阅读说明：本技术 一种背接触太阳能电池、组件及制备方法和系统 (Back contact solar cell, back contact solar module, preparation method and system ) 是由 沈承焕 陈程 季根华 赵影文 包杰 陈嘉 林建伟 于 2021-08-31 设计创作，主要内容包括：本发明涉及一种背接触太阳能电池、组件及制备方法和系统。该电池组件的制备方法为在电池的背表面制备主栅电极,以将电池分成若干个子电池,每个子电池均制备有交替排布的基电极和发射电极,每个子电池中,各发射电极的电流均汇聚于同一根主栅电极,而各基电极的电流均汇聚于另一根主栅电极,即得背接触太阳能电池；从背接触太阳能电池的对应主栅电极的正面位置开始切割,切至主栅电极表面为止,以制得多个用所述主栅电极串联的切割后的子电池,即得所述背接触太阳能电池组件。该制备方法通过背电极的结构设计,能实现背接触太阳能电池组件中相邻子电池之间的无线互连,进而能简化其子电池的互连工序,并能降低成本。(The invention relates to a back contact solar cell, a back contact solar cell module manufacturing method and a back contact solar cell module manufacturing system. Preparing a main grid electrode on the back surface of the cell to divide the cell into a plurality of sub-cells, wherein each sub-cell is provided with a base electrode and an emission electrode which are alternately arranged, the current of each emission electrode in each sub-cell is converged to the same main grid electrode, and the current of each base electrode is converged to the other main grid electrode, so that the back contact solar cell is obtained; and cutting from the front side position of the back contact solar cell corresponding to the main grid electrode until the front side position is cut to the surface of the main grid electrode so as to obtain a plurality of cut sub-cells connected in series by using the main grid electrode, namely the back contact solar cell module. According to the preparation method, through the structural design of the back electrode, the wireless interconnection between adjacent sub-cells in the back contact solar cell module can be realized, so that the interconnection process of the sub-cells can be simplified, and the cost can be reduced.)

1. A preparation method of a back contact solar cell module is characterized by comprising the following steps:

step S1, preparing a main grid electrode on the back surface of the cell to divide the cell into a plurality of sub-cells, wherein each sub-cell is prepared with base electrodes and emission electrodes which are alternately arranged, and in each sub-cell, the current of each emission electrode is converged to the same main grid electrode, and the current of each base electrode is converged to the other main grid electrode, thus obtaining the back contact solar cell;

and step S2, cutting from the front side position of the back contact solar cell corresponding to the main grid electrode until the front side position reaches the surface of the main grid electrode, so as to obtain a plurality of cut sub-cells connected in series by the main grid electrode, and thus obtaining the back contact solar cell module.

2. The method of claim 1, wherein the back contact solar cell module is prepared by the following steps,

in step S1, preparing the emitter electrode, the base electrode, and the main gate electrode by screen printing;

in step S2, the back contact solar cell is diced using laser.

3. A back contact solar cell obtained by the method for producing a back contact solar cell module according to any one of claims 1 to 2, wherein the back surface thereof comprises alternately arranged p + emitter regions and n + base regions in step S1; each p + emitter region is covered with an emitter electrode in segmented arrangement, each n + base region is covered with a base electrode in segmented arrangement, and vertically-arranged main grid electrodes are arranged between two adjacent sections of emitter electrodes, between two adjacent sections of base electrodes and on two sides of the back contact solar cell, so that the back contact solar cell is divided into a plurality of sub-cells by the main grid electrodes; in each sub-battery, each transmitting electrode extends along the same side direction and converges at one main grid electrode, and each base electrode extends along the direction opposite to the transmitting electrode and converges at the other main grid electrode, so that the adjacent two sub-batteries can be connected in series through the main grid electrodes.

4. The back contact solar cell of claim 3, wherein said p + emitter regions and n + base regions are each elongated and are arranged alternately with each other on the back surface of said back contact solar cell;

the width of the p + emitter region is 200-1000 um; the width of the n + base region is 200-1000 um.

