Solar cell and photovoltaic module
Provided is a solar cell and a photovoltaic module. The solar cell includes a silicon substrate, and the silicon substrate includes a front surface and a back surface arranged opposite to each other. P-type conductive regions and N-type conductive regions are alternately arranged on the back surface of the silicon substrate. Front surface field regions are located on the front surface of the silicon substrate and spaced from each other. The front surface field regions each corresponds to one of the P-type conductive regions or one of the N-type conductive regions. At least one front passivation layer is located on the front surface of the silicon substrate. At least one back passivation layer is located on surfaces of the P-type conductive regions and N-type conductive regions.
1. A method for manufacturing a solar cell, comprising:
forming, on a first surface of a silicon substrate, P-type conductive regions and N-type conductive regions that are alternately arranged;
forming, on a second surface of the silicon substrate, front diffusion layers spaced from one another;
forming at least one of front passivation layers or antireflection layers over upper surfaces of the front diffusion layers at the second surface of the silicon substrate;
forming back passivation layers on lower surfaces of the P-type conductive regions and the N-type conductive regions at the first surface of the silicon substrate; and
forming metal electrodes at the first surface of the silicon substrate,
wherein the front diffusion layers each corresponds to one of the P-type conductive regions or one of the N-type conductive regions, and
wherein the forming, on a first surface of a silicon substrate, P-type conductive regions and N-type conductive regions that are alternately arranged includes:
forming a dielectric layer over the first surface of the silicon substrate;
forming a silicon layer over a lower surface of the dielectric layer;
respectively doping alternately arranged first regions and second regions of the silicon layer so that a first region and a second region have opposite polarities; and
annealing the first surface of the silicon substrate to form alternately arranged first doped silicon layers and second doped silicon layers,
wherein subsequent to the annealing the first surface of the silicon substrate to form alternately arranged first doped silicon layers and second doped silicon layers, the method further comprises:
etching non-doped intrinsic silicon layer regions between the first doped silicon layers and the second doped silicon layers to form groove structures.
2. The method for manufacturing a solar cell according to claim 1 , wherein the dielectric layer is one of a silicon dioxide dielectric layer, a silicon nitride dielectric layer, an aluminum dielectric layer, a hafnium oxide dielectric layer or any combination thereof.
3. The method for manufacturing a solar cell according to claim 1 , wherein the dielectric layer has a thickness ranging from 0.5 nm to 2 nm.
4. The method for manufacturing a solar cell according to claim 1 , wherein the silicon layer has a thickness ranging from 10 nm to 100 nm.
5. The method for manufacturing a solar cell according to claim 1 , wherein one of the first region and the second region is doped as a P-type silicon layer, and the other one of the first region and the second region is doped as an N-type silicon layer.
6. The method for manufacturing a solar cell according to claim 1 , wherein the forming, on a first surface of a silicon substrate, P-type conductive regions and N-type conductive regions that are alternately arranged includes:
respectively doping alternately arranged first doping regions and second doping regions on the first surface of the silicon substrate so that the first doping regions and the second doping regions have opposite polarities; and
annealing the first surface of the silicon substrate to form alternately arranged P-type doped regions and N-type doped regions.
7. The method for manufacturing a solar cell according to claim 1 , wherein the forming, on a second surface of the silicon substrate, front diffusion layers spaced from one another includes:
texturing the second surface of the silicon substrate to form a textured structure;
doping alternately arranged third regions on the second surface of the silicon substrate; and
annealing the second surface of the silicon substrate to form alternately arranged front surface field regions.
8. The method for manufacturing a solar cell according to claim 7 , wherein prior to the texturing the second surface of the silicon substrate to form a textured structure, the method further comprises:
cleaning the silicon substrate to remove metal and/or organic contaminants.
9. The method for manufacturing a solar cell according to claim 7 , wherein the silicon substrate is an N-type substrate, each of the front surface field regions corresponds to one of the N-type conductive regions, and orthographic projections of the N-type conductive regions perpendicular to the second surface of the silicon substrate are within orthographic projections of the front surface field regions perpendicular to the second surface of the silicon substrate.
10. The method for manufacturing a solar cell according to claim 9 , wherein at least part of orthographic projections of the P-type conductive regions perpendicular to the second surface of the silicon substrate are within the orthographic projections of the front surface field regions perpendicular to the second surface of the silicon substrate.
11. The method for manufacturing a solar cell according to claim 7 , wherein the silicon substrate is a P-type substrate, the front surface field regions each corresponds to one of the P-type conductive regions, and orthographic projections of the P-type conductive regions perpendicular to the second surface of the silicon substrate are within orthographic projections of the front surface field regions perpendicular to the second surface of the silicon substrate.
12. The method for manufacturing a solar cell according to claim 11 , wherein at least part of orthographic projections of the N-type conductive regions perpendicular to the second surface of the silicon substrate are within the orthographic projections of the front surface field regions perpendicular to the second surface of the silicon substrate.
13. The method for manufacturing a solar cell according to claim 7 , wherein spacing regions are formed between adjacent ones of the P-type conductive regions and the N-type conductive regions, and orthographic projections of the spacing regions perpendicular to the second surface of the silicon substrate are within the orthographic projections of the front surface field regions perpendicular to the second surface of the silicon substrate.
14. The method for manufacturing a solar cell according to claim 13 , wherein each of the spacing regions has a width ranging from 20 μm to 150 μm.
15. The method for manufacturing a solar cell according to claim 7 , wherein each of the front surface field regions has a width in a range from 200 μm to 300 μm.
16. The method for manufacturing a solar cell according to claim 7 , wherein a total area of the front surface field regions accounts for 45% to 60% of an area of the second surface of the silicon substrate.
17. The method for manufacturing a solar cell according to claim 16 , wherein each of the front surface field regions has a doping concentration in a range from 5E18 cm −3 to 5E19 cm −3 , and each of the front surface field regions has a doping junction depth in a range from 20 nm to 150 nm.
18. The method for manufacturing a solar cell according to claim 17 , wherein each of the front surface field regions has a sheet resistance ranging from 300 Ω/sqr to 1300 Ω/sqr.