SOLAR CELL AND PROCESS FOR MANUFACTURING A SOLAR CELL
In various embodiments, a solar cell is provided, comprising: a substrate with a front-side and a rear-side, wherein at least the front-side receives light; a passivation layer on the rear-side of the substrate; local contact openings, which pass through the passivation layer and partially expose the rear-side of the substrate; and a first rear-side metallization on the passivation layer and in the local contact openings; wherein the plurality of the local contact openings are disposed such that they are completely covered by the first rear-side metallization.
1 . A solar cell comprising:
a substrate with a front-side and a rear-side, wherein at least the front-side receives light,
a passivation layer on the rear-side of the substrate;
a plurality of local contact openings in the form of linear trenches, which pass through the passivation layer and partially expose the rear-side of the substrate; and
a first rear-side metallization on the passivation layer and in the local contact openings;
wherein the plurality of the local contact openings are disposed such that they are completely covered by the first rear-side metallization.
2 . The solar cell of claim 1 ,
wherein the distance of the local contact openings to the edge of the first rear-side metallization is at least 10 μm, preferably at least 50 μm.
3 . The solar cell of claim 1 ,
wherein the first rear-side metallization includes aluminum.
4 . The solar cell of claim 1 ,
wherein the rear-side metallization comprises flat openings in the first rear-side metallization, which partially expose the passivation layer.
5 . The solar cell of claim 4 ,
wherein a second, preferably well solderable metallization is disposed in the flat openings.
6 . The solar cell of claim 5 ,
wherein the second metallization includes silver, nickel and/or zinc.
7 . The solar cell of claim 4 ,
wherein the flat openings divide the first rear-side metallization into a plurality of rear-side metallization segments, which are respectively disposed at a distance from each other, wherein each contact opening of the plurality of local contact openings is completely covered by a rear-side metallization segment of the plurality of rear-side metallization segments.
8 . The solar cell of claim 1 , further comprising:
at least one more local contact opening in the form of a linear trench, which passes through the passivation layer and partially exposes the rear-side of the substrate, wherein the further local contact opening is formed such that this is partially covered by the first rear-side metallization.
9 . The solar cell of claim 8 ,
wherein the further local contact opening is interrupted at one end section, which protrudes beyond the first rear-side metallization.
10 . The solar cell of claim 1 ,
wherein silver is contained in the local contact openings for forming a respective local contact with the rear-side of the substrate.
11 . The solar cell of claim 5 ,
wherein the second metallization is placed on the unopened passivation layer regions.
12 . A method for manufacturing a solar cell, the method comprising:
forming a passivation layer on the rear-side of a substrate;
forming local contact openings through the passivation layer, so that the rear-side of the substrate is partially exposed; and
forming a first rear-side metallization on the passivation layer and in the local contact openings;
wherein the local contact openings are disposed such that they are completely covered by the rear-side metallization.
13 . The method of claim 12 ,
wherein the local contact openings are formed by means of Laser beam.
14 . The method of claim 13 ,
wherein the extension of the local contact openings is restricted by controlling the Laser beam.
15 . The method of claim 13 ,
wherein the extension of the local contact openings is restricted by using at least one shadow-mask.
16 . The method of claim 12 ,
wherein the local contact openings are etched.
17 . The method of claim 12 ,
wherein the local contact openings are formed such that the distance from each single local contact opening of the local contact openings to the edge of the rear-side metallization is at least 10 μm, preferably at least 50 μm.
18 . The method of claim 12 ,
wherein the first rear-side metallization includes flat openings, which partially expose the passivation layer;
wherein the flat openings divide the first rear-side metallization into a plurality of rear-side metallization segments, which are respectively disposed at a distance from each other, wherein each contact opening of the plurality of local contact openings is completely covered by a rear-side metallization segment of the plurality of rear-side metallization segments.
19 . The method of claim 18 ,
wherein the flat openings are formed, in which the plurality of rear-side metallization segments is formed in the form of stripes; or wherein the flat openings are formed, in which a portion of the rear-side metallization is removed.
20 . The method of claim 12 , further comprising:
forming at least one more local contact opening in the form of a linear trench, which passes through the passivation layer and partially exposes the rear-side of the substrate, wherein the further contact opening is formed such that this is partially covered by the first rear-side metallization.
21 . The method of claim 20 ,
wherein the further local contact opening is formed interrupted at one end section, which protrudes beyond the first rear-side metallization.