering section along the first direction, it is advantageous to make the effective contact dimensions of the first welding and / or soldering section and the second welding and / or soldering section with the welding and / or soldering connection element substantially equal along the first direction, thereby ensuring that the welding and / or soldering connection element has good contact with the first welding and / or soldering section and the second welding and / or soldering section.

[0036] As a possible embodiment, the solar cell further comprises a second conductive material arranged on the second welding and / or soldering section. The advantageous effects in this case can be analyzed based on the advantageous effects of the solar cell, which also comprises the first conductive material described above, which will not be discussed in detail here.

[0037] As a possible embodiment, the distances between the ends of adjacent bus electrode segments with opposite conductivity types facing the edge of the cell substrate and the edge of the cell substrate are unequal. In this case, the collector electrodes of opposite conductivity types are distributed along the second direction at alternate spacings. At this time, the two collector electrodes with opposite conductivity types and near the edge of the cell substrate have different distances from the edge of the cell substrate along the second direction.Based on this, when the distances between the ends of adjacent bus electrode segments with opposite conductivity types facing the edge of the cell substrate and the edge of the cell substrate are unequal, the distance between the end of each bus electrode segment facing the edge of the cell substrate and the edge of the cell substrate can be adjusted according to the conductivity type of the bus electrode segment, which ensures that the bus electrode segment can carry out the charge carriers collected by the corresponding collector electrode. This contributes to reducing the distance between the end of the bus electrode segment facing the edge of the cell substrate and the collector electrodes with the same conductivity type as the bus electrode segment itself, thereby reducing the risk of leakage. Furthermore, the metal bond loss between the bus electrode segment and the cell substrate can be reduced.

[0038] As a possible embodiment, it is provided that the edges on a side of a plurality of first welding and / or soldering sections facing the bus electrode segments are flush or non-flush. In this case, if the edges of a side of the plurality of first welding and / or soldering sections facing the bus electrode segments are flush, it is advantageous to provide the sides of various first welding and / or soldering sections facing away from the cell substrate with the same surface, which contributes to providing a larger contact area between each first welding and / or soldering section and the welding and / or soldering connection element, thereby ensuring that the first welding and / or soldering section and the welding and / or soldering connection element have good electrical contact performance and relatively stable mechanical connection performance.Furthermore, if the edges of the side of the plurality of first welding and / or soldering sections facing the bus electrode segments are not flush, the advantageous effects may relate to the advantages described above when the distances between the ends of adjacent bus electrode segments having opposite conductivity types facing the edge of the cell substrate and the edge of the cell substrate are unequal, which will not be discussed in detail here.

[0039] As a possible embodiment, it is envisaged that the lengths of several bus electrode segments are equal or unequal. The advantageous effects in this case can be analyzed with reference to the advantageous effects in the case where the edges on a side facing the bus electrode segments of several first welding and / or soldering sections are flush or non-flush, which will not be discussed in detail here.

[0040] As a possible embodiment, it is provided that the solar cell further comprises an edge bus electrode, wherein the edge bus electrode is arranged at one end of the cell substrate along the first direction and extends along the second direction; wherein the maximum width of the edge bus electrode is smaller than the maximum width of the bus electrode segments.In this case, the presence of the edge bus electrode is conducive to the extraction of the charge carriers collected from the edge portion of the collector electrodes along the first direction and prevents the edge portion of the collector electrodes along the first direction from being broken so that the charge carriers cannot be discharged; alternatively, since the collector electrodes are separated at the interface with the welding and / or soldering connection element with a conductivity type opposite to their own, the problem that the charge carriers collected from the edge portion of the collector electrodes along the first direction cannot be discharged or is difficult to discharge is prevented, thereby reducing the power loss of solar cells.In addition, the maximum width of the edge bus electrode is smaller than the maximum width of the bus electrode segments, which contributes to reducing the metal bond loss between the edge bus electrode and the cell substrate and reducing the difficulty and amount of consumables used in manufacturing the edge bus electrode at the edge region of the cell substrate along the first direction.

[0041] As a possible embodiment, it is provided that the edge bus electrode is electrically coupled to at least some of the collector electrodes that have the same conductivity type as the edge bus electrode itself, and the ends of the collector electrodes that are electrically coupled to the edge bus electrode project beyond the edge bus electrode along the first direction. In this case, it is ensured that the edge portion of the collector electrodes can be electrically coupled to the edge bus electrode along the first direction, thereby ensuring that the charge carriers collected by the edge portion of the collector electrodes along the first direction can be discharged by the edge bus electrode.

[0042] As a possible embodiment, the solar cell described above further includes a voltage test point, and the voltage test point is arranged on the bus electrode segments. In this case, the width of the bus electrode segments is relatively large, and therefore, setting a voltage test point on the bus electrode segment can reduce the difficulty of contacting the corresponding electrode with the test probe, thereby ensuring the accuracy of the test result. If the solar cell is a back-contact cell, this also helps prevent short-circuit problems.

[0043] As a possible embodiment, it is provided that the distance by which the end of at least one of the bus electrode segments located at the edge of the cell substrate protrudes from the collector electrodes located at the edge of the cell substrate and electrically coupled to the bus electrode segments is greater than 0 and less than 0.12 mm.In the above case, it is possible to prevent the distance from being too large, which results in the end of at least one of the bus electrode segments facing an edge region of the target side along the second direction being close to the lower end of the cell base, which results in a risk of overlap and short circuit of the bus electrode segments when two adjacent solar cells are connected in series; moreover, it is possible to prevent the distance between the end of the bus electrode segments facing the edge region of the target side along the second direction and the collector electrodes having a conductivity type opposite to its own, which is located on the outermost side of the edge region of the target side along the second direction, from being small due to the large distance, which results in a high risk of current leakage, thereby ensuring higher electrical reliability of the back contact cell.

[0044] As a possible embodiment, among all bus electrode segments at the same end of the light-facing side along the second direction, the two bus electrode segments located on the outermost sides along the first direction are defined as the bus electrode segments of the first type, and the remaining bus electrode segments are defined as the bus electrode segments of the second type. The bus electrode segments of the first type are located on the outer side of an end of the corresponding collector electrodes facing the cell substrate along the first direction, wherein the solar cell further comprises a connecting electrode segment, wherein the bus electrode segments of the first type are electrically coupled to the corresponding first welding and / or soldering section via a connecting electrode segment.

[0045] When applying the above-mentioned technical solution, the bus electrode segments of the first type are arranged on the outside of the end of the corresponding collector electrodes facing the cell substrate along the first direction, and wherein the bus electrode segments of the first type are electrically coupled to the corresponding first welding and / or soldering section via a connecting electrode segment.At this time, the collector electrode located at the peripheral portion of the light-remote side along the second direction does not need to be electrically isolated from the first-type bus electrode segments having a conductivity type opposite to its own by setting a discontinuity point, thereby ensuring that the carriers collected by each part of the collector electrodes at the peripheral portion of the light-remote side along the second direction can be transferred to the corresponding bus electrode segment, thereby improving the collection efficiency of the carriers.

[0046] As a possible embodiment, the solar cell is a back-contact cell, and the target side is only the side of the cell substrate facing away from the light. In this case, at least some of the collector electrodes located at the edge regions at both ends of the target side along the second direction are discontinuous collector electrodes. The discontinuous collector electrodes have a discontinuity for spacing them apart from the bus electrode segments of the second type, which have a conductivity type opposite to the collector electrodes themselves, and the two ends of the discontinuous collector electrodes are spaced apart along the first direction from the bus electrode segments of the first type, which have a conductivity type opposite to the discontinuous collector electrodes.

[0047] As a possible embodiment, the collector electrodes, which are not electrically coupled to the bus electrode segments, are partially separated between two corresponding first welding and / or soldering sections arranged opposite one another. In this case, short circuits can be prevented and the electrical reliability of the back contact cell can be improved.

[0048] As a possible embodiment, it is provided that among all collector electrodes located at the edge regions at both ends of the target side along the second direction, the collector electrodes located at the outer sides are continuous collector electrodes and the remaining collector electrodes are discontinuous collector electrodes.

[0049] By applying the above-mentioned technical solution, in actual application, the part of the bus electrode segments facing the edge region of the target side along the second direction can extend to the collector electrodes having the opposite conductivity type to its own and located at the edge. At this time, the collector electrodes at the edge are set as continuous collector electrodes, which can increase the collection efficiency of the carriers of the collector electrodes at the edge under the premise of preventing short circuits and ensure that the recombination rate of the carriers in the edge region of the target side along the second direction is relatively low.

[0050] As a possible embodiment, the discontinuous collector electrodes comprise a plurality of collector electrode segments spaced apart from one another along the first direction. Furthermore, in the case where the width of at least one of the bus electrode segments gradually increases in a direction near the first welding and / or soldering section, the distances corresponding to different pairs of collector electrode segments of opposite conductivity type from the same bus electrode segment are different, each pair of collector electrode segments consisting of two adjacent collector electrode segments included in the same collector electrode array.

[0051] When applying the above-mentioned technical solution, in the case where the width of at least one of the bus electrode segments gradually increases in a direction near the first welding and / or soldering portion, the distances corresponding to different pairs of collector electrode segments with opposite conductivity type to the same bus electrode segment are different to prevent the corresponding pair of collector electrode segments with larger width corresponding to the same bus electrode segment from having a smaller distance, resulting in a higher risk of leakage, and at the same time, it can also be prevented that the corresponding pair of collector electrodes with smaller width corresponding to the same bus electrode segment from having a larger distance, resulting in poor collection ability of the charge carriers, which is advantageous to improve the working performance of back contact cell.

[0052] As a possible embodiment, it is provided that an end of at least one of the bus electrode segments facing an edge region of the target side along the second direction extends to a side of an edge region of the corresponding collector electrodes facing the edge region of the target side along the second direction, which side is electrically coupled to the bus electrode segments. In this case, it can be ensured that the bus electrode segments can be electrically coupled to the collector electrodes, which have the same conductivity type as the bus electrode segments themselves and are located on the outermost side of the edge region of the target side along the second direction, thereby ensuring that the charge carriers collected by the collector electrodes located on the outermost side of the edge region of the target side along the second direction can be led out.

[0053] As a possible embodiment, it is provided that an end of the bus electrode segments facing the first welding and / or soldering section is flush with an end of the first welding and / or soldering section facing the bus electrode segments. Alternatively, the end of the bus electrode segments facing the first welding and / or soldering section extends to a portion of a side of the first welding and / or soldering section facing away from the cell substrate.In this case, the end of the bus electrode segments facing the first welding and / or soldering section has the two arrangement solutions mentioned above, whereby the difficulty of manufacturing the bus electrode segments can be reduced, while at the same time ensuring that the bus electrode segments can be electrically coupled to the corresponding first welding and / or soldering section, and ensuring that the charge carriers collected by the bus electrode segments can be led out through the first welding and / or soldering section.

