IMM Triple-junction Solar Cells and Modules optimized for Space and Terrestrial Conditions

InGaP/GaAs/InGaAs inverted metamorphic triple junction (IMM-3J) solar cells fabricated by epitaxial layer transfer process onto film -have features of lightweight and flexible. The average efficiencies of 27.4cm ² cells developed for space and terrestrial applications are 30.8% and 34.5%, respectively. The lightweight module so called space solar sheets have been developed and tested by JAXA for space qualification. The terrestrial cell is optimized under AM1.5G condition. The terrestrial module in which 32 flexible cells are laminated by glasses showed 31.2% (AM1.5G) which is recognized as the world highest module efficiency. The module has been tested outdoor. Cost reduction technologies such as thinning epitaxial layer and reusing substrate have been investigated.