Absolute spectral responsivity measurements of solar cells by a hybrid optical technique.

An irradiance mode, absolute differential spectral response measurement system for solar cells is presented. The system is based on combining the monochromator-based approach of determining the power mode spectral responsivity of cells with an LED-based measurement to construct a curve representing the light-overfilled absolute spectral response of the entire cell. This curve can be used to predict the short-circuit current (I-sc) of the cell under the AM 1.5 standard reference spectrum. The measurement system is SI-traceable via detectors with primary calibrations linked to the NIST absolute cryogenic radiometer. An uncertainty analysis of the methodology places the relative uncertainty of the calculated I-sc at better than +/- 0.8%.