Advancements in GaInP/sub 2//GaAs/Ge solar cells - production status, qualification results and operational benefits

In 2001 Spectrolab completed design and qualification, and began production on the third-generation multijunction solar cell - the improved triple-junction GaInP/sub 2//GaAs/Ge. With over 21% AMO conversion efficiency at an operating temperature of 60/spl deg/C at end-of-life, this cell has 16% more power than competing dual-junction designs in GEO orbit after 15 years (7/spl times/10/sup 14/ 1-MeV electron equivalence). Spectrolab is currently qualifying the fourth-generation triple-junction solar cell capable of delivering over 22% AMO conversion efficiency under these same conditions, with a beginning-of-life operating efficiency of 28%.