CN215988781U

CN215988781U - Solar cell and photovoltaic module

Info

Publication number: CN215988781U
Application number: CN202121482548.6U
Authority: CN
Inventors: 赵德宝; 陈军; 李华; 刘继宇
Original assignee: Taizhou Longi Solar Technology Co Ltd
Current assignee: Taizhou Longi Solar Technology Co Ltd
Priority date: 2021-06-30
Filing date: 2021-06-30
Publication date: 2022-03-08
Anticipated expiration: 2031-06-30

Abstract

The utility model provides a solar cell and a photovoltaic module, which comprise: the backlight module comprises a semiconductor substrate, and a positive electrode, a negative electrode, a first insulating layer and a second insulating layer which are arranged on a backlight surface of the semiconductor substrate. In the utility model, the first insulating layer is arranged between the adjacent anode connecting points in the anode main grid electrode of the solar cell and covers the first end point of the cathode fine grid electrode close to the anode connecting grid line and a part containing the first end point, so that when the position of the welding strip deviates, the first insulating layer can avoid the contact between the welding strip and the cathode fine grid electrode, and similarly, the second insulating layer arranged between the adjacent cathode connecting points in the cathode main grid electrode can avoid the contact between the welding strip and the anode fine grid electrode, thereby ensuring that the welding strip can not generate short circuit under the condition of certain deviation, namely reducing the positioning precision and the operation requirement when the welding strip is welded, and further improving the yield of the finally prepared photovoltaic module.

Description

Solar cell and photovoltaic module

Technical Field

The utility model relates to the technical field of photovoltaics, in particular to a solar cell and a photovoltaic module.

Background

The back contact (IBC) solar cell is a solar cell in which the front surface of a cell does not have an electrode and both positive and negative electrodes are disposed on the back surface of the cell, so that the shielding of the electrode on the cell can be reduced, the short-circuit current of the cell can be increased, and the energy conversion efficiency of the cell can be improved.

In the existing back contact solar cell, the back of the cell may include a plurality of positive electrode main grid electrodes and negative electrode main grid electrodes distributed in an interdigital manner, and in the process of assembling a plurality of cells to obtain a photovoltaic module, two adjacent cells need to be connected by using a solder strip. For example, if a plurality of positive main grid electrodes and negative main grid electrodes which are distributed in an interdigital manner are arranged along the horizontal direction, a plurality of welding strips which are arranged along the vertical direction can be used for connecting adjacent battery pieces, specifically, insulating slurry which is distributed at equal intervals can be printed on the positive main grid electrodes and the negative main grid electrodes, the insulating slurry on the adjacent positive main grid electrodes and the insulating slurry on the negative main grid electrodes are arranged in a staggered manner, the insulating slurry on the positive main grid electrodes and the insulating slurry on the negative main grid electrodes are distributed in rows in the vertical direction, and therefore a plurality of welding strips can be welded along the insulating slurry which is distributed in rows in the vertical direction, so that a single welding strip is only connected with the plurality of positive main grid electrodes or the plurality of negative main grid electrodes, and the insulation between the positive main grid electrodes and the negative main grid electrodes is ensured.

However, in the prior art, the battery piece may further include a positive electrode fine grid electrode connected to the positive electrode main grid electrode and a negative electrode fine grid electrode connected to the negative electrode main grid electrode, and when the position of the welding strip is shifted, the welding strip connected to the positive electrode main grid electrode may contact the negative electrode fine grid electrode, or the welding strip connected to the negative electrode main grid electrode may contact the positive electrode fine grid electrode, thereby causing a short circuit. Therefore, for the back contact solar cell, the positioning accuracy and the operation requirement during welding of the solder strip are higher, so that the yield of the prepared photovoltaic module is lower.

SUMMERY OF THE UTILITY MODEL

The utility model provides a solar cell and a photovoltaic module, and aims to solve the problem that in the prior art, for a back contact solar cell, the positioning accuracy and the operation requirement during welding of a solder strip are higher, so that the yield of the prepared photovoltaic module is lower.

In a first aspect, an embodiment of the present invention provides a solar cell, where the solar cell includes:

the device comprises a semiconductor substrate, and a positive electrode, a negative electrode, a first insulating layer and a second insulating layer which are arranged on a backlight surface of the semiconductor substrate;

the positive electrode comprises a positive main grid electrode and a positive fine grid electrode, the negative electrode comprises a negative main grid electrode and a negative fine grid electrode, the positive main grid electrode and the negative main grid electrode are parallel to each other along a first direction and are arranged at intervals, and the positive main grid electrode comprises: a plurality of positive electrode connection points for connection with a conductive wire, and a positive electrode connection gate line connecting adjacent ones of the positive electrode connection points, the negative electrode main gate electrode comprising: the negative electrode connecting grid lines are used for connecting the negative electrode connecting points with the conducting wires;

the positive electrode fine grid electrode and the negative electrode fine grid electrode are parallel to each other along a second direction and are arranged at intervals, the positive electrode fine grid electrode is connected with the positive electrode main grid electrode and is separated from the negative electrode main grid electrode by a first preset distance, and the negative electrode fine grid electrode is connected with the negative electrode main grid electrode and is separated from the positive electrode main grid electrode by a second preset distance;

the first insulating layer is arranged between the adjacent positive electrode connecting points and covers a part of the positive electrode fine grid electrode between the adjacent positive electrode connecting points and a first end point of the negative electrode fine grid electrode close to the positive electrode connecting grid line, and the negative electrode fine grid electrode comprises a part of the first end point;

the second insulating layer is arranged between the adjacent negative electrode connecting points and covers a part of the negative electrode fine grid electrode between the adjacent negative electrode connecting points and a second end point, close to the negative electrode connecting grid line, of the positive electrode fine grid electrode, and the positive electrode fine grid electrode comprises a part of the second end point.

