TWI620334B - Back contact solar cell and module thereof - Google Patents

Abstract

A back contact solar cell module includes a plurality of back contact solar cells and a bus bar. The back contact solar cells are arranged along a length direction and include a solar substrate, a three electrode group and a first connection electrode. The solar substrate has a backlight surface; the electrode groups are alternately arranged in a width direction along the width direction of the backlight surface, and the electrode groups each comprise a lengthwise extending interdigitated bus bar and a plurality of yoke bus bars The intersecting fingers are finger electrodes, and the finger bus bars of each electrode group are disposed at a spacing interval, and the length of the finger finger electrodes is less than the pitch and greater than half of the pitch. The first connecting electrode is used to connect a plurality of electrode groups which belong to a first electrical group. The busbar is connected in series with a plurality of back contact solar cells along the length direction.

Description

Back contact solar cell and its module

The present invention relates to a back contact solar cell and a module thereof, and more particularly to a method for shortening a current transmission distance by using a plurality of electrode groups, and electrically connecting a plurality of electrode groups with a first connection electrode Contact solar cells and their modules.

In recent years, due to the rapid development of science and technology, the demand for energy has increased. However, the rapid development of science and technology has also caused damage to the ecological environment. Therefore, the development of clean energy that will not damage the ecological environment has become a key development goal of countries around the world, such as wind power. Water, solar energy, etc., among which solar energy is the most easily accessible natural resource, so the development of solar cells has also received much attention.

In general, a solar cell is a photovoltaic element formed by bonding P-type and N-type semiconductors, and electrodes are provided on the upper surface and the lower surface to guide current. When the solar cell is exposed to sunlight, the solar cell will Convert light energy directly into electrical energy. Since the upper surface of the solar cell is used to receive sunlight, in order to increase the light absorption area of the upper surface, the upper electrode is moved to the lower surface, and the positive and negative electrodes are disposed opposite to the lower surface. Research on contact solar cells is proposed.

The back contact solar cell mainly has a positive electrode and a negative electrode arranged in a staggered manner on the back surface of the solar substrate. Therefore, the positive electrode and the negative electrode often require a long finger electrode to collect the current generated by the solar substrate. Please refer to the first figure, which is a schematic plan view showing a back-contact solar cell of the prior art. As shown in the figure, a back contact solar cell 100 includes a solar substrate 1 and a plurality of finger electrodes 2, and the finger electrodes 2 are alternately disposed on the solar substrate 1, and the finger electrodes 2 are respectively coupled to the solar substrate. The two poles of 1 are guided by a current generated by the light irradiation of the solar substrate 1; wherein the current is transmitted from the solar substrate 1 to the finger electrodes 2, and then transmitted to the bus bars by the finger electrodes 2. However, the longer the current is transmitted from the finger electrode 2 to the bus bar, the larger the amount of current collected, and the greater the ohmic power loss (I ² R). In order to reduce the ohmic power loss, the resistivity required for the electrode material needs to be lower or a thicker metal layer is required to lower the impedance, but the electrode material having a low resistivity (such as pure silver) is expensive, and the thicker metal layer is a material. The amount of use is large, which in turn increases production costs.

In view of the fact that back-contact solar cells in the prior art require long finger electrodes, the longer the path of current flow from the finger electrodes to the bus bars, the greater the amount of current collected, resulting in ohmic power loss (ohmic) Power loss=I ² R) is also larger. In order to reduce the ohmic power loss, the resistivity required for the electrode material needs to be lower or a thicker metal layer is required to lower the impedance, but the electrode material having a low resistivity (such as pure silver) is expensive, and the thicker metal layer is a material. The amount of use is large, which in turn increases production costs.

Accordingly, the main object of the present invention is to provide a back contact solar cell and a module thereof, which are mainly disposed on a backlight surface of a solar substrate by staggering at least three electrode groups, thereby shortening current transfer by the finger electrodes. The path to the busbar reduces the loss of ohmic power. In addition, at least one first connecting electrode is used to electrically connect the same electrode group to make the current collection more uniform.

The necessary technical means for solving the problems of the prior art is to provide a back contact solar cell comprising a solar substrate, at least three electrode groups and at least one first connecting electrode. The solar substrate has a backlight surface; the electrode groups are alternately arranged in a width direction along the width direction of the backlight surface, and the electrode groups each comprise a finger busbar extending along a length direction perpendicular to the width direction. And a plurality of interdigitated fingers intersecting the interdigitated busbars, and the interdigitated busbars of the two adjacent electrode sets are disposed at a spacing interval, and the length of the interdigitated finger electrodes is less than the spacing and greater than One and a half of the spacing. The first connecting electrode is used to connect the electrode group to belong to at least two of the first electrical properties, and the first electrical system is one of a positive electrode and a negative electrode.

