The main objective of this project is the study of the various intra and intermolecular energy transfers with the aims to modify the solar spectrum by means of an adequate molecular system. This will permit to improve the similitude between the solar radiation and the absorbance of the photovoltaic materials. This change of spectrum must be realized without significant loss of energy by means of energy up and down-conversion cascades supported by a photoluminescent compound able to emit in the maximum absorption band of the photovoltaic material. The concentration of the solar light wavelength in the absorption band of the photovoltaic material may determine an increase in the number of photons able to excite the photovoltaic compound. This will result in an improvement of the electrical energy delivered by the solar cell. The research and development to be realized during this project will be essentially centred on the studies of molecular mix able to generate adequate energy cascades and their evaluation in terms of efficiency and chemical stability. Another part of the work will consist in the development of coatings or plastics containing such molecular systems to be directly applied on the solar cells superficies for an in situ evaluation of the results and for a quick emergence of such light concentrating devices.