23 March 2018
Magnolia to develop cost-effective, thin-film GaAs-based solar cells for reliable portable power
© Semiconductor Today Magazine / Juno PublishiPicture: Disco’s DAL7440 KABRA laser saw.
Magnolia Optical Technology Inc of Woburn, MA, USA (which develops thin-film and nanostructure-based technologies spanning the ultraviolet, visible and infrared spectrum for military sensors and commercial applications including solar cells) is working with the US Defense Advanced Research Projects Agency (DARPA) under a Phase II Small Business Innovation Research (SBIR) program ‘Development of High-Performance Thin-Film Solar Cells for Portable Power Applications’ (contract no. D15PC00222).
Photovoltaic devices can provide a portable source of electrical power for a wide variety of defense and commercial applications, including mobile power for dismounted soldiers, unmanned aerial vehicles (UAVs) and remote sensors. “The goal of the current program is to develop high-efficiency gallium arsenide (GaAs)-based solar cells that maintain their performance over changing environmental conditions, and that are thinner and thus more cost-effective to produce,” says chief technical officer Dr Roger Welser. “By combining thin III-V absorbers with advanced light-trapping structures, single-junction GaAs-based devices provide a means to deliver high-efficiency performance over a wide range of operating conditions at a fraction of the cost of the multi-junction structures typically employed for space power. In addition, the incorporation of nano-enhanced III-V absorbers provides a pathway to extend infrared absorption and increase the photovoltaic power conversion efficiency of cost-effective thin-film solar cells,” he adds.
“Changes in the solar spectrum can dramatically degrade the performance of traditional multi-junction devices – changes that occur naturally throughout the day, from season to season, and from location to location as sunlight passes through the earth’s atmosphere,” says Magnolia’s president Dr Ashok Sood. “Moreover, multi-junction III-V cells require thick, complex epitaxial layers and are therefore inherently expensive to manufacture,” he adds. “The technology under development as part of this DARPA-funded program addresses these key weaknesses in the established high-performance photovoltaic technology.”