Method of fabricating a solar cell
Methods of fabricating solar cells are described. A porous layer may be formed on a surface of a substrate, the porous layer including a plurality of particles and a plurality of voids. A solution may be dispensed into one or more regions of the porous layer to provide a patterned composite layer. The substrate may then be heated.
1. A method of fabricating a solar cell, the method comprising:
forming a porous layer on a surface of a substrate, the porous layer comprising a plurality of particles and a plurality of voids;
dispensing a solution into first and second regions, but not into a region between the first and second regions, of the porous layer to provide a patterned composite layer;
etching to remove the region between the first and second regions without etching the first and second regions; and, subsequently,
heating the substrate.
2. The method of claim 1 , wherein heating the substrate comprises consolidating the patterned composite layer.
3. The method of claim 1 , wherein dispensing the solution comprises dispensing a solution comprising a dopant source of charge carrier impurity atoms for the substrate.
4. The method of claim 3 , wherein heating the substrate comprises driving the charge carrier impurity atoms of the dopant source into the substrate.
5. The method of claim 4 , wherein the dopant source is an N-type dopant source for silicon, the method further comprising:
dispensing a second solution into one or more other regions of the porous layer to provide a dual-patterned composite layer, wherein dispensing the second solution comprises dispensing a solution comprising a P-type dopant source of charge carrier impurity atoms for the substrate, and wherein heating the substrate further comprises driving the charge carrier impurity atoms of the P-type dopant source into the substrate.
6. The method of claim 1 , wherein forming the porous layer on the surface of the substrate comprises forming each void of the plurality of voids to have a dimension suitable to receive the solution at the surface of the substrate and to restrict lateral diffusion of the solution.
7. The method of claim 1 , wherein dispensing the solution comprises using an ink jet process.
8. The method of claim 7 , wherein the solution has a viscosity of approximately 10 centipoise.
9. The method of claim 1 , wherein forming the porous layer on the substrate comprises forming the porous layer on, and conformal with, a surface having a surface roughness, wherein the porous layer has a thickness approximately in the range of 0.5-20 microns.
10. The method of claim 1 , wherein the porous layer is a solid, and wherein forming the porous layer comprises:
providing, as a mixture, the plurality of particles and a solvent; and
evaporating the solvent to provide the porous layer from the mixture.
11. A method of fabricating a solar cell, the method comprising:
forming a porous layer on a surface of a substrate, the porous layer comprising a plurality of particles and a plurality of voids;
dispensing a solution into first and second regions, but not into a region between the first and second regions, of the porous layer to provide a patterned composite layer, the solution comprising a dopant source of charge carrier impurity atoms for the substrate; and
etching to remove the region between the first and second regions without etching the first and second regions.
12. The method of claim 11 , wherein the dopant source is an N-type dopant source for silicon, the method further comprising:
dispensing a second solution into one or more other regions of the porous layer to provide a dual-patterned composite layer, wherein dispensing the second solution comprises dispensing a solution comprising a P-type dopant source of charge carrier impurity atoms for the substrate.
13. The method of claim 12 , wherein dispensing the solution and the second solution comprises dispensing both the solution and the second solution in a single pass of the porous layer.
14. The method of claim 12 , wherein dispensing the solution and the second solution comprises dispensing the solution in a first pass of the porous layer and dispensing the second solution in a second, separate, pass of the porous layer.
15. The method of claim 11 , wherein forming the porous layer on the surface of the substrate comprises forming each void of the plurality of voids to have a dimension suitable to receive the solution at the surface of the substrate and to restrict lateral diffusion of the solution.
16. The method of claim 11 , wherein dispensing the solution comprises using an ink jet process.
17. The method of claim 11 , wherein forming the porous layer on the substrate comprises forming the porous layer on, and conformal with, a surface having a surface roughness, wherein the porous layer has a thickness approximately in the range of 0.5-20 microns.
18. The method of claim 11 , wherein the porous layer is a solid, and wherein forming the porous layer comprises:
providing, as a mixture, the plurality of particles and a solvent; and
evaporating the solvent to provide the porous layer from the mixture.