Abstract:
A multi-junction photovoltaic device includes a germanium layer having pyramidal shapes with (111) facets exposed to form a textured surface. A first p-n junction is formed on or over the textured surface. Another p-n junction is formed over the first p-n junction and following the textured surface.
Abstract:
A solar cell structure includes stacked layers in reverse order on a germanium substrate. A heterostructure including an (In)GaAs absorbing layer and a disordered emitter layer is provided in the solar cell structures. Controlled spalling may be employed as part of the fabrication process for the solar cell structure, which may be single or multi-junction.
Abstract:
A multi-junction photovoltaic device includes a germanium layer having pyramidal shapes with (111) facets exposed to form a textured surface. A first p-n junction is formed on or over the textured surface. Another p-n junction is formed over the first p-n junction and following the textured surface.
Abstract:
An SOI substrate including a buried insulator layer positioned between a base substrate and a top semiconductor active layer is first provided. A semiconductor device can then be formed on and/or within a portion of the top semiconductor active layer. A bottommost surface of the buried insulator layer which is opposite a topmost surface of the buried insulator layer that forms an interface with the top semiconductor active layer can be then exposed. Ions can then be implanted through the bottommost surface of the buried insulator layer and into a portion of the buried insulator layer. The ions are implanted at energy ranges that do not disturb the buried insulator layer/top semiconductor active layer interface, while leaving a relatively thin portion of the buried insulator layer near the buried insulator layer/top semiconductor active layer interface intact.
Abstract:
A germanium lateral bipolar junction transistor (BJT) is formed employing a germanium-on-insulator (GOI) substrate. A silicon passivation layer is deposited on the top surface of a germanium layer in the GOI substrate. Shallow trench isolation structures, an extrinsic base region structure, and a base spacer are subsequently formed. A germanium emitter region, a germanium base region, and a germanium collector region are formed within the germanium layer by ion implantation. A silicon emitter region, a silicon base region, and a silicon collector region are formed in the silicon passivation layer. After optional formation of an emitter contact region and a collector contact region, metal semiconductor alloy regions can be formed. A wide gap contact for minority carriers is provided between the silicon base region and the germanium base region and between the silicon emitter region and the germanium emitter region.
Abstract:
Improved Fin Field Effect Transistors (FinFET) are provided, as well as improved techniques for forming fins for a FinFET. A fin for a FinFET is formed by forming a semi-insulating layer on an insulator that gives a sufficiently large conduction band offset (ΔEc) ranging from 0.05-0.6 eV; patterning an epitaxy mask on the semi-insulating layer, wherein the epitaxy mask has a reverse image of a desired pattern of the fin; performing a selective epitaxial growth within the epitaxy mask; and removing the epitaxy mask such that the fin remains on the semi-insulating layer. The semi-insulating layer comprises, for example, a III-V semiconductor material and optionally further comprises a Si δ-doping layer to supply electron carriers to the III-V channel.
Abstract:
Improved Fin Field Effect Transistors (FinFET) are provided, as well as improved techniques for forming fins for a FinFET. A fin for a FinFET is formed by forming a semi-insulating layer on an insulator that gives a sufficiently large conduction band offset (ΔEe) ranging from 0.05-0.6 eV; patterning an epitaxy mask on the semi-insulating layer, wherein the epitaxy mask has a reverse image of a desired pattern of the fin; performing a selective epitaxial growth within the epitaxy mask; and removing the epitaxy mask such that the fin remains on the semi-insulating layer. The semi-insulating layer comprises, for example, a III-V semiconductor material and optionally further comprises a Si δ-doping layer to supply electron carriers to the III-V channel.
Abstract:
Improved semiconductor substrates are provided that employ a wide bandgap material between the channel and the insulator. A semiconductor substrate comprises a channel layer comprised of a III-V material; an insulator layer; and a wide bandgap material between the channel layer and the insulator layer, wherein a conduction band offset (ΔEc) between the channel layer and the wide bandgap material is between 0.05 eV and 0.8 eV. The channel layer can be comprised of, for example, In1-xGaxAs or In1-xGaxSb, with x varying from 0 to 1. The wide bandgap material can be comprised of, for example, In1-yAlyAs, In1-yAlyP, Al1-yGayAs or In1-yGayP, with y varying from 0 to 1.
Abstract:
Solar cell structures that have improved carrier collection efficiencies at a heterointerface are provided by low temperature epitaxial growth of silicon on a III-V base. Additionally, a solar cell structure having improved open circuit voltage includes a shallow junction III-V emitter formed by epitaxy or diffusion followed by the epitaxy of SixGe1-x passivated by amorphous SiyGe1-y:H.
Abstract:
Photovoltaic devices such as solar cells having one or more field-effect hole or electron inversion/accumulation layers as contact regions are configured such that the electric field required for charge inversion and/or accumulation is provided by the output voltage of the photovoltaic device or that of an integrated solar cell unit. In some embodiments, a power source may be connected between a gate electrode and a contact region on the opposite side of photovoltaic device. In other embodiments, the photovoltaic device or integrated unit is self-powering.