5. The back-contact solar cell as claimed in claim 3 or 4, wherein the width of the emitter electrode is 100-500 um; the width of the base electrode is 100-500 um.

6. The back-contact solar cell as claimed in claim 3, wherein the spacing length between two adjacent segments of the emitter electrodes and between two adjacent segments of the base electrodes is 200 μm and 500 μm.

7. The back-contact solar cell as claimed in claim 3 or 6, wherein the width of the main gate electrode is 200-300um and the thickness is 20-40 um.

8. The back contact solar cell of claim 7, wherein the thickness of the main gate electrode is 25-35 um.

9. A back contact solar cell module, wherein the back contact solar cell module is prepared by the method for preparing a back contact solar cell module according to any one of claims 1-2.

10. A solar cell system comprising at least one solar cell module connected in series, characterized in that the solar cell module is a back-contact solar cell module according to claim 9.

Technical Field

The invention relates to the technical field of solar cells, in particular to a back contact solar cell, a back contact solar cell module manufacturing method and a back contact solar cell module manufacturing system.

Background

The solar cell is a semiconductor device for converting light energy into electric energy, and is a core device of solar photovoltaic power generation. In recent years, photovoltaic power generation technology, which is a mainstream technology for utilizing solar energy resources, is an important technology in the field of green energy development, and has been marketed and commercialized. With the updating iteration of the technology, the development trend of the photovoltaic module product is the continuous increase of the output power of the module.

The back contact solar cell is paid much attention as an efficient solar cell, and the light receiving surface of the back contact solar cell is not provided with any electrode, so that the shading loss caused by electrode patterns can be reduced, the light receiving area of a cell is effectively increased, and the conversion efficiency of the cell is improved; and the emitter electrode and the base electrode of the back contact solar cell are both arranged on the backlight surface of the cell piece.

In the prior art, for example, application No. CN201821499655.8 discloses a structure of a back contact heterojunction solar cell module, in which a main cell is divided into two sub-cells along a middle main gate electrode, one of the sub-cells needs to rotate 180 °, and then two sub-cells need to be soldered or bonded by a conductive adhesive tape to form an electrical contact therebetween, so as to connect two adjacent sub-cells in series, thereby obtaining the solar cell module. However, in the battery assembly, one of the sub-battery pieces needs to be rotated to interconnect the sub-batteries, so that the interconnection process of the adjacent sub-battery pieces is complicated, and solder strips (or conductive adhesives) are consumed to realize the electrical contact between the adjacent sub-battery pieces, that is, the solder strips need to be used to realize the wired interconnection between the sub-battery pieces, thereby further increasing the interconnection process of the sub-battery pieces, and the cost of the battery assembly is increased due to the input of the solder strips (or conductive adhesives).

Disclosure of Invention

One of the objectives of the present invention is to provide a method for manufacturing a back-contact solar cell module, which enables sub-cells in the back-contact solar cell module to be wirelessly interconnected, thereby simplifying the interconnection process of the sub-cells, improving the manufacturing efficiency, and reducing the cost.

The second objective of the present invention is to provide a back contact solar cell module.

The invention also aims to provide a solar cell system.

Based on the above, the invention discloses a preparation method of a back contact solar cell module, which comprises the following steps:

step S1, preparing a main grid electrode on the back surface of the cell to divide the cell into a plurality of sub-cells, wherein each sub-cell is prepared with base electrodes and emission electrodes which are alternately arranged, and in each sub-cell, the current of each emission electrode is converged to the same main grid electrode, and the current of each base electrode is converged to the other main grid electrode, thus obtaining the back contact solar cell;

and step S2, cutting from the front side position of the back contact solar cell corresponding to the main grid electrode until the front side position reaches the surface of the main grid electrode, so as to obtain a plurality of cut sub-cells connected in series by the main grid electrode, and thus obtaining the back contact solar cell module.

Preferably, in step S1, the emitter electrode, the base electrode, and the main gate electrode are prepared by screen printing (the back electrode of the back contact solar cell includes the emitter electrode, the base electrode, and the main gate electrode);

in step S2, the back contact solar cell is diced using laser.

