Abstract: A method for forming a high purity, copper indium gallium selenide (CIGS) bulk material is disclosed. The method includes sealing precursor materials for forming the bulk material in a reaction vessel. The precursor materials include copper, at least one chalcogen selected from selenium, sulfur, and tellurium, and at least one element from group IIIA of the periodic table, which may be selected from gallium, indium, and aluminum. The sealed reaction vessel is heated to a temperature at which the precursor materials react to form the bulk material. The bulk material is cooled in the vessel to a temperature below the solidification temperature of the bulk material and opened to release the formed bulk material. A sputtering target formed by the method can have an oxygen content of 10 ppm by weight, or less.

Abstract: A method is provided for converting optical energy to electrical energy in a spectrally adaptive manner. The method begins by directing optical energy into a first photovoltaic module that includes non-single crystalline semiconductor layers defining a junction such that a first spectral portion of the optical energy is converted into a first quantity of electrical energy. A second spectral portion of the optical energy unabsorbed by the first module is absorbed by a second photovoltaic module that includes non-single crystalline semiconductor layers defining a junction and converted into a second quantity of electrical energy. The first quantity of electrical energy is conducted from the first module to a first external electrical circuit along a first path. The second quantity of electrical energy is conducted from the second module to a second external electrical circuit along a second path that is in parallel with the first path.

Abstract: A method and apparatus for forming a thin film of a copper indium gallium selenide (CIGS)-type material are disclosed. The method includes providing first and second targets in a common sputtering chamber. The first target includes a source of CIGS material, such as an approximately stoichiometric polycrystalline CIGS material, and the second target includes a chalcogen, such as selenium, sulfur, tellurium, or a combination of these elements. The second target provides an excess of chalcogen in the chamber. This can compensate, at least in part, for the loss of chalcogen from the CIGS-source in the first target, resulting in a thin film with a controlled stoichiometry which provides effective light absorption when used in a solar cell.

Abstract: A hydro-thermal exchange unit (HTEU) for desalinating feed water in accordance with a humidification-dehumidification includes feed water, fresh water and gas conduit circuits for transporting feed water, fresh water, and gas, respectively. The unit also includes an evaporator through which a portion of the feed water conduit and the gas conduit pass. The evaporator causes evaporation of a portion of the feed water to produce vapor that is transported through the gas conduit. The unit also includes a condenser through which a portion of the gas conduit and the fresh water conduit pass. The condenser has input and output ports for coupling the gas and fresh water conduit circuits. The condenser extracts moisture from the vapor transported therethrough by the gas conduit. The extracted moisture is discharged through the fresh water conduit.

Abstract: A hydro-thermal exchange unit (HTEU) for desalinating feed water in accordance with a humidification-dehumidification includes feed water, fresh water and gas conduit circuits for transporting feed water, fresh water, and gas, respectively. The unit also includes an evaporator through which a portion of the feed water conduit and the gas conduit pass. The evaporator causes evaporation of a portion of the feed water to produce vapor that is transported through the gas conduit. The unit also includes a condenser through which a portion of the gas conduit and the fresh water conduit pass. The condenser has input and output ports for coupling the gas and fresh water conduit circuits. The condenser extracts moisture from the vapor transported therethrough by the gas conduit. The extracted moisture is discharged through the fresh water conduit.

Abstract: An ice resistant structure is provided which includes a self-supporting, structural platform, a retaining, protective layer and a subsurface anti-icing (AI) and/or de-icing (DI) layer. The retaining, protective layer is disposed over the self-supporting, structural platform. The subsurface anti-icing (AI) and/or de-icing (DI) layer is located between the self-supporting, structural platform and the retaining, protective layer. The subsurface Al and/or DI layer is a functional layer such that an Al and/or DI agent is released to a surface of the retaining protective layer by an activation mechanism responsive to a change in an environmental condition.

Abstract: A multilayer film or skin for free space optical data transmission includes a first outer layer. The first outer layer has a first laterally extending area that transmits optical data signals received over a range of incident angle. A second layer that includes a second laterally extending area underlies the first layer. At least a portion of the optical data signals received by the second layer from the first outer layer is focused or otherwise concentrated into a substantially reduced area. An optical detector receives the concentrated optical data signals from the second layer. An electrical connection extends from the optical detector to an external receiving device. The multilayer film or skin may be used, for example, in applications involving mobile free space optical communication platforms where low profile, volume and mass and/or enhanced platforms are important.

Abstract: An ice resistant structure is provided which includes a self-supporting, structural platform, a retaining, protective layer and a subsurface anti-icing (AI) and/or de-icing (DI) layer. The retaining, protective layer is disposed over the self-supporting, structural platform. The subsurface anti-icing (AI) and/or de-icing (DI) layer is located between the self-supporting, structural platform and the retaining, protective layer. The subsurface Al and/or DI layer is a functional layer such that an Al and/or DI agent is released to a surface of the retaining protective layer by an activation mechanism responsive to a change in an environmental condition.

