CN103943694A - Front electrode structure of solar cell - Google Patents

Abstract

The invention discloses a front electrode structure of a solar cell, which is configured on a substrate of the solar cell, and comprises: a plurality of bus electrode nets, the bus electrode nets being disposed on the substrate in a spaced-apart relationship, each of the bus electrode nets including: a bus electrode; and a plurality of finger electrodes arranged at intervals on two sides of the bus electrode. The front electrode structure of the solar cell can reduce the area of the front electrode of the solar cell, thereby achieving the specific effects of reducing the cost and not reducing the power generation efficiency.

Description

Front electrode structure of solar cell

technical field

The invention relates to a solar cell, in particular to a solar cell with a front electrode spacer.

Background technique

At present, due to the rapid development of technology in the solar cell industry, the luminous efficiency of the solar cell is getting higher and higher. But on the other hand, due to the fierce competition in the solar cell industry, all solar cell developers are striving to move toward higher efficiency and lower cost.

Please refer to FIG. 1A , which is a schematic diagram of the structure of a front electrode of a solar cell in the prior art. It is a front electrode structure using three bus electrodes 120 (Bus Bar Electrode) and multiple finger electrodes (Finger Electrode) 110 disposed on the substrate 100 . Since the front electrode including the bus electrode 120 and the finger electrode 110 is arranged on the light-receiving surface of the solar cell, the area occupied by it will have two effects: 1. The larger the area, the greater the silver paste requirement. The larger the cost, the higher the cost; 2. The larger the area, the occupied area will reduce the incident area of sunlight, which will reduce the efficiency of solar power generation.

However, not only the area occupied by the front electrode is related to the efficiency of solar power generation, but also the structure of the front electrode, that is, the impedance of the front electrode, will also affect the efficiency of the solar cell. Therefore, how to reduce the production cost without reducing the power generation efficiency has become one of the competitive weapons in the current solar cell industry.

In addition, please refer to FIG. 1B , which is an enlarged schematic diagram of a partial area 1 of the front electrode structure of a solar cell in the prior art. In order to reduce the area of the front electrode, the most common method is to reduce the line width of the finger electrodes. For example, the line width of 20-100 microns can be achieved at present. The smaller the line width, the more effectively the light-receiving area of the solar cell can be increased, thereby improving the power generation efficiency. However, the smaller the line width is, the more likely it is to cause other problems, such as the defects 111 and 112 in FIG. 1B . This broken line area is often produced during the formation of the front electrode, and it is considered as a defective product, and the broken line or the part of the extremely narrow line will cause the problem of uneven resistance distribution, which will cause the problem of reducing the power generation efficiency .

Therefore, how to reduce the area of the front electrode and improve the uniform distribution of resistance has become another core of the technology development of solar cell manufacturers.

Contents of the invention

The object of the present invention is to provide a front electrode structure of a solar cell, so as to reduce the area of the front electrode of the solar cell, so as to achieve specific effects of reducing cost without reducing power generation efficiency.

In order to achieve the above object, the present invention provides a front electrode structure of a solar cell, configured on a substrate of a solar cell, comprising: multiple sets of bus electrode nets, the bus electrode nets are isolated from each other and arranged on the substrate, each of the bus electrodes The electrode network includes: a bus electrode; a plurality of finger electrodes arranged at intervals on both sides of the bus electrode.

Wherein, the adjacent bus electrode grids are separated from each other by a width, and the width is between 30 microns and 5000 microns.

Wherein, the bus electrodes of the bus electrode network are substantially parallel to each other.

Wherein, the adjacent part of the bus electrode network forms an included angle with the bus electrode of the bus electrode network.

Wherein, the center of the bus electrode is located at the center of the bus electrode network where it is located.

Among them, each bus electrode network further includes:

At least one connection line, each of the connection lines connects the finger electrodes to connect the finger electrodes to each other.

Wherein, the line width of each connecting line is between 20 microns and 200 microns.

Wherein, the connection line is linear, wavy or tooth-shaped.

Wherein, the at least one connection line is disposed adjacent to the bus electrode network, and connects the finger electrodes to connect the finger electrodes to each other.

