SBIR-STTR Award

AmberWave proposes to demonstrate its proprietary technology in the epitaxial deposition of high-quality III-V compounds on Si substrates for photovoltaic applications. The technology employs AmberWave's proprietary SiGe epitaxial layers that allow the lattice mismatch and thermal expansion differences between Ge and Si to be controlled during the growth process. Ge is nearly lattice-matched to GaAs. AmberWave has also developed process control that allows the reproducible growth of antiphase-domain free GaAs/Ge interfaces with minimal interdiffusion. This GaAs/Ge interface control has been developed for molecular beam epitaxy and metal organic chemical vapor deposition. The result is Ge and GaAs device-quality thin films on Si substrates. AmberWave's business strategy is to develop high efficiency (.30%) III-V thin film solar cells on Si substrates for satellite power systems. Such cells will be more than 50% lighter than current GaAs/Ge cells which would more than double the power output per unit weight. Such an advance will have great value in BMDO satellite designs since these lighter cells will also decrease mass in other supporting systems. In Phase I, AmberWave proposes to demonstrate its GaAs/SiGe on Si fabrication process on 4-inch Si wafers and evaluate a prototype GaAs solar cell on Si. Anticipated Benefits and

Potential Commercial Applications:
AmberWave's technology can produce the lightest, highest power to weight ratio, least expensive, and most rugged solar cells. In Phase I AmberWave will fabricate an efficient Single junction, GaAs cell on Si as a prototype, demonstrating the viability and impact of AmberWave's state-of-the-art materials integration technology.

AmberWave Systems Corporation proposes a Phase II SBIR program with the following objectives: 1) demonstration of a laser with world record efficiency and reliability on Si and 2) development and commercial qualification of triple junction, III-V compound solar cell technology on Si substrates. III-V compound lasers and solar cells on Si will have advantages in cost, weight, strength and heat conduction over other comparable technologies on Ge, GaAs, or InP substrates. In addition, the ability to fabricate high performance, reliable lasers on Si would enable superior microelectronic technologies that take advantage or monolithic III-V/Si integration schemes. III-V compound optoelectronics monolithically integrated on Si substrates offer great commercial potential for space-based photovoltaics for communications satellites and for lasers integrated with Si microelectronics for on-chip and chip-to-chip I/O functions.

Keywords:
LASERS,PHOTOVOLTAICS, SILICON GERMANIUM ALLOYS, GALLIUM ARSENIDE INTEGRATION ON SILICION, OPTOELECTR