The invention also discloses a back contact solar cell which is prepared by the step S1 in the preparation method of the back contact solar cell module, wherein the back surface of the back contact solar cell comprises p + emitter regions and n + base regions which are alternately arranged; each p + emitter region is covered with an emitter electrode in segmented arrangement, each n + base region is covered with a base electrode in segmented arrangement, and vertically-arranged main grid electrodes are arranged between two adjacent sections of emitter electrodes, between two adjacent sections of base electrodes and on two sides of the back contact solar cell, so that the back contact solar cell is divided into a plurality of sub-cells by the main grid electrodes; in each sub-battery, each transmitting electrode extends along the same side direction and converges at one main grid electrode, and each base electrode extends along the direction opposite to the transmitting electrode and converges at the other main grid electrode, so that the adjacent two sub-batteries can be connected in series through the main grid electrodes.

Preferably, the p + emitter regions and the n + base regions are arranged alternately with each other in a long shape on the back surface of the back contact solar cell;

the width of the p + emitter region is 200-1000 um; the width of the n + base region is 200-1000 um.

Preferably, the width of the emission electrode is 100-500 um; the width of the base electrode is 100-500 um.

Preferably, the spacing length between two adjacent sections of the emitter electrodes and between two adjacent sections of the base electrodes is 200-500 um.

Preferably, the width of the main gate electrode is 200-300um, and the thickness is 20-40 um.

Further preferably, the thickness of the main gate electrode is 25-35 um.

The invention also discloses a back contact solar cell module which is prepared by the preparation method of the back contact solar cell module.

The invention also discloses a solar cell system which comprises at least one solar cell module connected in series, wherein the solar cell module is the back contact solar cell module.

Compared with the prior art, the invention at least comprises the following beneficial effects:

in the invention, the main grid electrode divides the back contact solar cell into a plurality of sub-cells, and in each sub-cell, the current of each emitter electrode is converged to the same main grid electrode, and the current of each base electrode is converged to the other main grid electrode; therefore, the main grid electrode between two adjacent sub-cells in each back-contact solar cell can simultaneously collect the currents of the emitter electrode and the base electrode, so that the back-contact solar cell assembly can be obtained by directly connecting the main grid electrodes between the two adjacent cut sub-cells in the back-contact solar cell in series in the preparation process of the back-contact solar cell assembly only by ensuring that the main grid electrode is not cut off in the cutting process of the sub-cells; because the series connection process of the main grid electrode does not need to rotate the sub-battery, and does not need to consume a welding strip (or conductive adhesive), the preparation method can realize the wireless interconnection among the sub-batteries in the back contact solar battery assembly, simplify the interconnection process of the sub-batteries, greatly improve the preparation efficiency of the back contact solar battery assembly, reduce the consumption of the interconnection of the sub-batteries and further greatly reduce the cost of the back contact solar battery assembly. In addition, since the two adjacent sub-cells are directly connected in series by the uncut main gate electrode, in a solar cell system formed by connecting a plurality of back contact solar cell modules in series, the number of back contact solar cells spliced per unit area is increased, and therefore, the module power potential is higher.

It should be noted that the cutting operation of the back contact solar cell is to avoid the formation of short circuit between two adjacent sub-cells.

Drawings

Fig. 1 is a schematic perspective view of each sub-cell of the back contact solar cell according to the embodiment after being cut.

Fig. 2 is a schematic structural diagram of a back electrode in a back contact solar cell according to the present embodiment.

Fig. 3 is a partially enlarged view of a back electrode in a back contact solar cell of the present embodiment.

The reference numbers illustrate: 1 back contact solar cell; 11 a sub-battery; a 12p + emitter region (or n + base region); a 13n + base region (or p + emitter region); 14 an emitter electrode (or base electrode); a 15-base electrode (or emitter electrode); 16 main gate electrode.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in further detail below.

