Investigation of Radiative Coupling from InGaAsP Quantum Wells for Improving End-of-Life (EOL) Efficiency in Multijunction Solar Cells

GaInP/(In)GaAs/Ge multijunction solar cells have been state-of-practice for power generation on spacecraft for over a decade but there are still potential improvements for end-of-life (EOL) efficiency. Radiative coupling between GaInP and (In)GaAs subcells is not typically considered in the EOL design of space solar cells because radiative recombination in the GaInP is effectively quenched by radiation-induced damage. This paper shows that quantum well structures incorporated into a GaInP subcell may be less sensitive to radiation damage, thereby enabling radiative coupling between subcells at EOL and providing a current boost in the (In)GaAs subcell to improve EOL efficiency.