Abstract: A solar cell having n-type and p-type interdigitated back contacts (IBCs), which cover the entire back surface of the absorber layer. The spatial separation of the IBCs is in a direction perpendicular to the back surface, thus providing borderless contacts having a zero-footprint separation. As the contacts are on the back, photons incident on the cell's front surface can be absorbed without any shadowing.

Abstract: A solar cell having n-type and p-type interdigitated back contacts (IBCs), which cover the entire back surface of the absorber layer. The spatial separation of the IBCs is in a direction perpendicular to the back surface, thus providing borderless contacts having a zero-footprint separation. As the contacts are on the back, photons incident on the cell's front surface can be absorbed without any shadowing.

Abstract: A method selectively diffuses dopants into a substrate wafer. The method comprises blanket depositing a doped liquid precursor including dopants on a surface of the substrate wafer to create a doped film on the surface of the substrate wafer, selectively forming a diffusion source in the doped film to selectively diffuse the dopants into the substrate wafer, and heating the doped film on the substrate wafer, wherein said heating the doped film diffuses the dopants from the doped film into the substrate wafer.

Abstract: A germanium-containing layer is deposited on a single crystalline bulk silicon substrate in an ambient including a level of oxygen partial pressure sufficient to incorporate 1%-50% of oxygen in atomic concentration. The thickness of the germanium-containing layer is preferably limited to maintain some degree of epitaxial alignment with the underlying silicon substrate. Optionally, a graded germanium-containing layer can be grown on, or replace, the germanium-containing layer. An at least partially crystalline silicon layer is subsequently deposited on the germanium-containing layer. A handle substrate is bonded to the at least partially crystalline silicon layer. The assembly of the bulk silicon substrate, the germanium-containing layer, the at least partially crystalline silicon layer, and the handle substrate is cleaved within the germanium-containing layer to provide a composite substrate including the handle substrate and the at least partially crystalline silicon layer.

Abstract: A method selectively diffuses dopants into a substrate wafer. The method comprises blanket depositing a doped liquid precursor including dopants on a surface of the substrate wafer to create a doped film on the surface of the substrate wafer, selectively forming a diffusion source in the doped film to selectively diffuse the dopants into the substrate wafer, and heating the doped film on the substrate wafer, wherein said heating the doped film diffuses the dopants from the doped film into the substrate wafer.

Abstract: A photovoltaic device includes a composition modulated semiconductor structure including a p-doped first semiconductor material layer, a first intrinsic compositionally-graded semiconductor material layer, an intrinsic semiconductor material layer, a second intrinsic compositionally-graded semiconductor layer, and an n-doped first semiconductor material layer. The first and second intrinsic compositionally-graded semiconductor material layers include an alloy of a first semiconductor material having a greater band gap width and a second semiconductor material having a smaller band gap with, and the concentration of the second semiconductor material increases toward the intrinsic semiconductor material layer in the first and second compositionally-graded semiconductor material layers.

Abstract: Methods for selectively diffusing dopants into a substrate wafer are provided. A liquid precursor is doped with dopants. The liquid precursor is selected from a group comprising monomers, polymers, and oligomers of silicon and hydrogen. The doped liquid precursor is deposited on a surface of the substrate wafer to create a doped film. The doped film is heated on the substrate wafer for diffusing the dopants from the doped film into the substrate wafer at different diffusion rates to create a heavily diffused region and a lightly diffused region in the substrate wafer. The method disclosed herein further comprises selective curing of the doped film on the surface of the substrate wafer. The selectively cured doped film acts as a diffusion source for selectively diffusing the dopants into the substrate wafer.

Abstract: A photovoltaic device includes a composition modulated semiconductor structure including a p-doped first semiconductor material layer, a first intrinsic compositionally-graded semiconductor material layer, an intrinsic semiconductor material layer, a second intrinsic compositionally-graded semiconductor layer, and an n-doped first semiconductor material layer. The first and second intrinsic compositionally-graded semiconductor material layers include an alloy of a first semiconductor material having a greater band gap width and a second semiconductor material having a smaller band gap with, and the concentration of the second semiconductor material increases toward the intrinsic semiconductor material layer in the first and second compositionally-graded semiconductor material layers.

Abstract: A germanium-containing layer is deposited on a single crystalline bulk silicon substrate in an ambient including a level of oxygen partial pressure sufficient to incorporate 1%-50% of oxygen in atomic concentration. The thickness of the germanium-containing layer is preferably limited to maintain some degree of epitaxial alignment with the underlying silicon substrate. Optionally, a graded germanium-containing layer can be grown on, or replace, the germanium-containing layer. An at least partially crystalline silicon layer is subsequently deposited on the germanium-containing layer. A handle substrate is bonded to the at least partially crystalline silicon layer. The assembly of the bulk silicon substrate, the germanium-containing layer, the at least partially crystalline silicon layer, and the handle substrate is cleaved within the germanium-containing layer to provide a composite substrate including the handle substrate and the at least partially crystalline silicon layer.

Abstract: A Schottky Barrier solar cell having at least one of a low work function region and a high work function region provided on the front or back surface of a lightly-doped absorber material, which may be produced in a variety of different geometries. The method of producing the Schottky Barrier solar cells allows for short processing times and the use of low temperatures.

Abstract: A solar cell having n-type and p-type interdigitated back contacts (IBCs), which cover the entire back surface of the absorber layer. The spatial separation of the IBCs is in a direction perpendicular to the back surface, thus providing borderless contacts having a zero-footprint separation. As the contacts are on the back, photons incident on the cell's front surface can be absorbed without any shadowing.

