Solar cell
A solar cell and a method for manufacturing the same are discussed. The solar cell includes a substrate of a first conductive type, an emitter layer of a second conductive type opposite the first conductive type, a plurality of first electrodes each including a first electrode layer connected to the emitter layer and a second electrode layer positioned on the first electrode layer, at least one first current collector connected to the plurality of first electrodes, and a second electrode connected to the substrate. The emitter layer forms a p-n junction along with the substrate. The first electrode layer has a first width and the second electrode layer has a second width less than the first width of the first electrode layer.
1. A method for manufacturing an electrode of a solar cell, the method comprising:
printing a first front electrode part paste on a semiconductor substrate using a screen printing method to form a first front electrode part pattern; and
printing a second front electrode part ink on the first front electrode part pattern using a roll printing method to form a second front electrode part pattern,
wherein the forming of the first front electrode part pattern includes simultaneously forming a first electrode layer pattern in a first direction and a first current collector pattern, which has a greater height than a height of the first electrode layer pattern, in a second direction crossing the first direction,
wherein the forming of the second front electrode part pattern includes printing the second front electrode part ink on the first electrode layer pattern to form a second electrode layer pattern on the first electrode layer pattern in the first direction, and
wherein an added height of the first electrode layer pattern and the second front electrode part pattern is equal to or greater than the height of the first current collector pattern.
2. The method of claim 1 , wherein in the forming of the second front electrode part pattern, a width of the second electrode layer pattern is less than a width of the first electrode layer pattern.
3. The method of claim 1 , wherein the forming of the second front electrode part pattern includes printing the second front electrode part ink on the first electrode layer pattern and the first current collector pattern to form a second electrode layer pattern having the same plane shape as the first front electrode part pattern.
4. The method of claim 3 , wherein in the forming of the second front electrode part pattern, a width of the second electrode layer pattern is less than a width of the first electrode layer pattern and a width of the first current collector pattern.
5. The method of claim 1 , wherein the forming of the second front electrode part pattern includes:
filling the second front electrode part ink in a groove of an intaglio printing plate corresponding to a formation location of the second front electrode part pattern to be formed; and
bringing the intaglio printing plate having a roll shape into contact with the at least a portion of the first front electrode part pattern on the semiconductor substrate and rotating the intaglio printing plate to transfer the second front electrode part ink filled in the groove of the intaglio printing plate to the at least a portion of the first front electrode part pattern on a surface of the semiconductor substrate.
6. The method of claim 1 , wherein the forming of the second front electrode part pattern includes:
filling the second front electrode part ink in a groove of an intaglio printing plate corresponding to a formation location of the second front electrode part pattern to be formed;
bringing the intaglio printing plate into contact with a roll-shaped blanket and rotating the intaglio printing plate to transfer the second front electrode part ink filled in the groove of the intaglio printing plate to a surface of the roll-shaped blanket; and
bringing the blanket into contact with the at least a portion of the first front electrode part pattern on semiconductor substrate and rotating the blanket to again transfer the second front electrode part ink transferred to the blanket to the at least a portion of the first front electrode part pattern on a surface of the semiconductor substrate.
7. The method of claim 1 , wherein the first front electrode part paste and the second front electrode part ink contain silver (Ag).
8. The method of claim 1 , wherein a silver (Ag) content of the first front electrode part paste is greater than a silver (Agconvent content of the second front electrode part ink.
9. The method of claim 1 , further comprising, before forming the second front electrode part pattern, drying the first front electrode part pattern.
10. The method of claim 1 , further comprising simultaneously firing the first front electrode part pattern and the second front electrode part pattern.