Solar cell emitter region fabrication using ion implantation
Methods of fabricating solar cell emitter regions using ion implantation, and resulting solar cells, are described. In an example, a method of fabricating alternating N-type and P-type emitter regions of a solar cell involves forming a silicon layer above a substrate. Dopant impurity atoms of a first conductivity type are implanted, through a first shadow mask, in the silicon layer to form first implanted regions and resulting in non-implanted regions of the silicon layer. Dopant impurity atoms of a second, opposite, conductivity type are implanted, through a second shadow mask, in portions of the non-implanted regions of the silicon layer to form second implanted regions and resulting in remaining non-implanted regions of the silicon layer. The remaining non-implanted regions of the silicon layer are removed with a selective etch process, while the first and second implanted regions of the silicon layer are annealed to form doped polycrystalline silicon emitter regions.
1. A back contact solar cell, comprising:
a monocrystalline silicon substrate having a light-receiving surface and a back surface;
a thin dielectric layer disposed on the back surface of the monocrystalline silicon substrate;
a polycrystalline silicon emitter region disposed on the thin dielectric layer, the polycrystalline silicon emitter region doped with impurity atoms;
a carbosilane layer disposed on, and aligned with, the polycrystalline silicon emitter region; and
a conductive contact structure disposed through the carbosilane layer and on the polycrystalline silicon emitter region.
2. The back contact solar cell of claim 1 , wherein the carbosilane layer is also doped with the impurity atoms.
3. The back contact solar cell of claim 1 , wherein the polycrystalline silicon emitter region is hydrogenated.
4. The back contact solar cell of claim 1 , further comprising texturized portions of the substrate adjacent to the polycrystalline silicon emitter region.
5. The back contact solar cell of claim 1 , wherein the impurity atoms are boron atoms.
6. The back contact solar cell of claim 1 , wherein the impurity atoms are phosphorous atoms.
7. A solar cell, comprising:
a thin dielectric layer disposed on a surface of a substrate;
a silicon layer disposed on the thin dielectric layer, the silicon layer doped with impurity atoms;
a carbon carbosilane layer disposed on the silicon layer, the carbon carbosilane layer aligned with and separate and distinct from the silicon layer; and
a conductive contact structure disposed through the carbon carbosilane layer and on the silicon layer.
8. The solar cell of claim 7 , wherein the carbon carbosilane layer is also doped with the impurity atoms.
9. The solar cell of claim 7 , wherein the silicon layer is hydrogenated.
10. The solar cell of claim 7 , further comprising texturized portions of the substrate.
11. The solar cell of claim 7 , wherein the impurity atoms are boron atoms or phosphorous atoms.