Gaasp solar cells placed on top of conventional silicon solar cell arrays can increase the energy conversion efficiency of the system as much as 100%. astropower division of astrosystems, inc. proposes to develop a high band gap top solar cell for attachment to conventionals ilicon solar cells.… More

The growth of gaas on silicon has long been recognized as a desirable approach for advance optoelectronic devices including optical integrated circuits, optical communicationbetween circuits and as a source of low-cost gaas layers forsolar cell and display applications. progress on the development… More

Optoelectronic sources, integrated as monolithic elements on silicon vlsi chips, offer important advantages in the transmission of information within the chip or between chips in advanced computer systems. the speed of optical-integrated vlsi devices is expected to be considerably higher than… More

The ultimate high-efficiency crystalline silicon solar cell design consists of a thin film of electrically-active silicon epitaxially grown on an oxide-overcoated, infrared-transparent gallium phosphide (gap) substrate. in addition to high conversion efficiency and intrinsic radiation resistance due… More

The effect of scaling down device dimensions of vlsi structures and the combination of increased circuit complexity during the scaling process is placing severe limitations on the minimum propagation delay of metallic interconnects. optical interconnects remove those speed limitations and offer a… More

The successful growth of gaas on silicon substrates using double selective liquid epitaxial (dsle) process has recently been accomplished. these results set the stage for the development of an extremely useful material--large planar wafers of smooth gaas on silicon. double selective liquid phase… More

The growth of device quality, large area gaas epitaxial layers on silicon substrates is recognized as an important technological development. the quality of heteroepitaxial layers of gaas on silicon are limited by gaas-si lattice mismatch and thermal coefficient mismatch. the defect density of the… More

Increases in solar cell efficiency can be achieved with tandem multi-junction structures to improve the performance and scale of space photovoltaic concentrators. the "top solar cell" tandem approach could increase energy conversion efficiency by as much as 100%. a self-supporting… More

Existing metallic-type contacts on gallium arsenide (gaas) have not been stable at high temperatures because of interdiffusion and/or alloying of the gaas top layer. high temperature contacts to gaas space photoltaic cells are being developed based on the formation of a highly-stable intermediate… More

Uniform large area, device quality indium phosphide (inp) epitaxial layers on insulating substrates could lead to the development of a new generation of producible, radiation-hardened microelectronic and optoelectroniv integrated circuits. inp alloys offer the advantages of: proven resistance to… More

High temperature (>600 degrees celsius) indium phosphide (inp) space solar cells are being developed to eliminate theproblems, surface decomposition and contact failure, encountered when inp solar cells are exposed to high temperatures. key to this program are the use of an encapsulant layer to… More

Electro-deposition of silicon films from liquid-metal solutions will be investigated. the objective is to develop a low-cost process for the production of high-efficiency thin-film photovoltaic devices. specifically, current-controlled growth of a silicon film on a substrate is accomplished using a… More

Astropower proposes to develop a large-scale, high-throughput liquid phase epitaxial (lpe) reactor for thefabrication of multi-layer iii-v semiconductor devices. a design goal of 1000 cm(2) per hour has been established while maintaining the key features of lpe: 1) highest material quality of all… More

Conformal vapor phase epitaxy (cvpe) is a new technique for two-dimensional constrained growth of thin semiconductor films using a halide vapor transport process. this technique will be applied to the growth of gaas and inp films on silicon and sapphire substrates. epitaxial-lateralovergrowth with… More

Solar cells are being fabricated using thin films of silicon on inexpensive, flexible cloth substrates. photovoltaic devices fabricated with these structures can demonstrate the high performance of crystalline silicon with the light weight of thin film solar cells. the result is a solar cell that… More

AstroPower is developing a highly sensitive UV detector based on epitaxial AlGaP/GaP heterostructures, a promising new material system for ultraviolet detectors. Detecting ultraviolet light is important to spectrophotometry, astronomy, high-energy physics, medicine, UV curing, photoresist exposure,… More

AstroPower is developing a new process for the growth of large area, thin film 3C-SiC using a proprietary deposition technique followed by liquid phase epitaxy (LPE). Successful development of the growth process will provide high quality, thin film SiC in typical silicon wafer areas, allowing… More

AstroPower will develop a two-junction monolithic tandem solar cell composed of (AlxGa1-x)0.51 In(0.49)P, which is lattice matched to GaAs, as the top cell in a three-junction, two-terminal tandem solar cell. This new tunable bandgap Al-Ga-In-P material is capable of current matching in a… More

1 New concepts in optical computing and optical interconnects require hardware developments of generic, compact, multi-element LED source array. A two dementional array of individually-addressable Light-emitting Diode optical emitters will be developed. An innovative CVD/LPE heteropitaxy technique… More

This program will demonstrate high specific power, lightweight, flexible, thin silicon solar cells. these solar cells can be directly substituted for existing state of the art silicon solar cells with the effect of significantly improving specific power, power/area, and power supply life. the… More

AstroPower is developing a two-junction monolithic tandem solar cell composed of (AlxGa1-x)0.51In.49P lattice matched to GaAs for use as the top cell in a three-junction, two-terminal tandem stack. This tunable bandgap material system is capable of current matching, at 2.03eV, in a two-junction… More

Astropower is proposing the development of an ultra-lightweight, high performance, thin light trapping gaas solar cell for advanced space power systems. a thin device leads to higher performance in terms of open circuit voltage, radiation resistance, and specific power. in a thin device, the… More

