TWI481048B - Solar cell and module comprising the same - Google Patents

Description

Solar cell and its module

The invention relates to a battery and a module thereof, in particular to a solar battery and a module thereof.

Known twinned solar cells mainly comprise: a battery body for converting light energy into electrical energy, and a front electrode and a back electrode for conducting current. The front electrode includes at least one elongated bus bar electrode and a plurality of finger bar electrodes laterally connected to the bus electrode. The bus electrode and the finger electrodes are manufactured by applying a conductive paste to a light receiving surface of the battery body by screen printing, and are solidified by a sintering process.

However, as the price of the conductive paste continues to increase, especially the silver paste having a better conductivity is expensive, and the bus electrode of the conventional battery has a continuous strip shape, the conductive paste is consumed in a large amount, resulting in a large amount of electricity. The production cost of the battery is high, and therefore, how to improve the structure of the bus electrode to save cost is an important issue. On the other hand, after the battery is manufactured, it is necessary to additionally solder a ribbon to the bus electrode of the battery to arrange a plurality of cells in series to form a battery module. Therefore, in the improvement of the bus electrode structure, it is also necessary to consider the welding bonding force between the bus electrode and the ribbon wire. If the welding bonding force between the ribbon wire and the bus electrode is not good, it is easy to package the module. Or the subsequent use of the ribbon wire off the problem, which in turn affects product reliability. Whether it is a general single-sided light-receiving battery or a bi-facial solar cell, the bus electrode has the above-mentioned question. question.

Accordingly, it is an object of the present invention to provide a solar cell and a module thereof which are capable of saving production costs and having good product reliability.

Therefore, the solar cell of the present invention comprises: a substrate having a first light receiving surface; a first bus electrode disposed on the first light receiving surface; and a plurality of the first light receiving surfaces disposed on the first light receiving surface and connected to the first The first finger electrode of the bus electrode. The first bus electrode includes a plurality of first electrode portions arranged in a first direction and having a circular shape, and partial portions of the adjacent first electrode portions overlap.

The solar cell module of the present invention comprises: a first plate and a second plate disposed opposite to each other, a plurality of solar cells arranged as described above and arranged between the first plate and the second plate, and one located at the first An encapsulating material between the sheet and the second sheet and surrounding the solar cells.

The effect of the invention: by the central hollowing design of the circular first electrode portions, the amount of conductive paste of the first bus electrode can be reduced to reduce the production cost. Moreover, the adjacent first electrode portions partially overlap and have a structural strengthening function, which can provide sufficient welding bonding force, so that the welding wire wires to be subsequently welded on the first bus electrode can be stably welded and adhered, and the welding wire is prevented from falling off. To make the product have good reliability.

The above and other technical contents, features and advantages of the present invention will be apparent from the following detailed description of FIG. Before the present invention is described in detail, it is to be noted that In the following description, similar elements are denoted by the same reference numerals.

Referring to Figures 1, 2 and 3, a first preferred embodiment of the solar cell module of the present invention comprises: a first plate 1 and a second plate 2 disposed opposite each other, and a plurality of arrays arranged on the first plate 1 The solar cell 3 between the second plate 2 and at least one of the first plate 1 and the second plate 2 are wrapped around the solar cells 3.

The first plate 1 and the second plate 2 are not particularly limited in implementation, and a glass or plastic plate may be used, and the plate on one side of the light receiving surface of the battery must be permeable to light. The material of the encapsulant 4 is, for example, a light transmissive ethylene vinyl acetate copolymer (EVA), or other related materials that can be used for solar cell module packaging.

The solar cells 3 are electrically connected through ribbons not shown. The configurations of the solar cells 3 are the same, and only one of them will be described below as an example.

The solar cell 3 includes a substrate 31, at least one first bus electrode 32, a plurality of first finger electrodes 33, and a back electrode 34.

The substrate 31 has an opposite first light receiving surface 311 and a back surface 312. An emitter layer 313 is disposed on the inner side of the first light receiving surface 311. A first anti-reflective layer 314 can be disposed on the emitter layer 313. . The substrate 31 is, for example, a germanium substrate, and one of the substrate 31 and the emitter layer 313 is an n-type semiconductor, and the other is a p-type semiconductor, thereby forming a p-n junction. The material of the first anti-reflective layer 314, such as tantalum nitride, can be used to reduce light reflection to increase the amount of light incident. Since the substrate 31, the emitter layer 313, and the first anti-reflection layer 314 are not the focus of the present invention, they will not be described.

