Ultra-Lightweight, High-Efficiency Epitaxial Lift-Off Solar Cells and Arrays Navy STTR FY2014.A Sol No.: Navy STTR FY2014.A Topic No.: N14A-T003 Topic Title: Ultra-Lightweight, High-Efficiency Epitaxial Lift-Off Solar Cells and Arrays Proposal No.: N14A-003-0118 Firm: MicroLink Devices 6457 Howard Street Niles, Illinois 60714 Contact: Christopher Stender Phone: (847) 588-3001 Web Site: www.mldevices.com Abstract: MicroLink Devices and the University of Notre Dame propose to develop an ultra-lightweight, high-efficiency, GaAs-based, multi-junction solar cell that will be suitable for use in future platforms requiring very high specific power (>3.0 kW/kg) and very high areal power density (>370 W/m2). We will achieve this result by reducing the metal content of MicroLink's current inverted metamorphic (IMM), epitaxial lift-off (ELO) solar cell and replacing the metal with robust, low-density, polymer-based materials that retain the flexibility and durability of ELO solar cell at a fraction of its present weight. We will also develop processes that are compatible with the fabrication equipment necessary for high-volume production of new "laminated" ELO solar cells to be developed in this program. The specific power target for laminated cells at the conclusion of the Phase I effort is 2.0 kW/kg under 1-sun AM1.5G illumination, which will be achieved by enhancing the present ELO IMM solar cell structure with a new, ultra-lightweight metal/polymer-based support. Benefits: A major potential application for the technology to be developed is in high-efficiency solar cell arrays for use with UAVs in both Government and commercial sectors, and in solar-powered spacecraft. The resulting lightweight, flexible solar cell arrays will be an attractive replacement for the existing stiff, heavy carbon fiber panel-based arrays. In addition to enabling long-range, high-endurance missions with small UAVs, the proposed technology will be a key enabler of high-altitude, long-endurance (HALE) solar-powered aircraft. These aircraft are proposed by DARPA (in the Vulture program) for ISRC missions in which the aircraft could remain on station for months or years. In order to increase the geographic area that the HALE aircraft can cover, it is essential that high efficiency solar cells be available in a lightweight, flexible package. Solar cell arrays fabricated using the method described in this proposal could be utilized in HALE vehicle designs. Other UAVs that could benefit from this cell technology include the Raven, the Skate, and the Zephyr. Another potential market for high-efficiency solar cell arrays is terrestrial energy production. The solar cell packaging techniques described herein could be adapted for use in solar blankets, which would be used for field energy generation by the military or by civilians. Return