Optionally, the second insulating layer further covers a negative electrode connection gate line between adjacent negative electrode connection points, and a part of the negative electrode fine gate electrode connected to the negative electrode connection gate line.

Optionally, the first insulating layer comprises a first section and a second section;

the first sub portion and the second sub portion are arranged on two opposite sides of the positive electrode connecting grid line, a third preset distance is arranged between the first sub portion and the positive electrode connecting grid line, and a fourth preset distance is arranged between the second sub portion and the positive electrode connecting grid line.

Optionally, the third preset distance is equal to the fourth preset distance;

the third preset distance and the fourth preset distance are 0.01-0.5 mm.

Optionally, the first insulating layer is arranged in a rectangular structure, and a fifth preset distance is formed between the side edge of the first insulating layer close to the positive connection point and the positive connection point;

the fifth preset distance is 0.1-1.5 millimeters.

Optionally, the second insulating layer is arranged in a rectangular structure, and a sixth preset distance is formed between the side edge of the second insulating layer close to the negative electrode connection point and the negative electrode connection point;

the sixth preset distance is 0.5-2 mm.

Optionally, a ratio of the size of the positive electrode connection point to the size of the first insulating layer along the second direction is 1:1.1-1:2, and a ratio of the size of the negative electrode connection point to the size of the second insulating layer along the second direction is 1:1.1-1: 2.

Optionally, the positive electrode connection point includes a central portion, and an outer edge portion disposed outside the central portion.

Optionally, in a range of a seventh preset distance from the positive electrode main gate electrode, the sizes of the positive electrode fine gate electrode in the first direction and the third direction are gradually reduced along a direction away from the positive electrode main gate electrode;

in the range of an eighth preset distance from the negative main grid electrode, the sizes of the negative fine grid electrode in the first direction and the third direction are gradually reduced along the direction far away from the negative main grid electrode;

wherein the third direction is perpendicular to the first direction and the second direction.

In a second aspect, an embodiment of the present invention provides a photovoltaic module, including: a plurality of the above solar cells and a plurality of conductive wires;

one end of the conductive wire is connected with a plurality of positive connection points in the positive electrode of the solar cell, and the other end of the conductive wire is connected with a plurality of negative connection points in the negative electrode of the adjacent solar cell.

The embodiment of the utility model provides a solar cell and a photovoltaic module, which comprise: the semiconductor substrate, positive electrode and negative electrode arranged on the backlight surface of the semiconductor substrate, a first insulating layer and a second insulating layer; the positive electrode includes anodal main grid electrode and anodal thin grid electrode, and the negative electrode includes negative pole main grid electrode and negative pole thin grid electrode, and anodal main grid electrode and negative pole main grid electrode are parallel to each other and the interval sets up along first direction, and anodal main grid electrode includes: a plurality of positive pole tie points for being connected with the conductor wire to and connect the positive pole connecting grid line of adjacent positive pole tie point, negative pole main grid electrode includes: a plurality of negative electrode connection points for connection with the conductive wires, and a negative electrode connection gate line connecting adjacent negative electrode connection points; the positive fine grid electrode and the negative fine grid electrode are parallel to each other and arranged at intervals along a second direction, the positive fine grid electrode is connected with the positive main grid electrode and is separated from the negative main grid electrode by a first preset distance, and the negative fine grid electrode is connected with the negative main grid electrode and is separated from the positive main grid electrode by a second preset distance; the first insulating layer is arranged between the adjacent positive electrode connecting points, covers a part of the positive electrode fine grid electrode between the adjacent positive electrode connecting points and a part of the negative electrode fine grid electrode, which is close to the first end point of the positive electrode connecting grid line, and comprises the first end point; the second insulating layer is arranged between the adjacent negative electrode connecting points and covers a part of the negative electrode fine grid electrode between the adjacent negative electrode connecting points and a part of the positive electrode fine grid electrode, which is close to the second end point of the negative electrode connecting grid line and comprises the second end point. In the utility model, the first insulating layer is arranged between the adjacent positive electrode connecting points in the positive electrode main grid electrode in the solar cell, and the first insulating layer covers the first end point of the negative electrode fine grid electrode close to the positive electrode connecting grid line and a part containing the first end point, so that when the position of the welding strip deviates, the first insulating layer can avoid the contact between the welding strip and the negative electrode fine grid electrode, and similarly, the second insulating layer arranged between the adjacent negative electrode connecting points in the negative electrode main grid electrode can avoid the contact between the welding strip and the positive electrode fine grid electrode, thereby ensuring that the welding strip can not generate short circuit under the condition of certain deviation, namely, the positioning precision and the operation requirement during welding of the welding strip can be reduced, and the yield of the finally prepared photovoltaic module is improved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the description of the embodiments of the present invention will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to these drawings without inventive labor.

Fig. 1 shows a schematic structural diagram of an IBC solar cell in an embodiment of the present invention;

FIG. 2 shows a schematic structural diagram of a solar cell in an embodiment of the utility model;

FIG. 3 is a schematic view of a partial structure of a solar cell according to an embodiment of the present invention;

FIG. 4 shows a schematic cross-sectional view of a solar cell in an embodiment of the utility model;

FIG. 5 shows a schematic structural diagram of a photovoltaic module in an embodiment of the utility model;

fig. 6 shows a schematic structural diagram of a photovoltaic module external module in an embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The IBC solar cell is one of the technical directions for realizing a high-efficiency crystalline silicon cell at present, and means that the front side of a cell does not have electrodes, and positive and negative electrodes are arranged on the back side of the cell, so that the shielding of the electrodes on the cell can be reduced, the short-circuit current of the cell is increased, and the energy conversion efficiency of the cell is improved.