Compared with the prior art, the current back contact solar cell requires a long finger electrode, but the longer the current is transmitted from the finger electrode to the bus bar, the larger the amount of current collected, and the ohmic power loss. (ohmic power loss = I ² R) is also larger. In order to reduce the ohmic power loss, the resistivity required for the electrode material needs to be lower, or a thicker metal layer is required to lower the impedance, but the electrode material having a low resistivity (such as sterling silver) is expensive, and the thicker metal The layer has a larger amount of material, which in turn increases production costs.

Therefore, in the back contact solar cell and the module thereof provided by the present invention, the three electrode groups are alternately arranged in a staggered manner on the backlight surface of the solar substrate, thereby shortening the current by the interdigitated finger electrode. Passing to the path of the finger busbar to effectively reduce the loss of ohmic power by shortening the path length of the finger-to-finger electrode to the finger busbar, thereby effectively contacting the solar cell with resistance in the back of the present invention When the material with higher coefficient forms the finger electrode, the same current transmission efficiency can be achieved, thereby reducing the production cost. In addition, when the electrode group of the same electrical property is electrically connected by the first connection electrode, current transmission can be effectively made more uniform.

In a preferred embodiment of the present invention, the electrode group includes two first finger electrode groups and at least one second finger electrode group, and the first finger electrode groups each include a first finger bus and a plurality of a finger-finger electrode, the first finger finger electrode is extended by at least one side of the first finger bus bar; the second finger electrode group is located between the two first finger electrode groups, and the second The finger electrode group includes a second finger bus bar and a plurality of second finger finger electrodes, and the second finger finger electrode extends from the second finger bus bar to both sides and the first finger finger The electrodes are staggered.

Wherein, since the second interdigitated finger electrode extends from the second interdigitated bus bar to both sides, it can be staggered with the first interdigitated finger electrodes disposed on both sides, compared with the conventional technology. The electrode needs to be extended from the one-finger bus bar to the bus bar of the other finger. The second finger electrode group is disposed between the two first finger electrode groups to make the second finger finger shape. The electrodes are staggered with the first interdigitated finger electrodes, which can not only effectively The current generated by the solar substrate is guided out, and the conduction path of the current to the finger busbar via the interdigitated finger electrode is shortened.

Preferably, in the back contact solar cell, the second finger electrode of the back contact solar cell is plural, and the back contact solar cell further comprises a second connecting electrode, and the second connecting electrode is used for The electrically connected electrode group belongs to at least two of the second electrical properties, and the second electrical system is the other one of the positive electrode and the negative electrode which is different from the first electrical property.

As described above, the back contact solar cell provided by the present invention, in actual use, treats two adjacent first or second finger electrodes as dissimilar electrical according to the requirements of the series connection. The electrodes are such that the back contact solar cell and the other back contact solar cell can be connected in series with each other.

The present invention provides a back contact solar cell module including a plurality of back contact solar cells and at least two bus bars for the necessary technical means for solving the problems of the prior art. The back contact solar cells are arranged along a length direction, and the back contact solar cells each comprise a solar substrate, at least three electrode groups, and at least one first connection electrode. The electrode groups are alternately arranged in a width direction along the width direction on the backlight surface, and the electrode groups each include an interdigitated bus bar extending in the longitudinal direction and a plurality of interdigitated finger electrodes extending in the width direction, and two phases The interdigitated electrode sets have a spacing between the interdigitated bus bars, and the interdigitated finger electrodes are less than the pitch and greater than one-half of the pitch. The first connecting electrode is used to connect the electrode group to at least two of the first electrical properties, and the first electrical system is one of a positive electrode and a negative electrode. The busbars are electrically connected in series along the length of the adjacent back contact solar cells. By confluence With the arrangement of the belt, a plurality of back contact solar cells can be connected in series with each other.

In a preferred embodiment of the present invention, the back contact solar cell module further includes an insulating layer disposed between the first connecting electrode and the bus bar to avoid the confluence and electrically connecting the same back contact solar energy. A short circuit is caused by the electrode group of the battery. Preferably, the material of the insulating layer is polyamidamine.

