TWM551346U - Dual-face solar cell and solar cell module - Google Patents

Description

Double-sided solar cell and solar cell module

The present invention relates to a solar cell, and more particularly to a double-sided solar cell capable of generating electricity on both sides and a solar cell module constructed thereby.

Solar cells are currently the most mature and widely used green energy technology. In order to improve the power generation efficiency of solar cells and reduce the cost of power generation, various solar cell structures have been continuously developed. Solar cells can be roughly classified into three types: germanium-based solar cells, compound semiconductor solar cells, and organic solar cells. Among them, the technology of germanium-based solar cells is the most mature and popular, especially the conversion efficiency of monocrystalline solar cells. The crown of solar cells.

Currently, the high-conversion-enhanced twin-crystal solar cells have a Hetero-junction with Intrinsic Thin Layer (HIT) and an Interdigitated Back Contact (IBC). Bifacial Solar Cell, emitter passivation and back-cell solar cell (PERC, Passivated Emitter and Rear Cell).

In addition, there is also a so-called shingled solar cell module which is composed of a plurality of solar cells connected in series. The solar cell constituting the shingled solar cell module has two bus electrodes, one of which is located on the upper surface and the other is located on the lower surface. As long as the bus electrode on the lower surface of one of the solar cells and the bus electrode on the upper surface of the other solar cell are electrically connected to each other through the conductive paste, the stacked solar cells can be formed in this order.

Since the bus electrode of the solar cell is sintered by the silver paste, for the tile type solar cell module, the two bus electrodes of the adjacent two solar cells overlap. If one of the bus electrodes can be reduced, the cost reduction effect can be achieved, and the power generation efficiency is not significantly reduced. However, if only one of the bus electrodes is simply removed, the conductive paste is usually designed to form a good bond with the metal bus electrode, and it is difficult to form a good bond with the surface of the solar cell substrate (usually a passivation layer). . Therefore, in the current series of solar cells of the shingled solar cell module, conductive paste is still used to combine the bus electrodes respectively located on different surfaces of the two solar cells.

In view of this, the present invention proposes a solar cell comprising a solar cell substrate, a bus electrode, a plurality of first finger electrodes, a plurality of second finger electrodes, and a plurality of conductive pads. The solar cell substrate has a first surface and a second surface opposite to each other and a first side and a second side opposite to each other. The bus electrode is disposed on the first surface of the solar cell substrate and extends along a first direction, and the bus electrode is adjacent to the first side of the solar cell substrate. The plurality of first finger electrodes are disposed on the first surface of the solar cell substrate and extend in a second direction different from the first direction, and one end of each of the first finger electrodes is connected to the bus electrode. The plurality of second finger electrodes are disposed on the second surface of the solar cell substrate and extend in the second direction. A plurality of conductive pads are disposed on the second surface of the solar cell substrate and spaced apart from the second finger electrodes in the first direction. Each of the conductive pads is connected to one end of the second finger electrode opposite thereto, and each of the conductive pads is adjacent to the second side of the solar cell substrate.

In an embodiment of the present invention, at least one conductive pad is connected to one end of the two or more second finger electrodes.

In one embodiment of the present invention, at least one of the conductive pads has a larger size than the other conductive pads.

In an embodiment of the present invention, the two ends of the at least one second finger electrode are free ends.

In an embodiment of the present invention, the second finger electrodes whose both ends are free ends are not adjacent to each other.

In an embodiment of the present invention, the second finger electrode is connected to the conductive pad to form an enlarged portion.

In an embodiment of the present invention, a plurality of vertical electrodes are further disposed on the second surface of the solar cell substrate, and the two ends of the vertical electrodes are respectively connected to the adjacent two second finger electrodes.

In an embodiment of the present invention, the vertical electrode is further disposed on the first surface of the solar cell substrate, and the two ends of the vertical electrodes disposed on the first surface are respectively connected to the adjacent two first finger electrodes.

In an embodiment of the present invention, the first direction is perpendicular to the second direction.

The present invention also proposes a solar cell module comprising a plurality of the aforementioned double-sided solar cells, wherein two adjacent solar cells of the double-sided solar cell are attached to another double-sided solar cell. Each of the conductive pads is connected in series to each other.