[0054] In a second aspect, the present application provides a photovoltaic module, wherein the photovoltaic module comprises the solar cells provided in the first aspect and various implementations thereof, as well as a welding and / or soldering connection element for connecting adjacent solar cells in series. The welding and / or soldering connection element is welded and / or soldered to the first welding and / or soldering section, and one end of the welding connection element protrudes beyond the first welding section.

[0055] As a possible embodiment, it is provided that the ratio of the length of the above-described welding and / or soldering connection element beyond the first welding and / or soldering section to the length of the bus electrode segment is greater than or equal to 5% and less than or equal to 20%.

[0056] By adopting the above-mentioned technical solution, the ratio of the length of the welding and / or soldering connecting member beyond the first welding and / or soldering portion to the length of the bus electrode segment is within the above range, whereby the contact area between the two ends of the welding and / or soldering connecting member along the second direction and the first welding and / or soldering portion can be prevented from being small due to the small ratio, thereby ensuring that the welding and / or soldering connecting member can come into contact with various areas on the surface on a side of the first welding and / or soldering portion facing away from the cell substrate, thereby resulting in a lower contact resistance between the two.Furthermore, the charge carriers collected by the collector electrodes between the first welding and / or soldering section and the edge of the cell substrate can be conducted to the welding and / or soldering connecting element via the bus electrode segments and the first welding and / or soldering section, so that the ratio is within the above-mentioned range. This also advantageously prevents the length of the part of the welding and / or soldering connecting element that does not need to be extended from being large due to the larger ratio, resulting in a larger amount of consumables. At the same time, it is helpful to prevent the connection stress between the welding and / or soldering connecting element and the bus electrode segments from becoming large due to the large ratio when the welding and / or soldering connecting element is in contact with the bus electrode segments, thereby improving the yield of the solar cell.

[0057] As a possible embodiment, it is provided that the lengths of the welding and / or soldering connection elements beyond the first welding and / or soldering section are less than or equal to 2 mm.

[0058] As a possible embodiment, it is provided that there is a contact or a gap between the welding and / or soldering connection element described above and the bus electrode segments.

[0059] The advantageous effects of the second aspect and its various implementations in the present application can be referred to the analysis of the advantageous effects of the first aspect and its various implementations, which will not be discussed in detail here. PRESENTATION OF THE REGISTRATION

[0060] The accompanying drawings described herein are intended to provide a deeper understanding of the present application and are incorporated herein by reference. The schematic embodiments of the present application and their description serve to illustrate the present application and do not unduly limit the present application. In the figures: Fig. 1 is a schematic diagram showing a distribution of the electrode structure of a solar cell with busbars in relevant technology; Fig. 2 is a schematic diagram showing a distribution of the electrode structure of a solar cell without a busbar in relevant art; Fig. 3 is a first schematic plan view of the structure on the light-facing side of the solar cell when the solar cell provided by embodiments of the present application is a back contact cell; Fig. 4 is a second schematic plan view of the structure on the non-light side of the solar cell when the solar cell provided by embodiments of the present application is a back contact cell; Fig. 5 is a first enlarged view of a partial structure on the side facing away from the light of the solar cell when the solar cell provided by embodiments of the present application is a back contact cell; Fig. 6 is a second enlarged view of a partial structure on the light-facing side of the solar cell when the solar cell provided by embodiments of the present application is a back contact cell; Fig. 7 is a third enlarged view of a partial structure on the side facing away from the light of the solar cell when the solar cell provided by embodiments of the present application is a back contact cell; Fig. 8 is a schematic diagram of the structure of a photovoltaic module formed by serially connecting solar cells provided by embodiments of the present application by means of welding and / or soldering connection elements.

[0061] List of reference symbols: 11 cell substrate, 12 collector electrodes, 13 bus electrode segments, 14 first welding and / or soldering section, 15 collector electrodes of the first type, 16 collector electrodes of the second type, 17 second welding and / or soldering section, 18 bus electrode segments of the first type, 19 bus electrode segments of the second type, 20 connecting electrode segment, 21 first end, 22 second end, 23 welding and / or soldering connecting element, 24 bus electrode, 25 edge bus electrode. CONCRETE EMBODIMENTS

[0062] In the following, embodiments of the present disclosure will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are only exemplary and are not intended to limit the scope of the present disclosure. Furthermore, descriptions of well-known structures and technologies are omitted from the following description to avoid unnecessary confusion of the concepts of the present disclosure.

[0063] The accompanying drawings illustrate various schematic structural representations according to embodiments of the present disclosure. These figures are not drawn to scale; some details are exaggerated and may be omitted for clarity. The shapes of the various regions and layers shown in the figures, as well as the relative sizes and positional relationships between them, are only exemplary and may actually vary due to manufacturing tolerances or technical limitations. Those skilled in the art may additionally design regions / layers with different shapes, sizes, and relative positions according to actual requirements.

[0064] In the context of the present disclosure, when a layer / element is considered to be "on top" of another layer / element, the layer / element may be directly on top of another layer / element, or there may be intervening layers / elements. Furthermore, when a layer / element is "on top" of another layer / element in one orientation, the layer / element may be "underneath" the other layer / element when reversed. In order to clarify the technical problems, technical solutions, and advantageous effects to be solved by the present application, the present application will be described in more detail below with reference to the drawings and embodiments.It is to be understood that the specific embodiments described herein are intended only to explain the present application, but not to limit the present application.

[0065] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply a relative importance or to implicitly specify the set of technical features specified. Thus, features defined as "first" and "second" may explicitly or implicitly include one or more of these features. Therefore, a feature preceded by the qualifier "first" or "second" may implicitly or explicitly include this feature one or more times. In the description of the present application, "several" means two or more unless expressly and specifically stated otherwise. "A number" means one or more than one unless expressly and specifically stated otherwise.

[0066] When describing the present application, it should be noted that the terms "assembly," "connection," and "connecting," unless expressly stated and limited otherwise, are to be understood in the broadest sense. For example, it may refer to a fixed connection, a detachable connection, or an integral connection; it may refer to a mechanical or electrical connection; it may refer to a direct connection or an indirect connection via an intermediate medium; it may refer to an internal communication between two elements or an interaction between the two elements. One of ordinary skill in the art can understand the specific meanings of the above terms in the present application according to specific situations.

[0067] Solar cells are currently being used on an increasingly large scale as a new energy alternative. Photovoltaic solar cells are devices that convert the sun's light energy into electrical energy. During their actual operation, solar cells utilize the photovoltaic principle to generate charge carriers, which are then extracted via electrodes, enabling efficient use of electrical energy.

[0068] In practical applications, solar cells can be divided into busbar solar cells and busless solar cells according to their different electrode structures. The electrode structure of the busbar solar cell includes multiple collector electrodes and at least one bus electrode. Different collector electrodes extend along the first direction and are spaced apart along the second direction. The bus electrode extends along the second direction and is electrically coupled to the collector electrodes of the same conductivity type as the bus electrode. As shown in Fig. 1, in the case where the busbar solar cell is a back-contact cell, the collector electrodes 12 are separated at the interface with the bus electrode 24 having a conductivity type opposite to their own to prevent leakage. Alternatively, the collector electrodes 12 may be insulated from the bus electrode 24 by providing an insulating material having a conductivity type opposite to their own. Based on this, in a busbar solar cell, the charge carriers collected by the collector electrodes 12 must pass through the bus electrode 24 before they can be collected at the welding and / or soldering portion, resulting in the transfer path of the charge carriers becoming longer and the transfer loss of the charge carriers passing through the bus electrode 24 increasing.Second, the bus electrode 24 increases the bonding area between the electrode structure and the cell substrate 11, resulting in a reduction in the open-circuit voltage of the solar cell. Furthermore, the formation of the bus electrode 24 requires the consumption of a large amount of electrode material, which is not conducive to reducing the manufacturing cost of the solar cell.

[0069] As in Fig. 2, the electrode structure of the busbarless solar cell does not include the above-mentioned bus electrode. Furthermore, the collector electrode 12 included in the busbarless solar cell has a widened electrode segment in a partial region along the first direction to be welded and / or soldered to the welding and / or soldering connecting member by the widened electrode segment. Based on this, although the metal bonding area between the electrode structure and the cell substrate 11 included in the busbarless cell is small, the welding and / or soldering contact area between the widened electrode segment and the welding and / or soldering band connecting member is also small, thereby achieving higher welding and / or soldering resistance and lower welding and / or soldering adhesion force.Second, in order to discharge all the charge carriers collected by all the collector electrodes 12, the welding and / or soldering joint must be welded and / or soldered together with the widened electrode segments of all the collector electrodes 12. Furthermore, after the photovoltaic module is formed by welding and / or soldering, the welding and / or soldering joint has a certain length, and the welding and / or soldering joint and the cell substrate 11 have different degrees of deformation after the heating and cooling of the welding and / or soldering, so the welding and / or soldering stress at the edge of the battery substrate 11 after welding and / or soldering is relatively large, and welding and / or soldering defects are likely to occur.In addition, the distance between the outer collector electrode 12 and the edge of the cell substrate 11 along the second direction is small, which may lead to separation of the edge collector electrode 12 during welding and / or soldering, and at the same time, the precision requirements for the strand welding and / or strand soldering machine are comparatively high, which makes the production of photovoltaic modules difficult.

[0070] To solve the above-mentioned technical problems, embodiments of the present application in the first aspect provide a solar cell. Specifically with regard to the distribution position of the electrodes, the solar cell provided by embodiments of the present application may be a double-sided contact cell, that is, one of the positive and negative electrodes of the solar cell is located on the light-facing side of the cell substrate 11 and the other is located on the light-facing side of the cell substrate 11. Alternatively, as in Fig. 3 to Fig. 6, the solar cell provided by embodiments of the present application may also be a back contact cell, i.e., the positive electrode and the negative electrode of the solar cell are both located on the side of the cell substrate 11 facing away from the light.

[0071] Furthermore, the solar cell provided by embodiments of the present application may be a solid solar cell from the division point of view; alternatively, as in Fig. 3 to Fig. As shown in Figure 6, the solar cell provided by embodiments of the present application may also be a split solar cell; the embodiments of the present application do not specifically limit the number of divisions of the above-mentioned split solar cell. For example, the above-mentioned split solar cell may be a half-split solar cell, a third-split solar cell, or a quarter-split solar cell.

