CN211828787U

CN211828787U - Large-sized cell, heterojunction solar cell and laminated tile assembly

Info

Publication number: CN211828787U
Application number: CN202020433716.1U
Authority: CN
Inventors: 尹丙伟; 孙俊; 陈登运; 李岩; 石刚
Original assignee: Chengdu Yefan Science and Technology Co Ltd
Current assignee: Tongwei Solar Hefei Co Ltd
Priority date: 2020-03-30
Filing date: 2020-03-30
Publication date: 2020-10-30
Anticipated expiration: 2030-03-30

Abstract

The utility model relates to a battery piece is big, heterojunction solar wafer and stack tile subassembly. The cell interface portion of the battery wafer is divided into a cutting region, a top surface bonding region and a top surface conductive contact region at the top surface. The cutting region is configured to enable a large piece of the battery sheet to be cut therealong; the top surface bonding regions and the top surface conductive contact regions are alternately arranged, the cutting regions and the top surface conductive contact regions are formed into one lapping edge of the cell, and the top surface conductive contact regions can be directly contacted with the bottom surface of another heterojunction solar cell after the cell is subjected to large splitting to realize conductive connection. The utility model provides a battery piece big piece can make things convenient for the lobe of a leaf operation, and is equipped with special bonding region and electrically conductive contact zone for the battery piece monolithic, and the production process and the performance of heterojunction solar wafer can be optimized in such setting.

Description

Large-sized cell, heterojunction solar cell and laminated tile assembly

Technical Field

The utility model relates to an energy field especially relates to a battery piece is big, heterojunction solar wafer and fold tile subassembly.

Background

With the increasing consumption of conventional fossil energy such as global coal, oil, natural gas and the like, the ecological environment is continuously deteriorated, and particularly, the sustainable development of the human society is seriously threatened due to the increasingly severe global climate change caused by the emission of greenhouse gases. Various countries in the world make respective energy development strategies to deal with the limitation of conventional fossil energy resources and the environmental problems caused by development and utilization. Solar energy has become one of the most important renewable energy sources by virtue of the characteristics of reliability, safety, universality, long service life, environmental protection and resource sufficiency, and is expected to become a main pillar of global power supply in the future.

In a new energy revolution process, the photovoltaic industry in China has grown into a strategic emerging industry with international competitive advantages. However, the development of the photovoltaic industry still faces many problems and challenges, and the conversion efficiency and reliability are the biggest technical obstacles restricting the development of the photovoltaic industry, while the cost control and the scale-up are economically restricted. The photovoltaic module is taken as a core component of photovoltaic power generation, and the development of high-efficiency modules by improving the conversion efficiency of the photovoltaic module is a necessary trend. Various high efficiency modules, such as shingles, half-sheets, multi-master grids, double-sided modules, etc., are currently emerging on the market. With the application places and application areas of the photovoltaic module becoming more and more extensive, the reliability requirement of the photovoltaic module becomes higher and higher, and particularly, the photovoltaic module with high efficiency and high reliability needs to be adopted in some severe or extreme weather frequent areas.

Under the background of vigorous popularization and use of green solar energy, the shingled assembly utilizes the electrical principle of low current and low loss (the power loss of the photovoltaic assembly is in direct proportion to the square of working current) so as to greatly reduce the power loss of the assembly. And secondly, the inter-cell distance region in the cell module is fully utilized to generate electricity, so that the energy density in unit area is high. In addition, the conductive adhesive with the elastomer characteristic is used for replacing a photovoltaic metal welding strip for a conventional assembly, the photovoltaic metal welding strip shows higher series resistance in the whole battery, and the stroke of a current loop of the conductive adhesive is far smaller than that of a welding strip, so that the laminated assembly becomes a high-efficiency assembly, and meanwhile, the outdoor application reliability is more excellent than that of the conventional photovoltaic assembly, and the laminated assembly avoids stress damage of the metal welding strip to the interconnection position of the battery and other confluence areas. Especially, under the dynamic (load action of natural world such as wind, snow and the like) environment with alternating high and low temperatures, the failure probability of the conventional assembly which is interconnected and packaged by adopting the metal welding strips is far higher than that of the laminated assembly which is interconnected and cut by adopting the conductive adhesive of the elastomer and packaged by the crystalline silicon battery small pieces.

The mainstream technology of the current tile stack assembly is to use a conductive adhesive to interconnect the cut battery pieces, wherein the conductive adhesive mainly comprises a conductive phase and a bonding phase. The conductive phase mainly comprises precious metals, such as pure silver particles or particles of silver-coated copper, silver-coated nickel, silver-coated glass and the like, and is used for conducting electricity among solar cells, the particle shape and distribution of the conductive phase are based on the requirement of optimal electricity conduction, and at present, more sheet-shaped or sphere-like combined silver powder with D50 being less than 10um is adopted. The adhesive phase is mainly composed of a high molecular resin polymer having weather resistance, and acrylic resin, silicone resin, epoxy resin, polyurethane, and the like are usually selected in accordance with the adhesive strength and weather resistance. In order to enable the conductive adhesive to achieve low contact resistance, low volume resistivity and high adhesion and maintain long-term excellent weather resistance, a conductive adhesive manufacturer can generally complete the design of a conductive phase and an adhesive phase formula, so that the performance stability of the laminated tile assembly under an initial stage environment corrosion test and long-term outdoor practical application is ensured.