In a preferred embodiment of the present invention, the electrode group includes two first finger electrode groups and at least one second finger electrode group. The first finger electrode groups each include a first finger bus bar and a plurality of first finger finger electrodes, and the first finger finger electrodes are extended from at least one side of the first finger bus bar, and the second The finger electrode group includes a second finger bus bar and a plurality of second finger finger electrodes, and the second finger finger electrode extends from both sides of the second finger bus bar and is coupled with the first finger The electrodes are staggered. Preferably, in the back contact solar cell module, the second finger electrode group is plural, and the back contact solar cell further comprises a second connection electrode, and the second connection electrode is used to connect the electrode group. Wherein the second electrical system is at least two of the second electrical properties, and the second electrical system is the other one of the positive electrode and the negative electrode different from the first electrical property; further, the second connecting electrode and the busbar are further disposed. There is an insulating layer, and the material of the insulating layer is polyamidamine.

The specific embodiments of the present invention will be further described by the following examples and drawings.

100a, 100b, 100c, 100d, 100e‧‧‧ back contact solar cells

1a, 1b, 1c, 1d, 1e‧‧‧ solar substrates

200a, 200b, 200c, 200d‧‧‧ back contact solar cell modules

21a, 21b, 21d, 21e‧‧‧ first finger fork bus

22a, 22b, 22d, 22e‧‧‧ first finger finger electrode

2a, 2b, 2c, 2d, 2e‧‧‧ first finger electrode group

31a, 31b, 31d, 31e‧‧‧ second finger fork bus

32a, 32b, 32d, 32e‧‧‧ second finger finger electrodes

3a, 3b, 3c, 3d, 3e‧‧‧ second finger electrode group

41a, 41b, 41c, 41d, 41e‧‧‧ first connecting electrode

42a, 42b, 42c, 42e‧‧‧ second connecting electrode

43d‧‧‧first connecting electrode

44d‧‧‧Second connection electrode

4a, 4b, 4c, 4d‧‧‧ confluence

5a, 5b, 5c, 5d‧‧‧ insulation

D1a, D1b, D1c‧‧‧ length direction

D2b‧‧‧width direction

FL1, FL2‧‧‧ length

W1, W2, W2‧‧‧ spacing

The first figure shows a schematic plan view of a back-contact solar cell of the prior art; 2 is a schematic view showing a back contact solar cell according to a first embodiment of the present invention; and a third view showing a back contact solar cell according to a second embodiment of the present invention; A schematic diagram of a back contact solar cell provided by a third embodiment of the present invention; a fifth diagram showing a back contact solar cell module according to a fourth embodiment of the present invention; and a sixth figure showing a fifth embodiment of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 7 is a schematic view showing a back contact solar cell module according to a sixth embodiment of the present invention; and FIG. 8 is a view showing a seventh embodiment of the present invention. A schematic diagram of a back contact solar cell provided; a ninth drawing showing a back contact solar cell module according to an eighth embodiment of the present invention; and a tenth drawing showing the back of the ninth embodiment of the present invention Schematic diagram of a contact solar cell.

Please refer to the second figure. The second figure shows a schematic diagram of the back contact solar cell provided by the first embodiment of the present invention. As shown in the second figure, the back contact solar cell 100a includes a solar substrate 1a, two first finger electrode groups 2a, two second finger electrode groups 3a, a first connecting electrode 41a, and a second connecting electrode 42a. .

The solar substrate 1a has a backlight surface (not shown). The first finger electrode groups 2a are disposed on both sides of the backlight surface, and the first finger electrode groups 2a each include a first finger bus bar 21a and a plurality of first finger finger electrodes 22a. The first interdigitated bus bar 21a extends toward a longitudinal direction D1a and is arranged on the backlight surface in a width direction D2a perpendicular to the longitudinal direction D1a. The first interdigitated finger electrode 22a extends from the first interdigitated bus bar 21a inwardly in the width direction D2a.

The two second finger electrode groups 3a are disposed on the backlight surface at a pitch W1, and are disposed between the two first finger electrode groups 2a at intervals of W1, and the second finger electrode group 3a includes one The second interdigitated bus bar 31a and the plurality of second interdigitated finger electrodes 32a. The second interdigital bus bar 31a extends in the longitudinal direction D1a and is arranged on the backlight surface in the width direction D2a. The second interdigitated finger electrode 32a extends from the second interdigitated bus bar 31a toward the two sides parallel to the width direction D2a, and the second interdigitated finger electrode 32a has a length FL1, and the length FL1 is smaller than The spacing W1 is greater than one half of the spacing W1. Similarly, the length of the first interdigitated finger electrode 22a (not shown) is also smaller than the distance between the second interdigitated busbar 31a and the first interdigitated busbar 21a (Fig. In this case, since the lengths of the finger electrodes (the first interdigitated finger electrode 22a or the second interdigitated finger electrode 32a) are smaller than the two adjacent interdigitated busbars (the first interdigitated busbar 21a and The spacing between the second finger bus bar 31a or the two second finger bus bars 31a), and the length of the finger electrodes is simultaneously greater than half of the pitch, so the finger electrodes do not touch the other finger bus bar, and It can be staggered with the finger electrodes extended by another bus bar.

