JP3184336U - Solar cell with tilted finger electrode - Google Patents

Abstract

A solar cell having an inclined finger electrode is provided.
A solar cell includes a battery body, one or more bus bar electrodes, and a plurality of finger electrodes. The battery body generates a plurality of charges by converting light energy into electrical energy. The bus bar electrode is formed on the front surface of the battery body. The finger electrode is formed on the front surface of the battery body and is electrically connected to the bus bar electrode. The included angle between the finger electrode and the bus bar electrode is not equal to 90 degrees, and the finger electrode and the bus bar electrode collect and output a plurality of charges.
[Selection] Figure 1

Description

The present invention relates to a solar cell, and more particularly to a solar cell having tilted finger electrodes.

A solar cell is a photoelectric element that converts energy. After irradiating sunlight, light energy is converted into electric energy, and this type of photoelectric element is referred to as a solar cell. From a physics perspective, it is also called a photovoltaic (photovoltaic, abbreviated PV) battery.

A conventional solar cell manufacturing method first provides a silicon substrate, and then performs chemical vapor deposition (for example, PECVD) on the silicon substrate to form an antireflection layer. Then, pattern screen printing and co-firing are performed to form an electrode on the antireflection layer, and the electrode penetrates the antireflection layer and is electrically connected to the silicon substrate.

  A front electrode of a conventional solar cell usually includes two bus bar electrodes and a plurality of finger electrodes. For a long time, both the finger electrode and the bus bar electrode were in an orthogonal state. Therefore, when the length direction of the bus bar electrode is a vertical direction, the length direction of the finger electrode is a horizontal direction. Due to this kind of customary regulations, the design of solar cells is limited and the light energy conversion efficiency of solar cells cannot be improved.

  An object of the present invention is to provide a solar cell having tilted finger electrodes to improve current collection efficiency.

  In order to achieve the above object, the present invention provides a solar cell including a battery body, one or more bus bar electrodes, and a plurality of finger electrodes. The battery body converts light energy into electrical energy and generates a plurality of charges. The bus bar electrode is formed on the front surface of the battery body. The finger electrode is formed on the front surface of the battery body and is electrically connected to the bus bar electrode. The included angle between the finger electrode and the bus bar electrode is not equal to 90 degrees, and the finger electrode and the bus bar electrode collect and output a plurality of charges.

  According to the embodiment of the present invention, the length of the inclined finger electrode per unit area is longer than the length of the conventional horizontal finger electrode without changing the number of finger electrodes, so that the current collecting efficiency can be improved. . In addition, since the finger electrode can have different design parameters, the sum of the length from all points located in front of the solar cell to the finger electrode and / or the bus bar electrode achieves the minimum value, The efficiency of the solar cell can be improved. In addition, since the height of the finger electrode is usually higher than that of the bus bar electrode, the inclination direction of the finger electrode can be adjusted to be parallel to the incident direction of sunlight by adjusting the angle of the finger electrode. Based on the shape of the object, it can be adjusted appropriately to prevent the sunlight from being blocked, and the power generation efficiency can be improved.

FIG. 1 is an overhead view of a solar cell according to an embodiment of the present invention. FIG. 2 is a bottom view of a solar cell according to an embodiment of the present invention. 3A is a cross-sectional view taken along line 3A-3A in FIG. 3B is a cross-sectional view taken along line 3B-3B of FIG. 4 to 14 are overhead views of solar cells which are a plurality of modified examples of FIG.

<Example>
FIG. 1 is an overhead view of a solar cell 1 according to an embodiment of the present invention. FIG. 2 is a bottom view of the solar cell 1 according to the embodiment of the present invention. 3A and 3B are cross-sectional views taken along lines 3A-3A and 3B-3B in FIG. 1, respectively. As shown in FIGS. 1 to 3B, the solar cell 1 of the present embodiment includes a battery body 10, one or more bus bar electrodes 20, and a plurality of finger electrodes 30. The solar cell may be a single crystal, polycrystalline or thin film solar cell.

  The battery body 10 generates a plurality of charges by converting light energy into electrical energy. In the present embodiment, the battery body 10 includes a substrate 11, and the substrate 11 includes a first type semiconductor layer 11A and a second type semiconductor layer 11B. For example, a P-type silicon substrate (referred to as a second-type semiconductor layer) may be used, and an N-type semiconductor layer (referred to as an N-type semiconductor layer) may be formed on the upper surface by doping. Alternatively, P-type or N-type materials can be grown for each layer by various deposition techniques.