Abstract: A germanium-containing layer is deposited on a single crystalline bulk silicon substrate in an ambient including a level of oxygen partial pressure sufficient to incorporate 1%-50% of oxygen in atomic concentration. The thickness of the germanium-containing layer is preferably limited to maintain some degree of epitaxial alignment with the underlying silicon substrate. Optionally, a graded germanium-containing layer can be grown on, or replace, the germanium-containing layer. An at least partially crystalline silicon layer is subsequently deposited on the germanium-containing layer. A handle substrate is bonded to the at least partially crystalline silicon layer. The assembly of the bulk silicon substrate, the germanium-containing layer, the at least partially crystalline silicon layer, and the handle substrate is cleaved within the germanium-containing layer to provide a composite substrate including the handle substrate and the at least partially crystalline silicon layer.

Abstract: A germanium-containing layer is deposited on a single crystalline bulk silicon substrate in an ambient including a level of oxygen partial pressure sufficient to incorporate 1%-50% of oxygen in atomic concentration. The thickness of the germanium-containing layer is preferably limited to maintain some degree of epitaxial alignment with the underlying silicon substrate. Optionally, a graded germanium-containing layer can be grown on, or replace, the germanium-containing layer. An at least partially crystalline silicon layer is subsequently deposited on the germanium-containing layer. A handle substrate is bonded to the at least partially crystalline silicon layer. The assembly of the bulk silicon substrate, the germanium-containing layer, the at least partially crystalline silicon layer, and the handle substrate is cleaved within the germanium-containing layer to provide a composite substrate including the handle substrate and the at least partially crystalline silicon layer.

Abstract: Methods for selectively diffusing dopants into a substrate wafer are provided. A liquid precursor is doped with dopants. The liquid precursor is selected from a group comprising monomers, polymers, and oligomers of silicon and hydrogen. The doped liquid precursor is deposited on a surface of the substrate wafer to create a doped film. The doped film is heated on the substrate wafer for diffusing the dopants from the doped film into the substrate wafer at different diffusion rates to create a heavily diffused region and a lightly diffused region in the substrate wafer. The method disclosed herein further comprises selective curing of the doped film on the surface of the substrate wafer. The selectively cured doped film acts as a diffusion source for selectively diffusing the dopants into the substrate wafer.

Abstract: A photovoltaic device includes a composition modulated semiconductor structure including a p-doped first semiconductor material layer, a first intrinsic compositionally-graded semiconductor material layer, an intrinsic semiconductor material layer, a second intrinsic compositionally-graded semiconductor layer, and an n-doped first semiconductor material layer. The first and second intrinsic compositionally-graded semiconductor material layers include an alloy of a first semiconductor material having a greater band gap width and a second semiconductor material having a smaller band gap with, and the concentration of the second semiconductor material increases toward the intrinsic semiconductor material layer in the first and second compositionally-graded semiconductor material layers.

Abstract: A low cost method is described for forming a textured Si surface such as for a solar cell which includes forming a dielectric layer containing pinholes, anisotropically etching through the pinholes to form inverted pyramids in the Si surface and removing the dielectric layer thereby producing a high light trapping efficiency for incident radiation.

Abstract: A method of texturing a surface of a substrate utilizing a phase-segregated mask and etching is disclosed. The resulting textured surface, which can be used as a component of a solar cell includes, in one embodiment, a randomly mixed collection of flat-topped and angled surfaces providing local high points and local low points. The flat-topped surfaces have an areal density of at least 1%, and the high points are coincident with the flat-topped surfaces. Moreover, a preponderance of said low points are approximately situated in a single common plane parallel to the plane defined by the flat-topped surfaces.

Abstract: A method for layer transfer using a boron-doped silicon germanium (SiGe) layer includes forming a boron-doped SiGe layer on a bulk silicon substrate; forming an upper silicon (Si) layer over the boron-doped SiGe layer; hydrogenating the boron-doped SiGe layer; bonding the upper Si layer to an alternate substrate; and propagating a fracture at an interface between the boron-doped SiGe layer and the bulk silicon substrate. A system for layer transfer using a boron-doped silicon germanium (SiGe) layer includes a bulk silicon substrate; a boron-doped SiGe layer formed on the bulk silicon substrate, such that the boron-doped SiGe layer is located underneath an upper silicon (Si) layer, wherein the boron-doped SiGe layer is configured to propagate a fracture at an interface between the boron-doped SiGe layer and the bulk silicon substrate after hydrogenation of the boron-doped SiGe layer; and an alternate substrate bonded to the upper Si layer.

Abstract: The invention provides a high temperature (about 1150° C. or greater) annealing process for converting thick polycrystalline Si layers on the order of 1 ?m to 40 ?m on a single crystal seed layer into thick single crystal Si layers having the orientation of the seed layer, thus allowing production of thick Si films having the quality of single crystal silicon at high rates and low cost of processing. Methods of integrating such high temperature processing into solar cell fabrication are described, with particular attention to process flows in which the seed layer is disposed on a porous silicon release layer. Another aspect pertains to the use of similar high temperature anneals for poly-Si grain growth and grain boundary passivation. A further aspect relates to structures in which these thick single crystal Si films and passivated poly-Si films are incorporated.

Abstract: A lost cost method for fabricating SOI substrates is provided. The method includes forming a stack of p-type doped amorphous Si-containing layers on a semiconductor region of a substrate by utilizing an evaporation deposition process. A solid phase recrystallization step is then performed to convert the amorphous Si-containing layers within the stack into a stack of p-type doped single crystalline Si-containing layers. After recrystallization, the single crystalline Si-containing layers are subjected to anodization and at least an oxidation step to form an SOI substrate. Solar cells and/or other semiconductor devices can be formed on the upper surface of the inventive SOI substrate.