Current Status of Photovoltaic Development at AFRL

Advances in design and manufacturing technology of crystalline multijunction solar cells have continued to push efficiencies higher. Triple junction cells with 28% efficiency are now available to the user and 30 % prototype cells have been demonstrated. Development of thin-film solar cell arrays is being aggressively funded for next-generation high power space platforms. Initial modules of thin-film photovoltaics comprised of amorphous silicon and Cu(In,Ga)Se₂ devices have been demonstrated. Space-compatible technologies for thin-film cell integration, contacts, and protective coatings are being developed. Cell-level development efforts aimed at increasing performance are continuing and progress is being made toward a 15% efficiency goal for cells on lightweight, flexible substrates. High temperature polymer substrates for Cu(In,Ga)Se₂ cells have been demonstrated. Thin-film solar arrays are promising for 3-7 times increase in specific power (W/kg) and stowed volume (W/m³) and a 3-5 times decrease in array cost ($/W) compared to state-of-the-art rigid panel solar arrays