And after being packaged, the battery assembly connected by the conductive adhesive is subjected to environmental erosion in outdoor practical use, for example, high and low temperature alternating expansion and contraction with heat generates relative displacement between the conductive adhesives. The most serious reason is that the current is connected in a virtual way or even disconnected, and the main reason is generally that the materials are combined and then are weak in mutual connection capacity. The weak connection capability mainly shows that a process operation window is needed for the operation of the conductive adhesive in the manufacturing process, and the window is relatively narrow in the actual production process and is very easily influenced by environmental factors, such as the temperature and humidity of an operation place, the time for which the conductive adhesive stays in the air after being coated and the like, so that the conductive adhesive loses activity. Meanwhile, the phenomenon of uneven sizing and missing easily occurs under the conditions of glue dispensing, glue spraying or printing process due to the characteristic change of glue, and great hidden danger is caused to the reliability of products. And the conductive adhesive mainly comprises high polymer resin and a large amount of noble metal powder, so that the cost is high, and the ecological environment is damaged to a certain extent (the production and processing of noble metals have great pollution to the environment). Moreover, the conductive adhesive belongs to a paste, has certain fluidity in the process of gluing or laminating, and is very easy to overflow to cause short circuit of the positive electrode and the negative electrode of the laminated interconnected battery string.

That is to say, for most of the laminated assemblies made by adopting the conductive adhesive bonding mode, the characteristics of weak mutual connection strength exist, the requirement of the manufacturing process on the environment is high, the glue overflow and short circuit are easy to occur in the process, the use cost is high, the production efficiency is low, and the like.

Furthermore, in order to realize the conductive connection of the individual heterojunction solar cells, it is usually necessary to provide electrodes on the surface of the heterojunction solar cells, and the electrodes are made of expensive metal, so the heterojunction solar cells usually have high cost.

In the manufacture of heterojunction solar cells, there is no large cell piece which can be formed into a heterojunction solar cell piece as described above and is easy to be subjected to a splitting operation.

It is therefore desirable to provide a large cell, heterojunction solar cell and a stack assembly that at least partially solves the above problems.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a battery piece is big, heterojunction solar wafer and fold tile subassembly. The utility model provides a battery piece is big can make things convenient for the lobe of a leaf operation, and is provided with the electrically conductive contact zone that is used for making the heterojunction solar wafer conductive connection behind the lobe of a leaf on the battery piece big and is used for applying the bonding region of binder, and the production process and the performance of heterojunction solar wafer can be optimized to such setting.

Further, the heterojunction solar cells formed by splitting can be electrically connected through direct contact of the light-transmitting conductive film and the sub-grid lines, so that an adhesive without conductive property can be used for fixing, and the advantages are at least as follows:

the conductive characteristic of the light-transmitting conductive film is good, the performance of the laminated assembly can be optimized, and the arrangement of electrodes can be omitted to reduce the cost;

two, binder can not have electric conductivity, therefore factors such as environmental erosion, high low temperature reversal, expend with heat and contract with cold easily destroy the conducting resin just can not influence the utility model discloses a shingle assembly, shingle assembly are difficult to appear the electric current virtual connection and open circuit, and the positive negative pole of the battery cluster that causes because the conducting resin overflows the glue opens circuit scheduling problem and can not take place yet.

According to one aspect of the present invention, there is provided a cell sheet large sheet for splitting to form a plurality of heterojunction solar cells, a plurality of said heterojunction solar cells being capable of being arranged in a cell string in a shingled manner,

wherein the large cell sheet comprises a substrate sheet, the substrate sheet comprises a center layer and light-transmitting conductive films arranged on the top surface and the bottom surface of the center layer, the large cell sheet is divided into a plurality of units arranged along a first direction, any two adjacent units are a first unit and a second unit, the first unit is formed into a first cell sheet after the large cell sheet is split, and the second unit is formed into a second cell sheet,

a top surface of an interface between the first unit and the second unit is divided into:

a cutting region extending in a direction perpendicular to the first direction, the cutting region configured to enable a large sheet of the battery sheet to be cut therealong; and

a top surface bonding region and a top surface conductive contact region disposed at one side of the cutting region and alternately disposed with the top surface conductive contact region in a direction perpendicular to the first direction, the cutting region and the top surface conductive contact region being formed as one overlapping edge of the second cell sheet,

wherein the top surface bonding region and the top surface conductive contact region are configured to enable an adhesive to be applied on a top surface of the top surface bonding region to be fixed to a bottom surface of a heterojunction solar cell sheet adjacent thereto when the second cell sheet is positioned in the cell string, and the top surface conductive contact region is configured to enable direct contact with the bottom surface of the heterojunction solar cell sheet adjacent thereto to achieve conductive connection.

In one embodiment, the top surface and/or the bottom surface of the substrate sheet of the cell large sheet is provided with a secondary grid line, and the secondary grid line of one of any adjacent pair of heterojunction solar cells can be in direct contact with the light-transmitting conductive film of the other one to realize conductive connection when a plurality of heterojunction solar cells formed by cell large sheet splitting are arranged into a cell string.

In one embodiment, the top surface of the base sheet of the larger sheet of cells has minor grid lines disposed thereon and extending into the top surface conductive contact area.

In one embodiment, the top surface of the base sheet of the large battery piece is provided with secondary grid lines, and the secondary grid lines are not arranged in the conductive contact area of the top surface.

In one embodiment, the top surface and the bottom surface of the base sheet of the cell piece are provided with secondary grid lines, and the secondary grid lines are configured in such a way that in a cell string formed by splitting the cell piece, the secondary grid lines on the regions facing each other of any two heterojunction solar cell pieces are staggered so as not to contact each other.

In one embodiment, a bottom surface bonding region and a bottom surface conductive contact region are further disposed on a bottom surface of an interface portion of the first unit and the second unit, the bottom surface bonding region and the bottom surface conductive contact region being located at the other side of the cutting region in the first direction and being alternately disposed in a direction perpendicular to the first direction, the bottom surface bonding region and the bottom surface conductive contact region being formed as one tap edge of the first battery sheet.

