Electrode structure of solar cell, solar cell, solar cell module and photovoltaic system

Abstract

The utility model is applicable to the field of photovoltaic technology, and provides an electrode structure of a solar cell, the solar cell, a solar cell module and a photovoltaic system.The electrode structure comprises a pad point, the pad point is provided with a plurality of corners in the circumferential direction, and at least one corner of the pad point is arranged to be of a corner cut structure. On the premise that the stable contact between the test probe and the pad point is not influenced, the size of the pad point is reduced, so that the consumption of silver paste for printing the pad point is reduced, and the production cost of the solar cell is reduced.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of photovoltaics, and particularly relates to an electrode structure of a solar cell, a solar cell, a solar cell module and a photovoltaic system. BACKGROUND

[0002] Efficiency improvement and cost reduction of crystalline silicon solar cells are the main theme of industry development, and electrode structure optimization is a key improvement point of solar cells. The electrode structure generally includes fine grid lines, main grid lines, pad points, etc. Among them, in order to ensure stable contact between the solar cell and the test probe, as shown in the prior art, it is usually necessary to provide a large-size regular pattern pad point on the solar cell, and the pad point is usually printed using silver paste, which consumes a large amount of silver paste and has high cost. Figure 1 The utility model discloses a solar cell electrode structure and a solar cell. UTILITY MODEL CONTENTS

[0003] The application provides a solar cell, which aims to solve the problems of large-size regular pattern pad points on the solar cell, the use of silver paste printing for the pad points, large consumption of silver paste and high cost.

[0004] In the first aspect, the application is implemented as follows: an electrode structure of a solar cell includes a pad point, the pad point has a plurality of corners in the circumferential direction, and at least one corner of the pad point is provided as a cut corner structure.

[0005] The application reduces the size of the pad point by providing at least one corner of the pad point as a cut corner structure without affecting the stable contact between the test probe and the pad point, thereby reducing the consumption of silver paste for printing the pad point and reducing the production cost of the solar cell.

[0006] Optionally, a long side of the pad point forms a cut edge based on the cut corner structure, the long side has a first length, and the cut edge has a second length, and the second length is 30% to 60% of the first length.

[0007] Optionally, it further includes a main grid, the pad point and the main grid are stacked, and the pad point and the main grid are in conductive contact.

[0008] Optionally, the pad points are a plurality of pad points, part of the plurality of pad points is arranged below the main grid, and another part of the plurality of pad points is arranged above the main grid.

[0009] Optionally, the width of the main grid has a first size, and the width of the pad point has a second size, and the first size is smaller than the second size.

[0010] Optionally, the ratio of the first size to the second size is greater than or equal to 1 / 5 and less than or equal to 1 / 2.

[0011] Optionally, the pad point has four corners, and each of the four corners of the pad point is arranged as the chamfered corner structure.

[0012] Optionally, the chamfered corner structure comprises a bevel, and the bevel is arranged between two adjacent cut edges of the pad point.

[0013] Optionally, the chamfered corner structure is a circular arc chamfered corner structure, and the bevel is a circular arc edge.

[0014] Optionally, the chamfered corner structure is a straight edge chamfered corner structure, and the bevel is a straight edge.

[0015] In a second aspect, a solar cell comprises the electrode structure of the solar cell as described above.

[0016] Optionally, the solar cell comprises four pad points arranged at four corners of the solar cell respectively.

[0017] In a third aspect, a solar cell module comprises the solar cell as described above.

[0018] In a fourth aspect, a photovoltaic system comprises the solar cell module. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is a structure diagram of a pad point in the related art;

[0020] Figure 2 is a structure diagram of a pad point provided in the present application;

[0021] Figure 3 is a structure diagram of a solar cell provided in the present application.

[0022] REFERENCE SIGNS

[0023] 100, pad point; 101, corner; 102, chamfered corner structure; 103, long edge; 104, cut edge; 105, bevel; 200, main grid; 300, solar cell. DETAILED DESCRIPTION

[0024] In order to make the objects, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. The examples of the embodiments are shown in the drawings, wherein the same or similar reference signs represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application. In addition, it should be understood that the specific embodiments described herein are only used to explain the present application and do not limit the present application.

[0025] In the description of the present application, it needs to be understood that the terms "length", "width", "upper", "lower", "left", "right", "horizontal", "top", "bottom", and the like indicate the orientation or positional relationship shown in the drawings based on the orientation or positional relationship, and are only for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.