[0072] As in Fig. 3 to Fig. 6, the solar cell provided by embodiments of the present application includes a cell substrate 11, collector electrodes 12, bus electrode segments 13, and a first welding and / or soldering portion 14. At least one of the light-facing side and the light-removing side of the cell substrate 11 is the target side. The collector electrodes 12 and the bus electrode segments 13 are arranged on a target side of the cell substrate 11. The collector electrodes 12 extend along the first direction, and different collector electrodes 12 located on the same target side are distributed at intervals from each other along the second direction. The first direction is different from the second direction. The bus electrode segments 13 are located at the edge regions of both ends of the target side along the second direction, and the bus electrode segments 13 extend along the second direction.The bus electrode segments 13 are electrically coupled to some of the collector electrodes 12 of the same conductivity type as the bus electrode segments. The first welding and / or soldering section 14 is arranged on a side of a corresponding bus electrode segment 13 facing away from an edge of the cell substrate 11 along the second direction and is electrically coupled to the corresponding bus electrode segment 13.

[0073] If the above technical solution is adopted, as in Fig. 3 to Fig. 6, the collector electrodes 12 and the bus electrode segments 13 included in the solar cell are arranged on the target side of the cell substrate 11. Furthermore, the bus electrode segments 13 are electrically coupled to some of the collector electrodes 12 of the same conductivity type as the bus electrode segments. At this time, when the solar cell is in the operating state, the charge carriers collected by the collector electrodes 12 located at the edge region of one end of the target side along the second direction can be brought together toward the bus electrode segments 13. Meanwhile, the first welding and / or soldering section 14 included in the solar cell is arranged on a side of the corresponding bus electrode segments 13 facing away from an edge of the cell substrate 11 along the second direction. Based on this, as shown in Fig. 3, Fig. 4 and Fig. 8, after the solar cells provided by embodiments of the present application have been connected in series by the welding and / or soldering connection element 23 to form a photovoltaic module, the welding and / or soldering connection element 23 only needs to be welded and / or soldered together with the first welding and / or soldering section 14 in order to collect the charge carriers collected by the collector electrode 12, which is located at the edge region at one end of the target side along the second direction, wherein the ends of the welding and / or soldering connection element 23 do not need to extend simultaneously to edge regions of the two ends of the cell substrate 11 along the second direction, therefore the effective welding and / or soldering length between the welding and / or soldering connection element 23 and the cell substrate 11 can be shortened, which contributes toto reduce the welding and / or soldering stress in the edge region of the cell substrate 11 along the second direction and thereby reduce the risk of a welding and / or soldering defect. At the same time, this can also reduce the welding and / or soldering accuracy requirements of the strand welding and / or soldering machine, which in turn reduces the manufacturing difficulties of the photovoltaic module. Secondly, this also prevents the ends of the welding and / or soldering connecting element 23 connecting two adjacent solar cells in the photovoltaic module from overlapping, which could result in a short circuit. Secondly, as shown in , Fig. 3 to Fig. 6, the bus electrode segments 13 are arranged at the edge regions at both ends of the target side along the second direction. In other words, the lengths of the bus electrode segments 13 included in the solar cell provided by embodiments of the present application are smaller than the length of the bus electrode included in the conventional busbar solar cell. Based on this, the collector electrodes 12 and the bus electrode segments 13 in the solar cell provided by embodiments of the present application have a smaller bonding area with the cell substrate 11 compared to the conventional busbar solar cell, which contributes to the solar cell having a higher open-circuit voltage, so that the material consumption in manufacturing the bus electrode segments 13 can also be reduced, which contributes to controlling the manufacturing cost of the solar cell.Furthermore, among all collector electrodes 12 on the same target side, the collector electrodes 12 electrically coupled to the bus electrode segments 13 are defined as first-type collector electrodes 15, and the remaining collector electrodes 12 are defined as second-type collector electrodes 16. Based on this, when the solar cells provided by embodiments of the present application are connected in series to form a photovoltaic module through the welding and / or soldering connection elements, the welding and / or soldering connection elements can be electrically coupled to the second-type collector electrodes 16 without the aid of a bus electrode.At this time, the transmission path of the charge carriers collected by the second type collector electrodes 16 to the welding and / or soldering connection element is shorter, which has a beneficial effect on reducing transmission losses and improving the working efficiency of the photovoltaic module formed by the solar cells provided by embodiments of the present application.

[0074] In the actual application process, the embodiments of the present application do not specifically limit the structure and material of the cell substrate, and do not specifically limit whether the light-facing side and the light-facing side of the cell substrate are the target side, which is determined according to the type of the solar cell and the actual application scenario, and no specific limitations are made here.

[0075] For example, if the solar cell provided by embodiments of the present application is a double-sided contact cell, the cell substrate may include a semiconductor base and a doped semiconductor layer formed on one side of the light-facing side or the light-facing side of the semiconductor base. The doped semiconductor layer has a conductivity type opposite to that of the semiconductor base. In the above case, only the light-facing side of the cell substrate may be the target side, or only the light-facing side of the cell substrate may be the target side, or both the light-facing side and the light-facing side of the cell substrate may be the target side.

[0076] Specifically, the material of the above semiconductor base can be semiconductor materials such as silicon, silicon germanium, germanium, or gallium arsenide. The conductivity type of the semiconductor base can be N-type or P-type. Regarding the doped semiconductor layer, if the conductivity type of the semiconductor base is N-type, the conductivity type of the doped semiconductor layer is P-type; if the conductivity type of the semiconductor base is P-type, the conductivity type of the doped semiconductor layer is N-type. Second, the material of the doped semiconductor layer can be semiconductor materials such as silicon, germanium, silicon carbide, or gallium arsenide. The doped semiconductor layer can be amorphous, microcrystalline, monocrystalline, nanocrystalline, polycrystalline, or the like in terms of the form of the internal arrangement of the substance.

[0077] For another example, if the solar cell provided by embodiments of the present application is a back-contact cell, the semiconductor substrate may comprise a semiconductor base and a doped semiconductor layer formed on or in a portion of the light-facing side of the semiconductor base. The doped semiconductor layer has a conductivity type opposite to that of the semiconductor base.In this case, in the actual process of manufacturing the semiconductor substrate, it is only necessary to form a doped semiconductor layer covering the entire non-light side of the semiconductor base, and remove a part of the doped semiconductor layer on the non-light side, so that two doping regions with opposite conductivity types can be formed on the non-light side, thereby solving the problem that the manufacturing process of solar cells is complicated by the need to perform two dopings with opposite conductivity types on the non-light side.

[0078] Specifically, when the semiconductor substrate comprises the above semiconductor base and a doped semiconductor layer formed on a portion of the light-remote side of the semiconductor base, the materials and conductivity types of the semiconductor base and the doped semiconductor layer may refer to the materials and conductivity types of the semiconductor base and the doped semiconductor layer included in the semiconductor substrate when the solar cell is a double-sided contact cell described above, which will not be discussed in detail here.

[0079] In some cases, the above semiconductor substrate may further include a passivation layer located between the semiconductor base and the doped semiconductor layer. The passivation layer may passivate at least the surface of the part where the semiconductor base contacts the doped semiconductor layer, thereby reducing the rate at which carriers recombine at the contact point between the two. Furthermore, the doped semiconductor layer formed on the passivation layer may achieve the selective collection of carriers of corresponding conductivity types in the semiconductor base, thus further improving the photoelectric conversion efficiency of the solar cell provided by embodiments of the present application. Specifically, the material of the passivation layer may be determined according to the material of the doped semiconductor layer.

[0080] For example, if the doped semiconductor layer is a doped amorphous silicon layer, a doped microcrystalline silicon layer, or a mixed layer of doped amorphous silicon and doped microcrystalline silicon, the passivation layer may be an intrinsic amorphous silicon layer, an intrinsic microcrystalline silicon layer, or a mixed layer of intrinsic amorphous silicon and intrinsic microcrystalline silicon. At this time, the doped semiconductor layer and the passivation layer may form a heterojunction structure.

[0081] If the doped semiconductor layer is still a doped polysilicon layer, for example, the passivation layer is a tunnel passivation layer. At this point, the doped semiconductor layer and the passivation layer can form a tunnel passivation contact structure. Furthermore, the material of the tunnel passivation layer can comprise any dielectric material that has a tunnel passivation effect. For example, the material of the tunnel passivation layer can comprise one or more of the following: silicon oxide, aluminum oxide, titanium oxide, hafnium dioxide, gallium oxide, tantalum pentoxide, niobium pentoxide, silicon nitride, silicon carbon nitride, aluminum nitride, titanium nitride, titanium carbon nitride, and the like.

[0082] In the above case, when the solar cell provided by embodiments of the present application is a back contact cell, only the light-facing side of the cell substrate is the target side, and the collector electrodes, the bus electrode segments and the first welding and / or soldering portion are located only on the light-facing side of the cell substrate.

[0083] For the above-mentioned collector electrodes, there are no particular restrictions on the morphology, quantity and distribution of the collector electrodes in the embodiments of the present application, which can be determined depending on the solar cell type and actual application scenario.

[0084] For example, if the solar cell provided by embodiments of the present application is a double-sided contact cell, different collector electrodes located on the same target side have the same conductivity type. Furthermore, the collector electrodes may be continuous collector electrodes or discontinuous collector electrodes.

[0085] As further, for example, in Fig. 3 to Fig. As shown in Figure 6, when the solar cell provided by embodiments of the present application is a back contact cell, among all the bus electrode segments 13 at the same end of the light-reverse side along the second direction, the two bus electrode segments 13 located on the outermost sides along the first direction are defined as the first-type bus electrode segments 18, and the remaining bus electrode segments 13 are defined as the second-type bus electrode segments 19. Based on this, the first-type collector electrodes 15 may be continuous collector electrodes, at which time the first-type collector electrodes 15 are spaced from the bus electrode segments 13 having a conductivity type opposite to their own by an insulating material to prevent a short circuit.

