CN219677266U

CN219677266U - Solar cell

Info

Publication number: CN219677266U
Application number: CN202321133949.XU
Authority: CN
Inventors: 李宏伟; 刘志远; 刘绍阳; 陈达明; 张学玲
Original assignee: Trina Solar Co Ltd
Current assignee: Trina Solar Co Ltd
Priority date: 2023-05-11
Filing date: 2023-05-11
Publication date: 2023-09-12
Anticipated expiration: 2033-05-11

Abstract

The present utility model provides a solar cell including: a silicon wafer and a plurality of gate lines. The silicon wafer comprises a light receiving surface and a backlight surface which are oppositely arranged. The grid lines are arranged on the light receiving surface and comprise a plurality of metal points arranged at intervals and metal lines connected with the metal points. The sum of the areas of the plurality of gate lines is 20% -50% of the area of the light receiving surface. The grid line is composed of the metal points and the metal lines, and compared with the scheme of the existing grid line, the whole area of the grid line is smaller, so that the shading area of the grid line on the light receiving surface is reduced, the light utilization rate is effectively improved to enhance the short-circuit current, the photoelectric conversion efficiency of the solar cell is further improved, and the market competitiveness of products is improved.

Description

Solar cell

Technical Field

The utility model relates to the technical field of batteries, in particular to a solar cell.

Background

The solar cell is a photoelectric semiconductor sheet which directly generates electricity by utilizing sunlight, and comprises a silicon wafer and grid lines arranged on a light receiving surface of the silicon wafer, wherein the grid lines are used for converging and outputting electric power generated by the silicon wafer, but the proportion of the grid lines shielding the light receiving surface is larger due to the defect of the existing structure, so that the photoelectric conversion efficiency of the whole solar cell is influenced, and the electric conversion efficiency is reduced.

Disclosure of Invention

The utility model aims to provide a solar cell with higher photoelectric conversion efficiency.

In order to achieve the above object, the present utility model provides a solar cell, comprising: the silicon wafer comprises a light receiving surface and a backlight surface which are oppositely arranged; the grid lines are arranged on the light receiving surface and comprise a plurality of metal points which are arranged at intervals and a metal line connected with the metal points; the width of the metal line is smaller than the width of the metal point along the width direction of the grid line; the sum of the areas of the grid lines is 20% -50% of the area of the light receiving surface.

The solar cell sheet as described above, wherein the sum of the areas of the plurality of metal points is 75% to 85% of the area of the grid line.

The solar cell panel is characterized in that the metal points are round in shape, and the diameters of the metal points are 30-150 um.

The solar cell sheet is characterized in that the distance between two adjacent metal points is 200um-2mm.

The solar cell sheet is characterized in that the metal points are aluminum points, and the metal wires are silver wires.

The solar cell panel is characterized in that the light receiving surface is provided with a plurality of grooves, and each metal point is located in each groove.

The solar cell as described above, wherein the metal points have a height greater than the depth of the grooves.

The solar cell as described above, wherein the metal dots cover the grooves.

The solar cell panel is characterized in that the grid lines are printed lines.

The solar cell panel comprises the metal wires, wherein the metal wires comprise a plurality of metal sub-wires, one metal point is arranged between two adjacent metal sub-wires, and the two metal sub-wires are connected with the metal point.

Compared with the prior art, the technical scheme has the following advantages:

compared with the scheme of the existing grid line, the grid line is composed of the metal points and the metal lines, and the overall area of the grid line is smaller, so that the shading area of the grid line on the light receiving surface is reduced, the light utilization rate is effectively improved to enhance the short-circuit current, the photoelectric conversion efficiency of the solar cell is further improved, and the market competitiveness of products is improved.

Drawings

The following drawings are only for purposes of illustration and explanation of the present utility model and are not intended to limit the scope of the utility model. Wherein:

fig. 1 is a schematic view showing a partial structure of a first embodiment of a solar cell according to the present utility model;

FIG. 2 is a schematic view showing a partial structure of a second embodiment of a solar cell according to the present utility model;

fig. 3 is a schematic view of a partial cross-sectional structure of a third embodiment of a solar cell according to the present utility model.