[0026] In addition, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly specified and limited.

[0027] In the description of the present application, it needs to be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connection" should be understood in a broad sense, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be mechanical connection, or electrical connection or can communicate with each other; it can be directly connected, or indirectly connected through an intermediate medium, or the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0028] In the present application, unless otherwise explicitly specified and limited, the "upper" or "lower" of the first feature to the second feature can include the direct contact of the first and second features, or the contact of the first and second features through another feature between them. Moreover, the "upper", "above" and "above" of the first feature to the second feature include the vertical above and oblique above of the first feature to the second feature, or only indicate that the horizontal height of the first feature is higher than that of the second feature. The "below", "below" and "below" of the first feature to the second feature include the vertical below and oblique below of the first feature to the second feature, or only indicate that the horizontal height of the first feature is less than that of the second feature.

[0029] The following disclosure provides many different embodiments, or examples, for implementing different structures of the present application. For the purpose of simplifying the present application, the components and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present application. In addition, the present application can repeatedly refer to numbers and / or letters in different examples, and such repetition is for the purpose of simplification and clarity, which does not indicate the relationship between the various embodiments and / or settings discussed. In addition, the present application provides examples of various specific processes and materials, but those skilled in the art can realize the application of other processes and / or the use of other materials.

[0030] As shown in Figure 2 An electrode structure of a solar cell includes pad points 100 and main grids 200, the main grids 200 and the pad points 100 are in conductive contact, the formation of the pad points 100 and the main grids 200 can be realized by printing metal paste to the surface of the solar cell 300 by screen printing to form the main grids 200 and the pad points 100 on the surface of the solar cell 300. Wherein, the metal paste can be silver paste, aluminum paste, etc. Here, the specific material of the metal paste is not limited, and in actual use, the skilled person can select the appropriate material according to the needs. Specifically, the main grid 200 line can be printed on the solar cell 300 first, and then the pad point 100 is printed on the main grid 200 line, or the pad point 100 can be printed on the solar cell 300 first, and then the main grid 200 is printed on the pad point 100, the present application does not limit this, as long as the main grid 200 and the pad point 100 are electrically connected.

[0031] Specifically, the pad points 100 can be contacted by a test probe to test the performance of the solar cell such as hot spot, EL, etc., which facilitates the detection of the yield of the solar cell 300 to meet the factory requirements.

[0032] In some embodiments, the pad points 100 have a plurality of corners 101 in the circumferential direction, and at least one corner 101 of the pad points 100 is provided as a chamfered corner structure 102. The chamfered corner structure 102 of the present application can be regarded as cutting off the protruding corner part at the corner 101 of the pad point 100. Since the test probe is usually in contact with the middle region of the pad point 100 when the test probe contacts the pad point 100, cutting off the corner 101 of the pad point 100 does not affect the testing function of the pad point 100, thereby reducing the consumption of silver paste for printing the pad point 100. It can be understood that the formation of the chamfered corner structure 102 of the pad point 100 can be designed accordingly in the electrode pattern, so that the pad point 100 printed on the solar cell 300 has the chamfered corner structure 102, thereby saving the use of paste.

[0033] It can be understood that the chamfer structure 102 is essentially a defect processing of the corner 101 of the pad point 100, which reduces the size of the pad point 100 under the premise of not affecting the connection of the main grid 200 and the main part of the pad point 100, so as to reduce the consumption of the printing pad point 100 paste.

[0034] In some embodiments, the pad point 100 has four corners 101, and the four corners 101 of the pad point 100 are all set as the chamfer structure 102. The test probe is usually designed as a pin structure, and the rectangular structure of the pad point 100 is convenient for adaptive contact with the test probe. The four corners 101 of the pad point 100 are all chamfered structures 102, which can reduce the size of the pad point 100 to the greatest extent, thereby reducing the paste consumption.

