Development of a long wavelength InGaAsP bottom solar cell for multijunction stacks

Long-wavelength InGaAsP solar cells have been fabricated that exhibit exceptional open-circuit voltage values for devices that have not yet been optimized. Quantum efficiency studies demonstrate that a long-wavelength InGaAsP bottom cell can perform well as a photon scavenger enhancing the performance of single-junction solar cells. InGaAsP bottom solar cells demonstrating a 5.1% AM0, 100X efficiency under AlGaAs material have been fabricated. With the current rate of development, it is projected that a 28% (AM0, 100X) space-qualified AlGaAs/InGaAsP tandem stack will be attainable in the short term.