Referring to fig. 1, fig. 1 shows a schematic structural diagram of an IBC solar cell in an embodiment of the present invention, which includes a semiconductor substrate 10, and a positive electrode 20 and a negative electrode 30 disposed on a backlight surface of the semiconductor substrate 10, where the positive electrode 20 may further include a positive main gate electrode 21 and a positive fine gate electrode 22, the negative electrode 30 may further include a negative main gate electrode 31 and a negative fine gate electrode 32, the positive main gate electrode 21 and the negative main gate electrode 31 are disposed in parallel and spaced with each other along a first direction a, and the positive fine gate electrode 22 and the negative fine gate electrode 32 are disposed in parallel and spaced with each other along a second direction B, that is, the positive fine gate electrode 22 and the negative fine gate electrode 32 are disposed in an interdigitated manner, and the first direction a and the second direction B are not parallel to each other.

Meanwhile, the positive fine gate electrodes 22 are distributed on the surface of the semiconductor substrate 10 and used for collecting the positive charge carriers generated on the surface of the semiconductor substrate 10 and transmitting and converging the collected positive charge carriers to the positive main gate electrode 21, that is, currents are formed and converged in the positive fine gate electrodes 22 and the positive main gate electrode 21; the negative fine grid electrode 32 is distributed on the surface of the semiconductor substrate 10, and is used for collecting negative charge carriers generated on the surface of the semiconductor substrate 10, and transmitting and collecting the collected negative charge carriers to the negative main grid electrode 31, that is, current is formed and collected in the negative fine grid electrode 32 and the negative main grid electrode 31. Therefore, the positive fine grid electrode 22 is connected to the positive main grid electrode 21 and is separated from the negative main grid electrode 31 by a first preset distance, that is, one end C of the positive fine grid electrode 22 is connected to the positive main grid electrode 21, and the other end D (the second end point) is separated from the negative main grid electrode 31 by the first preset distance, so that the connection with the negative main grid electrode 31 is realized, and the short circuit is avoided; the negative fine grid electrode 32 is connected with the negative main grid electrode 31 and is spaced from the positive main grid electrode 21 by a second preset distance, that is, one end E of the negative fine grid electrode 32 is connected with the negative main grid electrode 31, and the other end F (first end point) is spaced from the positive main grid electrode 21 by the second preset distance, so that the negative fine grid electrode is disconnected from the positive main grid electrode 21, and short circuit is avoided.

The first preset distance and the second preset distance may be equal to or unequal to each other, and the first preset distance and the second preset distance may be a distance between the main gate electrode and the thin gate electrode with opposite polarity when no short circuit occurs.

Further, a plurality of IBC solar cells are interconnected to form a photovoltaic module, so that the current generated and concentrated in the plurality of solar cells is further collected to supply power to an external device.

Specifically, the IBC solar cells are interconnected mainly by means of solder ribbon bonding or conductive backplane connection.

When the conductive backboard and the conductive adhesive are used for realizing conductive interconnection of the IBC solar cell, the conductive backboard is formed by laminating a copper foil layer and a backboard layer which are subjected to patterning treatment, patterning processing of the copper foil is complex, used insulating materials also need to be customized independently, the use of the large-area copper foil layer and the complexity of the process enable the production cost of interconnection of the conductive backboard to be high, and therefore the photovoltaic module cannot be produced in large scale.

However, because the positive electrode 20 and the negative electrode 30 of the IBC solar cell are both disposed on the backlight surface of the cell, the positive electrode 20 includes the positive main grid electrode 21 and the positive fine grid electrode 22, the negative electrode 30 includes the negative main grid electrode 31 and the negative fine grid electrode 32, when the positive main grid electrode 21 or the negative main grid electrode 31 is connected by the solder strip, the solder strip is slightly shifted, which causes the solder strip to contact with the opposite fine grid electrode, thereby causing a short circuit, for example, when the positive main grid electrode 21 is connected by the solder strip, if the solder strip is shifted, the solder strip will contact with the negative fine grid electrode 32, thereby conducting the positive main grid electrode 21 and the negative fine grid electrode 32, because carriers with opposite polarities exist in the positive main grid electrode 21 and the negative fine grid electrode 32, thereby causing a short circuit. Therefore, when the photovoltaic module is formed by interconnecting the IBC solar cells by the solder strips, the positioning precision requirement and the operation requirement on the solder strip welding are high, so that the yield of the prepared photovoltaic module is low.

Referring to fig. 2, fig. 2 shows a schematic structural diagram of a solar cell in an embodiment of the present invention, the solar cell includes: the cathode structure includes a semiconductor substrate 10, a cathode electrode 20 and an anode electrode 30 disposed on a backlight side of the semiconductor substrate 10, and a first insulating layer 40 and a second insulating layer 50.

The positive electrode 20 may further include a positive main grid electrode 21 and a positive fine grid electrode 22, the negative electrode 30 may further include a negative main grid electrode 31 and a negative fine grid electrode 32, the positive main grid electrode 21 and the negative main grid electrode 31 are parallel to and spaced from each other along a first direction a, the positive fine grid electrode 22 and the negative fine grid electrode 32 are parallel to and spaced from each other along a second direction B, that is, the positive fine grid electrode 22 and the negative fine grid electrode 32 are arranged in an interdigitated manner, and the first direction a is perpendicular to the second direction B.

In addition, the positive main gate electrode 21 in the solar cell may include: a plurality of positive electrode connection points 211 for connection with conductive lines, and a positive electrode connection gate line 212 connecting adjacent positive electrode connection points 211; the negative main gate electrode 31 may include: a plurality of negative electrode connection points 311 for connection with the conductive lines, and a negative electrode connection gate line 312 connecting adjacent negative electrode connection points 311. Correspondingly, one end C of the positive fine-gate electrode 22 is connected to the positive connection point 211 or the positive connection gate line 212, and the other end D (the second end point) is spaced from the negative connection point 311 or the negative connection gate line 312 by a first preset distance; one end E of the negative fine gate electrode 32 is connected to the negative connection point 311 or the negative connection gate line 312, and the other end F (first end) is spaced from the positive connection point 211 or the positive connection gate line 212 by a second predetermined distance.

