Back contact solar cell and photovoltaic module

Abstract

The present invention provides a back-contact solar cell and a photovoltaic module, and relates to the field of photovoltaic technology. The back-contact solar cell comprises: a plurality of collector doping regions extending along a first direction and spaced apart along a second direction; a first interval is provided between the end of the first collector doping region and the edge of the first battery, and a second collector doping region adjacent to the first collector doping region has a bending portion extending into the first interval at the end close to the edge of the first battery; in the battery body, at least two P-type collector doping regions and at least one N-type collector doping region are first collector doping regions, and the bending portions are P-type bending portions and N-type bending portions, and in the battery body, the number of N-type bending portions is greater than the number of P-type bending portions; or, the first collector doping region is only a P-type collector doping region, and the bending portions in the battery body only include N-type bending portions. The battery of the present invention has good passivation effect and less blackening of EL or PL at the battery edge.

Description

Technical Field

[0001] The invention relates to the field of photovoltaic technology, in particular to a back-contact solar cell and a photovoltaic module. Background Art

[0002] Back contact solar cell (Back Contact) is a back contact cell, in which the PN junction and metal contact are both arranged on the back of the cell, so that there is no electrode grid line blocking the front side, and the cell absorbs sunlight over a larger area, thereby improving the conversion efficiency and generating more electricity, so it has broad application prospects.

[0003] Patterning and metallization in back-contact solar cells are key steps to improve conversion efficiency and yield. The patterned distributed collector doping area can separate and collect carriers, as well as have a certain passivation effect.

[0004] However, the carrier separation and collection, as well as the passivation effects in existing back-contact solar cells are poor. Summary of the invention

[0005] The present invention provides a back-contact solar cell and a photovoltaic module, aiming to solve the problems of poor carrier separation and collection, and poor passivation effect in existing back-contact solar cells.

[0006] A first aspect of the present invention provides a back-contact solar cell, comprising:

[0007] The battery body comprises:

[0008] A plurality of collector doping regions extending along a first direction and spaced apart along a second direction; the first direction is different from the second direction;

[0009] The battery body comprises: two first battery edges and a second battery edge located between the two first battery edges, wherein the second battery edge is parallel to the first direction;

[0010] Among the plurality of collector doping regions, a first interval is provided between an end of a first collector doping region and an edge of a first battery, and a second collector doping region adjacent to the first collector doping region has a bending portion extending into the first interval at an end close to the edge of the first battery; the first collector doping region and the second collector doping region have opposite conductivity types;

[0011] The plurality of collector doping regions are divided into N-type collector doping regions and P-type collector doping regions;

[0012] In the battery body, at least two P-type collector doping regions and at least one N-type collector doping region are both first collector doping regions, the bending parts are P-type bending parts and N-type bending parts, and in the battery body, the number of N-type bending parts is greater than the number of P-type bending parts; or, the first collector doping region is only a P-type collector doping region, and the bending parts in the battery body only include N-type bending parts.

[0013] In an embodiment of the present invention, the bending portion includes: a P-type bending portion and an N-type bending portion. The inventors found that in the battery body, when the number of N-type bending portions is equal to the number of P-type bending portions, the edge EL (electroluminescence) or PL (photoluminescence) of the P-type collector doping region is more seriously blackened, especially, the edge EL or PL of the P-type collector doping region is more seriously blackened. The possible reason is that the passivation effect of the P-type collector doping region is not good. In view of the above problem, in the battery body of the present invention, the number of N-type bending portions is greater than the number of P-type bending portions, and the N-type collector doping region has a better passivation effect than the P-type collector doping region. The more N-type bending portions are, the passivation effect of more dead zones can be optimized, which solves the problem of blackening of EL or PL at the edge of the P-type collector doping region, and at the same time can improve the open circuit voltage and conversion factor of the back-contact solar cell, thereby further improving the conversion efficiency of the back-contact solar cell. Alternatively, there is only an N-type bend in the battery body, which can optimize the passivation effect of the dead zone, solve the problem of blackening of the EL or PL at the edge of the P-type collector doping area, and at the same time improve the open circuit voltage and conversion factor of the back contact solar cell, thereby further improving the conversion efficiency of the back contact solar cell. At the same time, the above-mentioned bend reduces the recombination of carriers in the dead zone due to the long transmission distance, so that the carriers in the dead zone can be efficiently collected and transmitted, which can improve the short-circuit current of the back contact solar cell, and can also improve the passivation effect of the battery edge, reduce the phenomenon of blackening of the EL or PL at the battery edge, and thus improve its conversion efficiency.

[0014] Optionally, the total area of ​​the N-type bending portion is greater than the total area of ​​the P-type bending portion; and / or,

[0015] The number of N-type bending portions is greater than the number of P-type bending portions, and the ratio of the number of N-type bending portions to the number of P-type bending portions is 3:1 to 11:1; and / or,

[0016] When the number of the N-type bending portions is greater than the number of the P-type bending portions, the area of ​​at least one N-type bending portion is less than or equal to the area of ​​at least one P-type bending portion.

[0017] Optionally, the N-type bending portion has a portion extending along the first direction, and the P-type bending portion has a portion extending along the first direction;

[0018] The battery body further comprises: an N-type silicon substrate, the plurality of current collector doping regions are located inside the N-type silicon substrate, and / or the plurality of current collector doping regions are located on the N-type silicon substrate;

[0019] The width of a portion of the N-type bending portion extending along the first direction is less than or equal to the width of a portion of the P-type bending portion extending along the first direction, and the width direction is the second direction.

[0020] Optionally, the bending portion includes: an edge bending portion adjacent to an edge of the second battery and a middle bending portion located on a side of the edge bending portion away from an edge of the second battery;

[0021] The area of ​​the edge bending portion is greater than the area of ​​the middle bending portion.

[0022] Optionally, the first battery edge includes: a first sub-battery edge A and a first sub-battery edge B, both of which have at least parallel portions;

[0023] The bending portions adjacent to the edge of the same first sub-cell among all the bending portions include: at least one P-type bending portion and at least two N-type bending portions, the number of N-type bending portions adjacent to the edge of the same first sub-cell is 2 to 30, and the number of P-type bending portions adjacent to the edge of the same first sub-cell is 1 to 4; or, the bending portions adjacent to the edge of the same first sub-cell among all the bending portions include only N-type bending portions, and the number of N-type bending portions adjacent to the edge of the same first sub-cell is 2 to 30.

[0024] Optionally, the battery body further includes: a second battery edge, the second battery edge at least having a portion parallel to the first direction; the second battery edge includes: a second sub-battery edge C and a second sub-battery edge D, both having at least a parallel portion;

[0025] The bent portions in all the bent portions that are adjacent to the edge of the same first sub-cell include: at least one P-type bent portion and at least two N-type bent portions, the P-type bent portion is only arranged adjacent to the second sub-cell edge C and / or the second sub-cell edge D, and the N-type bent portion is at least arranged adjacent to the second sub-cell edge C and / or the second sub-cell edge D, or,

[0026] The bent portions in all the bent portions that are adjacent to the edge of the same first sub-cell only include N-type bent portions, and the N-type bent portions are arranged at least adjacent to the edge C and / or the edge D of the second sub-cell.

[0027] Optionally, the first battery edge includes: a first sub-battery edge A and a first sub-battery edge B, both of which have at least parallel portions;

[0028] The bend portion adjacent to the edge A of the first sub-cell is a P-type bend portion, and the bend portion adjacent to the edge B of the first sub-cell is an N-type bend portion, the number of N-type bend portions adjacent to the same first sub-cell edge is 2 to 30, and the number of P-type bend portions adjacent to the same first sub-cell edge is 1 to 4; or,

[0029] The bend portion is only disposed adjacent to the edge A of the first sub-cell or only adjacent to the edge B of the first sub-cell, and the bend portion only has N-type bend portions, and the number of N-type bend portions adjacent to the same first sub-cell edge is 2 to 30 or the number of N-type bend portions is 1 to 4; or,

[0030] The bending portion close to the edge A of the first sub-cell and the bending portion close to the edge B of the first sub-cell are both N-type bending portions only, and the number of N-type bending portions close to the same edge of the first sub-cell is 2 to 30.

[0031] Optionally, the battery body further includes: a second battery edge, the second battery edge at least having a portion parallel to the first direction; the second battery edge includes: a second sub-battery edge C and a second sub-battery edge D, both having at least a parallel portion;

[0032] The bend adjacent to the edge A of the first subcell is a P-type bend, and the bend adjacent to the edge B of the first subcell is an N-type bend, the P-type bend is only adjacent to the second subcell edge C and the second subcell edge D, and the N-type bend is at least adjacent to the second subcell edge C and the second subcell edge D; or,

[0033] All the bending portions include only N-type bending portions, and the N-type bending portions are arranged at least adjacent to the edge C of the second sub-cell and / or the edge D of the second sub-cell.

[0034] Optionally, the battery body further includes:

[0035] An edge bus doping region extending along the second direction and adjacent to an edge of the first cell;

[0036] A connection doping region extending along the first direction and intersecting the edge bus doping region; the connection doping region and the first collector doping region are spaced apart; the area of ​​the inner region enclosed by the first collector doping region and the first extension region intersecting the edge bus doping region after extension, the edge bus doping region, the connection doping region adjacent to the first collector doping region, and the second extension region extending along the second direction and intersecting the first collector doping region is S;

[0037] The first collector doping region is a P-type collector doping region, and the area of ​​the N-type bending portion is 25% to 39% of S; and / or, the first collector doping region is an N-type collector doping region, and the area of ​​the P-type bending portion is 22% to 41% of S; and / or, the first collector doping region is an N-type collector doping region, and the area of ​​the inner region enclosed by the first collector doping region is S1, and the first collector doping region is a P-type collector doping region, and the area of ​​the inner region enclosed by the first collector doping region is S2; S1 is greater than S2.

[0038] Optionally, the first collector doping region is a P-type collector doping region, S≥1.3mm 2 ; and / or, the first collector doping region is an N-type collector doping region, S≥1.6mm 2 .

[0039] A second aspect of the present invention provides a back-contact solar cell, characterized in that it comprises: a cell body and an electrode structure located on the back side of the cell body;

[0040] The electrode structure comprises:

[0041] A plurality of collector grid lines extending along a first direction and spaced apart along a second direction; the first direction is different from the second direction;

[0042] The battery body comprises: two first battery edges and a second battery edge located between the two first battery edges, wherein the second battery edge is parallel to the first direction;

[0043] Among the plurality of collector grid lines, a second interval is provided between the end of a first collector grid line and the edge of the first battery, a second collector grid line adjacent to the first collector grid line has a bending section extending into the second interval at the end close to the edge of the first battery, and the polarities of the first collector grid line and the second collector grid line are opposite; the plurality of collector grid lines are divided into N-type collector grid lines and P-type collector grid lines;

[0044] In the electrode structure, at least two P-type collector grid lines and at least one N-type collector grid line are first collector grid lines, the bending segments are divided into P-type bending segments and N-type bending segments, and in the electrode structure, the number of the N-type bending segments is greater than the number of the P-type bending segments;

[0045] Alternatively, the first collector grid line is only a P-type collector grid line, and the bending section in the battery body only includes an N-type bending section.

[0046] Optionally, the total length of the N-type bending section is greater than the total length of the P-type bending section; and / or,

[0047] The number of the N-type bending segments is greater than the number of the P-type bending segments, and the ratio of the number of the N-type bending segments to the number of the P-type bending segments is 3:1 to 11:1.

[0048] Optionally, the N-type bending segment has a first portion extending along a first direction; the distance between the first portion and the adjacent P-type collector grid line is 1 / 3 to 2 / 3 of the distance between adjacent P-type collector grid lines; and / or,

[0049] The P-type bending segment has a second portion extending along the first direction; the distance between the second portion and the adjacent N-type collector grid line is 1 / 3 to 2 / 3 of the distance between adjacent N-type collector grid lines; and / or,

[0050] The N-type bending segment has a third portion extending along the second direction; the distance between the third portion and the end of the adjacent P-type collector grid line close to the edge of the first battery is 1 / 4 to 3 / 4 of the second interval; and / or,

[0051] The P-type bending segment has a fourth portion extending along the second direction; the distance between the fourth portion and the end of the adjacent N-type collector grid line close to the edge of the first battery is 1 / 4 to 3 / 4 of the second interval.

[0052] Optionally, the distance between the second portion and the adjacent N-type collector grid line is greater than the distance between the first portion and the adjacent P-type collector grid line, and / or the distance between the third portion and the end of the adjacent P-type collector grid line close to the edge of the first battery is equal to the distance between the fourth portion and the end of the adjacent N-type collector grid line close to the edge of the first battery.

[0053] Optionally, the N-shaped bending segment has a first portion extending along the first direction and a third portion extending along the second direction, and the length of the first portion is less than or equal to the length of the third portion.

[0054] Optionally, the N-type bending segment has a first portion extending along the first direction and a third portion extending along the second direction; the length of the first portion is greater than the distance between the third portion and the end of the adjacent P-type collector grid line close to the edge of the first battery, and the length of the third portion is equal to the distance between adjacent like-type collector grid lines; and / or,

[0055] The P-type bending section has a second portion extending along the first direction and a fourth portion extending along the second direction; the length of the second portion is greater than the distance between the fourth portion and the end of the adjacent N-type collector grid line close to the edge of the first battery.

[0056] Optionally, the electrode structure further includes:

[0057] A plurality of interconnecting parts having at least partial areas collinear in the second direction; the plurality of interconnecting parts include: first interconnecting parts and second interconnecting parts arranged alternately and at intervals along the first direction; the plurality of interconnecting parts include: an edge interconnecting part adjacent to an edge of the first battery;

[0058] An edge busbar extending along the second direction and located between the edge of the first battery and the edge interconnection portion; a first interconnection portion in the edge interconnection portion is electrically connected to the N-type edge busbar, and a second interconnection portion in the edge interconnection portion is electrically connected to the P-type edge busbar;

[0059] A connection electrode extending along a first direction and electrically connecting the edge interconnection portion and the edge bus grid line;

[0060] The N-type bending section has a first portion extending along a first direction; the length ratio of the connecting electrode electrically connected to the second interconnection portion in the edge interconnection portion to the first portion is 2:1 to 5:1; and / or,

[0061] The ratio of the length of the first portion to the dimension of the second interconnection portion in the edge interconnection portion in the first direction is 1:1.6 to 1:2.6; and / or,

[0062] The ratio of the length of the first portion to the dimension of the second interval in the first direction is 1:1.7 to 1:3.2; and / or,

[0063] The P-type bending section has a second portion extending along the first direction; the ratio of the length of the connecting electrode electrically connected to the first interconnection portion in the edge interconnection portion to the second portion is 1.2:1 to 2.7:1; and / or,

[0064] The ratio of the length of the second portion to the dimension of the second interval in the first direction is 1:0.8 to 1:2.4; and / or,

[0065] The ratio of the length of the second portion to the dimension of the first interconnection portion in the edge interconnection portion in the first direction is 1:1 to 1:1.4; and / or,

[0066] The N-shaped bending section has a third portion extending along the second direction; the ratio of the length of the third portion to the size of the second interconnection portion in the edge interconnection portion in the second direction is 1:1.1 to 1:2.3; and / or,

[0067] The P-shaped bending section has a fourth portion extending along the second direction; the ratio of the length of the fourth portion to the size of the first interconnection portion in the edge interconnection portion in the second direction is 1:1.1 to 1:2.4.