Wherein, between the second finger electrode group 3a and the first finger electrode group 2a The electrical properties of the adjacent two are different, that is, in the present embodiment, for example, the first finger electrode group 2a of the positive electrode is adjacent to the second finger electrode group 3a of the negative electrode, and the second finger electrode group of the negative electrode is formed. 3a is further adjacent to the second finger electrode group of the positive electrode (different from the other second finger electrode group of the second finger electrode group referred to by the component symbol 3a), and finally the second finger electrode group of the positive electrode is adjacent to the negative electrode a first interdigitated electrode group (different from the other first interdigitated electrode group of the first interdigitated electrode group indicated by the symbol 2a), that is, a staggered arrangement of positive and negative positive and negative; and, the first interdigitated finger electrode 22a And the second interdigitated finger electrodes 32a are also arranged in a staggered manner.

The first finger electrode group 2a and the second finger electrode group 3a are as described above, wherein the electrical properties of any adjacent ones are different, and the first connecting electrode 41a and the second connecting electrode 42a are in the width direction D2a. The first connecting electrode 41a is connected to the first finger electrode group 2a and the second finger electrode group 3a, and the first finger electrode group 2a and the second finger electrode group 3a are connected to the first electrical component (such as the positive electrode, but may also be the negative electrode). The second connecting electrode 41a is connected to the first finger electrode group 2a and the second finger electrode group 3a, and belongs to the second electrical property different from the first electrical property (such as a negative electrode, but may also be a positive electrode) By.

In summary, compared with the conventional back contact solar cell, two first finger electrode groups are disposed on both sides of the backlight surface of the solar substrate. Since the back contact solar cell of the present invention is in the first first fork At least one second finger electrode group is disposed between the electrode groups, so that the length of the first/second finger finger electrodes is smaller than the distance between the bus bars of two adjacent electrode groups and greater than the convergence of two adjacent electrode groups One-and-a-half of the distance between the rows, the effective decreasing current is transmitted to the path of the bus bar via the finger electrodes, thereby reducing the ohmic power loss (I ² R), and since the ohmic power loss is reduced, the material of the electrode can be A conductive metal having a higher resistivity but less expensive or a conductive paste replaces a metal having good electrical conductivity such as pure silver having a low resistivity but expensive, thereby reducing the production cost of the back contact solar cell.

Please refer to the third figure, which is a schematic view showing a back contact solar cell according to a first embodiment of the present invention. As shown, the back contact solar cell 100b includes a solar substrate 1b, six first finger electrode groups 2b, two second finger electrode groups 3b, a first connection electrode 41b, and a second connection electrode 42b. .

The solar substrate 1b has a backlight surface, and the first finger electrode group 2b is disposed on the backlight surface of the solar substrate 1b, and the first finger electrode group 2b each includes a first first fork extending along a length direction D1b. The bus bar 21b and the plurality of first interdigitated finger electrodes 22b extending from the first interdigital bus bar 21b in a width direction D2b perpendicular to the longitudinal direction D1b; wherein the solar substrate 1b has three sides on each side thereof One finger fork electrode group 2b, and the three first finger electrode groups 2b are disposed on the outermost first finger electrode group 2b with the first finger bus bar 21b disposed at the outermost side, and the first finger fork The finger electrodes 22b extend inwardly, and the other two first finger electrode groups 2b are disposed in opposite directions such that the first finger finger electrodes 22b of one of the two first finger electrode groups 2b are oriented The outer side is staggered with the first interdigitated finger electrodes 22b of the first interdigitated electrode group 2b disposed outside, and the other first interdigitated electrode group 2b is extended toward the inner side.