The battery of this embodiment includes two first bus electrodes 32 on the first light-receiving surface 311, and the first bus electrodes 32 can pass through the first anti-reflection layer 314 to contact the first light-receiving surface 311. Each of the first bus electrodes 32 includes a plurality of first electrode portions 321 arranged in a first direction 51 and having a circular shape, and the first bus electrodes 32 are along a second direction perpendicular to the first direction 51. 52 and arranged side by side. The partial portions of the adjacent first electrode portions 321 in each of the first bus electrodes 32 of the present embodiment overlap. Each of the first electrode portions 321 defines a center line 322 extending through the geometric center thereof (corresponding to the center of the embodiment) and extending along the second direction 52. Each of the first electrode portions 321 has two center lines. Connection points 323 intersecting each other and spaced apart from each other along the second direction 52. It should be noted that the number of the first bus electrodes 32 of the present invention is not limited to two, and may be, for example, one or three.

The first finger electrodes 33 are disposed on the first light receiving surface 311 and connected to the first bus electrodes 32. The first finger electrodes 33 can pass through the first anti-reflective layer 314 to contact the first Light receiving surface 311. The first finger electrodes 33 are spaced apart along the first direction 51, and each of the first finger electrodes 33 extends along the second direction 52. The first finger electrodes 33 are connected to the connection points 323 of the first electrode portions 321 . Specifically, a portion of the first finger electrodes 33 of the embodiment are connected between the two first bus electrodes 32 . Each of the first finger electrodes 33 between the two first bus electrodes 32 simultaneously connects two first electrode portions 321 disposed at the left and right sides; and a portion of the first finger electrodes 33 located at the left side of the first bus electrode 32 On the left side, the first finger electrodes 33 are respectively connected to the connection point 323 on the left side of each of the first first electrode portions 321 of the left first bus electrode 32; similarly, the part of the first A finger electrode 33 is located on the right side of the first bus electrode 32 on the right side, and the first finger electrodes 33 are respectively connected to the connection point 323 on the right side of each of the first electrode portions 321 of the right first bus electrode 32. .

Therefore, each of the first electrode portions 321 of the embodiment is connected to the two first finger electrodes 33, but in practice, each of the first electrode portions 321 or a portion of the first electrode portions 321 may be connected to only one first. Finger electrode 33. For example, in the present invention, only one first bus electrode 32 may be disposed, and each of the first electrode portions 321 of the first bus electrode 32 may be connected to only one first finger electrode 33.

The back electrode 34 is located on the back surface 312 of the substrate 31 and is used for outputting electric energy in cooperation with the first bus electrode 32 and the first finger electrode 33. However, since the back electrode 34 is not an improvement focus of the present invention, it will not be described again. .

The present invention replaces the known elongated and integrally solid-shaped bus electrode by each of the first bus electrodes 32 including the plurality of circular first electrode portions 321 due to the circular first electrode The central portion of the portion 321 is hollowed out, thereby reducing the amount of conductive paste of the first bus electrode 32 to reduce the production cost. Moreover, the adjacent first electrode portions 321 are partially overlapped, and the overlapping portions have a structural strengthening function, which helps to provide sufficient welding bonding force, so that the welding wire wires to be subsequently soldered on the first bus electrode 32 can be stably welded. And attached. In this way, the invention can reduce the production cost, and can also meet the requirements of the welding stability, so that the welded module can pass the subsequent tensile test and maintain the reliability of the product.

Referring to FIG. 4, the second preferred embodiment of the solar cell module of the present invention is substantially the same as the structure of the first preferred embodiment, except that the same A portion where the first finger electrode 33 is connected to the first bus electrode 32.

Since the adjacent first electrode portions 321 of each of the first bus electrodes 32 partially overlap, any two adjacent first electrode portions 321 of each of the first bus electrodes 32 form two along the second direction 52. The intersections 324 are separated from each other. The first finger electrodes 33 of the present embodiment are connected to the intersections 324 of the first electrode portions 321 .

This embodiment is also designed by the first and second overlapping first electrode portions 321 to achieve the same effect as the first preferred embodiment, and will not be described here.

The batteries of the above two embodiments are all single-sided light-receiving cells, but the electrode structure of the present invention can also be applied to a bi-facial solar cell, which will be described below by way of the following embodiments.

Referring to Figures 5 and 6, the third preferred embodiment of the solar cell module of the present invention is substantially the same as the structure of the first preferred embodiment. The following mainly describes different places. The solar cell 3 of the embodiment is a double-sided light receiving battery, and includes: a substrate 31, at least one first bus electrode 32, a plurality of first finger electrodes 33, at least one second bus electrode 35, and a plurality of second Finger electrode 36.

The substrate 31 has an opposite first light receiving surface 311 and a second light receiving surface 315. An emitter layer 313 is further disposed on the inner side of the first light receiving surface 311. The first layer is disposed on the emitter layer 313. Reflective layer 314. An electric field layer 316 is disposed on the inner side of the second light receiving surface 315, and a second anti-reflective layer 317 is disposed on the electric field layer 316. Wherein, the substrate 31 is, for example, a germanium substrate, and one of the substrate 31 and the emitter layer 313 is an n-type semiconductor, and the other One is a p-type semiconductor, which in turn forms a p-n junction. The electric field layer 316 has the same conductivity as the substrate 31, and the carrier concentration of the electric field layer 316 is larger than the carrier concentration of the substrate 31, and its function is to improve the carrier collection efficiency.

