Concentrating photovoltaic properties of GaInNAsSb/Ge dual junction tandem solar cell

In this work, the GaInNAsSb/Ge 2-junction (2J) tandem solar cell was fabricated for application to the latticematched 4J GaInP/GaAs/GaInNAsSb/Ge structure. We focused on the concentrating photovoltaic properties of GaInNAsSb based solar cells. In the present 2J cell, output current is limited by the Ge subcell. V_OC was the sum of each subcell. Under concentrated light, it was found that a V_OC increment with concentrated ratio for GaInNAsSb cell is higher than those for the conventional solar cells, such as GaAs and Ge. For 4J tandem solar cell under 1000 suns concentration, additional ~0.7 V of V_OC can be expected by addition of GaInNAsSb subcell to the conventional GaInP/GaAs/Ge structure.