Interdigitated Back Contact Silicon Solar Cells With Separating Grooves
First Claim
1. A method of fabricating an IBC solar cell, the method comprising:
- diffusing a first dopant into a rear surface of a semiconductor substrate such that first and second spaced-apart diffusion regions of the substrate have a first doping concentration and extends a first depth into the substrate from the rear surface, and are separated by a third diffusion region having a second doping concentration and extending a second depth into the substrate from the rear surface; and
forming a plurality of grooves in the rear surface of the semiconductor substrate such that the first diffusion region is separated from the third diffusion region by a first groove, and such that the second diffusion region is separated from the third diffusion region by a second groove.
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Accused Products
Abstract
Interdigitated back contact (IBC) solar cells are produced by depositing spaced-apart parallel pads of a first dopant bearing material (e.g., boron) on a substrate, heating the substrate to both diffuse the first dopant into corresponding first (e.g., p+) diffusion regions and to form diffusion barriers (e.g., borosilicate glass) over the first diffusion regions, and then disposing the substrate in an atmosphere containing a second dopant (e.g., phosphorus) such that the second dopant diffuses through exposed surface areas of the substrate to form second (e.g., n+) diffusion regions between the first (p+) diffusion regions (the diffusion barriers prevent the second dopant from diffusion into the first (p+) diffusion regions). The substrate material along each interface between adjacent first (p+) and second (n+) diffusion regions is then removed (e.g., using laser ablation) such that elongated grooves, which extend deeper into the substrate than the diffused dopant, are formed between adjacent diffusion regions.
102 Citations
16 Claims
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1. A method of fabricating an IBC solar cell, the method comprising:
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diffusing a first dopant into a rear surface of a semiconductor substrate such that first and second spaced-apart diffusion regions of the substrate have a first doping concentration and extends a first depth into the substrate from the rear surface, and are separated by a third diffusion region having a second doping concentration and extending a second depth into the substrate from the rear surface; and forming a plurality of grooves in the rear surface of the semiconductor substrate such that the first diffusion region is separated from the third diffusion region by a first groove, and such that the second diffusion region is separated from the third diffusion region by a second groove. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method of fabricating an IBC solar cell, the method comprising:
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diffusing a first dopant into a rear surface of a semiconductor substrate such that first and second spaced-apart diffusion regions of the substrate have a first doping concentration and extends a first depth into the substrate from the rear surface, and are separated by a third diffusion region having a second doping concentration and extending a second depth into the substrate from the rear surface; removing an elongated first portion of the semiconductor substrate that extends a third depth into the rear surface and is disposed between the first diffusion region and the third diffusion region such that the first diffusion region is entirely separated from the third diffusion region by a first groove; and removing an elongated second portion of the semiconductor substrate that extends said third depth into the rear surface and is disposed between the second diffusion region and the third diffusion region such that the second diffusion region is entirely separated from the third diffusion region by a second groove, wherein the third depth is greater than either of the first depth and the second depth. - View Dependent Claims (12, 13)
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14. A method of fabricating an IBC solar cell, the method comprising:
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diffusing a first dopant into a rear surface of a semiconductor substrate such that first and second spaced-apart diffusion regions of the substrate have a first doping concentration and extends a first depth into the substrate from the rear surface, diffusing a second dopant into the rear surface of the semiconductor substrate such that a third diffusion region of the substrate has a second doping concentration and extends a second depth into the substrate from the rear surface, the third diffusion region being disposed between the first and second diffusion regions; and removing an elongated first portion of the semiconductor substrate that extends a third depth into the rear surface and is disposed between the first diffusion region and the third diffusion region and an elongated second portion of the semiconductor substrate that extends said third depth into the rear surface and is disposed between the second diffusion region and the third diffusion region, said elongated first and second portions being formed such that the first diffusion region is entirely separated from the third diffusion region by a first groove, and such that the second diffusion region is entirely separated from the third diffusion region by a second groove, wherein the third depth is greater than either of the first depth and the second depth. - View Dependent Claims (15, 16)
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Specification