In one embodiment, each of the finger lines extends in the first direction, but each finger line of the bottom surface conductive contact area is not collinear with all other finger lines on the bottom surface of the base sheet.

In one embodiment, each of the cells has a conductive strip disposed on the bottom surface thereof separating the bottom surface bond region, the bottom surface conductive contact region and other areas of the bottom surface, the finger lines on the other areas of the bottom surface and the finger lines of the bottom surface conductive contact region both contacting.

In one embodiment, the light-transmitting conductive film extends over the entire top and bottom surfaces of the center layer.

In one embodiment, the light-transmissive conductive film is absent at the top surface bonding region and the bottom surface bonding region.

In one embodiment, the top surface of the interface portion between the pair of first units and the second units at the foremost end of the battery sheet is further provided with another set of top surface bonding regions and top surface conductive contact regions, which are located at the other side of the cutting region, and the another set of top surface bonding regions and top surface conductive contact regions are formed as one overlapping edge of the first battery sheet.

In one embodiment, no main grid line is arranged on the base substrate of the battery piece.

In one embodiment, the center layer includes a silicon wafer, a top-side intrinsic amorphous silicon thin film disposed on a top surface of the silicon wafer, a P-type amorphous silicon thin film disposed on a top surface of the top-side intrinsic amorphous silicon thin film, a bottom-side intrinsic amorphous silicon thin film disposed on a bottom surface of the silicon wafer, and an N-type amorphous silicon thin film disposed on a bottom surface of the bottom-side intrinsic amorphous silicon thin film.

According to the utility model discloses the second aspect provides a heterojunction solar wafer, heterojunction solar wafer by according to any one in the above-mentioned scheme the battery piece large lobe form.

In one embodiment, the light-transmissive electrically-conductive film extends over the entire top and bottom surfaces of the center layer, and the light-transmissive electrically-conductive film has the same thickness throughout such that when a bonding agent is applied to the top surface bonding region, the bonding agent protrudes from the light-transmissive electrically-conductive film such that when the heterojunction solar cell sheet is connected to another heterojunction solar cell sheet, the light-transmissive electrically-conductive films on the surfaces of the two heterojunction solar cell sheets opposite to each other are spaced apart by the bonding agent at the bonding agent.

In one embodiment, the light-transmissive conductive film is provided with a notch on the top surface bonding region, and when an adhesive is applied to the heterojunction solar cell, the adhesive is located in the notch and does not protrude from the light-transmissive conductive film.

In one embodiment, the top surface and/or the bottom surface of the substrate sheet is provided with a secondary grid line, so that the light-transmitting conductive film of one of the two heterojunction solar cell sheets connected in a shingled manner is in direct contact with the secondary grid line of the other.

In one embodiment, the lapped edge of the heterojunction solar cell sheet contacting another heterojunction solar cell sheet is provided with a top surface bonding region and a top surface conductive contact region which extend along the lapped edge and are alternately arranged on the lapped edge, and the secondary grid lines are also present in the top surface conductive contact region or are not present in the top surface conductive contact region.

In one embodiment, there are also finger lines within the top surface conductive contact region, and each finger line of the top surface conductive contact region and all finger lines on the surface of the top surface conductive contact region other than the top surface conductive contact region are not collinear, and

the heterojunction solar cell piece is provided with a conductive strip on the surface where the top surface conductive contact region is located, wherein the conductive strip separates the top surface conductive contact region, the top surface bonding region and other parts on the surface, and the minor grid lines of the top surface conductive contact region and the minor grid lines of other parts on the surface are in conductive connection with the conductive strip.

According to the utility model discloses the third aspect provides a stack tile subassembly, including the battery cluster, its characterized in that, the battery cluster is by a plurality of according to any one of above-mentioned heterojunction solar wafer with the mode of tiling in proper order continuous and form, each heterojunction solar wafer passes through the binder and fixes each other, and, be provided with vice grid line on the top surface of heterojunction solar wafer and/or the basal surface, adjacent two the printing opacity conducting film of one of heterojunction solar wafer can with the vice grid line direct contact of another in two heterojunction solar wafers realizes adjacent two electrically conductive connection between the heterojunction solar wafer.

In one embodiment, the binder is a non-conductive binder.

In one embodiment, the adhesive is a dot-structured adhesive made of acrylic resin, silicone resin, epoxy resin, or polyurethane.

In one embodiment, the adhesive is an adhesive comprising a curing agent, a cross-linking agent, a coupling agent, or a dot structure of rubber spheres.

According to the utility model, a large cell piece for manufacturing the heterojunction solar cell piece can be provided, a cutting area, a top surface bonding area and a top surface conductive contact area are formed in the connection area of each unit of the large cell piece, and the cutting area can facilitate the large cell piece splitting; the top surface bonding region and the top surface conductive contact region are formed as the lapping edge of one heterojunction solar cell, wherein a plurality of heterojunction solar cells formed after the cell is largely split can be arranged into a cell string in a tiling mode, and in the cell string, the top surface conductive contact region of one of any two adjacent heterojunction solar cells can be contacted with the other heterojunction solar cell, so that the light-transmitting conductive film of one of the two heterojunction solar cells is contacted with the secondary grid line of the other heterojunction solar cell to realize conductive connection; an adhesive for bonding adjacent heterojunction solar cells together can be applied to the top surface bonding region.

