Back contact solar cell, preparation method therefor, and photovoltaic module
The present application discloses a back contact solar cell, a preparation method therefor, and a photovoltaic module. In one example, a back contact solar cell includes a substrate, a first doped layer and a second doped layer alternately arranged on a first surface of the substrate. A doping type of the first doped layer is opposite to a doping type of the second doped layer. A first isolation region is provided between an edge of the substrate and a boundary of the first doped layer adjacent to the edge, a second isolation region is provided between the edge of the substrate and a boundary of the second doped layer adjacent to the edge. A width of at least a portion of the first isolation region is greater than a width of at least a portion of the second isolation region.
1 . A back contact solar cell, comprising:
a substrate, having a first surface and a second surface opposite to the first surface, wherein the substrate has an edge; and
a first doped layer and a second doped layer, alternately arranged on the first surface, wherein a doping type of the first doped layer is opposite to a doping type of the second doped layer, and wherein the doping type of the second doped layer is the same as a doping type of the substrate,
wherein a first isolation region is provided between the edge and a boundary of the first doped layer adjacent to the edge, a second isolation region is provided between the edge and a boundary of the second doped layer adjacent to the edge, wherein a width of at least a portion of the first isolation region is greater than a width of at least a portion of the second isolation region.
2 . The back contact solar cell according to claim 1 , wherein the edge comprises a first edge and a second edge opposite to the first edge, wherein:
the back contact solar cell is a full-cut solar cell, wherein the first surface is divided into two sections by a line perpendicular to the first edge and the second edge, wherein in one of the two sections, a width of the first isolation region formed between a boundary of the first doped layer and the first edge is greater than a width of the second isolation region formed between a boundary of the second doped layer and the second edge; or
the back contact solar cell is a half-cut solar cell, wherein a width of the first isolation region formed between a boundary of the first doped layer and the first edge is greater than a width of the second isolation region formed between a boundary of the second doped layer and the second edge.
3 . The back contact solar cell according to claim 1 , wherein the edge comprises a first edge, a second edge opposite to the first edge, and a third edge between the first edge and the second edge,
wherein the first doped layer and the second doped layer are arranged in an interdigitated manner, wherein the first doped layer comprises a first connecting portion and a plurality of first interdigitated portions, at least one of the first interdigitated portions being electrically connected to the first connecting portion, wherein the second doped layer comprises a second connecting portion and a plurality of second interdigitated portions, at least one of the second interdigitated portions being electrically connected to the second connecting portion,
wherein the first connecting portion and the second connecting portion extend along the first edge and the second edge, wherein more than one of the first interdigitated portions between the first connecting portion and the second connecting portion are distributed in a plurality of rows, wherein and more than one of the second interdigitated portions between the first connecting portion and the second connecting portion are distributed in a plurality of rows, wherein the first interdigitated portions in a plurality of rows and the second interdigitated portions in a plurality of rows are distributed in a staggered manner and at intervals; and wherein:
the back contact solar cell is a half-cut solar cell, wherein a width of the first isolation region formed between the first connecting portion and the first edge is greater than a width of the second isolation region formed between the second connecting portion and the second edge; or
the back contact solar cell is a full-cut solar cell, wherein a width of the first isolation region formed between the first connecting portion and the first edge is greater than a width of the second isolation region formed between the second connecting portion and the second edge.
4 . The back contact solar cell according to claim 3 , wherein one or more rows of the first interdigitated portions between the first connecting portion and the second connecting portion are continuous and uninterrupted, and one or more rows of the second interdigitated portions between the first connecting portion and the second connecting portion are continuous and uninterrupted.
5 . The back contact solar cell according to claim 3 , wherein a row of the first interdigitated portions between the first connecting portion and the second connecting portion is interrupted to form a plurality of segments, and a row of the second interdigitated portions between the first connecting portion and the second connecting portion is interrupted to form a plurality of segments.