Please refer to FIG. 1 and FIG. 2 , which are schematic diagrams showing a schematic view of one surface of the solar cell of the first embodiment and another surface, respectively, illustrating a double-sided power generation solar cell 10 including a solar cell. The substrate 11 , the bus electrode 12 , the plurality of first finger electrodes 13 , the plurality of second finger electrodes 14 , and the plurality of conductive pads 15 . The solar cell substrate 11 has a first surface 111 and a second surface 112 opposite to each other and a first side surface 113 and a second side surface 114 opposite to each other. As shown in FIG. 1 , the bus electrode 12 is disposed on the first surface 111 of the solar cell substrate 11 and extends in a first direction (for example, the Y-axis direction in the drawing, hereinafter collectively referred to as the Y-axis direction), and the bus electrode 12 is adjacent to the solar cell substrate. The first side 113 of the 11th. The plurality of first finger electrodes 13 are disposed on the first surface of the solar cell substrate 12 and in a second direction different from the Y-axis direction (for example, the X-axis direction in the drawing, hereinafter collectively referred to as the X-axis direction, the embodiment) The X-axis direction extends perpendicular to the Y-axis direction, wherein one end of each of the first finger electrodes 13 is connected to the bus electrode 12. In the present embodiment, the "the first side 113 of the solar cell substrate 11 adjacent to the bus electrode 12" mainly restricts the bus electrode 12 from being located at the center of the first surface 111, and is not intended to limit the boundary between the bus electrode 12 and the first side 113. No other components may exist. For example, the first finger electrode 13 may also partially extend between the bus electrode 12 and the first side surface 113. Further, the pattern of the bus electrode 12 is not limited to a linear strip shape, and may be formed by a hollowed-out region or a plurality of island electrodes spaced apart from each other as in the bus electrode described in the Republic of China No. M539701.

As shown in FIG. 2, a plurality of second finger electrodes 14 are provided on the second surface 112 of the solar cell substrate 11 and extend in the X-axis direction. A plurality of conductive pads 15 are disposed on the second surface 112 of the solar cell substrate 11 and spaced apart in the Y-axis direction. As shown, each of the conductive pads 15 is connected to one end of a second finger electrode 14, and each of the conductive pads 15 is adjacent to the second side 114 of the solar cell substrate 11. In the present embodiment, the "the second conductive surface 15 of the solar cell substrate 11 is adjacent to each other" is mainly to restrict the bus electrode 12 from being located at the center of the second surface 112, and is not intended to limit the conductive pads 15 and the second side surface 114. There should be no other components between them. For example, the second finger electrodes 14 may also partially extend between the connected conductive pads 15 and the second side surface 114.

Please refer to FIG. 3 to FIG. 5b , which are respectively a combined schematic view, a combined view, a side view of the stacked solar battery module and an enlarged view of a partial area P1 of FIG. 5 a , which illustrate two first embodiments. The solar cells 10a and 10b are combined with each other. The respective conductive pads 15 of the solar cell 10a on the second surface 112 are aligned with the bus electrodes 12 of the other solar cell 10b at the first surface 111, and the surfaces of the bus electrodes 12 and/or the conductive pads 15 may be coated with conductive Glue 19. Then, the conductive pad 15 of the solar cell 10a is superposed on the bus electrode 12 of the solar cell 10b, and the conductive pad 15 of the solar cell 10a and the bus electrode 12 of the solar cell 10b are electrically connected to each other through the conductive paste 19, as shown in FIG. 5b. In this way, the solar cells 10a and 10b can be connected in series to each other to form the stacked solar cell module 100. Of course, those skilled in the art can further connect more solar cells in series according to the assembly method described above and according to specific applications to form a stacked solar cell module with different power generation.

Compared with the conventional solar cell for the shingled solar cell module, one surface (second surface 112) of the solar cell 10 of the first embodiment is not provided with a bus electrode, but at a position where the bus electrode is originally disposed. The conductive pad 15 is provided to be connected to one end of the plurality of individual and second finger electrodes 14, thereby eliminating the silver paste originally used to form the bus electrode on the second surface 112, thereby reducing the production cost of the solar cell. In addition, even if the material of the conductive pad 15 of the second surface 112 is also selected as the silver paste, since the conductive pads 15 are spaced apart from each other, the amount of the silver paste can be saved and reduced as compared with the formation of the entire continuous bus electrode. The purpose of solar cell production costs.

