Back contact type photovoltaic module

Abstract

The invention discloses a back contact type photovoltaic module, and belongs to the technical field of photovoltaic modules. The battery piece comprises a substrate, doping layers and a passivation anti-reflection layer which are stacked in sequence, the first doping layers and the second doping layers extend in the first direction and are alternately arranged at intervals in the second direction, and an isolation area extending in the first direction is arranged between the first doping layer and the second doping layer which are adjacent to each other; the current collection grid lines comprise first current collection grid lines and second current collection grid lines which extend in the first direction, the first current collection grid lines penetrate through the passivation anti-reflection layer to be electrically connected with the first doping layer, and the second current collection grid lines penetrate through the passivation anti-reflection layer to be electrically connected with the second doping layer; the first bus electrode is arranged on the side, away from the doping layer, of the passivation anti-reflection layer, the first bus electrode extends in the second direction and is electrically connected with the at least two first collector grid lines, the projection of the first bus electrode in the thickness direction of the battery piece is overlapped with the isolation area, and the first bus electrode is prepared from non-burn-through slurry.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of photovoltaic modules, in particular to a back contact photovoltaic module. BACKGROUND

[0002] The back contact photovoltaic module includes a cell, and the cell includes a substrate, a doped layer and a passivation anti-reflection layer which are sequentially stacked. The doped layer includes a first doped layer and a second doped layer, and the conductive types of the first doped layer and the second doped layer are opposite. A first fine grid is arranged on the first doped layer, and a second fine grid is arranged on the second doped layer. The first fine grid is electrically connected to the first doped layer through the passivation anti-reflection layer, and the second fine grid is electrically connected to the second doped layer through the passivation anti-reflection layer, so as to collect the carriers collected by the doped layer through the first fine grid and the second fine grid. The surface of the cell is further provided with a first main grid extending along a second direction, and the first main grid is electrically connected to the plurality of first fine grids, so as to collect the carriers collected by the plurality of first fine grids through the first main grid. The first main grid is prepared by using silver paste, and the silver paste belongs to high-temperature paste. In the high-temperature process, the passivation anti-reflection layer is easily corroded and damaged, and is electrically connected to the second doped layer, so that the photovoltaic module appears a short circuit phenomenon.

[0003] In the related art, the first doped layer and the second doped layer are arranged in an interdigital structure, so that the first main grid avoids the second doped layer, and prevents the first main grid from being electrically connected to the second doped layer after damaging the passivation anti-reflection layer, thereby preventing the photovoltaic module from appearing a local short circuit phenomenon.

[0004] However, in the related art, the doped layer is arranged in an interdigital structure, which makes the preparation of the cell more complex and affects the preparation efficiency of the photovoltaic module. In addition, the arrangement of the doped layer in an interdigital structure causes serious carrier recombination at the edge of the doped layer, which affects the photoelectric conversion efficiency of the photovoltaic module. SUMMARY

[0005] The present application discloses a back contact photovoltaic module to solve or at least partially solve the problem that the doped layer is arranged in an interdigital structure in the prior art, which makes the preparation of the cell too complex and affects the preparation efficiency of the photovoltaic module and the photoelectric conversion efficiency of the photovoltaic module.

[0006] To solve the above technical problems, the present application is implemented as follows:

[0007] The application discloses a back contact type photovoltaic module, which comprises a cell piece, the cell piece comprises a substrate, a doped layer and a passivation anti-reflection layer which are sequentially stacked, the doped layer comprises a first doped layer and a second doped layer, the first doped layer and the second doped layer are both extended along a first direction and are alternately arranged along a second direction, the first doped layer and the second doped layer are opposite in conductive type, and the second direction intersects the first direction; a current collecting grid line, the current collecting grid line comprises a first current collecting grid line and a second current collecting grid line which are extended along the first direction, the first current collecting grid line is electrically connected with the first doped layer at least partially through the passivation anti-reflection layer, and the second current collecting grid line is electrically connected with the second doped layer at least partially through the passivation anti-reflection layer; and a first bus electrode, the first bus electrode is arranged on a side of the passivation anti-reflection layer away from the doped layer, the first bus electrode is extended along the second direction and is electrically connected with at least two first current collecting grid lines, a projection of the first bus electrode along the thickness direction of the cell piece overlaps the isolation area, and the first bus electrode is prepared by using a non-burn-through type paste.

[0008] In some embodiments, the non-burn-through type paste comprises at least one paste of copper, silver-coated copper, nickel or aluminum.

[0009] In some embodiments, the first bus electrode comprises at least one of a first pad, a first main grid, a first edge bus line and a first terminal line.

[0010] In some embodiments, the second current collecting grid line comprises a plurality of first sub-grid lines, the first sub-grid lines are all extended along the first direction and are arranged at intervals along the first direction, the first sub-grid lines have a first gap therebetween along the first direction, and the first bus electrode passes through the first gap; along the first direction, a distance L1 between an end of the first sub-grid line adjacent to the first bus electrode and the first bus electrode satisfies 0.15mm≤L1≤0.5mm; and / or, along the first direction, a width of the first gap is L6, and 0.5mm≤L6≤3mm is satisfied.

[0011] In some embodiments, along the first direction, the cell piece has a first side edge and a second side edge which are oppositely arranged; and the isolation area extends to overlap the first side edge and / or the second side edge along the first direction.

[0012] In some embodiments, the isolation regions are multiple, and the multiple isolation regions are arranged at intervals along the second direction; along the first direction, the cell has oppositely arranged first and second side edges, and the cell is provided with an isolation section at a position close to the first side edge and / or the second side edge, the isolation section extends along the second direction and connects at least two adjacent isolation regions.

[0013] In some embodiments, along the first direction, the cell has oppositely arranged first and second side edges; the cell is provided with a first connecting line at a position close to the first side edge and / or the second side edge, and the first connecting line is connected to the end portions of at least two second current collecting grid lines.

[0014] In some embodiments, the first connecting line is made of silver paste, and the projection of the first connecting line along the thickness direction of the cell is arranged in a staggered manner with the isolation regions; or the first connecting line is made of copper paste, and the projection of the first connecting line along the thickness direction of the cell overlaps with the isolation regions.

[0015] In some embodiments, along the first direction, the cell has oppositely arranged first and second side edges; the first bus electrode includes a first pad and a first edge bus line, the first pad is electrically connected to at least two first current collecting grid lines, along the first direction, the first edge bus line is arranged on the side of the first pad close to the first side edge or the second side edge, the first edge bus line extends along the second direction and is connected to the end portions of a plurality of first current collecting grid lines; the cell is further provided with a second connecting line, the second connecting line is connected to the first pad and the first edge bus line, and the second connecting line is made of non-burn-through paste.

[0016] In some embodiments, the second connecting line extends along the first direction and is located between the first pad and the first edge bus line; the projection of the second connecting line along the thickness direction of the cell overlaps with the second doped layer, and / or the projection of the second connecting line along the thickness direction of the cell overlaps with the isolation regions.

[0017] In some embodiments, the surface of the cell has a polished surface region extending along the first direction and arranged at intervals along the second direction, along the second direction, two adjacent polished surface regions have a suede region extending along the first direction between them; the projection of the first bus electrode along the thickness direction of the cell covers the polished surface region and the suede region.

[0018] The application discloses a back contact photovoltaic module, which comprises a cell piece, the cell piece comprises a substrate, a doped layer and a passivation anti-reflection layer which are sequentially stacked, the doped layer comprises a first doped layer and a second doped layer, the first doped layer and the second doped layer are both extended along a first direction and are alternately arranged along a second direction, the first doped layer and the second doped layer are opposite in conductive type, and the second direction intersects the first direction; a current collecting grid line, the current collecting grid line comprises a first current collecting grid line and a second current collecting grid line which are extended along the first direction, the first current collecting grid line is electrically connected with the first doped layer at least partially through the passivation anti-reflection layer, and the second current collecting grid line is electrically connected with the second doped layer at least partially through the passivation anti-reflection layer; and a first bus electrode, the first bus electrode is arranged on a side of the passivation anti-reflection layer away from the doped layer, the first bus electrode is extended along the second direction and is electrically connected with at least two first current collecting grid lines, a projection of the first bus electrode along a thickness direction of the cell piece overlaps the isolation area, and the first bus electrode is prepared by using non-burn-through type paste.

