Abstract: One embodiment of the present invention provides a method for fabricating solar cells. During operation, an anti-reflection layer is deposited on top of a semiconductor structure to form a photovoltaic structure, and a front-side electrode grid comprising a metal stack is formed on top of the photovoltaic structure. The metal stack comprises a metal-adhesive layer comprising Ti or Ta, and a conducting layer comprising Cu or Ag situated above the metal-adhesive layer.

Abstract: One embodiment of the present invention provides a wafer-carrier system used in a deposition chamber for carrying wafers. The wafer-carrier system includes a base susceptor and a top susceptor nested inside the base susceptor with its wafer-mounting side facing the base susceptor's wafer-mounting side, thereby forming a substantially enclosed narrow channel. The base susceptor provides an upward support to the top susceptor.

Abstract: One embodiment of the present invention provides a support system for providing dynamic support to a deposition reactor. The system includes a coupling mechanism configured to provide coupling between the deposition reactor and the support system, an attachment mechanism configured to attach the support system to an external frame, and at least one gas bellows situated between the coupling mechanism and the attachment mechanism.

Abstract: One embodiment of the present invention provides a solar cell. The solar cell includes a photovoltaic structure, a transparent-conductive-oxide (TCO) layer situated above the photovoltaic structure, and a front-side metal grid situated above the TCO layer. The TCO layer is in contact with the front surface of the photovoltaic structure. The metal grid includes at least one of: Cu and Ni.

Abstract: One embodiment of the present invention provides a solar cell with shade-free front electrode. The solar cell includes a photovoltaic body, a front-side ohmic contact layer situated above the photovoltaic body, a back-side ohmic contact layer situated below the photovoltaic body, a front-side electrode situated above the front-side ohmic contact layer, and a back-side electrode situated below the back-side ohmic contact layer. The front-side electrode includes a plurality of parallel metal grid lines, and the surface of at least one metal grid line is curved, thereby allowing incident light hitting the curved surface to be reflected downward and absorbed by the solar cell surface adjacent to the metal grid line.

Abstract: One embodiment of the present invention provides a gas-delivery system for delivering reaction gas to a reactor chamber. The gas-delivery system includes a main gas-inlet port for receiving reaction gases and a gas-delivery plate that includes a plurality of gas channels. A gas channel includes a plurality of gas holes for allowing the reaction gases to enter the reactor chamber from the gas channel. The gas-delivery system further includes a plurality of sub-gas lines coupling together the main gas-inlet port and the gas-delivery plate, and a respective sub-gas line is configured to deliver a portion of the received reaction gases to a corresponding gas channel.

Abstract: One embodiment of the present invention provides a tunneling junction based solar cell. The solar cell includes a base layer; a quantum-tunneling-barrier (QTB) layer situated adjacent to the base layer; an emitter; a surface field layer; a front-side electrode; and a back-side electrode.

Abstract: One embodiment of the present invention provides a solar cell. The solar cell includes a substrate, a first heavily doped crystalline-Si (c-Si) layer situated above the substrate, a lightly doped c-Si layer situated above the first heavily doped crystalline-Si layer, a second heavily doped c-Si layer situated above the lightly doped c-Si layer, a front side electrode grid situated above the second heavily doped c-Si layer, and a backside electrode grid situated on the backside of the substrate.

Abstract: One embodiment of the present invention provides a double-sided heterojunction solar cell. The solar cell includes a lightly doped epitaxial crystalline Si (c-Si) base layer, a front-side passivation layer situated on the front side of the lightly doped epitaxial c-Si base layer, a back-side passivation layer situated on the back side of the lightly doped epitaxial c-Si base layer, a front-side emitter situated on the surface of the front-side passivation layer, a back surface field (BSF) layer situated on the surface of the back-side passivation layer, a front-side electrode, and a back-side electrode.

Abstract: One embodiment provides a reactor for material deposition. The reactor includes a chamber and at least one gas nozzle. The chamber includes a pair of susceptors, each having a front side and a back side. The front side mounts a number of substrates. The susceptors are positioned vertically so that the front sides of the susceptors face each other, and the vertical edges of the susceptors are in contact with each other, thereby forming a substantially enclosed narrow channel between the substrates mounted on different susceptors. The gas nozzle includes a gas-inlet component situated in the center and a detachable gas-outlet component stacked around the gas-inlet component. The gas-inlet component includes at least one opening coupled to the chamber, and is configured to inject precursor gases into the chamber. The detachable gas-outlet component includes at least one opening coupled to the chamber, and is configured to output exhaust gases from the chamber.

Abstract: One embodiment of the present invention provides a double-sided heterojunction solar cell module. The solar cell includes a frontside glass cover, a backside glass cover situated below the frontside glass cover, and a number of solar cells situated between the frontside glass cover and the backside glass cover. Each solar cell includes a semiconductor multilayer structure situated below the frontside glass cover, including: a frontside electrode grid, a first layer of heavily doped amorphous Si (a-Si) situated below the frontside electrode, a layer of lightly doped crystalline-Si (c-Si) situated below the first layer of heavily doped a-Si, and a layer of heavily doped c-Si situated below the lightly doped c-Si layer. The solar cell also includes a second layer of heavily doped a-Si situated below the multilayer structure; and a backside electrode situated below the second layer of heavily doped a-Si.

