CN104409527A - Solar cell front grid line structure, solar cell and solar cell module - Google Patents

Abstract

The invention discloses a solar cell front grid line structure. The front grid line structure is structurally composed of at least three main grid lines and auxiliary grid lines which are arranged in a mode that a certain angle is reserved between the main grid lines and the auxiliary grid lines; the auxiliary grid lines between the adjacent main grid lines are of a non-continuous structure in the transverse direction, the auxiliary grid lines between the adjacent main grid lines are divided into left auxiliary grid lines and right auxiliary grid lines by a longitudinal partition; the left auxiliary grid lines and the right auxiliary grid lines are in asymmetrical arrangement in the transverse direction; the left ends of the left auxiliary grid lines are connected with the main grid line at the left side of the left auxiliary grid lines, and the right ends of the left auxiliary grid lines are connected in a segmented mode by short grid lines; the right ends of the right auxiliary grid lines are connected with the main grid line at the right side of the right auxiliary grid lines, and the left ends of the right auxiliary grid lines are connected in a segmented mode by short grid lines. Correspondingly, the invention further provides a solar cell applying the front grid line structure and a solar cell module. Adoption of the front grid line structure can effectively reduce the production cost and improve the photoelectric conversion efficiency of solar cells.

Description

Solar cell front grid structure, solar cell sheet and solar cell module

technical field

The present invention relates to the grid structure design of front electrode printing in solar cells, more specifically, the present invention relates to a solar cell front grid line structure, solar cells and solar cell components.

Background technique

In today's energy shortage situation, solar cells, as a renewable resource, have attracted widespread attention. In recent years, it has been vigorously developed, and large-scale solar cell factories have been established all over the world. While pursuing high conversion efficiency, reducing costs has also become a key point for various manufacturers to improve their competitiveness.

Crystalline silicon solar cells are mainly composed of four parts: front electrode, anti-reflection film, PN junction, and back electrode. The main function of the front electrode is to export the carriers generated by the PN junction by using high-conductivity metals for use by external circuits. The traditional front electrode is composed of a main gate and a sub-gate, which are continuous and intersected in an "H"-shaped structure. The role of the auxiliary gate is to collect current from the PN junction and deliver it to the main gate. The function of the main grid is to transport the current collected from the auxiliary grid in a certain direction in the component and conduct it to the welding strip.

The sub-gate of traditional crystalline silicon solar cells is a continuous structure, that is, the sub-gate continuous structure connected between two main grids. The continuous sub-gate is made of conductive silver paste. The sub-gates of conventional crystalline silicon solar cells are generally completely filled with conductive silver paste, which not only increases the huge unit consumption cost of silver paste; During the process, it is easy to generate a broken grid, which in turn affects the photoelectric conversion efficiency of the solar cell.

Therefore, there is a need for a method that can solve the problems of large consumption of silver paste and easy breakage of the sub-gates of crystalline silicon solar cells.

Contents of the invention

In order to solve the problems in the prior art that the consumption of silver paste in crystalline silicon solar cells is large, the auxiliary grid is easy to break, and the photoelectric conversion efficiency of the cell is reduced, the present invention provides a solar cell front grid structure, a solar cell and Solar modules.

According to one aspect of the present invention, a solar cell front grid structure is provided, the front grid structure is composed of at least 3 main grids and auxiliary grids arranged at a certain angle with the main grids;

The auxiliary grids between adjacent main grids have a discontinuous structure in the transverse direction, and the auxiliary grids between adjacent main grids are divided into left auxiliary grids and right auxiliary grids by longitudinal partitions;

The left auxiliary grid and the right auxiliary grid are arranged asymmetrically in the lateral direction;

The left end of the left auxiliary grid is connected to the main grid on the left, and the right end of the left auxiliary grid is connected in sections by short grid lines;

The right end of the right auxiliary gate is connected to the main gate on the right, and the left end of the right auxiliary gate is connected in sections by short gate lines.

According to a specific embodiment of the present invention, the short gate lines are connected to the right ends of 3 to 5 left auxiliary gates;

The short gate lines are connected to the left ends of 3-5 of the right auxiliary gates.

According to yet another specific embodiment of the present invention, the number of said busbars is 3-10.

According to yet another specific implementation manner of the present invention, the width of the busbar is 0.5mm˜2.0mm.

According to yet another specific embodiment of the present invention, the busbar is a segmented or continuous structure.

According to yet another specific implementation manner of the present invention, the number of the sub-gates is 80-130.

According to yet another specific embodiment of the present invention, the main gate and the auxiliary gate are vertically arranged.

According to yet another specific embodiment of the present invention, the partition has a width of 0.1mm-2mm.

