CN219800867U

CN219800867U - Electrode structure, solar cell, photovoltaic module and power utilization device

Info

Publication number: CN219800867U
Application number: CN202320988769.3U
Authority: CN
Inventors: 黄智�; 马海云; 李忠涌
Original assignee: Tongwei Solar Meishan Co Ltd
Current assignee: Tongwei Solar Meishan Co Ltd
Priority date: 2023-04-27
Filing date: 2023-04-27
Publication date: 2023-10-03
Anticipated expiration: 2033-04-27

Abstract

The utility model relates to the technical field of solar cells, in particular to an electrode structure, a solar cell, a photovoltaic module and an electric device. The electrode structure includes: a main gate including a first main gate and a second main gate located at an end of the first main gate; the auxiliary grid is arranged perpendicular to the first main grid; the bonding pad comprises a first bonding pad and a second bonding pad, and the first bonding pad is arranged at the junction of the first main gate and the second main gate; the second bonding pads are distributed on the first main grid along the first direction; the size of the first bonding pad along the second direction is 0.6-1.15 mm, the size of the first bonding pad along the first direction is 0.4-0.85 mm, the size of the second bonding pad along the second direction is 0.4-0.85 mm, the size of the second bonding pad along the first direction is 0.35-0.7 mm, the first direction is the length extending direction of the first main grid, and the second direction is the length extending direction of the auxiliary grid. The embodiment of the utility model reduces the area of the metalized area, improves the photoelectric conversion efficiency and reduces the cost on the premise of ensuring good structural performance of the electrode.

Description

Electrode structure, solar cell, photovoltaic module and power utilization device

Technical Field

The utility model relates to the technical field of solar cells, in particular to an electrode structure, a solar cell, a photovoltaic module and an electric device.

Background

Currently, the electrode structure of a solar cell mainly uses a screen printing technology to selectively print a metal pattern in a metallized area and to perform seal printing in a non-metallized area. Wherein, the noble metal silver is mainly used for printing the metal pattern.

When the printing area of the metalized area of the electrode structure is large, on one hand, more noble metal silver needs to be used, so that the material cost is high; on the other hand, the passivation layer of the solar cell is damaged, so that the surface metal composition of the solar cell is increased to influence the open circuit voltage, and especially the area of the metallization area on the front surface of the electrode structure can influence the effective illumination area of direct sunlight on the solar cell, influence the short-circuit current and further influence the photoelectric conversion efficiency of the solar cell. Therefore, it is necessary to continuously improve the electrode structure of the existing solar cell to solve the problem caused by the too large printing area of the metallization region.

Disclosure of Invention

In order to solve the technical problems, the utility model discloses an electrode structure, a solar cell, a photovoltaic module and an electric device, which are used for solving the problems that the electrode structure of the existing solar cell is high in cost and difficult to improve in photoelectric conversion efficiency due to the fact that the area of a metalized area is large.

In a first aspect, an embodiment of the present utility model discloses an electrode structure, including:

a main gate including a first main gate and a second main gate located at an end of the first main gate;

the auxiliary grid is arranged perpendicular to the first main grid;

the bonding pad comprises a first bonding pad and a second bonding pad, and the first bonding pad is arranged at the junction of the first main grid and the second main grid; the second bonding pads are distributed on the first main grid along a first direction;

the size of the first bonding pad along the second direction is 0.6-1.15 mm, the size of the first bonding pad along the first direction is 0.4-0.85 mm, the size of the second bonding pad along the second direction is 0.4-0.85 mm, the size of the second bonding pad along the first direction is 0.35-0.7 mm, the first direction is the length extending direction of the first main grid, and the second direction is the length extending direction of the auxiliary grid.

Optionally, the shape of the bonding pad is rectangular, elliptical, diamond or hexagonal.

Further, the height of the sub-gate along a cross section perpendicular to the second direction is 3 μm to 8 μm.

Further, the auxiliary grid is obtained by screen printing, the wire diameter of the screen is 6-15 mu m, the yarn thickness is 12-17 mu m, and the film thickness is 1.5-10 mu m.

Further, the screen plate has a wire diameter of 6 μm to 11 μm and a film thickness of 2 μm to 6 μm.

Further, the number of the main grids is 13-16.