The arrangement can facilitate the large splitting of the cell, and the heterojunction solar cells formed by splitting can be in conductive connection through the direct contact of the light-transmitting conductive film and the secondary grid line, so that the heterojunction solar cells can be fixed by using a binder without conductive property, and the arrangement has at least the following advantages:

Drawings

For a better understanding of the above and other objects, features, advantages and functions of the present invention, reference should be made to the preferred embodiments illustrated in the accompanying drawings. Like reference numerals in the drawings refer to like parts. It will be appreciated by persons skilled in the art that the drawings are intended to illustrate preferred embodiments of the invention without any limiting effect on the scope of the invention, and that the various components in the drawings are not to scale.

Fig. 1 shows a schematic top surface view of a battery plate wafer according to a first embodiment of the present invention;

fig. 2 is a partially enlarged view of a portion a in fig. 1;

fig. 3 is a partially enlarged view of a portion B in fig. 1;

FIG. 4 is a schematic bottom view of a large sheet of the battery cell of this embodiment;

fig. 5 is a partially enlarged view of a portion C in fig. 4;

fig. 6A and 6B are a schematic top surface view and a schematic bottom surface view of a single heterojunction solar cell formed by the large-scale splitting of the cell in fig. 1;

fig. 7 is a schematic view of the top surface of two of the heterojunction solar cells shown in fig. 6 after being arranged in a shingled manner;

FIG. 8 is a cross-sectional view taken along line A-A in FIG. 7;

fig. 9 is a schematic top surface view of a battery wafer according to a second embodiment of the present invention;

fig. 10 is a partial enlarged view of a portion D in fig. 9;

FIG. 11 is a schematic bottom surface view of the wafer of FIG. 9;

fig. 12 is a partial enlarged view of a portion E in fig. 11;

fig. 13 is a schematic top surface view of the wafer of fig. 9 after two of the large-split heterojunction solar cells are arranged in a shingled manner;

FIG. 14 is a schematic view taken along line B-B of FIG. 13;

fig. 15 is a schematic top surface view of a third embodiment of a wafer having a plurality of split-cell heterojunction solar cells according to the present invention, after two of the split-cell heterojunction solar cells are arranged in a shingled manner;

fig. 16 is a sectional view taken along line C-C in fig. 15.

Detailed Description

Referring now to the drawings, specific embodiments of the present invention will be described in detail. What has been described herein is merely a preferred embodiment in accordance with the present invention, and those skilled in the art will appreciate that other ways of implementing the present invention on the basis of the preferred embodiment will also fall within the scope of the present invention.

The present invention provides a large cell piece, a heterojunction solar cell piece and a manufacturing method thereof, and fig. 1 to 16 show several preferred embodiments of the large cell piece and the heterojunction solar cell piece of the present invention.

Fig. 1 to 8 show a first embodiment according to the present invention. Fig. 1 shows a cell wafer 100 in this embodiment, the cell wafer 100 being capable of being split to form a plurality of heterojunction solar cells. Among them, the battery sheet 100 includes a base sheet 11, and the base sheet 11 includes a center layer and light-transmitting conductive films 13 disposed on the top and bottom surfaces of the center layer. The center layer, in turn, includes, for example, a silicon wafer, a top-side intrinsic amorphous silicon thin film disposed on a top surface of the silicon wafer, a P-type amorphous silicon thin film disposed on a top surface of the top-side intrinsic amorphous silicon thin film, a bottom-side intrinsic amorphous silicon thin film disposed on a bottom surface of the silicon wafer, and an N-type amorphous silicon thin film disposed on a bottom surface of the bottom-side intrinsic amorphous silicon thin film.

The cell sheet 100 is divided into a plurality of cells 1 arranged in a linear direction, and any two adjacent cells 1 are a first cell and a second cell, wherein the first cell 1a forms a first cell sheet, and the second cell 1b forms a second cell sheet.

Referring to fig. 2, the interface portion 2 between the first unit 1a and the second unit 1b is divided at the top surface into a cutting region 21, a top surface bonding region 22, and a top surface conductive contact region 23. The cutting region 21 extends in a direction perpendicular to the arrangement direction of the solar cells, and the large cell pieces 100 can be split along the cutting region 21. After the splitting, the top surface bonding region 22 and the top surface conductive contact region 23 can be formed as the overlapping edge of the second cell sheet, and the top surface bonding region 22 and the top surface conductive contact region 23 are disposed at one side of the cutting region 21 and alternately disposed in a direction parallel to the cutting region 21 on the cell sheet large sheet 100.

After the large cell piece 100 is split, the second cell piece can be arranged in a shingled manner with another solar cell piece (e.g., the first cell piece), the bottom surface of which can be in direct contact with the top surface conductive contact region 23 of the second cell piece to achieve conductive connection, and the adhesive 9 for fixing the two heterojunction solar cell pieces can be applied on the top surface bonding region 22.

The top surface and/or the bottom surface of the battery piece large sheet 100 is provided with the secondary grid lines 12. In the present embodiment, the minor grid lines 12 are provided on both the top and bottom surfaces of the cell sheet 100. When two of the formed heterojunction solar cells are arranged in a shingled manner after the cell is split, the conductive connection is realized by the direct contact of the sub-grid lines 12 and the light-transmitting conductive film 13.

Preferably, referring to fig. 2, the subgrid 12 on the top surface of the cell tab 100 extends into the top surface conductive contact region 23.