Wherein, each of the connection lines connects the open ends of the finger electrodes to connect the finger electrodes to each other.

Wherein, two adjacent connecting lines are spaced apart from each other by a width, and the width is between 30 microns and 5000 microns.

Wherein, the at least one connection line is disposed adjacent to the bus electrode network, and connects the open ends of the finger electrodes to connect the finger electrodes to each other.

Wherein, the at least one connection line is arranged on both sides of each bus electrode network, and connects the open ends of the finger electrodes to connect the finger electrodes to each other.

Wherein, the two bus electrode nets disposed on both sides of the substrate further include:

A connection line is arranged on the side of the bus electrode network away from the other bus electrode network, and the connection line connects the open ends of the finger electrodes to connect the finger electrodes to each other.

The front electrode structure of the present invention can reduce the cost of the solar cell without compromising the power generation efficiency of the solar cell. In addition, the specific effects of improving the resistance uniformity of the finger electrodes of the solar cell and increasing the product yield without detracting from the power generation efficiency of the solar cell can also be achieved.

The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments, but not as a limitation of the present invention.

Description of drawings

FIG. 1A is a schematic diagram of the structure of a front electrode of a solar cell in the prior art.

FIG. 1B is a partially enlarged schematic view of the prior art solar cell front electrode structure shown in FIG. 1A .

FIG. 2A is a schematic diagram of an embodiment of the solar cell front electrode structure of the present invention.

FIG. 2B is a partially enlarged schematic view of the front electrode structure of the solar cell of the present invention shown in FIG. 2A .

FIG. 3A is a schematic diagram of another embodiment of the solar cell front electrode structure of the present invention.

FIG. 3B is a partially enlarged schematic view of the solar cell front electrode structure of the present invention shown in FIG. 3A .

FIG. 4A is a schematic diagram of another embodiment of the solar cell front electrode structure of the present invention.

FIG. 4B is a partially enlarged schematic view of the front electrode structure of the solar cell of the present invention shown in FIG. 4A .

FIG. 5A is a schematic diagram of another embodiment of the solar cell front electrode structure of the present invention.

FIG. 5B is a partially enlarged schematic view of the front electrode structure of the solar cell of the present invention shown in FIG. 5A .

Among them, reference signs:

1: local area

2: local area

3, 4, 5: bus electrode network

100: Substrate

110: finger electrode

111, 112: defects

120: bus electrode

130: connecting line

131, 132: connection line

Detailed ways

Please refer to FIG. 2A, which is a schematic diagram of an embodiment of the solar cell front electrode structure of the present invention; please refer to FIG. 2B simultaneously, which is an enlarged schematic diagram of a partial area 2 of the solar cell front electrode structure of the present invention in FIG. 2A. The solar cell front electrode structure of the present invention includes: a plurality of bus electrodes 120 (three bus electrodes 120 in this embodiment), and a plurality of finger electrodes 110 . Wherein, the bus electrodes 120 are disposed on the substrate 100 at intervals. In essence, in the embodiment of FIG. 2A , the front electrode structure of the solar cell includes three sets of bus electrode nets 3 , 4 , 5 , and these three sets of bus electrode nets 3 , 4 , 5 are isolated from each other and arranged on the substrate 100 . Each bus electrode network includes: a bus electrode 120 ; a plurality of finger electrodes 110 arranged at intervals on both sides of the bus electrode 120 .

Each individual bus electrode network can independently concentrate the current generated in its covered area to the bus electrode 120 via the finger electrodes 110 therein. Since the bus electrode nets are isolated from each other, the current generated in the area covered by each bus electrode net will not flow to other areas. In addition, the bus electrodes 120 in the bus electrode grids 3 , 4 , 5 are substantially parallel to each other. Also, the center of the bus electrode 120 is located at the center of the bus electrode network where it is located.

Adjacent bus electrode nets are spaced apart by a width d, such as the bus electrode nets 3 and 4 shown in FIG. 2B . The width d is between 30 microns and 5000 microns, and within this range, the efficiency of the solar cell does not decrease.