[0068] Optionally, the N-type bending section has a first portion extending along the first direction and a third portion extending along the second direction; the P-type bending section has a second portion extending along the first direction and a fourth portion extending along the second direction;

[0069] The distance between the first portion and the connection electrode electrically connected to the second interconnection portion in the edge interconnection portion is smaller than the distance between the second portion and the connection electrode electrically connected to the first interconnection portion in the edge interconnection portion;

[0070] The distance between the third portion and the P-type edge bus gate line is less than or equal to the distance between the fourth portion and the N-type bus gate line.

[0071] Optionally, the electrode structure further comprises: a lapped gate line extending along the second direction and electrically connecting the first collector gate line and the edge interconnection portion;

[0072] The N-type bending section has a third portion extending along the second direction; the ratio of the length of the overlapping gate line electrically connected to the P-type collector gate line to the third portion is 1:1.1 to 1:2; and / or,

[0073] The P-type bending section has a fourth portion extending along the second direction; the ratio of the length of the overlapping grid line electrically connected to the N-type collector grid line to the fourth portion is 1:0.6 to 1:1.8.

[0074] Optionally, the bending section includes: an edge bending section adjacent to an edge of the second battery and a middle bending section located on a side of the edge bending section away from the edge of the second battery;

[0075] The length of the edge bending section is greater than the length of the middle bending section.

[0076] Optionally, the length of an N-type bending segment is greater than or equal to the length of a P-type bending segment.

[0077] Optionally, the first battery edge includes: a first sub-battery edge A and a first sub-battery edge B, both of which have at least parallel portions;

[0078] The bending segments adjacent to the edge of the same first sub-cell among all the bending segments include: at least one P-type bending segment and at least two N-type bending segments, the number of N-type bending segments adjacent to the edge of the same first sub-cell is 2 to 30, and the number of P-type bending segments adjacent to the edge of the same first sub-cell is 1 to 4; or, the bending segments adjacent to the edge of the same first sub-cell among all the bending segments include only N-type bending segments, and the number of N-type bending segments is 2 to 30.

[0079] Optionally, the bending segments among all the bending segments adjacent to another edge of the same first sub-battery include: at least one P-type bending segment and at least two N-type bending segments, and the N-type bending segments and / or the P-type bending segments are symmetrically arranged about the diagonal line of the back side of the battery body.

[0080] Optionally, the battery body further includes: the second battery edge includes: a second sub-battery edge C and a second sub-battery edge D, both of which have at least parallel portions;

[0081] The bending segments in close proximity to the same first sub-cell edge among all the bending segments include: at least one P-type bending segment and at least two N-type bending segments, the P-type bending segment is only arranged close to the second sub-cell edge C and / or the second sub-cell edge D, and the N-type bending segment is at least arranged close to the second sub-cell edge C and / or the second sub-cell edge D, or,

[0082] The bending segments that are adjacent to the same first sub-cell edge among all the bending segments only include N-type bending segments, and the N-type bending segments are arranged at least adjacent to the second sub-cell edge C and / or the second sub-cell edge D.

[0083] Optionally, the first battery edge includes: a first sub-battery edge A and a first sub-battery edge B, both of which have at least parallel portions;

[0084] The bending section adjacent to the edge A of the first sub-cell is a P-type bending section, and the bending section adjacent to the edge B of the first sub-cell is an N-type bending section, the number of N-type bending sections adjacent to the same first sub-cell edge is 2 to 30, and the number of P-type bending sections adjacent to the same first sub-cell edge is 1 to 4; or,

[0085] The bending section adjacent to the edge A of the first sub-cell is a P-type bending section, and the bending section adjacent to the edge B of the first sub-cell is an N-type bending section, the number of N-type bending sections adjacent to the same first sub-cell edge is 2 to 30, and the number of P-type bending sections adjacent to the same first sub-cell edge is 2 to 30; or,

[0086] The bending section is only arranged adjacent to the edge A of the first sub-cell or adjacent to the edge B of the first sub-cell, and the bending section only has N-type bending sections, and the number of N-type bending sections adjacent to the same first sub-cell edge is 2 to 30 or the number of N-type bending sections is 1 to 4; or,

[0087] The bending section adjacent to the edge A of the first sub-cell and the bending section adjacent to the edge B of the first sub-cell are both N-type bending sections only. The number of N-type bending sections adjacent to the same edge of the first sub-cell is 2 to 30.

[0088] Optionally, the battery body further includes: the second battery edge includes: a second sub-battery edge C and a second sub-battery edge D, both of which have at least parallel portions;

[0089] The N-shaped bending section has a first portion extending along a first direction and a third portion extending along a second direction;

[0090] Along the second direction, the N-type bending segment includes an edge N-type bending segment arranged adjacent to the second sub-battery edge C and / or the second sub-battery edge D, and an intermediate N-type bending segment located on the side of the edge N-type bending segment away from the second battery edge, the length of the first part of the edge N-type bending segment is greater than the distance between the third part and the end of the adjacent P-type collector grid line close to the first battery edge, and the length of the first part of the intermediate N-type bending segment is less than the distance between the third part and the end of the adjacent P-type collector grid line close to the first battery edge; or,

[0091] The N-type bending section is only arranged adjacent to the second sub-cell edge C and / or the second sub-cell edge D, and the length of the first part of the edge N-type bending section is greater than the distance between the third part and the end of the adjacent P-type collector grid line close to the first battery edge.

[0092] Optionally, the second battery edge includes: a second sub-battery edge C and a second sub-battery edge D, both of which have at least parallel portions;

[0093] The N-type bending segment has a first portion extending along the first direction and a third portion extending along the second direction; the N-type bending segment is at least adjacent to the second sub-cell edge C and the second sub-cell edge D; the length of the first portion of the N-type bending segment adjacent to the second sub-cell edge C is greater than the length of the first portion of the N-type bending segment adjacent to the second sub-cell edge D; and / or, the P-type bending segment has a second portion extending along the first direction and a fourth portion extending along the second direction, the P-type bending segment is at least adjacent to the second sub-cell edge C and the second sub-cell edge D, and the length of the second portion of the P-type bending segment adjacent to the second sub-cell edge C is greater than the length of the second portion of the P-type bending segment adjacent to the second sub-cell edge D.

[0094] Optionally, the second battery edge includes: a second sub-battery edge C and a second sub-battery edge D, both of which have at least parallel portions;

[0095] The bending section adjacent to the edge A of the first sub-cell is a P-type bending section, and the bending section adjacent to the edge B of the first sub-cell is an N-type bending section, the P-type bending section is only arranged adjacent to the second sub-cell edge C and the second sub-cell edge D, and the N-type bending section is at least arranged adjacent to the second sub-cell edge C and the second sub-cell edge D; or,

[0096] All the bending segments only include N-type bending segments, and the N-type bending segments are arranged at least adjacent to the edge C of the second sub-cell and / or the edge D of the second sub-cell.

[0097] Optionally, the electrode structure further comprises: a plurality of edge interconnecting portions having at least partial areas collinear in the second direction and close to the edge of the first battery;

[0098] The bending section adjacent to the edge A of the first sub-cell is a P-type bending section, and the bending section adjacent to the edge B of the first sub-cell is an N-type bending section. In the electrode structure, the number of P-type bending sections is equal to the number of edge interconnection sections adjacent to the edge C of the second sub-cell and the edge D of the second sub-cell. In the electrode structure, the number of N-type bending sections is equal to twice the number of edge interconnection sections adjacent to the edge B of the first sub-cell among the edge interconnection sections; or,

[0099] All bending segments include only N-type bending segments, and in the electrode structure, the number of N-type bending segments is equal to twice the number of edge interconnection portions adjacent to a first sub-battery edge among the several edge interconnection portions; or, all bending segments include only N-type bending segments, and all N-type bending segments are arranged only adjacent to the first sub-battery edge A, the second sub-battery edge C, and the second sub-battery edge D, and in the electrode structure, the number of N-type bending segments is equal to the number of edge interconnection portions adjacent to the second sub-battery edge C and the second sub-battery edge D among the several edge interconnection portions.

[0100] Optionally, the electrode structure further comprises: a plurality of edge interconnecting portions having at least partial areas collinear in the second direction and close to the edge of the first battery;

[0101] The N-type bending segments and / or P-type bending segments in the battery body are arranged in pairs, and the paired N-type bending segments and / or P-type bending segments are located on both sides of the center line of the edge interconnection portion in the first direction.

[0102] A third aspect of the present invention provides a photovoltaic assembly, comprising: a plurality of any of the aforementioned back-contact solar cells, and a conductive interconnect extending along the second direction and electrically connected to the back-contact solar cells.

[0103] The above-mentioned back-contact solar cells and photovoltaic modules have the same or similar beneficial effects, which will not be described again here to avoid repetition. BRIEF DESCRIPTION OF THE DRAWINGS

[0104] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.

[0105] Figure 1 A schematic structural diagram of a first back-contact solar cell in an embodiment of the present invention is shown;

[0106] Figure 2 A schematic diagram showing a first partial enlarged structure of a back contact solar cell in an embodiment of the present invention is shown;

[0107] Figure 3 A second partial enlarged structural schematic diagram of a back contact solar cell in an embodiment of the present invention is shown;

[0108] Figure 4 A schematic structural diagram of a second back-contact solar cell in an embodiment of the present invention is shown;

[0109] Figure 5 A third partial enlarged structural schematic diagram of a back contact solar cell in an embodiment of the present invention is shown;

[0110] Figure 6 A fourth partial enlarged structural schematic diagram of a back-contact solar cell in an embodiment of the present invention is shown.

[0111] Description of the accompanying drawings:

[0112] 1-battery body, 11-first battery edge, A, B-first sub-battery edge, 13-second battery edge, C, D-second sub-battery edge, 12-first interval, 2-N-type collector doping region, 3-P-type collector doping region, 21-N-type bending portion, 31-P-type bending portion, 4-N-type collector grid line, 5-P-type collector grid line, 6-N-type bending section, 61-first part, 62-third part, 7-P-type bending section, 71-second part, 72-fourth part, 8-first connecting electrode, 9-N-type edge bus grid line, 10-P-type edge bus grid line, 14-second connecting electrode, 15-first interconnection part, 16-second interconnection part, 17-lapping grid line. DETAILED DESCRIPTION

[0113] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0114] Figures 1 to 6 All of them are schematic diagrams viewed from the backlight side of the back-contact solar cell. During normal operation of the back-contact solar cell, the side that mainly receives light is the light-facing side, and the backlight side is opposite to the light-facing side. Figure 1 It can be a schematic diagram of a whole solar cell. Figure 4 Can be Figure 1It can also be a schematic diagram of a single half-cell back-contact solar cell. Figure 1 and Figure 4 The ellipsis in the figure means that the electrode structure is partially omitted. Figure 5 yes Figure 3 A partial enlarged schematic diagram of . Figure 6 yes Figure 2 A local enlarged schematic diagram. The corresponding gate lines are set on the doped area of ​​the back contact solar cell, so Figure 1 , Figure 4 It can also correspond to the doped region. Figure 1 , Figures 4 to 6 In this application, the distance mentioned throughout the text may refer to the distance between the geometric centers of the two.

[0115] The present invention provides a back contact solar cell, referring to Figures 1 to 6 , the back-contact solar cell may include a battery body 1. The battery body 1 may include a PN junction, which can be used to separate carriers. The battery body 1 includes: a plurality of collector doping regions extending along a first direction p and spaced along a second direction q, wherein the first direction p and the second direction q are different, and the angle between the two is not limited, for example, they can be perpendicular to each other. The collector doping region is used to separate carriers and can play a certain passivation role. A collector grid line will be set on the collector doping region to collect carriers, and a bending section will be set on the bending portion to collect carriers.

[0116] The battery body 1 includes: two first battery edges 11 and a second battery edge 13 located between the two first battery edges 11 , and the second battery edge 13 is parallel to the first direction p. Figures 1 to 6 That is to say, the second battery edge 13 is only the upper edge and the lower edge extending in the left-right direction, and the second battery edge 13 does not include all chamfered parts. Among the edges of the battery body, except for the second battery edge 13, all are the first battery edge 11, that is to say, when the edge of the battery body includes chamfers, the first battery edge 11 also includes all chamfers. The first direction p is along the left-right direction, and the second direction q is along the up-down direction. Therefore, in the above-mentioned figures, the first battery edge 11 also extends roughly along the up-down direction and includes all chamfered parts, that is, the left battery edge and the right battery edge including all chamfers.

[0117] Reference Figure 2, among the several collector doping regions, there is a first gap 12 between the end of the first collector doping region and the edge of the first battery, and the second collector doping region adjacent to the first collector doping region has a bending portion extending into the first gap 12 at the end near the edge of the first battery. The starting position of the bending portion refers to the position in the adjacent second collector doping region where the extension starts along the second direction. For example, Figure 2 In the figure, the starting position of the bent portion is the position in the P-type collector doping region 3 adjacent to the N-type collector doping region 2 that starts to extend along the second direction q. Figure 2 The middle bending portion is the portion extending upward and rightward from the position extending along the second direction q from the P-type collector doping region 3. The conductivity types of the first collector doping region and the second collector doping region are opposite, that is, one of the first collector doping region and the second collector doping region includes an N-type collector doping region and the other includes a P-type collector doping region. Figure 2 The first collector doping region includes an N-type collector doping region 2, and there is a first gap 12 between the end of the N-type collector doping region 2 and the edge of the first battery. The P-type collector doping region 3 adjacent to the N-type collector doping region 2 has a P-type bending portion 31 extending into the first gap 12 at the end close to the edge of the first battery. More specifically, the first gap 12 between the end of the N-type collector doping region 2 and the edge of the first battery is a carrier transmission dead zone. By setting the P-type bending portion 31 entering the first gap, the recombination of carriers in the dead zone due to the long transmission distance is reduced, and the carriers in the dead zone can be efficiently collected and transmitted, which can improve the short-circuit current of the back contact solar cell, and can also improve the passivation effect of the battery edge, reduce the blackening phenomenon of the EL or PL at the battery edge, and thus improve its conversion efficiency. In the battery body, at least two P-type collector grid lines 5 and at least one N-type collector grid line 4 are first collector grid lines, and the bending section is divided into a P-type bending section 7 and an N-type bending section 6. Reference Figure 3 The first collector doping region includes a P-type collector doping region 3, and there is a first gap between the end of the P-type collector doping region 3 and the edge of the first battery. The N-type collector doping region 2 adjacent to the P-type collector doping region 3 has an N-type bending portion 21 extending into the first gap at the end close to the edge of the first battery. For example, Figure 3 In the figure, the starting position of the N-type bent portion 21 is the position in the N-type collector doping region 2 adjacent to the P-type collector doping region 3 where it starts to extend along the second direction by q. Figure 3The middle N-type bending portion 21 is the portion extending downward and rightward from the position extending along the second direction q from the N-type collector doping region 2. More specifically, the first interval between the end of the P-type collector doping region 3 and the edge of the first battery is a carrier transmission dead zone. By setting the N-type bending portion 21 entering the first interval, the recombination of carriers in the dead zone due to the long transmission distance is reduced, so that the carriers in the dead zone can be efficiently collected and transmitted, which can improve the short-circuit current of the back contact solar cell, and can also improve the passivation effect of the battery edge, reduce the blackening phenomenon of the battery edge EL or PL, and thus improve its conversion efficiency. The multiple collector doping regions include: at least one N-type collector doping region 2 and at least one P-type collector doping region 3, that is, the multiple collector doping regions are divided into N-type collector doping regions 2 and P-type collector doping regions 3, and an N-type collector grid line 4 is set on the N-type collector doping region 2, and a P-type collector grid line 5 is set on the P-type collector doping region 3 for collecting carriers or collecting current.