[0019] The doped layer in the present application includes a first doped layer and a second doped layer, both of which extend along a first direction and are alternately and spacedly arranged along a second direction, the first doped layer and the second doped layer are opposite in conductive type, and there is an isolation region between two adjacent first doped layers and second doped layers to block the first doped layer and the second doped layer through the isolation region, so as to avoid conduction between two adjacent first doped layers and second doped layers, thereby causing local short circuit of the photovoltaic module. The first current collecting grid line is electrically connected to the first doped layer at least partially through the passivation anti-reflection layer, and the second current collecting grid line is electrically connected to the second doped layer at least partially through the passivation anti-reflection layer, so as to collect carriers in the first doped layer through the first current collecting grid line and collect carriers in the second doped layer through the second current collecting grid line. The first bus electrode is arranged on a side of the passivation anti-reflection layer away from the doped layer, extends along the second direction, and is electrically connected to at least two first current collecting grid lines, the projection of the first bus electrode along the thickness direction of the cell piece overlaps with the isolation region, and the first bus electrode is prepared by using non-burn-through paste. The first bus electrode is prepared by using non-burn-through paste, on the one hand, the first bus electrode will not be electrically connected to the second doped layer by burning through the passivation anti-reflection layer, so as to avoid local short circuit of the photovoltaic module and improve the reliability of the photovoltaic module; on the other hand, compared with high-temperature silver paste, the first bus electrode is prepared by using base metal paste, which can further reduce the cost of the photovoltaic module and improve the market competitiveness of the photovoltaic module. In addition, since the first bus electrode will not burn through the passivation anti-reflection layer, the first bus electrode can pass through the isolation region between two adjacent first doped layers and second doped layers and cover at least one first doped layer and second doped layer at the same time, so as to be electrically connected to at least two first current collecting grid lines, thereby the carriers collected by the at least two first current collecting grid lines can be collected and transmitted to an external circuit.

[0020] In the present application, by arranging the doped layer as the first doped layer and the second doped layer extending along the first direction and alternately and spacedly arranged along the second direction, and arranging the isolation region extending along the first direction between two adjacent first doped layers and second doped layers, the structure of the doped layer is simpler, thereby helping to reduce the preparation difficulty of the doped layer, improve the preparation efficiency of the photovoltaic module, and improve the market competitiveness of the photovoltaic module.

[0021] Further, by the above arrangement, the area occupied by the isolation region is smaller, and the area occupied by the first doped layer and the second doped layer is larger, which not only reduces the carrier recombination caused by the edge of the isolation region, but also helps to improve the collection efficiency of the carriers generated by the first doped layer and the second doped layer on the substrate, and improve the photoelectric conversion efficiency of the photovoltaic module.

[0022] Further, in the present application, the doped layer comprises first doped layers and second doped layers which are arranged alternately and spaced apart along the second direction, the first collecting grid lines are electrically connected to the first doped layers at least partially through the passivation anti-reflection layer, and the second collecting grid lines are electrically connected to the second doped layers at least partially through the passivation anti-reflection layer, the first collecting grid lines and the second collecting grid lines also extend along the first direction, thereby helping to increase the contact area of the first collecting grid lines and the first doped layers and the contact area of the second collecting grid lines and the second doped layers, shorten the transmission path of the carriers, and improve the collection efficiency of the carriers, thereby helping to improve the photoelectric conversion efficiency of the photovoltaic module. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 A schematic diagram showing a partial structure of the back contact photovoltaic module in the embodiment of the present application Figure 1 ;

[0024] Figure 2 A schematic diagram showing a partial structure of the back contact photovoltaic module in the embodiment of the present application Figure 2 ;

[0025] Figure 3 A schematic diagram showing a partial structure of the back contact photovoltaic module in the embodiment of the present application Figure 3 ;

[0026] Figure 4 A schematic diagram showing a partial structure of the back contact photovoltaic module in the embodiment of the present application Figure 4 ;

[0027] Figure 5 A schematic diagram showing a partial structure of the back contact photovoltaic module in the embodiment of the present application Figure 5 ;

[0028] Figure 6 A schematic diagram showing a partial structure of the back contact photovoltaic module in the embodiment of the present application Figure 6 ;

[0029] Figure 7 A schematic diagram showing a partial structure of the back contact photovoltaic module in the embodiment of the present application Figure 5 ; Figure 1 ;

[0030] Figure 8 A schematic diagram showing a partial structure of the back contact photovoltaic module in the embodiment of the present application Figure 5 ; Figure 2 ;

[0031] Figure 9 A schematic diagram showing a partial structure of the back contact photovoltaic module in the embodiment of the present application Figure 7 ;

[0032] Figure 10 A schematic diagram showing a partial structure of the back contact photovoltaic module in the embodiment of the present application

[0033] Reference signs:

[0034] 10: battery piece; 11: substrate; 12: doped layer; 121: first doped layer; 122: second doped layer; 123: isolation region; 124: isolation section; 13: passivation anti-reflection layer; 14: first side edge; 15: second side edge; 16: first region; 17: polished surface region; 18: textured surface region;

[0035] 20: current collecting grid line; 21: first current collecting grid line; 22: second current collecting grid line; 221: first sub-grid line; 222: first gap;

[0036] 30: first bus electrode; 31: first pad; 32: first edge bus line; 33: first end line;

[0037] 40: first connecting line;

[0038] 50: second connecting line;

[0039] X: first direction; Y: second direction. DETAILED DESCRIPTION

[0040] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without any creative work under the premise that the embodiments are included in the scope of the present application.

[0041] It should be understood that the "one embodiment" or "an embodiment" mentioned throughout the specification means that the specific features, structures or characteristics related to the embodiment are included in at least one embodiment of the present application. Therefore, "in one embodiment" or "in an embodiment" appearing throughout the specification does not necessarily mean the same embodiment. In addition, these specific features, structures or characteristics can be combined in one or more embodiments in any suitable manner.

[0042] The embodiment of the present application discloses a back contact type photovoltaic module, which comprises a cell piece 10, the cell piece 10 comprises a substrate 11, a doped layer 12 and a passivation anti-reflection layer 13 which are sequentially stacked, the doped layer 12 comprises a first doped layer 121 and a second doped layer 122, the first doped layer 121 and the second doped layer 122 are both extended along a first direction X and are alternately and spacedly arranged along a second direction Y, there is an isolation area 123 extended along the first direction X between the adjacent two first doped layers 121 and the second doped layer 122, the conductive types of the first doped layer 121 and the second doped layer 122 are opposite, and the second direction Y intersects the first direction X; a current collecting grid line 20, the current collecting grid line 20 comprises a first current collecting grid line 21 and a second current collecting grid line 22 which are extended along the first direction X, the first current collecting grid line 21 is electrically connected with the first doped layer 121 at least partially through the passivation anti-reflection layer 13, and the second current collecting grid line 22 is electrically connected with the second doped layer 122 at least partially through the passivation anti-reflection layer 13; a first bus electrode 30, the first bus electrode 30 is arranged on a side of the passivation anti-reflection layer 13 away from the doped layer 12, the first bus electrode 30 is extended along the second direction Y and is electrically connected with at least two first current collecting grid lines 21, a projection of the first bus electrode 30 along the thickness direction of the cell piece 10 overlaps with the isolation area 123, and the first bus electrode 30 is prepared by using non-burn-through type paste.

[0043] The embodiment of the present application discloses a back contact type photovoltaic module, which has the characteristics of high photoelectric conversion efficiency and excellent appearance.

[0044] The back contact type photovoltaic module disclosed by the embodiment of the present application comprises a cell piece 10, the cell piece 10 is a core component of the back contact type photovoltaic module and can convert solar energy into electric energy. Figure 10 As shown in the figure, the cell piece 10 comprises a substrate 11, a doped layer 12 and a passivation anti-reflection layer 13. Along the thickness direction of the cell piece 10, the substrate 11 has a first surface and a second surface which are oppositely arranged. When the first surface is a light receiving surface of the substrate 11 facing the sunlight, i.e. a front surface, the second surface is a back surface of the substrate 11 facing away from the sunlight, i.e. a back surface. When the first surface is a back surface of the substrate 11 facing away from the sunlight, the second surface is a front surface of the substrate 11 facing the sunlight.

