Patent ID: 8073645

Claim:
An apparatus to characterize a multijunction solar cell, the apparatus comprising: a light-control system to effect a control of an intensity of one or more light beams illuminating the multijunction solar cell, the multijunction solar cell having a plurality of subcells, each subcell having associated thereto a subcell spectral range, each subcell to absorb light at wavelengths comprised within its subcell spectral range, the control of the intensity of the one or more light beams to vary a light intensity in the subcell spectral range of a particular subcell, to obtain varied light intensities, while maintaining substantially constant the light intensity in the subcell spectral ranges of the other subcells; an electrical characterization system to connect electrically to the multijunction solar cell, the electrical characterization system to measure, for each of the varied intensities, current flowing through the multijunction solar cell as a function of voltage applied to the multijunction solar cell; and a processing module to process current and voltage data associated to the varied intensities, to obtain processed data, the processed data to determine one more parameters of the particular subcell.