[0118] Reference Figure 1 , Figure 4, both the N-type collector grid line 4 and the P-type collector grid line 5 in the back contact solar cell have a bending section, therefore, both the N-type collector doping region 2 and the P-type collector doping region 3 in the back contact solar cell have a bending portion. In the battery body, at least two P-type collector grid lines 5 and at least one N-type collector grid line 4 are first collector grid lines, and the bending section includes: a P-type bending section 7 and an N-type bending section 6. That is, at least one first collector doping region includes an N-type collector doping region 2, and a first gap 12 is provided between the end of the N-type collector doping region 2 and the edge of the first battery. Then, the P-type collector doping region 3 adjacent to the N-type collector doping region 2 has a P-type bending portion 31 extending into the first gap 12 at the end near the edge of the first battery. At least one first collector doping region includes a P-type collector doping region 3, and a first gap is provided between the end of the P-type collector doping region 3 and the edge of the first battery. Then, the N-type collector doping region 2 adjacent to the P-type collector doping region 3 has an N-type bending portion 21 extending into the first gap at the end near the edge of the first battery. Therefore, the aforementioned bending portions are the P-type bending portion 31 and the N-type bending portion 21. The inventors found that in the battery body, when the number of N-type bends is equal to the number of P-type bends, the edge EL or PL of the P-type collector doping region is more seriously blackened, especially the edge EL or PL of the P-type collector doping region is more seriously blackened. The possible reason is that the passivation effect of the P-type collector doping region is poor. In view of the above problem, in the battery body 1 of the present invention, the number of N-type bends 21 is greater than the number of P-type bends 31, and the N-type collector doping region 2 has a better passivation effect than the P-type collector doping region 3. The number of N-type bends 21 is greater, which can optimize the passivation effect of more dead zones, solve the problem of EL or PL blackening at the edge of the P-type collector doping region 3, and at the same time improve the open circuit voltage and conversion factor of the back contact solar cell, thereby further improving the conversion efficiency of the back contact solar cell. It should be noted that on the basis that the number of N-type bends 21 is greater than the number of P-type bends 31, the difference between the two is not specifically limited.

[0119] In the back contact solar cell, only the N-type collector grid line 4 has a bending section, so only the N-type collector doping region in the back contact solar cell has a bending portion. The first collector doping region is only the P-type collector doping region, and there is a first interval between the end of the P-type collector doping region 3 and the edge of the first battery. Then the N-type collector doping region 2 adjacent to the P-type collector doping region 3 has an N-type bending portion 21 extending into the first interval at the end close to the edge of the first battery, so the bending portion in the battery body only includes the N-type bending portion 21. Since the N-type collector doping region has a better passivation effect than the P-type collector doping region, only the N-type bending portion 21 can optimize the passivation effect of the dead zone, solve the problem of blackening of EL or PL at the edge of the P-type collector doping region, and at the same time can improve the open circuit voltage and conversion factor of the back contact solar cell, thereby further improving the conversion efficiency of the back contact solar cell.

[0120] In the case where the bend in the battery body includes only the N-type bend 21, since there is no P-type bend, the area of ​​the P-type bend is 0. Optionally, in the case where the bend in the battery body includes the N-type bend 21 and the P-type bend 31, the total area of ​​the N-type bend 21 is greater than the total area of ​​the P-type bend 31, which is equivalent to increasing the area of ​​the N-type collector doping region 2, which can optimize the passivation effect of the dead zone, solve the problem of blackening of the EL or PL at the edge of the P-type collector doping region, and at the same time improve the open circuit voltage and conversion factor of the back contact solar cell, thereby further improving the conversion efficiency of the back contact solar cell.

[0121] When the bending portions in the battery body only include the N-type bending portions 21 , there are no P-type bending portions, and thus the number of the P-type bending portions is 0. Optionally, when the bending portion in the battery body includes an N-type bending portion 21 and a P-type bending portion 31, the number of N-type bending portions 21 is greater than the number of P-type bending portions 31, and the ratio of the number of N-type bending portions 21 to the number of P-type bending portions 31 is 3:1 to 11:1. The ratio of the two is set appropriately, which can not only optimize the passivation effect of the dead zone, solve the problem of blackening of EL or PL at the edge of the P-type collector doping region, but also improve the open circuit voltage and conversion factor of the back contact solar cell, thereby further improving the conversion efficiency of the back contact solar cell. Moreover, the number of N-type bending portions 21 is not too large, so that the carriers can be collected evenly. If too many P-type bending portions 31 are set, the area of ​​the N-type collector doping region in the battery body will be reduced, thereby causing the passivation effect of the battery body to deteriorate. If too few P-type bending portions 31 are set, the area of ​​the N-type collector doping region will be relatively larger, but more dead zones will be introduced, and effective collection of carriers cannot be achieved.

[0122] For example, the number of N-type bending portions 21 is greater than the number of P-type bending portions 31, and the ratio of the number of N-type bending portions 21 to the number of P-type bending portions 31 can be 3:1, 3.2:1, 4:1, 5:1, 6:1, 7:1, 7.5:1, 8:1, 8.7:1, 9:1, 10:1, 10.2:1, or 11:1.

[0123] It should be noted that, when the number of N-type bending portions 21 is greater than the number of P-type bending portions 31, and the ratio of the number of N-type bending portions to the number of P-type bending portions is 3:1 to 11:1, the area of ​​an N-type bending portion may be greater than or equal to the area of ​​a P-type bending portion, or the area of ​​an N-type bending portion may be smaller than the area of ​​a P-type bending portion, and no specific limitation is made to this.

[0124] Optionally, in the case where the number of N-type bends is greater than the number of P-type bends, the area of ​​at least one N-type bend 21 is less than or equal to the area of ​​at least one P-type bend 31. When the areas of the two are equal, the process parameters of the two are relatively close and the process is simple. In the case where the area of ​​at least one N-type bend 21 is smaller than the area of ​​at least one P-type bend 31, since the number of N-type collector doping regions is large, the N-type collector doping regions have a better passivation effect, and thus the passivation effect of the battery edge can also be improved, reducing the phenomenon of blackening of EL or PL at the battery edge, thereby improving its conversion efficiency. It should be noted that in the case where the area of ​​an N-type bend 21 is smaller than the area of ​​a P-type bend 31, the difference between the two is not specifically limited.

[0125] Optional, see Figures 2 to 6 The N-type bending portion 21 has a portion extending along the first direction p, and the P-type bending portion 31 has a portion extending along the first direction. The width of the portion of the N-type bending portion 21 extending along the first direction p is less than or equal to the width of the portion of the P-type bending portion 31 extending along the first direction p. The directions of the width here are all in the second direction q, that is, the portion of the P-type bending portion 31 extending along the first direction p has a larger size in the second direction q, and the width of the portion of the P-type bending portion 31 extending along the first direction p is larger. The battery body includes: an N-type silicon substrate, a plurality of collector doping regions located inside the N-type silicon substrate, and / or, a plurality of collector doping regions located on the N-type silicon substrate. The P-type bending portion 31 will form a PN heterojunction with the N-type silicon substrate, that is, a junction region. The width of the portion of the P-type bending portion 31 extending along the first direction p is larger, so that the junction area is larger. The larger the junction area / field area, the more conducive to improving the open circuit voltage and short circuit current. It should be noted that, when the width of the portion of the N-type bending portion 21 extending along the first direction p is less than or equal to the width of the portion of the P-type bending portion 31 extending along the first direction p, the difference in width between the two is not specifically limited.

[0126] Optional, see Figure 1 , Figure 4 , the bending section includes: an edge bending section adjacent to the edge of the second battery and a middle bending section located on the side of the edge bending section away from the edge of the second battery, therefore, the bending portion includes: an edge bending portion adjacent to the edge of the second battery and a middle bending portion located on the side of the edge bending portion away from the edge of the second battery. The area of ​​the edge bending portion is larger than the area of ​​the middle bending portion. Specifically, the battery edge may usually have more defects, so better passivation is required. Therefore, the area of ​​the edge bending portion is larger than the area of ​​the middle bending portion, providing a better passivation effect for the battery edge and avoiding the problem of blackening of the edge EL or PL.

[0127] Optionally, the first battery edge 11 includes: a first sub-battery edge A and a first sub-battery edge B, both of which have at least parallel portions, and both of which have at least portions parallel to the second direction q. Figure 1 In the embodiment, the bending segments close to the edge A of the first sub-cell among all the bending segments include: at least two N-type bending segments 6 and at least one P-type bending segment 7, the bending portions close to the edge B of the first sub-cell among all the bending segments include: at least two N-type bending segments 6 and at least one P-type bending segment 7, the number of N-type bending segments 6 close to the edge of the same first sub-cell is 2 to 30, and the number of P-type bending segments 7 close to the edge of the same first sub-cell is 1 to 4. For example, Figure 1 In the embodiment, the number of N-type bending segments 6 adjacent to the edge A of the first sub-battery among all the bending segments can be 8, the number of N-type bending segments 6 adjacent to the edge B of the first sub-battery among all the bending segments can be 8, the number of P-type bending segments 7 adjacent to the edge A of the first sub-battery among all the bending segments can be 2, and the number of P-type bending segments 7 adjacent to the edge B of the first sub-battery among all the bending segments can be 2. Corresponding to the bending portions, the bending portions adjacent to the same first sub-battery edge among all the bending portions include: at least one P-type bending portion and at least two N-type bending portions. The number of N-type bending portions adjacent to the same first sub-battery edge is 2 to 30, and the number of P-type bending portions adjacent to the same first sub-battery edge is 1 to 4. In the same first sub-battery edge, the numbers of N-type bending portions and P-type bending portions are relatively appropriate, which not only has a good passivation effect, but also is conducive to the separation and collection of carriers.

[0128] For example, the bending portions among all the bending portions adjacent to the edge of the same first sub-cell include: at least one P-type bending portion and at least two N-type bending portions, the number of N-type bending portions adjacent to the edge of the same first sub-cell can be 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, and the number of P-type bending portions adjacent to the edge of the same first sub-cell can be 1, 2, 3, 4.

[0129] Optional, Figure 1 In the embodiment, the bending segments adjacent to the edge A of the first sub-cell among all the bending segments include: at least two N-type bending segments 6 and at least one P-type bending segment 7, the bending portions adjacent to the edge B of the first sub-cell among all the bending segments include: at least two N-type bending segments 6 and at least one P-type bending segment 7, the number of N-type bending segments 6 adjacent to the same edge of the first sub-cell is 2 to 30, the number of P-type bending segments 7 adjacent to the same edge of the first sub-cell is 1 to 4, and the N-type bending segments 6 are symmetrically arranged with respect to the diagonal line of the back side of the battery body 1, and / or the P-type bending segments 7 are symmetrically arranged with respect to the diagonal line of the back side of the battery body 1. That is, the bending segments adjacent to another same first sub-cell edge among all the bending segments include: at least one P-type bending segment 7 and at least two N-type bending segments 6, and in the electrode structure, the N-type bending segments 6 and / or the P-type bending segments 7 are symmetrically arranged with respect to the diagonal line of the back side of the battery body 1. Corresponding to the bending portions, the bending portions in all the bending portions that are adjacent to the edge of another same first sub-battery include: at least one P-type bending portion and at least two N-type bending portions. In the battery body, the N-type bending portion and / or the P-type bending portion are symmetrically arranged about the diagonal line of the back side of the battery body 1, which is conducive to uniform and effective collection of carriers.

[0130] Or, the bending segments close to the edge A of the first sub-cell among all the bending segments only include: N-type bending segments, the bending portions close to the edge B of the first sub-cell among all the bending segments only include: N-type bending segments, and the number of N-type bending segments close to the same edge of the first sub-cell is 2 to 30. For example, the number of N-type bending segments close to the edge A of the first sub-cell among all the bending segments can be 8, and the number of N-type bending segments close to the edge B of the first sub-cell among all the bending segments can be 8. For another example, the number of N-type bending segments close to the edge A of the first sub-cell among all the bending segments can be 2, and the number of N-type bending segments close to the edge B of the first sub-cell among all the bending segments can be 2. Correspondingly, the bending portions close to the same edge of the first sub-cell among all the bending portions only include N-type bending portions, and the number of N-type bending portions close to the same edge of the first sub-cell is 2 to 30, which not only has a good passivation effect, but also facilitates the separation and collection of carriers.

[0131] For example, the bending portions adjacent to the edge of the same first sub-cell among all the bending portions only include N-type bending portions, and the number of N-type bending portions adjacent to the edge of the same first sub-cell can be 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, or 30.

[0132] Optional, see Figure 1 The second battery edge 13 includes: a second sub-battery edge C and a second sub-battery edge D, both of which have at least parallel portions, and both of which have at least portions parallel to the first direction p. Figure 1Among all the bending segments, the bending segments close to the first sub-cell edge A include: at least two N-type bending segments 6 and at least one P-type bending segment 7, the P-type bending segment 7 is only arranged close to the second sub-cell edge C and / or the second sub-cell edge D, the N-type bending segment 6 is at least arranged close to the second sub-cell edge C and / or the second sub-cell edge D, and at least two N-type bending segments 6 are arranged close to the second sub-cell edge C and / or the second sub-cell edge D, and both the N-type bending segment 6 and the P-type bending segment 7 are at least arranged close to the corner of the back contact solar cell. Figure 1 In the embodiment, the P-type bending section 7 is only arranged adjacent to the second sub-cell edge C and the second sub-cell edge D, the N-type bending section 6 is arranged adjacent to the second sub-cell edge C and the second sub-cell edge D, and the N-type bending section 6 is not only arranged adjacent to the second sub-cell edge C and the second sub-cell edge D, but also arranged at a position between the second sub-cell edge C and the second sub-cell edge D. Corresponding to the bending portion, the bending portion adjacent to the same first sub-cell edge in all the bending portions includes: at least one P-type bending portion and at least two N-type bending portions, the P-type bending portion is only arranged adjacent to the second sub-cell edge C and / or the second sub-cell edge D, and the N-type bending portion is at least arranged adjacent to the second sub-cell edge C and / or the second sub-cell edge D. Specifically, the corners of the back-contact solar cell may generally have more defects, and the N-type bending portion and the P-type bending portion are both arranged at least adjacent to the corners of the back-contact solar cell, which can better passivate the defects of the corners of the back-contact solar cell and further enhance the passivation effect.