  In addition, the solar cell 1 further includes an antireflection layer 12 positioned on the first-type semiconductor layer 11A of the substrate 11, and one or more bus bar electrodes 20 and a plurality of finger electrodes 30 form the antireflection layer 12. It penetrates and is electrically connected to the first type semiconductor layer 11A. The antireflection layer 12 has an effect of preventing reflection, does not reflect the light incident on the antireflection layer 12, and improves the usage rate of light.

  In the present embodiment, three bus bar electrodes 20 will be described as an example. However, the present invention is not limited to this, and the bus bar electrode 20 may be one, two, four, five, or other numbers. The bus bar electrode 20 is formed on the front surface 10 </ b> A of the battery body 10.

  The finger electrode 30 is formed on the front surface 10 </ b> A of the battery body 10 and is electrically connected to one or a plurality of bus bar electrodes 20. The included angle Ang between the finger electrode 30 and the bus bar electrode 20 is not 90 degrees, and the plurality of finger electrodes 30 and the one or more bus bar electrodes 20 collect and output a plurality of charges. In particular, the depression angle Ang may be between 0 and 90 degrees. Also, it includes 0 degrees but does not include 90 degrees.

  In addition, the solar cell 1 can further include one or a plurality of back surface electrodes 40 and a back surface metal layer 50. In this embodiment, three back electrodes will be described as an example, but the present invention is not limited to this. The number of back electrodes may be one, two, four or five. The back electrode 40 is formed on the back surface 10B of the battery body 10 and is electrically connected to the second type semiconductor layer 11B. The back surface 10B is located on the opposite side of the front surface 10A.

  The back metal layer 50 is formed on the back surface 10B of the battery body 10, and the one or more back electrodes 40 penetrate the back metal layer 50 and are electrically connected to the second type semiconductor layer 11B.

  In an embodiment of the present invention, the depression angle Ang is between 89 degrees and 74 degrees, and in particular, the depression angle Ang is between 88 degrees and 86 degrees.

  In FIG. 1, the depression angle Ang is equal to 80 degrees, and all of the finger electrodes 30 are inclined in the same direction, that is, all are inclined from the upper left to the lower right.

  In addition, the solar cell 1 can further include a peripheral electrode 60 that is formed on the front surface 10A of the battery body 10 and surrounds and electrically connects the bus bar electrode 20 and the plurality of finger electrodes 30. It is advantageous for collection and transmission. In this embodiment, as shown in FIG. 1, the peripheral electrode 60 is substantially parallel to the periphery of the battery body 10, so that some of the peripheral electrodes 60 are parallel to the bus bar electrode 20 and some of the other peripherals The electrode 60 is perpendicular to the bus bar electrode 20.

  In particular, line 3A-3A in FIG. 1 crosses bus bar electrode 20 and peripheral electrode 60, but does not cross finger electrode 30. 1 crosses the bus bar electrode 20, the peripheral electrode 60, and the finger electrode 30. Thus, as shown, FIGS. 3A and 3B are somewhat different.

  In addition, in FIG. 1, the finger electrode 30 is an asymmetric finger electrode, which is not symmetric with respect to any one bus bar electrode 20.

  4 to 12 are overhead views of solar cells which are a plurality of modified examples of FIG. As shown in FIG. 4, the depression angle Ang is equal to 75 degrees, and all of the finger electrodes 30 are inclined in the same direction. As shown in FIG. 5, the depression angle Ang is equal to 85 degrees, and all the finger electrodes 30 are inclined in the same direction. As shown in FIG. 6, the included angle Ang is equal to 88 degrees (which may also be referred to as 92 degrees), and all of these finger electrodes 30 are symmetrical with respect to the intermediate bus bar electrode 20, and The electrode 30 forms an arrow-shaped pattern. That is, the left half finger electrode 30 is inclined from the lower left to the upper right, the right half finger electrode 30 is inclined from the upper left to the lower right, and the right half finger electrode 30 is made to be in relation to the intermediate bus bar electrode 20. The right half finger electrode 30 is obtained as a mirror image. In FIG. 6, the solar cell has a direction on the appearance, and is not confused during assembly. Usually, when connecting a plurality of solar cells in series and parallel in a module factory, especially when the assembly process is interrupted, the assembly staff can know the directionality by using this kind of arrow sign, which is inconvenient when manufacturing solar cells. The problem of uniform characteristics can be overcome. In addition, it also has an aesthetic or special appearance effect visually.

