Solar battery, and solar battery panel and method for manufacturing same
A solar battery according to the present embodiment has an electrode, which includes a metal and an adhesive material, formed in a conductive region including a polycrystalline semiconductor layer, and thus, the electrical characteristics of the solar battery may be improved and the manufacturing process thereof may be simplified. More specifically, the solar battery includes a semiconductor substrate, and the conductive region including the polycrystalline semiconductor layer is positioned on one surface of the semiconductor substrate.
1 . A solar battery, comprising:
a semiconductor substrate;
a conductive region positioned on one surface of the semiconductor substrate and including a polycrystalline semiconductor layer;
an electrode connected to the conductive region including the polycrystalline semiconductor layer and including a metal and an adhesive material;
a back surface passivation film covering the conductive region and defining a contact hole, the electrode being formed inside the contact hole to be spaced apart from the back surface passivation film; and
an adhesive layer positioned between the electrode and a wiring material to electrically connect the electrode and the wiring material,
wherein the adhesive layer includes a solder material and an additional adhesive material that is different than the adhesive material, and
wherein the electrode protrudes to be rounded or convexed toward the wiring material to form a rounded or convexed portion, and a width of the adhesive layer gradually increases toward the wiring material while completely covering the rounded or convexed portion of the electrode, and
wherein the adhesive layer includes a margin portion that is positioned outside the electrode, that is in direct contact with the conductive region, and that is spaced apart from the back surface passivation film.
2 . The solar battery of claim 1 , wherein the metal includes a first metal, and a compound layer including a metal-semiconductor compound made of the first metal and a semiconductor material included in the polycrystalline semiconductor layer is partially formed to correspond to a first region at a boundary between the electrode and the conductive region.
3 . The solar battery of claim 2 , wherein the metal and the adhesive material are formed in contact with the polycrystalline semiconductor layer in a second region excluding the first region at the boundary between the electrode and the conductive region.
4 . The solar battery of claim 2 , wherein the first metal includes nickel, the semiconductor material includes silicon, and the compound layer includes nickel silicide.
5 . The solar battery of claim 3 , wherein an area of the first region is smaller than that of the second region.
6 . The solar battery of claim 2 , wherein the metal further includes a second metal having a lower resistivity than the first metal.
7 . The solar battery of claim 2 , wherein a part by weight of the first metal is 15 or less based on total 100 parts by weight of the metal in the electrode.
8 . The solar battery of claim 1 , wherein the electrode includes a single printed layer including the metal and the adhesive material.
9 . The solar battery of claim 8 , wherein a thickness of the electrode or the single printed layer is 10 μm or more.
10 . The solar battery of claim 1 , wherein the conductive region includes a first conductive region and a second conductive region spaced apart from each other on the one surface of the semiconductor substrate,
the electrode includes a first electrode connected to the first conductive region and a second electrode connected to the second conductive region, and
at least one of the first electrode and the second electrode includes the metal and the adhesive material.
11 . The solar battery of claim 1 , wherein the solder material includes bismuth.
12 . The solar battery of claim 1 , wherein the additional adhesive material includes an organic material.
13 . The solar battery of claim 1 , wherein the adhesive material includes a first material, and the additional adhesive material includes a second material that is removed in greater quantities than the first material during a hardening heat treatment or an adhesive heat treatment.
14 . The solar battery of claim 1 , wherein a part by weight of the adhesive material included in the electrode is greater than that of the additional adhesive material included in the adhesive layer.