Abstract: A multijunction solar cell including a metamorphic layer, and particularly the design and specification of the composition, lattice constant, and band gaps of various layers above the metamorphic layer in order to achieve reduction in “bowing” of the semiconductor wafer caused by the lattice mismatch of layers associated with the metamorphic layer.

Abstract: A multijunction solar cell and its method of fabrication, including an upper and a lower solar subcell each having an emitter layer and a base layer forming a photoelectric junction; a near infrared (NIR) wideband reflector layer disposed below the upper subcell and above the lower subcell for reflecting light in the spectral range of 900 to 1050 nm which represents unused and undesired solar energy and thereby reducing the overall solar energy absorptance in the solar cell and providing thermodynamic radiative cooling of the solar cell when deployed in space outside the atmosphere.

Abstract: A multijunction solar cell and its method of fabrication, including an upper and a lower solar subcell each having an emitter layer and a base layer forming a photoelectric junction; a near infrared (NIR) wideband reflector layer disposed below the upper subcell and above the lower subcell for reflecting light in the spectral range of 900 to 1050 nm which represents unused and undesired solar energy and thereby reducing the overall solar energy absorptance in the solar cell and providing thermodynamic radiative cooling of the solar cell when deployed in space outside the atmosphere.

Abstract: A multijunction solar cell and its method of fabrication, including an upper and a lower solar subcell each having an emitter layer and a base layer forming a photoelectric junction; a near infrared (NIR) wideband reflector layer disposed below the upper subcell and above the lower subcell for reflecting light in the spectral range of 900 to 1050 nm which represents unused and undesired solar energy and thereby reducing the overall solar energy absorptance in the solar cell and providing thermodynamic radiative cooling of the solar cell when deployed in space outside the atmosphere.

Abstract: A compaction wheel assembly includes a shaft, a plurality of compaction wheels along the shaft, and at least one bushing assembly. The bushing assembly includes first and second split bushings axially spaced-apart to form a space the upper and lower bushing housings removably secured together with the first and second split bushings therebetween to clamp the first and second split bushings about the shaft and at least one first shim located between the bushing housings at a front side of the shaft and at least one second shim located between the bushing housings at a rear side of the shaft to space the upper and lower bushing housings and upper and lower halves of the first and second split bushings. At least one of the first and second shims includes a slot configured for feeding grease to the space between the first and second split bushings.

Abstract: A remotely controlled VTOL aircraft includes an autopilot subsystem outputting helicopter control signals, and an autopilot subsystem outputting fixed wing control signals. A transition control subsystem is configured to receive said helicopter control signals, said fixed wing control signals, and a transition control signal. Control signals to be applied to the VTOL aircraft controls are calculated as a function of the transition percentage and weighting factors applied to the helicopter control signals and said fixed wing control signals.

Abstract: A multijunction solar cell including a substrate and at least one solar subcell having an emitter layer, a base layer, and a window layer adjacent to the emitter layer composed of a semiconductor window material, wherein the window material has a graded composition such that the material at the interface between the top surface of the emitter layer of the at least one solar subcell and the bottom surface of the window layer has a compression as measured by a delta in the Bragg angle from the substrate in a range of 0 to 500 arcseconds in compression, and material at the top surface of the window layer has a tension as measured by a delta in the Bragg angle from the substrate in a range of 50 to 700 arcseconds in tension, wherein the delta in the Bragg angle is obtained from a rocking curve from a triple axis coupled scan of ? and 2? (omega-2theta) using 1.5406 ? radiation.

Abstract: The present disclosure provides a multijunction solar cell comprising: an upper solar subcell having an indirect band gap semiconductor emitter layer composed of greater than 0.7 but less than 1.0 mole fraction aluminum and a base layer, the emitter layer and the base layer forming a heterojunction solar subcell; and a lower solar subcell disposed beneath the upper solar subcell, wherein the lower solar subcell has an emitter layer and a base layer forming a photoelectric junction. In some embodiments, the emitter layer of the upper solar subcell is an n-type AlxGa1-xAs layer with 0.7<x<1.0 and having a band gap of greater than 1.85 eV.

Abstract: A solar cell comprising a bulk germanium silicon growth substrate; a diffused photoactive junction in the germanium silicon substrate; and a sequence of subcells grown over the substrate, with the first grown subcell either being lattice matched or lattice mis-matched to the growth substrate.