  As shown in FIG. 7, the solar cell of this example has two bus bar electrodes 20. As shown in FIG. 8, the solar cell of this example has four bus bar electrodes 20. Thus, the tilted finger electrode can be applied to any situation, and the design can be changed according to each situation.

  When a plurality of solar cells 1 are connected in series, the bus bar electrode 10A on the front surface of the battery body 10 is connected to the back electrode 50 of the adjacent solar cell, and the solar cell module is assembled in this way. The appearance of all solar cell modules appears to have slanted finger electrodes, and when using the solar cell of FIG. 6, it becomes more obvious and uniform due to the direction indicated by the arrow sign, and when installed on the top surface of the building Further, a necessary direction can be indicated, for example, the direction of the arrow can be indicated to the north, south, east, west, and the like.

  As shown in FIG. 9, this embodiment is similar to FIG. 1, except that a plurality of finger electrodes 30 intersect each other. If the finger electrode 30 is not perpendicular to the bus bar electrode 20, the angle of intersection may be any angle. Such a design can also improve efficiency.

  As shown in FIG. 10, this embodiment is similar to FIG. 1 except that a plurality of finger electrodes 30 are parallel to the bus bar electrode 20, and the solar cell 1 further includes the bus bar electrode 20 and the finger electrode 30. Includes a plurality of laterally connected electrodes 70 electrically connected to each other. Similarly, the horizontal connecting electrode 70 is located in front of the battery body 10 and penetrates the antireflection layer. The width of the horizontal connecting electrode 70 can be adjusted as necessary, but is preferably smaller than the width of the bus bar electrode 20 in order to prevent a reduction in light shielding rate.

  As shown in FIG. 11, this embodiment is similar to FIG. 1, except that these finger electrodes 30 are horizontal, but the bus bar electrodes 20 have two inclined shapes. The shape of the back electrode 50 may thus be two inclined shapes or may be vertical. Such a design can also achieve the effects of the present invention, increase the total length of the bus bar electrodes or finger electrodes, and improve the efficiency.

  As shown in FIG. 12, the present embodiment is similar to FIG. 6, with the difference that all finger electrodes 30 are each divided into four blocks of an inclined array. Such a design can also achieve the effect of the present invention, and can increase the total length of the bus bar electrode or the finger electrode and improve the efficiency.

  As shown in FIG. 13, this embodiment is similar to FIG. 6, except that the finger electrodes 30 are symmetrical with respect to the left and right busbar electrodes 20 and have a visual effect having a different pattern. . 6 and 13 can also be combined so that the finger electrodes 30 are symmetrical with respect to the three bus bar electrodes 20.

  As shown in FIG. 14, the present example is similar to FIG. 9, and the difference is that the solar cell 1 further includes a connection electrode 35 connected to the adjacent finger electrode 30. The connection electrode 35 may be vertical (for example, parallel to the bus bar electrode 20 as shown in the left connection electrode 35) or non-vertical (for example, shown in the right connection electrode 35). The connection electrode 35 may be perpendicular to the finger electrode 30 or not perpendicular to the finger electrode 30. The number of connection electrodes 35 may be one or more. The connection electrodes 35 may be connected to only some finger electrodes 30 or may not be connected to all finger electrodes 30. The width of the connection electrode 35 may be equal to the width of the finger electrode 30 or may be slightly larger than the width of the finger electrode 30. This contributes to the derivation of charges and improves the efficiency of the solar cell. In particular, the dotted vertical or inclined connection electrode 35 may be installed between the bus bar electrode 20 and the peripheral edge of the solar cell, and is not necessarily installed between the two bus bar electrodes 20 as shown in the figure. do not have to.

  In the present invention, the solar cell having the above-described configuration allows the length of the inclined finger electrode per unit area to be longer than the length of the conventional horizontal finger electrode without changing the number of finger electrodes. The current collection efficiency can be increased. As a result of the calculation, compared to the horizontal finger electrode, the total length of the finger electrode having an inclination angle of 87 degrees is increased by 0.9%, and the total length of the finger electrode having an inclination angle of 85 degrees is increased by 0.88%, The total length of finger electrodes with a tilt angle of 80 degrees increased by 0.9%, the total length of finger electrodes with a tilt angle of 75 degrees increased by 0.89%, and a tilt angle of 88 degrees similar to FIG. 12 was used. The total length of the finger electrode is increased by 1.2%. Also, by providing the finger electrode with different design parameters so that all the points located in front of the solar cell reach the finger electrode and / or minimize the total length of the busbar electrode, Increase efficiency. Also, since the height of the finger electrode is usually higher than that of the bus bar electrode, the angle of the finger electrode may be adjusted so that the direction of inclination of the finger electrode is parallel to the incident direction of sunlight. Since it can adjust appropriately based on, it can reduce that sunlight is interrupted and can improve power generation efficiency. Further, the inclined finger electrode can indicate the direction of the solar cell during manufacture, which can be referred to by an assembly staff or a client, and can be easily assembled by an unaccustomed assembly staff or a client.