Example 1

Referring to fig. 1 to 3, a method for manufacturing a back contact solar cell module of this embodiment includes the following steps:

step S1, preparing a main grid electrode 16 on the back surface of the cell to divide the cell into a plurality of sub-cells 11, wherein each sub-cell 11 is prepared with base electrodes 15 and emitter electrodes 14 alternately arranged, and in each sub-cell 11, the current of each emitter electrode 14 is converged to the same main grid electrode 16, and the current of each base electrode 15 is converged to the other main grid electrode 16, so as to obtain the back contact solar cell 1; the specific structure is shown in fig. 2-3.

Step S1 is preferably to prepare the emitter electrode 14, the base electrode 15, and the main gate electrode 16 by screen printing (i.e., the back electrode of the back contact solar cell 1 includes the emitter electrode 14, the base electrode 15, and the main gate electrode 16); wherein the front and back surfaces of the back contact solar cell 1 are preferably provided with passivation layers for passivation of the cell surface, and the passivation layer of the back contact solar cell 1 is provided with laser-opened circular or square holes so that the emitter electrode 14 (or the base electrode 15) of the back electrode is electrically connected to the p + emitter region 12 (or the n + base region 13) through the holes to transmit current during the screen printing process.

Step S2, cutting the front surface of the back contact solar cell 1 corresponding to the main grid electrode 16 until the front surface of the main grid electrode 16 is cut, so as to obtain a plurality of cut sub-cells 11 connected in series by the main grid electrode 16, i.e. the back contact solar cell module of the present embodiment; after the cutting, two adjacent sub-cells 11 in the back contact solar cell 1 are cut, and the main gate electrode 16 between the two adjacent sub-cells 11 is not cut, so as to facilitate the preparation of a subsequent back contact solar cell module.

In step S2, the back contact solar cell 1 is preferably cut by laser to obtain a plurality of cut sub-cells 11 connected in series by the main gate electrode 16, so as to ensure that the main gate electrode 16 is not cut.

In summary, since the main gate electrode 16 between two adjacent sub-cells 11 in the back-contact solar cell 1 collects the current of the emitter electrode 14 and the base electrode 15 at the same time, and after step S2, two adjacent sub-cells 11 in the back-contact solar cell 1 are cut to ensure the normal use of the sub-cells 11, but the main gate electrode 16 between the two adjacent sub-cells 11 is not cut, in the preparation process of the back-contact solar cell module, the main gate electrode 16 can be directly used for series connection between two adjacent sub-cells 11 cut in the back-contact solar cell 1, and the series connection process does not need to rotate the sub-cells 11 nor consume solder strips (or conductive adhesives), so that the preparation method can realize the wireless interconnection between the sub-cells 11 in the back-contact solar cell module, simplify the interconnection process of the sub-cells 11, and greatly improve the preparation efficiency of the back-contact solar cell module, and the consumables of the sub-battery 11 interconnection can be reduced, and the cost of the back contact solar battery component is greatly reduced. In addition, since the series connection between two adjacent sub-cells 11 is directly realized by the main gate electrode 16 without being cut off, in a solar cell system formed by connecting a plurality of back contact solar cell modules in series, the number of back contact solar cells 1 spliced per unit area is increased, and thus, higher module power potential is obtained.

The present embodiment also discloses a back contact solar cell which is manufactured using step S1 in the manufacturing method of a back contact solar cell module described above, and referring to fig. 2 to 3, the back surface of the back contact solar cell 1 includes the p + emitter region 12, the n + base region 13, and the back electrode. Wherein, the resistivity of the back contact solar cell 1 is 1-7 omega-cm, preferably 3-5 omega-cm, and the thickness of the back contact solar cell 1 is 50-300um, preferably 100-260 um. The p + emitter regions 12 and the n + base regions 13 are each in a long shape, and the long-shaped p + emitter regions 12 and the long-shaped n + base regions 13 are alternately arranged on the back surface of the back contact solar cell 1.

