Method of forming contacts for a back-contact solar cell

1. A method of forming contacts for a solar cell, the method comprising:

forming a dielectric layer on a substrate;

forming a silicon layer over the dielectric layer;

forming a solid-state p-type dopant source on the silicon layer;

patterning the solid-state p-type dopant source, the patterning exposing regions of the silicon layer between the plurality of regions of the solid-state p-type dopant source;

forming an n-type dopant source layer over the exposed regions of the silicon layer and the plurality of regions of the solid-state p-type dopant source;

forming a plurality of n-type dopant-containing silicon regions between the plurality of regions of the solid-state p-type dopant source; and

forming trenches in the plurality of n-type dopant-containing silicon regions and partially in the substrate, wherein the trenches are formed between the plurality of n-type dopant-containing silicon regions and the plurality of regions of the solid-state p-type dopant source; and

heating the substrate to provide a plurality of n-type doped silicon regions among a plurality of p-type doped silicon regions.

2. The method of claim 1 , further comprising before to the heating:

removing the plurality of regions of the solid-state p-type dopant source.

3. The method of claim 2 , wherein removing the plurality of regions of the solid-state p-type dopant source comprises performing a wet etch technique.

4. The method of claim 2 , wherein removing the plurality of regions of the solid-state p-type dopant source comprises applying an aqueous hydrofluoric (HF) acid or aqueous hydrofluoric (HF) acid derivative.

5. The method of claim 1 , further comprising:

subsequent to forming the trenches, texturizing portions of the substrate exposed by the trenches.

6. The method of claim 5 , wherein forming the trenches and the texturizing is performed without a cure operation between the forming the trenches and the texturizing.

7. The method of claim 1 , wherein forming the n-type dopant source layer further comprises at least partially driving dopants from the plurality of regions of the solid-state p-type dopant source into the silicon layer.

8. A solar cell fabricated according to the method of claim 1 .

9. A method of forming contacts for a solar cell, the method comprising:

forming a tunnel oxide layer over a substrate;

forming a polysilicon layer over the tunnel oxide layer;

forming a solid-state p-type dopant source on the polysilicon layer;

patterning the solid-state p-type dopant source,

forming an n-type dopant source layer over the exposed regions of the polysilicon layer and the plurality of regions of the solid-state p-type dopant source;

forming a plurality of n-type dopant-containing polysilicon regions between the plurality of regions of the solid-state p-type dopant source; and

forming trenches in the plurality of n-type dopant-containing polysilicon regions and partially in the substrate, wherein the trenches are formed between the plurality of n-type dopant-containing polysilicon regions and the plurality of regions of the solid-state p-type dopant source; and

heating the substrate to provide a plurality of n-type doped polysilicon regions among a plurality of p-type doped polysilicon regions; and, subsequent to heating, forming conductive contacts coupled to the plurality of n-type dopant-containing silicon regions and the p-type dopant-containing silicon regions.

10. The method of claim 9 , further comprising before to the heating:

removing the plurality of regions of the solid-state p-type dopant source.

11. The method of claim 10 , wherein removing the plurality of regions of the solid-state p-type dopant source comprises performing a wet etch technique.

12. The method of claim 10 , wherein removing the plurality of regions of the solid-state p-type dopant source comprises applying an aqueous hydrofluoric (HF) acid or aqueous hydrofluoric (HF) acid derivative.

13. The method of claim 9 , further comprising:

subsequent to forming the trenches, texturizing portions of the substrate exposed by the trenches.

14. The method of claim 13 , wherein forming the trenches and the texturizing is performed without a cure operation between the forming the trenches and the texturizing.

15. The method of claim 9 , wherein forming the n-type dopant source layer further comprises at least partially driving dopants from the plurality of regions of the solid-state p-type dopant source into the polysilicon layer.

16. A solar cell fabricated according to the method of claim 9 .