Increasing the Specific Power of Epitaxial Lift-Off Solar Cells for Cost-Effective, High-Efficiency, Flexible Photovoltaics

Photovoltaics (solar cells) are an attractive technology to provide renewable energy sources for forward operating bases, man-portable power sources, and tactical applications. Solar arrays can provide base power greatly reducing the need for logistical fuels, continuous battery recharging for warfighters on the move, and integrated power sources for remote, autonomous systems, e.g. UAVs. To be effective, solar arrays must be lightweight, flexible, and provide high power density. Flexible solar arrays based on thin film photovoltaics have been fielded for some military applications, but their usefulness has been limited by their low efficiency. Si panels have attained efficiencies as high as 22% but but are made of glass and Al. Flexible amorphous Si or polycrystalline CIGS panels are less than 15% efficient. Higher efficiency, flexible solar cells have been demonstrated for space applications, but their cost has hindered terrestrial applications. New materials and manufacturing methodologies are needed to produce a solar cell that is lightweight, flexible, high efficiency, and affordable. The goal of this topic is to develop cost-effective, photovoltaic technologies that display high efficiencies in a flexible format.