Recent advances in high‐efficiency<i>III</i>–<i>V</i>multi‐junction solar cells for space applications: ultra triple junction qualification

Abstract

Abstract Recent advances in Spectrolab's high efficiency III – V multi‐junction space solar cells are reported. The latest generation GaInP/GaAs/Ge solar cells under production—the Ultra Triple Junction (UTJ)—have an average efficiency at maximum power of 28.0% (AM0, 28°C, 135.3 mW/cm 2 ) at beginning of life (BOL), and 22.6% at 60°C at end of life (EOL, 15 years in GEO orbit). This represents a 5.5% relative higher efficiency at EOL, compared with the previous generation Improved Triple Junction (ITJ) cells. The P/P 0 —for 1 MeV electrons after 10 15 cm −2 fluence has also improved to 0.86, compared with 0.84 for the ITJ cells. These and other performance results of UTJ solar cells are reviewed in comparison with ITJ solar cells. Copyright © 2005 John Wiley &amp; Sons, Ltd.