Abstract:
Methods of fabricating solar cell emitter regions with differentiated P-type and N-type regions architectures, and resulting solar cells, are described. In an example, a back contact solar cell can include a substrate having a light-receiving surface and a back surface. A first polycrystalline silicon emitter region of a first conductivity type is disposed on a first thin dielectric layer disposed on the back surface of the substrate. A second polycrystalline silicon emitter region of a second, different, conductivity type is disposed on a second thin dielectric layer disposed on the back surface of the substrate. A third thin dielectric layer is disposed over an exposed outer portion of the first polycrystalline silicon emitter region and is disposed laterally directly between the first and second polycrystalline silicon emitter regions. A first conductive contact structure is disposed on the first polycrystalline silicon emitter region. A second conductive contact structure is disposed on the second polycrystalline silicon emitter region. Metallization methods, include etching techniques for forming a first and second conductive contact structure are also described.
Abstract:
A bypass diode can include a first conductive region of a first conductivity type disposed above a substrate of a solar cell and a second conductive region of a second conductivity type disposed above the first conductive region. The bypass diode can include a thin dielectric region disposed directly between the first and second conductive regions.
Abstract:
Enhanced adhesion of seed layers for solar cell conductive contacts and methods of forming solar cell conductive contacts are described. For example, a method of fabricating a solar cell includes forming an adhesion layer above an emitter region of a substrate. A metal seed paste layer is formed on the adhesion layer. The metal seed paste layer and the adhesion layer are annealed to form a conductive layer in contact with the emitter region of the substrate. A conductive contact for the solar cell is formed from the conductive layer.
Abstract:
Methods of fabricating solar cells having passivation layers, and the resulting solar cells, are described. In an example, a solar cell includes a substrate having a first surface and a second surface. A plurality of emitter regions is disposed on the first surface of the substrate and spaced apart from one another. An amorphous silicon passivation layer is disposed on each of the plurality of emitter regions and between each of the plurality of emitter regions, directly on an exposed portion of the first surface of the substrate.
Abstract:
A method of fabricating a solar cell can include forming a dielectric region on a silicon substrate. The method can also include forming an emitter region over the dielectric region and forming a dopant region on a surface of the silicon substrate. In an embodiment, the method can include heating the silicon substrate at a temperature above 900 degrees Celsius to getter impurities to the emitter region and drive dopants from the dopant region to a portion of the silicon substrate.
Abstract:
A thin epitaxial silicon solar cell includes one or more layers of doped oxides on the backside. A silicon nitride layer that serves as a moisture barrier is formed on the one or more layers of doped oxides (207). The doped oxides provide dopants for forming doped regions in an epitaxial silicon layer. Metal contacts are electrically coupled to the doped regions through the silicon nitride layer and the one or more layers of doped oxides (208, 209).
Abstract:
Methods of fabricating solar cell emitter regions using silicon nano-particles and the resulting solar cells are described. In an example, a method of fabricating an emitter region of a solar cell includes forming a region of doped silicon nano-particles above a dielectric layer disposed above a surface of a substrate of the solar cell. A layer of silicon is formed on the region of doped silicon nano-particles. At least a portion of the layer of silicon is mixed with at least a portion of the region of doped silicon nano-particles to form a doped polycrystalline silicon layer disposed on the dielectric layer.
Abstract:
Tri-layer semiconductor stacks for patterning features on solar cells, and the resulting solar cells, are described herein. In an example, a solar cell includes a substrate. A semiconductor structure is disposed above the substrate. The semiconductor structure includes a P-type semiconductor layer disposed directly on a first semiconductor layer. A third semiconductor layer is disposed directly on the P-type semiconductor layer. An outermost edge of the third semiconductor layer is laterally recessed from an outermost edge of the first semiconductor layer by a width. An outermost edge of the P-type semiconductor layer is sloped from the outermost edge of the third semiconductor layer to the outermost edge of the third semiconductor layer. A conductive contact structure is electrically connected to the semiconductor structure.
Abstract:
Methods of fabricating solar cell emitter regions using substrate-level ion implantation, and resulting solar cells, are described. In an example, a method of fabricating a solar cell involves forming a lightly doped region in a semiconductor substrate by ion implantation, the lightly doped region of a first conductivity type of a first concentration. The method also involves forming a first plurality of dopant regions of the first conductivity type of a second, higher, concentration by ion implantation, the first plurality of dopant regions overlapping with a first portion of the lightly doped region. The method also involves forming a second plurality of dopant regions by ion implantation, the second plurality of dopant regions having a second conductivity type of a concentration higher than the first concentration, and the second plurality of dopant regions overlapping with a second portion of the lightly doped region and alternating with but not overlapping the first plurality of dopant regions.
Abstract:
A solar cell may include a substrate having a front side facing the sun to receive solar radiation during normal operation and a backside opposite the front side. The solar cell may further include a polysilicon layer formed over the backside of the substrate. A P-type diffusion region and an N-type diffusion region may be formed in the polysilicon layer to provide a butting PN junction. The P-type diffusion region may have a first dopant concentration level and the N-type diffusion region may have a second dopant concentration level such that the first dopant concentration level is less than the second dopant concentration level.