Meanwhile, referring to fig. 4 and 5, on the battery wafer bulk 100, a bottom surface bonding region 22a and a bottom surface conductive contact region 23a are further provided on the bottom surface of the interface portion 2 of the first unit 1a and the second unit 1 b. The bottom surface bonding regions 22a and the bottom surface conductive contact regions 23a are located at one side of the cutting region 21, and the bottom surface bonding regions 22a and the bottom surface conductive contact regions 23a are alternately arranged in a direction parallel to the cutting region 21. The bottom surface conductive contact region 23a and the bottom surface bonding region 22a together constitute one overlapping edge of the first cell piece. In the present embodiment, the finger line 12 is not disposed in the bottom surface conductive contact region 23 a.

As can be seen from fig. 2 and 5, the battery sheet 100 is configured to: the top surface conductive contact region 23 of the overlapping edge of the top surface of the first cell formed by the first unit 1a is provided with the minor grid lines 12, and the bottom surface conductive contact region 23a of the overlapping edge of the bottom surface is not provided with the minor grid lines 12, so that when two heterojunction solar cells are arranged in a shingled manner, the top surface conductive contact region 23 and the bottom surface conductive contact region 23a of the two heterojunction solar cells facing each other are in contact with each other, and at this time, the light-transmitting conductive film 13 of the heterojunction solar cell on the top side can be in direct contact with the minor grid lines 12 of the heterojunction solar cell on the bottom side to realize conductive connection.

It should be noted that, the references to "first cell" and "second cell" and "first cell" and "second cell" herein are relative descriptions rather than absolute descriptions, for example, a "first cell" in one pair of adjacent cells may also be a "second cell" in another pair of adjacent cells at the same time.

Turning now to fig. 1 and 3. It can be seen that the pair of first and

second units

1a and 1b at the foremost end of the battery sheet bulk 100 further includes another set of top surface bonding regions 22 and top surface conductive contact regions 23, that is, there are one set of top surface bonding regions 22 and top surface conductive contact regions 23 on both sides of the cutting region 21. The two sets of top surface bonding areas 22 and top surface conductive contact areas 23 are formed as top surfaces of the overlapping edges of the first and second battery sheets, respectively.

Fig. 6A and 6B show schematic views of the top and bottom surfaces of a single heterojunction solar cell composed of a single cell 1 after the cell mass 100 is split in the present embodiment. It can be seen that there are alternately arranged top surface bonding regions 22 and top surface conductive contact regions 23 at the edges on the top surface of a heterojunction solar cell for bridging with another heterojunction solar cell, there being a sub-grid line 12 within the top surface conductive contact region 23; there are alternately arranged a bottom surface bonding region 22a and a bottom surface conductive contact region 23a at an edge on a bottom surface of the heterojunction solar cell for overlapping with another heterojunction solar cell, and no sub-gate line 12 is arranged in the bottom surface conductive contact region 23 a.

Fig. 7 and 8 show the structure of two heterojunction solar cells made up of the above-described cells 1 after they have been connected in a shingled manner. It can be seen that when two heterojunction solar cells are connected in a shingled manner, in the region where they contact each other, the finger 12 of the top surface conductive contact region 23 of one and the light-transmitting conductive film 13 of the bottom surface conductive contact region 23a of the other are in direct contact to achieve conductive connection.

In this embodiment, after the heterojunction solar cells formed by splitting the large cell piece 100 are arranged in a tiling manner, the light-transmitting conductive film 13 and the sub-gate lines 12 are in direct contact with each other to realize conductive connection, so that the large cell piece 100 does not need to be provided with a main gate line, and such an arrangement can save silver paste and reduce cost, and can reduce the weight of the heterojunction solar cells.

Fig. 9 to 14 show a cell wafer 300 according to a second embodiment of the present invention and a heterojunction solar cell wafer resulting from its splitting. The structure of each component of this embodiment is similar to that of the previous embodiment, and therefore, the description of the same or similar parts as those of the previous embodiment is omitted.

The cell wafer 300 has a plurality of cells 31, and each cell 31 is formed into a heterojunction solar cell after the cell wafer is split. As shown in fig. 10, the top surface of the interface portion 32 of two adjacent cells 31 is divided into a cutting region 321, a top surface conductive contact region 323, and a top surface bonding region 322; as shown in fig. 12, the bottom surface of the interface portion 32 of two adjacent cells 31 is further provided with a bottom surface conductive contact region 323a and a bottom surface bonding region 322a at the other side of the cutting region 312. The top surface conductive contact region 323 and the top surface bonding region 322 form the top surface that can be formed as one landing edge of one heterojunction solar cell piece; the bottom surface conductive contact region 323a and the bottom surface bonding region 322a can be formed as a bottom surface of one tap edge of one heterojunction solar cell.

In the present embodiment, the top surface conductive contact region 323 on the top surface of the cell wafer 300 is not provided with the subgrid, and the bottom surface conductive contact region 323a on the bottom surface is provided with the subgrid.

Also, referring to fig. 12, the minor gate lines of the bottom surface conductive contact area 323a are staggered from the minor gate lines of other areas of the bottom surface, and each minor gate line in the bottom surface conductive contact area 323a is not collinear with all other minor gate lines on the bottom surface of the base sheet. A conductive strip 319 is also provided on the bottom surface of the substrate sheet to separate the finger lines of the bottom surface conductive contact area from other finger lines to conductively connect the finger lines and other finger lines in the bottom surface conductive contact area 323 a.

In the present embodiment, a state after the two split heterojunction solar cells are connected in a shingled manner is shown in fig. 13 and 14. It can be seen that, on the regions where the two heterojunction solar cells face each other, the sub-grid line of the bottom surface conductive contact region of one and the light-transmissive conductive film 313 of the top surface conductive contact region of the other are in direct contact to achieve conductive connection, and the adhesive 9 is disposed between the top surface bonding region and the bottom surface bonding region of the two heterojunction solar cells.