[0086] Alternatively, as in Fig. 3 to Fig. 6, at least some of the above first-type collector electrodes 15 may also be discontinuous collector electrodes; moreover, the first-type bus electrode segments 18 are located on the outside of the cell substrate-facing end of the corresponding collector electrodes 12 along the first direction, wherein the solar cell further comprises a connecting electrode segment 20, wherein the first-type bus electrode segments 18 are electrically coupled to the corresponding first welding and / or soldering section 14 via the connecting electrode segment 20.At this time, the discontinuous collector electrodes have a discontinuity for spacing them from the second-type bus electrode segments 19, which have a conductivity type opposite to the collector electrodes themselves, and the two ends of the discontinuous collector electrodes are spaced along the first direction from the first-type bus electrode segments 18, which have a conductivity type opposite to the discontinuous collector electrodes. In this case, the first-type bus electrode segments 18 are arranged on the outer side of the end of the corresponding collector electrodes 12 facing the cell substrate along the first direction, and the first-type bus electrode segments 18 are electrically coupled to the corresponding first welding and / or soldering section 14 via a connecting electrode segment 20.

[0087] At this time, the collector electrodes 12 located at the peripheral portion of the light-remote side along the second direction need not be electrically isolated from the first-type bus electrode segments 18 having a conductivity type opposite to its own by setting a discontinuity point, thereby ensuring that the carriers collected by each part of the collector electrodes 12 at the peripheral portion of the light-remote side along the second direction can be transferred to the corresponding bus electrode segment, thereby improving the collection efficiency of the carriers.

[0088] Specifically, the embodiments of the present application do not specifically limit the size of the discontinuity of the discontinuous collector electrodes and the morphology of the connecting electrode segment, as long as they can be applied to the solar cell provided by the embodiments of the present application. Each of the first-type collector electrodes may be a discontinuous collector electrode. Alternatively, among all the collector electrodes located at the edge regions at both ends of the target side along the second direction, the collector electrodes located at the outer sides are continuous collector electrodes, and the remaining collector electrodes are discontinuous collector electrodes.In this case, in actual application, the part of the bus electrode segments facing the edge region of the target side along the second direction can extend to the collector electrodes having the opposite conductivity type to its own and located at the edge. At this time, the collector electrodes at the edge are set as continuous collector electrodes, which can increase the collection efficiency of the carriers of the collector electrodes at the edge under the premise of preventing short circuits and ensure that the recombination rate of the carriers in the edge region of the target side along the second direction is relatively low.

[0089] As for the collector electrodes of the second type, as in Fig. 3 and Fig. 5, the collector electrodes of the second type 16 are continuous collector electrodes. At this time, the solar cell may additionally contain an insulating material (not shown in the figures). The insulating material is arranged on a part of the collector electrodes 12 not electrically coupled to the bus electrode segments 13 (i.e., the collector electrodes of the second type 16), which is located between two corresponding first welding and / or soldering sections 14 arranged opposite each other. Alternatively, as in Fig. 4 and Fig. 6, the second-type collector electrodes 16 may also be discontinuous collector electrodes; in other words, the collector electrodes 12 that are not electrically coupled to the bus electrode segments 13 are partially separated in a portion between two corresponding first welding and / or soldering portions 14 arranged opposite one another. In the above case, by inserting an insulating material or by separation, the welding and / or soldering connection element can be separated from the first-type collector electrodes 15 (collector electrodes 12 that are not electrically coupled to the bus electrode segments 13) having a conductivity type opposite to its own to prevent a short circuit.

[0090] The type and size of the insulation materials mentioned above can be determined depending on the actual application scenario and are not specifically limited here. The insulation material could be, for example, insulating adhesive or similar.

[0091] For example, the length of the insulating material along the first direction may be greater than or equal to 1 mm and less than or equal to 5 mm. For example, the length of the insulating material may be 1 mm, 2 mm, 3 mm, 4 mm, or 5 mm. In this case, the length of the insulating material along the first direction may be within the above range, which can prevent the welding and / or soldering connection element from being difficultly insulated by the insulating material from the collector electrodes having a conductivity type opposite to its own due to the short length of the insulating material, thus preventing a short circuit. Furthermore, a long length of the insulating material, which would result in a larger consumption of consumables corresponding to the insulating material, can also be avoided, thereby keeping the manufacturing cost of the solar cell under control.

[0092] For example, the width of the insulating material along the second direction may be greater than or equal to 1 mm and less than or equal to 10 mm. For example, the width of the insulating material may be 1 mm, 2 mm, 4 mm, 6 mm, 8 mm, or 10 mm, or the like. In this case, the width of the insulating material along the second direction is within the above-mentioned range, which can prevent the insulating material from being unable to completely cover the corresponding part of the first-type collector electrodes due to the narrow width of the insulating material, which makes it difficult to separate the welding and / or soldering connection element from the collector electrodes with a conductivity type opposite to its own by the insulating material to prevent a short circuit.In addition, due to the large width of the insulating material, it can also be prevented that the insulating material covers a portion of the collector electrodes (or the second welding and / or soldering portion) adjacent to it, resulting in the contact area between the collector electrodes (or the second welding and / or soldering portion) and the welding and / or soldering connecting elements being small.

[0093] Furthermore, the above second-type collector electrodes may have a widened electrode segment for welding and / or soldering to the welding and / or soldering band connecting element by means of the widened electrode segment. Along the second direction, the widened electrode segment of the above second-type collector electrodes is arranged between two opposite first welding and / or soldering sections of the same conductivity type as the second-type collector electrodes.

[0094] Alternatively, the above solar cell, as shown in Fig. 3 to Fig. 6, further comprises a second welding and / or soldering section 17. The second welding and / or soldering section 17 is electrically coupled to the corresponding collector electrodes of the second type 16, wherein the second welding and / or soldering section 17 is located between two first welding and / or soldering sections 14 which have the same conductivity type as itself and are arranged opposite one another. The second welding and / or soldering section 17 is electrically connected to at least one collector electrode of the second type 16. In this case, the second welding and / or soldering section 17 contained in the solar cell is electrically coupled to the corresponding collector electrodes of the second type 16, and the second welding and / or soldering section 17 is assigned to at least one collector electrode of the second type 16.At this time, when the solar cells provided by embodiments of the present application are connected in series via the welding and / or soldering connection elements to form a photovoltaic module, the welding and / or soldering connection elements can be welded and / or soldered together with the second type collector electrodes 16 via the second welding and / or soldering section 17.Compared to the method in which the part of the second-type collector electrode 16 located in the extension direction of the first welding and / or soldering portion 14 of the same conductivity type as the collector electrodes themselves along the second direction is arranged as a widened micro-electrode segment and realizes an electrical connection with the welding and / or soldering connection element, the contact area between the second welding and / or soldering portion 17 and the welding and / or soldering connection element is larger, which contributes to reducing the welding and / or soldering resistance between the welding and / or soldering connection element and the second-type collector electrodes 16 and improving the welding and / or soldering adhesion force between the welding and / or soldering connection element and the second-type collector electrodes 16.

[0095] Specifically, the embodiments of the present application do not specifically limit the size and morphology of the second welding and / or soldering portion as long as it can be applied to the solar cell provided by embodiments of the present application.

[0096] For example, the length of the second welding and / or soldering section along the first direction can be greater than or equal to 100 µm and less than or equal to 10,000 µm. For example, the length of the second welding and / or soldering section can be 100 µm, 500 µm, 1,000 µm, 3,000 µm, 6,000 µm, 9,000 µm, or 10,000 µm. In this case, the width of the second welding and / or soldering portion along the first direction is within the above range, which can prevent the need to strictly control the position of the welding and / or soldering connecting element on the solar cell during the welding and / or soldering process due to the narrow width of the second welding and / or soldering portion, thereby preventing the welding and / or soldering connecting element from being displaced and thereby not being welded and / or soldered to the second welding and / or soldering portion as required, thereby improving the welding and / or soldering yield.Furthermore, due to the larger width of the second welding and / or soldering portion, the second welding and / or soldering portion can also be prevented from having a larger bonding area with the cell substrate and a larger amount of consumables being used in the manufacture of the second welding and / or soldering portion, thereby ensuring that the solar cell has a higher working efficiency and reducing the manufacturing cost of the solar cell.

[0097] For example, the width of the above second welding and / or soldering section along the second direction may be greater than or equal to 100 µm and less than 500 µm. For example, the width of the second welding and / or soldering section may be 100 µm, 200 µm, 300 µm, 400 µm, or 500 µm, or the like.In this case, the length of the second welding and / or soldering portion along the second direction is within the above range, whereby the contact area between the second welding and / or soldering portion and the welding and / or soldering connecting member can be prevented from being limited due to the short length of the second welding and / or soldering portion, which contributes to reducing the welding and / or soldering resistance between the second welding and / or soldering portion and the welding and / or soldering connecting member and contributes to improving the welding and / or soldering adhesion force between the second welding and / or soldering portion and the welding and / or soldering connecting member, thereby reducing transmission losses and meanwhile improving the structural reliability of the photovoltaic module formed from the solar cells provided by embodiments of the present application.Furthermore, due to the increased length of the second welding and / or soldering section, it is also possible to prevent the second welding and / or soldering section from having a larger bonding area with the cell substrate and to use a larger amount of consumables in the manufacture of the second welding and / or soldering section, thereby ensuring that the solar cell has higher working efficiency and reducing the manufacturing cost of the solar cell. Furthermore, as shown in [figure omitted]. Fig. 3 to Fig. 6, when the solar cell provided by embodiments of the present application is a back contact cell, along the second direction, the width of the second welding and / or soldering portion 17 is within the above range, which can also prevent the width of the second welding and / or soldering portion 17 from being so large that the end of the second welding and / or soldering portion 17 overlaps with the adjacent collector electrodes 12 of the opposite conductivity type, resulting in a short circuit, thereby ensuring high electrical reliability of the solar cell.

[0098] As mentioned above, when the solar cell provided by embodiments of the present application additionally comprises an insulating material disposed on the second-type collector electrodes, the length of the insulating material along the first direction may be equal to the length of the second welding and / or soldering portion. Alternatively, the length of the insulating material may be greater than the length of the second welding and / or soldering portion; in this case, the placement position of the welding and / or soldering connection element on the solar cell can be prevented from being offset, causing the welding and / or soldering connection element to overlap the collector electrodes having a conductivity type opposite to its own, thereby preventing a short circuit.

[0099] Specifically, when the length of the insulating material is greater than the length of the second welding and / or brazing section, the difference between the length of the insulating material and the length of the second welding and / or brazing section can be determined according to the accuracy of the strand welding and / or strand brazing machine that can form the photovoltaic module and the actual application scenario, and no specific restrictions are made here.

[0100] Furthermore, in some cases, the solar cell also comprises a second conductive material arranged on the second welding and / or soldering section. In this case, in the process of connecting the solar cells provided by embodiments of the present application in series to form a photovoltaic module, the welding and / or soldering connection element can be welded and / or soldered together with the second welding and / or soldering section through the second conductive material to ensure that the welding and / or soldering connection element and the second welding and / or soldering section have good welding and / or soldering quality. Specifically, the second conductive material can be conductive adhesive, tin, silver, or another conductive material.

