Assessment of new components for space solar arrays

New photovoltaic space products and related components of various manufacturers have been tested under processing loads and space environment. Test specimens were advanced high efficiency solar cells in silicon and GaAs technology in combination with enhanced, blue-red-reflecting and low absorptance coverglasses, alternative terrestrial silicon solar cells, and newly developed ultrathin and tandem solar cells. The materials and processes applied considered GEO as well as LEO conditions. Ag- and Au-interconnectors, bus bars and wires were applied by resistance welding. 30cmx30cm-coupons were manufactured utilizing CFC-sandwich structures. The solar cells have been assembled with the related coverglass and tested on cell, SCA and coupon level After adaptation of the weld schedule the integration of the Ag- and Au-interconnectors did not cause any greater degradation of any cell type The application of blue-red-reflecting coverglasses on textured Si cells caused an average power loss of -2.7% at simultaneously improving the absorptance by 0.10. Transmission improvement of 0.7% could be demonstrated for CMO coverglasses. On GaAs cells the application of blue-red-reflecting coverglasses yielded contradictory results between -4% loss and +1.3% gain simultaneously improving the absorptance by 0.12. All space grade cells withstood GEO and LEO thermal cycling without any degradation Off-the-shelf terrestrial Si solar cells successfully withstood GEO thermal cycles.