[0035] Further, the long side 103 of the pad point 100 forms a cut edge 104 based on the chamfer structure 102, the long side 103 has a first length, and the cut edge 104 has a second length, the second length is 30% to 60% of the first length. In the embodiment of the present application, as shown in Figure 1 , based on the pad point 100 being a complete rectangular structure, at this time, the edge of the pad point 100 is the long side 103, as shown in Figure 2 , based on the pad point 100 having the chamfer structure 102, at this time, the edge of the pad point 100 is the cut edge 104, and the length of the cut edge 104 is 30% to 60% of the length of the long side 103. Within this range, on the one hand, it can ensure stable welding of the pad point 100 and the main grid 200 and stable contact of the pad point and the test probe, and on the other hand, it can maximize the size reduction of the pad point 100, thereby reducing the paste consumption. It can be understood that the cut edge 104 of the pad point 100 has two forms. When the long side 103 of the pad point 100 is provided with the chamfer structure 102 to form the cut edge 104, at this time, the length of the cut edge 104 is 45% to 60% of the length of the long side 103. When the long side 103 of the pad point is provided with the chamfer structure 102 to form the cut edge 104, at this time, the length of the cut edge 104 is 30% to 45% of the length of the long side 103.

[0036] In other embodiments, the pad point 100 can also be a circular structure. For the edge part of the circular structure of the pad point 100, a notch is processed, which also can achieve the effect of reducing the paste consumption of the printed pad point 100. Further, in order not to affect the connection of the pad point 100 and the main grid 200, the notch can be designed on the two side edge parts of the pad point 100 in the width direction of the main grid 200. The notch can be a single notch or multiple notches, and the shape of the notch can be an arc notch or a triangular notch. The present application does not limit the comparison.

[0037] In some embodiments, the pad point 100 and the main grid 200 are arranged in a stacked manner, and the pad point 100 and the main grid 200 are in conductive contact. Further, the pad point 100 and the main grid 200 partially overlap in the length direction, and the width of the pad point 100 is greater than the width of the main grid 200 to cover the main grid 200 in the width direction, that is, the width of the main grid 200 has a first size, and the width of the pad point 100 has a second size, and the first size is less than the second size. Preferably, the ratio of the first size to the second size is greater than or equal to 1 / 5 and less than or equal to 1 / 2, and the width of the pad point 100 is in such a size range, so that stable contact of the test probe and the pad point 100 can be achieved, and the consumption of the printed pad point 100 paste can be reduced. The length of the pad point 100 can be set according to the test needs, and for example, according to different sizes of the test probe, different sizes of the pad point 100 can be arranged on the solar cell 300 in the embodiments of the present application to match test probes of different sizes.

[0038] In some embodiments, the pad points are multiple, and part of the multiple pad points 100 are arranged below the main grid 200, and another part of the multiple pad points 100 are arranged above the main grid 200. In the embodiments of the present application, part of the multiple pad points 100 are arranged below the main grid 200, and another part of the multiple pad points 100 are arranged above the main grid 200, that is, the pad point 100 and the main grid 200 are not in the same plane, and the main grid 200 and the pad point 100 are in a structure of mutual superposition, so that the pad points 100 at different positions can be printed separately, the pad points 100 can be arranged in the second doped region when printing the grid lines of the first doped region, and the pad points 100 can be arranged in the first doped region when printing the grid lines of the second doped region, thereby avoiding simultaneous printing of the pad points 100 and the grid lines of the same polarity doped region, and further avoiding the problem of easy paste leakage of the screen mask at the pad point 100 position.

[0039] In the embodiments of the present application, the chamfer structure 102 includes a bevel 105 arranged between the two adjacent cut edges 104 of the pad point 100. After the corner 101 is arranged as the chamfer structure 102, the bevel 105 is formed at the corner 101, and the bevel 105 and the two adjacent cut edges 104 are naturally connected, forming a more smooth appearance, and the printed pad point has high quality.

[0040] In some embodiments, the chamfer structure 102 is a circular arc chamfer structure 102, and the bevel 105 is a circular arc edge. The design of the circular arc chamfer and the circular arc edge makes the pad point 100 have a more smooth and round appearance, and the shape of the pad point is regular.

[0041] In some embodiments, the corner-cut structure 102 is a straight-edge corner-cut structure 102, and the bevel 105 is a straight edge. The straight-edge corner-cut structure 102 is relatively simple to process and the precision is easy to control, and the processing of the straight edge does not require a complex mold or process, so it is easier to achieve high precision and high-quality production.

[0042] As shown in FIG. 1, in an embodiment of the present application, a solar cell 300 includes the electrode structure of the solar cell described above. The technical effects of the present application are the same as those of the electrode structure of the solar cell described above, and will not be repeated here. Figure 3

[0043] The solar cell 300 includes at least four pad points 100 arranged at the four corners of the solar cell 300, respectively, to facilitate identification and positioning of the cell in subsequent electrode printing processes. In addition, in subsequent soldering of the solder strip, the pad point 100 can serve as a point for welding with the solder strip. Since the pad point 100 is connected to the main grid, it is not necessary to set a soldering point or a soldering layer at the pad point of the main grid during soldering, which can reduce the use of solder paste.