Specifically, when the adjacent solar cells are connected by using the conductive wire (solder ribbon), the positive electrode connection point 211 and the negative electrode connection point 311 may be soldered as a solder ribbon with the solder ribbon extending along the positive electrode main grid electrode 21 and the negative electrode main grid electrode 31.

Further, the first insulating layer 40 is disposed at a position between the adjacent positive electrode connection points 211 and covers a portion of the positive electrode fine gate electrode 22 between the adjacent positive electrode connection points 211, and the first end point of the negative electrode fine gate electrode 32 close to the positive electrode connection gate line 212 and a portion including the first end point, that is, the first insulating layer 40 covers a portion of the negative electrode fine gate electrode 32 which is most adjacent to the positive electrode connection gate line 212, wherein the first end point is an end point F of the two end points E, F of the negative electrode fine gate electrode 32 which is close to the positive electrode connection gate line 212. Therefore, the first insulating layer 40 can play a role in isolating the negative electrode fine grid electrode 32 from the positive electrode main grid electrode 21, so that when a photovoltaic module is formed by interconnecting solar cells by using solder strips, even if the solder strips arranged at the positions corresponding to the positive electrode main grid electrode 21 and connected with the positive electrode connecting point 211 deviate to a certain extent, the solder strips are not in contact with the negative electrode fine grid electrode 32, and further the positive electrode main grid electrode 21 and the negative electrode fine grid electrode 32 are prevented from being conducted, that is, the first insulating layer 40 can prevent a short circuit from being formed between the positive electrode main grid electrode 21 and the negative electrode fine grid electrode 32, so that the positioning precision and the operation requirement during welding of the solder strips can be reduced, and the yield of the finally prepared photovoltaic module is improved.

Accordingly, the second insulating layer 50 is disposed at a position between the adjacent negative electrode connection points 311, and covers a portion of the negative electrode fine gate electrode 32 between the adjacent negative electrode connection points 311, and a second end of the positive electrode fine gate electrode 22 close to the negative electrode connection gate line 312 and a portion including the second end, that is, the second insulating layer 50 covers a portion of the positive electrode fine gate electrode 22 which is most adjacent to the negative electrode connection gate line 312, wherein the second end is an end D of the two end points C, D of the positive electrode fine gate electrode 22 which is close to the negative electrode connection gate line 312. Therefore, the second insulating layer 50 can play a role in isolating the positive electrode fine grid electrode 22 from the negative electrode main grid electrode 31, so that when a photovoltaic module is formed by interconnecting solar cells by using solder strips, even if the solder strips arranged at the positions corresponding to the negative electrode main grid electrode 31 and connected with the negative electrode connecting point 311 deviate to a certain extent, the solder strips cannot be in contact with the positive electrode fine grid electrode 22, and further the negative electrode main grid electrode 31 and the positive electrode fine grid electrode 22 are prevented from being conducted, namely, the second insulating layer 50 can prevent the negative electrode main grid electrode 31 and the positive electrode fine grid electrode 22 from being short-circuited, so that the positioning precision and the operation requirement during solder strip welding can be reduced, and the yield of the finally prepared photovoltaic module is improved.

In the embodiment of the present invention, the first insulating layer 40 is disposed between the adjacent positive electrode connection points 211, and the second insulating layer 50 is disposed between the adjacent negative electrode connection points 311, that is, the positions corresponding to the positive electrode connection points 211 and the negative electrode connection points 311 may not be provided with an insulating layer, because the positive electrode connection points 211 and the negative electrode connection points 311 are used as welding points to be welded to a welding strip, that is, the connection strength between the positive electrode connection points 211 and the negative electrode connection points 311 and the welding strip is high, and the welding strip at the positive electrode connection points 211 and the negative electrode connection points 311 is not prone to position shift, so that the welding strip is not prone to contact with a fine grid electrode with opposite polarity, thereby avoiding short circuit.

To sum up, in the embodiment of the present invention, the method includes: the semiconductor substrate, positive electrode and negative electrode arranged on the backlight surface of the semiconductor substrate, a first insulating layer and a second insulating layer; the positive electrode includes anodal main grid electrode and anodal thin grid electrode, and the negative electrode includes negative pole main grid electrode and negative pole thin grid electrode, and anodal main grid electrode and negative pole main grid electrode are parallel to each other and the interval sets up along first direction, and anodal main grid electrode includes: a plurality of positive pole tie points for being connected with the conductor wire to and connect the positive pole connecting grid line of adjacent positive pole tie point, negative pole main grid electrode includes: a plurality of negative electrode connection points for connection with the conductive wires, and a negative electrode connection gate line connecting adjacent negative electrode connection points; the positive fine grid electrode and the negative fine grid electrode are parallel to each other and arranged at intervals along a second direction, the positive fine grid electrode is connected with the positive main grid electrode and is separated from the negative main grid electrode by a first preset distance, the negative fine grid electrode is connected with the negative main grid electrode and is separated from the positive main grid electrode by a second preset distance, and the first direction is perpendicular to the second direction; the first insulating layer is arranged between the adjacent positive electrode connecting points, covers a part of the positive electrode fine grid electrode between the adjacent positive electrode connecting points and a part of the negative electrode fine grid electrode, which is close to the first end point of the positive electrode connecting grid line, and comprises the first end point; the second insulating layer is arranged between the adjacent negative electrode connecting points and covers a part of the negative electrode fine grid electrode between the adjacent negative electrode connecting points and a part of the positive electrode fine grid electrode, which is close to the second end point of the negative electrode connecting grid line and comprises the second end point. In the utility model, the first insulating layer is arranged between the adjacent positive electrode connecting points in the positive electrode main grid electrode in the solar cell, and the first insulating layer covers the first end point of the negative electrode fine grid electrode close to the positive electrode connecting grid line and a part containing the first end point, so that when the position of the welding strip deviates, the first insulating layer can avoid the contact between the welding strip and the negative electrode fine grid electrode, and similarly, the second insulating layer arranged between the adjacent negative electrode connecting points in the negative electrode main grid electrode can avoid the contact between the welding strip and the positive electrode fine grid electrode, thereby ensuring that the welding strip can not generate short circuit under the condition of certain deviation, namely, the positioning precision and the operation requirement during welding of the welding strip can be reduced, and the yield of the finally prepared photovoltaic module is improved.

