초록 ▼

A solar cell includes polysilicon P-type and N-type doped regions on a backside of a substrate, such as a silicon wafer. An interrupted trench structure separates the P-type doped region from the N-type doped region in some locations but allows the P-type doped region and the N-type doped region to

A solar cell includes polysilicon P-type and N-type doped regions on a backside of a substrate, such as a silicon wafer. An interrupted trench structure separates the P-type doped region from the N-type doped region in some locations but allows the P-type doped region and the N-type doped region to touch in other locations. Each of the P-type and N-type doped regions may be formed over a thin dielectric layer. Among other advantages, the resulting solar cell structure allows for increased efficiency while having a relatively low reverse breakdown voltage.

대표청구항 ▼

1. A method of fabricating a solar cell, the method comprising: forming a first dielectric layer on a solar cell substrate;forming a P-type doped region and an N-type doped region on a backside of a solar cell substrate, the P-type and N-type doped regions being over the first dielectric layer, the

1. A method of fabricating a solar cell, the method comprising: forming a first dielectric layer on a solar cell substrate;forming a P-type doped region and an N-type doped region on a backside of a solar cell substrate, the P-type and N-type doped regions being over the first dielectric layer, the backside being opposite a front side of the solar cell that faces the sun during normal operation, the substrate comprising an N-type silicon wafer;physically separating the P-type doped region and the N-type doped region in some locations and allowing the P-type doped region and the N-type doped region to touch in other locations; anddepositing a second dielectric over the P-type doped region and the N-type doped region;wherein the P-type doped region comprises polysilicon that is pre-doped with a P-type dopant prior to deposition over the first dielectric layer and the N-type doped region comprises polysilicon that is pre-doped with an N-type dopant prior to formation over the first dielectric layer. 2. The method of claim 1 wherein the P-type doped region and the N-type doped region are physically separated by an interrupted trench. 3. The method of claim 2 further comprising: randomly texturing a surface of the interrupted trench. 4. The method of claim 1 wherein the second dielectric layer comprises silicon nitride. 5. The method of claim 1 further comprising: electrically coupling a first metal contact finger to the P-type doped region on the backside of the substrate; andelectrically coupling a second metal contact finger to the N-type doped region on the backside of the substrate. 6. A method of fabricating a solar cell, the method comprising: forming a P-type doped region and an N-type doped region on a backside of a solar cell substrate, the P-type and N-type doped regions being over a dielectric layer separating the P-type and N-type doped regions from a solar cell substrate, the backside being opposite a front side of the solar cell that faces the sun during normal operation; andphysically separating the P-type doped region and the N-type doped region in some locations and allowing the P-type doped region and the N-type doped region to touch in other locations;wherein the P-type doped region comprises polysilicon that is pre-doped with a P-type dopant prior to deposition over the dielectric layer and the N-type doped region comprises polysilicon that is pre-doped with an N-type dopant prior to formation over the dielectric layer. 7. The method of claim 6 wherein the P-type doped region and the N-type doped region are physically separated by an interrupted trench. 8. The method of claim 6 further comprising: randomly texturing a surface of the interrupted trench. 9. The method of claim 6 further comprising: electrically coupling a first metal contact finger to the P-type doped region on the backside of the substrate; andelectrically coupling a second metal contact finger to the N-type doped region on the backside of the substrate. 10. The method of claim 6 wherein the dielectric layer comprises silicon dioxide. 11. The method of claim 6 wherein the solar cell substrate comprises an N-type silicon wafer. 12. A method of fabricating a solar cell, the method comprising: forming a P-type doped region and an N-type doped region on a backside of a solar cell substrate, the P-type and N-type doped regions being over a dielectric layer separating the P-type and N-type doped regions from a solar cell substrate, the backside being opposite a front side of the solar cell that faces the sun during normal operation; andforming an interrupted trench that physically separates the P-type doped region and the N-type doped region in some locations, the interrupted trench dividing the dielectric layer in the some locations where the P-type doped region and the N-type doped region are physically separated by the interrupted trench. 13. The method of claim 12 further comprising: randomly texturing a surface of the interrupted trench. 14. The method of claim 12 further comprising: electrically coupling a first metal contact finger to the P-type doped region on the backside of the substrate; andelectrically coupling a second metal contact finger to the N-type doped region on the backside of the substrate. 15. The method of claim 12 wherein the P-type doped region comprises polysilicon that is pre-doped with a P-type dopant prior to deposition over the dielectric layer and the N-type doped region comprises polysilicon that is pre-doped with an N-type dopant prior to formation over the dielectric layer. 16. The method of claim 12 wherein forming the P-type doped region comprises: diffusing dopants from a dopant source to a polysilicon layer, the dopant source being a layer of material formed over the polysilicon layer. 17. The method of claim 12 wherein the solar cell substrate comprises an N-type silicon wafer.