Ang: depression angle 1: solar cells 3A-3A and 3B-3B: wire 10: battery body 10A: front surface 10B: back surface 11: substrate 11A: first type semiconductor layer 11B: second type semiconductor layer 12: antireflection layer 20: Bus bar electrode 30: Finger electrode 35: Connection electrode 40: Back electrode 50: Back metal layer 60: Peripheral electrode 70: Horizontal connection electrode

FIG. 1 is an overhead view of a solar cell according to an embodiment of the present invention. FIG. 2 is a bottom view of a solar cell according to an embodiment of the present invention. 3A is a cross-sectional view taken along line 3A-3A in FIG. 3B is a cross-sectional view taken along line 3B-3B of FIG. FIG. 4 is an overhead view of a solar cell which is a plurality of modified examples of FIG. FIG. 5 is an overhead view of a solar cell which is a plurality of modified examples of FIG. FIG. 6 is an overhead view of a solar cell which is a plurality of modified examples of FIG. FIG. 7 is an overhead view of a solar cell which is a plurality of modified examples of FIG. FIG. 8 is an overhead view of a solar cell which is a plurality of modified examples of FIG. FIG. 9 is an overhead view of a solar cell which is a plurality of modified examples of FIG. FIG. 10 is an overhead view of a solar cell which is a plurality of modified examples of FIG. FIG. 11 is an overhead view of a solar cell which is a plurality of modified examples of FIG. FIG. 12 is an overhead view of a solar cell which is a plurality of modified examples of FIG. FIG. 13 is an overhead view of a solar cell which is a plurality of modified examples of FIG. FIG. 14 is an overhead view of a solar cell which is a plurality of modified examples of FIG.

Claims (12)

A battery body that converts light energy into electrical energy and generates multiple charges;
One or more bus bar electrodes formed on one front surface of the battery body;
A plurality of finger electrodes formed on the front surface of the battery body and electrically connected to the one or more bus bar electrodes;
The depression angle between the finger electrode and the bus bar electrode is not equal to 90 degrees, and the plurality of finger electrodes and the one or more bus bar electrodes collect and output the plurality of charges. battery. The battery body includes a substrate, the substrate includes a first type semiconductor layer and a second type semiconductor layer,
The solar cell is
An antireflection layer located in the first type semiconductor layer of the substrate;
One or more back electrodes formed on the back surface of the battery body and electrically connected to the second type semiconductor layer;
A back metal layer formed on the back surface of the battery body;
Further comprising
Here, the one or more bus bar electrodes and the plurality of finger electrodes penetrate the antireflection layer and are electrically connected to the first-type semiconductor layer, and the one or more back electrodes are the back surface The solar cell according to claim 1, wherein the solar cell is electrically connected to the second-type semiconductor layer through a metal layer.   The solar cell according to claim 1, wherein the depression angle is between 89 degrees and 74 degrees.   2. The solar cell according to claim 1, wherein the one or more bus bar electrodes are two, three, four, or five bus bar electrodes.   The solar cell according to claim 1, wherein the one or more bus bar electrodes are three bus bar electrodes, and all of the plurality of finger electrodes are inclined in the same direction.   The one or more bus bar electrodes are three bus bar electrodes, and all of the plurality of finger electrodes are symmetrical with respect to an intermediate bus bar electrode located in the middle of the three bus bar electrodes; The solar cell according to claim 1, wherein the plurality of finger electrodes form an arrow-shaped pattern.   2. The solar cell according to claim 1, further comprising a peripheral electrode formed on the front surface of the battery body and surrounding and electrically connecting the one or more bus bar electrodes and the plurality of finger electrodes.   The solar cell according to claim 1, wherein the plurality of finger electrodes intersect each other.   The solar cell of claim 1, wherein the finger electrode is parallel to the one or more bus bar electrodes.   The solar cell according to claim 9, further comprising a plurality of laterally connected electrodes electrically connected to the one or more bus bar electrodes and the plurality of finger electrodes.   The solar cell according to claim 1, wherein the finger electrodes are asymmetric finger electrodes.   The solar cell according to claim 1, further comprising a connection electrode connected to the adjacent finger electrode.