[0133] Or, the bending segments close to the first sub-cell edge A among all the bending segments only include: N-type bending segments, the bending portions close to the first sub-cell edge B among all the bending segments only include: N-type bending segments, and the N-type bending portions are arranged at least close to the second sub-cell edge C and / or the second sub-cell edge D. For example, there may be 8 N-type bending segments close to the first sub-cell edge A among all the bending segments, and there may be 8 N-type bending segments close to the first sub-cell edge B among all the bending segments, and the N-type bending portions are arranged close to the second sub-cell edge C and the second sub-cell edge D, and the N-type bending portions are also arranged at a position between the second sub-cell edge C and the second sub-cell edge D. For another example, there are two N-type bending sections adjacent to the edge A of the first sub-cell among all the bending sections, there are two N-type bending sections adjacent to the edge B of the first sub-cell among all the bending sections, the N-type bending sections are arranged adjacent to the edge C of the second sub-cell and the edge D of the second sub-cell, and the N-type bending sections are also arranged between the edge C of the second sub-cell and the edge D of the second sub-cell. Corresponding to the bending portions, the bending portions adjacent to the same edge of the first sub-cell among all the bending portions only include the N-type bending portions, and the N-type bending portions are arranged adjacent to at least the edge C of the second sub-cell and / or the edge D of the second sub-cell, which not only has a good passivation effect, but also facilitates the separation and collection of carriers.

[0134] Optional, see Figure 4 , the first battery edge includes: a first sub-battery edge A and a first sub-battery edge B, both of which have at least parallel parts. The first sub-battery edge A and the first sub-battery edge B here can refer to the above-mentioned related records. In order to avoid repetition, they are not repeated here. The bending portion adjacent to the first sub-battery edge A is a P-type bending segment 7, and the bending segment adjacent to the first sub-battery edge B is an N-type bending segment 6. That is, in the second direction, the P-type bending segment 7 and the N-type bending segment 6 are respectively arranged at the edge position on one side. The number of N-type bending segments adjacent to the same first sub-battery edge is 2 to 30, and the number of P-type bending segments adjacent to the same first sub-battery edge is 1 to 4. For example, Figure 4 In the embodiment, the number of N-type bending sections adjacent to the edge of the same first sub-cell can be 8, and the number of P-type bending sections adjacent to the edge of the same first sub-cell can be 2. The bending sections correspond to the bending portions, the bending portion adjacent to the edge A of the first sub-cell is a P-type bending portion, and the bending portion adjacent to the edge B of the first sub-cell is an N-type bending portion. The number of N-type bending portions adjacent to the edge of the same first sub-cell is 2 to 30, and the number of P-type bending portions adjacent to the edge of the same first sub-cell is 1 to 4. Not only is the passivation effect good, but it is also beneficial to the collection and conduction of carriers.

[0135] For example, the bending portion adjacent to the edge A of the first sub-cell is a P-type bending portion, and the bending portion adjacent to the edge B of the first sub-cell is an N-type bending portion. The number of N-type bending portions adjacent to the same edge of the first sub-cell can be 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, and the number of P-type bending portions adjacent to the same edge of the first sub-cell can be 1, 2, 3, 4.

[0136] Or, the first battery edge includes: a first sub-battery edge A and a first sub-battery edge B, both of which have at least parallel parts. The first sub-battery edge A and the first sub-battery edge B here can refer to the above-mentioned related records. In order to avoid repetition, they are not repeated here. The bending section is only adjacent to the first sub-battery edge A or only adjacent to the first sub-battery edge B, and the bending section only has an N-type bending section 6. The number of N-type bending sections adjacent to the same first sub-battery edge is 2 to 30, or the number of N-type bending sections adjacent to the same first sub-battery edge is 1 to 4. For example, the bending section is only adjacent to the first sub-battery edge A and the bending section only has an N-type bending section 6. The number of N-type bending sections adjacent to the same first sub-battery edge is 8. For another example, the bending section is only adjacent to the first sub-battery edge A and the bending section only has an N-type bending section 6. The number of N-type bending sections adjacent to the same first sub-battery edge is 2. The bending section is arranged to correspond to the bending portion, the bending portion is only close to the edge A of the first sub-battery or only close to the edge B of the first sub-battery, and the bending portion only has an N-type bending portion, and the number of N-type bending portions close to the same first sub-battery edge is 2 to 30 or the number of N-type bending portions is 1 to 4, which not only has a good passivation effect but also is conducive to the collection and conduction of carriers.

[0137] For example, the bending portion is only arranged adjacent to the edge A of the first sub-cell or only adjacent to the edge B of the first sub-cell, and the bending portion only has an N-type bending portion. The number of N-type bending portions adjacent to the same first sub-cell edge can be 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, or the number of N-type bending portions adjacent to the same first sub-cell edge can be 1, 2, 3, 4.

[0138] Optionally, the bending portion adjacent to the edge A of the first sub-cell and the bending portion adjacent to the edge B of the first sub-cell are both only N-type bending portions, and the number of N-type bending portions adjacent to the same first sub-cell edge is 2 to 30. That is, there are only N-type bending portions in the back-contact solar cell, and the N-type bending portions are arranged at the bending portion adjacent to the edge A of the first sub-cell and the bending portion adjacent to the edge B of the first sub-cell, and the number of N-type bending portions adjacent to the same first sub-cell edge is 2 to 30. The N-type bending portions have a relatively symmetrical passivation effect on the first sub-cell edge A and the first sub-cell edge B.

[0139] For example, the bend portion adjacent to the edge A of the first sub-cell and the bend portion adjacent to the edge B of the first sub-cell are both only N-type bend portions, and the number of N-type bend portions adjacent to the same first sub-cell edge can be 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, or 30.

[0140] Optionally, the second battery edge includes: a second sub-battery edge C and a second sub-battery edge D, both of which have at least parallel portions. For reference, the above-mentioned related records may be referred to here. In order to avoid repetition, they are not described here. Figure 4 , the bending section adjacent to the edge A of the first sub-cell is a P-type bending section 7, and the bending section adjacent to the edge B of the first sub-cell is an N-type bending section 6, the P-type bending section 7 is only arranged adjacent to the second sub-cell edge C and the second sub-cell edge D, and the N-type bending section 6 is at least arranged adjacent to the second sub-cell edge C and the second sub-cell edge D, that is, the P-type bending section 7 is only arranged at the head and tail positions in the second direction, and the N-type bending section 6 is at least arranged at the head and tail positions in the second direction, and whether it is arranged at the middle position in the second direction is not limited. For example, Figure 4 In the embodiment, the P-type bending section 7 is only arranged adjacent to the second subcell edge C and the second subcell edge D, the N-type bending section 6 is arranged adjacent to the second subcell edge C and the second subcell edge D, and the N-type bending section 6 is also arranged at positions other than the second subcell edge C and the second subcell edge D. The bending sections correspond to the bending portions, the bending portion adjacent to the first subcell edge A is the P-type bending portion, and the bending portion adjacent to the first subcell edge B is the N-type bending portion, the P-type bending portion is only arranged adjacent to the second subcell edge C and the second subcell edge D, and the N-type bending portion is at least arranged adjacent to the second subcell edge C and the second subcell edge D. Specifically, the N-type bending portion and the P-type bending portion are both arranged at least at the head and tail positions in the second direction, that is, at the corner position of the back contact solar cell. The corner position of the back contact solar cell may usually have more defects, and the N-type bending portion and the P-type bending portion are both arranged at least at the head and tail positions in the second direction, which can further reduce the defects at the corner position of the back contact solar cell and further improve the passivation effect of the back contact solar cell.

[0141] Optionally, all bending segments include only N-type bending segments 6, which are arranged at least close to the second sub-cell edge C and / or the second sub-cell edge D. The bending segments correspond to the bending portions, and all bending portions include only N-type bending portions, which are arranged at least close to the second sub-cell edge C and / or the second sub-cell edge D. The passivation effect of the N-type bending portions is better, and the N-type bending portions are at least arranged at the head and tail positions in the second direction, which can further reduce the defects at the corner positions of the back-contact solar cell and further improve the passivation effect of the back-contact solar cell.

[0142] Optional, see Figure 2 , Figure 3The battery body also includes: an edge bus doping region extending along the second direction q and adjacent to the edge of the first battery, and an edge bus grid line is arranged above the edge bus doping region for extracting carriers. The battery body also includes: a connecting doping region extending along the first direction and intersecting with the edge bus doping region, and a connecting electrode is arranged on the connecting doping region for electrically connecting the edge bus grid line and the edge interconnection portion. The connecting doping region is spaced apart from the first collector doping region to avoid short circuit. The widths of the edge bus doping region and the connecting doping region are both greater than or equal to the width of the collector doping region. Specifically, the edge bus grid line and the connecting electrode are mainly used to extract current, and the current passing through them is large, so their widths are large, which is conducive to current collection. Therefore, the widths of the edge bus doping region and the connecting doping region are both greater than or equal to the width of the collector doping region.

[0143] The area of ​​the inner region enclosed by the first collector doping region and the first extension region intersecting the edge bus doping region after extension, the edge bus doping region, the connection doping region adjacent to the first collector doping region, and the second extension region extending along the second direction and intersecting the first collector doping region is S, for example, it can be approximately Figure 2 In the figure, the area of ​​the inner region enclosed by the N-type collector grid line marked 4 and the first extension line intersecting the N-type edge collector grid line 9 after extension, the N-type edge collector grid line 9, the first connection electrode 8 adjacent to the N-type collector grid line marked 4, and the second extension line extending along the second direction q and intersecting the N-type collector grid line marked 4. Or it can be roughly: Figure 3 In the figure, the area of ​​the internal region enclosed by the P-type collector gate line marked 5 and the third extension line which is extended to intersect with the P-type edge collector gate line 10, the P-type edge collector gate line 10, the second connecting electrode 14 adjacent to the P-type collector gate line marked 5, and the fourth extension line which is extended along the second direction q to intersect with the P-type collector gate line marked 5.

[0144] Optionally, the first collector doping region is a P-type collector doping region, the area of ​​the N-type bend portion is 25% to 39% of S, and the size relationship between the area of ​​the N-type bend portion 21 and the area S corresponding to the first collector doping region being the P-type collector doping region is set more reasonably, which not only has a good passivation effect, but also is conducive to the effective collection of carriers. And / or, the first collector doping region is an N-type collector doping region, the area of ​​the P-type bend portion 31 is 22% to 41%, and the size relationship between the area of ​​the P-type bend portion 31 and the area S corresponding to the first collector doping region being the N-type collector doping region is set more reasonably, which not only has a good passivation effect, but also is conducive to the effective collection of carriers.

[0145] For example, the first collector doping region is a P-type collector doping region, and the area of ​​the N-type bending portion can be 25% S, 25.7% S, 26% S, 27% S, 28% S, 29% S, 30% S, 31.5% S, 32% S, 35% S, 39% S. For another example, the first collector doping region is an N-type collector doping region, and the area of ​​the P-type bending portion 31 can be 22% S, 23.7% S, 26% S, 27.7% S, 28% S, 29% S, 30% S, 31.5% S, 33% S, 35% S, 39% S, 41% S.

[0146] Optionally, the first collector doping region is an N-type collector doping region, and the area of ​​the inner region enclosed by the first collector doping region is S1; the first collector doping region is a P-type collector doping region, and the area of ​​the inner region enclosed by the first collector doping region is S2, and S1 is greater than S2. When S1 is greater than S2, the dead zone area of ​​the N region is large, which can improve the passivation effect of the battery body, and the number and area of ​​the corresponding bending parts introduced are more appropriate, which can effectively improve the edge passivation and carrier collection efficiency. It should be noted that the difference between the two is not specifically limited.

[0147] Optionally, the first collector doping region is a P-type collector doping region, S≥1.3mm 2 , and / or, the first collector doping region is an N-type collector doping region, S≥1.6mm 2 That is, when the first collector doping region is a P-type collector doping region, the area S of the inner region surrounded by the first collector doping region is ≥ 1.3 mm 2 In the case where the first collector doping region is an N-type collector doping region, the area S of the inner region surrounded by the first collector doping region is ≥ 1.6 mm 2 The P-type bending portion 31 is introduced only when the P-type bending portion 31 is used. In this case, the number and area of ​​the corresponding bending portions introduced are relatively appropriate, which can effectively improve the edge passivation and carrier collection efficiency, and can also avoid waste.

[0148] For example, if the first collector doping region is a P-type collector doping region, S may be 1.3 mm. 2 , 1.33mm 2 , 1.4mm 2 , 1.42mm 2 , 1.35mm 2 , 1.38mm 2 , 1.39mm 2 , 1.45mm 2 , 1.44mm 2For another example, if the first collector doping region is an N-type collector doping region, S may be 1.6 mm. 2 , 1.63mm 2 , 1.7mm 2 , 1.74mm 2 , 1.75mm 2 , 1.68mm 2 , 1.69mm 2 , 1.75mm 2 , 1.74mm 2 .

[0149] The present invention also provides a back-contact solar cell, which may include a cell body 1. The cell body 1 may refer to the above-mentioned related records, and will not be described here to avoid repetition. The back-contact solar cell may also include: an electrode structure, which is mainly used to collect and conduct carriers and conduct current.

[0150] The electrode structure may include: a plurality of collector grid lines extending along a first direction and spaced apart along a second direction, the collector grid lines being used to collect and transmit carriers, the first direction p being different from the second direction q, the battery body 1 including: two first battery edges 11 and a second battery edge 13 located between the two first battery edges 11, the second battery edge being parallel to the first direction p, reference may be made to the aforementioned related records, and in order to avoid repetition, they will not be described here.

[0151] Among the above-mentioned several collector grid lines, there is a second gap between the end of the first collector grid line and the edge 11 of the first battery, and the second collector grid line adjacent to the first collector grid line has a bending section extending into the second gap at the end close to the edge of the first battery. The polarity of the first collector grid line and the second collector grid line are opposite. The several collector grid lines are divided into N-type collector grid lines and at least one P-type collector grid line, where the N-type collector grid line corresponds to the aforementioned N-type collector doping region 2, and the N-type collector grid line 4 is arranged on the N-type collector doping region 2, and the P-type collector grid line 5 corresponds to the aforementioned P-type collector doping region 3, and the P-type collector grid line 5 is arranged on the P-type collector doping region 3.

[0152] Reference Figure 1 , Figure 4In the electrode structure, at least two P-type collector grid lines 5 and at least one N-type collector grid line 4 are first collector grid lines, and the bending sections are divided into P-type bending sections 7 and N-type bending sections 6. In the electrode structure, the number of N-type bending sections 6 is greater than the number of P-type bending sections 7, which can optimize the passivation effect of more dead zones, solve the problem of blackening of EL or PL at the edge of the P-type collector doping area, and at the same time improve the open circuit voltage and conversion factor of the back contact solar cell, thereby further improving the conversion efficiency of the back contact solar cell. It should be noted that on the basis that the number of N-type bending sections 6 is greater than the number of P-type bending sections 7, the difference between the two is not specifically limited. Or, the first collector grid line is only a P-type collector grid line 5, and the bending section in the battery body only includes an N-type bending section 6. Since the N-type collector doping region has a better passivation effect than the P-type collector doping region, there is only an N-type bending section 6 in the electrode structure, that is, there is only an N-type bending portion 21 in the battery body, which can optimize the passivation effect of the dead zone and solve the problem of blackening of EL or PL at the edge of the P-type collector doping region. At the same time, the open circuit voltage and conversion factor of the back-contact solar cell can be improved, thereby further improving the conversion efficiency of the back-contact solar cell.