The second finger electrode groups 3b are disposed on the backlight surface of the solar substrate 1b at a pitch W2, and the second finger electrode groups 3b each include an edge. a second interdigitated bus bar 31b extending in the longitudinal direction D1b and a plurality of second interdigitated finger electrodes 32b extending from the opposite sides of the second interdigital bus bar 31b in the width direction D2b and the width direction, and second One of the lengths FL2 of the interdigitated finger electrodes 32b is smaller than the spacing W2 and larger than one half of the spacing W2; wherein the second interdigitated finger electrodes 32b of the two second interdigitated electrode groups 3b are staggered with each other, and the second The second interdigitated finger electrodes 32b extending outward from the two-finger electrode group 3b are alternately arranged with the first interdigitated finger electrodes 22b, respectively.

The first finger electrode group 2b and the second finger electrode group 3b as described above, wherein the electrical properties of any adjacent ones are different, and the first connecting electrode 41b and the second connecting electrode 42b are in the width direction D2b. The first connecting electrode 42b is connected to the first and second finger electrode groups 2b and the second finger electrode group 3b, and the first finger electrode group 2b and the second finger electrode group 3b are connected to the first electrical component (such as the positive electrode, but may also be the negative electrode). The second connecting electrode 42b is connected to the first finger electrode group 2b and the second finger electrode group 3b, and belongs to the second electrical property different from the first electrical property (such as a negative electrode, but may also be a positive electrode) By.

In summary, compared with the conventional back contact solar cell, two first finger electrode groups are disposed on both sides of the backlight surface of the solar substrate, since the back contact solar cell 100b of the present invention is in the first place. At least one second finger electrode group 3b is disposed between the finger electrode groups 2b, and the length of the first/second finger finger electrodes 22b, 32b is smaller than the distance between the bus bars 21b, 31b of the two adjacent electrode groups and greater than One-and-a-half of the distance between the bus bars 21b, 31b of the two adjacent electrode groups can effectively reduce the current passing through the finger electrodes to the path of the bus bar, thereby reducing ohmic power loss (I ² R), and due to ohms The power loss is reduced, so the material of the electrode can be a conductive metal with a higher resistivity but less expensive, or a conductive adhesive, instead of a metal having good electrical conductivity such as pure silver having a low resistivity but expensive, thereby reducing the back contact solar cell. Production costs. Meanwhile, the back contact solar cell 100b of the present invention has connection electrodes 41b and 42b for respectively connecting the electrode groups of the same electrical power, so that the originally separated electrode groups are connected in series, so that at least one bus bar is required The current of the electrode groups of the same electrical group is derived, and a back contact solar cell requires only two bus bars to discharge the current collected by all the electrode groups, which can reduce the use of the bus bar and is connected by the connecting electrode. The technology of the same electrode group, the bus bar only needs to be connected with one of the connected electrode groups, so that the distribution position of the bus bar can be freely adjusted, so that the back contact solar cell can also be compatible with the existing solar energy. Modular wiring design.

In other embodiments, the angle between the first finger finger electrode of the present invention and the first finger bus bar, and the angle between the second finger finger electrode and the second finger bus bar are greater than 0 degrees. And no more than 90 degrees, so the first interdigitated finger electrode and the second interdigitated finger electrode may intersect perpendicular or at an angle to the bus bar.

Please refer to the fourth figure, which is a schematic view showing a back contact solar cell according to a third embodiment of the present invention. As shown in the figure, the back contact solar cell 100c includes a solar substrate 1c, eight first finger electrode groups 2c, two second finger electrode groups 3c, a first connection electrode 41c, and A second connection electrode 42c. In this embodiment, between the solar cell 100c and the solar cell 100b described above The difference is only that the solar cell 100c is connected to the two first finger electrode groups 2c separated by the first finger electrode group 2c on both sides of the solar substrate 1c by the first connection electrode 41c and the second connection electrode 42c.

Please refer to FIG. 2 and FIG. 5 , which are schematic diagrams showing a back contact solar cell module according to a fourth embodiment of the present invention. The back contact solar cell module 200a includes a plurality of back contact solar cells 100a (only two are shown) and four bus bars 4a. The bus bar 4a electrically connects the back contact solar cell 100a in the longitudinal direction D1a. Wherein, since the back contact solar cell 100a has been described in the above first embodiment and the second figure, no further utterance is added here.

