Conversion efficiency values of silicon photovoltaic cells were significantly enhanced, by surface coating of the organically modified silicate (ORMOSIL) composite phosphor films incorporating europium(III) phenanthroline and terbium(III) bipyridine complexes. Relative maximal outputs of the coated single-crystal (c-Si) and amorphous silicon (a-Si) photovoltaic devices compared with those of the uncoated c-Si and a-Si ones were increased to 118 and 108%, respectively, by optimizing for the complex concentration of the ORMOSIL composite films under air mass 1.5 (100 mW cm(-2)), owing to the effective optical conversion from the ultraviolet fraction of sunlight to visible lights by the lanthanide complexes incorporated into the ORMOSIL matrix.