In a second aspect, embodiments of the present utility model provide a solar cell comprising a solar cell substrate, and an electrode structure according to the first aspect on the solar cell substrate.

Optionally, the solar cell is a passivation contact solar cell, a heterojunction solar cell, a back contact solar cell or a stacked solar cell.

In a third aspect, embodiments of the present utility model provide a photovoltaic module obtained by connecting solar cells according to the second aspect in series and/or in parallel.

In a fourth aspect, an embodiment of the present utility model provides an electric device, where the electric device includes an electric device body and the solar cell according to the second aspect, and the solar cell is used to supply power to the electric device body.

Compared with the prior art, the utility model has the beneficial effects that:

the embodiment of the utility model effectively reduces the area of the metalized area of the electrode structure by controlling and shrinking the sizes of the first bonding pad and the second bonding pad on the premise of ensuring good performance of the electrode structure, thereby being beneficial to improving the photoelectric conversion efficiency and reducing the cost of the solar cell. The size of the bonding pad is smaller than that of the bonding pad in the prior art, and a smaller area of a metallization area can be provided, so that the contact area between an electrode structure and a substrate of a solar cell is reduced, metal contact recombination is reduced, shielding of sunlight is reduced, and photoelectric conversion efficiency is improved; on the other hand, the consumption of the noble metal silver paste by the bonding pad is reduced, thereby reducing the production cost.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the drawings used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present utility model, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic view of an electrode structure according to an embodiment of the present utility model;

FIG. 2 is an enlarged schematic view of the structure at A in FIG. 1;

fig. 3 is a diagram showing various modifications of the bonding pad in the electrode structure according to the embodiment of the present utility model.

Reference numerals:

1. a main grid; 11. a first main gate; 12. a second main gate; 2. an auxiliary grid; 3. a bonding pad; 31. a first bonding pad; 32. and a second bonding pad.

Detailed Description

The following description of the embodiments of the present utility model will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present utility model, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

In the present utility model, the terms "upper", "lower", "left", "right", "front", "rear", "top", "bottom", "inner", "outer", "middle", "vertical", "horizontal", "lateral", "longitudinal" and the like indicate an azimuth or a positional relationship based on that shown in the drawings. These terms are only used to better describe the present utility model and its embodiments and are not intended to limit the scope of the indicated devices, elements or components to the particular orientations or to configure and operate in the particular orientations.

Also, some of the terms described above may be used to indicate other meanings in addition to orientation or positional relationships, for example, the term "upper" may also be used to indicate some sort of attachment or connection in some cases. The specific meaning of these terms in the present utility model will be understood by those of ordinary skill in the art according to the specific circumstances.

Furthermore, the terms "mounted," "configured," "provided," "connected," and "connected" are to be construed broadly. For example, it may be a fixed connection, a removable connection, or a unitary construction; may be a mechanical connection, or an electrical connection; may be directly connected, or indirectly connected through intervening media, or may be in internal communication between two devices, elements, or components. The specific meaning of the above terms in the present utility model can be understood by those of ordinary skill in the art according to the specific circumstances.

Furthermore, the terms "first," "second," and the like, are used primarily to distinguish between different devices, elements, or components (the particular species and configurations may be the same or different), and are not used to indicate or imply the relative importance and number of devices, elements, or components indicated. Unless otherwise indicated, the meaning of "a plurality" is two or more.

The technical scheme of the utility model will be further described with reference to the examples and the accompanying drawings.

For solar cells, the metallized regions of the electrode structure have a significant impact on the photoelectric conversion efficiency and the production cost of the solar cell. In terms of photoelectric conversion efficiency, when the metallized area of the electrode structure is too large, not only is the passivation layer of the solar cell easily damaged and the surface metal recombination increased to affect the open circuit voltage, but also when the metallized area of the electrode structure on the front side of the solar cell is too large, the effective illumination area of direct sunlight is reduced to affect the short circuit current, and the photoelectric conversion efficiency of the solar cell is affected. In terms of production cost, the main grid, the auxiliary grid and other structures of the electrode structure are all made of silver paste by a printing process, so that the larger the metallization area is, the higher the silver paste consumption is, and the higher the production cost of the solar cell is. Therefore, in order to optimize the photoelectric conversion efficiency and reduce the production cost of the solar cell, it is necessary to continuously optimize the relevant structure of the electrode structure and its parameters.