In the plurality of back contact solar cell modules 200a of the present embodiment, the bus bar 4a electrically connects the first interdigital bus bar 21a and the second interdigital bus bar 31a belonging to the positive electrode respectively. The first interdigitated bus bar 21a and the second interdigitated bus bar 31a belonging to the negative electrode of the former back contact solar cell 100a, and the bus bar 4a respectively respectively belong to the first interdigital bus bar 21a and the second interdigital fork belonging to the negative electrode The bus bar 31a is electrically connected to the first interdigital bus bar 21a and the second interdigital bus bar 31a belonging to the positive electrode in the latter back contact solar cell 100a, so that the plurality of back contact solar cells 100a are connected in series by the bus bar 4a. Up, that is, when the first interdigitated electrode group 2a and the second interdigitated electrode group 3a of one of the plurality of back contact solar cells 100a are electrically aligned with positive, negative, positive, and negative electrodes, adjacent to each other The back contact solar cell 100a is electrically arranged with negative, positive, negative and positive electrodes, and the bus bar 4a is respectively the positive electrode of the first finger electrode group 2a and the second finger electrode group 3a. Connected to the previous back contact solar cell 100a belongs to the negative The first finger electrode group 2a and the second finger electrode group 3a belonging to the negative electrode are respectively connected to the negative electrode in the latter contact solar cell 100a. However, since the two back contact solar cells 100a are electrically connected in series via the bus bar 4a, the bus bar 4a is connected to the second finger electrode group 3a of the back contact solar cell 100a in series with the other back contact type. In the first finger electrode group 2a of the solar cell 100a, since the second finger electrode group 3a is located between the two first finger electrode groups 2a, the bus bar 4a is used to electrically connect the two first finger electrodes. The first connection electrode 41a of the group 2a overlaps, and in order to prevent the first finger electrode 2a and the second finger electrode 3a from being electrically connected to the bus bar 4a through the first connection electrode 41a, a short circuit occurs, which is more in this embodiment. The insulating layer 5a is disposed between the first connection electrode 41a and the bus bar 4a, thereby effectively preventing the occurrence of a short circuit phenomenon.

Please refer to FIG. 6 and FIG. 7 , which are schematic diagrams showing a back contact solar cell module according to a fifth embodiment of the present invention; and a seventh figure showing the back contact provided by the sixth embodiment of the present invention. Schematic diagram of a solar cell module. As shown, the back contact solar cell modules 200b, 200c each include a plurality of back contact solar cells 100b, 100c (both shown in the figure) and six bus bars 4b, 4c. The bus bars 4b and 4c are connected in series with the back contact solar cell 100b and the back contact solar cell 100c in the longitudinal directions D1b and D1c, respectively. In the fifth embodiment, the plurality of back contact solar cells 100b are connected in series by the bus bar 4b, and the plurality of back contact solar cells 100c are connected in series by the bus bar 4c in the sixth embodiment, In the fourth embodiment, the plurality of back contact solar cells 100a are connected in series by the bus bar 4a. In the same way, the first finger fork busbar and the second finger fork busbar which are positive poles in the back contact solar cell are electrically connected to the first finger fork which belongs to the negative pole in the front back contact solar cell, respectively. The busbar and the second yoke busbar are electrically connected to the first yoke busbar and the second yoke busbar of the back contact type solar cell respectively, and the second back contact type solar cell is positively connected The first finger fork bus bar and the second finger fork bus bar.

Please refer to the third and sixth figures at the same time, wherein the back contact solar cell module of the sixth figure comprises the back contact solar cell 100b which is the same as the third figure, and the first connection of the back contact solar cell 100b The second insulating layer 5b is disposed on the electrode 41b and the second connecting electrode 42b, so that when the first strap fork busbar 21b and the second fingerbar busbar 31b of the back contact solar cell 100b are electrically connected in series, respectively, in the busbar 4b, The first yoke bus bar 21b (or the second yoke bus bar 31b) is prevented from being transparently insulated by the insulating layer 5b located between the first connecting electrode 41b (or the second connecting electrode 42b) and the bus bar 4b. A connection electrode 41b (or the second connection electrode 42b) and the bus bar 4b are short-circuited to the second interdigitated bus bar 31b (or the first interdigital bus bar 21b) of the same back contact solar cell 100b; The back contact solar cell module 200c is the same as the back contact solar cell 100c of the fourth figure, and is connected to the first connection electrode 41c and the second connection electrode 42c of the solar cell 100c, and the third and upper sides are equivalent to the third The figure shown A fourth insulating layer 5c is disposed on a connecting electrode 41b and a second connecting electrode 42b to insulate between the connecting electrode and the bus bar 4c. In the embodiment, the insulating layers 5b and 5c are polyimides. But not limited to Therefore, by the arrangement of the insulating layers 5b, 5c, it can be effectively prevented that in the back contact solar cell module, the first interdigitated electrode group/second interdigitated electrode group belonging to the positive electrode is connected by the busbar The second interdigitated electrode group/first interdigitated electrode group of the negative electrode is in contact with each other to cause a short circuit. In other embodiments, the insulating layer may also be disposed only on a region where the bus bar covers the connection electrode, and the portion where the connection electrode is not covered by the bus bar does not need to be provided with the insulating layer.