[0045] It should be noted that the cell piece 10 in the embodiment of the present application, also known as a solar cell piece, can be a back contact type cell piece, and the electrodes of the back contact type cell piece are all arranged on the back surface of the cell piece. The back contact type cell piece includes but is not limited to a back contact type heterojunction solar cell piece (HBC cell piece), a back contact type tunnel oxide passivated contact cell piece (TBC cell piece), a composite passivation back contact type cell piece (HPBC cell piece), a back contact type hybrid cell piece (HTBC cell piece) and the like.

[0046] The following will take the back surface of the first surface as the base 11 and the front surface of the second surface as the base 11 as an example to make a related description of the back contact photovoltaic module disclosed in the embodiments of the present application. That is, the photovoltaic module disclosed in the embodiments of the present application is a back contact photovoltaic module.

[0047] The doped layer 12 and the passivation anti-reflection layer 13 in the embodiments of the present application are sequentially stacked on the first surface of the base 11, that is, the doped layer 12 and the passivation anti-reflection layer 13 are sequentially stacked on the back surface of the base 11. The doped layer 12 includes the first doped layer 121 and the second doped layer 122 which are alternately and spaced apart along the second direction Y and extend along the first direction X, and the adjacent two first doped layers 121 and second doped layers 122 have an isolation region 123 therebetween, which extends along the first direction X. The conductive types of the first doped layer 121 and the second doped layer 122 are opposite, and the first doped layer 121 and the second doped layer 122 are blocked by the isolation region 123 to avoid conduction of the first doped layer 121 and the second doped layer 122, thereby avoiding local short circuit of the photovoltaic module and affecting the reliability of the photovoltaic module.

[0048] It should be noted that the first direction X in the embodiments of the present application can be the length direction of the cell piece 10, or the width direction of the cell piece 10. When the first direction X is the length direction of the cell piece 10, the second direction Y is the width direction of the cell piece 10. When the first direction X is the width direction of the cell piece 10, the second direction Y is the length direction of the cell piece 10.

[0049] The following will take the first direction X as the length direction of the cell piece 10 and the second direction Y as the width direction of the cell piece 10 as an example to make a related description of the embodiments of the present application.

[0050] The back contact photovoltaic module disclosed in the embodiments of the present application further includes a current collecting grid line 20, which can be electrically connected with the doped layer 12 through the passivation anti-reflection layer 13. Specifically, a first current collecting grid line 21 can be arranged on the side of the passivation anti-reflection layer 13 away from the first doped layer 121, and the first current collecting grid line 21 can at least partially pass through the passivation anti-reflection layer 13 and be electrically connected with the first doped layer 121 together to collect the carriers in the first doped layer 121. A second current collecting grid line 22 can be arranged on the side of the passivation anti-reflection layer 13 away from the second doped layer 122, and the second current collecting grid line 22 can at least partially pass through the passivation anti-reflection layer 13 and be electrically connected with the second doped layer 122 together to collect the carriers in the second doped layer 122.

[0051] Exemplarily, in the embodiments of the present application, the current collecting grid line 20 can be a single-layer structure. For example, the current collecting grid line 20 can be a silver paste of burn-through type. In the preparation process of the photovoltaic module, the high-temperature silver paste can be disposed on the side of the passivation anti-reflection layer 13 away from the first doped layer 121 by means of screen printing, and the first current collecting grid line 21 can be formed by high-temperature sintering. The first current collecting grid line 21 can burn through the passivation anti-reflection layer 13 and be electrically connected to the first doped layer 121 to collect the carriers in the first doped layer 121. The high-temperature silver paste can be disposed on the side of the passivation anti-reflection layer 13 away from the second doped layer 122 to form the second current collecting grid line 22. The second current collecting grid line 22 can burn through the passivation anti-reflection layer 13 and be electrically connected to the second doped layer 122 to collect the carriers in the second doped layer 122 by high-temperature sintering.

[0052] In other embodiments, the current collecting grid line 20 can be a multi-layer structure. The layer of the current collecting grid line 20 in contact with the first doped layer 121 and the second doped layer 122 is a seed layer, and the part covering the seed layer is the main layer of the current collecting grid line 20. The seed layer can be a non-burn-through type material, such as nickel, titanium, etc. The passivation anti-reflection layer 13 is at least partially opened and filled with the non-burn-through type material, and then the main layer of the current collecting grid line 20 is formed by screen printing, thereby forming the first current collecting grid line 21 and the second current collecting grid line 22. The main layer of the current collecting grid line at least partially passes through the passivation anti-reflection layer 13 and forms electrical connection through the seed layer and the doped layer 12. The seed layer can also be a burn-through type paste, such as silver paste. The silver seed layer is electrically connected to the first doped layer 121 and the second doped layer 122 by local printing process and high-temperature sintering, and then the main layer of the current collecting grid line is formed by screen printing, thereby forming the first current collecting grid line 21 and the second current collecting grid line 22. The main layer of the current collecting grid line can be formed by selecting a non-burn-through type paste, such as silver-coated copper, copper paste, nickel paste, etc., to reduce the cost of the photovoltaic module and improve the market competitiveness of the photovoltaic module.

[0053] Of course, the above is only an individual example of the specific forming method of the first current collecting grid line 21 and the second current collecting grid line 22, and is not a limitation of the present application. In the embodiments of the present application, the current collecting grid line 20 is provided as a high-temperature silver paste, and the silver paste is sintered at high temperature to form electrical contact with the doped layer 12 through the passivation anti-reflection layer 13, thereby improving the contact performance.

[0054] In some embodiments, the material of the passivation anti-reflection layer 13 can be an insulating material. Exemplarily, the insulating material can include at least one of silicon nitride, silicon oxynitride, and aluminum oxide.

[0055] It should be noted that the passivation and anti-reflection layer 13 in the embodiments of the present application can be a single-layer structure or a multi-layer structure. The structure of the passivation and anti-reflection layer 13 is not specifically limited in the embodiments of the present application, and it can be set according to the needs of the solar cell. Exemplarily, for a TBC cell, the passivation and anti-reflection layer 13 on the back light surface can include a double-layer structure, and the passivation and anti-reflection layer is an aluminum oxide and silicon nitride layer arranged in a stack away from the silicon substrate direction. Among them, the aluminum oxide can provide good passivation effect, the silicon nitride has good anti-reflection effect, and the aluminum oxide and silicon nitride are arranged in a stack to further improve the passivation and anti-reflection effect, thereby improving the photoelectric conversion efficiency of the photovoltaic module.

[0056] The back contact photovoltaic module disclosed in the embodiments of the present application further includes a first bus electrode 30, which is arranged on the side of the passivation and anti-reflection layer 13 away from the doped layer 12. The first bus electrode 30 extends along the second direction Y and is electrically connected together with at least two first current collecting grid lines 21 to collect the carriers collected by the first current collecting grid lines 21 and transmit the collected carriers to an external circuit.

[0057] It should be noted that when the first bus electrode 30 extends along the second direction Y and is connected to at least two first current collecting grid lines 21, the first bus electrode 30 will cross the second current collecting grid line 22. An insulating layer can be arranged between the first bus electrode 30 and the second current collecting grid line 22 to block the first bus electrode 30 and the second current collecting grid line 22 through the insulating layer, so as to avoid the conduction of the first bus electrode 30 and the second current collecting grid line 22, which causes the local short circuit phenomenon of the photovoltaic module and affects the photoelectric conversion efficiency of the photovoltaic module. Alternatively, the second current collecting grid line 22 is arranged to include a plurality of first sub-grid lines 221 extending along the first direction X and arranged at intervals along the first direction X, and the first bus electrode 30 passes through the first gap 222 and is electrically connected together with at least two first current collecting grid lines 21. To avoid the conduction of the first bus electrode 30 and the second current collecting grid line 22, which causes the local short circuit phenomenon of the photovoltaic module and affects the photoelectric conversion efficiency of the photovoltaic module.

[0058] It should be noted that in the embodiments of the present application, the projection of the first bus electrode 30 in the thickness direction of the battery piece 10 overlaps the isolation area 123, and the first bus electrode 30 is prepared by using non-burn-through paste. The first bus electrode 30 is prepared by using non-burn-through paste, that is, the first bus electrode 30 will not burn through the passivation anti-reflection layer 13 and the second doped layer 122 to be electrically connected together, so as to avoid the local short circuit phenomenon of the photovoltaic module and affect the photoelectric conversion efficiency of the photovoltaic module. The first bus electrode 30 can pass through the isolation area 123 between the adjacent two first doped layers 121 and the second doped layer 122 to be electrically connected with at least two first current collecting grid lines 21, so as to collect the carriers collected by the at least two first current collecting grid lines 21 and transmit the collected carriers to the external circuit.