ASTROPOWER PROPOSES TO DEVELOP A LIGHTWEIGHT, HIGH PERFORMANCE, ULTRA-THIN ELECTROSTATICALLY BONDED GaAs SOLAR CELL WITH COPLANAR BACK CONTACTS. THE INNOVATIVE DESIGN INCORPORATES LIGHT TRAPPING, ADHESIVELESS COVER SLIDE BONDING, AND ELIMINATES GRID SHADING. THIS NOVEL DEVICE WILL EXHIBIT INCREASED… More

The growth and development of a (gap)1-x(zns)x-based material is being engineered to prepare an uteropolar, direct bandgap material. this type of material with bandgap in excess of 2.6 ev can be employed in blue light-emitting diodes, and in uv detectors capable of superior performance compared to… More

Astropower is developing gallium phosphide energy converters optimized for radio luminescent light-based power supplies. a "two-step" or "indirect" process is used where a phosphor is excited by radioactive decay products to produce light that is then converted to electricity by a gap energy… More

Astropower proposes to develop a lightweight, high efficiency, monolithically interconnected thin silicon solar cell array. the array incorporates an innovative technique to achieve electrical isolation and interconnection of the array elements. a monolithically interconnected array technology… More

ASTROPOWER PROPOSES TO DEVELOP A NEW FRONT-ILLUMINATED, ALUMINUM GALLIUM PHOSPHIDE (AlGaP) BASED, CHARGE-COUPLED DEVICE (CCD), ULTRAVIOLET (UV) IMAGING ARRAY. THIS NOVEL ARRAY TECHNOLOGY HAS NEVER BEEN SUCCESSFULLY DEVELOPED. THREE NEW INNOVATIONS WILL BE NECESSARY TO ACOMPLISH THE AlGaP CCD. THESE… More

A novel silicon deposition process capable of depositing high quality thin-film silicon layers on low cost supporting substrates will be investigated in phase i. the substrate will include a reflector for light trapping. the planned deposition process will allow the formation of silicon layers 20… More

Investigators are developing monolithically integrated bicolor edge emitter-detector pairs for wavelength-division multiplexing in fiber optic communications. this device utilizes laterally graded a1xga1-xas layers formed by liquid phase epitaxial deposition onto a continuously moving substrate. … More

The solar cell application of crystalline silicon thin-film, photocoltaic (pv) technologies is currently limited by the high cost of the silicon raw material. this is a result of the carbothermal reduction metallurgical process used to create the semiconductor-grade silicon from silica. there is a… More

AstroPower proposes to develop intense, mass-producible, low-cost 4 to 5 micron light-emitting diodes (LED's) using liquid-phase heteroepitaxy of lattice-matched InAsSb on GaSb substrates. The brightest visible LEDs (Ultrabrights) currently available are being produced commercially by the liquid… More

Epitaxial gallium phosphide (gap) will be studied as a promising new material for the manufacture of particle detectors. due to a high indirect bandgap and exceptional crystalline quality, epitaxial gallium phosphide detectors will provide superior performance in high-temperature, high-radiation… More

AstroPower proposes to develop a lightweight, high performance, ultra-thin electrostatically bonded GaAs solar cell with an all back contact, zero-grid obscuration structure. The unique design incorporates light trapping, adhesiveless cover slide bonding, and eliminates grid shading. This innovation… More

The Phase I Project will develop a comprehensive model to evaluate and optimize state-of-the-art light-emitting diodes for optical memories, optical computing, and fiber or free-space photonic interconnects. The innovation is the development of resonant optical cavity LEDs and a proprietary low-cost… More

AstroPower proposes to develop gallium phosphide (GaP) ultraviolet (UV) sensors for engine combustion control. The UV spectra from the free radial combustion components correlates with combustion effectivity in terms of predetonation, and provides a real time basis for central control of excess air… More

We propose a new epitaxial growth technology for low-defect SiC substrates based on metallic solution growth of SiC on silicon and SiC wafers. A significant feature of the our approach is the use of epitaxial lateral overgrowth for "defect filtering." In the Phase I proposal, we present arguments… More

There is much need for lasers with emission wavelengths in the mid-infrared (2 to 5 microns) for applications that include molecular spectroscopy, environmental and atmospheric trace gas analysis, long haul fiber communications, laser surgery, and atmospheric free-space laser transmission. The… More

AstroPower proposes to develop a new high voltage solar cell for photovoltaic linear concentrator arrays based on our thin GaAs solar cell and epitaxial lateral overgrowth technologies and applying lateral segment interconnection techniques. This solar cell design has several advantages which make… More

AstroPower proposes to develop a new ultra-thin gallium arsenide solar cell for space applications, that will result in significantly higher performance compared to conventional gallium arsenide and silicon solar cells. This design incorporates a "floating" junction on the front of the ultra-thin… More

AstroPower proposes to develop high performance, room temperature, mass-producible, low-cost infrared detectors using liquid-phase heteroepitaxy of lattice-matched InGaAsSb and AlGaAsSb on GaSb substrates. The structure of these detectors will be a Separate Absorption and Multiplication Avalanche… More

117 Thallium-Containing III-V Quaternary Compound Semiconductor for Use in Infrared Detection--AstroPower, Inc., Solar Park, Newark, DE 19716-2000; (302) 366-0400 Mr. Zane A. Shellenbarger, Principal Investigator Mr. Thomas J. Stiner, Business Official DOE Grant No.… More

We propose exploratory development of new epitaxial growth technologies for low-defect GiN epitaxial structures and surrogate substrates. A significant feature of our approach is epitaxial latval overgrowth for "defect filtering." We present arguments that such epitaxial lateral overgrowth will lead… More

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