Alternatively, referring to fig. 3, fig. 3 is a schematic partial structure diagram of a solar cell in an embodiment of the present invention, in which a size of the positive electrode connection point 211 along the second direction B is greater than a size of the positive electrode connection gate line 212 along the second direction B, and a size of the negative electrode connection point 311 along the second direction B is greater than a size of the negative electrode connection gate line 312 along the second direction B, so that the positive electrode connection point 211 and the negative electrode connection point 311 with larger sizes are used as a solder joint to be connected to a solder strip. The second insulating layer 50 disposed between the adjacent negative connection points 311 may further cover the negative connection gate line 312 between the adjacent negative connection points 311 and a portion of the negative fine gate electrode 32 connected to the negative connection gate line 312, so that the structure of the second insulating layer 50 disposed between the adjacent negative connection points 311 is an integrated structure, which is beneficial to the process preparation of the second insulating layer 50.

In the embodiment of the present invention, the negative electrode connection point 311, the negative electrode connection gate line 312, and the negative electrode fine gate electrode 32 may all be silver electrodes prepared from silver paste, when a solder strip is used to connect adjacent solar cells, the negative electrode connection point 311 is used as a solder point to be soldered to the solder strip, and the solder strip extends along the negative electrode main gate electrode 31, the second insulating layer 50 covering the negative electrode connection gate line 312 may prevent the solder strip from contacting the negative electrode connection gate line 312, so as to prevent the solder coating on the surface of the solder strip from dissolving and phagocytosing silver in the negative electrode connection gate line 312 to cause the negative electrode connection gate line 312 to be soldered to the solder strip, thereby ensuring reliability of the negative electrode connection gate line 312.

The first insulating layer 40 disposed between the adjacent positive electrode connection points 211 covers a portion of the positive electrode fine gate electrode 22 and a portion of the negative electrode fine gate electrode 32 (a portion closest to the positive electrode connection gate line 212) close to the first end point of the positive electrode connection gate line 212 and including the first end point, but may not cover the positive electrode connection gate line 212, that is, the first insulating layer 40 located at a position corresponding to the positive electrode main gate electrode 21 is a dispersed structure, so that the amount of insulating paste used for preparing the first insulating layer 40 can be reduced, and the cost can be reduced.

It should be noted that the positive electrode connecting grid line 212 and the positive electrode fine grid electrode 22 may both be aluminum electrodes prepared from aluminum paste, and since an aluminum oxide layer may be generated on the surface of the aluminum electrode and may not be welded to the solder strip, when the solder strip is used to connect adjacent solar cells, the positive electrode connecting point 211 is used as a solder strip to be welded to the solder strip, and the solder strip extends along the positive electrode main grid electrode 21, the positive electrode connecting grid line 212 may be in contact with the solder strip and may not be welded by the solder strip, and therefore the first insulating layer 40 may not be disposed on the positive electrode connecting grid line 212, so as to form a dispersed structure different from the integrated structure of the second insulating layer 50.

Alternatively, referring to fig. 3, the first insulating layer 40 may include a first subsection 41 and a second subsection 42, the first subsection 41 and the second subsection 42 are disposed at two opposite sides of the anode connecting grid line 212, that is, the first insulating layer 40 of the dispersed structure may be formed by two parts located at two opposite sides of the anode connecting grid line 212, and the first subsection 41 is spaced apart from the anode connecting grid line 212 by a third predetermined distance, and the second subsection 42 is spaced apart from the anode connecting grid line 212 by a fourth predetermined distance.

In the embodiment of the present invention, the first subsection 41 and the second subsection 42 may have the same or different shapes and areas, the third predetermined distance may be provided between the first subsection 41 and the positive electrode connecting grid line 212, and the fourth predetermined distance may be provided between the second subsection 42 and the positive electrode connecting grid line 212, and if the shapes and areas of the first subsection 41 and the second subsection 42 are the same, and the third predetermined distance is provided between the first subsection 41 and the positive electrode connecting grid line 212, and the fourth predetermined distance is provided between the second subsection 42 and the positive electrode connecting grid line 212, it is explained that the first subsection 41 and the second subsection 42 are symmetrically disposed at two opposite sides of the positive electrode connecting grid line 212.

The third preset distance and the fourth preset distance can be determined according to the offset distance of the solder strip, so that the solder strip is ensured not to be in contact with the fine grid electrode with opposite polarity under the condition of certain offset.

As can be seen from the above, the shapes and areas of the first insulating layer 40 and the second insulating layer 50, and the overlapping areas of the fine gate electrodes with the corresponding polarities may be the same or different.