[0059] In the embodiments of the present application, by arranging the doped layer 12 as the first doped layer 121 and the second doped layer 122 extending along the first direction X and alternately and spaced apart along the second direction Y, the adjacent two first doped layers 121 and the second doped layer 122 have the isolation area 123 extending along the first direction X, so as to make the structure of the doped layer 12 more simple, thereby helping to reduce the preparation difficulty of the doped layer 12, improve the preparation efficiency of the photovoltaic module, and improve the market competitiveness of the photovoltaic module.

[0060] Further, through the above arrangement, the area occupied by the isolation area 123 is smaller, and the area occupied by the first doped layer 121 and the second doped layer 122 is larger, not only reducing the carrier recombination caused by the edge of the isolation area 123, but also helping to improve the collection efficiency of the carriers generated by the first doped layer 121 and the second doped layer 122 to the substrate 11, and improve the photoelectric conversion efficiency of the photovoltaic module.

[0061] Further, in the embodiments of the present application, the doped layer 12 includes the first doped layer 121 and the second doped layer 122 extending along the first direction X and alternately and spaced apart along the second direction Y, the first current collecting grid line 21 is electrically connected with the first doped layer 121 at least partially through the passivation anti-reflection layer 13, the second current collecting grid line 22 is electrically connected with the second doped layer 122 at least partially through the passivation anti-reflection layer 13, and the first current collecting grid line 21 and the second current collecting grid line 22 also extend along the first direction X, thereby helping to increase the contact area of the first current collecting grid line 21 and the first doped layer 121 and the contact area of the second current collecting grid line 22 and the second doped layer 122, shorten the transmission path of the carriers, and improve the collection efficiency of the carriers, thereby helping to improve the photoelectric conversion efficiency of the photovoltaic module.

[0062] It should be noted that in the embodiments of the present application, the non-burn-through paste includes but is not limited to low-temperature silver paste, copper paste, silver-coated copper paste, aluminum paste, etc. In the embodiments of the present application, the specific material of the non-burn-through paste is not limited too much, and any non-burn-through paste can be used.

[0063] In some embodiments, the non-penetrating paste includes at least one of copper paste, silver-coated copper paste, nickel paste, and aluminum paste.

[0064] In some embodiments, the non-penetrating paste includes at least one of copper paste, silver-coated copper paste, nickel paste, and aluminum paste.

[0065] In some embodiments, the non-penetrating paste includes at least one of copper paste, silver-coated copper paste, nickel paste, and aluminum paste.

[0066] Further, compared with silver paste, the copper paste, the silver-coated copper paste, the nickel paste, and the aluminum paste have lower cost, thereby helping to reduce the cost of the photovoltaic module and improve the market competitiveness of the photovoltaic module. Figures 1 to 6 As shown in FIG. 1, the first bus electrode 30 includes at least one of a first solder pad 31, a first main grid, a first edge bus line 32, and a first terminal line 33.

[0067] As shown in FIG. 1, the first bus electrode 30 includes at least one of a first solder pad 31, a first main grid, a first edge bus line 32, and a first terminal line 33. Figures 1 to 6 As shown in FIG. 1, the first bus electrode 30 includes at least one of a first solder pad 31, a first main grid, a first edge bus line 32, and a first terminal line 33.

[0068] In some embodiments, the first bus electrode 30 includes at least one of the first solder pad 31, the first main grid, the first edge bus line 32, and the first terminal line 33.

[0069] In some embodiments, the first bus electrode 30 includes at least one of the first solder pad 31, the first main grid, the first edge bus line 32, and the first terminal line 33. Figure 1As shown, the second current collecting grid line 22 includes a plurality of first sub-grid lines 221, each of which extends along the first direction X and is arranged at intervals along the first direction X, and a first gap 222 is formed between adjacent first sub-grid lines 221. The first bus electrode 30 passes through the first gap 222. The end of the first sub-grid line 221 adjacent to the first bus electrode 30 has a first distance L1 from the first bus electrode 30 along the first direction X, and 0.15mm≤L1≤0.5mm is satisfied.

[0070] As shown in the drawings, Figure 1 As shown in the drawings, the second current collecting grid line 22 in the embodiment of the present application includes a plurality of first sub-grid lines 221, each of which extends along the first direction X and is arranged at intervals along the first direction X, and a first gap 222 is formed between adjacent first sub-grid lines 221. The first bus electrode 30 passes through the first gap 222, which can avoid the conduction between the first bus electrode 30 and the second current collecting grid line 22, causing local short circuit of the photovoltaic module and affecting the photoelectric conversion efficiency of the photovoltaic module. Further, the first bus electrode 30 is electrically connected to at least two first current collecting grid lines 21, which can collect the carriers collected by the at least two first current collecting grid lines 21 through the first bus electrode 30 and transmit the collected carriers to an external circuit.

[0071] It should be noted that the end of the first sub-grid line 221 adjacent to the first bus electrode 30 has a first distance L1 from the first bus electrode 30 along the first direction X, and the first distance L1 is greater than or equal to 0.15mm and less than or equal to 0.5mm. If the first distance L1 is less than 0.15mm, the first sub-grid line 221 is easy to conduct with the first bus electrode 30, causing local short circuit of the photovoltaic module. If the first distance L1 is greater than 0.5mm, it will affect the extension length of the first sub-grid line 221 along the first direction X, reduce the contact area of the first sub-grid line 221 with the second doped layer 122, and affect the collection efficiency of the first sub-grid line 221 to the carriers in the second doped layer 122, affecting the photoelectric conversion efficiency of the photovoltaic module.

[0072] For example, the first distance L1 between the end of the first sub-grid line 221 adjacent to the first bus electrode 30 and the first bus electrode 30 along the first direction X can be 0.15mm, 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm, etc.

[0073] In some embodiments, the width of the first gap 222 along the first direction X is L6, and 0.5mm≤L6≤3mm is satisfied.

[0074] In the embodiments of the present application, along the first direction X, the width L6 of the first gap 222 is greater than or equal to 0.5 mm and less than or equal to 3 mm. For example, along the first direction X, the width L6 of the first gap 222 can be 0.5 mm, 1.0 mm, 1.5 mm, 2.0 mm, 2.5 mm, 3.0 mm, etc.

[0075] If along the first direction X, the width of the first gap 222 is less than 0.5 mm, the end of the first sub-grid line 221 is easy to overlap with the first bus electrode 30, and the first sub-grid line 221 is electrically connected together with the first bus electrode 30, resulting in a local short circuit phenomenon of the photovoltaic module, affecting the photoelectric conversion efficiency of the photovoltaic module. If along the first direction X, the width of the first gap 22 is greater than 3 mm, the gap between the two adjacent first sub-grid lines 221 is too large, and the length of the first sub-grid line 221 along the first direction X is short, which will affect the collection efficiency of the first sub-grid line 221 to the carriers, affecting the photoelectric conversion efficiency of the photovoltaic module.

[0076] In some embodiments, along the second direction Y, the distance between the two adjacent first current collecting grid lines 21 or the two adjacent second current collecting grid lines 22 is a second distance L2, which satisfies 0.3 mm≤L2≤1.5 mm.

[0077] It can be understood that along the second direction Y, the distance between the two adjacent first current collecting grid lines 21 is a second distance L2, and the second distance L2 is greater than or equal to 0.3 mm and less than or equal to 1.5 mm. For example, along the second direction Y, the second distance L2 between the two adjacent first current collecting grid lines 21 can be 0.3 mm, 0.4 mm, 0.5 mm, 0.7 mm, 0.9 mm, 1.0 mm, 1.2 mm, 1.4 mm, 1.5 mm, etc.

[0078] Alternatively, along the second direction Y, the distance between the two adjacent second current collecting grid lines 22 is a second distance L2, and the second distance L2 is greater than or equal to 0.3 mm and less than or equal to 1.5 mm. For example, along the second direction Y, the second distance L2 between the two adjacent second current collecting grid lines 22 can be 0.3 mm, 0.4 mm, 0.5 mm, 0.8 mm, 1.0 mm, 1.2 mm, 1.4 mm, 1.5 mm, etc.

