Description: With recent advances in MicroLink's inverted metamorphic (IMM) multijunction epitaxial lift off (ELO) solar cells, new opportunities for solar cell packaging are possible that leverage the inherent physical flexibility of these high efficiency solar cells. Novel photovoltaic (PV) blankets can be constructed with these flexible and modular solar cells. Arrays of these ELO solar cells are first interconnected and then laminated to a flexible Tedlar backsheet. Thin coverglass protecting the cell from space environments is then applied onto the top of each cell and secured with space-grade encapsulants. High volume pick and place tooling from the semiconductor wafer industry can be applied to this assembly process to realize substantial cost reduction in the assembly of these solar cell modules. The resulting modular high efficiency photovoltaic blankets can readily be used as a drop-in replacement for current solar cells mounted on solar panels. Since the photovoltaic blanket is composed of several solar cells pre-assembled into an array format, the assembly process is streamlined where arrays of multiple cells are now placed down during panel assembly. Since MicroLink's IMM ELO solar cells are flexible, the resulting solar array module is also flexible and can be readily applied and conformed to flat and curved surfaces on a spacecraft. With this flexible module approach, large solar array concepts having high specific powers and improved stowage capabilities can be achieved. ATK's UltraFlex Solar Array System is a potential platform where these flexible modules could be applied.

Benefits: This work will ultimately result in lightweight, flexible solar panels that contain very efficient multi-junction solar cells. NASA applications for such panels include very large solar cell panels for solar electric propulsion (SEP) and replacements for the conventional panels in solar-powered satellites.

The lightweight, efficient, flexible solar panels resulting from this work will be suitable for the following non-NASA applications: commercial and military spacecraft, novel spacecraft such as Cubesats, solar powered unmanned aerial vehicles (UAVs), and solar blankets for mobile terrestrial energy harvesting.