Disclosed is a solar cell that comprises a substrate made of a semiconductor material, a first amorphous semiconductor layer placed on one region of the substrate and being of one conductivity type, a second amorphous semiconductor layer placed on another region of the substrate and being of another conductivity type, a substantially intrinsic i-type amorphous semiconductor layer provided above the first amorphous semiconductor layer, a third amorphous semiconductor layer provided on the i-type amorphous semiconductor layer and being of the other conductivity type, a first crystalline semiconductor layer placed between the first amorphous semiconductor layer and the i-type amorphous semiconductor layer and being of the one conductivity type, and a second crystalline semiconductor layer placed between the first crystalline semiconductor layer and the i-type amorphous semiconductor layer and being of the other conductivity type.
1. A solar cell comprising:
a substrate;
a first amorphous semiconductor layer arranged at a first region of the substrate and being of a first conductivity type;
a second amorphous semiconductor layer arranged at a second region of the substrate and being of a second conductivity type;
a substantially intrinsic i-type amorphous semiconductor layer provided above the first amorphous semiconductor layer;
a third amorphous semiconductor layer provided on the i-type amorphous semiconductor layer and being of the second conductivity type;
a first crystalline semiconductor layer arranged between the first amorphous semiconductor layer and the i-type amorphous semiconductor layer and being of the first conductivity type; and
a second crystalline semiconductor layer arranged between the first crystalline semiconductor layer and the i-type amorphous semiconductor layer and being of the second conductivity type.
2. The solar cell according to claim 1 , wherein
the first and second crystalline semiconductor layers are made of a microcrystalline semiconductor.
3. The solar cell according to claim 1 , wherein
the one conductivity type is an n-type, and
the other conductivity type is a p-type.
4. The solar cell according to claim 1 , further comprising:
a second substantially intrinsic i-type amorphous semiconductor layer provided between the first amorphous semiconductor layer and the substrate.
5. The solar cell according to claim 1 , wherein
the first crystalline semiconductor layer has a thickness of about 1 nm to 30 nm.
6. The solar cell according to claim 1 , wherein
the first crystalline semiconductor layer has a thickness of about 1 nm to 15 nm.
7. The solar cell according to claim 1 , wherein
the second crystalline semiconductor layer has a thickness of about 1 nm to 30 nm.
8. The solar cell according to claim 1 , wherein
the second crystalline semiconductor layer has a thickness of about 1 nm to 15 nm.
9. The solar cell according to claim 2 , wherein
the microcrystalline semiconductor is made substantially of semiconductor crystal grains.
10. The solar cell according to claim 2 , wherein
the second crystalline semiconductor includes a semiconductor amorphous region and a semiconductor crystal grains region.