For example, the first insulating layer 40 disposed between the adjacent positive electrode connection points 211 may cover the positive electrode connection gate line 212, so that the structure of the first insulating layer 40 disposed between the adjacent positive electrode connection points 211 is an integrated structure, while the second insulating layer 50 disposed between the adjacent negative electrode connection points 311 may also cover the negative electrode connection gate line 312, and the structure of the second insulating layer 50 disposed between the adjacent negative electrode connection points 311 is an integrated structure. In this case, the first insulating layer 40 and the second insulating layer 50 have the same shape and are all of an integrated structure.

Meanwhile, the first insulating layer 40 disposed between the adjacent positive electrode connection points 211 may not cover the positive electrode connection gate line 212, and the structure of the first insulating layer 40 disposed between the adjacent positive electrode connection points 211 may be a dispersed structure including the first subsections 41 and the second subsections 42. The second insulating layer 50 between the adjacent negative electrode connection points 311 covers the negative electrode connection grid line 312, and the structure of the second insulating layer 50 between the adjacent negative electrode connection points 311 is an integrated structure. At this time, the first insulating layer 40 and the second insulating layer 50 have different structures, the first insulating layer 40 has a dispersed structure, and the second insulating layer 50 has an integrated structure.

Optionally, the third preset distance may be equal to the fourth preset distance, and the third preset distance and the fourth preset distance are 0.01 to 0.5 mm. The arrangement can ensure that the first insulating layer 40 can cover the end part of the negative fine grid electrode 32, which is closest to the positive main grid electrode 21, and avoid the contact between the welding strip and the negative fine grid electrode 32 and the generation of short circuit. Preferably, the third and fourth preset distances may be 0.05-0.1 mm in consideration of process margin, prevention of short circuit, and manufacturing cost.

Alternatively, the first insulating layer 40 may be configured to have a rectangular structure, a dimension of the first insulating layer 40 along the first direction a configured to have a rectangular structure may be greater than a dimension along the second direction B, and a fifth preset distance may be provided between a side of the first insulating layer 40 close to the positive electrode connection point 211 and the positive electrode connection point 211, where the fifth preset distance may be 0.1-1.5 mm, so as to ensure that a distance between one end of the first insulating layer 40 close to the positive electrode connection point 211 and the positive electrode connection point 211 is within a proper range. The distance between one end of the first insulating layer 40 close to the positive electrode connection point 211 and the positive electrode connection point 211 is not too small, so that the situation that the insulating glue for preparing the first insulating layer 40 flows and extends to the positive electrode connection point 211 to influence the connection reliability between the positive electrode connection point 211 and the welding strip is avoided; meanwhile, the distance between one end of the first insulating layer 40 close to the positive connection point 211 and the positive connection point 211 is not too large, so that the negative fine grid line 32 is prevented from being arranged in the gap between the first insulating layer 40 and the positive connection point 211, and if the negative fine grid line 32 is arranged in the gap, the welding strip may contact with the negative fine grid line 32, so that short circuit occurs.

Optionally, the second insulating layer 50 may be configured to have a rectangular structure, a size of the second insulating layer 50 configured to have the rectangular structure along the first direction a may be greater than a size of the second direction B, and a sixth preset distance may be provided between a side of the second insulating layer 50 close to the negative electrode connection point 311 and the negative electrode connection point 311, where the sixth preset distance may be 0.5 to 2 millimeters, so as to ensure that a distance between one end of the second insulating layer 50 close to the negative electrode connection point 311 and the negative electrode connection point 311 is within a proper range. The distance between one end of the second insulating layer 50 close to the negative electrode connection point 311 and the negative electrode connection point 311 is not too small, so that the situation that the insulating glue for preparing the second insulating layer 50 flows and expands to the negative electrode connection point 311 to influence the connection reliability between the negative electrode connection point 311 and the welding strip is avoided; meanwhile, the distance between one end of the second insulating layer 50 close to the negative connection point 311 and the negative connection point 311 is not too large, so that the situation that the gap between the second insulating layer 50 and the negative connection point 311 has the positive fine grid line 22 is avoided, and because the second insulating layer 50 is not arranged in the gap, if the gap has the positive fine grid line 22, the solder strip may contact with the positive fine grid line 22, and a short circuit occurs.

In the embodiment of the present invention, the size of the first insulating layer 40 in the first direction a may be smaller than the size of the second insulating layer 50 in the first direction a. This is because the material characteristics of aluminum and silver make the line width (the dimension along the second direction B) and the height (the dimension along the third direction) of the positive fine gate line 22 prepared from aluminum relatively large, and the line width (the dimension along the second direction B) and the height (the dimension along the third direction) of the negative fine gate electrode 32 prepared from silver relatively small, so that the probability that the solder ribbon connected to the positive connection point 211 and the negative fine gate electrode 32 contact each other is low, and therefore, the dimension of the first insulating layer 40 in the first direction a can be set smaller than the dimension of the second insulating layer 50 in the first direction a, so that the dimension of the first insulating layer 40 can be reduced on the premise of ensuring the connection reliability, and the amount of the insulating paste is reduced to reduce the production cost.

Alternatively, the ratio of the dimension (width) of the positive electrode connection point 211 to the first insulating layer 40 in the second direction B in the solar cell is 1:1.1-1:2, and the ratio of the dimension (width) of the negative electrode connection point 311 to the second insulating layer 50 in the second direction B is 1:1.1-1: 2. Since the size (bandwidth) of the solder ribbon connecting the positive electrode connection point 211 or the negative electrode connection point 311 in the second direction B is generally smaller than the size of the positive electrode connection point 211 or the negative electrode connection point 311 in the second direction B, the ratio of the sizes of the positive electrode connection point 211 and the first insulating layer 40 in the second direction B and the ratio of the sizes of the negative electrode connection point 311 and the second insulating layer 50 in the second direction B are greater than 1:1.1, it is possible to ensure that the widths of the first insulating layer 40 and the second insulating layer 50 are greater than the bandwidth of the solder ribbon, thereby being able to ensure a certain process margin, so that even if some solder ribbons are arranged slightly obliquely, the contact between the solder ribbon and the fine-grid electrode of the opposite polarity can be prevented from generating a short circuit. Meanwhile, making the ratio of the sizes of the positive electrode connection point 211 and the first insulating layer 40 in the second direction B and the ratio of the sizes of the negative electrode connection point 311 and the second insulating layer 50 in the second direction B smaller than 1:2 can reduce the manufacturing cost by preventing the excessive use of the first insulating layer 40 and the second insulating layer 50.