[0153] It should be noted that the starting position of the bending section refers to the position where the adjacent second collector grid line starts to extend along the second direction. Figure 2 In the figure, the starting position of the bending section is the position where the P-type collector grid line 5 adjacent to the N-type collector grid line 4 starts to extend along the second direction q. Figure 2 The middle bending section is a portion extending upward and rightward from the position where the P-type collector grid line 5 extends along the second direction q. Figure 3 In the figure, the starting position of the N-type bending section is the position where the N-type collector grid line 4 adjacent to the P-type collector grid line 5 starts to extend along the second direction q. Figure 3 The middle N-type bending section is a portion extending downward and rightward from a position extending along the second direction q in the N-type collector grid line 4 .

[0154] Optionally, the total length of the N-type bending segment 6 is greater than the total length of the P-type bending segment 7. Since the N-type collector doping region has a better passivation effect than the P-type collector doping region, the total length of the N-type bending segment 6 is longer, which can optimize the passivation effect of more dead zones and solve the problem of blackening of EL or PL at the edge of the P-type collector doping region. At the same time, it can improve the open circuit voltage and conversion factor of the back contact solar cell, thereby further improving the conversion efficiency of the back contact solar cell. The difference between the two is not specifically limited.

[0155] Optionally, the number of N-type bending segments 6 is greater than the number of P-type bending segments 7, and the ratio of the number of N-type bending segments 6 to the number of P-type bending segments 7 is 3:1 to 11:1. The ratio of the two is set appropriately, which can not only optimize the passivation effect of the dead zone, solve the problem of blackening of EL or PL at the edge of the P-type collector doping area, but also improve the open circuit voltage and conversion factor of the back-contact solar cell, thereby further improving the conversion efficiency of the back-contact solar cell. Moreover, the number of N-type bending segments 6 is not too much, so that the carriers can be collected evenly.

[0156] For example, the number of N-type bending segments 6 is greater than the number of P-type bending segments 7, and the ratio of the number of N-type bending segments 6 to the number of P-type bending segments 7 can be 3:1, 3.3:1, 4:1, 5:1, 6:1, 7:1, 7.5:1, 8:1, 8.7:1, 9:1, 10:1, 10.2:1, or 11:1.

[0157] Optional, see Figure 3 , Figure 5 The N-type bending section has a first part 61 extending along the first direction p. The distance d1 between the first part 61 and the adjacent P-type collector grid line 5 is 1 / 3 to 2 / 3 of the distance d2 between adjacent P-type collector grid lines 5, which can fully avoid short circuits and avoid space waste. At the same time, during the electrode preparation process, the process window can be expanded to reduce the process difficulty of electrode preparation. For example, the distance d1 between the first part 61 and the adjacent P-type collector gate line 5 can be 1 / 3, 11 / 30, 2 / 5, 13 / 30, 7 / 15, 1 / 2, 8 / 15, 17 / 30, 3 / 5, 19 / 30, or 2 / 3 of the distance d2 between adjacent P-type collector gate lines 5. There is no limitation on the specific value of d1. For example, d1 can be 350um, 365um, 369um, 380um, 392um, 400um, 415um, 420um, 433um, 450um, 470um, 494um, 500um, 503um, 529um, 565um, or 590um.

[0158] Optional, see Figure 2 , Figure 6The P-type bending section has a second part 71 extending along the first direction p. The distance d3 between the second part 71 and the adjacent N-type collector grid line 4 is 1 / 3 to 2 / 3 of the distance d4 between adjacent N-type collector grid lines 4, which can fully avoid short circuits and avoid space waste. At the same time, during the electrode preparation process, the process window can be expanded to reduce the process difficulty of electrode preparation. For example, the distance d3 between the second part 71 and the adjacent N-type collector grid line 4 can be 1 / 3, 11 / 30, 2 / 5, 13 / 30, 7 / 15, 1 / 2, 8 / 15, 17 / 30, 3 / 5, 19 / 30, or 2 / 3 of the distance d4 between adjacent N-type collector grid lines 4. There is no limitation on the specific value of d3. For example, d3 can be 440um, 465um, 463um, 480um, 492um, 500um, 505um, 520um, 533um, 550um, 570um, 530um, or 472um.

[0159] Figure 5 yes Figure 3 Optional, see Figure 3 , Figure 5 The N-type bending section has a third portion 62 extending along the second direction q, and the distance d5 between the third portion 62 and the end of the adjacent P-type collector grid line 5 close to the edge of the first battery is Figure 3 , Figure 5 , the distance between the third portion 62 and the left end of the P-type collector grid line marked 5, Figure 3 , Figure 5 In the figure, the edge of the first battery is located on the left side of the P-type edge busbar line 10, and d5 is 1 / 4 to 3 / 4 of the second interval between the left end of the P-type collector grid line marked 5 and the edge of the first battery, which can fully avoid short circuits and waste of space. At the same time, during the electrode preparation process, the process window can be expanded to reduce the process difficulty of electrode preparation. For example, the distance d5 between the third part 62 and the end of the adjacent P-type collector grid line 5 close to the edge of the first battery can be 1 / 4, 11 / 40, 3 / 10, 13 / 40, 7 / 20, 3 / 8, 2 / 5, 17 / 40, 9 / 20, 19 / 40, 1 / 2, 21 / 40, 11 / 20, 23 / 40, 3 / 5, 5 / 8, 13 / 20, 27 / 40, 3 / 10, 7 / 10, 29 / 40, 3 / 4 of the aforementioned second interval, and there is no limitation on the specific value of d5. For example, d5 can be 550um, 570um, 580um, 600um, 650um, 670um, 700um, 750um, 800um, 830um, 890um, 900um, 920um, 940um, 950um.

[0160] Figure 6 yes Figure 2Optional, see Figure 2 , Figure 6 The P-type bending section has a fourth portion 72 extending along the second direction q, and the distance d6 between the fourth portion 72 and the end of the adjacent N-type collector grid line 4 close to the edge of the first battery is Figure 2 , Figure 6 , the distance between the fourth portion 72 and the left end of the N-type collector grid line marked 4, Figure 2 , Figure 6 In the embodiment, the edge of the first battery is located on the left side of the N-type edge busbar line 9, and d6 is 1 / 4 to 3 / 4 of the second interval between the left end of the N-type collector grid line marked 4 and the edge of the first battery, which can fully avoid short circuits and avoid space waste. At the same time, during the electrode preparation process, the process window can be expanded to reduce the process difficulty of electrode preparation. For example, the distance d6 between the third portion 62 and the end of the adjacent P-type collector grid line 5 close to the edge of the first battery can be 1 / 4, 11 / 40, 3 / 10, 13 / 40, 7 / 20, 3 / 8, 2 / 5, 17 / 40, 9 / 20, 19 / 40, 1 / 2, 21 / 40, 11 / 20, 23 / 40, 3 / 5, 5 / 8, 13 / 20, 27 / 40, 3 / 10, 7 / 10, 29 / 40, 3 / 4. There is no limitation on the specific value of d6. For example, d6 can be 500um, 530um, 580um, 600um, 650um, 670um, 700um, 750um, 800um, 830um, 890um, 900um, 920um, 970um, and 1000um.

[0161] Optional, see Figures 2 to 6 The P-type bending section has a second portion 71 extending along the first direction p, and the distance d3 between the second portion 71 and the adjacent N-type collector grid line 4 is greater than the distance d1 between the first portion 61 and the adjacent P-type collector grid line 5, which is beneficial to improving the open circuit voltage and short circuit current. It should be noted that when d3 is greater than d1, the difference in width between the two is not specifically limited.

[0162] Optional, see Figures 2 to 6 The distance d5 between the third part 62 and the end of the adjacent P-type collector grid line 5 close to the edge of the first battery is equal to the distance d6 between the fourth part 72 and the end of the adjacent N-type collector grid line 4 close to the edge of the first battery, which can fully avoid short circuits and has good process compatibility and a simpler process.

[0163] Optional, see Figure 3The N-type bending section has a first portion 61 extending along a first direction p and a third portion 62 extending along a second direction q. The length of the first portion 61 is less than or equal to the length of the third portion 62, which can fully utilize the space, facilitate the collection of carriers, and avoid the risk of short circuit. When the length of the first portion 61 is not equal to the length of the third portion 62, the difference between the two is not specifically limited.

[0164] Optional, see Figure 3 , Figure 5 The N-type bending section has a first portion 61 extending along a first direction p and a third portion 62 extending along a second direction q. The length of the first portion 61 is greater than the distance d5 between the third portion 62 and the end of the adjacent P-type collector grid line 5 close to the edge of the first battery, which can make full use of the space. At the same time, while meeting the collection of edge carriers, the slurry used for the collector grid line can be minimized. The length of the third portion 62 is equal to the distance between adjacent collector grid lines of the same polarity. Here, adjacent collector grid lines of the same polarity refer to: the length of the third portion 62 is equal to the distance d4 between two adjacent N-type collector grid lines 4, or the first portion 61 and an N-type collector grid line 4 are arranged flush, and the third portion can be set at the same time in the process of setting the N-type collector grid line 4. The third portion is easy to set. There is no specific limitation on the length of the first portion 61. For example, the length of the first portion 61 may be 580um, 584um, 590um, 600um, 610um, 620um, 625um, 631.30um, 630um, 643um, 652um, 660um. There is no specific limitation on the length of the third portion 62. For example, the length of the third portion 62 may be 880um, 884um, 890um, 900um, 910um, 920um, 925um, 931.30um, 930um, 943um, 952um, 960um.

[0165] Optional, see Figure 2 , Figure 6The P-type bending section has a second portion 71 extending along the first direction p and a fourth portion 72 extending along the second direction. The length of the second portion 71 is greater than the distance d6 between the fourth portion 72 and the end of the adjacent N-type collector grid line 4 close to the edge of the first battery, which can make full use of the space. At the same time, while meeting the collection of edge carriers, the slurry used for the collector grid line can be minimized. The length of the second portion 71 is not specifically limited. For example, the length of the second portion 71 can be 800um, 814um, 850um, 888um, 900um, 950um, 977um, 1000um, 1031.30um, 1030um, 1074um, 1100um, 1120um, 1182um, 1200um. There is no specific limitation on the length of the fourth portion 72. For example, the length of the fourth portion 72 may be 860um, 874um, 890um, 888um, 900um, 905um, 915um, 930um, 931.30um, 955um, 960um, or 970um.

[0166] Optional, see Figures 1 to 4 , the electrode structure also includes: a plurality of interconnecting parts having at least partial areas collinear in the second direction q. In the subsequent process of forming a battery string or a photovoltaic module, a conductive interconnecting part can be set at the above-mentioned collinear position. The conductive interconnecting part can be a welding strip or the like. The plurality of interconnecting parts include: a first interconnecting part 15 and a second interconnecting part 16 arranged alternately and at intervals along the first direction p. Along the second direction, the size of the interconnecting part is greater than or equal to the size of the collector grid line. Specifically, the interconnecting part is mainly used to conduct current outward, and the current passing through it is large, so its size is large, which is conducive to the passage of current. The interconnecting part here can be a welding pad, etc., which is not specifically limited. The plurality of interconnecting parts include: an edge interconnecting part adjacent to the edge 11 of the first battery.

[0167] The electrode structure further includes: an edge busbar extending along the second direction q and located between the first battery edge 11 and the edge interconnection portion, the edge busbar being used to collect carriers or current and conduct them to the interconnection portion. Along the first direction p, the size of the interconnection portion is greater than or equal to the size of the edge busbar. Specifically, the interconnection portion is mainly used to conduct current outward, and the current passing through it is relatively large, so its size is relatively large, which is conducive to the passage of current. Figure 2 , the first interconnection portion 15 in the edge interconnection portion is electrically connected to the N-type edge busbar line, referring to Figure 3 , the second interconnection 16 in the edge interconnection is electrically connected to the P-type edge busbar line. It should be noted that the back contact solar cell can be a busbar-free back contact solar cell, or can be a busbar-equipped contact solar cell, which is not specifically limited. In a busbar-free back contact solar cell, the edge busbar lines can be intermittently distributed.

[0168] The electrode structure further includes: a connecting electrode extending along the first direction p and electrically connecting the edge interconnection portion and the edge busbar line. Figure 2 The electrode structure further includes: a first connecting electrode 8 extending along the first direction p and electrically connecting the first interconnection portion 15 and the N-type edge busbar line, referring to Figure 3 The electrode structure further includes: a second connection electrode 14 extending along the first direction p and electrically connecting the second interconnection portion 16 and the P-type edge bus gate line.

[0169] Reference Figure 3 The N-type bending section has a first portion 61 extending along the first direction p, and the connecting electrode electrically connected to the second interconnection portion 16 in the edge interconnection portion is the second connecting electrode 14 here, and the length ratio with the first portion 61 is 2:1 to 5:1, which makes full use of the space, is conducive to the collection and transmission of carriers, and does not introduce the risk of short circuit. For example, the length ratio of the second connecting electrode 14 to the first portion 61 can be: 2:1, 2.2:1, 2.5:1, 2.71:1, 2.8:1, 3:1, 3.5:1, 4:1, 4.2:1, 4.6:1, 4.72:1, 5:1.

[0170] Optionally, the ratio of the length of the first portion 61 to the size of the second interconnection portion 16 in the edge interconnection portion in the first direction p is 1:1.6 to 1:2.6, which makes full use of the space, facilitates the collection and transmission of carriers, and does not introduce short circuit risks. For example, the ratio of the length of the first portion 61 to the size of the second interconnection portion 16 in the edge interconnection portion in the first direction p can be: 1:1.6, 1:1.7, 1:1.9, 1:2, 1:2.1, 1:2.3, 1:2.4, 1:2.5, 1:2.55, 1:2.6.

[0171] There is a second interval between the end of the P-type collector grid line and the edge of the first battery, and the size of the second interval in the first direction is Figure 3 In the figure, the distance between the left end of the P-type collector grid line marked 5 and the leftmost edge of the first battery, optionally, the length of the first portion 61 and the second interval between the left end of the P-type collector grid line marked 5 and the left first battery edge is 1:1.7 to 1:3.2, which makes full use of the space, facilitates the collection and transmission of carriers, and does not introduce short circuit risks. For example, the ratio of the length of the first portion 61 to the size of the second interval in the first direction can be: 1:1.7, 1:1.8, 1:1.9, 1:2, 1:2.3, 1:2.45, 1:2.5, 1:2.7, 1:2.95, 1:3, 1:3.2.