According to another aspect of the present invention, a solar cell sheet is provided, including a substrate, a PN junction located on the front surface of the substrate, a front electrode located on the front surface of the substrate, and a back electrode located on the back surface of the substrate , characterized in that the front electrode structure adopts the solar cell front grid line structure according to any one of claims 1-7.

According to still another aspect of the present invention, a solar cell module is provided, comprising a bottom plate, a plurality of solar cell sheets as claimed in claim 8, and a welding ribbon, wherein:

The plurality of solar cells are arranged sequentially on the base plate, wherein the front surfaces of the plurality of solar cells face the same direction;

The plurality of solar cells are connected in series through the ribbon.

In the solar cell front grid line structure provided by the present invention, the sub-grid between two adjacent main grids is divided into a left sub-grid and a right sub-grid, which saves the amount of paste used and reduces the production cost; and because the original One of the auxiliary grids is separated into two parts, which effectively reduces the risk of the auxiliary grid breaking during production or use, and improves the photoelectric conversion efficiency of the solar cell.

Description of drawings

Other characteristics, objects and advantages of the present invention will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings:

Fig. 1 is a structural schematic diagram of a specific embodiment of a front grid line structure of a solar cell provided according to the present invention;

FIG. 2 is a partially enlarged schematic diagram of the front grid wire structure of the solar cell shown in FIG. 1 .

The same or similar reference numerals in the drawings represent the same or similar components.

Detailed ways

The following disclosure provides many different embodiments or examples for implementing different structures of the present invention. To simplify the disclosure of the present invention, components and arrangements of specific examples are described below. Furthermore, the present invention may repeat reference numerals and/or letters in different instances. This repetition is for the purpose of simplicity and clarity and does not in itself indicate a relationship between the various embodiments and/or arrangements discussed. It should be noted that components illustrated in the figures are not necessarily drawn to scale. Descriptions of well-known components and processing techniques and processes are omitted herein to avoid unnecessarily limiting the present invention.

Referring to FIG. 1 and FIG. 2 , the solar cell front grid structure provided by the present invention is composed of at least 3 main grids and a sub-grid 3 arranged at a certain angle to the main grid 1 . Preferably, the main grid 1 and the auxiliary grid 3 are vertically arranged at 90°.

Wherein, the number of the bus bars 1 is 3-10, for example: 3, 6 or 10. The number of the sub-gates is 80-130, for example: 80, 100 or 130.

Optionally, the busbar 1 has a width of 0.5mm˜2.0mm, for example: 0.5mm, 1.3mm or 2.0mm. In addition, the structure of the busbar 1 is not limited, that is, a continuous structure or a segmented structure may be used. It is preferable to use a segmented structure as the busbar 1, which can reduce the amount of silver paste used and reduce costs; moreover, it can also reduce light shading and improve the utilization rate of light.

The sub-gates 3 between adjacent main grids 1 are discontinuous in the transverse direction, and the sub-gates 3 between adjacent main grids 1 are divided into left sub-gates 31 and right sub-gates 32 by vertical partitions 2 . The width of the partition 2 is 0.1mm-2.0mm, for example: 0.1mm, 1.0mm or 2.0mm.

Preferably, the partition 2 has the same width as the main grid 1 .

The left sub-gate 31 and the right sub-gate 32 are arranged asymmetrically in the lateral direction. Since the left sub-gate 31 and the right sub-gate 32 are separated by the partition 2, if a symmetrical structure is to be formed, when the left sub-gate 31 or the right sub-gate 32 is abnormally printed and the grid is broken, it will not be able to effectively collect Carriers affect the conversion efficiency of the battery and increase the production defect rate, resulting in cost waste. However, the left sub-grid 31 and the right sub-grid 32 in the present invention can be printed in an asymmetric arrangement, which greatly reduces the complexity of the production process and reduces the production cost; at the same time, it reduces the failure rate of electrode printing and improves production efficiency. efficiency and yield.

In order to ensure that the left sub-gate 31 and the right sub-gate 32 separated by the partition 2 can conduct electricity continuously, the left end of the left sub-gate 31 is connected to the main grid 1 on the left, and the right end of the left sub-gate 31 is connected by a short gate Lines 41 are connected in segments; the right end of the right sub-gate 32 is connected to the main grid 1 on the right, and the left end of the right sub-gate 32 is connected in segments by short gate lines 42 . Too many sub-gates connected by short gate lines will increase the risk of grid breakage and reduce cell efficiency; while too few sub-gates connected by short gate lines will increase process complexity and increase production costs. Therefore, preferably, the short gate line 41 connects the right ends of 3-5 left sub-gates 31 ; the short gate line 42 connects the left ends of 3-5 right sub-gates 32 .

