Solar cell, manufacturing method thereof, and photovoltaic module
A solar cell includes a semiconductor substrate, in which a rear surface of the semiconductor substrate having non-pyramid-shaped microstructures, the non-pyramid-shaped microstructures include two or more first substructures at least partially stacked on one another, and a one-dimensional size of the surface of the outermost first substructure is less than or equal to 45 μm; a first passivation layer located on a front surface of the semiconductor substrate; first and second tunnel oxide layers located on the non-pyramid-shaped microstructures; first and second doped conductive layers located on a surface of the first and second tunnel oxide layers, the first and second doped conductive layer has different conductive types; a second passivation layer located on a surface of the first and second doped conductive layers; and electrodes formed by penetrating through the second passivation layer to be in contact with the first and second doped conductive layers.
1 . A solar cell, comprising:
a semiconductor substrate, wherein a rear surface of the semiconductor substrate includes non-pyramid-shaped microstructures, the non-pyramid-shaped microstructures include two or more first substructures at least partially stacked on one another, a surface of the first substructure is polygonal, and in a direction away from the rear surface and perpendicular to the rear surface, a distance between a surface of the outermost first substructure and a surface of an adjacent first substructure is equal to or less than 2 μm; and wherein a front surface of the semiconductor substrate includes pyramid-shaped microstructures, the pyramid-shaped microstructures include a top portion away from the front surface of the semiconductor substrate and a bottom portion close to the front surface of the semiconductor substrate, and in a direction away from the front surface and perpendicular to the front surface, a distance between the top portion and the bottom portion of the pyramid-shaped microstructure is less than or equal to 5 μm;
a first passivation layer located on a front surface of the semiconductor substrate;
a tunnel oxide layer located on the non-pyramid-shaped microstructures of the rear surface of the semiconductor substrate;
a doped conductive layer located on a surface of the tunnel oxide layer; and
a second passivation layer located on a surface of the doped conductive layer.
2 . The solar cell according to claim 1 , wherein a one-dimensional size of a surface of the outermost first substructure is less than or equal to 45 μm.
3 . The solar cell according to claim 1 , wherein a shape of the polygonal plane of the first substructure includes at least one of a diamond, a square, a trapezoid, a substantially diamond, a substantially square or a substantially trapezoid.
4 . The solar cell according to claim 1 , wherein the first passivation layer includes at least one of a silicon oxide layer, an aluminum oxide layer, a silicon nitride layer or a silicon oxynitride layer.
5 . The solar cell according to claim 4 , wherein the first passivation layer has a thickness ranging from 10 nm to 120 nm.
6 . The solar cell according to claim 1 , wherein the first passivation layer is a stacked layer of an aluminum oxide layer, a silicon nitride layer and a silicon oxynitride layer.
7 . The solar cell according to claim 6 , wherein the aluminum oxide layer has a thickness ranging from 2 nm to 10 nm.
8 . The solar cell according to claim 6 , wherein the silicon nitride layer has a thickness ranging from 40 nm to 80 nm.
9 . The solar cell according to claim 6 , wherein the silicon oxynitride layer has a thickness ranging from 10 nm to 60 nm.
10 . The solar cell according to claim 1 , wherein the second passivation layer includes at least one of a silicon nitride layer, a silicon oxide layer or a silicon oxynitride layer.
11 . The solar cell according to claim 10 , wherein the second passivation layer has a thickness ranging from 70 nm to 120 nm.
12 . The solar cell according to claim 1 , wherein the tunnel oxide layer includes at least one of a silicon oxide layer, an aluminum oxide layer, a silicon oxynitride layer, a molybdenum oxide layer or a hafnium oxide layer.
13 . The solar cell according to claim 12 , wherein the tunnel oxide layer has a thickness ranging from 0.8 nm to 2 nm.
14 . The solar cell according to claim 1 , wherein a thickness of the tunnel oxide layer on a top surface of the outermost first substructure is less than a thickness of the tunnel oxide layer on a side surface of the outermost first substructure.
15 . The solar cell according to claim 14 , wherein a thickness difference between the tunnel oxide layer on the top surface of the outermost first substructure and the tunnel oxide layer on a side surface of the outermost substructure is less than or equal to 0.15 nm.
16 . The solar cell according to claim 1 , wherein a band gap width of the tunnel oxide layer is greater than 3.0 eV.
17 . The solar cell according to claim 1 , wherein the doped conductive layer has a thickness ranging from 60 nm to 200 nm.
18 . A photovoltaic module, comprising:
a plurality of solar cell strings, wherein each of the plurality of solar cell strings comprises solar cells, and at least one of the solar cells comprises:
a semiconductor substrate, wherein a rear surface of the semiconductor substrate includes non-pyramid-shaped microstructures, the non-pyramid-shaped microstructures include two or more first substructures at least partially stacked on one another, a surface of the first substructure is polygonal, and in a direction away from the rear surface and perpendicular to the rear surface, a distance between a surface of the outermost first substructure and a surface of an adjacent first substructure is equal to or less than 2 μm; and wherein a front surface of the semiconductor substrate includes pyramid-shaped microstructures, the pyramid-shaped microstructures include a top portion away from the front surface of the semiconductor substrate and a bottom portion close to the front surface of the semiconductor substrate, and in a direction away from the front surface and perpendicular to the front surface, a distance between the top portion and the bottom portion of the pyramid-shaped microstructure is less than or equal to 5 μm;
a first passivation layer located on a front surface of the semiconductor substrate;
a tunnel oxide layer located on the non-pyramid-shaped microstructures of the rear surface of the semiconductor substrate;
a doped conductive layer located on a surface of the tunnel oxide layer; and
a second passivation layer located on a surface of the doped conductive layer.
19 . The photovoltaic module according to claim 18 , wherein a one-dimensional size of a surface of the outermost first substructure is less than or equal to 45 μm.
20 . The photovoltaic module according to claim 18 , wherein a shape of the polygonal plane of the first substructure includes at least one of a diamond, a square, a trapezoid, a substantially diamond, a substantially square or a substantially trapezoid.