As far as the actual manufacturing process is concerned, no matter it is by one-time screen printing or two-time screen printing, those skilled in the art can use the usual manufacturing technology in this field to realize the present invention after the disclosure of the present invention. The making of the invention is not repeated here.

Next, please refer to FIG. 3A, which is a schematic diagram of another embodiment of the solar cell front electrode structure of the present invention; please refer to FIG. 3B synchronously, which is an enlarged schematic diagram of a partial area 2 of the solar cell front electrode structure of the present invention in FIG. 3A . In this embodiment, a configuration of a plurality of connection lines 130 is added. The connecting wire 130 connects the open ends of the finger electrodes to connect the finger electrodes to each other, as shown in FIGS. 3A and 3B . Wherein, the line width of each connection line 130 is between 20 micrometers (μm) and 200 micrometers (μm), and within this range, the solar cell will not produce a situation where the efficiency of the solar cell is significantly lowered. The two adjacent connection lines 130 are spaced apart by a width d, and the width d is between 30 micrometers and 5000 micrometers. In addition, as far as the embodiment shown in FIG. 3A and 3B is concerned, the connecting line 130 is linear, and as far as other embodiments are concerned, the connecting line 130 may also be wave-shaped or tooth-shaped, or other shapes. As for the connection lines of different shapes, there is no need for a fixed distance from each other, as long as the width d of the distance between each other is kept within the range of the aforementioned width d.

In the embodiment of FIG. 3A, 3B, after the open ends of the finger electrodes 110 are connected to each other by the connecting wire 130, the high Resistive problems (as generated during printing) are improved and efficiency can be increased.

The embodiments shown in FIGS. 2A , 2B, 3A and 3B are embodiments in which the adjacent parts of two adjacent sets of bus electrode grids are parallel to the bus electrode 120 . In terms of other embodiments, the adjacent parts of two adjacent sets of bus electrode grids 3 , 4 may not be parallel to the bus electrodes 120 .

Please refer to FIG. 4A, which is a schematic diagram of another embodiment of the solar cell front electrode structure of the present invention; please refer to FIG. 4B simultaneously, which is a partially enlarged schematic diagram of the solar cell front electrode structure of the present invention in FIG. 4A. In this embodiment, the adjacent positions of the two bus electrode grids 3 and 4 form an included angle θ with the bus electrode 120, and the included angle θ may be 0 to ±10 degrees.

Similarly, in the embodiments shown in FIGS. 4A and 4B , connection lines can also be added to connect the open ends of the finger electrodes 110 to each other. In addition, the solar cell industry often uses electroluminescence (EL) to detect disconnection. When a disconnection occurs as shown in FIG. 1B , the solar cell will be considered as a defective product. Using the connecting wire design of the present invention can effectively improve the problem of broken wires (black spots and black lines on the EL) and improve product yield.

Please refer to FIG. 5A , which is a schematic diagram of another embodiment of the solar cell front electrode structure of the present invention; please refer to FIG. 5B simultaneously, which is a partially enlarged schematic diagram of the solar cell front electrode structure of the present invention in FIG. 5A . The connection lines 131 , 132 are opposite to each other and spaced apart by a width d, and the width d is between 30 μm and 5000 μm. In addition to the linear shape, the connection line 130 can also be wave-shaped or tooth-shaped, or other shapes, as mentioned above.

Summarizing the above embodiments, there are several ways to configure the connection lines as follows:

I. the most side (also can be referred to as frame) of the bus electrode network 3,5 that is configured on the left and right sides, that is, the embodiment of Fig. 2A, 4A; In other words, the connection line can be configured on the bus electrode network On the side away from the other bus electrode network, connecting wires connect the finger electrodes to connect the finger electrodes to each other. The connection wires can be connected to the open ends of the finger electrodes, or can be connected to the finger electrodes in other ways, for example, close to the center of the finger electrodes, close to the open ends with a certain distance, and so on.