6 is a schematic view showing one surface of a solar cell according to a second embodiment of the present invention, showing a solar cell 20, which is different from the solar cell 10 of the first embodiment in the arrangement of the conductive pads. . In the second embodiment, at least one conductive pad 251 (six in the drawing) is simultaneously connected to one end of the two or more second finger electrodes 14 while having at least one conductive pad 252 (three in the figure) One is connected to only one end of one second finger electrode 14.

Referring to FIG. 7, a schematic diagram of one surface of a solar cell according to a third embodiment of the present invention, showing a solar cell 30, which is different from the solar cell 10 of the first embodiment in the arrangement of the conductive pads. . In the third embodiment, at least one conductive pad 351 (two in the drawing) is simultaneously connected to one end of the three second finger electrodes 14; at least one conductive pad 352 (two in the drawing) is simultaneously Connected to one end of the two second finger electrodes 14; at least one conductive pad 353 (five in the drawing) is connected to only one end of one of the second finger electrodes 14. In addition, as shown in FIG. 7, the size of the conductive pad 351 is larger than the size of the conductive pad 352, and the size of the conductive pad 352 is larger than the size of the conductive pad 353.

Please refer to FIG. 8 , which is a schematic diagram of one surface of a solar cell according to a fourth embodiment of the present invention, which illustrates a solar cell 40 , which is similar to the solar cell 10 of the first embodiment in the configuration of the conductive pad. the way. In the fourth embodiment, the two ends of the at least one second finger electrode 14 are free ends, that is, no conductive pads 15 are connected. In addition, when the embodiment includes a plurality of second finger electrodes 14 whose both ends are free ends, the second finger electrodes 14 whose both ends are free ends are not adjacent to each other, that is, at least between each other. A second finger electrode 14 having a conductive pad 15 connected to one end thereof.

Please refer to FIG. 9 and FIG. 10 , which are schematic diagrams of one surface of the solar cell of the fifth embodiment and a schematic view of another surface, respectively, showing a solar cell 50 . The main difference between the fifth embodiment and the first embodiment is that the second surface 112 further includes a plurality of vertical electrodes 56, and the two ends of the vertical electrodes 56 are respectively connected to the adjacent two second finger electrodes 14. In this way, if the second finger electrode 14 is broken, the carrier at the broken line can still be collected along the vertical electrode 56 to the adjacent second finger electrode 14. In addition, when the solar cell module 100 is formed, if a certain conductive pad 15 is not electrically connected to the corresponding bus electrode to cause a partial short circuit, the carrier near the second finger electrode 14 to which the short-circuited conductive pad 15 is connected is generated. Similarly, it is also possible to move along the vertical electrode 56 to the nearest second finger electrode 14 to be collected and utilized, and the overall power generation efficiency is not significantly lowered due to poor connection of the single conductive pad 15. In the present embodiment, the pitch of the adjacent two vertical electrodes 56 in the Y-axis direction may be exactly equal to the pitch of the adjacent two second finger electrodes 14 in the Y-axis direction.

As shown in FIG. 10, in this embodiment, a plurality of vertical electrodes 57 may be selectively disposed on the first surface 111, and the two ends of the vertical electrodes 57 are respectively connected to the adjacent two first fingers. Electrode 13. In this way, if the first finger electrode 13 is broken, the carrier at the disconnection can still be collected along the vertical electrode 57 to the adjacent first finger electrode 13 for collection and utilization.