In the case where the first insulating layer 40 includes the first subsection 41 and the second subsection 42, the dimension of the first insulating layer 40 in the second direction B is the sum of the dimensions of the first subsection 41 and the second subsection 42 in the second direction B.

Alternatively, referring to fig. 3, the positive connection point 211 may include a central portion 2111, and an outer edge portion 2112 disposed outside the central portion 2111.

In the embodiment of the present invention, the central portion 2111 of the positive electrode connection point 211 may be a silver electrode prepared from silver paste, and the outer edge portion 2112 may be an aluminum electrode prepared from aluminum paste, so that the amount of silver used can be reduced, and the cost can be saved.

Optionally, in a range of a seventh preset distance from the positive main grid electrode 21, the size (width) in the first direction a and the size (height) in the third direction may gradually decrease along a direction away from the positive main grid electrode 21, that is, the width and height of the end, close to the negative main grid electrode 31, of the positive fine grid electrode 22 are smaller, so that the possibility of contact between the solder strip corresponding to the negative main grid electrode 31 and the positive fine grid electrode 22 may be reduced.

Accordingly, the size (width) of the negative electrode fine grid electrode 32 in the first direction a and the size (height) of the negative electrode fine grid electrode 32 in the third direction may be gradually decreased in a direction away from the negative electrode main grid electrode 31 within an eighth preset distance from the negative electrode main grid electrode 31, that is, the width and height of the end of the negative electrode fine grid electrode 32 close to the positive electrode main grid electrode 21 are smaller, so that the possibility of contact between the solder strip corresponding to the positive electrode main grid electrode 21 and the negative electrode fine grid electrode 32 may be reduced.

The third direction is perpendicular to the first direction A and the second direction B, and the seventh preset distance and the eighth preset distance can be determined according to the offset distance of the solder strip, so that the solder strip is further ensured not to be in contact with the fine grid electrode with opposite polarity under the condition of certain offset.

Fig. 4 is a schematic cross-sectional view of a solar cell in an embodiment of the present invention, in which, as shown in fig. 4, a positive electrode 20 is disposed on an N-type diffusion region 60 in a backlight surface of a semiconductor substrate 10, and a negative electrode 30 is disposed on a P-type diffusion region 70 in the backlight surface of the semiconductor substrate 10. The light-facing surface of the semiconductor substrate 10 may be a textured structure obtained by texturing, and meanwhile, an antireflection layer 80 may be disposed on the light-facing surface of the semiconductor substrate 10 to increase the solar rays absorbed by the solar cell, thereby improving the efficiency of the solar cell.

The embodiment of the utility model also provides a photovoltaic module which comprises a plurality of solar cells and a plurality of conducting wires, wherein one end of each conducting wire is connected with a plurality of positive electrode connection points in a positive electrode of each solar cell, and the other end of each conducting wire is connected with a plurality of negative electrode connection points in a negative electrode of each adjacent solar cell, so that the solar cells are electrically connected with the adjacent solar cells, and the currents generated and gathered in the solar cells and the adjacent solar cells are further collected.

Fig. 5 shows a schematic structural diagram of a photovoltaic module according to an embodiment of the present invention, as shown in fig. 5, the photovoltaic module may include a first solar cell 91, a second solar cell 92, and a third solar cell 93, and a first conductive wire 101, a second conductive wire 102, and a third conductive wire 103, wherein each conductive wire may be a solder strip capable of being soldered.

Specifically, the first conductive line 101 extends in a first direction a of a backlight surface of the first solar cell 91, one end of the first conductive line extends out of the first solar cell 91 and is connected to a bus bar or other solar cells, and the other end of the first conductive line can be connected to a plurality of positive connection points 211 of the first solar cell 91 by using a conductive adhesive or by welding, and meanwhile, in order to prevent the first conductive line 101 from contacting the negative fine grid electrode 32 in the first solar cell 91, the first insulating layer 40 can be arranged, so that the first conductive line 101 is electrically insulated from the negative fine grid electrode 32 by the first insulating layer 40, and a short circuit is avoided; the second conductive wires 102 are extended in the first direction a of the backlight surfaces of the first solar cell 91 and the second solar cell 92, one end of each of the second conductive wires is connected to the plurality of negative electrode connection points 311 of the first solar cell 91, and the other end of each of the second conductive wires is connected to the plurality of positive electrode connection points 211 of the second solar cell 92, meanwhile, the second insulating layer 50 may be disposed in the first solar cell 91 so that the second conductive wires 102 are electrically insulated from the positive electrode fine grid electrodes 22 in the first solar cell 91 through the second insulating layer 50, and the first insulating layer 40 may be disposed in the second solar cell 92 so that the second conductive wires 102 are electrically insulated from the negative electrode fine grid electrodes 32 in the second solar cell 92 through the first insulating layer 40; the third conductive wire 103 extends in the first direction a of the backlight surfaces of the second solar cell 92 and the third solar cell 93, one end of the third conductive wire is connected to the plurality of negative electrode connection points 311 of the second solar cell 92, and the other end of the third conductive wire is connected to the plurality of positive electrode connection points 211 of the third solar cell 93, meanwhile, the second insulating layer 50 may be disposed in the second solar cell 92, so that the third conductive wire 103 is electrically insulated from the positive electrode fine gate electrode 22 in the second solar cell 92 by the second insulating layer 50, and the first insulating layer 40 may be disposed in the third solar cell 93, so that the third conductive wire 103 is electrically insulated from the negative electrode fine gate electrode 32 in the third solar cell 93 by the first insulating layer 40.