[0172] Reference Figure 2, the P-type bending section has a second portion 71 extending along the first direction p; the connecting electrode electrically connected to the first interconnection portion 15 in the edge interconnection portion is the first connecting electrode 8 here, and the ratio of the length of the second portion 71 is 1.2:1 to 2.7:1, which makes full use of the space, is conducive to the collection and transmission of carriers, and does not introduce the risk of short circuit. For example, the ratio of the length of the first connecting electrode 8 to the second portion 71 can be 1.2:1, 1.3:1, 1.4:1, 1.52:1, 1.6:1, 1.7:1, 1.8:1, 1.9:1, 2.1:1, 2.31:1, 2.45:1, 2.5:1, 2.6:1, 2.7:1.

[0173] There is a second interval between the end of the N-type collector grid line and the edge of the first battery, and the size of the second interval in the first direction is Figure 2 The distance between the left end of the N-type collector grid line marked 4 and the leftmost edge of the first battery is Figure 2 , the ratio of the length of the second portion 71 to the dimension of the second interval in the first direction is Figure 2 In the embodiment, the ratio of the length of the second portion 71 and the second interval between the left end point of the N-type collector grid line marked 4 and the leftmost edge of the first battery is 1:0.8 to 1:2.4, which makes full use of the space, is conducive to the collection and transmission of carriers, and does not introduce short circuit risks. For example, the ratio of the length of the second portion 71 and the size of the second interval in the first direction can be: 1.0.8, 1.1, 1:1.4, 1:1.5, 1:1.6, 1:1.7, 1:1.9, 1:2, 1:2.1, 1:2.3, 1:2.4.

[0174] Reference Figure 2 , the ratio of the length of the second portion 71 to the size of the first interconnection portion 15 in the edge interconnection portion in the first direction p is 1:1 to 1:1.4, which makes full use of the space, facilitates the collection and transmission of carriers, and does not introduce short circuit risks. For example, the ratio of the length of the second portion 71 to the size of the first interconnection portion 15 in the edge interconnection portion in the first direction p can be 1:1, 1:1.1, 1:1.15, 1:1.2, 1:1.22, 1:1.24, 1:1.3, 1:1.32, 1:1.35, 1:1.4.

[0175] Optional, see Figure 3The N-type bending section has a third portion 62 extending along the second direction, and the ratio of the length of the third portion 62 to the size of the second interconnection portion 16 in the edge interconnection portion in the second direction q is 1:1.1 to 1:2.3, which makes full use of the space, is conducive to the collection and transmission of carriers, and does not introduce short circuit risks. For example, the ratio of the length of the third portion 62 to the size of the second interconnection portion 16 in the edge interconnection portion in the second direction q can be 1:1.1, 1:1.17, 1:1.15, 1:1.2, 1:1.22, 1:1.44, 1:1.65, 1:1.72, 1:1.85, 1:1.99, 1:2, 1:2.15, 1:2.3.

[0176] Optional, see Figure 2 The P-type bending section has a fourth portion 72 extending along the second direction q, and the ratio of the length of the fourth portion 72 to the size of the first interconnection portion 15 in the edge interconnection portion in the second direction is 1:1.1 to 1:2.4, which makes full use of the space, is conducive to the collection and transmission of carriers, and does not introduce short circuit risks. For example, the ratio of the length of the fourth portion 72 to the size of the first interconnection portion 15 in the edge interconnection portion in the second direction can be 1:1.1, 1:1.17, 1:1.15, 1:1.2, 1:1.22, 1:1.44, 1:1.65, 1:1.72, 1:1.85, 1:1.99, 1:2, 1:2.15, 1:2.3, 1:2.4.

[0177] Optional, see Figures 2 to 6The N-type bending section has a first portion 61 extending along the first direction p and a third portion 62 extending along the second direction q, and the P-type bending section has a second portion 71 extending along the first direction p and a fourth portion 72 extending along the second direction q. The distance d7 between the first portion 61 and the connecting electrode electrically connected to the second interconnection portion 16 in the edge interconnection portion, that is, the second connecting electrode 14, is smaller than the distance d8 between the second portion 71 and the connecting electrode electrically connected to the first interconnection portion 15 in the edge interconnection portion, that is, the first connecting electrode 8, which makes full use of the space, is conducive to the collection and transmission of carriers, and is conducive to improving the open circuit voltage and short circuit current. There is no specific limitation on the specific sizes of d7 and d8. For example, the distance d7 between the first portion 61 and the second connecting electrode 14 can be 640um, 650um, 666um, 690um, 700um, 740um, 788um, 810um, 840um, 860um, 900um, 930um, 980um. For example, the distance d8 between the second portion 71 and the first connection electrode 8 may be 1100um, 1150um, 1200um, 1290um, 1300um, 1340um, 1388um, 1350um, 1400um, 1480um, 1500um, 1510um, 1580um, or 1600um.

[0178] Optional, see Figures 2 to 6 The N-type bending section has a third portion 62 extending along the second direction, and the distance d9 between the third portion 62 and the P-type edge busbar line 10 is less than or equal to the distance d10 between the fourth portion 72 and the N-type edge busbar line 9, which makes full use of the space, facilitates the collection and transmission of carriers, and improves the open circuit voltage and short circuit current. There is no specific limitation on the specific sizes of d9 and d10. For example, d9 can be 530um, 550um, 600um, 630um, 670um, 680um, 700um, 710um, 720um, 730um. For example, the distance d10 between the fourth portion 72 and the N-type edge bus gate line 9 may be 600um, 610um, 620um, 640um, 650um, 680um, 700um, 710um, 720um, 730um, 740um, 755um, 780um, or 800um.

[0179] Optional, see Figures 1 to 4 The electrode structure further includes: a lapped gate line extending along the second direction q and electrically connecting the first collector gate line and the edge interconnection portion.

[0180] Optional, see Figure 3The N-type bending section has a third portion 62 extending along the second direction q, and the ratio of the length of the overlapping gate line 17 electrically connected to the P-type collector gate line 5 to the third portion 62 is 1:1.1 to 1:2, which makes full use of the space, facilitates the collection and transmission of carriers, and does not introduce a short circuit risk. For example, the ratio of the length of the overlapping gate line 17 electrically connected to the P-type collector gate line 5 to the third portion 62 can be 1:1.1, 1:1.2, 1:1.3, 1:1.4, 1:1.5, 1:1.6, 1:1.7, 1:1.8, 1:1.9, 1:2.

[0181] Optional, see Figure 2 The P-type bending section has a fourth portion 72 extending along the second direction q, and the ratio of the length of the overlapping gate line 17 electrically connected to the N-type collector gate line 4 to the fourth portion 72 is 1:0.6 to 1:1.8, which makes full use of the space, facilitates the collection and transmission of carriers, and does not introduce a short circuit risk. For example, the ratio of the length of the overlapping gate line 17 electrically connected to the N-type collector gate line 4 to the fourth portion 72 can be 1:0.6, 1:0.72, 1:0.93, 1:1, 1:1.15, 1:1.26, 1:1.37, 1:1.48, 1:1.59, 1:1.8.

[0182] Reference Figure 1 , Figure 4 The bending section includes: an edge bending section adjacent to the edge of the second battery and a middle bending section located on the side of the edge bending section away from the edge of the second battery. The length of the edge bending section is greater than the length of the middle bending section, and the corresponding bending portion includes, that is, the area of ​​the edge bending portion is greater than the area of ​​the middle bending portion. Specifically, the battery edge may usually have more defects and therefore requires better passivation. Therefore, the area of ​​the edge bending portion is greater than the area of ​​the middle bending portion, providing a better passivation effect for the battery edge and avoiding the problem of blackening of the edge EL or PL.

[0183] Optionally, the length of an N-type bending section 6 is greater than or equal to the length of a P-type bending section 7, which can improve the passivation effect and avoid the problem of edge EL or PL becoming black. When the two are not equal, the difference between the two is not specifically limited.

[0184] Optionally, the first battery edge 11 includes: a first sub-battery edge A and a first sub-battery edge B, both of which have at least parallel portions, and both of which have at least portions parallel to the second direction q. Figure 1In the embodiment, the bending segments close to the edge A of the first sub-cell among all the bending segments include: at least two N-type bending segments and at least one P-type bending segment, the bending segments close to the edge B of the first sub-cell among all the bending segments include: at least two N-type bending segments and at least one P-type bending segment, the number of N-type bending segments close to the edge of the same first sub-cell is 2 to 30, and the number of P-type bending segments close to the edge of the same first sub-cell is 1 to 4. For example, Figure 1 In the embodiment, there can be 8 N-type bending segments close to the edge A of the first sub-battery among all the bending segments, 8 N-type bending segments close to the edge B of the first sub-battery among all the bending segments, 2 P-type bending segments close to the edge A of the first sub-battery among all the bending segments, and 2 P-type bending segments close to the edge B of the first sub-battery among all the bending segments. The numbers of N-type bending segments and P-type bending segments are relatively appropriate, which not only has a good passivation effect, but also is conducive to the separation and collection of carriers.

[0185] For example, the bending segments adjacent to the edge of the same first sub-cell among all the bending segments include: at least one P-type bending segment and at least two N-type bending segments, the number of N-type bending segments adjacent to the edge of the same first sub-cell can be 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, and the number of P-type bending segments adjacent to the edge of the same first sub-cell can be 1, 2, 3, 4.

[0186] Optional, Figure 1 Among all the bending segments, the bending segments close to the edge A of the first sub-battery include: at least two N-type bending segments 6 and at least one P-type bending segment 7, and the bending portions close to the edge B of the first sub-battery include: at least two N-type bending segments 6 and at least one P-type bending segment 7, the number of N-type bending segments 6 close to the edge of the same first sub-battery is 2 to 30, the number of P-type bending segments 7 close to the edge of the same first sub-battery is 1 to 4, and the N-type bending segments 6 are symmetrically arranged with respect to the diagonal line of the back of the battery body 1, and / or the P-type bending segments 7 are symmetrically arranged with respect to the diagonal line of the back of the battery body 1. That is, the bending segments close to the edge of another same first sub-battery among all the bending segments include: at least one P-type bending segment 7 and at least two N-type bending segments 6, and in the electrode structure, the N-type bending segments 6 and / or the P-type bending segments 7 are symmetrically arranged with respect to the diagonal line of the back of the battery body 1, which is conducive to uniform and effective collection of carriers.

[0187] Or, the bending sections of all bending sections adjacent to the edge A of the first sub-cell only include: N-type bending sections, the bending sections of all bending sections adjacent to the edge B of the first sub-cell only include: N-type bending sections, and the number of N-type bending sections adjacent to the same edge of the first sub-cell is 2 to 30. For example, there are 8 N-type bending sections adjacent to the edge A of the first sub-cell among all bending sections, and there are 8 N-type bending sections adjacent to the edge B of the first sub-cell among all bending sections. For example, there are 2 N-type bending sections adjacent to the edge A of the first sub-cell among all bending sections, and there are 2 N-type bending sections adjacent to the edge B of the first sub-cell among all bending sections, which not only has a good passivation effect, but also facilitates the separation and collection of carriers.

[0188] For example, the bending portions adjacent to the edge of the same first sub-cell in the bending segments only include N-type bending segments, and the number of N-type bending segments adjacent to the edge of the same first sub-cell can be 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, or 30.

[0189] Optional, see Figure 1 , the second battery edge 13 includes: a second sub-battery edge C and a second sub-battery edge D, both of which have at least parallel portions, and both of which have at least portions parallel to the first direction p. For example, Figure 1 Among all the bending segments, the bending segments close to the edge A of the first subcell include: at least two N-type bending segments and at least one P-type bending segment, the P-type bending segment is only arranged close to the second subcell edge C and / or the second subcell edge D, and the N-type bending segment is at least arranged close to the second subcell edge C and / or the second subcell edge D, and at least two N-type bending segments are arranged close to the second subcell edge C and / or the second subcell edge D, and both the N-type bending segment and the P-type bending segment are at least arranged close to the corner of the back contact solar cell. For example, Figure 1 In the embodiment, the P-type bending section is only arranged close to the second sub-cell edge C and the second sub-cell edge D, the N-type bending section is arranged close to the second sub-cell edge C and the second sub-cell edge D, and in addition to being arranged close to the second sub-cell edge C and the second sub-cell edge D, the N-type bending section is also arranged at a position between the second sub-cell edge C and the second sub-cell edge D, which can better passivate the defects at the corners of the back contact solar cell and further improve the passivation effect.

[0190] Or, the bending segments close to the first sub-cell edge A among all the bending segments only include: N-type bending segments, the bending segments close to the first sub-cell edge B among all the bending segments only include: N-type bending segments, and the N-type bending segments are at least arranged close to the second sub-cell edge C and / or the second sub-cell edge D. For example, there are 8 N-type bending segments close to the first sub-cell edge A among all the bending segments, there are 8 N-type bending segments close to the first sub-cell edge B among all the bending segments, the N-type bending segments are arranged close to the second sub-cell edge C and the second sub-cell edge D, and the N-type bending segments are also arranged at the position between the second sub-cell edge C and the second sub-cell edge D. For example, there are two N-type bending segments adjacent to the edge A of the first sub-battery among all the bending segments, there are two N-type bending segments adjacent to the edge B of the first sub-battery among all the bending segments, the N-type bending segments are arranged adjacent to the second sub-battery edge C and the second sub-battery edge D, and the N-type bending segments are also arranged between the second sub-battery edge C and the second sub-battery edge D, which not only has a good passivation effect, but also is conducive to the separation and collection of carriers.

[0191] Optional, see Figure 4 , the first battery edge includes: a first sub-battery edge A and a first sub-battery edge B, both of which have at least parallel parts. The first sub-battery edge A and the first sub-battery edge B here can refer to the above-mentioned related records. In order to avoid repetition, they are not repeated here. The bending section adjacent to the first sub-battery edge A is a P-type bending section 7, and the bending section adjacent to the first sub-battery edge B is an N-type bending section 6. The number of N-type bending sections adjacent to the same first sub-battery edge is 2 to 30, and the number of P-type bending sections adjacent to the same first sub-battery edge is 1 to 4. For example, Figure 4 In the embodiment, the number of N-type bending segments adjacent to the edge of the same first sub-cell can be 8, and the number of P-type bending segments adjacent to the edge of the same first sub-cell can be 2, which not only has a good passivation effect but also is conducive to the collection and conduction of carriers.

[0192] For example, the bending section adjacent to the edge A of the first sub-cell is a P-type bending section, and the bending section adjacent to the edge B of the first sub-cell is an N-type bending section. The number of N-type bending sections adjacent to the same edge of the first sub-cell can be 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, and the number of P-type bending sections adjacent to the same edge of the first sub-cell can be 1, 2, 3, 4.

[0193] Optionally, the bending section adjacent to the edge A of the first sub-battery is a P-type bending section, and the bending section adjacent to the edge B of the first sub-battery is an N-type bending section. The number of N-type bending sections adjacent to the same edge of the first sub-battery is 2 to 30, and the number of P-type bending sections adjacent to the same edge of the first sub-battery is 2 to 30. This not only has a good passivation effect, but also is beneficial to the collection and conduction of carriers. For example, the bending section adjacent to the edge A of the first sub-cell is a P-type bending section, and the bending section adjacent to the edge B of the first sub-cell is an N-type bending section. The number of N-type bending sections adjacent to the same edge of the first sub-cell can be 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, and the number of P-type bending sections adjacent to the same edge of the first sub-cell can be 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30.