However, in the process of optimizing the electrode structure, the smaller the metalized area of the electrode structure is, the better, for example, when the widths of the grid lines such as the main grid and the auxiliary grid of the electrode structure are smaller, the welding reliability of the component and the battery and other indexes affecting the quality performance of the battery are easily affected. The inventor of the present utility model has therefore proposed an electrode structure that can reasonably optimize a metallization region while ensuring the soldering reliability of a solar cell, and reduce the metallization region while avoiding the cases of pseudo soldering, cold soldering, and the like.

In a first aspect, embodiments of the present utility model provide an electrode structure. Referring to fig. 1 and 2, fig. 1 is a schematic structural diagram of an electrode structure according to an embodiment of the present utility model, and fig. 2 is an enlarged schematic structural diagram of a portion a in fig. 1, where the electrode structure includes:

a main gate 1 including a first main gate 11 and a second main gate 12 located at an end of the first main gate 11;

the auxiliary grid 2 is arranged perpendicular to the first main grid 11;

the bonding pad 3, the bonding pad 3 comprises a first bonding pad 31 and a second bonding pad 32, the first bonding pad 31 is arranged at the intersection of the first main grid 11 and the second main grid 12, and the second bonding pad 32 is distributed on the first main grid 11 along the first direction;

the dimensions of the first bonding pad 31 along the second direction are 0.6 mm-1.15 mm, the dimensions of the first bonding pad 31 along the first direction are 0.4 mm-0.85 mm, the dimensions of the second bonding pad 32 along the second direction are 0.4 mm-0.85 mm, the dimensions of the second bonding pad 32 along the first direction are 0.35 mm-0.7 mm, the first direction is the length extending direction of the first main grid 11, and the second direction is the length extending direction of the auxiliary grid 2.

The first main grid 11 is a line-shaped main grid 1, which is a main component of the main grid 1 and is composed of a plurality of first main grids 11 which are arranged along a first direction and have the same interval distance with each other. The second main grid 12 is a fish-fork type main grid 1 and is arranged at the edge positions of two end parts of the first main grid 11, and the second main grid 12 and the first main grid 11 realize the intersection diversion of current through the second bonding pad 32. The sub-gate 2 is a linear sub-gate 2, and is composed of a plurality of sub-gates 2 arranged in the second direction and having the same distance apart from each other. In the embodiment of the present utility model, the auxiliary grid 2 is disposed perpendicular to the first main grid 11, and the auxiliary grid 2 is also disposed intersecting the second main grid 12 (i.e., the fish-fork-shaped main grid 1). It should be understood that although the second main grid 12 is the harpoon-shaped main grid 1, the deviation angle between the longitudinal direction and the first direction is small, and thus the sub-grid 2 and the second main grid 12 are also substantially perpendicular to each other. In addition, when the electrode structure is arranged in a solar cell, the sub-grid 2 can realize good ohmic contact with a solar cell substrate through high-precision calibration and is used for collecting carriers.

Wherein the first bonding pad 31 and the second bonding pad 32 are respectively a large-size bonding pad 3 and a small-size bonding pad 3, the first bonding pad 31 is arranged at the junction of the first main grid 11 and the second main grid 12, and the second bonding pad 32 is distributed on the first main grid 11 along the first direction; in actual use, a solder strip is soldered at the position of the solder pad 3 for conducting current. By the structural arrangement of the main gate 1, the auxiliary gate 2 and the bonding pad 3, the collection of carriers and the current conduction can be realized. Specifically, through good ohmic contact between the auxiliary grids 2 and the solar cell substrate, a plurality of auxiliary grids 2 can effectively collect carriers so as to form current; since the sub-gate 2 and the main gate 1 are perpendicular to each other, a current can be conducted to the main gate 1 and then conducted through the pad 3 on the main gate 1.