[0079] In the embodiment of the present application, along the second direction Y, the second distance L2 between two adjacent first collector grid lines 21 or two adjacent second collector grid lines 22 is set to be greater than or equal to 0.3 mm and less than or equal to 1.5 mm, so that the second distance L2 between two adjacent first collector grid lines 21 or two adjacent second collector grid lines 22 is smaller, thereby allowing more first collector grid lines 21 and second collector grid lines 22 to be arranged on the solar cell 10, thereby improving the carrier collection efficiency and improving the photoelectric conversion efficiency of the photovoltaic module. It can be understood that the smaller the second distance L2 between two adjacent second collector grid lines 22, the more compact the arrangement of the second doped layers 122 below the second collector grid lines 22, thereby helping to increase the effective power generation area of ​​the solar cell 10 and improve the photoelectric conversion efficiency of the photovoltaic module.

[0080] If the second distance L2 between two adjacent first collector grid lines 21 or two adjacent second collector grid lines 22 along the second direction Y is less than 0.3 mm, the distance between the first collector grid lines 21 and the second collector grid lines 22 is too close, and the isolation region 123 is too narrow, which places higher requirements on the process of the cell 10 and increases the difficulty of processing the cell 10. In addition, the isolation effect of the isolation region 123 is weakened, making the cell 10 more susceptible to local short circuits, which in turn affects the photoelectric conversion efficiency of the photovoltaic module.

[0081] If the second distance L2 between two adjacent first collector grid lines 21 or two adjacent second collector grid lines 22 along the second direction Y is greater than 1.5 mm, the isolation region 123 is too wide, which will reduce the area occupied by the first doped layer 121 and the second doped layer 122 and reduce the photoelectric conversion efficiency of the photovoltaic module.

[0082] That is, along the second direction Y, the second distance L2 between two adjacent first collector grid lines 21 or two adjacent second collector grid lines 22 is set to be greater than or equal to 0.3 mm and less than or equal to 1.5 mm. This allows for more first collector grid lines 21 and more second collector grid lines 22 to be arranged within each cell 10, thereby helping to improve the photovoltaic conversion efficiency of the photovoltaic module. Furthermore, the isolation effect of the isolation region 123 is also good, thereby preventing local short circuits in the photovoltaic module. Furthermore, the process requirements and processing difficulty of the cell 10 are also relatively moderate.

[0083] In some embodiments, as Figure 2 As shown, the first bus electrode 30 includes a first solder pad 31, which is electrically connected to at least two first collector grid lines 21; along the first direction X, the width of the first solder pad 31 is L3, satisfying 0.6mm≤L3≤2.0mm, and / or, along the second direction Y, the length of the first solder pad 31 is L4, satisfying 0.6mm≤L4≤1.5mm.

[0084] As shown in FIG. 1, the first bus electrode 30 in the embodiment of the present application can be a first pad 31, and the first pad 31 is electrically connected with the at least two first current collecting grid lines 21 together to collect the carriers collected by the at least two first current collecting grid lines 21 through the first pad 31 and transmit the collected carriers to an external circuit. Figure 2

[0085] It should be noted that the width L3 of the first pad 31 in the embodiment of the present application along the first direction X is greater than or equal to 0.6 mm and less than or equal to 2.0 mm. Exemplarily, the width L3 of the first pad 31 along the first direction X is 0.6 mm, 0.8 mm, 1.0 mm, 1.2 mm, 1.4 mm, 1.6 mm, 1.8 mm, 2.0 mm, etc.

[0086] In the embodiment of the present application, the length L4 of the first pad 31 along the second direction Y is greater than or equal to 0.6 mm and less than or equal to 1.5 mm. Exemplarily, the length L4 of the first pad 31 along the second direction Y is 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, etc.

[0087] If the width L3 of the first pad 31 along the first direction X is less than 0.6 mm, the first pad 31 has poor ability to collect carriers, which affects the photoelectric conversion efficiency of the photovoltaic module. If the width L3 of the first pad 31 along the first direction X is greater than 2.0 mm, the first pad 31 will overlap with the end of the first sub-grid line 221, the first pad 31 will be conductive with the first sub-grid line 221, which causes a local short circuit phenomenon of the photovoltaic module, affecting the photoelectric conversion efficiency of the photovoltaic module.

[0088] If the length L4 of the first pad 31 along the second direction Y is less than 0.6 mm, that is, the extension length of the first pad 31 along the second direction Y is less than the second distance between the adjacent two first current collecting grid lines 21, the first pad 31 cannot be electrically connected to the adjacent two first current collecting grid lines 21. If the length of the first pad 31 along the second direction Y is greater than 1.5 mm, the length of the first pad 31 extending along the second direction Y is too long, and the material amount of the first pad 31 is too large, which causes the cost of the photovoltaic module to be relatively high, affecting the market competitiveness of the photovoltaic module.

[0089] In some embodiments, as shown in FIG. 1, the cell piece 10 has the first side edge 14 and the second side edge 15 oppositely arranged along the first direction X; and the isolation region 123 extends to overlap with the first side edge 14 and / or the second side edge 15 along the first direction X. Figure 2

[0090] As shown in FIG. 1, the first bus electrode 30 in the embodiment of the present application can be a first pad 31, and the first pad 31 is electrically connected with the at least two first current collecting grid lines 21 together to collect the carriers collected by the at least two first current collecting grid lines 21 through the first pad 31 and transmit the collected carriers to an external circuit. Figure 2 ​​As shown in FIG. 1, the battery piece 10 has a first side edge 14 and a second side edge 15 arranged oppositely along the first direction X. The isolation region 123 extends to overlap the first side edge 14 along the first direction X, and / or the isolation region 123 extends to overlap the second side edge 15 along the first direction X.

[0091] In some embodiments, as shown in FIG. 1, the isolation region 123 can extend to the outside of the first edge busbar 32 along the first direction X and overlap the second side edge 15. Alternatively, the isolation region 123 can extend to the outside of the first edge busbar 32 along the first direction X and overlap the first side edge 14. Figure 7 Figure 8 As shown in FIG. 1, the isolation region 123 can extend to the outside of the first edge busbar 32 along the first direction X and overlap the second side edge 15. Alternatively, the isolation region 123 can extend to the outside of the first edge busbar 32 along the first direction X and overlap the first side edge 14.

[0092] It can be understood that in this case, the first doped layer 121 and the second doped layer 122 extend to overlap the first side edge 14 along the first direction X, and / or the first doped layer 121 and the second doped layer 122 extend to overlap the second side edge 15 along the first direction X. This makes the structure of the doped layer 12 simpler, thereby helping to reduce the difficulty of preparing the doped layer 12. For example, if the doped layer 12 is prepared by laser etching to form the first doped layer 121 and the second doped layer 122, the path of the laser spot can be reduced, the preparation efficiency of the photovoltaic module can be improved, and the market competitiveness of the photovoltaic module can be improved.

[0093] Further, by the above arrangement, the isolation region 123 extends to overlap the second side edge 15 along the first direction X. This makes the area occupied by the isolation region 123 smaller and the area occupied by the first doped layer 121 and the second doped layer 122 larger, thereby helping to improve the collection efficiency of the carriers generated by the first doped layer 121 and the second doped layer 122 on the substrate 11 and improve the photoelectric conversion efficiency of the photovoltaic module.

[0094] In some embodiments, as shown in FIG. 1, the isolation region 123 includes a plurality of isolation regions 123 arranged at intervals along the second direction Y. The battery piece 10 has a first side edge 14 and a second side edge 15 arranged oppositely along the first direction X. The battery piece 10 is provided with an isolation section 124 at a position close to the first side edge 14 and / or the second side edge 15. The isolation section 124 extends along the second direction Y and connects at least two adjacent isolation regions 123. Figure 2 As shown in FIG. 1, the isolation region 123 in the embodiment of the present application includes a plurality of isolation regions 123 arranged at intervals along the second direction Y. Each isolation region 123 blocks the adjacent first doped layer 121 and the second doped layer 122, thereby avoiding the conduction of the adjacent first doped layer 121 and the second doped layer 122 and causing the photovoltaic module to have a local short circuit phenomenon, which affects the photoelectric conversion efficiency of the photovoltaic module.