[0194] Or, the first battery edge includes: a first sub-battery edge A and a first sub-battery edge B, both of which have at least parallel parts. The first sub-battery edge A and the first sub-battery edge B here can refer to the above-mentioned related records. In order to avoid repetition, they will not be repeated here. The bending section is only adjacent to the first sub-battery edge A or only adjacent to the first sub-battery edge B, and the bending section only has an N-type bending section 6, and the number of N-type bending sections is 2 to 30, or the number of N-type bending sections is 1 to 4. For example, the bending section is only adjacent to the first sub-battery edge A and the bending section only has an N-type bending section 6, and the number of N-type bending sections can be 8. For another example, the bending section is only adjacent to the first sub-battery edge A and the bending section only has an N-type bending section 6, and the number of N-type bending sections is 2, which not only has a good passivation effect, but also is conducive to the collection and conduction of carriers.

[0195] For example, the bending section is only arranged close to the edge A of the first sub-cell or only close to the edge B of the first sub-cell and the bending section only has N-type bending sections. The number of N-type bending sections close to the same first sub-cell edge can be 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, or the number of N-type bending sections close to the same first sub-cell edge can be 1, 2, 3, 4.

[0196] Optionally, the bending segment adjacent to the edge A of the first sub-cell and the bending segment adjacent to the edge B of the first sub-cell are both only N-type bending segments, and the number of N-type bending segments adjacent to the same first sub-cell edge is 2 to 30. That is to say, there are only N-type bending segments in the back-contact solar cell, and the N-type bending segments are arranged at the bending segment adjacent to the edge A of the first sub-cell and the position adjacent to the edge B of the first sub-cell, and the number of N-type bending segments adjacent to the same first sub-cell edge is 2 to 30. The N-type bending segments have a relatively symmetrical passivation effect on the first sub-cell edge A and the first sub-cell edge B.

[0197] For example, the bending segment adjacent to the edge A of the first sub-cell and the bending segment adjacent to the edge B of the first sub-cell are both only N-type bending segments, and the number of N-type bending segments adjacent to the same first sub-cell edge can be 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, or 30.

[0198] Optional, see Figure 1 , the second battery edge includes: a second sub-battery edge C and a second sub-battery edge D, both of which have at least parallel parts. Here, the aforementioned related records can be referred to. In order to avoid repetition, they will not be repeated here. The N-type bending segment 6 has a first part 61 extending along the first direction p and a third part 62 extending along the second direction q. Along the second direction q, the N-type bending segment 6 includes an edge N-type bending segment arranged adjacent to the second sub-battery edge C and / or the second sub-battery edge D, and an intermediate N-type bending segment located on the side of the edge N-type bending segment away from the second battery edge. The length of the first part 61 of the edge N-type bending segment is greater than the distance d5 between the third part of the edge N-type bending segment and the end of the adjacent P-type collector grid line 5 close to the first battery edge, and the length of the first part 61 of the intermediate N-type bending segment is less than the distance d5 between the third part of the intermediate N-type bending segment and the end of the adjacent P-type collector grid line 5 close to the first battery edge. Specifically, since edge carriers are not easy to collect, the length of the first part 61 of the edge N-type bending segment is longer, which is conducive to the collection of edge carriers.

[0199] Optionally, the N-type bending segment 6 is only arranged close to the second sub-battery edge C and / or the second sub-battery edge D, and the length of the first part 61 of the edge N-type bending segment 6 is greater than the distance d5 between the third part 62 of the edge N-type bending segment 6 and the end of the adjacent P-type collector grid line 5 close to the edge of the first battery. The length of the first part 61 of the edge N-type bending segment is longer, which is beneficial to the collection of edge carriers.

[0200] Optionally, the second battery edge includes: a second sub-battery edge C and a second sub-battery edge D, both of which have at least parallel parts. The aforementioned relevant parts can be referred to here. In order to avoid repetition, they will not be described here. The N-type bending segment 6 has a first part 61 extending along the first direction and a third part 62 extending along the second direction. The N-type bending segment 6 is at least arranged adjacent to the second sub-battery edge C and the second sub-battery edge D; the length of the first part 61 of the N-type bending segment 6 adjacent to the second sub-battery edge C is greater than the length of the first part 61 of the N-type bending segment 6 adjacent to the second sub-battery edge D. At the position adjacent to the second sub-battery edge D, the length of the first part 61 of the N-type bending segment 6 is slightly shorter, which reserves some space for the setting of certain structures and is as conducive to the collection of edge carriers as possible. And / or, the P-type bending segment 7 has a second part 71 extending along the first direction and a fourth part 72 extending along the second direction, the P-type bending segment 7 is arranged at least close to the second sub-cell edge C and the second sub-cell edge D, the length of the second part of the P-type bending segment 7 close to the second sub-cell edge C is greater than the length of the second part of the P-type bending segment close to the second sub-cell edge D, and at the position close to the second sub-cell edge D, the length of the second part 71 of the P-type bending segment 7 is slightly shorter, which reserves some space for the setting of certain structures and is as conducive to the collection of edge carriers as possible.

[0201] Optionally, the second battery edge includes: a second sub-battery edge C and a second sub-battery edge D, both of which have at least parallel portions. For reference, the above-mentioned related records may be referred to here. In order to avoid repetition, they are not described here. Figure 4 , the bending section adjacent to the edge A of the first sub-cell is a P-type bending section 7, and the bending section adjacent to the edge B of the first sub-cell is an N-type bending section 6, the P-type bending section 7 is only arranged adjacent to the second sub-cell edge C and the second sub-cell edge D, and the N-type bending section 6 is at least arranged adjacent to the second sub-cell edge C and the second sub-cell edge D, that is, the P-type bending section 7 is only arranged at the head and tail positions in the second direction, and the N-type bending section 6 is at least arranged at the head and tail positions in the second direction, and whether it is arranged at the middle position in the second direction is not limited. For example, Figure 1 In the figure, the P-type bending segment 7 is only arranged close to the second sub-cell edge C and the second sub-cell edge D, the N-type bending segment 6 is arranged close to the second sub-cell edge C and the second sub-cell edge D, and the N-type bending segment 6 is also arranged at positions other than the second sub-cell edge C and the second sub-cell edge D, which can further reduce the defects at the corner positions of the back-contact solar cell and further enhance the passivation effect of the back-contact solar cell.

[0202] Optionally, all the bending segments include only N-type bending segments 6, and the N-type bending segments 6 are arranged at least close to the second sub-cell edge C and / or the second sub-cell edge D, which can further reduce defects at the corner positions of the back-contact solar cell and further enhance the passivation effect of the back-contact solar cell.

[0203] Optional, see Figure 4 , the electrode structure also includes: a plurality of edge interconnections that are collinear in at least part of the second direction q and are adjacent to the edge of the first battery. The bending section adjacent to the edge A of the first sub-battery is a P-type bending section 7, and the bending section adjacent to the edge B of the first sub-battery is an N-type bending section 6. In the electrode structure, the number of P-type bending sections 7 is equal to the number of edge interconnections adjacent to the second sub-battery edge C and the second sub-battery edge D in the plurality of edge interconnections. The number of edge interconnections adjacent to the second sub-battery edge C and the second sub-battery edge D in the edge interconnections is two edge interconnections on a diagonal line of the battery body. Therefore, the number of P-type bending sections 7 is equal to 2, that is, the P-type bending section 7 is only provided near the edge interconnections at the two ends of the edge A of the first sub-battery, and only one P-type bending section 7 is provided near the edge interconnections at each of the two end positions. In this electrode structure, the number of N-type bending segments 6 is equal to twice the number of edge interconnections adjacent to the first sub-battery edge B among the several edge interconnections, that is, N-type bending segments 6 are arranged near each edge interconnection of the first sub-battery edge B, and two N-type bending segments 6 are arranged near each edge interconnection of the first sub-battery edge B. The passivation effect of the N-type collector doping area is better. The edge position defects of the battery body are usually more. If more N-type bending segments 6 are arranged at the edge of the battery body, the edge position defects of the battery body can be fully passivated, and the passivation effect is better.

[0204] Optionally, the bending segments only include N-type bending segments. In the electrode structure, the number of N-type bending segments is equal to twice the number of edge interconnections adjacent to an edge of a first sub-battery among the edge interconnections. That is to say, there are only N-type bending segments in the electrode structure, and the N-type bending segments are all arranged adjacent to an edge interconnection at an edge of a first sub-battery, and two N-type bending segments 6 are arranged near each edge interconnection at an edge of a first sub-battery. The passivation effect of the N-type collector doping region is better. The edge position defects of the battery body are usually more. If more N-type bending segments 6 are arranged at the edge of the battery body, the edge position defects of the battery body can be fully passivated, and the passivation effect is better.

[0205] Optionally, the bending segments only include N-type bending segments, and all N-type bending segments are only arranged adjacent to the first sub-battery edge A, the second sub-battery edge C and the second sub-battery edge D. In the electrode structure, the number of N-type bending segments is equal to the number of edge interconnections adjacent to the second sub-battery edge C and the second sub-battery edge D among the several edge interconnections. That is to say, there are only N-type bending segments in the electrode structure, and the N-type bending segments are all arranged adjacent to the two edge interconnections at the end of a first sub-battery edge A, and an N-type bending segment 6 is arranged near each edge interconnection of the two edge interconnections at the end of a first sub-battery edge. The passivation effect of the N-type collector doping region is better. The edge position defects of the battery body are usually more. The N-type bending segment 6 is arranged at the edge of the battery body, which can fully passivate the edge position defects of the battery body and has a better passivation effect.

[0206] Optionally, the N-type bending section is at least disposed adjacent to the second sub-cell edge C and / or the second sub-cell edge D. Figure 2 , Figure 3 , the electrode structure further includes: an edge interconnection portion disposed adjacent to the edge of the first battery and only adjacent to the edge C and / or the edge D of the second sub-battery, the electrode structure further includes: an edge busbar extending along the second direction q and located between the edge of the first battery and the edge interconnection portion, along the first direction p, the size of the interconnection portion is greater than or equal to the size of the edge busbar line, here you can refer to the above-mentioned related records, and can achieve the same or similar beneficial effects, in order to avoid repetition, no further description is given here. Figure 2 , Figure 3 , the electrode structure also includes: a connecting electrode extending along the first direction p and electrically connecting the edge interconnection portion and the edge bus bar line. The aforementioned related records can also be referred to here, and the same or similar beneficial effects can be achieved. In order to avoid repetition, they will not be described here.

[0207] Optional, see Figure 1 , Figure 4 The electrode structure also includes: a plurality of edge interconnections that are collinear in at least some areas in the second direction q and are close to the edge of the first battery. The edge interconnections here can refer to the aforementioned related records. In order to avoid repetition, they will not be repeated here. The N-type bending segments and / or P-type bending segments in the battery body are arranged in pairs, and the paired N-type bending segments and / or P-type bending segments are located on both sides of the center line of the edge interconnection in the first direction p, so that the passivation effect is improved more symmetrically and the pattern of the electrode structure is more beautiful.

[0208] The present invention also provides a photovoltaic module, which includes: a plurality of any of the aforementioned back-contact solar cells. The photovoltaic module may also include packaging films located on both sides of the back-contact solar cells, etc., which are not specifically limited.

[0209] The photovoltaic module also includes: a conductive interconnect extending along the aforementioned second direction q and electrically connected to the back-contact solar cell. More specifically, the conductive interconnect can be electrically connected to the interconnection portion in the back-contact solar cell. The conductive interconnect mentioned in the entire application can be used to connect adjacent back-contact solar cells in series in the second direction q.

[0210] It should be noted that the related parts of the back-contact solar cells and photovoltaic modules of the present application can be referenced to each other, and in order to avoid repetition, the related parts are briefly described.

[0211] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0212] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation modes, which are merely illustrative rather than restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the present invention and the claims, all of which are within the protection of the present invention.

Claims

1. A back contact solar cell, characterized in that: include: The battery body comprises: A plurality of collector doping regions extending along a first direction and spaced apart along a second direction; the first direction is different from the second direction; The battery body comprises: two first battery edges and a second battery edge located between the two first battery edges, wherein the second battery edge is parallel to the first direction; Among the plurality of collector doping regions, a first interval is provided between an end of a first collector doping region and an edge of a first battery, and a second collector doping region adjacent to the first collector doping region has a bending portion extending into the first interval at an end close to the edge of the first battery; the first collector doping region and the second collector doping region have opposite conductivity types; The plurality of collector doping regions are divided into N-type collector doping regions and P-type collector doping regions; In the battery body, at least two P-type collector doping regions and at least one N-type collector doping region are first collector doping regions, the bent portion is a P-type bent portion and an N-type bent portion, and in the battery body, the number of the N-type bent portions is greater than the number of the P-type bent portions; Or, the first collector doping region is only a P-type collector doping region, and the bending portion in the battery body only includes an N-type bending portion; The battery body also includes: An edge bus doping region extending along the second direction and adjacent to an edge of the first cell; A connection doping region extending along the first direction and intersecting the edge collector doping region; the connection doping region and the first collector doping region are spaced apart from each other; The area of ​​the inner region enclosed by the first collector doping region and the first extension region intersecting the edge bus doping region after extension, the edge bus doping region, the connection doping region adjacent to the first collector doping region, and the second extension region extending along the second direction and intersecting the first collector doping region is S; The first collector doping region is a P-type collector doping region, S≥1.3mm 2 ; and / or, the first collector doping region is an N-type collector doping region, S≥1.6mm 2 .

2. The back contact solar cell according to claim 1, characterized in that: The total area of ​​the N-type bending portion is greater than the total area of ​​the P-type bending portion; and / or, The number of the N-type bending portions is greater than the number of the P-type bending portions, and the ratio of the number of the N-type bending portions to the number of the P-type bending portions is 3:1 to 11:1; and / or, When the number of the N-type bending portions is greater than the number of the P-type bending portions, the area of ​​at least one N-type bending portion is less than or equal to the area of ​​at least one P-type bending portion.

3. The back contact solar cell according to claim 1, characterized in that: The N-type bending portion has a portion extending along the first direction, and the P-type bending portion has a portion extending along the first direction; The battery body further comprises: an N-type silicon substrate, the plurality of current collector doping regions are located inside the N-type silicon substrate, and / or the plurality of current collector doping regions are located on the N-type silicon substrate; The width of a portion of the N-type bending portion extending along the first direction is less than or equal to the width of a portion of the P-type bending portion extending along the first direction, and the width direction is the second direction.

4. The back contact solar cell according to claim 1, characterized in that: It is characterized in that The bending portion includes: an edge bending portion adjacent to the edge of the second battery and a middle bending portion located on a side of the edge bending portion away from the edge of the second battery; The area of ​​the edge bending portion is greater than the area of ​​the middle bending portion.