Referring to FIG. 8 and FIG. 9 , FIG. 8 is a schematic diagram showing a back contact solar cell according to a seventh embodiment of the present invention; and FIG. 9 is a back contact solar cell according to an eighth embodiment of the present invention. Schematic diagram of the battery module. As shown, the back contact solar cell module 200d includes a plurality of back contact solar cells 100d (only two are shown) and a plurality of bus bars 4d (only one is shown); wherein, the back contact solar energy The battery 100d includes a solar substrate 1d, two first finger electrode groups 2d, a second finger electrode group 3d, and a first connection electrode 41d.

The solar substrate 1d has a backlight surface (not shown). The first finger electrode group 2d is disposed on both sides of the backlight surface, and the first finger electrode group 2d includes a first finger bus bar 21d and a plurality of first finger finger electrodes 22d, and the first The interdigitated finger electrode 22d extends from one side of the first interdigitated bus bar 21d. The second finger electrode group 3d is disposed on the backlight surface and located between the two first finger electrode groups 2d, and the second finger electrode group 3d includes a second finger bus bar 31d and a plurality of second fingers a finger electrode 32d, and the second finger finger electrode 32d is extended from both sides of the second finger bus bar 31d, and the second finger finger electrode 32d is respectively The first interdigitated finger electrodes 22d on the left and right sides are alternately arranged. The first connection electrode 41d is electrically connected to the two first finger electrode groups 2d. The electrical properties of any two adjacent between the second finger electrode group 3d and the first finger electrode group 2d are different, that is, in the embodiment, the first finger electrode group 2d, for example, the positive electrode, is adjacent to each other. a second finger electrode group 3d of the negative electrode, and a second finger electrode group 3d of the negative electrode is further adjacent to the first finger electrode group of the positive electrode (different from the first first electrode group of the first finger electrode group indicated by the component symbol 2d) The finger electrode group) forms a staggered arrangement of positive and negative, but is not limited thereto.

The bus bar 4d includes a first connection electrode 43d and a second connection electrode 44d connected to the first connection electrode 43d. The first connection electrode 43d is a second finger electrode group 3d connected to a back contact solar cell 100d. The second connection electrode 44d is connected to the first first finger electrode group 2d of the other back contact solar cell 100d, whereby a plurality of back contact solar cells 100d are connected in series.

Please refer to the tenth figure, which shows a schematic diagram of a back contact solar cell according to a ninth embodiment of the present invention. As shown, the back contact solar cell 100e includes a solar substrate 1e, two first finger electrode groups 2e, two second finger electrode groups 3e, a first connection electrode 41e, and a second connection electrode 42e.

The solar substrate 1e has a backlight surface. The first finger electrode group 2e is disposed on both sides of the backlight surface, and the first finger electrode group 2e includes a first finger bus bar 21e and a plurality of first finger finger electrodes 22e, and the first The interdigitated finger electrodes 22e are extended from both sides of the first interdigitated bus bar 21e. The second finger electrode group 3e is disposed on the backlight surface and located between the two first finger electrode groups 2e, and the second finger electrode group 3e includes one The second interdigitated bus bar 31e and the plurality of second interdigitated finger electrodes 32e extend from both sides of the second interdigital bus bar 31e.

The electrical properties of any two adjacent between the second finger electrode group 3e and the first finger electrode group 2e are different, that is, in the embodiment, the first finger electrode group 2e, for example, the positive electrode, is adjacent to each other. a second finger electrode group 3e of the negative electrode, and a second finger electrode group 3e of the negative electrode is further adjacent to the second finger electrode group of the positive electrode (different from the other second of the second finger electrode group referred to by the component symbol 3e) The second finger electrode group of the last positive electrode is further adjacent to the first finger electrode group of the negative electrode (different from the other first finger electrode group of the first finger electrode group indicated by the component symbol 2e) That is, a staggered arrangement of positive and negative positive and negative is formed; and, the adjacent first interdigitated finger electrodes 22e and the second interdigitated finger electrodes 32e are alternately arranged. As described above, since the present invention further electrically connects a plurality of back contact solar cells in a bus bar to form a back contact solar cell module, and when the bus bar overlaps with the first/second finger electrode groups, An insulating layer is disposed between the bus bar and the first/second finger electrode group to avoid a short circuit.