[0101] Regarding the distribution of the various second welding and / or brazing sections, as shown in Fig. 3 to Fig. 6, at least some of the second welding and / or soldering sections 17 may be arranged parallel along the second direction. Alternatively, various second welding and / or soldering sections may also be distributed alternately along the second direction.When at least some of the second welding and / or soldering portions 17 can be arranged in parallel along the second direction, it is advantageous to arrange the second welding and / or soldering portions 17 regularly distributed in the second direction, which prevents the high requirement for the adjustment accuracy of the welding and / or soldering connecting member contacting various second welding and / or soldering portions 17 by the automatic strand welding and / or strand soldering machine from occurring due to the disorderly distribution of the various second welding and / or soldering portions 17, and thus contributes to reducing the difficulty in connecting adjacent solar cells by the welding and / or soldering connecting member.

[0102] Secondly, as in Fig. 3 to Fig. 6, a center line of at least some of the second welding and / or soldering sections 17 along the second direction may be collinear with a center line of at least one bus electrode segment 13 along the second direction. Alternatively, the center line of at least some of the second welding and / or soldering sections along the second direction may not be collinear with a center line of at least one bus electrode segment along the second direction, but the center line of at least some of the second welding and / or soldering sections along the second direction may be substantially parallel to the center line of at least one bus electrode segment 13 along the second direction. Alternatively,that the center line of at least some of the second welding and / or soldering sections along the second direction is arranged obliquely to a center line of at least one bus electrode segment along the second direction. If a center line of at least some of the second welding and / or soldering sections 17 along the second direction is collinear with a center line of at least one bus electrode segment 13 along the second direction, the center line of at least some of the second welding and / or soldering sections 17 is located on the same extension line as the center line of at least one bus electrode segment 13 along the second direction, thereby preventing the center lines of the two from being offset along the second direction and thereby improving the adjustment accuracy of the welding and / or soldering connection element,which contacts the second welding and / or soldering section 17 and the first welding and / or soldering section 14, which is electrically coupled to the bus electrode segment 13, by the automatic strand welding and / or soldering machine, is high, thereby reducing the difficulty of connecting adjacent solar cells to each other by the welding and / or soldering connecting element.

[0103] In addition, as in Fig. 3 to 6, at least some of the second welding and / or soldering sections 17 are arranged in parallel along the second direction, and wherein a gap exists along the second direction between one second welding and / or soldering section 17 and another adjacent second welding and / or soldering section 17. In this case, at least one of the collector electrodes 12 is interrupted at the gap, or at least one of the collector electrodes 12 extends continuously through the gap.In this case, after the adjacent solar cells are connected to each other by the welding and / or soldering joining member, the welding and / or soldering joining member can be electrically insulated by the distance of the collector electrodes 12 by which they are interrupted at the gap and the collector electrodes 12 having a conductivity type opposite to their own, and it is not necessary to use insulating materials such as insulating adhesive or the like, which contributes to reducing the cost of connecting solar cells and also to reducing the labor for attaching insulating material to the gap.The size of the gap between the second welding and / or soldering portion 17 and another adjacent second welding and / or soldering portion 17 can be determined according to the distance between adjacent collector electrodes 12 and the size of the second welding and / or soldering portion 17, with no specific limitations imposed here. Furthermore, the distance by which at least one of the collector electrodes 12 is separated at the gap can be determined according to the actual application scenario, as long as it can be applied to the solar cell provided by embodiments of the present application.

[0104] For the above-mentioned bus electrode segments, the embodiments of the present application do not specifically limit the morphology of the bus electrode segments and the number of the bus electrode segments, as long as the charge carriers collected by the collector electrodes at the two end edges of the target side along the second direction can be transferred to the first welding and / or soldering section via the bus electrode segments,

[0105] For example, the width of at least one of the bus electrode segments along the first direction may be less than or equal to 500 µm. For example, the width of at least one of the bus electrode segments may be 10 µm, 50 µm, 100 µm, 200 µm, 300 µm, 400 µm, 500 µm, or the like. In this case, the width of at least one of the bus electrode segments along the first direction is within the above range, which can prevent the bus electrode segments from having a larger width, thereby resulting in a larger metal bonding area between the bus electrode segments and the cell substrate, and thus ensuring a higher open-circuit voltage of the solar cell. At the same time, the amount of consumables in the production of the bus electrode segments can also be reduced.Second, when the solar cell provided by embodiments of the present application is a back contact cell, the width of at least one of the bus electrode segments is within the above-mentioned range, which can also prevent the amount of consumables of insulating material arranged at the interface of the collector electrodes and the bus electrode segments having a conductivity type opposite to their own at the edge regions of both ends of the target side along the second direction from being relatively large due to the large width of the bus electrode segments.Or it will prevent the collector electrodes at the edge regions of both ends of the target side along the second direction from being separated by a large distance at the interfaces with the bus electrode segments having a conductivity type opposite to their own, and ensure that the collection efficiency of the charge carriers at the edge regions at both ends of the target side along the second direction is high.

[0106] Specifically, the widths of different parts of the above bus electrode segments along the second direction can be the same or different. The width ratio of different parts of the bus electrode segments along the second direction can be determined according to the shape requirements of the bus electrode segments in actual application scenarios.

[0107] For example, the widths of the above bus electrode segments gradually increase along the direction of the first welding and / or soldering section. In this case, it is advantageous to increase the contact area between the bus electrode segments and the first welding and / or soldering section, thereby reducing transmission loss. At the same time, the connection stability between the bus electrode segments and the first welding and / or soldering section can be improved, thereby increasing the reliability of the solar cell structure. Specifically, the widths of the bus electrode segments can increase linearly or parabolically in a direction of the first welding and / or soldering section.

[0108] In the case where the solar cell provided by embodiments of the present application is a back-contact cell, at least some of the collector electrodes located at the edge regions at both ends of the target side along the second direction are discontinuous collector electrodes, as mentioned above. The discontinuous collector electrodes comprise a plurality of collector electrode segments distributed at intervals from one another along the first direction.Furthermore, in the case where the width of at least one of the bus electrode segments gradually increases in a direction of the first welding and / or soldering portion, the distances corresponding to different pairs of collector electrode segments of opposite conductivity type to the same bus electrode segment may be the same or different, and each pair of collector electrode segments consists of two adjacent collector electrode segments included in the same collector electrode.When the respective pitches of the corresponding pairs of collector electrode segments with opposite conductivity types to the same bus electrode segment are different, it can prevent the corresponding pair of collector electrode segments with larger width corresponding to the same bus electrode segment from having a smaller pitch, resulting in a higher risk of leakage, and at the same time, it can also prevent the corresponding pair of collector electrodes with smaller width corresponding to the same bus electrode segment from having a larger pitch, resulting in poor carrier collection ability, which is beneficial to improve the working performance of back contact cell.

[0109] Specifically, when the width of at least one of the bus electrode segments gradually increases in a direction of the first welding and / or soldering portion, the distances corresponding to different pairs of collector electrode segments of opposite conductivity type from the same bus electrode segment can be determined according to the width of the different regions of the bus electrode segment and the leakage protection requirements in actual application scenarios, with no specific limitations being imposed here.

[0110] Regarding the specific shape of the bus electrode segments, the cross-sectional shape of the bus electrode segment may be, for example, a rectangle, a trapezoid, an ellipse, a rhombus, or the like.

[0111] Furthermore, it can be seen that within a certain range, the longer the bus electrode segments, the greater the number of electrical couplings between the bus electrode segments and the collector electrodes. The greater the distance between the respective ends of the welding and / or soldering connection element connecting different solar cells in series and the edge region of one end of the cell substrate along the second direction, the lower the welding and / or soldering voltage. However, as the lengths of the bus electrode segments are longer, the bonding area of ​​the bus electrode segments and the cell substrate is larger, and the corresponding amount of consumables is larger. Meanwhile, the loss of charge carriers collected by the collector electrodes located at the edge region of the target side along the second direction and transferred to the welding and / or soldering connection element is greater.On this basis, the lengths of the bus electrode segments and the ratio between the lengths of the bus electrode segments and the width of the cell substrate can be determined according to the requirements of the above-mentioned welding and / or soldering voltage, the bonding area and the transmission loss in the actual application scenario and the like.

[0112] For example, the length of at least one of the bus electrode segments along the second direction can be less than or equal to 10 mm. For example, the length of at least one of the bus electrode segments along the second direction can be greater than or equal to 1 mm and less than or equal to 7 mm. For example, the length of at least one bus electrode segment can be 1 mm, 2 mm, 4 mm, 6 mm, 8 mm, or 10 mm.In this case, the length of at least one of the bus electrode segments is within the above range, which can prevent a larger metal bonding area between the bus electrode segment and the cell substrate due to the long length of the bus electrode segment, and thus ensure a higher open-circuit voltage of the solar cell; meanwhile, it also ensures that the amount of consumables used in the manufacture of the bus electrode segments can be reduced, and the loss of charge carriers collected by the collector electrodes and transferred to the welding and / or soldering connection element can be reduced.

[0113] For example, along the second direction, a ratio between the length of at least one of the bus electrode segments and the width of the cell substrate may be less than or equal to 12%. For example, the ratio between the length of at least one bus electrode segment and the width of the cell substrate may be 4.5%, 5%, 7%, 9%, 10%, 12%, or the like. The advantageous effects in this case can be analyzed with reference to the above-described advantageous effects of at least one of the bus electrode segments having a length of less than or equal to 10 mm and will not be described in detail here.

[0114] Specifically, the lengths of the multiple bus electrode segments may be equal, or the lengths of the multiple bus electrode segments may be unequal. When the lengths of the multiple bus electrode segments are equal, this helps simplify the pattern complexity of the electrode structure of the solar cell and reduces the manufacturing difficulty of the electrode structure. Furthermore, the collector electrodes of opposite conductivity types are alternately spaced along the second direction. At this time, along the second direction, the two collector electrodes of opposite conductivity types and near the edge of the cell substrate have different distances from the edge of the cell substrate. Based on this, when the lengths of the multiple bus electrode segments are not equal, the length of each bus electrode segment can be adjusted according to the conductivity type of the bus electrode segment.This ensures that the bus electrode segment can carry out the charge carriers collected by the corresponding collector electrodes, which helps reduce the distance between the end of the bus electrode segment facing the edge of the cell substrate and the collector electrodes with the same conductivity type as the bus electrode segment itself, thereby reducing the risk of leakage. Furthermore, the metal bond loss between the bus electrode segment and the cell substrate can be reduced.

