Electroluminescence and photoluminescence characterization of multijunction solar cells

A combined electroluminescence and photoluminescence setup for a fast, nondestructive, and high-resolution characterization of large-area lattice matched GaInP2 /Ga(In)As/Ge triple-junction space solar cells was developed. In contrast with electroluminescence, where coupling effects between the subcells appear, all subcells can be analyzed independently in photoluminescence imaging, using three monochromatic light sources. This will be demonstrated by way of example for a partly irradiated cell. Alternatively, electroluminescence combined with simulation program with integrated circuit emphasis network simulations constitutes a powerful tool to extract quantitative information despite the coupling effects. Sheet resistances and shunts in individual subcells can be accurately modeled with this method.