According to another aspect of the present invention, there is also provided a solar cell, comprising a substrate (usually a square silicon wafer), a PN junction positioned on the front surface of the substrate, a front electrode positioned on the front surface of the substrate, and a back electrode located on the back surface of the substrate. Wherein, the structure of the front electrode adopts the front grid line structure of the solar cell mentioned above, and for the sake of simplicity, the structure of the front electrode will not be repeated here. The back electrode is located on the back surface (ie, the backlight surface) of the solar battery sheet, and the structure of the back electrode is not particularly limited in the present invention. Preferably, the back electrode adopts the same structure as the front gate line structure.

Due to the adoption of the front grid line structure of the aforementioned solar cell, the solar cell provided by the present invention has a simple preparation process, a low defect rate of the cell due to broken auxiliary grids, and high photoelectric conversion efficiency. In addition, due to the use of the grid line structure on the front side of the solar cell, the solar cell provided by the present invention has a different appearance structure from the traditional solar cell. In this way, when the solar battery sheet provided by the present invention is used to form a solar module, new possibilities can be provided for the circuit design and appearance structure of the solar battery module.

According to yet another aspect of the present invention, a solar cell module is also provided, including a bottom plate and a plurality of the aforementioned solar cells, and for the sake of brevity, the structure of the solar cells will not be described again here. The light-absorbing surfaces of all the solar cells face upward, that is, the front surfaces of the solar cells face the same direction. Adjacent solar cells are connected in series through a ribbon, that is, one end of the ribbon is welded to the main grid of one solar cell, and the other end of the ribbon is welded to the back electrode of another solar cell, so that the solar cell All solar cells in the module are connected in series.

Compared with traditional solar cell components, the solar cell component provided by the invention has high photoelectric conversion efficiency; it has various circuit designs and appearance structures.

Although the example embodiments and their advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made to these embodiments without departing from the spirit and scope of the invention as defined by the appended claims. For other examples, those of ordinary skill in the art will readily understand that the order of process steps may be varied while remaining within the scope of the present invention.

In addition, the scope of application of the present invention is not limited to the process, mechanism, manufacture, material composition, means, method and steps of the specific embodiments described in the specification. From the disclosure of the present invention, those of ordinary skill in the art will easily understand that for the processes, mechanisms, manufacturing, material compositions, means, methods or steps that currently exist or will be developed in the future, they are implemented in accordance with the present invention Corresponding embodiments described which function substantially the same or achieve substantially the same results may be applied in accordance with the present invention. Therefore, the appended claims of the present invention are intended to include these processes, mechanisms, manufacture, material compositions, means, methods or steps within their protection scope.

Claims (10)

1. A front grid line structure of a solar cell, wherein the front grid line structure is composed of at least 3 main grids and auxiliary grids arranged at a certain angle with the main grids; The auxiliary grids between adjacent main grids have a discontinuous structure in the transverse direction, and the auxiliary grids between adjacent main grids are divided into left auxiliary grids and right auxiliary grids by longitudinal partitions; The left auxiliary grid and the right auxiliary grid are arranged asymmetrically in the lateral direction; The left end of the left auxiliary grid is connected to the main grid on the left, and the right end of the left auxiliary grid is connected in sections by short grid lines; The right end of the right auxiliary gate is connected to the main gate on the right, and the left end of the right auxiliary gate is connected in sections by short gate lines. 2. The front grid line structure according to claim 1, wherein the short grid lines are connected to the right ends of 3 to 5 left auxiliary grids; The short gate lines are connected to the left ends of 3-5 of the right auxiliary gates. 3 . The front gridline structure according to claim 1 , wherein the number of the busbars is 3-10. 4 . 4. The front grid line structure according to claim 1, wherein the busbar has a width of 0.5mm˜2.0mm. 5. The front grid line structure according to claim 1, wherein the busbar is a segmented or continuous structure. 6 . The front gridline structure according to claim 1 , wherein the number of the sub-gates is 80-130. 7. The front grid line structure according to claim 1, wherein the main grid and the auxiliary grid are vertically arranged. 8. The front grid line structure according to claim 1, wherein the width of the partition is 0.1 mm˜2 mm. 9. A solar cell, comprising a substrate, a PN junction positioned on the front surface of the substrate, a front electrode positioned on the front surface of the substrate, and a back electrode positioned on the back surface of the substrate, wherein the The front electrode structure adopts the solar cell front grid line structure according to any one of claims 1-7. 10. A solar cell assembly, comprising a base plate, a plurality of solar cell sheets and welding strips as claimed in claim 8, wherein: The plurality of solar cells are arranged sequentially on the base plate, wherein the front surfaces of the plurality of solar cells face the same direction; The plurality of solar cells are connected in series through the ribbon.