The embodiment of the utility model effectively reduces the area of the metalized area of the electrode structure by controlling and reducing the sizes of the first bonding pad 31 and the second bonding pad 32 on the premise of ensuring good performance of the electrode structure (including the conditions of no false bonding, bonding tape falling off and the like), thereby being beneficial to improving the photoelectric conversion efficiency and reducing the cost of the solar cell. The embodiment of the utility model adopts the bonding pad 3 with smaller size, and provides smaller area of the metallization region, which not only can reduce metal contact recombination, but also can reduce shielding of sunlight, and improves photoelectric conversion effect from two aspects. Moreover, the reduction of the size of the bonding pad 3 can reduce the consumption of silver paste by the bonding pad 3, thereby reducing the production cost.

It is understood that a dimension of the first pads 31 in the second direction of 0.6mm to 1.15mm includes any point within this range of values, such as a dimension of the first pads 31 in the second direction of 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1.0mm, 1.1mm, or 1.15mm. The dimension of the first pad 31 in the first direction being 0.4mm to 0.85mm includes any point value within this range of values, such as a dimension of the first pad 31 in the first direction being 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.75mm, 0.8mm or 0.85mm. The dimension of the second pad 32 in the second direction being 0.4mm to 0.85mm includes any point within this range of values, such as a dimension of the second pad 32 in the second direction being 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.75mm, 0.8mm, or 0.85mm. The dimension of the second pad 32 in the first direction being 0.35mm to 0.7mm includes any point within this range of values, such as a dimension of the second pad 32 in the first direction being 0.35mm, 0.4mm, 0.45mm, 0.5mm, or 0.55mm.

The structures and parameters related to the pad 3, the sub-gate 2 and the main gate 1 are further described below.

Referring to fig. 3, fig. 3 shows various alternative modification structures of the bonding pad 3 in the electrode structure according to the embodiment of the present utility model. In the embodiment of the present utility model, the shape of the pad 3 may be rectangular, elliptical, diamond-shaped, or hexagonal. The first pad 31 and the second pad 32 may be the same shape pad 3, or may be different shapes of pads 3, respectively, without limitation. In view of simplification of the manufacturing process, it is preferable that the first pad 31 and the second pad 32 employ the same shape of the pad 3.

When the pad 3 is rectangular, the length of the first pad 31 in the second direction is 0.6mm to 1.15mm, the width of the first pad 31 in the first direction is 0.4mm to 0.85mm, the length of the second pad 32 in the second direction is 0.4mm to 0.85mm, and the width of the second pad 32 in the first direction is 0.35mm to 0.7mm. When the pad 3 is elliptical, the major axis of the first pad 31 in the second direction is 0.6mm to 1.15mm, the minor axis of the first pad 31 in the first direction is 0.4mm to 0.85mm, the major axis of the second pad 32 in the second direction is 0.4mm to 0.85mm, and the minor axis of the second pad 32 in the first direction is 0.35mm to 0.7mm. When the bonding pad 3 is diamond-shaped, the diagonal length of the first bonding pad 31 along the second direction is 0.6 mm-1.15 mm, the diagonal length of the first bonding pad 31 along the first direction is 0.4 mm-0.85 mm, the diagonal length of the second bonding pad 32 along the second direction is 0.4 mm-0.85 mm, and the diagonal length of the second bonding pad 32 along the first direction is 0.35 mm-0.7 mm. When the bonding pad 3 is a hexagon, it is preferable to set the bonding pad as a parallel hexagon, and one set of opposite sides of the parallel hexagon are parallel to the second direction, and the other two sets of opposite sides have equal side lengths. When the bonding pad 3 is hexagonal, the diagonal length of the first bonding pad 31 along the second direction is 0.6 mm-1.15 mm, the height of the first bonding pad 31 along the first direction is 0.4 mm-0.85 mm, the diagonal length of the second bonding pad 32 along the second direction is 0.4 mm-0.85 mm, and the height of the second bonding pad 32 along the first direction is 0.35 mm-0.7 mm.

Preferably, the shape of the pad 3 is diamond or hexagonal. The use of the two shapes of pads 3 with the same size of pads 3 has a smaller area than the use of rectangular or elliptical pads 3, which is advantageous in further reducing the consumption of silver paste.

In the embodiment of the utility model, the height of the sub-gate 2 in the cross section perpendicular to the second direction is 3 μm to 8 μm. Wherein a height of the sub-grid 2 in a cross section perpendicular to the second direction of 3 μm to 8 μm comprises any point value within this range of values, e.g. a height of the sub-grid 2 in a cross section perpendicular to the second direction of 3 μm, 4 μm, 5 μm, 6 μm, 7 μm or 8 μm.