Please refer to FIG. 11 and FIG. 12 , which are schematic diagrams of one surface of the solar cell of the sixth embodiment and a schematic view of another surface, respectively, showing a solar cell 60 . As shown in FIG. 11, one of the main differences between the present embodiment and the fifth embodiment is that the second surface 112 is further provided with a vertical electrode 66, and the two ends of the vertical electrode 66 are respectively connected to the solar cell 60 in the Y-axis direction. Two second finger electrodes 14 at the edges. In this way, if the second finger electrode 14 is disconnected, the carrier at the disconnection can move along the vertical electrode 66 to the nearest second finger electrode 14 regardless of where the wire break occurs. Can be collected and utilized. Similarly, when the solar cell module 100 is formed, if a certain conductive pad 15 is not electrically connected to the corresponding bus electrode to cause a partial short circuit, the vicinity of the second finger electrode 14 to which the short-circuited conductive pad 15 is connected is loaded. The sub-segment can also be collected and moved along the vertical electrode 66 to the nearest second finger electrode 14 without causing a significant drop in overall power generation efficiency due to poor connection of the single conductive pad 15.

In addition, as shown in FIG. 12, the first surface 111 of the solar cell 60 may further be provided with a vertical electrode 67, and the two ends of the vertical electrode 67 are respectively connected to the two first fingers which are closest to the edge of the solar cell 60 in the Y-axis direction. Electrode 13. As described above, if the first finger electrode 13 is broken, the carrier at the broken line can be moved along the vertical electrode 67 to the adjacent first finger electrode 13 to be collected regardless of where the wire break occurs. use.

Please refer to FIG. 13 and FIG. 14 , which are respectively a plan view of the second surface of the solar cell of the first embodiment and an enlarged view (1 ) of the partial region P2 of FIG. 13 . In order to ensure an electrical connection between the conductive pad 15 and the second finger electrode 14, the second finger electrode 14 and the conductive pad 15 may be intentionally overlapped with each other, as shown in FIG.

Please refer to FIG. 15 and FIG. 16 , which are enlarged views ( 2 ) and ( 3 ) of the partial region P2 of FIG. 13 respectively, which illustrate another electrical connection between the conductive pad 15 and the second finger electrode 14 . The way. As shown in FIG. 15, the second finger electrode 14 is connected to the conductive pad 15 to form an enlarged portion 75, and the conductive pad 15 and the enlarged portion 75 overlap each other, as shown in FIG. A case where the conductive pad 15 and the second finger electrode 14 are less likely to be broken. In addition, the enlarged portion 75 may have two as shown in FIG. 17 and FIG. 18, respectively located on two sides of the conductive pad 15, and the conductive pad 15 and the two enlarged portions 75 also partially overlap each other. 19 and 20, the enlarged portion 75 may also be in a square shape (depending on the geometry of the conductive pad 15) unless the conductive pad 15 is heavily offset from the enlarged portion 75 during formation. Otherwise, there is inevitably a portion overlapping between the conductive pad 15 and the enlarged portion 75, which further ensures that the conductive pad 15 and the second finger electrode 14 are less likely to be disconnected. The material of the enlarged portion 75 is generally the same as that of the second finger electrode 14 (for example, sintered by an aluminum paste), and can be formed together with the first finger electrode 14 in the same process.

The common characteristic of the above embodiments is that the bus electrodes of one surface of the solar cell for forming the shingled solar cell module are replaced by conductive pads, thereby saving silver paste and reducing the production cost of the solar cell.

The technical content of the present invention has been disclosed above in several embodiments, but it is not intended to limit the creation of the present invention. Anyone who is familiar with the skill of the art should make some changes and refinements without departing from the spirit of the present creation. Therefore, the scope of protection of this creation is subject to the definition of the scope of the patent application.

100‧‧‧Stacked solar battery module
10, 10a, 10b‧‧‧ solar cells
11‧‧‧Solar cell substrate
111‧‧‧ first surface
112‧‧‧ second surface
113‧‧‧ first side
114‧‧‧ second side
12‧‧‧Concurrent electrode
13‧‧‧First finger electrode
14‧‧‧Second finger electrode
15‧‧‧Electrical mat
19‧‧‧Conductive adhesive
20‧‧‧ solar cells
251‧‧‧Electrical mat
252‧‧‧Electrical mat
30‧‧‧ solar cells
351‧‧‧Electrical mat
352‧‧‧Electrical mat
353‧‧‧Electrical mat
40‧‧‧ solar cells
50‧‧‧ solar cells
56‧‧‧Vertical electrode
57‧‧‧Vertical electrode
60‧‧‧ solar cells
66‧‧‧Vertical electrode
67‧‧‧Vertical electrode
75‧‧‧Expanding Department

