Solar cell and photovoltaic module
This application discloses a solar cell and a photovoltaic module. In one example, a solar cell includes a first surface and a second surface opposite to each other, and a side surface connecting the first surface and the second surface. The side surface includes a cut surface, the cut surface including a cut edge adjacent to the first surface and a break edge adjacent to the second surface. A first passivation layer is formed on the cut surface. The first passivation layer includes an aluminum oxide passivation layer. The cut surface includes a first region adjacent to the cut edge and a second region farther away from the cut edge than the first region. A ratio of oxygen to aluminum in at least a part of the first region is greater than a ratio of oxygen to aluminum in at least a part of the second region.
1 . A solar cell, comprising:
a first surface and a second surface opposite to each other, wherein the first surface is a light receiving surface or a back surface of the solar cell; and
a side surface connecting the first surface and the second surface, wherein the side surface comprises a cut surface, the cut surface comprising a cut edge adjacent to the first surface and a break edge adjacent to the second surface, and wherein the cut surface comprises a plurality of first groove structures; and
a first passivation layer formed on the cut surface, wherein the first passivation layer comprises aluminum oxide,
wherein the cut surface comprises a first region adjacent to the cut edge and a second region farther away from the cut edge than the first region, wherein a ratio of oxygen to aluminum in at least a part of the first region is greater than a ratio of oxygen to aluminum in at least a part of the second region.
2 . The solar cell according to claim 1 , wherein the cut surface comprises a plurality of crack structures, wherein the plurality of first groove structures are located in the first region,
wherein a thickness of the first passivation layer is greater than a depth of the plurality of first groove structures and less than a depth of the plurality of crack structures.
3 . The solar cell according to claim 2 , wherein:
the depth of the plurality of first groove structures is less than 1.2 μm; or
the depth of the plurality of crack structures is greater than or equal to 1 μm.
4 . The solar cell according to claim 1 , wherein a thickness of the first passivation layer is greater than or equal to 30 nm and less than or equal to 200 nm.
5 . The solar cell according to claim 1 , wherein a difference in aluminum content between the at least a part of the second region and the at least a part of the first region is greater than 3%.
6 . The solar cell according to claim 2 , wherein the plurality of first groove structures are adjacent to the cut edge, the plurality of first groove structures comprise end portions extending from the cut edge towards the break edge, and
wherein a boundary formed by the end portions of the plurality of first groove structures has a wavy shape or a zigzag shape.
7 . The solar cell according to claim 1 , wherein the cut surface comprises an edge region and a middle region, wherein the edge region is adjacent to the cut edge or the break edge, and the middle region is located on a middle part of the cut surface, and
wherein a roughness of the first passivation layer in the middle region is less than a roughness of the first passivation layer in the edge region.
8 . The solar cell according to claim 6 , wherein a spacing between peaks of the wavy shape or the zigzag shape is greater than or equal to 3 μm and less than or equal to 20 μm.
9 . The solar cell according to claim 6 , wherein an angle between an extending direction of a crack structure and an extending direction of a first groove structure is greater than or equal to 45° and less than 90°.
10 . The solar cell according to claim 6 , wherein in the cut surface, an extending length of a groove structure of the plurality of first groove structures is greater than or equal to 1 μm and less than or equal to 20 μm.
11 . The solar cell according to claim 1 , wherein the first surface comprises a plurality of second groove structures adjacent to the cut edge.
12 . The solar cell according to claim 11 , wherein in a direction away from the cut edge, an extending length of a groove structure of the plurality of second groove structures is greater than or equal to 20 μm and less than or equal to 100 μm.
13 . The solar cell according to claim 11 , further comprising: a second passivation layer formed in an edge region of the first surface, wherein the edge region of the first surface is close to the cut surface, and wherein the second passivation layer and the first passivation layer are continuously distributed.
14 . The solar cell according to claim 13 , wherein in a direction from an edge of the first surface to a center region of the first surface, a width of the second passivation layer is greater than an extending length of a groove structure of the plurality of second groove structures.
15 . The solar cell according to claim 13 , wherein in a direction from an edge of the first surface to a center region of the first surface, a width of the second passivation layer is greater than or equal to 0.05 mm and less than or equal to 2 mm.
16 . The solar cell according to claim 13 , wherein a thickness of the first passivation layer is greater than a thickness of the second passivation layer.
17 . The solar cell according to claim 13 , wherein in a direction from an edge of the first surface to a center region of the first surface, a thickness of the second passivation layer gradually decreases.
18 . The solar cell according to claim 13 , wherein a thickness of the second passivation layer is greater than or equal to 30 nm and less than or equal to 200 nm.