The shape and arrangement of the first bus electrode 32 and the first finger electrode 33 of this embodiment are the same as those of the first preferred embodiment, and will not be described here. The second bus electrode 35 and the second finger electrode 36 of the embodiment are disposed on the second light-receiving surface 315 through the second anti-reflection layer 317, and the shapes of the second bus electrode 35 and the second finger electrode 36 The configuration may be the same as that of the first bus electrode 32 and the first finger electrode 33. Therefore, each of the second bus electrodes 35 includes a plurality of second electrode portions 351 arranged in the first direction 51 and having a circular shape. And local portions of the adjacent second electrode portions 351 overlap.

Of course, the shape and arrangement of the second bus electrode 35 and the second finger electrode 36 may be the same as those of the first bus electrode 32 and the first finger electrode 33 in the second preferred embodiment (as shown in the figure). 4).

The above is only the preferred embodiment of the present invention, and the scope of the invention is not limited thereto, that is, the simple equivalent changes and modifications made by the scope of the invention and the description of the invention are All remain within the scope of the invention patent.

1‧‧‧ first plate

2‧‧‧Second plate

3‧‧‧Solar battery

31‧‧‧Substrate

311‧‧‧The first light-receiving surface

312‧‧‧ back

313‧‧ ‧ emitter layer

314‧‧‧First anti-reflection layer

315‧‧‧Second light-receiving surface

316‧‧‧ electric field layer

317‧‧‧Second anti-reflective layer

32‧‧‧First bus electrode

321‧‧‧Electrode

322‧‧‧ center line

323‧‧‧ Connection point

324‧‧‧ meeting point

33‧‧‧First finger electrode

34‧‧‧Back electrode

35‧‧‧Second bus electrode

351‧‧‧Second electrode section

36‧‧‧Second finger electrode

4‧‧‧Package

51‧‧‧First direction

52‧‧‧second direction

1 is a partial cross-sectional view showing a first preferred embodiment of a solar cell module of the present invention; and FIG. 2 is a cross-sectional view showing a solar cell of the first preferred embodiment; 3 is a top plan view of the solar cell of the first preferred embodiment; FIG. 4 is a top plan view of a solar cell according to a second preferred embodiment of the solar cell module of the present invention; and FIG. 5 is a solar cell module of the present invention. A schematic cross-sectional view of a solar cell of a third preferred embodiment; and FIG. 6 is a bottom plan view of the solar cell of the third preferred embodiment.

3‧‧‧Solar battery

31‧‧‧Substrate

314‧‧‧First anti-reflection layer

32‧‧‧First bus electrode

321‧‧‧Electrode

322‧‧‧ center line

323‧‧‧ Connection point

33‧‧‧First finger electrode

51‧‧‧First direction

52‧‧‧second direction

Claims (6)

A solar cell comprising: a substrate having a first light receiving surface; a first bus electrode disposed on the first light receiving surface and comprising a plurality of first electrodes arranged in a first direction and having a circular shape And partially overlapping portions of the adjacent first electrode portions; and the plurality of first finger electrodes are disposed on the first light receiving surface and connected to the first bus electrodes. The solar cell of claim 1, wherein each of the first electrode portions is connected to at least one of the first finger electrodes. The solar cell of claim 2, wherein the first finger electrodes are spaced apart along the first direction, and each of the first finger electrodes is along a second perpendicular to the first direction a direction extending; defining, at each of the first electrode portions, a center line extending through the geometric center thereof and extending along the second direction, each of the first electrode portions having two connection points intersecting the center line and spaced apart from each other, The first finger electrodes connect the connection points of the first electrode portions. The solar cell of claim 2, wherein the first finger electrodes are spaced apart along the first direction, and each of the first finger electrodes is along a second perpendicular to the first direction The direction extension; any two adjacent first electrode portions together form two mutually spaced intersections, and the first finger electrodes connect the intersections of the first electrode portions. The solar cell of claim 1, wherein the substrate further has a second light receiving surface opposite to the first light receiving surface, the The solar cell further includes a second bus electrode disposed on the second light receiving surface and a plurality of second finger electrodes, the second bus electrode including a plurality of second holes arranged in the first direction and having a circular shape The electrode portion overlaps a portion of the adjacent second electrode portion, and the second finger electrodes are connected to the second bus electrode. A solar cell module comprising: a first plate and a second plate disposed opposite to each other; and a solar cell according to any one of claims 1 to 5, arranged on the first plate and the Between the second plates; and a packaging material between the first plate and the second plate, and wrapped around the solar cells.