Abstract: A multi-junction solar cell includes a plurality of photovoltaic cell layers that are electrically connected and stacked to define upper and lower subcells having at least one step difference therebetween that exposes portions of the lower subcell such that, responsive to incident illumination, a current density of the exposed portions of the lower subcell is greater than that of portions thereof having the upper subcell thereon. Related devices and fabrication methods are also discussed.

Abstract: Embodiments of the invention provide silicon-based nanoparticle composites, where the silicon nanoparticles are highly luminescent. Preferred embodiments of the invention are Si—O solid composite networks, e.g., glass, having a homogenous distribution of luminescent hydrogen terminated silicon nanoparticles in a homogenous distribution throughout the solid. Embodiments of the invention also provide fabrication processes for silicon-based silicon nanoparticle composites. A preferred method for forming a silicon-based nanoparticle composite disperses hydrogen terminated silicon nanoparticles and an inorganic precursor of an organosilicon gel in an aprotic solvent to form a sol. A catalyst is mixed into the sol. The sol is then permitted to dry into a gel of the silicon-based nanoparticle composite.

Abstract: Multiple films of red-green-blue (RGB) luminescent silicon nanoparticles are integrated in a cascade configuration as a top coating in an ultraviolet/blue light emitting diode (LED) to convert it to a white LED. The configuration of RGB luminescent silicon nanoparticle films harnesses the short wavelength portion of the light emitted from the UV/blue LED while transmitting efficiently the longer wavelength portion. The configuration also reduces damaging heat and/or ultraviolet effects to both the device and to humans.

Abstract: A semiconductor fabrication method involving the use of eSiGe is disclosed. The eSiGe approach is useful for applying the desired stresses to the channel region of a field effect transistor, but also can introduce complications into the semiconductor fabrication process. Embodiments of the present invention disclose a two-step fabrication process in which a first layer of eSiGe is applied using a low hydrogen flow rate, and a second eSiGe layer is applied using a higher hydrogen flow rate. This method provides a way to balance the tradeoff of morphology, and fill consistency when using eSiGe. Embodiments of the present invention promote a pinned morphology, which reduces device sensitivity to epitaxial thickness, while also providing a more consistent fill volume, amongst various device widths, thereby providing a more consistent eSiGe semiconductor fabrication process.

Abstract: Multiple films of red-green-blue (RGB) luminescent silicon nanoparticles are integrated in a cascade configuration as a top coating in an ultraviolet/blue light emitting diode (LED) to convert it to a white LED. The configuration of RGB luminescent silicon nanoparticle films harnesses the short wavelength portion of the light emitted from the UV/blue LED while transmitting efficiently the longer wavelength portion. The configuration also reduces damaging heat and/or ultraviolet effects to both the device and to humans.

Abstract: Germanium circuit-type structures are facilitated. In one example embodiment, a multi-step growth and anneal process is implemented to grow Germanium (Ge) containing material, such as heteroepitaxial-Germanium, on a substrate including Silicon (Si) or Silicon-containing material. In certain applications, defects are generally confined near a Silicon/Germanium interface, with defect threading to an upper surface of the Germanium containing material generally being inhibited. These approaches are applicable to a variety of devices including Germanium MOS capacitors, pMOSFETs and optoelectronic devices.

Abstract: Germanium circuit-type structures are facilitated. In one example embodiment, a multi-step growth and anneal process is implemented to grow Germanium (Ge) containing material, such as heteroepitaxial-Germanium, on a substrate including Silicon (Si) or Silicon-containing material. In certain applications, defects are generally confined near a Silicon/Germanium interface, with defect threading to an upper surface of the Germanium containing material generally being inhibited. These approaches are applicable to a variety of devices including Germanium MOS capacitors, pMOSFETs and optoelectronic devices.

Abstract: Germanium circuit-type structures are facilitated. In one example embodiment, a multi-step growth and anneal process is implemented to grow Germanium (Ge) containing material, such as heteroepitaxial-Germanium, on a substrate including Silicon (Si) or Silicon-containing material. In certain applications, defects are generally confined near a Silicon/Germanium interface, with defect threading to an upper surface of the Germanium containing material generally being inhibited. These approaches are applicable to a variety of devices including Germanium MOS capacitors, pMOSFETs and optoelectronic devices.

Abstract: A semiconductor fabrication method involving the use of eSiGe is disclosed. The eSiGe approach is useful for applying the desired stresses to the channel region of a field effect transistor, but also can introduce complications into the semiconductor fabrication process. Embodiments of the present invention disclose a two-step fabrication process in which a first layer of eSiGe is applied using a low hydrogen flow rate, and a second eSiGe layer is applied using a higher hydrogen flow rate. This method provides a way to balance the tradeoff of morphology, and fill consistency when using eSiGe. Embodiments of the present invention promote a pinned morphology, which reduces device sensitivity to epitaxial thickness, while also providing a more consistent fill volume, amongst various device widths, thereby providing a more consistent eSiGe semiconductor fabrication process.

Abstract: Germanium circuit-type structures are facilitated. In one example embodiment, a multi-step growth and anneal process is implemented to grow Germanium (Ge) containing material, such as heteroepitaxial-Germanium, on a substrate including Silicon (Si) or Silicon-containing material. In certain applications, defects are generally confined near a Silicon/Germanium interface, with defect threading to an upper surface of the Germanium containing material generally being inhibited. These approaches are applicable to a variety of devices including Germanium MOS capacitors, pMOSFETs and optoelectronic devices.

Abstract: Germanium circuit-type structures are facilitated. In one example embodiment, a multi-step growth and anneal process is implemented to grow Germanium (Ge) containing material, such as heteroepitaxial-Germanium, on a substrate including Silicon (Si) or Silicon-containing material. In certain applications, defects are generally confined near a Silicon/Germanium interface, with defect threading to an upper surface of the Germanium containing material generally being inhibited. These approaches are applicable to a variety of devices including Germanium MOS capacitors, pMOSFETs and optoelectronic devices.

Abstract: The invention provides a method for the formation of silicon nanoparticles, in sizes that fluoresce, by electrodeposition of silicon material onto a non-reactive (with HF) metal (e.g., platinum) surface from a solution of silicate and HF or HF/H2O2. In an embodiment of the invention, a positively biased substrate with a platinum surface is immersed in a solution of sodium metasilicate in HF/H2O2, a current is drawn and a coating of silicon nanoparticles is formed on the platinum surface.

Abstract: In the invention, an electrochemical etching of crystalline germanium or a germanium alloy produces well-segregated chromatic clusters of nanoparticles. Distinct strong bands appear in the photoluminescence spectra under 350 nm excitation with the lowest peaks in wavelength identified to be at 430, 480, and 580 and 680-1100 nm. The material may be dispersed into a discrete set of luminescent nanoparticles of 1-3 nm in diameter, which may be prepared into colloids and reconstituted into films, crystals, etc.