In other embodiments of the present invention, the back contact solar cell may further include four electrode groups having staggered arrangement of different electrical properties, wherein the electrode groups are arranged in a positive electrode-negative electrode-positive electrode-anode mode, or a negative electrode. The positive electrode-negative electrode is arranged in a positive electrode manner, that is, at least one second finger electrode group is disposed between the two first finger electrode groups, and at least one connecting electrode is used to connect two electrode groups of the same electrical polarity. It can also be understood that when the back contact solar cell has more staggered electrode groups of different electrical properties, at least one second finger electrode group is disposed between the two first finger electrode groups, and At least one connecting electrode is used to connect two electrodes of the same electrical polarity.

It can be seen from the above embodiments of the present invention that the present invention has industrial utilization value. The above embodiments are merely illustrative of the preferred embodiments of the present invention, and those skilled in the art will be able to make various other modifications and changes in the embodiments described herein. However, various modifications and changes made in accordance with the embodiments of the present invention are still within the scope of the invention and the scope of the invention.

Claims (10)

A back contact solar cell comprising: a solar substrate having a backlight surface; at least three electrode groups, the electrode groups being alternately arranged in a width direction on the backlight surface, and the electrodes Each of the electrode groups includes a finger bus bar extending along a length direction perpendicular to the width direction, and a plurality of finger finger electrodes intersecting the finger bus bar, wherein the finger bus bars of the electrode groups The length of the interdigitated finger electrodes is less than the pitch and is greater than one half of the pitch; and at least one first connecting electrode is electrically connected to the electrode groups. At least two of the first electrical properties, the first electrical system being one of a positive electrode and a negative electrode. The back contact solar cell of claim 1, wherein the electrode groups each comprise: two first finger electrode groups, each comprising: a first finger bus bar; and a plurality of first fingers An interdigitated electrode extending from at least one side of the first interdigitated bus bar; and at least one second interdigitated electrode set between the two first interdigitated electrode sets, and the second interdigitated The electrode group includes: a second finger bus bar disposed at intervals between the first finger bus bars of the two first finger electrode groups; and a plurality of second finger finger electrodes At least from the second yoke bus One side extends and is staggered with the first interdigitated finger electrodes. The back contact solar cell of claim 2, wherein the second finger electrode group is plural, and the back contact solar cell further comprises a second connection electrode, the second connection electrode And connecting to the electrode groups, which belong to at least two of a second electrical property, wherein the second electrical system is the other one of the positive electrode and the negative electrode different from the first electrical property. A back contact solar cell module comprising: a plurality of back contact solar cells arranged along a length direction, the back contact solar cell comprising: a solar substrate having a backlight surface; at least three electrode groups, The electrode groups are alternately arranged on the backlight surface along a width direction perpendicular to the length direction, and the electrode groups each include an interdigitated bus bar extending along the length direction, and a plurality of An interdigitated finger electrode intersecting the interdigitated bus bar, wherein the interdigitated bus bars of the electrode sets are disposed at a spacing interval, and the lengths of the interdigitated finger electrodes are less than the spacing and greater than the spacing And at least one first connecting electrode for connecting at least two of the first electrical groups, wherein the first electrical system is one of a positive electrode and a negative electrode; and at least one bus bar The back contact solar cells are electrically connected in series along the length direction. Such as the back contact solar cell module described in claim 4, An insulating layer is disposed between the first connecting electrode and the bus bar. The back contact solar cell module according to claim 5, wherein the insulating layer is made of polyamidamine. The back contact solar cell module of claim 4, wherein the electrode groups comprise: two first finger electrode groups, each comprising: a first finger bus bar; and a plurality of first An interdigitated finger electrode extending from at least one side of the first interdigitated bus bar; and at least one second interdigitated electrode set between the two first interdigitated electrode sets, and the second finger The fork electrode group includes: a second finger bus bar disposed at intervals between the first finger bus bars of the two first finger electrode groups; and a plurality of second finger finger electrodes And extending from at least one side of the second interdigitated bus bar and staggered with the first interdigitated finger electrodes. The back contact solar cell module of claim 7, wherein the second interdigitated electrode assembly is plural, and the back contact solar cell further comprises a second connecting electrode, the second The connecting electrode is electrically connected to the electrode group and belongs to at least two of the second electrical properties, and the second electrical system is the other one of the positive electrode and the negative electrode different from the first electrical property. The back contact solar cell module of claim 8, further comprising an insulating layer disposed between the second connecting electrode and the bus bar. The back contact solar cell module according to claim 9, wherein the insulating layer is made of polyamine.