Methods of emitter formation in solar cells
First Claim
1. A method of forming a solar cell device, comprising:
- depositing a dielectric layer on a substrate;
patterning the dielectric layer to form a mask, thereby forming a pattern of exposed regions of the substrate;
disposing a first amount of a first dopant within the exposed regions of the substrate;
disposing a second amount of a second dopant within the exposed regions of the substrate, the dielectric layer, and the substrate below the dielectric layer after disposing the first dopant within the exposed regions, thereby forming a first doped region and a second doped region within the substrate, wherein the first dopant has a higher atomic mass than the second dopant; and
heating the substrate so that the first dopant diffuses a first depth within the substrate and the second dopant diffuses a second depth within the substrate, wherein the second depth of the second doped region is deeper than the first depth of the first doped region.
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Accused Products
Abstract
Embodiments of the invention contemplate high efficiency emitters in solar cells and novel methods for forming the same. One embodiment of the improved emitter structure, called a high-low type emitter, optimizes the solar cell performance by equally providing low contact resistance to minimize ohmic losses and isolation of the high surface recombination metal-semiconductor interface from the junction to maximize cell voltage. Another embodiment, called an alternating doping type emitter, provides regions of alternating doping type for use with point contacts in the back-contact solar cells. One embodiment of the methods includes depositing and patterning a doped or undoped dielectric layer on a surface of a substrate, implanting a fast-diffusing dopant and/or a slow-diffusing dopant into the substrate either simultaneously or sequentially, and annealing the substrate to drive in the dopants. Another embodiment of the methods includes using a physical mask to form a patterned dopant distribution in a substrate.
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Citations
30 Claims
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1. A method of forming a solar cell device, comprising:
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depositing a dielectric layer on a substrate; patterning the dielectric layer to form a mask, thereby forming a pattern of exposed regions of the substrate; disposing a first amount of a first dopant within the exposed regions of the substrate; disposing a second amount of a second dopant within the exposed regions of the substrate, the dielectric layer, and the substrate below the dielectric layer after disposing the first dopant within the exposed regions, thereby forming a first doped region and a second doped region within the substrate, wherein the first dopant has a higher atomic mass than the second dopant; and heating the substrate so that the first dopant diffuses a first depth within the substrate and the second dopant diffuses a second depth within the substrate, wherein the second depth of the second doped region is deeper than the first depth of the first doped region. - View Dependent Claims (6, 7, 8, 9, 10, 11, 12, 13)
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2. A method of forming a solar cell device, comprising:
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forming a dielectric layer on a surface of a substrate; removing a portion of the dielectric layer from the surface to expose a portion of the substrate; disposing a first amount of a first dopant within a region of the substrate which is adjacent to the exposed portion of the substrate; disposing a second amount of a second dopant within the region of the substrate; and heating the substrate to cause the first dopant to diffuse a first depth within the substrate and the second dopant to diffuse a second depth within the substrate, wherein the second depth is greater than the first depth. - View Dependent Claims (14, 15, 16, 17, 18, 19)
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3. A method of forming a solar cell device, comprising:
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positioning a physical mask over a surface of a substrate; disposing a first dopant into a first region of the substrate through an opening formed in the physical mask; disposing a second dopant into the region of the substrate through the opening formed in the physical mask; and heating the substrate to form a second region and a third region, wherein the concentration of the first dopant in the second region is greater than the second dopant concentration, the concentration of the second dopant in the third region is greater than the first dopant concentration, and the second region is closer to the surface of the substrate than the third region. - View Dependent Claims (20, 21, 22, 23, 24, 30)
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4. A method of forming a solar cell device, comprising:
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depositing a doped dielectric layer on a surface of a substrate, wherein the doped dilectric layer contains a first dopant material; removing a first region of the doped dielectric layer from the surface to form an opening in the doped dielectric layer and thereby expose a first portion of the substrate; disposing a second dopant material through the opening in the doped dielectric layer and within the first portion of the substrate which is adjacent to the surface of the substrate; heating the substrate to cause the first dopant material and the second dopant material to diffuse into the substrate; and removing a second region of the doped dielectric layer from the substrate to expose a second portion of the substrate. - View Dependent Claims (25, 26, 27, 28, 29)
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5. A method of forming a solar cell device, comprising:
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depositing a dielectric layer on a substrate; patterning the dielectric layer to form a mask, thereby forming a pattern of exposed regions of the substrate; disposing a first amount of a first dopant within the exposed regions of the substrate; disposing a second amount of a second dopant within the exposed regions of the substrate and the dielectric layer after disposing the first dopant within the exposed regions, thereby forming a first doped region and a second doped region within the substrate, wherein the first dopant has a higher atomic mass than the second dopant; and heating the substrate so that the first dopant diffuses a first depth within the substrate and the second dopant diffuses a second depth within the substrate, wherein the second depth of the second doped region is deeper than the first depth of the first doped region.
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Specification