Fig. 1 is a schematic view showing one surface of a solar cell of the first embodiment of the present invention. Fig. 2 is a schematic view showing another surface of the solar cell of the first embodiment of the present invention. [Fig. 3] A schematic view of the assembly of the stacked solar battery module of the present invention. [Fig. 4] A combination diagram of the stacked solar battery module of the present invention. [Fig. 5a] A side view of the tiled solar cell module of the present invention. [Fig. 5b] is an enlarged view of a partial area P1 of Fig. 5a. Fig. 6 is a schematic view showing one surface of a solar cell of the second embodiment of the present invention. Fig. 7 is a schematic view showing one surface of a solar cell of the third embodiment of the present invention. 8 is a schematic view showing one surface of a solar cell of a fourth embodiment of the present invention. 9 is a schematic view showing one surface of a solar cell of a fifth embodiment of the present invention. Fig. 10 is a schematic view showing another surface of the solar cell of the fifth embodiment of the present invention. Fig. 11 is a schematic view showing one surface of a solar cell of the sixth embodiment of the present invention. Fig. 12 is a schematic view showing another surface of the solar cell of the sixth embodiment of the present invention. Fig. 13 is a plan view schematically showing a second surface of the solar cell of the first embodiment of the present invention. FIG. 14 is an enlarged view (1) of a partial region P2 of FIG. [Fig. 15] is an enlarged view (2) of the partial region P2 of Fig. 13. Fig. 16 is an enlarged view (3) of a partial region P2 of Fig. 13. FIG. 17 is an enlarged view (4) of a partial region P2 of FIG. FIG. 18 is an enlarged view (5) of a partial region P2 of FIG. FIG. 19 is an enlarged view (6) of a partial region P2 of FIG. FIG. 20 is an enlarged view (7) of a partial region P2 of FIG.

10‧‧‧ solar cells

11‧‧‧Solar cell substrate

112‧‧‧ second surface

113‧‧‧ first side

114‧‧‧ second side

14‧‧‧Second finger electrode

15‧‧‧Electrical mat

Claims (10)

A double-sided solar cell comprising: a solar cell substrate having a first surface and a second surface opposite to each other and a first side and a second side opposite to each other; a bus electrode disposed on the first surface And extending in a first direction, the bus electrode is adjacent to the first side of the solar cell substrate; the plurality of first finger electrodes are disposed on the first surface and extend in a second direction different from the first direction, One end of each of the first finger electrodes is connected to the bus electrode; a plurality of second finger electrodes are disposed on the second surface and extend along the second direction; and a plurality of conductive pads are disposed on the second surface and along the The first direction is spaced apart from the second finger electrodes, and each of the conductive pads is connected to one end of the second finger electrode opposite thereto, and the conductive pads are adjacent to the second side of the solar cell substrate. The double-sided solar cell of claim 1, wherein at least one of the conductive pads is connected to one or more ends of the second finger electrodes. The double-sided solar cell of claim 2, wherein at least one of the conductive pads has a size larger than a size of each of the other conductive pads. The double-sided solar cell of claim 1, wherein at least one of the second finger electrodes has a free end. The double-sided solar cell according to claim 4, wherein the second finger electrodes whose both ends are free ends are not adjacent to each other. The double-sided solar cell of claim 1, wherein the second finger electrode is connected to the conductive pad to form an enlarged portion. The double-sided solar cell according to any one of claims 1 to 6, further comprising a plurality of vertical electrodes disposed on the second surface, the two ends of each of the vertical electrodes being respectively connected to the adjacent two of the second finger electrodes . The double-sided solar cell of claim 7, wherein the vertical electrodes are disposed on the first surface, and the two ends of the vertical electrodes disposed on the first surface are respectively connected to the adjacent two first fingers. electrode. The double-sided solar cell of claim 8, wherein the first direction is perpendicular to the second direction. A solar cell module comprising the double-sided solar cell according to any one of claims 1 to 9, wherein in the two-sided solar cell adjacent to the two-sided solar cell, one of the bus electrodes of the double-sided solar cell and the other The conductive pads of the double-sided solar cell are connected to each other to form a series connection.