Abstract: An energy conversion device, particularly electromagnetic energy, such as sunlight and the like, comprising a transparent polymer sheet having an edge and a surface, on which said electromagnetic radiation can impact, and a photovoltaic cell mechanically coupled with said edge of said polymer sheet, capable of transforming in an electrical current the radiation incident on it, characterized in that said polymer sheet comprises a polymeric matrix having silicon nanostructures, functionalized with organic binders, said polymeric sheet being then luminescent with respect to a portion of said electromagnetic radiation, so as to convey the same, through a wave-guide, towards said photovoltaic cell. Also disclosed is a method for realizing a polymeric matrix, for the manufacture of a transparent polymer sheet.