In the embodiment of the utility model, the cross section of the conductive wire can be in a circular or rectangular structure, and the width of the conductive wire with the rectangular cross section is larger than the thickness of the conductive wire, so that the connection reliability between the conductive wire and the solar cell can be improved. The line width of the conductive lines may be 0.5 to 2 mm, and the number of conductive lines respectively connected to the positive electrode connection point 211 and the negative electrode connection point 311 in one solar cell may be 5 to 15. The distance between adjacent conductive lines may be 4-8 mm.

Preferably, the line width of the conductive lines may be 0.5 to 1.5 mm, and the distance between adjacent conductive lines is greater than or equal to 2 mm and less than or equal to 0.5 times the length of the semiconductor substrate in the first direction.

In the embodiment of the utility model, the conductive wire can be connected to the positive electrode connection point or the negative electrode connection point on the backlight surface of each solar cell through a conductive adhesive or welding. The conductive adhesive may be a solder paste including tin or a tin-containing alloy, or a conductive paste formed by including tin or a tin-containing alloy in epoxy resin, acrylic resin, or silicone resin.

Fig. 6 shows a schematic structural diagram of an external photovoltaic module in an embodiment of the present invention, and as shown in fig. 6, the external photovoltaic module may further connect a plurality of photovoltaic modules shown in fig. 5 in parallel, so as to converge and export currents generated by the plurality of photovoltaic modules, so as to supply power to an external device.

Specifically, a plurality of solar cells 90 may be connected in series by using the conductive wires 100 to obtain a photovoltaic module, and then the plurality of photovoltaic modules are connected in parallel by using the bus bars 110 to obtain the external module of the photovoltaic module. Among them, the solar cell 90 may include a first solar cell 91, a second solar cell 92, and a third solar cell 93, and the conductive wire 100 in the photovoltaic module may include a first conductive wire 101, a second conductive wire 102, and a third conductive wire 103. One end of the first conductive wire 101 is connected to the bus bar 110, and the other end is connected to the positive connection point 211 in the backlight surface of the first solar cell 91; one end of the second conductive wire 102 is connected to the negative connection point 311 in the backlight surface of the first solar cell 91, and the other end is connected to the positive connection point 211 in the backlight surface of the second solar cell 92; one end of the third conductive wire 103 is connected to the negative connection point 311 in the backlight surface of the second solar cell 92, and the other end is connected to the positive connection point 211 in the backlight surface of the third solar cell 93. Therefore, the first solar cell 91, the second solar cell 92 and the third solar cell 93 are connected by the first conductive wire 101, the second conductive wire 102 and the third conductive wire 103 to obtain a photovoltaic module, the first solar cell 91, the second solar cell 92 and the third solar cell 93 are generated and collected, and further, the currents generated and collected by the plurality of photovoltaic modules can be further collected into the bus bar 110 to supply power to external equipment.

It should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

Through the above description of the embodiments, those skilled in the art will clearly understand that the method of the above embodiments can be implemented by software plus a necessary general hardware platform, and certainly can also be implemented by hardware, but in many cases, the former is a better implementation manner. Based on such understanding, the technical solutions of the present invention may be embodied in the form of a software product, which is stored in a storage medium (such as ROM/RAM, magnetic disk, optical disk) and includes instructions for enabling a terminal (such as a mobile phone, a computer, a server, an air conditioner, or a network device) to execute the method according to the embodiments of the present invention.

While the present invention has been described with reference to the embodiments shown in the drawings, the present invention is not limited to the embodiments, which are illustrative and not restrictive, and it will be apparent to those skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope of the utility model as defined in the appended claims.

Claims

1. A solar cell, comprising:

2. The solar cell of claim 1, wherein the second insulating layer further covers a negative electrode connecting grid line between adjacent negative electrode connecting points, and a portion of the negative electrode fine grid electrode connected to the negative electrode connecting grid line.

3. The solar cell of claim 1, wherein the first insulating layer comprises a first subsection and a second subsection;

4. The solar cell according to claim 3,

the third preset distance is equal to the fourth preset distance;

the third preset distance and the fourth preset distance are 0.01-0.5 mm.

5. The solar cell according to any one of claims 1 to 4, wherein the first insulating layer is provided in a rectangular structure, and a side of the first insulating layer close to the positive electrode connection point is spaced from the positive electrode connection point by a fifth preset distance;

the fifth preset distance is 0.1-1.5 millimeters.

6. The solar cell according to any one of claims 1 to 4, wherein the second insulating layer is provided in a rectangular structure, and a side of the second insulating layer close to the negative electrode connection point is spaced from the negative electrode connection point by a sixth preset distance;

the sixth preset distance is 0.5-2 mm.

7. The solar cell according to any one of claims 1 to 4, wherein the ratio of the dimension of the positive electrode connection point to the first insulating layer in the second direction is 1:1.1 to 1:2, and the ratio of the dimension of the negative electrode connection point to the second insulating layer in the second direction is 1:1.1 to 1: 2.

8. The solar cell of any of claims 1-4, wherein the positive connection point comprises a central portion and an outer edge portion disposed outside the central portion.

9. Solar cell according to any of claims 1 to 4,

in a range of a seventh preset distance from the positive electrode main gate electrode, the sizes of the positive electrode fine gate electrode in the first direction and the third direction are gradually reduced along a direction far away from the positive electrode main gate electrode;

10. A photovoltaic module comprising a plurality of solar cells of any one of claims 1-9 and a plurality of electrically conductive wires;