Solar cell and method of manufacturing
Disclosed herein are a solar cell and a method of manufacturing the same. The solar cell module includes a semiconductor substrate, a first passivation film located on a front surface of the semiconductor substrate, a second passivation film located on a rear surface of the semiconductor substrate, a front electric field region located on the first passivation film on the front surface of the semiconductor substrate and being of a same conductivity-type as that of the semiconductor substrate, an emitter region located on the second passivation film on the rear surface of the semiconductor substrate and being of a conductivity-type opposite that of the semiconductor substrate, first electrodes conductively connected to the front electric field region, and second electrode conductively connected to the emitter region.
1. A solar cell comprising:
a semiconductor substrate;
a first passivation film located on a front surface of the semiconductor substrate;
a second passivation film located on a rear surface of the semiconductor substrate;
a front electric field region located on the first passivation film on the front surface of the semiconductor substrate and being of a same conductivity-type as that of the semiconductor substrate;
an emitter region located on the second passivation film on the rear surface of the semiconductor substrate and being of a conductivity-type opposite that of the semiconductor substrate;
first electrodes conductively connected to the front electric field region; and
second electrodes conductively connected to the emitter region,
wherein a ratio of a thickness of the emitter region to a thickness of the second passivation film is greater than a ratio of a thickness of the front electric field region to a thickness of the first passivation film; and
wherein the thickness of the front electric field region is 1 nm to 10 nm, and the thickness of the emitter region is 3 nm to 15 nm.
2. The solar cell according to claim 1 , wherein the thickness of the emitter region is greater than the thickness of the front electric field region.
3. The solar cell according to claim 1 , wherein:
an energy bandgap of the front electric field region is greater than an energy bandgap of the semiconductor substrate; and
an energy bandgap of the emitter region is greater than the energy bandgap of the semiconductor substrate.
4. The solar cell according to claim 1 , wherein the front electric field region and the emitter region include at least one of doped amorphous silicon, amorphous silicon oxide, amorphous silicon carbide, indium gallium zinc oxide, titanium oxide and molybdenum oxide.
5. The solar cell according to claim 1 , wherein at least one of the first and second passivation films includes an intrinsic amorphous silicon layer.
6. The solar cell according to claim 1 , wherein the thickness of the second passivation film is equal to or greater than the thickness of the first passivation film.
7. The solar cell according to claim 1 , wherein at least one of the emitter region and the front electric field region includes a first part and a second part having a higher doping concentration than that of the first part, and
wherein a thickness of the first part is greater than a thickness of the second part.
8. The solar cell according to claim 1 , wherein:
the front electric field region includes a first electric field part located on the first passivation film, and a second electric field part located on the first electric field part and having a higher doping concentration than that of the first electric field part;
the emitter region includes a first emitter part located on the second passivation film, and a second emitter part located on the first emitter part and having a higher doping concentration than that of the first emitter part; and
a ratio of the doping concentration of the second emitter part to the doping concentration of the first emitter part is equal to or greater than a ratio of the doping concentration of the second electric field part to the doping concentration of the first electric field part, and the doping concentration of the first emitter part with a second conductivity-type dopant is equal to or smaller than the doping concentration of the first electric field part with a first conductivity-type dopant.
9. The solar cell according to claim 1 , wherein:
at least one of the first electrodes and the second electrodes include a transparent electrode layer and a metal electrode layer located on the transparent electrode layer; and
the transparent electrode layer includes at least one of indium tin oxide (ITO), aluminum zinc oxide (AZO), boron zinc oxide (BZO), indium tungsten oxide (IWO), indium cesium oxide (ICO), and indium titanium tantalum oxide.
10. The solar cell according to claim 9 , wherein the transparent electrode layer further includes hydrogen.
11. The solar cell according to claim 1 , wherein:
the first electrodes include a first transparent electrode layer formed on the front electric field region, and a first metal electrode layer located on the first transparent electrode layer;
the second electrodes include a second transparent electrode layer formed on the emitter region, and a second metal electrode layer located on the second transparent electrode layer; and
a thickness of the first transparent electrode layer is greater than a thickness of the second transparent electrode layer.
12. The solar cell according to claim 1 , wherein:
the semiconductor substrate and the front electric field region are of an n-type; and
the emitter region is of a p-type.
13. The solar cell according to claim 1 , wherein first uneven parts and second uneven parts are provided on the front surface of the semiconductor substrate.
14. The solar cell according to claim 13 , wherein a mean size of the second uneven parts is smaller than a mean size of the first uneven parts.
15. The solar cell according to claim 1 , wherein the thickness of the first passivation film is 1 nm to 5 nm, and the thickness of the second passivation film is 1 nm to 7 nm.