Reference numerals illustrate:

10. a silicon wafer; 11. a light receiving surface; 12. a backlight surface;

20. a gate line; 21. a metal dot; 22. a metal wire; 221. a metal sub-line;

30. a groove.

Detailed Description

The utility model is further described in detail below by means of the figures and examples. The features and advantages of the present utility model will become more apparent from the description.

The word "exemplary" is used herein to mean "serving as an example, embodiment, or illustration. Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. Although various aspects of the embodiments are illustrated in the accompanying drawings, the drawings are not necessarily drawn to scale unless specifically indicated.

In addition, the technical features described below in the different embodiments of the present utility model may be combined with each other as long as they do not collide with each other. The following discussion provides various embodiments of the utility model. Although each embodiment represents a single combination of applications, different embodiments of the utility model may be substituted or combined, and the utility model is therefore to be considered to include all possible combinations of the same and/or different embodiments described. Thus, if one embodiment comprises A, B, C and another embodiment comprises a combination of B and D, then the present utility model should also be considered to include embodiments comprising one or more of all other possible combinations comprising A, B, C, D, although such an embodiment may not be explicitly recited in the following. In addition, the technical features described below in the different embodiments of the present utility model may be combined with each other as long as they do not collide with each other.

As shown in fig. 1, the solar cell provided by the present utility model includes: a silicon wafer 10 and a plurality of gate lines 20.

The silicon wafer 10 includes a light receiving surface 11 and a backlight surface 12 disposed opposite to each other.

The grid lines 20 are arranged on the light receiving surface 11, and the grid lines 20 comprise a plurality of metal points 21 arranged at intervals and metal lines 22 connected with the metal points 21; and the distance between two adjacent metal points 21 is 200um-2mm. In one embodiment of the present utility model, the metal dots 21 are circular in shape, and the diameter of the metal dots 21 is 30um to 150um to satisfy the carrier transport characteristics.

The sum of the areas of the plurality of gate lines 20 is 20% -50% of the area of the light receiving surface 11.

The grid line 20 in the utility model is composed of the metal points 21 and the metal lines 22, and compared with the scheme of the existing grid line, the whole area of the grid line 20 is smaller, so that the shading area of the grid line 20 on the light receiving surface 11 is reduced, the light utilization rate is effectively improved to enhance the short-circuit current, the photoelectric conversion efficiency of the solar cell is further improved, and the market competitiveness of the product is improved.

As shown in fig. 2, in one embodiment of the present utility model, the metal line 22 includes a plurality of metal sub-lines 221, a metal point 21 is disposed between two adjacent metal sub-lines 221, and both metal sub-lines 221 are connected to the metal point 21.

The above structure reduces the use of the material for forming the metal lines 22 and the overall manufacturing price of the gate lines 20, thereby reducing the overall manufacturing cost of the product and further increasing the market competitiveness of the product.

In one embodiment of the present utility model, the sum of the areas of the plurality of metal points 21 is 75% to 85% of the area of the gate line 20.

Under the condition that the grid line 20 can effectively guide current, the shading area of the grid line 20 on the light receiving surface 11 is effectively reduced, so that the light utilization rate is effectively improved to enhance the short-circuit current, the photoelectric conversion efficiency of the solar cell is further improved, and the market competitiveness of products is improved.

In one embodiment of the present utility model, metal dots 21 are aluminum dots and metal lines 22 are silver lines.

The conductivity of silver is better, and under the condition of meeting the use requirement, the width of the metal wire 22 can be smaller, so that the whole area of the grid wire 20 is smaller, the shading area of the grid wire 20 on the light receiving surface 11 is reduced, the light utilization rate is effectively improved to enhance the short-circuit current, the photoelectric conversion efficiency of the solar cell is further improved, and the market competitiveness of the product is improved. In addition, the structure of aluminum dots and silver wires improves the conductivity of the electrode, so that the filling factor of the battery is improved, the photoelectric conversion efficiency of the solar cell is improved, and the market competitiveness of the product is improved.