Abstract: A stretchable photovoltaic device, a stretchable photovoltaic module and a carrier for facilitating formation of a stretchable photovoltaic device and/or module are provided. The stretchable photovoltaic device includes a stretchable part, at least one photovoltaic cell and a surface over which that at least one photovoltaic cell is disposed. The stretchable part has a given length that is operable to change in response to a force being applied to the device. The given length may, for example, elongate when the force causes the device to elongate. Alternative and/or additionally, the given length may compress when the force causes the device to compress.

Abstract: Embodiments of apparatus for providing distributed airborne wireless communications are provided herein. In some embodiments, a distributed communication payload includes: a payload control electronics module; an air-to-user link module to provide wireless communication links between airborne platforms and end-user devices; and an air-to-air link module to provide wireless communication links between airborne platforms; wherein the air-to-user and air-to-air link modules are subdivided into multiple sections that can be disposed on different airborne platforms.

Abstract: Embodiments of apparatus for providing distributed airborne wireless communications are provided herein. In some embodiments, a distributed communication payload includes: a payload control electronics module; an air-to-user link module to provide wireless communication links between airborne platforms and end-user devices; and an air-to-air link module to provide wireless communication links between airborne platforms; wherein the air-to-user and air-to-air link modules are subdivided into multiple sections that can be disposed on different airborne platforms.

Abstract: A method of: providing one or more spent sputtering targets comprising a photovoltaic compound and grinding the photovoltaic compound in an inert environment to form a powder.

Abstract: A photovoltaic device is provided which includes a plurality of junction layers. Each junction layer includes a plurality of photovoltaic cells electrically connected to one another. At least one of the junction layers is at least in part optically transmissive. The junction layers are arranged in a stack on top of each other.

Abstract: Methods and apparatus for an adaptable solar airframe are provided herein. In some embodiments, an adaptable solar airframe includes a solar PV system having at least one solar tracking system and being able to follow the sun position in order to increase sunlight collection and power output; and an expandable body having an aerodynamic cross-section that minimizes parasitic air drag at any given thickness of the body, further being at least partially transparent to sunlight, further enclosing the solar PV system, and further being able to change its shape in response to changes in the positions of the solar PV system.

Abstract: Methods and apparatus are provided for using a renewable source of energy such as solar, wind, or geothermal energy. In some embodiments, the method may include generating electric energy from a renewable form of energy at a plurality of locations at which reside an electric power line associated with an electric power grid. The electric energy generated at each location may be transferred to the electric power line to thereby supply electric energy to the electric power grid.

Abstract: Methods for optical restricting are described. An example of the invention relates to a method of restricting the brightness of a light source. The method can include: absorbing, in absorber material of a photo-restrictor, at least a portion of a primary emission produced by the light source; producing first photoexcitations in the absorber material characterized by a first excitation density; transferring the first photoexcitations from the absorber material to an emitter material of the photo-restrictor thereby producing second photoexcitations characterized by a second excitation density; and producing a secondary emission from the emitter material.

Abstract: Apparatus for optical restricting are described. An example of the invention relates to an apparatus for restricting the brightness of a light source. The apparatus can include an absorber material configured to absorb at least a portion of a primary emission produced by the light source and producing photoexcitations in response thereto; and an emitter material configured to receive the photoexcitations from the absorber material and producing a secondary emission therefrom, wherein an amount of the secondary emission is restricted with respect to an amount of the primary emission.

Abstract: Methods and apparatus for unmanned long endurance flights are provided herein. In some embodiments, a lightweight solar wing for unmanned aircraft may include at least one airfoil profile, a top surface, a bottom surface, a leading edge, a trailing edge, wing tips, and at least one photovoltaic cell, wherein the surfaces and edges follow an arched bow shape across a span of the wing. In some embodiments, an unmanned solar-powered aircraft may include at least one lightweight solar wing as described above, at least one fuselage, and at least one propeller, wherein the fuselage is placed below the solar wing and contains an electric motor, battery, and electronics.

Abstract: A method is provided for fabricating a thin film semiconductor device. The method includes providing a plurality of raw semiconductor materials. The raw semiconductor materials undergo a pre-reacting process to form a homogeneous compound semiconductor target material. The compound semiconductor target material is deposited onto a substrate to form a thin film having a composition substantially the same as a composition of the compound semiconductor target material.

Abstract: A method is provided for producing a hybrid multi junction photovoltaic device. The method begins by providing a plurality of planar photovoltaic semi-transparent modules. Each of the modules is a fully functional, thin-film, photovoltaic device and includes first and second conductive layers and at least first and second semiconductor layers disposed between the conductive layers. The first and second semiconductor layers define a junction at an interface therebetween. The method continues by disposing the modules one on top of another and hybridly adhering them to each other. At least one of the modules is configured to convert a first spectral portion of optical energy into an electrical voltage and transmit a second spectral portion of optical energy to another of the junctions that is configured to convert at least part of the second spectral portion of optical energy into an electrical voltage.