Fig. 15-16 show a third embodiment according to the invention. In the present embodiment, the structural diagram of the large cell is omitted, and only a schematic diagram of the solar cell 41 formed after the large cell is split and arranged in a shingled manner is shown.

In the embodiment, the top surface conductive contact area on the top surface and the bottom surface conductive contact area on the bottom surface of the battery piece are both provided with the secondary grid lines. However, the finger lines on the top surface conductive contact area and the bottom surface conductive contact area are configured as: when two heterojunction solar cells are connected in a shingled manner, the sub-grid lines on the top surface conductive contact region and the bottom surface conductive contact region, which face each other, are staggered from each other without contacting.

As shown in fig. 16, when the two heterojunction solar cells 41 are connected in a shingled manner, the light-transmitting conductive film 413 of the top surface conductive contact region of one contacts the bottom sub-grid line 412a of the bottom surface conductive contact region of the other; and the top finger 412b of the top surface conductive contact region is in direct contact with the light-transmitting conductive film 413 of the bottom surface conductive contact region.

In the three embodiments described above, the individual components can also have other preferred arrangements than those already described above.

For example, the adhesive is preferably a nonconductive adhesive. In selecting the adhesive material, various factors are considered, such as the influence on the electrical connectivity, the mechanical strength, and the reliability of the product, and the factors of application compatibility and cost are also considered. Preferably, a liquid or non-conductive material with high fluidity is selected to facilitate the penetration into the lap joint gaps between the adjacent heterojunction solar cells. The optional material of the adhesive can be made of acrylic resin, silicone resin, epoxy resin or polyurethane, and in order to form a certain thickness, an auxiliary agent such as a curing agent, a cross-linking agent, a coupling agent or a rubber ball can be added.

Because the binder does not have electric conductivity, factors such as environmental erosion, high and low temperature alternation, expend with heat and contract with cold easily destroy the conducting resin just can not influence the utility model discloses a shingle assembly and heterojunction solar wafer, shingle assembly and heterojunction solar wafer are difficult to appear that the electric current connects in vain and opens circuit, and have reduced the requirement of the coating precision of binder. Moreover, as the conductive adhesive is not needed to be arranged, the problems of open circuit of the positive electrode and the negative electrode of the battery string and the like caused by adhesive overflow can be avoided. In addition, because the conductivity of the adhesive is not required, the production cost of the laminated assembly is also reduced.

The adhesive may also have a variety of arrangements. For example, the adhesive may be in a dot shape, and a plurality of adhesives are intermittently disposed on the overlapping edges of each pair of adjacent two heterojunction solar cells; or the adhesive can be strip-shaped and extends along the overlapped edge of each pair of adjacent two heterojunction solar cells; alternatively, the adhesive may be applied on the top surface of the plurality of heterojunction solar cells such that the adhesive spans the plurality of heterojunction solar cells, in which case the adhesive is preferably multiple and the multiple adhesives are arranged parallel to each other on the top surface of the cell string; still alternatively, a plurality of adhesives may be applied to the top and/or bottom surfaces of the heterojunction solar cell, and the adhesives may not be parallel to each other.

Preferably, the adhesive is applied to each heterojunction solar cell and then interconnects the solar cells to each other.

For another example, the light-transmitting conductive film may be provided as: extending over the top and bottom surfaces of the entire substrate sheet and the light-transmitting conductive film has a uniform thickness throughout before the individual heterojunction solar cells are interconnected with each other. Thus, for example, for a light-transmissive conductive film on the top surface of the core layer, after the application of the adhesive on the light-transmissive conductive film at the top surface adhesive region, the adhesive protrudes upwardly from the light-transmissive conductive film; for the light-transmitting conductive film on the bottom surface of the core layer, after the adhesive is applied on the light-transmitting conductive film at the bonding region of the bottom surface, the adhesive protrudes downward from the light-transmitting conductive film.

In this way, when two solar cells are connected in a shingled manner, the light-transmitting conductive films on the surfaces opposite to each other are bent at the adhesive by pressing of the adhesive, so that the light-transmitting conductive films of both are spaced at a position immediately adjacent to the adhesive. The arrangement mode is simple, and extra processing is not needed to be carried out on the light-transmitting conductive film, so that the production efficiency is high, and the cost is low.

As an alternative to the above, the light-transmitting conductive film is provided with a notch at a position where the adhesive is provided to at least partially accommodate the adhesive, so that when two solar cells are interconnected in a shingled manner, the light-transmitting conductive films of the two are in close contact, and there is no bending or the like of the contact surfaces. The problem that the light-transmitting conductive film is extruded and deformed to generate is avoided through the arrangement, and the adhesive is stably accommodated in the notch, so that the problem that the adhesive falls off and loses efficacy and the like can be avoided.

Preferably, the light-transmitting conductive films of the top side and/or the bottom side of the heterojunction solar cell sheet may have a multi-layer structure, and the light transmittance of each of the light-transmitting conductive films increases in a direction pointing outward from the central layer in a direction perpendicular to the central layer. The arrangement can improve the aspects of carrier offset rate, light transmittance, conductivity and the like of the heterojunction solar cell, avoid the problems of low filling factor and low open circuit current, and enable the heterojunction solar cell to have higher photoelectric conversion rate.

The present invention also provides a preferred example of a method of manufacturing a shingle assembly as described above. The manufacturing method comprises the following steps: manufacturing a battery piece large sheet according to the embodiment; cutting along each cutting area of the large cell piece, so that the large cell piece is split into a plurality of solar cell pieces; and connecting a plurality of solar battery pieces in a tiling mode through an adhesive without conductive property, so that the light-transmitting conductive film of one of two adjacent solar battery pieces is in direct contact with the secondary grid line of the other solar battery piece to realize conductive connection.