Compared with the parameter setting that the cross section height of the auxiliary grid 2 is larger than 8 mu m, when the cross section height of the auxiliary grid 2 is controlled to be 3-8 mu m, the embodiment of the utility model can reduce the consumption of silver paste dosage through the reduction of the height and can avoid obviously increasing the transmission resistance caused by the excessively low height. When the height of the cross section of the auxiliary grid 2 is larger than 8 mu m, the silver paste consumption is still large, and the effect of further reducing the silver paste consumption cannot be achieved. When the height of the cross section of the auxiliary grid 2 is smaller than 3 mu m, on one hand, the transmission resistance of the auxiliary grid 2 is obviously increased to influence the current transmission effect, and on the other hand, the auxiliary grid 2 is also influenced by the volatilization of organic matters in silver paste due to high-temperature sintering, so that the risk of grid breakage occurs. Therefore, the cross section height range of the auxiliary grid 2 in the embodiment of the utility model can avoid the condition that the transmission resistance is increased to influence the current transmission and can reduce the risk of grid breakage on the basis of being beneficial to further reducing the silver paste consumption and the cost.

As an alternative embodiment, the purpose of reducing the cross-sectional height of the secondary grating 2 can be achieved by further optimizing the screen structure in the screen printing technique. In the embodiment of the utility model, the auxiliary grid 2 is obtained by screen printing, the wire diameter of the screen is 6-15 mu m, the yarn thickness is 12-17 mu m, and the film thickness is 1.5-10 mu m. Wherein the wire diameter of the screen is 6 μm to 15 μm includes any point value within the numerical range, for example, the wire diameter of the screen is 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 11 μm, 12 μm, 13 μm, 14 μm or 15 μm. Yarn thicknesses of 12 μm to 17 μm include any point in the range of values, for example yarn thicknesses of 12 μm, 13 μm, 14 μm, 15 μm, 16 μm or 17 μm. The film thickness of 1.5 μm to 10 μm includes any value within the range of values, for example, film thickness of 1.5 μm, 2 μm, 2.5 μm, 3 μm, 4 μm, 5 μm, 5.5 μm, 6 μm, 8 μm, 8.5 μm, 9 μm or 10 μm.

The wire diameter, the yarn thickness and the film thickness of the screen plate are further reduced to the ranges, so that the height of the cross section of the auxiliary grid 2 is reduced to 3-8 mu m, and the purposes of further reducing the silver paste consumption and reducing the cost are achieved. Preferably, the wire diameter of the screen is 6-11 mu m, and the film thickness is 2-6 mu m, so that the height of the cross section of the auxiliary grid 2 is controlled and reduced in the range, and the service life of screen printing is not influenced by the lower total thickness of the screen cloth.

In the embodiment of the utility model, the number of the main grids 1 is preferably 13 to 16. For example, the SMBB (SuperMulti-bus) technology is adopted to control and obtain a larger number of main grids 1 with smaller spacing, for example, the number of main grids 1 is 13, 14, 15 or 16. The reasonable increase of the number of the main grids 1 can reduce the transmission distance of the surface auxiliary grids 2, so that the grid line transmission resistance is reduced, and the series resistance is reduced, thereby further weakening the influence on the series resistance caused by the reduction of the cross section height of the auxiliary grids 2, and being beneficial to further simultaneously taking into account the improvement of the photoelectric conversion efficiency and the reduction of the production cost.

In a second aspect, the present utility model provides a solar cell comprising a solar cell substrate, and an electrode structure according to the first aspect on the solar cell substrate. The solar cell adopts the electrode structure, which is beneficial to improving the photoelectric conversion efficiency and reducing the production cost.

The solar cell may be a passivation contact solar cell, a heterojunction solar cell, a back contact solar cell or a stacked solar cell. The electrode structure described in the first aspect is applicable to the various solar cells described above.

The solar cell substrate is a semiconductor substrate, and may be a silicon substrate, for example. The solar cell substrate has a first surface and a second surface that are disposed opposite to each other, and the electrode structure may be disposed on the first surface, the second surface, or both surfaces.

In a third aspect, the present utility model provides a photovoltaic module formed by connecting and packaging solar cells as described in the second aspect in series and/or parallel.