In the back-contact solar cell 1, each p + emitter region 12 is covered with a segmented emitter electrode 14 (such as the emitter electrodes 14 which are transversely segmented in fig. 2-3), each n + base region 13 is covered with a segmented base electrode 15 (such as the base electrodes 15 which are transversely segmented in fig. 2-3), and vertically arranged main grid electrodes 16 (such as the main grid electrodes 16 which are longitudinally arranged in fig. 2-3) are respectively arranged between two adjacent segments of emitter electrodes 14, between two adjacent segments of base electrodes 15 and on two sides of the back-contact solar cell 1, so that the back-contact solar cell 1 is divided into a plurality of sub-cells 11 by the main grid electrodes 16; in each sub-cell 11, each transmitting electrode 14 extends along the same side direction (e.g. the left side in fig. 2-3) and converges to one main grid electrode 16, so that in each sub-cell 11, the current of each transmitting electrode 14 can converge to the same main grid electrode 16, and each base electrode 15 extends along the opposite side direction (e.g. the right side in fig. 2-3) of the transmitting electrode 14 and converges to the other main grid electrode 16, so that the current of each base electrode 15 can converge to the other main grid electrode 16. In this way, the back electrode of the back contact solar cell 1 is obtained, which includes the emitter electrode 14, the base electrode 15, and the main gate electrode 16 described above.

The back contact solar cell 1 is formed by designing a back electrode structure: the back contact solar cell 1 is divided into a plurality of sub-cells 11 by the main grid electrode 16 through the segmented arrangement of the emitter electrodes 14 and the base electrodes 15 and the arrangement of the main grid electrode 16, and in each sub-cell 11, the current of each emitter electrode 14 can be converged to the same main grid electrode 16, and the current of each base electrode 15 can be converged to another main grid electrode 16; the main grid electrode 16 between two adjacent sub-cells 11 in each back contact solar cell 1 can be simultaneously focused to the current of the emitter electrode 14 and the base electrode 15, so as to facilitate the preparation of a back contact solar cell module.

Wherein, the width of the p + emitter region 12 is 200-1000um, preferably 400-800um, the width of the n + base region 13 is 200-1000um, preferably 200-400um, and more preferably the ratio of the width of the p + emitter region 12, the width of the n + base region 13 and the width of the gap region is 6: 3: 1, to ensure the arrangement of the back electrode and the performance of the battery, and to prevent the leakage of electricity; the width of the emitter electrode 14 is 100-500um, preferably 200-400um, and the width of the base electrode 15 is 100-500um, preferably 200-400um, to ensure the current conduction and the performance of the back electrode.

The spacing length between two adjacent sections of the emitter electrodes 14 is 200-.

Further, the width of the main gate electrode 16 is 200-; the thickness of the main grid electrode 16 is 20-40um, preferably 25-35um, more preferably 30-35um, so that when the sub-cells 11 are cut by laser, the main grid electrode 16 is not easy to cut off, and further, in the subsequent back contact solar cell module preparation process, the main grid electrode 16 is directly adopted between every two adjacent sub-cells 11 to be connected in series, so that wireless interconnection between the sub-cells 11 in the back contact solar cell module is realized, the preparation process of the back contact solar cell module is simplified, the preparation efficiency of the back contact solar cell module is improved, consumable materials for interconnection of the sub-cells 11 can be reduced, and the cost is reduced.

The embodiment also discloses a back contact solar cell module which is prepared by the preparation method of the back contact solar cell module.

The embodiment also discloses a solar cell system which comprises at least one solar cell module connected in series, wherein the solar cell module is the back contact solar cell module.

While preferred embodiments of the present invention have been described, additional variations and modifications of these embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims be interpreted as including preferred embodiments and all such alterations and modifications as fall within the scope of the embodiments of the invention.

The technical solutions provided by the present invention are described in detail above, and the principle and the implementation of the present invention are explained in this document by applying specific examples, and the descriptions of the above examples are only used to help understanding the method and the core idea of the present invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, there may be variations in the specific embodiments and the application scope, and in summary, the content of the present specification should not be construed as a limitation to the present invention.