In this case, the adhesive can be applied to the transparent conductive film of each heterojunction solar cell before the transparent conductive films are connected to each other. Specifically, for two cells adjacent to each other (referred to as a first heterojunction solar cell and a second heterojunction solar cell), the step of connecting them in a shingled manner by means of an adhesive having no conductive property comprises the following steps in sequence: applying an adhesive on the light-transmitting conductive film of the top surface bonding region of the first heterojunction solar cell sheet; and connecting the first heterojunction solar cell piece and the second heterojunction solar cell piece in a tiling mode, and fixing the two heterojunction solar cell pieces with each other through a bonding agent.

Preferably, the method further comprises the following steps between the step of applying a binder on the first heterojunction solar cell sheet and the step of interconnecting the first and second heterojunction solar cell sheets to each other: an adhesive is also applied on the light-transmitting conductive film of the bottom surface adhesive region of the second heterojunction solar cell sheet.

Alternatively, the adhesive may be applied to the heterojunction solar cells after the cells are arranged in a shingled manner. Such a manner may in turn be implemented by several different implementation methods.

Wherein the step of applying the adhesive may comprise: and applying adhesive intermittently along the overlapped edges of each pair of adjacent heterojunction solar cells so that the adhesive is formed into a plurality of dot-shaped structures arranged at intervals along the overlapped edges.

Alternatively, the step of applying the adhesive may comprise: and continuously applying the adhesive along the overlapped edges of each pair of adjacent heterojunction solar cell pieces, so that the adhesive is formed into a strip-shaped structure extending along the overlapped edges.

Alternatively, the step of applying the adhesive may comprise: and continuously applying the adhesive along the arrangement direction of each heterojunction solar cell so that the adhesive spans the plurality of heterojunction solar cells.

Preferably, the above-mentioned several ways of applying the adhesive can be realized by spraying, dripping, rolling, printing, and brushing.

Also preferably, the adhesive may be applied by using a mesh plate provided with a hollowed-out portion, the method of applying the adhesive including the steps of: and positioning a screen plate on the top surface of each arranged heterojunction solar cell, and coating an adhesive on the screen plate so that the adhesive is printed at a required position through the hollow part.

As above, since the center layer of the heterojunction solar cell also has a multi-layer structure, the method of manufacturing the entire heterojunction solar cell includes: arranging a silicon wafer; providing a top intrinsic amorphous silicon film on the top surface of the silicon wafer and a bottom intrinsic amorphous silicon film on the bottom surface of the silicon wafer; disposing a light-transmitting conductive film on a top surface of the top-side intrinsic amorphous silicon thin film and on a bottom surface of the bottom-side intrinsic amorphous silicon thin film; and arranging an auxiliary grid line on the light-transmitting conductive film. Preferably, the method of manufacturing the monolithic heterojunction solar cell does not comprise the step of providing the bus bar.

The utility model provides a battery piece is big can make things convenient for the lobe of a leaf operation, and is provided with the electrically conductive contact zone that is used for heterojunction solar wafer conductive connection on the battery piece big and is used for applying the bonding region of binder, and the production process and the performance of heterojunction solar wafer can be optimized in such setting.

The foregoing description of various embodiments of the invention is provided to one of ordinary skill in the relevant art for the purpose of illustration. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. As noted above, various alternatives and modifications of the present invention will be apparent to those skilled in the art of the above teachings. Thus, while some alternative embodiments are specifically described, other embodiments will be apparent to, or relatively easily developed by, those of ordinary skill in the art. The present invention is intended to embrace all such alternatives, modifications and variances of the present invention described herein, as well as other embodiments that fall within the spirit and scope of the present invention as described above.

Reference numerals:

battery piece

large sheet

100, 300

Unit

1, 31

Solar cell 41

Boundary portion

2, 32

Cutting

zone

21, 312

Top

surface bonding area

22, 322

Top surface

conductive contact regions

23, 323

Base sheet 11, 311

Finger

12, 312

Top finger line 412b

Bottom sub-grid line 412a

Bottom

surface bonding regions

22a, 322a

Bottom surface

conductive contact regions

23a, 323a

Light-transmitting

conductive films

13, 313, 413

Adhesive 9

Conducting strip 319

Claims

1. A cell wafer is used for splitting to form a plurality of heterojunction solar cells which can be arranged into a cell string in a tiling way,

characterized in that a top surface of an interface between the first unit and the second unit is divided into:

a top surface bonding region and a top surface conductive contact region disposed at one side of the cutting region and alternately disposed with the top surface conductive contact region in a direction perpendicular to the first direction, the cutting region and the top surface conductive contact region being formed as a top surface of one overlapping edge of the second cell sheet,

wherein the top surface bonding region and the top surface conductive contact region are configured to enable an adhesive to be applied on a top surface of the top surface bonding region to be fixed to a bottom surface of a heterojunction solar cell sheet adjacent thereto when the second cell sheet is positioned in the cell string, and the top surface conductive contact region is configured to enable a conductive connection by being in direct contact with the bottom surface of the heterojunction solar cell sheet adjacent thereto.

2. The battery piece large sheet according to claim 1, wherein the top surface and/or the bottom surface of the substrate piece of the battery piece large sheet is provided with secondary grid lines, and when a plurality of heterojunction solar battery pieces formed by battery piece large sheet splitting are arranged into a battery string, the secondary grid lines of one of any adjacent pair of heterojunction solar battery pieces can be in direct contact with the light-transmitting conductive film of the other one to realize conductive connection.

3. A wafer according to claim 2 wherein the substrate of the wafer has a top surface with minor grid lines disposed thereon and extending into the top surface conductive contact area.