[0095] Figure 2 As shown in FIG. 1, the isolation region 123 in the embodiment of the present application includes a plurality of isolation regions 123 arranged at intervals along the second direction Y. Each isolation region 123 blocks the adjacent first doped layer 121 and the second doped layer 122, thereby avoiding the conduction of the adjacent first doped layer 121 and the second doped layer 122 and causing the photovoltaic module to have a local short circuit phenomenon, which affects the photoelectric conversion efficiency of the photovoltaic module.

[0096] ​​In the embodiment of the present application, an isolation segment 124 is provided near the first side 14 of the cell 10. The isolation segment 124 extends along the second direction Y and connects two adjacent isolation regions 123. The isolation regions 123 do not extend to the first side 14 of the cell 10. The isolation regions 123 are connected to the isolation segment 124 near the first side 14 of the cell 10. It can be understood that along the first direction X, one side of the isolation segment 124 is the first doped layer 121, and the other side of the isolation segment 124 is the end doped layer. The conductivity type of this end doped layer is the same as that of the second doped layer 122.

[0097] That is, along the first direction X, one side of the isolation segment 124 is the first doped layer 121, and the side of the isolation segment 124 near the first side 14 of the cell 10 is an end doped layer. This end doped layer has the same doping type as the second doped layer 122, and at least two adjacent second doped layers 122 are connected via the end doped layer. A first connecting wire 40 is provided on the end doped layer, which collects carriers generated near the first side 14 of the cell 10 to improve the photovoltaic module's photoelectric conversion efficiency.

[0098] It should be noted that the conductivity type of the first connection line 40 provided on the end doped layer is the same as that of the second collector gate lines 22 , and the first connection line 40 provided on the end doped layer is electrically connected to at least two second collector gate lines 22 .

[0099] It should be noted that in the embodiment of the present application, the arrangement of the isolation segment 124 near the second side 15 of the cell 10 is the same as the arrangement of the isolation segment 124 near the first side 14 of the cell 10 described above.

[0100] In other embodiments, Figure 9 As shown, an isolation segment 124 is provided on the outer side of the first edge bus bar 32 near the second side 15. The isolation segment 124 extends along the second direction Y and connects two adjacent isolation regions 123. The isolation region 123 does not extend to the second side 15 of the cell 10. The isolation region 123 is connected to the isolation segment 124 near the second side 15 of the cell 10. It can be understood that along the first direction X, one side of the isolation segment 124 is the second doped layer 122, and the other side of the isolation segment 124 is the end doped layer. The conductivity type of this end doped layer is the same as that of the first doped layer 121.

[0101] During the processing of photovoltaic modules, it is necessary to form an isolation area 123 and an isolation segment 124 on the surface of the cell 10 by laser scanning. The above setting can reduce the damage of the laser to the processing table during the processing of photovoltaic modules and improve the utilization time of the processing table.

[0102] In some embodiments, asFigures 2 to 4 As shown, the battery piece 10 has a first side edge 14 and a second side edge 15 arranged oppositely along the first direction X; the first connecting line 40 is arranged at a position close to the first side edge 14 and / or the second side edge 15 of the battery piece 10, and the first connecting line 40 is connected to the end portions of the at least two second current collecting grid lines 22.

[0103] As shown, the battery piece 10 has a first side edge 14 and a second side edge 15 arranged oppositely along the first direction X; the first connecting line 40 is arranged at a position close to the first side edge 14 and / or the second side edge 15 of the battery piece 10, and the first connecting line 40 is connected to the end portions of the at least two second current collecting grid lines 22. Figures 2 to 4 As shown, the battery piece 10 has a first side edge 14 and a second side edge 15 arranged oppositely along the first direction X; the first connecting line 40 is arranged at a position close to the first side edge 14 and / or the second side edge 15 of the battery piece 10, and the first connecting line 40 is connected to the end portions of the at least two second current collecting grid lines 22.

[0104] As shown, the battery piece 10 has a first side edge 14 and a second side edge 15 arranged oppositely along the first direction X; the first connecting line 40 is arranged at a position close to the first side edge 14 and / or the second side edge 15 of the battery piece 10, and the first connecting line 40 is connected to the end portions of the at least two second current collecting grid lines 22.

[0105] As shown, the battery piece 10 has a first side edge 14 and a second side edge 15 arranged oppositely along the first direction X; the first connecting line 40 is arranged at a position close to the first side edge 14 and / or the second side edge 15 of the battery piece 10, and the first connecting line 40 is connected to the end portions of the at least two second current collecting grid lines 22. Figure 2 As shown, the battery piece 10 has a first side edge 14 and a second side edge 15 arranged oppositely along the first direction X; the first connecting line 40 is arranged at a position close to the first side edge 14 and / or the second side edge 15 of the battery piece 10, and the first connecting line 40 is connected to the end portions of the at least two second current collecting grid lines 22. Figure 3 Figure 4 As shown, the battery piece 10 has a first side edge 14 and a second side edge 15 arranged oppositely along the first direction X; the first connecting line 40 is arranged at a position close to the first side edge 14 and / or the second side edge 15 of the battery piece 10, and the first connecting line 40 is connected to the end portions of the at least two second current collecting grid lines 22.

[0106] As shown, the battery piece 10 has a first side edge 14 and a second side edge 15 arranged oppositely along the first direction X; the first connecting line 40 is arranged at a position close to the first side edge 14 and / or the second side edge 15 of the battery piece 10, and the first connecting line 40 is connected to the end portions of the at least two second current collecting grid lines 22. Figure 2 As shown, the battery piece 10 has a first side edge 14 and a second side edge 15 arranged oppositely along the first direction X; the first connecting line 40 is arranged at a position close to the first side edge 14 and / or the second side edge 15 of the battery piece 10, and the first connecting line 40 is connected to the end portions of the at least two second current collecting grid lines 22.

[0107] As shown, the battery piece 10 has a first side edge 14 and a second side edge 15 arranged oppositely along the first direction X; the first connecting line 40 is arranged at a position close to the first side edge 14 and / or the second side edge 15 of the battery piece 10, and the first connecting line 40 is connected to the end portions of the at least two second current collecting grid lines 22. Figure 3 Figure 4 ​​As shown, the first connecting line 40 is made of low-temperature copper paste, which will not burn through the passivation anti-reflection layer 13. That is, the first connecting line 40 does not need to avoid the second doped layer 122, and the projection of the first connecting line 40 along the thickness direction of the cell sheet 10 can overlap with the isolation area 123, so as to set the first connecting line 40 on the side of the passivation anti-reflection layer 13 away from the doped layer 12, collect the carriers collected by the first current collecting grid line 21 through the first connecting line 40, and transmit the collected carriers to the external circuit, and in addition, the cost of the cell can be further reduced.

[0108] In some embodiments, as Figure 5 shown, along the first direction X, the cell sheet 10 has a first side edge 14 and a second side edge 15 arranged oppositely; the first bus electrode 30 includes a first pad 31 and a first edge bus line 32, the first pad 31 is electrically connected to at least two first current collecting grid lines 21, the first edge bus line 32 is arranged on the side of the first pad 31 close to the first side edge 14 or the second side edge 15 along the first direction X, the first edge bus line 32 extends along the second direction Y and is connected to the end of the plurality of first current collecting grid lines 21; the cell sheet 10 further has a second connecting line 50 connected to the first pad 31 and the first edge bus line 32, the second connecting line 50 is made of non-burn-through paste.

[0109] As Figure 5 shown, the first bus electrode 30 disclosed in the embodiments of the present application includes a first pad 31 and a first edge bus line 32. Among them, the first pad 31 is electrically connected to at least two first current collecting grid lines 21, so as to collect the carriers collected by the at least two first current collecting grid lines 21 through the first pad 31, and transmit the collected carriers to the external circuit.

[0110] Along the first direction X, the first edge bus line 32 is arranged at the position of the first pad 31 close to the first side edge 14 or the second side edge 15 of the cell sheet 10, the first edge bus line 32 extends along the second direction Y and is connected to the end of the plurality of first current collecting grid lines 21, so as to collect the carriers generated by the plurality of first current collecting grid lines 21 through the first edge bus line 32, and transmit the collected carriers to the external circuit.