As shown in fig. 3, in one embodiment of the present utility model, a plurality of grooves 30 are disposed on the light receiving surface 11, and each metal point 21 is located in the groove 30. In one embodiment of the present utility model, the height of the metal dots 21 is greater than the depth of the grooves 30. In another embodiment of the utility model, the metal dots 21 cover the openings of the grooves 30.

The provision of the grooves 30 increases the contact area between the metal points 21 and the silicon wafer 10, thereby increasing the connection force between the metal points 21 and the silicon wafer 10, so that the metal points 21 are more firmly fixed on the silicon wafer 10.

In one embodiment of the utility model, the grid lines are printed lines, namely, the grid lines are made in a screen printing mode, on one hand, the screen printing operation is simple, so that the production efficiency of the solar cell is improved, the production and manufacturing cost of the product is reduced, and the market competitiveness of the product is improved. On the other hand, the screen printing can enable the grid lines to be firmly fixed on the silicon wafer, and the situation that partial grid lines fall off and grid breakage occurs is reduced.

The manufacturing process of the grid line is as follows: carrying out laser grooving on the light receiving surface of the silicon wafer, wherein the laser grooving can be round, square, elliptic and the like, and the laser grooving is preferably round; the technological parameters such as laser slotting power, frequency and the like are specifically set according to the parameters of an actual battery; the laser grooving is exemplified by a round shape, the diameter of the laser grooving is 30um-150um, and the interval between two laser grooving is 200um-2mm; the laser device for laser grooving can be picosecond laser, nanosecond laser and the like; forming a grid line of the backlight surface by penetrating silver paste on the backlight surface, printing aluminum paste at a laser grooving position to form aluminum paste points, wherein the printing area of the aluminum paste is larger than the laser grooving area; silver paste (non-burning-through paste) is printed between two aluminum paste points to form silver paste lines, and the aluminum paste points and the silver paste lines form grid lines of a light receiving surface.

In the description of the present utility model, it should be noted that the terms "mounted," "connected," and "connected" are to be construed broadly, unless otherwise specifically defined and limited. The term "plurality" means two or more, unless expressly defined otherwise. The specific meaning of the above terms in the present utility model will be understood in specific cases by those of ordinary skill in the art.

The utility model has been described above in connection with preferred embodiments, which are, however, exemplary only and for illustrative purposes. On this basis, the utility model can be subjected to various substitutions and improvements, and all fall within the protection scope of the utility model.

Claims

1. A solar cell, the solar cell comprising:

the silicon wafer comprises a light receiving surface and a backlight surface which are oppositely arranged; and

the grid lines are arranged on the light receiving surface and comprise a plurality of metal points arranged at intervals and metal lines connected with the metal points;

the width of the metal line is smaller than the width of the metal point along the width direction of the grid line;

the sum of the areas of the grid lines is 20% -50% of the area of the light receiving surface.

2. The solar cell according to claim 1, wherein,

the sum of the areas of the metal points is 75% -85% of the area of the grid line.

3. The solar cell according to claim 1, wherein,

the metal points are round in shape, and the diameters of the metal points are 30um-150um.

4. The solar cell according to claim 3, wherein,

the distance between two adjacent metal points is 200um-2mm.

5. The solar cell according to claim 1, wherein,

the metal points are aluminum points, and the metal wires are silver wires.

6. The solar cell according to claim 1, wherein,

the light receiving surface is provided with a plurality of grooves, and each metal point is arranged in each groove.

7. The solar cell according to claim 6, wherein,

the height of the metal points is larger than the depth of the grooves.

8. The solar cell according to claim 6, wherein,

the metal points cover the grooves.

9. The solar cell according to claim 1, wherein,

the grid lines are printed lines.

10. The solar cell according to claim 1, wherein,

the metal wire comprises a plurality of metal sub-wires, one metal point is arranged between two adjacent metal sub-wires, and the two metal sub-wires are connected with the metal point.