4. The battery piece large sheet according to claim 2, wherein the base sheet of the battery piece large sheet is provided with secondary grid lines on the top surface, and the secondary grid lines are not present in the top surface conductive contact region.

5. The battery piece large sheet according to claim 2, wherein the battery piece large sheet is provided with minor grid lines on the top surface and the bottom surface of the base sheet, and the minor grid lines are configured in such a way that in a battery string consisting of heterojunction solar battery pieces formed by splitting the cell large sheet, the minor grid lines on the regions facing each other of any two heterojunction solar battery pieces are staggered so as not to contact each other.

6. The battery piece large sheet according to claim 5, wherein a bottom surface bonding region and a bottom surface conductive contact region are further provided on a bottom surface of an interface portion of the first unit and the second unit, the bottom surface bonding region and the bottom surface conductive contact region being located at the other side of the cutting region in the first direction and the bottom surface bonding region and the bottom surface conductive contact region being alternately arranged in a direction perpendicular to the first direction, the bottom surface bonding region and the bottom surface conductive contact region being formed as a bottom surface of one overlapping edge of the first battery piece.

7. The wafer of claim 6, wherein each of the minor grid lines extends in the first direction, but each minor grid line of the bottom surface conductive contact area is not collinear with all other minor grid lines on the bottom surface of the substrate wafer.

8. The battery piece wafer of claim 7, wherein the bottom surface of each of the cells has a conductive strip disposed thereon that separates the bottom surface bonding area, the bottom surface conductive contact area, and other areas of the bottom surface, and wherein the minor grid lines on the other areas of the bottom surface and the minor grid lines of the bottom surface conductive contact area are in contact.

9. The battery wafer platelet of claim 6, wherein the light-transmissive electrically conductive film extends over the entire top and bottom surfaces of the center layer.

10. The battery piece macro of claim 6, wherein the light-transmissive electrically conductive film is absent at the top surface bond regions and the bottom surface bond regions.

11. The battery sheet according to claim 1, wherein the top surface of the interface between the pair of first units and the second units at the foremost end of the battery sheet is further provided with another set of top surface bonding regions and top surface conductive contact regions, which are located at the other side of the cutting region, and formed as the top surface of one overlapping edge of the first battery sheet.

12. The battery piece large sheet as claimed in claim 1, wherein the base sheet of the battery piece large sheet is not provided with the main grid lines.

13. The battery slice large as claimed in claim 1, wherein the central layer comprises a silicon slice, a top-side intrinsic amorphous silicon thin film disposed on the top surface of the silicon slice, a P-type amorphous silicon thin film disposed on the top surface of the top-side intrinsic amorphous silicon thin film, a bottom-side intrinsic amorphous silicon thin film disposed on the bottom surface of the silicon slice, and an N-type amorphous silicon thin film disposed on the bottom surface of the bottom-side intrinsic amorphous silicon thin film.

14. A heterojunction solar cell sheet formed by a large sheet of the cell sheet according to any one of claims 1 to 13.

15. The heterojunction solar cell of claim 14, wherein the light-transmissive electrically-conductive film extends over the entire top and bottom surfaces of the central layer, and wherein the light-transmissive electrically-conductive film has the same thickness throughout such that when an adhesive is applied to the top surface bonding region, the adhesive protrudes from the light-transmissive electrically-conductive film such that the light-transmissive electrically-conductive films on the surfaces of the two heterojunction solar cells opposite each other are spaced apart by the adhesive at the adhesive when the heterojunction solar cell is connected to another heterojunction solar cell.

16. The heterojunction solar cell of claim 14, wherein the light-transmissive conductive film is provided with a notch at the top surface bonding region, and when an adhesive is applied to the heterojunction solar cell, the adhesive is located in the notch and does not protrude from the light-transmissive conductive film.

17. The heterojunction solar cell of claim 14, wherein the top and/or bottom surface of the substrate sheet is provided with minor grid lines such that the light-transmissive conductive film of one of the two heterojunction solar cells connected in a shingled manner is in direct contact with the minor grid lines of the other.

18. The heterojunction solar cell of claim 17, wherein the lapped edge of the heterojunction solar cell in contact with another heterojunction solar cell is provided with top surface bonding regions and top surface conductive contact regions extending along the lapped edge and alternately arranged on the lapped edge, and there are also secondary grid lines in the top surface conductive contact regions or there are no secondary grid lines in the top surface conductive contact regions.

19. The heterojunction solar cell of claim 18 wherein there are also minor grid lines within the top surface conductive contact region, and each minor grid line of the top surface conductive contact region is not collinear with all minor grid lines on the surface of the top surface conductive contact region except for the top surface conductive contact region, and

20. A stack module comprising a cell string, wherein the cell string is formed by connecting a plurality of heterojunction solar cells according to any one of claims 14 to 19 in a stack manner, each heterojunction solar cell is fixed to each other by an adhesive, and the top surface and/or the bottom surface of each heterojunction solar cell is provided with a minor grid line, and the light-transmitting conductive film of one of two adjacent heterojunction solar cells can be in direct contact with the minor grid line of the other of the two heterojunction solar cells to realize an electrically conductive connection between the two adjacent heterojunction solar cells.

21. The shingle assembly of claim 20 wherein the adhesive is a non-conductive adhesive.

22. The tile stack assembly of claim 20, wherein the adhesive is a dot structured adhesive made of acrylic, silicone, epoxy, or polyurethane.

23. The shingle assembly of claim 20, wherein the adhesive is an adhesive comprising a dot structure of curing agents, cross-linking agents, coupling agents, or rubber balls.