Solar cells having hybrid architectures including differentiated p-type and n-type regions with offset contacts
A solar cell, and methods of fabricating said solar cell, are disclosed. The solar cell can include a first emitter region over a substrate, the first emitter region having a perimeter around a portion of the substrate. A first conductive contact is electrically coupled to the first emitter region at a location outside of the perimeter of the first emitter region.
1. A method of fabricating a solar cell, the method comprising:
forming a first emitter region over a substrate, the first emitter region having a perimeter around a portion of the substrate;
forming a first conductive contact electrically coupled to the first emitter region only at a location outside of the perimeter of the first emitter region through an opening in a first insulator layer, the first conductive contact having a portion that extends vertically over the first emitter region, wherein a portion of the first emitter region at the location outside of the perimeter of the first emitter region is not in direct physical contact with the substrate; and
forming a second insulator layer over the substrate, wherein a second portion of the first emitter region is within one or more openings in the second insulator layer and along a top surface of the second insulator layer, and wherein the second portion of the first emitter region is in contact with sidewalls of the one or more openings of the second dielectric layer and is in contact with the top surface of the second insulator layer.
2. The method of claim 1 , further comprising:
forming a first semiconductor layer over the substrate, wherein the first emitter region is in a first portion of the first semiconductor layer, and the location outside of the perimeter of the first emitter region is on a second portion of the first semiconductor layer.
3. The method of claim 2 , wherein the first portion of the first semiconductor layer is continuous with the second portion of the first semiconductor layer.
4. The method of claim 2 , further comprising:
forming a second semiconductor layer between the second insulator layer and the substrate, the second semiconductor layer having a conductivity type opposite a conductivity type of the first semiconductor layer, and the second semiconductor layer included in a second emitter region of the solar cell.
5. The method of claim 4 , wherein the second insulator layer has another opening, the method further comprising:
forming a second conductive contact electrically coupled to the second semiconductor layer at a location beneath the other opening of the second insulator layer.
6. The method of claim 2 , wherein the first semiconductor layer comprises polycrystalline silicon, and the substrate comprises monocrystalline silicon.
7. The method of claim 6 , further comprising:
forming a dielectric layer between the first semiconductor layer and the substrate.