Solar cell and photovoltaic module

1 . A solar cell, comprising:

a substrate including a center region and edge regions, wherein the edge regions are respectively arranged on two opposing sides of the center region;

a plurality of fingers arranged at intervals along a first direction, each of plurality of fingers extending along a second direction, the plurality of fingers including a number of fingers in the center region;

a plurality of pad groups arranged at intervals along the second direction, wherein each pad group of the plurality of pad groups includes a plurality of pads arranged at intervals along the first direction, and the plurality of pads include a number of pads in the center region that are respectively connected to the number of fingers in the center region; and

a plurality of busbars arranged at intervals along the second direction, wherein each of the plurality of busbars is connected to a respective pad group of some of the plurality of pad groups, and at least one of the plurality of pad groups is disposed between two adjacent busbars of the plurality of busbars;

wherein a respective pad of the plurality of pads includes a first end portion, a body portion and a second end portion connected in sequence along the second direction, a length of each of the first end portion and the second end portion in the first direction is greater than a length of the body portion in the first direction, and a width of each of the first end portion and the second end portion in the second direction is less than a width of the body portion in the second direction.

2 . The solar cell according to claim 1 , wherein every two adjacent busbars of the plurality of busbars have a space therebetween with at least one of the plurality of pad groups located in the space.

3 . The solar cell according to claim 2 , wherein two adjacent busbars of the plurality of busbars have a first space therebetween with a single pad group of the plurality of pad groups located in the first space, and two other adjacent busbars of the plurality of busbars have a second space therebetween with at least two of the plurality of pad groups located in the second space.

4 . The solar cell according to claim 1 , wherein the plurality of busbars include:

first busbars, wherein a respective first busbar of the first busbars is connected to every pad of a respective pad group of the plurality of pad groups; and

second busbars, wherein a respective second busbar of the second busbars is connected to some pads of a respective pad group of the plurality of pad groups.

5 . The solar cell according to claim 4 , wherein at least one of the plurality of pad groups is located in a space between a first busbar of the first busbars and an adjacent second busbar of the second busbars.

6 . The solar cell according to claim 4 , wherein each of the first busbars has a width in the second direction that is greater than a width of any of the second busbars in the second direction.

7 . The solar cell according to claim 1 , wherein the substrate includes a front surface and a rear surface opposite to each other, wherein both the front surface and the rear surface are provided with the plurality of fingers, the plurality of pad groups, and the plurality of busbars, and wherein at least some of the plurality of busbars on the front surface have orthographic projections on the front surface that are interleaved with orthographic projections, on the front surface, of the plurality of busbars on the rear surface.

8 . The solar cell according to claim 1 , wherein the substrate includes a front surface and a rear surface opposite to each other, and wherein the front surface is provided with the plurality of fingers, the plurality of pad groups, and the plurality of busbars, and the rear surface is provided with the plurality of fingers and the plurality of pad groups.

9 . The solar cell according to claim 1 , wherein the plurality of pad groups has a number being N, and the plurality of busbars has a number being n, wherein N/4≤n<N, and both n and N are positive integers.

10 . The solar cell according to claim 1 , wherein the plurality of pad groups has a number in a range of 15 to 22.

11 . The solar cell according to claim 1 , wherein the plurality of busbars has a number in a range of 4 to 11.

12 . The solar cell according to claim 1 , wherein an orthographic projection of a pad closest to one of the edge regions among the number of pads in the center region has a first area on the substrate, an orthographic projection of a pad farthest away from the edge regions among the number of pads in the center region has a second area on the substrate, and the first area is greater than the second area.

13 . The solar cell according to claim 1 , wherein the substrate includes a front surface and a rear surface;

wherein the plurality of fingers include:

70 to 150 first fingers disposed on the front surface; and

80 to 400 second fingers disposed on the rear surface; and

wherein the plurality of pad groups include:

a plurality of first pad groups disposed on the front surface, wherein a respective pad of the plurality of pads of each of the plurality of first pad groups is connected to a respective one of the plurality of first fingers.

14 . The solar cell according to claim 13 , wherein each of the plurality of first fingers has a width in a range of 10 μm to 30 μm, and each of the plurality of second fingers has a width in a range of 15 μm to 50 μm.

15 . The solar cell according to claim 13 , wherein each of the plurality of first fingers has a height in a range of 6 μm to 30 μm, and each of the plurality of second fingers has a height in a range of 4 μm to 25 μm.

16 . The solar cell according to claim 13 , wherein the plurality of first pad groups have a number in a range of 12 to 26.

17 . The solar cell according to claim 13 , wherein the plurality of busbars include a plurality of first busbars disposed on the front surface; and wherein the plurality of first busbars are connected to the plurality of first pad groups, and at least one of the plurality of first pad groups is disposed between two adjacent first busbars of the plurality of first busbars.

18 . The solar cell according to claim 17 , wherein:

the plurality of pad groups further include a plurality of second pad groups disposed on the rear surface, wherein a respective pad of the plurality of pads of each of the plurality of second pad groups is connected to a respective one of the plurality of second fingers, and the plurality of first pad groups have orthographic projections on the front surface that are interleaved with orthographic projections of the plurality of second pad groups on the front surface; and

the plurality of busbars include a plurality of second busbars disposed on the rear surface, wherein each of the plurality of second busbars are connected to a respective one of the plurality of second pad groups, and the plurality of first busbars have orthographic projections on the front surface that are interleaved with orthographic projections of the plurality of second busbars on the front surface.

19 . A photovoltaic module, comprising:

at least one cell string each formed by connecting a plurality of solar cells, wherein each of the plurality of solar cells includes:

a substrate including a center region and edge regions, wherein the edge regions are respectively arranged on two opposing sides of the center region;

a plurality of fingers arranged at intervals along a first direction, each of plurality of fingers extending along a second direction, the plurality of fingers including a number of fingers in the center region;

a plurality of pad groups arranged at intervals along the second direction, wherein each pad group of the plurality of pad groups includes a plurality of pads arranged at intervals along the first direction, and the plurality of pads include a number of pads in the center region that are respectively connected to the number of fingers in the center region; and

a plurality of busbars arranged at intervals along the second direction, wherein each of the plurality of busbars is connected to a respective pad group of some of the plurality of pad groups, and at least one of the plurality of pad groups is disposed between two adjacent busbars of the plurality of busbars;

wherein a respective pad of the plurality of pads includes a first end portion, a body portion and a second end portion connected in sequence along the second direction, a length of each of the first end portion and the second end portion in the first direction is greater than a length of the body portion in the first direction, and a width of each of the first end portion and the second end portion in the second direction is less than a width of the body portion in the second direction;

at least one welding strip each connected to two adjacent solar cells, wherein each of the at least one welding strip is connected to each of the plurality of pad groups in a respective one of the two adjacent solar cells;

at least one encapsulation layer each covering a surface of the at least one cell string; and

at least one cover plate each covering a surface of a respective encapsulation layer facing away from the at least one cell string.

20 . The photovoltaic module according to claim 19 , wherein the plurality of solar cells in each of the at least one cell string are arranged at intervals along the first direction, and busbars in one of two adjacent solar cells in each of the at least one cell string are interleaved with busbars in the other of the two adjacent solar cells in the second direction.