In a fourth aspect, the present utility model provides an electrical device comprising an electrical device body and a solar cell as described in the second aspect for powering the electrical device body. The power utilization device may be, for example, an automobile or an airplane, or may be a mobile phone, a smart watch, or the like.

The technical scheme and effects of the embodiments of the present utility model are further described below with reference to more specific embodiments.

Example 1

The embodiment provides a solar cell, which comprises a solar cell substrate and an electrode structure positioned on the back surface of the solar cell substrate. The solar cell substrate is a 182 size silicon wafer. The electrode structure includes:

the auxiliary grid is arranged perpendicular to the first main grid;

the bonding pad comprises a first bonding pad and a second bonding pad, and the first bonding pad is arranged at the junction of the first main gate and the second main gate; the second pads are distributed on the first main gate along the first direction.

The first bonding pad and the second bonding pad are rectangular bonding pads, the length of the first bonding pad along the second direction is 0.9mm, the width of the first bonding pad along the first direction is 0.75mm, the length of the second bonding pad along the second direction is 0.7mm, and the width of the second bonding pad along the first direction is 0.55mm. The first direction is the length extending direction of the first main grid, and the second direction is the length extending direction of the auxiliary grid.

Wherein the height of the cross section of the auxiliary grid along the direction perpendicular to the second direction is 4.48 mu m, the width is 42.73 mu m, the auxiliary grid is obtained by screen printing, the mesh number of the screen printing is 520 meshes, the line diameter is 15 mu m, the yarn thickness is 12 mu m, and the film thickness is 3 mu m. The number of the main grids is 16, and the distance between the adjacent main grids is 10.8mm.

Example 2

The present embodiment provides a solar cell differing from the solar cell of embodiment 1 only in the sub-grids of the electrode structure, in which the height of the sub-grids along the cross section perpendicular to the second direction is 3 μm, the wire diameter of the screen is 6 μm, the yarn thickness is 14 μm, and the film thickness is 2 μm.

Example 3

The present embodiment provides a solar cell differing from the solar cell of embodiment 1 only in the sub-grids of the electrode structure, in which the height of the sub-grids along the cross section perpendicular to the second direction is 7.5 μm, the wire diameter of the screen is 9 μm, the yarn thickness is 17 μm, and the film thickness is 10 μm.

Example 4

The present embodiment provides a solar cell, which is different from the solar cell of embodiment 1 only in the pad size of the electrode structure, in this embodiment, the first pad and the second pad are rectangular pads, the length of the first pad along the second direction is 0.6mm, the width of the first pad along the first direction is 0.4mm, the length of the second pad along the second direction is 0.4mm, and the width along the first direction is 0.35mm.

Example 5

The present embodiment provides a solar cell, which is different from the solar cell of embodiment 1 only in the size of the bonding pad of the electrode structure, in this embodiment, the first bonding pad and the second bonding pad are rectangular bonding pads, the length of the first bonding pad along the second direction is 1.1mm, the width of the first bonding pad along the first direction is 0.8mm, the length of the second bonding pad along the second direction is 0.8mm, and the width along the first direction is 0.7mm.

Comparative example 1

This comparative example provides a solar cell which differs from the solar cell of example 1 only in the size of the bonding pads of the electrode structure. In this comparative example, the first pad and the second pad were rectangular pads, the length of the first pad in the second direction was 1.2mm, the width in the first direction was 0.9mm, the length of the second pad in the second direction was 0.9mm, and the width in the first direction was 0.75mm.

Comparative example 2

This comparative example provides a solar cell, which differs from the solar cell of example 1 only in the electrode structure. In this comparative example, the height of the sub-grids in the cross section perpendicular to the second direction was 8.81 μm, the width was 34.69 μm, the wire diameter of the screen was 19 μm, the yarn thickness was 15 μm, the film thickness was 4 μm, and the number of the main grids was 12.

Comparative example 3

This comparative example provides a solar cell which differs from the solar cell of example 1 only in the number of main grids of the electrode structure. In this comparative example, the number of main grids was 12, and the pitch between adjacent main grids was 15mm. Compared with comparative example 3, the space between the main grids is reduced by 4.2mm, and the transmission distance of the surface auxiliary grids is shortened, so that the grid line transmission resistance is reduced, the series resistance is reduced, and the influence on the series resistance possibly caused by the reduction of the height of the auxiliary grids is further weakened.