[0044] A solar cell module includes the solar cell described above. Based on the solar cell described above, those skilled in the art know that a plurality of the solar cell and / or other corresponding existing accessories can be used to obtain a corresponding cell module.

[0045] In the present embodiment, a plurality of solar cells in the cell module can be sequentially connected in series to form a cell string, thereby realizing series connection of the current. For example, the solar cells can be connected in series by means of solder strips (bus bars, interconnection strips), conductive back sheets, etc. It can be understood that in such embodiments, the cell module can also include a metal frame, a back sheet, photovoltaic glass, and an adhesive film. The adhesive film can be filled between the front and back surfaces of the back-contact cell, photovoltaic glass, adjacent solar cells, etc., and can be a transparent adhesive with good light transmission and aging resistance, such as EVA adhesive film or POE adhesive film. The specific choice can be made according to actual conditions, and is not limited here.

[0046] ​A photovoltaic system includes a solar cell assembly. In the present embodiment, the photovoltaic system can be applied in a photovoltaic power station, such as a ground power station, a roof power station, a water surface power station, etc., and can also be applied in a device or apparatus that utilizes solar energy to generate power, such as a user solar power source, a solar street lamp, a solar car, a solar building, etc. Of course, it can be understood that the application scenarios of the photovoltaic system are not limited to the above, that is, the photovoltaic system can be applied in all fields that need to utilize solar energy to generate power. Taking a photovoltaic power generation system network as an example, the photovoltaic system can include a photovoltaic array, a combiner box and an inverter, the photovoltaic array can be an array combination of a plurality of cell assemblies, for example, a plurality of cell assemblies can form a plurality of photovoltaic arrays, the photovoltaic arrays are connected to the combiner box, the combiner box can combine the currents generated by the photovoltaic arrays, the combined currents flow through the inverter to be converted into alternating current required by a power grid, and then the converted alternating current is connected to the power grid to realize solar power supply

[0047] In the description of the present specification, the description referring to the terms "some embodiments", "exemplary embodiments", "examples", "specific examples", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the described embodiments or examples are included in at least one embodiment or example of the present application. In the present specification, the exemplary description of the above terms does not necessarily mean the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics can be combined in any one or more embodiments or examples in a suitable manner.

[0048] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An electrode structure of a solar cell, characterized by, The pad point has a plurality of corners in a circumferential direction, at least one of the corners of the pad point is arranged as a bevel structure, and the pad point and the main grid are arranged in a stack and in conductive contact.

2. The electrode structure of a solar cell according to claim 1, wherein A long side of the pad point forms a cut edge based on the bevel structure, the long side has a first length, and the cut edge has a second length, the second length being 30-60% of the first length.

3. The electrode structure of a solar cell according to claim 1, wherein The pads are a plurality, part of the plurality of pad points is arranged below the main grid, and another part of the plurality of pad points is arranged above the main grid.

4. The electrode structure of a solar cell according to claim 1, wherein The main grid has a first size in width, and the pad point has a second size in width, the first size being smaller than the second size.

5. The electrode structure of a solar cell according to claim 4, wherein The ratio of the first size to the second size is greater than or equal to 1 / 5 and less than or equal to 1 / 2.

6. The electrode structure of a solar cell according to claim 1, wherein The pad point has four corners, and the four corners of the pad point are all arranged as the bevel structure.

7. The electrode structure of a solar cell according to claim 1, wherein The bevel structure includes a bevel edge arranged between two adjacent cut edges of the pad point.

8. The electrode structure of a solar cell according to claim 7, wherein The bevel structure is a circular arc bevel structure, and the bevel edge is a circular arc edge.

9. The electrode structure of a solar cell according to claim 7, wherein The bevel structure is a straight edge bevel structure, and the bevel edge is a straight edge.

10. A solar cell, characterized by, An electrode structure of a solar cell according to any one of claims 1-9.

11. The solar cell of claim 10, wherein the first and second doped regions are formed by implanting dopants into the first and second surfaces of the substrate. The solar cell includes at least four pad points arranged at four corners of the solar cell, respectively.

12. A solar cell module, characterized by, A solar cell according to any one of claims 10-11.

13. A photovoltaic system characterized by, A solar cell module according to claim 12.

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