II. Arranged on both sides of each bus electrode network 3, 4, 5, as shown in the embodiment of Fig. 3A, 5A. In other words, the connecting wires are arranged on both sides of each bus electrode network, and connect the finger electrodes to connect the finger electrodes to each other. The connection wires can be connected to the open ends of the finger electrodes, or can be connected to the finger electrodes in other ways, for example, close to the center of the finger electrodes, close to the open ends with a certain distance, and so on.

III. It is only disposed adjacent to the bus electrode network, that is, adjacent to the bus electrode network 3, 4, and disposed adjacent to the bus electrode network 4, 5 (not shown), in this embodiment , that is, does not contain the border. In other words, the connecting wires are disposed adjacent to the bus electrode network, and connect the finger electrodes to connect the finger electrodes to each other. The connection wires can be connected to the open ends of the finger electrodes, or can be connected to the finger electrodes in other ways, for example, close to the center of the finger electrodes, close to the open ends with a certain distance, and so on.

In some embodiments of the present invention, the front electrode structure of the present invention can reduce the cost of the solar cell without compromising the power generation efficiency of the solar cell. In addition, in some other embodiments of the present invention, the resistance uniformity of the finger electrodes of the solar cell can be improved to improve the product yield without compromising the power generation efficiency of the solar cell.

Certainly, the present invention also can have other various embodiments, without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and deformations according to the present invention, but these corresponding changes All changes and modifications should belong to the protection scope of the claims of the present invention.

Claims (14)

1. A front electrode structure of a solar cell configured on a substrate of a solar cell, characterized in that the front electrode structure comprises: A plurality of sets of bus electrode nets, the bus electrode nets are isolated from each other and arranged on the substrate, each of the bus electrode nets includes: a bus electrode; and A plurality of finger electrodes are arranged on both sides of the bus electrode at intervals. 2 . The front electrode structure of a solar cell according to claim 1 , wherein the adjacent bus electrode grids are separated from each other by a width, and the width is between 30 micrometers and 5000 micrometers. 3 . The front electrode structure of a solar cell according to claim 1 , wherein the bus electrodes of the bus electrode network are substantially parallel to each other. 4 . 4 . The front electrode structure of a solar cell according to claim 1 , wherein the adjacent portion of the bus electrode network forms an included angle with the bus electrode of the bus electrode network. 5. The front electrode structure of a solar cell according to claim 1, wherein the center of the bus electrode is located at the center of the bus electrode network where it is located. 6. The front electrode structure of a solar cell according to claim 1, wherein each bus electrode network further comprises: At least one connection line, each of the connection lines connects the finger electrodes to connect the finger electrodes to each other. 7 . The front electrode structure of a solar cell according to claim 6 , wherein the width of each connecting line is between 20 μm and 200 μm. 8 . The front electrode structure of a solar cell according to claim 6 , wherein the connection line is in a line shape, a wave shape or a tooth shape. 9 . The front electrode structure of a solar cell according to claim 6 , wherein the at least one connection line is disposed adjacent to the bus electrode network, and connects the finger electrodes to connect the finger electrodes to each other. 10 . The front electrode structure of a solar cell according to claim 6 , wherein each of the connection lines connects the open ends of the finger electrodes to connect the finger electrodes to each other. 11 . 11 . The front electrode structure of a solar cell according to claim 10 , wherein two adjacent connection lines are spaced apart from each other by a width, and the width is between 30 micrometers and 5000 micrometers. 12. The front electrode structure of a solar cell according to claim 10, wherein the at least one connection line is disposed adjacent to the bus electrode network, and connects the open ends of the finger electrodes so that the finger electrodes are connected to each other. connect. 13. The front electrode structure of a solar cell according to claim 10, wherein the at least one connection line is arranged on both sides of each of the bus electrode nets, and connects the open ends of the finger electrodes to make the finger electrodes The electrodes are connected to each other. 14. The front electrode structure of a solar cell according to claim 1, wherein the two bus electrode nets disposed on both sides of the substrate further comprise: A connection line is arranged on the side of the bus electrode network away from the other bus electrode network, and the connection line connects the open ends of the finger electrodes to connect the finger electrodes to each other.