[0115] Furthermore, the distances between the ends of adjacent bus electrode segments with opposite conductivity types facing the edge of the cell substrate and the edge of the cell substrate can be unequal or equal. The advantageous effects when the distances between the ends of adjacent bus electrode segments with opposite conductivity types facing the edge of the cell substrate and the edge of the cell substrate are unequal can be seen from the analysis of the advantageous effects when the lengths of the multiple bus electrode segments are unequal, as described above, which will not be repeated here.

[0116] The end of at least one of the bus electrode segments facing an edge region of the target side along the second direction may be in contact with the corresponding collector electrodes, which are electrically coupled to the bus electrode segment. Alternatively, an end of at least one of the bus electrode segments facing an edge region of the target side along the second direction may also extend to a side of an edge region of a corresponding collector electrode, which is electrically coupled to the bus electrode segment, facing the edge region of the target side along the second direction.In this case, it can be ensured that the bus electrode segment can be electrically coupled to the collector electrodes having the same conductivity type as the bus electrode segment itself and located on the outermost side of the edge region of the target side along the second direction, thereby ensuring that the charge carriers collected by the collector electrodes located on the outermost side of the edge region of the target side along the second direction can be led out.

[0117] As for the end of the bus electrode segment facing the first welding and / or soldering section, the end of the bus electrode segment facing the first welding and / or soldering section can be flush with an end of the first welding and / or soldering section facing the bus electrode segment. Alternatively, the end of the bus electrode segment facing the first welding and / or soldering section can also extend to a portion of a side of the first welding and / or soldering section facing away from the cell substrate.In this case, the end of the bus electrode segment facing the first welding and / or soldering section has the two arrangement solutions mentioned above, whereby the difficulty of manufacturing the bus electrode segment can be reduced, while at the same time ensuring that the bus electrode segment can be electrically coupled to the corresponding first welding and / or soldering section, and ensuring that the charge carriers collected by the bus electrode segment can be led out through the first welding and / or soldering section.

[0118] Specifically, the distance by which an end of at least one of the bus electrode segments facing an edge region of the target side along the second direction extends to a side of an edge region of the corresponding collector electrodes electrically coupled to the bus electrode segment facing the edge region of the target side along the second direction, and the length by which the end of the bus electrode segment facing the first welding and / or soldering section extends to a portion of a side of the first welding and / or soldering section facing away from the cell substrate can be determined according to actual manufacturing accuracy and actual needs, with no specific limitations being imposed here.

[0119] For example, the distance by which the end of at least one of the bus electrode segments located at the edge of the cell substrate protrudes from the collector electrodes located at the edge of the cell substrate and electrically coupled to the bus electrode segment may be greater than 0 and less than 0.12 mm. For example, the distance by which the end of at least one of the bus electrode segments located at the edge of the cell substrate protrudes from the collector electrodes located at the edge of the cell substrate and electrically coupled to the bus electrode segment may be 0.02 mm, 0.04 mm, 0.06 mm, 0.08 mm, 0.1 mm, 0.11 mm, or the like.In the above case, it is possible to prevent the distance from being too large, which results in the end of at least one of the bus electrode segments facing an edge region of the target side along the second direction being close to the lower end of the cell base, which results in a risk of overlap and short circuit of the bus electrode segments when two adjacent solar cells are connected in series; moreover, it is possible to prevent the distance between the end of the bus electrode segment facing the edge region of the target side along the second direction and the collector electrodes having a conductivity type opposite to its own, which is located on the outermost side of the edge region of the target side along the second direction, from being small due to the large distance, which results in a high risk of current leakage, thereby ensuring higher electrical reliability of the back contact cell.

[0120] In addition, the length of the bus electrode segments also affects the number of collector electrodes located at the edge region of one end of the target side along the second direction. Based on this, the number of collector electrodes located at the edge region of one end of the target side along the second direction and the ratio between the number of collector electrodes located at the edge region of one end of the target side along the second direction and the total number of all collector electrodes located on the target side can be determined based on the length of the bus electrode segments, the distance between the collector electrodes, and the width of the collector electrodes.

[0121] For example, the ratio of the number of collector electrodes arranged at the edge region of one end of the target side along the second direction to the total number of all collector electrodes arranged on the target side may be less than or equal to 12%. For example, the ratio of the number of collector electrodes arranged at the edge region of one end of the target side along the second direction to the total number of all collector electrodes arranged on the target side may be 4.5%, 5%, 7%, 9%, 10%, 12%, or the like. The advantageous effects in this case can be analyzed by referring to the advantageous effects of the number of bus electrode segments at the same end on the same target side along the second direction being less than or equal to 30, as described above, which will not be discussed in detail here.

[0122] For the number of bus electrode segments, the number of bus electrode segments affects the length of the transfer path of the charge carriers in the corresponding area of ​​the collector electrodes and the bonding area of ​​the bus electrode segments and the cell substrate, so the number of bus electrode segments can be determined based on the requirements of transmission loss and bonding area in actual application scenarios.

[0123] For example, the number of bus electrode segments located on the same side of the same target side along the second direction may be greater than or equal to 6 and less than or equal to 30. For example, the number of bus electrode segments on the same side of the same target side along the second direction may be 6, 8, 10, 15, 20, 25, or 30, or the like.In this case, the number of bus electrode segments at the same end of the same target side along the second direction is within the above-mentioned range, which can prevent the charge carriers from having to travel a longer distance on the collector electrodes before they can be collected at the bus electrode segments due to the above-mentioned small number, which contributes to reducing transmission losses and also contributes to reducing the risk that corresponding charge carriers cannot be transported to the bus electrode segments after the collector electrodes break. Furthermore, the above-mentioned large number can also prevent a large bonding area between all the bus electrode segments located at the edge regions at both ends of the target side along the second direction and the cell substrate, and a large amount of consumables for at least all the bus electrode segments.

[0124] Regarding the distribution of the bus electrode segments, as shown in Fig. 3 to Fig. 6, different bus electrode segments 13 at the same end of the same target side along the second direction are spaced from each other along the first direction, and wherein the solar cell comprises two bus electrode segments 13 arranged opposite each other at different ends of the same target side along the second direction. Furthermore, the two opposite bus electrode segments 13 are not connected to each other. In this case, the distribution of the different bus electrode segments 13 on the target side is made more regular, which contributes to reducing the difficulty of connecting adjacent solar cells to each other.At the same time, the two opposing bus electrode segments 13 are not connected to each other, which ensures that the total length of the two bus electrode segments 13 opposing each other along the second direction is shorter than the length of the entire bus electrode included in the conventional solar cell, thereby ensuring that the metal bond loss between the bus electrode segments 13 and the cell substrate 11 is reduced and the amount of consumables used in the manufacture of the bus electrode segments 13 is reduced. At the same time, it is also helpful to ensure that the charge carriers collected by the collector electrodes 12 arranged between the two opposing bus electrode segments 13 have lower transmission losses.

[0125] In one example, the solar cell described above may further include a voltage test point, and the voltage test point is arranged on the bus electrode segments. In this case, the widths of the bus electrode segments are relatively large, and therefore, setting a voltage test point on the bus electrode segments can reduce the difficulty of contacting the corresponding electrode with the test probe, thereby ensuring the accuracy of the test result. At the same time, if the solar cell is a back-contact cell, this also helps prevent the occurrence of short-circuit problems. Specifically, the specific position of the voltage test point on the bus electrode segments can be determined according to actual requirements. For example, the voltage test point can be provided at the intersection of the bus electrode segments and the collector electrodes.

[0126] In one example, the solar cell mentioned above, as in Fig. 4, further comprise an edge bus electrode 25, wherein the edge bus electrode 25 is arranged at one end of the cell substrate 11 along the first direction and extends along the second direction. Furthermore, the maximum width of the edge bus electrode 25 is smaller than the maximum width of the bus electrode segments 13.In this case, the presence of the edge bus electrode 25 is conducive to the extraction of the charge carriers collected from the edge portion of the collector electrodes 12 along the first direction and prevents the edge portion of the collector electrodes 12 along the first direction from being broken, so that the charge carriers cannot be discharged; alternatively, since the collector electrodes 12 are separated at the interface with the welding and / or soldering connection element with a conductivity type opposite to their own, the problem that the charge carriers collected from the edge portion of the collector electrodes 12 along the first direction cannot be discharged or are difficult to discharge is prevented, thereby reducing the power loss of solar cells.Furthermore, the maximum width of the edge bus electrode 25 is smaller than the maximum width of the bus electrode segments 13, which is advantageous for reducing the metal bond loss between the edge bus electrode 25 and the cell substrate 11, and reducing the difficulty and amount of consumables used in manufacturing the edge bus electrode 25 at the edge region of the cell substrate 11 along the first direction.

[0127] Specifically, the width of the edge bus electrode can be determined according to the actual application scenario, with no specific restrictions imposed here. If the edge bus electrode is electrically coupled to the collector electrodes, which are at least partially of the same conductivity type as the edge bus electrode itself, the ends of the collector electrodes electrically coupled to the edge bus electrode can just touch the edge bus electrode along the first direction. Alternatively, the ends of the collector electrodes electrically coupled to the edge bus electrode can also protrude beyond the edge bus electrode along the first direction.In this case, it is ensured that the edge portion of the collector electrodes along the first direction can be electrically coupled to the edge bus electrode, thereby ensuring that the charge carriers collected by the edge portion of the collector electrodes along the first direction can be discharged through the edge bus electrode.

[0128] For the first welding and / or soldering section, at least one first welding and / or soldering section and the bus electrode segments electrically coupled to the first welding and / or soldering section may be a non-integrated structure. Alternatively, at least one first welding and / or soldering section and the bus electrode segments electrically coupled to the first welding and / or soldering section may be an integral structure. The above at least one first welding and / or soldering section and the bus electrode segments electrically coupled to it are an integrated structure, which means that the at least one first welding and / or soldering section and the bus electrode segments electrically coupled to it are made of the same material and are manufactured at the same time.Based on this, when at least one first welding and / or soldering section and the bus electrode segments electrically coupled to the first welding and / or soldering section are an integral structure, there are no pores at the junction between the at least one first welding and / or soldering section and the bus electrode segments electrically coupled to the first welding and / or soldering section, which contributes to improving the contact performance between the first welding and / or soldering section and the bus electrode segments electrically coupled to itself and reducing transmission losses.

[0129] The size of the first welding and / or soldering portion may be determined according to the requirements of welding and / or soldering resistance and welding and / or soldering adhesion force between the welding and / or soldering connecting element and the first welding and / or soldering portion, as well as the bonding area of ​​the first welding and / or soldering portion and the cell substrate in actual application scenarios.