Abstract: One embodiment of the present invention provides a double-sided heterojunction solar cell module. The solar cell includes a frontside glass cover, a backside cover situated below the frontside glass cover, and a number of solar cells situated between the frontside glass cover and the backside glass cover. Each solar cell includes a semiconductor multilayer structure situated below the frontside glass cover, including: a frontside electrode grid, a first layer of heavily doped amorphous Si (a-Si) situated below the frontside electrode, a layer of lightly doped crystalline-Si (c-Si) situated below the first layer of heavily doped a-Si, and a layer of heavily doped c-Si situated below the lightly doped c-Si layer. The solar cell also includes a second layer of heavily doped a-Si situated below the multilayer structure; and a backside electrode situated below the second layer of heavily doped a-Si.

Abstract: One embodiment of the present invention provides a solar cell. The solar cell includes a metallurgical-grade Si (MG-Si) substrate, a first layer of heavily doped crystalline-Si situated above the MG-Si substrate, a layer of lightly doped crystalline-Si situated above the first heavily doped crystalline-Si layer, a backside ohmic-contact layer situated on the backside of the MG-Si substrate, a second layer of heavily doped crystalline-Si situated above the lightly doped crystalline-Si layer, a first layer of dielectric situated above the second heavily doped crystalline-Si layer, a second layer of dielectric situated above the first dielectric layer, and front electrodes situated above the second dielectric layer.

Abstract: One embodiment of the present invention provides a heterojunction solar cell. The solar cell includes a metallurgical-grade Si (MG-Si) substrate, a layer of heavily doped crystalline-Si situated above the MG-Si substrate, a layer of lightly doped crystalline-Si situated above the heavily doped crystalline-Si layer, a backside ohmic-contact layer situated on the backside of the MG-Si substrate, a passivation layer situated above the heavily doped crystalline-Si layer, a layer of heavily doped amorphous Si (a-Si) situated above the passivation layer, a layer of transparent-conducting-oxide (TCO) situated above the heavily doped a-Si layer, and a front ohmic-contact electrode situated above the TCO layer.

Abstract: One embodiment provides an apparatus for material deposition. The apparatus includes a reaction chamber, and a pair of susceptors. Each susceptor has a front side mounting substrates and a back side. The front sides of the vertically positioned susceptors face each other, and the vertical edges of the susceptors are in contact with each other. The apparatus also includes a number of gas nozzles for injecting reaction gases. The gas flow directions inside the chamber can be alternated by controlling the gas nozzles. The gas nozzles are configured to inject a small amount of purge gas including at least one of: HCl, SiCl4, and H2 when the gas nozzles are not injecting reaction gas. The apparatus includes a number of heating units situated outside the reaction chamber. The heating units are arranged in such a way that they radiate heat energy directly to the back sides of the susceptors.

Abstract: One embodiment provides an apparatus for material deposition. The apparatus includes a reaction chamber, and a pair of susceptors. Each susceptor has a front side and a back side, and the front side mounts substrates. The susceptors are positioned vertically in such a way that the front sides of the susceptors face each other, and the vertical edges of the susceptors are in contact with each other, thereby forming a substantially enclosed narrow channel between the substrates. The apparatus also includes a number of gas nozzles for injecting reaction gases. The gas nozzles are controlled in such a way that gas flow directions inside the chamber can be alternated, thereby facilitating uniform material deposition. The apparatus includes a number of heating units situated outside the reaction chamber. The heating units are arranged in such a way that they radiate heat energy directly to the back sides of the susceptors.

Abstract: One embodiment of the present invention provides a method for fabricating a solar cell. The method includes: melting a metallurgical-grade (MG) Si feedstock, lowering a single-crystalline Si seed to touch the surface of the molten MG-Si, slowly pulling out a single-crystal Si ingot of the molten MG-Si, processing the Si ingot into single crystal Si wafers to form MG-Si substrates for subsequent epitaxial growth, leaching out residual metal impurities in the MG-Si substrate, epitaxially growing a layer of single-crystal Si thin film doped with boron on the MG-Si substrate, doping phosphor to the single-crystal Si thin film to form an emitter layer, depositing an anti-reflection layer on top of the single-crystal Si thin film, and forming the front and the back electrical contacts.

Abstract: One embodiment of the present invention provides a solar cell. The solar cell includes a substrate; a polycrystalline Si (poly-Si) thin-film layer which includes a p+ layer situated above the substrate, wherein the poly-Si thin-film layer is hydrogenated; a contact under-layer situated between the foreign substrate and the poly-Si thin-film layer; a metal layer situated below the contact layer, wherein part of the metal layer reaches the p+ layer through the contact under-layer; an n-type doped amorphous-Si (a-Si) thin-film layer situated above the poly-Si thin-film layer forming a heterojunction; an optional intrinsic layer situated between the poly-Si thin-film layer and the n-type doped a-Si thin-film layer; a transparent conductive layer situated above the n-type doped a-Si thin-film layer; and a front-side electrode situated above the transparent conductive layer.