The solar cells of examples 1 to 3 and comparative examples 1 to 2 were subjected to electrical property tests, and the results are shown in table 1 below.

Table 1 results of performance test of solar cells of examples 1 to 5 and comparative examples 1 to 2

As can be seen from the above table, compared with comparative examples 1 to 3, the electrode structure of the embodiment of the utility model can obviously reduce the consumption of silver paste under the condition that the overall photoelectric conversion efficiency is improved, and is beneficial to saving the cost. As can be seen from the test results of comparative example 1 and example 1, after the size of the bonding pad is reduced, the photoelectric conversion efficiency (Eta), the open circuit voltage (Uoc), the short circuit current (Isc) and the like are all improved, so that the metallization area of the solar cell is reduced, the metal contact recombination is reduced, the open circuit voltage is improved, and the related passivation layer burning-through area is changed due to the reduction of the metallization area, the passivation effect is better, and the open circuit voltage is also improved.

As can be seen from comparing the test results of the embodiment 1 and the comparative example 2, the electrode structure obtained by adjusting the screen structure parameters to reduce the height of the auxiliary grid and simultaneously adjusting the number of the main grids in the embodiment of the utility model has the advantages that the photoelectric conversion efficiency (Eta) can be improved by 0.096%, the open circuit voltage (Uoc) can be improved by 1.1mV, the short circuit current (Isc) can be improved by 24.7mA, and the silver paste consumption can be reduced by 20.5 mg.

As can be seen from comparing the test results of the embodiments 1 and 3, the embodiment of the present utility model reduces the distance between adjacent main gates by increasing the number of main gates, thereby shortening the carrier transmission path, reducing the transmission resistance, and further improving all the photoelectric conversion efficiency (Eta), particularly the short-circuit current (Isc). Meanwhile, the silver paste consumption is still reduced by 18.4mg, and the requirements of improving the solar cell performance and reducing the cost can be simultaneously met by adding the main grid. As can be seen from comparative examples 1, 2 and 3, the present utility model has more remarkable effect of improving the overall performance of the solar cell by optimizing the number of main grids and the related structural parameters of the sub-grids together.

The electrode structure, the solar cell, the photovoltaic module and the power utilization device disclosed in the embodiments of the present utility model are described in detail, and specific examples are applied to illustrate the principles and the implementation modes of the present utility model, and the description of the above embodiments is only used to help understand the technical scheme and the core idea of the present utility model: meanwhile, as those skilled in the art will vary in the specific embodiments and application scope according to the idea of the present utility model, the present disclosure should not be construed as limiting the present utility model in summary.

Claims

1. An electrode structure, characterized in that the electrode structure comprises:

the auxiliary grid is arranged perpendicular to the first main grid;

2. The electrode structure of claim 1, wherein the pads are rectangular, oval, diamond-shaped, or hexagonal in shape.

3. The electrode structure according to claim 1, wherein a height of the sub-gate in a cross section perpendicular to the second direction is 3 μm to 8 μm.

4. The electrode structure according to claim 3, wherein the sub-grid is obtained by screen printing, the screen has a line diameter of 6 μm to 15 μm, a yarn thickness of 12 μm to 17 μm, and a film thickness of 1.5 μm to 10 μm.

5. The electrode structure according to claim 4, wherein the screen has a wire diameter of 6 μm to 11 μm and a film thickness of 2 μm to 6 μm.

6. The electrode structure of claim 3, wherein the number of the main grids is 13 to 16.

7. A solar cell, characterized in that the solar cell comprises a solar cell substrate and an electrode structure according to any of claims 1 to 6 on the solar cell substrate.

8. The solar cell of claim 7, wherein the solar cell is a passivation contact solar cell, a heterojunction solar cell, a back contact solar cell, or a stacked solar cell.

9. A photovoltaic module, characterized in that it is obtained by connecting solar cells according to claim 7 or 8 in series and/or in parallel.

10. An electricity consumption device, characterized in that it comprises an electricity consumption device body and a solar cell according to claim 7 or 8 for powering the electricity consumption device body.