[0130] For example, the length of the first welding and / or soldering section along the first direction may be greater than or equal to 100 µm and less than or equal to 10,000 µm. For example, the length of the first welding and / or soldering section may be 100 µm, 500 µm, 1,000 µm, 3,000 µm, 6,000 µm, 9,000 µm, or 10,000 µm. In this case, the length of the first welding and / or soldering portion along the first direction is within the above range, which can prevent the position of the welding and / or soldering connecting element on the solar cell from having to be strictly controlled during the welding and / or soldering process due to the short length of the first welding and / or soldering portion, thereby preventing the welding and / or soldering connecting element from being displaced and thereby not being welded and / or soldered to the first welding and / or soldering portion as required, thereby improving the welding and / or soldering yield.In addition, due to the increased length of the first welding and / or soldering portion, the first welding and / or soldering portion can also be prevented from having a larger bonding area with the cell substrate and a larger amount of consumables being used in the manufacture of the first welding and / or soldering portion, thereby ensuring that the solar cell has a higher working efficiency and reducing the manufacturing cost of the solar cell.

[0131] For example, the width of the first welding and / or soldering section along the second direction may be greater than or equal to 100µm and less than or equal to 10000µm.

[0132] For example, the width of the first welding and / or soldering section may be 100µm, 1000µm, 3000µm, 6000µm, 9000µm or 10000µm or the like.In this case, the width of the first welding and / or soldering portion along the second direction is within the above range, whereby the contact area between the first welding and / or soldering portion and the welding and / or soldering joining member can be prevented from being limited due to the narrow width of the first welding and / or soldering portion, which contributes to reducing the welding and / or soldering resistance between the first welding and / or soldering portion and the welding and / or soldering joining member and contributes to improving the welding and / or soldering adhesion force between the first welding and / or soldering portion and the welding and / or soldering joining member, thereby reducing transmission losses and meanwhile improving the structural reliability of the photovoltaic module formed from the solar cells provided by embodiments of the present application.In addition, due to the larger width of the first welding and / or soldering portion, the first welding and / or soldering portion can also be prevented from having a larger bonding area with the cell substrate and a larger amount of consumables being used in the manufacture of the first welding and / or soldering portion, thereby ensuring that the solar cell has a higher working efficiency and reducing the manufacturing cost of the solar cell.

[0133] Specifically, the width of the above first welding and / or brazing section may be equal to the width of the second welding and / or brazing section. Alternatively, as shown in Fig. 3 to Fig. 6, the width of the first welding and / or soldering portion 14 may be greater than the width of the second welding and / or soldering portion 17. In this case, the contact area between the first welding and / or soldering portion 14 and the welding and / or soldering connection element can be increased, which has a beneficial effect on reducing the welding and / or soldering resistance between the first welding and / or soldering portion 14 and the welding and / or soldering connection element and improving the welding and / or soldering adhesion force between the first welding and / or soldering portion 14 and the welding and / or soldering connection element. Furthermore, this can also prevent the width of the second welding and / or soldering portion 17 from becoming too large, which would result in a larger bonding area between the second welding and / or soldering portion 17 and the cell substrate 11, thereby ensuring that the solar cell has higher operational reliability.

[0134] Specifically, when the width of the first welding and / or brazing section is larger than the width of the second welding and / or brazing section, the difference between the two can be determined according to the actual application scenario, and no specific restrictions are made here.

[0135] In addition, as in Fig. 3 to Fig. 6, the length of the above first welding and / or soldering portion 14 may be equal to the length of the second welding and / or soldering portion 17. Of course, the length of the first welding and / or soldering portion 14 and the length of the second welding and / or soldering portion 17 do not need to be the same. The length of the first welding and / or soldering portion 14 and the length of the second welding and / or soldering portion 17 affect the effective contact size between them and the welding and / or soldering connection element along the first direction. Furthermore, in the actual manufacturing process, deviations in the placement position of the welding and / or soldering connection element on the solar cell may occur due to equipment accuracy issues.Therefore, when the length of the first welding and / or soldering section 14 is equal to the length of the second welding and / or soldering section 17 along the first direction, it is advantageous to make the effective contact dimensions of the first welding and / or soldering section 14 and the second welding and / or soldering section 17 with the welding and / or soldering connection element substantially equal along the first direction, thereby ensuring that the welding and / or soldering connection element has good contact with the first welding and / or soldering section 14 and the second welding and / or soldering section 17.

[0136] Regarding the relative positional relationship, as in the Fig. 3 to 6, the side of the above first welding and / or soldering section 14 facing away from the bus electrode segments 13 is not connected to the collector electrodes 12, which is adjacent to the first welding and / or soldering section in the second direction and has the same conductivity type.In this case, it is advantageous to reduce the number of collector electrodes 12 that are electrically coupled to the first welding and / or soldering section 14 so that the charge carriers collected by the collector electrodes 12 next to the side of the first welding and / or soldering section 14 facing away from the bus electrode segments 13 can be transferred directly to the welding and / or soldering connection element, which contributes to reducing the transmission loss of charge carriers collected by the collector electrodes 12 next to the side of the first welding and / or soldering section 14 facing away from the bus electrode segments 13 and transferred to the welding and / or soldering connection element.

[0137] Furthermore, the edges of a side of the plurality of first welding and / or soldering sections facing the bus electrode segments may or may not be flush. In this case, if the edges of a side of the plurality of first welding and / or soldering sections facing the bus electrode segments are flush, it is advantageous to provide the sides of different first welding and / or soldering sections facing away from the cell substrate with the same surface, which contributes to providing a larger contact area between each first welding and / or soldering section and the welding and / or soldering connection element, thereby ensuring that the first welding and / or soldering section and the welding and / or soldering connection element have good electrical contact performance and relatively stable mechanical connection performance.Furthermore, if the edges of the side of the plurality of first welding and / or soldering sections facing the bus electrode segments are not flush, the advantageous effects may relate to the advantages described above when the distances between the ends of adjacent bus electrode segments having opposite conductivity types facing the edge of the cell substrate and the edge of the cell substrate are unequal, which will not be discussed in detail here.

[0138] For example, if the edges of a side of the plurality of first welding and / or soldering sections facing the bus electrode segments are flush, the lengths of different bus electrode segments may be unequal. Conversely, if the edges of a side of the first welding and / or soldering sections facing the bus electrode segments are not flush, the lengths of different bus electrode segments may preferably be equal, so that the total length of the structure formed by the first welding and / or soldering section and the bus electrode segments in contact with the first welding and / or soldering section is substantially equal along the second direction, so that the currents collected by different first welding and / or soldering sections have the same strength, which is beneficial for reducing power loss.

[0139] In some cases, the above solar cell may further comprise a first conductive material disposed on the first welding and / or soldering portion. In this case, in the process of connecting the solar cells provided by embodiments of the present application in series to form a photovoltaic module, the welding and / or soldering connecting member may be welded and / or soldered together with the first welding and / or soldering portion through the first conductive material to ensure that the welding and / or soldering connecting member and the first welding and / or soldering portion have good welding and / or soldering quality. The type of the first conductive material can be determined by reference to the type of the second conductive material described above and is not specifically limited here.

[0140] In addition, in the actual application process, as in Fig. 3, Fig. 4 and Fig. 7, the first welding and / or soldering section 14, which is located on the outside along the first direction, is defined to have a first end 21 and a second end 22, which are arranged opposite each other along the second direction, wherein the second end 22 is closer to the edge of the cell substrate 11 along the second direction compared to the first end 21. In the above case, the conductivity type of the collector electrodes 12 adjacent to the outside of the second end 22 can be the same as the conductivity type of the first welding and / or soldering section 14, which is located on the outside. Alternatively, as shown in Fig. 7, the conductivity type of the collector electrodes 12 adjacent to the outside of the second end 22 may be opposite to the conductivity type of the first welding and / or soldering section 14 located on the outside.

[0141] In a second aspect, embodiments of the present application provide a photovoltaic module, wherein the photovoltaic module comprises the solar cells provided in the first aspect and various implementations thereof, as well as a welding and / or soldering connection element for connecting adjacent solar cells in series. The welding and / or soldering connection element is welded and / or soldered to the first welding and / or soldering section, and one end of the welding and / or soldering connection element protrudes beyond the first welding and / or soldering section.

[0142] As a possible embodiment, it is provided that there is a contact or a gap between the welding and / or soldering connection element described above and the bus electrode segments.

[0143] As a possible embodiment, it is provided that the ratio of the length of the above-described welding and / or soldering connection element beyond the first welding and / or soldering section to the lengths of the bus electrode segments is greater than or equal to 5% and less than or equal to 20%.

[0144] By adopting the above-mentioned technical solution, the ratio of the length of the welding and / or soldering connecting element beyond the first welding and / or soldering portion to the lengths of the bus electrode segments is within the above range, whereby the contact area between the two ends of the welding and / or soldering connecting element along the second direction and the first welding and / or soldering portion can be prevented from being small due to the small ratio, thereby ensuring that the welding and / or soldering connecting element can come into contact with various areas on the surface on a side of the first welding and / or soldering portion facing away from the cell substrate, thereby resulting in a lower contact resistance between the two.Furthermore, the charge carriers collected by the collector electrodes between the first welding and / or soldering section and the edge of the cell substrate can be conducted to the welding and / or soldering connecting element via the bus electrode segments and the first welding and / or soldering section, so that the ratio is within the above-mentioned range. This also advantageously prevents the length of the part of the welding and / or soldering connecting element that does not need to be extended from being large due to the larger ratio, resulting in a larger amount of consumables. At the same time, it is helpful to prevent the connection stress between the welding and / or soldering connecting element and the bus electrode segments from becoming large due to the large ratio when the welding and / or soldering connecting element is in contact with the bus electrode segments, thereby improving the yield of the solar cell.

[0145] As a possible embodiment, it is provided that the lengths of the welding and / or soldering connection elements beyond the first welding and / or soldering section are less than or equal to 2 mm.

[0146] The advantageous effects of the second aspect and its various implementations in the embodiments of the present application can be referred to the analysis of the advantageous effects of the first aspect and its various implementations, which will not be discussed in detail here.

[0147] The above description does not provide a detailed explanation of technical details such as patterning and etching of each layer. However, those skilled in the art should understand that various technical means can be used to form layers, regions, and the like into desired shapes. Furthermore, to form the same structure, those skilled in the art may also devise methods that do not exactly correspond to those described above. Furthermore, although each embodiment has been described separately above, this does not mean that the measures in each embodiment cannot be advantageously used in combination.

