Prototype development - flexible Cu(In,Ga)Se2 thin film solar cells for space applications

Flexible thin film technologies find increased attention with device efficiencies approaching values comparable to rigid substrates. In particular the high power to weight ratio plus the superior radiation hardness of flexible thin film solar cells make them an attractive alternative to current technologies for space power generation. This contribution reports on latest advances in the development of prototypes of single Cu(In,Ga)Se₂ solar cells on titanium foil with a total area of 27 cm². The development of a dedicated baseline technology for cell processing is outlined and improvements with respect to process reproducibility and yield are discussed. Losses in cell performance due to scaling up the device area are evaluated. Efficiencies of 13.7 % and 12.2 % under AM1.5 and AM0 illumination respectively have been reached so far.