High efficiency GaAs/GaSb tandem solar cells and tandem circuit cards

Infrared-sensitive GaSb cells and visible-light-sensitive GaAs cells designed for satellite applications are described. The best component cell efficiencies add up to 28.1% under concentrated sunlight (30*, AM0). Two-terminal tandem cell circuit cards containing nine transparent GaAs cells mounted over holes on the front side of a ceramic double-sided printed circuit card and nine GaSb cells mounted on the back side of the same card have been fabricated and tested. Circuit level conversion efficiencies over 25% (AM0) are demonstrated. >