SOLAR CELL EMITTER REGION FABRICATION USING ION IMPLANTATION

摘要

Methods of fabricating solar cell emitter regions using ion implantation, and resulting solar cells, are described. In an example, a back contact solar cell includes a crystalline silicon substrate having a light-receiving surface and a back surface. A first polycrystalline silicon emitter region is disposed above the crystalline silicon substrate. The first polycrystalline silicon emitter region is doped with dopant impurity species of a first conductivity type and further includes ancillary impurity species different from the dopant impurity species of the first conductivity type. A second polycrystalline silicon emitter region is disposed above the crystalline silicon substrate and is adjacent to but separated from the first polycrystalline silicon emitter region. The second polycrystalline silicon emitter region is doped with dopant impurity species of a second, opposite, conductivity type. First and second conductive contact structures are electrically connected to the first and second polycrystalline silicon emitter regions, respectively.

主权项

1. A method of fabricating alternating N-type and P-type emitter regions of a solar cell, the method comprising:
forming a silicon layer above a substrate; implanting dopant impurity species of a first conductivity type in the silicon layer to form first implanted regions and resulting in non-implanted regions of the silicon layer; implanting ancillary impurity species into the first implanted regions of the silicon layer, the ancillary impurity species different from the dopant impurity species of the first conductivity type; implanting dopant impurity species of a second, opposite, conductivity type 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; removing the remaining non-implanted regions of the silicon layer with a selective etch process preserving at least a portion of the first implanted regions and preserving the second implanted regions of the silicon layer; and annealing the first implanted regions and the second implanted regions of the silicon layer to form doped polycrystalline silicon emitter regions.