Claims

[1] Solar cell, characterized bythat the solar cell comprises a cell substrate (11), collector electrodes (12), bus electrode segments (13), and a first welding and / or soldering and / or brazing section (14); wherein at least one of the light-facing side and the light-remote side of the cell substrate (11) is a target side; wherein the collector electrodes (12) and the bus electrode segments (13) are arranged on the target side of the cell substrate (11); wherein the collector electrodes (12) extend along a first direction, and wherein different collector electrodes (12) located on the same target side are distributed at intervals from one another along a second direction; wherein the first direction is different from the second direction; wherein the bus electrode segments (13) are located at the edge regions of both ends of the target side along the second direction, wherein the bus electrode segments (13) extend along the second direction;wherein the bus electrode segments (13) are electrically coupled to some of the collector electrodes (12) of the same conductivity type as the bus electrode segments (13); wherein the first welding and / or soldering section (14) is arranged on a side of a corresponding bus electrode segment (13) facing away from an edge of the cell substrate (11) along the second direction and is electrically coupled to the corresponding bus electrode segment (13); [2] Solar cell according to claim 1, characterized by that the side of the first welding and / or soldering section (14) facing away from the bus electrode segment (13) is not connected to the collector electrodes (12), which side adjoins the first welding and / or soldering section (14) in the second direction and has the same conductivity type. [3] Solar cell according to claim 1, characterized bythat different bus electrode segments (13) are distributed at the same end of the same target side along the second direction from each other along the first direction at intervals from each other, and wherein the solar cell comprises two bus electrode segments (13) arranged opposite each other at different ends of the same target side along the second direction; wherein the two opposite bus electrode segments (13) are not connected to each other. [4] Solar cell according to claim 1, characterized bythat along the second direction, the length of at least one of the bus electrode segments (13) is less than or equal to 10 mm; and / or wherein along the second direction, a ratio between the length of at least one of the bus electrode segments (13) and the width of the cell substrate (11) is less than or equal to 12%; and / or wherein along the first direction, a width of at least one of the bus electrode segments (13) is greater than or equal to 10 µm and less than or equal to 500 µm; and / or wherein the width of at least one of the bus electrode segments (13) gradually increases towards the first welding and / or soldering section (14); and / or wherein the number of bus electrode segments (13) located at the same end of the same target side along the second direction is greater than or equal to 6 and less than or equal to 30. [5] Solar cell according to claim 1, characterized bythat the ratio of the number of collector electrodes (12) arranged at the edge region of one end of the target side along the second direction to the total number of all collector electrodes (12) arranged on the target side is less than or equal to 12%. [6] Solar cell according to claim 1, characterized by in that the first welding and / or soldering section (14) and the bus electrode segments (13) electrically coupled to the first welding and / or soldering section (14) form a one-piece structure; and / or wherein the solar cell further comprises a first conductive material arranged on the first welding and / or soldering section (14). [7] Solar cell according to claim 1, characterized bythat along the first direction, a length of the first welding and / or soldering section (14) is greater than or equal to 100 µm and less than or equal to 10,000 µm; and / or wherein along the second direction, a width of the first welding and / or soldering section (14) is greater than or equal to 100 µm and less than or equal to 10,000 µm. [8] Solar cell according to one of claims 1 to 7, characterized by that, among all collector electrodes (12) on the same target side, the collector electrodes (12) that are electrically coupled to the bus electrode segments (13) are defined as collector electrodes of the first type (15) and the remaining collector electrodes (12) are defined as collector electrodes of the second type (16); wherein the solar cell further comprises a second welding and / or soldering section (17); wherein the second welding and / or soldering section (17) is electrically coupled to at least one of the collector electrodes of the second type (16). [9] Solar cell according to claim 8, characterized by that at least some of the second welding and / or soldering sections (17) are arranged in parallel along the second direction; and / or wherein a center line of at least some of the second welding and / or soldering sections (17) along the second direction is collinear with a center line of at least one of the bus electrode segments (13) along the second direction. [10] Solar cell according to claim 8, characterized by that at least some of the second welding and / or soldering sections (17) are arranged in parallel along the second direction; wherein a gap exists along the second direction between a second welding and / or soldering section (17) and another adjacent second welding and / or soldering section (17); wherein at least one of the collector electrodes (12) is interrupted at the gap or at least one of the collector electrodes (12) runs continuously through the gap. [11] Solar cell according to claim 8, characterized by in that along the first direction, a length of the second welding and / or soldering section (17) is greater than or equal to 100 µm and less than or equal to 10,000 µm; and / or wherein along the second direction, a width of the second welding and / or soldering section (17) is greater than or equal to 100 µm and less than 500 µm; and / or wherein the width of the first welding and / or soldering section (14) is greater than or equal to the width of the second welding and / or soldering section (17); and / or wherein the length of the first welding and / or soldering section (14) is equal to the length of the second welding and / or soldering section (17); and / or wherein the solar cell further comprises a second conductive material arranged on the second welding and / or soldering section (17). [12] Solar cell according to one of claims 1 to 7, characterized bythat the distances between the ends of adjacent bus electrode segments (13) with opposite conductivity types facing the edge of the cell substrate (11) and the edge of the cell substrate (11) are unequal. [13] Solar cell according to one of claims 1 to 7, characterized by that the edges on a side facing the bus electrode segments (13) of a plurality of first welding and / or soldering sections (14) are flush or not flush. [14] Solar cell according to one of claims 1 to 7, characterized by that the lengths of several bus electrode segments (13) are equal or unequal. [15] Solar cell according to one of claims 1 to 7, characterized byin that the solar cell further comprises an edge bus electrode (25), wherein the edge bus electrode (25) is arranged at one end of the cell substrate (11) along the first direction and extends along the second direction; wherein the maximum width of the edge bus electrode (25) is smaller than the maximum width of the bus electrode segments (13). [16] Solar cell according to claim 15, characterized by that the edge bus electrode (25) is electrically coupled to at least some of the collector electrodes (12) which have the same conductivity type as the edge bus electrode (25) itself, and the ends of the collector electrodes (12) which are electrically coupled to the edge bus electrode (25) project beyond the edge bus electrode (25) along the first direction. [17] Solar cell according to one of claims 1 to 7, characterized by that the solar cell also comprises a voltage test point, wherein the voltage test point is arranged on a bus electrode segment (13). [18] Solar cell according to one of claims 1 to 7, characterized by that the distance by which the end of at least one of the bus electrode segments (13) located at the edge of the cell substrate (11) protrudes from the collector electrodes (12) located at the edge of the cell substrate (11) and electrically coupled to the bus electrode segment (13) is greater than 0 and less than 0.12 mm. [19] Solar cell according to one of claims 1 to 7, characterized byin that the target side is the side facing away from the light, wherein, among all the bus electrode segments (13) at the same end of the side facing away from the light along the second direction, the two bus electrode segments (13) located on the outermost sides along the first direction are defined as the bus electrode segments of the first type (18), and the remaining bus electrode segments (13) are defined as the bus electrode segments of the second type (19); wherein the bus electrode segments of the first type (18) are located on the outer side of an end of the corresponding collector electrodes (12) facing the edge of the cell substrate (11) along the first direction, wherein the solar cell further comprises a connecting electrode segment (20), wherein the bus electrode segments of the first type (18) are electrically coupled to the corresponding first welding and / or soldering section (14) via a connecting electrode segment (20). [20] Solar cell according to claim 19, characterized by in that the solar cell is a back contact cell; wherein at least some of the collector electrodes (12) located at the edge regions at both ends of the target side along the second direction are discontinuous collector electrodes (12); wherein the discontinuous collector electrodes (12) have a discontinuity for spacing them apart from the bus electrode segments of the second type (19), which have a conductivity type opposite to the collector electrodes (12) themselves, and wherein the two ends of the discontinuous collector electrodes (12) are spaced apart along the first direction from the bus electrode segments of the first type (18), which have a conductivity type opposite to the discontinuous collector electrodes (12). [21] Solar cell according to claim 20, characterized byin that the collector electrodes (12) that are not electrically coupled to the bus electrode segments (13) are partially separated between two corresponding first welding and / or soldering sections (14) that are arranged opposite one another; and / or wherein, among all the collector electrodes (12) located at the edge regions at both ends of the target side along the second direction, the collector electrodes (12) located at the outer sides are continuous collector electrodes (12) and the remaining collector electrodes (12) are discontinuous collector electrodes (12). [22] Solar cell according to claim 20, characterized byin that the discontinuous collector electrodes (12) comprise a plurality of collector electrode segments distributed at intervals from one another along the first direction; wherein, in the case where the width of at least one of the bus electrode segments (13) gradually increases in a direction of the first welding and / or soldering section (14), the distances corresponding to different pairs of collector electrode segments of opposite conductivity type from the same bus electrode segment (13) are different, each pair of collector electrode segments representing two adjacent collector electrode segments encompassed by the same collector electrode (12). [23] Solar cell according to one of claims 1 to 7, characterized byin that an end of at least one of the bus electrode segments (13) facing an edge region of the target side along the second direction extends to a side of an edge region of the corresponding collector electrodes (12) facing the edge region of the target side along the second direction, which side is electrically coupled to the bus electrode segment (13); and / or wherein an end of the bus electrode segment (13) facing the first welding and / or soldering section (14) is flush with an end of the first welding and / or soldering section (14) facing the bus electrode segment (13); or wherein the end of the bus electrode segment (13) facing the first welding and / or soldering section (14) extends to a section of a side of the first welding and / or soldering section (14) facing away from the cell substrate (11). [24] Photovoltaic module, characterized byin that the photovoltaic module comprises the following: a solar cell according to one of claims 1 to 23; and a welding and / or soldering connection element (23) for connecting adjacent solar cells in series; wherein the welding and / or soldering connection element (23) is welded and / or soldered to the first welding and / or soldering section (14), wherein the end of the welding and / or soldering connection element (23) projects beyond the first welding and / or soldering section (14). [25] Photovoltaic module according to claim 24, characterized by that the ratio of the length of the welding and / or soldering connection element (23) beyond the first welding and / or soldering section (14) to the lengths of the bus electrode segments (13) is greater than or equal to 5% and less than or equal to 20%; or wherein the lengths of the bus electrode segments (13) beyond the first welding and / or soldering section (14) are less than or equal to 2 mm. [26] Photovoltaic module according to claim 24 or 25, characterized bythat there is a contact or a gap between the welding and / or soldering connection element (23) and the bus electrode segments (13).

Images