Performance Study of Lattice-Matched Multijunction Solar Cells Incorporating GaInNAsSb Junctions with 0.7 - 1.4 eV Bandgap

We report on the progress made in the development of lattice-matched multijunction solar cells employing dilute nitride sub-cells. In particular, we report on upright four-junction architecture with bandgaps of 0.9 eV, 1.2 eV, 1.4 eV and 1.9 eV The four-junction solar cell includes two dilute nitride sub-junctions. This structure exhibited an efficiency of 29% at 1-sun AM1.5D illumination, which is the highest level reported for such architecture so far. In addition, we report on the progress in developing lattice-matched solar cell materials with a bandgap down to 0.7 eV, which enable the fabrication of highly efficient five- or six-junction solar cells on GaAs. We estimate that under 1000 suns illumination these five- or six-junction cells could reach over 50% efficiencies.