Spatially and spectrally resolved electroluminescence measurement system for photovoltaic characterisation

A system that combines the advantages of fast global electroluminescence (EL) imaging and detailed spectrally resolved EL measurements is presented. A charge-coupled device camera-based EL imaging system is used to measure the intensity of radiative recombination of the photovoltaic (PV) device spatially resolved over its full area. A monochromator-based system is utilised to measure localised emission spectra at given points of interest. Measurements of multi-crystalline and amorphous silicon PV devices demonstrate the potential to investigate radiative defects and reveal performance variations and non-uniformities. This links inhomogeneities much closer to device physics than using camera-based EL only.