6 . The back contact solar cell according to claim 3 , wherein the third edge is adjacent to a boundary of the first interdigitated portions; or the third edge is adjacent to a boundary of the second interdigitated portions.
7 . The back contact solar cell according to claim 3 , wherein one end of the third edge is connected to an end of the first edge by a first chamfer, and an other end of the third edge is connected to an end of the second edge by a second chamfer, wherein a boundary of the first doped layer is adjacent to the first chamfer, and a boundary of the second doped layer is adjacent to the second chamfer, and
wherein:
the boundary of the first doped layer adjacent to the first chamfer is a stepped edge; and/or
the boundary of the second doped layer adjacent to the second chamfer is an arc-shaped edge; and/or
a spacing distance between a tip of a second interdigitated portion close to the first chamfer and the first connecting portion is greater than a spacing distance between a tip of remaining second interdigitated portions and the first connecting portion, wherein the spacing distance is measured along an extending direction of the third edge; and/or
a spacing distance between a tip of a first interdigitated portion close to the second chamfer and the second connecting portion is greater than a spacing distance between a tip of remaining first interdigitated portions and the second connecting portion, wherein the spacing distance is measured along an extending direction of the third edge.
8 . The back contact solar cell according to claim 3 , wherein one end of the third edge is connected to an end of the first edge by a first chamfer, and an other end of the third edge is connected to an end of the second edge by a second chamfer, wherein:
the first interdigitated portions are adjacent to the third edge, wherein an edge of a tip of a first interdigitated portion close to the second connecting portion is a beveled edge, the beveled edge being inclining toward a direction closer to the second chamfer in a direction away from the third edge; or
the second interdigitated portions are adjacent to the third edge, wherein an edge of a tip of a second interdigitated portion close to the first connecting portion is a beveled edge, the beveled edge inclining toward a direction closer to the first chamfer in a direction away from the third edge.
9 . The back contact solar cell according to claim 3 , wherein a width of a portion of the first connecting portion adjacent to the first edge is d 1 , and a width of a portion of the second connecting portion adjacent to the second edge is d 2 , d 1 <d 2 .
10 . The back contact solar cell according to claim 9 , wherein 600 μm≤d 1 ≤800 μm, and 800 μm≤d 2 ≤1100 μm.
11 . The back contact solar cell according to claim 1 , wherein the edge comprises a first edge, a second edge arranged opposite to the first edge, and a third edge located between the first edge and the second edge,
wherein the first doped layer comprises a plurality of first strip-shaped portions extending along an extending direction the third edge, and the second doped layer comprises a plurality of second strip-shaped portions extending along the extending direction the third edge,
wherein the plurality of first strip-shaped portions and the plurality of second strip-shaped portions are sequentially and alternately spaced apart along an extending direction of the first edge or the second edge, and wherein heads of two ends of the first strip-shaped portions and the second strip-shaped portions are respectively adjacent to the first edge and the second edge.
12 . The back contact solar cell according to claim 11 , wherein a boundary of the second strip-shaped portions is adjacent to the third edge.
13 . The back contact solar cell according to claim 1 , wherein;
a width of the first isolation region ranges from 80 μm to 200 μm; and/or
a width of the second isolation region ranges from 10 μm to 50 μm; and/or
a difference between the width of the first isolation region and the width of the second isolation region is greater than or equal to 30 μm and less than or equal to 190 μm.
14 . The back contact solar cell according to claim 1 , wherein the first isolation region and/or the second isolation region has a portion recessed into the substrate, wherein a side of the recessed portion facing away from a side wall of the substrate comprises an inclined portion that inclines relative to the first surface, wherein an angle between the inclined portion and the first surface is greater than or equal to 53° and less than or equal to 57°.
15 . The back contact solar cell according to claim 1 , wherein the first isolation region and/or the second isolation region has a portion recessed into the substrate, wherein a bottom surface of the recessed portion comprises a textured structure comprising a pyramidal textured structure.