[0111] As Figure 5 shown, the second connecting line 50 is arranged between the first pad 31 and the first edge bus line 32, and the first pad 31 and the first edge bus line 32 are electrically connected through the second connecting line 50, so that the carriers collected by the first edge bus line 32 can be transmitted to the first pad 31 and then transmitted to the external circuit through the first pad 31.

[0112] It should be noted that the second connecting line 50 in the embodiment of the present application is prepared by using non-burn-through type paste. That is, the second connecting line 50 will not burn through the passivation anti-reflection layer 13, so that the second connecting line 50 can avoid burning through the passivation anti-reflection layer 13, being in conduction with the second doped layer 122, and causing the photovoltaic module to have a local short circuit phenomenon, thereby affecting the photoelectric conversion efficiency of the photovoltaic module.

[0113] In some embodiments, as shown in Figure 5 、 Figure 7 、 Figure 8 illustrated, the second connecting line 50 extends along the first direction X and is located between the first pad 31 and the first edge busbar 32; a projection of the second connecting line 50 along the thickness direction of the cell piece 10 overlaps the second doped layer 122, and / or a projection of the second connecting line 50 along the thickness direction of the cell piece 10 overlaps the isolation region 123.

[0114] As shown in Figure 5 illustrated, the second connecting line 50 in the embodiment of the present application extends along the first direction X, one end of the second connecting line 50 is connected to the first edge busbar 32, and the other end is connected to the first pad 31, so as to conduct the first edge busbar 32 and the first pad 31 through the second connecting line 50, thereby transmitting the carriers collected by the first edge busbar 32 to the first pad 31, and transmitting the carriers to the external circuit through the first pad 31.

[0115] It should be noted that the projection of the second connecting line 50 along the thickness direction of the cell piece 10 in the embodiment of the present application can overlap the second doped layer 122, the projection of the second connecting line 50 along the thickness direction of the cell piece 10 can overlap the isolation region 123, and the projection of the second connecting line 50 along the thickness direction of the cell piece 10 can also partially overlap the second doped layer 122 and partially overlap the isolation region 123.

[0116] Since the second connecting line 50 is prepared by using non-burn-through type paste, the second connecting line 50 will not burn through the passivation anti-reflection layer 13 and be in conduction with the second doped layer 122. Therefore, even if the projection of the second connecting line 50 along the thickness direction of the cell piece 10 overlaps the second doped layer 122 and / or the projection of the second connecting line 50 along the thickness direction of the cell piece 10 overlaps the isolation region 123, the second connecting line 50 will not be in conduction with the second doped layer 122, causing the photovoltaic module to have a local short circuit phenomenon, thereby affecting the photoelectric conversion efficiency of the photovoltaic module. Therefore, the position of the second connecting line 50 can be flexibly set so as to electrically connect the first pad 31 and the first edge busbar 32 through the second connecting line 50.

[0117] In addition, if the projection of the second connecting wire 50 along the thickness direction of the cell sheet 10 overlaps with the first doped layer 121, the area of the first doped layer 121 under the first pad 31 and the second connecting wire 50 is too large, and there is a problem of current mismatch, and black spots may appear in the back-end EL test. Therefore, when the projection of the second connecting wire 50 along the thickness direction of the cell sheet 10 overlaps with the second doped layer 122, and / or the projection of the second connecting wire 50 along the thickness direction of the cell sheet 10 overlaps with the isolation region 123, the problem of current mismatch can be avoided, and the cell yield can be improved. Further, the projection of the second connecting wire 50 along the thickness direction of the cell sheet 10 overlaps with the second doped layer 122, which can increase the area of the second doped layer 122, which is beneficial to the collection of carriers, thereby helping to improve the photoelectric conversion efficiency of the photovoltaic module.

[0118] In some embodiments, as shown in Figure 5 、 7 、 Figure 8 , the cell sheet 10 has a first region 16 adjacent to the first pad 31 along the second direction Y; the first region 16 includes the isolation region 123 and / or the second doped layer 122, and the cell sheet 10 does not have the current collecting grid line 20 in the first region 16.

[0119] As shown in Figure 5 、 Figure 7 、 Figure 8 , the region adjacent to the first pad 31 on the cell sheet 10 along the second direction Y is set as the first region 16. The first region 16 can include the isolation region 123, the first region 16 can include the second doped layer 122, and the first region 16 can include part of the isolation region 123 and part of the second doped layer 122.

[0120] The cell sheet 10 does not have the current collecting grid line 20 in the first region 16. It can be understood that when the first region 16 includes the second doped layer 122, the second current collecting grid line 22 will not be arranged on the second doped layer 122 in the first region 16. In order to avoid the first pad 31 extending along the second direction Y to overlap with the second current collecting grid line 22, the first pad 31 and the second current collecting grid line 22 are conductive, which causes the photovoltaic module to have a local short circuit phenomenon, affecting the photoelectric conversion efficiency of the photovoltaic module.

[0121] Further, the above arrangement can also avoid the first solder strip extending along the second direction Y to overlap with the second current collecting grid line 22, causing the first solder strip and the second current collecting grid line 22 to be conductive, causing the photovoltaic module to have a local short circuit phenomenon, affecting the photoelectric conversion efficiency of the photovoltaic module.

[0122] In some embodiments, the doping type of the first doped layer 121 is opposite to that of the substrate 11; along the second direction Y, the width of the first doped layer 121 is greater than the width of the second doped layer 122.

[0123] In the embodiment of the present application, the doping type of the first doping layer 121 is opposite to that of the substrate 11. That is, the doping type of the second doping layer 122 is the same as that of the substrate 11. Along the second direction Y, the width of the first doping layer 121 is set to be greater than the width of the second doping layer 122 to balance the light absorption and carrier collection efficiency of the first doping layer 121 and the second doping layer 122.

[0124] Exemplarily, substrate 11 is an N-type silicon substrate, first doped layer 121 is P-type doped polysilicon, and second doped layer 122 is an N-type doped polysilicon layer. Along the second direction Y, the width of first doped layer 121 is greater than the width of second doped layer 122. The P-type doped polysilicon layer and the N-type substrate form an emitter. Increasing the emitter area is more conducive to increasing the short-circuit current of the cell, thereby improving the photoelectric conversion efficiency of the photovoltaic module.

[0125] In some embodiments, as Figure 10 As shown, the surface of the battery cell 10 has polished surface areas 17 extending along the first direction X and arranged at intervals along the second direction Y. Along the second direction Y, there is a velvet area 18 extending along the first direction X between two adjacent polished surface areas 17; the projection of the first bus electrode 30 along the thickness direction of the battery cell 10 covers the polished surface area 17 and the velvet area 18.

[0126] like Figure 10 As shown, the surface of the cell 10 has polished surface areas 17 extending along the first direction X and spaced apart along the second direction Y. Along the second direction Y, there is a velvet area 18 extending along the first direction X between two adjacent polished surface areas 17. It can be understood that the areas corresponding to the first doped layer 121 and the second doped layer 122 are polished surface areas 17, while the areas corresponding to the isolation area 123 are velvet areas 18. The areas corresponding to the first doped layer 121 and the second doped layer 122 are set as polished surface areas 17, which is more conducive to the uniform deposition of the first doped layer 121 and the second doped layer 122, improving the film quality and reducing defects. The areas corresponding to the isolation area 123 are set as velvet areas 18, which can increase the light trapping effect and improve the bifaciality of the cell 10. Exemplarily, the substrate 11 is an N-type silicon substrate, the first doped layer 121 is a P-type doped polysilicon, the second doped layer 122 is an N-type doped polysilicon layer, and a tunneling oxide layer is provided between the silicon substrate 11 and the P-type doped polysilicon and the N-type doped polysilicon. The battery structure is a back contact tunneling oxide layer passivated contact battery (TBC battery).

[0127] The first busbar 30 in the embodiments of the present application extends along the second direction Y, and a projection of the first busbar 30 along the thickness direction of the cell sheet 10 covers the polished surface region 17 and the textured surface region 18. That is, the first busbar 30 can overlap the plurality of polished surface regions 17 and textured surface regions 18. On the one hand, the first busbar 30 is prepared by using non-burn-through paste, so that the first busbar 30 will not burn through the passivation anti-reflection layer 13 and the second doped layer 122 to be electrically connected together, thereby avoiding the local short circuit phenomenon of the photovoltaic module. On the other hand, the textured surface region 18 can increase the tension between the busbar 30 and the substrate 11, and the polished surface region 17 can provide good contact, and the busbar formed on the polished surface region 17 has higher flatness and better quality, thereby achieving an optimized balance between the quality of the busbar and the bonding force between the busbar and the cell sheet body. In addition, the busbar arranged in the textured surface region 18 has a rough electrode surface, which can increase the bonding force between the busbar and the subsequent solder ribbon. Further, the first busbar 30 overlaps the textured surface region 18 and is electrically connected to at least two first current collecting grid lines 21, so as to collect the carriers collected by the at least two first current collecting grid lines 21 and transmit the collected carriers to an external circuit.