Abstract: A multijunction solar cell and its method of fabrication, including an upper and a lower solar subcell each having an emitter layer and a base layer forming a photoelectric junction; a near infrared (NIR) wideband reflector layer disposed below the upper subcell and above the lower subcell for reflecting light in the spectral range of 900 to 1050 nm which represents unused and undesired solar energy and thereby reducing the overall solar energy absorptance in the solar cell and providing thermodynamic radiative cooling of the solar cell when deployed in space outside the atmosphere.

Abstract: A multijunction solar cell including a metamorphic layer, and particularly the design and specification of the composition, lattice constant, and band gaps of various layers above the metamorphic layer in order to achieve reduction in “bowing” of the semiconductor wafer caused by the lattice mismatch of layers associated with the metamorphic layer.

Abstract: A solar cell comprising a bulk germanium silicon growth substrate; a diffused photoactive junction in the germanium silicon substrate; and a sequence of subcells grown over the substrate, with the first grown subcell either being lattice matched or lattice mis-matched to the growth substrate.

Abstract: A remotely controlled VTOL aircraft includes an autopilot subsystem outputting helicopter control signals, and an autopilot subsystem outputting fixed wing control signals. A transition control subsystem is configured to receive said helicopter control signals, said fixed wing control signals, and a transition control signal. Control signals to be applied to the VTOL aircraft controls are calculated as a function of the transition percentage and weighting factors applied to the helicopter control signals and said fixed wing control signals.

Abstract: A remotely controlled VTOL aircraft includes an autopilot subsystem outputting helicopter control signals, and an autopilot subsystem outputting fixed wing control signals. A transition control subsystem is configured to receive said helicopter control signals, said fixed wing control signals, and a transition control signal. Control signals to be applied to the VTOL aircraft controls are calculated as a function of the transition percentage and weighting factors applied to the helicopter control signals and said fixed wing control signals.

Abstract: The present disclosure provides a multijunction solar cell comprising: an upper solar subcell having an indirect band gap semiconductor emitter layer composed of greater than 0.8 but less than 1.0 mole fraction aluminum and a base layer, the emitter layer and the base layer forming a heterojunction solar subcell; and a lower solar subcell disposed beneath the upper solar subcell, wherein the lower solar subcell has an emitter layer and a base layer forming a photoelectric junction. In some embodiments, the emitter layer of the upper solar subcell is an n-type AlxGa1-xAs layer with 0.8<x<1.0 and having a band gap of greater than 2.0 eV.

Abstract: A multijunction solar cell and its method of fabrication, including an upper and a lower solar subcell each having an emitter layer and a base layer forming a photoelectric junction; a near infrared (NIR) wideband reflector layer disposed below the upper subcell and above the lower subcell for reflecting light in the spectral range of 900 to 1050 nm which represents unused and undesired solar energy and thereby reducing the overall solar energy absorptance in the solar cell and providing thermodynamic radiative cooling of the solar cell when deployed in space outside the atmosphere.

Abstract: A four junction solar cell having an upper first solar subcell composed of a semiconductor material having a first band gap; a second solar subcell adjacent to said first solar subcell and composed of a semiconductor material having a second band gap smaller than the first band gap and being lattice matched with the upper first solar subcell; a third solar subcell adjacent to said second solar subcell and composed of a semiconductor material having a third band gap smaller than the second band gap and being lattice matched with the second solar subcell; and a fourth solar subcell adjacent to and lattice mismatched from said third solar subcell and composed of a semiconductor material having a fourth band gap smaller than the third band gap; wherein the fourth subcell has a direct bandgap of greater than 0.75 eV, and the average band gap of the solar cell is equal to or greater than 1.35 eV.

Abstract: A solar cell comprising a bulk germanium silicon growth substrate; a diffused photoactive junction in the germanium silicon substrate; and a sequence of subcells grown over the substrate, with the first grown subcell either being lattice matched or lattice mis-matched to the growth substrate.

Abstract: A solar cell comprising a bulk germanium silicon growth substrate; a diffused photoactive junction in the germanium silicon substrate; and a sequence of subcells grown over the substrate, with the first grown subcell either being lattice matched or lattice mis-matched to the growth substrate.

Abstract: An electric lamp assembly 10 for emitting near infrared radiation includes a reflector housing 20 and a lamp vessel 24 positioned within the reflector housing. A source of illumination 28 is enclosed within the lamp vessel. A continuous multi-layer interference film 40 on an exterior surface 42 of the lamp vessel transmits near infrared radiation within the range of 850-1100 nm and is substantially non-transmissive towards visible radiation.