5. The back-contact solar cell according to any one of claims 1 to 4, characterized in that: The first collector doping region is a P-type collector doping region, and the area of ​​the N-type bending portion is 25% to 39% of S; and / or, the first collector doping region is an N-type collector doping region, and the area of ​​the P-type bending portion is 22% to 41% of S; and / or, the first collector doping region is an N-type collector doping region, and the area of ​​the inner region enclosed by the first collector doping region is S1, the first collector doping region is a P-type collector doping region, and the area of ​​the inner region enclosed by the first collector doping region is S2, and S1 is greater than S2.

6. A back contact solar cell, characterized in that: include: A battery body and an electrode structure located on the back side of the battery body; The electrode structure comprises: A plurality of collector grid lines extending along a first direction and spaced apart along a second direction; the first direction is different from the second direction; The battery body comprises: two first battery edges and a second battery edge located between the two first battery edges, wherein the second battery edge is parallel to the first direction; Among the plurality of collector grid lines, a second interval is provided between the end of a first collector grid line and the edge of the first battery, a second collector grid line adjacent to the first collector grid line has a bending section extending into the second interval at the end close to the edge of the first battery, and the polarities of the first collector grid line and the second collector grid line are opposite; the plurality of collector grid lines are divided into N-type collector grid lines and P-type collector grid lines; In the electrode structure, at least two P-type collector grid lines and at least one N-type collector grid line are first collector grid lines, the bending segments are divided into P-type bending segments and N-type bending segments, and in the electrode structure, the number of the N-type bending segments is greater than the number of the P-type bending segments; Or, the first collector grid line is only a P-type collector grid line, and the bending section in the battery body only includes an N-type bending section; The battery body also includes: An edge bus doping region extending along the second direction and adjacent to an edge of the first cell; A connection doping region extending along the first direction and intersecting the edge collector doping region; the connection doping region and the first collector doping region are spaced apart from each other; The area of ​​the inner region enclosed by the first collector doping region and the first extension region intersecting the edge bus doping region after extension, the edge bus doping region, the connection doping region adjacent to the first collector doping region, and the second extension region extending along the second direction and intersecting the first collector doping region is S; The first collector doping region is a P-type collector doping region, S≥1.3mm 2 ; and / or, the first collector doping region is an N-type collector doping region, S≥1.6mm 2 .

7. The back contact solar cell according to claim 6, characterized in that: The total length of the N-type bending section is greater than the total length of the P-type bending section; and / or, The number of the N-type bending segments is greater than the number of the P-type bending segments, and the ratio of the number of the N-type bending segments to the number of the P-type bending segments is 3:1 to 11:

1.

8. The back contact solar cell according to claim 6, characterized in that: The N-type bending segment has a first portion extending along a first direction; the distance between the first portion and the adjacent P-type collector grid line is 1 / 3 to 2 / 3 of the distance between adjacent P-type collector grid lines; and / or, The P-type bending segment has a second portion extending along the first direction; the distance between the second portion and the adjacent N-type collector grid line is 1 / 3 to 2 / 3 of the distance between adjacent N-type collector grid lines; and / or, The N-type bending segment has a third portion extending along the second direction; the distance between the third portion and the end of the adjacent P-type collector grid line close to the edge of the first battery is 1 / 4 to 3 / 4 of the second interval; and / or, The P-type bending segment has a fourth portion extending along the second direction; the distance between the fourth portion and the end of the adjacent N-type collector grid line close to the edge of the first battery is 1 / 4 to 3 / 4 of the second interval.

9. The back contact solar cell according to claim 8, characterized in that: The distance between the second portion and the adjacent N-type collector grid line is greater than the distance between the first portion and the adjacent P-type collector grid line, and / or the distance between the third portion and the end of the adjacent P-type collector grid line close to the edge of the first battery is equal to the distance between the fourth portion and the end of the adjacent N-type collector grid line close to the edge of the first battery.

10. The back contact solar cell according to claim 6, characterized in that: The N-shaped bending section has a first portion extending along a first direction and a third portion extending along a second direction, and the length of the first portion is less than or equal to the length of the third portion.

11. The back contact solar cell according to claim 6, characterized in that: The N-type bending section has a first portion extending along the first direction and a third portion extending along the second direction; the length of the first portion is greater than the distance between the third portion and the end of the adjacent P-type collector grid line close to the edge of the first battery, and the length of the third portion is equal to the distance between adjacent like-type collector grid lines; and / or, The P-type bending section has a second portion extending along the first direction and a fourth portion extending along the second direction; the length of the second portion is greater than the distance between the fourth portion and the end of the adjacent N-type collector grid line close to the edge of the first battery.

12. The back contact solar cell according to claim 6, characterized in that: The electrode structure further comprises: A plurality of interconnecting parts having at least partial areas collinear in the second direction; the plurality of interconnecting parts include: first interconnecting parts and second interconnecting parts arranged alternately and at intervals along the first direction; the plurality of interconnecting parts include: an edge interconnecting part adjacent to an edge of the first battery; An edge busbar extending along the second direction and located between the edge of the first battery and the edge interconnection portion; a first interconnection portion in the edge interconnection portion is electrically connected to the N-type edge busbar, and a second interconnection portion in the edge interconnection portion is electrically connected to the P-type edge busbar; A connection electrode extending along a first direction and electrically connecting the edge interconnection portion and the edge bus grid line; The N-type bending section has a first portion extending along a first direction; a length ratio of a connecting electrode electrically connected to a second interconnection portion in the edge interconnection portion to the first portion is 2:1 to 5:1; and / or, The ratio of the length of the first portion to the dimension of the second interconnection portion in the edge interconnection portion in the first direction is 1:1.6 to 1:2.6; and / or, The ratio of the length of the first portion to the dimension of the second interval in the first direction is 1:1.7 to 1:3.2; and / or, The P-type bending section has a second portion extending along the first direction; the ratio of the length of the connecting electrode electrically connected to the first interconnection portion in the edge interconnection portion to the second portion is 1.2:1 to 2.7:1; and / or, The ratio of the length of the second portion to the dimension of the second interval in the first direction is 1:0.8 to 1:2.4; and / or, The ratio of the length of the second portion to the dimension of the first interconnection portion in the edge interconnection portion in the first direction is 1:1 to 1:1.4; and / or, The N-shaped bending section has a third portion extending along the second direction; the ratio of the length of the third portion to the size of the second interconnection portion in the edge interconnection portion in the second direction is 1:1.1 to 1:2.3; and / or, The P-shaped bending section has a fourth portion extending along the second direction; the ratio of the length of the fourth portion to the size of the first interconnection portion in the edge interconnection portion in the second direction is 1:1.1 to 1:2.

4.

13. The back contact solar cell according to claim 12, characterized in that: The N-type bending section has a first portion extending along the first direction and a third portion extending along the second direction; the P-type bending section has a second portion extending along the first direction and a fourth portion extending along the second direction; The distance between the first portion and the connection electrode electrically connected to the second interconnection portion in the edge interconnection portion is smaller than the distance between the second portion and the connection electrode electrically connected to the first interconnection portion in the edge interconnection portion; The distance between the third portion and the P-type edge bus gate line is less than or equal to the distance between the fourth portion and the N-type edge bus gate line.

14. The back contact solar cell according to claim 12, characterized in that: The electrode structure further includes: a lapped gate line extending along the second direction and electrically connecting the first collector gate line and the edge interconnection portion; The N-type bending section has a third portion extending along the second direction; the ratio of the length of the overlapping gate line electrically connected to the P-type collector gate line to the third portion is 1:1.1 to 1:2; and / or, The P-type bending section has a fourth portion extending along the second direction; the ratio of the length of the overlapping grid line electrically connected to the N-type collector grid line to the fourth portion is 1:0.6 to 1:1.

8.

15. The back-contact solar cell according to any one of claims 6 to 14, characterized in that: The bending section includes: an edge bending section adjacent to the edge of the second battery and a middle bending section located on a side of the edge bending section away from the edge of the second battery; The length of the edge bending section is greater than the length of the middle bending section.

16. The back-contact solar cell according to any one of claims 6 to 14, characterized in that: The length of an N-type bending section is greater than or equal to the length of a P-type bending section.

17. The back contact solar cell according to claim 6, characterized in that: The first cell edge includes: a first sub-cell edge A and a first sub-cell edge B, both of which have at least parallel portions; The bending segments adjacent to the edge of the same first sub-cell among all the bending segments include: at least one P-type bending segment and at least two N-type bending segments, the number of N-type bending segments adjacent to the edge of the same first sub-cell is 2 to 30, and the number of P-type bending segments adjacent to the edge of the same first sub-cell is 1 to 4; or, the bending segments adjacent to the edge of the same first sub-cell among all the bending segments include only N-type bending segments, and the number of N-type bending segments adjacent to the edge of the same first sub-cell is 2 to 30.

18. The back contact solar cell according to claim 17, characterized in that: The bending segments adjacent to the edge of another same first sub-battery among all the bending segments include: at least one P-type bending segment and at least two N-type bending segments, and the N-type bending segments and / or the P-type bending segments are symmetrically arranged about the diagonal line of the back side of the battery body.

19. The back contact solar cell according to claim 17 or 18, characterized in that: The second battery edge includes: a second sub-battery edge C and a second sub-battery edge D, both of which have at least parallel portions; The bending segments in close proximity to the same first sub-cell edge among all the bending segments include: at least one P-type bending segment and at least two N-type bending segments, the P-type bending segment is only arranged close to the second sub-cell edge C and / or the second sub-cell edge D, and the N-type bending segment is at least arranged close to the second sub-cell edge C and / or the second sub-cell edge D, or, The bending segments that are adjacent to the same first sub-cell edge among all the bending segments only include N-type bending segments, and the N-type bending segments are arranged at least adjacent to the second sub-cell edge C and / or the second sub-cell edge D.

20. The back contact solar cell according to claim 6, characterized in that: The first cell edge includes: a first sub-cell edge A and a first sub-cell edge B, both of which have at least parallel portions; The bending section adjacent to the edge A of the first sub-cell is a P-type bending section, and the bending section adjacent to the edge B of the first sub-cell is an N-type bending section, the number of N-type bending sections adjacent to the same first sub-cell edge is 2 to 30, and the number of P-type bending sections adjacent to the same first sub-cell edge is 1 to 4; or, The bending section adjacent to the edge A of the first sub-cell is a P-type bending section, and the bending section adjacent to the edge B of the first sub-cell is an N-type bending section, the number of N-type bending sections adjacent to the same first sub-cell edge is 2 to 30, and the number of P-type bending sections adjacent to the same first sub-cell edge is 2 to 30; or, The bending section is only arranged adjacent to the edge A of the first sub-cell or adjacent to the edge B of the first sub-cell, and the bending section only has N-type bending sections, and the number of N-type bending sections adjacent to the same first sub-cell edge is 2 to 30 or the number of N-type bending sections is 1 to 4; or, The bending section adjacent to the edge A of the first sub-cell and the bending section adjacent to the edge B of the first sub-cell are both N-type bending sections only. The number of N-type bending sections adjacent to the same edge of the first sub-cell is 2 to 30.

21. The back contact solar cell according to claim 20, characterized in that: The second battery edge includes: a second sub-battery edge C and a second sub-battery edge D, both of which have at least parallel portions; The N-shaped bending section has a first portion extending along a first direction and a third portion extending along a second direction; Along the second direction, the N-type bending segment includes an edge N-type bending segment arranged adjacent to the second sub-battery edge C and / or the second sub-battery edge D, and an intermediate N-type bending segment located on the side of the edge N-type bending segment away from the second battery edge, the length of the first part of the edge N-type bending segment is greater than the distance between the third part and the end of the adjacent P-type collector grid line close to the first battery edge, and the length of the first part of the intermediate N-type bending segment is less than the distance between the third part and the end of the adjacent P-type collector grid line close to the first battery edge; or, The N-type bending section is only arranged adjacent to the second sub-cell edge C and / or the second sub-cell edge D, and the length of the first part of the edge N-type bending section is greater than the distance between the third part and the end of the adjacent P-type collector grid line close to the first battery edge.

22. The back contact solar cell according to claim 20, characterized in that: The second battery edge includes: a second sub-battery edge C and a second sub-battery edge D, both of which have at least parallel portions; The N-type bending segment has a first portion extending along the first direction and a third portion extending along the second direction; the N-type bending segment is at least adjacent to the second sub-cell edge C and the second sub-cell edge D; the length of the first portion of the N-type bending segment adjacent to the second sub-cell edge C is greater than the length of the first portion of the N-type bending segment adjacent to the second sub-cell edge D; and / or, the P-type bending segment has a second portion extending along the first direction and a fourth portion extending along the second direction, the P-type bending segment is at least adjacent to the second sub-cell edge C and the second sub-cell edge D, and the length of the second portion of the P-type bending segment adjacent to the second sub-cell edge C is greater than the length of the second portion of the P-type bending segment adjacent to the second sub-cell edge D.

23. The back contact solar cell according to claim 20, characterized in that: The second battery edge includes: a second sub-battery edge C and a second sub-battery edge D, both of which have at least parallel portions; The bending section adjacent to the edge A of the first sub-cell is a P-type bending section, and the bending section adjacent to the edge B of the first sub-cell is an N-type bending section, the P-type bending section is only arranged adjacent to the second sub-cell edge C and the second sub-cell edge D, and the N-type bending section is at least arranged adjacent to the second sub-cell edge C and the second sub-cell edge D; or, All the bending segments only include N-type bending segments, and the N-type bending segments are arranged at least adjacent to the edge C of the second sub-cell and / or the edge D of the second sub-cell.

24. The back contact solar cell according to claim 23, characterized in that The electrode structure further comprises: a plurality of edge interconnecting portions having at least partial areas collinear in the second direction and adjacent to the edge of the first battery; The bending section adjacent to the edge A of the first sub-cell is a P-type bending section, and the bending section adjacent to the edge B of the first sub-cell is an N-type bending section. In the electrode structure, the number of P-type bending sections is equal to the number of edge interconnection sections adjacent to the edge C of the second sub-cell and the edge D of the second sub-cell. In the electrode structure, the number of N-type bending sections is equal to twice the number of edge interconnection sections adjacent to the edge B of the first sub-cell among the edge interconnection sections; or, All bending segments include only N-type bending segments, and in the electrode structure, the number of N-type bending segments is equal to twice the number of edge interconnection portions adjacent to a first sub-battery edge among the several edge interconnection portions; or, all bending segments include only N-type bending segments, and all N-type bending segments are arranged only adjacent to the first sub-battery edge A, the second sub-battery edge C, and the second sub-battery edge D, and in the electrode structure, the number of N-type bending segments is equal to the number of edge interconnection portions adjacent to the second sub-battery edge C and the second sub-battery edge D among the several edge interconnection portions.

25. The back-contact solar cell according to any one of claims 17, 18, 20 to 24, characterized in that: The electrode structure further comprises: a plurality of edge interconnecting portions having at least partial areas collinear in the second direction and adjacent to the edge of the first battery; The N-type bending segments and / or P-type bending segments in the battery body are arranged in pairs, and the paired N-type bending segments and / or P-type bending segments are located on both sides of the center line of the edge interconnection portion in the first direction.

26. A photovoltaic module, characterized in that: include: A back-contact solar cell as claimed in any one of claims 1 to 25, and a conductive interconnection extending along the second direction and electrically connected to the back-contact solar cell.

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