16 . The back contact solar cell according to claim 1 , wherein:
a length and/or a width of the substrate ranges from 166 μm to 210 μm; and/or
a thickness of the substrate ranges from 100 μm to 170 μm; and/or
a thickness of the first doped layer and/or the second doped layer ranges from 150 nm to 400 nm; and/or
a third isolation region is arranged between the first doped layer and the second doped layer, a width of the third isolation region ranging from 60 μm to 200 μm.
17 . A photovoltaic module, comprising:
at least two back contact solar cells, wherein each back contact solar cell comprises:
a substrate, having a first surface and a second surface opposite to the first surface, wherein the substrate has an edge; and
a first doped layer and a second doped layer, alternately arranged on the first surface, wherein a doping type of the first doped layer is opposite to a doping type of the second doped layer, and wherein the doping type of the second doped layer is the same as a doping type of the substrate, wherein a first isolation region is provided between the edge and a boundary of the first doped layer adjacent to the edge, a second isolation region is provided between the edge and a boundary of the second doped layer adjacent to the edge, wherein a width of at least a portion of the first isolation region is greater than a width of at least a portion of the second isolation region; and
a plurality of electrical connectors, wherein the plurality of electrical connectors connect the at least two back contact solar cells.
18 . The photovoltaic module according to claim 17 , wherein the edge comprises a first edge and a second edge arranged opposite to the first edge,
wherein the first doped layer and the second doped layer are arranged in an interdigitated manner, wherein the first doped layer comprises a first connecting portion and a plurality of first interdigitated portions, at least one of the first interdigitated portions being electrically connected to the first connecting portion,
wherein the second doped layer comprises a second connecting portion and a plurality of second interdigitated portions, at least one of the second interdigitated portions being electrically connected to the second connecting portion,
wherein the first connecting portion and the second connecting portion extend along the first edge and the second edge, wherein more than one of the first interdigitated portions between the first connecting portion and the second connecting portion are distributed in a plurality of rows, wherein and more than one of the second interdigitated portions between the first connecting portion and the second connecting portion are distributed in a plurality of rows, wherein the first interdigitated portions in a plurality of rows and the second interdigitated portions in a plurality of rows being distributed in a staggered manner and at intervals,
wherein the back contact solar cell is a half-cut solar cell, the first connecting portion being adjacent to the first edge, and the second connecting portion being adjacent to the second edge, and
wherein orthographic projections of the plurality of electrical connectors do not overlap with the first connecting portion of the first doped layer and/or the second connecting portion of the second doped layer adjacent to the first edge and/or the second edge.
19 . A preparation method for a back contact solar cell, comprising:
providing a substrate, the substrate having a first surface and a second surface opposite to the first surface, the first surface having an edge;
forming a first doped layer on the first surface of the substrate and patterning the first doped layer, a doping type of the first doped layer being opposite to a doping type of the substrate;
forming a second doped layer on the first surface of the substrate and patterning the second doped layer, a doping type of the second doped layer being opposite to the doping type of the first doped layer; and
forming a first isolation region through the first doped layer along a thickness direction of the substrate when patterning the first doped layer or the second doped layer, the first isolation region spacing the first doped layer from the edge; and forming a second isolation region through the second doped layer along the thickness direction of the substrate, the second isolation region spacing the second doped layer from the edge, wherein a width of the first isolation region is greater than a width of the second isolation region.
20 . The preparation method for a back contact solar cell according to claim 19 , wherein forming the first isolation region running through the first doped layer comprises:
irradiating, with a laser, a portion of the first doped layer at a position corresponding to the first isolation region, and
forming the first isolation region running through the first doped layer along the thickness direction of the substrate by etching using an etching solution, and wherein
forming the second isolation region through the second doped layer comprises:
forming the second isolation region through the second doped layer along the thickness direction of the substrate by etching using the etching solution.