[0128] In some embodiments, the length of the first busbar 30 along the second direction Y is L5, and L5≥L2 is satisfied.

[0129] In the embodiments of the present application, the length L5 of the first busbar 30 along the second direction Y is greater than or equal to the distance L2 between the adjacent two first current collecting grid lines 21. In this way, the first busbar 30 can be electrically connected to the adjacent two first current collecting grid lines 21, so as to collect the carriers collected by the adjacent two first current collecting grid lines 21 through the first busbar 30 and transmit the collected carriers to an external circuit.

[0130] If the length L5 of the first busbar 30 along the second direction Y is less than the distance L2 between the adjacent two first current collecting grid lines 21, the first busbar 30 cannot be electrically connected to the adjacent two first current collecting grid lines 21, and the first busbar 30 cannot collect the carriers collected by the adjacent two first current collecting grid lines 21. If the length L5 of the first busbar 30 along the second direction Y is greater than the distance L2 between the adjacent two first current collecting grid lines 21, the first busbar 30 is easy to contact the second current collecting grid line 22, which increases the risk of short circuit and also increases the cost of the busbar 30.

[0131] It should be noted that each of the embodiments in the present specification is described in a progressive manner, and each embodiment focuses on the difference from other embodiments. The same or similar parts of each embodiment can be referred to each other.

[0132] While the optional embodiments of the application have been described, additional modifications and changes can occur to persons skilled in the art upon reading the preceding description. It is therefore desired to be included in the appended claims as optional embodiments of the application and all modifications and changes which come within the scope of the embodiments of the application.

[0133] Finally, it should be noted that, in this document, relational terms such as first and second, and the like can be used solely to distinguish one entity from another entity without necessarily implying any actual relationship or order between such entities. Also, the terms "comprises", "comprising", or any other variation thereof are intended to cover a non-exclusive inclusion, such that a process or method that comprises a list of elements does not include only those elements but can also include other elements not expressly listed or inherent to such process or method. Items under "consisting of are intended to exclude any element not specifically named after "consisting of.

[0134] The above detailed description of the technical solutions provided by the application has been described in detail, and the principles and implementation modes of the application are described by applying specific examples in this document. For those skilled in the art, according to the principles and implementation modes of the application, the specific implementation modes and application scope will be changed. In summary, the content of this specification should not be understood as a limitation of the application.

Claims

1. A back contact photovoltaic module, characterized by, include: A cell (10), the cell (10) comprising a substrate (11), a doping layer (12) and a passivation anti-reflection layer (13) stacked in sequence, the doping layer (12) comprising a first doping layer (121) and a second doping layer (122), the first doping layer (121) and the second doping layer (122) both extending along a first direction (X) and arranged alternately and spaced along a second direction (Y), an isolation region (123) extending along the first direction (X) is provided between two adjacent first doping layers (121) and second doping layers (122), the first doping layer (121) and the second doping layer (122) having opposite conductivity types, and the second direction (Y) intersecting the first direction (X); A collector grid line (20), the collector grid line (20) comprising a first collector grid line (21) and a second collector grid line (22) extending along the first direction (X), the first collector grid line (21) at least partially passing through the passivation anti-reflection layer (13) and being electrically connected to the first doped layer (121), and the second collector grid line (22) at least partially passing through the passivation anti-reflection layer (13) and being electrically connected to the second doped layer (122); A first bus electrode (30), the first bus electrode (30) is arranged on a side of the passivation anti-reflection layer (13) away from the doping layer (12), the first bus electrode (30) extends along the second direction (Y) and is electrically connected to at least two of the first collector grid lines (21), a projection of the first bus electrode (30) along the thickness direction of the battery cell (10) overlaps with the isolation region (123), and the first bus electrode (30) is made of a non-burn-through slurry.

2. The back contact photovoltaic assembly of claim 1, wherein, The non-fire-through slurry includes at least one slurry selected from the group consisting of copper, silver-clad copper, nickel, and aluminum.

3. The back contact photovoltaic assembly of claim 1, wherein, The first busbar electrode (30) comprises at least one of a first pad (31), a first main grid, a first edge busbar (32), and a first terminal line (33).

4. The back contact photovoltaic assembly of claim 1, wherein, The second collector grid line (22) comprises a plurality of first sub-grid lines (221), the plurality of first sub-grid lines (221) all extending along the first direction (X) and spaced apart along the first direction (X), a first gap (222) being provided between adjacent first sub-grid lines (221), and the first bus electrode (30) passing through the first gap (222); Along the first direction (X), a first distance L1 is present between the end of the first sub-grid line (221) adjacent to the first bus electrode (30) and the first bus electrode (30), satisfying 0.15 mm ≤ L1 ≤ 0.5 mm; And / or, along the first direction (X), the width of the first gap (222) is L6, satisfying 0.5mm≤L6≤3mm.

5. The back contact photovoltaic assembly of claim 1, wherein, Along the first direction (X), the battery cell (10) has a first side edge (14) and a second side edge (15) that are arranged opposite to each other; The isolation region (123) extends along the first direction (X) to overlap with the first side (14) and / or the second side (15).

6. The back-contact photovoltaic module according to claim 1, characterized in that: The isolation regions (123) are arranged in multiple rows along the second direction (Y); The battery piece (10) has first and second side edges (14, 15) opposite to each other along the first direction (X), and an isolation section (124) is arranged at a position close to the first or second side edge (14, 15) of the battery piece (10), the isolation section (124) extends along the second direction (Y) and connects at least two adjacent isolation regions (123).

7. The back contact photovoltaic assembly of claim 1, wherein, The battery piece (10) has first and second side edges (14, 15) opposite to each other along the first direction (X); The battery piece (10) has a first connecting line (40) arranged at a position close to the first or second side edge (14, 15), the first connecting line (40) is connected to the end portions of at least two second current collecting grid lines (22).

8. The back contact photovoltaic assembly of claim 7, wherein, The first connecting line (40) is made of silver paste, and the projection of the first connecting line (40) on the thickness direction of the battery piece (10) is arranged in a staggered manner with the isolation regions (123). Alternatively, the first connecting line (40) is made of copper paste, and the projection of the first connecting line (40) on the thickness direction of the battery piece (10) overlaps with the isolation regions (123).

9. The back contact photovoltaic assembly of claim 1, wherein, The battery piece (10) has first and second side edges (14, 15) opposite to each other along the first direction (X); The first bus electrode (30) includes a first pad (31) and a first edge bus line (32), the first pad (31) is electrically connected to at least two first current collecting grid lines (21), along the first direction (X), the first edge bus line (32) is arranged on the side of the first pad (31) close to the first or second side edge (14, 15), the first edge bus line (32) extends along the second direction (Y) and is connected to the end portions of multiple first current collecting grid lines (21); The battery piece (10) further has a second connecting line (50) connected to the first pad (31) and the first edge bus line (32), the second connecting line (50) is made of non-burn-through paste.

10. The back contact photovoltaic assembly of claim 9, wherein, The second connecting line (50) extends along the first direction (X) and is located between the first pad (31) and the first edge bus line (32); The projection of the second connecting line (50) on the thickness direction of the battery piece (10) overlaps with the second doped layer (122), or the projection of the second connecting line (50) on the thickness direction of the battery piece (10) overlaps with the isolation regions (123).

11. The back contact photovoltaic assembly of claim 1, wherein, The surface of the battery piece (10) has a polishing surface area (17) extending along the first direction (X) and arranged at intervals along the second direction (Y), and between two adjacent polishing surface areas (17) along the second direction (Y), there is a suede surface area (18) extending along the first direction (X); The projection of the first bus electrode (30) along the thickness direction of the battery piece (10) covers the polishing surface area (17) and the suede surface area (18).

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