METAL-ASSISTED ETCH COMBINED WITH REGULARIZING ETCH
A silicon-containing substrate including a top surface which comprises nanostructuring having a plurality of rounded depressions with depths greater than 20 nm.
1 . A silicon-containing substrate having a top surface which comprises nanostructuring having a plurality of rounded depressions with depths greater than 20 nm.
2 . The substrate of claim 1 , comprising polycrystalline silicon.
3 . The substrate of claim 2 , wherein the nanostructuring was formed through a metal-assisted chemical etching.
4 . The substrate of claim 3 , wherein a plurality of the rounded depressions have depths greater than 50 nm.
5 . The substrate of claim 4 , further comprising at least one screen printed contact.
6 . The substrate of claim 4 , wherein a plurality of the rounded depressions have depths greater than 100 nm.
7 . The substrate of claim 6 , further comprising at least one screen printed contact.
8 . The substrate of claim 6 , further comprising residual metal deposits in at least some of the rounded depressions.
9 . The substrate of claim 4 , further comprising residual metal deposits in at least some of the rounded depressions.
10 . The substrate of claim 3 , further comprising a p-n junction, wherein a plurality of the depressions have depths greater than 100 nm.
11 . The substrate of claim 10 , wherein the p-n junction is a diffused p-n junction.
12 . The substrate of claim 11 , wherein the p-n junction is below the plurality of rounded depressions.
13 . The substrate of claim 12 , wherein the rounded depressions have a density on the substrate of at least 10 per square micron.
14 . The substrate of claim 12 , wherein the rounded depressions have a density on the substrate of at least 20 per square micron.
15 . The substrate of claim 12 , wherein the substrate has at least one region measuring 1 micron by 1 micron with at least 10 rounded depressions.
16 . The substrate of claim 15 , wherein the substrate has at least one region measuring 1 micron by 1 micron with at least 20 rounded depressions.
17 . The substrate of claim 15 , further comprising a SiN passivation layer in contact with the nanostructuring.
18 . The substrate of claim 17 , further comprising residual metal deposits in at least some of the rounded depressions.
19 . The substrate of claim 18 , wherein the residual metal deposits comprise Ag.
20 . The substrate of claim 12 , further comprising residual metal deposits in at least some of the rounded depressions.
21 . The substrate of claim 20 , further comprising at least one screen printed contact.
22 . The substrate of claim 21 , further comprising a rear contact.
23 . The substrate of claim 20 , where the residual metal deposits comprise Ag.