Application of InGaP/GaAs/InGaAs triple junction solar cells to space use and concentrator photovoltaic

InGaP(1.88eV)/GaAs(1.43eV)/InGaAs(0.98eV) triple junction solar cells with high efficiencies of 37.9% (AM1.5G) and 44.4% (AM1.5D, 302-suns) have been attained by inverted lattice-mismatch fabrication procedure. Cell structure was optimized to improve radiation resistance for space use. Lightweight space solar sheet has been developed by using the film type triple junction cells. Good performance of the solar sheet has been confirmed in reliability test and demonstrated in space flight test. Concentrator module using the triple junction cells have shown over 10% higher efficiency than the present type InGaP/(In)GaAs/Ge triple junction cells. High performance of the concentrator module has been demonstrated in outdoor field testing.