Rare earth organic complexes as down-shifters to improve Si-based solar cell efficiency

This work reports on the optical and electrical characterization of crystalline silicon based solar modules encapsulated with ethylene-vinyl-acetate layers (that is the encapsulating matrix used nowadays by the photovoltaic industry) doped with a single europium complex whose sensitized region is broadened due to the presence of a co-ligand. Such europium doped EVA layers are able to realize down-shifting of photons with wavelength lower than 460 nm without introducing modifications of the industrial process leading to the fabrication of the photovoltaic modules. This effect has been proven under Air Mass 1.5 conditions (simulating terrestrial applications), where a 2.9% relative increase of the total power delivered by the encapsulated modules has been observed, allowing a reduction in the watt-peak price. (C) 2010 Elsevier B.V. All rights reserved.